How would one go about the modelling of a dissolved species? I want to model how dissolved oxygen moves through a basin, with a the oxygen species flux being specified at a wall (approximated free surface) and at a nominated inlet.

It is possible to assume that the dissolved oxygen will not affect the hydrodynamics in anyway, so I may be able to make an analogous case with heat transfer, by setting the diffusifity of heat to that of the mass species; but I will have to ensure fluid density is constant along with a few other things. Do you think this is a valid approach? Is there a way of dealing with dissolved species in Fluent5.2 (I haven't come across it)?

Any other ideas on how I could proceed would be greatly appreciated.

cheers,

Matthew.

Dear Matthew Brannock

Of course, you can make an analogous case with heat transfer. Combined heat and mass transfer is called as 'double diffusive convection. That is, fluid flow with heat transfer and mass transfer. Species mass transport equation is the same as heat transport equation(energy equation), except material property. Thermal diffusion(and convection) is a special case inh the point of view of double diffusive convection. So, the same way, your interest, species diffusion(and convection) is also special case of double diffusive convection. So what is difference between thermal convection and species diffususion ? You can get mush insight if you get the papers related to the 'Double Diffusive Convection'. If you have difficulties to get them, just tell me. I will introduce some papers, including mine.

Sincerely Jinwook.