Implementing a wall modeled LES channel flow

[marchdf]

This PR adds:

• an analytical Smagorinsky channel test
• a constant shear stress wall model boundary condition

TODO:

• lift restrictions of wall normal direction, or at least guard against it
• add regtest
• document convergence run

FYI: @asalmgren @mbkuhn @moprak-nrel @AMLattanzi

Co-authored-by: moprak-nrel 120606615+moprak-nrel@users.noreply.github.com

[marchdf]

I hate to ask but... are you going to do this for vorticity, laplacian, q-critierion, and gradient as well?

[mbkuhn]

I hate to ask but... are you going to do this for vorticity, laplacian, q-critierion, and gradient as well?

This PR will only address the operators in ABLStats and turbulence modeling. Which means only gradient and strainrate. But the others can be addressed in a future PR.