Wind turbine blade airfoil family

Abstract

The present application discloses a family of wind turbine blade airfoils, including a first airfoil family, a second airfoil family, and a third airfoil family, each of which includes multiple airfoils, each airfoil including a leading edge, an upper surface, a trailing edge, and a lower surface, the connecting line from the leading edge to the trailing edge being a chord line, each airfoil in the first airfoil family having a first relative thickness d1 within a range of 17.1% ≤ d1 ≤ 26.3%; each airfoil in the second airfoil family having a second relative thickness d2 within a range of 28.5% ≤ d2 ≤ 36.8%; each airfoil in the third airfoil family having a third relative thickness d3 within a range of 37.9% ≤ d3 ≤ 63.0%; and the ratio of the distance from the maximum thickness of each airfoil to the leading edge to the chord length is within a range of 26.5% to 35.0%. The wind turbine blade airfoil family of this application can improve the core characteristic parameters of the airfoil aerodynamic structure, including design lift characteristics, lift-to-drag ratio characteristics, critical stall characteristics, leading edge roughness sensitivity, geometric area, cross-sectional moment of inertia, etc., to meet the blade development requirements of high performance, low cost, high aerodynamic adaptability and lightweight.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of wind power generation, and particularly relates to a wind power blade airfoil family. BACKGROUND

[0002] With the development of large-scale wind power blades and the development of wind resources under complex and diverse ground objects and terrain, the design and manufacturing of large-scale wind power blades face contradictory requirements including high aerodynamic efficiency, low load, aerodynamic adaptability of complex environment, aeroelastic stability, high structural rigidity, low material cost, easy production and manufacturing, and operation and maintenance, etc. At present, the general airfoils used for blade design lack airfoils with excellent comprehensive performance, especially high-performance thick airfoils and high-lift large-thickness airfoils, so it is difficult to meet the requirements of low-cost and lightweight blade development. SUMMARY

[0003] The present application provides a wind power blade airfoil family, which can improve the airfoil performance, including the design of lift characteristics, lift-drag ratio characteristics, critical stall characteristics, leading edge roughness sensitivity, cross-sectional moment of inertia, etc. The efficiency-load characteristics of the blade can be fundamentally improved, and the roughness sensitivity of the power generation performance of the blade can be improved, which is beneficial to the low-cost and lightweight design of the blade.

[0004] The present application provides a wind power blade airfoil family, which includes a first airfoil family, a second airfoil family and a third airfoil family. The first airfoil family, the second airfoil family and the third airfoil family each include a plurality of airfoils. Each airfoil includes a leading edge, an upper surface, a trailing edge and a lower surface connected in sequence. The connecting line from the leading edge to the trailing edge is a chord line. The ratio of the maximum thickness between the upper surface and the lower surface to the length of the chord line is the relative thickness. Each airfoil in the first airfoil family has a first relative thickness d1, and the first relative thickness d1 has the following range: 17.1%≤d1≤26.3%. Each airfoil in the second airfoil family has a second relative thickness d2, and the second relative thickness d2 has the following range: 28.5%≤d2≤36.8%. Each airfoil in the third airfoil family has a third relative thickness d3, and the third relative thickness d3 has the following range: 37.9%≤d3≤63.0%. The ratio of the distance from the maximum thickness of each airfoil to the leading edge to the length of the chord line ranges from 26.5% to 35.0%.

[0005] The wind power blade airfoil family as above, wherein in the first airfoil family, the ratio of the distance from the maximum thickness of each airfoil to the leading edge to the length of the chord line ranges from 27.1% to 34.4%; in the second airfoil family, the ratio of the distance from the maximum thickness of each airfoil to the leading edge to the length of the chord line ranges from 26.5% to 29.9%; and in the third airfoil family, the ratio of the distance from the maximum thickness of each airfoil to the leading edge to the length of the chord line ranges from 26.7% to 35.0%.

[0006] The wind turbine airfoil family as claimed in the preceding paragraph, wherein the ratio of the maximum camber of each airfoil to the length of the chord line ranges from 1.83% to 4.57%.

[0007] The wind turbine airfoil family as claimed in the preceding paragraph, wherein in the first airfoil family the ratio of the maximum camber of each airfoil to the length of the chord line ranges from 3.47% to 4.57%; in the second airfoil family the ratio of the maximum camber of each airfoil to the length of the chord line ranges from 2.44% to 3.07%; and in the third airfoil family the ratio of the maximum camber of each airfoil to the length of the chord line ranges from 1.83% to 2.67%.

[0008] The wind turbine airfoil family as claimed in the preceding paragraph, wherein the ratio of the distance from the maximum camber to the leading edge of each airfoil to the length of the chord line ranges from 42.9% to 84.5%.

[0009] The wind turbine airfoil family as claimed in the preceding paragraph, wherein in the first airfoil family the ratio of the distance from the maximum camber to the leading edge of each airfoil to the length of the chord line ranges from 42.9% to 78.4%; in the second airfoil family the ratio of the distance from the maximum camber to the leading edge of each airfoil to the length of the chord line ranges from 74.2% to 82.8%; and in the third airfoil family the ratio of the distance from the maximum camber to the leading edge of each airfoil to the length of the chord line ranges from 75.1% to 84.5%.

