Three-order Bessel type guide vane design method and vane pump

Abstract

The invention discloses a three-order Bezier type guide vane design method and a vane pump, and the method comprises the following steps: determining a guide vane skeleton line by using a three-order Bezier curve and an amplification coefficient; and determining the thickness of the guide vane, wherein the change rule of the thickness of the guide vane along the guide vane bone line is given according to the airfoil thickness change rule. The guide vane can be quickly shaped, the flow field in the vane pump is smoothed, the pressure pulsation of the vane pump at each working condition point is effectively reduced, and the energy performance of the vane pump is improved.

Description

Technical Field

[0001] The invention relates to the technical field of vane pumps, and in particular to a third-order Bessel-type guide vane design method and a vane pump. Background Art

[0002] In recent years, vane pumps have been widely used in energy, aerospace, marine power and other fields due to their compact structure and excellent performance. With the improvement of military and civilian equipment requirements, higher requirements are placed on the energy performance of vane pumps. The guide vane shape of traditional vane pumps is relatively simple, which makes it difficult to meet the pressure pulsation design requirements of various operating points of the pump. Therefore, it is urgent to develop a high-energy and efficient vane pump guide vane design method.

[0003] In traditional vane pump design methods, the guide vane skeleton is mostly designed using straight lines, simple arcs, multi-segment lines, high-order polynomial functions, etc. These methods are either too simple, with poor controllability, and difficult to meet design requirements; or too complex, with too many control parameters, and difficult to achieve rapid shaping of the guide vanes. Summary of the invention

[0004] The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, one purpose of the present invention is to provide a vane pump that can achieve rapid shaping of the guide vanes, smooth the flow field inside the vane pump, effectively reduce the pressure pulsation of the vane pump at various operating points, and improve the energy performance of the vane pump.

[0005] According to the vane pump of the embodiment of the present invention, the guide vane of the vane pump comprises:

[0006] A guide vane bone line, wherein the guide vane bone line is determined by a third-order Bezier curve and an amplification coefficient; the two ends of the guide vane bone line are the guide vane inlet and the guide vane outlet, respectively; wherein the guide vane inlet has a guide vane bone line inlet abscissa, a guide vane bone line inlet ordinate and a guide vane bone line inlet slope, and the guide vane bone line inlet abscissa, the guide vane bone line inlet ordinate and the guide vane bone line inlet slope are determined by a given guide vane inlet placement angle; the guide vane outlet has a guide vane bone line outlet abscissa, a guide vane bone line outlet ordinate and a guide vane bone line outlet slope, and the guide vane bone line outlet abscissa, the guide vane bone line outlet ordinate and the guide vane bone line outlet slope are determined by a given guide vane outlet placement angle;

[0007] The guide vane thickness, the variation rule of the guide vane thickness along the guide vane bone line is given according to the airfoil thickness rule.

[0008] Compared with the traditional vane pump, the vane pump in the embodiment of the present invention has a guide vane skeleton line determined by a third-order Bezier curve and a magnification coefficient. Therefore, for any given geometric conditions of the guide vane inlet and guide vane outlet, the guide vane skeleton line design of the vane pump can be quickly completed, and a smooth transition of the guide vane skeleton line can be ensured, thereby smoothing the flow field inside the vane pump, effectively reducing the impact on the guide vane inlet, reducing the guide vane resistance, effectively reducing the pressure pulsation of the vane pump at various operating points, and improving the energy performance of the vane pump, that is, effectively improving the output power and efficiency of the pump at the design operating point.

[0009] In some embodiments, the third-order Bezier curve is controlled by four Bezier points, which are the first point, the second point, the third point and the fourth point in sequence; the definition equation of the third-order Bezier curve is:

[0010]

[0011] The expression of the abscissa and ordinate forms of the third-order Bezier curve is obtained from the definition equation:

[0012]

[0013] Wherein, P0(x0,y0), P1(x1,y1), P2(x2,y2), P3(x3,y3) are the first point, the second point, the third point, and the fourth point;

[0014] The magnification factor includes a radial magnification factor and a tangential magnification factor, and the radial magnification factor and the tangential magnification factor are respectively: K r =R,K l =L;

[0015] Among them, K r is the radial magnification factor, K l is the tangential magnification factor, R is the transverse length of the guide vane bone line, and L is the longitudinal length of the guide vane bone line.

