CFD Online Discussion Forums - Extract U data on plane

Hello,

I'm trying to extract U data (velocity) from a certain plane. After I ran the simulation, I've got a whole domain from OpenFOAM to ParaView:
Attachment 89866

However, I don't need U values for the whole domain. What I need is U value only on the circular plane in red colour as shown below:
Attachment 89867

This plane was defined in the SnappyHexMesh:

Code:

/*--------------------------------*- C++ -*----------------------------------*\

  =========                 |

  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox

   \\    /   O peration     | Website:  https://openfoam.org

    \\  /    A nd           | Version:  9

     \\/     M anipulation  |

\*---------------------------------------------------------------------------*/

FoamFile

{

    format      ascii;

    class       dictionary;

    object      snappyHexMeshDict;

}

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



#includeEtc "caseDicts/mesh/generation/snappyHexMeshDict.cfg"



castellatedMesh on;

snap            on;

addLayers       off;



geometry

{

    buildings

    {

        type triSurfaceMesh;

        file "buildings.stl";

    }



    refinementCylinder

    {

        type searchableCylinder;

        point1          (0 0 0);

        point2          (0 0 190);

        radius          350; 

    }

};

The plane is Z = 1.5m height from the refinementCylinder.

How can I export U value only on the circular plan to the ParaView?

Which code do I have to add in OpenFOAM? Since I am new for OpenFOAM, please help.

Thanks in advance!