亚声速球/柱尾流对激光传输影响的数值模拟  

Numerical simulation of laser propagation effects through subsonic hemispherical/cylindrical wake

作　　者：关奇[1] 杜太焦[1] 陈志华[1] 闫伟[1] 彭国良[1] 

机构地区：[1]西北核技术研究所,陕西西安710024

出　　处：《红外与激光工程》2017年第9期33-39,共7页Infrared and Laser Engineering

基　　金：国家自然科学基金(91330205)

摘　　要：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0.11μm增加到0.28μm;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0.04μm;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.

关 键 词：尾流 气动光学效应 激光传输 大涡模拟 

分 类 号：TN241[电子电信—物理电子学]