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 › Concentration fields in openLB › Reply To: Concentration fields in openLB July 22, 2024 at 8:30 pm #8990 shotaParticipant Simply, call the coupling operator every n-th time step using if(iT%n == 0) or something alike.