[Lab_001]

Hi,
I am working on a project about welding. I use FLUENT vof to simulate the melting pool . During the calculation, I found that the surface tension define in my udf code have some problems and caused a whole area shape changing. Here is my code:
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DEFINE_PROPERTY(surf_tension,c,t)
{
real surf;
int curr,i,j;
real temp1=C_T(c,t);
if(temp1>=1700)
surf=1.0-0.0003*(temp1-1700);
else if(temp1>=2980)
surf=0.41;
else
surf=1.0;
return surf;
}
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My surface tension seems like effect all the areas when temp1>=1700 and causes a whole area shape changing to my model. I think it should only effect the cell temp1>=1700. Is there anyone know what happen to that?