Turbine guide vane airfoil with small turning angle wide adaptability and design method thereof

Abstract

The present application relates to the field of aero-engine and gas turbine design, and discloses a turbine guide vane profile with small turning angle wide adaptability and a design method thereof.The basin side of the turbine guide vane profile adopts S-shaped structure with convex front section and concave rear section, and the whole is in the shape of shuttle, which is suitable for small turning angle working condition.The corresponding design method determines the design working condition point and boundary condition in combination with turbine full working condition aerodynamic parameters, iteratively optimizes modeling parameters such as profile wedge angle, leading and trailing edge arc, and profile control point, and completes profile finalization through aerodynamic loss checking, which can match the design requirements of small turning angle guide vane.The turbine guide vane profile can avoid the defects of conventional crescent-shaped profile blocking airflow and flow separation occurring in the profile basin side, effectively reduces the aerodynamic angle of attack loss, keeps the profile low loss and smooth flow field in a wide range of working condition changes, and guarantees the wide working condition adaptation ability and operation stability of the turbine guide vane.

Description

Technical Field

[0001] This invention relates to the field of aero-engine and gas turbine design, and discloses a turbine guide vane profile with small turning angle and wide adaptability and its design method. Background Technology

[0002] During the startup and operation of aero-engines and gas turbines, the high-pressure turbine (gas turbine) and low-pressure turbine operate under multiple conditions, including a wide range of expansion ratios and speeds. This necessitates adaptability of the turbine guide vane inlet to these diverse operating conditions. For variable geometry low-pressure turbines, adjusting the guide vane installation angle allows for flow regulation, thereby adjusting the expansion ratio distribution between the high and low-pressure turbines and the engine bypass ratio, ultimately optimizing engine performance. Both adjusting the guide vane installation angle and operating conditions result in changes to the aerodynamic parameters at the guide vane inlet. When the high and low-pressure turbines rotate in opposite directions, the airflow turning angle at the low-pressure turbine guide vane is relatively small, posing design challenges for the guide vane flow organization and the convergence design of the variable geometry guide vane flow channel.

[0003] The drawbacks of existing technologies are as follows: When the inlet airflow has a wide angle of attack and the aerodynamic parameters vary significantly, conventional turbine guide vane profiles are prone to significant separation on the back side of the blade, resulting in a substantial loss of aerodynamic angle of attack. For turbine guide vane profiles with small turning angles, the flow channel tends to converge first and then expand when adjusting the installation angle, and the blade throat is not located in the area formed by the trailing edge and the back of the blade, causing flow instability.

[0004] Therefore, the design of guide vane profiles for subsonic low-pressure turbines with small turning angles and wide operating conditions is a problem that needs to be solved. Summary of the Invention

[0005] The purpose of this invention is to provide a turbine guide vane profile with small turning angle and wide adaptability and its design method, so as to solve the problem of turbine guide vane profile design with small turning angle and wide adaptability under multiple operating conditions in the prior art.

[0006] To achieve the above-mentioned technical effects, the technical solution adopted by the present invention is as follows:

[0007] A turbine guide vane profile with small turning angle and wide adaptability, wherein the vane profile has an S-shaped basin side profile, the basin side profile including an outwardly convex section and an inwardly concave section. The convex segment is located at one end near the leading edge, and the concave segment is located at one end near the trailing edge, with a smooth connection between the convex segment and the concave segment; Wherein, the airflow turning angle of the turbine guide vane profile is less than or equal to 30°.

[0008] Furthermore, the back side profile and the basin side profile of the turbine guide vane are both third-order Bezier curves.

[0009] Furthermore, the inlet upper wedge angle of the turbine guide vane profile and the lower wedge angle of the inlet The value range is 5° to 40°.

