CFD Online Discussion Forums - question about createMesh.H

In file createMesh.H, an instance 'mesh' of type 'fvMesh' is created

Code:

 Foam::fvMesh mesh

    (

        Foam::IOobject

        (

            Foam::fvMesh::defaultRegion,

            runTime.timeName(),

            runTime,

            Foam::IOobject::MUST_READ

        )

    );

Question 1: Is the following constructor from fvMesh.H used in the above case?

Code:

explicit fvMesh(const IOobject& io);

Question 2: In the above code, what does defaultRegion indicate?

I found following information about 'defaultRegion' in polyMesh.H and polyMesh.C

Code:

    //- Return the default region name

    static word defaultRegion;

Code:

namespace Foam

{

defineTypeNameAndDebug(polyMesh, 0);



word polyMesh::defaultRegion = "region0";

word polyMesh::meshSubDir = "polyMesh";

}

Code:

const Foam::fileName& Foam::polyMesh::dbDir() const

{

    if (objectRegistry::dbDir() == defaultRegion)

    {

        return parent().dbDir();

    }

    else

    {

        return objectRegistry::dbDir();

    }

}

Question 2 continued: What is region0 and why is it equal to 'defaultRegion' ?