Wind turbine blade airfoil family

Abstract

A wind turbine blade airfoil family, comprising a first airfoil family, a second airfoil family, and a third airfoil family, each of which comprises a plurality of airfoils. Each airfoil in the first airfoil family has a first relative thickness d1, having the range of 17.1%≤d1≤26.3%; each airfoil in the second airfoil family has a second relative thickness d2, having the range of 28.5%≤d2≤36.8%; each airfoil in the third airfoil family has a third relative thickness d3, having the range of 37.9%≤d2≤63.0%; the range of the ratio of the distance from the maximum thickness position of each airfoil to the front edge to the chord length is 26.5%-35.0%. The airfoil family can improve the efficiency-load characteristics of blades, increase the stall margin of blades, the roughness sensitivity of the power generation performance, etc., and is conducive to the low-cost and lightweight design of blades.

Description

Wind turbine blade airfoil family

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to Chinese patent application 202311733041.7, filed on December 15, 2023, entitled “Wind turbine blade airfoil family,” the entire contents of which are incorporated herein by reference. Technical Field

[0003] The present application belongs to the field of wind power generation technology, and in particular relates to a family of wind turbine blade airfoils. Background Art

[0004] With the increasing size of wind turbine blades and the development of wind resources in complex and diverse terrains, the design and manufacture of large wind turbine blades face conflicting requirements, including high aerodynamic efficiency, low load, aerodynamic adaptability in complex environments, aeroelastic stability, high structural rigidity, low material cost, and ease of production, manufacturing, and maintenance. Currently, general-purpose airfoils used in blade design lack excellent overall performance, especially high-performance thick airfoils and high-lift thick airfoils, making it difficult to meet the requirements of low-cost and lightweight blade development.

[0005] Summary of the Invention

[0006] The present application provides a family of wind turbine blade airfoils that can improve airfoil performance, including core aerodynamic structural properties such as design lift characteristics, lift-to-drag ratio characteristics, critical stall characteristics, leading edge roughness sensitivity, and section inertia moment. It can fundamentally improve the efficiency-load characteristics of the blades, increase the stall margin of the blades, the roughness sensitivity of the power generation performance, etc., and is conducive to the low-cost and lightweight design of the blades.

[0007] 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 multiple 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 a 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%≤d2≤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%.

[0008] As shown in the above wind turbine blade airfoil family, 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 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 ranges from 26.5% to 29.9%; 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 ranges from 26.7% to 35.0%.

[0009] In the above-mentioned wind turbine blade airfoil family, the airfoil has a maximum camber, and the ratio of the maximum camber of each airfoil to the length of the chord is in the range of 1.83% to 4.57%.

[0010] As shown in the above wind turbine blade airfoil family, in the first airfoil family, the ratio of the maximum camber of each airfoil to the length of the chord 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 ranges from 2.44% to 3.07%; in the third airfoil family, the ratio of the maximum camber of each airfoil to the length of the chord ranges from 1.83% to 2.67%.

[0011] In the above wind turbine blade airfoil family, the ratio of the distance from the maximum curvature point to the leading edge of each airfoil to the length of the chord line ranges from 42.9% to 84.5%.

[0012] As shown in the above wind turbine blade airfoil family, in the first airfoil family, the ratio of the distance from the maximum curvature of each airfoil to the leading edge to the length of the chord ranges from 42.9% to 78.4%; in the second airfoil family, the ratio of the distance from the maximum curvature of each airfoil to the leading edge to the length of the chord ranges from 74.2% to 82.8%; in the third airfoil family, the ratio of the distance from the maximum curvature of each airfoil to the leading edge to the length of the chord ranges from 75.1% to 84.5%.

[0013] In the above wind turbine blade airfoil family, the ratio of the leading edge radius to the chord length ranges from 1.7% to 26.7%.

[0014] As shown in the above wind turbine blade airfoil family, in the first airfoil family, the ratio of the radius of the leading edge of each airfoil to the length of the chord is in the range of 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 is in the range of 6.7% to 8.9%; in the third airfoil family, the ratio of the radius of the leading edge of each airfoil to the length of the chord is in the range of 20.6% to 26.7%.

