1 Reply Latest reply on Nov 4, 2014 9:52 AM by Jared Conway

    Diffusion and Porous Media

    Martin Rommel

      Hi

       

      I'm trying to do two things in the simulator:

       

      1. Simulate the diffusion of oxygen through a piece of liver tissue which is suspended in the middle of a flow stream, see picture. My question is can the simulator handle this? I have modeled the tissue as a isotropic porous media, which has a porosity of 0.4. However, I am a bit in doubt about what I need to specify as the length and area of this media. Would that simply be (a) the area of the front section and the length of the entire slice along the flow or (b) is it the total surface area of the slice and the length along the flow direction?

      Also can the simulator handle tortuosity and permeability?

       

      Liver chip.png

       

      2. Simulate the diffusion of Oxygen and CO2 through a thin PDMS membrane into a fluid flow above it, see figure. Basically the question is the same as my first one. What would I specify as area and lengths, if I considered the thin gas permeable PDMS membrane to be a isotropic porous media?

       

      Gas System.png

        • Re: Diffusion and Porous Media
          Jared Conway

          1a > the properties you input into the engineering database are based on your sample, flow simulation will scale it up based on the model that you actually use.

          1b > can you elaborate on what you want tortuosity and permeability to do? the porous medium properties are well defined in the help if you want to look into how they work

          2 > do not believe this is possible with flow simualtion. flow simualtion does not handle mixing of different species or the "chemical-type" diffusion i think you're looking for, have you seen this done in other CFD?