KR101764400B1 - Duct apparatus for ship with twist type stator - Google Patents

Abstract

The present invention relates to a ductwork for a vessel equipped with a twist-type stator. Particularly, the present invention secures structural safety in case of damage by slamming while improving propulsion efficiency by being installed in front of a propeller of a vessel. The present invention comprises: a duct surrounding the back of a vessel at the front part of the propeller with a certain distance; and a plurality of stators, extended outwards from the duct, where an end part is extended in a radial direction of the duct and passes the duct while being combined to the back of the vessel. At least one of the stators, reflecting the fact that the flow characteristic of seawaters is different inside and outside the duct, is separated into an inner part in the inside of the duct and an outer part in the outside of the duct, and is characterized as a twist stator with different pitch angles between the inner and outer parts.

Description

TECHNICAL FIELD [0001] The present invention relates to a duct device for a ship having a twist type stator for improving propulsion efficiency.

BACKGROUND OF THE INVENTION 1. Field of the Invention [0002] The present invention relates to a duct device for a ship, and more particularly, to a duct device for a ship having a twist type stator installed in front of a propeller of a ship to secure structural safety to improve breakage due to slamming while improving propulsion efficiency .

In general, the main function of a propeller mounted on a ship is to convert rotational motion into linear motion. The wings of the propeller are inclined to the rotating surface so that they push the water while rotating, and the ship moves forward in reaction to this force.

However, the flow of water before and after the propeller is not formed in a perfect linear direction but is formed by a rotating current like a vortex due to propeller rotation. In other words, since the propeller generates propulsion force while rotating, the tangential velocity of the propeller rotation direction is generated on the downstream of the propeller.

Therefore, complex propulsion systems have been researched and developed to recover kinetic energy loss in propeller wake due to tangential velocity. For example, they include a contra rotating propeller (CRP), a propeller boss cap fin (PBCF), a vane wheel, and a pre-swirl stator.

However, in the case of a reciprocating propeller (CRP), it is possible to maximize the propulsion efficiency by recovering the kinetic energy in the rotational direction, but it is almost impossible to apply it to the large-sized line due to the complex axis, The device is a current-carrying wing. It has already been reported that this device has been applied to commercial vessels in the Mitsubishi shipyard in Japan since the early 1980s, or since the 1980s.

The current stabilizing vane improves the propelling efficiency of the propeller by changing the inflow angle of the fluid toward the propeller from the front of the propeller, and recover the kinetic energy loss in the rotational direction. In addition, a cylindrical duct connecting the blades of the current-stabilizing blades is constructed by accelerating the forward fluid of the propeller due to inhaling generated during the operation of the propeller, an additional thrust generated in the duct itself, It accelerates and rectifies the fluid to improve the propulsion efficiency and reduce the propulsion force of the propeller.

FIG. 1 is a state diagram showing a state in which a current-stabilizing blade according to the prior art is installed on a ship. In order to give a tangential velocity opposite to a tangential velocity induced by a propeller 20 installed at the rear of the ship 10, By providing the electric current stabilizing vane (30) in front of the propeller (20), loss of energy in the rotational direction of the propeller (20) in the direction of rotation is minimized, thereby improving the propulsion efficiency.

As shown in Fig. 2 (a), the current-stabilizing wing used in the Mitsubishi Shipyard of Japan has symmetrical left and right wings having the same number of wings as the port and star wings.

On the other hand, in the case of a low-speed non-large-sized ship, since the flow ascends upward due to the influence of the linearity on the propeller surface, a larger rotation speed is generated due to the addition of the propeller- Starboards vary a lot in terms of rotation direction. Based on this phenomenon, as shown in Figs. 2 (b) and 2 (c), the number of wings on the starboard side (right side in the drawing) is made smaller than the number of wings on the left side Asymmetric current stabilization wings have been developed and applied to ships.

