Performance analysis of minichannel heat sink with oblong cavities and diverse pin fin configurations

Passive heat transfer techniques in minichannel heat sinks (MCHS) provide effective thermal management solutions for high heat flux applications. The current study introduces a three-dimensional numerical analysis conducted to explore the flow and heat transfer characteristics of MCHS utilizing two passive techniques: incorporating pin fins with oblong-shaped cavities. Four types of pin fin shapes were developed, including tear-drop (MCOC-TDPF), pyramidal (MCOC-PPF), conical (MCOC-CPF), and oval (MCOC-OPF), respectively. The study is carried out under a laminar flow regime with Reynolds number ranging from 100 to 1000. The overall performance of these designs is assessed through a comparative analysis of traditional MCHS based on average Nusselt number, friction factor, and overall performance factor. Among these designs, MCOC-CPF exhibited superior thermal performance compared to the other three configurations, with a maximum performance factor of 2.25 at a Reynolds number of 1000. Furthermore, the influence of conical pin fin taper ratio (β) on the thermal enhancement of MCOC-CPF is also analyzed. Four values of conical pin fin taper ratio (β) have been considered, namely 1/6, 1/3, 1/2, and 2/3. The results revealed that β = 1/3 achieved an optimal overall performance of 2.39 at Reynolds number Re = 1000.