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Surface reaction - diffusion: Robin condition
Posted Aug 26, 2013, 2:50 p.m. EDT Chemical Reaction Engineering Version 4.2 1 Reply
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Hello,
I am working on implementing a reaction-diffusion model. I have a particle in solution, where a reaction is occurring at the surface. I want to implement a Robin condition in the boundary of the particle (so that -D(dCa/dr)|surface = k*(Ca-Ca,b). Here, Ca,b is the concentration of A in the bulk. I am using the modules of "Transport of Diluted Species" and "Surface reactions" but so far, I have only found the option of setting the value of the flux at the particle surface but this is not what I am looking for - I want the flux to be tied to Ca via a rate law (and thus define the reaction rate constant). I am unable to find how to implement the Robin condition, and I would appreciate if somebody can help me out with this. I searched the discussion forum but I haven't found an answer. Thanks for your time.
Maria
I am working on implementing a reaction-diffusion model. I have a particle in solution, where a reaction is occurring at the surface. I want to implement a Robin condition in the boundary of the particle (so that -D(dCa/dr)|surface = k*(Ca-Ca,b). Here, Ca,b is the concentration of A in the bulk. I am using the modules of "Transport of Diluted Species" and "Surface reactions" but so far, I have only found the option of setting the value of the flux at the particle surface but this is not what I am looking for - I want the flux to be tied to Ca via a rate law (and thus define the reaction rate constant). I am unable to find how to implement the Robin condition, and I would appreciate if somebody can help me out with this. I searched the discussion forum but I haven't found an answer. Thanks for your time.
Maria
1 Reply Last Post Aug 29, 2013, 3:30 a.m. EDT
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Posted:
1 decade ago
Use the flux boundary condition, and write your expression k*(Ca-Ca,b) (+ or - depending the direction of the flux) into the corresponding box.