KR101195140B1 - Propulsion efficiency enhancing apparatus for duct type thruster using nozzle - Google Patents

Abstract

The present invention forms a convex lifting surface on the outer surface of the airfoil duct part, and a part of the driving capacity of the vertical drive shaft for the propeller is utilized to eject the peripheral flow backward by forming a jet flow on the outer surface or the inner surface of the airfoil duct part. Accordingly, an object of the present invention is to provide an apparatus for improving propulsion efficiency of a duct type propeller using a nozzle capable of improving thrust of an entire propeller.
The propulsion efficiency improvement device of the duct type propeller using the nozzle of the present invention is the propeller casing (16) of one end 209a of the duct body (209) formed in the airfoil cross-section of the hollow (E, E1) extending in an annular or return type Inserted into the groove (16a), the other end 209b of the duct body 209 is coupled to the support (16b) extending from the propeller casing 16, the liftable outer surface 219 or inner surface 218 ) Is installed in the airfoil ducts 210 and 210a having the jet injection nozzles N, N1, N2, and N3, and the propeller casing 16 or the hull 9 from the water inlet 11, 12. And a fluid supply device 220 for compressing the sucked water to provide high pressure water to the nozzles N, N1, N2, and N3.

Description

Propulsion efficiency improvement device of duct type propeller using nozzles {PROPULSION EFFICIENCY ENHANCING APPARATUS FOR DUCT TYPE THRUSTER USING NOZZLE}

The present invention relates to an apparatus for improving propulsion efficiency of a duct type thruster using a nozzle, and more particularly, azimuth thruster such as a drill vessel, a floating structure, a floating crude oil production storage facility, and the like. Or it relates to a propulsion efficiency improvement device of the duct type propeller using a nozzle that can be applied to the duct type propulsion device.

Generally, swing or duct type propulsion devices are used for dynamic positioning to maintain the position and bow angle of the vessel.

Ducted propellers may include propeller type propellers and ducts because of the high tidal currents and waves, and the need for greater thrust at low speeds.

As the ship's capacity has recently increased and the required work has been advanced, the thrust required for the ship has increased.

On the other hand, since the thrust capacity of the conventional general swing propulsion device is limited, the number of swing propulsion devices installed in the ship is increasing to 3 to 6 or more. In other words, in order to obtain and build more competitive high-tech ships, a turning type propulsion system with improved propulsion efficiency is required.

As shown in FIG. 1, the swing-type propulsion device according to the related art includes an under water unit 3 including an duct 1 and a propeller 2, and an under water unit 3 in all directions. And a propeller drive device (not shown) for turning in any one direction, and a propeller drive device having a power transmission mechanism for transmitting rotational force to the propeller (2).

The propeller 2 is installed to rotate inside the duct 1 so that the fluid in front of the swing propulsion device flows to the rear of the swing propulsion device to generate thrust.

The thrust generation thus depends on the propeller 2, and in the case of the drillship, the position and bow angle are maintained by using a plurality of swing-type propellers.

The duct 1 is installed to improve the inflow and ejection efficiency of the fluid when the propeller 2 is driven, which is used solely for the purpose of improving the propulsion efficiency of the propeller 2.

In addition, the cavitation phenomenon caused by the generation of the cavity C by the propeller driving in the fluid is more serious in the propeller 2 of the underwater unit 3 according to the trend toward larger size of the swing propulsion device and improved high speed rotation performance. Can be generated.

Cavitation may also occur in an area where the flow velocity is reduced by the casing 4 outside the vertical drive shaft VS for transmitting rotational force to the propeller shaft PS of the propeller 2.

Such cavitation may generate vibrations and noises, which may be transmitted to the hull along the duct 1 and the casing 4 and propagate out of the hull, causing underwater noise regulation problems.

In addition, the swing-type propulsion device of the prior art generates an output depending only on the driving of the propeller, has a disadvantage that the propulsion efficiency is very low.

In addition, the swing propulsion device of the prior art is a duct surrounding the propeller is used only for the inflow and ejection efficiency of the fluid when driving the propeller, there is no means for increasing the thrust or improve the propulsion efficiency.

An object of the present invention devised to solve such a problem is to form a lifting surface of the convex shape on the outer surface or the inner surface of the airfoil duct portion, a part of the driving force of the vertical drive shaft for the propeller outer surface or the inner surface of the airfoil duct portion As it is used to form a jet flow in the to provide a propulsion efficiency improving device of the duct type propeller using a nozzle that can improve the propulsion efficiency of the entire propeller.

