We consider materials with large pores interconnected by thin long channels saturated with an incompressible fluid. In the absence of fluid flow, solute transport in the porous network is diffusion controlled, however, solute transport can be enhanced when the porous network is subjected to a cyclic flow with zero time average velocity. We develop a mathematical model to analyze this physical p...

In this paper, we compare the effectiveness of three preconditioning strategies in simulations of variably saturated flow. Using Richards’ equation as our model, we solve the nonlinear system using a Newton-Krylov method. Since Krylov solvers can stagnate, resulting in slow convergence, we investigate different strategies of preconditioning the Jacobian system. Our work uses a multigrid method ...

International Journal of Computational Fluid Dynamics Publication details, including instructions for authors and subscription information: http://www.informaworld.com/smpp/title~content=t713455064 Modelling microscale flow and colloid transport in saturated porous media Hui Gao a; Jie Han b; Yan Jin b; Lian-Ping Wang a a Department of Mechanical Engineering, University of Delaware, Newark, DE,...

Preferential flow in unsaturated porous media, in the form of fingers and channels, has been observed to take place in different types of media and at different scales. The preferential flow is caused by fluid instabilities, created by density or viscosity differences, or because of heterogeneities in the geological media. In this study, two very different types of preferential flow problems ar...

Standard Galerkin finite element methods for variably saturated groundwater flow have several deficiencies. For instance, local oscillations can appear around sharp infiltration fronts without the use of mass-lumping, and velocity fields obtained from differentiation of pressure fields are discontinuous at element boundaries. Here, we consider conforming finite element discretizations based on ...

The interfacial instabilities important to the modeling of critical heat flux (CHF) in reduced-gravity systems are sensitive to even minute body forces, especially for small coolant velocities. Understanding these effects is of paramount importance to both the reliability and safety of two-phase thermal management loops proposed for future space and planetary-based thermal systems. Unfortunatel...

This study examines the use of Picard and Newton iteration to solve the nonlinear, saturated ground water flow equation. Here, a simple three-node problem is used to demonstrate the convergence difficulties that can arise when solving the nonlinear, saturated ground water flow equation in both homogeneous and heterogeneous systems with and without nonlinear boundary conditions. For these cases,...

(Preliminary Report.) The model formulation and existence theory is described for diffusion of a barotropic fluid through a partially saturated poroelastic composite medium consisting of two components. This includes the Barenblatt-Biot doublediffusion model of elastic deformation and laminar flow in a fissured medium, such as consolidation processes in a system of fissures distributed througho...