[0010] A turbine guide vane design method with small turning angle and wide adaptability, for designing turbine guide vane profiles with small turning angle and wide adaptability as described above, includes the following steps: Step 1: Determine the typical operating points of the turbine based on the aerodynamic parameters and performance requirements of the turbine at multiple operating points; Step 2: Under typical turbine operating conditions, design the initial aerodynamic scheme for the turbine on a turbine-stage basis; Step 3: Based on the initial aerodynamic scheme of the turbine, determine the typical operating points of the turbine guide vanes and the corresponding design state aerodynamic parameters; Step 4: Under typical operating conditions and upstream and downstream boundary conditions of the turbine guide vane, perform aerodynamic loss assessment on the given initial airfoil and determine whether it meets the design requirements. If it does, the initial airfoil is used as the final airfoil and output; otherwise, optimize the airfoil parameters and repeat the aerodynamic loss assessment until the final airfoil of the turbine guide vane is output. The airfoil parameters include the inlet upper wedge angle, inlet lower wedge angle, leading edge radius, trailing edge radius, and the positions of various control points on the back side profile and the basin side profile of the turbine guide vane.

[0011] Furthermore, the aerodynamic parameters of the design state include the upstream turbine blade outlet airflow parameters and the downstream turbine blade inlet aerodynamic parameters of the turbine guide vane.

[0012] Furthermore, the design requirements include a total pressure recovery coefficient threshold and a preset range for the outlet airflow angle.

[0013] Furthermore, the control points of the pelvic side profile include a first pelvic side control point P1 and a second pelvic side control point P2; the first pelvic side control point P1 is located near the leading edge and is used to adjust the curvature of the convex segment; the second pelvic side control point P2 is located near the trailing edge and is used to adjust the curvature of the concave segment.

[0014] Furthermore, the control points of the dorsal profile include a first dorsal control point B1, a second dorsal control point B2, a third dorsal control point B3, and a fourth dorsal control point B4; the first dorsal control point B1 and the second dorsal control point B2 are located near the leading edge, and the third dorsal control point B3 and the fourth dorsal control point B4 are located near the trailing edge. The first dorsal control point B1, the second dorsal control point B2, the third dorsal control point B3, and the fourth dorsal control point B4 are used together to adjust the curvature of the dorsal profile.

[0015] Furthermore, the values ​​of the first control point P1 and the second control point P2 on the pelvic side are in the range of 0 to 1; the values ​​of the first control point B1, the second control point B2, the third control point B3, and the fourth control point B4 on the dorsal side are in the range of -2 to 5.

[0016] Compared with the prior art, the beneficial effects of this invention are: The invention employs an S-shaped structure with an outwardly convex section connecting the leading edge and an inwardly concave section connecting the trailing edge, forming an overall shuttle-shaped blade. For small turning angle conditions with an airflow turning angle ≤30°, it can effectively avoid the problems of airflow obstruction at the leading edge and flow separation on the blade basin side of conventional meniscus blades, reducing aerodynamic angle of attack loss. At the same time, under wide operating conditions with adjustable guide vane installation angle and significant changes in inlet airflow angle of attack, it can always ensure that the blade channel maintains good convergence and the flow state is stable, improving the operating condition adaptability and aerodynamic performance of the turbine guide vane.

