膜片式轻气炮破膜做功机理研究

针对轻气炮隔离膜片展开过程中流体与结构的相互影响,基于FCBI单元法,引入Johnson-Cook弹塑性本构模型,采用流固耦合的方法对此过程进行数值仿真,得到膜片周围流场特性和膜片的动力学响应。以膜片展开速度和低压侧压力变化作为性能评价指标,分析了破膜压力、高压侧注气温度、膜片厚度及开槽形状等因素对膜片展开性能的影响。计算结果表明:破膜压力越高,高压侧注气温度越高,且膜片在满足强度要求的情况下越薄,越有利于提高发射管内压力; 采用开槽方式为六道凹槽的膜片对展开过程最为有利。仿真结果揭示了膜片式轻气炮破膜做功机理,再现了膜片展开的过程,为轻气炮膜片结构的优化设计与内弹道性能的优化提供重要参考。

Mechanism Research on Rupturing Diaphragm and Workingof Diaphragm-based Light-gas Gun

The fluid and structure interact when the isolated diaphragm expands in light-gas gun. Aiming at this problem,the fluid-structure interaction model based on FCBI element method and Johnson-Cook elastic-plastic model were established to simulate the process. The changing law of internal flow field around the diaphragm was obtained as well as the dynamic response of diaphragm. The speed of diaphragm deployment and the change of low-pressure side pressure were taken as performance evaluation indicators. The effects of rupturing pressure,temperature of high-pressure side gas injection and groove shape on the deployment performance were analyzed. The results show that the higher the rupturing pressure,the higher the temperature of high-pressure side,and the thinner the diaphragm meeting the requirement of strength. The diaphragm with six grooves benefits to the process of expanding. The simulation results reveal the mechanism about rupturing diaphragm and working of diaphragm-based light-gas gun,and reappear the process of expanding. The study offers reference for optimal design of diaphragm and improvement about performance of interior ballistics.