OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Segmentation fault for OpenLB 1.5 › Reply To: Segmentation fault for OpenLB 1.5 August 10, 2022 at 2:37 pm #6768 FBukreevKeymaster Hi Fany, for the wall the temperature BC is correct, for inlet and outlets You shuold take the setAdvectionDiffusionConvectionBoundary in Your case. This is the zero gradient BC. BR, Fedor