A rigid double sail and method for reducing the influence of vortex shedding

Abstract

The present invention relates to the technical field of rigid sail wings, and in particular to a rigid double sail and method for weakening the influence of vortex shedding. The rigid double sail for weakening the influence of vortex shedding of the present invention comprises a main sail and a follower sail, wherein a slit is provided between the main sail and the follower sail, at least one skin is provided between the trailing edge of the main sail and the leading edge of the follower sail, and a plurality of groups of pores of different sizes are provided on the skin; the adjusting device also comprises a first driving device, wherein the first driving device controls any group of the pores of the skin to be in the slit position; the tensioning device comprises a second driving device, wherein the second driving device controls the tensioning of the skin. The present invention solves the problem that under the continuous vibration caused by vortex shedding, the sail wing and the mast will suffer fatigue damage and structural instability, which will have a serious impact on the service life of the sail wing, the working efficiency and the safety of the sailboat.

Description

Technical Field

[0001] The invention relates to the technical field of rigid sail wings, in particular to a rigid double sail and a method for weakening the influence of vortex shedding. Background Art

[0002] Compared with soft sails, rigid sails tend to have higher working efficiency, so rigid sails are increasingly used as auxiliary propulsion systems for unmanned ships. Rigid sails act like wings and usually have a solid outer shell. Using rigid sails on ships can provide additional propulsion power, which can greatly reduce the fuel consumption and exhaust emissions of ships.

[0003] The double-sail wing with a mainsail and a tailsail can not only increase the windward area to generate greater thrust, but also can rotate the tailsail according to needs to make it have a suitable angle of attack, thereby flexibly realizing turning, speed change and other maneuvers.

[0004] However, due to the slit between the mainsail and the trailing sail, the slit jet and the mainsail's wake affect the aerodynamic characteristics of the trailing sail. Under certain circumstances, the airflow passing through the slit will produce strong vortex shedding, which can cause the sail wing to vibrate violently and continuously.

[0005] Under the strong and continuous vibration caused by vortex shedding, the sail wing and mast will suffer fatigue damage and structural instability, which will have a serious impact on the service life of the sail wing, work efficiency and safety of the sailboat. Summary of the invention

[0006] The purpose of the present invention is to propose a rigid double sail and method for weakening the influence of vortex shedding, so as to solve the problems that the sail wing and the mast will suffer fatigue damage and structural instability under the continuous vibration caused by vortex shedding, which will have a serious impact on the service life of the sail wing, work efficiency and safety of the sailboat.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] In one aspect, the present invention provides a rigid double sail for reducing the effects of vortex shedding, comprising a main sail, a follower sail, an adjusting device and a tensioning device;

[0009] There is a slit between the main sail and the secondary sail, at least one skin is arranged between the trailing edge of the main sail and the leading edge of the secondary sail, and a plurality of groups of pores of different sizes are arranged on the skin;

[0010] The adjustment device comprises a first driving device, which adjusts any group of the apertures in the skin to be in the position of a slit;

[0011] The tensioning device comprises a second drive device, which controls the tensioning of the skin.

[0012] On the basis of the above scheme and as a preferred scheme of the above scheme: the skin is in the shape of an annular belt, and the two ends of the skin are respectively arranged inside the main sail and the secondary sail, and the main sail and the secondary sail are both provided with openings for the skin to pass through.

[0013] On the basis of the above scheme and as a preferred scheme of the above scheme: the openings are respectively arranged on the upper and lower sides of the trailing edge of the main sail and the leading edge of the trailing sail.

[0014] On the basis of the above solution and as a preferred solution of the above solution: the opening is gap-matched with the skin.

[0015] On the basis of the above solution and as a preferred solution of the above solution: an elastic filler is provided at the opening, and the elastic filler is filled between the opening and the skin.

