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When one of its telecommunications systems underwent a major
revision, Lucent enlisted Coolit to determine the impact on
thermal performance. The new board design had dramatically
boosted power levels on certain components and required six new
custom heat sinks to cool. Using Coolit, the company
successfully optimized these heat sinks, without relying on
prototypes.
Typically, each heat sink design/prototype/testing cycle
requires 4 weeks and thousands of dollars in material and labor
costs. With multiple heat sinks, this cost can severely restrict
the number of design scenarios, and make design optimization
prohibitive. Coolit eliminated this cost and schedule bind.
Modeling the system with over ten heat sinks with fins as thin as
0.008" (0.2 mm) proved complicated and porous media models of
heat sinks were used to keep design iterations within one day. However, developing
porous media models required time and as always happens with
lumped parameter models it resulted in a loss of detail. For
example, in pin-fin heat sinks, the model will deliver the
correct flow and heat transfer through the heat sinks, but not
a description of flow and heat transfer between the
individual fins. Even with this simplified modeling, Coolit
still predicted temperature and flow conditions to within better
than 10%.
The problems of lumped parameter models have been eliminated
with the new embedded mesh technology found in Coolit v5.0. The
new technology enabled the modeling of all heat sinks and other
components without any approximations thereby eliminating the
time required to build compact models of components. The model
fidelity and hence predictive accuracy were increased while
still delivering order of magnitude increases in calculation
speeds. Revisiting the Lucent design using embedded mesh
technology resulted in about 4 hours per iteration (vs the
original 24).
Lucent greatly values Coolit's exceptional ease-to-use and
its short learning curve. The mechanical design group does not
have a dedicated thermal designer, and when a new project comes
along, engineers can start using the software immediately - no
training or retraining is required.
Lucent uses Daat customer support as a valuable resource for
prompt and knowledgeable answers. The company has frequently
asked the support engineers to critique its thermal models. And
Lucent has been pleased to find that Daat takes suggestions
seriously. Coolit v5.0 contains a library of filters that were
added based on a Lucent suggestion. With this library, an
engineer can select an air filter element by company name and
have the filter parameters entered automatically.
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