Can Channelflow easily switch to a Neumann boundary condition for wall pressure?
The Dirichlet boundary condition currently imposed keeps the pressure during a Couette flow at zero on the wall and causes the pressure to dip below zero (to -0.5 Pa) in the center. You can easily veritfy this by running:
randomfield -Nx 65 -Ny 33 -Nz 65 -Lx 10 -Lz 10 -m 0.001 zero.nc
simulateflow -nu 0.000016 -T 100 -dt 0.004 -vdt false -dT 1 zero.nc
I was hoping to study the stability of Couette laminar flow and turbulent flow for which the normal dP/dy=0 (Neumann boundary condition). Wouldn’t dP/dy=0 at the wall be more physical?