Computational Domain and Meshing for Complex Geometry
 

Hi,

Could some help explain how does one create the right shaped computational domain for complex geometries? From my understanding, there are three types, H grid (basic Square/ Rectangle domain), O grid (Circular Domain) and C grid (a combination of both). However, after divulging in some research I have noticed that many people make their own shaped domain, and don't seem to understand how to do this, and this is primarily for complex geometries such as space capsules. So could someone explain how to create such a domain and then mesh it properly?

Thanks

If you're using Open source software, you can use GMSH for creating C,O,H type grids.
For complex geometries such as space capsules, you would break the domain into smaller parts, then mesh them independently. If you want a completely structured grid, that would be called as multi-block structured grid. See image.


However, creating such multi-block structured grids can be difficult using Open Source tools like GMSH. Generally in industry, practitioners use ICEM-CFD or Pointwise or other commercial tools to generate such grids, as they provide a better user experience.

Ah, I see that makes sense. So when splitting the grid into a multi-block grid, is there specific to the type of shape that the outer boundary (connecting the different blocks) such as a square/circle etc.

You could if you wanted to.

It could be an elliptical, circular, cylindrical, cubical, spherical domain.
Generally we follow the shapes used in literature, to remain consistent.

There are also Y-blocks to use to mesh around sharp corners.

scStream creates nice multi-blooks as well.