An object of the present invention described above, the one end portion of the duct body formed in the annular or return form of the airfoil cross section of the hollow structure is inserted into the groove of the propeller casing, the other end of the duct body is coupled to the support extending from the propeller casing, Airflow duct portion having a jet injection nozzle is formed on the outer surface or the inner surface that can generate lift, and a fluid supply device which is installed in the propeller casing or hull, compresses the water sucked from the water intake port to provide high pressure water to the nozzle. It can be achieved by the propulsion efficiency improving device of the duct type propeller using a nozzle including.

Further, according to the present invention, the fluid supply device is one or more suction pipes respectively connected to the water intake port, a valve device connected to the suction pipe to open and close the pipeline, the drive coupled to the vertical drive shaft of the propeller casing of the hull A diffuser structure includes a gear, a driven gear coupled to rotate by the drive gear, a clutch connecting one end to receive a rotational force from the driven gear and connecting the other end to the output shaft, and an impeller coupled to the output shaft. It may include an impeller device provided in the intake water to make high-pressure water, and a valve clutch controller for controlling the operation of the valve device and the clutch to adjust the flow rate or flow rate of the water.

Propulsion efficiency improvement device of the duct type propeller using the nozzle of the present invention forms a convex lifting surface on the outer surface or the inner surface of the airfoil duct portion, and forming a nozzle on the outer surface or the inner surface of the airfoil duct portion, through the nozzle As high pressure water is injected, jet flow is formed on the outer surface or the inner surface of the airfoil duct part, so that the fluid around the airfoil duct part flows toward the outer surface or the inner surface of the airfoil duct part and is sprayed to the rear of the airfoil duct part together with the jet flow. Thus, there is an advantage that the injected fluid itself can lead to increased thrust or improved propulsion efficiency.

In addition, the propulsion efficiency improvement device of the duct type propeller using the nozzle of the present invention, when the fluid around the air duct portion flows along the outer surface or the inner surface of the air duct portion, the flow rate of the fluid flowing into the propeller side of the duct type propeller The increase is small, which has the advantage of preventing the thrust of the propeller itself from being reduced. As a result, the propulsion efficiency of the duct type propeller is relatively improved by the fluid sprayed to the rear of the duct part along the outer surface or the inner surface of the airfoil duct part. It can be effected. In this case, however, the cross section of the duct becomes a decelerated form, and thus the thrust increase effect due to the lift of the airfoil duct itself may be lost. In other words, the thrust loss caused by the fluid sprayed along the outer surface or the inner surface of the airfoil tuck portion and the thrust loss of the airfoil duct portion itself need to be determined, and in another example, it is used for torpedoes that must suppress the cavity generation extremely. Can be useful when In addition, when the air flows along the inner surface of the airfoil, the thrust of the propeller itself may be reduced due to the increase of the flow velocity of the airflow duct.However, the design of the propeller may be performed by adjusting the pitch of the propeller. Designing for fluid velocity can prevent thrust reduction.

In addition, the propulsion efficiency improving device of the duct type propeller using the nozzle of the present invention has the advantage that can be used as an alternative to reduce the number of installation of a general duct type propeller in a large ship.

1 is a perspective view for explaining the configuration of a swing-type propulsion device according to the prior art.
Figure 2 is a block diagram for explaining the configuration of the propulsion efficiency improving apparatus of the duct type propeller using a nozzle according to an embodiment of the present invention.
3A is a cross-sectional view of the nozzle formed on the outer surface of the airfoil duct part.
3B is a cross-sectional view of the nozzle formed on the inner surface of the airfoil duct part.
4 is a cross-sectional view illustrating an application example of the airfoil duct portion according to the present invention.

Hereinafter, with reference to the accompanying Figures 2 to 4 will be described in detail the propulsion efficiency improving apparatus of the duct type propeller using a nozzle according to an embodiment of the present invention.

The following specific examples are merely illustrative of the propulsion efficiency improving device of the duct type propeller using the nozzle according to the present invention, it is not intended to limit the scope of the present invention.

Figure 2 is a block diagram for explaining the configuration of the propulsion efficiency improving apparatus of the duct type propeller using a nozzle according to an embodiment of the present invention.

