Convective heat transfer in porous channels with 90-deg turned flow

Abstract

This study experimentally investigated the convective heat transfer and pressure drop in porous channels with 90-deg turned flow. Aluminum foams with a porosity of 0.93 were used. The size of the aluminum foams was fixed. Variable parameters were the ratio of the entry width to the porous sink height ( W j / H), the pore density of the aluminum foam (PPI, pore per inch) and the Reynolds number ( Re). Experimental results reveal that the wall temperature was maximal at the corner under perpendicular flow entry. It fell along the channel axis until x/ H was about 1.0, finally approaching a constant value. Parametric studies indicate that increasing Re increased the average Nusselt number ( Nu ¯ ) and the effects of W j / H and PPI on Nu ¯ were negligible. The friction factor ( C f) generally declined as Re increased, PPI decreased or W j / H increased. Besides, increasing W j / H or reducing PPI slightly increased Nu ¯ at a given pumping power. Additionally, the heat transfer and pressure drop in porous channels with straight flow were also measured for comparison.