Turbulent flow of a gas-solid suspension through a channel

The objective of the present work is to study the flow of gas-solid suspension in planar channels of finite dimensions using a coupled Large Eddy Simulations-Discrete Element Model (LES-DEM) approach. Dynamic k-equation subgrid scale model (DKSGS) is used to compute the fluctuations in the subgrid-scale. First, the simulation is performed for a vertical channel with periodicity in the spanwise direction in order to compare the results with the Direct Numerical Simulation- Hard sphere (DNS-HS) simulations. Second, the simulation is performed for vertical channels with confined span, in which the wall effect along spanwise and cross-stream directions is investigated. Each term of the kinetic energy and momentum balance equations is computed to understand the significance of individual effects at different solid concentrations within the channel. Simulations are performed for Re of 3300 and particle Stokes numbers of 32 and 105. It is observed that the nature of attenuation of the turbulent intensity depends on the grid selection,n even though particle free flow is grid converged.