Rob,nThanks for your response. nI made a 3D model and enabled the Eulerian Wall Film model as well. My conditions on the wall are that I don't consider any heating resulting in evaporation/condensation, but just a falling water film, which is driven by shear force as well as gravity, and I would like to look at CO2 absorption into the thin water film. My 3D geo (a box) has two parts, a small thin section including water, and the other big section is filled with gas, where I initialize the solution using the patch option. I have one water inlet from the top and an outflow condition on the bottom. nI was aware of the mesh size, and my mesh size was smaller than my film thickness; nonetheless, solving for these conditions, even without the mass transfer, I get a weird solution for my flow where it shifts to the opposite side of the inlet (please see a snapshot of the flow condition after 1 (s) attached), and in all the steps of my solution for the Eulerian wall, I get no information at all. I should add that I am only considering the thin film flow, with the mixtures I mentioned previously (mixture 1: water + CO2; mixture 2: CO2 + CO2_dummy) with a Mixture multiphase model, and I do not consider DPM mechanisms such as splashing, rebounding, etc. nor do I consider phase change and accretion. I initialize the thin film solving for continuity, momentum, energy and I input only initial conditions, all set to be zero (except for the temperature which I consider to be 300 K). Now I have 2 questions:n1) Considering these conditions, why is my flow behaving that way?n2) Why do I not get anything for the film flow (I still have not added the mass transfer, just want to look at the thin film flow for now)?.Sorry for the long message, and I do appreciate your help on this. nn