[0015] In the above wind turbine blade airfoil family, the ratio of the thickness of the trailing edge to the length of the chord line ranges from 0.34% to 42.9%.

[0016] As shown in the above wind turbine blade airfoil family, in the first airfoil family, the ratio of the thickness of the trailing edge of each airfoil to the length of the chord 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 ranges from 0.48% to 1.68%; in the third airfoil family, the ratio of the thickness of the trailing edge of each airfoil to the length of the chord ranges from 17.91% to 42.9%.

[0017] 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

[0018] 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.

[0019] FIG1 is a schematic structural diagram of a blade provided in an embodiment of the present application;

[0020] FIG2 is a schematic diagram of three outer thin airfoil geometric profiles of the first airfoil family provided in an embodiment of the present application;

[0021] FIG3 is a schematic diagram of geometric profiles of two mid-thick airfoils of the second airfoil family provided in an embodiment of the present application;

[0022] FIG4 is a schematic diagram of geometric profiles of three blade root thick airfoils of the third airfoil family provided in an embodiment of the present application;

[0023] FIG5 is a schematic diagram showing a comparison of the maximum thickness positions of a new airfoil provided by an embodiment of the present application and a reference airfoil;

[0024] FIG6 is a schematic diagram showing 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;

[0025] FIG7 is a schematic diagram showing a comparison of aerodynamic efficiency-load characteristic curves of a mid-thickness airfoil of the second airfoil family provided in an embodiment of the present application;

[0026] FIG8 is a schematic diagram showing a comparison of aerodynamic efficiency-load characteristic curves of a blade root thick airfoil of the third airfoil family provided in an embodiment of the present application;

[0027] FIG9 is a schematic diagram of an application layout solution of an exemplary new airfoil family provided in an embodiment of the present application.

[0028] Explanation of the accompanying figures: 10, leading edge; 20, upper surface; 30, trailing edge; 40, lower surface; 50, chord line; 60, camber line. DETAILED DESCRIPTION

[0029] 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.

[0030] As shown in Figure 1, the geometric characteristic parameters of the airfoil are defined as follows:

[0031] 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.

[0032] 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.

[0033] 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.

[0034] 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.

[0035] 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.

[0036] 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.

[0037] 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.

[0038] As shown in Figures 1 to 9, an embodiment of the present application provides a wind turbine 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 all include multiple airfoils, each airfoil includes 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 the relative thickness. Each airfoil in the first airfoil family has a first relative thickness d1, and the first relative thickness d1 has a The range is as follows: 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%≤d2≤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.

[0039] In specific implementation, the wind turbine blade airfoil family 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 applicable to different parts of the blade. The three airfoil families each 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 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 applicable to the middle region of the blade, i.e., the portion between the blade tip and the blade root; and 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 region of the blade, i.e., the blade root. For different regions of the blade, the first, second, and third airfoil families of the embodiment of the present application have different relative thickness ranges, which are targeted in design and can be relatively independently set according to the overall shape of the blade, thereby optimizing various parameters of the wind turbine blade. The ratio of the distance from the maximum thickness point of each airfoil to the leading edge 10 to the length of the chord line 50 ranges from 26.5% to 35.0%. Within this range, the maximum thickness of the airfoil is located close to the aerodynamic center, resulting in high aeroelastic stability for the wind turbine blade. Furthermore, the relative thickness range of each airfoil and the range of the maximum thickness position can affect the laminar flow boundary of the airfoil, significantly influencing parameters such as the airfoil's drag level and maximum lift-to-drag ratio.

[0040] Specifically, the first airfoil family includes three airfoils, and the first relative thicknesses d1 of the three airfoils are 18%, 21% and 25% respectively; the second airfoil family includes two airfoils, and the second relative thicknesses d2 of the two airfoils are 30% and 35% respectively; the third airfoil family includes three airfoils, and the third relative thicknesses d3 of the three airfoils are 40%, 50% and 60% respectively.

