Numerical investigation of the effect of fins added to metal foam on heat transfer using air and water coolants

Advancements in technology have led to a continuous increase in the amount of heat generated within electronic equipment, despite the reduction in their size and the increase in their functionalities. Due to the escalating heat loads, enhancing cooling performance has become more critical in applications. Metal foams have recently emerged as a prominent method to enhance heat transfer in cooling systems, primarily due to their great surface-to-volume ratios. However, the issue arises when high porosity values are involved, particularly when a high thermal conductivity fluid such as water is used, as it presents difficulty in ensuring heat conduction along the height of the metal foam. Consequently, integrating fins with metal foams has been documented in the literature as a means to increase the Nusselt number on the heated surface. In this study, in contrast to the existing literature, the effect of using metal foam combined with fins was examined with two separate fluids possessing dissimilar thermal conductivities: a high thermal conductivity fluid (water) and a low thermal conductivity fluid (air). The metal foams were modeled using Computational Fluid Dynamics (CFD) software with porous medium parameters. The metal foam used is made of aluminum material and exhibits a high porosity level of 90%. Additionally, the impact of varying the number of fins was investigated as a parameter, and its effect on the heat transfer from the heated surfaces for both fluids was examined using ANSYS Fluent software. In the study, it was observed that when air is used as the fluid, the addition of fins increases efficiency with increasing air velocity, while the temperature rise on the wall can be reduced by up to 43%. Conversely, when water is used as the fluid, the addition of fins decreases efficiency with increasing water velocity, yet the temperature rise on the wall can be reduced by up to 48%.