Blade three-dimensional heat exchange boundary calculation method

Abstract

The method for calculating the three-dimensional heat exchange boundary of the blade comprises the following steps that a three-dimensional coordinate system of the blade is established, and a three-dimensional flow field of the blade is obtained through a computational fluid mechanics method; establishing a blade two-dimensional coordinate system, and obtaining a two-dimensional grid; establishing a conversion relation between the three-dimensional coordinates and the two-dimensional coordinates of the same position of the blade; streamlines on the blades are extracted in the three-dimensional flow field, and heat exchange boundaries and three-dimensional coordinates of discrete points on the streamlines are obtained; the three-dimensional coordinates of the discrete points on the streamline are converted into point locations in a two-dimensional coordinate system, and heat exchange boundaries are assigned to the point locations; interpolation is carried out on the heat exchange boundary of the point location in the two-dimensional grid, and the heat exchange boundary of each point location in the two-dimensional coordinate system is calculated. According to the blade three-dimensional heat exchange boundary calculation method, more accurate heat exchange boundary conditions can be obtained.

Description

Technical Field

[0001] The invention relates to the field of blades of aircraft engines, and in particular to the field of blade thermal boundary calculation methods. Background Art

[0002] In order to design high-pressure turbine blades that can work normally in high-temperature environments, it is necessary to accurately predict the three-dimensional temperature distribution of the entire blade during the turbine blade cooling design process, and judge whether the design meets the material allowable temperature requirements based on the results. Whether the blade temperature distribution of the turbine blade under the actual working environment can be accurately predicted is the prerequisite for judging whether the cooling structure meets the design requirements during the design process. The three-dimensional temperature field simulation calculation of the blade is essentially a solid heat conduction calculation. Its calculation accuracy is directly related to the accuracy of the applied boundary conditions. The key to obtaining accurate three-dimensional temperature distribution of the blade during the simulation process is to accurately give the heat exchange boundary conditions on the gas side of the blade.

[0003] The boundary conditions on the gas side of the blade include the heat transfer boundary conditions of the blade body and the edge plate. For the crownless moving blade structure of the high-pressure turbine, the heat transfer boundary on the flat blade tip or the grooved blade tip must also be considered. Usually, when calculating the blade temperature field, the heat transfer boundary on the gas side applied is the third type of heat transfer boundary that requires the heat transfer coefficient and heat transfer temperature to be given.

[0004] The existing methods for calculating the heat transfer boundary of the blade surface can be roughly divided into two categories: one is to directly use the computational fluid dynamics (CFD) method to solve, and the other is to use engineering algorithms. The CFD method simulates and solves the flow field in a three-dimensional coordinate system to obtain more data information, but the solution calculation cycle is long and is not suitable for rapid iteration in the early multi-scheme comparison design stage. The use of engineering algorithms to solve is based on the fact that turbine aerodynamics is the upstream discipline of blade cooling design. Usually, when the blade shape parameters are given, the three-dimensional viscous flow field calculation of the aerodynamic flow channel based on CFD software has been completed. Therefore, when calculating the external heat transfer boundary of the cooling design, the design calculation results of the aerodynamics discipline can be directly borrowed. However, the engineering algorithm method is difficult to take into account the three-dimensional flow effect and three-dimensional interpolation. The transition of the heat transfer boundary between the edge plate and the blade body is discontinuous, which makes the calculation accuracy low.

[0005] In view of this, it is necessary to propose a heat transfer boundary calculation method in order to improve the accuracy of engineering algorithms. Summary of the invention

[0006] An object of the present invention is to provide a method for calculating the three-dimensional heat transfer boundary of a blade, which can obtain a heat transfer coefficient with higher accuracy.

