干涉瑞利散射测速技术在跨超声速风洞的湍流度测试应用研究

为了测量高速流场的湍流度，研究了基于法布里-珀罗（Fabry-Pérot）干涉仪的干涉瑞利散射测速技术。设计了干涉瑞利散射速度测量装置，主要由大功率窄线宽连续激光器、法布里-珀罗干涉仪和高帧频EMCCD相机组成，激光器提供连续光源照射流场形成气体分子瑞利散射，并通过法布里-珀罗干涉仪和EMCCD，实现了对流场气体分子瑞利散射光谱精细分辨，获得了高时间分辨速度测量结果。经过理论分析，该装置的速度分辨率为1.23m/s；通过与热线风速仪湍流度测量实验的结果进行对比，验证了干涉瑞利散射测速技术具备流场湍流度非接触测量能力；利用干涉瑞利散射测速装置，在0.3m×0.3m跨超声速风洞上，开展了Ma3.0条件下流场湍流度测量实验，获得了超声速流场的平均速度和湍流度测量结果，装置时间采样率达到4kHz。

Measurement of turbulence velocity fluctuations in transonic wind tunnel using Interferometric Rayleigh Scattering diagnostic technique

The interferometric Rayleigh scattering diagnostic technique for the time-resolved velocity measurement of the transonic wind tunnel is studied. The velocity-measurement apparatus, consisted of a CW laser, a high resolution Fabry-Pérot interferometer and a high-speed EMCCD camera, is designed. Rayleigh scattering light is produced as the flow irradiated by the laser. Then the light is collected and analyzed accurately by the Fabry-Pérot interferometer and the camera. Theoretically, this systematic velocity-measurement accuracy can reach 1.23m/s. Measurement accuracy is then evaluated by comparing with hot wire anemometry results. Moreover, the distributions of velocity and turbulence intensity in a supersonic flow at Mach number 3.0 are obtained quantitatively. The sampling rate in this measurement reached about 4 kHz.