Pool Boiling of Water and FC-72 on Copper and Graphite Foams

Pool boiling heat transfer of water and FC-72 on thin blocks, 3 mm, of metal and mesophase graphite foams bonded on a high flux heat source is studied experimentally. Two blocks of 80 ppi (90% porosity) and 30 ppi (95% porosity) copper foams, and a block of graphite foam (75% porosity) were tested. Experimental results on foam structures are compared with those of plain surface. Significant enhancement was achieved in boiling of water on the 30 ppi copper foam, while no enhancement was observed on the 80 ppi copper and the graphite foams. In the case of FC-72 boiling, however, a substantial enhancement was achieved on all foams. Results of the experiment and enhancement in different boiling regimes are discussed.