Laser Die Thermal FEM

While investigating laser life I spent some time involved in the thermal analysis of the elements of the laser case. Not having any published data on the thermal performance of the laser die and case led me to develop a finite element thermal model (FEM) of the package. To do this I first needed to find FEM software within my budget. After looking at several commercial packages that were crippled for evaluation I settled on an Open Source code.

The software I settled on is actually multiple packages. The heart of the software is Elmer which is a 3D solver available both as a GUI and command line solver (http://www.csc.fi/english/pages/elmer). The input I use to Elmer is a mesh in *.unv format. I generate the mesh by importing *.step files into Salome (http://www.salome-platform.org/) and defining geometry groups then meshing.

For viewing the results there are post processors built into Elmer, or you can use ParaView (http://www.paraview.org/) which is also Open Source.

The ElmerSolver is a multiphysics solver with no limitations on the number of nodes other than the computing / memory limitations of your hardware. Even further Elmer evidently is capable of parallel computing.


Mesh



The figure on the right shows the mesh of the laser package.





Below are the postprocessing results for the thermal analysis showing the overall package and a close up of the die.

Overall





 

 





Die



Elmer has been used for both steady state and transient thermal analysis and has aided greatly in the understanding of the laser thermal performance. I'm a fan of Elmer.