Bionic guide vane and design method

Abstract

The application discloses a bionic guide vane and a design method. The bionic guide vane comprises a front edge protrusion and a back protrusion. The front edge protrusion is arranged on a front edge part of an original guide vane and mainly changes in a trigonometric function mode. The back protrusion is arranged on a pressure surface and a suction surface of the original guide vane and is linearly enlarged based on the original guide vane profile. Through the front edge protrusion and the back protrusion, the running track of water flow can be effectively changed, and the effect of reducing pressure pulsation in a guide vane wake flow area is achieved.

Description

Technical Field

[0001] This invention relates to the field of water energy utilization and hydropower generation, and in particular to a biomimetic guide vane and its design method. Background Technology

[0002] Guide vanes, as an important component of hydroelectric generator sets, play a crucial role in guiding water flow into the runner and controlling the flow rate. When the guide vanes are open, the gap between them increases, expanding the channel area for fluid passage and increasing the flow rate; conversely, when the guide vanes are closed, the channel area decreases, reducing the flow rate. By controlling the movement of the guide vanes, the flow rate and velocity of the fluid can be effectively regulated, enabling the equipment to adapt to different operating conditions and flexibly adjust power output to meet the grid's dispatch requirements.

[0003] Currently, conventional guide vanes are mainly composed of overlapping airfoils of the same type. When the unit operates in the low-load region, the guide vane angle of attack increases, and flow separation leads to increased pressure pulsation. Excessive pressure pulsation can reduce the stability of the unit. Therefore, effectively reducing pressure pulsation in the guide vane wake region is crucial to ensuring the stable operation of the hydropower unit. Summary of the Invention

[0004] The purpose of this invention is to solve the above-mentioned technical problems and provide a biomimetic guide vane and design method. By improving the shape and structure of the guide vane, the pressure pulsation in its wake region is reduced, thereby improving the operational stability of the unit.

[0005] To achieve the above objectives, the present invention provides the following solution: A biomimetic guide vane and its design method are provided, characterized in that: it includes a leading edge protrusion and a back protrusion, the leading edge protrusion is disposed on the leading edge portion of the guide vane, and the back protrusion is disposed on the pressure surface and suction surface of the guide vane.

[0006] Preferably, the leading edge protrusion is varied using trigonometric functions, and the dorsal protrusion is linearly enlarged based on the original guide vane airfoil.

[0007] Preferably, the leading edge protrusion satisfies the following formula: ; ; (1) in The leading edge protrusion magnification factor is typically taken as 0.05 to 0.1. C Represents the airfoil chord length; Represents characteristic frequencies; N Represents the number of protrusions; H Represents the height of the guide vane; The ratio of the protrusion length to the guide vane height is generally taken as... ~1; Take positive integers; where x , z represent xoz The coordinates of any point on the contour line of the biomimetic guide vane airfoil on the plane, with the origin as the coordinates. o It is located at the midpoint of the leading edge of the guide vane.

[0008] Preferably, the dorsal protrusion satisfies the following formula: ; (2) in s Represents the overall magnification factor; where x , y represent xoy The position coordinates of any point on the contour line of the biomimetic guide vane airfoil on the plane; x 0 , y 0 represent xoy The coordinates of the centroid of the original guide vane airfoil on the plane; x 1, y 1 represents xoy The position coordinates of any point on the original guide vane airfoil profile on the plane.

[0009] As a preferred embodiment, the overall magnification factor of the biomimetic guide vane s Satisfy the following formula: ; (3).

[0010] As a preferred embodiment, the biomimetic guide vane design steps are as follows: A. Give 、 、N Assignment ， The protrusion shape of the leading edge of the biomimetic guide vane is determined according to formula (1).

[0011] B. Combine formulas (2) and (3), and take different... z value Determine the horizontal cross-sectional shape of the biomimetic guide vane at different heights.

[0012] C. The horizontal cross-sections of the biomimetic guide vanes at different heights are arranged along the height... z The directional smooth connection forms the back curved surface (pressure surface and suction surface) of the biomimetic guide vane.

[0013] D. The guide vane is a complete three-dimensional biomimetic guide vane composed of the curved back surface and the upper and lower end surfaces of the guide vane.

[0014] The beneficial effects of this invention are: by using the concept of bionics, this invention can biomimeticly modify the traditional guide vane. Through the protrusions on the leading edge and the back, it can effectively change the trajectory of the water flow, effectively suppress flow separation, and reduce the pressure pulsation in the wake region of the guide vane. Attached Figure Description

[0015] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the embodiments will be briefly introduced below. Obviously, the 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.

[0016] Figure 1 This is a schematic diagram showing the origin of the coordinate system for the leading edge protrusion formula and the cross-sectional shape of the leading edge protrusion. Figure 2 This is a schematic diagram showing the origin of the coordinate system for the back protrusion formula and any horizontal cross-sectional shape of the back protrusion. Figure 3 This is a view of the curved surface of the back of the biomimetic guide vane of the present invention; Figure 4 This is a schematic diagram of the biomimetic guide vane structure of the present invention. Detailed Implementation

[0017] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] The purpose of this invention is to provide a biomimetic guide vane and its design method, which improves the stability of unit operation by reducing pressure pulsation in the wake region through improvements to the shape and structure of the movable guide vane.