However, according to the related art, although the change of the flow characteristics of the seawater according to the port and starboard of the ship is considered, there is no consideration of the flow characteristics of the seawater formed depending on the distance from the axis of the stern, There was a limit.

Furthermore, there is no optimal design method to secure both the improvement of the propulsion efficiency and the structural safety. Therefore, there is a need for an optimal design of an innovative method.

Korean Published Patent Application No. 2014-0118373 (Oct. 10, 2014)

Accordingly, the present invention has been made to solve the above-mentioned problems of the related art, and it is an object of the present invention to provide a propeller of the present invention, which is installed in front of a propeller of a ship to improve propulsion efficiency and to secure structural safety to prevent breakage due to slamming And to provide a marine duct device having a twist type stator.

In order to accomplish the above object, the present invention provides a duct device for a ship, comprising: a duct installed at a front side of a propeller so as to surround the rear of the ship; And a plurality of stator extending in a radial direction of the duct in a state where one end portion is coupled to the rear of the ship and extending to the outside of the duct after passing through the duct, The duct is divided into an inner portion positioned on the inner side of the duct and an outer portion positioned on the outer side of the duct and the twist angle formed between the inner portion and the outer portion is different from that of the duct, And the stator is a feature of the technical construction.

Here, the pitch angle of the twist stator may be changed within a range of 60% of the diameter of the propeller.

Also, the inner pitch angle of the twist stator is -10 to +10 degrees, and the outer pitch angle is -20 degrees to +40 degrees.

Further, in the twist stator, the front-rear width of the inner side positioned at the inner side of the duct is narrower than the front-rear width of the outer side positioned at the outer side of the duct, so that the swirling flow can be further increased in front of the propeller have.

In addition, the duct may be installed in a region where the flow velocity of seawater is 60% or less of the speed of the ship.

In addition, the diameter of the duct may be 60% or less of the diameter of the propeller.

In addition, the stator is provided at two or more of the stator at the port of the ship, and one or more stator is installed at the starboard of the ship.

In addition, when the azimuth angle is calculated in the direction of starboard rotation with reference to the uppermost side, the stator is installed at one of the remaining regions except the azimuthal angle range of 225 to 285 degrees, and the azimuth angle is 75 degrees And the stator is installed at one point out of the remaining areas except for the range of -105 to -105 degrees.

In addition, at least one twist stator is installed at each of the port and starboard sides of the ship.

The length of the stator may be 50 to 150% of the diameter of the propeller.

In addition, the front and rear width of the duct may be formed to be 5 to 30% of the diameter of the propeller.

The distance between the center of the propeller and the duct may be 3 to 40% of the diameter of the propeller.

The half stator may further include a half stator having one end coupled to the inner surface of the duct while the other end is coupled to the rear of the ship to reinforce the strength.

The half stator is formed at a lower center of a shaft of the stern, in which a fluid load is relatively large due to a large flow velocity of seawater. The duct is formed in an eccentric shape biased upward from an axial center of a stern, Is formed to be short.

The duct may have a circular, elliptical or polygonal shape.

The ducting device for a ship having a twist type stator according to the present invention can be installed in front of a propeller of a ship to ensure structural safety in order to improve propulsion efficiency and to prevent breakage due to slamming.

The twist stator having different pitch angles between the inside and the outside of the duct makes it possible to differentially control the propulsion efficiency of the propeller in accordance with the flow direction and the flow velocity of the seawater which are formed differently from the inside and the outside of the duct .

In addition, a combination of a twist stator and a half stator, which is installed exclusively on the inner side of the duct, makes it possible to improve the propulsion efficiency on the outside of the duct and to optimize the structural stability by reinforcing the strength on the inside of the duct.

