采用内部测温估计表面热流在高超声速风洞试验中的应用
Application of surface-heat-flux estimation by measuring model interior temperature in hypersonic wind tunnel tests
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摘要: 表面热流预估方法利用试验件内部的温度来预估其表面热流。该方法的最大优点是测量温度的热电偶是内埋在试验件内部,不与外界的高温气流直接接触。该方法为高超声速飞行器飞行实验估计表面热流提供一种可行的途径。为了验证该方法在预测外界流场特性方面的能力,在航天空气动力技术研究院(CAAA)的 FD-03风洞中开展了一系列高超声速气动热风洞试验。试验中采用一块铝合金试验板,部分试验采用光滑平板,其余试验在试验平板的表面添加拌线以干扰外界流场。而后采用热流估计方法预估试验板的表面热流。预估结果表明,如由拌线产生的激波等外流场的强烈变化将在估计的热流结果中得到清晰的显示。Abstract: A series of hypersonic wind tunnel tests are implemented to estimate the aero-heat-ing flux of a test plate.The heat flux at the heated surface is not directly measured,but is esti-mated by solving an inverse heat conduction problem (IHCP)based on measured temperature at the back surface or inside of the plate.The most outstanding advantage of this method is that the temperature sensors do not contact with the high temperature outflow directly,but are embed ded inside the plate.Therefore,it provides an alternative approach to estimate the high tempera-ture surface heat flux for practical hypersonic vehicle flight tests.The primary aim of this paper is to verify the applicability of this method to predict the flow characteristics of the outflow filed. The hypersonic wind tunnel tests are implemented in FD-03 WT of China Academy of Aerospace Aerodynamics (CAAA).Some tests apply a smooth plate in general hypersonic wind tunnel tests;and others adopt a test plate bounded with a trip line to interrupt the boundary layer of the plate.As shown in the heat flux estimated results,severe changes in the outflow such as shock waves caused by the trip line can be predicted by the estimated heat flux.