Heat transfer characteristics investigations on liquid-cooled integrated micro pin-fin chip with gradient distribution arrays and double heating input for intra-chip micro-fluidic cooling

Targeting at improving temperature uniformity for intra-chip cooling, present work experimentally and numerically investigates the influence of flow rate, heat flux density, fluid inlet temperature and double side heating power on thermal performance in embedded micro-pin fin chip using HFE7100 as the coolant. It is found appropriately increasing flow rate to form enhanced flow fluctuations could effectively improve temperature uniformity by flow impingement, mixing and local acceleration effect. However, the influence of changing fluid inlet temperature is weak. With increasing flow rate, the proportion of convection thermal resistance gradually reaches a plateau and dominants the total thermal resistance. Importantly, double side heating power significantly exacerbates the challenge of thermal management, resulting in a 50% reduction of the addressed heat flux limit and almost one factor of increment in maximum temperature gradient. Notably, present gradient distribution design could address a heat flux limit of 140 W/cm(2), increasing by 30 W/cm(2) than that in uniform arrangement. According to local Nu curve, the significant heat transfer enhanced zones are obtained in gradient distribution chip where local Nu obviously increases. These zones effectively inhibit the rise of temperature and provide a more uniform temperature distribution downstream. (C) 2020 Elsevier Ltd. All rights reserved.