Angle of attack control device and passive angle of attack airfoil sail

Abstract

This invention provides an angle-of-attack control device and a passive angle-of-attack airfoil sailboat, belonging to the field of passive angle-of-attack control for rigid sails. The angle-of-attack control device includes an airfoil sail and a rotating mechanism. The airfoil sail includes an airfoil sail surface, a mast, and a base matching the mast. The mast is perpendicular to the base and rotatably connected to the base. The mast is fixedly connected to the bottom of the airfoil sail surface. The rotating mechanism is located at the top of the airfoil sail surface. The rotating mechanism includes a motor and a rotating drum. The motor includes a rotation drive component, a speed-changing component, and an output shaft. The motor is located at the top of the airfoil sail surface, and the output shaft is parallel to the mast and fixedly connected to the rotating drum. This passive angle-of-attack airfoil sailboat includes a double hull and multiple angle-of-attack control devices, which are arranged in an array on the double hull. Using the angle-of-attack control device and passive angle-of-attack airfoil sailboat provided by this invention can solve the problems of excessively large airfoil sail structures, insufficient mainsail area, and insufficient propulsion in existing technologies.

Description

Technical Field

[0001] This invention relates to the field of passive angle of attack control for rigid sails, and particularly to an angle of attack control device and a passive angle of attack airfoil sailboat. Background Technology

[0002] Modern sails mostly employ lift propulsion, based on the lift principle of airfoils. They use airfoil shapes as the cross-sectional shape of the sail. The lift and drag of rigid airfoil sails are significantly affected by the angle of attack, therefore the sail angle needs to be adjusted in real time according to the wind direction to achieve optimal propulsion performance. There are two existing types of angle-of-attack control: active and passive. Active angle-of-attack control uses a wind direction sensor to obtain the incoming flow direction and then controls the mast rotation via a motor to achieve the target angle of attack. Passive angle-of-attack control, on the other hand, allows the mast rotational freedom, and its sail angle of attack control is achieved through other structural components. In a multi-sail system, the interaction between the sails causes the wake of the upstream sail to affect the angle of attack of the downstream sail. There will be a change between the incoming wind direction angle and the wind direction angle passing through the upstream airfoil sail, and the wind direction angle will usually become smaller. Therefore, in order to achieve the best propulsion effect, the sail angles of each sail in a multi-sail system are different, which increases the complexity of the active angle of attack control of each sail in a multi-sail system. Therefore, when using passive angle of attack control, it can automatically correct according to the current incoming wind direction and select the optimal incoming wind angle of attack.

[0003] The existing passive angle-of-attack control technology is a tail-wing type of angle-of-attack control method. A small airfoil sail is designed behind the mainsail. By controlling the angle of attack of the tail-wing airfoil sail, the lift coefficient is changed, thereby changing the torque exerted by the tail wing on the mast, which in turn changes the angle of attack of the mainsail, thus controlling the angle of attack.

[0004] The passive angle-of-attack control technology in the present technology is based on the tail fin. Its structure is too large, which will reduce the area of ​​the mainsail within the limited space of the hull and reduce the propulsion performance of the sail. Summary of the Invention

[0005] This invention provides an angle-of-attack control device and a passive angle-of-attack airfoil sailboat, which solves the problems of excessively large airfoil sail structures, insufficient mainsail area, and inadequate propulsion in existing technologies. The technical solution is as follows:

[0006] In a first aspect, embodiments of the present invention provide an angle-of-attack control device, including an airfoil sail and a rotation mechanism.

[0007] The airfoil includes an airfoil surface, a mast, and a base that matches the mast. The mast is perpendicular to the base and is rotatably connected to the base. The mast is fixedly connected to the bottom of the airfoil surface, and the rotating mechanism is located at the top of the airfoil surface.

[0008] The rotating mechanism includes a motor and a rotating drum. The motor can drive the rotating drum to rotate, and the axis of rotation of the rotating drum is parallel to the mast.

[0009] Optionally, a deflector is provided between the mast and the bottom of the airfoil, and the deflector is arranged parallel to the base.

[0010] Optionally, a flow guide support plate is provided between the rotating mechanism and the top of the airfoil, the flow guide support plate is arranged parallel to the base, and the rotating mechanism is disposed on the flow guide support plate.

[0011] Optionally, the guide plate and the guide support plate are two circular plates with the same diameter.

[0012] Optionally, the rotating mechanism is disposed on the chord of the airfoil.