Referring to Figure 2, the propulsion efficiency improvement device of the duct type propeller using the nozzle of the present invention is a duct type propeller 10 corresponding to any one of a propulsion device having or using a swing-type or omnidirectional propeller, a duct propeller, a duct. Can be mounted and used.

The apparatus for improving propulsion efficiency according to the present invention includes at least one nozzle for water jet injection (N) so as to attract the surrounding fluid by the water jet injection of the nozzle and the shape of the airfoil to perform the jet toward the rear of the propulsion direction. Airfoil duct 210 having a duct body 209 having a hollow (E) structure having a vertical drive shaft 17 for the propeller 19 to provide high pressure water to the hollow (E) of the airfoil duct 210 (17). It may include a fluid supply device 220 is driven by.

The duct body 209 of the airfoil duct 210 may be a duct casing extending the airfoil cross section of the hollow (E) structure in an annular shape.

One end 209a of the duct body 209 may be inserted and fixed in the groove 16a of the propeller casing 16, and the other end 209b of the duct body 209 extends from the propeller casing 16. It can be coupled to the hollow shaft-shaped support 16b having a fixed wing cross section.

The duct body 209 of the airfoil duct unit 210 may be fixed to the groove 16a and the support 16b of the propeller casing 16 to be supported.

The shape and size of the nozzle N may not be limited in the present invention, and may be variously designed and used corresponding to the duct type propeller 10.

For example, the nozzle N may be formed on the outer surface 219 as indicated by reference numeral N1 of FIG. 3A, and also on the inner surface 218 as indicated by reference numeral N2 of FIG. 3B. .

The nozzle N may be formed as a fixed nozzle having a shape and a nozzle hole size fixed by a design in advance, or a variable nozzle that adjusts the nozzle hole according to an operating situation using a variable blade assembly.

The airfoil duct unit 210 may have a airfoil designed by the experiment for the operation efficiency of the present invention, or may have a airfoil selected from the existing airfoil data (for example, NACA airfoil, etc.) according to the specification of the duct type propeller.

The outer surface 219 or the inner surface 218 of the airfoil duct 210 may refer to the outer or inner circumferential surface of the airfoil duct 210 having a structurally annular circumferential shape, dynamic lifting Can mean cotton. For example, the outer surface 219 or the inner surface 218 of the airfoil duct 210 may be defined as a lifting surface having a convex shape corresponding to the airfoil that can be optimized for the present invention.

When jet flow is generated on the outer surface 219 or the inner surface 218 of the airfoil duct 210, a relatively low dynamic pressure is formed to form an outer surface 219 of the airfoil duct 210. Alternatively, the fluid around the inner surface 218 is attracted to the outer surface 219 or the inner surface 218 to be accelerated and sprayed to the rear of the airfoil duct 210 to improve the propulsion efficiency of the duct type propeller 10. .

In addition, the inner surface 218 or the outer surface 219 of the airfoil duct 210 may be defined as a pressure surface having a relatively smooth shape. The inner surface 218 or the outer surface 219 may also correspond to the inner circumferential surface or outer circumferential surface of the airfoil duct unit 210 in a structural shape.

The hollow (E) structure may provide a flow space for delivering the high pressure water supplied from the fluid supply device 220 toward the nozzle (N).

This hollow (E) structure may be formed in an annular shape along the circumferential direction in the interior of the airfoil duct 210. In this case, the sucked water may be distributed over the entire air duct portion 210 so that a water jet having a circular tube shape may be generated through the nozzle N.

The water jet spray nozzle N is located at the front tip of the airfoil duct 210, that is, the rear of the airfoil duct 210 at the outer surface 219 or the inner surface 218 of the leading edge. It may be formed in an annular shape along the circumferential direction of the airfoil duct part 210 through the side tip, that is, the hole toward the trailing edge.

The water jet is a suction of water such as seawater into the fluid supply device 220 and then pressurized by the fluid supply device 220 to supply the inside of the hollow E of the airfoil duct part 210 through the nozzle N. The injected high pressure water refers to a jet flow flowing at high speed along the outer surface 219 or the inner surface 218 of the airfoil duct 210.

The duct type propeller 10 to be used in the present invention may basically be equipped with a turning actuator and a propeller driving apparatus (not shown) that meet the technical specifications of the turning propeller.

For example, the duct type propeller 10 may have a propeller casing 16 that is pivotable so as to be oriented in one of all directions by the swing actuator. The duct type propeller 10 has a propeller shaft 18 connected through a power transmission mechanism such as a bevel gear so as to be rotated by the vertical drive shaft 17, and a propeller 19 mounted at the end of the propeller shaft 18. Can be.