[0016] On the basis of the above scheme and as a preferred scheme of the above scheme: the adjusting device also includes a first roller, the first roller is rotatably arranged in the mainsail, the first driving device is a rotational drive, the first driving device is arranged in the mainsail, and the first driving device is transmission-connected to the first roller; the skin passes around the first roller; the first driving device drives the first roller to rotate to control the movement of the skin.

[0017] On the basis of the above scheme and as a preferred scheme of the above scheme: a plurality of protrusions are evenly distributed around the first roller, and the skin is provided with grooves evenly arranged along the length direction, and the protrusions can be embedded in the grooves during the rotation of the first roller.

[0018] On the basis of the above scheme and as a preferred scheme of the above scheme: the tensioning device also includes a second roller, the second roller is rotatably arranged in the follower sail, the second driving device is a rotational drive, the second driving device is arranged in the follower sail and is transmission connected to the second roller; the skin is wrapped around the second roller, the cross-section of the second roller is a cam shape, and the second driving device drives the second roller to rotate to tension the skin.

[0019] On the basis of the above scheme and as a preferred scheme of the above scheme: the tensioning device also includes a roller, both ends of which are slidably connected in the follower sail, the sliding direction of the roller is perpendicular to the axial direction of the roller, the second driving device is a linear reciprocating drive, the second driving device is arranged in the follower sail to connect the roller, and the second driving device controls the roller to slide away from or close to the main sail.

[0020] On the basis of the above scheme and as a preferred scheme of the above scheme: the skin is a linear strip structure, the trailing edge of the mainsail and the leading edge of the follower sail are respectively provided with openings, and the two ends of the skin are respectively passed through the openings and are arranged in the mainsail and the follower sail.

[0021] On the other hand, the present invention provides a method for weakening the influence of vortex shedding, comprising the rigid double sail; a vibration detection device is arranged on the main sail and / or the secondary sail; and the method comprises the following steps:

[0022] Step 1: monitoring the vibration of the main sail or the slave sail by means of the vibration detection device;

[0023] Step 2: Set the maximum and minimum vibration thresholds;

[0024] Step three, when the vibration detection device detects that the vibration of the main sail or the slave sail exceeds a maximum threshold, the first driving device controls the area of ​​the pores in the slit position of the skin to change until the vibration is lower than a minimum threshold.

[0025] On the basis of the above solution and as a preferred solution of the above solution: in the step 3, the manner in which the area of ​​the pores in the slit position of the skin is controlled by the first driving device to change is:

[0026] A multiple adjustment method is adopted, wherein the first driving device is actuated once every N seconds, and each action of the first driving device causes the area of ​​the pores in the slit position of the skin to become smaller;

[0027] If the vibration is lower than the minimum threshold within N seconds, stop adjusting;

[0028] The value range of N is 3-10.

[0029] On the basis of the above scheme and as a preferred scheme of the above scheme: in the step three, when the area of ​​the pores of the skin at the slit position is already the smallest during the adjustment process, the first driving device controls the area of ​​the pores of the skin at the slit position to return to the maximum; and then continues to adjust.

[0030] In order to solve the problems that the sail wing and the mast may suffer fatigue damage and structural instability under the continuous vibration caused by vortex shedding, which will have a serious impact on the service life of the sail wing, the working efficiency and the safety of the sailboat, the present invention has the following advantages:

[0031] The rigid double sail for reducing the influence of vortex shedding of the present invention is provided with a porous skin at the slit between the main sail and the trailing sail, so that the vortex shed from one side of the main sail is blocked from reaching the opposite side through the slit between the main sail and the trailing sail, thereby avoiding or reducing the vibration of the sail wing caused by vortex shedding.

[0032] The rigid double sail for weakening the influence of vortex shedding of the present invention has pores of various sizes and arrangement areas on the skin; pores of each size occupy a certain area of ​​space, and when vortex shedding has been continuously generated and caused to vibrate the sail wing, the pore arrangement of the skin in the slit is changed to disrupt the airflow characteristics passing through the slit, thereby blocking the vortex shedding phenomenon or reducing the strength of the vortex.

