[ripperjack]

Hi foamers,

I want to output some slices during run time, e.g., a x-z plane of velocity at y=1.0 in a channel. I can do it after the simulation using the "sample" utility, but that way I have to output the whole fields every time step, which makes the output data very huge. So is there a way to output just some slices during run time? (may be adding sth in controlDict?) Many thanks in advance!

Regards,

[bmikuz]

Hi ripperjack

use function object sampling -> surfaces. For example:
for a z-cut of velocity field just append this text at the bottom of controlDict:

functions
{ 
    my_surfaces
    {    
    type        surfaces;
    interpolationScheme cellPoint;
    functionObjectLibs ( "libsampling.so" );
    enabled         true; // this is just a switch on/off for that function
    outputControl   timeStep; 
    outputInterval  2; // the surface will be stored every 2nd time step (for example)
    surfaceFormat    vtk;    
    surfaces
    (
        zCut
        {
        // Cutingplane using iso surface
        type            cuttingPlane;
        planeType       pointAndNormal;
        pointAndNormalDict
        {
            basePoint       (0.0 0.0 0.12);
            normalVector    (0.0 0.0 1.0);
        }
        interpolate     true;       
        }
    );

    fields
    (
    U
    );
    }
}

In this case you will find the z-planes of velocities in the postProcessing/my_surfaces directory, which will be filled on-the-fly during the runing of simulation.