A numerical investigation of velocity and temperature distribution on a heat sink with hexagonal fins facing at different angles in a rectangular duct.

The cooling of hot surfaces through drawing heat by means of fins attached to the surface is widely used technique in many systems. The fins increase the heat transfer surface area, thereby improving the heat transfer. In this study, the velocity and temperature distributions of the working fluid, air, flowing at constant temperature and constant Reynolds numbers over the hexagonal fins, placed in a rectangular duct, having the same surface area and same arrangement but facing at different angles to the flow plane; 0°, 15° and 30°, were analyzed numerically. Computational fluid dynamics (CFD) analysis was carried out with Ansys Fluent. The results were obtained for pressure drop, temperature and velocity distributions at all angles (0°, 15° and 30°). As a result of the analyses performed, 15° facing angle was concluded to be the best by the virtue of the fact that the heat transfer coefficient was improved by the renewal of the boundary layer and by the turbulence occurred between the fins. [ABSTRACT FROM AUTHOR]