Chimera meshes
 

Dear all,

I'd like to go a little bit in detail about chimera meshes, how they work and the advantages and disadvantages of using them.

Could you please recommend any book or papers to get me started?

thanking in advance for your kind regards

Sail.

Sorry, I don't know of a definitive paper or book that can help you out. The best I can recommend is to go to ntrs.nasa.gov or aiaa.org. NASA has done a lot of work with Chimera.

One of the top considerations in regards to Chimera is whether one wants to go with a structured or unstructured solver. If one goes with a structured solver, then Chimera has significant benefits in regards to gridding. Another consideration is if one has moving parts, then Chimera (either structured or unstructured) is nice since the grids around the moving parts can remain constant. Of course one doesn't need Chimera for that, but it is helpful.

A weak point in regards to Chimera is the interface between the grids. It tends to bring down the max CFL number that can be used, thus slowing down the convergence process.

If you are programming up a structured Chimera scheme, then it can be a pain. You'll need to deal with hole punching, determining point connections, and integrating the pressures on surfaces. Another aspect is trying to determine the point connections for points close to the surface. I don't know of many free public domain gridding or library package that deal with structured Chimera. You can get Chimera Grid Tools or DiRTlib and Suggar for free, but they are ITAR. Not sure why other than to say it was funded by the government, but different topic. Overture also has overset tools and it is available to all.

Are you using a structured or unstructured solver? Or, are you also asking what are the advantages and disadvantages of structured vs. unstructured solvers?