[0041] As shown in Figure 5, Figure 5 is a schematic diagram comparing the maximum thickness position of the new airfoil provided in the embodiment of the present application and the reference airfoil. Compared with the airfoils of the same thickness in the general DU airfoil, the first airfoil family and the second airfoil family in the embodiment of the present application, except for the airfoil with a relative thickness of 21%, the maximum thickness position of the airfoil in the embodiment of the present application is closer to the aerodynamic center line of the airfoil (i.e., the aerodynamic center position). Therefore, the use of the airfoil in the airfoil family in the embodiment of the present application can improve the aeroelastic stability of large blades.

[0042] The wind turbine blade airfoil family of the embodiments 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 range of the maximum thickness position of the airfoil is 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 range of the maximum thickness position of the airfoil is 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 range of the maximum thickness position of the airfoil is 0.267 to 0.350.

[0043] During 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 at different relative thicknesses, so that each thin airfoil in the first airfoil family has low resistance characteristics and high lift-to-drag ratio characteristics, which is beneficial to enhancing the overall aerodynamic efficiency of the wind turbine blade.

[0044] In the wind turbine blade airfoil family of the embodiment of the present application, the airfoil has a maximum camber, and the ratio of the maximum camber of each airfoil to the length of the chord 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 50 is the relative camber.

[0045] The wind turbine 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 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 50 ranges from 2.44% to 3.07%; in the third airfoil family, the ratio of the maximum camber of each airfoil to the length of the chord 50 ranges from 1.83% to 2.67%.

[0046] In specific implementation, the range setting of the maximum camber in each airfoil family can affect the asymmetry of the airfoil flow. By adjusting and setting the appropriate camber characteristics, the aerodynamic characteristics of the airfoil such as the design lift coefficient, maximum lift coefficient, critical stall angle of attack, and stall smoothness can be improved.

[0047] Specifically, the first airfoil family includes three airfoils, and the ratios of the maximum camber of the three airfoils to the length of the chord 50 are 4.35%, 4.00% and 3.65% respectively; the second airfoil family includes two airfoils, and the ratios of the maximum camber of the two airfoils to the length of the chord 50 are 2.92% and 2.57% respectively; the third airfoil family includes three airfoils, and the ratios of the maximum camber of the three airfoils to the length of the chord 50 are 1.93%, 2.07% and 2.54% respectively.

[0048] In the wind turbine blade airfoil family of the embodiment of the present application, the ratio of the distance from the maximum camber point of each airfoil to the leading edge 10 to the length of the chord line 50 ranges from 42.9% to 84.5%.

[0049] The wind turbine blade airfoil family of the embodiments of the present application, wherein, in the first airfoil family, the ratio of the distance from the maximum curvature of each airfoil to the leading edge 10 to the length of the chord 50 ranges from 42.9% to 78.4%, that is, the range of the maximum curvature position of the airfoil is 0.429 to 0.784; in the second airfoil family, the ratio of the distance from the maximum curvature of each airfoil to the leading edge 10 to the length of the chord 50 ranges from 74.2% to 82.8%, that is, the range of the maximum curvature position of the airfoil is 0.742 to 0.828; in the third airfoil family, the ratio of the distance from the maximum curvature of each airfoil to the leading edge 10 to the length of the chord 50 ranges from 75.1% to 84.5%, that is, the range of the maximum curvature position of the airfoil is 0.751 to 0.845.

[0050] In practice, the range of the ratio between the distance from the airfoil's maximum camber to the leading edge 10 and the length of the chord line 50 within each airfoil family can influence the asymmetry of the airfoil flow and the boundary layer separation characteristics. By properly setting the maximum camber position, the airfoil's lift characteristics, including the design lift coefficient, maximum lift coefficient, critical stall angle of attack, and stall flatness, can be improved, facilitating the development of low-cost and lightweight blades.

[0051] Specifically, the first airfoil family includes three airfoils, and the ratios of the distances from the maximum curvature of the three airfoils to the leading edge 10 to the length of the chord 50 are 45.2%, 70.4% and 74.7% respectively; the second airfoil family includes two airfoils, and the ratios of the distances from the maximum curvature of the two airfoils to the leading edge 10 to the length of the chord 50 are 78.9% and 78.1% respectively; the third airfoil family includes three airfoils, and the ratios of the distances from the maximum curvature of the three airfoils to the leading edge 10 to the length of the chord 50 are 79.0%, 80.5% and 79.2% respectively.

