Dsmc Method In The Numerical Simulation Of Circulating Fluidized Bed

In this paper, the interaction and the motion of particles in CFB (Circulating Fluidized Bed) are simulated by DSMC (Direct Simulation Monte-Carlo Method), which is combined with discrete particle model.The main works are shown as followed:1. Based on discrete particle model, particle motion is simulated by DSMC in CFB. The algorithm and computational procedures are also described in the paper.2. Based on DSMC, a new method of sampling and revivifying for disposing collision among particles is proposed.3. DSMC method is combined with hard-sphere model to calculate the collision between particles. The modified Nanbu method is improved according to the rule of one-to-one collision in the hard-sphere model.4. The influences of some parameters on CFB are discussed and the simulation results are analyzed.The main conclusions are given as followed:1. By the way of the sampling and revivifying method, the existence of ring-core structure of particle motion is shown, the fact that the lower part is a dense region and the upper part is a dilute region is also proved.2. The modified Nanbu method is improved, which decreases the number of collision and computational time.3. The bigger ratio of real particle and sample is, the shorter time the computation uses.4. Both diameter and density of particles have little influence on numbers ofparticles that take part in colliding.5. When the numbers, diameter, density of particles are increased, the gas radial velocities are decreased.6. When the density of particles is increased, voidage is decreased.