Abstract: Frostytech departs from the usual pixel fodder for a brief look at some cooling technologies you have never seen before. We touch on some fun tests from the unpublished Frostytech archives and collect all the thermodynamics research we've reported on into one location.
Annex C) Heat Exchangers, Microchannel, Capilliary, Spray Watercooling
NASA Radial Heat Exchanger For Watercooling
Engineers working for
NASA have developed a new kind of Radial Flow Heat exchanger with a
"thermal effectiveness of 0.99 with a mass of only 2.5 kg and a fractional
pressure drop of only 6 percent." The device is produced by Creare, Inc.
who specialize in fluid dynamics and heat transfer. It would be
interesting to see if this kind of device is adaptable to PC cooling.
| Wire Mesh Heatsinks: Screen-fin Technology
In this paper by Chen Li and R. A. Wirtz, entitled "Development of a High Performance Heat Sink Based on
Screen-Fin Technology", a novel high-performance heat sink based
on screen-fin technology is outlined and tested for effectiveness.
The picture above shows top and side views of a simple screen-fin heat
sink - a heatsink whose cooling fins are made from sections of copper
screen soldered to a copper base plate. The heatsinks' fin structure
consists of a screen-fin oriented perpendicular to the heat sink base, and
laid out in a serpentine arrangement so there is a very big surface area
and a reasonable pressure drop.
"The tests show that coolant pressure drop and Stanton
number are sensitive to the angle of incidence of the superficial mass
velocity. The modified friction factor is found to increase rapidly as 0,
while the modified Colburn -factor is observed to become small. As a
consequence, configurations with 90 will maximize the heat transfer rate
while they minimize coolant pressure drop. On the other hand,
configurations having 90 generally present a minimum heat transfer surface
"The design attributes of a air-cooled heat sink with a
footprint of 76.2 mm 63.5 mm (3 2.5 ) and 38.1 mm (1.5 ) tall screen-fins
deployed as multiple rows in a serpentine configuration is investigated.
The design is optimized to operate at 62 Pa (0.25 in H O). The overall
conductance is found to be 4.3 W C with 8 l/s coolant consumption."
This is quite an
interesting approach into a method of enhancing cooling fins I haven't
seen commercially attempted before... you can find a listing of other
papers by Richard A. Wirtz here
that expand upon the theme of screen laminates, meshes, and lattices as
heat exchanger surfaces.
|Silicon loop heat pipe wicks:|
NASA: "The University of Cincinnati, along with Texas A
& M, Thermacore, GRC and LaRC, has pioneered the macro-porous silicon
wet-etching process, and has performed preliminary testing to demonstrate
the concept of a silicon loop heat pipe wick. This ability to fabricate a
loop heat pipe in silicon would allow a very small temperature drop
between the die and the ultimate heat sink, the radiator. Current
radiators for space applications typically operate at the box baseplate
temperature, which is near 25 °C.
If a space-based radiator could operate at a much higher temperature,
say, at the temperature of a die (~ 125 °C), the radiator weight savings
would be substantial, since thermal radiation heat transfer is a function
of temperature to the fourth power."
|Liquid Cooling Technique Uses Microfluidic
"A new technique for fabricating liquid cooling channels onto the backs of
high-performance integrated circuits could allow denser packaging of chips
while providing better temperature control and improved reliability. In
addition to the cooling channels, the researchers have also built
through-chip holes and polymer pipes that would allow the on-chip cooling
system to be connected to embedded fluidic channels built into a printed
wiring board. They have already demonstrated that the on-chip microfluidic
channels can be connected at the same time the IC is connected
electronically – using a conventional automated process known as flip-chip
Cryo Tech and New Cooling Technologies You Have Never Seen
2: Thermoacoustic Cooling
3: Phase Change Waterchilling
4: Conduction PCB Cooling via Cold Plate Heat Exchangers
5: The Stirling Cycle Cryo Cooler
6: Annex. A) Graphite, Carbon Foam/Fiber, Polymer Heatsinks
7: Annex A) Graphite, Carbon Foam/Fiber, Polymer Heatsinks
8: Annex B) Diamond, Nano-structure and Metal Foam Heatsinks
9: Annex B) Diamond, Nano-structure and Metal Foam Heatsinks
10: — Annex C) Heat Exchangers, Microchannel, Capilliary, Spray Watercooling
11: Annex C) Heat Exchangers, Microchannel, Capilliary, Spray Watercooling
12: Annex C) Heat Exchangers, Microchannel, Capilliary, Spray Watercooling
13: Annex D) Computational Fluid Dynamics and Innovative Heatsink Tech
List all Frostytech.com heat sinks that Frostytech tested?
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