February 5, 2021 at 3:25 pm
Ansys Employee
actually, looks pretty good. Residuals in transient have some different meaning then in steady-state. All you should be looking is residuals go done ~ 1e-03 within each step. Keep in mind that once you switch to transient, you start recovering transient artifacts (propagating waves) which otherwise don't exist in steady-state. Since this is a closed domain, waves inevitable reflect off the walls, maybe travel upstream along the tube. They should eventually dissipate, My suggestion is to switch to a constant time step, use a larger step at flow CFL ~ 1, and keep coupled. This should allow you to flash out initial transient faster.n