FRICTION FACTOR OF THE FLUID FLOW THROUGH POROUS MEDIA

Abstract

This paper deals with the theoretical foundations aimed for modeling and simulation of fluid flow through porous structures and related friction. Different approaches to determination of the analytical solution of the friction factor are presented, as well as formulas that are used in specific flow regimes. Review of fluid types from aspect of viscosity are shown, namely Newtonian and non-Newtonian fluids and related aspects of the fluid behaviour. Review of the established dependencies of the friction factor on the influential factors is presented, such as on Reynolds number, pore geometry, permeability and inertia coefficients. Differences between smooth and rough surfaces in contact with the fluid are observed, from aspects of friction. Geometry of the porous structure essentially influences the flow and governs the friction, as well as the surface roughness. The pressure drop within a porous structure is directly influenced by the permeability and drags force coefficients and can well characterise cellular materials. Wall roughness typically enhances the turbulence and transition from laminar to turbulent flows appears earlier for rough than for smooth surfaces. One short example of CFD modeling of the fluid flow through porous media is shown, as well as generation of the Voronoi based open cell pattern.