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

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 (Wj/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 Wj/H   and PPI on Nu¯ were negligible. The friction factor (Cf) generally declined as Re increased, PPI decreased or Wj/H increased. Besides, increasing Wj/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.