[0010] The wind turbine airfoil family as claimed in the preceding paragraph, wherein the ratio of the radius of the leading edge to the length of the chord line ranges from 1.7% to 26.7%.

[0011] The wind turbine airfoil family as claimed in the preceding paragraph, wherein in the first airfoil family the ratio of the radius of the leading edge of each airfoil to the length of the chord line ranges from 1.7% to 3.6%; in the second airfoil family the ratio of the radius of the leading edge of each airfoil to the length of the chord line ranges from 6.7% to 8.9%; and in the third airfoil family the ratio of the radius of the leading edge of each airfoil to the length of the chord line ranges from 20.6% to 26.7%.

[0012] The wind turbine airfoil family as claimed in the preceding paragraph, wherein the ratio of the thickness of the trailing edge to the length of the chord line ranges from 0.34% to 42.9%.

[0013] The wind turbine airfoil family as claimed in the preceding paragraph, wherein in the first airfoil family the ratio of the thickness of the trailing edge of each airfoil to the length of the chord line ranges from 0.34% to 0.42%; in the second airfoil family the ratio of the thickness of the trailing edge of each airfoil to the length of the chord line ranges from 0.48% to 1.68%; and in the third airfoil family the ratio of the thickness of the trailing edge of each airfoil to the length of the chord line ranges from 17.91% to 42.9%.

[0014] The wind turbine blade airfoil family of the present application includes a first airfoil family, a second airfoil family and a third airfoil family. The three airfoil families are respectively applicable to different parts of the blade. The three airfoil families include multiple airfoils. The first relative thickness d1 of each airfoil in the first airfoil family has a range of 17.1% ≤ d1 ≤ 26.3%, which is applicable to the outer area of ​​the blade. The second relative thickness d2 of each airfoil in the second airfoil family has a range of 28.5% ≤ d2 ≤ 36.8%, which is applicable to the middle part of the blade. The third relative thickness d3 of each airfoil in the third airfoil family has a range of 37.9% ≤ d3 ≤ 63.0%, which is applicable to the inner area of ​​the blade. The maximum thickness of each airfoil is from the front to the back. The ratio of the distance from the leading edge to the length of the chord is in the range of 26.5% to 35.0%. Within this range, the maximum thickness position is close to the aerodynamic center. The three airfoil families of the wind turbine blade airfoil family of the present application improve the core characteristic parameters of the airfoil aerodynamic-structure by adjusting the geometric shape characteristics of the airfoil, such as relative thickness and maximum thickness position, relative curvature and maximum curvature position, leading edge radius, trailing edge thickness, etc., including design lift characteristics, lift-to-drag ratio characteristics, critical stall characteristics, leading edge roughness sensitivity, geometric area, section inertia moment, etc., thereby achieving high performance, low cost, high aerodynamic adaptability and lightweight and other blade development requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the following is a brief introduction to the drawings required for use in the embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without any creative work.

[0016] Figure 1 This is a schematic structural diagram of a blade provided in an embodiment of the present application;

[0017] Figure 2 Schematic diagram of three outer thin airfoil geometric profiles of the first airfoil family provided in an embodiment of the present application;

[0018] Figure 3 Schematic diagram of geometric profiles of two mid-thick airfoils of the second airfoil family provided in an embodiment of the present application;

[0019] Figure 4 Schematic diagram of geometric profiles of three blade root thick airfoils of the third airfoil family provided in an embodiment of the present application;

[0020] Figure 5 Schematic diagram comparing the maximum thickness position of the new airfoil provided by the embodiment of the present application and the reference airfoil;

[0021] Figure 6 Schematic diagram of a comparison of aerodynamic efficiency-load characteristic curves of the outer thin airfoil of the first airfoil family provided in an embodiment of the present application;

[0022] Figure 7 2 is a schematic diagram comparing aerodynamic efficiency-load characteristic curves of the mid-thickness airfoil of the second airfoil family provided in an embodiment of the present application;

[0023] Figure 8 2 is a schematic diagram comparing aerodynamic efficiency-load characteristic curves of the blade root thick airfoil of the third airfoil family provided in an embodiment of the present application;

[0024] Figure 9 It is a schematic diagram of an application layout solution of an exemplary new airfoil family provided in an embodiment of the present application.

[0025] Description of Figure Numbers:

[0026] 10. Leading edge; 20. Upper surface; 30. Trailing edge; 40. Lower surface; 50. Chord line; 60. Camber line. DETAILED DESCRIPTION

[0027] The features and exemplary embodiments of various aspects of the present application will be described in detail below. In order to make the purpose, technical solutions and advantages of the present application clearer, the present application will be further described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only intended to explain the present application, rather than to limit the present application. For those skilled in the art, the present application can be implemented without the need for some of these specific details. The following description of the embodiments is merely to provide a better understanding of the present application by illustrating the examples of the present application.

[0028] like Figure 1 As shown, the geometric characteristic parameters of the airfoil are defined as follows:

[0029] The median camber line 60 is used to represent the curve formed by the midpoints of the upper surface 20 and the lower surface 40 of the airfoil at the same horizontal coordinate and vertical coordinate.

[0030] The leading edge 10 and the leading edge radius are used to indicate that the frontmost point of the camber line 60 of the airfoil is called the leading edge 10 of the airfoil, and the radius of the inscribed circle at the leading edge 10 is called the leading edge radius.

