A tapered inlet/outlet flow manifold for planar, air-cooled oblique-finned heat sink

Abstract

Flow maldistribution compromises thermal and hydraulic performances of heat sinks. The oblique-finned heat sink is a multichannel heat sink comprising parallel (primary) and collinear oblique (secondary) channels and it was reported to suffer from a self-induced flow migration in liquid and air cooling. In this study, a novel tapered inlet/outlet flow manifold was proposed for the planar oblique-finned heat sink. Two heat sink configurations (oblique angles of 30° and 45°) and three flow manifold configurations (of 5%, 10%, and 20% wider flow domains) were investigated. Flow migration characteristics were studied via numerical simulations. Wind tunnel measurements, supported by infrared thermography, were performed to characterize thermal and hydraulic performances on a wide range of air flow rates. The flow manifold was observed to provide a favorable distribution of secondary flows in the spanwise direction of the heat sink. Up to 50% increase in Nusselt number with a negligible increase in pressure drop was observed with the 45° oblique-finned heat sink once the flow manifold was incorporated. 30° oblique angle −10% flow manifold combination provided the lowest heat sink temperature and the most uniform wall temperature. The novel tapered inlet/outlet flow manifold is the first effort reported in the literature to reduce the adverse effects of flow migration through the planar oblique-finned heat sinks.