Steady-State Membrane CFD SimulationPressure contours on both sides of a membrane For a steady-state simulation the residuals and force profile should be something similar to those in the tutorial "Flow Over a Double-Sided Membrane".Is an unsteady flow simulation necessary for a steady state model?
If you run a steady-state simulation for an unsteady flow then you will get poor results, but as I just pointed out there is usually a good indication from the steady-state results that an unsteady simulation was necessary.What is wrong with my CFD simulation?
Something is also wrong, as expected, with the residuals. For a steady-state simulation you should see all residuals reduce relatively smoothly toward or below 1e-3 with increasing iterations. Steady-State Membrane CFD SimulationPressure contours on both sides of a membraneHow to tell if flow is stable or unsteady?
If you see persistent oscillations in the residuals plot (solver diagnostics) and/or oscillations in a key monitor, such as a drag force monitor, with increasing iterations then that's a good indicator the flow may be unsteady (transient) and the simulation needs to be run as an unsteady simulation.