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CyclicAMI: Problems with pressure field

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Old   September 20, 2012, 00:10
Default CyclicAMI: Problems with pressure field
  #1
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Thomas S
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Hello,

I am working with cyclicAMI boundary condition. But on the edges to other bcs I am getting weird results for the pressure field.
I have attached a screenshot to make my problem clear.

And that is the content of .../0/p:

PHP Code:
/*--------------------------------*- C++ -*----------------------------------*| =========                 |                                                 |
| \      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \    /   O peration     | Version:  2.0.1                                 |
|   \  /    A nd           | Web:      www.OpenFOAM.com                      |
|    \/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
FoamFile
{
    
version     2.0;
    
format      ascii;
    class       
volScalarField;
    
object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 100000;

boundaryField
{
inlet
{
       
type            zeroGradient;
}
outlet
{
        
type            fixedValue
        
value           uniform 100000;
}
wall
{
        
type            zeroGradient;
}
vane
{
        
type            zeroGradient;
}
side1
{
        
type            cyclicAMI;
}
side2
{
        
type            cyclicAMI;
}
inject
{
       
type            zeroGradient;
}
sym
{
    
type        slip;
}
hole
{
        
type            zeroGradient;
}
vane_inflow
{
        
type            zeroGradient;
}

Does anybody know what is wrong in my simulation? Thank you very much for your help!!

Regards, Thomas
Attached Images
File Type: jpg cyclic1.jpg (23.6 KB, 158 views)
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Old   September 21, 2012, 09:20
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Hugh Ingham
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I have a similar problem with my pressure field when I use cyclicAMI. Can I ask why you didn't just use cyclic conditions?
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Old   September 23, 2012, 21:58
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Thomas S
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Hey,

the cyclic Boundary condition never worked for me in this model. I had always mismatching problems with the mesh. (I am using Salome 6.3 for the mesh generation). But with AMI it seemed to work. Though it looks like that OpenFoam sets some default boundary conditions on the edges.

Does anyone knows how to solve this issue?
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Old   November 14, 2012, 04:41
Default Similar issue
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Hey Thomas,
Did you manage to solve your problem? I am having a very similar issue.
Javier
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Old   January 10, 2013, 15:15
Default cyclicAMI pressure boundary
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Shantan
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I have also the same problem! does somebody have any idea or could comment on it, if it would be a bug?!
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Old   January 10, 2013, 15:34
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Thomas S
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Hey,

no sorry, I never solved the problem. I just neglected it in the end....

But let me know if you find a solution!
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Old   January 11, 2013, 18:17
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I successfully used cyclicAMIs for turbomachinery flow simulation. I don't know, if you are using MRF. However, I experienced promblems when not correctly defining the "nonRotatingPatches" in the MRFDict.
Chandsome likes this.
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Old   January 24, 2013, 06:41
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Dongyue Li
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I am having a very similar issue too.....
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Old   February 21, 2013, 06:51
Default cyclicAMI for nonConformal meshes
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prasant
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Hello All,

Did anybody face an issue while using cyclicAMI on nonConformal Meshes?
My case is an impeller with volute also. Impeller is having pure Hexhedral and volute is having tetrahedral grid. I am giving cyclicAMI boundary condition for those interfaces.

I am giving mass flow at outlet and totalPressure at inlet.

By using the above settings, Mass is not balancing. The issue is, data is not transferring between these two interfaces. because of cyclicAMI.

And also Temperature values are not coming correct at outlet. Actually Ggi (OpenFOAM-1.6-Extd) is working fine with these settings. but here, Compressible solver with MRF is not available in this version. I modified the code. But there are some other issues.

So, Finally I came back to OpenFOAM current version (i.e) OF-2.1.1.

Please help me, If anybody success with cyclicAMI boundary conditon.

Regards
Prasant.
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Old   February 21, 2013, 12:04
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Can you post your boundary file and the weithing factors for your case?
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Old   February 22, 2013, 04:51
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Hello,

I am attaching my boundary file and weithing factors here:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class polyBoundaryMesh;
location "constant/polyMesh";
object boundary;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

8
(
r1-default
{
type wall;
nFaces 4176;
startFace 410703;
}
r1-hub
{
type wall;
nFaces 4914;
startFace 414879;
}
r1-inlet
{
type patch;
nFaces 864;
startFace 419793;
}
r1-shroud
{
type wall;
nFaces 4914;
startFace 420657;
}
s1-to-r1-side-2
{
type cyclicAMI;
nFaces 1008;
startFace 425571;
matchTolerance 0.0001;
neighbourPatch s1-to-r1-side-1;
transform noOrdering;

}
s1-default
{
type wall;
nFaces 16418;
startFace 426579;
}
s1-outlet
{
type patch;
nFaces 360;
startFace 442997;
}
s1-to-r1-side-1
{
type cyclicAMI;
nFaces 1926;
startFace 443357;
matchTolerance 0.0001;
neighbourPatch s1-to-r1-side-2;
transform noOrdering;

}
)

// ************************************************** *********************** //
and weithing factors are

Selecting thermodynamics package hPsiThermo<pureMixture<constTransport<specieThermo <hConstThermo<perfectGas>>>>>
AMI: Creating addressing and weights between 1008 source faces and 1926 target faces
AMI: Patch source weights min/max/average = 0.96403269, 1.0072789, 0.99952117
AMI: Patch target weights min/max/average = 0.83982674, 1.0035554, 0.99658895

Please view it and help me regarding this.

Thanks & Regards
Prasant
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Old   April 28, 2014, 09:25
Default No solution
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Víctor Mendoza García
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Hey Foamers...
Exactly the same here... and not solution. The edges take the pressure (atmospherical in my cases) and stays in a fixed value during all the simulation. This creates a non realistic field. Best regards,

Victor Mendoza
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Old   May 9, 2014, 10:05
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  #13
Ros
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Rostyslav Lyulinetskyy
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Hi,

I am having the same problem with the pressure field. I already tested it on a straight channel with cyclicAMI and cyclic BC's. Only with the cyclic BC the pressure field is correctly calculated.

My geometry is similar to the geometry posted by Thomas. So in my case only cyclicAMI can work.

Does anyone have an idea what to do?

Thanks
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Old   June 28, 2014, 08:34
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M. C.
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Hi all,

any news about cyclic AMI Problem?
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