[0052] In the wind turbine blade airfoil family according to the embodiment of the present application, 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%.

[0053] The wind turbine blade 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 of each airfoil to the length of the chord 50 ranges from 1.7% to 3.6%; in the second airfoil family, 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 airfoil family, 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%.

[0054] In practice, the range of the ratio of the leading edge radius 10 to the chord length 50 of each airfoil family can influence the laminar flow range, leading edge transition position, and stall separation characteristics of the airfoil, thus significantly impacting factors such as leading edge roughness sensitivity. By setting an appropriate leading edge radius, the leading edge roughness sensitivity of the airfoil's aerodynamic performance can be effectively reduced, improving the aerodynamic adaptability of the wind turbine blade airfoil to complex environments.

[0055] Specifically, the first airfoil family includes three airfoils, and the ratios of the radius of the leading edge 10 of the three airfoils to the length of the chord 50 are 1.8%, 2.4% and 3.4% respectively; the second airfoil family includes two airfoils, and the ratios of the radius of the leading edge 10 of the two airfoils to the length of the chord 50 are 7.1% and 8.5% respectively; the third airfoil family includes three airfoils, and the ratios of the radius of the leading edge 10 of the three airfoils to the length of the chord 50 are 13.8%, 21.7% and 25.4% respectively.

[0056] In the wind turbine blade airfoil family according to the embodiment of the present application, 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%.

[0057] The wind turbine blade 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 of each airfoil to the length of the chord 50 ranges from 0.34% to 0.42%; in the second airfoil family, 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 airfoil family, 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%.

[0058] In specific implementation, the setting of the ratio range of the thickness of the trailing edge 30 of the airfoil in each airfoil family to the length of the chord line 50 can affect the adverse pressure gradient and downwash effect of the airfoil boundary layer flow, thereby having an important impact on the lift coefficient, drag coefficient, critical stall angle of attack and roughness sensitivity. By setting a suitable trailing edge thickness, it helps to further improve the lift characteristics of the airfoil and reduce the roughness sensitivity of the leading edge, which helps to further improve the aerodynamic adaptability of the wind turbine blade.

[0059] Specifically, the first airfoil family includes three airfoils, and the ratios of the thickness of the trailing edge 30 of the three airfoils to the length of the chord 50 are 0.36%, 0.40% and 0.40% respectively; the second airfoil family includes two airfoils, and the ratios of the thickness of the trailing edge 30 of the two airfoils to the length of the chord 50 are 0.50% and 1.60% respectively; the third airfoil family includes three airfoils, and the ratios of the thickness of the trailing edge 30 of the three airfoils to the length of the chord 50 are 18.86%, 29.20% and 40.86% respectively.

[0060] In addition, the relative thickness, trailing edge thickness, leading edge radius, etc. of the airfoil have a decisive effect on parameters such as the cross-sectional area and second-order moment of inertia of the airfoil. Appropriate parameter settings can help improve the geometric structural properties of the airfoil and help improve the structural efficiency of the applied blades, thereby achieving low-cost and lightweight development of blades.

[0061] Therefore, the three airfoil families of the wind turbine blade airfoil family of the present application improve the aerodynamic-structural properties of the airfoil by improving the geometric shape characteristics of the airfoil, such as relative thickness, maximum thickness position, relative curvature, maximum curvature position, leading edge radius and trailing edge thickness, including core aerodynamic characteristic parameters such as design lift coefficient, maximum lift-to-drag ratio, critical stall angle of attack, maximum lift coefficient and low roughness sensitivity, as well as geometric structural characteristic parameters such as cross-sectional area, circumference, second-order moment of inertia, which helps to achieve high performance, low cost, high aerodynamic adaptability and lightweight and other blade development requirements.

[0062] As shown in FIG2 , FIG2 is a schematic diagram of three outer thin airfoil geometric profiles of the first airfoil family provided in an embodiment of the present application.

