On the fluidization/sedimentation velocity of a homogeneous suspension in a low-inertia fluid

The modeling of the fluidization or sedimentation velocity a suspension solid particles is revisited by examining experiments conducted in either liquid gas. A general expression found case negligible fluid inertia, i.e. at low Reynolds Archimedes number. It built as product an isolated particle three non-dimensional corrections that each takes into account specific physical mechanism. first correction reflects variation buoyancy with concentration. second describes how drag force increases concentration inertia. third one accounts for further increase when inertia increased. Remarkably, only relies on single independent groups control problem: (1) volume fraction ?s; (2) ratio ?s/?pack where ?pack bed packing concentration; (3) Stokes number St0, which characterizes and controls their agitation. Moreover, onset instability separates homogeneous regime from heterogeneous to be controlled similarly Empirical expressions are given, provide reliable tool predict velocities all values numbers. present results emphasize crucial role often disregarded previous approaches, such Richardson Zaki.