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Modeling Laser with changing focal distance and position

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Hello All,

I am extremely new to Comsol and have a few questions I put what I think is the most difficult in the title.

I have 2 materials which are in contact, I want to model heating up one of these materials with a laser, modeled as a truncated cone with an elliptical cross-section. I want to be able to vary both the distance the beam is from the boundary and the distance of the focal point from the surface.

In addition I wanted to simulate the contact resistance between the pressed surfaces.

Does anyone have a suggestion for how to do either of these?

Thank you,

John

1 Reply Last Post Apr 14, 2011, 2:39 p.m. EDT
Ivar KJELBERG COMSOL Multiphysics(r) fan, retired, former "Senior Expert" at CSEM SA (CH)

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Posted: 1 decade ago Apr 14, 2011, 2:39 p.m. EDT
Hi

I believe you should start by sorting out your model and chopping it into smaller sections, oner physics a time, you talk about contact pressure and related (heat?) conduction, of heating due to incident radiation, and of optical propagation. These can, and in my view, be treated separately, to check that they solve correctly, BEFORE you mix them. In my experience, this is the quickest way, even if the route seems longer.

Questions you should ask yourself, and scribble down on a piece of paper are sketch of the volumes involved, input output energy flux, material constants needed, then decide 2D/3D (the first is the easiest to start with), what kind of mesh denisty and time stepping, for each case etc. I can only suggest to start without the RF as modelling the optics is tricky and RAM demanding, hence also slow to simulate hence lengthy to debug. RF/optics could be left for the desert ;)

--
Good luck
Ivar
Hi I believe you should start by sorting out your model and chopping it into smaller sections, oner physics a time, you talk about contact pressure and related (heat?) conduction, of heating due to incident radiation, and of optical propagation. These can, and in my view, be treated separately, to check that they solve correctly, BEFORE you mix them. In my experience, this is the quickest way, even if the route seems longer. Questions you should ask yourself, and scribble down on a piece of paper are sketch of the volumes involved, input output energy flux, material constants needed, then decide 2D/3D (the first is the easiest to start with), what kind of mesh denisty and time stepping, for each case etc. I can only suggest to start without the RF as modelling the optics is tricky and RAM demanding, hence also slow to simulate hence lengthy to debug. RF/optics could be left for the desert ;) -- Good luck Ivar

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