Meshing a 3D, tapered and twisted blade with Gambit-TGrid
 

Hi everyone, hope some of you may help me, 'cause I'm really going crazy...

I need to make a mesh of a 3D blade, highly tapered and twisted (it's a wind turbine blade), I'm using Gambit for the boundary mesh and then TGrid for the volume mesh.

My domain is an emisphere with a symmetrical boundary in the xy plane while the blade extends into the z direction.

I meshed the blade surface with a refined grid, the external spherical surface with a coarse grid and the xy circular plane with a size function with a growth rate of 1.2 such as the grid passes from the refined one of the blade to the coarser one of the external boundary.

Then I import the boundary mesh in TGrid, create a boundary layer of prism and automesh the rest.

Well, what I got is quite disappointing, the mesh behaves quite well close to the xy plane, but as I go more inside the domain I loose the smooth transition from refined to coarse grid and the change in size between the last element of the boundary layer and the first of the tri mesh is too much.

How can I have a better control on the volume mesh, does TGrid have something like the size functions of Gambit?

I also tried to create a multiblock mesh with a smaller cilinder surrounding the blade and setting a moderate refined grid on its surface. But then TGrid passes from the refined grid of the blade, to a coarse grid inside the cilinder (quite faster) then the grid refines again approaching the cilinder boundaries to coarsen again leaving it.

Anyone experencied similar things?

I would appreciate your help.
Thanks
G.