snGradCorrection
 

Has anyone tried implementing snGradCorrection? I tried to modify wallGradU by replacing snGrad with snGradCorrection and its simply throwing up.

Doesn't wallGradU calculate the NORMAL gradient of wall? Does the gradient of a scalar direction necessarily has to be along normal?

What is the difference between
1. U.boundaryField()[patchi].snGrad() and
2. Calculating gradient of U and then inner product of gradU and the surface normal

I am trying to build expression for 2., but getting errors.

Thank you.