• Henry Weller's avatar
    blockMesh: New experimental support for projecting block face point to geometric surfaces · 00920318
    Henry Weller authored
    For example, to mesh a sphere with a single block the geometry is defined in the
    blockMeshDict as a searchableSurface:
    
        geometry
        {
            sphere
            {
                type searchableSphere;
                centre (0 0 0);
                radius 1;
            }
        }
    
    The vertices, block topology and curved edges are defined in the usual
    way, for example
    
        v 0.5773502;
        mv -0.5773502;
    
        a 0.7071067;
        ma -0.7071067;
    
        vertices
        (
            ($mv $mv $mv)
            ( $v $mv $mv)
            ( $v  $v $mv)
            ($mv  $v $mv)
            ($mv $mv  $v)
            ( $v $mv  $v)
            ( $v  $v  $v)
            ($mv  $v  $v)
        );
    
        blocks
        (
            hex (0 1 2 3 4 5 6 7) (10 10 10) simpleGrading (1 1 1)
        );
    
        edges
        (
            arc 0 1 (0 $ma $ma)
            arc 2 3 (0 $a $ma)
            arc 6 7 (0 $a $a)
            arc 4 5 (0 $ma $a)
    
            arc 0 3 ($ma 0 $ma)
            arc 1 2 ($a 0 $ma)
            arc 5 6 ($a 0 $a)
            arc 4 7 ($ma 0 $a)
    
            arc 0 4 ($ma $ma 0)
            arc 1 5 ($a $ma 0)
            arc 2 6 ($a $a 0)
            arc 3 7 ($ma $a 0)
        );
    
    which will produce a mesh in which the block edges conform to the sphere
    but the faces of the block lie somewhere between the original cube and
    the spherical surface which is a consequence of the edge-based
    transfinite interpolation.
    
    Now the projection of the block faces to the geometry specified above
    can also be specified:
    
        faces
        (
            project (0 4 7 3) sphere
            project (2 6 5 1) sphere
            project (1 5 4 0) sphere
            project (3 7 6 2) sphere
            project (0 3 2 1) sphere
            project (4 5 6 7) sphere
        );
    
    which produces a mesh that actually conforms to the sphere.
    
    See OpenFOAM-dev/tutorials/mesh/blockMesh/sphere
    
    This functionality is experimental and will undergo further development
    and generalization in the future to support more complex surfaces,
    feature edge specification and extraction etc.  Please get involved if
    you would like to see blockMesh become a more flexible block-structured
    mesher.
    
    Henry G. Weller, CFD Direct.
    00920318
arcEdge.H 3.15 KB