Effect of Porous Fin Property on Thermohydraulic Performance of Porous‐Fin Microchannels at Different Geometric Configurations

Abstract

The utilization of porous‐fin microchannel (PFM) heat sinks has become prevalent for the cooling of microelectronic chips. This paper employs three‐dimensional simulation to examine the potential benefits of substituting a solid fin with a porous fin for enhancing the thermohydraulic performance. The influence of porous structure features on the thermal and hydraulic behavior of the PFMs at different geometrical configurations is investigated. Results show that in all configurations, employing a porous fin reduces the pressure drop. The heat transfer in PFMs is influenced by the convection in the main fluid path as well as convection in the porous fin structure. An increase in the permeability of the porous fins results in enhanced overall heat transfer due to the augmented convection within the fins. On the contrary, an increase in fin porosity leads to a heat transfer reduction as the effective thermal conductivity of the fin is diminished. The possibility of enhancing thermal performance via the substitution of the solid fin with a porous fin is diminished as the height of the microchannel increases. This is attributed to the weak vertical thermal diffusion of the porous material. Moreover, the findings indicate that the geometric configuration of microchannels has an essential role in heat transfer performance of the porous fin. For instance, the thermal resistance of the PFM with a height ratio of 1.5, porosity of 0.85, and permeability of K = 5 × 10−8m2 is 10.4% less than that of the solid‐fin microchannel (SFM). However, by decreasing the permeability to K = 5 × 10−10m2, the thermal resistance of PFM was 26% higher than that of the SFM.