Is the boundary surface normal guaranteed to always point away from the fluid domain? This seems to be the case, though I am not fully sure where or how this comes into the picture (if at the meshing stage, or inside PyFR). Understanding this may help me with a plugin that I am writing that integrates mass and momentum fluxes at boundaries.
Yes, normals are always outward facing.
Regards, Freddie.
Thank you! I also had a quick question about the sign of the moments reported by the FluidForces plugin. Does a positive value of moment correspond to clockwise direction? I wonder what would be the proper way to interpret the directions.