CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > FLUENT

Adsorption Rate for a Chemical Reaction on Catalytic Porous Media

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   April 28, 2013, 04:22
Question Adsorption Rate for a Chemical Reaction on Catalytic Porous Media
  #1
New Member
 
Mitra Karami
Join Date: Feb 2010
Posts: 4
Rep Power: 7
mitra is on a distinguished road
Hi,
I'm running a program in Fluent which involves chemical reactions which occur in porous media (catalyst). I have Arrhenius rate expressions for these reaction. let me check something first:

1-Is it correct to define them as wall surface reactions (and not volumetric)?

My main question is about the rate of production (or consumption) of species. As you know in addition of reaction rates, it depends on "adsorption rate". I have this expression also, it's a polynomial that each sentence is exponential functions of temperature and partial pressure. But

2- How can I apply them to fluent? Through which panel?

Thank you in advance
Mitra
mitra is offline   Reply With Quote

Old   April 29, 2013, 13:29
Default
  #2
Senior Member
 
A CFD free user's Avatar
 
A-A Azarafza
Join Date: Jan 2013
Posts: 187
Rep Power: 4
A CFD free user is on a distinguished road
Hi
You need to use source term of your zone boundary and define your reaction consumption or production directly using a UDF. If you have an Arrhenius reaction, you don't need to use UDF, you can define it easily in reaction panel.
__________________
Regard yours
A CFD free user is offline   Reply With Quote

Old   April 29, 2013, 14:57
Question How to execute more than one surface reaction rate through udf?
  #3
New Member
 
Mitra Karami
Join Date: Feb 2010
Posts: 4
Rep Power: 7
mitra is on a distinguished road
Thank you.

Meanwhile literature survive, I found a new set of reaction rates which are more useful for my work. (kmole/kg_cat.h). they are functions of partial pressure of species and temperature. the rate expressions are NOT Arrhenius.
I have a new question now:

I have 4 reactions. when writing a udf (define_sr_rate), how can I apply the rate of production (or consumption) for each species, which is a polynomial function of each reaction rate?
mitra is offline   Reply With Quote

Old   April 29, 2013, 15:25
Default
  #4
Senior Member
 
A CFD free user's Avatar
 
A-A Azarafza
Join Date: Jan 2013
Posts: 187
Rep Power: 4
A CFD free user is on a distinguished road
You need to use SOURCE macro to define the rate of your species separately and then hook them up to the pertinent UDF in source tab of the B.C.
Hope it helps
__________________
Regard yours
A CFD free user is offline   Reply With Quote

Old   May 20, 2014, 08:29
Default
  #5
New Member
 
Kostis Chatzi
Join Date: Apr 2014
Location: Greece
Posts: 20
Rep Power: 3
kostis217 is on a distinguished road
hi guys , i want to use UDF in order to define the catalytic reaction rate of c3h8 which depends on the concentration of propane.can you give any clue ?
kostis217 is offline   Reply With Quote

Reply

Tags
adsorption rate, fluent, reaction modelling

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
Porous media setup issues in Fluent Bernard Van FLUENT 26 July 24, 2015 18:24
Segmentation fault in running alternateSteadyReactingFoam,why? NewKid OpenFOAM 18 January 20, 2011 17:55
porous media with chemical reaction Arvind Phate FLUENT 2 July 18, 2005 13:52
Porous media and chemical reaction pepa FLUENT 10 August 20, 2003 05:24
chemical reaction - decompostition La S. Hyuck CFX 1 May 23, 2001 00:07


All times are GMT -4. The time now is 00:12.