Impinging round jet studies in a cylindrical enclosure with and without a porous layer: Part II—LDV measurements and simulations

Abstract

This paper presents laser Doppler velocimetry (LDV) measurements and computational fluid dynamics (CFD) simulations for the same system as in Part I, a turbulent fluid layer overlying a saturated porous medium. The measurements are made to consolidate on the flow visualisation experiments which was used to qualitatively evaluate the numerical model in Part I. Comparisons between the simulations presented in Part I and the LDV measurements are made in Part II, for a quantitative evaluation of the numerical model. The simulations were carried out with two different turbulence models and one laminar flow model for the porous medium. For all simulations, a low-Reynolds number k– ε turbulence model is used for the fluid layer. Predictions with one of the turbulence models with only Darcy damping for the porous medium is found to be quantitatively superior. Predictions with the laminar flow model and another turbulence model with Darcy and Forchheimer modification terms in the turbulence transport equations for the porous medium was similar. Simulations with these two models gave better results for the highest fluid height investigated, especially close to the interface between the fluid layer and the porous medium. The turbulence kinetic energy profiles in the fluid layer showed relatively good agreement with predictions by all three models for the porous medium.