Performance enhancement of the double-layered micro-channel heat sink by use of tapered channels

In this paper performance of a double -layered micro-channel heat sink with tapered lower and upper channels (TDL-MCHS) is investigated numerically. Initially, numerical results were validated with results available in the literature and then uniformity of bottom wall temperature, thermal resistance and pressure drop for TDL-MCHS was evaluated for different flow rates of coolant and convergence angles. The results showed that by increasing the flow rate of coolant and the convergence angle of channels, thermal resistance ratio (lambda(R)) and maximum bottom wall temperature difference ratio (lambda(Delta T)) are reduced. Whereas, pressure drop is increased. In addition, increasing the volumetric flow rate of coolant and convergence angle of channels, reduced the temperature gradient in bottom wall of the heat sink. Thermal performance was improved through increasing the channels convergence angle, although more pressure drop occurred and therefore increased pumping power was required. The convergence angle for optimal temperature distribution and thermal resistance ratio in terms of pumping power, was angle of 4 degrees. Maintaining constant overall volume for the micro-channel heat sink, and changing the channel angles caused improvements in its thermal performance. This new design of micro-channel heat sink have the potential to be employed for developing new generations of heat sinks with higher heat rejection capabilities for microelectronic devices. (C) 2016 Elsevier Ltd. All rights reserved.