OpenCFD Ltd. have introduced feature edge handling into snappyHexMesh — their automatic, parallelised, hexadral mesher for complex CAD, released with OpenFOAM.
Complex geometries may contain sudden changes in surface normal direction, e.g. between sides of a box, or across a crease in a surface. Such a feature can be resolved reasonably well by refining cells locally around it. However the feature can be better resolved by aligning edges in the mesh with it. The sudden change in surface normal direction can then be directly represented by an equivalent change in surface normal direction of mesh faces across feature.
The image below shows feature edge handling in action. On this flange geometry, a mesh has been generated with barely enough cells to resolve the geometry. Nevertheless, with the feature edge handling, mesh edges are aligned with surface features so that the geometry is well represented by the coarse mesh.
This development was undertaken at OpenCFD by Mattijs Janssens, the creator of snappyHexMesh. Like everything OpenCFD produces, it will be released free and open source. It will be available in the next release of OpenFOAM; we hope OpenFOAM users find it useful.
11th April 2011