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At Maryland based ATEC, a new heat transfer device is under development
that promises to deliver substantial performance improvements over
conventional heat sinks. The design combines a microgroove-surfaced heat sink
with fluid manifold cooling. A series of manifolds direct fluid in and out of
a section of the microgrooves, causing the fluid to vaporize and pass onto the
condenser before being recirculated.
Researchers are using Coolit to study how variations in microgroove
design impact its thermal-hydraulic performance, and how the various designs
stand up against the performance of a conventional straight finned heat sink
of identical volume. Further simulations seek to determine how parameters,
such as manifold spacing can be manipulated to optimize design performance.
Simulations are run over a range of inlet air velocities, and steady-state
temperatures and heat loads are used to calculate overall heat transfer
coefficients at each air flow rate. The heat transfer coefficient of the
micro-groove heat sink is much higher than that of the conventional heat sink,
and the pressure drop is higher across the manifolded micro-groove heat sink,
due to changes in air direction as air moves in and out of the micro-grooves.
Unlike conventional air-cooled heat sinks that have fairly simple
geometries, the manifold microgroove heat sink is more demanding on CFD
software. The microgroove geometry contains a much higher number of air
channels and even at high flow rates, the Reynolds number within the narrow
micro-grooves is low.
When comparing designs, researchers find Coolit saves them a significant
amount of time. It is fast and accurate, and unlike competitive software,
there is no need to export and convert data sets. Results can be quickly and
easily cut and pasted into a spreadsheet for comparison.
Accessing previously run files is also a snap-a fraction of a minute
compared to competitive software which could take up to 20 minutes to
retrieve. Furthermore, Coolit costs less than competitive offerings.
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