EP3210876B1 - Propelling efficiency enhancing device - Google Patents
Propelling efficiency enhancing device Download PDFInfo
- Publication number
- EP3210876B1 EP3210876B1 EP15853182.2A EP15853182A EP3210876B1 EP 3210876 B1 EP3210876 B1 EP 3210876B1 EP 15853182 A EP15853182 A EP 15853182A EP 3210876 B1 EP3210876 B1 EP 3210876B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- swirl
- stator
- propeller
- stators
- swirl stator
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Active
Links
- 230000002708 enhancing effect Effects 0.000 title claims description 76
- 238000009434 installation Methods 0.000 claims description 28
- 230000000052 comparative effect Effects 0.000 description 7
- 230000007423 decrease Effects 0.000 description 7
- 238000005266 casting Methods 0.000 description 6
- 238000000034 method Methods 0.000 description 6
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 6
- 239000012530 fluid Substances 0.000 description 4
- 230000000694 effects Effects 0.000 description 3
- 238000011156 evaluation Methods 0.000 description 3
- 238000012986 modification Methods 0.000 description 3
- 230000004048 modification Effects 0.000 description 3
- 230000006866 deterioration Effects 0.000 description 1
- 230000002542 deteriorative effect Effects 0.000 description 1
- 230000003628 erosive effect Effects 0.000 description 1
- 230000001141 propulsive effect Effects 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H1/00—Propulsive elements directly acting on water
- B63H1/02—Propulsive elements directly acting on water of rotary type
- B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
- B63H1/14—Propellers
- B63H1/26—Blades
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H1/00—Propulsive elements directly acting on water
- B63H1/02—Propulsive elements directly acting on water of rotary type
- B63H1/12—Propulsive elements directly acting on water of rotary type with rotation axis substantially in propulsive direction
- B63H1/14—Propellers
- B63H1/28—Other means for improving propeller efficiency
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B63—SHIPS OR OTHER WATERBORNE VESSELS; RELATED EQUIPMENT
- B63H—MARINE PROPULSION OR STEERING
- B63H5/00—Arrangements on vessels of propulsion elements directly acting on water
- B63H5/07—Arrangements on vessels of propulsion elements directly acting on water of propellers
- B63H5/16—Arrangements on vessels of propulsion elements directly acting on water of propellers characterised by being mounted in recesses; with stationary water-guiding elements; Means to prevent fouling of the propeller, e.g. guards, cages or screens
Definitions
- the present invention relates to a propulsion efficiency enhancing apparatus.
- pre-swirl stators are typically used.
- the pre-swirl stators make, when a propeller rotates to move the vessel forward, the flow of water around the stern bent in the opposite direction of the rotation direction of the propeller so that the water can flow to the propeller.
- swirling flow generated by the pre-swirl stators is absorbed by the propeller so that the propulsion efficiency of the propeller can be enhanced.
- the pre-swirl stators act as resistance when the vessel sails, resulting in a deterioration of the resistance performance of the vessel.
- Document JP 2010 179869 A shows a propulsion performance enhancement device comprising a fin and a current plate in which damage of the fin by rolling-in of a foreign matter shall be avoided.
- Two right and left fins are provided at a slight lower side in a width direction and at an obliquely upper side, and a radius of the fin in the obliquely upper side is made to 85-115% of the propeller radius.
- a radius of the slightly downward fin in the width direction is made to 35-55% of the propeller radius, and a wing end plate is provided on a distal end.
- Document JP 2011 121569 A discusses a propulsion performance improving device of a ship, which prevents a propeller from beingt damaged by a vortex generated by reacton fins. It includes a pluratlity of reaction finxs arranged on the front side of a propeller to generate a swirling flowin the inverse direction of the rotational direction of the propeller and radially extending with a rotary shaft of the propeller as the center.
- the reaction fins include a first reaction fin extending obliquely upward and two further reaction fins extending in the horizontal direction or obliquely downward. A first distance to the blade end of the reaction fin extending obliquely upward from the rotary shaft is larger than a propeller radius of the propeller. A second distance to the blade end of the further reaction fins from the rotary shaft is smaller than the propeller radius.
- Document KR 2012 0126910 A shows a propeller duct structure for a ship with fins in rows.
- the strucure flows parallel flow into a propeller by smoothly flowing fluid because the fins are asymmetrically installed inside a duct member.
- the trailing edge of a reaction fin projecting radially is composed of a blade root leading edge connected to the blade root of the reaction fin, and a blade tip trailing edge connected to the blade tip of the reaction fin.
- An angle made by the blade tip trailing edge with the blade tip is larger than an angle made by the blade oot trailing edge with the blade tip.
- Document KR 2014 0085644 relates to a pre-swirl stator of a ship, which is provided to increase propulsion efficiency and to decrease erosion of the surface of a propeller.
- the pre-swirl stator discussed therein is fixed on a shaft of the propeller propelling the ship, and placed on the front side of the propeller.
- the pre-swirl stator comprises a stator body and a stator end plate formed on the end of the stator body, wherein the stator end plate is formed toward one side of the stator body and has a semi-elliptical shape.
- An aspect of the present disclosure is to provide a propulsion efficiency enhancing apparatus configured to reduce resistance applied onto pre-swirl stators.
- another aspect of the present disclosure is to provide a propulsion efficiency enhancing apparatus including pre-swirl stators capable of reducing cavitation influencing the propeller. More specifically, the propulsion efficiency enhancing apparatus is configured to reduce cavitation that is generated around the tip portions of the pre-swirl stators.
- a propulsion efficiency enhancing apparatus including a plurality of pre-swirl stators disposed ahead of a propeller, and arranged radially with respect to a rotation axis of the propeller, wherein the pre-swirl stators are located in a region of a rotation surface of the propeller, where the propeller rotates upward, among the left and right regions of the rotation surface of the propeller, a span length of at least one pre-swirl stator of the pre-swirl stators is different from span lengths of the remaining pre-swirl stators, and a span length of a pre-swirl stator arbitrarily selected from among the pre-swirl stators is longer than or equal to a span length of another pre-swirl stator located just below the selected pre-swirl stator.
- the span lengths of the pre-swirl stators may be reduced sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- the number of the pre-swirl stators may be three, and an installation angle of a first pre-swirl stator located at the uppermost position among the pre-swirl stators may be in a range of 30 degrees to 50 degrees, an installation angle of a second pre-swirl stator located at the middle position may be in a range of 60 degrees to 80 degrees, and an installation angle of a third pre-swirl stator located at the lowermost position may be in a range of 100 degrees to 120 degrees.
- a span length of the first pre-swirl stator may be in a range of 0.9 times to 1.1 times of the radius of the propeller
- a span length of the second pre-swirl stator may be in a range of 0.8 times to 1.0 times of the radius of the propeller
- a span length of the third pre-swirl stator may be in a range of 0.6 times to 0.8 times of the radius of the propeller
- the span lengths of the pre-swirl stators may be reduced sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- the pre-swirl stators may be arranged toward the front direction sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- Chord lengths of the pre-swirl stators may be reduced, at the same radius with respect to the rotation axis, in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- the tip portions of the pre-swirl stators have smaller pitch angles than the remaining portions of the pre-swirl stators.
- a winglet may be formed in the tip portion of each pre-swirl stator, and the winglet is bent toward a suction surface or a pressure surface.
- the pitch angles of the tip portions may be reduced continuously toward the tips of the tip portions.
- the tip portions may have lengths of 0.1 times to 0.3 times of the span lengths of the pre-swirl stators.
- the corners of the tips of the tip portions may be rounded, as seen from the pressure surface.
- An additional member may be formed in the tip portion of each pre-swirl stator, and the additional member may be in the shape of a plate extending toward a suction surface and a pressure surface.
- the span length of at least one of the pre-swirl stators arranged radially is different from those of the remaining pre-swirl stators, and the span length of a pre-swirl stator arbitrarily selected from among the pre-swirl stators is longer than or equal to that of another pre-swirl stator located just below the selected pre-swirl stator, it is possible to reduce resistance applied onto the pre-swirl stators in correspondence to the velocity of inflow, and to enhance the propulsion efficiency of the propeller.
- the winglets may be formed in the tip portions of the pre-swirl stators to reduce cavitation generated around the tip portions.
- the additional members may be formed in the tip portions of the pre-swirl stators to reduce cavitation generated around the tip portions.
- FIG. 1 is a side view of a propulsion efficiency enhancing apparatus 100 according to a first embodiment of the present disclosure
- FIG. 2 is a rear view of the propulsion efficiency enhancing apparatus 100 according to the first embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 100 may include pre-swirl stators 110, 120, and 130.
- the pre-swirl stators 100, 120, and 130 are disposed ahead of propeller 20, and arranged radially with respect to the rotation axis X of the propeller 20.
- the pre-swirl stators 110, 120, and 130 induce water entering the propeller 20 to flow in the opposite direction of the rotation direction of the propeller 20, thus generating swirling flow in the opposite direction of the rotation direction of the propeller 20.
- the swirling flow generated by the pre-swirl stators 110, 120, and 130 enters the propeller 20 to reduce swirling flow generated in the rotation direction of the propeller 20, thereby enhancing the propulsion efficiency of the propeller 20.
- the pre-swirl stators 110, 120, and 130 may be installed at the stern boss 15 of the vessel body 10, although not limited to this.
- three pre-swirl stators 110, 120, and 130 may be provided.
- the pre-swirl stator 110 located at the uppermost position is referred to as a "first pre-swirl stator 110”
- the pre-swirl stator 120 located at the middle position is referred to as a “second pre-swirl stator 120”
- the pre-swirl stator 130 located at the lowermost position is referred to as a "third pre-swirl stator 130".
- the number of the pre-swirl stators is, for convenience of description, three, however the number of the pre-swirl stators is not limited.
- the propeller 20 may rotate in a clockwise direction, when seen in a rear direction as shown in FIG. 2 .
- all of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may be located in the left region of the rotation surface P of the propeller 20, where the propeller 20 rotates upward, among the left and right regions of the rotation surface P.
- the direction of inflow entering the propellers 20 may become the opposite direction of the rotation direction of the propeller 20 so that an angle of attack with respect to the sections of the blades of the propeller 20 increases, and a relatively great propulsion force is generated due to the increase of the angle of attack.
- the direction of inflow entering the propeller 20 may become the same direction as the rotation direction of the propeller 20 so that an angle of attack with respect to the sections of the blades of the propeller 20 decreases, and a relatively small propulsion force is generated due to the decrease of the angle of attack.
- the pre-swirl stators 110, 120, and 130 in the left region of the rotation surface P of the propeller 20 to generate flow in the opposite direction of the rotation direction of the propeller 20 in inflow entering the propeller 20, it is possible to increase an angle of attack with respect to the sections of the blades of the propeller 20, and to enhance the propulsion efficiency of the propeller 20.
- the propeller 20 may rotate in a counterclockwise direction as seen in the rear direction, unlike FIG. 2 .
- all of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may be located in the right region of the rotation surface P of the propeller 20, where the propeller 20 rotates upward, among the left and right regions of the rotation surface P.
- the span lengths of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may be reduced sequentially in the order from the first pre-swirl stator 110 located at the uppermost position to the third pre-swirl stator 130 located at the lowermost position.
- first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may have different span lengths. Also, one arbitrarily selected from among the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 has a longer span length than another one located just below the selected one.
- the span lengths of the pre-swirl stators 110, 120, and 130 may mean distances from the rotation axis X of the propeller 20 to the tips of the pre-swirl stators 110, 120, and 130.
- FIG. 3 shows a flow distribution of wake entering the propeller, represented on the rotation surface of the propeller, in the barehull having no pre-swirl stators, as seen in the front direction from the propeller.
- the velocities of inflow respectively entering the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 sequentially arranged radially with respect to the rotation axis X may increase.
- the span lengths of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may be reduced sequentially.
- the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 can prevent resistance from increasing according to the increase in velocity of inflow, in the order from the first pre-swirl stator 110 to the third pre-swirl stator 130.
- the flow velocity of wake on the rotation surface of the propeller (20 of FIG. 1 ) may intend to be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of a vertical line V, when the rotation axis X of the propeller (20 of FIG. 1 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree.
- the velocities of inflow respectively entering the third pre-swirl stator 130, the second pre-swirl stator 120, and the first pre-swirl stator 110 sequentially arranged radially with respect to the rotation axis X may decrease.
- the span lengths of the third pre-swirl stator 130, the second pre-swirl stator 120, and the first pre-swirl stator 110 may increase sequentially.
- the third pre-swirl stator 130, the second pre-swirl stator 120, and the first pre-swirl stator 110 may have a more improved function of generating swirling flow in the opposite direction of the rotation direction of the propeller (20 of FIG. 1 ), in the order from the third pre-swirl stator 130 to the first pre-swirl stator 110.
- the pre-swirl stators 110, 120, and 130 may have a more improved function of generating swirling flow in the opposite direction of the rotation direction of the propeller (20 of FIG. 1 ), at the lower velocity of inflow.
