Application and Research of the Particle Element Model in Ignition Process of Large-Particle High-Density Charge

ABSTRACT

In order to describe the movement characteristics of large-particle high-density charge and the development process of flow field and flame spreading in the chamber, a new modified and simplified particle element model was established based on Eulerian-Lagrangian approach, and the gas governing equations are discretized with the fifth-order WENO scheme. The experiment was carried out on the visualized experiment platform, and the relevant data were recorded by the data acquisition instrument and high-speed photography system. The results show that the numerical simulation results are in good agreement with the experiment, and the particle element model describes the process of particle motion accurately, which indicated that the problem of flow characteristics in the period of ignition and flame spreading in high-density charge solved effectively by the model. In the initial period of the ignition, the particles in the high-density charging bed moved slowly, and the law of the particles almost the same. The pressure in the middle chamber fluctuates obviously when the particles start to move. The gap in high-density charge would lead to throttling of the discontinuity surface, resulting in pressure fluctuation at the interface and the discontinuity surface of gas-phase velocity. The effects of different ignition and charging conditions on flame spreading performance are investigated and this study lays important practical significance to the application of the model on problem solution.

KEYWORDS:

• Internal ballistic
• The Particle Element Model
• Computational fluid dynamics
• Eulerian-Lagrangian approach
• Gas-solid two phase flow