[0007] To achieve the above-mentioned purpose, a method for calculating the three-dimensional heat exchange boundary of a blade includes the following steps: establishing a three-dimensional coordinate system for the blade, and obtaining the three-dimensional flow field of the blade in the three-dimensional coordinate system by means of computational fluid dynamics; and also includes the following steps: establishing a two-dimensional coordinate system for the blade, and obtaining a two-dimensional grid; establishing a conversion relationship between the three-dimensional coordinates and the two-dimensional coordinates of the same position of the blade; extracting streamlines on the blade in the three-dimensional flow field, and obtaining the heat exchange boundary and three-dimensional coordinates of discrete points on the streamlines; converting the discrete points into points in the two-dimensional coordinate system, and assigning the heat exchange boundary to the points; using the heat exchange boundary at the points to interpolate in the two-dimensional grid, and calculating the heat exchange boundary of each point in the two-dimensional coordinate system.

[0008] In one or more embodiments, a blade body two-dimensional coordinate system and a blade edge plate two-dimensional coordinate system are established respectively.

[0009] In one or more embodiments, the arc length direction of the blade airfoil is defined as the first dimension of the blade airfoil two-dimensional coordinate system, and the radial direction of the blade airfoil is defined as the second dimension of the blade airfoil two-dimensional coordinate system.

[0010] In one or more embodiments, the suction surface trailing edge is arranged in the positive direction of the first dimension, the pressure surface trailing edge is arranged in the negative direction of the first dimension, and the blade leading edge root is defined as the origin.

[0011] In one or more embodiments, the blade axial direction is defined as a first dimension of a two-dimensional coordinate system of an edge plate, and the blade circumferential direction is defined as a second dimension of the two-dimensional coordinate system of an edge plate.

[0012] In one or more embodiments, the leading edge of the edge plate is set in the negative direction of the first dimension, the trailing edge of the edge plate is set in the positive direction of the first dimension, and the leading edge point of the edge plate on the pressure surface side of the blade is defined as the origin.

[0013] In one or more embodiments, the blade includes a blade body, an edge plate, and a contour line at the connection between the blade body and the edge plate. Before calculating the heat exchange boundary parameters of each point in the two-dimensional coordinate system, the method also includes a contour line heat exchange boundary calculation step: obtaining a mapping relationship between the position on the contour line between the blade body two-dimensional coordinate system and the edge plate two-dimensional coordinate system; obtaining blade body edge points close to the contour line in the blade body two-dimensional coordinate system and heat exchange boundary parameters of the blade body edge points, obtaining edge plate edge points close to the contour line in the edge plate two-dimensional coordinate system and heat exchange boundary parameters of the edge plate edge points; obtaining the distances from the blade body edge points and the edge plate edge points to the contour line; and interpolating the heat exchange boundary parameters of the edge plate edge points and the blade body edge exchange points with the distance as a weight to obtain the heat exchange boundary parameters on the contour line.

[0014] In one or more embodiments, a plurality of streamlines on the blade pressure surface, the blade suction surface and the edge plate of the blade in the three-dimensional flow field are extracted respectively.

[0015] In one or more embodiments, streamlines at 1% to 5% of the blade height of the lower edge plate are extracted, and streamlines at 95% to 99% of the blade height of the upper edge plate are extracted.

[0016] In one or more embodiments, the heat exchange boundary includes a heat transfer coefficient and a recovery temperature.

[0017] In one or more embodiments, the blade three-dimensional coordinate system uses the blade radial direction as the Y axis, the blade axial direction as the X axis, and the direction perpendicular to the X and Y axes as the Z axis.

[0018] The above-mentioned three-dimensional heat transfer boundary calculation method of the blade constructs the conversion relationship between the three-dimensional coordinate system and the two-dimensional coordinate system, and extracts the three-dimensional flow field information of the blade by the computational fluid dynamics method, assigns it to the two-dimensional coordinate system and performs interpolation processing to obtain the heat transfer coefficient at each location within the two-dimensional coordinate system grid of the blade, and then obtains the three-dimensional, continuously distributed blade body and edge plate heat transfer coefficient boundary, which improves the calculation accuracy of the heat transfer coefficient of the entire surface of the blade gas side. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] The above and other features, properties and advantages of the present invention will become more apparent through the following description in conjunction with the accompanying drawings and embodiments, in which:

[0020] Figure 1 It is a schematic diagram of a turbine blade in a three-dimensional coordinate system;