- an installation angle a of the first pre-swirl stator 110 may be in a range of 30 degrees to 50 degrees
- an installation angle b of the second pre-swirl stator 120 may be in a range of 60 degrees to 80 degrees
- an installation angle c of the third pre-swirl stator 130 may be in a range of 100 degrees to 120 degrees.
- the installation angles a, b, and c may be angles of the installation positions of the pre-swirl stators 110, 120, and 130 in the counterclockwise direction with respect to the upper section of the vertical line V, when the rotation axis X of the propeller 20 is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree.
- first pre-swirl stator 110 the second pre-swirl stator 120, and the third pre-swirl stator 130 are disposed respectively at the installation angles a, b, and c, resistance in the flow distribution of wake can be minimized.
- FIG. 4 shows experimental data used in a test for deducing the propulsion efficiency enhancing apparatus 100 according to the first embodiment of the present disclosure.
- the horizontal axis X represents the span lengths of the pre-swirl stators 110, 120, and 130 with respect to the radius R of the propeller 20, and the vertical axis Y represents resistance values calculated through computational fluid dynamics.
- FIG. 4 shows resistance applied to each segment of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130, divided by 0.1 times of the radius R of the propeller 20, through computational fluid dynamics, when the installation angle of the first pre-swirl stator 110 (Stator 1) is in the range of 30 degrees to 50 degrees, the installation angle of the second pre-swirl stator 120 (Stator 2) is in the range of 60 degrees to 80 degrees, the installation angle of the third pre-swirl stator 130 (Stator 3) is in the range of 100 degrees to 120 degrees, and the span lengths of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 are 1.0 times of the radius R of the propeller 20, in the condition of wake as shown in FIG. 3 .
- resistance applied to the first pre-swirl stator 110 changes to plus (+) at 0.9 times or more of the radius R of the propeller 20
- resistance applied to the second pre-swirl stator 120 changes to plus (+) at 0.8 times or more of the radius R of the propeller 20
- resistance applied to the third pre-swirl stator 130 changes to plus (+) at 0.7 times or more of the radius R of the propeller 20.
- the span length of the first pre-swirl stator 110 may be decided to be in a range of 0.9 times to 1.1 times of the radius R of the propeller 20
- the span length of the second pre-swirl stator 120 may be decided to be in a range of 0.8 times to 1.0 times of the radius R of the propeller 20
- the span length of the third pre-swirl stator 110 may be decided to be in a range of 0.6 times to 0.8 times of the radius R of the propeller 20.
- the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may have a swept back wing shape.
- the trailing edges of the pre-swirl stators 110, 120, and 130 may be located on a straight line that is vertical to the rotation axis X.
- the pre-swirl stators 110, 120, and 130 can be located closest to the propeller 20 so that swirling flow generated by the pre-swirl stators 110, 120, and 130 and flowing in the opposite direction of the rotation direction of the propeller 20 can directly enter the propeller 20, thereby enhancing the propulsion efficiency of the propeller 20.
- chord lengths of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 at the same radius R with respect to the rotation axis X may be reduced sequentially.
- the chord lengths may mean the lengths from the leading edges to the trailing edges in the cross-sections of the pre-swirl stators 110, 120, and 130.
- the shorter chord lengths of the pre-swirl stators 110, 120, and 130 may mean smaller contact areas with inflow entering the pre-swirl stators 110, 120, and 130.
- the longer chord lengths of the pre-swirl stators 110, 120, and 130 may mean larger contact areas with inflow entering the pre-swirl stators 110, 120, and 130.
- the velocity of wake on the rotation surface P of the propeller (20 of FIG. 1 ) may be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of the vertical line V, when the rotation axis X of the propeller (20 of FIG. 1 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree.
- the velocities of inflow respectively entering the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 sequentially arranged radially with respect to the rotation axis X may increase.
- the chord lengths of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may be reduced sequentially.
- the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may prevent resistance from increasing according to the increase in velocity of inflow, in the order from the first pre-swirl stator 110 to the third pre-swirl stator 130.
- the installation angles a, b, and c of the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may have predetermined ranges.
- the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 may be respectively installed within the installation angle ranges.
- two or more first pre-swirl stators 110, two or more second pre-swirl stators 120, and two or more third pre-swirl stators 130 may be respectively installed within the installation angle ranges.
- the pre-swirl stators 110, 120, or 130 located within each installation angle range may have the same span length.
- FIG. 5 shows a propulsion efficiency enhancing apparatus 200 according to a second embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 200 may include a first pre-swirl stator 210, a second pre-swirl stator 220, and a third pre-swirl stator 230.
- the first pre-swirl stator 210, the second pre-swirl stator 220, and the third pre-swirl stator 230 according to the current embodiment may have the same features as the first pre-swirl stator 110, the second pre-swirl stator 120, and the third pre-swirl stator 130 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted.
- the first pre-swirl stator 210, the second pre-swirl stator 220, and the third pre-swirl stator 230 may be arranged sequentially toward the front direction. That is, the third pre-swirl stator 230 may be located at the foremost position, the second pre-swirl stator 220 may be located at the middle position, and the first pre-swirl stator 210 may be located at the rearmost position.
- first pre-swirl stator 210, the second pre-swirl stator 220, and the third pre-swirl stator 230 are spaced predetermined distances in the longitudinal direction of the vessel body, resistance applied onto the vessel body can be reduced compared to when the pre-swirl stators 210, 220, and 230 are arranged on the same line in the longitudinal direction of the vessel body.
- FIG. 6 shows a comparative example 100 and an experimental example 200 for performance evaluation of the propulsion efficiency enhancing apparatuses according to the first embodiment and the second embodiment
- FIG. 7 shows propulsion force reduction coefficients t for the comparative example 100 and the experimental example 200 of FIG. 6 .
- FIG. 6A shows the propulsion efficiency enhancing apparatus (hereinafter, referred to as a "comparative example 100") according to the first embodiment of the present disclosure in which stators are located on the same line in the longitudinal direction of the vessel body
- FIG. 6B shows the propulsion efficiency enhancing apparatus (hereinafter, referred to as an "experimental example 200") according to the second embodiment of the present disclosure in which stators are located sequentially toward the front direction.
- resistance for each example and resistance applied onto the vessel body upon self-propulsion for each example can be deduced, and the propulsion force reduction coefficients t as shown in FIG. 7 can be obtained through the deduced resistance.
- the propulsion force reduction coefficient t of the experimental example 200 is smaller than the propulsion force reduction coefficient t of the comparative example 100.
- the results are obtained since the venturi effect generated between the pre-swirl stators 210, 220, and 230 is weakened when the first pre-swirl stator 210, the second pre-swirl stator 220, and the third pre-swirl stator 230 are spaced predetermined distances in the longitudinal direction of the vessel body, to reduce resistance applied onto the vessel body.
- a distance D1 between the first pre-swirl stator 210 and the second pre-swirl stator 220 in the longitudinal direction of the vessel body, and a distance D2 between the second pre-swirl stator 220 and the third pre-swirl stator 230 in the longitudinal direction of the vessel body may be in a range of 0.05 times to 0.15 times of the diameter of the propeller 20.
- the pre-swirl stators 210, 220, and 230 may become distant from the propeller 20 so that flow induced by the pre-swirl stators 210, 220, and 230 does not sufficiently enter the propeller 20, thereby deteriorating the propulsion efficiency of the propeller 20.
- the distances D1 and D2 between the pre-swirl stators 210, 220, and 230 are smaller than the range, resistance applied onto the vessel body may increase by the venturi effect generated between the pre-swirl stators 210, 220, and 230.
- the number of the pre-swirl stators is, for convenience of description, three, however, the number of pre-swirl stators is not limited to three.
- the number of the pre-swirl stators may be two.
- the pre-swirl stator located at the upper position is referred to as a "first pre-swirl stator”
- the pre-swirl stator located at the lower position is referred to as a "second pre-swirl stator”.
- an installation angle of the first pre-swirl stator may be in a range of 45 degrees to 75 degrees
- an installation angle of the second pre-swirl stator may be in a range of 90 degrees to 120 degrees.
- the ranges of the installation angles may be calculated by the same method as described above in the previous embodiment.
- the span length of the first pre-swirl stator is longer than that of the second pre-swirl stator.
- the span length of the second pre-swirl stator located at the lower position may be shorter than that of the first pre-swirl stator located at the upper position.
- the span length of the first pre-swirl stator may be in a range of 0.8 times to 1.0 times of the radius of the propeller 20
- the span length of the second pre-swirl stator may be in a range of 0.6 times to 0.8 times of the radius of the propeller 20.
- the ranges of the span lengths may be calculated by the same method as described above in the previous embodiment.
- first pre-swirl stator and the second pre-swirl stator may have a swept back wing shape.
- chord length of the first pre-swirl stator may be longer than that of the second pre-swirl stator.
- the chord length of the second pre-swirl stator located at the lower position may be shorter than that of the first pre-swirl stator located at the upper position.
- the second pre-swirl stator may be positioned ahead of the first pre-swirl stator.
- the distance between the first pre-swirl stator and the second pre-swirl stator may be in a range of 0.05 times to 0.15 times of the diameter of the propeller.
- the number of the pre-swirl stators may be three.
- the pre-swirl stator 110 located at the uppermost position is referred to as a "first pre-swirl stator”
- the pre-swirl stator 120 located at the middle position is referred to as a "second pre-swirl stator”
- the pre-swirl stator 130 located at the lowermost position is referred to as a "third pre-swirl stator”.
- an installation angle of the first pre-swirl stator 110 may be in a range of 30 degrees to 50 degrees
- an installation angle of the second pre-swirl stator 120 may be in a range of 60 degrees to 80 degrees
- an installation angle of the third pre-swirl stator 130 may be in a range of 100 degrees to 120 degrees.
- the ranges of the installation angles may be calculated by the same method as described above in the previous embodiments.
- the span length of the first pre-swirl stator 110 may be longer than that of the second pre-swirl stator 120, and the span length of the second pre-swirl stator 120 may be longer than that of the third pre-swirl stator 130.
- the span lengths of the pre-swirl stators 110 to 130 may be reduced sequentially in the order from the first pre-swirl stator 110 located at the uppermost position to the third pre-swirl stator 130 located at the lowermost position.
- the span length of the first pre-swirl stator 110 may be in a range of 0.9 times to 1.1 times of the radius R of the propeller 20
- the span length of the second pre-swirl stator 120 may be in a range of 0.8 times to 1.0 times of the radius R of the propeller 20
- the span length of the third pre-swirl stator 130 may be in a range of 0.6 times to 0.8 times of the radius R of the propeller 20.
- the ranges of the span lengths may be calculated by the same method as described above in the previous embodiments.
- the length of the pre-swirl stator located at the upper position may be decided to be longer than that of the pre-swirl stator located at the lower position.
- FIG. 8 is a side view of a propulsion efficiency enhancing apparatus 300 according to a third embodiment of the present disclosure
- FIG. 9 is a rear view of the propulsion efficiency enhancing apparatus 300 according to the third embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 300 may include pre-swirl stators 310, 320, and 330.
- the pre-swirl stators 310, 320, and 330 induce water entering the propeller 20 to flow in the opposite direction of the rotation direction of the propeller 20, thus generating swirling flow in the opposite direction of the rotation direction of the propeller 20.
- the swirling flow generated by the pre-swirl stators 310, 320, and 330 may enter the propeller 20 to reduce swirling flow generated in the rotation direction of the propeller 20, thereby enhancing the propulsion efficiency of the propeller 20.
- the pre-swirl stators 310, 320, and 330 may be installed at the stern boss 15 of the vessel body 10, although not limited to this.
- the number of the pre-swirl stators 310, 320, and 330 is, for convenience of description, three, however, the number of pre-swirl stators 310, 320, and 330 is not limited to three.
- the propulsion efficiency enhancing apparatus 300 may include a plurality of pre-swirl stators.
- FIG. 10 is a view for describing the pre-swirl stators of the propulsion efficiency enhancing apparatus 300 according to the third embodiment of the present disclosure.
- the left direction represents the front direction of the pre-swirl stator 310
- the right direction represents the rear direction of the pre-swirl stator 310.
- the tip portions 311, 321, and 331 of the pre-swirl stators 310, 320, and 330 have smaller pitch angles than the remaining portions 312, 322, and 332 of the pre-swirl stators 310, 320, and 330.
- the remaining portions 312, 322, and 332 of the pre-swirl stators 310, 320, and 330 may have the same pitch angle or partially different pitch angles.
- an angle of attack with respect to inflow entering the tip portions 311, 321, and 331 may be reduced so that cavitation generated around the tip portions 311, 321, and 331 can be reduced.
- cavitation generated by the tip portions 311, 321, and 331 of the pre-swirl stators 310, 320, and 330 may less influence the propeller 20, thereby effectively maintaining the propulsion efficiency of the propeller 20.
