基于CFD-DEM算法的固体火箭发动机气-固两相流模拟

The multi-phase flow in Solid Rocket Motor (SRM) is a typical complex multi-scale flow, which plays an important role in influencing the performance and safety of SRM. The particle erosion on ablate layer and the thrust lose of gas-particle flow are the long-term concerns in solid propellant system. Compared to the conventional Two Fluid Model (TFM) and Lagrange Method, the Discrete Element Method (DEM) based gas-particle simulation is able to describe the particle behavior on microscopic level, such as particle-particle collides, particle-gas interaction force and particle-wall interaction force, and hence it has extensive applications in different areas. The Computational Fluid Dynamic (CFD) is coupled with DEM to predict the gas-particle flow in SRM. The results indicate that compared to the conventional methods, CFD-DEM could provide rich information, such as particle-particle contacts, particle-gas interactions, and all sorts of forces acted on particles. Particles are accumulated in the wall region of nozzle convergent part, in the throat, and in the central area of nozzle divergent part, which subsequently leads to frequent collides among particles and high angular velocity of particles. Drag force appears higher in the region where gas is accelerated. CFD-DEM simulation provide a new way to study the gas-particle flow in SRM, and reveal rich information on micro- and macro-level, thus would deliver new perspectives to understand the multi-phase flow in SRM, the particle erosions and so on.