In this paper, all experimental investigation was performed to study the heat transfer performance of metal foam heat sinks of different pore densities subjected to oscillating flow Under various oscillatory frequencies. The variations of pressure drop and flow velocity along the kinetic Reynolds number of oscillating flow through aluminum foams Were compared. The measured pressure drops, velocities and surface ternperatures of oscillating flow through aluminum 10, 20 and 40 PPI foams were presented in detail. The calculated cycle-averaged local temperature and Nusselt number for different kinetic Reynolds numbers were analyzed and compared with finned heat sinks. The results of length -averaged Nusselt number for both oscillating and steady flows indicate that higher heat transfer rates call be obtained in metal foams Subjected to oscillating flow. For the purpose of designing a novel heat sink using metal foam, the characteris ties of the pumping power of the cooling system for aluminum foam with different pore densities were also analyzed. (c) 2005 Elsevier Ltd. All rights reserved.