- the tip portions 311, 321, and 331 may have lengths LT of 0.1 times to 0.3 times of the span lengths LX of the pre-swirl stators 310, 320, and 330.
- the span lengths LX of the pre-swirl stators 310, 320, and 330 may mean distances from the rotation axis X of the propeller 20 to the tips of the pre-swirl stators 310, 320, and 330.
- the present applicant has performed a test on a general pre-swirl stator in which the pitch angles of the tip portions are not smaller than those of the remaining portions, and found that cavitation generated around the tips of the pre-swirl stators flows to a slipstream to hit the surfaces of the propeller hard.
- the present applicant has found that the general pre-swirl stator dominantly generates swirling flow in the opposite direction of the rotation direction of the propeller in a region of 0.7 times to 0.9 time of the span length of the pre-swirl stator.
- the lengths of the tip portions 311, 321, and 331 may be decided to be in a range of 0.1 times to 0.3 times of the span lengths of the pre-swirl stators 310, 320, and 330.
- the pitch angles of the tip portions 311, 321, and 331 may be reduced continuously toward the tips. In this case, additional cavitation that may be generated when the shapes of the tip portions 311, 321, and 331 are discontinuous can be effectively prevented.
- the corners of the tips of the tip portions 311, 321, and 331 may be, as shown in FIG. 10 , rounded, as seen from a pressure surface 301 (or a suction surface).
- the front and rear corners of the tip portions 311, 321, and 331 may be rounded, as seen from the lateral sides.
- cavitation generated around the tip portions 311, 321, and 331 can be reduced, compared to the general pre-swirl stators in which the front and rear corners of the tip portions are squared as seen from the lateral sides.
- the tip portions 311, 321, and 331 may be fabricated by casting. In this case, the tip portions 311, 321, and 331 can be easily fabricated so that the pre-swirl stators 310, 320, and 330 including the tip portions 311, 321, and 331 can also be easily fabricated. Alternatively, the tip portions 311, 321, and 331 may be fabricated by any other various methods, instead of casting.
- the tip portions 311, 321, and 331 may be fabricated separately, and then coupled with the remaining portions 312, 322, and 332 of the pre-swirl stators 310, 320, and 330, although not limited to this.
- the present applicant has discovered that the propulsion efficiency enhancing apparatus 300 configured as described above can reduce cavitation, through a cavitation tunnel test.
- FIG. 11 is a view for comparing the chord lengths of the pre-swirl stators shown in FIG. 8 at the same radius with respect to the rotation axis of the propeller.
- a pre-swirl stator arbitrarily selected from among the first pre-swirl stator 310, the second pre-swirl stator 320, and the third pre-swirl stator 330 at the same radius with respect to the rotation axis X of the propeller 20 may have a longer chord length than another pre-swirl stator located just below the selected pre-swirl stator.
- chord lengths of the first pre-swirl stator 310, the second pre-swirl stator 320, and the third pre-swirl stator 330 at the same radius R with respect to the rotation axis X of the propeller 20 may be reduced sequentially.
- the chord lengths of the pre-swirl stators 310, 320, and 330 may mean the lengths from the leading edges 302 to the trailing edges 303 in the cross-sections of the pre-swirl stators 310, 320, and 330.
- the shorter chord lengths of stators may mean smaller contact areas with inflow entering the stators.
- the longer chord lengths of stators may mean larger contact areas with inflow entering the stators.
- the velocity of wake on the rotation surface P of the propeller (20 of FIG. 8 ) may intend to be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of a vertical line V, when the rotation axis X of the propeller (20 of FIG. 8 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree.
- the velocities of inflow respectively entering the first pre-swirl stator 310, the second pre-swirl stator 320, and the third pre-swirl stator 330 sequentially arranged radially with respect to the rotation axis X may increase.
- the chord lengths of the first pre-swirl stator 310, the second pre-swirl stator 320, and the third pre-swirl stator 330 may be reduced sequentially.
- the first pre-swirl stator 310, the second pre-swirl stator 320, and the third pre-swirl stator 330 may prevent resistance from increasing according to the increase in velocity of inflow, in the order from the first pre-swirl stator 310 to the third pre-swirl stator 330.
- FIG. 12 shows a propulsion efficiency enhancing apparatus 400 according to a fourth embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 400 may include a first pre-swirl stator 410, a second pre-swirl stator 420, and a third pre-swirl stator 430.
- the first pre-swirl stator 410, the second pre-swirl stator 420, and the third pre-swirl stator 430 according to the current embodiment may have the same features as the first pre-swirl stator 310, the second pre-swirl stator 320, and the third pre-swirl stator 330 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted.
- a pre-swirl stator arbitrarily selected from among the first pre-swirl stator 410, the second pre-swirl stator 420, and the third pre-swirl stator 430 may be located behind another pre-swirl stator located just below the selected pre-swirl stator.
- the first pre-swirl stator 410, the second pre-swirl stator 420, and the third pre-swirl stator 430 may be arranged sequentially toward the front direction. That is, the first pre-swirl stator 410 may be located at the rearmost position, the second pre-swirl stator 420 may be located at the middle position, and the third pre-swirl stator 430 may be located at the foremost position.
- first pre-swirl stator 410, the second pre-swirl stator 420, and the third pre-swirl stator 430 are spaced predetermined distances in the longitudinal direction of the vessel body 10, resistance applied onto the vessel body 10 can be reduced compared to when the pre-swirl stators 410, 420, and 430 are arranged on the same line in the longitudinal direction of the vessel body 10.
- FIG. 13 is a side view of a propulsion efficiency enhancing apparatus 500 according to a fifth embodiment of the present disclosure
- FIG. 14 is a rear view of the propulsion efficiency enhancing apparatus 500 according to the fifth embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 500 may include pre-swirl stators 510, 520, and 530.
- the pre-swirl stators 510, 520, and 530 induce water entering the propeller 20 to flow in the opposite direction of the rotation direction of the propeller 20, thus generating swirling flow in the opposite direction of the rotation direction of the propeller 20.
- the swirling flow generated by the pre-swirl stators 510, 520, and 530 may enter the propeller 20 to reduce swirling flow generated in the rotation direction of the propeller 20, thereby enhancing the propulsion efficiency of the propeller 20.
- the pre-swirl stators 510, 520, and 530 may be installed at the stern boss 15 of the vessel body 10, although not limited to this.
- the number of the pre-swirl stators 510, 520, and 530 is, for convenience of description, three, however, the number of pre-swirl stators 510, 520, and 530 is not limited to three.
- the propulsion efficiency enhancing apparatus 500 may include a plurality of pre-swirl stators.
- winglets 5111, 5211, and 5311 may be formed in the tip portions 511, 521, and 531 of the pre-swirl stators 510, 520, and 530.
- the winglets 5111, 5211, and 5311 may be bent toward a suction surface 502 from the tips of the tip portions 511, 521, and 531.
- the winglets 5111, 5211, and 5311 may be bent toward a pressure surface 501 from the tips of the tip portions 511, 521, and 531.
- the winglets 5111, 5211, and 5311 may be bent vertically from the tips of the tip portions 511, 521, and 531, although not limited to this.
- the winglets 5111, 5211, and 5311 can reduce swirling flow generated around the tips of the tip portions 511, 521, and 531, thereby consequentially suppressing the generation of cavitation.
- the tip portions 511, 521, and 531 may be fabricated by casting. In this case, the tip portions 511, 521, and 531 can be easily fabricated so that the pre-swirl stators 510, 520, and 530 including the tip portions 511, 521, and 531 can also be easily fabricated. Alternatively, the tip portions 511, 521, and 531 may be fabricated by any other various methods, instead of casting.
- the winglets 5111, 5211, and 5311 may be integrated into the tip portions 511, 521, and 531, although not limited to this.
- FIG. 15 shows the cross-section of the tip portion of the pre-swirl stator according to the fifth embodiment of the present disclosure
- FIG. 16 shows the cross-section of the remaining portion of the pre-swirl stator according to the fifth embodiment of the present disclosure.
- the tip portions 511, 521, and 531 of the pre-swirl stators 510, 520, and 530 may have no cambers, and the remaining portions 512, 522, and 532 may have cambers.
- cambers may be formed in all of the tip portions 511, 521, and 531 and the remaining portions 512, 522, and 532. Also, it is possible that cambers are formed in the tip portions 511, 521, and 531 of the pre-swirl stators 510, 520, and 530, and no cambers are formed in the remaining portions 512, 522, and 532.
- FIG. 17 is a view for describing the pre-swirl stators of the propulsion efficiency enhancing apparatus 500 according to the fifth embodiment of the present disclosure.
- the tip portions 511, 521, and 531 may have lengths LT of 0.1 times to 0.3 times of the span lengths LX of the pre-swirl stators 510, 520, and 530.
- the span lengths LX of the pre-swirl stators 510, 520, and 530 may means distances from the rotation axis X of the propeller 20 to the tips of the pre-swirl stators 510, 520, and 530.
- the present applicant has performed a test on a pre-swirl stator in which a camber is formed in the entire area from the root portion to the tip portion, and found that cavitation generated around the tip of the pre-swirl stator flows to a slipstream to hit the surfaces of the propeller hard.
- the pre-swirl stator in which the camber is formed in the entire area dominantly generates swirling flow in the opposite direction of the rotation direction of the propeller 20 in a region of 0.7 times and 0.9 time of the span length of the pre-swirl stator.
- the lengths of the tip portions 511, 521, and 531 may be decided to be in a range of 0.1 times to 0.3 times of the span lengths of the pre-swirl stators 510, 520, and 530.
- tip portions 511, 522, and 531 having the lengths are fabricated without forming any cambers, cavitation generated around the tip portions 511, 521, and 531 can be effectively reduced.
- the corners of the tips of the tip portions 511, 521, and 531 may be, as shown in FIGS. 13 and 17 , rounded, as seen from the pressure surface 501 (or the suction surface 502).
- the shapes of the tips of the tip portions 511, 521, and 531 can reduce the generation of cavitation.
- the present applicant has discovered that the propulsion efficiency enhancing apparatus 500 configured as described above can reduce cavitation, through a cavitation tunnel test.
- the propulsion efficiency enhancing apparatus 500 will be described with reference to FIGS. 13 and 14 , under an assumption that the propulsion efficiency enhancing apparatus 500 has a plurality of pre-swirl stators.
- the propulsion efficiency enhancing apparatus 500 may include three pre-swirl stators 510, 520, and 530.
- the pre-swirl stator 510 located at the uppermost position is referred to as a "first pre-swirl stator 510”
- the pre-swirl stator 520 located at the middle position is referred to as a "second pre-swirl stator 520”
- the pre-swirl stator 530 located at the lowermost position is referred to as a "third pre-swirl stator 530".
- the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 disposed ahead of the propeller 20, and spaced from each other.
- the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 are arranged radially with respect to the rotation axis X of the propeller 20, as shown in FIG. 14 .
- the propeller 20 may rotate in the clockwise direction, as shown in FIG. 14 .
- all of the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 may be located in the left region of the rotation surface P of the propeller 20, where the propeller 20 rotates upward, among the left and right regions of the rotation surface P.
- the direction of inflow entering the propeller 20 may become the opposite direction of the rotation direction of the propeller 20 so that an angle of attack with respect to the sections of the blades of the propeller 20 increases, and a relatively great propulsion force is generated due to the increase of the angle of attack.
- the direction of inflow entering the propeller 20 may become the same direction as the rotation direction of the propeller 20 so that an angle of attack with respect to the sections of the blades of the propeller 20 decreases, and a relatively small propulsion force is generated due to the decrease of the angle of attack.
- the pre-swirl stators 510, 520, and 530 in the left region of the rotation surface P of the propeller 20 to generate flow in the opposite direction of the rotation direction of the propeller 20 in inflow entering the propeller 20, it is possible to increase an angle of attack with respect to the sections of the blades of the propeller 20, and to enhance the propulsion efficiency of the propeller 20.
- the propeller 20 may rotate in the counterclockwise direction as seen in the rear direction.
- all of the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 may be located in the right region of the rotation surface P of the propeller 20, where the propeller 20 rotates upward, among the left and right regions of the rotation surface P.
- the span lengths of the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 may be reduced sequentially in the order from the first pre-swirl stator 510 located at the uppermost position to the third pre-swirl stator 530 located at the lowermost position.
- a pre-swirl stator arbitrarily selected from among the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 may have a longer span length than another pre-swirl stator located just below the selected pre-swirl stator.
- the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 may have a swept back wing shape.
- the trailing edges of the pre-swirl stators 510, 520, and 530 may be located on a straight line that is vertical to the rotation axis X.
- the pre-swirl stators 510, 520, and 530 can be located closest to the propeller 20 so that swirling flow generated by the pre-swirl stators 510, 520, and 530 and flowing in the opposite direction of the rotation direction of the propeller 20 can directly enter the propeller 20, thereby enhancing the propulsion efficiency of the propeller 20.
