Lattice Boltzmann simulations of the effect of particles movement on momentum transfer process

The particle vibration in a gas-solid fluidized bed has a significant effect on transfer process. Lattice Boltzmann method coupled with an improved immersed moving boundary method is used to simulate the single particle vibration with different amplitude A/D and frequency k = fe/f0, and the effect of two-particle vibration with different arrangement and spacing on the drag coefficient, lift coefficient and vortex shedding frequency. The results show that when one single particle oscillating transversely at Re = 100, with increasing A/D, particle locking range becomes larger and the drag coefficient inside the locking interval is larger than that outside, which is beneficial to transfer process. When one single particle oscillating stream wisely at A/D = 1.50, the fluid flow mode changes from 2S→2P→2P+2S→chaos with increasing k. At the same A/D when k < 1.25, the drag coefficient of the transversely oscillating particles is larger than that of the stream wisely oscillating particles, but when k > 1.25, it is opposite. Therefore, the particle transversely oscillating is more favorable for transport at k < 1.25, and the particle stream wisely oscillating is more favorable for transport at k > 1.25. The formation of mutual inhibition vortices of the series double particles reduces the drag coefficient, which is not conductive to the transfer, on the contrary, the parallel double particles promote the transfer, and the effect is the best when H = 3D. The above numerical results provide an idea for strengthening transfer process. © 2023 Chemical Industry Press. All rights reserved.