Hyperbolic fitting method for compressible fluid turbulence measurement test data

Abstract

The invention discloses a hyperbolic fitting method for compressible fluid turbulence measurement test data. The method comprises the following steps: (1), carrying out data acquisition preparation; (2), opening a to-be-measured wind tunnel, and carrying out measuring by using a hot-wire anemometer under an incoming Mach number M to obtain a to-be-fitted two-dimensional scatter sequence; (3), performing hyperbolic fitting on the to-be-fitted two-dimensional scatter sequence by using an iterative method based on a Lagrange multiplier neural network, and carrying out solving to obtain a fittingresult; and (4), solving a turbulence degree result. According to the method, hyperbolic fitting is carried out on compressible fluid turbulence measurement test data by using the iterative method based on the Lagrange multiplier neural network and the turbulence is calculated by using the fitting result; compared with a traditional method represented by an SOE method, the method has the advantages that the turbulence solving accuracy is high, the robustness is high, and a feasible method is provided for hyperbolic fitting of compressible fluid turbulence measurement test data.

Description

technical field [0001] The invention belongs to the field of experimental aerodynamics, in particular to a hyperbola fitting method for measuring test data of compressible fluid turbulence. Background technique [0002] As we all know, wind tunnel test is the most effective method for aerodynamic research. Even today, when the numerical simulation based on the rapid development of computer technology is becoming more and more perfect, and the model flight test technology is improving day by day, it is still necessary to carry out the necessary model wind tunnel test. It is an indispensable link in the research of complex aerodynamic characteristics in the process of aircraft research and development. The fine design of advanced large aircraft requires high accuracy of wind tunnel test results. Wind tunnel flow field turbulence, as an important dynamic flow field quality, will affect the accuracy of wind tunnel test results, such as aircraft force and moment The calculation ...

AI Technical Summary

Problems solved by technology

However, in the process of actual measurement and data acquisition, due to the unsteady characteristics of the flow, the two-dimensional scattered points may deviate from the hyperbolic distribution, and even approximate straight lines and other conic distributions, which bring difficulties to the solution of turbulence fitting.

[0004] Many scholars have studied the hyperbola fitting method, and the methods used include the Hough Transform (HF) method, the least squares (Least Squares, LS) fitting method, and the solution of overdetermined equations (Solution of overdetermined equations, SOE) method and other traditional methods, among which the SOE method is the most widely used, but none of the above methods can overcome the problem that the scatter point distribution deviates from the hyperbola due to the unsteady characteristics of the flow

Therefore, it is necessary to establish a robust hyperbolic fitting method to avoid errors in the measurement results of compressible fluid turbulence caused by fitting results errors

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