- a pre-swirl stator arbitrarily selected from among the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 at the same radius with respect to the rotation axis X of the propeller 20 may have a longer chord length than another pre-swirl stator located just below the selected pre-swirl stator.
- chord lengths of the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 at the same radius R with respect to the rotation axis X of the propeller 20 may be reduced sequentially.
- the chord lengths of the pre-swirl stators 510, 520, and 530 may mean the lengths from the leading edges to the trailing edges in the cross-sections of the pre-swirl stators 510, 520, and 530.
- the shorter chord lengths of stators may mean smaller contact areas with inflow entering the stators.
- the longer chord lengths of stators may mean larger contact areas with inflow entering the stators.
- the velocity of wake on the rotation surface P of the propeller (20 of FIG. 13 ) may intend to be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of a vertical line V, when the rotation axis X of the propeller (20 of FIG. 13 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree.
- the velocities of inflow respectively entering the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 sequentially arranged radially with respect to the rotation axis X may increase.
- the chord lengths of the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 may be reduced sequentially.
- the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 may prevent resistance from increasing according to the increase in velocity of inflow, in the order from the first pre-swirl stator 510 to the third pre-swirl stator 530.
- FIG. 18 shows a propulsion efficiency enhancing apparatus 600 according to a sixth embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 600 may include a first pre-swirl stator 610, a second pre-swirl stator 620, and a third pre-swirl stator 630.
- the first pre-swirl stator 610, the second pre-swirl stator 620, and the third pre-swirl stator 630 according to the current embodiment may have the same features as the first pre-swirl stator 510, the second pre-swirl stator 520, and the third pre-swirl stator 530 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted.
- a pre-swirl stator arbitrarily selected from among the first pre-swirl stator 610, the second pre-swirl stator 620, and the third pre-swirl stator 630 may be located behind another pre-swirl stator located just below the selected pre-swirl stator.
- the first pre-swirl stator 610, the second pre-swirl stator 620, and the third pre-swirl stator 630 may be arranged sequentially toward the front direction. That is, the first pre-swirl stator 610 may be located at the rearmost position, the second pre-swirl stator 620 may be located at the middle position, and the third pre-swirl stator 630 may be located at the foremost position.
- first pre-swirl stator 610, the second pre-swirl stator 620, and the third pre-swirl stator 630 are spaced predetermined distances in the longitudinal direction of the vessel body 10, resistance applied onto the vessel body 10 can be reduced compared to when the pre-swirl stators 610, 620, and 630 are arranged on the same line in the longitudinal direction of the vessel body 10.
- FIG. 19 is a side view of a propulsion efficiency enhancing apparatus 700 according to a seventh embodiment of the present disclosure
- FIG. 20 is a rear view of the propulsion efficiency enhancing apparatus 700 according to the seventh embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 700 may include pre-swirl stators 710, 720, and 730.
- the pre-swirl stators 710, 720, and 730 induce water entering the propeller 20 to flow in the opposite direction of the rotation direction of the propeller 20, thus generating swirling flow in the opposite direction of the rotation direction of the propeller 20.
- the swirling flow generated by the pre-swirl stators 710, 720, and 730 may enter the propeller 20 to reduce swirling flow generated in the rotation direction of the propeller 20, thereby enhancing the propulsion efficiency of the propeller 20.
- the pre-swirl stators 710, 720, and 730 may be installed at the stern boss 15 of the vessel body 10, although not limited to this.
- the number of the pre-swirl stators 710, 720, and 730 is, for convenience of description, three, however, the number of the pre-swirl stators 710, 720, and 730 is not limited to three.
- the propulsion efficiency enhancing apparatus 700 may include a plurality of pre-swirl stators.
- additional members 7111, 7211, and 7311 may be formed in the tip portions 711, 721, and 731 of the pre-swirl stators 710, 720, and 730.
- the additional members 7111, 7211, and 7311 may be formed in the tips of the tip portions 711, 721, and 731.
- the additional members 7111, 7211, and 7311 can reduce swirling flow generated around the tips of the tip portions 711, 721, and 731, thereby consequentially suppressing the generation of cavitation.
- the additional members 7111, 7211, and 7311 may function as winglets.
- the additional members 7111, 7211, and 7311 may be in the shape of a plate extending toward the suction surface and the pressure surface.
- the additional members 7111, 7211, and 7311 may be arranged vertically to the tip portions 711, 721, and 731, although not limited to this.
- the additional members 7111, 7211, and 7311 may be fabricated separately, and then weld-bonded with the tip portions 711, 721, and 731. Alternatively, the additional members 7111, 7211, and 7311 may be integrated into the tip portions 711, 721, and 731 by casting.
- the tip portions 711, 721, and 731 may be fabricated by casting, and then coupled with the remaining portions 712, 722, and 732 of the pre-swirl stators 710, 720, and 730, although not limited to this.
- FIG. 21 shows a propulsion efficiency enhancing apparatus 800 according to an eighth embodiment of the present disclosure.
- the propulsion efficiency enhancing apparatus 800 may include a first pre-swirl stator 810, a second pre-swirl stator 820, and a third pre-swirl stator 830.
- the first pre-swirl stator 810, the second pre-swirl stator 820, and the third pre-swirl stator 830 according to the current embodiment may have the same features as the first pre-swirl stator 710, the second pre-swirl stator 720, and the third pre-swirl stator 730 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted.
- a pre-swirl stator arbitrarily selected from among the first pre-swirl stator 810, the second pre-swirl stator 820, and the third pre-swirl stator 830 may be located behind another pre-swirl stator located just below the selected pre-swirl stator.
- first pre-swirl stator 810, the second pre-swirl stator 820, and the third pre-swirl stator 830 may be arranged sequentially toward the front direction. That is, the first pre-swirl stator 810 may be located at the rearmost position, the second pre-swirl stator 820 may be located at the middle position, and the third pre-swirl stator 830 may be located at the foremost position.
- first pre-swirl stator 810, the second pre-swirl stator 820, and the third pre-swirl stator 830 are spaced predetermined distances in the longitudinal direction of the vessel body 10, resistance applied onto the vessel body 10 can be reduced compared to when the pre-swirl stators 810, 820, and 830 are arranged on the same line in the longitudinal direction of the vessel body 10.
Description
- The present invention relates to a propulsion efficiency enhancing apparatus.
- In order to enhance the propulsion efficiency of a vessel, pre-swirl stators are typically used. The pre-swirl stators make, when a propeller rotates to move the vessel forward, the flow of water around the stern bent in the opposite direction of the rotation direction of the propeller so that the water can flow to the propeller. At this time, swirling flow generated by the pre-swirl stators is absorbed by the propeller so that the propulsion efficiency of the propeller can be enhanced.
- However, the pre-swirl stators act as resistance when the vessel sails, resulting in a deterioration of the resistance performance of the vessel.
- Document
JP 2010 179869 A - Document
JP 2011 121569 A - Document
KR 2012 0126910 A - In Document
JP 2004 306839 A - Document
KR 2014 0085644 - An aspect of the present disclosure is to provide a propulsion efficiency enhancing apparatus configured to reduce resistance applied onto pre-swirl stators.
- Also, another aspect of the present disclosure is to provide a propulsion efficiency enhancing apparatus including pre-swirl stators capable of reducing cavitation influencing the propeller. More specifically, the propulsion efficiency enhancing apparatus is configured to reduce cavitation that is generated around the tip portions of the pre-swirl stators.
- In accordance with an aspect of the present disclosure, there is provided a propulsion efficiency enhancing apparatus including a plurality of pre-swirl stators disposed ahead of a propeller, and arranged radially with respect to a rotation axis of the propeller, wherein the pre-swirl stators are located in a region of a rotation surface of the propeller, where the propeller rotates upward, among the left and right regions of the rotation surface of the propeller, a span length of at least one pre-swirl stator of the pre-swirl stators is different from span lengths of the remaining pre-swirl stators, and a span length of a pre-swirl stator arbitrarily selected from among the pre-swirl stators is longer than or equal to a span length of another pre-swirl stator located just below the selected pre-swirl stator.
- The span lengths of the pre-swirl stators may be reduced sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- The number of the pre-swirl stators may be three, and an installation angle of a first pre-swirl stator located at the uppermost position among the pre-swirl stators may be in a range of 30 degrees to 50 degrees, an installation angle of a second pre-swirl stator located at the middle position may be in a range of 60 degrees to 80 degrees, and an installation angle of a third pre-swirl stator located at the lowermost position may be in a range of 100 degrees to 120 degrees.
- A span length of the first pre-swirl stator may be in a range of 0.9 times to 1.1 times of the radius of the propeller, a span length of the second pre-swirl stator may be in a range of 0.8 times to 1.0 times of the radius of the propeller, and a span length of the third pre-swirl stator may be in a range of 0.6 times to 0.8 times of the radius of the propeller, and the span lengths of the pre-swirl stators may be reduced sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- The pre-swirl stators may be arranged toward the front direction sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- Chord lengths of the pre-swirl stators may be reduced, at the same radius with respect to the rotation axis, in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- The tip portions of the pre-swirl stators have smaller pitch angles than the remaining portions of the pre-swirl stators.
- A winglet may be formed in the tip portion of each pre-swirl stator, and the winglet is bent toward a suction surface or a pressure surface.
- The pitch angles of the tip portions may be reduced continuously toward the tips of the tip portions.
- The tip portions may have lengths of 0.1 times to 0.3 times of the span lengths of the pre-swirl stators.
- The corners of the tips of the tip portions may be rounded, as seen from the pressure surface.
- An additional member may be formed in the tip portion of each pre-swirl stator, and the additional member may be in the shape of a plate extending toward a suction surface and a pressure surface.
- According to the embodiments of the present disclosure, since the span length of at least one of the pre-swirl stators arranged radially is different from those of the remaining pre-swirl stators, and the span length of a pre-swirl stator arbitrarily selected from among the pre-swirl stators is longer than or equal to that of another pre-swirl stator located just below the selected pre-swirl stator, it is possible to reduce resistance applied onto the pre-swirl stators in correspondence to the velocity of inflow, and to enhance the propulsion efficiency of the propeller.
- Also, since the pitch angles of the tip portions of the pre-swirl stators are smaller than those of the remaining portions, an angle of attack with respect to inflow entering the tip portions can become relatively small so as to reduce cavitation generated around the tip portions, and to reduce influence of cavitation generated around the tip portions on the propeller, thereby effectively maintaining the propulsion efficiency of the propeller.
- Also, the winglets may be formed in the tip portions of the pre-swirl stators to reduce cavitation generated around the tip portions.
- Also, the additional members may be formed in the tip portions of the pre-swirl stators to reduce cavitation generated around the tip portions.
-
-
FIG. 1 is a side view of a propulsion efficiency enhancing apparatus according to a first embodiment of the present disclosure. -
FIG. 2 is a rear view of the propulsionefficiency enhancing apparatus 100 according to the first embodiment of the present disclosure. -
FIG. 3 shows a flow distribution of wake entering the propeller, represented on the rotation surface of the propeller, in the barehull having no pre-swirl stators, as seen in the front direction from the propeller. -
FIG. 4 shows experimental data used in a test for deducing the propulsion efficiency enhancing apparatus according to the first embodiment of the present disclosure. -
FIG. 5 shows a propulsion efficiency enhancing apparatus according to a second embodiment of the present disclosure. -
FIG. 6A shows a comparative example for performance evaluation of the propulsion efficiency enhancing apparatuses according to the first and second embodiments of the present disclosure. -
FIG. 6B shows an experimental example for performance evaluation of the propulsion efficiency enhancing apparatuses according to the first embodiment and the second embodiment, -
FIG. 7 shows propulsion force reduction coefficients for the comparative example and the experimental example ofFIG. 6 . -
FIG. 8 is a side view of a propulsion efficiency enhancing apparatus according to a third embodiment of the present disclosure, -
FIG. 9 is a rear view of the propulsion efficiency enhancing apparatus according to the third embodiment of the present disclosure. -
FIG. 10 is a view for describing the pre-swirl stators of the propulsion efficiency enhancing apparatus according to the third embodiment of the present disclosure. -
FIG. 11 is a view for comparing the chord lengths of the pre-swirl stators shown inFIG. 8 at the same radius with respect to the rotation axis of the propeller. -
FIG. 12 shows a propulsion efficiency enhancing apparatus according to a fourth embodiment of the present disclosure. -
FIG. 13 is a side view of a propulsion efficiency enhancing apparatus according to a fifth embodiment of the present disclosure, and -
FIG. 14 is a rear view of the propulsion efficiency enhancing apparatus according to the fifth embodiment of the present disclosure. -
FIG. 15 shows the cross-section of the tip portion of the pre-swirl stator according to the fifth embodiment of the present disclosure, -
FIG. 16 shows the cross-section of the remaining portion of the pre-swirl stator according to the fifth embodiment of the present disclosure. -
FIG. 17 is a view for describing the pre-swirl stators of the propulsion efficiency enhancing apparatus according to the fifth embodiment of the present disclosure. -
FIG. 18 shows a propulsion efficiency enhancing apparatus according to a sixth embodiment of the present disclosure. -
FIG. 19 is a side view of a propulsion efficiency enhancing apparatus according to a seventh embodiment of the present disclosure, -
FIG. 20 is a rear view of the propulsion efficiency enhancing apparatus according to the seventh embodiment of the present disclosure. -
FIG. 21 shows a propulsion efficiency enhancing apparatus according to an eighth embodiment of the present disclosure. - The present disclosure allows various variations and includes various embodiments, and specific embodiments of the present disclosure will be illustrated in the accompanying drawings and described in detail in the detailed description. However, the present disclosure is not limited to these specific embodiments, and it should be understood that all modifications, equivalents, and substitutes can be made without departing from the technical idea and range of the present disclosure. In the following description, when it is determined that the detailed description of the related art well-known in the art may make the gist of the present disclosure obscure, the detailed description will be omitted.
