OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › "WARNING: no discreteNormal is found " in the free energy model › Reply To: "WARNING: no discreteNormal is found " in the free energy model September 21, 2019 at 10:24 pm #4548 savisParticipant Dear Simon, I believe that this is because of boundary nodes that aren’t beside any inner fluid nodes. You should hopefully be able to resolve this simply using “superGeometry.clean();” after the material numbers are assigned. Best wishes, Sam