Natural convection heat transfer performance of finned heat sinks with different fin materials and geometries

Effective thermal management of electronic devices using passive cooling is a significant engineering challenge. This experimental study looks at how fin material and design affect the natural convection heat transfer of heat sinks attached to a vertical aluminum plate. Four configurations were tested under steady-state conditions: a flat plate, plates with horizontal aluminium fins, vertical aluminium fins, and copper fins arranged in a V-shape. The experiments covered heater input powers from 25 to 150 W, and we measured surface temperatures with calibrated K-type thermocouples. We calculated the heat transfer coefficient, Nusselt number, and the difference between surface and ambient temperatures to assess thermal performance. This experimental study systematically investigates the influence of fin geometry and material on natural convection heat transfer from a vertically heated aluminium plate under identical steady-state conditions. Three fin materials (aluminium, copper, and brass) and three configurations (vertical, horizontal, and V-shaped fins) were examined over a heater input range of 25-150 W. Surface temperatures were measured using calibrated K-type thermocouples (± 0.5 °C accuracy). The heat transfer coefficient, Nusselt number, enhancement ratio, and thermal resistance were calculated using energy balance relations. The copper V-fin configuration achieved a maximum heat transfer coefficient of 47.66 W/m² K at 150 W, representing a 30-40% enhancement compared to the plain plate. Surface temperature reduction reached 15-20% depending on heat input. All results are supported by quantitative uncertainty analysis (± 6-8%).These findings provide experimentally validated guidance for the optimization of passive natural convection heat sinks.