[tareqkh]

Hello All,

I hope that you are all having a wonderful weekend. I have been working on a small project using simpleFoam (Flow over a cylinder at Re=40). I have implemented the force function in order to obtain the drag and compare to the experimental result. I want to prove that the drag force that I have obtained comes from the pressure force. However, I am unable to filter the data in the post-processing folder since it is a little bit messy. Can some of you guide me in this issue...


Regards,

[tareqkh]

Can someone help?

[pablodecastillo]

Study motorbike tutorial, and you can change forcecoef by forces, google it for a couple minutes and done

[tareqkh]

I would really appreciate your help, if could provide clear explanations in this regards.

Thank you

[pablodecastillo]

Maybe i am missundertanding to you, but if you want to extract forces, it is so easy like in controlfile at the endo of the file add:
functions
{
#include "forces"
}

And in system folder create a file forces with:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.3.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/

forces1
{
type forces;

functionObjectLibs ( "libforces.so" );

outputControl timeStep;
timeInterval 1;

log yes;

patches ( motorBikeGroup );
rhoName rhoInf; // Indicates incompressible
rhoInf 1; // Redundant for incompressible

CofR (0.72 0 0); // Axle midpoint on ground


/*
binData
{
nBin 20; // output data into 20 bins
direction (1 0 0); // bin direction
cumulative yes;
}
*/
}


// ************************************************** *********************** //

And if you want to integrate your own functions, i add a *.H with code like:

const volScalarField& p_ = mesh_.lookupObject<volScalarField>("p"); //was p



Fmine[0] =
gSum
(
p_.boundaryField()[patchI]*
mesh_.Sf().boundaryField()[patchI]
);

You can modify this calculation.

Best,