ISSN Online: 2377-424X
ISBN Print: 978-1-56700-474-8
ISBN Online: 978-1-56700-473-1
International Heat Transfer Conference 16
TURBULENT TRANSPORT OVER ANISOTROPIC POROUS MEDIA
Resumo
Planar PIV measurements of flows over anisotropic porous media are carried out. Three kinds of anisotropic porous media (cases 1-3) are considered to form a bottom wall of fully developed channel flows. Their wall permeability tensor is designed to have anisotropic elements. The wall-normal component (wall-normal permeability): Kyy, is always larger than the other components by the factor of 1.3-170. Case 1 has the largest wall-normal permeability that is 88 times larger than those of cases 2 and 3. Hence, Kcase1yy >> Kcase2yy = Kcase3yy. The streamwise component (streamwise permeability): Kxx, of case 1 is 25% smaller than that of case 2 while case 3's is 25% larger than case 2's. Hence, Kcase3xx > Kcase2xx > Kcase1xx. The range of the
measured Reynolds number is Reb=900-13000 to cover laminar to turbulent flows. It is found that the turbulent flow profiles depend on the streamwise permeability. Indeed, the turbulence level accords with the order
of Kcase3xx > Kcase2xx > Kcase1xx. The larger Kxx produces the stronger turbulence. However, from a quadrant analysis, it is found that sweeps and ejections near the porous media are clearly influenced by both the wall-normal and streamwise permeabilities.