- Hereinafter, the embodiments of the present disclosure will be described in detail with reference to the appended drawings, and in the following description provided with reference to the appended drawings, the same or corresponding components will be represented by the same reference numerals, and the same description will be not repeated for avoiding redundant description.
-
FIG. 1 is a side view of a propulsionefficiency enhancing apparatus 100 according to a first embodiment of the present disclosure, andFIG. 2 is a rear view of the propulsionefficiency enhancing apparatus 100 according to the first embodiment of the present disclosure. - Referring to
FIGS. 1 and2 , the propulsionefficiency enhancing apparatus 100 may includepre-swirl stators pre-swirl stators propeller 20, and arranged radially with respect to the rotation axis X of thepropeller 20. - The
pre-swirl stators propeller 20 to flow in the opposite direction of the rotation direction of thepropeller 20, thus generating swirling flow in the opposite direction of the rotation direction of thepropeller 20. The swirling flow generated by thepre-swirl stators propeller 20 to reduce swirling flow generated in the rotation direction of thepropeller 20, thereby enhancing the propulsion efficiency of thepropeller 20. - The
pre-swirl stators stern boss 15 of thevessel body 10, although not limited to this. - According to the current embodiment, three
pre-swirl stators pre-swirl stator 110 located at the uppermost position is referred to as a "firstpre-swirl stator 110", thepre-swirl stator 120 located at the middle position is referred to as a "secondpre-swirl stator 120", and thepre-swirl stator 130 located at the lowermost position is referred to as a "thirdpre-swirl stator 130". - Meanwhile, in the current embodiment, the number of the pre-swirl stators is, for convenience of description, three, however the number of the pre-swirl stators is not limited.
- According to the current embodiment, the
propeller 20 may rotate in a clockwise direction, when seen in a rear direction as shown inFIG. 2 . In this case, all of the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may be located in the left region of the rotation surface P of thepropeller 20, where thepropeller 20 rotates upward, among the left and right regions of the rotation surface P. - In regard of this, in the right region of the rotation surface P of the
propeller 20, the direction of inflow entering thepropellers 20 may become the opposite direction of the rotation direction of thepropeller 20 so that an angle of attack with respect to the sections of the blades of thepropeller 20 increases, and a relatively great propulsion force is generated due to the increase of the angle of attack. - Meanwhile, in the left region of the rotation surface P of the
propeller 20, the direction of inflow entering thepropeller 20 may become the same direction as the rotation direction of thepropeller 20 so that an angle of attack with respect to the sections of the blades of thepropeller 20 decreases, and a relatively small propulsion force is generated due to the decrease of the angle of attack. - Accordingly, by locating the
pre-swirl stators propeller 20 to generate flow in the opposite direction of the rotation direction of thepropeller 20 in inflow entering thepropeller 20, it is possible to increase an angle of attack with respect to the sections of the blades of thepropeller 20, and to enhance the propulsion efficiency of thepropeller 20. - Alternatively, the
propeller 20 may rotate in a counterclockwise direction as seen in the rear direction, unlikeFIG. 2 . In this case, all of the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may be located in the right region of the rotation surface P of thepropeller 20, where thepropeller 20 rotates upward, among the left and right regions of the rotation surface P. - According to the current embodiment, the span lengths of the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may be reduced sequentially in the order from the firstpre-swirl stator 110 located at the uppermost position to the thirdpre-swirl stator 130 located at the lowermost position. - In other words, the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may have different span lengths. Also, one arbitrarily selected from among the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 has a longer span length than another one located just below the selected one. - The span lengths of the
pre-swirl stators propeller 20 to the tips of thepre-swirl stators -
FIG. 3 shows a flow distribution of wake entering the propeller, represented on the rotation surface of the propeller, in the barehull having no pre-swirl stators, as seen in the front direction from the propeller. - In the flow distribution of wake, the velocities of inflow respectively entering the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 sequentially arranged radially with respect to the rotation axis X may increase. - In correspondence to the increase in velocity of inflow, the span lengths of the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may be reduced sequentially. In this case, the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 can prevent resistance from increasing according to the increase in velocity of inflow, in the order from the firstpre-swirl stator 110 to the thirdpre-swirl stator 130. - In another aspect, referring to
FIGS. 2 and3 , the flow velocity of wake on the rotation surface of the propeller (20 ofFIG. 1 ) may intend to be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of a vertical line V, when the rotation axis X of the propeller (20 ofFIG. 1 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree. In the flow distribution of wake, the velocities of inflow respectively entering the thirdpre-swirl stator 130, the secondpre-swirl stator 120, and the firstpre-swirl stator 110 sequentially arranged radially with respect to the rotation axis X may decrease. - In correspondence to the decrease in velocity of inflow, the span lengths of the third
pre-swirl stator 130, the secondpre-swirl stator 120, and the firstpre-swirl stator 110 may increase sequentially. - In this case, the third
pre-swirl stator 130, the secondpre-swirl stator 120, and the firstpre-swirl stator 110 may have a more improved function of generating swirling flow in the opposite direction of the rotation direction of the propeller (20 ofFIG. 1 ), in the order from the thirdpre-swirl stator 130 to the firstpre-swirl stator 110. Thepre-swirl stators FIG. 1 ), at the lower velocity of inflow. - Referring to
FIGS. 1 and2 , in the flow distribution of wake as shown inFIG. 3 , an installation angle a of the firstpre-swirl stator 110 may be in a range of 30 degrees to 50 degrees, an installation angle b of the secondpre-swirl stator 120 may be in a range of 60 degrees to 80 degrees, and an installation angle c of the thirdpre-swirl stator 130 may be in a range of 100 degrees to 120 degrees. - Herein, the installation angles a, b, and c may be angles of the installation positions of the
pre-swirl stators propeller 20 is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree. - If the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 are disposed respectively at the installation angles a, b, and c, resistance in the flow distribution of wake can be minimized. -
FIG. 4 shows experimental data used in a test for deducing the propulsionefficiency enhancing apparatus 100 according to the first embodiment of the present disclosure. InFIG. 4 , the horizontal axis X represents the span lengths of thepre-swirl stators propeller 20, and the vertical axis Y represents resistance values calculated through computational fluid dynamics. -
FIG. 4 shows resistance applied to each segment of the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130, divided by 0.1 times of the radius R of thepropeller 20, through computational fluid dynamics, when the installation angle of the first pre-swirl stator 110 (Stator 1) is in the range of 30 degrees to 50 degrees, the installation angle of the second pre-swirl stator 120 (Stator 2) is in the range of 60 degrees to 80 degrees, the installation angle of the third pre-swirl stator 130 (Stator 3) is in the range of 100 degrees to 120 degrees, and the span lengths of the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 are 1.0 times of the radius R of thepropeller 20, in the condition of wake as shown inFIG. 3 . - Referring to
FIG. 4 , resistance applied to the firstpre-swirl stator 110 changes to plus (+) at 0.9 times or more of the radius R of thepropeller 20, resistance applied to the secondpre-swirl stator 120 changes to plus (+) at 0.8 times or more of the radius R of thepropeller 20, and resistance applied to the thirdpre-swirl stator 130 changes to plus (+) at 0.7 times or more of the radius R of thepropeller 20. - Referring to
FIG. 2 , according to the experimental data, the span length of the firstpre-swirl stator 110 may be decided to be in a range of 0.9 times to 1.1 times of the radius R of thepropeller 20, the span length of the secondpre-swirl stator 120 may be decided to be in a range of 0.8 times to 1.0 times of the radius R of thepropeller 20, and the span length of the thirdpre-swirl stator 110 may be decided to be in a range of 0.6 times to 0.8 times of the radius R of thepropeller 20. - In this case, resistance caused by inflow entering the
pre-swirl stators - Meanwhile, the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may have a swept back wing shape. The trailing edges of thepre-swirl stators pre-swirl stators propeller 20 so that swirling flow generated by thepre-swirl stators propeller 20 can directly enter thepropeller 20, thereby enhancing the propulsion efficiency of thepropeller 20. - Meanwhile, the chord lengths of the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 at the same radius R with respect to the rotation axis X may be reduced sequentially. Herein, the chord lengths may mean the lengths from the leading edges to the trailing edges in the cross-sections of thepre-swirl stators - The shorter chord lengths of the
pre-swirl stators pre-swirl stators pre-swirl stators pre-swirl stators - Referring to
FIGS. 2 and3 , the velocity of wake on the rotation surface P of the propeller (20 ofFIG. 1 ) may be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of the vertical line V, when the rotation axis X of the propeller (20 ofFIG. 1 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree. - In the flow distribution of wake, the velocities of inflow respectively entering the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 sequentially arranged radially with respect to the rotation axis X may increase. - In correspondence of the increase in velocity of inflow, the chord lengths of the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may be reduced sequentially. In this case, the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may prevent resistance from increasing according to the increase in velocity of inflow, in the order from the firstpre-swirl stator 110 to the thirdpre-swirl stator 130. - Meanwhile, as described above, the installation angles a, b, and c of the first
pre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may have predetermined ranges. In the propulsionefficiency enhancing apparatus 100 according to the current embodiment, the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 may be respectively installed within the installation angle ranges. - According to a second embodiment, two or more first
pre-swirl stators 110, two or more secondpre-swirl stators 120, and two or more thirdpre-swirl stators 130 may be respectively installed within the installation angle ranges. In this case, thepre-swirl stators -
FIG. 5 shows a propulsionefficiency enhancing apparatus 200 according to a second embodiment of the present disclosure. Referring toFIG. 5 , the propulsionefficiency enhancing apparatus 200 according to the current embodiment may include a firstpre-swirl stator 210, a secondpre-swirl stator 220, and a thirdpre-swirl stator 230. - The first
pre-swirl stator 210, the secondpre-swirl stator 220, and the thirdpre-swirl stator 230 according to the current embodiment may have the same features as the firstpre-swirl stator 110, the secondpre-swirl stator 120, and the thirdpre-swirl stator 130 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted. - The first
pre-swirl stator 210, the secondpre-swirl stator 220, and the thirdpre-swirl stator 230 may be arranged sequentially toward the front direction. That is, the thirdpre-swirl stator 230 may be located at the foremost position, the secondpre-swirl stator 220 may be located at the middle position, and the firstpre-swirl stator 210 may be located at the rearmost position. - As such, if the first
pre-swirl stator 210, the secondpre-swirl stator 220, and the thirdpre-swirl stator 230 are spaced predetermined distances in the longitudinal direction of the vessel body, resistance applied onto the vessel body can be reduced compared to when thepre-swirl stators -
FIG. 6 shows a comparative example 100 and an experimental example 200 for performance evaluation of the propulsion efficiency enhancing apparatuses according to the first embodiment and the second embodiment, andFIG. 7 shows propulsion force reduction coefficients t for the comparative example 100 and the experimental example 200 ofFIG. 6 . -
FIG. 6A shows the propulsion efficiency enhancing apparatus (hereinafter, referred to as a "comparative example 100") according to the first embodiment of the present disclosure in which stators are located on the same line in the longitudinal direction of the vessel body, andFIG. 6B shows the propulsion efficiency enhancing apparatus (hereinafter, referred to as an "experimental example 200") according to the second embodiment of the present disclosure in which stators are located sequentially toward the front direction. - By interpreting resistance and self-propulsion performance through computational fluid dynamics on the comparative example 100 and the experimental example 200 shown in
FIG. 6 , resistance for each example and resistance applied onto the vessel body upon self-propulsion for each example can be deduced, and the propulsion force reduction coefficients t as shown inFIG. 7 can be obtained through the deduced resistance. - Referring to
FIG. 7 , it can be seen that the propulsion force reduction coefficient t of the experimental example 200 is smaller than the propulsion force reduction coefficient t of the comparative example 100. - The results are obtained since the venturi effect generated between the
pre-swirl stators pre-swirl stator 210, the secondpre-swirl stator 220, and the thirdpre-swirl stator 230 are spaced predetermined distances in the longitudinal direction of the vessel body, to reduce resistance applied onto the vessel body. - Referring to
FIG. 5 , a distance D1 between the firstpre-swirl stator 210 and the secondpre-swirl stator 220 in the longitudinal direction of the vessel body, and a distance D2 between the secondpre-swirl stator 220 and the thirdpre-swirl stator 230 in the longitudinal direction of the vessel body may be in a range of 0.05 times to 0.15 times of the diameter of thepropeller 20. - If the distances D1 and D2 between the
pre-swirl stators pre-swirl stators propeller 20 so that flow induced by thepre-swirl stators propeller 20, thereby deteriorating the propulsion efficiency of thepropeller 20. - Also, if the distances D1 and D2 between the
pre-swirl stators pre-swirl stators - Meanwhile, in the above-described embodiments, the number of the pre-swirl stators is, for convenience of description, three, however, the number of pre-swirl stators is not limited to three.
