CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

User Defined Reaction Rate

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

LinkBack Thread Tools Search this Thread Display Modes
Old   December 13, 1999, 10:30
Default User Defined Reaction Rate
John McKelliget
Posts: n/a
I dont understand how a UDF for a reaction rate, which is attached to the appropriate function hook, is then attached to a reaction in the reaction panel. All I get are inputs for arrenhius reactions. Also, what if you have more than one reaction - there is only one function hook.

I know I am missing something basic but the manual does not address this issue.

I am using finite rate model, three species, two reactions.

  Reply With Quote

Old   December 17, 1999, 11:44
Default Re: User Defined Reaction Rate
Joe Maruszewski
Posts: n/a
When you supply a UDF for reaction rate, this happens: 1) Fluent calculates the reaction rate using the methods selected by you in the reaction panel, 2) the UDF you supplied is called, allowing you to modify the reaction rate. Since the UDF is called for every reaction, what you have to do is only modify the reaction rate for any reactions for which you do not want the default behavior.

To check for a specific reaction, you would look at the reaction structure (the variable "r" if you created your UDF using DEFINE_VR_RATE(name, c, t, r, mw, yi, rr, rr_t)). You can do something like this to check for a particular reaction:

if (STREQ(r->name,"reaction-1"))

modify rr here;


  Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
[General] Paraview User defined view prapanj ParaView 3 January 3, 2014 21:54
user defined turbulence model manuutin STAR-CD 5 October 14, 2009 06:29
UDF - Derivatives for User Defined Memory Variable Sandilya Garimella FLUENT 0 January 14, 2008 11:39
User Defined Scalars - Returning Values Carlos V. FLUENT 0 April 19, 2006 19:18
Usage of user defined functions Gowrish FLUENT 1 October 26, 2005 08:44

All times are GMT -4. The time now is 16:20.