爆炸抛撒粒子群数值模拟

Numerical simulation of the particle dissipation as a result of strong explosion

瓦斯煤尘爆炸卷扬和消防灭火弹以及抑爆器是爆炸抛撒粒子群问题在工业安全生产中的应用。基于离散颗粒元建立了爆炸抛撒粒子群模型,编写了计算爆炸抛撒粒子群程序。用自编程序对不同装填层数、不同颗粒粒径等粒子群抛撒问题进行数值模拟。粒子群的初速度分布与颗粒数目满足正态分布。当粒子装填层数相同、粒径不同时,粒子云的厚度随着时间的变化均近似于线性增长。在爆炸抛撒的早期,两种粒子云的厚度近似于相同;在爆炸抛撒的后期,小粒径颗粒形成的粒子云体积略大于大粒径颗粒的粒子云体积。

The paper is aimed to propose a numerically simulated model to imitate the particle dissipation as the result of strong explosion based on the discrete the particle dissipation method. For our research purpose, we have calculated and discussed the influence of the particle size and particle layers to the process of particle dissipation along with the particle velocity and the number of particles in conformity with the normal distribution. The thickness of the particle cloud can be said in some ways similar to the linear growth with time. When dissipated by the explosion, the particle size may have a great influence on the rate of the particles, because different particle sizes mean different amounts of particle mass and particle drag, which tend to lead to the different dissipation velocities of the particles. The particles velocity and the number of particles conform to the normal distribution. The thickness of particle cloud is similar to linear growth with time while the layers of particle are the same and radius of particle is different. At the early stages of the process, beth the thickness of the cloud and the number of the particles are similar to each other; while at the end of the process, the smaller particles of the cloud would become slightly larger than the larger ones. When experimented with the particle dissipation caused by the explosion, we have formulated a rule of the particle dissipation boundary velocities, which may have impact on the target plate by using high-speed camera, deep craters on the target plates and so on. Through simulated experiment by calculating the cede, this rule proves to be in conformity with the results of the calculation and experiment. At the same time, it also helps to verify the accuracy of the particle model and calculating code. And finally a particle model has been proposed to describe the issue of particles＇ dissipation model as a result of the detonation products detonated. The interaction progress between the detonation and the particles＇ dissipation has also been achieved by means of the calculation code named Object-MMIC. The conditions are given such as charge mass ratio, particle packing layers, particles affecting the particle dissipation. The model proposed by this paper is thus expected to help to lay a solid theoretical foundation to the study of particles＇ dissipation caused by the detonated products and the violent explosion.