【摘要】 强激光辐照于固体平面靶产生高温、高压等离子体喷射,进而对固体靶产生力学推进效应,这是烧蚀模式激光推进的基本原理。采用针对高温气体(等离子体)电离度的一种近似计算方法,以及具有五阶精度的广义Godunov差分格式-加权本质无振荡格式WENO(Weighted Essentially Non-Oscillatory Schemes),对强激光烧蚀固体靶产生等离子体喷射推进效应进行数值模拟。计算了固体靶面横向尺寸与激光光斑大小对推进效应影响的耦合关系,以及不同靶面结构烧蚀压力随时间的变化及其推进效应参数变化。数值模拟结果表明,靶面横向尺寸与光斑大小具有最优耦合值;固体靶面增加约束喷管结构对激光推进效应明显增大,并且随着约束喷管位置的不同,对激光推进效应增大的影响也有较大差异。更多还原

【Abstract】 Under the irradiation of high power laser,the surface matter of solid target can be vaporized and ionized instantly.The ejected high temperature and high pressure plume generates propulsion force,this is the fundamental of ablated laser propulsion.A general Godunov finite difference WENO(Weighted Essentially Non-Oscillatory)-schemes which have fifth-order accuracy is used to conduct a numerical calculation for laser ablated solid target and its ablated propulsion efficiency.Simulation results show that the propulsion efficiency is dependent to varied degrees on the coupling of target cross direction radius with the laser spot size;the confined geometry of the target surface strengthens the propulsion efficiency dramatically.更多还原