Numerical Simulation And Experimental Study On The Regulation Process Of Proportional SDACS

Recently,with the penetration capability of missile improving rapidly,better mobility and maneuverability of the divert and attitude control system(DACS)has been required.The proportional DACS has the advantages of simple structure and low cost,with better maneuverability and controllability.The proportional DACS has become one of the preferred alternatives for DACS abroad.The theoretical and experimental research on the proportional attitude control thruster were carried out by this paper.In order to probe the steady state characteristics and the structural design optimization of the pintle thruster,the three-dimensional steady state numerical simulation of the thruster was carried out.The side inlet leads to the asymmetry of the internal flow field,and there are subsonic recirculation zone,oblique shock wave and flow separation in the internal flow field.With the valve opening increased,the thrust increases linearly,and the thrust can be continuously adjusted.In structural design,the inlet angle and the pintle surface type have some effects on the thruster.And the new designed pintle thruster can greatly reduce the pintle load.A two-dimensional axisymmetric model of pintle thruster was established.And the unsteady working characteristics of thruster were studied by using dynamic mesh method and custom inlet conditions.The simulation result showed that the inlet pressure,inlet mass flow and thrust of thruster gradually increase with the pintle close to the throat,and the thrust continuous regulation was realized.With the increase of pintle movement speed,the pressure of gas chamber and the thrust were lagging behind.And the higher the pressure exponent of propellant burning rate is,the larger the thrust change range is.The numerical simulation of fluid-solid coupling heat transfer of pintle thruster was carried out in order to study the heat transfer of shell and pintle in the working process of pintle thruster.It can be seen that the throttling area,the position of oblique shock wave and the end of pintle are the worst parts of the thermal environment of pintle thruster.The heat transfer characteristics of C/C composites and ceramic matrix composites were obtained.And the heat transfer velocity increases with the increase of inlet pressure.The cold gas test on the performance of the pintle thruster was conducted based on the design and construction of thruster,test system,drive system and gas supply system.In order to verify the accuracy of the test stand,the static test was carried out to verify the capability of pintle thruster to achieve continuous thrust adjustment.And the hysteresis phenomenon of the pressure and thrust of the pintle thruster was verified by dynamic test.This paper mainly studied the structural design,flow field characteristics,thermal protection and cold test of proportional attitude control thruster.The research result has certain guiding significance to the design and engineering application of the proportional SDACS.