[0013] Optionally, the rotating mechanism is disposed at the edge of the flow guide support plate.

[0014] Optionally, two rotating mechanisms are provided, and they are respectively located at both ends of the airfoil sail chord.

[0015] Optionally, the mast and the airfoil can be detachably connected.

[0016] Secondly, embodiments of the present invention provide a passive angle-of-attack wing-shaped sailboat, including the angle-of-attack control device described in any of the preceding claims, and also including a catamaran, with the base disposed on the catamaran.

[0017] Optionally, multiple airfoils and rotating mechanisms are provided, and the multiple airfoils are arranged in an array on the catamaran.

[0018] The beneficial effects of the technical solutions provided in the embodiments of the present invention include at least the following:

[0019] The present invention provides an angle-of-attack control device and a passive angle-of-attack airfoil sail. By controlling the speed and direction of rotation of the rotating mechanism set on the airfoil sail, the angle of attack of the incoming wind direction can be controlled, so that the airfoil sail can obtain the best propulsion force. It eliminates the need for a tail fin design, saves a lot of space on the hull, and allows for the design of the airfoil sail surface to be as large as possible, further improving the propulsion force received by the airfoil sail under the action of wind. It can effectively solve the problems of excessively large airfoil sail structure, insufficient mainsail area, and insufficient propulsion force in the prior art. Attached Figure Description

[0020] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0021] Figure 1 This is a force diagram of the airfoil provided in an embodiment of the present invention;

[0022] Figure 2 This is provided by the embodiments of the present invention. Figure 1 Enlarged view of point A;

[0023] Figure 3 This is a schematic diagram of the airfoil sail pressure provided in an embodiment of the present invention;

[0024] Figure 4 This is a schematic diagram of the forces acting on a passive angle-of-attack airfoil provided in an embodiment of the present invention;

[0025] Figure 5 This is a schematic diagram of a passive angle-of-attack wing-type sailboat provided in an embodiment of the present invention.

[0026] In the diagram: 1-Airfoil sail; 11-Airfoil sail surface; 12-Mast; 13-Base; 14-Guide plate; 15-Guide support plate; 2-Rotating mechanism; 21-Motor; 211-Rotating drive component; 212-Speed ​​change component; 213-Output shaft; 22-Rotating drum; 3-Catamaran. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

[0028] Figure 1 This is a force diagram of the airfoil provided in an embodiment of the present invention; Figure 2 This is provided by the embodiments of the present invention. Figure 1 Enlarged view of point A; Figure 3 This is a schematic diagram of the airfoil sail pressure provided in an embodiment of the present invention; Figure 4 This is a schematic diagram of the forces acting on a passive angle-of-attack airfoil provided in an embodiment of the present invention; Figure 5 This is a schematic diagram of a passive angle-of-attack wing-type sailboat provided in an embodiment of the present invention.

[0029] like Figures 1 to 3The angle of attack control device shown includes an airfoil 1 and a rotating mechanism 2. The airfoil 1 includes an airfoil surface 11, a mast 12 and a base 13 that matches the mast 12. The mast 12 is perpendicular to the base 13 and the mast 12 and the base 13 are rotatably connected. The mast 12 is fixedly connected to the bottom of the airfoil surface 11. The rotating mechanism 2 is located on the top of the airfoil surface 11.

[0030] The rotating mechanism 2 includes a motor 21 and a rotating drum 22. The motor 21 can drive the rotating drum 22 to rotate, and the axis of rotation of the rotating drum 22 is parallel to the mast 12.

[0031] For example, in an embodiment of the present invention, the rotating mechanism 2 includes a motor 21 and a rotating drum 22. The motor 21 includes a rotation drive component 211, a speed change component 212 and an output shaft 213. The motor 21 is disposed on the top of the airfoil sail 11. The output shaft 213 is parallel to the mast 12 and is fixedly connected to the center of one end face of the rotating drum 22. The rotation drive component 211 can drive the rotating drum 22 to rotate, and the speed change component 212 can change the rotation speed of the rotating drum 22.

