Discussion Forum

Hi

you cannot change the topology = geometry shape, but you could try to change the the material density and other properties if the temperature goes above a given value, hence you bleaches and simulate material removal. But I'm not sure how to, perhaps following some of the ideas of the non linear variable from the model Library "Loaded_knee", a nice "topology Optimisation (without really changing the entity topology)

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Good luck
Ivar

Hi Ivar,

Thanks for the help.
That is a clever idea, I shall give it a go.

Regards,
Adam.

Hi,

Please tell me if you are successful as I am trying to model something very similar. I am new to the thermodynamic analysis in Comsol so the question might be basic. I think Ivar answered this in his post by stating that the density can be changed but just to be sure:

Can phase changes occur during the simulation?

For example. If water is heated to its boiling point by a source, you said that the density can be changed in Comsol to correspond to water vapor. However, there is also a change in vapor pressure which will result in some acoustic effects. Can vapor pressure also be changed in a similar way?

Pretty much, I'm trying to simulate the violent boiling of water with a temperature input and a pressure distribution output.

Thanks

For boiling, see this model
www.comsol.com/showroom/gallery/3972/

For the removing/adding material see this model:
www.comsol.com/showroom/gallery/2112/

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Niklas

Dear Ivar:

I'm doing the modeling of laser machining. I already have heat transfer model, in which I can see the temperature profile.

I would like to remove the elements which is above the vaporization temp of the material to actually see the material removal by laser machining but I don't know how to do this.

I'm already using the level set method to distinguish between liquid and solid phase but no sucess for vapour phase.

If required I can send you the model file.

Please guide me.

Hitesh

Hi,
do you solved the problem? I find a lot of papers use the ALE to track the moving boundary.
but after lot of tries(using the prescribed mesh displacement), only to fail. Could you mind giving me some tips?
Thanks. Best wishes to you and your family.

Dear Ivar:

I'm doing the modeling of laser machining. I already have heat transfer model, in which I can see the temperature profile.

I would like to remove the elements which is above the vaporization temp of the material to actually see the material removal by laser machining but I don't know how to do this.

I'm already using the level set method to distinguish between liquid and solid phase but no sucess for vapour phase.

If required I can send you the model file.

Please guide me.

Hitesh

I'm starting my modeling now in laser ablation of metals using COMSOL, if you have any material that help me please send it to me.

Regards,
Fatema

Hello Ivar,

I haved developed laser heating of a double layered material. Now I would like to remove some parts of top layered material. Can you please give me some idea in doing it.

Thanking you.

Meera kunden

Hello,

I have developed laser heating of a double layered material. Now I would like to remove some parts of top layered material. Can you please give me some idea in doing it.

Thanking you.

Meera kunden

Hello,

I have developed laser heating of a double layered material. Now I would like to remove some parts of top layered material. Can you please give me some idea in doing it.

Thanking you.

Meera kunden

Dear Meera

I am facing the same simulations than you. Did you solve the problem of removing parts?

Best wishes
Juan

hi , i am facing the same model is anyone would help me please?

maher

Here is a blog on thermal ablation that you may find helpful:
www.comsol.com/blogs/modeling-thermal-ablation-for-material-removal/
Best regards,
Jeff

Hello sir.

I am iterseted in the same as you already did. Can you tell me how to distingush between the solid and liquid? I am not interested in the evaporization. I am intersted in melting only.

Any documents or tutorials will be appreciated.

Thanks and best
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A. I. Gad