Design of vertical fin arrays with heat pipes used for high-power light-emitting diodes

•Thermal designs for Light-Emitting Diodes (LEDs) with vertical fin arrays and heat pipes.•Thermal designing and optimization combined natural convection and radiation.•Optimization of fin spacing with empirical correlations and numerical simulation.•Manufacture and experimental validation for the optimized thermal design. As Light-Emitting Diodes (LEDs) are negatively affected by high temperature, the thermal design for them is critical for better light quality, reliability and lifetime. In this work, a thermal design of vertical fin arrays with heat pipes as passive cooling was applied. The heat pipes can supply high thermal conductivity with much less weight and volume compared to copper or aluminum base and consequently less obstruction to air flow with enhanced natural convection. As the natural convection and radiation dominate heat transfer in this case, the optimum vertical fin spacing was calculated by the most used empirical correlations. Then, the design was numerical investigated by Computational Fluid Dynamics (CFD) to obtain best thermal performance. As the fin spacing was both optimized by correlations and modelling, the optimum thermal design achieved. Finally, we manufactured and tested the design experimentally which consistently approved the thermal design compared to correlations and simulation.