OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Periodic Outlet Boundary Conditions ( nonequilibrium extrapolation method) › Reply To: Periodic Outlet Boundary Conditions ( nonequilibrium extrapolation method) March 29, 2023 at 4:16 pm #7327 FBukreevKeymaster In first case you track the separate points moving with Newtonian equation system and in the Eulerian case you regard particles as a concentration cloud.