[0021] Figure 2 It is a schematic diagram of the two-dimensional coordinate system of the blade body;

[0022] Figure 3 It is a schematic diagram of the two-dimensional coordinate system of the edge plate;

[0023] Figure 4 is a schematic diagram of the three-dimensional mesh of the blade surface;

[0024] Figure 5 It is the streamline extraction diagram;

[0025] Figure 6 It is a schematic diagram of an O-type topology flow channel;

[0026] Figure 7 It is the position representation of each discrete point on the blade streamline in the two-dimensional coordinate system of the blade;

[0027] Figure 8 It is the position representation of each discrete point on the edge plate streamline in the edge plate two-dimensional coordinate system;

[0028] Fig. 9 It is a flow chart of the calculation method of blade three-dimensional heat transfer boundary;

[0029] Fig.10 It is a specific flow chart of an embodiment of a method for calculating the three-dimensional heat transfer boundary of a blade. DETAILED DESCRIPTION

[0030] The present invention is further described below in conjunction with specific embodiments and drawings. More details are elaborated in the following description to facilitate a full understanding of the present invention. However, the present invention can obviously be implemented in a variety of other ways different from the description herein. Those skilled in the art can make similar generalizations and deductions based on actual application situations without violating the connotation of the present invention. Therefore, the protection scope of the present invention should not be limited by the content of this specific embodiment.

[0031] It should be noted that these and other subsequent drawings are only examples and are not drawn to scale, and should not be used to limit the actual scope of protection required by the present invention.

[0032] The existing methods for calculating the heat transfer boundary of the blade surface are generally divided into two categories: directly solving by CFD method and solving by engineering algorithm.

[0033] The direct solution using CFD method is: to obtain the heat transfer coefficient, generally at least two calculation examples need to be calculated. The gas recovery temperature distribution on the blade surface is obtained through the adiabatic wall boundary condition calculation example. The heat flux density distribution or wall temperature distribution on the blade surface is obtained through the constant wall temperature or constant heat flux wall boundary condition calculation example. The heat transfer coefficient distribution is obtained by superimposing the two calculation examples using the formula h=q / ΔT. To reduce the error, multiple constant wall temperature or constant heat flux density conditions need to be calculated. The advantage of this method is that it can obtain the three-dimensional heat transfer boundary of the entire surface of the gas side, and the heat transfer coefficient accuracy is relatively high. The disadvantage is that the calculation cycle is long and it is not suitable for rapid iteration in the early multi-scheme comparison design stage.

[0034] The methods for solving the heat transfer boundary of the blade body by engineering algorithms are: one is to extract the Mach number distribution on several streamlines on the blade body surface; the other is to extract the Mach number distribution of several relative blade height sections, and then solve the boundary layer two-dimensional differential equation to obtain the heat transfer coefficient and recovery temperature along these streamlines or relative blade heights as the heat transfer boundary when calculating the temperature field. For the method of extracting the streamlines of the blade body, there is a lack of a three-dimensional interpolation method for the entire surface of the blade body. Generally, the parameters on the discrete points are directly loaded into the blade calculation domain as the heat transfer boundary on the gas side. In the software related to the CFD method, such as Fluent, zero-dimensional interpolation is performed, and the interpolation accuracy is low; for the method of extracting the relative blade height section, three-dimensional interpolation is more convenient, but the heat transfer coefficient and recovery temperature solved along the relative blade height section do not consider the three-dimensional flow effect of the gas in the blade channel, and the calculation accuracy is also lacking.

[0035] Therefore, the above two methods commonly used in engineering algorithms cannot take into account both three-dimensional flow effects and three-dimensional interpolation.