FIG. 1 and FIG. 2 are views for explaining a conventional duct ducting device
FIG. 3 and FIG. 4 are views for explaining the theoretical background for the construction of a ducting apparatus for a ship according to the present invention.
5 is a view showing a state of use in which a ship duct device according to an embodiment of the present invention is installed on a ship
6A is a perspective view for explaining a configuration of a ducting apparatus for a ship according to an embodiment of the present invention;
FIG. 6B is a perspective view of a twist stator in a marine duct device according to an embodiment of the present invention. FIG.
7 is a view for explaining the concept of the pitch angle of the twist stator in the marine duct device according to the embodiment of the present invention.
FIG. 8 is a graph showing the characteristics of a rebound characteristic when a ship duct device according to an embodiment of the present invention is applied.
9 is a perspective view for explaining a ducting device for a ship according to a first modified embodiment of the present invention.
10 is a perspective view for explaining a marine duct device according to a second modified embodiment of the present invention.

A duct for a ship having a twist type stator according to embodiments of the present invention will be described in detail with reference to the accompanying drawings. The present invention is capable of various modifications and various forms, and specific embodiments are illustrated in the drawings and described in detail in the text. It is to be understood, however, that the invention is not intended to be limited to the particular forms disclosed, but on the contrary, is intended to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the invention. Like reference numerals are used for like elements in describing each drawing. In the accompanying drawings, the dimensions of the structures are enlarged to illustrate the present invention, and are actually shown in a smaller scale than the actual dimensions in order to understand the schematic structure.

Also, the terms first and second, etc. may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as a second component, and similarly, the second component may also be referred to as a first component. On the other hand, unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs. Terms such as those defined in commonly used dictionaries are to be interpreted as having a meaning consistent with the contextual meaning of the related art and are to be interpreted as either ideal or overly formal in the sense of the present application Do not.

3 to 4 are reference graphs for explaining the theoretical background for the construction of the ducting device for a ship according to the present invention.

As shown in the drawing, the present invention precisely analyzes the rebound characteristics of a stern (SB) equipped with a propeller, and differently applies the design of the duct and the stator to the regions where the rebound characteristics are different based on the analysis, But also to ensure structural safety at all times.

3 (a) is a graph showing the model scale (Rn = 1e7) rebound characteristic on the propeller side of the model test when the duct device is not applied. The longitudinal direction measured from the propeller plane )) Velocity distributions (shown in color by X-velocity color table) and flow vectors are shown. As a result, it can be seen that the flow angle changes according to r / R in each region. Thus, when the pitch angle of the stator is uniformly applied, the propulsion efficiency is improved in some areas, It can be expected that it will deteriorate.

For example, a part of FIG. 3 (a), which is a graph showing the model scale (Rn = 1e7) rebound characteristics on the propeller side of the model test, is cut away, The azimuth angle is 30 degrees and the flow vector is upward in the 0.8r / R region, but in the 0.5r / R region, the flow vector is in the opposite direction . FIG. 3 (b) is a graph showing the reflux characteristics of the actual ship. In the graph, the flow direction of the seawater represented by the flow vector or the critical points at which the flow angle changes are represented by red lines. As can be seen here, it can be seen that in the case of the critical points at which the flow angle changes, the flow velocity of the seawater is formed in the region of 60% or less (dark green and blue region) with respect to the traveling speed of the ship. (Note that the flow rate of the seawater refers to the relative speed of the ship and sea water when the ship's speed is assumed to be 1 with the ship's traveling direction on the propeller plane being the reference axis (X axis) In the graph of FIG. 3 (b), the flow rate of the seawater is the highest, and the flow rate of the seawater is the highest In the area of 180 degrees of azimuth appearing, a black circle having a radius of 60% from the center of the ship to a point where the flow rate of the seawater is 60% is shown. The flow direction of the sea water indicated by the red line or the critical point If it is in the inner area of the black circle and it is not (azimuth angle of 0 degrees), the flow rate of the seawater is not more than 60% based on the speed of the ship. I can do it. The flow rate of the seawater has a great influence on the duct and the stator. When the flow rate of the seawater is 80% of the ship speed, the resistance of the duct is almost doubled as compared with 60% of the ship speed. Therefore, it is necessary to design the installation position of the duct in consideration of the flow velocity of the seawater and the flow direction critical points of the sea water described above, and to design the pitch angle of the stator at the inner side and the outer side of the duct. If this is not the case, problems will occur in both the duct and the stator, and ducts and stator breakage or cracking accidents will actually occur. FIG. 4 (b) shows an area from 0 degree to 90 degrees of azimuth in FIG. 3 (b), which includes a point where the above-described black circle crosses a red line connecting the above- have. The red and blue lines of this area are where the stator is normally installed and are the intersection of the red lines connecting the black circles described above and the flow direction threshold of the seawater. Here, since the flow velocity of the seawater is formed to be high, careful design must be performed with different pitch angle of the state from the inside and the outside of the duct.