[0031] Trailing edge 30 and trailing edge thickness: The last point of the camber line 60 of the airfoil is called the trailing edge 30, and the distance between the upper surface 20 and the lower surface 40 of the airfoil at the trailing edge 30 is called the trailing edge thickness.

[0032] The chord line 50 and the chord length are used to indicate that the line between the leading edge 10 and the trailing edge 30 of the airfoil is called the chord line 50 of the airfoil, and the length of the chord line 50 is called the chord length of the airfoil.

[0033] Camber, used to express the maximum vertical distance from the camber line 60 to the chord line 50, is called the airfoil camber, and the ratio of camber to chord length is called relative camber.

[0034] Thickness, the distance between the upper surface 20 and the lower surface 40 along the direction perpendicular to the chord line 50 is called the airfoil thickness. Conventionally, the relative thickness of an airfoil refers to the ratio of the maximum thickness of the entire airfoil to the chord length.

[0035] It should be noted that the chord length in the embodiments of the present application is the reference line of the airfoil, and the geometric characteristic parameter values ​​of the airfoil are all relative values ​​obtained with reference to the chord length of the airfoil. That is, in the coordinate system of the airfoil, the length of the chord length is 1, the front end of the airfoil near the leading edge 10 is the coordinate origin, the horizontal coordinate at the rear end of the trailing edge 30 is 1, and the vertical coordinate is symmetrical about the horizontal axis. Therefore, the maximum thickness position of the airfoil refers to the horizontal coordinate of the maximum thickness of the airfoil in the airfoil coordinate system, and the maximum camber position of the airfoil refers to the horizontal coordinate of the maximum camber in the airfoil coordinate system.

[0036] like Figures 1 to 9 As shown, an embodiment of the present application provides a family of wind turbine blade airfoils, which includes a first airfoil family, a second airfoil family, and a third airfoil family. The first airfoil family, the second airfoil family, and the third airfoil family each include a plurality of airfoils, each airfoil including a leading edge 10, an upper surface 20, a trailing edge 30, and a lower surface 40 connected in sequence. The connecting line from the leading edge 10 to the trailing edge is a chord 50. The ratio of the maximum thickness between the upper surface 20 and the lower surface 40 to the length of the chord 50 is a relative thickness. Each airfoil in the first airfoil family has a first relative thickness d1. The first relative thickness d1 has the following characteristics: Range: 17.1%≤d1≤26.3%; each airfoil in the second airfoil family has a second relative thickness d2, and the second relative thickness d2 has the following range: 28.5%≤d2≤36.8%; each airfoil in the third airfoil family has a third relative thickness d3, and the third relative thickness d3 has the following range: 37.9%≤d3≤63.0%; the ratio of the distance from the maximum thickness of each airfoil to the leading edge 10 to the length of the chord line 50 ranges from 26.5% to 35.0%, that is, the range of the maximum thickness position of each airfoil is 0.265 to 0.350.

[0037] In specific implementation, the airfoil family of the wind turbine blade of the embodiment of the present application includes a first airfoil family, a second airfoil family and a third airfoil family, the three airfoil families are respectively suitable for different parts of the blade, and the three airfoil families each include a plurality of airfoils. The first relative thickness d1 of each airfoil in the first airfoil family has a range of 17.1%≤d1≤26.3%, which is suitable for the outer region of the blade, i.e., the blade tip. The second relative thickness d2 of each airfoil in the second airfoil family has a range of 28.5%≤d2≤36.8%, which is suitable for the middle part of the blade, i.e., the part between the blade tip and the blade root. The third relative thickness d3 of each airfoil in the third airfoil family has a range of 37.9%≤d3≤63.0%, which is suitable for the inner region of the blade, i.e., the blade root. For different regions of the blade, the first airfoil family, the second airfoil family and the third airfoil family of the embodiment of the present application have different relative thickness ranges, which are targeted in design and can be set relatively independently according to the shape of the whole blade, so that the parameters of the wind turbine blade are optimized. The ratio of the distance from the maximum thickness of each airfoil to the leading edge 10 to the length of the chord line 50 ranges from 26.5% to 35.0%. In this range, the maximum thickness position of the airfoil is close to the aerodynamic center, which makes the wind turbine blade have high aeroelastic stability. On the other hand, the setting of the relative thickness range and the maximum thickness position range of each airfoil can affect the range of the laminar boundary of the airfoil, thereby having an important influence on the drag level, maximum lift-drag ratio and other parameters of the airfoil.

[0038] Specifically, the first airfoil family includes three airfoils, and the first relative thickness d1 of the three airfoils is 18%, 21% and 25% respectively. The second airfoil family includes two airfoils, and the second relative thickness d2 of the two airfoils is 30% and 35% respectively. The third airfoil family includes three airfoils, and the third relative thickness d3 of the three airfoils is 40%, 50% and 60% respectively.