- For example, the number of the pre-swirl stators may be two. Hereinafter, for convenience of description, the pre-swirl stator located at the upper position is referred to as a "first pre-swirl stator", and the pre-swirl stator located at the lower position is referred to as a "second pre-swirl stator".
- In this case, an installation angle of the first pre-swirl stator may be in a range of 45 degrees to 75 degrees, and an installation angle of the second pre-swirl stator may be in a range of 90 degrees to 120 degrees. The ranges of the installation angles may be calculated by the same method as described above in the previous embodiment.
- The span length of the first pre-swirl stator is longer than that of the second pre-swirl stator. In other words, the span length of the second pre-swirl stator located at the lower position may be shorter than that of the first pre-swirl stator located at the upper position.
- Also, the span length of the first pre-swirl stator may be in a range of 0.8 times to 1.0 times of the radius of the
propeller 20, and the span length of the second pre-swirl stator may be in a range of 0.6 times to 0.8 times of the radius of thepropeller 20. The ranges of the span lengths may be calculated by the same method as described above in the previous embodiment. - Also, the first pre-swirl stator and the second pre-swirl stator may have a swept back wing shape.
- Also, the chord length of the first pre-swirl stator may be longer than that of the second pre-swirl stator. In other words, the chord length of the second pre-swirl stator located at the lower position may be shorter than that of the first pre-swirl stator located at the upper position.
- Also, the second pre-swirl stator may be positioned ahead of the first pre-swirl stator. In this case, the distance between the first pre-swirl stator and the second pre-swirl stator may be in a range of 0.05 times to 0.15 times of the diameter of the propeller.
- As another example, the number of the pre-swirl stators may be three. Hereinafter, for convenience of description, the
pre-swirl stator 110 located at the uppermost position is referred to as a "first pre-swirl stator", thepre-swirl stator 120 located at the middle position is referred to as a "second pre-swirl stator", and thepre-swirl stator 130 located at the lowermost position is referred to as a "third pre-swirl stator". - In this case, an installation angle of the first
pre-swirl stator 110 may be in a range of 30 degrees to 50 degrees, an installation angle of the secondpre-swirl stator 120 may be in a range of 60 degrees to 80 degrees, and an installation angle of the thirdpre-swirl stator 130 may be in a range of 100 degrees to 120 degrees. The ranges of the installation angles may be calculated by the same method as described above in the previous embodiments. - Also, the span length of the first
pre-swirl stator 110 may be longer than that of the secondpre-swirl stator 120, and the span length of the secondpre-swirl stator 120 may be longer than that of the thirdpre-swirl stator 130. In other words, the span lengths of thepre-swirl stators 110 to 130 may be reduced sequentially in the order from the firstpre-swirl stator 110 located at the uppermost position to the thirdpre-swirl stator 130 located at the lowermost position. - Also, the span length of the first
pre-swirl stator 110 may be in a range of 0.9 times to 1.1 times of the radius R of thepropeller 20, the span length of the secondpre-swirl stator 120 may be in a range of 0.8 times to 1.0 times of the radius R of thepropeller 20, and the span length of the thirdpre-swirl stator 130 may be in a range of 0.6 times to 0.8 times of the radius R of thepropeller 20. The ranges of the span lengths may be calculated by the same method as described above in the previous embodiments. Also, in the overlapping areas of the ranges, the length of the pre-swirl stator located at the upper position may be decided to be longer than that of the pre-swirl stator located at the lower position. -
FIG. 8 is a side view of a propulsionefficiency enhancing apparatus 300 according to a third embodiment of the present disclosure, andFIG. 9 is a rear view of the propulsionefficiency enhancing apparatus 300 according to the third embodiment of the present disclosure. - Referring to
FIGS. 8 and9 , the propulsionefficiency enhancing apparatus 300 may includepre-swirl stators - The
pre-swirl stators propeller 20 to flow in the opposite direction of the rotation direction of thepropeller 20, thus generating swirling flow in the opposite direction of the rotation direction of thepropeller 20. The swirling flow generated by thepre-swirl stators propeller 20 to reduce swirling flow generated in the rotation direction of thepropeller 20, thereby enhancing the propulsion efficiency of thepropeller 20. - The
pre-swirl stators stern boss 15 of thevessel body 10, although not limited to this. - In the current embodiment, the number of the
pre-swirl stators pre-swirl stators efficiency enhancing apparatus 300 may include a plurality of pre-swirl stators. -
FIG. 10 is a view for describing the pre-swirl stators of the propulsionefficiency enhancing apparatus 300 according to the third embodiment of the present disclosure. InFIG. 10 , the left direction represents the front direction of thepre-swirl stator 310, and the right direction represents the rear direction of thepre-swirl stator 310. - Referring to
FIG. 10 , thetip portions pre-swirl stators portions pre-swirl stators portions pre-swirl stators - If the pitch angles of the
tip portions portions tip portions tip portions tip portions pre-swirl stators propeller 20, thereby effectively maintaining the propulsion efficiency of thepropeller 20. - The
tip portions pre-swirl stators pre-swirl stators propeller 20 to the tips of thepre-swirl stators - The present applicant has performed a test on a general pre-swirl stator in which the pitch angles of the tip portions are not smaller than those of the remaining portions, and found that cavitation generated around the tips of the pre-swirl stators flows to a slipstream to hit the surfaces of the propeller hard.
- Also, the present applicant has found that the general pre-swirl stator dominantly generates swirling flow in the opposite direction of the rotation direction of the propeller in a region of 0.7 times to 0.9 time of the span length of the pre-swirl stator.
- Based on the test results, in order for the
pre-swirl stators tip portions pre-swirl stators - If the pitch angles of the
tip portions portions tip portions - The pitch angles of the
tip portions tip portions - The corners of the tips of the
tip portions FIG. 10 , rounded, as seen from a pressure surface 301 (or a suction surface). In other words, the front and rear corners of thetip portions - In this case, cavitation generated around the
tip portions - The
tip portions tip portions pre-swirl stators tip portions tip portions - The
tip portions portions pre-swirl stators - The present applicant has discovered that the propulsion
efficiency enhancing apparatus 300 configured as described above can reduce cavitation, through a cavitation tunnel test. -
FIG. 11 is a view for comparing the chord lengths of the pre-swirl stators shown inFIG. 8 at the same radius with respect to the rotation axis of the propeller. - Referring to
FIGS. 8 to 11 , a pre-swirl stator arbitrarily selected from among the firstpre-swirl stator 310, the secondpre-swirl stator 320, and the thirdpre-swirl stator 330 at the same radius with respect to the rotation axis X of thepropeller 20 may have a longer chord length than another pre-swirl stator located just below the selected pre-swirl stator. - In other words, the chord lengths of the first
pre-swirl stator 310, the secondpre-swirl stator 320, and the thirdpre-swirl stator 330 at the same radius R with respect to the rotation axis X of thepropeller 20 may be reduced sequentially. Herein, the chord lengths of thepre-swirl stators edges 302 to the trailingedges 303 in the cross-sections of thepre-swirl stators - The shorter chord lengths of stators may mean smaller contact areas with inflow entering the stators. In contrast, the longer chord lengths of stators may mean larger contact areas with inflow entering the stators.
- Also, the velocity of wake on the rotation surface P of the propeller (20 of
FIG. 8 ) may intend to be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of a vertical line V, when the rotation axis X of the propeller (20 ofFIG. 8 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree. - In the flow distribution of wake, the velocities of inflow respectively entering the first
pre-swirl stator 310, the secondpre-swirl stator 320, and the thirdpre-swirl stator 330 sequentially arranged radially with respect to the rotation axis X may increase. - In correspondence of the increase in velocity of inflow, the chord lengths of the first
pre-swirl stator 310, the secondpre-swirl stator 320, and the thirdpre-swirl stator 330 may be reduced sequentially. In this case, the firstpre-swirl stator 310, the secondpre-swirl stator 320, and the thirdpre-swirl stator 330 may prevent resistance from increasing according to the increase in velocity of inflow, in the order from the firstpre-swirl stator 310 to the thirdpre-swirl stator 330. -
FIG. 12 shows a propulsionefficiency enhancing apparatus 400 according to a fourth embodiment of the present disclosure. Referring toFIG. 12 , the propulsionefficiency enhancing apparatus 400 according to the current embodiment may include a firstpre-swirl stator 410, a secondpre-swirl stator 420, and a thirdpre-swirl stator 430. - The first
pre-swirl stator 410, the secondpre-swirl stator 420, and the thirdpre-swirl stator 430 according to the current embodiment may have the same features as the firstpre-swirl stator 310, the secondpre-swirl stator 320, and the thirdpre-swirl stator 330 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted. - In the current embodiment, a pre-swirl stator arbitrarily selected from among the first
pre-swirl stator 410, the secondpre-swirl stator 420, and the thirdpre-swirl stator 430 may be located behind another pre-swirl stator located just below the selected pre-swirl stator. - In other words, the first
pre-swirl stator 410, the secondpre-swirl stator 420, and the thirdpre-swirl stator 430 may be arranged sequentially toward the front direction. That is, the firstpre-swirl stator 410 may be located at the rearmost position, the secondpre-swirl stator 420 may be located at the middle position, and the thirdpre-swirl stator 430 may be located at the foremost position. - As such, if the first
pre-swirl stator 410, the secondpre-swirl stator 420, and the thirdpre-swirl stator 430 are spaced predetermined distances in the longitudinal direction of thevessel body 10, resistance applied onto thevessel body 10 can be reduced compared to when thepre-swirl stators vessel body 10. -
FIG. 13 is a side view of a propulsionefficiency enhancing apparatus 500 according to a fifth embodiment of the present disclosure, andFIG. 14 is a rear view of the propulsionefficiency enhancing apparatus 500 according to the fifth embodiment of the present disclosure. - Referring to
FIGS. 13 and14 , the propulsionefficiency enhancing apparatus 500 may includepre-swirl stators - The
pre-swirl stators propeller 20 to flow in the opposite direction of the rotation direction of thepropeller 20, thus generating swirling flow in the opposite direction of the rotation direction of thepropeller 20. The swirling flow generated by thepre-swirl stators propeller 20 to reduce swirling flow generated in the rotation direction of thepropeller 20, thereby enhancing the propulsion efficiency of thepropeller 20. - The
pre-swirl stators stern boss 15 of thevessel body 10, although not limited to this. - In the current embodiment, the number of the
pre-swirl stators pre-swirl stators efficiency enhancing apparatus 500 may include a plurality of pre-swirl stators. - In the current embodiment,
winglets tip portions pre-swirl stators - The
winglets suction surface 502 from the tips of thetip portions winglets pressure surface 501 from the tips of thetip portions - The
winglets tip portions - The
winglets tip portions - The
tip portions tip portions pre-swirl stators tip portions tip portions - The
winglets tip portions -
FIG. 15 shows the cross-section of the tip portion of the pre-swirl stator according to the fifth embodiment of the present disclosure, andFIG. 16 shows the cross-section of the remaining portion of the pre-swirl stator according to the fifth embodiment of the present disclosure. - Referring to
FIGS. 14 to 16 , thetip portions pre-swirl stators portions - Since the
tip portions pressure surface 501 and thesuction surface 502 may be reduced to reduce the generation of cavitation. However, unlike this, in thepre-swirl stators tip portions portions tip portions pre-swirl stators portions - If the remaining
portions FIG. 13 ) can be more effectively induced in the opposite direction of the rotation direction of the propeller (20 ofFIG. 13 ), compared to when the remainingportions -
FIG. 17 is a view for describing the pre-swirl stators of the propulsionefficiency enhancing apparatus 500 according to the fifth embodiment of the present disclosure. - Referring to
FIGS. 13 and17 , thetip portions pre-swirl stators pre-swirl stators propeller 20 to the tips of thepre-swirl stators - The present applicant has performed a test on a pre-swirl stator in which a camber is formed in the entire area from the root portion to the tip portion, and found that cavitation generated around the tip of the pre-swirl stator flows to a slipstream to hit the surfaces of the propeller hard.
