[Nek5000-users] set obj for internal fluid surface

[nek5000-users at lists.mcs.anl.gov]

All,

I'm working with the calc_torque routine, and I want to calculate the torque/drag along a surface within the fluid domain (not on the boundary).  Is there a straight-forward way to "set_obj" for such a surface?  It's straightforward for external fluid boundaries, as you can just search on certain boundary conditions and grab those element faces.  It's not so clear for me how to do the same for some internal surface.

Thanks.
--Mike