[CrazySkunk]

I am looking to study the convective-dissolution of propanone in water using the multispecies model in FLUENT. I have specified the substance mass fraction (0.1) at a small bottom wall section. I have tried both steady-state (unconverged due to backflow despite elongation of the outlet and fine mesh) and transient simulations (good convergence after a few time steps). I am interested in determining the flux of acetone. However, the flux rate is zero at the boundary where the mass fraction boundary condition was applied. However, the mass flow rate at the outlet is non-zero.

I do not think applying a source term will necessarily help as I am trying to determine the flux and not apply it as a boundary condition. My question is, how do I determine the local (at a certain point in the boundary) flux of acetone at the boundary? I want to get a plot of the acetone flux with streamwise distance.

Thank you for your help. Have a lovely day ahead.