[0036] Generally speaking, the heat transfer boundary of the blade edge plate is solved by dividing the edge plate into three sections, front, middle and back. Different one-dimensional empirical formulas are used for each section to calculate the heat transfer coefficient and recovery temperature respectively. The advantage of the engineering algorithm is the fast calculation speed. Generally, the heat transfer boundary of the gas side surface of the blade can be obtained within a few minutes. The disadvantage is that the heat transfer boundary calculation method of the blade body cannot be interpolated in three dimensions, or the three-dimensional flow effect cannot be considered. In addition, different algorithms are used for the blade body and the edge plate, resulting in discontinuous transition of the heat transfer boundary between the edge plate and the blade body, and discontinuous transition of the heat transfer boundary at the connection between the upper section and the section of the front, middle and back three sections of the edge plate, which may cause temperature gradients that do not match the actual situation at the segmented position, resulting in distortion of the thermal stress calculation results and affecting the strength assessment conclusion.

[0037] The three-dimensional heat transfer boundary calculation method for blades disclosed in the present invention can solve the problem that the heat transfer coefficient and recovery temperature calculated using the Mach number on several streamlines on the blade surface in the above-mentioned engineering algorithm cannot be interpolated in three dimensions, the problem that the heat transfer boundary calculation method on the edge plate and the blade calculation method are not unified, and the problem that the heat transfer boundary of the blade and the edge plate is discontinuous at the intersecting contour lines.

[0038] Reference Figure 1 It is understood that the three-dimensional coordinate system of the blade takes the blade radial direction as the Y axis, the blade axial direction as the X axis, and the direction perpendicular to the X and Y axes as the Z axis. Generally speaking, the three-dimensional flow field calculation results of the aerodynamic flow channel can be obtained based on the blade three-dimensional coordinate system and the computational fluid dynamics (CFD) method.

[0039] The three-dimensional heat exchange boundary calculation method of the blade disclosed in the present invention also includes the following steps after establishing the three-dimensional coordinate system of the blade and obtaining the three-dimensional flow field of the blade in the three-dimensional coordinate system based on the computational fluid dynamics method: establishing a two-dimensional coordinate system for the blade and obtaining a two-dimensional grid; establishing a conversion relationship between the three-dimensional coordinates and the two-dimensional coordinates of the same position of the blade; using the computational fluid method to extract the streamlines on the blade, and obtaining the heat exchange boundary and three-dimensional coordinates of the discrete points on the streamlines; converting the three-dimensional coordinates of the discrete points on the streamlines into points in the two-dimensional coordinate system, and assigning a heat exchange boundary to the point; interpolating the heat exchange boundary at the point in the two-dimensional grid, and calculating the heat exchange boundary of each point in the two-dimensional coordinate system.

[0040] The established two-dimensional coordinate system is a dimensionless two-dimensional coordinate system. For ease of description, the two dimensions of the two-dimensional coordinate system are named U and V respectively. To distinguish the two-dimensional coordinate systems of the blade body and the edge plate, they are marked with subscripts b and e respectively. The position in the two-dimensional coordinate system is called a "point position (U, V)", and the position in the three-dimensional coordinate system is called a "discrete point (X, Y, Z)". Therefore, the same position of the blade can be represented by a discrete point (X, Y, Z) or a point position (U, V), and there is a conversion relationship between the two coordinates.

[0041] Continue to refer to Figure 1 As shown, the blade 10 includes different structures such as a blade body 11, a lip plate 12, and a contour line 19 at the connection between the blade body 11 and the lip plate 12. The blade body 11 includes a leading edge 14 and a trailing edge 13, and also includes a pressure surface 16 on one side and a suction surface 17 on the other side. Considering the different structural distributions of the blades, the following are established respectively: Figure 2 The blade two-dimensional coordinate system and Figure 3 The two-dimensional coordinate system of the edge plate is shown.

[0042] For the blade 11, in some embodiments, the arc length direction of the blade 11 is defined as the first dimension Ub of the blade two-dimensional coordinate system, and the radial direction of the blade 11 is defined as the second dimension Vb of the blade two-dimensional coordinate system, and the blade two-dimensional coordinate system and the two-dimensional grid are constructed, such as Figure 2 As shown. The two-dimensional grid is formed by interweaving horizontal and vertical longitude lines 101 and latitude lines 102. The grid lines in the same direction as the mainstream flow are latitude lines 102, and the grid lines along the radial or circumferential direction are longitude lines 101. For the blade grid, the longitude coordinate range is (-1, 1) and the latitude coordinate range is (0, 1).

