稠密颗粒床中点火传火过程的两维两相流数值模拟

TWO-DIMENSIONAL TWO-PHASE FLOW NUMERICAL SIMULATION OF IGNITION AND FLAMESPREADING PROCESS IN DENSE PARTICLES BED

本文结合火炮工程背景,建立伴随化学反应的稠密颗粒群气固两相非定常两维轴对称流和点火器内的非定常一维两相流数学模型,并考虑点火器对主装药床的耦合作用。采用MacCormack两步差分格式,模拟点火传火过程中火焰传播及其物理量沿轴向和径向变化规律。部分计算结果与实验结果相吻合。发现点火开始阶段存在明显的径向效应,当火焰波传到固壁后,轴向流占主要优势。

An unsteady two-dimensional two-phase axial-symmetrical flow modelfor dense particles with chemical reaction and an unsteady one-dimensional two-phase flow model for igniter are established to analyze the interior ballistics of gun. In the model, the coupling effect of the igniter on the main charge bed is considered. The two-step MacCor-mack difference method is employed to compute the flame spreading process and the variation of physical parameters along the axial and radial directions. A part of the results is in good agreement with the experimental ones. It is found that the radial effect is important only at the beginning and the axial flow gains the upper hand after the flame waves reach the wall.