Due to recent bot attacks we have changed the sign-up process. If you want to participate in our forum please send a message via our contact form. › Forums › 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