[0043] Furthermore, the trailing edge of the suction surface is set in the positive direction of the first dimension, the trailing edge of the pressure surface is set in the negative direction of the first dimension, and the leading edge root of the blade is defined as the origin, such as Figure 2 A in the figure indicates the trailing edge of the pressure side, B indicates the trailing edge of the suction side, C indicates the blade tip of the pressure side, D indicates the blade tip of the suction side, E indicates the blade root of the pressure side, and F indicates the blade root of the suction side. The Ub coordinate of the leading edge of the blade is defined as 0, the Ub coordinate of the trailing edge of the suction side is defined as 1, and the Ub coordinate of the trailing edge of the pressure side is defined as -1; the Vb coordinate of the contour line where the blade body intersects with the lower edge plate (inner ring edge plate) is defined as 0, and the Vb coordinate of the contour line where the blade body intersects with the upper edge plate (outer ring edge plate) is defined as 1, that is, a two-dimensional coordinate system of the blade body is established, and any discrete point on the combustion side surface of the blade body in the three-dimensional coordinate system can find the corresponding point (Ub, Vb) in the two-dimensional coordinate system through the conversion relationship between the three-dimensional coordinates and the two-dimensional coordinates of the blade body.

[0044] For the edge plate 12, a two-dimensional coordinate system is established in a blade channel on the edge plate. In some embodiments, the blade axial direction, that is, the X direction in the three-dimensional coordinate system, is defined as the first dimension Ue of the edge plate two-dimensional coordinate system, and the blade circumferential direction is defined as the second dimension Ve of the edge plate two-dimensional coordinate system, such as Figure 3 The leading edge of the edge plate is set in the negative direction of the first dimension, the trailing edge of the edge plate is set in the positive direction of the first dimension, and the leading edge point of the edge plate on the pressure surface side of the blade is defined as the origin, as shown in Figure 3 The G area is the leading edge of the edge plate, the H area is the trailing edge of the edge plate, the J area is the side of the edge plate close to the suction surface, and the K area is the side of the edge plate close to the pressure surface. The engine axis position Ue coordinate of the leading edge point of the edge plate is defined as 0, the engine axis position Ue coordinate of the trailing edge point of the edge plate is defined as 1, the contour line Ve coordinate of the intersection of the pressure surface of the blade and the edge plate is defined as 0, and the contour line Ve coordinate of the intersection of the suction surface of the blade and the edge plate is defined as 1.

[0045] It should be noted that the axial length of the edge plate is usually longer than the circumferential length of the blade body, so the Ue coordinate value of a point on the edge plate may be less than 0 or greater than 1.

[0046] After the blade body two-dimensional coordinate system and the edge plate two-dimensional coordinate system are established, orthogonal two-dimensional grids are established with a step size of 0.1 or 0.05 or 0.02 or 0.01, respectively, and a plane grid with a grid density of 11 or 21 or 51 or 101 can be obtained. Figure 2 A plane mesh with a density of 11 is shown. The mesh density should be chosen to be close to the density of the computational domain mesh for blade heat conduction calculations. For the edge plate mesh, the meridian coordinate range is (l,r), where l≤0 and r≥1, and the latitude coordinate range is (0,1).

[0047] It should be noted that when using CFD software to calculate the flow field in the cascade channel, if the calculation domain established is an O-shaped topology structure with the blade in the middle and periodic boundaries on both sides, such as Figure 6 When calculating the U and V values ​​of each discrete point on the edge plate streamline, some streamlines should be rotated by one blade cycle so that the V coordinates of all discrete points fall within the interval (0,1), as shown in Figure 8 shown.

