CFD study of liquid-cooled heat sinks with microchannel flow field configurations for electronics, fuel cells, and concentrated solar cells Bladimir Ramos-Alvarado a, 1 , Peiwen Li a, * , Hong Liu a , Abel Hernandez-Guerrero b a Department of Aerospace and Mechanical Engineering, The University of Arizona, Tucson, AZ 85721, USA b Department of Mechanical Engineering, University of Guanajuato, Salamanca, Guanajuato, Mexico article info Article history: Received 19 January 2011 Accepted 10 April 2011 Available online 22 April 2011 Keywords: Microchannel Heat sinks Liquid-cooled Novel flow fields abstract A study of the heat transfer performance of liquid-cooled heat sinks with conventional and novel micro- channel flow field configurations for application in electronic devices, fuel cells, and concentrated solar cells is presented in this paper. The analyses were based on computations using the CFD software ANSYS FLUENT Ò . The flow regime in heat sinks is constrained to laminar flow in the study. Details of the heat transfer performance, particularly, the uniformity of temperature distribution on the heating surface, as well as the pressure losses and pumping power in the operation of the studied heat sinks were obtained. Comparisons of the flow distribution uniformity in multiple flow channels, temperature uniformity on heating surfaces, and pumping power consumption of heat sinks with novel flow field configurations and conventional flow field configurations were conducted. It was concluded that the novel flow field configurations studied in this work exhibit appreciable benefits for application in heat sinks. Ó 2011 Elsevier Ltd. All rights reserved. 1. Introduction High-power-density electronic devices, fuel cell power sources (such as proton exchange membrane fuel cell stacks), and concen- trated solar panels all need effective cooling for safe and highly efficient operation. Heat sinks with relatively large flat plate geom- etries are often needed for cooling of fuel cell stacks [1e3] and concentrated solar cells, which is one of the newest forms of solar energy technology [4e7]. Currently, air-cooled heat sinks are the most viable solutions for cooling electronic devices, primarily because of their low cost and high reliability [8]. A large amount of research work on air-cooled heat sinks has been published in the past several decades, and significant improvements of heat sink designs have been achieved based on CFD analyses [9,10] and experimental investigations [11e 13]. For high-heat-releasing electronics [13], air cooling methods have been found to be insufficient in recent years. To improve the heat dissipation flux per unit area in a heat sink, liquid cooling is becoming more and more popular [14e16]. For fuel cell stacks and concen- trated solar panels, liquid cooling is the main available option [4e6]. Liquids usually have a higher heat capacity and thermal conductivity than air, and therefore can significantly improve the heat transfer rate, and lower the maximum temperature level on a heat sink. Some liquids can also be managed so as to take advantage of phase change heat transfer, which can dramatically improve the cooling capability of heat sinks [17,18]. With the advancement of fabrication technologies, micro- channel heat exchangers have been developed in the last two decades. Micro-channel heat exchangers enable liquid to flow through channels of a hydraulic diameter of 100e1000 mm and the heat transfer surface area can be dramatically increased. Heat sinks with micro-channels are suitable for high flux heat dissipation in a broad range of high performance electronics [19]. A significant amount of research work on heat sinks using micro- channels has been published [20e23], and general heat transfer characteristics and enhancements have been studied. However, these works paid insufficient attention to one important issue: the maldis- tribution of a flow to multiple channels on a flat plate [24]. Heat sinks fabricated with micro and miniaturized flow channels often employ multiple parallel flow channels for heat transfer. The smaller channels provide increased heat transfer surface area; however, the inlet and exit manifolds are also very important as they facilitate the necessary distribution of fluid and provide connections to external inlet and outlet conduits. A less uniform flow distribution often lowers the heat sink’s efficiency by causing local high temperatures (and local high thermal stresses) as well as creating overall high pressure losses which translate into increased pumping power consumption for heat sink operation. There are several publications which have touched upon the issue of flow maldistribution from a fluid mechanics perspective * Corresponding author. E-mail address: peiwen@email.arizona.edu (P. Li). 1 On leave from University of Guanajuato, Mexico. Contents lists available at ScienceDirect Applied Thermal Engineering journal homepage: www.elsevier.com/locate/apthermeng 1359-4311/$ e see front matter Ó 2011 Elsevier Ltd. All rights reserved. doi:10.1016/j.applthermaleng.2011.04.015 Applied Thermal Engineering 31 (2011) 2494e2507