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

Combustion Problem

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

LinkBack Thread Tools Search this Thread Display Modes
Old   September 2, 2003, 16:45
Default Combustion Problem
Posts: n/a
I am completing an internship in the United States and I have been asked to simulate a simple combustion chamber in Fluent 6.1. However I am unsure if I am using the correct setup because the results seem to be inaccurate as when I run it in unsteady after 10 seconds the whole domain seems to be overheated too quickly. My chamber is 300mm by 70mm and the domain is 2000mm by 1000mm. I have the outer boundary of the domain set to an outflow.

The setup is basically a 2D rectangle, with fuel as n-heptane injected from the middle of the chamber as droplets. I setup n-heptane in PrePDF for the species I had read in a tutorial so I am pretty sure they are correct. For the injections I have choosen to have group injections so I can have a spray angle and I have the stochastic model turned on.

For the species in Fluent I choose non-premixed because I wish to inject air also. However I cannot find air in the list of inert injections so any suggestions on that would be helpful as I am currently injecting oxygen and nitrogen separately.

I am using the k-epsilon turbulence model with DPM turned on and also droplet collision and droplet breakup turned on.

I have everything set to 300K and I patch a surface in the combustion chamber for ignition. Which works perfectly well.

Can anyone give me any suggestions to how I could improve this or any settings I have missed out? I know you cannot give me individual values to use because that is dependent on the case itself and I will just have to figure those out alone such as injection speed, diameter, mass flow rate etc etc. I am just wanting to know if this setup is accurate or if I am missing things.

Also I orginally wished to use JP-4 aviation fuel but I could not figure out how I could specify this in PrePDF (I understand I could change the thermo.db in prePDF but I do not know what values to use or what other species are produced) and also how would I choose it as an injection in Fluent, I guess it is the same problem as choosing air as the injection.

Thank you

  Reply With Quote

Old   September 3, 2003, 05:22
Default Re: Combustion Problem
Posts: n/a
Have you acitvated the rdiation model? What is your wall boundary conditions?
  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
hel (turbulent viscosity ratio limited) for supersonic combustion problem omar.2002bh FLUENT 2 September 5, 2012 11:04
Problem using EDM for combustion nakul FLUENT 1 August 11, 2011 05:01
A problem with combustion Luk Main CFD Forum 1 April 28, 2008 09:55
Combustion problem rupal CFX 0 April 21, 2008 05:29
problem in incomplete nonpremixed combustion muro FLUENT 0 September 28, 2007 06:54

All times are GMT -4. The time now is 02:12.