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unexpected result => fluid is going out !

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Old   November 20, 2014, 05:38
Question unexpected result => fluid is going out !
  #1
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otadol
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Good morning everybody !

EDIT#3 : all I Need is some advise about my BCīs please !


Iīm doing my master Thesis on this software.

My Topic is about create an RTM simulation and validate the best solver I can use with.

I created a tank (at the bottom), a tube and plate (at the top) which is my composite.

http://i.imgur.com/Z2wUMpW.png => global view
http://i.imgur.com/hPLnPAU.png => top view (Composite plate)
http://i.imgur.com/T5ID7Mx.png => top view zoom (Composite plate)
http://i.imgur.com/SyjQN9l.png => bottom view (tank)


The meshing is OK as the checkMesh.

What I would like to simulate is : resin in the tank (alpha1) and put pressure on the bottom of the tank (inletWall) (here 3bars) to inject my resin into the Composite plate.

When I set reverse gravity g(0 0 9.81) I can get kind of results I would like to have into the composite plate.

But to be closer the reality I set normal gravity (0 0 -9.81) and I have unexpeted result : MY FLUID RUN AWAY BY THE BOTTOM OF THE TANK to completly disappear! instead of being pushed by the pressure and go into the composite plate

I tried many times to change setting like BCs but nothing change or not like I want. (FLUID is still running away by the bottom of the tank)

Iīm pretty sure my problem is due to bad BCs or may be the solverīsettings
Before trying porousInterFoam, Iīm using interFoam just to check the alpha1īs behavior.



I used to go on this usefull Forum to fix my problems, but this time I need to ask your help !

here my "0" files some from the "system" folder then the full folder.


ALPHA1 :

Code:
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object alpha;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 0 0 0 0 0 0];
internalField uniform 0;
boundaryField
{ 
inletWall
{
type inletOutlet;
inletValue uniform 0;
value uniform 0;
}
 
tankWall
{
type zeroGradient; //slip?
}
 
cylinderWall
{
type zeroGradient; //slip?
}
 
compositeWall
{
type zeroGradient;
}
 
outletWall //side composite wall
{
 
type inletOutlet;
inletValue uniform 0;
value uniform 0;
}
 
}
// ************************************************************************* //
p_rgh :

Code:
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object p_rgh;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [1 -1 -2 0 0 0 0];
internalField uniform 0;
boundaryField
{
inletWall
{
type fixedValue; 
value uniform 300000;
 
// type totalPressure;
// p0 uniform 0;
// U U;
// phi phi;
// rho rho;
// psi none;
// gamma 1;
// value uniform 300000; //-----------------------------------------
}
tankWall
{
type fixedFluxPressure;
value uniform 0;
}
cylinderWall
{
type fixedFluxPressure;
value uniform 0;
}
compositeWall
{
type fixedFluxPressure;
value uniform 0;
}
outletWall
{
type fixedValue; 
value uniform 0;
}
}
// ************************************************************************* //
U :

Code:
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
location "0";
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
dimensions [0 1 -1 0 0 0 0];
internalField uniform (0 0 0);
boundaryField
{
inletWall
{
type pressureInletOutletVelocity;
value uniform (0 0 0);
}
tankWall
{
type fixedValue;
value uniform (0 0 0);
}
cylinderWall
{
type fixedValue;
value uniform (0 0 0);
}
compositeWall
{
type fixedValue;
value uniform (0 0 0);
}
 
outletWall
{
type pressureInletOutletVelocity;
value uniform (0 0 0);
}
 
}
 
// ************************************************************************* //

EDIT #1 :
http://imgur.com/S5jJXAc actual simulation
http://imgur.com/WzacnsO expected
this difference is because the first one is not into a porous Zone.

EDIT #2 :
during Simulation there is an other stuff unexpected :
http://imgur.com/VTjR7rF

Looks like the fluid "splash" first on the Composite plate, creating lots of turbulences.

Do you think it is that?
May be is it better I try to start with the resin into the tube? or increase the pressure with the time, not 3 bars at the beginning (but I donīt know how to do)



I hope I have been clear about this post !
Can someone can show me or explain me how to fix up my problem?

Thank you very much.
Attached Files
File Type: zip RTMSimulationSave - original one.zip (11.8 KB, 4 views)

Last edited by cramsdead; November 27, 2014 at 10:51.
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Old   November 20, 2014, 07:29
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  #2
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Artem Shaklein
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cramsdead, hello.
What about resin density?
If | \rho g_z | > | \Delta p |, then pressure isn't enough to lift heavy weight.
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Old   November 20, 2014, 10:08
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  #3
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otadol
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Hello ARTem and thank for your reply.

I managed to "push" my resin into my composite plate but the result still unexpected if we compare to the reality.

http://imgur.com/S5jJXAc actual simulation
http://imgur.com/WzacnsO expected

do you have any idea what Parameter I have to Play on to have something better?

Thank you.
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Old   November 20, 2014, 23:57
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Artem Shaklein
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hello, cramsdead.

Is the mesh quality affects on your solution? Try coarser/finer one.
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Old   November 26, 2014, 08:13
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hello ARTem,

I donīt think the mesh quality really affect the results.

but first, can you validate my boundary conditions please?

Thank you
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