[0032] The mast 12 penetrates the airfoil 11 along its length and is fixedly connected to it in the direction of rotation. The joint point between the mast 12 and the airfoil 11 is located on the chord line of the airfoil 11. The cross-section of the airfoil 11 is selected as the NACA0018 airfoil, which is a symmetrical arc structure with its chord line as the axis of symmetry. When the rotating mechanism 2 is not working, the airfoil 1 automatically maintains a zero angle of attack state. When the rotating mechanism 2 is working, such as... Figure 1 As shown, the force analysis diagram of the airfoil 1 is shown. The airfoil is mainly subjected to two torques. One is the torque b formed by the resultant aerodynamic force on the surface of the airfoil 11, the magnitude of which is related to the angle of attack a of the incoming wind direction. The other is the torque c generated by the rotating mechanism 2 based on the Magnus effect, the magnitude and direction of which are related to the rotation speed and rotation direction of the rotating mechanism 2.

[0033] During operation, in order to maintain balance, the airfoil 11, since the mast 12 and the base 13 are freely rotatably connected, when the rotation speed and direction of the rotating mechanism 2 are controlled to control the torque c generated by the Magnus effect, the mast 12 will drive the airfoil 11 to automatically rotate to a suitable angle to achieve a suitable angle of attack a to change the torque b, thereby balancing the force on itself. Thus, the purpose of controlling the angle of attack a by controlling the rotation speed and direction of the rotating mechanism 2 is achieved.

[0034] Compared to existing technologies that use a tail fin-based angle-of-attack control method, which has an excessively large structure and results in a smaller mainsail area within the limited hull space, thus reducing the propulsion performance of the sail, the angle-of-attack control device provided by this invention can control the angle of attack of the incoming wind direction by controlling the rotation speed and direction of the rotating mechanism 2 set on the airfoil 1. This allows the airfoil 1, which serves as the mainsail, to obtain optimal propulsion. It eliminates the need for a tail fin design, saving a significant amount of hull space and allowing for a larger airfoil surface 11. This further enhances the propulsion force received by the airfoil 1 under wind conditions, effectively solving the problems of excessively large airfoil structures, insufficient mainsail area, and inadequate propulsion in existing technologies.

[0035] Optionally, a deflector 14 is provided between the mast 12 and the bottom of the airfoil 11, with the deflector 14 positioned parallel to the base 13.

[0036] Exemplary, in embodiments of the present invention, such as Figure 3 and Figure 4 As shown, the airfoil 11 is divided into a high-pressure zone f and a low-pressure zone g by a chord k between the leading edge d and the trailing edge e. According to Bernoulli's principle, the direction of the airflow will generate lift h and drag i on the airfoil 11. The propulsion j of the airfoil 11 generated by the incoming airflow is provided by the lift h generated by Bernoulli's principle. The greater the pressure difference between the high-pressure zone f and the low-pressure zone g, the greater the propulsion j of the airfoil. At the bottom edge of the airfoil 11, because the low-pressure zone g and the high-pressure zone f are close, the surface fluid will have a velocity component from the high-pressure zone f to the low-pressure zone g. At the same time, it will reduce the pressure difference between the high-pressure zone f and the low-pressure zone g on the edge of the sail, thus reducing the propulsion performance of the edge sail. By setting a guide plate 14 at the bottom of the airfoil 11, the high-pressure zone f and the low-pressure zone g of the sail in the edge area can be effectively separated, thereby increasing the propulsion j of the airfoil 11.

[0037] Optionally, a flow guide support plate 15 is provided between the rotating mechanism 2 and the top of the airfoil 11. The flow guide support plate 15 is set parallel to the base 13, and the rotating mechanism 2 is set on the flow guide support plate 15.

[0038] Exemplary, in embodiments of the present invention, such as Figure 3 and Figure 4As shown, at the top edge of the airfoil sail 11, the low-pressure zone g and the high-pressure zone f are relatively close, causing the surface fluid to have a velocity component from the high-pressure zone f to the low-pressure zone g. This also reduces the pressure difference between the high-pressure zone f and the low-pressure zone g on the edge sail, thus decreasing the propulsion performance of the edge sail. By setting a flow guide support plate 15 on the top of the airfoil sail 11, the high-pressure zone f and the low-pressure zone g on the edge sail can be effectively separated, increasing the propulsion force j on the airfoil sail 11. Simultaneously, mounting the rotating mechanism 2 on the flow guide support plate 15 provides effective support for the rotating mechanism 2, improving the stability of this angle-of-attack control device.

[0039] Optionally, the flow guide plate 14 and the flow guide support plate 15 are two circular plates with the same diameter.

