Overset update fixes

[sseraj]

Purpose

I made some fixes to the full and fast oversetUpdateMode options.

full was not working because #27 changed the cutCallback function signature but did not change it for full mode.
fast was not working in parallel because the pointer to xCen was deleted in this commit: b32cfb4.

This was leading to errors like this:

At line 1947 of file ../overset/oversetCommUtilites.F90
Fortran runtime error: Array bound mismatch for dimension 2 of array 'commpattern' (0/3)

I also fixed the adjoint routines for fast mode and updated the docs to make the drawbacks of these options clear.

Expected time until merged

One week

Type of change

• Bugfix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (non-backwards-compatible fix or feature)
• Code style update (formatting, renaming)
• Refactoring (no functional changes, no API changes)
• Documentation update
• Maintenance update
• Other (please describe)

Testing

I expanded the cube overset tests to test all three overset update modes. The fast and full tests fail without the fixes in this PR.

Checklist

• I have run flake8 and black to make sure the code adheres to PEP-8 and is consistently formatted
• I have run unit and regression tests which pass locally with my changes
• I have added new tests that prove my fix is effective or that my feature works
• I have added necessary documentation

[codecov]

Codecov Report

Merging #225 (75df0bb) into main (ea9b0ed) will increase coverage by 0.30%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##             main     #225      +/-   ##
==========================================
+ Coverage   41.04%   41.35%   +0.30%     
==========================================
  Files          13       13              
  Lines        3793     3794       +1     
==========================================
+ Hits         1557     1569      +12     
+ Misses       2236     2225      -11     

Impacted Files	Coverage Δ
adflow/pyADflow.py	68.42% <100.00%> (+0.51%)	⬆️

📣 Codecov can now indicate which changes are the most critical in Pull Requests. Learn more

[joanibal]

Looks good. I have just a few questions.

[joanibal]

So the routine always existed it just wasn't being used?

[sseraj]

This is related to your first question. For some reason, the fast and full updates were grouped in the residual and derivative routines. As with updateOversetConnectivity, the AD routines also only apply for fast mode. The AD routines existed and worked, but they were commented out some time ago by Ney, who was using the full update.

[anilyil]

Just left a minor comment. The rest of the PR looks good to me.