Learning Forum

[waqas12345]

Hello everyone. I am trying to simulate a laser welding process using VOF/energy/laminar flow/melting and solidfication.

I have used two phases in my simulation. One is a gas at the top and another is a aluminum solid at the bottom.

Regarding the surface tension at the interface between these two phases, I want to ask that whether the surface tension as a source term is added by the fluent solver itself or we have to make UDF for that?

I went through the theory guide where some description about normal component of the surface tension was given. Also, it was mentioned that tangential surface tension is also added by the fluent solver but the description was not given.

Due to restriction about posting any snapshot of related fluent documentation, I am attaching an image from the research manuscript.

[aitor.amatriain]

You have all the details available in the Fluent User's Guide:
14.3.9. Surface Tension and Adhesion (ansys.com)

[waqas12345]

Thanx for your reply .
Is it a user guide or theorey guide? I guess you are pointing towards the clause 18.3.9 which is actually in theory guide.

[aitor.amatriain]

Yes, that was my mistake

[Rob]

In general the Theory Guide covers the maths and the User's Guide tells you where to find the buttons.

[waqas12345]

Thanx Rob...Actually I want to ask that does Fluent itself adds normal and tangential component of surface tension or we have to make a UDF to be added into momentum source term?

[Rob]

It does what it says in the documentation, I can't comment beyond that. is free to do so as they're not Ansys staff.

[aitor.amatriain]

from the link that I posted I see that ANSYS Fluent does not consider thermocapillary forces, so you have to include it by means of a source term in the momentum equation.

[waqas12345]

Thanx Rob and Aitor.

[aitor.amatriain]

You are welcome!