[0039] As shown in FIG. 4, FIG. 5 and FIG. 6, the maximum thickness position of the new airfoil provided by the embodiment of the present application is compared with the maximum thickness position of the reference airfoil. Figure 5 As shown in FIG. 4, FIG. 5 and FIG. 6, the maximum thickness position of the new airfoil provided by the embodiment of the present application is compared with the maximum thickness position of the reference airfoil. Figure 5 As shown in FIG. 4, FIG. 5 and FIG. 6, the maximum thickness position of the new airfoil provided by the embodiment of the present application is compared with the maximum thickness position of the reference airfoil.

[0040] The wind power blade airfoil family of the embodiment of the present application, wherein, in the first airfoil family, the ratio of the distance from the maximum thickness of each airfoil to the leading edge 10 to the length of the chord line 50 ranges from 27.1% to 34.4%, that is, the maximum thickness position of the airfoil ranges from 0.271 to 0.344; in the second airfoil family, the ratio of the distance from the maximum thickness of each airfoil to the leading edge 10 to the length of the chord line 50 ranges from 26.5% to 29.9%, that is, the maximum thickness position of the airfoil ranges from 0.265 to 0.299; in the third airfoil family, the ratio of the distance from the maximum thickness of each airfoil to the leading edge 10 to the length of the chord line 50 ranges from 26.7% to 35.0%, that is, the maximum thickness position of the airfoil ranges from 0.267 to 0.350.

[0041] In specific implementation, since the first relative thickness d1, the second relative thickness d2, and the third relative thickness d3 are all different, the maximum thickness positions of the airfoils in the first airfoil family, the airfoils in the second airfoil family, and the airfoils in the third airfoil family are also different for different relative thicknesses, so that each airfoil family can have a suitable maximum thickness position under different relative thicknesses, so that each airfoil in the first airfoil family has low resistance characteristics and high lift-drag ratio characteristics, which is beneficial to enhancing the aerodynamic efficiency of the wind power blade as a whole.

[0042] The wind power blade airfoil family of the embodiment of the present application, wherein the airfoil has a maximum camber, and the ratio of the maximum camber of each airfoil to the length of the chord line 50 ranges from 1.83% to 4.57%. It should be noted that the ratio of the maximum camber to the length of the chord line 50 is the relative camber.

[0043] The wind power blade airfoil family of the embodiment of the present application, wherein, in the first airfoil family, the ratio of the maximum camber of each airfoil to the length of the chord line 50 ranges from 3.47% to 4.57%; in the second airfoil family, the ratio of the maximum camber of each airfoil to the length of the chord line 50 ranges from 2.44% to 3.07%; and in the third airfoil family, the ratio of the maximum camber of each airfoil to the length of the chord line 50 ranges from 1.83% to 2.67%.

[0044] In specific implementation, the range of the maximum camber in each airfoil family can affect the asymmetry of airfoil flow, and by adjusting and setting a suitable camber characteristic, the aerodynamic characteristics such as the design lift coefficient, the maximum lift coefficient, the critical stall angle of attack, and the stall flattening characteristic of the airfoil can be improved.

[0045] Specifically, the first airfoil family includes three airfoils, and the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of the three airfoils is 4.35%, 4.00% and 3.65% respectively; the second airfoil family includes two airfoils, and the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of the two airfoils is 2.92% and 2.57% respectively; the third airfoil family includes three airfoils, and the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of the three airfoils is 1.93%, 2.07% and 2.54% respectively.

[0046] The wind power blade airfoil family of the embodiment of the present application, wherein the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of each airfoil ranges from 42.9% to 84.5%.

[0047] The wind power blade airfoil family of the embodiment of the present application, wherein in the first airfoil family, the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of each airfoil ranges from 42.9% to 78.4%, i.e. the range of the maximum camber position of the airfoil is 0.429-0.784; in the second airfoil family, the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of each airfoil ranges from 74.2% to 82.8%, i.e. the range of the maximum camber position of the airfoil is 0.742-0.828; in the third airfoil family, the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of each airfoil ranges from 75.1% to 84.5%, i.e. the range of the maximum camber position of the airfoil is 0.751-0.845.

[0048] In specific implementation, the ratio between the distance from the maximum camber to the leading edge 10 and the length of the chord line 50 of the airfoil in each airfoil family is set in a range, which can affect the asymmetry and boundary layer separation characteristics of the airfoil flow. By setting a suitable maximum camber position, the design lift coefficient, maximum lift coefficient, critical stall angle of attack, stall smoothness characteristics and other lift characteristics of the airfoil can also be improved, which is conducive to realizing the blade development requirements of low cost and light weight.

[0049] Specifically, the first airfoil family includes three airfoils, and the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of the three airfoils is 45.2%, 70.4% and 74.7% respectively; the second airfoil family includes two airfoils, and the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of the two airfoils is 78.9% and 78.1% respectively; the third airfoil family includes three airfoils, and the ratio of the distance from the maximum camber to the leading edge 10 to the length of the chord line 50 of the three airfoils is 79.0%, 80.5% and 79.2% respectively.

[0050] The wind power blade airfoil family of the embodiment of the present application, wherein the ratio of the radius of the leading edge 10 to the length of the chord line 50 ranges from 1.7% to 26.7%.

[0051] The wind turbine airfoil family of the embodiments of the present application, wherein, in the first airfoil family, the ratio of the radius of the leading edge 10 to the length of the chord line 50 of each airfoil ranges from 1.7% to 3.6%; in the second airfoil family, the ratio of the radius of the leading edge 10 to the length of the chord line 50 of each airfoil ranges from 6.7% to 8.9%; in the third airfoil family, the ratio of the radius of the leading edge 10 to the length of the chord line 50 of each airfoil ranges from 20.6% to 26.7%.

