Enhancement of the cooling performance of a pin fin heat sink based on the chimney effect using aluminum tape

Abstract

Conventional methods of improving the heat dissipation performance of heat sinks require either modifying existing heat sink geometries or installing additional structures to induce chimney effect. These methods can be problematic to apply if there are limitations of space and cost. In this study, we address the aforementioned problems by developing a novel method of inducing the chimney effect by attaching aluminum tape to a pin fin heat sink. Geometric parameters for optimization were the width and attachment position of the aluminum tape, and changes in the thermal resistance of the pin fin heat sink with a rectangular base were observed according to its orientation angle. First, the widths and attachment positions of the outer and inner aluminum tape strips that minimized the thermal resistance of the heat sink were derived through simulation. The thermal resistance of the heat sink was estimated to be reduced by 10.8% or 7.7%, respectively, only by attaching the outer or the inner aluminum tape strip with optimal width to the top of the pin fin, and it was found to be further reduced by attaching both the outer and inner aluminum tape strips simultaneously. As the next step, the simulation results were verified by experimentally measuring the thermal resistance of actual pin fin heat sinks with and without aluminum tape. It was found that the thermal resistance of the pin fin heat sink was reduced by up to 17.1% by inducing the chimney effect simply through the attachment of both the outer and inner aluminum tape strips with optimal widths to the top of the pin fin. For all heat sink orientation angles tested in the range 0°−180°, the thermal resistance was found to be lower when the aluminum tape was attached than when it was not attached. As a result, the heat dissipation performance could be improved without changing heat sink geometry and by requiring no additional space to install a chimney structure. Our study results show that the safety of heat-generating devices that require heat dissipation can be significantly improved by enhancing the heat dissipation performance of heat sinks if the width and attachment position of the aluminum tape are optimized.