I am using pimpleFoam with this fvSolution: p { solver PBiCGStab; preconditioner FDIC; tolerance 1e-4; relTol 0.01; } pFinal { $p; tolerance 5e-5; relTol 0; } "(U|k|omega)" { solver PBiCGStab; preconditioner DILU; tolerance 1e-06; relTol 0.1; } "(U|k|omega)Final" { solver PBiCGStab; //smoothSolver; preconditioner DILU; //symGaussSeidel; tolerance 1e-06; relTol 0; } } PIMPLE { correctPhi no; nOuterCorrectors 50; nCorrectors 2; nNonOrthogonalCorrectors 2; pRefCell 1001; pRefValue 0; residualControl { p { tolerance 5e-3; relTol 0; } } } potentialFlow { nNonOrthogonalCorrectors 20; } relaxationFactors { fields { p 0.7; pcorr 0.7; } equations { "(k|omega|U)" 0.7; "(k|omega|U)Final" 1; } }