[0063] Specifically, Table 1 shows the geometric characteristic parameters of the three airfoils in the first airfoil family, including six geometric characteristic parameters: relative thickness, maximum thickness position, relative camber, maximum camber position, leading edge radius, and trailing edge thickness. All three airfoils are suitable for the outer area of ​​the blade, that is, the tip part of the blade.

[0064] Table 1

[0065] As shown in FIG3 , FIG3 is a schematic diagram of two medium-thick airfoil geometric profiles of the second airfoil family provided in an embodiment of the present application.

[0066] Table 2 shows the geometric characteristic parameters of the two airfoils in the second airfoil family, including six geometric characteristic parameters: relative thickness, maximum thickness position, relative camber, maximum camber position, leading edge radius and trailing edge thickness. Both airfoils are suitable for the middle area of ​​the blade, that is, the area between the tip and the root of the blade.

[0067] Table 2

[0068] As shown in FIG4 , FIG4 is a schematic diagram of geometric profiles of three blade root large thickness airfoils of the third airfoil family provided in an embodiment of the present application.

[0069] Table 3 shows the geometric characteristic parameters of the three airfoils in the third airfoil family, including six geometric characteristic parameters: relative thickness, maximum thickness position, relative camber, maximum camber position, leading edge radius and trailing edge thickness. All three airfoils are suitable for the inner area of ​​the blade, that is, the root of the blade.

[0070] Table 3

[0071] As shown in Table 4, the relative structural characteristic parameters of the eight airfoil thicknesses in the embodiments of this application are shown, as well as the relative structural parameter characteristics of the eight airfoils of the same thickness as those in this application, which are commonly used DU airfoils. The structural characteristic parameters include the area, perimeter, second-order cross-sectional moment skinIyy, and second-order cross-sectional moment skinIxx of the airfoil.

[0072] Table 4

[0073] Table 4 shows that in the first airfoil family, the three thin airfoils with relative thicknesses of 18%, 21%, and 25% have contour perimeters of 2.079, 2.093, and 2.126, respectively; cross-sectional areas of 0.108, 0.122, and 0.143, respectively; section moments of inertia skinIyy of 0.2004, 0.2041, and 0.2134, respectively; and section moments of inertia skinIxx of 0.0081, 0.0103, and 0.0143, respectively. In the second airfoil family, the two thick airfoils with relative thicknesses of 30% and 35% have contour perimeters of 2.167 and 2.218, respectively; cross-sectional areas of 0.171 and 0.201, respectively; section moments of inertia skinIyy of 0.2178 and 0.2239, respectively; and section moments of inertia skinIxx of 0.0204 and 0.0280, respectively. In the third airfoil family, the contour circumferences 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 section moments of inertia skinIyy are 0.2639, 0.3032, and 0.3423 respectively; and the section moments of inertia skinIxx are 0.0477, 0.0834, and 0.1293 respectively.

[0074] Compared with the DU airfoil of the same relative thickness, the structural characteristic parameters of the five airfoils in the first and second airfoil families in the embodiment of the present application are not much different from the structural characteristic parameters of the five airfoils with the same thickness in the DU airfoil; and for the blade root area with higher structural property requirements, that is, the three airfoils in the third airfoil family in the embodiment of the present application, their structural characteristic parameters are greatly improved relative to the structural characteristic parameters of the three airfoils with the same thickness in the DU airfoil, among which the airfoil circumference is increased by about 5%; the cross-sectional area is increased by about 20%; the section moment of inertia skinIyy is increased by 9% to 16%; and the section moment of inertia skinIxx is increased by 18% to 24%.

[0075] As shown in Table 5, the relative aerodynamic parameters of the three thicknesses of the first airfoil family in the embodiments of the present application are shown, as well as the relative aerodynamic parameters of the three airfoils of the same thickness as those in the present application, among the currently used DU airfoils and RF high-lift airfoils. The aerodynamic parameters in Table 5 include the design lift coefficient, maximum lift-to-drag ratio, stall angle of attack, maximum lift coefficient, stall smoothing parameter, lift roughness sensitivity, and roughness maximum lift.

