CFD Online Discussion Forums - co-efficient of drag and lift

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co-efficient of drag and lift

Hi everyone,
I have started using openFoam since last two months.
I am studying flow past a cylinder kept between two infinitely large plates. Reynolds no. is 500 and strouhal no. is 0.18.I want to get the co-efficient of drag and lift. How can i get the values?Also can you suggest appropriate boundary conditions.

Thanks in advance.

regards
Subhankar

Hi,

You can get them by forces functions to place inside system/controDict.
For example, if you look to /tutorials/compressible/sonicFoam/ras/nacaAirfoil/system/controlDict
you will fine the following:

Code:

functions

{

    forces

    {

        type            forceCoeffs;

        libs ( "libforces.so" );

        writeControl   timeStep;

        writeInterval  1;



        patches

        (

            WALL10

        );



        log         true;

        rhoInf      1;

        CofR        (0 0 0);

        liftDir     (-0.239733 0.970839 0);

        dragDir     (0.970839 0.239733 0);

        pitchAxis   (0 0 1);

        magUInf     618.022;

        lRef        1;

        Aref        1;

    }

}

Good Luck !

Regards,
T.D.