# how I can increase the accuracy of flow pressure ?

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 September 20, 2013, 16:40 how I can increase the accuracy of flow pressure ? #1 Senior Member   Join Date: Jun 2011 Posts: 151 Rep Power: 7 i all I have simulated flow around a cylinder by OF and FLUENT In both software, I use a high quality and fine structure mesh which lead to y+<5 over walls and use Kw-sst model also the setting for OF and FLUENT is as follow FLUENT BCs: inlet ========> velocity inlet U=7m/sec k=.2 omega=170 outlet=======> pressure outlet FLUENT settigs solver =============> PISO residual=1e-5 In OF I have used pimpleFoam and setting are as follow any help will be appreciated Code: ```object k; dimensions [ 0 2 -2 0 0 0 0 ]; internalField uniform 0.2; boundaryField { outlet { type zeroGradient; } inlet { type fixedValue; value uniform .2; } circle { type kLowReWallFunction; value uniform 1e-6; } frontAndBackPlanes { type empty; }``` Code: ``` object omega; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [ 0 0 -1 0 0 0 0 ]; internalField uniform 170; boundaryField { outlet { type zeroGradient; } inlet { type fixedValue; value uniform 170; } circle { type omegaWallFunction; value uniform 1e-6; }``` Code: ``` object U; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [ 0 1 -1 0 0 0 0 ]; internalField uniform ( 0 0 0 ); boundaryField { } circle { type fixedValue; value uniform ( 0 0 0 ); } wall { type fixedValue; value uniform ( 0 0 0 ); } inlet { type fixedValue; value uniform ( 7. 0 0 ); } outlet { type zeroGradient;``` Code: ``` object nut; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // dimensions [ 0 2 -1 0 0 0 0 ]; internalField uniform 0; boundaryField { wallup { type nutUSpaldingWallFunction; value uniform 0; } wallp { type nutUSpaldingWallFunction; value uniform 0; } outlet { type calculated; value uniform 0; } inlet { type calculated; value uniform 0; } circle { type nutUSpaldingWallFunction; value uniform 0; }``` Code: ``` object fvSchemes; } // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // ddtSchemes { default Euler; } gradSchemes { default Gauss linear ; } divSchemes { default none; div(phi,U) Gauss limitedLinearV 1; div(phi,k) Gauss limitedLinear 1;// div(phi,omega) Gauss limitedLinear 1;// div((nuEff*dev(T(grad(U))))) Gauss linear; div((nuEff*dev(grad(U).T()))) Gauss linear; } laplacianSchemes { default Gauss linear corrected; } interpolationSchemes { default linear; } snGradSchemes { default corrected; } fluxRequired { default no; // pcorr ; p; }``` Code: ```solvers { p { solver GAMG; tolerance 1e-5; relTol 0; smoother GaussSeidel; nPreSweeps 1; nPostSweeps 2; cacheAgglomeration true; directSolveCoarsest true; agglomerator faceAreaPair; nCellsInCoarsestLevel 100; mergeLevels 1; minIter 1; } pFinal { solver GAMG; tolerance 1e-9; relTol 0; smoother GaussSeidel; nPreSweeps 1; nPostSweeps 2; cacheAgglomeration true; agglomerator faceAreaPair; nCellsInCoarsestLevel 100; mergeLevels 1; minIter 1; } "(U|k|omega)" { solver smoothSolver; smoother GaussSeidel; tolerance 1e-5; relTol 0; nSweeps 1; minIter 1; } "(UFinal|kFinal|omegaFinal)" { solver smoothSolver; smoother GaussSeidel; tolerance 1e-6; relTol 0.0; nSweeps 1; minIter 1; } } PIMPLE { nOuterCorrectors 4; nCorrectors 2; nNonOrthogonalCorrectors 3; pRefCell 0; pRefValue 0; correctPhi no; // momentumPredictor yes;```