[0033] The rigid double sail for weakening the influence of vortex shedding of the present invention has a tensioning device that can loosen the skin following the adjustment of the slave sail to facilitate the movement of the slave sail when the angle of the slave sail relative to the main sail changes; and can also tighten the skin during or after the adjustment. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 It is a schematic diagram of the structure of the rigid double sail for reducing the influence of vortex shedding of the present invention;

[0035] Figure 2 It is a schematic structural diagram of the rigid double sails for reducing the influence of vortex shedding according to the present invention from another perspective;

[0036] Figure 3 is a schematic diagram of a second roller of the present invention;

[0037] Figure 4 This is a schematic structural diagram of another embodiment of the rigid double sail for reducing the influence of vortex shedding of the present invention;

[0038] Figure 5 It is a schematic diagram of an application of one embodiment of the tensioning device of the present invention;

[0039] Figure 6 for Figure 5 A magnified view of part A;

[0040] Figure 7 It is a schematic diagram of the arrangement of the elastic filler of the present invention;

[0041] Figure 8 This is a flow chart of the method for reducing the influence of vortex shedding of the present invention;

[0042] Fig. 9 Schematic diagram of the vorticity on the sail surface.

[0043] Description of reference numerals:

[0044] 100. Mainsail;

[0045] 101. Open your mouth;

[0046] 102. Elastic filler;

[0047] 200, from the sail;

[0048] 300, regulating device;

[0049] 301, first roller;

[0050] 302, a first driving device;

[0051] 303, raised portion;

[0052] 304, Grooving;

[0053] 400, tensioning device;

[0054] 401, second driving device;

[0055] 421, second roller;

[0056] 431, roller;

[0057] 432. Linear guide;

[0058] 433, slider;

[0059] 500, skinning;

[0060] 501, pores;

[0061] 600. Slit. DETAILED DESCRIPTION

[0062] The technical solutions in the embodiments of the present invention are described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments.

[0063] See also Figure 1-9 This embodiment discloses a rigid double sail and method for reducing the influence of vortex shedding, which solves the problem that the sail wing and mast will suffer fatigue damage and structural instability under the continuous vibration caused by vortex shedding, which will have a serious impact on the service life of the sail wing, work efficiency and safety of the sailboat. Among them, the rigid double sail for reducing the influence of vortex shedding of the present invention is provided with a skin 501 with a hole 501 at the slit 600 between the main sail 100 and the secondary sail 200, and the skin 500 is used to prevent the vortex shed from one side of the main sail 100 from reaching the opposite side through the slit 600 between the main sail 100 and the secondary sail 200 to form Fig. 9The vortex shedding shown (the box in the attached figure is the vortex that sheds from the main sail and reaches the opposite side through the slit), thereby avoiding or reducing the vibration of the sail wing caused by the vortex shedding. At the same time, the pores 501 on the skin 500 have a variety of sizes and layout areas; each size of the pores 501 occupies a certain area of ​​space. When the vortex shedding phenomenon has been continuously generated and caused the sail wing to vibrate, the arrangement of the pores 501 of the skin 500 in the slit 600 is changed to disrupt the airflow characteristics through the slit 600, thereby blocking the vortex shedding phenomenon or reducing the intensity of the vortex. As the same technical concept of the present invention, the method of weakening the influence of vortex shedding of the present invention monitors the vibration of the main sail 100 or the slave sail 200 through a vibration detection device and feeds back to the control module, and the control module controls the skin 500 to adjust the arrangement of the pores 501 in the slit 600 to achieve blocking or weakening the vibration caused by the vortex shedding phenomenon.

[0064] like Figure 5 As shown, a plurality of groups of pores 501 of different sizes are provided on the skin 500 , and are arranged in a variety of ways. The areas of the pores 501 in different regions are different, so that the area adjustment of the pores 501 in the slit is convenient.

