Guide plate structure for reducing cavitation bubbles of semi-suspension rudder

Abstract

The utility model belongs to the technical field of ship design, and particularly discloses a cavitation-reducing guide plate structure of a semi-suspension rudder, a first guide plate and a second guide plate can effectively restrain transverse streaming in a gap between a notch of a rudder blade body and a rudder horn, cavitation denudation in the gap is reduced, and the service life of the rudder blade body is prolonged. The first flow guide plate and the second flow guide plate can increase the speed circulation of longitudinal streaming on the surface of the rudder blade body, cavitation bubbles are effectively reduced, the maneuvering performance of a ship can be improved to a certain degree, meanwhile, the first flow guide plate and the second flow guide plate are small in size, and the influence on frictional resistance generated on the wet surface area of the rudder blade body is small. The requirements of reducing the cost and the construction difficulty of a shipyard are met, and the applicability is very high.

Description

Technical Field

[0001] The utility model relates to the technical field of ship design, in particular to a flow deflector structure for reducing cavitation of a semi-suspended rudder. Background Technique

[0002] The rudder is arranged behind the propeller, mainly to meet the requirements of ship maneuverability and course stability. It is the most commonly used ship course control device and also requires a certain anti-cavitation performance to avoid the risk of cavitation erosion. For a conventional semi-suspended rudder system, serious cavitation erosion is likely to occur at the vertical and horizontal gaps between the semi-suspended rudder blade body and the hanging rudder arm. For high-speed ships equipped with semi-suspended rudders, even if the role of the propeller is not considered, the severe pulsation and flow separation occurring at the vertical and horizontal gaps between the rudder and the hanging rudder arm in the high-speed oncoming flow are extremely likely to cause cavitation erosion. Therefore, in the design of the semi-suspended rudder of high-speed ships, it is necessary to maintain the integrity of the airfoil section or reduce the lateral flow around the gap between the rudder and the hanging rudder arm to minimize the cavitation erosion at the gap.

[0003] The methods adopted in the prior art still have the following disadvantages:

[0004] 1. When designing the structure, try to minimize the gap between the rudder blade body and the hanging rudder arm to reduce turbulence; however, due to the requirements of rudder rotation and construction, the gap between the rudder blade body and the hanging rudder arm is too small, which is likely to cause the rudder blade body to collide with the hanging rudder arm during rudder rotation and pose a severe challenge to the construction precision control of the shipyard;

[0005] 2. Adopt a mechanical structure to maintain the integrity of the airfoil section and block the inflow of the gap; however, it is exposed and immersed in seawater for a long time, corroded by seawater or attached by marine organisms, resulting in the rotation failure or even detachment of the mechanical structure and being unable to form a long-term effective block of the inflow of the gap;

[0006] 3. Stick a stainless steel protective film on the surface of the rudder blade body to prevent the rudder blade body from being cavitation-corroded; however, it cannot avoid the generation of cavitation, and will also increase the cost of the shipyard and reduce the satisfaction of the shipowner with the ship;

[0007] 4. Adopting a fully suspended rudder or other high-performance twisted rudders will greatly increase the cost of the shipyard.

[0008] In view of this, the utility model provides a flow deflector structure for reducing cavitation of a semi-suspended rudder. Content of the Utility Model

[0009] The purpose of the utility model is to provide a flow deflector structure for reducing cavitation of a semi-suspended rudder, which can effectively inhibit the lateral flow around the gap between the rudder blade body and the hanging rudder arm and reduce the cavitation erosion of the rudder to solve the above problems.

[0010] To achieve the above object, the present utility model provides the following technical solutions: A flow deflector structure for reducing cavitation of a semi-suspended rudder, comprising a first flow deflector and a second flow deflector.

[0011] The first flow deflector is arranged above the notch of the rudder blade body, and includes a port side flow deflector and a starboard side flow deflector, which are symmetrically arranged in two separate parts based on the port and starboard sides;

[0012] The second flow deflector is arranged below the notch of the rudder blade body, and includes an integrally formed port and starboard side flow deflector adapted to the lower notch of the rudder blade body 1.

[0013] As a preferred technical solution of the present utility model, the distance between the lower end of the first flow deflector and the upper end of the notch of the rudder blade body is 0 - 10 mm, and the front end of the first flow deflector is flush with the notch of the rudder blade body in the vertical direction.

[0014] As a preferred technical solution of the present utility model, the overall length of the first flow deflector is one-fifth of the length of the corresponding section of the rudder blade body on the port or starboard side.

[0015] As a preferred technical solution of the present utility model, the front end of the first flow deflector is chamfered, and the rear end is rounded to make it fit the upper notch of the rudder blade body 1.

[0016] As a preferred technical solution of the present utility model, the distance between the upper end of the second flow deflector and the lower end of the notch of the rudder blade body is 0 - 10 mm.

[0017] As a preferred technical solution of the present utility model, the front end of the second flow deflector extends 100 mm beyond the leading edge of the rudder blade body, the rear end of the second flow deflector is in the same vertical direction as the rear end of the first flow deflector, and the rear end of the second flow deflector is rounded.

