Flexible swing wing of underwater bionic propeller and flexible swing wing design method

Abstract

The invention relates to the technical field of swing wing structure design, in particular to a flexible swing wing of an underwater bionic propeller and a flexible swing wing design method.The flexible swing wing is provided with a flexible swing wing body and is characterized in that a driving rod mounting hole is formed in the front end of the flexible swing wing body, and a driving rod is inserted into the driving rod mounting hole; at least two parallel beam holes are formed in the portion, on the rear side of the driving rod mounting hole, of the flexible swing wing body, based on the S-shaped deformation rule of parallel beams, when the flexible swing wing is subjected to the hydrodynamic force effect, more deformation of the flexible swing wing occurs at the position close to the front half portion of the wing section, a certain attack angle is formed, small deformation of the rear half portion of the wing section is kept, and therefore the flexible swing wing is more flexible. Therefore, the flexible swing wing keeps a good hydrodynamic geometrical shape, and the hydrodynamic performance is improved.

Description

Technical Field

[0001] The invention relates to the technical field of swing wing structure design, in particular to a flexible swing wing of an underwater bionic propeller and a flexible swing wing design method. Background Art

[0002] As we all know, the swing wing is a high-efficiency, high-maneuverability bionic propulsion device, which can be used for ship swing wing thrust increase or drive oscillating flow turbines. As a propulsion device, the swing wing can be roughly divided into three types according to the driving form: the first is a fully active driven rigid wing; the second is a semi-active spring-constrained rigid wing; the third is a flexible swing wing.

[0003] The first type is a fully actively driven rigid wing, the best form of which is a combined heave + pitch motion, with a certain phase difference between the two degrees of freedom. This requires a complex mechanism to achieve the linkage drive of the two degrees of freedom, or directly adopt independent drive and linkage control of the two degrees of freedom. Both of these methods make the drive mechanism of the swing wing complex, difficult to achieve, and reduce reliability. Some researchers have also simplified the drive mechanism by limiting one of the degrees of freedom, such as a swing wing with pure heave motion, or a swing wing with pure pitch motion, but these designs have greatly reduced the performance of the swing wing.

[0004] The second type is a semi-active spring-constrained rigid wing, which is also in the best form of a combined heave + pitch motion, but it usually uses active drive for its heave motion, while the pitch motion is controlled by a combination of torsion spring constraints and hydrodynamic pitch torque. The latter is a passive control that simplifies the drive mechanism, but there is also another problem, that is, in an underwater working environment, the torsion spring is easily corroded and fatigued.

[0005] The third type is the flexible swing wing. Because it uses flexible materials such as rubber or silicone, it can adapt to certain working requirements by deforming under the action of hydrodynamics, so it only needs to be driven by heave motion. In this way, the drive mechanism is simplified and it also has good anti-fatigue performance. However, there are also problems with the flexible swing wing. The main reason is that its deformation law is often difficult to achieve the optimal geometric shape through design, resulting in reduced hydrodynamic performance of the flexible swing wing. Summary of the invention

[0006] The purpose of the present invention is to solve the deficiencies of the above-mentioned prior art and to provide a flexible swing wing and a flexible swing wing design method for an underwater bionic propulsion device with a simple structure that utilizes the deformation characteristics of parallel beams to control the deformation law of the flexible swing wing, thereby improving the hydrodynamic performance of the flexible swing wing.

[0007] The technical solution adopted by the present invention to solve its technical problem is: A flexible wing of an underwater bionic thruster is provided with a flexible wing body. It is characterized in that a driving rod mounting hole is provided at the front end of the flexible wing body, a driving rod is inserted into the driving rod mounting hole, and at least two parallel beam holes are provided on the flexible wing body behind the driving rod mounting hole.

[0008] Both end faces of the flexible wing body of the present invention are provided with flexible material sealing layers, and the flexible material sealing layers cover both end faces of the flexible wing body to seal the parallel beam holes.

[0009] The wing surface of the flexible wing body of the present invention is wrapped with a reinforcing fiber layer to prevent tearing when the flexible wing deforms.

[0010] The driving rod mounting hole of the present invention is set as a special-shaped hole, and the part of the driving rod inserted into the driving rod mounting hole is matched with the special-shaped hole, which increases the connection area between the driving rod and the wing, provides sufficient rigidity for the front part of the wing, improves the adhesion, and the part of the driving rod extending out of the driving rod mounting hole at one end is cylindrical for easy connection with the driver.

