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Simulating laser heating of a sample

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Hi guys,

I am a completely new user of COMSOL. I am trying to simulate a cylindrical sample being heated up by a laser. I want to find the 3-D temperature distribution within the sample. What type of heat transfer boundary conditions and initial conditions would you suggest?

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What I tried and didn't work:

Boundary conditions:
1. Defined a Heat source at the beam spot with a total power.

Initial Conditions:
2. I defined an initial Tempearature to which the sample is preheated.

Materials:
1. Defined thermal conductivity
2. Defined density
3. Defined specific heat capacity

It does not converge.
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Any help would be much appriciated.

Thanks in advance,

Boyan

5 Replies Last Post 28 set 2014, 15:49 GMT-4

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Posted: 1 decade ago 9 lug 2012, 19:19 GMT-4
What may help: go to "Community" on the COMSOL website. In "Community" go to "model exchange." In the search window (magnifying glass) type laser. Close to the top of the listing is a simulation of the laser as a moving heat source. Also what I find interesting and very valuable is a 3D guassian Maxwell representation for a laser. The gaussian distribution seems to be a reasonable way to represent Maxwell's equations for a laser. If you have the rf module, importing this model should not be a problem.

If you have only thermal and mechanical, there should be no problem in importing the moving heating source.

Your email shows version 4.2a. You should be able to get version 4.3.

I am struggling to do laser sintering myself. Perhaps a discussion would be useful. I am somewhat new to COMSOL myself.

--
Arthur Rupel
arthur.rupel@us.army.mil
What may help: go to "Community" on the COMSOL website. In "Community" go to "model exchange." In the search window (magnifying glass) type laser. Close to the top of the listing is a simulation of the laser as a moving heat source. Also what I find interesting and very valuable is a 3D guassian Maxwell representation for a laser. The gaussian distribution seems to be a reasonable way to represent Maxwell's equations for a laser. If you have the rf module, importing this model should not be a problem. If you have only thermal and mechanical, there should be no problem in importing the moving heating source. Your email shows version 4.2a. You should be able to get version 4.3. I am struggling to do laser sintering myself. Perhaps a discussion would be useful. I am somewhat new to COMSOL myself. -- Arthur Rupel arthur.rupel@us.army.mil

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Posted: 1 decade ago 10 lug 2012, 14:05 GMT-4
Hey Arthur,

Your advice was immensely useful :). I managed to set up a simple simulation based on the "laser heating - self guided tutorial".

What exactly are you struggling with? Maybe I can ask some of my colleagues which are more proficient with the program for help.

Cheers,

Boyan
Hey Arthur, Your advice was immensely useful :). I managed to set up a simple simulation based on the "laser heating - self guided tutorial". What exactly are you struggling with? Maybe I can ask some of my colleagues which are more proficient with the program for help. Cheers, Boyan

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Posted: 1 decade ago 10 lug 2012, 14:23 GMT-4

This is a tough one:
1. em generating heat and structural deformations on an indiviudal and adjacent steel powder grains about 6 um.
There may be various phenomena involved: for example joule heating, the skin effect, the dominance in ferromagnetic grains to heating by the magnetic rather than electric fields., etc. Also what are the ideal frequencies for the laser for heating for these grains? My guess is to evaluate the natural frequencies of the grains and test these with similiar frequencies of the laser. If there are better methods, I would be interested.

2. The change of state of the grain during the heating, melting, and cooling processes. This again is a hard one.

Again I do not expect much since much of this is new.

Thanks,
--
Arthur Rupel
This is a tough one: 1. em generating heat and structural deformations on an indiviudal and adjacent steel powder grains about 6 um. There may be various phenomena involved: for example joule heating, the skin effect, the dominance in ferromagnetic grains to heating by the magnetic rather than electric fields., etc. Also what are the ideal frequencies for the laser for heating for these grains? My guess is to evaluate the natural frequencies of the grains and test these with similiar frequencies of the laser. If there are better methods, I would be interested. 2. The change of state of the grain during the heating, melting, and cooling processes. This again is a hard one. Again I do not expect much since much of this is new. Thanks, -- Arthur Rupel

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Posted: 1 decade ago 2 nov 2012, 07:05 GMT-4
Hi Arthur,

But does this "Laser Heating" package work on 4.1?
I tried, but it says ' ...created in a later version of comsol...'

thank you.
sankeerth.
Hi Arthur, But does this "Laser Heating" package work on 4.1? I tried, but it says ' ...created in a later version of comsol...' thank you. sankeerth.

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Posted: 1 decade ago 28 set 2014, 15:49 GMT-4
Hello,

I am Meera Kunden and I am beginner of COMSOL user. I would like develop a heat transfer to a stationary double layered material using moving laser. The laser is moving in meander shape. Can any one please suggest me how to set the path for the laser in meander shape.

With regards;
Meera
Hello, I am Meera Kunden and I am beginner of COMSOL user. I would like develop a heat transfer to a stationary double layered material using moving laser. The laser is moving in meander shape. Can any one please suggest me how to set the path for the laser in meander shape. With regards; Meera

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