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采用Tr-PIV(Time-resolved Particle Image Velocimetry)技术对机翼湍流尾流场的非定常现象进行了测量分析。试验获得了流场瞬时速度场的基本结构演化、流场的湍流强度分布、涡量场、雷诺应力场以及湍流空间相关系数;通过功率谱分析对速度场进行了相位分解,获取了相位平均下的湍流积分尺度。基于泰勒冻结假设及采用“以时代空”的方法获得了湍流时间积分尺度,同时直接采用速度场空间相关方法获得湍流空间积分尺度,并对二者作了比较分析,讨论了该假设的适用性。
The time-resolved Particle Image Velocimetry (Tr-PIV) technique was used to measure and analyze the unsteady wake turbulence field. The basic structural evolution of instantaneous velocity field, the turbulence intensity distribution, the vorticity field, the Reynolds stress field and the turbulence spatial correlation coefficient of the flow field were obtained. The phase decomposition of velocity field was carried out by power spectrum analysis, and the phase average The turbulent integral scale. The turbulence time integral scale was obtained based on the Taylor freeze assumption and adopting the method of “time-space”. At the same time, the turbulence space integral scale was directly obtained by using the velocity field-space correlation method, and the two were compared and analyzed. applicability.