[0018] Compared with the prior art, the beneficial effects of the present utility model are:

[0019] While effectively reducing cavitation, the present utility model can improve the maneuverability of the ship to a certain extent, and can also meet the requirements of reducing the cost and construction difficulty of the shipyard, and has strong applicability. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 It is a schematic diagram of the overall assembled structure of the semi-suspended rudder of the present utility model for a ship;

[0021] Figure 2 It is a schematic diagram of the overall sectional structure of the semi-suspended rudder of the present utility model for a ship;

[0022] Figure 3 It is a schematic diagram of the assembled structure of the first flow deflector of the present utility model;

[0023] Figure 4Schematic diagram of the assembly structure of the second deflector of the present utility model;

[0024] In the figure: 1, rudder blade body; 2, hanging rudder arm; 3, first deflector; 4, second deflector. Specific embodiments

[0025] The following will clearly and completely describe the technical solutions in the embodiments of the present utility model with reference to the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all of the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present utility model.

[0026] In the description of the present utility model, it should be noted that the orientation or positional relationship indicated by the terms "vertical", "upper", "lower", "horizontal", etc. is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present utility model and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation of the present utility model.

[0027] In the description of the present utility model, it should also be noted that unless otherwise clearly specified and limited, the terms "set", "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected, or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those of ordinary skill in the art, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances.

[0028] Please refer to Figures 1-4 , the present utility model provides a technical solution: a deflector structure for reducing cavitation of a semi-suspended rudder. A deflector structure that is offset from the line type of the rudder blade body 1 by an equal distance is added outside the rudder blade body 1, including a first deflector 3 and a second deflector 4.

[0029] The first deflector 3 is arranged above the notch of the rudder blade body 1 and includes a port deflector and a starboard deflector. It is symmetrically arranged in two parts based on the port and starboard. As Figure 3 shown, the distance between the lower end of the first deflector 3 and the upper end of the notch of the rudder blade body 1 is 0 - 10 mm. The front end of the first deflector 3 is flush with the notch of the rudder blade body 1 in the vertical direction. The overall length of the first deflector 3 is about one-fifth of the length L of the corresponding section of the rudder blade body 1 on the side, with a thickness of 15 - 30 mm and a width of 100 mm. And it is chamfered based on the front end of the first deflector 3, and rounded at the rear end of the first deflector 3 to make it fit the upper notch of the rudder blade body 1;

[0030] The second deflector 4 is arranged below the notch of the rudder blade body 1 and includes integrally formed port and starboard deflectors adapted to the lower notch of the rudder blade body 1. As Figure 4 shown, the distance between the upper end of the second deflector 4 and the lower end of the notch of the rudder blade body 1 is 0 to 10 mm. The front end of the second deflector 4 extends 100 mm beyond the leading edge of the rudder blade body 1. The rear end of the second deflector 4 is in the same vertical direction as the rear end of the first deflector 3, with a thickness of 15 to 30 mm, a width of 100 mm, and the rear end of the second deflector 4 is rounded off.

[0031] Specifically, the first deflector 3 and the second deflector 4 can effectively inhibit the lateral flow around the gap between the notch of the rudder blade body 1 and the hanging rudder arm 2, reduce the cavitation erosion of the gap here, and the first deflector 3 and the second deflector 4 can increase the velocity circulation of the longitudinal flow on the surface of the rudder blade body 1. While effectively reducing cavitation, it can improve the maneuverability of the ship to a certain extent. At the same time, the first deflector 3 and the second deflector 5 are small in size and have little impact on the frictional resistance of the wetted surface area of the rudder blade body 1. It meets the requirements of reducing the cost and construction difficulty of the shipyard and has strong applicability.

[0032] Although the embodiments of the present invention have been shown and described, those of ordinary skill in the art can understand that various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principle and spirit of the present invention. The scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A semi-suspended rudder cavitation-reducing deflector structure, characterized in that: It includes a first deflector (3) and a second deflector (4). The first deflector (3) is arranged above the notch of the rudder blade body (1), and includes a port deflector and a starboard deflector, which are symmetrically arranged in two parts based on the port and starboard. The second deflector (4) is arranged below the notch of the rudder blade body (1), and includes an integrally formed port and starboard deflector adapted to the lower notch of the rudder blade body (1).

2. The flow deflector structure for reducing cavitation of a semi-suspended rudder according to claim 1, characterized in that: The distance between the lower end of the first deflector (3) and the upper end of the notch of the rudder blade body (1) is 0 to 10 mm, and the front end of the first deflector (3) is flush with the vertical direction of the notch of the rudder blade body.

3. The deflector structure for reducing cavitation of a semi-suspended rudder according to claim 2, characterized in that: The overall length of the first deflector (3) is one-fifth of the sectional length of the corresponding side of the rudder blade body (1).

4. A deflector structure for reducing cavitation of a semi-suspended rudder according to claim 3, characterized in that: The front end of the first deflector (3) is chamfered, and the rear end of the first deflector (3) is rounded to adapt to the upper notch of the rudder blade body (1).

5. The flow deflector structure for reducing cavitation of a semi-suspended rudder according to claim 1, characterized in that: The distance between the upper end of the second deflector (4) and the lower end of the notch of the rudder blade body is 0 to 10 mm.

6. A flow deflector structure for reducing cavitation of a semi-suspended rudder according to claim 5, characterized in that: The front end of the second deflector (4) extends 100 mm beyond the leading edge of the rudder blade body. The rear end of the second deflector (4) is in the same vertical direction as the rear end of the first deflector (3), and the rear end of the second deflector (4) is rounded.

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