Comparison of the thermal and pressure drop characteristics of a conventional fin block and partially metal foam embedded heat sinks

Ataer, Süleyman Kaancan
Despite the downsizing of the electronic components, the increase in the power consumption of the electronic components and correspondingly the rise in the loss of power that transforms into heat have given a momentum in the search for different cooling methods for thermal sinks by the thermal engineers. Excessively heated regions that form on the small areas where the heat generating components contact the heat sinks create a thermal resistance for the heat flow from the surface of the component to the chassis and trap the thermal energy. The reasons for the preference of the metal foam for this study are the suitability for the forced convection and the conduction heat transfer methods as well as having a large heat transfer surface area. In this research, metal foams with 4,8,16 pores/cm aluminium having 93% porosity and copper metal foam having 90% porosity that are integrated into a heat sink with a special geometry was designed and built. During the process of the experiments, the thermal resistances and the pressure losses of the metal foam integrated heat sinks were tested by applying different heat fluxes and different air speeds to the specimens. Differences in the thermal performances of the heat sinks were observed by enforcing the specially manufactured heaters. In the first part of test scenarios smaller heaters were contacted only to the top side of the metal foam embedded regions of the heat sink chassis. In the second part of test scenarios the entire top surface of heat sink was heated with longer type heaters. Within the scope of the experiments, the performances of the designed heat sinks were compared with specially produced fin block which is known as one of the commonly used cooling methods. Experimental results were compared with the results that were obtained from the CFD and interpreted accordingly. As a result, how much improvement could be achieved was revealed and recommendations were made for the future projects and applications in partial use of metal foam of thermal management. It was observed that partial metal foam utilization is more efficient than a conventional aluminum fin block in thermal management.