Capillary Rise With bubbe inside problem

block · February 8, 2016, 19:15

Hi Foamers,

I am trying to model capillary rise in interFoam however during my simulation in a capillary with diameter 1e-3m and height 30e-3 there seem to be bubbles appearing at the bottom which is very strange.

I just wanted to see if anyone has any idea why might that be? please see photo attached to see the bug.

Kind Regards

Rimsha

bubble.jpg

kmooney · February 11, 2016, 13:54

Hi Rimsha,

Whats your boundary condition settings at the inlet?

block · February 11, 2016, 14:51

Hi kmooney

thank you for the reply, i have the following inlet conditions:

alpha.water:

inlet
{
type inletOutlet;
value uniform 1;
inletValue uniform 1;
}

p_grh

inlet
{
type fixedValue;
value uniform 0;
}

velocity:

inlet
{
type pressureInletOutletVelocity;
value uniform (0 0 0);
}

kmooney · February 11, 2016, 14:52

I would retry the case with alpha inlet bc as fixedValue 1 (instead of inletOutlet) and see if that helps.

block · February 11, 2016, 15:57

Hiya,

I have tried that however the deltaT becomes very small and the simulation stops as co max is exceeded.

Therefore i am unable to get a solution.

Kind regards

Rimsha

kmooney · February 12, 2016, 00:08

Are you using setFields to set the first few cells in from the inlet to alpha=1? Some simulations have strange startup effects if there is an alpha=1 inlet and the cells just inside are alpha=0.

block · February 12, 2016, 10:26

Yes i am using setFields, are you suggesting i should not use fields or use either one?

February 8, 2016, 19:15	Capillary Rise With bubbe inside problem	#1
block New Member Rimsha Join Date: Jan 2016 Posts: 25 Rep Power: 10	Hi Foamers, I am trying to model capillary rise in interFoam however during my simulation in a capillary with diameter 1e-3m and height 30e-3 there seem to be bubbles appearing at the bottom which is very strange. I just wanted to see if anyone has any idea why might that be? please see photo attached to see the bug. Kind Regards Rimsha bubble.jpg

February 12, 2016, 00:08		#6
kmooney Senior Member Kyle Mooney Join Date: Jul 2009 Location: San Francisco, CA USA Posts: 323 Rep Power: 17	Are you using setFields to set the first few cells in from the inlet to alpha=1? Some simulations have strange startup effects if there is an alpha=1 inlet and the cells just inside are alpha=0. Lennart.H likes this.

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February 11, 2016, 13:54		#2
kmooney Senior Member Kyle Mooney Join Date: Jul 2009 Location: San Francisco, CA USA Posts: 323 Rep Power: 17	Hi Rimsha, Whats your boundary condition settings at the inlet?

February 11, 2016, 14:51		#3
block New Member Rimsha Join Date: Jan 2016 Posts: 25 Rep Power: 10	Hi kmooney thank you for the reply, i have the following inlet conditions: alpha.water: inlet { type inletOutlet; value uniform 1; inletValue uniform 1; } p_grh inlet { type fixedValue; value uniform 0; } velocity: inlet { type pressureInletOutletVelocity; value uniform (0 0 0); }

February 11, 2016, 14:52		#4
kmooney Senior Member Kyle Mooney Join Date: Jul 2009 Location: San Francisco, CA USA Posts: 323 Rep Power: 17	I would retry the case with alpha inlet bc as fixedValue 1 (instead of inletOutlet) and see if that helps.

February 11, 2016, 15:57		#5
block New Member Rimsha Join Date: Jan 2016 Posts: 25 Rep Power: 10	Hiya, I have tried that however the deltaT becomes very small and the simulation stops as co max is exceeded. Therefore i am unable to get a solution. Kind regards Rimsha

February 12, 2016, 10:26		#7
block New Member Rimsha Join Date: Jan 2016 Posts: 25 Rep Power: 10	Yes i am using setFields, are you suggesting i should not use fields or use either one?