OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Density when the boussinesq assumption is used › Reply To: Density when the boussinesq assumption is used July 21, 2021 at 8:54 am #5832 mgaedtkeKeymaster Hi mengqiang, you should use the reference density, which is in most cases given by the density at mean temperature. Best, Max