[0011] The driving rod of the present invention is arranged within the range of the leading edge L of the wing, 0.1c < L < 0.2c, where c is the chord length, and the minimum thickness t of the flexible material on the outer edge of the driving rod 0 is not less than 1% of the chord length c.

[0012] The length of the parallel beam hole of the present invention is L 1 , the thickness from the parallel beam hole to the edge of the flexible wing is t 1 , t 1 is not less than 0.5% of the chord length c, the thickness of the support partition between the two parallel beam holes is b 1 , the distance between the parallel beam hole and the driving rod is also b 1 , b 1 ≥2t 1 .

[0013] A design method for a flexible wing of an underwater bionic thruster is characterized in that the steps of the design method are as follows: (1) Determine the wing parameters: Design the wing chord length c, in m, design the span h, in m, design the forward speed V, in m / s, and design the heave motion speed U at the middle position of the heave motion, in m / s; (2) Calculate the hydrodynamic angle θ according to the wing parameters: The formula for the hydrodynamic angle θ is: θ = arctan(U / V). Substitute the parameters in step (1) into the above formula to obtain the hydrodynamic angle θ, in rad; (3) Determine the angle of attack α of the flexible swing wing after deformation and obtain the deformation d of the tail of the swing wing: According to the formula β=θ-α and the formula d=βc, substitute the determined angle of attack α of the flexible swing wing after deformation and the hydrodynamic angle θ in step (2) into the above formula to obtain the deformation d of the tail of the swing wing, in m, and the angle of attack α of the flexible swing wing after deformation, in rad; (4) Calculate the force F on the flexible flap: According to the formula F = ρ(U 2 +V 2 )hcα / 2, substitute the parameters in step (1) and step (3) into the above formula to obtain the flexible flap force F, in N; (5) Determine the elastic modulus of the flexible flap and the number of parallel beam holes to obtain the length of the parallel beam holes as L 1 The thickness from the parallel beam hole to the edge of the flexible swing wing is t 1 Ratio: elastic modulus E of the designed flexible swing wing, unit is MPa, the number of designed parallel beams is N, According to the relation Available Substitute the elastic modulus E of the flexible swing wing, the number of designed parallel beams N, the span h of step (1), the deformation d of the swing wing tail of step (3), and the force F of the flexible swing wing of step (5) into the above formula, and we can get the length of the parallel beam hole as L. 1 The thickness from the parallel beam hole to the edge of the flexible swing wing is t 1 The ratio of (6) Obtain the thickness t from the parallel beam hole to the edge of the flexible swing wing 1 , length L of parallel beam hole 1 , the thickness of the supporting partition between the two parallel beam holes, and the distance b between the parallel beam hole and the driving rod 1 :The design requires the thickness t from the parallel beam hole to the edge of the flexible swing wing 1 Not less than 0.5% of the chord length c. According to step (1), the value of the chord length c is proportional to t 1 Take the value, and then according to step (5), the length of the parallel beam hole is L 1 The thickness from the parallel beam hole to the edge of the flexible swing wing is t 1 The length of the parallel beam hole is obtained by the ratio of 1 , design requirements b 1 ≥2t 1 Therefore, according to the thickness t from the parallel beam hole to the edge of the flexible swing wing 1 For b 1 The thickness t from the parallel beam hole to the edge of the flexible swing wing is finally obtained. 1 , length L of parallel beam hole 1, the thickness of the supporting partition between the two parallel beam holes, and the distance b between the parallel beam hole and the driving rod 1 , the thickness from the parallel beam hole to the edge of the flexible swing wing t 1 , length L of parallel beam hole 1 , the thickness of the supporting partition between the two parallel beam holes, and the distance b between the parallel beam hole and the driving rod 1 The unit is mm; (7) Wrapping the reinforcing fiber layer and the flexible material sealing layer: bonding the flexible material sealing layer to the two end surfaces of the flexible swing wing body, the flexible material sealing layer covers the two end surfaces of the flexible swing wing body to seal the parallel beam holes, and the wing surface of the flexible swing wing body is wrapped with the reinforcing fiber layer; (8) Inflation inside the parallel beam hole: Pressurize and inflate the inside of the parallel beam hole to balance the external water pressure.