[0065] In the present disclosure, Figure 1-7 The rigid double sail for weakening the influence of vortex shedding of the present invention comprises a main sail 100, a secondary sail 200, an adjusting device 300 and a tensioning device 400; a slit 600 is provided between the main sail 100 and the secondary sail 200, at least one skin 500 is provided between the trailing edge of the main sail 100 and the leading edge of the secondary sail 200, and a plurality of groups of pores 501 of different sizes are provided on the skin 500; the adjusting device 300 comprises a first driving device 302, and the first driving device 302 controls any group of pores 501 of the skin 500 to be at the position of the slit 600; the tensioning device 400 comprises a second driving device 401, and the second driving device 401 controls the tensioning of the skin 500.

[0066] The skin 500 can prevent the vortex shed from one side of the main sail 100 from reaching the opposite side through the slit 600 between the main sail 100 and the secondary sail 200, thereby avoiding or reducing the vibration of the sail wing caused by the vortex shedding. When the angle of the secondary sail 200 relative to the main sail 100 changes, the tensioning device 400 can follow the adjustment of the secondary sail 200 to loosen the skin 500 to facilitate the movement of the secondary sail 200; at the same time, the skin 500 can also be tightened during or after the adjustment.

[0067] In the present disclosure, Figure 1-6As shown, the skin 500 is in the shape of an annular belt, and the two ends of the skin 500 are respectively arranged inside the main sail 100 and the secondary sail 200. The main sail 100 and the secondary sail 200 are both provided with openings 101 for the skin 500 to pass through. The adjusting device 300 is arranged in the main sail 100, and the tensioning device 400 is arranged in the secondary sail 200. The adjusting device 300 can control the skin 500 to move back and forth, and the arrangement of the pores 501 on the skin 500 in the slit 600 and the distribution area of ​​the pores 501 are adjusted by controlling the skin 500 to move back and forth. The tensioning device 400 maintains the tensioned state of the skin 500 during and after the adjustment of the secondary sail 200.

[0068] In the present disclosure, Figure 1 , Figure 4 As shown, the openings 101 are respectively arranged at the upper and lower sides of the trailing edge of the main sail 100 and the leading edge of the secondary sail 200. The upper and lower surfaces of the skin 500 are respectively located at the upper and lower sides of the main sail 100 and the secondary sail 200, and the opening 101 on the main sail 100 is as close to the trailing edge of the main sail 100 as possible, and the opening 101 on the secondary sail 200 is as close to the leading edge of the secondary sail 200 as possible, so as to reduce the influence of the skin 500 on the airflow on the surfaces of the main sail 100 and the secondary sail 200.

[0069] In the disclosed embodiment, in order to improve the passability of the skin 500 during the adjustment process, the opening 101 and the skin 500 are clearance-matched.

[0070] In the disclosed embodiment, an elastic filler 102 is fixedly disposed at the opening 101, and the elastic filler 102 is filled between the opening 101 and the skin 500 to eliminate the gap between the opening 101 and the skin 500, thereby preventing the airflow from impacting the gap of the opening 101 and affecting the airflow on the surface of the main sail 100 and the trailing sail 200. The elastic filler 102 may be made of rubber, nylon, copper or other materials.

[0071] In the present disclosure, Figure 1 , Figure 6 As shown, the adjustment device 300 further includes a first roller 301, which is rotatably arranged in the main sail 100, and a first driving device 302 is a rotary drive, which is arranged in the main sail 100 and is in transmission connection with the first roller 301; the skin 500 passes around the first roller 301; the first driving device 302 drives the first roller 301 to rotate to control the movement of the skin 500. This is beneficial to the adjustment and control of the skin 500, wherein the first driving device 302 can selectively use a servo control motor.

[0072] In the present disclosure, Figure 6As shown, a plurality of protrusions 303 are evenly distributed around the first roller 301, and the skin 500 is provided with grooves 304 evenly arranged along the length direction, and the protrusions 303 can be embedded in the grooves 304 during the rotation of the first roller 301. The cooperation between the protrusions 303 and the grooves 304 can prevent the first roller 301 and the skin 500 from relative slipping during the rotation of the first roller 301 to control the movement of the skin 500, resulting in inaccurate control. This solution can achieve an accurate synchronous control effect.

