柔性整流罩地面展开试验仿真分析与飞行状态分离预测

摘要

大型整流罩的地面分离试验难以在真空环境下进行,为实现对飞行状态中分离情况的准确预测,需根据地面试验数据修正建立的有限元模型.基于耦合欧拉-拉格朗日算法,对大型柔性整流罩的地面展开试验进行流体与固体耦合仿真分析,获得了整流罩在空气阻力作用下展开的运动特性及呼吸变形,结果表明仿真结果与试验数据一致,验证了该模型及方法的正确性.采用相同模型对飞行状态下的整流罩分离进行仿真预示,并分析了空气阻力、轴向过载对分离特性和呼吸运动的影响规律.研究表明:空气阻力会降低整流罩的运动速度和呼吸运动频率,增大呼吸运动幅值;随着轴向过载的增大,呼吸运动幅度增大;整流罩的呼吸运动与其1阶振型相关.%It is difficult to conduct the ground separation test of large-scale rocket fairings under vacuum condition.To predict the fairing separation during extra-atmospheric flight,the established finite element (FE) model should be corrected by using the ground separation test data.The ground separation test of a large-scale flexible fairing is simulated by the coupled Eulerian-Lagrangian method.The motion characteristics and breathing deformation data of fairing separating under air resistance are obtained and agree well with the test data,which verifies the correctness of the model and the method.The separation of rocket fairing during extra-atmosphere flight is simulated with the same FE model,and the effects of air resistance and axial overload on fairing separation and deformation characteristics are analyzed.The results show that the air resistance attenuates the velocity and breathing vibration frequency of rocket fairing,but increases the amplitude of the breathing motion;the amplitude of breathing motion increases with the increasing in axial overload,meanwhile,the breathing motion of fairing is related to the first-order vibration mode.