UDF for coal combustion in multiphase flow
 

Hello,

I am modelling packed bed coal combustion with fluent.
For this purpose i am using Eulerian- Granular multiphase model in Ansys Fluent 12.

My question is regarding with UDF to activate heterogeneous reaction in between phases.I have little experience with UDF's and UDF mentioned in fluent help files is completely different than my problem.

I have seen macro 'DEFINE_HET_RXN_RATE', but was not able to write UDF for simple reaction C+0.5O2=>CO.
where reaction constant K can be written as k=17.9Exp[-13750/T].

Can anyone has some experience to write such UDF to add into multiphase model?

Don't know exactly why your simple reaction did not work, and I have not worked with the heterogeneous rxn macro. However, I have used the volume rxn macro and particle laws somewhat. My only real piece of advice is to pay very close attention to the units and form of the equation. When I have not worked it out on paper first, the code has never worked. Good luck.

Thanks for your reply,
Well, i have a problem with defining domain in which heterogeneous reaction takes place. I have no idea how to write that in a UDF.

Tiana.

I am working in something similar. But I am doing gasification instead of combustion.
Dis you manage to sort out your problem? I would appreciate any advice in setting up 'DEFINE_HET_RXN_RATE'

hi
I'm also working on gasification modeling in a fluidised bed reactor. can anyone suggest me solver parameters for convergence? can i input my reactions in UDF in any other form other than the normal Arr form???

Hi all,

I am also doing simulation of biomass gasification in fluidized bed reactor. if anyone have any idea to make UDF code foe heterogeneous reaction please help me. i had gone through sample code for the heterogeneous reaction macro.i am confused with specification of domain and thread in my problem. may i use the same sample for arrhenius rate constant for my problem?

thanks and regards,
prishor

I have modeled Fixed-Bed combustion. But I think there is no need of using UDF for fluidized bed. Should think of it on a proper time.

Various codes for DEFINE_HET_RXN_RATE here
 

Dear Fluent users in our forum,

I have ever tried my best to write the a UDF for heterogeneous reactions but actually but I did not success yet. I have also asked several experienced users but I still did not get any replies.
Today, I have just found a long code for various kinds of heterogeneous reactions and I would like to share to all of you if you are interested in because I think science is belonged to the world not to any single person.

Enjoy your research work and hope we can share and discuss further on the CFD simulation of multiphase processes!

Finally, you can find the code attached in this post.

it was very helpful the code tha you attached . I want to model biomass gasification in a plasma gasifier . If anyone have some experience on that and how to write the UDF and wants to help me i would be grateful . Also i found a code of udf for coal gasification . If anyone wants it i can send it

Comustion modeling in a reactor
 

Can anyone help me and attach UDF file which may apply in reactor for solving combustion and calcinations reactions. Above attach file is helpful in how to proceed for writing UDFs.

With regards
Gajendra gaurav

i think the code is short of a file that defines initial values，can you find it，very
 

i think the code is short of a file that defines initial values，can you find it，very thank you。my mailbox is 1032993302@qq.com

Dear friend,

did guy could make a UDF for a single step reaction.
I'm using eulerian eulerian multi phase model. any example would be very appraiciate.

I have been trying to do coal gasification CFD since graduation. If you have coal gasification related UDFs, you can send me an email haojiehan1994@gmail.com, thank you very much.

Dear friends，
does anyone know how to modify porosity or void fraction when using Eulerian- Granular multiphase model？