I don’t have the bandwidth to go through this whole code.
Store the velocity and or pressure to file, for instance after applying the bc to a function in the V or Q space.
See for instance: Struggling with vector values bcdirichlet - #15 by dokken
which shows how to check them.
This depends on what system you are running DOLFINx on, and how you have installed dolfinx. Without further information it is hard to help.
I wouldn’t go for pressure conditions when it comes to splitting schemes. You can choose whatever method you might like (like setting it strongly after solving the pressure correciton step). It does mean that you are walking in uncharted territory (at least as far as I know) when it comes to guaranteed convergence of the scheme.
what do you mean with a pow?