EXPERIMENTAL INVESTIGATION OF CONVECTION HEAT TRANSFER FROM OPEN-CELLED METAL FOAM BLOCKS

In this paper, an experimental study was conducted to investigate the convection heat transfer inside a horizontal rectangular channel where open-celled aluminum-foam blocks with different pore densities [10, 20, and 40 pores per inch (PPI)] are located. Air was used as the working fluid. The lower surface of the channel was equipped with 8 × 2 arrays of aluminum-foam blocks subjected to uniformheat flux. All remaining surfaces were insulated. The experimental parametric study was made for foam aspect ratios (ARs) of 0.25, 0.5, and 0.75 at various Reynolds and Grashof numbers. The Reynolds number, based on the channel hydraulic diameter of the rectangular channel, was varied from 497 to 7807, while the Grashof number ranged from 4.3 × 107 to 2.9 × 108. The effects of the pore density and aluminum-foam AR are reported. The results obtained show that the row-averaged Nusselt number increases with decreasing pore density, and with increasing AR of the foam blocks. For AR = 0.75, the thermal performance of the aluminum foam with a pore density of 10 PPI is about 51.1 and 85.4% higher than for 20 and 40 PPI, respectively.