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

ືNeed help for partially premixed combustion model

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

Reply
 
LinkBack Thread Tools Display Modes
Old   September 30, 2016, 05:49
Default Need help for partially premixed combustion model?
  #1
lem
New Member
 
lemthong
Join Date: May 2016
Posts: 7
Rep Power: 3
lem is on a distinguished road
Sponsored Links
Hi all,

I am simulating biomass-producer gas combustion in a cylindrical chamber has single inlet/outlet.

Diameter of chamber is 250 mm/length 500 mm.
diameter of inlet/outlet are 50 mm.
Meshed with tetrahedral for whole of domain and inflation for chamber wall.
Achieved 203061 elements, skewness Max 0.764, and orthogonal quality 0.999.

Model:
Energy, Standard k-e, Standard wall Fn, P1 and Partially Premixed-combustion Model.

PDF table creation:
Chemical equilibrium, Non-adiabatic with fuel stream rich flammability 0.6

Boundary tab: mole fraction of producer gas is (0.14 h2, 0.456 n2, 0.017 o2, 0.24 co, and 0.147 co2) with 470k temperature for both fuel/oxidizer.

Materials: selected absorption coefficient as wsggm-domain-based and cement properties for the wall.

BCs:
Inlet: mass flow rate 0.04 kg/s, turbulent intensity 10%, hydraulic diameter 0.05m, 470 for temperatures, and mean mixture fraction, 0.529 (based on stoichiometry air-producer gas mixture).
Outlet: pressure outlet, turbulent in 10%, hydraulic diameter 0.05m, backflow progress 1, and backflow Temperature 1000k.
Wall: heatflux 4800, internal emissivity 0.7, wall thickness 0.1m.

Solution Methods: SIMPLE and First Order Upwind (in the first solution).
Solution procedure:
1) selected equations for solving included Flow, Turbulence, Energy and P1
initialization with all zones, enter 1 for progress variable.
2) adapt region on inlet zone and patch with 0 for progress variable and solve for all equation (by flowing the tutorial of Partially Premixed combustion).

After some iterations, I checked the results it seems like no reaction inside chamber.
My understanding, the mole fraction of CO should be as an initial value in bottom (or near inlet zone) and slowly decreased next till into the top of chamber (or near outlet zone).
But in my solution seems like achieving constant value of CO inside the chamber.
Even I patched in high temperature (2000k) and tried with different methods, but got the same results.

I dont know what is wrong with my solution... can anyone help to fix this?

Thank you!
Lem


see the results




Last edited by lem; October 1, 2016 at 23:29.
lem is offline   Reply With Quote
Sponsored Links

Reply

Thread Tools
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 On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
premixed combustion using Zimont model bob FLUENT 12 January 9, 2017 14:02
combustion model in premixed combustion chamber wuyu FLUENT 7 October 21, 2015 13:18
Combustion Model - Laminar Flamelet Model spg1g14 CFX 0 August 5, 2015 18:13
Premixed combustion model - help! HeKhalil ANSYS 0 November 22, 2012 06:39
How can I model H2-AIR combustion popi CFX 8 August 16, 2007 05:32

Sponsored Links


All times are GMT -4. The time now is 14:47.