[PenPencil]

Hi all,

I was wondering if you could help me integrate the shear stress over the surface of a 2D body. The problem is that of an incompressible, laminar and unsteady flow of a Newtonian fluid with a Gmsh-generated mesh.

First, I calculated the wall shear stress by the following:

pimpleFoam -postProcess -func wallShearStress

Second, I tried:

postProcess -func 'patchIntegrate(name=cylinder1,wallShearStress)'

to integrate the wall shear stress over my patch 'cylinder1'. As a result, I have gotten the directory postProcessing/patchIntegrate\(name\=cylinder1\,wallShearStress\) with a '.dat' file. I believe my procedure is not correct, since a vector was written in the '.dat' file, as opposed to finding the result of which is a scalar.
However, I have not figured out how to properly do this. Could anyone help, please?

Notes:
1 - I gather Paraview usually is a solution to this as well from older threads, but I intend to use a script and Paraview would not fit into my purposes. But indeed, my calculation does not have to be done using some built-in function of OpenFOAM, as I could post-process elsewhere, provided I had the lengths/areas corresponding to the wall shear stress on each edge of the mesh.
2 - Undoubtedly, OpenFOAM API library and C++ are quite useful in situations like this one, but I am not experienced in them (and to be honest, this is probably the one time in my research that this knowledge would be useful to me, which explains why I haven't felt motivated to learn them...). If you could help me with a solution other than those involving this, I would be most grateful!



Thank you so much

Best regards,
I.