Two-level Safety Numerical And Experimental Study Of Single-gun Double-pulse Engine

Double-pulse solid rocket engine is a solid rocket engine capable of two ignitions.It is a new solid rocket engine that uses two combustion chambers and uses different propellant fuel as a power device.Its advantage is that it has high controllability,simple structure and high stability.In this paper,a solid rocket motor is taken as the research object,and a combination of theoretical research and numerical simulation is used to establish a metal diaphragm structure suitable for studying the dual pulse isolation device under different working pressure conditions of the first pulse and second pulse combustion chambers.Design of mathematical methods and physical models.At the same time,this paper needs to analyze the influence of the engine structure on the flow field distribution in the combustion chamber.The main research contents of this article are as follows:(1)The support frame and metal diaphragm structure of the interstage isolation device were designed,and the pressure and fracture calculation model of the metal diaphragm was established.The pressure and fracture process of the metal diaphragm was numerically calculated by using ABAQUS software.A verification scheme for the pressure and rupture test of the metal diaphragm is designed,and the test layout,test device structure design,experimental steps and contents are explained.The test device was used to carry out pressure and rupture related tests on the metal diaphragm,and it was verified that the designed metal diaphragm meets the requirements of the dual pulse engine,and the numerical simulation method used was reliable and effective.And the effective numerical simulation method is used to find out the required pressure law of the metal diaphragm when the diameter of the doublepulse solid rocket engine increases according to the preformed nick.(2)Aiming at the first pulse and second pulse linkage ignition test of the dual-pulse solid rocket engine,the first pulse combustion chamber wall burn-through phenomenon occurred.This paper changes the engine structure including the diameter of the small holes at the stage and the first pulse combustion chamber diameter.And the opening angle of the small holes between the stages,the control variable method is used to design four models with different sizes for the three structures.Corresponding physical calculation models were established,and numerical simulation calculations were performed using FLUENT software.Based on the numerical simulation results,the gas phase and particle phase flow distribution characteristics were analyzed and the effects on the pressure,temperature and velocity in the combustion chamber were analyzed.When the two-pulse combustion chamber is in normal operation,the cause of the damage position of the first pulse combustion chamber wall near the front end appears.