Natural convective heat transfer from interrupted rectangular fins

Heatsinks are widely used in various industrial applications to cool electronic, power electronic, telecommunications, and automotive components. Those components might be either high-power semiconductor devices, e.g., diodes, thyristors, IGBTs and MOSFETs, or integrated circuits, e.g. audio amplifiers, microcontrollers and microprocessors. More precisely, the passive cooling heatsinks are widely used in CPU cooling, audio amplifiers and power LED cooling. In the work herein, steady-state external natural convection heat transfer from verticallymounted rectangular interrupted finned heatsinks is investigated. After regenerating and validating the existing analytical results for continuous fins, a systematic numerical, experimental, and analytical study is conducted on the effect of the fin array and single wall interruption. FLUENT and COMSOLMultiphysics software are used in order to develop a twodimensional numerical model for investigation of fin interruption effects. To perform an experimental study and to verify the analytical and numerical results, a custom-designed testbed was developed in Simon Fraser University (SFU). Results show that adding interruptions to vertical rectangular fins enhances the thermal performance of fins and reduces the weight of the fin arrays, which in turn, can lead to lower manufacturing costs. The optimum interruption length for maximum fin array thermal performance is found and a compact relationship for the Nusselt number based on geometrical parameters for interrupted walls is presented using a blending technic for two asymptotes of interruption length.