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-   -   How to solve for transport with large source term (http://www.cfd-online.com/Forums/main/12908-how-solve-transport-large-source-term.html)

yong February 1, 2007 11:54

How to solve for transport with large source term
 
Hi,

I am developing FORTRAN code for catalytic combustion: 1D transport with hetergeneous reaction occuring on side wall. The mass transfer from the bulk flow to the catalyst surface is modeled by emperical correlation ( Sherwood number = 4.0). The species concentration at the catalyst surface, which is implicit, must be be determined by the flux balance between the transport from the bulk flow to the surface and the total reaction rate in catalyst. I realized it is time comsuming to get the converged solution. Could any one tell me if there is any good scheme for this aplication ? (BTW, this is different from the general homogeneous combustion, which does not need to solve the additional surface concentration for mass balance purpose)

Thanks for your advice and comments in advance!


Harish February 2, 2007 04:02

Re: How to solve for transport with large source t
 
what kind of equation do you obtain by the flux balance.May be people can give some idea looking at it as a mathematical problem.

yong February 2, 2007 10:31

Re: How to solve for transport with large source t
 
Thanks for your response, Harish.

The additional equation need to solve is the mass flux balance:

h(Y_bulk - Y_surf) = ReactionRate(Y_surf)

where Y_bulk is the species concentration of the bulk flow, and Y_surf is the concentration at the surface. Y_bulk will be solbed with 1D transport (NS eqn) and the local reaction rate is a function of surface species concentration, temperature and catalyst loading.

The difficulity comes from the implicit Y_surf, which may affect the reaction rate greatly.

Any sugestion is highly appriciate.



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