大型固体发动机双堵盖喷管冷态打开运动过程仿真研究OA

A two-dimensional axisymmetric model of the obverse and reverse closures of a large solid rocket motor nozzle was established.Under cold gas pressurization conditions,the opening process of the large-size nozzle double closures was simulated.The variation laws of pressure,force,and velocity before and after the impact opening,collision,and ejection of the double closures were obtained.The simulation results were compared with ground test data.The calculation results reveal that the obverse closure is opened first under load,then accelerated toward the reverse closure;the reverse closure is opened with a delay,moving along the same direction as the obverse closure but with a lower initial velocity.Due to the fact that the mass of the reverse closure is 15.2 times that of the obverse closure,a collision between the two is inevitable during their motion.According to the principle of conservation of momentum,the collision can lead to the transfer of kinetic energy from the obverse closure to the reverse closure,manifested by a transient increase in the velocity of the reverse closure and a corresponding decrease in the velocity of the obverse closure,after which both are ejected together from the nozzle.The simulation results are in good agreement with ground test data,with an error of only 8%between the simulated and tested velocities of the reverse closure at the nozzle exit,indicating that the simulation model for the double closure motion process is reasonable and the results are accurate and credible.