Computational Assessment of the Heat Transfer Coefficient Under Forced Convection of Multiple Metal Foam Fins Heat Sinks

The use of metal foams in thermal applications such as heat sinks, heat exchangers, and other heat recovery systems has been increased in the last 2 decades. That being said, the studies were mostly experimental in nature. Due to the complexity of metal foams, most of the results were useful from a qualitative point of view rather than quantitative. With the improvement in computational means, micro-CT scan has been used to develop realistic 3D metal foam models. These models in the literature mostly focus on extracting mechanical and thermal properties, or study the behavior of the metal foam material. In this work, a micro-CT scan metal foam heat sink model is used to study the effect of having multiple metal foam fins on the heat transfer coefficient (h). The calibration of the heat transfer coefficients show that the assumption used in the literature of a fixed h value is not valid. The variation of the h value of each metal foam fin is used to study its effect on the performance of a two and three metal foam fins heat sinks by investigating the thermal resistance and the effectiveness of the heat sink. It was found that even though there is an increase in the thermal resistance, increasing the number of fins will improve the effectiveness in a nonlinear fashion. It is suggested that even with the improvement in the effectiveness, a variation in the height of the metal foam fins will improve the efficiency.