Due to recent bot attacks, newly registered users are required to send a message via our contact form in order to be able to post in the forum. OpenLB – Open Source Lattice Boltzmann Code › Forums › on OpenLB › General Topics › Fluid with externally defined mass-force › Re: Fluid with externally defined mass-force March 28, 2018 at 7:44 am #2819 mathiasKeymaster Please, have a look at the poiseuille examples. Best Mathias