[0040] Exemplary, in embodiments of the present invention, such as Figure 3 and Figure 4 As shown, the purpose of setting the guide vane 14 and the guide support plate 15 is to separate the high-pressure zone f and the low-pressure zone g of the edge sail. The design of the guide vane shape is optimal based on the surface pressure field distribution. The circular design can take into account the pressure field distribution of the leading edge d and the two sides of the wing surface, further improving the thrust j of the airfoil sail 11. At the same time, it is easy to process and reduces the manufacturing cost of this angle of attack control device. The guide vane 14 and the guide support plate 15 have the same diameter to minimize the space occupied by the entire device. In the actual application of this angle of attack control device, it can save space and improve the practicality of this angle of attack control device.

[0041] Optionally, the rotating mechanism 2 is located on the chord of the airfoil 11.

[0042] Exemplary, in embodiments of the present invention, such as Figure 1 and Figure 3 As shown, according to the Magnus effect, when the same direction and speed are applied to the rotating drum 22, the lateral force m generated by the rotating drum 22 is the largest when the rotating mechanism 2 is set on the chord k of the airfoil sail 11. This increases the maximum torque generated by the rotating drum 22 on the airfoil sail 1, thereby enabling it to cope with the force generated by the wind direction on the airfoil sail 11 under faster flow speeds. By setting the rotating mechanism 2 on the chord k of the airfoil sail 11, the applicability of this angle of attack control device is improved.

[0043] Optionally, the rotating mechanism 2 is disposed at the edge of the flow guide support plate 15.

[0044] Exemplary, in embodiments of the present invention, such as Figure 1 and Figure 3As shown, placing the rotating mechanism 2 at the edge of the flow guide support plate 15 can increase the lever arm length of the lateral force m generated by the rotating cylinder 22, further increasing the maximum torque generated by the rotating cylinder 22 on the airfoil sail 1, thereby being able to cope with the force generated by the wind direction on the airfoil sail surface 11 under faster flow speed. By placing the rotating mechanism 2 at the edge of the flow guide support plate 15, the applicability of this angle of attack control device is further improved.

[0045] Optionally, there are two rotating mechanisms 2, which are respectively located at both ends of the chord of the airfoil 11.

[0046] Exemplary, in embodiments of the present invention, such as Figure 1 and Figure 3 As shown, on the flow guide support plate 15, two rotating mechanisms 2 with opposite rotation directions are respectively set at both ends of the chord line of the airfoil sail 11. The two rotating mechanisms 2 can generate opposite lateral forces m at the same time, which further increases the maximum torque generated by the rotating cylinder 22 on the airfoil sail 1, thereby being able to cope with the force generated by the wind direction on the airfoil sail 11 under faster flow speed. By setting two rotating mechanisms 2 at both ends of the chord line k of the airfoil sail 11, the applicability of this angle of attack control device is further improved.

[0047] Optionally, the mast 12 and the airfoil 11 can be detachably connected.

[0048] For example, in this embodiment of the invention, the mast 12 and the airfoil sail 11 are detachably connected. During the use of the device, the airfoil sail 11 will be eroded by seawater and wind. After a long period of use, it will affect the propulsion force provided to the device. At this time, the airfoil sail 11 can be disassembled and replaced. The detachable connection between the mast 12 and the airfoil sail 11 improves the applicability of this angle of attack control device.

[0049] For example, in an embodiment of the present invention, a design method is provided for determining the position of the mast 12 and the parameters of the rotating drum 22 based on the incoming wind direction and the size of the airfoil sail 11. The method is as follows:

[0050] The aerodynamic torque b on mast 12:

[0051] b = 0.5ρV 2 MHC l (a)L cos a+0.5ρV 2 MHC d (a)L sin a+0.5ρV 2 M 2 HC m (a) (1)

[0052] Where α is the angle of attack, and ρ is the density of the incoming fluid, taken as 1.29 kg / m³. 3V is the incoming flow velocity; L is the distance between the midpoint of the chord of mast 12 and airfoil 11; M is the chord length of airfoil 11; H is the spanwise height of airfoil 11; C l (a) is the lift coefficient of the airfoil surface at an angle of attack of α; C d (a) is the drag coefficient of the airfoil surface at an angle of attack of α; C m (a) is the moment coefficient of the airfoil sail at an angle of attack of α. C l (a) C d (a) and C m (a) It can be obtained from the Airfoil Tools Airfoil Database.

[0053] Determining L determines the position of mast 12. The angle of attack α of airfoil 11 ranges from 5 to 15 degrees. Choosing an appropriate L allows the torque b to increase within the working range.

[0054] Based on the maximum calculated torque b under typical operating conditions, select appropriate parameters for the rotary drum 22.