[0076] Table 5

[0077] As can be seen from Table 5, the design lift coefficients of the three airfoils with relative thicknesses of 18%, 21%, and 25% in the first airfoil family in the embodiment of the present application are 1.33, 1.19, and 1.48, respectively, which are 58%, 8%, and 36% higher than those of the DU airfoils with the same thickness, respectively. The maximum lift-to-drag ratios are 202.3, 192.7, and 180.5, respectively, which are 24%, 14%, and 16% higher than those of the DU airfoils with the same thickness, respectively. The critical stall angles of attack are 12°, 11°, and 11°, respectively, which are comparable to those of the DU airfoils with the same thickness. While significantly improving the design lift coefficient and maximum lift-to-drag ratio, the maximum lift coefficient of the new airfoil is effectively limited (all less than 1.85), and it has a relatively gentle stall characteristic (the stall gentleness parameter is lower than that of another series of reference airfoils RF characterized by a high lift coefficient). In terms of leading edge roughness sensitivity, the maximum lift coefficient remains relatively high under rough conditions, which are 1.70, 1.64, and 1.59 respectively; the maximum lift sensitivity parameters under rough conditions are 1.8%, 3.0%, and 12.8% respectively, which have low roughness sensitivity characteristics and meet the design specifications. Compared with existing general-purpose airfoils, the airfoils in the first airfoil family of the embodiment of the present application have significant advantages in terms of design lift coefficient and maximum lift-to-drag ratio while maintaining smooth stall characteristics and low roughness sensitivity. In specific implementation, the outer airfoils of the blades in the first airfoil family of the embodiment of the present application, on the basis of maintaining low roughness sensitivity and smooth stall characteristics, improve the aerodynamic efficiency of the airfoil by about 20% and the design lift by about 20%.

[0078] Referring also to Figure 6, Figure 6 shows a comparison of smooth and rough surface airfoils with a relative thickness of 18% in the present application embodiment, as well as a comparison of smooth and rough surface airfoils with a relative thickness of 18% 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 embodiment have significant advantages in design lift coefficient and maximum lift-to-drag ratio compared to the general-purpose DU airfoil. Furthermore, among the same airfoils, the smooth surface airfoils also have advantages in design lift coefficient and maximum lift-to-drag ratio.

[0079] As shown in Table 6, the relative aerodynamic parameters of two airfoil thicknesses of the second airfoil family in the embodiments of the present application are shown, as well as the relative aerodynamic parameters of two airfoils of the same thickness as those of the present application in currently used DU airfoils and FFA airfoils. The aerodynamic parameters in Table 6 include the design lift coefficient, maximum lift-to-drag ratio, stall angle of attack, maximum lift coefficient, lift roughness sensitivity, and roughness maximum lift.

[0080] Table 6

[0081] Table 6 shows that the design lift coefficients of the two airfoils with relative thicknesses 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 28% and 44% higher than those of DU airfoils with the same thickness; the maximum lift-to-drag ratios are 175.4 and 180.5, respectively, which are 32% and 42% higher than those of DU airfoils with the same thickness; the critical stall angles of attack are 15° and 15°, respectively, which are more than 2° higher than those of DU airfoils with the same thickness; and the lift sensitivity parameters are 27.28% and 43.85%, respectively, meeting the airfoil design specifications. The airfoils of the second airfoil family in the embodiment of the present application have significant advantages over existing general-purpose airfoils in terms of design lift coefficient, maximum lift-to-drag ratio, and critical stall angle of attack. In specific implementation, the mid-thickness airfoils of the second airfoil family in the embodiment of the present application have an aerodynamic efficiency improvement of more than 30%.

[0082] Referring also to Figure 7, Figure 7 shows a comparison of airfoils with smooth and rough surfaces at a relative thickness of 35% in the present application, as well as airfoils with smooth and rough surfaces at a relative thickness of 35% 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 under conditions of the same roughness. Furthermore, among the same airfoils, the airfoils with smooth surfaces also have advantages in terms of design lift coefficient and maximum lift-to-drag ratio.