The duct and the stator are installed in consideration of the flow rate of the seawater on the propeller plane and the flow direction of the seawater as described above and the duct is installed in the region where the flow velocity of the seawater on the propeller plane is 60% And the stator has a unique twist shape in which pitch angles are formed differently from the inside and the outside of the duct, thereby improving the propulsion efficiency and preventing breakage due to slamming and the like. In order to install the duct in the area below 60 of the speed of the ship, the velocity of the seawater is set to 60% of the speed of the ship in the 180 degree azimuth area where the flow velocity of the seawater is the fastest on the propeller side of the ship. A duct may be provided to surround the rear end of the ship so as to be spaced apart from the ship. All parts of the duct are then included in the area where the flow rate of seawater is less than 60% of the ship's speed.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, a configuration of a marine duct device according to an embodiment of the present invention will be described in detail.

FIG. 6A is a perspective view for explaining a configuration of a ducting apparatus for a ship according to an embodiment of the present invention, FIG. 6B is a perspective view of a ship ducting apparatus according to an embodiment of the present invention, FIG. FIG. 7 is a view for explaining the concept of pitch angle of a twist stator in a marine duct device according to an embodiment of the present invention, and FIG. 8 is a perspective view of a twist stator according to an embodiment of the present invention. FIG. 5 is a graph illustrating a rebound characteristic when the ducting device for a ship according to the embodiment is applied.

As shown in the drawings, a duct device 100 according to an embodiment of the present invention includes a duct 110 installed at a front side of a propeller to surround a rear SB of the ship, A straight stator 120 and a twist stator 120 extending in a radial direction of the duct 110 and passing through the duct 110 and extending to the outside of the duct 110, 130).

It should be noted that the twist stator 130 may have a shape that has not existed so far in the embodiment of the present invention. The twist stator 130 is provided with an inner side portion 130a located inside the duct 110 and an outer side portion located outside the duct 110 in consideration of the fact that the flow characteristics of seawater are different between the inside and the outside of the duct 110 130b, respectively, and pitch angles between them are formed differently from each other. The twist stator 130 having a pitch different from that of the duct 110 is formed in a twisted shape twisting the waist. The structure of the twist stator 130 can reduce the resistance due to the flow velocity while improving the propulsion efficiency both inside and outside the duct 110 even if the flow direction and the flow velocity of the seawater are different from each other inside and outside the duct 110 This makes it easier to design optimization.

The pitch angle of the twist stator 130 means the angle of rotation of the twist stator 130 about its longitudinal center axis, and the pitch angle of the twist stator 130, The twist stator 130 is calculated as to how much the twist stator 130 has rotated on the basis of the width direction line SL coinciding with the longitudinal center line XL of the ship. For example, in FIG. 7, it is assumed that the twist stator is positioned in the opposite radial direction (toward the center of the duct from the outside of the duct), and the counterclockwise rotation is defined as the reverse The inner side 130a of the twist stator 130 is formed to have a pitch angle of -10 degrees by being rotated by 10 degrees in the reverse direction, The outer portion 130b of the twist stator is shown rotated by 40 degrees in a positive direction to form a pitch angle of +40 degrees.