[0048] After the three-dimensional flow field in the blade and cascade channel is calculated by commercial or self-compiled CFD software, 3 to 8 streamlines on the blade pressure surface, blade suction surface and edge plate are extracted respectively, such as Figure 5As shown, the three-dimensional coordinate parameters (X, Y, Z) of several discrete points on these streamlines arranged in the flow direction and aerodynamic parameters such as gas pressure, gas temperature and Mach number are obtained. When extracting streamlines on the edge plate, it is preferred to extract streamlines at a certain blade height away from the edge plate, such as extracting streamlines at 1% to 5% of the blade height of the lower edge plate, and extracting streamlines at 95% to 99% of the blade height of the upper edge plate. Through the two-dimensional coordinate system and transformation relationship defined above, the point positions (U, V) of the discrete points (X, Y, Z) on these streamlines in the two-dimensional coordinate system are obtained.

[0049] Based on the three-dimensional coordinate parameters and aerodynamic parameters on the above streamlines, the heat transfer coefficient and recovery temperature of these discrete points on the streamlines are obtained using external heat transfer calculation tools or empirical formulas, and then the heat transfer boundaries of these positions on the streamlines are obtained, and the heat transfer coefficient and recovery temperature of the position are assigned to the points in the two-dimensional coordinate system.

[0050] For the area on the contour line, since the streamlines generally do not flow along the contour line where the blade body and the edge plate intersect, if the heat transfer boundaries of the blade body and the edge plate are extrapolated separately in the absence of corresponding data points near the contour line, the heat transfer boundaries of the blade body and the edge plate will be discontinuous near the contour line, which violates the real physical laws and may cause a large temperature gradient in this area when calculating the temperature field.

[0051] In order to make the heat transfer boundary of the blade body and the edge plate continuous, it is also necessary to establish a calculation method that uses the coordinate parameters and heat transfer boundary parameters on the streamlines of the blade body and the edge plate at the same time and obtains the heat transfer boundary on the contour line through interpolation. Specifically, the method includes the following steps: first, obtaining the mapping relationship between the grid points on the contour line where the blade and the edge plate intersect in the blade body two-dimensional coordinate system and the edge plate two-dimensional coordinate system, that is, given the coordinates of any point (Ub, Vb) on the contour line of the blade body two-dimensional coordinate system (where Vb=0 or Vb=1), the coordinates of the point in the edge plate two-dimensional coordinate system (Ue, Ve) (where Ve=0 or Ve=1, 0≤Ue≤1) can be obtained; obtaining the blade body edge points close to the contour line in the blade body two-dimensional coordinate system and the heat exchange boundary parameters of the blade body edge points, obtaining the edge plate edge points close to the contour line in the edge plate two-dimensional coordinate system and the heat exchange boundary parameters of the edge plate edge points; obtaining the distance from the blade body edge point to the point with coordinates (Ub, Vb) on the contour line and the distance from the edge plate edge point to the point with coordinates (Ue, Ve) on the contour line; interpolating the heat exchange boundary parameters of the edge plate edge points and the heat exchange boundary parameters of the blade body edge points with distance as weight, and obtaining the heat exchange boundary parameters on the contour line. That is, the streamlines closest to the contour line are selected from the streamlines on the blade and the edge plate respectively. According to the distance from the discrete points on the streamline to the contour line and the heat transfer boundary, the distance is used as the weighted interpolation to obtain the heat transfer coefficient and recovery temperature at the intersection of all longitude and latitude lines on the contour line.

[0052] After obtaining the heat transfer coefficient and recovery temperature on the contour line and the heat transfer coefficient and recovery temperature at the points in the two-dimensional coordinate system converted from the discrete points on the streamline, the heat transfer coefficient and recovery temperature at each point in the two-dimensional grid can be obtained by performing linear interpolation in the two-dimensional grid, that is, the heat transfer coefficient and recovery temperature values ​​at each three-dimensional position of the blade are obtained, thus obtaining the heat transfer boundary result on the gas side of the blade based on the three-dimensional real streamline interpolation.

[0053] Below through Fig.10 An embodiment shown introduces a method for calculating the three-dimensional heat transfer boundary of a blade.

[0054] Perform steps S101 and S102 to establish Figure 2 and Figure 3 The 2D coordinate system and target grid are shown.

[0055] Steps S103 and S104 are performed to obtain streamlines based on CFD examples, and based on the coordinates of each point on the streamline, heat transfer boundaries of discrete points on the streamline, such as heat transfer coefficients and recovery temperatures, are obtained through linear interpolation.