[0083] As shown in Table 7, Table 7 shows the relative aerodynamic characteristic parameters of the three thicknesses of the third airfoil family in the embodiments of the present application, as well as the relative aerodynamic parameter characteristics of the three airfoils of the same thickness as those in the present application in currently used DU airfoils. The aerodynamic characteristic parameters in Table 7 include the design stall angle of attack, maximum lift coefficient, lift roughness sensitivity, rough maximum lift, and rough stall angle of attack.

[0084] Table 7

[0085] 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.

[0086] Referring also to Figure 8, Figure 8 shows a comparison of smooth and rough surface airfoils with a relative thickness of 40% in the present application embodiment, as well as a comparison of smooth and rough surface 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 embodiment have significant advantages in design lift coefficient and maximum lift-to-drag ratio compared to the general-purpose DU airfoil. Furthermore, among the same airfoils, the smooth surface airfoils also have advantages in design lift coefficient and maximum lift-to-drag ratio.

[0087] 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.

[0088] Table 8

[0089] 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.

[0090] Based on the airfoil in the embodiment of the present application, there can be a variety of application layout schemes in blade design, including partially replacing the existing airfoil family and completely adopting the new airfoil of this embodiment for blade aerodynamic design layout, as shown in Figure 9.

[0091] It should be noted that, in this document, relational terms such as first and second, etc., are used only to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprises," "comprising," or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article, or device comprising a series of elements includes not only those elements, but also other elements not explicitly listed, or elements inherent to such process, method, article, or device. In the absence of further limitations, the elements defined by the phrase "comprising..." do not exclude the presence of other identical elements in the process, method, article, or device comprising the elements.

[0092] The above description is only a specific embodiment of the present application. Those skilled in the art will clearly understand that for the convenience and brevity of description, the specific working processes of the systems, modules and units described above can refer to the corresponding processes in the aforementioned method embodiments, and will not be repeated here. It should be understood that the scope of protection of the present application is not limited thereto. Any person skilled in the art can easily think of various equivalent modifications or replacements within the technical scope disclosed in the present application, and these modifications or replacements should be included in the scope of protection of the present application.

Claims

1. A wind turbine blade airfoil family, comprising 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 (50), a ratio of a maximum thickness between the upper surface (20) and the lower surface (40) to a length of the chord (50) is a relative thickness, and each of the airfoils in the first airfoil family has a first relative thickness The first relative thickness d1 has the following range: 17.1%≤d1≤26.3%; each of the airfoils 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 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%≤d2≤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) is in the range of 26.5% to 35.0%.

2. The wind turbine blade airfoil family according to claim 1, wherein: In the first family of 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 27.1% to 34.4%; in the second family of 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 29.9%; in the third family of 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 26.7% to 35.0%.

3. The wind turbine blade airfoil family according to claim 1, 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%.

4. The wind turbine blade airfoil family according to claim 3, wherein: In the first family of airfoils, the ratio of the maximum camber of each airfoil to the length of the chord (50) ranges from 3.47% to 4.57%; in the second family of airfoils, the ratio of the maximum camber of each airfoil to the length of the chord (50) ranges from 2.44% to 3.07%; in the third family of airfoils, the ratio of the maximum camber of each airfoil to the length of the chord (50) ranges from 1.83% to 2.67%.

5. The wind turbine blade airfoil family according to claim 1, wherein: 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%.

6. The wind turbine blade airfoil family according to claim 5, wherein: In the first family of airfoils, the ratio of the distance from the maximum curvature 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 curvature 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 curvature of each airfoil to the leading edge (10) to the length of the chord (50) ranges from 75.1% to 84.5%.

7. The wind turbine blade airfoil family according to claim 1, 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%.

8. The wind turbine blade airfoil family according to claim 7, wherein: 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) is in the range of 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) is in the range of 6.7% to 8.9%; and 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) is in the range of 20.6% to 26.7%.

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

10. The wind turbine blade airfoil family according to claim 9, wherein: 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) is in the range of 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) is in the range of 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) is in the range of 17.91% to 42.9%.

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