May I know the recommended way of calculating wall y+ in PyFR?
For the upcoming v3 release:
It depends a little on if you want instantaneous or time-averaged y+ results. For the former use the regular writer with write-gradients = True for the latter use the time average plugin with suitable averaging variables that involve gradients.
In either case configure the plugin as:
[...]
region = my_boundary
This will write one layer of elements around the surface. Then, use pyfr export boundary ... to export the surface to an .VTU file. The calculator in ParaView can then do the remaining bits.
Regards, Freddie.