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

Pre-mixed combustion- Laminar finite rate model

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 25, 2004, 19:21
Default Pre-mixed combustion- Laminar finite rate model
  #1
Shankar
Guest
 
Posts: n/a
Hello all,

I am dealing with pre-mixed combustion in a closed chamber.After defining the chemical mechanism and activating all the reactions, I have a small zone in the centre of the chamber where I patch the temperature to be above the ignition temperature(which is equivalent to an electric spark).

The reaction mechanism is defined based on the literature available for this particular mixture of fuel.

But I am not getting convergence. Is there anything wrong with the way I am starting the reactions? I have floating operating pressure for this kind of premixed combustion inside a closed chamber.The geometry is simple(cube) and so are the boundary conditions.

I couldnt find this paper in our library, does anybody have this: Westbrook, C.K. and Dryer F.L., (1981) "Simplified Reaction Mechanisms for the Oxidation of Hydrocarbon Fuels in Flames" CST, 27, pp.31-43

Thanks and Regards, Shankar.

  Reply With Quote

Old   March 25, 2004, 20:51
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #2
cg
Guest
 
Posts: n/a
Use the coupled solver
  Reply With Quote

Old   March 25, 2004, 23:55
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #3
Shankar
Guest
 
Posts: n/a
Hi CG,

I am using coupled solver only.

I think thats the default option in FLUENT?

  Reply With Quote

Old   March 26, 2004, 05:22
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #4
zxaar
Guest
 
Posts: n/a
i don't think coupled is default option in fluent. check again.
  Reply With Quote

Old   March 26, 2004, 18:24
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #5
Shankar
Guest
 
Posts: n/a
Thanks to both of you, 'coupled' is not the default option in FLUENT, but it seems like if I use 'coupled', I cannot use floating operating pressure?

Shankar.
  Reply With Quote

Old   March 29, 2004, 07:18
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #6
zxaar
Guest
 
Posts: n/a
one more thing i do have the paper u mentioned but there is a problem, i am in portugal and i left the paper in india, i only have the appendix here in which reaction mechanism is given, if you want that i can scan that and send you
  Reply With Quote

Old   March 29, 2004, 16:19
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #7
Shankar
Guest
 
Posts: n/a
Hi Zxaar,

That would be awesome if you could e-mail it to me.

Thanks, Shankar.
  Reply With Quote

Old   March 30, 2004, 21:37
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #8
Shankar
Guest
 
Posts: n/a
Using the coupled solver did not solve the problem. I get the following error: 'couldnt allocate the fine level co-efficient matrix'. Any idea whats wrong?

Shankar.
  Reply With Quote

Old   March 31, 2004, 06:18
Default Re: Pre-mixed combustion- Laminar finite rate mode
  #9
zxaar
Guest
 
Posts: n/a
i also do have the same experience, but to my surprize for the same case and same boundary conditions sometimes it works without complaining, i have found similar case with edc, i mean i have same grid same boundary conditions and same chem mech file, in one case it runs without a prob, in other it gives me some failure. i am not able to sort it out.
  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
Use of k-epsilon and k-omega Models Jade M Main CFD Forum 40 January 27, 2023 08:18
Problem on EDC model for coal combustion lei FLUENT 4 September 3, 2015 10:39
finite rate mutistep combustion torn Main CFD Forum 2 April 25, 2015 00:19
Liquid rocket engine non-premixed combustion model Erik FLUENT 2 November 28, 2013 15:09
Laminar Model danillocafaldo CFX 5 August 16, 2010 11:43


All times are GMT -4. The time now is 03:57.