Research And Design Of Wind Tunnel Test System For A Two-dimensional Variable Geometry Inlet With Rotating Cowl

It is well known internationally that two-dimensional variable geometry inlet with rotating cowl is suitable for hypersonic aircraft.Design of this kind of inlet is always studied and verified through wind tunnel simulation test.So far,the technology of variable geometry inlet is still in frontier internationally in the field of hypersonic aircraft.In the domestic,most researches on the technology are still in the theoretical stage,experimental verifications have just started,available experience is rare.According to the present technology domestically,design of a complete test system is proposed in this thesis for a two-dimensional variable geometry inlet by means of analysis and study of the test requirement and characteristic in the situation of lack of experience.The works what have been done are presented in this thesis.Firstly,according to the requirement of aerodynamic contour of inlet and requirement of study,the structure of test model has been designed in the base of relieving constraints from wind tunnel and variable geometry characteristic of inlet.Secondly,works of comparative analysis for motion control modes of model’s cowl,proposing a motion control strategy for cowl based on electric servo cylinder,designing hardware matching of control system,communication mode and control software,giving parameters of system control and calibration of the angular position have been done.Thirdly,analysis of the aerodynamic parameters for test,design of steady and dynamic data measurement and acquisition system for this test and establishment of relation in time domain of cowl state and test data is completed herein.Finally,by studying the noise characteristics of dynamic test data and comparing the common noise reduction methods,a treatment method of noise reduction for dynamic test data,which is based on wavelet transform,is proposed and designed to be noise reduction software by using MATLAB wavelet tools.The measures to how to achieve the ideal effect of noise reduction have also been given for this software.In summary,the wind tunnel test system of two-dimensional variable geometry inlet with rotating cowl has practical engineering value to test verification of this kind of inlet,and builda good platform for the following study and other similar wind tunnel test systems.