OpenLB – Open Source Lattice Boltzmann Code › Forums › on Lattice Boltzmann Methods › General Topics › Advection Diffusion D3Q19 Boundary Condition › Reply To: Advection Diffusion D3Q19 Boundary Condition April 29, 2021 at 5:34 pm #5639 stephanModerator Dear Mathis, you are welcome, thanks for starting the discussion! Yes, including a ramp up for the concentration could be helpful. Approximating the profile with a smoothed out concentration might also help. BR Stephan