[0052] In specific implementation, the setting of the ratio of the radius of the leading edge 10 to the length of the chord line 50 of each airfoil in each airfoil family can affect the laminar flow range or the leading edge transition position and the stall separation characteristics of the airfoil, thereby having an important impact on the leading edge roughness sensitivity. By setting a suitable leading edge radius, the leading edge roughness sensitivity of the airfoil aerodynamic performance can be effectively reduced, and the aerodynamic adaptability of the wind turbine airfoil to complex environments is improved.

[0053] Specifically, the first airfoil family includes three airfoils, and the ratio of the radius of the leading edge 10 to the length of the chord line 50 of the three airfoils is 1.8%, 2.4% and 3.4% respectively; the second airfoil family includes two airfoils, and the ratio of the radius of the leading edge 10 to the length of the chord line 50 of the two airfoils is 7.1% and 8.5% respectively; the third airfoil family includes three airfoils, and the ratio of the radius of the leading edge 10 to the length of the chord line 50 of the three airfoils is 13.8%, 21.7% and 25.4% respectively.

[0054] The wind turbine airfoil family of the embodiments of the present application, wherein the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 ranges from 0.34% to 42.9%.

[0055] The wind turbine airfoil family of the embodiments of the present application, wherein, in the first airfoil family, the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 of each airfoil ranges from 0.34% to 0.42%; in the second airfoil family, the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 of each airfoil ranges from 0.48% to 1.68%; in the third airfoil family, the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 of each airfoil ranges from 17.91% to 42.9%.

[0056] In specific implementation, the setting of the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 of each airfoil in each airfoil family can affect the adverse pressure gradient and the downwash effect of the boundary layer flow of the airfoil, thereby having an important impact on the lift coefficient, the drag coefficient, the critical stall angle of attack and the roughness sensitivity. By setting a suitable trailing edge thickness, the lift characteristics of the airfoil can be further improved and the leading edge roughness sensitivity can be reduced, which is helpful to further improve the aerodynamic adaptability of the wind turbine.

[0057] Specifically, the first airfoil family includes three airfoils, and the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 of the three airfoils is 0.36%, 0.40% and 0.40% respectively; the second airfoil family includes two airfoils, and the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 of the two airfoils is 0.50% and 1.60% respectively; the third airfoil family includes three airfoils, and the ratio of the thickness of the trailing edge 30 to the length of the chord line 50 of the three airfoils is 18.86%, 29.20% and 40.86% respectively.

[0058] In addition, the relative thickness, trailing edge thickness, leading edge radius and the like of the airfoil have a decisive effect on the parameters such as the cross-sectional area and the second-order cross-sectional moment of inertia of the airfoil, and through appropriate parameter setting, the geometric structural properties of the airfoil are helped to be improved, and the structural efficiency of the applied blade is helped to be improved, and the development of low-cost and lightweight blades is realized.

[0059] Therefore, the three airfoil families of the wind power blade airfoil family of the present application improve the airfoil aerodynamic-structural properties by improving the geometric shape characteristics of the airfoil, such as the relative thickness, maximum thickness position, relative camber, maximum camber position, leading edge radius and trailing edge thickness, including core aerodynamic characteristic parameters such as design lift coefficient, maximum lift-drag ratio, critical stall angle of attack, maximum lift coefficient and low roughness sensitivity, and geometric structural characteristic parameters such as cross-sectional area, circumference and second-order moment of inertia, which help to realize the blade development requirements of high performance, low cost, high aerodynamic adaptability and lightweight and the like.

[0060] As shown in Figure 2 , FIG. 1 is a schematic diagram of three outer thin airfoil geometric profiles of a first airfoil family provided by an embodiment of the present application. Figure 2

[0061] Specifically, the geometric characteristic parameters of the three airfoils in the first airfoil family shown in Table 1 include six geometric characteristic parameters, including relative thickness, maximum thickness position, relative camber, maximum camber position, leading edge radius and trailing edge thickness, and the three airfoils are all suitable for the outer side region of the blade, i.e. the tip portion of the blade.

[0062] Table 1

[0063]

[0064] As shown in Figure 3 , FIG. 2 is a schematic diagram of two medium-thickness airfoil geometric profiles of a second airfoil family provided by an embodiment of the present application. Figure 3

[0065] ​​The geometric characteristic parameters of two airfoils in the second airfoil family shown in Table 2 include six geometric characteristic parameters, i.e., relative thickness, maximum thickness position, relative camber, maximum camber position, leading edge radius and trailing edge thickness, and the two airfoils are suitable for the middle region of the blade, i.e., the region between the blade tip and the blade root.

[0066] Table 2

[0067]

[0068] As shown in Table 4, Table 4 shows the relative structural characteristic parameters of the eight-thickness airfoils in the embodiment of the present application, and the relative structural characteristic parameters of the eight-thickness airfoils of the currently common DU airfoil with the same thickness as the present application. The structural characteristic parameters include the area, the perimeter, the second cross-sectional moment skinIyy and the second cross-sectional moment skinIxx of the airfoil. Figure 4 Figure 4 The schematic diagrams of three blade root large-thickness airfoils of the third airfoil family provided by the embodiment of the present application are shown in Table 3.

