Two-dimensional (2D) snappyHexMesh operation.
 

Hi everyone.

I am hoping to simulate flow around an object similar to a circular cylinder, in two-dimensions. I started with the (successful) motorcycle tutorial, reduced the through thickness (y-axis) dimension of my blockMesh to about 1% of the x and z dimensions and set a single cell through the thickness, with several cells along the other two dimensions. I created a closed STL surface with gmsh of my object, such that a volume was defined whose major faces (looking like circles) intersected the blockMesh walls from the tutorial; the through thickness walls joined the major faces, creating a closed volume. All seemed well on viewing the mesh: I could see a circle of small thickness, with refined cells around it.

However, snappyHexMesh refinement is refining in all three Cartesian axes, resulting in cells being generated through the thickness of the mesh when, I believe, I need to keep to a single cell through the thickness for two-dimensional analysis. Inspection of the cylinder wall shows cell splitting has occurred in the y direction, as well as splitting in the desired x and z directions.

Setting empty boundary conditions in the blockMeshDict did not prevent the refinement.

Please, is there a way to prevent refinement in one of the Cartesian axes? If I am going about this the wrong way, I'd love to know!
I'm attempting to do a similar thing to that described in the manual,
only the manual made no mention of preventing splitting through the
thickness of the paper!

I am using Build : 1.7.0-113391ee57bd, on Ubuntu Lucid 64.

All the best,

Mark.