Experimental study of forced convection in metallic porous block subject to a confined slot jet

This study experimentally investigated the convective heat transfer and pressure drop in the metallic porous block with a confined slot air jet. Aluminum foam block with the porosity of 0.93 and the pore density of 10 PPI (pores per inch) was used. The size of the aluminum foam block was fixed. Variable parameters were the ratio of the jet nozzle width to the porous block height (Wj/H), the ratio of the jet-to-foam tip distance to the porous block height (C/H) and the jet Reynolds number (Re). Experimental results reveal that the wall temperature at the stagnation point (x/L=0) under the slot jet flow was minimal, and monotonously rise along the channel axis until the channel exit. Parametric studies indicate that increasing Re increased the average Nusselt number (Nu), decreasing Wj/H slightly increased Nu, and the effect of C/H on Nu were negligible. The dimensionless pressure drop (CfRe22(L/Wj)) increased as Re increased or Wj/H declined. The effect of C/H on CfRe22(L/Wj) does not seem regular. Besides, The Nu in the configuration without by-pass flow (i.e. C/H=0) generally exceeded that with by-pass flow (i.e. C/H=1–3) at a given dimensionless pumping power (CfRe32(L/Wj)). Within the successfully measured parameter (Wj/H=0.22–0.35, C/H=0–3 and ), the largest Nu under the same CfRe32(L/Wj) appeared on Wj/H=0.35 and C/H=0.