[0019] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] Example 1: like Figures 1 to 4 As shown, a biomimetic guide vane and its design method are provided, including a leading edge protrusion and a back protrusion; wherein the leading edge protrusion is set on the leading edge part of the guide vane, and the back protrusion is set on the pressure surface and suction surface of the guide vane, and the original guide vane has a horizontal cross section of NACA0012 airfoil.

[0021] Furthermore, such as Figure 1As shown, guide vane height H It is 120mm, chord length C It is 150mm. Take 0.1, Pick , N Therefore, the leading edge protrusion function satisfies the following expression: ; ; in x, z represent xoz The coordinates of any point on the contour line of the biomimetic guide vane airfoil on the plane, with the origin point o located at the middle of the leading edge protrusion segment.

[0022] Furthermore, such as Figure 2 As shown, since the leading edge protrusion is set as a sine function, the dorsal protrusion function satisfies the following expression: ; ; in s Representing the overall magnification factor, since the dorsal protrusion not only needs to vary in the span direction but also needs to vary uniformly in the chord direction, s satisfies the following formula: ; in x , y represent xoy The position coordinates of any point on the contour line of the biomimetic guide vane airfoil on the plane; x 0 , y 0 represent xoy The coordinates of the centroid of the original guide vane airfoil on the plane; x 1, y 1 represents xoy The position coordinates of any point on the original guide vane airfoil profile on the plane.

[0023] Furthermore, such as Figure 3 As shown, the horizontal cross-section of the biomimetic guide vane at different heights is shown along the height. z The directional smooth connection forms the back curved surface (pressure surface and suction surface) of the biomimetic guide vane.

[0024] Furthermore, such as Figure 4 As shown, a complete three-dimensional biomimetic guide vane is formed by the curved back surface and the upper and lower end surfaces of the guide vane.

[0025] Furthermore, such as Figure 1 and Figure 2At point a behind the trailing edge of the guide vane shown, at an angle of attack of 10 degrees, the average value of the pressure pulsation amplitude of the bionic guide vane is 28% lower than that of the original guide vane.

[0026] It should be noted that regardless of the type of function used for the leading edge protrusion and the dorsal protrusion, they are all within the scope of protection of this invention.

[0027] It should be further noted that, for those skilled in the art, it will be apparent that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention. No reference numerals in the claims should be construed as limiting the scope of the claims.

Claims

1. A biomimetic guide vane, characterized in that: It includes a leading edge protrusion and a back protrusion. The leading edge protrusion is located on the leading edge part of the guide vane, and the back protrusion is located on the pressure surface and suction surface of the guide vane. Front view of the biomimetic guide vane xoz Plane: The leading edge protrusion satisfies the following formula: ； ； (1) in Represents the amplification factor of the leading edge protrusion; C Represents the airfoil chord length; Represents characteristic frequencies; N Represents the number of protrusions; H Represents the height of the guide vane; This represents the ratio of the protrusion length to the guide vane height. Take positive integers; where x , z represent xoz The coordinates of any point on the contour line of the biomimetic guide vane airfoil on the plane, with the origin as the coordinates. o Located at the midpoint of the leading edge of the guide vane; Top view of the biomimetic guide vane xoy Plane: The dorsal protrusion satisfies the following formula: ； (2) in s Represents the overall magnification factor; in x , y represent xoy The position coordinates of any point on the contour line of the biomimetic guide vane airfoil on the plane; x 0 , y 0 represent xoy The coordinates of the centroid of the original guide vane airfoil on the plane; x 1, y 1 represents xoy The position coordinates of any point on the original airfoil profile of the guide vane on the plane; Bionic guide vane overall magnification factor s Satisfy the following formula: ； (3)。 2. The biomimetic guide vane according to claim 1, characterized in that: The leading edge protrusions are varied using trigonometric functions, while the dorsal protrusions are linearly enlarged based on the original guide vane airfoil.

3. A design method for a biomimetic guide vane as described in claim 1, characterized in that: The design steps are as follows: A. Give 、 、N Assignment ， The protrusion shape of the leading edge of the biomimetic guide vane is determined according to formula (1); B. Solve equations (2) and (3) simultaneously, and take different... z value Determine the shape of the horizontal cross-section of the biomimetic guide vane at different heights; C. The horizontal cross-sections of the biomimetic guide vanes at different heights are arranged along the height... z The directions are smoothly connected to form the back curved surface of the biomimetic guide vane, namely the pressure surface and the suction surface; D. The guide vane is a complete three-dimensional biomimetic guide vane composed of the curved back surface and the upper and lower end surfaces of the guide vane.

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