摘要
火箭弹自力弹射离筒前尾焰一直被限制在低压室内,为弹体提供附加的发射动力,但也导致发动机工作过程中的背压较高,使其燃气流场特性不同于自力发射。为研究火箭弹自力弹射过程中低压室内复杂的燃气流动特性,以二维轴对称N⁃S方程为基础,建立了自力弹射低压室燃气流场的计算模型。利用建立的计算模型对超声速冲击射流试验进行了仿真,得到的流场特征及数据与试验结果吻合良好。在此基础上,采用动网格技术,对弹体的出筒过程进行了非定常数值模拟。结果表明,自力弹射过程中,起始冲击波会导致流场产生震荡,随流场发展震荡逐渐消失;弹体出筒过程中,喷管出口燃气流会在欠膨胀状态和过膨胀状态之间转换,流场震荡结束后,燃气流稳定在过膨胀状态;结合某特定型号火箭弹,相比于自力发射,在相同发射条件下,自力弹射的出筒速度提高410.86%,出筒时间缩短74.34%。
The exhaust plume generated by self⁃ejection launcher is sealed in a low pressure chamber until the tail leaves the launcher barrel,providing an additional ejection force and resulting in an excessive back pressure during the working course of rock⁃et motor.Therefore,the characteristics of the wake field are different from that of the free launch.In order to study the characteristic of the wake field during the rocket self⁃ejection,a calculation model for the wake field based on two⁃dimension axisymmetric Navier⁃Stokes equation was developed.The flow field characteristics and the results of supersonic impinging jet were simulated by the pro⁃posed model,which were consistent with the actual experiment.Subsequently,the whole process of rocket self⁃ejection was simulated by using the dynamic grid technology.The results show that the flow field oscillation will be induced by the initial shock wave gener⁃ated in the self⁃ejection process,which disappears with the development of the flow field.The flow at the nozzle exit will change be⁃tween under expansion and over expansion states,which will maintain the state of over expansion after the completion of flowfield os⁃cillation.By contrast to self⁃launching under the same condition,the launching velocity of the self⁃ejection of some specific rocket in⁃creases by 410.86%,and the launching time decreases by 74.34%,respectively.
作者
宋健
宋向华
蔡蒨
佘湖清
SONG Jian;SONG Xianghua;CAI Qian;SHE Huqing(Yichang Testing Technique Research Institue,Yichang443000,China)
出处
《固体火箭技术》
CAS
CSCD
北大核心
2021年第6期839-849,共11页
Journal of Solid Rocket Technology
关键词
自力弹射
燃气射流
动网格
数值模拟
self⁃ejection
jet flow
dynamic mesh
numerical simulation