Wherein an inner pitch angle of the twist stator is formed at an angle of 10 degrees in the reverse direction to an angle in the range of 10 degrees in the forward direction and the outer pitch angle is formed at any angle from 20 degrees in the reverse direction to 40 degrees in the normal direction A ducting device for a ship.

Hereinafter, the marine duct device according to the embodiment of the present invention will be described in more detail with reference to the respective components.

The duct 110 is installed in such a manner as to surround the rear SB of the ship in front of the propeller as described above. The duct 110 is installed in a region where the flow velocity of the seawater is less than 60% of the speed of the ship so that the resistance against the seawater is not excessively increased. When the duct 110 is installed in a place where the flow rate of the seawater is 60% of the speed of the ship, the resistance can be reduced to about twice that of the case where the duct 110 is installed in the place where the flow rate of the seawater is 80% It is. For this purpose, if the duct diameter of the duct 110 is set to 60% or less of the diameter of the propeller, the installation position of the duct 110 is roughly included in the region where the flow rate of the seawater is 60% or less of the speed of the ship. The duct 110 may be circular or elliptical. However, it is not necessarily limited to the shape of the duct 110 as long as it satisfies the above conditions, and it is not necessary to form the duct 110 concentrically with respect to the axis of the stern SB . The configuration in which the duct 110 is not provided concentrically with respect to the axis of the stern SB can make a significant difference in structure, which will be described later in detail through modified embodiments. Also, the duct 110 is shown as being formed in a circular shape in the drawing, but it may have an elliptical shape or a polygonal shape.

The length of the duct 110 may be 5 to 30% of the diameter of the propeller, and the distance between the center of the propeller and the duct 110 may be 3 to 40% of the diameter of the propeller. .

The straight stator 120 has a shape that one end extends in the radial direction of the duct 110 in a state where it is coupled to the rear SB of the ship and extends to the outside after passing through the duct 110 . The twist stator 130 is disposed on the inner side of the duct 110 and on the outer side of the duct 110 to reflect the fact that the flow characteristics of the seawater are different between the inside and the outside of the duct 110, And outer side portions 130b, so that pitch angles therebetween are formed to be different from each other. The length (span length) of such stator may be formed to be 50 to 150% of the propeller diameter.

The straight stator 120 and the twist stator 130 may be installed at two or more positions on the port of the ship and one or more positions on the starboard of the ship to improve the propulsion efficiency. The stator is installed at one of the remaining areas excluding the azimuthal range of 225 to 285 degrees from the port of the ship when the azimuth is calculated in the direction of the ship and one point of the remaining area except the azimuth angle of 75 to 105 degrees As shown in FIG. This is because when the slamming occurs, the intake angle of the stator can be maintained at 15 degrees or more to minimize the impact pressure. Then, as shown in the graph of the rebound characteristic of FIG. 8, the swirling current increases in the starboard ship, while the swirling current is increased to about 20% of the ship speed in the starboard ship. This increases the flow angle into the propeller, which further improves the propulsion efficiency of the propeller.

Here, the portion where the pitch angle of the twist stator 130 is changed is preferably within a range of 60% of the diameter of the propeller, which is a boundary region in which the flow direction and the flow velocity of the seawater are changed. Such a configuration is naturally accomplished by positioning the duct 110 within a range of 60% of the diameter of the propeller since the pitch angle change of the twist stator 130 is made inside and outside the duct 110 as a center.

Subsequently, a marine duct device according to a modified embodiment will be described.

9 is a perspective view for explaining a marine duct device according to a first modified embodiment of the present invention.

As shown in the drawing, the duct device according to the first modification of the present invention is characterized in that the front-rear width (chord length) of the inner side part 130a located inside the duct 110 in the twist stator 130 is larger than the front- (Chord length) of the outer side portion 130b located on the outer side.

Such a configuration can increase the deviation of the sea water from the inside and outside of the duct 110 with respect to the flow direction, thereby effectively increasing the swirling flow, thereby contributing to the propelling efficiency of the propeller.