[0073] In some embodiments, such as Figure 1-3 As shown, the tensioning device 400 further includes a second roller 421, which is rotatably disposed in the secondary sail 200, and the second driving device 401 is a rotary drive, which can be selectively controlled by a servo motor, and the second driving device 401 is disposed in the secondary sail 200 and is transmission-connected to the second roller 421; the skin 500 passes around the second roller 421, and the cross-section of the second roller 421 is in a cam shape, and the second driving device 401 drives the second roller 421 to rotate to tension the skin 500. Figure 3 As shown, the cam shape is an eccentric circle.

[0074] In some embodiments, the tensioning device 400 is different from Figure 1-3 The structure shown. Figure 4-5 As shown, the tensioning device 400 also includes a roller 431, both ends of which are slidably connected in the secondary sail 200, and the sliding direction of the roller 431 is perpendicular to the axial direction of the roller 431. The second driving device 401 is a linear reciprocating drive, and a servo electric push rod, an electric cylinder, etc. can be selected. The second driving device 401 is arranged in the secondary sail 200 to connect the roller 431, and the second driving device 401 controls the roller 431 to slide away from or close to the main sail 100. In order to facilitate the sliding control of the roller 431, a linear guide rail 432 is arranged in the secondary sail 200, and then a slider 433 is arranged to slide with the guide rail, and the roller 431 is rotatably connected to the slider 433. The second driving device 401 is connected to the slider 433 to control the sliding of the roller 431, thereby controlling the tensioning of the skin 500.

[0075] In some embodiments, the skin 500 is a linear strip structure, which is not directly shown in the drawings. The rear edge of the main sail 100 and the front edge of the secondary sail 200 are respectively provided with openings 101, and the two ends of the skin 500 are respectively passed through the openings 101 and arranged in the main sail 100 and the secondary sail 200. The arrangement and adjustment of the pores 501 of the skin 500 in the slit 600 can be controlled by moving the skin 500 back and forth in the slit 600. The adjustment method includes adjusting by setting a roller in the form of winding and releasing, or adjusting by the translation and sliding of the whole or one end. However, due to the limitation of the space inside the sail, it is preferred that the two ends of the skin 500 are respectively provided with the form of winding and releasing.

[0076] In the embodiments of the present disclosure, on the other hand, Figure 8 As shown, based on the same technical concept of the present invention, a method for weakening the influence of vortex shedding is provided, comprising any of the above-mentioned rigid double sails; a vibration detection device is arranged on the main sail and / or the slave sail; and the following steps are included:

[0077] Step 1, monitoring the vibration of the main sail or the follower sail by means of a vibration detection device;

[0078] Step 2: Set the maximum and minimum vibration thresholds;

[0079] Step three, when the vibration detection device detects that the vibration of the mainsail or the follower sail exceeds the maximum threshold, the first driving device controls the area of ​​the pores in the slit position of the skin to change until the vibration is lower than the minimum threshold.

[0080] In some embodiments, the method for weakening the influence of vortex shedding includes any of the above-mentioned rigid double sails; a vibration detection device is arranged on the main sail and / or the slave sail; and includes the following steps: including the rigid double sails; and also including a control module; a vibration detection device is arranged on the main sail 100 and / or the slave sail 200; the first driving device 302 and the vibration detection device are respectively connected to the control module; and includes the following steps:

[0081] Step 1: monitor the vibration of the main sail 100 or the secondary sail 200 through a vibration detection device and feed back to the control module;

[0082] Step 2, setting the maximum and minimum thresholds of vibration in the control module;

[0083] Step three, when the control module detects through the vibration detection device that the vibration of the main sail 100 or the slave sail 200 exceeds the maximum threshold, the control module controls the first driving device 302, and controls the area of ​​the pore 501 of the skin 500 at the slit 600 position to change through the first driving device 302 until the vibration is lower than the minimum threshold.