[0017] The design method of this invention relies on the aerodynamic parameters of the turbine under all operating conditions to determine the design operating point and boundary conditions of the turbine guide vane. It combines the shape parameters such as the blade wedge angle, leading and trailing edge small circle parameters, and profile control points for iterative optimization, and completes the blade shape finalization through aerodynamic loss verification. It can accurately match the design requirements of turbine guide vanes with small turning angles. It solves the problems of easy flow separation, flow channel convergence followed by expansion, and flow instability during the adjustment of wide angle of attack and installation angle under traditional design methods. The blade designed by this invention can maintain a low loss and smooth flow field under a wide range of inlet angle of attack and guide vane installation angle changes, and can ensure the wide operating condition adaptability and operational stability of the turbine guide vane. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the turbine guide vane airfoil with small turning angle and wide adaptability in the embodiment; Figure 2 This is a schematic diagram of a turbine guide vane with small turning angle and wide adaptability, and its corresponding throat, as shown in the embodiment. Figure 3 This is a schematic diagram of the blade flow corresponding to the turbine guide vane with small turning angle and wide adaptability in the embodiment. Figure 4 This is a schematic diagram of the blade flow corresponding to the existing airflow turning angle turbine guide vane in the embodiment; Figure 5 This is a first flowchart of the turbine guide vane airfoil design method with small turning angle and wide adaptability in the embodiment; Figure 6 This is a second flowchart of the turbine guide vane airfoil design method with small turning angle and wide adaptability in the embodiment; Figure 7 This is a schematic diagram of the turbine guide vane profile when the installation angle is -10° in the embodiment. Figure 8 This is a schematic diagram of the turbine guide vane profile when the installation angle is 0° in the embodiment; Figure 9 This is a schematic diagram of the turbine guide vane profile when the installation angle is 10° in the embodiment; Figure 10 This is a channel convergence curve of the turbine guide vane profile when the installation angle is -10° in the embodiment. Figure 11 This is a channel convergence curve of the turbine guide vane profile when the installation angle is 0° in the embodiment. Figure 12 This is a channel convergence curve of the turbine guide vane profile when the installation angle is 10° in the embodiment. Figure 13 This is a graph showing the variation of the turbine guide vane loss coefficient with the inlet angle of attack in the embodiment. Figure 14 This is a streamline diagram of the turbine guide vane inlet angle of attack when the angle of attack is -15° in the embodiment. Figure 15 This is a streamline diagram of the turbine guide vane inlet angle of attack when it is 0° in the embodiment; Figure 16 This is a streamline diagram of the turbine guide vane inlet angle of attack of 15° in the embodiment. Figure 17 This is a streamline diagram of the turbine guide vane inlet angle of attack of 30° in the embodiment. Among them, 1-dorsal profile, 2-front arc, 3-tail arc, 4-pelvis profile, 41-outward convex section, 42-inward concave section. Detailed Implementation

[0019] The present invention will now be described in further detail with reference to the embodiments and accompanying drawings. However, this should not be construed as limiting the scope of the above-described subject matter of the present invention to the following embodiments; all technologies implemented based on the content of the present invention fall within the scope of the present invention.

[0020] See Figures 1 to 3 The present invention provides a turbine guide vane profile with small turning angle and wide adaptability, comprising: The turbine guide vane profile 4 has an S-shaped basin side profile, which includes an outwardly convex section 41 and an inwardly concave section 42. The convex segment 41 is located at one end near the leading edge, and the concave segment 42 is located at one end near the trailing edge, and the convex segment 41 and the concave segment 42 are smoothly connected. Wherein, the airflow turning angle of the turbine guide vane profile is less than or equal to 30°.

[0021] Based on the same inventive concept, see [link to inventive concept] Figures 5 to 6The present invention also provides a turbine guide vane design method with small turning angle and wide adaptability, for designing the aforementioned turbine guide vane profile with small turning angle and wide adaptability, comprising the following steps: Step 1: Determine the typical operating points of the turbine based on the aerodynamic parameters and performance requirements of the turbine at multiple operating points; Step 2: Under typical turbine operating conditions, design the initial aerodynamic scheme for the turbine on a turbine-stage basis; Step 3: Based on the initial aerodynamic scheme of the turbine, determine the typical operating points of the turbine guide vanes and the corresponding design state aerodynamic parameters; Step 4: Under typical operating conditions and upstream and downstream boundary conditions of the turbine guide vane, perform aerodynamic loss assessment on the given initial airfoil and determine whether it meets the design requirements. If it does, the initial airfoil is used as the final airfoil and output; otherwise, optimize the airfoil parameters and repeat the aerodynamic loss assessment until the final airfoil of the turbine guide vane is output. The airfoil parameters include the inlet upper wedge angle, inlet lower wedge angle, leading edge arc radius 2, trailing edge arc radius 3, and the positions of various control points on the back side profile 1 and the basin side profile 4.

[0022] The turbine guide vane of this invention adopts an S-shaped structure in which the outer convex section 41 of the basin-side profile 4 connects to the leading edge and the inner concave section 42 connects to the trailing edge. The overall shape of the vane forms a shuttle-shaped shape. For small turning angle conditions with airflow turning angle ≤30°, it can effectively avoid the problems of airflow obstruction at the leading edge and flow separation on the basin side of conventional meniscus vanes, and reduce aerodynamic angle of attack loss. At the same time, under wide operating conditions where the guide vane installation angle is adjustable and the inlet airflow angle of attack changes significantly, it can always ensure that the blade channel maintains good convergence and the flow state is stable, thereby improving the operating condition adaptability and aerodynamic performance of the turbine guide vane.