- Also, the present applicant has discovered that the pre-swirl stator in which the camber is formed in the entire area dominantly generates swirling flow in the opposite direction of the rotation direction of the
propeller 20 in a region of 0.7 times and 0.9 time of the span length of the pre-swirl stator. - Based on the test results, in order for the
pre-swirl stators tip portions pre-swirl stators - If the
tip portions tip portions - In the current embodiment, the corners of the tips of the
tip portions FIGS. 13 and17 , rounded, as seen from the pressure surface 501 (or the suction surface 502). The shapes of the tips of thetip portions - The present applicant has discovered that the propulsion
efficiency enhancing apparatus 500 configured as described above can reduce cavitation, through a cavitation tunnel test. - Hereinafter, the propulsion
efficiency enhancing apparatus 500 will be described with reference toFIGS. 13 and14 , under an assumption that the propulsionefficiency enhancing apparatus 500 has a plurality of pre-swirl stators. - Referring to
FIGS. 13 and14 , the propulsionefficiency enhancing apparatus 500 according to the current embodiment may include threepre-swirl stators pre-swirl stator 510 located at the uppermost position is referred to as a "firstpre-swirl stator 510", thepre-swirl stator 520 located at the middle position is referred to as a "secondpre-swirl stator 520", and thepre-swirl stator 530 located at the lowermost position is referred to as a "thirdpre-swirl stator 530". - The first
pre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 disposed ahead of thepropeller 20, and spaced from each other. For example, the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 are arranged radially with respect to the rotation axis X of thepropeller 20, as shown inFIG. 14 . - In the current example, the
propeller 20 may rotate in the clockwise direction, as shown inFIG. 14 . In this case, all of the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 may be located in the left region of the rotation surface P of thepropeller 20, where thepropeller 20 rotates upward, among the left and right regions of the rotation surface P. - In regard of this, in the right region of the rotation surface P of the
propeller 20, the direction of inflow entering thepropeller 20 may become the opposite direction of the rotation direction of thepropeller 20 so that an angle of attack with respect to the sections of the blades of thepropeller 20 increases, and a relatively great propulsion force is generated due to the increase of the angle of attack. - Meanwhile, in the left region of the rotation surface P of the
propeller 20, the direction of inflow entering thepropeller 20 may become the same direction as the rotation direction of thepropeller 20 so that an angle of attack with respect to the sections of the blades of thepropeller 20 decreases, and a relatively small propulsion force is generated due to the decrease of the angle of attack. - Accordingly, by locating the
pre-swirl stators propeller 20 to generate flow in the opposite direction of the rotation direction of thepropeller 20 in inflow entering thepropeller 20, it is possible to increase an angle of attack with respect to the sections of the blades of thepropeller 20, and to enhance the propulsion efficiency of thepropeller 20. - Alternatively, the
propeller 20 may rotate in the counterclockwise direction as seen in the rear direction. In this case, unlikeFIG. 14 , all of the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 may be located in the right region of the rotation surface P of thepropeller 20, where thepropeller 20 rotates upward, among the left and right regions of the rotation surface P. - The span lengths of the first
pre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 may be reduced sequentially in the order from the firstpre-swirl stator 510 located at the uppermost position to the thirdpre-swirl stator 530 located at the lowermost position. In other words, a pre-swirl stator arbitrarily selected from among the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 may have a longer span length than another pre-swirl stator located just below the selected pre-swirl stator. - Referring to
FIG. 13 , the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 may have a swept back wing shape. In this case, the trailing edges of thepre-swirl stators - In this case, the
pre-swirl stators propeller 20 so that swirling flow generated by thepre-swirl stators propeller 20 can directly enter thepropeller 20, thereby enhancing the propulsion efficiency of thepropeller 20. - Referring to
FIG. 13 , a pre-swirl stator arbitrarily selected from among the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 at the same radius with respect to the rotation axis X of thepropeller 20 may have a longer chord length than another pre-swirl stator located just below the selected pre-swirl stator. - In other words, the chord lengths of the first
pre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 at the same radius R with respect to the rotation axis X of thepropeller 20 may be reduced sequentially. Herein, the chord lengths of thepre-swirl stators pre-swirl stators - The shorter chord lengths of stators may mean smaller contact areas with inflow entering the stators. In contrast, the longer chord lengths of stators may mean larger contact areas with inflow entering the stators.
- Referring to
FIG. 14 , the velocity of wake on the rotation surface P of the propeller (20 ofFIG. 13 ) may intend to be higher at a greater angle in the clockwise or counterclockwise direction with respect to the upper section of a vertical line V, when the rotation axis X of the propeller (20 ofFIG. 13 ) is the center, and the upper section of the vertical line V passing the rotation axis X is 0 degree. - In the flow distribution of wake, the velocities of inflow respectively entering the first
pre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 sequentially arranged radially with respect to the rotation axis X may increase. - In correspondence of the increase in velocity of inflow, the chord lengths of the first
pre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 may be reduced sequentially. In this case, the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 may prevent resistance from increasing according to the increase in velocity of inflow, in the order from the firstpre-swirl stator 510 to the thirdpre-swirl stator 530. -
FIG. 18 shows a propulsionefficiency enhancing apparatus 600 according to a sixth embodiment of the present disclosure. Referring toFIG. 18 , the propulsionefficiency enhancing apparatus 600 according to the current embodiment may include a firstpre-swirl stator 610, a secondpre-swirl stator 620, and a thirdpre-swirl stator 630. - The first
pre-swirl stator 610, the secondpre-swirl stator 620, and the thirdpre-swirl stator 630 according to the current embodiment may have the same features as the firstpre-swirl stator 510, the secondpre-swirl stator 520, and the thirdpre-swirl stator 530 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted. - In the current embodiment, a pre-swirl stator arbitrarily selected from among the first
pre-swirl stator 610, the secondpre-swirl stator 620, and the thirdpre-swirl stator 630 may be located behind another pre-swirl stator located just below the selected pre-swirl stator. - In other words, the first
pre-swirl stator 610, the secondpre-swirl stator 620, and the thirdpre-swirl stator 630 may be arranged sequentially toward the front direction. That is, the firstpre-swirl stator 610 may be located at the rearmost position, the secondpre-swirl stator 620 may be located at the middle position, and the thirdpre-swirl stator 630 may be located at the foremost position. - As such, if the first
pre-swirl stator 610, the secondpre-swirl stator 620, and the thirdpre-swirl stator 630 are spaced predetermined distances in the longitudinal direction of thevessel body 10, resistance applied onto thevessel body 10 can be reduced compared to when thepre-swirl stators vessel body 10. -
FIG. 19 is a side view of a propulsionefficiency enhancing apparatus 700 according to a seventh embodiment of the present disclosure, andFIG. 20 is a rear view of the propulsionefficiency enhancing apparatus 700 according to the seventh embodiment of the present disclosure. - Referring to
FIGS. 19 and20 , the propulsionefficiency enhancing apparatus 700 may includepre-swirl stators - The
pre-swirl stators propeller 20 to flow in the opposite direction of the rotation direction of thepropeller 20, thus generating swirling flow in the opposite direction of the rotation direction of thepropeller 20. The swirling flow generated by thepre-swirl stators propeller 20 to reduce swirling flow generated in the rotation direction of thepropeller 20, thereby enhancing the propulsion efficiency of thepropeller 20. - The
pre-swirl stators stern boss 15 of thevessel body 10, although not limited to this. - In the current embodiment, the number of the
pre-swirl stators pre-swirl stators efficiency enhancing apparatus 700 may include a plurality of pre-swirl stators. - In the current embodiment,
additional members tip portions pre-swirl stators - The
additional members tip portions additional members tip portions additional members - The
additional members additional members tip portions - The
additional members tip portions additional members tip portions - The
tip portions portions pre-swirl stators -
FIG. 21 shows a propulsionefficiency enhancing apparatus 800 according to an eighth embodiment of the present disclosure. Referring toFIG. 21 , the propulsionefficiency enhancing apparatus 800 according to the current embodiment may include a firstpre-swirl stator 810, a secondpre-swirl stator 820, and a thirdpre-swirl stator 830. - The first
pre-swirl stator 810, the secondpre-swirl stator 820, and the thirdpre-swirl stator 830 according to the current embodiment may have the same features as the firstpre-swirl stator 710, the secondpre-swirl stator 720, and the thirdpre-swirl stator 730 according to the previous embodiment, and accordingly, detailed descriptions thereof will be omitted. - In the current embodiment, a pre-swirl stator arbitrarily selected from among the first
pre-swirl stator 810, the secondpre-swirl stator 820, and the thirdpre-swirl stator 830 may be located behind another pre-swirl stator located just below the selected pre-swirl stator. - In other words, the first
pre-swirl stator 810, the secondpre-swirl stator 820, and the thirdpre-swirl stator 830 may be arranged sequentially toward the front direction. That is, the firstpre-swirl stator 810 may be located at the rearmost position, the secondpre-swirl stator 820 may be located at the middle position, and the thirdpre-swirl stator 830 may be located at the foremost position. - As such, if the first
pre-swirl stator 810, the secondpre-swirl stator 820, and the thirdpre-swirl stator 830 are spaced predetermined distances in the longitudinal direction of thevessel body 10, resistance applied onto thevessel body 10 can be reduced compared to when thepre-swirl stators vessel body 10. - It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention by adding, changing, or removing one or more components, without departing from the scope of the inventions. Thus, it is intended that the present invention covers the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.
- 10: vessel body
- 15: stern boss
- 20: propeller
- 100, 200, 300, 400, 500, 600, 700, 800: propulsion efficiency enhancing apparatus
- 110, 210, 310, 410, 510, 610, 710, 810: first pre-swirl stator
- 120, 220, 320, 420, 520, 620, 720, 820: second pre-swirl stator
- 130, 230, 330, 430, 530, 630, 730, 830: third pre-swirl stator
Claims (11)
- A propulsion efficiency enhancing apparatus (300) for a vessel,
comprising a plurality of pre-swirl stators and a propeller (20),
the plurality of pre-swirl stators (310, 320, 330) disposed ahead of the propeller (20), and arranged radially with respect to a rotation axis of the propeller (20),
wherein the pre-swirl stators (310, 320, 330) are located in a left region or a right region of a rotation surface of the propeller where the propeller (20) rotates upward, to generate flow in a direction opposite to a rotation direction of the propeller (20) in an inflow entering the propeller (20), to increase an angle of attack with respect to sections of blades of the propeller (20), and wherein
a span length of at least one pre-swirl stator of the pre-swirl stators (310, 320, 330) is different from span lengths of the remaining pre-swirl stators, and
a span length of a pre-swirl stator arbitrarily selected from among the pre-swirl stators (310, 320, 330) is longer than or equal to a span length of another pre-swirl stator located just below the selected pre-swirl stator,
characterized in that
tip portions (311, 321, 331) of the pre-swirl stators (310, 320, 330) have smaller pitch angles than remaining portions (312, 322, 332) of the pre-swirl stators (310, 320, 330). - The propulsion efficiency enhancing apparatus (300) according to claim 1, wherein the span lengths of the pre-swirl stators (310, 320, 330) are reduced sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- The propulsion efficiency enhancing apparatus (300) according to claim 1 or 2, wherein the number of the pre-swirl stators (310, 320, 330) is three, and
wherein an installation angle of a first pre-swirl stator (310) located at the uppermost position among the pre-swirl stators (310, 320, 330) is in a range of 30 degrees to 50 degrees, an installation angle of a second pre-swirl stator (320) located at the middle position is in a range of 60 degrees to 80 degrees, and an installation angle of a third pre-swirl stator (330) located at the lowermost position is in a range of 100 degrees to 120 degrees,
the installation angles of the pre-swirl stators (310, 320, 330) being angles of installation positions of the pre-swirl stators (310, 320, 330) with respect to an upper section of a vertical line (V) passing through the rotation axis of the propeller (20), the rotation axis of the propeller (20) being a center and the upper section of the vertical line (V) being 0 degrees. - The propulsion efficiency enhancing apparatus (300) according to claim 3, wherein a span length of the first pre-swirl stator (310) is in a range of 0.9 times to 1.1 times of the radius of the propeller (20), a span length of the second pre-swirl stator (320) is in a range of 0.8 times to 1.0 times of the radius of the propeller (20), and a span length of the third pre-swirl stator (330) is in a range of 0.6 times to 0.8 times of the radius of the propeller (20), and
wherein the span lengths of the pre-swirl stators (310, 320, 330) are reduced sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position. - The propulsion efficiency enhancing apparatus (300) according to claim 1 or 2, wherein the pre-swirl stators (310, 320, 330) are arranged toward the front direction sequentially in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- The propulsion efficiency enhancing apparatus (300) according to claim 1 or 2, wherein chord lengths of the pre-swirl stators (310, 320, 330) are reduced, at the same radius with respect to the rotation axis, in the order from the pre-swirl stator located at the uppermost position to the pre-swirl stator located at the lowermost position.