10 is a perspective view for explaining a marine duct device according to a second modified embodiment of the present invention.

As shown in the drawing, in a marine duct device according to a second modified embodiment of the present invention, one end is coupled to the inner surface of the duct 110 in a state where one end is coupled to the rear SB of the ship, And a half stator 140 formed to be limited to only the inner region of the duct 110 in the shape of a cylinder. Such a half stator 140 is formed below the shaft center of the rear SB of the ship, which has a relatively large flow rate of seawater so that the strength of the duct device can be structurally reinforced.

It should be noted that although only one half stator 140 is shown in the drawing, two or more half stator 140 may be installed.

In addition to the structure in which the rear portion SB of the ship is reinforced by the half stator 140, the duct 110 is formed in an eccentric configuration shifted upward from the axial center of the stern SB. As a result, the half stator 140 can be formed to have a shorter length, which is advantageous in enduring the fluid load applied to the lower side of the shaft center of the stern SB.

As described above, the second modified embodiment of the present invention has a relatively rigid structure at the lower side of the shaft center of the stern SB, which has a relatively large fluid load due to the eccentric configuration of the duct 110 together with the half stator 140 . Such a configuration can be said to be completely compatible with the configuration of the present invention in which the outside of the duct 110 is focused on improving the propulsion efficiency and the inside of the duct 110 is focused on improving the structural safety. have.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments. It is clear that the present invention can be suitably modified and applied in the same manner. Therefore, the above description does not limit the scope of the present invention, which is defined by the limitations of the following claims.

110: duct 120: straight stator
130: twist stator 140: half stator

Claims (16)

A duct installed in front of the propeller and surrounding the rear of the ship;
And a plurality of stator extending in a radial direction of the duct in a state where one end is coupled to the rear of the ship and extending to the outside of the duct after passing through the duct,
At least one of the plurality of stator is divided into an inner portion located inside the duct and an outer portion located outside the duct, reflecting the fact that the flow characteristics of seawater are different between the inside and the outside of the duct, and the pitch between the inner portion and the outer portion A twist stator having different angles,
The inner side and outer side of the twist stator have the same central axis in the longitudinal direction and the pitch angle is changed on the same central axis and the pitch angle of the outer side of the twist stator is changed in the range of -10 to +30 relative to the inner side And,
The half stator further includes a half stator having one end limitedly coupled to the inner circumferential surface of the duct while the other end thereof is coupled to the rear end of the ship for strength reinforcement, And the duct is formed in an eccentric shape biased upward from the axis center of the stern so that the length of the half stator is shorter than that of the inner side of the twist stator,
Wherein the pitch angle of the twist stator is changed within a range of 60% of the diameter of the propeller, the pitch angle of the inner side of the twist stator is in a range of -10 degrees to +10 degrees, Wherein the front and rear widths of the inner side portions are formed to be narrower than the front and rear widths of the outer side portions located on the outer side of the duct so that the swirling flow can be further increased in front of the propeller,
When the azimuth angle is calculated in the direction of starboard rotation on the basis of the uppermost side, the stator is installed in two or more positions in the region other than the azimuth angle range of 225 to 285 degrees, and the azimuth angle 75 Wherein at least one of the stator is provided in the remaining region except for the range of -105 to -105 degrees, and at least one twist stator is installed at each of the port and starboard of the ship. delete delete delete delete The method according to claim 1,
Wherein the diameter of the duct is 60% or less of the diameter of the propeller. delete delete delete The method according to claim 1,
Wherein the length of the stator is in the range of 50 to 150% of the diameter of the propeller. The method according to claim 1,
Wherein the front and rear widths of the ducts are formed in a range of 5 to 30% of the diameter of the propeller. The method according to claim 1,
Wherein a distance between the center of the propeller and the duct is in a range of 3 to 40% of the diameter of the propeller. delete delete delete delete

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