[Euan001]

Hi

I am modelling a tidal stream turbine, I am looking at the flow over it when the rotor is parked so I am not homing in on forces acting on the blades as they are rotating but essentially considering the turbine as a bluff body in the fluid stream.

I have a hybrid mesh with Tets over the turbine and Hex in the volume. I have a cylinder of Tets around the turbine which is surrounded by a box which is split up so it can be meshed using sweep meshing then another box for the rest of the fluid domain.

I am using face sizings on the surface of the turbine to refine the mesh. I am currently performing a mesh dependency study and am decreasing the size of the elements on the surface of the turbine.

The mesh is fine until I either reduce the element size below a certain value or reduce the growth rate and then it fails to generate.

At first the mesher highlighted a problem just on one of the blades (see picture) so I went back to the geometry and deleted that blade and copied the geometry in the form of an array from one of the working blades.

I then tried to remesh and the problem now appears to have moved from the blade to the nose cone (see second pic), which ANSYS had no trouble meshing before.

I cannot understand it . They are both smooth surfaces with nothing really in close proximity.

Any help would be much appreciated.

[siw]

Do you have Inflation Layer(s) (to generate prisms) on all the walls? Is your CAD model of the turbine stitched together nicely? Make an image on the turbine CAD in the region indicated as the problem.