级间热分离流场干扰特性及动力学数值研究

Numerical investigation on flow field interference characteristics and dynamics of interstage thermal separation

采用数值模拟方法并结合动网格技术对导弹级间热分离过程的非定常流场和刚体运动进行耦合计算,分析级间段内外两侧流场结构的变化规律,并对一级弹体进行了动力学分析。研究结果表明,二级弹体发动机喷管处于过膨胀状态,随着分离过程的进行,喷管内正激波不断向下游移动,激波强度不断减弱。级间间隙处的横向喷流与外界超声速自由来流形成复杂的流动干扰现象,干扰流场中分离激波和羽流激波强度逐渐减弱并向下游移动。干扰流场流动分离区域面积随着飞行高度增大而不断扩大。随着分离过程的进行,级间段表现为初期憋压、后期泄压的状态,一级弹体轴向载荷呈现初期迅速上升、峰值后迅速下降,再小幅度波动后缓慢下降的规律;随着飞行高度增加,一级弹体侧向位移均向对应坐标轴负方向变化。

By using numerical simulation methods and combining dynamic grid technology,the unsteady flow field and rigid body motion during the interstage thermal separation were coupled calculated.The changes in the flow field structure both inside and outside the interstage were analyzed,and the dynamic analysis of the first stage missile body was conducted.The research results indicate that the nozzle of the two-stage projectile engine is in an overexpansion state,and as the separation process progresses,the normal shock wave inside the nozzle continuously moves downstream,and the shock wave intensity continuously weakens.The lateral jet at the interstage gap forms a complex flow interference phenomenon with the external supersonic free flow,and the separation shock wave and plume shock wave intensity in the interference flow field gradually weaken and move downstream.The area of the flow separation area in the interference flow field continuously expands with the increase of flight altitudeduring the separation process,and the interstage segment exhibits a state of initial pressure suppression and later pressure relief.The axial load of the first stage projectile shows a pattern of rapid increase in the initial stage and rapid decreases after peak value,and slow decreases after small fluctuations.As the flight altitude increases,the lateral displacement of the first stage projectile changes in the negative direction of the corresponding coordinate axis.