[PCabrita]

Dear FD Members,

I am not sure if this is the right place to post such message, I am new here and also I am new to CFD world. My research is focused on phloem transport in plants, namely on applying fluid mechanics to it. Basically, phloem transport is the flow of sap within specialized plant cells that run in tubes throughout the whole plant body. Physically, is it on what you describe as creeping flow (Stokes flow regime). Considering its main physiological aspects (to which I am quite familiar with) I managed to describe how do pressure and velocity change with time and distance (axysimmetrical flow in cylindrical coordinates) and I would like to do the same regarding concentration. I used what some call unsteady Stokes equation and the stream function formalism. This is not anything new as it has been generally solved and particularly to many systems that some of you are probably familiar with. However, never on plants. The novelty here is how it can be used to describe physiologically such type of flows within plants. What I got is an analytical solution for pressure and velocity and I would like to obtain a similar solution for concentration; probably the most relevant parameter for biologists. The change in concentration is mostly convectively driven although there is diffusion through the lateral walls. Solute exchange through the walls is diffusive and given by the permeability of the membrane (wall) time the concentration difference between the inside ou the outside medium. Therefore, I would like to solve the advection equation with the velocity described already by the unseatdy Stokes equation. However, this seems to be far beyond my capabilities and that is why I am asking your help here. I have all the boundary conditions needed and thouroughly described and I would appreciate any thoughful inputs from you in case you are insterested and even better if you would like to join me in this quest.

Thanks in advance,

Paulo

[ivan-s]

is use COMSOL. Not because I'm totally excited about it, it has its issues, but I think that this kind of problem with multiple physical models is well-targeted to COMSOL. There may be other softs out there which are appropriate, and personally, I'd like to hear about them as well.