CN-115718959-B - Method and system for designing blade angle of compressor

CN115718959BCN 115718959 BCN115718959 BCN 115718959BCN-115718959-B

Abstract

The invention relates to the technical field of axial flow, centrifugal and diagonal flow compressors, and solves the problem of long time period consumption in the design of the existing compressor blades, in particular to a method and a system for designing the blade angle of the compressor, wherein the blade angle design method comprises the following steps of firstly normalizing the chord length of each section blade profile of the blade into a closed interval [0,1]; the method comprises the steps of analyzing the relative position of a blade angle relative to the chord length of a blade profile, recording the relative position as x, wherein x is E [0,1], establishing a plurality of groups of polynomials to represent the blade angle distribution form, recording the corresponding piecewise functions of the plurality of groups of polynomials in a closed interval [0,1] as f (x), establishing a function program, introducing a plurality of groups of columns Q, R, S and T, analyzing and calculating the f (x), and adjusting the coefficients of the polynomials to quickly modify the blade angle distribution form of the compressor. The invention realizes the modification of the blade angle distribution form by adjusting the polynomial coefficient, and realizes the rapid iteration of the modeling of the compressor blade.

Inventors

XU GUOHUA
LI DU
HE DAN
ZHANG JINLUN
YIN YUEQIAN
CAI XIN
CAO JUN

Assignees

中国航发湖南动力机械研究所

Dates

Publication Date: 20260505
Application Date: 20221021

Claims (10)

1. A method for compressor blade angle design, the method comprising the steps of: firstly, normalizing chord length of each section profile of the blade into a closed interval [0,1]; analyzing the relative position of the blade angle with respect to the chord length of the blade profile and marking as x, wherein x is E [0,1]; Establishing a plurality of groups of polynomials to represent a blade angle distribution form, wherein the corresponding piecewise functions of the plurality of groups of polynomials in a closed interval [0,1] are marked as f (x), x is a unique independent variable of f (x), the plurality of groups of polynomials comprise a plurality of groups of three-degree polynomials, and the plurality of groups of three-degree polynomials comprise two groups/three groups of three-degree polynomials; Establishing a function program, introducing a group of arrays Q, R, S and T, analyzing and calculating the f (x) to obtain a group of coordinates of a new blade angle, wherein the function program comprises the following steps: dividing the closed interval [0,1] into N equal parts to obtain a number sequence with N+1 elements: Constructing a plurality of columns: Constructing a plurality of columns: wherein , Is the inlet angle of the blade shape, Is a blade-shaped outlet angle; Constructing a plurality of columns: The new blade angle has a set of coordinates of ; The method further comprises the steps of: the coefficients of the polynomial are adjusted to quickly modify the compressor blade angular distribution pattern.
2. A method for compressor blade angle design according to claim 1, wherein the implementation of the two sets of cubic polynomials representing the blade angle distribution form comprises the steps of: inserting a point into the closed section [0,1], wherein the corresponding value of the point in the closed section [0,1] is marked as t, and the closed section [0,1] is divided into two adjacent sections by a point; For two adjacent intervals, two sets of cubic polynomials are established to represent the distribution of blade angles.
3. The method for designing a blade angle of a compressor as set forth in claim 2, wherein the two adjacent intervals include [0, t ], [ t,1], wherein the value interval of t is (0, 1).
4. A method for compressor blade angle design according to claim 1 or 2, characterized in that the two sets of cubic polynomials are respectively: , wherein, A, b, c and d are coefficients of the corresponding polynomial and are variable constants; , wherein, E, f, g and h are coefficients of the corresponding polynomial and are variable constants.
5. A method for compressor blade angle design as defined in claim 4, wherein, And The corresponding piecewise function is: the f (x) is first-order conductive at x=t.
6. A method for compressor blade angle design according to claim 1, wherein the implementation of the three sets of cubic polynomials representing the blade angle distribution form comprises the steps of: Inserting two points into a closed interval [0,1], wherein corresponding values of the two points in the closed interval [0,1] are respectively marked as t 1 、t 2 , and the closed interval [0,1] is divided into three adjacent intervals by t 1 and t 2 ; for three adjacent intervals, three sets of cubic polynomials are established to represent the distribution of blade angles.
7. The method of claim 6, wherein the three adjacent intervals include [0, t 1 )、[t 1 ,t 2 )、[t 2 , 1], wherein , t 1 、t 2 is (0, 1), and t 1 ＜t 2 .
8. The method for compressor blade angle design of claim 6, wherein the three sets of cubic polynomials are each: , wherein, A 1 、b 1 、c 1 and d 1 are coefficients of the corresponding polynomials and are variable constants; , wherein, E 1 、f 1 、g 1 and h 1 are coefficients of the corresponding polynomials and are variable constants; , wherein, K 1 、m 1 、n 1 and q 1 are coefficients of the corresponding polynomials and are variable constants.
9. A method for compressor blade angle design as defined in claim 8, wherein, 、 And The corresponding piecewise function is: the f (x) is uniformly rank-conductive at x=t 1 and x=t 2 .
10. A system for compressor blade angle design, characterized in that the system for blade angle design comprises, The data processing unit is used for normalizing the chord length of each section profile of the blade into a closed interval [0,1]; The extraction variable unit is used for analyzing the relative position of the blade angle with respect to the chord length of the blade profile and is marked as x, and the x is E [0,1]; The modeling unit is used for establishing a plurality of groups of polynomials to represent a blade angle distribution form, wherein the corresponding piecewise functions of the plurality of groups of polynomials in a closed interval [0,1] are marked as f (x), x is the unique independent variable of f (x), the plurality of groups of polynomials established by the modeling unit comprise a plurality of groups of three-degree polynomials, and the plurality of groups of three-degree polynomials comprise two groups/three groups of three-degree polynomials; A calculation unit for creating a function program, introducing a set of arrays Q, R, S and T, analyzing and calculating the f (x) to obtain a set of coordinates of a new blade angle, the calculation unit comprising, when creating the function program, A first module for dividing the closed space [0,1] into N equal parts to obtain a series of N+1 elements ; The second module is used for constructing a plurality of columns: And a third module for constructing a plurality of columns: wherein , Is the inlet angle of the blade shape, Is a blade-shaped outlet angle; fourth module for constructing a series of The new blade angle has a set of coordinates (Q i ,T i ), i ε [0, N ]; And the fast iteration unit is used for adjusting the coefficients of the polynomial to quickly modify the angular distribution form of the compressor blade.

