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采用大涡模拟的方法计算了来流速度为0.5~0.7 Ma情况下横向球/柱形结构附近的流场,给出了密度和光程差的统计结果,并采用相屏法研究了几种流场对激光传输的影响。结果表明:密度扰动均方根和光程差均方根随着来流速度和发射孔径的增加而增大;Ma从0.5增至0.7时,孔径为0.5 m情况下,密度扰动均方根增长了90%,孔径为0.25 m情况下,光程差均方根增长了90%;Ma=0.6情况下,孔径从0.25 m增加到0.75 m时,两个参数各增加了4倍。激光Strehl比随来流速度和发射孔径的增大而减小;发射孔径为0.25 m情况下,随着Ma从0.5增加至0.7,Strehl比从0.236下降至0.045;Ma=0.6情况下,发射孔径从0.25 m增加至0.75 m过程中,Strehl下降了90%。
The large-eddy simulation method was used to calculate the flow field near the transverse ball / column structure with the flow velocity from 0.5 to 0.7 Ma. The statistical results of density and optical path difference were given. Effect of field on laser transmission. The results show that the rms root mean square and the optical path difference rms increase with the increase of the flow velocity and the emission aperture. The mean square root of the density disturbance increases when Ma increases from 0.5 to 0.7 and the aperture is 0.5 m 90% and the aperture of 0.25 m, the root mean square of optical path difference increased by 90%. When the aperture was increased from 0.25 m to 0.75 m with Ma = 0.6, the two parameters increased four times respectively. The laser Strehl ratio decreases with the increase of the flow velocity and the emission aperture. When the emission aperture is 0.25 m, the Strehl ratio decreases from 0.236 to 0.045 as Ma increases from 0.5 to 0.7. The emission aperture Strehl decreased by 90% from 0.25 m to 0.75 m.