Added ProcessCFL to the fieldUtils for FieldConvert for Inc flow

Issue/feature addressed

• Add a new feature to the FieldConvert to calculate the CFL over the domain for an incompressible flow solution

• We have similar functionality in solver/IncNavierStokes/Utilities/CFLStep.cpp file however there exists a couple of shortcomings with it as follows:

  • The input file format is not flexible. The only acceptable format is mesh and conditions in a single file.
  • The flow field must be provided as an initial condition to the input file. This means that for each solution file the user needs to manually change the initial condition or make a new input file. Hence, it is not convenient for examining several solution files
  • It sets up the whole equation system to compute the CFL number but this can be done without setting up the equation system.
  • It is restricted to Incompressible Navier-Stokes flow
  • It is more natural to have this functionality in the FieldConvert which then can also be extended to cover compressible flow and other solvers too in one place

Proposed solution

• The fix for the above mentioned problems with the CFLStep in Utilities of NavierStokes solver requires almost the same effort as to creat the new functionality for the FieldConvert to calculate the CFL field.
• A new Process module is added to the FieldConvert to calculate the CFL number over the entire domain.

Implementation

• see above

Tests

• Added 3 tests to FieldConvert's Tests

Notes

• No further comments

Checklist

• Functions and classes, or changes to them, are documented.
• User guide/documentation is updated.
• Changelog is updated.
• Suitable tests added for new functionality.
• Newly added files are correctly formatted.
• License added to any new files.
• No extraneous files have been added (e.g. compiler output or test data files).