The fluid supply device 220 may be installed inside the hull 9 or the propeller casing 16.

The high pressure water pressurized from the fluid supply device 220 may be transferred through the duct transfer pipe 211 and the first and second transfer outlets 212 and 212a through the entire hollow E of the airfoil duct portion 210. 4 may be distributed only to the upper hollow E1 of the other airfoil duct part 210a according to the application shown in FIG. 4.

The fluid supply device 220 includes a valve device 121, an impeller device 221, an output shaft 222, a clutch 223, a driven gear 224, a drive gear 225, and a valve clutch controller 226. can do.

The fluid supply device 220 includes a drive gear 225 coupled to the vertical drive shaft 17 of the propeller casing 16, a driven gear 224 coupled to rotate by the drive gear 225, and such driven members. It may include a clutch 223 connected to one end and the other end to the output side shaft 222 to receive the rotational force from the gear 224.

The fluid supply device 220 may include a centrifugal compressor type impeller device 221 having an impeller coupled to the output shaft 222 in the diffuser structure.

The fluid supply device 220 is a valve device 121 for supplying water sucked to the impeller device 221 through the plurality of water inlets 11 and 12, the suction pipes 13 and 14, and the valve connection pipe 15. It can have

The valve device 121 is formed of a well-known valve mechanism or structure, and controls the flow rate by opening and closing the pipelines of the suction pipes 13 and 14, changing the conveying direction of water, simultaneously opening or closing the valves, and controlling the opening and closing amount. Can be in charge of.

The valve device 121 closes the other when opening one of the main suction pipe 13 and the auxiliary suction pipe 14, or simultaneously opens or closes the main suction pipe 13 and the auxiliary suction pipe 14 simultaneously. It may have a driver of the electron valve structure to perform the operation. Such a driver can be connected to the valve clutch controller 226 as to open and close the valves used in known valve control techniques.

On the other hand, one end of the duct transfer pipe 211 may be connected to the output port of the impeller device 221 through.

The other end of the duct transfer pipe 211 may be connected to the branch pipe 211a inside the propeller casing 16.

The duct transfer pipe 211 and the branch pipe 211a may be installed by using a free space between the pre-installed machinery inside the propeller casing 16.

One end of the branch pipe 211a may extend to the upper first transport outlet 212 of the duct body 209.

The other end of the branch pipe 211a may extend through the lower part of the propeller casing 16 and the inside of the support 16b to the second transport outlet 212a at the lower side of the duct body 209.

Thus, the duct transfer pipe 211 may be connected to penetrate the first and second transfer outlets (212, 212a).

One end of the valve connection pipe 15 may be connected to the input port of the impeller device 221 through. The other end of the valve connection pipe 15 may be connected to the discharge port of the valve device 121 through.

The main inlet pipe 13 for the first water inlet 11 and the auxiliary inlet pipe 14 for the second water inlet 12 may be piped to the corresponding inlet port formed in the valve device 121.

One end of the main suction pipe 13 may be piped to the first water suction port 11, and one end of the auxiliary suction pipe 14 may be piped to the second water suction hole 12.

Depending on the operating state of the valve device 121, water may be sucked through any one of the first water inlet 11 and the second water inlet 12, or the first water inlet 11 and the second water inlet ( Water can be inhaled using 12) simultaneously.

The first water inlet 11 and the second water inlet 12 may be used as a means for introducing or inhaling water toward the fluid supply device 220.

The first water inlet 11 is formed at the opposite end of the propeller 19 in the propeller casing 16, so that the water can be configured to enter directly upon propulsion.

The second water intake 12 may be used when the first water intake 11 is blocked by foreign substances in the water or the like, or when water intake above the capacity that can be inhaled through the first water intake 11 is required.

The second water inlet 12 may be formed on the stern side shell plate, left and right bow plate of the hull 9 except for the propeller casing 16 and may be configured to indirectly perform fluid suction.

The valve clutch controller 226 may be configured to control the opening and closing operation of the valve device 121, the shaft connection or the interrupting operation of the clutch 223.

The clutch 223 may have a driver for mechanically connecting or interrupting the shaft by electronic control, and may play a role of connecting or interrupting a rotational force between the driven gear 224 and the output shaft 222.

