A non-Darcy model for recirculating flow through a fluid-sediment interface in a cylindrical container

TLDR: In this article, a mathematical model for axisymmetric laminar flow generated by a rotating disk inside a cylinder with an open top, containing a viscous fluid above as layer of fluid-saturated porous medium is presented.

Abstract: A numerical investigation has been undertaken to characterize the axisymmetric laminar flow generated by a rotating disk inside a cylinder with an open top, containing a viscous fluid above as layer of fluid-saturated porous medium. The mathematical model is based on a continuum approach for both fluid and porous regions. Attention is focussed on conditions favouring steady, stable, axisymmetric solutions of the Darcy-Brinkman-Lapwood equation. The accuracy of the method is verified by solving some vortex flow problems in disk-cylinder geometries and comparing the results with: (a) existing numerical solutions and, (b) experimental pressure measurements in a similar geometry. Calculations are performed to investigate the fluid exchange between the porous region (porewater) and the overlying water. Results indicate that flow through composite (fluid-sediment) systems can be handled with good accuracy by the method presented here. With our approach the magnitude of advective porewater transport in sediments may be predicted. This finding is important for improved designs of flux chambers and also for understanding advective transport phenomena.