[0069] The geometric characteristic parameters of three airfoils in the third airfoil family shown in Table 3 include six geometric characteristic parameters, i.e., relative thickness, maximum thickness position, relative camber, maximum camber position, leading edge radius and trailing edge thickness, and the three airfoils are suitable for the inside region of the blade, i.e., the blade root.

[0070] Table 3

[0071]

[0072] As shown in Table 4, Table 4 shows the relative structural characteristic parameters of the eight-thickness airfoils in the embodiment of the present application, and the relative structural characteristic parameters of the eight-thickness airfoils of the currently common DU airfoil with the same thickness as the present application. The structural characteristic parameters include the area, the perimeter, the second cross-sectional moment skinIyy and the second cross-sectional moment skinIxx of the airfoil.

[0073] Table 4

[0074]

[0075] ​From Table 4, it can be seen that in the first airfoil family, the profile perimeters of the three thin airfoils with relative thicknesses of 18%, 21%, and 25% are 2.079, 2.093, and 2.126, respectively; the cross-sectional areas are 0.108, 0.122, and 0.143, respectively; the cross-sectional moments of inertia skin Iyy are 0.2004, 0.2041, and 0.2134, respectively; and the cross-sectional moments of inertia skin Ixx are 0.0081, 0.0103, and 0.0143, respectively. In the second airfoil family, the profile perimeters of the two thick airfoils with relative thicknesses of 30% and 35% are 2.167 and 2.218, respectively; the cross-sectional areas are 0.171 and 0.201, respectively; the cross-sectional moments of inertia skin Iyy are 0.2178 and 0.2239, respectively; and the cross-sectional moments of inertia skin Ixx are 0.0204 and 0.0280, respectively. In the third airfoil family, the profile perimeters of the three blade root thick airfoils with relative thicknesses of 40%, 50%, and 60% are 2.412, 2.588, and 2.766, respectively; the cross-sectional areas are 0.291, 0.388, and 0.483, respectively; the cross-sectional moments of inertia skin Iyy are 0.2639, 0.3032, and 0.3423, respectively; and the cross-sectional moments of inertia skin Ixx are 0.0477, 0.0834, and 0.1293, respectively.

[0076] Compared with the DU airfoils with the same relative thickness, the structural characteristic parameters of the five airfoils in the first and second airfoil families of the present application are not much different from those of the five airfoils in the DU airfoils with the same thickness. However, the structural characteristic parameters of the three airfoils in the third airfoil family of the present application are greatly improved compared with those of the three airfoils in the DU airfoils with the same thickness, in which the airfoil perimeter is increased by about 5%, the cross-sectional area is increased by about 20%, the cross-sectional moment of inertia skin Iyy is increased by 9% to 16%, and the cross-sectional moment of inertia skin Ixx is increased by 18% to 24%.

[0077] As shown in Table 5, the relative aerodynamic characteristic parameters of the three thickness airfoils in the first airfoil family of the present application are shown in Table 5, as well as the relative aerodynamic characteristic parameters of the three airfoils with the same thickness in the currently common DU airfoils and RF high-lift airfoils. The aerodynamic characteristic parameters in Table 5 include the design lift coefficient, the maximum lift-drag ratio, the stall angle of attack, the maximum lift coefficient, the stall smoothness parameter, the lift roughness sensitivity, and the rough maximum lift.

[0078] Table 5

[0079]

[0080] From Table 5, it can be seen that the design lift coefficients of the three airfoils with relative thicknesses of 18%, 21%, and 25% in the first airfoil family in the embodiments of the present application are 1.33, 1.19, and 1.48, respectively, which are increased by 58%, 8%, and 36% respectively relative to the DU airfoil with the same thickness. The maximum lift-drag ratios are 202.3, 192.7, and 180.5, respectively, which are increased by 24%, 14%, and 16% respectively relative to the DU airfoil with the same thickness. The critical stalling angles of attack are 12°, 11°, and 11°, respectively, which are equivalent to that of the DU airfoil with the same thickness. While the design lift coefficients and the maximum lift-drag ratios are greatly increased, the maximum lift coefficients of the new airfoils are effectively limited (all less than 1.85), and the airfoils have relatively gentle stalling characteristics (the stalling gentleness parameter is lower than that of another series of reference airfoils RF characterized by high lift coefficients). In terms of the leading edge roughness sensitivity, the maximum lift coefficients under the rough condition are still relatively high, being 1.70, 1.64, and 1.59, respectively. The maximum lift sensitivity parameters under the rough condition are 1.8%, 3.0%, and 12.8%, respectively, which have low roughness sensitivity characteristics and meet the design specifications. The airfoils in the first airfoil family of the embodiments of the present application have significant advantages in the design lift coefficients and the maximum lift-drag ratios while maintaining low roughness sensitivity and gentle stalling characteristics relative to the existing general airfoils. In specific implementations, the airfoils outside the blades in the first airfoil family in the embodiments of the present application have an airfoil aerodynamic efficiency increased by about 20% and a design lift increased by about 20% on the basis of maintaining low roughness sensitivity and gentle stalling characteristics.

