Two-dimensional Supersonic Flow Field Numerical Study Of The Strong Laser Beam Interference

High-power laser beam has enormous using prospect in science and military affairs. In lots of case, to make and use high-power laser beam will connect with supersonic flow. High-power laser beam will be aberrated and gas flow field will be thermal bloomed when beam pass through the flow field. The study about the interaction mechanism of high-power laser beam with supersonic flow field has caught more and more attention.This paper is the mechanism study of "The interaction of high power laser with supersonic free shear layer" which support by National Natural Science Foundation of China. This paper used NND-2M scheme and numerically solved 2D whole N-S equation and obtained the time average distribution of flow field, used explicit algorithm and fast Fourier transform methods to solve the equation which control the translation of light beam in turbulent medium. We studied the influence of 2D supersonic free shot flow to the far field intensity distribution of 10.6 um and 1.315um laser beam when flow is in different inflow Mach number and pressure. The results show: laser beam far field intensity distribution deflect to the wave length increasing direction, the influence to laser beam far field intensity distribution of different inflow Mach number is little than the influence of different inflow pressure; flow field has more aberration to 1.315um laser beam than to 10.6um laser beam. We studied the influence of 2D supersonic slope flow to the far field intensity distribution of 10.6um and 1.315um laser beam when flow is in different inflow Mach number. The results show that laser beam far field intensity deflect to the wave length increasing direction about 0.2m~0.3m when beam pass through flow field and propagate 1km in static atmosphere.High-power laser beam will have thermal booming effect when it pass through gas flow field. This paper studied the thermal booming effect of 106W high power laser beam in different absorption coefficient when it pass through 2D supersonic(Inflow Mach number is 2.0) shot flow and use this example to discuss the thermal booming effect of high power laser beam to supersonic flow field. The results show: thermal blooming isn't distinctness when absorption coefficient is little (6.5 x 10~5/m )but distinctness when absorption coefficient is large(6.5x10-1/m).