[hhh]

hai friends,

I am doing 2d airfoil analysis, i have doubt about the result i got ie Cl(f) and Cl(r) it means what? and also i mention in red colour

/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2.1.0                                 |
|   \\  /    A nd           | Web:      www.OpenFOAM.org                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : 2.1.0-0bc225064152
Exec   : simpleFoam
Date   : Jun 11 2013
Time   : 14:42:35
Host   : "ubuntu"
Case   : /home/toshiba/OpenFOAM/toshiba-2.1.0/run/tutorials/incompressible/simpleFoam/ku/airFoil2D
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create mesh for time = 0

Reading field p

Reading field U

Reading/calculating face flux field phi

Selecting incompressible transport model Newtonian
Selecting RAS turbulence model SpalartAllmaras
SpalartAllmarasCoeffs
{
    sigmaNut        0.66666;
    kappa           0.41;
    Cb1             0.1355;
    Cb2             0.622;
    Cw2             0.3;
    Cw3             2;
    Cv1             7.1;
    Cv2             5;
}

No field sources present

SIMPLE: convergence criteria
field p     tolerance 1e-05
    field U     tolerance 1e-05
    field nuTilda     tolerance 1e-05


Starting time loop

Time = 1

smoothSolver:  Solving for Ux, Initial residual = 0.999993, Final residual = 0.0558381, No Iterations 4
smoothSolver:  Solving for Uy, Initial residual = 1, Final residual = 0.0760732, No Iterations 2
GAMG:  Solving for p, Initial residual = 1, Final residual = 0.0991895, No Iterations 39
time step continuity errors : sum local = 0.00119979, global = 6.26709e-16, cumulative = 6.26709e-16
smoothSolver:  Solving for nuTilda, Initial residual = 0.999999, Final residual = 0.0701398, No Iterations 4
ExecutionTime = 36.7 s  ClockTime = 37 s

forces output:
    forces(pressure,viscous)((257697 5.20299e+06 7.66604e-16),(6.53254 1.33905 -1.89121e-21))
    moment(pressure,viscous)((-3.39084e-17 -1.06156e-16 2.50963e+06),(4.47879e-23 -2.14236e-22 0.66735))

forceCoeffs output:
    Cm    = 901.996
    Cd    = 415.85
    Cl    = 1857.68
    Cl(f) = 1830.84
    Cl(r) = 26.8427

Time = 2

smoothSolver:  Solving for Ux, Initial residual = 0.623192, Final residual = 0.0517858, No Iterations 4
smoothSolver:  Solving for Uy, Initial residual = 0.445407, Final residual = 0.0284221, No Iterations 4
GAMG:  Solving for p, Initial residual = 0.711508, Final residual = 0.0608906, No Iterations 11
time step continuity errors : sum local = 0.000802196, global = 1.48748e-15, cumulative = 2.11418e-15
smoothSolver:  Solving for nuTilda, Initial residual = 0.258696, Final residual = 0.0187245, No Iterations 4
ExecutionTime = 45.88 s  ClockTime = 46 s

forces output:
    forces(pressure,viscous)((168327 3.88357e+06 2.72499e-16),(23.6262 2.65695 -2.24632e-21))
    moment(pressure,viscous)((-2.10668e-17 -5.5126e-17 1.89813e+06),(5.34685e-23 -6.75307e-22 1.37948))

forceCoeffs output:
    Cm    = 682.213
    Cd    = 301.9
    Cl    = 1385.1
    Cl(f) = 1374.76
    Cl(r) = 10.3358

please guide me