Some aspects of solute dispersion in particle suspensions

A. BOSCHAN; B. OCAMPOA; M. ANNICHINI; G. GAUTHIER

Bordeaux

Congreso; ComFlowPore 2015 Complex Fluid Flow in Porous Media; 2015

CNRS Francia, IFP Energies Nouvelles

Previous experiments for pressure driven low-Reynolds flows in a parallel-plate model of porous medium have shown that, for certain flow rate and particle volumetric fraction ranges, the presence of macroscopic particles reduces the dispersivity of a dissolved passive solute. In those experiments, the confinement of the flow generated the shear stress that gives rise to shear-induced migration of the particles, which in turn is the primary mechanism causing the observed reduction. Because of this, in aim to investigate solute dispersion in a settling suspension, we study experimentally the influence of the confinement in the motion of the particles, by analyzing the mean and the fluctuation of their velocities as a function of the particle volume fraction and typical confinement length. The results showed that velocity fluctuations increased with the particle volume fraction and the confinement length. The influence of the size of particle clusters (or blobs) on the velocity fluctuations was also studied.