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-   -   Sources for multiphase multicomponent reaction sys (https://www.cfd-online.com/Forums/cfx/20374-sources-multiphase-multicomponent-reaction-sys.html)

Liwau May 18, 2004 04:57

Sources for multiphase multicomponent reaction sys
 
Dear Specialists,

I have trouble in setting sources for a multiphase multicompoent reaction system. The system likes this: gas + solid; reactions occur in gas phase; mass transfer exists between gas phase and solid phase. Of course, solid phase should be looked as liquid because Euler approach is adopted. When setting Fluid Sources, I don't know how to set the items under the Continuity Frame. Could anybody tell me the guidances? Thanks.

Liwau

test May 19, 2004 00:41

Re: Sources for multiphase multicomponent reaction
 
Hi,

Well I am not sure if you are using CFX-5.6 or 5.7! Assuming that you are using 5.6... You are talking of a phasic reaction... The reaction has to b broken down into steps!

1. Devolatilization of volatiles from the solid phase 2. Combustion of volatiles in gas phase 3. Combustion of char left from in the solid phase.

I am not sure what kind of reactor you are looking at.. However you can contact your local CFX support team and ask them to give you an example problem of bio-mass combustion.. It would be difficult to explain you the details in the mail now, since this analysis is very involved. You ahve to create lot of subdomain and define the source term only in the continuity equation.

Let me know if you require further help


Phil May 20, 2004 11:36

Re: Sources for multiphase multicomponent reaction
 
The use of multiple subdomains for this type of calculation is now unnecessary in CFX-5.7. There is a new option to respect the specified mass fractions even if the mass source is negative.

tec May 20, 2004 23:08

Re: Sources for multiphase multicomponent reaction
 
Dear test:

As your description for this problem, I want to use CFX4 to model the devolatilization of volatiles from the solid phase 2. Should I use User Fortran (which one) and how to deal with the .fc file simulataneously ?

Furthermore, I also need to track the history of solid phase 2 (char) in the flow field.

Thanks for your attention.


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