[0014] In step (7) of the present invention, the thickness of the flexible material sealing layer is 1.5%-2.5% of the chord length, and the thickness of the reinforcing fiber layer is 1.5%-2.5% of the chord length; In step (8) of the present invention, the internal air pressure of the parallel beam hole is the same as the external water pressure, which is used to balance the external water pressure and prevent the parallel beam hole from being sunken due to the water pressure.

[0015] The present invention adopts the above structure and method, and has the advantages of simple structure, utilizing the deformation characteristics of parallel beams to control the deformation law of the flexible swing wing, thereby improving the hydrodynamic performance of the flexible swing wing, etc. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a schematic diagram of the structure of the present invention.

[0017] Figure 2 It is a structural schematic diagram of the driving rod of the present invention.

[0018] Figure 3 It is a structural diagram of the flexible swing wing without parallel beam hole structure of the present invention.

[0019] Figure 4 It is a structural diagram of a flexible swing wing with a parallel beam hole structure of the present invention.

[0020] Figure 5 It is the deformation state diagram of the flexible swing wing, where the dotted line is the original wing shape and the solid line is the wing shape after force deformation.

[0021] Figure 6 It is a deformation state diagram of the flexible swing wing under the action of hydrodynamic force. The long dashed line is the original flexible swing wing, the solid line is the geometric deformation of the flexible swing wing of this patent, and the short dashed line is the ideal rigid airfoil with a certain angle of attack.

[0022] Reference numerals: flexible wing body 1, drive rod 2, parallel beam holes 3, flexible material sealing layer 4, reinforcing fiber layer 5. Detailed implementation manners

[0023] The present invention will be further described below in conjunction with the accompanying drawings: As shown in the accompanying drawings, a flexible wing of an underwater bionic thruster is provided with a flexible wing body 1. It is characterized in that a drive rod mounting hole is provided at the front end of the flexible wing body 1, a drive rod 2 is inserted into the drive rod mounting hole, and at least two parallel beam holes 3 are provided on the flexible wing body 1 behind the drive rod mounting hole.

[0024] The above drive rod 2 and the drive rod mounting hole are adhesively bonded by glue or directly embedded inside the drive rod mounting hole.

[0025] Furthermore, flexible material sealing layers 4 are provided on both end faces of the flexible wing body 1, and the flexible material sealing layers 4 cover both end faces of the flexible wing body 1 to seal the parallel beam holes 3.

[0026] Furthermore, the wing surface of the flexible wing body 1 is wrapped with a reinforcing fiber layer 5 to prevent tearing when the flexible wing deforms.

[0027] Furthermore, the drive rod mounting hole is set as a special-shaped hole, and the part of the drive rod 2 inserted into the drive rod mounting hole fits with the special-shaped hole, increasing the connection area between the drive rod 2 and the wing, providing sufficient rigidity for the front part of the wing, improving the adhesive force. The part of the drive rod 2 extending out of the drive rod mounting hole at one end is cylindrical, facilitating connection with the driver.

[0028] Furthermore, the drive rod 2 is arranged within the range of the leading edge L of the wing, 0.1c < L < 0.2c, where c is the chord length, and the minimum thickness t of the flexible material on the outer edge of the drive rod 2 0 is not less than 1% of the chord length c.

[0029] Furthermore, the length of the parallel beam hole 3 is L 1 , the thickness from the parallel beam hole 3 to the edge of the flexible wing is t 1 , t 1 is not less than 0.5% of the chord length c, the thickness of the support partition between the two parallel beam holes 3 is b 1 , the distance between the parallel beam hole 3 and the drive rod 2 is also b 1 , b 1 ≥2t 1 .

