[WhiteW]

Hi to everybody.
I'm running some simulation on an airplane using both Fluent and OpenFoam 2.3.0 in order to do a comparison. I'm using the compressible solver rhoSimplecFoam and I have found a resolution strategy for OF in order to obtain a convergence:
- 100 iterations with energy equation deactivated (through fvOptions)
- first order schema until the residual are 1e-4
- second-like order schema
This strategy grants me a good accordance in the global pressure and velocity fields. The pressure field on the airplane surfaces also seems to be correct.
However the force coefficients, the drag and lift forces are very different in OpenFoam and I don't understand the reason. I attached an image of the force report for Fluent and OpenFoam analysis(I converted the OF results in fluent format using foamMeshToFluent and foamDataToFluent commands).
I report the setting used in controlDict, fvSolution and fvSchemes.
The boundary I'm using are:
p - inlet: totalPressure - outlet: fixedValue
U - inlet_ pressureInletVelocity - outlet: pressureInletOutletVelocity
T - inlet: totalTemperature - outlet: inletOutletTotalTemperature
Turbulence model - the k-omega SST.
Has someone some advice in order to fit the forces output?
Thanks in advance,
[WhiteW

ControlDict

application     rhoSimpleFoam;
startFrom       latestTime;
startTime       0;
stopAt          endTime;
endTime         6000;
deltaT          1;
writeControl    timeStep;
writeInterval   200;
purgeWrite      0;
writeFormat     ascii;
writePrecision  9;
writeCompression off;   
timeFormat      general;
timePrecision   9;
graphFormat     raw;
runTimeModifiable true;
libs
(
 "libforces.so"
 );
functions
{
	forces
	{
		type forces;
		functionObjectLibs ( "libforces.so" );
		outputControl timeStep;
		outputInterval 1;
		patches
			(
			 wall_fuselage
			 wall_nose
			 wall_sponson
			 wall_junction
			 wall_tail
			 wall_wing_nacelle
			 wall_nacelle
			 wall_pianetto_orizzontale1
			 wall_raccordo_pianetti
			 wall_pianetto_verticale
			);
		pName p;
		UName U;
		rhoName rhoInf;
		log true;
		rhoInf 1.16;
		CofR (0.98460 0 0.35195);            
		pitchAxis (0 -1 0);
	}
}

fvOptions

source1
{
    type            temperatureLimitsConstraint;
    selectionMode   all;
    active          true;

        temperatureLimitsConstraintCoeffs
        {
            Tmin     294.18;
            Tmax     294.19;
        }
}

fvSchemes 1st order:

ddtSchemes
{
	default             steadyState;
}

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

divSchemes
{
	default             bounded Gauss upwind;
	div(phi,U)          bounded Gauss upwind;
	div((muEff*dev2(T(grad(U)))))      Gauss linear;
}

laplacianSchemes
{
	default Gauss linear corrected;
}

interpolationSchemes
{
	default         linear;
}

snGradSchemes
{
	default         corrected;
}

fluxRequired
{
	default         no;
	p;
}

fvSchemes 1st-2nd order

ddtSchemes
{
	default             steadyState;
}

gradSchemes
{
	default             cellLimited Gauss linear 1;
	grad(U)             cellMDLimited Gauss linear 1;
}

divSchemes
{
	default             bounded Gauss linearUpwind cellLimited Gauss linear 1;
	div(phi,U)          bounded Gauss linearUpwindV cellMDLimited Gauss linear 1;
	div((muEff*dev2(T(grad(U)))))      Gauss linear;
}

laplacianSchemes
{
	default Gauss linear corrected;
}

interpolationSchemes
{
	default         linear;
}

snGradSchemes
{
	default         corrected;
}

fluxRequired
{
	default         no;
	p;
}

fvSolution

solvers
{
p
    {
        solver          GAMG;
        tolerance       1e-09;
        relTol          0.1;
        smoother        GaussSeidel;
        cacheAgglomeration off;
        nCellsInCoarsestLevel 800;
        agglomerator    faceAreaPair;
        mergeLevels     1;
        maxIter         40;
    }
rho
    {
        solver          GAMG;
        tolerance       1e-09;
        relTol          0.1;
        smoother        GaussSeidel;
        cacheAgglomeration false;
        nCellsInCoarsestLevel 800;
        agglomerator    faceAreaPair;
        mergeLevels     1;
        maxIter         20;
    }
U
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps 	2;
        tolerance       1e-09;
        relTol          0.1;
        maxIter         40;
    }

h
    {
        solver          PBiCG;
        preconditioner  DILU;
        tolerance       1e-09;
        relTol          0.1;
        maxIter         20;
    }
k
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps 	2;
        tolerance       1e-09;
        relTol          0.1;
        maxIter         20;
    }
omega
    {
        solver          smoothSolver;
        smoother        GaussSeidel;
        nSweeps 	2;
        tolerance       1e-09;
        relTol          0.1;
        maxIter         20;
    }
e  
    {
        solver          GAMG;
        tolerance       1e-08;
        relTol          0.1;
        smoother        GaussSeidel;
        nPreSweeps      0;
        nPostSweeps     2;
        nFinestSweeps   2;
        cacheAgglomeration true;
        nCellsInCoarsestLevel 800;
        agglomerator    faceAreaPair;
        mergeLevels     1;
    }
}

SIMPLE
{
    nNonOrthogonalCorrectors 4;
    pMin            pMin [1 -1 -2 0 0 0 0] 90000;
    pMax            pMax [1 -1 -2 0 0 0 0] 105000;
    rhoMin          rhoMin [1 -3 0 0 0 0 0] 1.12; //then changed to 1.08
    rhoMax          rhoMax [1 -3 0 0 0 0 0] 1.20;  //then changed to 1.24

    residualControl //tutorial
    {
        p               1e-4;
        U               1e-4;
        e               1e-4;
        "(k|epsilon|omega)" 1e-3;
    }
}

relaxationFactors
{
        p               0.3;
        rho             0.1;
        e               0.7;
        U               0.7;
        h               0.7;
        k               0.7;
        omega           0.7;
}