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采用数值方法分析研究强激光束在对流风作用下的热晕效应。湍流数值模拟采用雷诺平均及大涡模拟(RANS/LES)混合方法,即脱体涡方法,同时耦合J-B模型,而利用双时间步进行非定常问题迭代求解;光在流场和自由空间的传输计算采用波动光学方法,并根据远场光斑分布情况进行定性与定量分析。研究考察了0.1 MW功率0、.1 m口径的Gauss光束在1,5和10 m/s对流风作用下的热晕效应。结果表明,对流风作用下的热晕效应是非定常作用过程;对流风速度越低,激光热晕效应越强,其中1 m/s的热晕效应最强,其远场光斑畸变最严重;对流风速度越低,热晕效应非定常作用特性越明显,尤其1m/s的热晕效应在5 s观察时间内仍在发展变化,而5 m/s和10 m/s的热晕效应在3 s以后已趋于稳定。
The numerical method is used to analyze the thermal halo effect of intense laser beam under convective wind. The turbulent numerical simulation uses the Reynolds-averaged and Large eddy simulation (RANS / LES) hybrid method, that is, the so-called off-body vortex method and the coupled JB model simultaneously, and uses two time steps to iteratively solve the unsteady problems. The transmission of light in the flow field and the free space Calculation using wave optics method, and according to the far field spot distribution qualitative and quantitative analysis. The thermal halo effect of Gaussian beams with 0.1 MW and 0 .1 m caliber at 1, 5 and 10 m / s convective winds was investigated. The results show that the thermal halo effect under the action of convection wind is an unsteady process. The lower the convection wind velocity is, the stronger the thermal halo effect is. The 1 m / s thermal halo effect is the strongest, and the far field spot distortion is the most serious. The more the flow velocity is lower, the more obvious the thermal halo effect is. In particular, the thermal halo effect at 1 m / s is still changing within 5 s, while the thermal halo effect at 5 m / s and 10 m / s is between 3 After s has stabilized.