[0023] The design method of this invention relies on the aerodynamic parameters of the turbine under all operating conditions to determine the design operating point and boundary conditions of the turbine guide vane. It combines the shape parameters such as the blade wedge angle, leading and trailing edge small circle parameters, and profile control points for iterative optimization, and completes the blade shape finalization through aerodynamic loss verification. It can accurately match the design requirements of turbine guide vanes with small turning angles. It solves the problems of easy flow separation, flow channel convergence followed by expansion, and flow instability during the adjustment of wide angle of attack and installation angle under traditional design methods. The blade designed by this invention can maintain a low loss and smooth flow field under a wide range of inlet angle of attack and guide vane installation angle changes, and can ensure the wide operating condition adaptability and operational stability of the turbine guide vane.

[0024] Example This embodiment further details the turbine guide vane profile with small turning angle and wide adaptability and its design method, as follows.

[0025] See Figures 1 to 3The turbine guide vane with small turning angle and wide adaptability in this embodiment is a subsonic low-pressure turbine guide vane, which is formed by the back side profile 1, the leading edge arc 2, the trailing edge arc 3 and the basin side profile 4.

[0026] The leading edge arc 2 and trailing edge arc 3 correspond to the leading edge small circle and trailing edge small circle, respectively. The radii of the leading edge arc 2 and trailing edge arc 3 are controlled by the radii of the leading edge small circle and trailing edge small circle, respectively. The dorsal side profile 1 and the basin side profile 4 are both third-order Bézier curves, and the basin side profile 4 is S-shaped. Specifically, the basin side profile 4 includes an outwardly convex section 41 and an inwardly concave section 42. The outwardly convex section 41 is connected to the leading edge end of the dorsal side profile 1 through the leading edge arc 2, and the inwardly concave section 42 is connected to the trailing edge end of the dorsal side profile 1 through the trailing edge arc 3.

[0027] In this embodiment, the airflow deflection angle of the turbine guide vane profile is defined as follows: ,in, The airflow deflection angle of the turbine guide vane profile. The inlet airflow angle (the angle between the inlet airflow angle and the top line) of the turbine guide vane. This refers to the outlet airflow angle (the angle between the airflow and the top line) of the turbine guide vane profile. In this embodiment, the airflow deflection angle of the turbine guide vane profile is... The angle is less than or equal to 30° to form a small turning angle blade. In this embodiment, the difference between the inlet and outlet airflow angles of the blade is matched with the airflow turning angle. The flow channel as a whole is in a converging shape along the flow direction. This avoids the unfavorable structure of the flow channel first converging and then expanding in the traditional design, thus avoiding the problems of flow separation and a surge in flow loss. It can ensure the flow stability under all operating conditions.

[0028] This embodiment adopts a basin-side profile 4 with a partial outward convexity near the leading edge and a partial inward concavity near the trailing edge. At the same time, the airflow turning angle of the turbine guide vane is less than or equal to 30°, thereby forming a shuttle-shaped blade with both the head and back sides convex and the tail side constricted. This is to adapt to aerodynamic parameters with small inlet and outlet airflow turning angles, while increasing the adaptability of the leading edge to a wide range of airflow angles of attack. It can also avoid flow separation on the blade basin side and reduce flow losses.

[0029] See Figure 4 In existing technologies, the airflow deflection angle of most turbines... At around 80°, the blade shape becomes crescent-shaped. Under aerodynamic parameters where the inlet and outlet airflow turning angles are small, the downward-curving leading edge region obstructs the airflow, easily causing flow separation at the blade base and resulting in significant flow losses. (See also...) Figure 3 The present invention uses an airflow turning angle of less than or equal to 30°. The small turning angle blade shape, along with the local outward convexity of the basin side profile 4, can adapt to aerodynamic parameters with small turning angles of inlet and outlet airflow. At the same time, it increases the adaptability of the leading edge to a wide range of airflow attack angles, making it less prone to flow separation and resulting in low flow loss.

