气固两相流模拟的随机离散模型

§1.引言 气固两相流动形式是最复杂的两相流动实例,其系统中的颗粒浓度较高,颗粒间的碰撞经常发生,从而导致细观层次上的颗粒运动具有复杂性,对于两相流动系统,拟流体模型以其大规模模拟的可行性在数值模拟领域中居重要地位。但是,拟流体模型的连续性假设

THE STOCHASTIC DISCRETE MODEL FOR SIMULATING GAS-SOLID TWO-PHASE FLOW

A stochastic discrete model is proposed for simulating the dynamic behaviors of gas-solid systems. In the model, the motions of solid phase are obtained by calculating individual particle motions while gas flow is obtained by solving the Navier-Stokes equation including two-phase interaction. For the calculation of solid phase, the motion process of each particle is decomposed into the collision process and suspension process. Momentum conservation of collision mechanics controls the interaction between colliding particles, while the state of each suspended particle is fully dominated by the equation of force balance over that particle. Inaddition to gravity, drag force and pressure, other unclear factors are described as random force in the suspension process. As a result, the proposed model has given some numerical simulations of gas-solid systems, in which different random forces are used. It indicates that the stochastic discrete model can be used to simulate qualitatively the dynamic behaviors of gas-solid two-phase flow.