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

Burning Velocity Model (BVM) to simulate pure premixed turbulent flame

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 22, 2015, 21:28
Post Burning Velocity Model (BVM) to simulate pure premixed turbulent flame
  #1
New Member
 
Saad Akhtar
Join Date: Oct 2013
Posts: 1
Rep Power: 0
saad.akhtar312 is on a distinguished road
Hi,

I have been using BVM model to simulate pure premixed turbulent METHANE-AIR flames under lean conditions inside a gas turbine combustor. I have some queries with regards to accuracy of BVM in predicting the species profile for pure premixed flames.

1) The flamelet library generated by the RIF tool in cfx (Using GRI-MECH 3.0) maps the species profile for a range of mixture fraction values. However in a 100% premixed flame, mixture fraction has a constant value (zero mixture fraction variance as well) and the reaction zone is modeled by reaction progress variable. How will the cfd solver update the species profile from the flamelet library for pure premixed flames then considering the fact that RIF maps the species concentration for a range of mixture fraction values?

2) Using constant mixture fraction and 0 mixture fraction variance as boundary conditions for pure premixed flames, I simulated the flame using BVM. As far as temperature profile is concerned the agreement between simulation and experiment result is excellent. However the species profile for the intermediate radicals is extremely poor. For example the OH specie contour is very similar to CO2 i.e. minimum in fresh reactant and maximum in the burnt products. However the OH concentration should only exist in the reaction zone (0 in fresh and burnt products). Same goes for other intermediate radicals such as CH2O, O, H2 etc.

3) Now FLUENT 15.0 has a similar model implementation under the name of FGM (Flamelet generated manifold). An additional feature in this model is a separate option for premixed flamelet generation (In CFX RIF there is no such option). I simulated the same problem using FGM in fluent for premixed flamelet and the was able to get right results for the intermediate radicals (such as OH, CH2O, O etc.). From this observation can I deduce that CFX-RIF does not have the capability to simulate correctly the species profile for intermediate radicals, since the flamelet library generated by cfx-RIF is for non-premixed flamelet?

I will be really grateful to the experienced users in the field of turbulent reacting flow for their precious feedback.
saad.akhtar312 is offline   Reply With Quote

Old   April 29, 2024, 09:51
Question BVM (partially Mixed)
  #2
New Member
 
Bishwajit Nandi
Join Date: Apr 2024
Posts: 7
Rep Power: 2
bishwajitdgp is on a distinguished road
I have imported Butane Oxygen WD1 reaction from reaction library. I have selected k-omega as turbulence model and BVM (partially Mixed) as combustion model. But I could not select the reaction from the reaction list.

Can anyone help me on this regard?
bishwajitdgp is offline   Reply With Quote

Old   April 29, 2024, 18:50
Default
  #3
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,841
Rep Power: 144
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
I do not do combustion modelling so will not be able to help you much, but I can recommend that the CFX tutorials are the best place to start when you are working out how to set up a model. Have you looked at the CFX tutorials on combustion modelling?

Also ANSYS Support has lots more tutorials available as well. If you have access the ANSYS Support this is very useful as well as it covers a far wider range of models than the tutorials.
__________________
Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.
ghorrocks is offline   Reply With Quote

Reply

Tags
bvm, cfx, fgm, lean premixed flames, turbulent combustion

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
Reynolds transport, turbulence model, etc Beginner Main CFD Forum 1 January 7, 2009 06:36
Stretch and Quenching in Premixed Turbulent Flames JK Main CFD Forum 0 April 2, 2006 15:05
Boundary conditions for a flame burning with wind David Main CFD Forum 2 February 4, 2005 06:59
Variables Definition in CFX Solver 5.6 R P CFX 2 October 26, 2004 03:13
About burning velocity Sheng Chen Main CFD Forum 0 June 29, 2004 01:32


All times are GMT -4. The time now is 13:29.