喷管长度对直筒型激光推力器推进性能的影响  

Effect of Nozzle Length on the Propulsion Performance of a Cylindrical Thruster

作　　者：李龙[1] 王波[1,2] 唐志平[1] 胡晓军[1] 

机构地区：[1]中国科学技术大学近代力学系,安徽合肥230027 [2]中国工程物理研究院,四川绵阳621999

出　　处：《高压物理学报》2014年第2期191-196,共6页Chinese Journal of High Pressure Physics

基　　金：国家自然科学基金(11302221)

摘　　要："烧蚀模式"激光推进是利用强激光烧蚀推力器自身携带的工质产生的高温高压气团反喷进行驱动的,推力器的喷管构型对推进性能有重要影响。鉴于此,从实验和数值模拟两个方面研究了喷管长度对直筒型激光推力器推进性能的影响。实验发现,衡量推进性能的2个主要参数冲量耦合系数和比冲均随着喷管长度的增加而增加,不过前者的增长呈渐缓趋势。综合考虑推进参数和推力器自重的影响,导出了推力器获得最大单脉冲速度增量(ΔvT)的最佳喷管长度公式。数值模拟得到的不同喷管长度推力器推进参数的变化规律与实验结果基本吻合:若喷管长度过短,则高压气体未能充分作用于推力器就被排出筒外,造成了能量的浪费;若喷管长度过长,筒内压力的衰减则成为影响推进性能的主要因素,从而解释了直筒型推力器的推进性能的增长趋势随喷管长度增加而逐渐趋缓的原因。＂Ablation mode＂ laser propulsion works on the counterforce generated during the interaction between high-power laser and propellant carried by thruster. The structural geometry of the nozzle of ＂ablation mode＂ laser propulsion thruster has important influence on the propulsion performance. The effect of nozzle length L on propulsion performance was carried out by experiment and numerical simulation. Experimental results indicate that both the momentum coupling coefficient and the specific impulse increase as L increases, but the increasing tendency of momentum coupling coefficient slows down with the increase of L. Considering the effects of both propulsion parameters and weight of thruster,the formula of optimal length of nozzle is derived with the largest velocity increment of the thruster. The thrust-time curves and impulse-time curves are obtained by numerical study using soft- ware FLUENT. The simulation results agree with the experimental results.

关 键 词：激光推进 烧蚀模式 直筒型推力器 喷管长度 

分 类 号：O39[理学—工程力学] V439.3[理学—力学]