Comparative study on hydraulic and thermal characteristics of minichannel heat sink with different secondary channels in parallel and counter flow directions

With the challenges of continuous shrinking, weight reduction, and high heat flux rate of sophisticated microelectronic devices, the advancement of heat-releasing devices, such as minichannel heat sinks, becomes necessary. In this present study, the thermo-hydraulic characteristics of Mini-Channel Heat Sink (MnCHS) with different secondary channel shapes, such as rectangular, oblique, and curvy, are numerically investigated and compared with Conventional Mini-Channel Heat Sink (CMnCHS). Here, the curvy secondary channel is the novel shape, and the thermo-hydraulic characteristics of the newly proposed shape are also reported in this study. For this purpose, the 3D structure of MnCHS with a water fluid domain was considered in the single-phase flow regime. Laminar fluid flow conditions (Re=150-1050) were employed at the inlet, and a constant heat flux of 200kW/m2 was applied at the bottom plane of the minichannel. The results showed no significant enhancement in thermal and hydraulic performance in parallel flow direction for any minichannel configuration, including the newly proposed shape. However, when counter flow was employed, the results indicated that the average Nu number increased and the total thermal resistance decreased significantly with Re for the newly proposed shape. Moreover, all counter flow cases showed a notable enhancement in Nu number and a reduction in thermal resistance. Besides that, all cases exhibited reduced pressure drop penalties at lower Re (<600) and slightly increased pressure drop penalties at higher Re (600-1050). In comparison to the CMnCHS, the maximum Performance Evaluation Criteria (PEC) value of 1.69 was achieved for rectangular fin with straight secondary channel, whereas PEC values of 1.56 and 1.53 were recorded for oblique fin and newly proposed shape at Re=1050, respectively. © 2023 The Author(s)