CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Running, Solving & CFD

Getting inverted results on mass-fraction

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

Reply
 
LinkBack Thread Tools Display Modes
Old   March 22, 2016, 08:58
Default Getting inverted results on mass-fraction
  #1
New Member
 
Abdiwe
Join Date: Jan 2015
Location: Vienna
Posts: 2
Rep Power: 0
Abdiwe is on a distinguished road
Hello everyone

I‘m modeling a flow inside cylindrical tube filled with the catalyst and this tube is exposed to a constant heat flux (100000 W/m2). The inlet gas is ammonia under around 600 K and 50 bar and when the gas go through the catalyst inside the tube it dissociate to nitrogen and hydrogen. The flow is turbulent, i calculate the viscosity resistance, inertial resistance, porosity and the surface to volume ratio (because i assume it’s wall surface reaction). My reaction is based on Arrhenius equation, so i thought i don’t need to write UDF function. When i applied all these conditions the reaction occur, however, the mass fraction result isn't correct. Based on the equation of my reaction 2NH3 ------ N2 + 3H2 which means the result of dissociated ammonia is very much 20 - 30 % N2 and 60 - 70 % H2 and about 10% NH3 (not dissociated). However, I'm getting exactly the opposite 60-70% N2 and 20 - 30% H2 and i don't know exactly why this is happening. Do you have any idea how can i solve this problem? Please help

Cheers

Abdiwe

[ Moderator note: This post was moved from here: Mass fraction stange results ]

Last edited by Abdiwe; April 5, 2016 at 09:46. Reason: see "Moderator note:"
Abdiwe is offline   Reply With Quote

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
Species Mass fraction in Fluent prashantthaker208 FLUENT 4 July 3, 2014 23:41
mass fraction of species Lilly FLUENT 3 July 25, 2011 05:00
about Mass Fraction Jaloha CFX 0 June 16, 2008 12:42
CFX Solver Memory Error mike CFX 1 March 19, 2008 08:22
gradient of species mass fraction zhou FLUENT 0 March 3, 2004 23:55


All times are GMT -4. The time now is 08:51.