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对一种基于成像的激光相关测速技术进行了理论和实验研究。利用光散射理论模拟了成像测量系统对单个颗粒的光信号响应特点,分析了颗粒粒径和探头直径对信号及其频谱的影响,研究了测量体在光轴方向的有效长度。针对信号特点,研究了信号处理参数,分析了分段相关性计算中窗口宽度对计算结果的影响及其选择依据,并对窗函数和信号预平移等优化方法进行了研究。成功地对一脉冲喷雾爆破区高浓度流场进行了测试,获得了不同脉冲宽度下喷雾速度变化规律和轴向径向分布,测试结果与文献报道结果基本吻合,表明基于成像的相关测速系统可以很好地应用于喷嘴出口附近高浓度流场的测试。
A theoretical and experimental study of an imaging-based laser-related velocity measurement technique is carried out. Using the light scattering theory to simulate the optical response characteristics of the imaging system to a single particle, the effects of the particle size and the diameter of the probe on the signal and its spectrum are analyzed. The effective length of the measuring body in the direction of the optical axis is studied. According to the characteristics of the signal, the signal processing parameters are studied. The influence of window width on the calculation results and the selection basis are analyzed, and the optimization methods such as window function and signal pre-shift are studied. The high concentration flow field in a pulsed bursting blasting zone was successfully tested. The variation of spray velocity and axial radial distribution under different pulse widths were obtained. The test results basically agree with those reported in the literature, indicating that the imaging related speed measuring system can It is well suited for testing high concentration flow fields near the nozzle exit.