Modelling of turbulent gas-particle flows with focus on two-way coupling effects on turbophoresis

An Eulerian model was developed for turbulent gas-particle flow that takes into account the influence of particles on the gas-phase turbulence. For the description of the particle-phase stress the kinetic theory of granular flow and the simpler Hinze model were adopted. A K-ω model was used as the gas phase turbulence model. The difference between one- and two-way coupling was investigated for different particle volume fractions and particle diameters. It was found that particles with a much higher density than the fluid substantially affect the gas-phase in turbulent channel flow for particle volume fractions as low as 10− 4. The models with the particle-phase stress described by the kinetic theory of granular flow and the simpler Hinze model produce similar results for particles with small response times but deviate for larger response times. The study shows that two-way coupling and the turbophoretic effect must be taken into account in models even at relatively low particle volume fractions.

Mean velocity of the gas-phase for four different particle diameters and a simulation without particles. ρp = 910 kg/m3 and Φ0 = 2 ⋅ 10− 4.Figure optionsDownload as PowerPoint slideHighlights
► An Eulerian two-phase flow for turbulent gas-particle flows is developed.
► Gas-particle flow in a vertical channel is simulated.
► Influence of two-way coupling is significant for volume fractions as low as 10−4.
► Particles strongly accumulate near the wall due to turbophoresis.
► Hinze's model for particle fluctuations is accurate only in dilute flows.