[0030] A design method for a flexible wing of an underwater bionic thruster is characterized in that the design method steps are as follows: (1) Determine the parameters of the swing wing: design swing wing chord length c, in meters, design span h, in meters, design forward speed V, in meters per second, and design heave speed U at the middle position of heave motion, in meters per second; (2) Calculate the hydrodynamic angle θ based on the flap parameters: The formula for the hydrodynamic angle θ is: θ = arctan (U / V). Substitute the parameters in step (1) into the above formula to obtain the hydrodynamic angle θ, in rad; (3) Determine the angle of attack α of the flexible swing wing after deformation and obtain the deformation d of the tail of the swing wing: According to the formula β=θ-α and the formula d=βc, substitute the determined angle of attack α of the flexible swing wing after deformation and the hydrodynamic angle θ in step (2) into the above formula to obtain the deformation d of the tail of the swing wing, in m, and the angle of attack α of the flexible swing wing after deformation, in rad; (4) Calculate the force F on the flexible flap: According to the formula F = ρ(U 2 +V 2 )hcα / 2, substitute the parameters in step (1) and step (3) into the above formula to obtain the flexible flap force F, in N; (5) Determine the elastic modulus of the flexible swing wing and the number of parallel beam holes 3 to obtain the length of the parallel beam hole 3 as L 1 The thickness of the parallel beam hole 3 to the edge of the flexible swing wing is t 1 Ratio: elastic modulus E of the designed flexible swing wing, unit is MPa, the number of designed parallel beams is N, According to the relation Available Substitute the elastic modulus E of the flexible swing wing, the number of designed parallel beams N, the span h in step (1), the deformation d of the swing wing tail in step (3), and the force F on the flexible swing wing in step (5) into the above formula, and we can get the length of the parallel beam hole 3 as L. 1 The thickness of the parallel beam hole 3 to the edge of the flexible swing wing is t 1 The ratio of (6) Obtain the thickness t from the parallel beam hole 3 to the edge of the flexible swing wing 1 , the length L of the parallel beam hole 3 1 , the thickness of the supporting partition between the two parallel beam holes 3, the distance b between the parallel beam hole 3 and the driving rod 2 1 :The design requires the thickness t from the parallel beam hole 3 to the edge of the flexible swing wing 1 Not less than 0.5% of the chord length c. According to step (1), the value of the chord length c is proportional to t 1 The length of the parallel beam hole 3 obtained in step (5) is L 1 The thickness of the parallel beam hole 3 to the edge of the flexible swing wing is t1 The length of the parallel beam hole 3 is obtained by the ratio of 1 , design requirements b 1 ≥2t 1 Therefore, according to the thickness t from the parallel beam hole 3 to the edge of the flexible swing wing 1 For b 1 The thickness t from the parallel beam hole 3 to the edge of the flexible swing wing is finally obtained. 1 , the length L of the parallel beam hole 3 1 , the thickness of the supporting partition between the two parallel beam holes 3, the distance b between the parallel beam hole 3 and the driving rod 2 1 , the thickness t from the parallel beam hole 3 to the edge of the flexible swing wing 1 , the length L of the parallel beam hole 3 1 , the thickness of the supporting partition between the two parallel beam holes 3, the distance b between the parallel beam hole 3 and the driving rod 2 1 The unit is mm; (7) Wrapping the reinforcing fiber layer 5 and the flexible material sealing layer 4: The flexible material sealing layer 4 is bonded to both end surfaces of the flexible swing wing body 1. The flexible material sealing layer 4 covers the both end surfaces of the flexible swing wing body 1 to seal the parallel beam holes 3. The wing surface of the flexible swing wing body 1 is wrapped with the reinforcing fiber layer 5. (8) Inflation inside parallel beam hole 3: Pressurize and inflate the inside of parallel beam hole 3 to balance the external water pressure.

[0031] Furthermore, in step (7), the thickness of the flexible material sealing layer is 1.5%-2.5% of the chord length, and the thickness of the reinforcing fiber layer is 1.5%-2.5% of the chord length; Furthermore, in step (8), the internal air pressure of the parallel beam holes is the same as the external water pressure, which is used to balance the external water pressure and prevent the parallel beam holes from being sunken due to the water pressure.