[0081] Reference is made to Figure 6 , Figure 6 The comparison of the airfoils with a relative thickness of 18% and the smooth surface and the rough surface in the embodiments of the present application and the airfoils with a relative thickness of 18% and the smooth surface and the rough surface in the DU airfoil is shown in Table 5, which shows the aerodynamic efficiency (lift-drag ratio)-load (lift coefficient) characteristic curves of the four different airfoils. It can be seen that the airfoils in the first airfoil family of the embodiments of the present application have significant advantages in the design lift coefficients and the maximum lift-drag ratios relative to the general DU airfoils, and the airfoils with the smooth surface also have advantages in the design lift coefficients and the maximum lift-drag ratios in the same airfoils.

[0082] As shown in Table 6, the relative aerodynamic characteristic parameters of the two thickness airfoils in the second airfoil family in the embodiments of the present application and the relative aerodynamic parameters of the two airfoils with the same thickness in the currently used DU airfoils and FFA airfoils are shown in Table 6. The aerodynamic characteristic parameters in Table 6 include the design lift coefficient, the maximum lift-drag ratio, the stalling point angle of attack, the maximum lift coefficient, the lift roughness sensitivity, and the rough maximum lift.

[0083] Table 6

[0084]

[0085] From Table 6, it can be seen that the design lift coefficients of the two airfoils with relative thickness of 30% and 35% in the second airfoil family in the embodiment of the present application are 1.63 and 1.91 respectively, which are increased by 28% and 44% respectively relative to the DU airfoil with the same thickness; the maximum lift-drag ratios are 175.4 and 180.5 respectively, which are increased by 32% and 42% respectively relative to the DU airfoil with the same thickness; the critical stall angles of attack are 15° and 15° respectively, which are increased by more than 2° relative to the DU airfoil with the same thickness; and the lift sensitivity parameters are 27.28% and 43.85% respectively, which meet the airfoil design specification. The airfoils in the second airfoil family in the embodiment of the present application have significant advantages in the design lift coefficient, the maximum lift-drag ratio, the critical stall angle of attack and the like relative to the existing general airfoils. In a specific implementation, the airfoils in the second airfoil family in the embodiment of the present application have aerodynamic efficiency increased by more than 30%.

[0086] Referring to Figure 7 , Figure 7 The comparison of the airfoils with relative thickness of 35% and the smooth surface and the rough surface in the embodiment of the present application and the airfoils with relative thickness of 35% and the smooth surface and the rough surface in the DU airfoil is shown in Table 6, which shows the aerodynamic efficiency (lift-drag ratio)-load (lift coefficient) characteristic curves of the four different airfoils. It can be seen that the airfoils in the first airfoil family in the embodiment of the present application have significant advantages in the design lift coefficient and the maximum lift-drag ratio relative to the general DU airfoil under the condition of the same roughness, and the airfoils with the smooth surface also have advantages in the design lift coefficient and the maximum lift-drag ratio among the same airfoils.

[0087] As shown in Table 7, the relative aerodynamic characteristic parameters of the three thickness airfoils in the third airfoil family in the embodiment of the present application and the relative aerodynamic parameters of the three airfoils with the same thickness in the currently used DU airfoil are shown in Table 7. The aerodynamic characteristic parameters in Table 7 include the design stall point angle of attack, the maximum lift coefficient, the lift roughness sensitivity, the maximum roughness lift and the roughness stall angle of attack.

[0088] Table 7

[0089]

[0090] Table 7 shows that the maximum lift coefficients of the three airfoils in the third airfoil family of the present embodiment, with relative thicknesses of 40%, 50%, and 60%, are 3.15, 3.44, and 3.88, respectively, which are 34%, 45%, and 69% higher than those of the DU airfoil of the same thickness. The critical stall angles of attack are 20°, 20°, and 20°, respectively, which are more than 6° higher than those of the DU airfoil of the same thickness. The lift sensitivity parameters are 29.07%, 32.59%, and 30.21%, respectively, which are much lower than the roughness sensitivity parameters of the DU airfoil of the same thickness. While meeting the airfoil design specifications, the three thicker airfoils in the present embodiment have significant advantages over the DU airfoil in terms of critical stall angle of attack, maximum lift coefficient, and low roughness sensitivity.

[0091] For reference Figure 8 , Figure 8 Figure 2 shows a comparison of smooth and rough airfoils with a relative thickness of 40% in the present application, as well as a comparison of smooth and rough airfoils with a relative thickness of 40% in the DU airfoil, showing the aerodynamic efficiency (lift-to-drag ratio)-load (lift coefficient) characteristic curves of the four different airfoils. It can be seen that the airfoils in the first airfoil family of the present application have significant advantages over the general-purpose DU airfoils in terms of design lift coefficient and maximum lift-to-drag ratio. Furthermore, among the same airfoils, the smooth airfoils also have advantages in terms of design lift coefficient and maximum lift-to-drag ratio.

[0092] As shown in Table 8, Table 8 shows that under the condition of a 120m-class blade, the original airfoil layout scheme that completely adopts the DU airfoil and the new airfoil layout scheme that partially adopts the airfoil in the airfoil family of the embodiment of the present application are compared in terms of clean surface power generation, rough surface power generation, blade root load and rough surface power generation loss.

