双束燃气射流与整装式液体装药相互作用的实验和数值模拟

为了探索整装式液体发射药火炮(BLPG)内弹道稳定性的控制方法,设计了5 级圆柱渐扩型观察室和圆柱观察室,开展了双束燃气射流在液体药模拟工质中扩展的实验研究。实验结果表明,渐扩型结构能够抑制Taylor 空腔与Kelvin-Helmholtz 不稳定性效应的正反馈机制。在实验基础上,建立了三维非稳态数理模型,模拟了不同观察室结构下,双束燃气射流在液体工质中的扩展过程,获得了射流场中密度、压力和温度的分布图。模拟结果表明:圆柱渐扩型观察室中,由于渐扩台阶的诱导作用,强化了气液在径向的湍流掺混效应,抑制了射流的轴向湍流度;且射流的外轮廓相对较光滑。双束射流轴向位移的计算值与实验结果吻合较好。

Experiment and Numerical Simulation for Interaction of Twin Gas Jets and Bulk-loaded Liquid Charge

The five-stage cylindrical stepped-wall observation chamber and cylindrical observation chamber are designed to explore the control method of interior ballistic stability of bulk-loaded liquid propellent gun(BLPG). The propagating process of twin gas jets in liquid medium is experimentally studied. The experimental data indicates that the stepped-wall structures can restrain the positive feedback mechanism of the Taylor cavity and Kelvin-Helmholtz instability. Based on the experiment, a three-dimensional mathematical model is established. The expansion process of twin gas jet in liquid medium in different observation chambers is simulated. The distribution maps of density, pressure and temperature were obtained. The simulated results show that, in the cylindrical stepped-wall observation chamber, the effect of turbulent mixing of gas-liquid along the radial direction is enhanced and the axial turbulent intensity is suppressed due to the induction of steps, and the outlines of twin jets are smooth relatively. The simulated results of axial displacements of twin gas jets in liquid coincide well with the experiment data.