Development of an engineering approach to computations of turbulent flows in composite porous/fluid domains

Abstract

The purpose of this paper is to develop an engineering approach to computations of turbulent flows in composite domains partly occupied by a clear fluid and partly by a fluid saturated porous medium. Previous research concerning turbulent flows in porous media indicates that the effect of porous media is to dampen turbulence. Therefore, in porous/fluid domains the penetration depth of turbulent eddies into the porous region is expected to be small. The authors suggest assuming that the flow over the whole porous region remains laminar and matching turbulent flow solution in the clear fluid region with the laminar flow solution in the turbulent flow region. Although the flow in the porous region is assumed to be laminar, linear Darcy or Brinkman–Darcy models cannot be utilized to describe momentum transport in the porous region because of large filtration velocity. The momentum transport model in the porous layer utilized in this research is based on the Brinkman–Forchheimer-extended Darcy equation, which allows the accounting for deviation from linearity and also allows a smooth matching of the filtration velocity at the porous/fluid interface. Because of the large filtration velocity in the porous region, the energy equation in the porous region also accounts for the thermal dispersion effects.