[0032] An example of the design method is as follows: (1) Determine the parameters of the swing wing: the swing wing chord length c = 0.5 m, span h = 2 m, forward speed V = 1 m / s, and the heave speed U = 0.5 m / s at the middle position of the heave motion; (2) Calculate the hydrodynamic angle θ based on the flap parameters: The formula for the hydrodynamic angle θ is: θ = arctan (U / V). Substitute the parameters in step (1) into the above formula, and the hydrodynamic angle θ = arctan (U / V) = 0.46 rad; (3) Determine the angle of attack α of the flexible swing wing after deformation and obtain the deformation d of the tail of the swing wing: According to the formula β=θ-α and the formula d=βc, the angle of attack α=8°=0.14rad of the flexible swing wing after deformation and the hydrodynamic angle θ in step (2) are substituted into the above formula to obtain β=θ-α=0.32rad, and then the deformation d=βc=0.16m can be obtained; (4) Calculate the force F on the flexible flap: According to the formula F = ρ(U 2 +V 2 )hcα / 2, substituting the parameters in step (1) and step (3) into the above formula, we can obtain the flexible flap force F=ρ(U2+V2)hcα / 2=200N; (5) Determine the elastic modulus of the flexible swing wing and the number of parallel beam holes 3 to obtain the length of the parallel beam hole 3 as L 1 The thickness of the parallel beam hole 3 to the edge of the flexible swing wing is t 1 Ratio: The elastic modulus of the designed flexible swing wing is E=100MPa, the number of parallel beams is N=2, According to the relation Available Substitute the elastic modulus E of the flexible swing wing, the number of designed parallel beams N, the span h in step (1), the deformation d of the swing wing tail in step (3), and the force F on the flexible swing wing in step (5) into the above formula, and we can get the length of the parallel beam hole 3 as L. 1 The thickness of the parallel beam hole 3 to the edge of the flexible swing wing is t 1 The ratio is 32; (6) Obtain the thickness t from the parallel beam hole 3 to the edge of the flexible swing wing 1 , the length L of the parallel beam hole 3 1 , the thickness of the supporting partition between the two parallel beam holes 3, the distance b between the parallel beam hole 3 and the driving rod 2 1 :The design requires the thickness t from the parallel beam hole 3 to the edge of the flexible swing wing 1 Not less than 0.5% of the chord length c. According to step (1), the value of the chord length c is proportional to t 1 The length of the parallel beam hole 3 obtained in step (5) is L 1 The thickness of the parallel beam hole 3 to the edge of the flexible swing wing is t 1 The length of the parallel beam hole 3 is obtained by the ratio of 1 , design requirements b 1 ≥2t 1 Therefore, according to the thickness t from the parallel beam hole 3 to the edge of the flexible swing wing 1 For b 1The thickness t from the parallel beam hole 3 to the edge of the flexible swing wing is finally obtained. 1 , the length L of the parallel beam hole 3 1 , the thickness of the supporting partition between the two parallel beam holes 3, the distance b between the parallel beam hole 3 and the driving rod 2 1 , take t1=0.5%c=2.5mm, then L1=80mm. Design b1=4t1=10mm; (7) Wrapping the reinforcing fiber layer 5 and the flexible material sealing layer 4: The flexible material sealing layer 4 is bonded to both end surfaces of the flexible swing wing body 1. The flexible material sealing layer 4 covers the both end surfaces of the flexible swing wing body 1 to seal the parallel beam holes 3. The wing surface of the flexible swing wing body 1 is wrapped with the reinforcing fiber layer 5. (8) Inflation inside parallel beam hole 3: Pressurize and inflate the inside of parallel beam hole 3 to balance the external water pressure.

[0033] In step (7), the thickness of the flexible material sealing layer is 1.5%-2.5% of the chord length, preferably 0.01 m, and the thickness of the reinforcing fiber layer is 1.5%-2.5% of the chord length, preferably 0.01 m; In the step (8), the internal air pressure of the parallel beam hole is the same as the external water pressure, which is used to balance the external water pressure and prevent the parallel beam hole from being sunken due to the water pressure.

[0034] The above-mentioned flexible material can be made of rubber or silicone, the flexible material sealing layer 4 is made of rubber or silicone, the reinforcing fiber layer 5 is a fabric formed by reinforcing fiber structure and organic fiber or inorganic fiber attached to the surface of the flexible swing wing body 1, and the driving rod 2 and the driving rod mounting hole on the flexible swing wing plate body of the above scheme are designed to be a special-shaped structure, and the special-shaped structure can be Figure 1 and Figure 2 The special-shaped structure in Figure 3-Figure 6 The special-shaped structure in the invention increases the connection area between the driving rod 2 and the swing wing, provides sufficient rigidity for the front part of the swing wing, improves the bonding force, and wraps the reinforcing fiber layer 5 on the surface to improve the fatigue resistance under large deformation conditions without affecting the operation of the parallel beam. Due to the adoption of the above structure and method, based on the S-shaped deformation law of the parallel beam, when the flexible swing wing is subjected to the hydrodynamic force, more deformation occurs at a position close to the front half of the airfoil to form a certain angle of attack, while the rear half of the wing maintains a smaller deformation, thereby allowing the flexible swing wing to maintain a better hydrodynamic geometry and improve the hydrodynamic performance. The invention has the advantages of simple structure, utilizing the deformation characteristics of the parallel beam to control the deformation law of the flexible swing wing, thereby improving the hydrodynamic performance of the flexible swing wing, and the like.

