Evaluation of Active Heat Sinks Design under Forced Convection-Effect of Geometric and Boundary Parameters.

Eva C Silva,Álvaro M Sampaio,António J Pontes

doi:10.3390/ma14082041

Abstract

This study shows the performance of heat sinks (HS) with different designs under forced convection, varying geometric and boundary parameters, via computational fluid dynamics simulations. Initially, a complete and detailed analysis of the thermal performance of various conventional HS designs was taken. Afterwards, HS designs were modified following some additive manufacturing approaches. The HS performance was compared by measuring their temperatures and pressure drop after 15 s. Smaller diameters/thicknesses and larger fins/pins spacing provided better results. For fins HS, the use of radial fins, with an inverted trapezoidal shape and with larger holes was advantageous. Regarding pins HS, the best option contemplated circular pins in combination with frontal holes in their structure. Additionally, lattice HS, only possible to be produced by additive manufacturing, was also studied. Lower temperatures were obtained with a hexagon unit cell. Lastly, a comparison between the best HS in each category showed a lower thermal resistance for lattice HS. Despite the increase of at least 38% in pressure drop, a consequence of its frontal area, the temperature was 26% and 56% lower when compared to conventional pins and fins HS, respectively, and 9% and 28% lower when compared to the best pins and best fins of this study.

Highlights

All electronic devices dissipate heat during their operation
This study aims to evaluate the performance of different heat sinks
The thermal performance of heat sinks design under forced convection, varying geometric and boundary parameters, was conducted by computational fluid dynamics simulation with ANSYS Fluent

Summary

Introduction

All electronic devices dissipate heat during their operation. By providing heat dissipation, a heat sink prevents overheating and plays an imperative role in temperature regulation. Heat sinks increase heat dissipation from a heat source to the surroundings, providing low thermal resistance (Equation (1)) and a lowpressure loss path between them [1]. They can be divided into two main categories: active and passive cooling techniques. The use of natural techniques is known as passive thermal management while forced heat dissipation, e.g., by cooling fans, improving heat transfer, is referred to as active thermal management [2,3,4,5]. The main advantages of passive cooling techniques are their simplicity and lower cost of operation. The most typical material for heat sinks is aluminium, offering a good balance between weight, cost, and thermal properties [8,9,10,11]

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Conclusion