This work experimentally explored the free convection heat transfer characteristics of finned heat sink with sintered-metal-beads layers. It has been proven that the metallic porous media can enhance the forced convection heat transfer efficiently. This work sintered the metal beads to adhere onto the both side surfaces of each radial plate fin of the metallic heat sink, and investigated whether the sintered-metal-beads layers promote the free convection heat transfer or not. The 0.5~0.85mm-diameetr bronze beads were employed. They were sintered smooth with the radial plate fins of the copper heat sink by thin layers at high temperature. The experimental groups were the plate-shape sintered-metal-beads and strip-shape sintered-metal-beads heat sinks. The pure copper finned heat sink was set as the control group. The results demonstrated that the thermal resistances of the experimental groups were separately 20.7% and 11.6% higher than that of the control group at the smaller temperature difference between the heated surface and the ambient (△T≈30°C); while the thermal resistances of the experimental groups were separately 15.3% and 6.9% higher than that of the control group at △T≈60°C. In general, the present sintered-metal-beads layers cannot strengthen the free convection heat transfer.
Effect of aluminum-foam heat sink on inclined hot surface temperature in the case of free convection heat transfer
