水下垂直发射筒口压力波动特性分析

Analysis on the Characteristics of Pressure Wave Near Tube for Underwater Vertical Launch

筒口压力场的波动特性对于发射装置的设计和飞行器水下点火时机的选择至关重要。通过CFD仿真计算和试验结果分析,给出了筒口压力波形,归纳出了压力波动的量值模型。研究结果表明,飞行器出筒后筒口压力出现第一个峰值,经历了一个脉宽大约为峰值脉宽2倍的波谷后,达到第二个峰值,之后以较为稳定的频率波动,波动幅值近似以指数规律迅速衰减。从第二个波峰开始,压力波可以用有阻尼的振动方程近似表示;波动频率随流场欧拉数的增大而增大,与欧拉数的倒数近似成线性关系,可为飞行器的水下发射设计提供参考。

The pressure field near the tube has great influence on the underwater launching.The CFD simulation and test results analysis were employed to investigate the propagation characteristics of the pressure near the tube.The wave form of the pressure was obtained,the quantity model of the pressure fluctuations and the relationship with the Euler number were generalized.The results shows that,the first peak value of the pressure appears as the vehicle moves away from the tube,and after a wave valley continuing for about two times of the wave peak pulse width,the second peak value arises,and then the pressure fluctuates regularly at certain frequency.Meanwhile,the wave amplitudes damps exponentially.The damping vibration equation can be used to approximate the pressure wave movement process after the second wave peak.The pressure fluctuation frequency grows as the Euler number increases,which is close to linear relationship within certain range.