Patch Creation in Multi-Block Mesh
 

Hi,

I have been working on creating a mesh of Bolund Hill using the open source code 'terrainBlockMesher'. This essentially creates a detailed blockMeshDict file from an STL surface geometry, which can then be meshed quickly and easily with blockMesh.

I am studying the effects of non-uniform surface roughness for use in the nutKAtmRoughWallFunction. My approach is to supply z0 as a nonuniform List<scalar> entry in a separate file, which is #included in the 'nut' dictionary. My best understanding is that this is a valid approach, although documentation is limited... I also assume that one roughness value is needed per patch face.

My problem is however, that this utility uses a large number of blocks, and hence the face ordering is confusing. The z0 values I was supplied with are in x-wise, y-wise order and hence do not line up with the faces on the 'ground' patch directly. The STL region has 13 blocks in both the x and y directions, each with 10 cells, which creates a pretty confusing pattern of face orderings! :confused:

I want to be able to create a wall-type patch in my domain (over the STL file area - see picture) where I can specify the surface roughnesses. At the moment I have no idea how to do this... I have considered applications such as creatBaffles/splitMeshRegions/createPatch - but do not know how to use them in my case. Any experience with these functions would be greatly appreciated if they are indeed applicable?

Any advice anyone could give with this problem would be really helpful!

Many Thanks :)

Hi James

Have you solved this problem yet. I am also facing the same face ordering problem using terrain block mesher .As tbm is unable to produce cyclic patches I tried to use createPatch utility but due to this face ordering problem I am unable to generate the patch.
The details of my problem are on the following link.Please advice if you come up with a solution asap.
http://www.cfd-online.com/Forums/ope...x-terrain.html