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New Member
Tommaso Pascon
Join Date: Mar 2016
Posts: 18
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Hello everyone,
I'm trying to simulate a 2D VAWT based on the following paper: http://docsdrive.com/pdfs/ansinet/jest/2011/302-312.pdf Turbine diameter: 8m NACA2415, chord length 1m; Vfree = 4 m/s; TSR = 1.5 = omega Turbulence model RNG Kepsilon with wall function. I see that I have similar values for the highest torque (around 80Nm) while I also get negative values in some regions. Since I'm noticing this as a common behavior in all my simulations, what could be the cause of this negative torque? ![]() If someone can give me some tips would be much appreciated. U Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volVectorField; object U; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 1 -1 0 0 0 0]; internalField uniform (0 0 0); boundaryField { sides { type empty; } blades { type movingWallVelocity; value uniform (0 0 0); } inlet { type fixedValue; value uniform (4 0 0); } bottom { type symmetryPlane; } outlet { type zeroGradient; } top { type symmetryPlane; } #include "include/ami" } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; object p; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -2 0 0 0 0]; internalField uniform 0; boundaryField { sides { type empty; } blades { type zeroGradient; } inlet { type zeroGradient; } bottom { type symmetryPlane; } outlet { type fixedValue; value uniform 0; } top { type symmetryPlane; } #include "include/ami" } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object k; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -2 0 0 0 0]; internalField uniform 0.0615; boundaryField { sides { type empty; } blades { type kqRWallFunction; value uniform 0.0615; } inlet { type fixedValue; value uniform 0.0615; } bottom { type symmetryPlane; } outlet { type zeroGradient; } top { type symmetryPlane; } #include "include/ami" } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object epsilon; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -3 0 0 0 0]; internalField uniform 0.036; boundaryField { sides { type empty; } blades { type epsilonWallFunction; value uniform 0.036; } inlet { type fixedValue; value uniform 0.036; } bottom { type symmetryPlane; } outlet { type zeroGradient; } top { type symmetryPlane; } #include "include/ami" } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.3.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class volScalarField; location "0"; object nut; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [0 2 -1 0 0 0 0]; internalField uniform 0; boundaryField { sides { type empty; } blades { type nutkWallFunction; value uniform 0; } inlet { type calculated; value uniform 0; } bottom { type symmetryPlane; } outlet { type calculated; value uniform 0; } top { type symmetryPlane; } #include "include/ami" } // ************************************************************************* // Code:
//c++ ami00 { type cyclicAMI;value $internalField; } ami01 { type cyclicAMI;value $internalField; } //ami10 { type cyclicAMI;value $internalField; } //ami11 { type cyclicAMI;value $internalField; } Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.4.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; location "constant"; object dynamicMeshDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dynamicFvMesh dynamicMotionSolverFvMesh; motionSolver solidBody; cellZone rotor; solidBodyMotionFunction rotatingMotion; origin (0 0 0); axis (0 0 1); omega 1.5; //14.96 rad/s // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 1.5 | | \\ / A nd | Web: http://www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; object fvSolution; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // myPTolerance 1e-4; myTolerance 1e-10; myRelaxation 1; solvers { "(p|pFinal|pcorr)" { solver GAMG; mergeLevels 1; smoother GaussSeidel; agglomerator faceAreaPair; nCellsInCoarsestLevel 1500; tolerance $myPTolerance; relTol 0; } "(U|UFinal|k|kFinal|omega|omegaFinal|epsilon|epsilonFinal|nuTilda|nuTildaFinal)"//epsilon|R { solver smoothSolver;//PBiCG smoother GaussSeidel;//preconditioner DILU; tolerance $myTolerance; relTol 0; } } PIMPLE { correctPhi no; nOuterCorrectors 1; nCorrectors 3; nNonOrthogonalCorrectors 1; pRefCell 0; pRefValue 0; } relaxationFactors { fields { p $myRelaxation; } equations { k $myRelaxation; U $myRelaxation; omega $myRelaxation; epsilon $myRelaxation; nuTilda $myRelaxation; } } // ************************************************************************* // Code:
/*--------------------------------*- 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 dictionary; object fvSchemes; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ddtSchemes { default Euler; } gradSchemes { default Gauss linear; grad(p) Gauss linear; grad(U) Gauss linear; } divSchemes { default none;//Gauss linearUpwind leastSquares; //div(phi,U) Gauss linearUpwind grad(U); div(phi,U) Gauss upwind; //div(phi,U) Gauss linearUpwind leastSquares;//upwind;//linearUpwind grad(U); div(phi,nuTilda) Gauss upwind;//linearUpwind leastSquares;//upwind;//limitedLinear 1; div(phi,k) Gauss upwind;//linearUpwind leastSquares;//upwind;//limitedLinear 1; div(phi,omega) Gauss upwind;//linearUpwind leastSquares;//upwind;//limitedLinear 1; div(phi,epsilon) Gauss upwind;//linearUpwind leastSquares;//upwind; div((nuEff*dev2(T(grad(U))))) Gauss linear; } laplacianSchemes { default Gauss linear limited 1; } interpolationSchemes { default linear; } snGradSchemes { default corrected; } fluxRequired { default no; pcorr; p; } // ************************************************************************* // Code:
/*--------------------------------*- C++ -*----------------------------------*\ | ========= | | | \\ / F ield | OpenFOAM: The Open Source CFD Toolbox | | \\ / O peration | Version: 2.4.0 | | \\ / A nd | Web: www.OpenFOAM.org | | \\/ M anipulation | | \*---------------------------------------------------------------------------*/ FoamFile { version 2.0; format ascii; class dictionary; location "system"; object controlDict; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // applicationClass pimpleDyMFoam; startFrom latestTime; endTime 83; stopAt endTime; deltaT 1; writeControl adjustableRunTime; writeInterval 5; cycleWrite 0; writeFormat ascii; writePrecision 6; writeCompression uncompressed; timeFormat general; timePrecision 6; runTimeModifiable yes; adjustTimeStep yes; maxCo 1; maxDeltaT 0.023; functions { blades { patches (blades); CofR (0 0 0); //Origin for moment calculations outputControl timeStep;outputInterval 2; type forces;functionObjectLibs ("libforces.so");pName p;UName U;rho rhoInf;rhoInf 1.225;log true; } forceCoeffs { type forceCoeffs; functionObjectLibs ( "libforces.so" ); outputControl timeStep; outputInterval 2; patches ( "blades" ); pName p; UName U; rho rhoInf; log true; liftDir (0 1 0); dragDir (1 0 0); CofR (0 0 0); pitchAxis (0 0 1); magUInf 4; rhoInf 1.225; lRef 4; Aref 8; } // ************************************************************************* // |
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