Effect of Orientation on the Thermal Performance of a PCM-Based Finned Heat Sinks

The present study investigates the effect of orientation on phase change material (PCM)-based finned heat sink (HS). The heat sinks are made of aluminum with an outer diameter of 58 mm, an inner diameter of 48 mm, and a height of 55 mm with different configurations like (i) bare heat sink, (ii) heat sink with central stem, (iii) heat sink with three fins having a central gap, and (iv) heat sink with four fins. The PCM considered for the experimental work is n-eicosane. The fins of a thickness of 2 mm and stem having a diameter of 5 mm are placed for the purpose of thermal conductivity enhancement. Experiments are conducted on all heat sinks with a constant fill ratio of 99%, and charging and discharging times are recorded. Of them, the heat sink with four partitions gives better results, and further, the experimental investigations are carried out on four fin heat sink at different orientations (0°, 45°, 90°, 135°, 180°) and at different power levels ranging from 6 to 12 W. The charging is done to a set point temperature of 50 °C. The discharging is done under natural convection conditions at controlled room temperature. Based on the experimental results, the heat sink performance depends on orientation as the gravitational and buoyancy force directions vary.