[0055] The torque c generated by the rotating drum 22 on the mast 12 is:

[0056] c=F2(0.5E1+0.5ML)cos a+F1(0.5E2+0.5M+L)cos a

[0057] F1=0.5ρV 2 E2H2C l前置 (n,V C )

[0058] F2=0.5ρV 2 E1H1C l后置 (n,V C (2)

[0059] Where E1 is the diameter of the front rotating drum; E2 is the diameter of the rear rotating drum; H1 is the height of the front rotating drum; H2 is the height of the rear rotating drum; F1 is the lateral force of the rear rotating drum; F2 is the lateral force of the front rotating drum; n is the rotational speed of the rotating drum sail; V C C is the linear velocity of the rotating drum. l前置 (n, V) C () is a rotational speed of n and a linear velocity of V. C The lift coefficient of the front rotating drum at that time; C l后置 (n, V) C () is a rotational speed of n and a linear velocity of V. C The lift coefficient of the rear rotating drum at that time; C l前置 (n, V) C ) and C l后置 (n, V) CThe data was obtained from the literature "Numerical Study on Aerodynamic Performance of Spinner Sails". It should be noted that the aforementioned front and rear spinners correspond to... Figure 1 The two rotating drums in the middle.

[0060] Based on the maximum rotational speed n of the rotating drum 22, appropriate rotating drum diameters E1 and E2 are selected. The lift coefficient of the rotating drum 22 is determined in the literature "Numerical Study on Aerodynamic Performance of Rotary Sail". Furthermore, an appropriate rotating drum height is selected so that the calculated torque c of the rotating drum 22 on the mast 12 is equal to the maximum value of the torque b.

[0061] For example, in an embodiment of the present invention, a design embodiment provided through the above design method has the following specific design parameters:

[0062] Design an angle-of-attack control device for an airfoil 11 with a chord length of 10 meters and a height of 30 meters under an incoming flow rate of 8 m / s.

[0063] Calculate the Reynolds number of the airfoil:

[0064]

[0065] Among them, R e is the Reynolds number; μ is the aerodynamic viscosity coefficient, taken as 1.87 × 10⁻⁶. -5 Pa·s;o is the characteristic length, which in this invention is the length of the chord k of the airfoil sail.

[0066] The Reynolds number calculated in this embodiment is: 5.5 × 10⁻⁶ 6

[0067] The aerodynamic coefficients of the airfoil sail at various angles of attack α were obtained from the Airfoil Tools Airfoil Database. The operating conditions of the airfoil sail are angles of attack from 5 degrees to 15 degrees.

[0068]

[0069] Calculate the position of mast 12:

[0070] The mast 12 is pre-set to be located at a distance of d30% of the chord length from the leading edge, so L = 2m.

[0071] Substituting into the formula, we can obtain the aerodynamic torque b on mast 12:

[0072]

[0073] The torque b increases at all angles of attack a, and each value is positive, which meets the requirements. Mast 12 is positioned at 30% of the chord length from the leading edge d.

[0074] Calculate the structural parameters of the rotating drum 22:

[0075] The maximum rotational speed of the rotating drum 22 is set to 3 r / s, and the diameter of the rotating drum 22 is pre-selected as 2 meters. The lift coefficient data can be obtained from the reference "Numerical Study on Aerodynamic Performance of Rotary Sail".

[0076] C l (3,20)=5.92

[0077] Let b = c, and substitute the parameters into formula (2) to get:

[0078] H1 = H2 = 6.6m

[0079] Therefore, the structural parameters of the rotating drum 22 are: diameter 2 meters, height 6.6 meters. The angle of attack α can be adjusted by controlling the rotational speed of the motor 21.

[0080] The airfoil cross-section is selected from the NACA series; in this embodiment, the NACA0018 airfoil is chosen. To ensure that the airfoil sail 11 automatically maintains a zero angle of attack when the rotor 22 is not rotating, the mast 12 is positioned close to the leading edge of the airfoil to ensure that, as... Figure 1 When operating at the angle of attack 'a' shown, the torque 'b' exerted by the incoming wind on the mast 12 is counterclockwise, and the torque 'b' increases accordingly with the increase of angle of attack 'a'. The relative positions of the mast 12 and the airfoil sail 11 vary slightly depending on the airfoil cross-section shape. The torque 'b' of the airfoil sail 11 at various angles of attack 'a' and its position on the mast 12 can be obtained through experiments and numerical simulations to select a suitable relative position for the mast 12. Determining the position of the mast 12 determines the curve of torque 'b' versus angle of attack 'a', and thus determines the torque 'c' required by the rotary drum 22 to maintain different angles of attack 'a'. The lateral force 'm' perpendicular to the incoming flow direction on the rotary drum 22 can be calculated using Jukovsky's theorem. By selecting a rotary drum 22 of appropriate size and rotational speed, sufficient force can be provided by the rotary drum 22 to maintain the target angle of attack 'a'.

