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My Apologies: Laminar Flow and Transport

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Help with a model combining laminar flow of a fluid and diffusion

Hello everyone, I am currently working with a basic transport model. It is composed of two gases flowing through two micro-channels in a block of PDMS. Modeling diffusion is my goal, any advice?
I know the diffusion coeficients for N2 and O2 diffusing into the PDMS; however, I do not know the Dij for O2 diffusing into N2 as they both diffuse into the PDMS. In addition, the volumetric flow-rate of N2 is 10 to 20 times that of O2. I determined the flux from the equations in Perry's but I am not sure that the model is set up right. Thanks and have great day!

I had some difficulties attaching my model and a visio schematic. Here is the mph file.
Any help would be greatly appreciated.

Kind regards, Steve


2 Replies Last Post 10.10.2011, 20:03 GMT-4

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Posted: 1 decade ago 22.07.2011, 03:37 GMT-4
just saying there is an "edit" button at the bottom of the post, to avoid the multiple thread thing if you forget something .....
just saying there is an "edit" button at the bottom of the post, to avoid the multiple thread thing if you forget something .....

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Posted: 1 decade ago 10.10.2011, 20:03 GMT-4
Thank you, friend. I realized this after I decreased the window 'view' from 100 to 90 percent which allowed the edit button to be in view. I was able to solve the model with some help from the kind folks in Ohio. The key was solving the laminar flow physics first (using fine mesh structures) and then coupling those physics with the diffusion physics. Instead of utilizing Fickian diffusion, I used Maxwell-Stephan diffusion, because it was closer to a more realistic model. Currently, I am preparing to build the actual micro-fluidic chip in the laboratory. It is exciting!

Thank you and kind regards,
Steven
Thank you, friend. I realized this after I decreased the window 'view' from 100 to 90 percent which allowed the edit button to be in view. I was able to solve the model with some help from the kind folks in Ohio. The key was solving the laminar flow physics first (using fine mesh structures) and then coupling those physics with the diffusion physics. Instead of utilizing Fickian diffusion, I used Maxwell-Stephan diffusion, because it was closer to a more realistic model. Currently, I am preparing to build the actual micro-fluidic chip in the laboratory. It is exciting! Thank you and kind regards, Steven

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