Numerical Investigation of Geometric Parameters Effects on Heat Transfer Enhancement in a Manifold Microchannel Heat Sink

Microchannel heat sink has been employed and as a part of electronic equipment extensively investigated. In this investigation, heat transfer and fluid flow features of laminar flow of water in a manifold microchannel heat sink (MMHS) was numerically simulated. Selected heat flux was ۱۰۰ W/m^۲ and water was as working fluid. The effect of length of inlet/outlet ratio (λ=Linlet/Loutlet), the height of microchannel (Hch), and width of the microchannel (Wch) at Reynolds number (Re) range from ۲۰ to ۱۰۰ as independent parameters on the fluid flow and heat transfer features were examined. Obtained results demonstrate that in MMHS, the impinging jet on the bottom channel surface, inhibits the growth of hydrodynamic and thermal boundary layers, resulting in an enhanced heat transfer rate. Also, by increasing Re and keeping the geometric parameters constant, the heat transfer rate increases. Based on the present investigation, for low Re, it is better to choose a λ=Linlet/Loutlet >۱ and for high Re, choose a λ<۱. For low Re, maximum of performance evaluation criterion (PECmax) is obtained at Hch=۳۰۰µm, and for high Re, PECmax is obtained at Hch=۲۴۰µm. for Re=۲۰ to ۱۰۰, the maximum of PECmax is ۱.۷۶۵ and obtained at Re=۱۰۰ and Hch=۲۴۰µm.

Keywords:

Manifold microchannel heat sink , thermophysical properties , Heat transfer enhancement , Performance evaluation criterion