悬浮RDX炸药粉尘爆轰的数值模拟

用两相流模型对悬浮RDX炸药粉尘爆轰波进行了数值模拟。RDX炸药颗粒在爆轰波阵面后的高温高速气流中加速并升温,颗粒表面发生熔化。参考液滴在高速气流作用下剥离的效应,假设炸药熔化部分在高速气流的作用下发生剥离,破碎成极小的颗粒,瞬时发生分解反应,释放出能量支持爆轰波传播。数值模拟了在不同粒径和浓度的悬浮RDX炸药粉尘中爆轰波的发展与传播过程,得到了爆轰波流场中气-固两相的物理量分布,并确定了爆轰波参数。在较低的RDX粉尘浓度条件下,爆轰波阵面压力的峰值曲线出现振荡。当RDX粉尘浓度在80~150 g/m3时,数值模拟得到的爆轰波阵面压力峰值曲线的振荡是规则的;当RDX粉尘浓度为70 g/m3时,爆轰波阵面压力峰值曲线出现不规则振荡。

Numerical Simulation of Suspended RDX Dust Detonation in a Shock Tube

Dust detonation of RDX particles suspended in air was numerically studied with two-phase flow model. Behind the leading shock front of detonation, RDX particles were accelerated and heated by the gas flow. Melt of RDX occurred on the surface of particles. It was assumed that melted part of particle was stripped by the gas flow and decomposition reaction happened instantaneously, during the energy is released to support the propagation of detonation wave. Development and propagation of dust detonation with different particle sizes and different concentration was numerically simulated and the parameters of detonation were obtained. Distribution of pressure, temperature, velocity behind leading shock front was calculated. Parameters of dust detonation were determined. When the concentration of RDX dust is low, pulsating mode of peak pressure history of detonation front occurred. Numerical simulation results showed that when the concentration of RDX dust was between 80 g/m³ and 150 g/m³, history of peak pressure of detonation wave front was regular pulsating. When the concentration was 70 g/m³, the pulsating was irregular.