Heat-dissipation performance of cylindrical heat sink with perforated fins

Abstract

The temperature of light-emitting diode (LED) light bulbs must be managed to maintain their performance and increase their lifespan, and the design and application of an appropriate LED heat sink are particularly important for temperature management. This study investigated the heat-dissipation performance of a heat sink with perforated fins on a cylindrical base. To improve the heat-dissipation performance of the heat sink, the effects of the size and number of perforations per fin were examined. A larger number of perforations with a smaller size were found to be favorable for the improvement of the heat-dissipation performance. Both the size and number of perforations, however, had threshold values for lowering the thermal resistance. Moreover, the heat-dissipation performance was numerically analyzed according to the Rayleigh number, number of fins, fin inclination angle, and orientation angle of the heat sink. In addition, the numerical analysis method used was experimentally verified. As the number of fins increased, the thermal resistance decreased because of the corresponding increase in the heat-dissipation area of the heat sink. Furthermore, the thermal resistance was found to vary with respect to the fin inclination angle, making it possible to reduce the degradation of the heat-dissipation performance by varying the orientation angle. On this basis, a correlation was derived for predicting the thermal resistance of the cylindrical heat sink with perforated fins. The derived correlation accurately predicted the thermal resistance within a maximum error of 5.25%.