Particle Distribution in Shear and Pressure-Driven Suspension Flow

The nature of the particle concentration field in a suspension flow is determined by effective stresses occurring in the dispersed phase of the flow. These stresses are equivalent to the momentum flux densities that are caused by random particle fluctuations. Fluctuations of three different physical origins can be important: pseudo-turbulent (due to the mean relative fluid flow working at random concentrational fluctuations), shear-induced, and thermal fluctuations. This paper deveelops simplified heuristic models to describe hydrodynamically induced fluctuations in flows of fine suspensions for which interparticle collisions are inessential. These approximate models are proven to adequately describe some phenomena inherent to suspension flow and are in satisfactory agreement with experimental observations.