固体火箭发动机燃烧室结构径向振动与内弹道性能的耦合计算

研究了由推进剂药柱和壳体组成的燃烧室结构径向振动对发动机内弹道性能的影响。在一维非定常内弹道方程中,分别考虑了结构径向振动对内弹道方程和燃速的影响,研究了在给定燃烧截面内,由于燃烧室压强变化引起的结构径向振动。据弹性力学理论和振动机理,得到了简化的等效径向振动方程;对内弹道和结构径向振动进行了耦合计算,分析表明当内弹道出现周期性的压强振荡时,会引发与结构径向振动之间的耦合作用,使得燃烧室压强振荡振幅上升一个量级,对发动机的工作安全产生危害。

Coupling computation on radial vibration of chamber structure and internal ballistic property for solid rocket motor

The effect of radial vibration of the chamber structure composed of propellant grain and case on the internal ballistic property of solid rocket motor(SRM) was investigated.The one-dimensional nonsteady internal ballistic equations were used to calculate internal ballistic property of SRM,and the effects of radial vibration of the chamber structure on internal ballistic equation and burning rate were taken into account respectively.For given combustion section,radial vibration of the chamber structure due to the change of pressure was investigated.A simplified equivalent radial vibration equation was obtained based on elastic theory and vibration mechanism.Coupling calculation of internal ballistic property and radial vibration of the chamber structure was carried out.The analysis results show that periodic pressure oscillation of internal ballistics can lead to coupling action between internal ballistics and structure vibration,and make vibration amplitude of the chamber pressure rise an order of magnitude,which is unfavorable to safe working of motor.