[jianjiao.08]

Hi, I am doing the simulation in FLUENT using eulerian method to model the gas generating electrode in water, trying to get a gas fraction profile near the electrode at different height. But due to the extremely small mass inlet (about 3.1e-9, simplified as a mass inlet boundary condition instead of a surface reaction), the gas fraction profile only consists of two point: one is 0.5(as be given as a boundary condition) and the other is 0.(as attached) However when I give it a much higher mass inlet, say 0.031, the profile makes sense. As have no clue about how I can fix it, can anybody help?

Besides, it seems like that the calculation starts before the inlet boundary (the electrode surface position is x=5.5cm), can you explain why?

Thanks in advance!