Claims

1. A flexible swing wing of an underwater bionic propeller, provided with a flexible swing wing body, characterized in that: The front end of the flexible wing body is provided with a driving rod mounting hole, a driving rod is inserted into the driving rod mounting hole, and at least two parallel beam holes are provided on the flexible wing body behind the driving rod mounting hole.

2. The flexible swing wing of an underwater bionic propeller according to claim 1, characterized in that: Both end faces of the flexible wing body are provided with flexible material sealing layers, and the flexible material sealing layers cover both end faces of the flexible wing body to seal the parallel beam holes.

3. The flexible swing wing of the underwater bionic propeller according to claim 1, characterized in that: The wing surface of the flexible wing body is wrapped with a reinforcing fiber layer to prevent tearing when the parallel beam holes of the flexible wing are deformed.

4. The flexible swing wing of the underwater bionic propeller according to claim 1, characterized in that: The driving rod mounting hole is set as a special-shaped hole, and the part of the driving rod inserted into the driving rod mounting hole is matched with the special-shaped hole, which increases the connection area between the driving rod and the wing, provides sufficient rigidity for the front part of the wing, improves the adhesion, and the part of the driving rod extending out of the driving rod mounting hole at one end is cylindrical for easy connection with the driver.

5. The flexible swing wing of the underwater bionic propeller according to claim 1, characterized in that: The driving rod is arranged within the range of the leading edge L of the wing, 0.1c < L < 0.2c, where c is the chord length, and the minimum thickness t0 of the flexible material on the outer edge of the driving rod is not less than 1% of the chord length c.

6. The flexible swing wing of the underwater bionic propeller according to claim 1, characterized in that: The length of the parallel beam hole is L1, the thickness from the parallel beam hole to the edge of the flexible wing is t1, t1 is not less than 0.5% of the chord length c, the thickness of the support partition between the two parallel beam holes is b1, and the distance between the parallel beam hole and the driving rod is also b1, b1 ≥ 2t1.

7. A design method for a flexible swing wing of an underwater bionic propeller, characterized in that: The design method steps are as follows: (1) Determine the wing parameters; (2) Calculate the hydrodynamic angle θ according to the wing parameters; (3) Determine the angle of attack α of the flexible wing after deformation and obtain the deformation amount d of the wing tail; (4) Calculate the force F on the flexible wing; (5) Determine the elastic modulus of the flexible wing and the number of parallel beam holes to obtain the ratio of the length L1 of the parallel beam hole to the thickness t1 from the parallel beam hole to the edge of the flexible wing; (6) Obtain the thickness t1 from the parallel beam hole to the edge of the flexible wing, the length L1 of the parallel beam hole, the thickness of the support partition between the two parallel beam holes, and the distance b1 between the parallel beam hole and the driving rod: The design requirement is that the thickness t1 from the parallel beam hole to the edge of the flexible wing is not less than 0.5% of the chord length c, and the design requirement is b1 ≥ 2t; (7) Wrap the reinforcing fiber layer and the flexible material sealing layer; (8) Inflate the inside of the parallel beam hole.

8. The method for designing a flexible swing wing of an underwater bionic propeller according to claim 7, characterized in that: In the step (7), the thickness of the flexible material sealing layer is 1.5% - 2.5% of the chord length, and the thickness of the reinforcing fiber layer is 1.5% - 2.5% of the chord length.

9. The method for designing a flexible swing wing of an underwater bionic propeller according to claim 7, characterized in that: In the step (8), the internal air pressure of the parallel beam hole is the same as the external water pressure, which is used to balance the external water pressure and prevent the parallel beam hole from being sunken under the action of the water pressure.

Images