The Steam Explosion Propulsion Mechanism Research

In this dissertation, the mechanism of vapor explosion propulsion has been studied using numerical methods. Based on BLEVE(boiling liquid expanding vapor explosion) phenomenon and theory、fluid mechanics fundamental equations、boiling and coring mechanism and multiphase fluid theory, a numerical model of vapor explosion propulsion is built. Propulsion process of the model is studied. Numerical result reveals the evolution of fluid structure. Pressure plots of three monitoring points, tail pressure and bullet velocity are studied. Six numerical models of different initial temperature and different filling ration are built. Numerical simulations have been done on each model. The influence of different initial parameters on propulsion process and results has been studied.Based on relating theories and numerical results, these conclusions are acquired:1、On the numerical model of523k initial temperature,30%filling ratio, bubbles appear very shortly after process starts, the closer to the liquid surface, the more bubbles formed. Pressure of the liquid rises by three times due to the vigorous boiling caused by pressure loss rendering liquid to superheat state. Bullet velocity gets to265m/s.2、Initial temperature of liquid has significant influence on vapor explosion results. Maximum pressure of liquid gets higher with higher initial temperature, but the times of pressure rise decreases. Maximum pressure of monitoring points gets higher with higher initial temperature. Bullet velocities are265m/s、301m/s and345m/s.3、Filling ratio also has significant influence on vapor explosion results. Maximum pressure of liquid gets higher with higher filling ratio, so does maximum pressure of monitoring points. Bullet velocities are301m/s、25m/s and367m/s.Through theoretical and numerical analysis, a systematical understanding of the mechanism of vapor explosion propulsion is achieved. Research shows that vapor explosion propulsion has significant technical application value.