abstract
Heat transfer due to oscillating water flow in open-cell aluminum-foam pipe subjected to constant wall
heat flux was investigated experimentally. The foam had 20 pores per inch and a porosity of 87.6%. Three
flow displacements 1.5, 1.9 and 2.2 pipe diameters, at kinetic Reynolds numbers in the range 1873–9366
were applied. Higher flow displacement and higher frequency generally produced higher heat transfer
rates and led to lower and more uniform wall temperature. The flow displacement had the most profound
influence on heat transfer. A correlation was obtained for the time- and length-average Nusselt number
as a function of non-dimensional flow displacement and kinetic Reynolds number. The dependence on
kinetic Reynolds number might be universal for oscillating heat transfer in porous media. Steady-state
heat transfer experiments were also conducted in the same porous medium and test facility.
Oscillating flow was seen to produce lower rates of heat transfer compared to steady flow. This unexpected
finding was explained. The current results were compared to other studies from the literature
employing oscillating air and water flows in various kinds of porous media. Some agreements and disagreements
were stated and discussed.