Effect of particle clusters on turbulence modulations in liquid flow laden with fine solid particles

Studies on particle distributions and interactions between the particles and the liquid turbulence are extremely significant and can help to improve efficiency of industrial processes and final product quality. In this paper, the particle distribution and the particle-turbulence interaction in the solid-liquid flow were investigated in detail by a numerical method. The governing equations of the liquid were solved by direct numerical simulations and the particle was tracked by Newtonian motion equations considering the effects of drag force, lift force, pressure gradient force, and virtual mass force. Two-way coupling was used to explain the effect of the particles on the turbulence. The results showed that the vortex has a great influence on the particle distribution. Most of the particles aggregate at the centre of the channel. Particle clusters along the vortex circumference modulate the development of the vortex. The turbulence modulations showed anisotropy. The Reynolds stress is slightly reduced in a broad range; the energy balance is changed; and an extra term is introduced to maintain a new energy balance.