Rob
Forum Moderator

Backflow information needs to be known, or backflow avoided. However, if the solver is diverging chances are the backflow isn't helping but is also being caused by the diverging solution. A starting point will be the phase you'd expect at the boundary at what you'd estimate the species fractions to be if the device worked. Ie use the design calculations to estimate back flow. Ideally, extend the domain to stop it occurring.Â