[0056] Steps S105 and S106 are performed. A discrete point (X, Y, Z) of a certain position of the blade in the three-dimensional coordinate system can be represented by a site (U, V) in the two-dimensional coordinate system through a conversion relationship. Therefore, the two-dimensional coordinates of the discrete points on the streamline in the two-dimensional coordinate system are calculated so that all the discrete points on the streamline fall within the defined interval, such as Figure 7 and Figure 8 Then, the coordinate parameters of the intersection of each streamline and the meridian of the two-dimensional grid, as well as the heat transfer coefficient and the recovery temperature value at the intersection are obtained by means such as linear interpolation.

[0057] Step S107 is performed to establish a mapping relationship between the blade and edge plate two-dimensional coordinate systems. The mapping relationship obtained in this step is used for the subsequent calculation of the contour line heat exchange boundary. In order to make the heat exchange boundary of the blade and edge plate continuous, the mapping relationship between the grid points on the contour line where the blade and edge plate intersect in the blade two-dimensional coordinate system (Ub, Vb) and the edge plate two-dimensional coordinate system (Ue, Vee) is obtained by linear interpolation or second-order interpolation. The position of the contour line can be characterized in the blade two-dimensional coordinate system (Ub, Vb) and the edge plate two-dimensional coordinate system (Ue, Vee).

[0058] Step 108 is performed to calculate the heat exchange boundary on the contour line by using the above-mentioned distance-weighted interpolation method.

[0059] Then, the heat transfer boundary parameters of the discrete points on the known streamlines in the two-dimensional grid are calculated, and the heat transfer boundary on the contour line, that is, the heat transfer coefficient and recovery temperature values ​​on each longitude line with a V coordinate of 0 or 1, are calculated through step S108. Then, the heat transfer coefficient and recovery temperature values ​​at the intersection of the longitude and latitude lines of all two-dimensional grids can be interpolated to obtain the heat transfer boundary of the target grid point.

[0060] Finally, S110 is performed. In step S102, all coordinates at the intersection of the target grid are obtained. In step S109, the heat exchange boundary of the target grid point is obtained, so the heat exchange boundary result of the blade gas side obtained based on the three-dimensional real streamline interpolation is obtained. According to the input file format requirements of the blade solid heat conduction calculation software, the external heat exchange boundary is sorted.

[0061] The above method establishes a heat transfer boundary calculation method that considers the three-dimensional flow effect on the entire surface of the gas side of the blade, and establishes a conversion method between the three-dimensional blade surface curved coordinate system and the two-dimensional plane coordinate system, so that the heat transfer boundary on the discrete streamline can be three-dimensionally interpolated to the entire surface of the blade body or edge plate. An interpolation method for the heat transfer boundary on the intersecting contour line of the blade body and the edge plate is also established, so that the heat transfer boundary transition between the blade body and the edge plate is continuous, thereby effectively improving the calculation accuracy of the heat transfer boundary and maintaining the calculation efficiency advantage of the original engineering algorithm.

[0062] At the same time, the above introduction uses specific words to describe the embodiments of the present application. For example, "one embodiment", "an embodiment", and / or "some embodiments" refer to a certain feature, structure or characteristic related to at least one embodiment of the present application. Therefore, it should be emphasized and noted that "one embodiment" or "an embodiment" or "an alternative embodiment" mentioned twice or more in different positions in this specification does not necessarily refer to the same embodiment. In addition, certain features, structures or characteristics in one or more embodiments of the present application can be appropriately combined.

[0063] Although the present invention is disclosed as above with preferred embodiments, it is not intended to limit the present invention. Any person skilled in the art may make possible changes and modifications without departing from the spirit and scope of the present invention. Therefore, any modification, equivalent change and modification made to the above embodiments according to the technical essence of the present invention without departing from the content of the technical solution of the present invention shall fall within the protection scope defined by the claims of the present invention.

