垂直弹射系统弹射初始阶段内流场数值分析

针对燃气活塞弹射装置在垂直发射系统中的应用,采用计算流体软件Fluent的源项法,用UDF(用户自定义函数)编译来实现火药燃气的质量、动量、能量向高压室的注入,对弹射初始阶段高压室和低压室内燃气流场进行了数值分析,得出以下结论:高压室压力在破膜前快速上升,破膜后缓慢上升的趋势,在高压上下两端压力应力集中,低压室呈中间和两端压力应力集中现象,同时高压室形成的低速燃气经导管产生激波形成超声速燃气流撞击低压室,并分析了压力和速度对弹射装置的影响。计算结果表明,该方法能够较好地仿真弹射装置燃气流场的特性,为弹射装置优化设计和装药设计提供理论依据。

A Numerical Analysis for the Initial Stage Inner Flow Field in Vertical Ejection System

In view of the application of jet piston ejection mechanism in vertical ejection system, the source item method and user defined function (UDF) technique of CFD fluent software are used to inject mass, momentum and energy of propellant gas into high pressure chamber, the jet flow field in the high pressure chamber and the low pressure chamber at the initial stage is analyzed numerically, the pressure and the velocity distribution and changes are obtained, and the influence on the ejection mechanism from the pressure and the velocity is analyzed. The computation results show that this method can well simulate the ejection mechanism characteristics of the inner flow field, and can provide a theoretical basis for ejection mechanism and propellant design.