[0016] In some embodiments, the first point coincides with the starting point of the third-order Bezier curve, and the coordinates of the first point are P0(0,0); the fourth point coincides with the end point of the third-order Bezier curve, and the coordinates of the fourth point are P3(1,1).

[0017] In some embodiments, for any guide vane inlet placement angle and any guide vane outlet placement angle, the guide vane bone line has a smooth transition, and the starting slope and the ending slope of the third-order Bezier curve are respectively:

[0018]

[0019] Among them, k1 is the starting point slope of the third-order Bezier curve, k2 is the ending point slope of the third-order Bezier curve, K1 and K2 are the guide vane bone line inlet slope and the guide vane bone line outlet slope given according to the guide vane inlet installation angle and the guide vane outlet installation angle, respectively.

[0020] In some embodiments, the shape of the third-order Bezier curve is controlled only by the abscissa of the second point and the abscissa of the third point, and the expression of the third-order Bezier curve is:

[0021]

[0022] The invention also proposes a third-order Bessel-type guide vane design method.

[0023] According to the third-order Bessel guide vane design method of the embodiment of the present invention, the third-order Bessel guide vane is the guide vane of the vane pump according to the embodiment of the present invention, and the third-order Bessel guide vane design method comprises the following steps:

[0024] The guide vane bone line is determined using the third-order Bezier curve and the magnification factor;

[0025] The guide vane thickness is determined, and the variation rule of the guide vane thickness along the guide vane bone line is given according to the variation rule of the airfoil thickness.

[0026] The third-order Bessel-type guide vane design method of the embodiment of the present invention determines the guide vane skeleton line by utilizing the third-order Bessel curve and the amplification coefficient. For any given geometric conditions of the guide vane inlet and the guide vane outlet, the guide vane skeleton line design of the vane pump can be quickly completed, and a smooth transition of the guide vane skeleton line can be ensured, thereby smoothing the flow field inside the vane pump, effectively reducing the impact of the guide vane inlet, reducing the guide vane resistance, effectively reducing the pressure pulsation of the vane pump at each operating point, and improving the energy performance of the vane pump, that is, effectively improving the output power and efficiency of the pump at the design operating point.

[0027] In some embodiments, the third-order Bezier curve is controlled by four Bezier points, which are the first point, the second point, the third point and the fourth point in sequence. The first point coincides with the starting point of the third-order Bezier curve, and the coordinate of the first point is P0 (0, 0). The fourth point coincides with the end point of the third-order Bezier curve, and the coordinate of the fourth point is P3 (1, 1). The parametric equation of the guide vane bone line is expressed as follows:

[0028]

[0029] Among them, K r is the radial magnification factor, K lis the tangential magnification coefficient, K1 and K2 are the guide vane bone line inlet slope and the guide vane bone line outlet slope given according to the guide vane inlet installation angle and the guide vane outlet installation angle, respectively, and x1 and x2 are the horizontal coordinates of the second point and the third point, respectively.

[0030] In some embodiments, the airfoil thickness variation law is a NACA airfoil thickness variation law.

[0031] Additional aspects and advantages of the present invention will be given in part in the following description and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 A schematic diagram of the partial structure of a vane pump according to an embodiment of the present invention;

[0034] Figure 2 A schematic diagram of a guide vane skeleton line of a vane pump according to an embodiment of the present invention;

[0035] Figure 3 A third-order Bezier curve diagram of a guide vane skeleton line of a vane pump according to an embodiment of the present invention;

[0036] Figure 4 The figure is a schematic diagram of the thickness variation of the guide vanes of a vane pump according to an embodiment of the present invention.

[0037] Reference numerals:

[0038] Guide vane 1; guide vane skeleton line 11; guide vane inlet 12; guide vane outlet 13; guide vane inlet placement angle α1; guide vane outlet placement angle α2; upper cover plate 2; blade 3; upper ring plate 4. DETAILED DESCRIPTION

[0039] Embodiments of the present invention are described in detail below, examples of which are shown in the accompanying drawings, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain the present invention, and cannot be understood as limiting the present invention.

[0040] Combine the following Figures 1 to 4 A vane pump according to an embodiment of the present invention will be described.