Description

Method and system for designing blade angle of compressor Technical Field The invention relates to the technical field of axial flow, centrifugal and diagonal flow compressors, in particular to a method and a system for designing blade angles of a compressor. Background The impeller machinery applies work to the gas through rotation, so that the purpose of compressing the gas is achieved, the types of the aero-engine gas compressor can be divided into a multi-stage axial flow mode, an axial flow centrifugal mode, an oblique flow centrifugal mode and the like, and a relatively high supercharging ratio is achieved through the mode that the gas compressor continuously rotates to compress the gas. The ability of a single stage compressor to compress gas is often determined by the rim work, which is related to the compressor blade angular distribution, which is a key factor in determining the aerodynamic performance of the compressor. Different compressors have different inlet conditions and load levels and different blade angle distribution forms. The geometrical shape of the compressor blade is obtained by superposing thickness distribution on a camber line of the blade, and the camber line of the blade can be obtained by integrating the blade angle along the chord line of the blade, so that the geometrical shape of the compressor blade is determined by the distribution form of the blade angle, and the geometrical shape of the compressor blade is one of core factors in the design activity of the compressor. The distribution of the blade angles of the air compressor is often represented by a group of discrete data points, and the geometrical shape of the air compressor blade is changed by repeatedly adjusting the discrete points on the blade angle curve, so that the design target is realized. With the continuous improvement of index requirements of aero-engine power, oil consumption and the like, the pneumatic load of the air compressor is also continuously improved, the geometric shape of the air compressor blade is more distorted, more discrete points are needed for more accurately expressing the angular distribution of the blade, and therefore, the blade with the geometric shape meeting the requirements is designed, and the consumed time period is more. At present, when an axial flow compressor, a centrifugal compressor and an oblique flow compressor are designed, the geometric shape of the blade is modified by adjusting the blade angle distribution, because the blade angles are often represented by one or more groups of discrete data points, different blade angle distribution forms of the compressor are different, the blade angle data points of a plurality of blades are often required to be adjusted to complete the design of the compressor, the adjustment of the blade angle data points has large workload and long time consumption period, the development of the design technology of the compressor is restricted, and the improvement of performance indexes is restricted, so that a method and a system for the blade angle design of the compressor are needed to be provided to shorten the period of the blade angle design. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a method and a system for designing a blade angle of a gas compressor, and aims to solve the problems that a large number of blade angle data points need to be adjusted, the workload is large and the time consumption period is long in the current gas compressor blade design by utilizing a polynomial to express the distribution form of the blade angle of the gas compressor and calculating and adjusting the polynomial coefficient to shorten the blade angle design period. In order to achieve the purpose, the invention provides a method for designing the blade angle of a compressor, which comprises the following steps: firstly, normalizing chord length of each section profile of the blade into a closed interval [0,1]; analyzing the relative position of the blade angle with respect to the chord length of the blade profile and marking as x, wherein x is E [0,1]; establishing a plurality of groups of polynomials to represent a blade angle distribution form, wherein the corresponding piecewise functions of the plurality of groups of polynomials in a closed interval [0,1] are marked as f (x), and x is the unique independent variable of f (x); Establishing a function program, introducing a group of arrays Q, R, S and T, and analyzing and calculating the f (x) to obtain a group of coordinates of a new blade angle; the coefficients of the polynomial are adjusted to quickly modify the compressor blade angular distribution pattern. Preferably, the function establishment procedure includes the steps of: Dividing the closed interval [0,1] into N equal parts to obtain a number sequence Q= { Q 0,Q1,Q2,…QN}＝{x0,x1,x2,…xN }, wherein the number sequence Q= { Q 0,Q1,Q2,…QN}＝{x0,x1,x2,…xN }, the number sequence of the N+1 elements is