CFD software solves LED heat problem

Tag : v3 housing

Thermal design typically represents the greatest challenge in LEDsystem design projects because 75 to 85% of the energy used todrive LEDs is converted to heat and must be conducted from the LEDdie.

"The lighting systems manufacturer built a prototype of theirdesign and discovered that the temperature of the LED quickly roseabove its maximum operating temperature", said Koen Beyers,President of Voxdale.

"Who knows how long it would have taken them to solve the problemby modifying and re-testing the prototype until they found a designthat worked".
"The big problem with this approach is that you don't have any ideawhat is causing the problem so you are essentially flailing aroundin the dark".

"In the past, CFD required the user to have a deep understanding ofthe computational aspects of fluid dynamics in order to be certainof obtaining accurate results", Beyers said.

"But in the last few years a new generation of CFD software hasbeen introduced that eliminates the need for engineers to masterthe computational part of CFD and instead allows them to focus onthe fluid dynamics of the product".

"EFD.Pro, the CFD software that we use, uses native Pro/Engineercomputer-aided design (CAD) data and automatically grids the flowspace and manages flow parameters as object-based features".

Beyers modelled the prototype using Pro/Engineer and entered thematerials properties and boundary conditions required for CFDsimulation.
Defining all of the information needed to convert the CAD geometry to a CFD model took about 30 minutes.
Then Beyers gave the command for the CFD software to mesh the fluidpath around and through the housing.

The simulation results showed the original designers had notprovided enough outlets to enable the air to flow freely throughthe housing.
Beyers modified the design to increase the outlet area whilekeeping in mind that the manufacturers wanted to minimise theirsize for aesthetic reasons.
His new design increased the flow through the housing whileensuring that air stayed in the housing long enough forconsiderable heat to be transferred to it.
He also tried a few different variants of the heat sink to optimisetheir geometry in order to reduce the size of the outlets.

The new design met all of the client's requirements. Request a free brochure from Flomerics ...
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