[0081] like Figures 4 to 5 The passive angle-of-attack wing-type sailboat shown includes any one of the angle-of-attack control devices 1-8, and also includes a catamaran 3, with a base 13 mounted on the catamaran 3.

[0082] For example, in this embodiment of the invention, the angle of attack control device is installed on the catamaran 3, and the base 13 is fixedly connected to the deck of the catamaran 3. The propulsion force generated by the aforementioned incoming wind direction on the airfoil sail 11 is converted into the propulsion force on the catamaran 3.

[0083] Compared to existing passive angle-of-attack wing-shaped sailboats with tail fins, the passive angle-of-attack wing-shaped sailboat provided in this embodiment of the invention eliminates the tail fin structure, reduces the volume of the angle-of-attack control device, and allows for the use of a larger area of ​​airfoil sail 11 on a catamaran 3 of the same size, thereby generating greater propulsion for the catamaran 3.

[0084] Optionally, multiple airfoil sails 1 and rotating mechanisms 2 are provided, and the multiple airfoil sails 1 are arranged in an array on the catamaran 3.

[0085] For example, in this embodiment of the invention, multiple airfoil sails 1 are arranged in an array on the catamaran 3. On a catamaran 3 of the same size, the total area of ​​multiple small airfoil sails 11 is larger than that of a single large airfoil sail 11. By setting multiple airfoil sails 1, the total area of ​​the airfoil sails 11 on the catamaran 3 can be increased. At the same time, setting multiple airfoil sails 1 facilitates the assembly of this passive angle-of-attack airfoil sailboat and makes it more convenient to replace the airfoil sails 11 when necessary.

[0086] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains. The terms “first,” “second,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0087] The above description is merely an optional embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An angle-of-attack control device, characterized in that, It includes an airfoil (1) and a rotating mechanism (2). The airfoil (1) includes an airfoil surface (11), a mast (12) and a base (13) that matches the mast (12). The mast (12) is perpendicular to the base (13). The mast (12) and the base (13) are rotatably connected. The mast (12) is fixedly connected to the bottom of the airfoil surface (11). The rotating mechanism (2) is located at the top of the airfoil surface (11). The rotating mechanism (2) includes a motor (21) and a rotating drum (22). The motor (21) can drive the rotating drum (22) to rotate. The axis of rotation of the rotating drum (22) is parallel to the mast (12). A flow guide support plate (15) is provided between the rotating mechanism (2) and the top of the airfoil (11). The flow guide support plate (15) is arranged parallel to the base (13). The rotating mechanism (2) is arranged on the flow guide support plate (15) to effectively separate the high pressure area and the low pressure area of ​​the top edge region of the airfoil (11) and improve the propulsion force received by the airfoil (11). The rotating mechanism (2) is located on the chord of the airfoil (11) and on the edge of the guide support plate (15). There are two rotating mechanisms (2) respectively located at both ends of the chord of the airfoil (11) to increase the maximum torque generated by the rotating cylinder (22) on the airfoil (1).

2. The angle-of-attack control device according to claim 1, characterized in that, A guide plate (14) is provided between the mast (12) and the bottom of the airfoil (11), and the guide plate (14) is arranged parallel to the base (13).

3. The angle-of-attack control device according to claim 2, characterized in that, The flow guide plate (14) and the flow guide support plate (15) are two circular plates with the same diameter.

4. The angle-of-attack control device according to claim 1, characterized in that, The mast (12) and the airfoil (11) are detachably connected.

5. A passive angle-of-attack wing-shaped sailboat, comprising the angle-of-attack control device as described in any one of claims 1 to 4, characterized in that, It also includes a catamaran (3), on which the base (13) is mounted.

6. A passive angle-of-attack wing-type sailboat according to claim 5, characterized in that, Multiple airfoils (1) and multiple rotating mechanisms (2) are provided, and multiple airfoils (1) are arranged in an array on the catamaran (3).

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