[0041] According to the vane pump of the embodiment of the present invention, Figure 1As shown, the vane pump includes an impeller and a guide vane 1. The impeller includes an upper cover plate 2, a lower cover plate (not shown in the figure) and blades 3 arranged between the upper cover plate 2 and the lower cover plate; the guide vane 1 is arranged between an upper ring plate 4 located at the outer periphery of the upper cover plate 2 and a lower ring plate (not shown in the figure) located at the outer periphery of the lower cover plate.

[0042] Among them, Figure 2 and Figure 3 As shown, the guide vane 1 of the vane pump includes: a guide vane bone line 11 and a guide vane thickness. The guide vane bone line 11 is determined by a third-order Bezier curve and an amplification coefficient; the two ends of the guide vane bone line 11 are a guide vane inlet 12 and a guide vane outlet 13 respectively; wherein the guide vane inlet 12 has a guide vane bone line inlet horizontal coordinate, a guide vane bone line inlet vertical coordinate and a guide vane bone line inlet slope, and the guide vane bone line inlet horizontal coordinate, the guide vane bone line inlet vertical coordinate and the guide vane bone line inlet slope are determined by a given guide vane inlet placement angle α1; the guide vane outlet 13 has a guide vane bone line outlet horizontal coordinate, a guide vane bone line outlet vertical coordinate and a guide vane bone line outlet slope, and the guide vane bone line outlet horizontal coordinate, the guide vane bone line outlet vertical coordinate and the guide vane bone line outlet slope are determined by a given guide vane outlet placement angle α2.

[0043] The variation rule of the guide vane thickness along the guide vane bone line 11 is given according to the airfoil thickness rule, and the airfoil thickness rule can be selected from the NACA airfoil thickness rule, etc. Figure 4 As shown, a rule of variation of the guide vane thickness is illustrated, wherein Th is the guide vane thickness and Lm is the relative guide vane bone line length.

[0044] Compared with the traditional vane pump, the vane pump of the embodiment of the present invention has a guide vane skeleton line 11 determined by a third-order Bezier curve and an amplification coefficient. Therefore, for any given geometric conditions of the guide vane inlet 12 and the guide vane outlet 13, the guide vane skeleton line 11 of the vane pump can be quickly designed, and a smooth transition of the guide vane skeleton line 11 can be ensured, thereby smoothing the flow field inside the vane pump, effectively reducing the impact of the guide vane inlet 12, reducing the resistance of the guide vane 1, and effectively reducing the pressure pulsation of the vane pump at each operating point, thereby improving the energy performance of the vane pump, that is, effectively improving the output power and efficiency of the pump at the design operating point.

[0045] In some embodiments, Figure 3 As shown, the third-order Bezier curve is controlled by four Bezier points, which are the first point, the second point, the third point and the fourth point respectively; the definition equation of the third-order Bezier curve is:

[0046]

[0047] The expression of the abscissa and ordinate of the third-order Bezier curve is obtained from the definition equation:

[0048]

[0049] Among them, P0(x0,y0), P1(x1,y1), P2(x2,y2), P3(x3,y3) are the first point, the second point, the third point, and the fourth point;

[0050] The magnification factor includes radial magnification factor and tangential magnification factor. The radial magnification factor and tangential magnification factor are: K r =R,K l =L;

[0051] Among them, K r is the radial magnification factor, K l is the tangential magnification coefficient, R is the transverse length of the guide vane bone line 11, and L is the longitudinal length of the guide vane bone line 11.

[0052] In this embodiment, the guide vane skeleton 11 is determined by using a third-order Bezier curve and a magnification coefficient. For any given geometric conditions of the guide vane inlet 12 and the guide vane outlet 13, the guide vane skeleton 11 of the vane pump can be quickly designed, and a smooth transition of the guide vane skeleton 11 can be ensured, thereby smoothing the flow field inside the vane pump, effectively reducing the impact of the guide vane inlet 12, reducing the resistance of the guide vane 1, and effectively reducing the pressure pulsation of the vane pump at each operating point, thereby improving the energy performance of the vane pump.

[0053] In some embodiments, Figure 2 and Figure 3 As shown, the first point coincides with the starting point of the third-order Bezier curve, that is, coincides with the guide vane inlet 12, and the coordinate of the first point is P0 (0, 0). The fourth point coincides with the end point of the third-order Bezier curve, that is, coincides with the guide vane outlet 13, and the coordinate of the fourth point is P3 (1, 1).

