某双脉冲发动机燃烧室两相流场数值分析

摘要

某双脉冲固体火箭发动机试验后出现一脉冲绝热层纵向烧蚀不均匀现象,一脉冲前段绝热层出现“凹坑”.为了解其原因,应用数值计算方法,采用FLUENT计算平台,对此发动机燃烧室内两相流场进行了数值模拟.计算结果表明,由于双脉冲发动机级间通道的存在,使得燃气流在一脉冲燃烧室内出现后台阶流动,气流发生分离再附着过程,气流再附着点附近刚好为绝热层烧蚀较为剧烈的部位,同时颗粒相随气流撞击在绝热层壁面位置,也与“凹坑”部位重合.因此,气流再附着过程及颗粒相冲刷过程为影响一脉冲绝热层纵向烧蚀不均匀现象的重要原因.%The lengthways erosion of the insulation in the dual-pulse solid rocket motor was uneven after the experimentation, and the pit appeared on the insulation of the forepart of I-pulse-chamber. In order to find out the reason of this phenomenon, the numerical simulation of two-phase flow in the combustion chamber was made with FLUENT. The backward-facing step flow appears in I-pulse-chamber,because of the channel between the I and II chamber of the dual-pulse SRM, which causes the flow separation. From the simulation result,the serious erosion of the insulation in I-pulse-chamber occurs on the place of realtachment and the part of the particles ablation. Therefore,the flow reattachment and the particles ablation are the important causes of the uneven erosion of the insulation in I-pulse-chamber.