CN-122020864-A - Modeling method of non-axisymmetric end wall of compressor based on accompanying shape optimization

CN122020864ACN 122020864 ACN122020864 ACN 122020864ACN-122020864-A

Abstract

The application provides a compressor non-axisymmetric end wall modeling method based on accompanying shape optimization, which belongs to the technical field of aeroengine compressor design, and specifically comprises the steps of sequentially completing building a blade grid single-channel original geometric model by taking an axisymmetric end wall compressor as an optimization object, structuring grid division, obtaining isentropic efficiency of the compressor designed by the axisymmetric end wall through flow field simulation, building an optimization object and constraint conditions, solving design variable sensitivity based on the accompanying shape optimization method, arranging control points on the outer surface of the end wall, calculating total displacement of the control points in combination with the sensitivity, realizing end wall grid deformation through a radial basis function, and performing iterative optimization after simulating and verifying the performance of the current end wall geometric configuration until the end wall meets the optimization object and constraint conditions. The application improves the optimization efficiency and modeling precision of the end wall of the air compressor, improves the isentropic efficiency of the air compressor, and ensures that the performance parameters of the air compressor after optimization are stable.

Inventors

LIANG JINHUA
ZHU RUI

Assignees

太行国家实验室

Dates

Publication Date: 20260512
Application Date: 20260414

Claims (8)

1. The modeling method of the non-axisymmetric end wall of the air compressor based on the accompanying shape optimization is characterized in that the air compressor designed by adopting the axisymmetric end wall is taken as an optimization object, the geometric configuration of the optimized non-axisymmetric end wall is obtained, and the modeling method of the non-axisymmetric end wall of the air compressor comprises the following steps: step 1, extracting a single blade cascade channel of a gas compressor designed by adopting an axisymmetric end wall, and establishing an original geometric model of the single blade cascade channel comprising blades of the gas compressor and the axisymmetric end wall; step 2, dividing the original geometric model into structural grids, and encrypting the grids of the axisymmetric end wall surface and the areas of the blade surface; step 3, introducing the structured grid of the original geometric model into flow field simulation software, setting boundary conditions and a turbulence model, and solving a three-dimensional Reynolds average Navier-Stokes equation to obtain isentropic efficiency of the compressor designed by adopting axisymmetric end walls; step 4, maximizing the isentropic efficiency of the air compressor under the optimized non-axisymmetric end wall geometric configuration to be a preset value of an isentropic efficiency increasing value set by an optimization target, and introducing a pressure ratio penalty function and a flow ratio penalty function to construct a total objective function with constraint; step 5, solving the sensitivity of the total objective function to the design variable which takes the grid node displacement of the current end wall based on the accompanying shape optimization method; step 6, arranging control points on the outer surface of the current end wall according to a preset rule, and encrypting and arranging the control points in the areas of the outer surface of the current end wall corresponding to the front edge and the rear edge of the blade; Step 7, calculating the total displacement of each control point according to the sensitivity, wherein the total displacement is formed by superposing the accumulated displacement and the sensitivity driving displacement, and controlling the total displacement of each control point to be within the range of 0.01-0.1 mm; Step 8, establishing an interpolation field according to the total displacement of each control point by adopting a radial basis function method, calculating the displacement of each grid node of the current end wall, and deforming the grids of the current end wall to form grids and geometric configurations of the non-axisymmetric end wall; Step 9, replacing the end wall grid in the original geometric model with the current end wall grid to form a new structured grid, introducing the new structured grid into flow field simulation software, performing flow field simulation by adopting the boundary conditions and the turbulence model in the step 3, obtaining isentropic efficiency, pressure ratio and flow of the compressor under the current end wall geometric configuration, and verifying the performance of the current end wall geometric configuration; And step 10, judging whether the isentropic efficiency increasing value of the air compressor under the current end wall geometric configuration reaches a preset value of the isentropic efficiency increasing value, if so, outputting the geometric configuration of the non-axisymmetric end wall formed in the step 8, and if not, repeating the steps 5 to 9 for iteration until the isentropic efficiency of the air compressor under the latest end wall geometric configuration meets the optimization target, and outputting the latest geometric configuration of the non-axisymmetric end wall, wherein the current end wall in each iteration is the non-axisymmetric end wall formed in the step 8 in the last optimization process.
2. The method for shaping a non-axisymmetric end wall of a compressor based on accompanying shape optimization as claimed in claim 1, wherein in said step 2, the mesh side length of the axisymmetric end wall surface and the blade surface is equal to or less , wherein, The chord length of the blade; the grid gradient in the blade grid channel is controlled within 1.2, the grid orthogonality of the structured grid is more than or equal to 0.85, and the grid maximum stretching ratio of the structured grid is less than or equal to 20.
3. The method for modeling a non-axisymmetric end wall of a compressor based on accompanying shape optimization as claimed in claim 1, wherein the preset value of the isentropic efficiency increase in step 4 is 0.3%.
4. The method for modeling a non-axisymmetric end wall of a compressor based on accompanying shape optimization as defined in claim 1, wherein in the step 4, the total objective function is: ; Wherein, the The overall objective function is represented as such, Representing the isentropic efficiency of the compressor at the current end wall geometry, Representing the pressure ratio penalty function, Representing a flow ratio penalty function, For the pressure ratio penalty factor, Is a traffic ratio penalty factor.
5. The method for modeling a non-axisymmetric end wall of a compressor based on accompanying shape optimization according to claim 1, wherein in the step 5, the formula for solving the sensitivity of the total objective function to the design variable of the displacement of the grid nodes of the current end wall is: ; Wherein, the As a function of the overall objective function, To the front end wall The displacement of the nodes of the grid, In order to be sensitive to this, In order to be a lagrangian operator, The transpose of the representation vector is performed, In order to provide a flow control equation, Is a flow field variable for the cascade channels in the current endwall geometry.
6. The method for shaping a non-axisymmetric end wall of a compressor based on accompanying shape optimization as claimed in claim 1, wherein in said step 6, the perpendicular distance from the outer surface of the present end wall at the control point in the region of the outer surface of the present end wall corresponding to the vane leading edge and vane trailing edge is The spacing between adjacent control points in the region of the outer surface of the front end wall corresponding to the leading edge and trailing edge of the blade is , wherein, Is the pitch of the blade; The perpendicular distance between the control point and the outer surface of the current end wall in the areas except the areas of the outer surface of the current end wall corresponding to the front edge and the rear edge of the blade is The spacing between adjacent control points in regions other than the regions of the outer surface of the leading end wall corresponding to the leading and trailing edges of the blade are , wherein, Is the chord length of the blade.
7. The method for modeling a non-axisymmetric end wall of a compressor based on accompanying shape optimization as defined in claim 5, wherein in step 7, the calculation formula of the total displacement is: ; Wherein, the Is the first The total displacement of the individual control points is, Is the current first The cumulative displacement amounts of the individual control points, As a function of the overall objective function, To the front end wall The displacement of the individual grid points, In order to be sensitive to this, As the coefficient of displacement, the degree of displacement, 。
8. The method for modeling a non-axisymmetric end wall of a compressor based on shape optimization according to claim 7, wherein in the step 8, the formula for calculating the displacement of each grid node is: ; Wherein, the To the front end wall The amount of displacement of the individual mesh nodes, To the front end wall The coordinates of the nodes of the grid, Is the first The coordinates of the individual control points are used, To control the total number of points, As a function of the radial basis function, Is the first The weight coefficients of the individual control points, The method is obtained by solving according to the following steps: ; Wherein, the Is the first The coordinates of the individual control points are used, Is the first Total displacement of the control points.

