一种高超声速稀薄流激波干扰气动热测量技术

针对高超声速稀薄来流条件下的激波干扰气动热测量问题，设计了一种适用长时间、中低热流量值(5~500 kW/m2)的带封装结构的量热计，采用空气隔热设计方式降低其侧向传热，实现了有效一维传热，延长了测试时间；并通过热流传感器标定试验，实现了热流高精度测量。为验证量热计的测量性能，开展了地面标定实验和基于双锥模型的高超声速低密度风洞激波/边界层干扰实验(M10和M12)，量热计与同轴热电偶的测量结果进行对比分析。研究结果表明，本文所设计的量热计适用于稀薄来流条件下激波干扰引起的复杂气动热问题的热流测量。相比于同轴热电偶，量热计响应时间较慢，但对于较大热流，由于极大减轻了侧向传热的影响，测量精度较高。同轴热电偶对低量值热流(5~20 kW/m2)的测量性能较好，信噪比(SNR)较高。研究成果为开展高超声速低密度风洞稀薄流激波干扰气动热试验研究提供支撑。

An Aerothermodynamics Measuring Technique for Shock Interactions in Hypersonic Low Density Flow

A novel calorimeter suitable for long time and medium/low heat flux (5~500 kW/m2) measurement is proposed in this paper to investigate the aerothermodynamic problems induced by shock interactions in hypersonic low density flow. The calorimeter is designed by a way of air gap insulation to alleviate the lateral heat transfer, which approximates the one dimensional heat conduction and consequently extends its effective measuring time. Then, the fabricated calorimeters are calibrated to improve the accuracy of measurement. In order to validate the performance of the calorimeter, the calibration experiment and hypersonic low density wind tunnel experiment with a double cone model are carried out. The heat flux measured by the calorimeter is compared with the coaxial thermocouple results. The results show that the response time of the calorimeter is longer than that of the coaxial thermocouple; but for a larger heat flux, the measurement accuracy of the calorimeter is higher because the lateral heat transfer is greatly alleviated. The coaxial thermocouple has better performance in low heat flux (5~20 kW/m2) measurement with a larger signal to noise ratio (SNR). The research provides a measurement technique for the investigation on shock wave/boundary layer interactions in hypersonic low density wind tunnel.