Numerical Simulation Of Interior Ballistic Processes In The Light Gas Gun Driven By Oxyhydrogen Detonation

Light gas gun is a kind of common hypervelocity?launcher,which plays an important role in studying the end effect of hypervelocity collision.The traditional light gas gun mainly adopts high-pressure gas or powder gas as the driving energy,but either has disadvantages about high molecular weight of driving gas or limited driving energy.In order to further increase the velocity of the projectile,using oxyhydrogen detonation to drive light gas gun is appeared,which is high about the energy utilization rate.But now the research is mainly based on experiment both at home and abroad,lack of systematically research on its internal ballistic process.Therefore,this paper simulates the internal ballistic process of light gas gun driven by oxyhydrogen detonation,which mainly studies the detonation process under high pressure in the combustion chamber,summarizes regular pattern of the projectile movement,and provides guidance for debugging light gas gun.The main work and conclusion are as follows:(1)The numerical model of the two-dimensional transient viscous gas reaction flow model is established,in which standard turbulence model and Peng-Robinson gas equation of state are used to describe turbulence and real gas effect respectively.9 species 19 steps detailed chemical kinetics model of hydrogen and oxygen is considered.?The numerical simulation is based on PISO algorithm,using UDF and dynamic mesh techniques to simulate the movement of projectile in barrel.The reliability of this model is verified by the experimental result.(2)Numerical analysis of oxyhydrogen detonation process in the combustion chamber of light gas gun is done,which can get the development process of detonation wave in the chamber.Considering different reaction mechanisms,the roles of different species playing in the detonation are analyzed.The influence of ignition energy,gas ratio,gas pressure,and chamber structure to detonation process has been studied.Since then,experiment of measuring the pressure in combustion chamber of oxyhydrogen detonation process is conducted.(3)Internal ballistic process of one stage light gas gun driven by oxyhydrogen detonation is simulated,by which variations of base pressure under the projectile,velocity of projectile and shock wave reflection transmission are obtained.By analyzing the impact of composition and pressure of gas,the position of the ignition,the length of combustion chamber and the weight of the projectile on its internal ballistic performance,this paper summarize the effective ways to improve the speed of the projectile.