The valve clutch controller 226 is connected to the driver of the clutch 223 to control the shaft connection or operation of the clutch 223, or is connected to the actuator of the electromagnetic valve structure to control the operation of the valve device 121, the conventional circuit control A circuit can be provided.

Such a fluid supply device 220 may be installed inside the hull 9 or may be installed inside the propeller casing 16 through a compact design.

In the present invention, the principle that the peripheral fluid is injected with the jet flow may be used according to the shape characteristic of the airfoil according to the jet of water.

In the present invention, a part of the propeller operating capacity injected for the impeller device 221 of the fluid supply device 220, that is, a part of the driving capacity of the vertical drive shaft 17 for the propeller 19 is generated by the water jet injection and the lift force generated by the airfoil. Since the amount of additional thrust generated is less, the propulsion efficiency of the duct type propeller can be improved as a result.

Hereinafter, a method of operating the fluid supply device 220 will be described.

First, the valve clutch controller 226 transmits a control signal to the valve device 121 to open the input port for the main suction pipe 13, and the water impeller through the first water suction port 11 and the main suction pipe 13. To be transportable towards the device 221. At this time, the valve device 121 closes the auxiliary suction pipe 14.

The valve clutch controller 226 connects the clutch 223. In this case, the rotational force of the drive gear 225 and the driven gear 224 of the vertical drive shaft 17 is transmitted to the impeller of the impeller device 221 through the clutch 223 and the output shaft 222.

As a result, the impeller 221 in which the impeller rotates in the diffuser structure like the centrifugal compressor is transferred through the first water inlet 11, the main suction pipe 13, the valve device 121, and the valve connecting pipe 15. Increase the pressure of water to make high pressure water.

The high pressure water thus produced is transferred through the duct transfer pipe 211 and the first and second transfer outlets 212 and 212a through the entire hollow E of the airfoil duct part 210.

The high pressure water transmitted to the hollow E is sprayed from the outer surface 219 or the inner surface 218 of the airfoil duct part 210 through the nozzle N of the airfoil duct part 210 to generate a water jet. .

The water jet is further accelerated at the outer surface 219 or the inner surface 218 of the airfoil duct 210 by the airfoil shape feature to form a jet flow.

When a higher flow rate is required by the jet flow, or when a problem occurs in the first water intake port 11, the valve clutch controller 226 transmits a control signal to the valve device 121, so that the auxiliary suction pipe 14 may be used. By opening the input port, external water can be supplied to the impeller device 221 through the first or second water suction ports 11 and 12, and the main suction pipe 13 or the auxiliary suction pipe 14.

As shown in FIG. 3A or 3B, high pressure water may be injected from the nozzles N1 and N2 of the airfoil duct part 210.

At this time, when defining the high-pressure water initially injected through the nozzles (N1, N2) as the flow rate 1, as the outer surface 219 or the inner surface 218 of the airfoil duct unit 210 acts as a lifting surface, the duct The fluid around the outer surface 219 or the inner surface 218 of the portion 210 is directed toward the outer surface 219 or the inner surface 218 so that the water jet of the flow rate increased by at least one airfoil duct portion 210. It may be accelerated and sprayed to the rear of the airfoil duct 210 along the outer surface 219 or the inner surface 218 of the propeller (19) as described above. In addition to the main thrust by), the overall thrust of the propeller can be improved.

In particular, in the case of FIG. 3A, when a flow is formed at the outer surface 219 of the airfoil duct part 210, the velocity at which the flow rate inside the inner surface 218 of the airfoil duct part 210 flows toward the propeller 19. Since the increase in is small, the increase in the accelerated flow rate can help prevent the decrease in the main thrust of the propeller 19. However, in this case, the inner surface 218 has a shape of the airfoil duct 210 of the deceleration type in which the diameter or the inner diameter of the duct increases toward the rear of the airfoil duct part 210 as opposed to the basic acceleration duct having a flat shape. This can be effectively used for torpedoes which should extremely suppress the generation of cavities.

On the other hand, as shown in Figure 4, the method of fluid intake, in addition to the installation position of the first, second water intake port (11, 12) mentioned above in Figure 2, within the range that does not disturb the fluid field, hull ( 9) Alternatively, a separate water inlet may be further formed in another part of the propeller casing of the duct type propeller 10a (for example, a ship bower, etc.), and then the fluid is supplied through a separate pipe connected to a separate water inlet. It may be configured to supply water to the device 220.