[0054] In this embodiment, the guide vane skeleton 11 is determined by using a third-order Bezier curve and an amplification factor. Under any given geometric conditions of the guide vane inlet 12 and the guide vane outlet 13, by coinciding the first point with the starting point of the third-order Bezier curve and setting the coordinates of the first point to P0 (0, 0), and coinciding the fourth point with the end point of the third-order Bezier curve and setting the coordinates of the fourth point to P3 (1, 1), it is beneficial to simplify the control parameters, so as to quickly complete the final design of the guide vane skeleton 11 of the vane pump, and ensure a smooth transition of the guide vane skeleton 11, thereby smoothing the flow field inside the vane pump, effectively reducing the impact of the guide vane inlet 12, reducing the resistance of the guide vane 1, effectively reducing the pressure pulsation of the vane pump at each operating point, and improving the energy performance of the vane pump.

[0055] In some embodiments, for any guide vane inlet placement angle α1 and guide vane outlet placement angle α2, the guide vane bone line 11 has a smooth transition, and the starting slope and the ending slope of the third-order Bezier curve are respectively:

[0056]

[0057] Among them, k1 is the starting point slope of the third-order Bezier curve, k2 is the ending point slope of the third-order Bezier curve, K1 and K2 are the guide vane bone line inlet slope and guide vane bone line outlet slope given according to the guide vane inlet installation angle α1 and the guide vane outlet installation angle α2, respectively.

[0058] In this embodiment, the guide vane skeleton 11 is determined by using a third-order Bezier curve and an amplification factor. Under the geometric conditions of any given guide vane inlet 12 and guide vane outlet 13, by further giving the guide vane skeleton inlet slope and the guide vane skeleton outlet slope according to the guide vane inlet installation angle α1 and the guide vane outlet installation angle α2, it is beneficial to simplify the control parameters, so as to quickly complete the final design of the guide vane skeleton 11 of the vane pump, and ensure a smooth transition of the guide vane skeleton 11, thereby smoothing the flow field inside the vane pump, effectively reducing the impact of the guide vane inlet 12, reducing the resistance of the guide vane 1, effectively reducing the pressure pulsation of the vane pump at each operating point, and improving the energy performance of the vane pump.

[0059] In some embodiments, the shape of the third-order Bezier curve is controlled only by the abscissa of the second point and the abscissa of the third point, and the expression of the third-order Bezier curve is:

[0060]

[0061] In this embodiment, the guide vane skeleton 11 is designed using a third-order Bezier curve. Under any given geometric constraints, the control parameters are simplified to achieve dual-parameter control of the guide vane skeleton 11, that is, by controlling the horizontal coordinate of the second point and the horizontal coordinate of the third point, the guide vane skeleton 11 of the vane pump can be quickly designed, and a smooth transition of the guide vane skeleton 11 can be ensured, thereby smoothing the flow field inside the vane pump, effectively reducing the impact of the guide vane inlet 12, reducing the resistance of the guide vane 1, and effectively reducing the pressure pulsation of the vane pump at each operating point, thereby improving the energy performance of the vane pump.

[0062] Combine the following Figures 1 to 4 The third-order Bessel guide vane design method according to an embodiment of the present invention is described.

[0063] like Figures 1 to 4 As shown, according to the third-order Bessel guide vane design method of the embodiment of the present invention, the third-order Bessel guide vane is the guide vane 1 in the vane pump of the embodiment of the present invention, and the third-order Bessel guide vane design method includes the following steps:

[0064] The guide vane bone line 11 is determined using a third-order Bezier curve and a magnification factor.

[0065] The thickness of the guide vane is determined. The variation rule of the thickness of the guide vane along the guide vane skeleton line 11 is given according to the variation rule of the airfoil thickness.

[0066] The third-order Bessel-type guide vane design method of the embodiment of the present invention determines the guide vane skeleton 11 by utilizing the third-order Bessel curve and the amplification coefficient. For any given geometric conditions of the guide vane inlet 12 and the guide vane outlet 13, the guide vane skeleton 11 of the vane pump can be quickly designed, and a smooth transition of the guide vane skeleton 11 can be ensured, thereby smoothing the flow field inside the vane pump, effectively reducing the impact of the guide vane inlet 12, reducing the resistance of the guide vane 1, and effectively reducing the pressure pulsation of the vane pump at each operating point, thereby improving the energy performance of the vane pump, that is, effectively improving the output power and efficiency of the pump at the design operating point.

