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

Non-premixed comb. temp prediction; PDF problem

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   October 5, 2005, 05:30
Default Non-premixed comb. temp prediction; PDF problem
  #1
K. Jagus
Guest
 
Posts: n/a
Hello,

I am doing a steady state simulation of combustion in combustion chamber. Fuel is liquid diesel, injected by pressure swirl. The problem is that I do get too high temperature values on the walls of the air blast. 3200K is far too high. The maximum value calculated by the PREPDF was determined to be 2274K. Any suggestions? Is it due to the wrong species chosen in PREPDF? Also, I am unable to read either the pdf table or the input file into the prepdf once i create them. It says couldn't determine the file format and unable tor ead file. Thank You in advance for any suggestions.
  Reply With Quote

Old   October 5, 2005, 06:31
Default Re: Non-premixed comb. temp prediction; PDF proble
  #2
RoM
Guest
 
Posts: n/a
For high temperature flames (>1500K) dissociated species become important so you will have to include some of them in your pdf. I would add at least OH, O(atomic) and H(atomic) to account for the dissociation of water. Other intermediate species you might consider are CH2O,CO,HNO2 and H2O2.

Good Luck

RoM
  Reply With Quote

Old   October 5, 2005, 06:46
Default Re: Non-premixed comb. temp prediction; PDF proble
  #3
K. Jagus
Guest
 
Posts: n/a
I will be trying this shortly. Thank You very much. As for O and H however i think I did include them. Problem is I cannot look up the lookup table in PREPDF
  Reply With Quote

Old   October 5, 2005, 08:41
Default Re: Non-premixed comb. temp prediction; PDF proble
  #4
Mary
Guest
 
Posts: n/a
I had such problem !

Try this in PrePDf

Display-Options-Rendering

and then check Fluent stroked font

Mary
  Reply With Quote

Old   October 5, 2005, 09:32
Default Re: Non-premixed comb. temp prediction; PDF proble
  #5
K. Jagus
Guest
 
Posts: n/a
I tried it, unfortunately it did not help.
  Reply With Quote

Reply


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
Problem of torque prediction in CFX Patrick CFX 6 September 19, 2013 06:51
premixed flame modeling problem peiyong wang CFX 1 July 18, 2008 13:02
Problem with pdf reading(unable to get properties) João Pimentel Main CFD Forum 0 September 11, 2006 09:49
PDF problem olivier FLUENT 2 September 5, 2001 04:45
Symmetric problem - Asymmetric prediction Mark Main CFD Forum 14 January 29, 2001 14:21


All times are GMT -4. The time now is 06:37.