[0030] See Figure 2 The inlet upper wedge angle of the turbine guide vane profile and the lower wedge angle of the inlet The value ranges from 5 to 40°. In this embodiment, the inlet upper wedge angle is... Imported lower wedge angle This embodiment limits the upper wedge angle of the inlet. and the lower wedge angle of the inlet The range of blade profiles can be optimized to improve the airflow introduction effect at the leading edge, adapt to a wide range of inlet angle of attack and guide vane installation angle changes, further avoid the leading edge from blocking the airflow, suppress flow separation, and at the same time ensure that the blade profile leading edge shape is reasonable, so that the blade channel always maintains stable convergence characteristics, effectively control aerodynamic losses, and enhance the blade profile's wide operating condition adaptability under small turning angle conditions.

[0031] It should be noted that, in Figure 2 middle, , These are the inlet and outlet configuration angles of the airfoil, respectively. , These are the inlet airflow angle and outlet airflow angle of the airfoil, respectively. The inlet angle of attack of the blade profile is equal to the difference between the inlet configuration angle and the inlet airflow angle. ; This refers to the width of the throat.

[0032] Based on the same inventive concept, see [link to inventive concept] Figures 5 to 6 This embodiment also provides a turbine guide vane design method with small turn angle and wide adaptability, used to design the aforementioned turbine guide vane profile with small turn angle and wide adaptability, including the following steps: Step 1: Determine the typical operating point and design point of the turbine. Based on the aerodynamic parameters and performance requirements of the turbine at multiple operating points, the typical operating point of the turbine is determined. In implementing this step, the typical operating point of the turbine is determined based on the aerodynamic parameters at multiple operating points and by comprehensively considering the performance requirements at these multiple operating points, and this determination is used as the design point.

[0033] Step 2: Preliminary Design of Turbine Stage Under typical turbine operating conditions, the initial aerodynamic scheme of the turbine is designed on a turbine-stage basis, resulting in the overall flow path layout of the turbine stage, the distribution relationship of the high- and low-pressure turbine expansion ratios, and the inlet airflow angle of the turbine guide vanes. airflow turning angle Imported angle of attack Aerodynamic parameters such as range, inlet and outlet Mach number, and variable geometry blade installation angle adjustment range, as well as upstream and downstream aerodynamic boundary conditions of the turbine guide vane, provide support for subsequent screening of typical operating points of the turbine guide vane and extraction of aerodynamic parameters of the guide vane design state.

[0034] Step 3: Determine the typical operating point parameters of the turbine guide vanes Based on the initial aerodynamic scheme of the turbine, the typical operating points of the turbine guide vanes and the corresponding design state aerodynamic parameters are determined. The typical operating points of the turbine guide vanes refer to the operating conditions corresponding to different guide vane installation angles, different inlet airflow angles, and different outlet Mach numbers. The design state aerodynamic parameters include the outlet airflow parameters of the upstream turbine blades and the inlet aerodynamic parameters of the downstream turbine moving blades.

[0035] Step 4: Leaf shape design, optimization and evaluation Under typical operating conditions and upstream and downstream boundary conditions of the turbine guide vane, aerodynamic losses are evaluated for a given initial airfoil, and it is determined whether the design requirements are met. If they are met, the initial airfoil is used as the final airfoil and output; otherwise, the airfoil parameters are optimized, and the aerodynamic loss evaluation is repeated until the final airfoil of the turbine guide vane is output. The airfoil parameters include the inlet upper wedge angle, inlet lower wedge angle, leading edge arc radius 2, trailing edge arc radius 3, and the positions of various control points on the back side profile 1 and the basin side profile 4. The design requirements include the total pressure recovery coefficient threshold and the preset range of the outlet airflow angle.

[0036] In implementing this step, firstly, based on the design state aerodynamic parameters and upstream and downstream boundary conditions of the turbine guide vane at typical operating points, the initial airfoil of the turbine guide vane is determined. Then, according to the design state aerodynamic parameters and upstream and downstream boundary conditions of the turbine guide vane at typical operating points, given the inlet total temperature and pressure direction, outlet static pressure, and outlet Mach number of the initial airfoil, a three-dimensional numerical simulation is performed on the initial airfoil. Based on the simulation results, the flow field details are compared and analyzed to determine the simulated values ​​of the total pressure recovery coefficient and the outlet airflow angle of the initial airfoil.