[0084] The method for weakening the influence of vortex shedding monitors the vibration of the main sail 100 or the secondary sail 200 through a vibration detection device and feeds back to the control module, and the control module controls the skin 500 to adjust the arrangement of the pores 501 in the slit 600, so as to block or weaken the vibration caused by the vortex shedding phenomenon.

[0085] In the disclosed embodiment, when the vibration of the main sail 100 or the slave sail 200 is lower than the minimum threshold, there is no need to adjust the area of ​​the gap 501 of the skin 500 at the position of the slit 600 through the first driving device 302, and the first driving device 302 is in an inactive or stopped state; when the vibration detection device detects that the vibration of the main sail 100 or the slave sail 200 exceeds the maximum threshold, continue to adjust according to the above step three.

[0086] In the embodiment of the present disclosure, in step 3, the first driving device 302 controls the change of the area of ​​the pore 501 of the skin 500 at the position of the slit 600 by: adopting a multiple adjustment method, specifically, the first driving device 302 operates once every N seconds, and each time the first driving device 302 operates, the area of ​​the pore 501 of the skin 500 at the position of the slit 600 becomes smaller; if the vibration is lower than the minimum threshold value within N seconds, the adjustment is stopped. N seconds can be 3-10 seconds; although the range of N seconds includes but is not limited to 3-10 seconds, and can be more than 10 seconds, it is usually a detection cycle of every 5 seconds, and the first driving device 302 operates once every 5 seconds.

[0087] In the disclosed embodiment, in step three, when the area of ​​the pore 501 of the skin 500 at the slit 600 is already the smallest during the adjustment process, the first drive device 302 controls the area of ​​the pore 501 of the skin 500 at the slit 600 to return to the maximum; and then continues to adjust.

[0088] In some embodiments, the vibration detection device includes an angle sensor, which is disposed in the slave sail 200. The angle sensor cooperates with the control module to monitor the angle change and change frequency of the slave sail 200. Normally, the slave sail 200 has a natural vibration of 0.5-1.5 Hz during operation. However, when vortex shedding occurs, the vibration frequency will reach 2-5 Hz, accompanied by an angle change of plus or minus 1-2 degrees. When the vibration caused by vortex shedding is relatively strong, the vibration frequency may even exceed 5 Hz, and the angle change may reach plus or minus 3 degrees, or even higher.

[0089] In view of this situation, the maximum threshold of vibration is set to 3 Hz and the minimum threshold is set to 1.5 Hz in the control module; as long as the vibration frequency exceeds 3 Hz, the control module controls the first driving device 302 to control the skin 500 to weaken the vortex shedding until the vibration frequency is less than the minimum threshold of 1.5 Hz.

[0090] In some embodiments, the vibration detection device includes an acceleration sensor, which is arranged in the main sail 100, or in the slave sail 200, or in both the main sail 100 and the slave sail 200. The acceleration sensor detects the positive and negative changes of acceleration to determine the vibration frequency, and the magnitude of the acceleration is used to determine the influence of the vibration caused by vortex shedding on the force of the main sail 100 and the slave sail 200. Similarly, the maximum threshold of vibration is set to 3Hz and the minimum threshold is set to 1.5Hz in the control module; as long as the vibration frequency of the main sail 100 or the slave sail 200 exceeds 3Hz, the first drive device 302 is controlled to control the skin 500 to act to weaken the vortex shedding. The vibration frequencies of the main sail 100 and the slave sail 200 that need to be weakened are both less than the minimum threshold of 1.5Hz.

[0091] In some embodiments, the vibration detection device includes a simple sensor that monitors changes in vibration frequency.

