OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Free surface boundary conditions › Reply To: Free surface boundary conditions April 10, 2023 at 5:52 pm #7389 Wolfmeister7Participant Thank you very much for your reply. I will use Smag. model with BGK. One more clarification. I do not know about Pressure BC in OpenLB package, can it handle the following case: v(u, w), u=dw/dy=0 on the upper boundary? Or Pressure BC handles it somehow different?