- The propulsion efficiency enhancing apparatus (300) according to claim 1, wherein an additional member is formed in the tip portion (311, 321, 331) of each pre-swirl stator (310, 320, 330), and the additional member is in the shape of a plate extending toward a suction surface and a pressure surface.
- The propulsion efficiency enhancing apparatus (300) according to claim 1 or 7, wherein the pitch angles of the tip portions (311, 321, 331) are reduced continuously toward the tips of the tip portions (311, 321, 331).
- The propulsion efficiency enhancing apparatus (300) according to claim 1 or 7, wherein the tip portions (311, 321, 331) have lengths of 0.1 times to 0.3 times of the span lengths of the pre-swirl stators (310, 320, 330).
- The propulsion efficiency enhancing apparatus (300) according to claim 1 or 7 , wherein the corners of the tips of the tip portions (311, 321, 331) are rounded, as seen from the pressure surface.
- The propulsion efficiency enhancing apparatus (300) according to claim 1, wherein a winglet is formed in the tip portion (311, 321, 331) of each pre-swirl stator (310, 320, 330), and the winglet is bent toward a suction surface or a pressure surface.
Applications Claiming Priority (5)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
KR1020140145333A KR101722002B1 (en) | 2014-10-24 | 2014-10-24 | Propulsion efficiency enhancing apparatus |
KR1020150028543A KR101701741B1 (en) | 2015-02-27 | 2015-02-27 | Propulsion efficiency enhancing apparatus |
KR1020150028911A KR102247759B1 (en) | 2015-03-02 | 2015-03-02 | Propulsion efficiency enhancing apparatus |
KR1020150069353A KR102260455B1 (en) | 2015-05-19 | 2015-05-19 | Propulsion efficiency enhancing apparatus |
PCT/KR2015/009692 WO2016064091A1 (en) | 2014-10-24 | 2015-09-16 | Propelling efficiency enhancing device |
Publications (3)
Publication Number | Publication Date |
---|---|
EP3210876A1 EP3210876A1 (en) | 2017-08-30 |
EP3210876A4 EP3210876A4 (en) | 2018-05-09 |
EP3210876B1 true EP3210876B1 (en) | 2019-11-06 |
Family
ID=55761093
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP15853182.2A Active EP3210876B1 (en) | 2014-10-24 | 2015-09-16 | Propelling efficiency enhancing device |
Country Status (5)
Country | Link |
---|---|
EP (1) | EP3210876B1 (en) |
JP (1) | JP6444501B2 (en) |
CN (1) | CN107000825B (en) |
ES (1) | ES2767317T3 (en) |
WO (1) | WO2016064091A1 (en) |
Families Citing this family (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JP7145945B2 (en) * | 2017-10-31 | 2022-10-03 | サムスン・ヘヴィー・インダストリーズ・カンパニー・リミテッド | Propulsion efficiency improvement device |
CN113879483B (en) * | 2021-11-10 | 2022-12-06 | 上海外高桥造船有限公司 | Mounting method of energy-saving stator |
Family Cites Families (18)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS6490895A (en) * | 1987-10-01 | 1989-04-07 | Mitsubishi Heavy Ind Ltd | Slim vessel provided with reaction fin |
JP2948413B2 (en) * | 1991-11-14 | 1999-09-13 | 三菱重工業株式会社 | Reaction fin device for ships |
JP2004306839A (en) * | 2003-04-09 | 2004-11-04 | Mitsubishi Heavy Ind Ltd | Ship |
JP4684778B2 (en) * | 2005-06-15 | 2011-05-18 | エムエイチアイマリンエンジニアリング株式会社 | Small ship propulsion performance improvement device |
CN101234667B (en) * | 2007-02-01 | 2012-06-06 | 大宇造船海洋株式会社 | Asymmetry prerotation stator for ship |
WO2010046961A1 (en) * | 2008-10-20 | 2010-04-29 | 三菱重工業株式会社 | Twin skeg ship |
JP5137258B2 (en) * | 2009-02-09 | 2013-02-06 | 流体テクノ有限会社 | Propulsion performance improvement device |
JP2010195153A (en) * | 2009-02-24 | 2010-09-09 | Mitsubishi Heavy Ind Ltd | Reaction fin device for ship and ship |
KR20100103982A (en) * | 2009-03-16 | 2010-09-29 | 대우조선해양 주식회사 | Pre-swirl stator of ship |
JP5281559B2 (en) * | 2009-12-14 | 2013-09-04 | 三菱重工業株式会社 | Ship propulsion performance improvement device |
JP5510798B2 (en) * | 2010-01-09 | 2014-06-04 | 株式会社栗之浦ドック | Ship propulsion performance improvement device |
JP5467483B2 (en) * | 2010-01-09 | 2014-04-09 | 株式会社栗之浦ドック | Ship propulsion performance improvement device |
KR20120121112A (en) * | 2011-04-26 | 2012-11-05 | 현대중공업 주식회사 | Pre-swirl Stator of Ship |
KR101723240B1 (en) * | 2011-05-13 | 2017-04-18 | 현대중공업 주식회사 | Propeller Duct Structure of Ship with Multi-Column Fin |
CN202244050U (en) * | 2011-08-17 | 2012-05-30 | 上海船舶研究设计院 | Reaction fin in front of oar |
TW201339052A (en) * | 2012-03-23 | 2013-10-01 | Csbc Corp Taiwan | Asymmetrical fin device for ship |
KR101846581B1 (en) * | 2012-12-26 | 2018-04-09 | 현대중공업 주식회사 | Pre-swirl Stator of Ship |
JP2014151775A (en) * | 2013-02-08 | 2014-08-25 | Mitsubishi Heavy Ind Ltd | Propulsion unit |
-
2015
- 2015-09-16 CN CN201580057690.7A patent/CN107000825B/en active Active
- 2015-09-16 WO PCT/KR2015/009692 patent/WO2016064091A1/en active Application Filing
- 2015-09-16 EP EP15853182.2A patent/EP3210876B1/en active Active
- 2015-09-16 JP JP2017522171A patent/JP6444501B2/en active Active
- 2015-09-16 ES ES15853182T patent/ES2767317T3/en active Active
Non-Patent Citations (1)
Title |
---|
None * |
Also Published As
Publication number | Publication date |
---|---|
CN107000825A (en) | 2017-08-01 |
JP2017531594A (en) | 2017-10-26 |
ES2767317T3 (en) | 2020-06-17 |
WO2016064091A1 (en) | 2016-04-28 |
JP6444501B2 (en) | 2018-12-26 |
CN107000825B (en) | 2019-08-30 |
EP3210876A1 (en) | 2017-08-30 |
EP3210876A4 (en) | 2018-05-09 |
Similar Documents
Publication | Publication Date | Title |
---|---|---|
JP5276670B2 (en) | Twin Skeg ship | |
JP2008239060A (en) | Stern oblong duct and vessel | |
KR102144840B1 (en) | Propeller with small duct, and ship | |
JP2006347285A (en) | Stern structure of vessel, and designing method thereof | |
JP2010195153A (en) | Reaction fin device for ship and ship | |
JP5081455B2 (en) | Asymmetrical front wing of a ship | |
JP2008260445A (en) | Vessel | |
WO2016158725A1 (en) | Vessel | |
EP3210876B1 (en) | Propelling efficiency enhancing device | |
JP4684778B2 (en) | Small ship propulsion performance improvement device | |
JP4382120B2 (en) | Turbine fin with duct | |
KR101066213B1 (en) | Flow Improving Device of Wing Type with Wake Reduction ? Advenced Force Generation | |
KR100946968B1 (en) | Pre-swirl Stator improving ability to maneuver in vessel | |
KR20110101002A (en) | Rudder for vessel | |
EP2143631A1 (en) | Asymmetric preswirl stator of ship | |
JP5558048B2 (en) | Marine composite energy-saving propulsion device and single-axle-two-steer ship | |
KR20130003573A (en) | Pre-swirl stator of a ship | |
JP6138680B2 (en) | Duct equipment | |
KR102260442B1 (en) | Propulsion efficiency enhancing apparatus | |
KR20120068250A (en) | Duct structure for ship | |
KR102260455B1 (en) | Propulsion efficiency enhancing apparatus | |
TWI508897B (en) | Ship propulsion system and ship | |
JP2005145397A (en) | Fin device | |
KR101701741B1 (en) | Propulsion efficiency enhancing apparatus | |
KR20110012656A (en) | Boss cap of propeller in ship |
Legal Events
Date | Code | Title | Description |
---|---|---|---|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE |
|
PUAI | Public reference made under article 153(3) epc to a published international application that has entered the european phase |
Free format text: ORIGINAL CODE: 0009012 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE |
|
17P | Request for examination filed |
Effective date: 20170424 |
|
AK | Designated contracting states |
Kind code of ref document: A1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
AX | Request for extension of the european patent |
Extension state: BA ME |
|
DAV | Request for validation of the european patent (deleted) | ||
DAX | Request for extension of the european patent (deleted) | ||
A4 | Supplementary search report drawn up and despatched |
Effective date: 20180411 |
|
RIC1 | Information provided on ipc code assigned before grant |
Ipc: B63H 1/26 20060101ALI20180405BHEP Ipc: B63H 1/28 20060101ALI20180405BHEP Ipc: B63H 5/16 20060101AFI20180405BHEP |
|
GRAP | Despatch of communication of intention to grant a patent |
Free format text: ORIGINAL CODE: EPIDOSNIGR1 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: GRANT OF PATENT IS INTENDED |
|
INTG | Intention to grant announced |
Effective date: 20190405 |
|
GRAS | Grant fee paid |
Free format text: ORIGINAL CODE: EPIDOSNIGR3 |
|
GRAA | (expected) grant |
Free format text: ORIGINAL CODE: 0009210 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: THE PATENT HAS BEEN GRANTED |
|
AK | Designated contracting states |
Kind code of ref document: B1 Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR |
|
REG | Reference to a national code |
Ref country code: GB Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: EP Ref country code: AT Ref legal event code: REF Ref document number: 1198404 Country of ref document: AT Kind code of ref document: T Effective date: 20191115 |
|
REG | Reference to a national code |
Ref country code: IE Ref legal event code: FG4D |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R096 Ref document number: 602015041384 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: FI Ref legal event code: FGE |
|
REG | Reference to a national code |
Ref country code: NL Ref legal event code: MP Effective date: 20191106 |
|
REG | Reference to a national code |
Ref country code: LT Ref legal event code: MG4D |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BG Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200206 Ref country code: NO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200206 Ref country code: SE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: PT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200306 Ref country code: LV Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: PL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: LT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: GR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200207 Ref country code: NL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20200306 Ref country code: HR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: RS Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
REG | Reference to a national code |
Ref country code: ES Ref legal event code: FG2A Ref document number: 2767317 Country of ref document: ES Kind code of ref document: T3 Effective date: 20200617 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AL Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: EE Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: DK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: RO Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: CZ Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
REG | Reference to a national code |
Ref country code: DE Ref legal event code: R097 Ref document number: 602015041384 Country of ref document: DE |
|
REG | Reference to a national code |
Ref country code: AT Ref legal event code: MK05 Ref document number: 1198404 Country of ref document: AT Kind code of ref document: T Effective date: 20191106 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: SM Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: SK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
PLBE | No opposition filed within time limit |
Free format text: ORIGINAL CODE: 0009261 |
|
STAA | Information on the status of an ep patent application or granted ep patent |
Free format text: STATUS: NO OPPOSITION FILED WITHIN TIME LIMIT |
|
26N | No opposition filed |
Effective date: 20200807 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: AT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: SI Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: IT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
REG | Reference to a national code |
Ref country code: CH Ref legal event code: PL |
|
GBPC | Gb: european patent ceased through non-payment of renewal fee |
Effective date: 20200916 |
|
REG | Reference to a national code |
Ref country code: BE Ref legal event code: MM Effective date: 20200930 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: LU Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200916 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: FR Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200930 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: BE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200930 Ref country code: CH Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200930 Ref country code: GB Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200916 Ref country code: LI Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200930 Ref country code: IE Free format text: LAPSE BECAUSE OF NON-PAYMENT OF DUE FEES Effective date: 20200916 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: TR Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: MT Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: CY Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
PG25 | Lapsed in a contracting state [announced via postgrant information from national office to epo] |
Ref country code: MK Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 Ref country code: MC Free format text: LAPSE BECAUSE OF FAILURE TO SUBMIT A TRANSLATION OF THE DESCRIPTION OR TO PAY THE FEE WITHIN THE PRESCRIBED TIME-LIMIT Effective date: 20191106 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: FI Payment date: 20230912 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: DE Payment date: 20230726 Year of fee payment: 9 |
|
PGFP | Annual fee paid to national office [announced via postgrant information from national office to epo] |
Ref country code: ES Payment date: 20231006 Year of fee payment: 9 |