[0067] In some embodiments, the third-order Bezier curve is controlled by four Bezier points, which are the first point, the second point, the third point and the fourth point in sequence. The first point coincides with the starting point of the third-order Bezier curve, and the coordinate of the first point is P0 (0, 0). The fourth point coincides with the end point of the third-order Bezier curve, and the coordinate of the fourth point is P3 (1, 1). The parametric equation of the guide vane bone line 11 is expressed as follows:

[0068]

[0069] Among them, K r is the radial magnification factor, K l is the tangential magnification coefficient, K1 and K2 are the guide vane bone line inlet slope and guide vane bone line outlet slope given by the guide vane inlet installation angle α1 and the guide vane outlet installation angle α2, respectively, x1 and x2 are the abscissas of the second point and the abscissas of the third point, respectively.

[0070] This third-order Bessel guide vane design method can quickly complete the design of the guide vane skeleton line 11 for any given inlet and outlet geometric conditions, effectively reduce the impact of the guide vane inlet 12, and reduce the resistance of the guide vane 1.

[0071] Specifically, the guide vane 1 includes: a guide vane skeleton line 11 and a guide vane thickness.

[0072] The two ends of the guide vane bone line 11 are respectively a guide vane inlet 12 and a guide vane outlet 13; wherein, the guide vane inlet 12 has a guide vane bone line inlet horizontal coordinate, a guide vane bone line inlet vertical coordinate and a guide vane bone line inlet slope, and the guide vane bone line inlet horizontal coordinate, the guide vane bone line inlet vertical coordinate and the guide vane bone line inlet slope are determined by a given guide vane inlet placement angle α1; the guide vane outlet 13 has a guide vane bone line outlet horizontal coordinate, a guide vane bone line outlet vertical coordinate and a guide vane bone line outlet slope, and the guide vane bone line outlet horizontal coordinate, the guide vane bone line outlet vertical coordinate and the guide vane bone line outlet slope are determined by a given guide vane outlet placement angle α2.

[0073] The variation rule of the guide vane thickness along the guide vane skeleton line 11 is given according to the airfoil thickness rule, and the airfoil thickness rule may be selected from the NACA airfoil thickness rule and the like.

[0074] The third-order Bezier curve is controlled by four Bezier points, which are the first point, the second point, the third point and the fourth point. The definition equation of the third-order Bezier curve is:

[0075]

[0076] The expression of the abscissa and ordinate of the third-order Bezier curve is obtained from the definition equation:

[0077]

[0078] Among them, P0(x0,y0), P1(x1,y1), P2(x2,y2), P3(x3,y3) are the first point, the second point, the third point, and the fourth point;

[0079] The magnification factor includes radial magnification factor and tangential magnification factor. The radial magnification factor and tangential magnification factor are: K r =R,K l =L;

[0080] Among them, K r is the radial magnification factor, K l is the tangential magnification coefficient, R is the transverse length of the guide vane bone line 11, and L is the longitudinal length of the guide vane bone line 11 (as shown in 2).

[0081] For any guide vane inlet placement angle α1 and guide vane outlet placement angle α2, the guide vane bone line 11 has a smooth transition, and the starting slope and the ending slope of the third-order Bezier curve are:

[0082]

[0083] Among them, k1 is the starting point slope of the third-order Bezier curve, k2 is the ending point slope of the third-order Bezier curve, K1 and K2 are the guide vane bone line inlet slope and guide vane bone line outlet slope given according to the guide vane inlet installation angle α1 and the guide vane outlet installation angle α2, respectively.

[0084] The shape of the third-order Bezier curve is only controlled by the abscissas x1 and x2 of the second Bezier point P1 and the third Bezier point P2, and its expression is:

[0085]

[0086] The guide vane bone line 11 is determined by using a third-order Bezier curve and a magnification coefficient. The parameter equation of the guide vane bone line 11 is expressed as:

[0087]

[0088] Compared with the traditional vane pump, the vane pump having the guide vane 1 obtained by the three-order Bessel guide vane design method according to the embodiment of the present invention can effectively reduce the flow impact from the outlet of the vane 3 to the guide vane 1 and reduce the pressure pulsation. The pressure pulsation of the vane pump is reduced by 3% under the design working condition, which can prove the feasibility and superiority of the three-order Bessel guide vane design method.

