A numerical study of the thermal performance of an impingement heat sink - Fin shape optimization

This paper presents the results of a numerical analysis of the performance of an impingement heat sink designed for use with a specific blower as a single unit. These self-contained heat sinks/blowers, which cause impingement type flow on the heat sink fins, are now commonly used for desktop microprocessors. One of the objectives of this study was to examine the effect of the shape of the heat sink fins, particularly near the center of the heat sink. The pressure gradient at the center of the heat sink, near the base, tends to be substantial and this significantly reduces airflow and hence transport in that region. Different fin shapes and airflow rates were studied with the objective of searching for an optimal heat sink design that would improve the thermal performance. The fin shapes examined were all parallel plate fins with material removed from the region near the center of the heat sink along the length and height of the fins. Seventeen different designs were compared, and an 'optimum' heat sink shape is reported that results in a lower operating temperature and pressure gradient.