DAFunction- viscous dissipation added

[Ananth-Narayan-IITM]

Purpose

For most of the topology optimization, viscous dissipation will be used as objective function which is to be minimized. Thus, added subclass- DAFunctionViscousDissipation under the class DAFunction such that users can utilize/ update this function

Type of change

This is addition to DAFunction class

For details on viscous dissipation, refer Olesen2005

Testing

The code is verified and working fine. However, needs verification which is ongoing. Shall update in case of any changes

Checklist

Put an x in the boxes that apply.

• 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

Please let me know in case of addition details.

[codecov]

Codecov Report

❌ Patch coverage is 3.22581% with 30 lines in your changes missing coverage. Please review.
✅ Project coverage is 77.49%. Comparing base (040f25b) to head (1b2db70).

Files with missing lines	Patch %	Lines
.../adjoint/DAFunction/DAFunctionViscousDissipation.C	3.70%	26 Missing ⚠️
.../adjoint/DAFunction/DAFunctionViscousDissipation.H	0.00%	4 Missing ⚠️

❌ Your patch check has failed because the patch coverage (3.22%) is below the target coverage (50.00%). You can increase the patch coverage or adjust the target coverage.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #1001      +/-   ##
==========================================
- Coverage   77.62%   77.49%   -0.13%     
==========================================
  Files         321      323       +2     
  Lines       17793    17824      +31     
==========================================
+ Hits        13811    13812       +1     
- Misses       3982     4012      +30     

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[friedenhe]

@Ananth-Narayan-IITM , the cpp_format test failed, check: https://github.com/mdolab/dafoam/actions/runs/28873032017/job/85891037232?pr=1001

Please use the Clang_format to reformat the .H and .C codes you added.

Also, please add a simple regression test to this test file: https://github.com/mdolab/dafoam/blob/main/tests/runUnitTests_DAFunction.py. Basically, we need to make sure all newly added codes are run in the reg_tests.