[0089] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "illustrative embodiments", "examples", "specific examples", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner.

[0090] Although the embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the claims and their equivalents.

Claims

1. A vane pump, characterized in that: The guide vane of the vane pump comprises: A guide vane bone line, wherein the guide vane bone line is determined by a third-order Bezier curve and an amplification coefficient; the two ends of the guide vane bone line are the guide vane inlet and the guide vane outlet, respectively; wherein the guide vane inlet has a guide vane bone line inlet abscissa, a guide vane bone line inlet ordinate and a guide vane bone line inlet slope, and the guide vane bone line inlet abscissa, the guide vane bone line inlet ordinate and the guide vane bone line inlet slope are determined by a given guide vane inlet placement angle; the guide vane outlet has a guide vane bone line outlet abscissa, a guide vane bone line outlet ordinate and a guide vane bone line outlet slope, and the guide vane bone line outlet abscissa, the guide vane bone line outlet ordinate and the guide vane bone line outlet slope are determined by a given guide vane outlet placement angle; The guide vane thickness, the variation rule of the guide vane thickness along the guide vane bone line is given according to the airfoil thickness rule.

2. The vane pump according to claim 1, characterized in that: The third-order Bezier curve is controlled by four Bezier points, which are the first point, the second point, the third point and the fourth point in sequence; the definition equation of the third-order Bezier curve is: The expression of the abscissa and ordinate forms of the third-order Bezier curve is obtained from the definition equation: Wherein, P0(x0,y0), P1(x1,y1), P2(x2,y2), P3(x3,y3) are the first point, the second point, the third point, and the fourth point; The magnification factor includes a radial magnification factor and a tangential magnification factor, and the radial magnification factor and the tangential magnification factor are respectively: K r =R,K l =L; Among them, K r is the radial magnification factor, K l is the tangential magnification factor, R is the transverse length of the guide vane bone line, and L is the longitudinal length of the guide vane bone line.

3. The vane pump according to claim 2, characterized in that: The first point coincides with the starting point of the third-order Bezier curve, and the coordinate of the first point is P0(0,0). The fourth point coincides with the end point of the third-order Bezier curve, and the coordinate of the fourth point is P3(1,1).

4. The vane pump according to claim 3, characterized in that: For any guide vane inlet placement angle and guide vane outlet placement angle, the guide vane bone line has a smooth transition, and the starting slope and the ending slope of the third-order Bezier curve are respectively: Among them, k1 is the starting point slope of the third-order Bezier curve, k2 is the ending point slope of the third-order Bezier curve, K1 and K2 are the guide vane bone line inlet slope and the guide vane bone line outlet slope given according to the guide vane inlet installation angle and the guide vane outlet installation angle, respectively.

5. The guide vane of the vane pump according to claim 4, characterized in that: The shape of the third-order Bezier curve is controlled only by the abscissa of the second point and the abscissa of the third point, and the expression of the third-order Bezier curve is:

6. A third-order Bessel guide vane design method, characterized in that: The third-order Bessel guide vane is the guide vane of the vane pump according to any one of claims 1 to 5, and the third-order Bessel guide vane design method comprises the following steps: The guide vane bone line is determined using the third-order Bezier curve and the magnification factor; The guide vane thickness is determined, and the variation rule of the guide vane thickness along the guide vane bone line is given according to the variation rule of the airfoil thickness.

7. The third-order Bessel guide vane design method according to claim 6, characterized in that: The third-order Bezier curve is controlled by four Bezier points, which are the first point, the second point, the third point and the fourth point in sequence. The first point coincides with the starting point of the third-order Bezier curve, and the coordinate of the first point is P0 (0, 0). The fourth point coincides with the end point of the third-order Bezier curve, and the coordinate of the fourth point is P3 (1, 1). The parametric equation of the guide vane bone line is expressed as follows: Among them, K r is the radial magnification factor, K l is the tangential magnification coefficient, K1 and K2 are the guide vane bone line inlet slope and the guide vane bone line outlet slope given according to the guide vane inlet installation angle and the guide vane outlet installation angle, respectively, and x1 and x2 are the horizontal coordinates of the second point and the third point, respectively.

8. The third-order Bessel guide vane design method according to claim 6, characterized in that: The airfoil thickness variation law is the NACA airfoil thickness variation law.

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