Claims

1. The method for calculating the three-dimensional heat transfer boundary of a blade includes the following steps: Establish the three-dimensional coordinate system of the blade, Obtaining the three-dimensional flow field of the blade in the three-dimensional coordinate system by means of computational fluid dynamics; It is characterized in that The following steps are also included: Establish a two-dimensional coordinate system for the blade and obtain a two-dimensional grid; Establish the conversion relationship between the three-dimensional coordinates and the two-dimensional coordinates of the same position of the blade; Extracting streamlines on blades in the three-dimensional flow field, and obtaining heat exchange boundaries and three-dimensional coordinates of discrete points on the streamlines; Converting the discrete points into points in a two-dimensional coordinate system, and assigning the heat exchange boundary to the points; The heat exchange boundary at the point is interpolated in the two-dimensional grid to calculate the heat exchange boundary of each point in the two-dimensional coordinate system.

2. The blade three-dimensional heat exchange boundary calculation method according to claim 1, characterized in that: The blade body two-dimensional coordinate system and the edge plate two-dimensional coordinate system are established respectively.

3. The blade three-dimensional heat exchange boundary calculation method according to claim 2, characterized in that: The arc length direction along the blade airfoil is defined as the first dimension of the blade airfoil two-dimensional coordinate system, and the radial direction of the blade airfoil is defined as the second dimension of the blade airfoil two-dimensional coordinate system.

4. The blade three-dimensional heat exchange boundary calculation method according to claim 3, characterized in that: The trailing edge of the suction surface is set in the positive direction of the first dimension, the trailing edge of the pressure surface is set in the negative direction of the first dimension, and the root of the leading edge of the blade is defined as the origin.

5. The blade three-dimensional heat exchange boundary calculation method according to claim 3 or 4, characterized in that: The blade axial direction is defined as the first dimension of the edge plate two-dimensional coordinate system, and the blade circumferential direction is defined as the second dimension of the edge plate two-dimensional coordinate system.

6. The blade three-dimensional heat exchange boundary calculation method according to claim 5, characterized in that: The leading edge of the edge plate is set in the negative direction of the first dimension, the trailing edge of the edge plate is set in the positive direction of the first dimension, and the leading edge point of the edge plate located on the pressure surface side of the blade is defined as the origin.

7. The blade three-dimensional heat exchange boundary calculation method according to claim 2, characterized in that: The blade includes a blade body, an edge plate, and a contour line of a connection between the blade body and the edge plate. Before calculating the heat exchange boundary parameters of each point in the two-dimensional coordinate system, the method also includes a contour line heat exchange boundary calculation step: Obtaining a mapping relationship between the position on the contour line and the blade two-dimensional coordinate system and the edge plate two-dimensional coordinate system; Obtaining blade edge points and heat exchange boundary parameters of blade edge points close to the contour line in the blade two-dimensional coordinate system, and obtaining edge plate edge points and heat exchange boundary parameters of edge plate edge points close to the contour line in the edge plate two-dimensional coordinate system; Obtain the distance from the blade edge point and the edge plate edge point to the contour line; The heat exchange boundary parameters of the edge point of the edge plate and the heat exchange boundary parameters of the blade edge point are interpolated with the distance as a weight to obtain the heat exchange boundary parameters on the contour line.

8. The blade three-dimensional heat exchange boundary calculation method according to claim 1, characterized in that: The blade pressure surface, blade suction surface and multiple streamlines on the edge plate of the blade in the three-dimensional flow field are extracted respectively.

9. The blade three-dimensional heat exchange boundary calculation method according to claim 8, characterized in that: The streamlines at 1% to 5% of the blade height of the lower edge plate are extracted, and the streamlines at 95% to 99% of the blade height of the upper edge plate are extracted.

10. The blade three-dimensional heat exchange boundary calculation method according to claim 1, characterized in that: The heat exchange boundary includes a heat exchange coefficient and a recovery temperature.

11. The blade three-dimensional heat exchange boundary calculation method according to claim 1, characterized in that: The blade three-dimensional coordinate system takes the blade radial direction as the Y axis, the blade axial direction as the X axis, and the direction perpendicular to the X and Y axes as the Z axis.

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