EXPERIMENTAL STUDY OF SUBCOOLED POOL BOILING HEAT TRANSFER ON METAL FOAM

The present experimental study is focused on subcooled pool boiling heat transfer on aluminum metal foam at atmospheric pressure. Experiments are conducted with open-cell metal foam of different porosity and different thickness, using water as the working fluid. The surface superheat ranges up to 15 degrees C, with maximum heat flux of about 30 W/cm(2). The thermal performance of pool boiling on metal foams is compared to that on a roughened copper surface of the same dimensions. The thickness and the geometry of metal foams significantly influence the pool boiling heat transfer coefficient. The effect of orientation on the thermal performance in metal foam is also studied. The surface temperature excursion at boiling incipience and small hysteresis is observed in the experiments. When the metal foam thickness is reduced, hysteresis becomes more significant.