Free surface problem: level set, kinematic free surface or ?

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sebastien ROUQUETTE
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Joined: 05 Nov 2011, 16:50
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Location: Nimes, France

Free surface problem: level set, kinematic free surface or ?

Post by sebastien ROUQUETTE »

Good evening dear community,

I'm still performing simulation about arc welding (GTAW one).

My simulation only takes into account heat transfer and fluid flow (see my old posts!).

So i would like to add a "free surface" on the top of the molten metal pool (or weld pool). The aim is to observe the shape of the molten pool under the pressure of electric arc and fluid force in molten pool.

As my problem is only 2D axi symmetric (static welding operation of few seconds), i can't use "kinematic free surface" that is made for 2D or 3D... I tried the "free surface with constant flux" but my normal is negative (to the free surface)... So i though to use the "level set method" but there no lots of posts about it.

I found 4 tests cases under the name "Level set {1, 2, 3a and 3b}... Level set can be used in 2D, 2D axi symmetric and 3D... so wonderful but i don't really understand how to use it correctly. i think that the "Level Set 2" test case was interesting for my application but i don't understand these things in the "fill.sif" file:
********************************************************************
In "material" section:
LevelSet Bandwidth = Real $ bw

Inside Viscosity = Real 1.0
Outside Viscosity = Real 0.1

Inside Density = Real 1.0
Outside Density = Real 0.1

Levelset Velocity 1 = Equals Velocity 1
Levelset Velocity 2 = Equals Velocity

what are the meaning of these parameters?
*****************************************************************
In "intial conditions", i see:
Surface = Variable Coordinate 1
Real MATC "tx-xinit"
******************************************************************
in "BC n°2":
Surface = Equals Surface

Why this sentence here?
********************************************************

I don't know if i can apply it to my case? if this approach is suitable.
Maybe, i have to work in 3D but the idea was to save some cpu time.

Cheers guys
Have a good week end
See you soon

PS: i attached the elmer test case called "levelset2"
Attachments
MyStuff.f90
(1.84 KiB) Downloaded 289 times
fill.sif
(3.04 KiB) Downloaded 276 times
fill.grd
(654 Bytes) Downloaded 275 times
Rouquette Sébastien
University of Montpellier / Mechanical and Civil Engineering Lab. / Welding Group
annier
Posts: 1168
Joined: 27 Aug 2013, 13:51
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Re: Free surface problem: level set, kinematic free surface or ?

Post by annier »

Hi Sebastien,
During my previous interaction with Peter regarding the use of Level set for distinguishing 2 phases, he had suggested me that Level set method has a lot of things to be done in Elmer for its general application. You can write to Peter for the details of the code so that it can be customized for your physical formulation.

Yours Sincerely,
Anil Kunwar
Anil Kunwar
Faculty of Mechanical Engineering, Silesian University of Technology, Gliwice
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