采用大涡模拟方法计算了来流速度为0.4 Ma情况下球/柱形结构附近的流场, 根据密度数据计算了光程差及气动相屏, 并研究了尾流对激光传输的影响。结果表明: 光程差空间均方根的时间平均值随发射角增大而增大, 发射角从120°增加到148°时, 其数值从0.11 μm增加到0.28 μm; 光程差空间均方根随时间变化剧烈, 发射角为148°时, 其时间均方根可达0.04 μm; 球/柱尾流对激光传输有很大影响, 发射角为148°情况下, Strehl比的时间平均值为0.33, 并且Strehl比的时间平均值随发射角的增大而减小, 发射角从120°增加到148°过程中, Strehl比的时间平均值减小了59%; Strehl比随时间变化剧烈, 其时间均方根大于0.05。

Compressible large eddy simulation was carried out to study the flow field around a hemispherical/cylindrical structure at Mach number of Ma=0.4. Optical path difference and aero-optical phase were calculated according to density data obtained by the large eddy simulation method, and then the aero-optical effect of the wake was studied. The results show that the time-averaged root-mean-square of optical path difference increases with the angle of projection, and it varies from 0.11 μm to 0.28 μm when the angle of projection increases from 120°to 148°. Besides, the root-mean-square of optical path difference changes dramatically over time, and its temporal root-mean-square value reaches 0.04 μm when the angle of projection is 148°. The wake of the hemispherical/cylindrical structure has great effect on laser propagation, and the time-averaged Strehl ratio is 0.33 for the angle of projection of 148°. The time-averaged Strehl ratio decreases with the angle of projection, and it reduces 59% when angle of projection increases from 120°to 148°. The Strehl ratio also changes dramatically over time, and its temporal root-mean-square value is 0.05.