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IDProjectCategoryView StatusLast Update
0002977OpenFOAMBugpublic2018-06-11 11:04
Reporterameyv05 Assigned Tohenry  
PriorityhighSeveritymajorReproducibilityalways
Status closedResolutionno change required 
PlatformubuntuOS Version16.04 
Summary0002977: force coefficients not printed
DescriptionHello,

I am solving for a potential flow around an airfoil. I use the potentialFOAM solver and compute the flow.
When I try to compute the force coefficients, it runs but doesn't produce the force coefficient result. I have following things in my controlDict file and the force coefficients files:
functions
{
    #include "forceCoeffs"
};

forceCoeffs1
{
    type forceCoeffs;

    libs ("libforces.so");

    writeControl timeStep;
    timeInterval 1;

    log yes;

    patches (walls);
    rho rhoInf;
    rhoInf 1;
    liftDir (0 0 1);
    dragDir (1 0 0);
    CofR (0.72 0 0);
    pitchAxis (0 1 0);
    magUInf 10;
    lRef 1;
    Aref 1;
   
}
Earlier I thought, it wasn't reading the pressure and velocity values, so I had it in the file, but it doesn't help. Here is a part of the log file.

potentialFlow: Operating solver in PISO mode

Reading velocity field U

Constructing pressure field p

Constructing velocity potential field Phi

No MRF models present


Calculating potential flow
forces forceCoeffs1:
    Not including porosity effects
forceCoeffs forceCoeffs1:
    Not including porosity effect
TagsNo tags attached.

Activities

henry

2018-06-11 10:46

manager   ~0009733

Currently the forces and forceCoeffs functionObjects are not setup to operate on a potential solution. There is also an issue with time execution because the potential solver does not increment time but if you run

    postProcess -fields "(p U)"

you will see the fundamental problem

Executing functionObjects


--> FOAM FATAL ERROR:
No valid model for viscous stress calculation

    From function Foam::tmp<Foam::GeometricField<Foam::SymmTensor<double>, Foam::fvPatchField, Foam::volMesh> > Foam::functionObjects::forces::devRhoReff() const
    in file forces/forces.C at line 277.

ameyv05

2018-06-11 11:00

reporter   ~0009734

Thank you. I had a doubt it might not work for potential flow.

So, is there a work around for this problem?

Amey

henry

2018-06-11 11:04

manager   ~0009735

You will need to write a version of the forceCoeffs functionObject which operates on a potential solution.

henry

2018-06-11 11:04

manager   ~0009736

The forces and forceCoeffs functionObjects are not setup to operate on a potential solution.

Issue History

Date Modified Username Field Change
2018-06-11 10:05 ameyv05 New Issue
2018-06-11 10:46 henry Note Added: 0009733
2018-06-11 11:00 ameyv05 Note Added: 0009734
2018-06-11 11:04 henry Note Added: 0009735
2018-06-11 11:04 henry Assigned To => henry
2018-06-11 11:04 henry Status new => closed
2018-06-11 11:04 henry Resolution open => no change required
2018-06-11 11:04 henry Note Added: 0009736