# filling a tank with water

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June 11, 2014, 10:50
filling a tank with water
#1
New Member

ashwin
Join Date: Jul 2012
Location: erlangen
Posts: 26
Rep Power: 9
Hello,

I am trying to fill a tank with water as shown in the figure. The red line indicates the water inlet at t=0 and the green line indicates the air exit. The picture was taken at 46 secs with the timestep being 0.0001. I have been running the case for over two weeks and the water level stopped to be filled in as in the screenshot. I am using the following initial conditions.

alpha.water
Code:
```dimensions      [0 0 0 0 0 0 0];

internalField   uniform 0;

boundaryField
{
inlet
{
type            inletOutlet;
inletValue      uniform 1;
value           uniform 1;
}
outlet
{
}
walls
{
}
}```
p_rgh
Code:
```dimensions      [1 -1 -2 0 0 0 0];

internalField   uniform 0;

boundaryField
{
inlet
{
type            fixedFluxPressure;
value           uniform 0;
}

outlet
{
type            outletInlet;
outletValue	uniform 0;
value		uniform 0;
}

walls
{
type            totalPressure;
p0              uniform 0;
U               U;
phi             phi;
rho             rho;
psi             none;
gamma           1;
value           uniform 0;
}

}```
U
Code:
```dimensions      [0 1 -1 0 0 0 0];

internalField   uniform (0 0 0);

boundaryField
{
inlet
{
type           fixedValue;
value           uniform (2 0 0);
}

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

walls
{
type            fixedValue;
value           uniform (0 0 0);
}

}```
Can somebody indicate me where I am going wrong or tell me how to speed up the calculation.

Regards
Ashwin
Attached Images
 filling .jpg (12.9 KB, 238 views)

June 11, 2014, 19:11
#2
Senior Member

Wouter van der Meer
Join Date: May 2009
Location: Elahuizen, Netherlands
Posts: 198
Rep Power: 12
hello ashghan,
The problem is the pressure definition. The number of variables is not equal to the number of freedom. Your system needs a point where the pressure is known.
If you look at the angledDuct turorial and remove the viscosity things (in 0 dir two boundaries, in fvOptions remove all you have a working case. I did this with a simple form of your fueltank? It ran for less than 4 hours.
I enclosed my case, but I had to remove the mesh because of the size restrictions.

Hope this helps
Wouter
Attached Images
 time18_5.jpg (22.3 KB, 193 views)
Attached Files
 fueltank.tar.gz (2.5 KB, 159 views)

Last edited by wouter; June 15, 2014 at 19:00.

June 18, 2014, 09:28
#3
New Member

ashwin
Join Date: Jul 2012
Location: erlangen
Posts: 26
Rep Power: 9
Hey,

Yeah it works. Thanks

Quote:
 Originally Posted by wouter hello ashghan, The problem is the pressure definition. The number of variables is not equal to the number of freedom. Your system needs a point where the pressure is known. If you look at the angledDuct turorial and remove the viscosity things (in 0 dir two boundaries, in fvOptions remove all you have a working case. I did this with a simple form of your fueltank? It ran for less than 4 hours. I enclosed my case, but I had to remove the mesh because of the size restrictions. Hope this helps Wouter

August 21, 2017, 08:15
Help
#4
New Member

Join Date: Feb 2013
Posts: 22
Rep Power: 9
Hi,

I am trying to solve water filling bottle tutorial from long back (http://www.tfd.chalmers.se/~hani/kur...Hemida_VOF.pdf). I am not getting reasonable results.

I used inlet velocity as 0.1 m/sec. I am attaching my FOAM files. Please kindly let me know what mistake I am doing.
Attached Files
 bottlefill.zip (8.9 KB, 14 views)