<p>Due to the successive attenuation of microelectronic devices, sophisticated circuit assembly, expeditious growth of power densities and heat dissipation, incapableness of heat extraction of the conventional parallel flow mini heat sink, the advancement of heat extraction technologies become significant. This study represents a numerical investigation of the compatibleness of mini heat sink with high heat dissipation rate, the effectiveness of cooling, the fluid flow patterns inside channels, and the heat transfer performance of parallel flow mini heat sink with the enhancement of secondary channels fluid flow by integrating versatility of interconnector. Therefore, a novel shape, rectangular fin with rounded ends, mini heat sink was proposed in order to originate the redevelopment of the thermal boundary layer and flow mixing. The repetitive use of rectangular fin with rounded ends causes the hydrodynamic boundary layer redevelopment at each leading edge of the rounded ends fin. Furthermore, a mini heat sink with rectangular interconnectors, and a mini heat sink with oblique fin were investigated to visualize the redevelopment of the hydrodynamic boundary layer with a comparison of conventional parallel flow mini heat sink. The redevelopment of the hydraulic boundary layer is responsible for the decreasing trend of the average thermal boundary thickness, hence, the heat transfer performance is increased due to the flow mixing and thermal boundary layer re-initialization. In this study, hydrodynamic characteristics of water as fluid in the single-phase regime with the three-dimensional structure of a mini heat sink consisting of an aspect ratio (height to width) and hydraulic diameter of  1/3 and 750 micrometer, respectively. The three-dimensional structure models were discretized using the finite volume method (FVM) in order to yield several vanishingly small chunks, and then governing equations were solved iteratively using simple scheme. To examine the consequence of coolant flows insides the mini heat sinks, the flow was considered under laminar flow conditions at Reynolds numbers&nbsp;range of 100 to 1100 with an incessant heat flux of 200 KW/m<sup>2</sup> was applied at the bottom surface of the mini heat sink. The parameters for evaluating the heat transfer performance of all cases were non-dimensional velocity, non-dimensional pressure, non-dimensional temperature, friction factor, overall Nusselt Number, and thermal resistance. Thereafter, the performance evaluating criteria (PEC) was implemented for all cases to compare with the conventional one. The results showed that the overall Nu&nbsp;number, for the newly proposed rectangular fin with rounded ends shape mini heat sink, increases and the total thermal resistance decreases significantly when compared with the parallel flow mini heat sinks. A maximum increment of Nu&nbsp;number was recorded at Re=1045 for the newly proposed parallel flow mini heat sink up to 106% as compared to the conventional parallel flow mini heat sink.</p>

Evaluation of Hydraulic and Thermal Characteristics of Interconnected Parallel Flow Mini Heat Sink

Paper Proceedings: https://asmedigitalcollection.asme.org/IMECE/IMECE2021/volume/85543

ASME 2021 International Mechanical Engineering Congress and Exposition (IMECE2021)

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