[0092] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A method for reducing the effects of vortex shedding for a rigid twin sail, characterized in that: The rigid double sail comprises a main sail, a follower sail, an adjusting device and a tensioning device; There is a slit between the main sail and the secondary sail, at least one skin is arranged between the trailing edge of the main sail and the leading edge of the secondary sail, and a plurality of groups of pores of different sizes are arranged on the skin; The adjustment device comprises a first driving device, which adjusts any group of the apertures in the skin to be in the position of a slit; The tensioning device includes a second drive device, and the second drive device controls the tensioning of the skin; The main sail and / or the secondary sail are provided with a vibration detection device; the method comprises the following steps: Step 1: monitoring the vibration of the main sail or the slave sail by means of the vibration detection device; Step 2: Set the maximum and minimum vibration thresholds; Step three, when the vibration detection device detects that the vibration of the main sail or the slave sail exceeds a maximum threshold, the first driving device controls the area of ​​the pores in the slit position of the skin to change until the vibration is lower than a minimum threshold.

2. The method for reducing the influence of vortex shedding according to claim 1, characterized in that: The skin is in the shape of an annular belt, and two ends of the skin are respectively arranged inside the main sail and the secondary sail, and the main sail and the secondary sail are both provided with openings for the skin to pass through.

3. The method for reducing the influence of vortex shedding according to claim 2, characterized in that: The openings are respectively arranged at upper and lower sides of the rear edge of the main sail and the front edge of the trailing sail.

4. The method for reducing the influence of vortex shedding according to claim 2, characterized in that: The opening is clearance-matched with the skin.

5. The method for reducing the influence of vortex shedding according to claim 4, characterized in that: An elastic filler is arranged at the opening, and the elastic filler is filled between the opening and the skin.

6. The method for reducing the influence of vortex shedding according to claim 2, characterized in that: The adjusting device also includes a first roller, which is rotatably arranged in the mainsail; the first driving device is a rotationally driven device, which is arranged in the mainsail and is transmission-connected to the first roller; the skin passes around the first roller; the first driving device drives the first roller to rotate to control the movement of the skin.

7. The method for reducing the influence of vortex shedding according to claim 6, characterized in that: A plurality of protrusions are evenly distributed around the first roller, and the skin is provided with grooves evenly arranged along the length direction. The protrusions can be embedded in the grooves during the rotation of the first roller.

8. The method for reducing the influence of vortex shedding according to claim 2, characterized in that: The tensioning device also includes a second roller, which is rotatably arranged in the follower sail, and the second driving device is a rotationally driven device, which is arranged in the follower sail and is transmission-connected to the second roller; the skin is wrapped around the second roller, and the cross-section of the second roller is cam-shaped, and the second driving device drives the second roller to rotate to tension the skin.

9. The method for reducing the influence of vortex shedding according to claim 2, characterized in that: The tensioning device also includes a roller, both ends of which are slidably connected in the follower sail, and the sliding direction of the roller is perpendicular to the axial direction of the roller. The second driving device is a linear reciprocating drive, and the second driving device is arranged in the follower sail to connect the roller. The second driving device controls the roller to slide away from or close to the main sail.

10. The method for reducing the influence of vortex shedding according to claim 1, characterized in that: The skin is a linear belt-shaped structure, the trailing edge of the mainsail and the leading edge of the secondary sail are respectively provided with openings, and two ends of the skin are respectively passed through the openings and are arranged in the mainsail and the secondary sail.

11. The method for reducing the influence of vortex shedding according to claim 1, characterized in that: In the step 3, the manner in which the area of ​​the pores in the slit position of the skin is controlled by the first driving device to change is: A multiple adjustment method is adopted, wherein the first driving device is actuated once every N seconds, and each action of the first driving device causes the area of ​​the pores in the slit position of the skin to become smaller; If the vibration is lower than the minimum threshold within N seconds, stop adjusting; The value range of N is 3-10.

12. The method for reducing the influence of vortex shedding according to claim 11, characterized in that: In the step three, when the area of ​​the pores in the slit position of the skin is already the smallest during the adjustment process, the first driving device controls the area of ​​the pores in the slit position of the skin to return to the maximum; and then continues to adjust.

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