Computational Domain and Meshing for Complex Geometry

ashf9 · February 25, 2021, 04:41

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

aerosayan · February 25, 2021, 05:28

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.

ashf9 · February 25, 2021, 07:13

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.

aerosayan · February 25, 2021, 07:43

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.

aero_head · February 25, 2021, 10:05

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

CFDfan · February 26, 2021, 12:01

Quote:

Originally Posted by aerosayan

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.

scStream creates nice multi-blooks as well.

February 25, 2021, 04:41	Computational Domain and Meshing for Complex Geometry	#1
ashf9 New Member Ash Join Date: Feb 2021 Posts: 20 Rep Power: 5	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

February 25, 2021, 07:43		#4
aerosayan Senior Member Sayan Bhattacharjee Join Date: Mar 2020 Posts: 495 Rep Power: 8	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. aero_head likes this.

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February 25, 2021, 07:13		#3
ashf9 New Member Ash Join Date: Feb 2021 Posts: 20 Rep Power: 5	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.

February 25, 2021, 10:05		#5
aero_head Senior Member Kira Join Date: Nov 2020 Location: Canada Posts: 435 Rep Power: 9	There are also Y-blocks to use to mesh around sharp corners.