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

Problem with Non-Premixed model (coal burner)

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 4, 2007, 11:44
Default Problem with Non-Premixed model (coal burner)
  #1
Nando
Guest
 
Posts: n/a
Hello:

Im modeling a coal burner with non-premixed model. Ive got one fuel stream (coal) and two oxidizer stream with different compositions.

I must apply two-mixture-fraction approach.(three stream with different composition).DPM iteraction every 25 continuous phase iteraction.

Ive a problem about this approach:

Fluent update properties continuous phase every ten iterations. I plot some variables (temperature,O2,mass flow rate).

When Fluent do this update properties, these variables increase or decrease its value too much (example: Tempearture changes from 2000 K to 500 K approximately, it changes from 500 to 2000 at the next update it happens every 10 iterations).

The solution cant converge because of these great changes of the fluid properties.I dont understand this approach.

Could somebody explain me two mixture fraction approach?

How can i converge my case?

My english is so bad.Im sorry.

Thanks
  Reply With Quote

Reply

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
Use of k-epsilon and k-omega Models Jade M Main CFD Forum 40 January 27, 2023 08:18
Nonpremixed Combustion Model for Coal Gasification C.Y.Ler FLUENT 2 April 29, 2014 09:51
Polyflow Simulation with ViscoElastic Model memory problem sid2909 ANSYS 0 May 10, 2010 06:27
premixed flame modeling problem peiyong wang CFX 1 July 18, 2008 13:02
A Problem with setting the time step in VOF model Le FLUENT 2 July 20, 2006 23:00


All times are GMT -4. The time now is 02:47.