关键词: 计算流体力学-离散单元法, 液固, 水平窄矩形通道

Abstract: Extensive research on the liquid-solid two-phase transportation in horizontal circular tubes has been conducted, but the liquid-solid two-phase hydrodynamics and the solid phase diffusion characteristics in narrow rectangular channels are rarely reported. The glass beads-water two-phase hydrodynamics in horizontal narrow rectangular channel with 12mm height are investigated by the approach of experimental method and CFD-DEM simulation. The pressure gradient characteristics, the solid phase flow characteristics, the statistical properties, and the solid phase diffusion characteristics are explored. Simulation results showed that a dilute disperse phase and a dense cluster phase were formed in the process of solid movement. The dense cluster phase is elevated and accelerated along the horizontal direction. Increasing solid concentration can reduce the non-uniform degree of the solid distribution while enhance the asymmetry of the solid vertical velocity profiles. The vertical solid dispersion intensity can be suppressed with the increase of the solid concentration. Three distinct regions are identified along the vertical direction, corresponding to the near-wall region, the solid highly-collisional region, and the dilute particle-laden region, respectively. The viscous-turbulent interface interacts with the particles in the near-wall region, which drives the particles away from the bottom wall and thus leads to the greatest standard variances of the solid stream-wise velocity and the solid concentration. In the solid highly-collisional region, the fluctuation of the solid vertical velocity is larger because of the chaos motion than that in two other regions. The standard variances of the solid stream-wise velocity and the solid concentration keep little change in the solid highly-collisional flow region and then decay rapidly to zero in the dilute particle-laden region.

Key words: CFD-DEM, liquid-solid, horizontal narrow rectangular channel