Study On Multi-Physics Fields Coupling Of The Gas Secondary Injection System In The Solid Rocket Motor

Thrust vector control technology is an important means to control the pitching and deflection of vehicle,and in recent years it is more and more widely used in the rocket engines.An investigation is made on the subject of the gas secondary injection TVC system,to investigate the fluid-solid-heat coupling problem of a control piston working in high temperature flow field,to search for the change law of the thermal stress of the piston during this process,and to provide important reference for the design of the solid rocket gas secondary injection system.The loose coupling method is adopted in this paper,as well as CFD software FLUENT and FEM software ABAQUS,to investigate the fluid-solid-heat coupling problem of the gas secondary injection control piston working in the flow field.The MpCCI interface software achieve the two-way coupling calculation between the CFD and FEM software by exchanging the data of wall heat flux and wall temperature near the coupled wall.Loose coupling method is used to simulate the hypersonic flow aerodynamic heating on a stainless steel tube,the results of the shock wave position and shape are consistent with the wind tunnel experiment,and as well as the stagnation temperature and the distribution of tube structure,the error is below 1%,it proves the accuracy of the calculation method.On the basis of the study above,a three-dimensional multi-field numerical simulation is made to simulate the real working condition of the motor with different work conditions of the control piston,and the change law of the distribution of piston temperature and thermal stress are got under different working conditions,the dangerous region of the moving piston is found and an improvement program is raised to improve the structure and the movement plan of the piston.Through the comparison of the two working conditions above,the influence of the latent heat is analyzed,and an improvement program of the material of the piston is put forward.High efficiency and high reliability of the results are the character of the loose coupling method used in this paper.The analysis and conclusion result from the previous method have both theoretical values and engineering application values.