LAUSR

Abstract The objective of this study is to significantly enhance the heat removal capacity of naturally cooled heat sinks (NCHx) of battery chargers for small electric vehicles. To this end, thermal performance of NCHx with various fin geometries and identical footprints, are experimentally and numerically studied under multiple orientations, namely: (i) horizontal, (ii) vertical, and (iii) sideways. The effect of surface anodization is also investigated. A number of finned heat sinks are designed and prototyped including (i) inclined fins (benchmark case), (ii) inclined interrupted fins, (iii) straight interrupted fins, and (iv) pin fins. Studied NCHx share the same footprint of a commercial battery charger IC650 from Delta-Q Technologies. The experimental results before the surface anodization indicate that the inclined interrupted fins can offer the desired thermal improvement under all tested orientations compared to the benchmark case, while the straight interrupted fins are more suitable for applications at vertical orientation and the pin fins operate relatively better at horizontal orientation. A notable overall enhancement of thermal performance, up to 27%, is achieved after anodization, depending on the fin geometries and orientations. The study also shows that the inclined interrupted fin heat sink is the most versatile to operate under various installation orientations, where it can improve thermal performance up to 21%, 24%, and 22%, at horizontal, vertical, and sideways orientation respectively, due to enhancements in both natural convection and thermal radiation.