[0037] Finally, it is determined whether the simulated total pressure recovery coefficient of the initial airfoil is lower than the total pressure recovery coefficient threshold, and whether the simulated outlet airflow angle of the initial airfoil is within the preset range of the outlet airflow angle. If the above design requirements are met, the initial airfoil is used as the final airfoil and output. Otherwise, the parameters of the airfoil are optimized, and the inlet upper wedge angle, inlet lower wedge angle, leading edge small circle radius, trailing edge small circle radius of the turbine guide vane are adjusted, and the position of the control point on the back side of the basin is adjusted within the range of values ​​to obtain the optimized airfoil. Then, aerodynamic loss assessment is performed until the final airfoil of the turbine guide vane is output.

[0038] It should be noted that the parameters of the blade profile include the inlet upper wedge angle of the turbine guide vane. , Imported lower wedge angle The radius of the leading edge small circle, the radius of the trailing edge small circle, and the positions of each control point on the dorsal side profile 1 and the basin side profile 4.

[0039] In this embodiment, see Figure 2 The back profile 1 of the turbine guide vane is a third-order Bézier curve. The control points of the back profile 1 include a first back control point B1, a second back control point B2, a third back control point B3, and a fourth back control point B4. The first back control point B1 and the second back control point B2 are located near the leading edge, while the third back control point B3 and the fourth back control point B4 are located near the trailing edge. These four control points work together to adjust the curvature of the back profile 1. Furthermore, during the design process, the values ​​of control points B1 to B4 are set between 0 and 1.

[0040] The turbine guide vane's side profile 4 is also a third-order Bézier curve. The control points for the side profile 4 include a first control point P1 and a second control point P2. The first control point P1 is located near the leading edge and is used to adjust the curvature of the convex section 41. The second control point P2 is located near the trailing edge and is used to adjust the curvature of the concave section 42. This embodiment uses control points on the back side of the vane to adjust the profile contour during blade design, thereby achieving a small turning angle and a profile design with a locally convex leading edge and a concave trailing edge. During design, the values ​​of control points P1 and P2 range from -2 to 5.

[0041] When performing this step, the inlet upper wedge angle of the turbine guide vane profile is adjusted. , Imported lower wedge angle The leading edge small circle radius, trailing edge small circle radius, and control point on the back side of the blade basin are used to control the shape of the guide vane blade profile, thereby constructing a blade shape that meets the requirements. To meet multiple design requirements such as adaptability to a wide range of angles of attack, adjustable blade installation angle, and channel convergence, when constructing the blade basin side profile 4, various parameters are adjusted to make the profile convex outward at the leading edge of the basin side and concave inward at the tail edge, forming a spindle-shaped blade shape with both the head and back sides of the basin convex outward and the tail constricted. This ensures both wide adaptability to a wide range of incoming flow angles of attack and installation angles and good convergence of the blade channel at small turning angles.

[0042] Step 5: Output the final airfoil and aerodynamic loss assessment results.

[0043] In an example of a wide-adaptive turbine guide vane design with a small turning angle, the aerodynamic parameters are as follows: inlet airflow angle 125°, outlet airflow angle The airflow turning angle is 27°. 28°, imported angle of attack The range is -15° to +30°, the inlet Mach number is 0.54, the outlet Mach number is 0.75, and the variable geometry airfoil installation angle adjustment range is ±10°. The selected parameter values ​​are as follows: inlet upper wedge angle... Imported lower wedge angle The values ​​of control points B1~B4 for the back-side profile 1 are 0.60, 0.65, 0.92, and 0.1, respectively. The values ​​of control points for the bowl-side profile 4 are P1=0.15 and P2=-0.35. The guide vane profiles at installation angles of -10°, 0°, and 10° are shown in the figure. Figures 7 to 9 The corresponding channel convergence is shown in [reference]. Figures 10 to 12 This indicates that the airfoil channel convergence is good when the installation angle is adjusted within ±10°.

[0044] Figure 13 The total pressure loss coefficient of the turbine guide vane as a function of the inlet angle of attack is given. The curve of change at the angle of attack of the inlet Within the range of variation, the total pressure loss coefficient of the turbine guide vane is the smallest when the inlet angle of attack is -5 to 0°. As the angle of attack deviates, the loss increases, but the change in the turbine guide vane loss coefficient does not exceed 0.7%, indicating that the turbine blade profile has good wide adaptability.

