Liquid-solid flows using smoothed particle hydrodynamics and the discrete element method

This study presents a computational method combining smoothed particle hydr odynamics (SPH) and the discrete element method (DEM) ta model flows contai ning a viscous fluid and macroscopic solid particles. The two-dimensional n umerical simulations are validated by comparing the wake size, drag coeffic ient and local heat transfer for flow past a circular cylinder at Reynolds numbers near 100. The central focus of the work, however, is in computing f lows of liquid-solid mixtures, such as the classic shear-cell experiments o f Bagnold. Hence, the simulations were performed for neutrally buoyant part icles contained between two plates for different solid fractions, fluid vis cosities and shear rates. The tangential force resulting from the presence of particles shows an increasing dependence on the shear rate as observed i n the Bagnold experiments. The normal force shows large variations with tim e, whose source is presently unclear but independent of the direct collisio ns between particles and the walls. (C) 2001 Elsevier Science B.V. All righ ts reserved.