optimization works on heat sinks assume that the heat is evenly distributed
over the entire base area of the heat sink, and therefore, do not account for
the additional temperature rise caused by a smaller heat source (the contact
area is smaller than the base area) 2,3.
Athel et.al 4In this work, a detailed
approach to utilize micro-computed tomography scan to create a detailed and
accurate 3D metal foam model is discussed. The developed model and approach provides more insight into the coupled
behavior of metal foam heat sinks by being able to calculate the developed
stresses due to the thermal loading of the heat sinks.
Fang et al. 5 developed a detailed 3D mesoscale
closed-cell metal foam model to and tested it under static and dynamic loadings
in a ?nite element frame of work.
The 3D model was developed using algorithms to generate the 3D convex polyhedrons
modeling the pores with random shapes in closed-cell metallic foams. The
effect of various parameters such as the pore size and pore density on the mechanical behavior was
studied and validated.
Another approach for developing closed cell
metal foam computational models was presented by Zheng et al. 6. In their
model, they created a nuclei and copied it as much as needed to construct the
Ji Li et.al 7 The spreading resistance in a heat sink base
with different contact areas and different heat transfer boundary conditions
has been investigated
numerically with a non dimensionalized 3D heat transfer model and the optimal
dimensionless base thickness were obtained.
From the numerical results, relations among
different heat transfer mechanisms (natural or forced, air or liquid),
different area ratios of a heat sink to a heating source, and the lowest
thermal resistance have been obtained and discussed.
Kim et al. 8 conducted an experimental
investigation on forced
air cooling by using manifold micro-channel heat sinks. They studied the effects of geometrical
parameters – primarily of the
heat transfer structure – on the thermal performance of the system and demonstrated a 35% lower thermal
resistance than that of a
traditional micro-channel heat sink.
Escher 9 The thermal performance of the heat sink was evaluated by a
three-dimensional model of a unit cell of the heat transfer structure. This
model was used to study the basic physical phenomena and to investigate the
sensitivity of the thermal and hydrodynamic performance of the heat sink on the
independent design parameters.
Ryu et al. 10 performed a three-dimensional analysis of the thermal
performance of a unit
cell 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 presenting
the industry with formidable challenges in maintaining processor temperatures
below critical values, in order
to circumvent a range of important failure modes, 11.
These challenges have stimulated a number of
cooling innovations, including the use of highly conductive inserts to provide more ef?cient pathways to heat
removal, 12, and a number of promising liquid cooling methods. The latter
include on-chip cooling, direct liquid jet impingement and di electric liquid
immersion which removes heat by convection currents .
Chen et al. 13 developed a
three-dimensional thermoelectric generator model in order to simplify the
design and optimization of the system and the thermoelectric device. The widely
used commercial code FLUENT and user-de?ned functions (UDFs) were used to model
the ?uid behaviors and thermoelectric power output. The 3D modelling results
provided detailed pro?les of the temperature, Seebeck potential, current
density, power, and ef?ciency.
Yang et al. 14 studied numerically the
optimization of the heat transfer characteristics and ?uid ?ow of air jet impingement on a rotating and a
stationary heat sink. They found that a heat transfer enhancement is noticeable
in the case of smaller Reynolds number (Re = 5019) and Nusselt number augments
with decreasing Reynolds number.
Min Seo et.al 15 In this study, a
thermoelectric cooler model with a heat sink was developed using CFD. A model
was developed with heat sinks. To investigate the effect of the various design
parameters of the heat sink, the heat transfer process was analyzed.
and Garimella 16 performed experimental and numerical investigations on the ?ow
?eld and pressure drop for water ?ow
in rectangular microchannels. It was found that the conventional correlations o?er
reliable predictions for the laminar ?ow.