[Beingzzz]

Dear all,I was planning to do some cylinder bypassing in the pipeline and first planned the 2D case with reference to wingmotion in pimpleFoam, but after a while I get the following error (forces forces: not including porosity effects)What changes should I make to improve this situation or have a better idea thanks.

/*--------------------------------*- C++ -*----------------------------------*\
========= |
\\ / F ield | OpenFOAM: The Open Source CFD Toolbox
\\ / O peration | Website: https://openfoam.org
\\ / A nd | Version: 7
\\/ M anipulation |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ("libsixDoFRigidBodyMotion.so");

motionSolver sixDoFRigidBodyMotion;

patches (scylinder);
innerDistance 10;
outerDistance 8;

mass 1;
centreOfMass (0 16.125 0.5);
momentOfInertia (1.958864357 3.920839234 2.057121362);

g (0 -9.81 0);
rho rhoInf;
rhoInf 1;
report on;


solver
{
type symplectic;
}

constraints
{

yAxis
{
sixDoFRigidBodyMotionConstraint axis;
axis (0 1 0);
}
}

restraints
{

axialSpring
{
sixDoFRigidBodyMotionRestraint linearAxialAngularSpring;

axis (0 1 0);
stiffness 700;
damping 0.5;
}
}

[Krapf]

Originally Posted by Beingzzz

but after a while I get the following error (forces forces: not including porosity effects)

This is not an error message. Take a look at the last few lines of the log file.

[Beingzzz]

Originally Posted by Krapf

This is not an error message. Take a look at the last few lines of the log file.

Thanks, you're right. This is the last picture in question. I then modified the mesh density, the mesh motion parameters of the moving mesh and the pressure solver in fvsolution, but it only advanced the calculation a little bit, and then the equation collapsed. Is it because of the wall, there is a size limit on the upload file and I can't show the full case. Thanks again.

--> FOAM FATAL ERROR:
Continuity error cannot be removed by adjusting the outflow.
Please check the velocity boundary conditions and/or run potentialFoam to initialise the outflow.
Total flux              : 1.92691e+06
Specified mass inflow   : 0
Specified mass outflow  : 56904.1
Adjustable mass outflow : 2.10588e-14


    From function bool Foam::adjustPhi(Foam::surfaceScalarField&, const volVectorField&, Foam::volScalarField&)
    in file cfdTools/general/adjustPhi/adjustPhi.C at line 107.

[Krapf]

I'm not sure if I can help you with that. What are your pressure/velocity boundary conditions at inlet and outlet? Does it run without this error if you deactivate the dynamic mesh?

[Beingzzz]

Originally Posted by Krapf

I'm not sure if I can help you with that. What are your pressure/velocity boundary conditions at inlet and outlet? Does it run without this error if you deactivate the dynamic mesh?

The same conditions I've run smoothly using icoFoam, I've posted the other setup files later. I have a feeling there is something wrong with the parameter settings. Anyway thank you very much.
fvsolusion

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  7
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
    
    object      fvSolution;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

solvers
{
     "pcorr.*"
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-05;
        relTol          0;
    }
    p
    {
        $pcorr;
        tolerance        1e-7;
        relTol           0.01;
    }

    pFinal
    {
        $p;
        tolerance        1e-7;
        relTol           0;
    }

    U
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-05;
        relTol          0;
    }
	
	UFinal
    {
        $U;
        tolerance       1e-05;
        relTol          0;
    }
	"(k|nut|omega)"
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-06;
        relTol          0.01;
    }

    "(k|nut|omega)Final"
    {
        $U;
        tolerance       1e-06;
        relTol          0;
    }
	cellDisplacement
    {
        solver          smoothSolver;
        smoother        symGaussSeidel;
        tolerance       1e-06;
        relTol          0.01;
    }
}


PIMPLE
{
    correctPhi          yes;
    nOuterCorrectors    2;
    nCorrectors         1;
    nNonOrthogonalCorrectors 0;
pRefCell 1001; 
pRefValue 0; 
}

relaxationFactors
{
    fields
    {
        p               0.3;
    }
    equations
    {
        "(U|k|omega)"   0.7;
        "(U|k|omega)Final" 1.0;
    }
}

cache
{
    grad(U);
}


// ************************************************************************* //

fvschemes

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  7
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/
FoamFile
{
    version     2.0;
    format      ascii;
    class       dictionary;
   
    object      fvSchemes;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

ddtSchemes
{
    default         Euler;
}

gradSchemes
{
    default         Gauss linear;
    grad(p)         Gauss linear;
	grad(U)         Gauss linear;
}

divSchemes
{
    default         none;
	div(phi,U)      Gauss linearUpwind grad(U);
    div(phi,k)      Gauss limitedLinear 1;
    div(phi,omega)  Gauss limitedLinear 1;
    div((nuEff*dev2(T(grad(U))))) Gauss linear;
}

laplacianSchemes
{
    default         Gauss linear limited corrected 0.5;
}

interpolationSchemes
{
    default         linear;
}

snGradSchemes
{
    default         corrected;
}

wallDist
{
    method meshWave;
}
// ************************************************************************* //

[mAlletto]

There is tutorial available which computes 2d vortex induced vibration (viv) of a circular cylinder in laminar flow:


https://wiki.openfoam.com/Vortex_ind...ichael_Alletto


This may be helpful

[ansab_sindhu]

Hi,

Your tutorial is quite helpful, How can we calculate phase angle in python?

Originally Posted by mAlletto

There is tutorial available which computes 2d vortex induced vibration (viv) of a circular cylinder in laminar flow:


https://wiki.openfoam.com/Vortex_ind...ichael_Alletto


This may be helpful

[mAlletto]

Which phase angle do you mean

[ansab_sindhu]

phase angle between the lift force vector and cylinder motion displacement.
(for 2Dof Motion). I heard one can calculate using Hilbert transform but I still need to learn.

Originally Posted by mAlletto

Which phase angle do you mean

[mAlletto]

Did you try to use the dot product to calculate the phase angle