A wind turbine blade structure with enhanced lift and noise reduction that imitates a whale's tail fin

Abstract

The present invention discloses a wind turbine blade structure that increases lift and noise by imitating a whale's tail fin. The structure includes a basic airfoil NACA 0012 blade body 1 and a whale's tail fin flap 4. The whale's tail fin flap is located at the trailing edge of the basic airfoil blade and is symmetrically distributed on both sides of the suction surface 2 and the pressure surface 3 of the blade. The overall height of the whale's tail fin flap is 3.57% of the local chord length of the blade, and the deployment angle of the tail fin flap is 116°. The present invention can achieve effective control of flow separation, significantly reduce pressure pulsation at the trailing edge of the blade, improve the flow structure of the blade wake, increase the lift coefficient of the blade, and reduce the drag coefficient. In addition, it can also effectively reduce aerodynamic noise.

Description

Technical Field

[0001] The invention relates to the technical field of wind power generation, in particular to a bionic trailing edge wind power generator blade structure modification design. Background Art

[0002] Wind turbines generate noticeable noise when in operation, which has a significant impact on the physical and mental health of nearby residents and the migration of birds.

[0003] The wind turbine airfoil is the key to ensure the good dynamic performance of the wind turbine. Excellent wind turbine airfoils can effectively improve the aerodynamic performance of the blades, improve the wind turbine energy efficiency, and thus improve the utilization rate of wind energy. Therefore, the reasonable selection of wind turbine types and parameters and the optimization of wind turbine airfoil structures have a positive effect on increasing the airfoil lift coefficient, reducing the drag coefficient, controlling flow separation and reducing noise. Therefore, designing a new blade that increases lift, reduces drag and reduces noise has important practical application value. Summary of the invention

[0004] Based on the above analysis and actual needs, the present application aims to provide a wind turbine blade with increased lift and noise that imitates a whale's tail fin. The wind turbine blade structure with increased lift and noise that imitates a whale's tail fin can effectively control the flow separation of the boundary layer, improve the vortex structure in the wake area of ​​the blade, and weaken the turbulent boundary layer trailing edge noise generated when the turbulent boundary layer flows over the trailing edge of the blade. Therefore, the tail fin flap structure can improve the lift-to-drag ratio of the blade, improve the aerodynamic performance of the blade and effectively reduce noise.

[0005] The purpose of this application is mainly achieved through the following technical solutions:

[0006] The present application provides a wind turbine blade structure that increases lift and noise by imitating a whale's tail fin. The bionic blade structure comprises a basic airfoil blade body, and is characterized in that a whale's tail fin-like flap structure is arranged at the trailing edge of the basic airfoil blade body.

[0007] Furthermore, the whale tail fin-shaped flap is arranged at the trailing edge of the basic airfoil blade, and the position of the flap can be adjusted according to the position of the separation point.

[0008] Furthermore, the whale tail fin flaps are symmetrically distributed on both sides of the suction surface and the pressure surface of the blade.

[0009] Furthermore, the overall height H of the whale tail fin flap is 3.57% of the local chord length.

[0010] Furthermore, the deployment angle θ of the whale tail fin flap is 116°.

[0011] Furthermore, the whale tail fin flap obtains the outline of a typical whale tail fin through image processing, and the specific structural profile parameters are shown in Table 1, and then scaled according to the proportion to obtain a tail fin flap structure based on bionics. The whale tail fin flap can effectively improve the tail vortex flow that originally interacts with the suction surface and the pressure surface sliding down and converging at the trailing edge, thereby weakening the aerodynamic noise in the trailing edge area. At the same time, the whale tail fin flap structure improves the lift-to-drag ratio of the blade.

[0012]

[0013]

[0014] Compared with the prior art, this application can achieve the following beneficial effects:

[0015] (a) The whale-shaped flap effectively controls the flow separation on the airfoil surface, improves the aerodynamic characteristics of the airfoil, and increases the lift-to-drag ratio of the airfoil;

[0016] (b) By controlling the interaction between the trailing vortices on the suction side and the pressure side, the vortex structure in the trailing edge of the blade is improved, thereby reducing aerodynamic noise;

[0017] (c) Simple structure, low production cost and strong feasibility. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 A two-dimensional schematic diagram of the structure of a wind turbine blade that imitates a whale's tail fin to increase lift and noise;

[0019] Figure 2 It is a schematic diagram of an embodiment of a whale tail fin flap in a wind turbine blade structure that imitates a whale tail fin to increase lift and noise;

[0020] Figure 3 It is a schematic diagram of the whale tail fin structure of the present invention.

[0021] Reference numerals:

[0022] 1- basic airfoil blade body; 2- blade suction surface; 3- blade pressure surface; 4- whale tail fin lift and noise reduction component structure; H- overall height of whale tail fin flap, mm; θ- whale tail fin deployment angle, degrees. DETAILED DESCRIPTION

[0023] The specific implementation modes of the present invention are further described in detail below with reference to the accompanying drawings.

[0024] The present invention is designed as Figure 1 and Figure 2A blade structure for increasing lift and reducing noise is shown, wherein the main body of the wind turbine blade structure for increasing lift and reducing noise is a basic airfoil NACA0012 blade, and a whale tail fin-shaped flap is installed at the trailing edge of the airfoil, and the whale tail fin-shaped flap is installed at the trailing edge of the basic airfoil, and is symmetrically distributed on both sides of the pressure surface and suction surface of the blade. The shape of the whale tail fin flap is obtained by image processing of the whale tail fin image to obtain the external contour of the tail fin. The overall height of the flap is 3.57% of the local chord length. The flap deployment angle θ is 116°, that is, the angle between the single-sided flap and the airfoil chord line is 58°. The whale tail fin structure may not be in the same horizontal plane as the basic airfoil, which is determined by the local incoming flow characteristics.

[0025] The embodiments described above are only preferred implementation examples of the present invention and are not intended to limit the scope of implementation of the present invention. Therefore, all changes made according to the shape and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A wind turbine blade structure that increases lift and noise by imitating a whale tail fin, the structure mainly comprising a basic airfoil blade body (1) and a whale tail fin flap (4), and the outstanding features thereof are: The whale tail fin flap (4) is provided at the trailing edge of the basic airfoil blade body (1), and is proportionally scaled according to the whale tail fin prototype. The whale tail fin flap is symmetrically distributed on both sides of the blade suction surface (2) and the blade pressure surface (3), and forms a certain angle with the airfoil chord line. The overall height of the whale tail fin flap (4) is 3.57% of the local chord length of the blade. The deployment angle of the whale tail fin flap (4) is 116°. The whale tail fin flap (4) can effectively improve the trailing edge noise and instability of aerodynamic characteristics caused by the direct interaction of vortices with different pressures on the blade suction surface (2) and the blade pressure surface (3) at the trailing edge. Therefore, the structure can effectively improve the aerodynamic characteristics of the airfoil, enhance the lift-to-drag ratio of the airfoil, and has a significant noise reduction effect.

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