[0045] When the inlet angle of attack of the turbine guide vane At that time, the streamlines of the turbine guide vanes are like Figures 14 to 17 As shown, the turbine guide vanes exhibit smooth flow lines and no separation within a wide range of angles of attack (45° angle of attack variation).

[0046] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A turbine guide vane profile with small turning angle and wide adaptability, characterized in that, The turbine guide vane profile (4) has an S-shaped basin side profile (4), which includes an outwardly convex section (41) and an inwardly concave section (42). The convex segment (41) is located at one end near the leading edge, and the concave segment (42) is located at one end near the trailing edge, and the convex segment (41) and the concave segment (42) are smoothly connected. Wherein, the airflow turning angle of the turbine guide vane profile is less than or equal to 30°.

2. The turbine guide vane profile with small turning angle and wide adaptability according to claim 1, characterized in that, The back side profile (1) and the basin side profile (4) of the turbine guide vane are both third-order Bezier curves.

3. The turbine guide vane profile with small turning angle and wide adaptability according to claim 2, characterized in that, The inlet upper wedge angle of the turbine guide vane profile and the lower wedge angle of the inlet The value range is 5° to 40°.

4. A turbine guide vane design method with small turning angle and wide adaptability, used to design turbine guide vane profiles with small turning angle and wide adaptability as described in any one of claims 1-3, characterized in that, Includes the following steps: Step 1: Determine the typical operating points of the turbine based on the aerodynamic parameters and performance requirements of the turbine at multiple operating points; Step 2: Under typical turbine operating conditions, design the initial aerodynamic scheme for the turbine on a turbine-stage basis; Step 3: Based on the initial aerodynamic scheme of the turbine, determine the typical operating points of the turbine guide vanes and the corresponding design state aerodynamic parameters; Step 4: Under the typical operating conditions of the turbine guide vane and the upstream and downstream boundary conditions, perform aerodynamic loss assessment on the given initial airfoil and determine whether it meets the design requirements. If it does, the initial airfoil is used as the final airfoil and output. Otherwise, optimize the airfoil parameters and repeat the aerodynamic loss assessment until the final airfoil of the turbine guide vane is output. The airfoil parameters include the inlet upper wedge angle, inlet lower wedge angle, leading edge arc (2) radius, trailing edge arc (3) radius, and the positions of each control point on the back side profile (1) and the basin side profile (4).

5. The turbine guide vane design method with small turning angle and wide adaptability according to claim 4, characterized in that, The aerodynamic parameters of the design state include the upstream turbine blade outlet airflow parameters and the downstream turbine blade inlet aerodynamic parameters.

6. The turbine guide vane design method with small turning angle and wide adaptability according to claim 5, characterized in that, The design requirements include the total pressure recovery coefficient threshold and the preset range of the outlet airflow angle.

7. The turbine guide vane design method with small turning angle and wide adaptability according to claim 6, characterized in that, The control points of the pelvic side profile (4) include a first pelvic side control point P1 and a second pelvic side control point P2; the first pelvic side control point P1 is located near the front edge and is used to adjust the curvature of the convex segment (41); the second pelvic side control point P2 is located near the tail edge and is used to adjust the curvature of the concave segment (42).

8. The turbine guide vane design method with small turning angle and wide adaptability according to claim 7, characterized in that, The control points of the back side profile (1) include a first back side control point B1, a second back side control point B2, a third back side control point B3, and a fourth back side control point B4. The first back side control point B1 and the second back side control point B2 are located near the leading edge, and the third back side control point B3 and the fourth back side control point B4 are located near the trailing edge. The first back side control point B1, the second back side control point B2, the third back side control point B3, and the fourth back side control point B4 are used together to adjust the curvature of the back side profile (1).

9. The turbine guide vane design method with small turning angle and wide adaptability according to claim 8, characterized in that, The values ​​of the first control point P1 and the second control point P2 on the pelvic side are in the range of 0 to 1; the values ​​of the first control point B1, the second control point B2, the third control point B3, and the fourth control point B4 on the dorsal side are in the range of -2 to 5.

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