The airfoil duct portion 210a may be formed in an annular shape in the circumferential direction, but the airfoil cross section of the hollow E1 structure in the airfoil duct portion 210a may be formed to extend along a semicircumference to be returned.

In this way, the selection of the fluid intake method may be changed fluidly according to the situation of the duct type propeller 10a.

In addition, the method of distributing suctioned water is different from the airfoil duct portion 210a illustrated in FIG. 4, unlike water is distributed throughout the hollow E in the airfoil duct portion 210 illustrated in FIGS. 2 and 3 described above. In the water can be distributed only to the upper hollow (E1).

That is, the lower body of the airfoil duct portion 210a may be formed to have a solid cross section, and the upper body may be formed to have an upper hollow E1.

In this case, the upper nozzle N3 may be formed in a return type along the outer circumferential direction of the upper outer surface 219a or the inner surface 218 of the airfoil duct part 210a.

In addition, the high pressure water may be applied to be supplied toward the airfoil duct portion 210a via the support structure 16c of the propeller 19. This may be differentiated according to the structural form or the geometrical features of the duct type propeller 10a.

Such a technical configuration of the present invention will be understood by those skilled in the art that the present invention can be implemented in other specific forms without changing the technical spirit or essential features of the present invention. Therefore, the scope of the present invention is represented by the following claims rather than the foregoing description, and all changes or modifications derived from the meaning and scope of the claims and equivalent concepts are included in the scope of the present invention. Should be interpreted.

10, 10a: duct type propeller 11, 12: water intake
16 propeller casing 121 valve device
210, 210a: airfoil duct 220: fluid supply device
221: impeller device 222: output shaft
223: clutch 224: driven gear
225: drive gear 226: valve clutch controller

Claims (6)

Insert one end of the duct body in which the airfoil cross section of the hollow structure is annular or return type is inserted into the groove of the propeller casing, and the other end of the duct body is coupled to the support extending from the propeller casing, and the liftable outer or inner surface is possible. Airfoil duct section formed with a nozzle for jet jet in the,
A fluid supply device installed in the propeller casing or the hull and compressing the water sucked from the water intake port to provide high pressure water to the nozzle;
The airfoil duct part
The nozzle is perforated with the hollow in a direction toward the trailing edge of the airfoil duct portion at the outer surface or inner surface of the leading edge of the airfoil duct portion, and annularly or semicircularly along the outer circumferential direction of the airfoil duct portion. Formed,
As the jet flow according to the injection of the high-pressure water injected through the nozzle is formed on the outer surface or the inner surface of the airfoil duct portion, the fluid around the airfoil duct portion flows toward the outer surface or the inner surface of the airfoil duct portion Sprayed to the rear of the airfoil duct with jet flow
Propulsion efficiency improvement device of duct type propeller using nozzle.
The method of claim 1,
The water inlet is formed at any one or more of the end of the propeller casing, the stern side shell plate, the left and right bow shell plate opposite the propeller
Propulsion efficiency improvement device of duct type propeller using nozzle.
delete The method of claim 1,
The fluid supply device
At least one suction pipe each piped to the water suction port;
A valve device connected to the suction pipe to open and close the pipe;
A drive gear coupled to the vertical drive shaft of the propeller casing of the hull;
A driven gear coupled to rotate by the drive gear;
A clutch connected to one end and a second end connected to an output shaft to receive a rotational force from the driven gear;
An impeller device having an impeller coupled to the output side shaft in a diffuser structure to make suction water into high pressure water;
And a valve clutch controller that controls the operation of the valve device and the clutch to regulate the flow rate or flow rate of water.
Propulsion efficiency improvement device of duct type propeller using nozzle.
The method according to any one of claims 1, 2 and 4,
A propeller rotated by the propeller shaft of the duct type propeller is disposed in the air space of the air duct part, and the high pressure water supplied from the fluid supply device to the air duct part is injected through the nozzle of the air duct part to form an outer surface of the air duct part. Or when jet flow is formed along the inner surface, the peripheral fluid is induced toward the outer surface or the inner surface of the airfoil duct by the jet flow and flows together with the jet flow to form an increased thrust.
Propulsion efficiency improvement device of duct type propeller using nozzle.
The method according to any one of claims 1, 2 and 4,
The nozzle is formed of a fixed nozzle or a variable nozzle for adjusting the nozzle hole size is fixed nozzle hole size
Propulsion efficiency improvement device of duct type propeller using nozzle.

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