Mass transfer coef.

Numerical methods and mathematical models of Elmer
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Gary R
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Location: Long Beach CA, USA

Mass transfer coef.

Post by Gary R »

Hi all,
I am trying to set up an Advection Diffusion problem where an ideal gas is flowing through a boundary at a given rate (mols/s) into an area of air. ElmerGUI shows 3 possible flux boundary types, Concentration flux, Mass Transfer Coefficient and External Concentration. It would seem that Mass Transfer Coefficient BC would be the type to specify since I have a flow rate in mols/s. What I can't figure out is the relation between the flow rate and and the MT Coefficient. Could someone help?

Gary R
kevinarden
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Re: Mass transfer coef.

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Gary R
Posts: 162
Joined: 12 Apr 2012, 07:23
Antispam: Yes
Location: Long Beach CA, USA

Re: Mass transfer coef.

Post by Gary R »

Thanks for the reply. I have read the models manual several times but your reference didn't register. After rereading that part, I concluded that I am using the wrong formula. My model seems to lend itself to the use of the Navier Stokes equation instead of the Advection Diffusion equation.

One of the parameters of interest is the point where the stream velocity exceeds the diffusion rate of air into the hydrogen stream. The diffusion rate can be handled as a separate problem. The overall problem seems to be reducing to something that can be handled with pencil and paper.

Gary R
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