Experimental investigation of the potential of metallic porous inserts in enhancing forced convective heat transfer

The present experimental work investigates the effect of a metallic porous matrix, inserted in a pipe, on the rate of heat transfer. The pipe is subjected to a constant and uniform heat flux. The effects of porosity and thickness of the porous matrix on the heat transfer rate and pressure drop are investigated. That is, the surface temperature distribution along a heated section of the pipe, the pressure drop over this section, as well as the inlet temperature of the air were continuously monitored with a data acquisition system and recorded when steady-sate conditions were attained. The results obtained for a range of Reynolds numbers 1000-4500, comprise both laminar and turbulent regime. Also, the results are compared with the clear flow case where no porous insert was used. It is shown that higher heat transfer rates are achieved when using porous inserts at the expense of a reasonable pressure drop, which depends on the permeability of the porous matrix.