Conventionally, mostoptimization works on heat sinks assume that the heat is evenly distributedover the entire base area of the heat sink, and therefore, do not account forthe additional temperature rise caused by a smaller heat source (the contactarea is smaller than the base area) 2,3.Athel et.al 4In this work, a detailedapproach to utilize micro-computed tomography scan to create a detailed andaccurate 3D metal foam model is discussed.
The developed model and approach provides more insight into the coupledbehavior of metal foam heat sinks by being able to calculate the developedstresses due to the thermal loading of the heat sinks.Fang et al. 5 developed a detailed 3D mesoscaleclosed-cell metal foam model to and tested it under static and dynamic loadingsin a ?nite element frame of work.The 3D model was developed using algorithms to generate the 3D convex polyhedronsmodeling the pores with random shapes in closed-cell metallic foams. Theeffect of various parameters such as the pore size and pore density on the mechanical behavior wasstudied and validated.Another approach for developing closed cellmetal foam computational models was presented by Zheng et al.
6. In theirmodel, they created a nuclei and copied it as much as needed to construct themodel.Ji Li et.al 7 The spreading resistance in a heat sink basewith different contact areas and different heat transfer boundary conditionshas been investigatednumerically with a non dimensionalized 3D heat transfer model and the optimaldimensionless base thickness were obtained.From the numerical results, relations amongdifferent heat transfer mechanisms (natural or forced, air or liquid),different area ratios of a heat sink to a heating source, and the lowestthermal resistance have been obtained and discussed.Kim et al. 8 conducted an experimentalinvestigation on forcedair cooling by using manifold micro-channel heat sinks.
They studied the effects of geometricalparameters – primarily of theheat transfer structure – on the thermal performance of the system and demonstrated a 35% lower thermalresistance than that of atraditional micro-channel heat sink.W.Escher 9 The thermal performance of the heat sink was evaluated by athree-dimensional model of a unit cell of the heat transfer structure.
Thismodel was used to study the basic physical phenomena and to investigate thesensitivity of the thermal and hydrodynamic performance of the heat sink on theindependent design parameters.Ryu et al. 10 performed a three-dimensional analysis of the thermalperformance of a unitcell of a manifold micro-channel heat sink and studied its sensitivity on the design variables. The inexorable rise in heat ?ux densities from micro-electronic components and devices is presentingthe industry with formidable challenges in maintaining processor temperaturesbelow critical values, in orderto circumvent a range of important failure modes, 11.
These challenges have stimulated a number ofcooling innovations, including the use of highly conductive inserts to provide more ef?cient pathways to heatremoval, 12, and a number of promising liquid cooling methods. The latterinclude on-chip cooling, direct liquid jet impingement and di electric liquidimmersion which removes heat by convection currents .Chen et al. 13 developed athree-dimensional thermoelectric generator model in order to simplify thedesign and optimization of the system and the thermoelectric device. The widelyused commercial code FLUENT and user-de?ned functions (UDFs) were used to modelthe ?uid behaviors and thermoelectric power output.
The 3D modelling resultsprovided detailed pro?les of the temperature, Seebeck potential, currentdensity, power, and ef?ciency.Yang et al. 14 studied numerically theoptimization of the heat transfer characteristics and ?uid ?ow of air jet impingement on a rotating and astationary heat sink. They found that a heat transfer enhancement is noticeablein the case of smaller Reynolds number (Re = 5019) and Nusselt number augmentswith decreasing Reynolds number.YoungMin Seo et.al 15 In this study, athermoelectric cooler model with a heat sink was developed using CFD. A modelwas developed with heat sinks.
To investigate the effect of the various designparameters of the heat sink, the heat transfer process was analyzed. Liuand Garimella 16 performed experimental and numerical investigations on the ?ow?eld and pressure drop for water ?owin rectangular microchannels. It was found that the conventional correlations o?erreliable predictions for the laminar ?ow.