Description

Modeling method of non-axisymmetric end wall of compressor based on accompanying shape optimization Technical Field The application relates to the field of aeroengine compressor design, in particular to a compressor non-axisymmetric end wall modeling method based on accompanying shape optimization. Background The compressor is used as a core component of an aeroengine, and the efficiency of the compressor directly influences the thrust and the fuel economy of the engine. The traditional gas compressor adopts axisymmetric end wall design, secondary flow loss is easy to generate in an end wall area, so that efficiency is reduced, and the existing non-axisymmetric end wall modeling method is independent of parameterization modeling and test iteration, has the problems of long optimization period and low sensitivity calculation precision, and can not meet the design requirements of the efficient and accurate gas compressor. Disclosure of Invention In view of the above, the application provides a method for modeling a non-axisymmetric end wall of a compressor based on accompanying shape optimization, which solves the problems in the prior art and improves the efficiency and the accuracy of modeling the non-axisymmetric end wall of the compressor. The application provides a compressor non-axisymmetric end wall modeling method based on accompanying shape optimization, which adopts the following technical scheme: The modeling method of the non-axisymmetric end wall of the air compressor based on accompanying shape optimization uses the air compressor designed by the axisymmetric end wall as an optimization object to obtain the geometric configuration of the optimized non-axisymmetric end wall, and the modeling method of the non-axisymmetric end wall of the air compressor comprises the following steps: step 1, extracting a single blade cascade channel of a gas compressor designed by adopting an axisymmetric end wall, and establishing an original geometric model of the single blade cascade channel comprising blades of the gas compressor and the axisymmetric end wall; step 2, dividing the original geometric model into structural grids, and encrypting the grids of the axisymmetric end wall surface and the areas of the blade surface; step 3, introducing the structured grid of the original geometric model into flow field simulation software, setting boundary conditions and a turbulence model, and solving a three-dimensional Reynolds average Navier-Stokes equation to obtain isentropic efficiency of the compressor designed by adopting axisymmetric end walls; step 4, maximizing the isentropic efficiency of the air compressor under the optimized non-axisymmetric end wall geometric configuration to be a preset value of an isentropic efficiency increasing value set by an optimization target, and introducing a pressure ratio penalty function and a flow ratio penalty function to construct a total objective function with constraint; step 5, solving the sensitivity of the total objective function to the design variable which takes the grid node displacement of the current end wall based on the accompanying shape optimization method; step 6, arranging control points on the outer surface of the current end wall according to a preset rule, and encrypting and arranging the control points in the areas of the outer surface of the current end wall corresponding to the front edge and the rear edge of the blade; Step 7, calculating the total displacement of each control point according to the sensitivity, wherein the total displacement is formed by superposing the accumulated displacement and the sensitivity driving displacement, and controlling the total displacement of each control point within the range of 0.01-0.1 mm so as to avoid excessive deformation of the grid; Step 8, establishing an interpolation field according to the total displacement of each control point by adopting a radial basis function method, calculating the displacement of each grid node of the current end wall, and deforming the grids of the current end wall to form grids and geometric configurations of the non-axisymmetric end wall; Step 9, replacing the end wall grid in the original geometric model with the current end wall grid to form a new structured grid, introducing the new structured grid into flow field simulation software, performing flow field simulation by adopting the boundary conditions and the turbulence model in the step 3, obtaining isentropic efficiency, pressure ratio and flow of the compressor under the current end wall geometric configuration, and verifying the performance of the current end wall geometric configuration; And step 10, judging whether the isentropic efficiency increasing value of the air compressor under the current end wall geometric configuration reaches a preset value of the isentropic efficiency increasing value, if so, outputting the geometric configuration of the non-axisymmetric end wall formed in the step 8, and if not, rep