[aks2200]

Hello Everyone,

I did sphere meshing in ICEM for my project on Low frequency fluctuations over sphere using DES. Due to the long simulation time I have to use coarse or medium mesh.
I started by making geometry in CATIA with sphere, computational domain and wake behind sphere (Schematic attached below), then I imported it in ICEM, made a density box with wake geometry of size 300 and ratio of 1.3 and made two domains, one for solid(sphere) and another one for fluid domain. Made required changes in part mesh setup (image below) and computed Robust(Octree), after that I deleted the volume and applied smoothing with laplacian and finally computed Delaunay.

Now my question, Is this whole process is correct, I can't generate anything after simulation in FLUENT or OpenFOAM, I mean I can't able to visualize vortex moreover OpenFOAM shows only 0.4% of volume RANS is working and rest is LES. Can some one help me in refinement of mesh?

One last question is, how to figure out time step size. My minimum size limit in part mesh setup is 0.5. Is this is delx or something else. If I use this value my time step is coming out 0.0001 which is way too small (for Mach 0.2) for simulation of such long period.

[diamondx]

The process of meshing is right. Note that you don't have to delete your mesh to create a delaunay mesh. other issue should be addressed in fluent section I think

[aks2200]

Thanx for your reply diamondx

If I do not delete volume mesh generated before delaunay mesh then elements are also generated inside of sphere. Moreover I am working in OpenFOAM and it shows only 0.03% of total volume over which RANS is working and rest is LES.
Do you know how to do a proper mesh for DES simulation?
Thanx once again

[diamondx]

I don't really know the requirement of a DES simulation. perhaps you should check ansys documentation, or scientific papers...