[0093] Table 8

[0094]

[0095] Table 8 shows that compared to the original airfoil layout, the new airfoil layout replaces the 40%-thick airfoil in the DU airfoil with the 40%-thick airfoil in the third airfoil family in the embodiment of this application. This improves blade power generation (by 0.5%) and reduces blade root steady-state load (by 0.3%). The roughness sensitivity of the blade is also reduced. Therefore, the airfoil family in the embodiment of this application is effective in improving blade performance.

[0096] Based on the airfoil in the embodiment of the present application, there are a variety of application layout schemes in blade design, including partially replacing the existing airfoil family and completely adopting the new airfoil of the embodiment for blade aerodynamic design layout, such as Figure 9 shown.

[0097] It should be noted that, in the present document, relational terms such as first and second and the like can be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Moreover, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0098] The above description is merely illustrative of the application, and not restrictive. Various modifications can be made by those skilled in the art without departing from the scope of the application. Thus, it is intended that the scope of the application should be determined by the appended claims and their equivalents.

Claims

1. A wind turbine blade airfoil family, characterized in that: The invention comprises a first airfoil family, a second airfoil family and a third airfoil family, wherein the first airfoil family, the second airfoil family and the third airfoil family each comprise a plurality of airfoils, each of the airfoils comprises a leading edge (10), an upper surface (20), a trailing edge (30) and a lower surface (40) connected in sequence, a connecting line from the leading edge (10) to the trailing edge is a chord line (50), a ratio of a maximum thickness between the upper surface (20) and the lower surface (40) to a length of the chord line (50) is a relative thickness, each of the airfoils in the first airfoil family has a first relative thickness d1, and the first relative thickness d1 has the following range: 17.1%≤d1≤26.3%, wherein the first airfoil family comprises an 18% thickness airfoil, a 21% thickness airfoil and a 25% thickness airfoil; the second airfoil family comprises an 18% thickness airfoil, a 21% thickness airfoil and a 25% thickness airfoil; Each of the airfoils in the family has a second relative thickness d2, and the second relative thickness d2 has the following range: 28.5%≤d2≤36.8%, wherein the second airfoil family includes 30% thickness airfoils and 35% thickness airfoils; each of the airfoils in the third airfoil family has a third relative thickness d3, and the third relative thickness d3 has the following range: 37.9%≤d3≤63.0%, wherein the third airfoil family includes 40% thickness airfoils, 50% thickness airfoils and 60% thickness airfoils; the ratio of the distance from the maximum thickness of each airfoil to the leading edge (10) to the length of the chord (50) ranges from 26.5% to 35.0%, and the ratio of the maximum camber of each airfoil to the length of the chord (50) ranges from 1.83% to 4.57%, The characteristic parameters of the maximum thickness position and relative camber of each airfoil are as follows: 。 2. The wind turbine blade airfoil family according to claim 1, characterized in that: The ratio of the distance from the maximum curvature of each airfoil to the leading edge (10) to the length of the chord line (50) ranges from 42.9% to 84.5%.

3. The wind turbine blade airfoil family according to claim 2, characterized in that: In the first family of airfoils, the ratio of the distance from the maximum camber of each airfoil to the leading edge (10) to the length of the chord (50) ranges from 42.9% to 78.4%; in the second family of airfoils, the ratio of the distance from the maximum camber of each airfoil to the leading edge (10) to the length of the chord (50) ranges from 74.2% to 82.8%; in the third family of airfoils, the ratio of the distance from the maximum camber of each airfoil to the leading edge (10) to the length of the chord (50) ranges from 75.1% to 84.5%, The characteristic parameters of the maximum camber position of each airfoil are as follows:

4. The wind turbine blade airfoil family according to claim 1, characterized in that: The ratio of the radius of the leading edge (10) to the length of the chord (50) ranges from 1.7% to 26.7%.

5. The wind turbine blade airfoil family according to claim 4, characterized in that: In the first family of airfoils, the ratio of the radius of the leading edge (10) of each airfoil to the length of the chord (50) ranges from 1.7% to 3.6%; in the second family of airfoils, the ratio of the radius of the leading edge (10) of each airfoil to the length of the chord (50) ranges from 6.7% to 8.9%; in the third family of airfoils, the ratio of the radius of the leading edge (10) of each airfoil to the length of the chord (50) ranges from 20.6% to 26.7%, The characteristic parameters of the leading edge radius of each airfoil are as follows:

6. The wind turbine blade airfoil family according to claim 1, characterized in that: The ratio of the thickness of the trailing edge (30) to the length of the chord (50) ranges from 0.34% to 42.9%.

7. The wind turbine blade airfoil family according to claim 6, characterized in that: In the first family of airfoils, the ratio of the thickness of the trailing edge (30) of each airfoil to the length of the chord (50) ranges from 0.34% to 0.42%; in the second family of airfoils, the ratio of the thickness of the trailing edge (30) of each airfoil to the length of the chord (50) ranges from 0.48% to 1.68%; in the third family of airfoils, the ratio of the thickness of the trailing edge (30) of each airfoil to the length of the chord (50) ranges from 17.91% to 42.9%, The characteristic parameters of the leading edge radius of each airfoil are as follows:

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