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

Low Pressure Surface Coverage

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

Reply
 
LinkBack Thread Tools Display Modes
Old   April 25, 2013, 12:00
Default Low Pressure Surface Coverage
  #1
New Member
 
Natali
Join Date: Apr 2013
Posts: 21
Rep Power: 4
Natali_Beginner is on a distinguished road
Hello guys,
I am recently start working with FLUENT, but I have been working for 10 years in chemistry and combustion. So, this question that I am asking relates just to the FLUENT manipulation.
I am simulating combustion in low pressure. So, surface coverage is low in that pressure that seems reasonable.
However, its low rate value in FLUENT doesn't make sense. In fact, FLUENT doesn't have progress in that after some iterations and the surface coverage remains unchanged.
Do you have any suggestion how to get rid of that?
I am entering some coverage-dependent reaction parameters but it doesn't work.
I really appreciate if you help me since I am so stuck on that
Thanks,
Natali
Natali_Beginner is offline   Reply With Quote

Old   April 25, 2013, 19:46
Default
  #2
New Member
 
Natali
Join Date: Apr 2013
Posts: 21
Rep Power: 4
Natali_Beginner is on a distinguished road
Hey Guys,
I am really praying somebody helps me from this annoying problem.
Thanks,
Natali
Natali_Beginner is offline   Reply With Quote

Old   April 26, 2013, 14:32
Default
  #3
New Member
 
Natali
Join Date: Apr 2013
Posts: 21
Rep Power: 4
Natali_Beginner is on a distinguished road
Any Help?
I am really in problem.
Natali_Beginner is offline   Reply With Quote

Old   April 26, 2013, 14:39
Default
  #4
Member
 
Parisa
Join Date: Feb 2013
Posts: 51
Rep Power: 4
Parisa_Khiabani is on a distinguished road
Hey Natali,
There is an option in the surface chemistry as coverage dependent reaction. Did you check that?
By default, its values are zero. maybe you want to change them to a realistic value.
Did you check the Knudsen number in your problem? Be careful that the knudsen number not become very high, say 0.1

Parisa
Parisa_Khiabani is offline   Reply With Quote

Old   April 26, 2013, 14:50
Default
  #5
New Member
 
Natali
Join Date: Apr 2013
Posts: 21
Rep Power: 4
Natali_Beginner is on a distinguished road
Thanks Parisa,
Yes, I tried that too. However, it doesn't work although at the beginning just a little bit more progress in coverage is seen, but it will be stopped.
the Knudsen number is in the range of continuum approach. So it shouldn't have any problem.
I am really confused and exhausted about this problem.

Natali
Natali_Beginner is offline   Reply With Quote

Old   April 26, 2013, 14:56
Default
  #6
Member
 
Parisa
Join Date: Feb 2013
Posts: 51
Rep Power: 4
Parisa_Khiabani is on a distinguished road
So, do you have any estimate about the real times or values?
The reactions reach to equilibrium soon in low pressure and maybe you get correct results.
Idk
Parisa_Khiabani is offline   Reply With Quote

Old   April 26, 2013, 15:16
Default
  #7
New Member
 
Natali
Join Date: Apr 2013
Posts: 21
Rep Power: 4
Natali_Beginner is on a distinguished road
I don't have exact values to compare.
But I know that the surface coverage should keep changing.
Natali_Beginner is offline   Reply With Quote

Old   April 26, 2013, 15:21
Default
  #8
Member
 
Parisa
Join Date: Feb 2013
Posts: 51
Rep Power: 4
Parisa_Khiabani is on a distinguished road
Can you send me your case?
Parisa_Khiabani is offline   Reply With Quote

Old   April 26, 2013, 15:23
Default
  #9
Member
 
Parisa
Join Date: Feb 2013
Posts: 51
Rep Power: 4
Parisa_Khiabani is on a distinguished road
I sent you already my Email.
Parisa_Khiabani is offline   Reply With Quote

Old   April 26, 2013, 15:26
Default
  #10
New Member
 
Natali
Join Date: Apr 2013
Posts: 21
Rep Power: 4
Natali_Beginner is on a distinguished road
Check your Email, please.
Thanks,
Natali
Natali_Beginner is offline   Reply With Quote

Old   April 28, 2013, 02:19
Default
  #11
New Member
 
Natali
Join Date: Apr 2013
Posts: 21
Rep Power: 4
Natali_Beginner is on a distinguished road
Hello guys,
I am seriously praying somebody can help me to solve this issue. This seems very annoying and boring.
Thanks,
Natali
Natali_Beginner 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
Pressure velocity decoupling in low mach compressible flow Meeranandan Main CFD Forum 0 February 13, 2013 04:47
Layers don't fully surround surface EVBUCF OpenFOAM Native Meshers: snappyHexMesh and Others 14 August 20, 2012 04:31
Pulsatile pressure inlet with pressure outlet a.lynchy FLUENT 3 March 23, 2012 14:45
[ICEM] Problems with coedge curves and surfaces tommymoose ANSYS Meshing & Geometry 0 August 5, 2011 16:02
Pressure BCs or Periodic BCs for model of frost on vertical surface? andy.eco FLUENT 2 March 26, 2010 03:02


All times are GMT -4. The time now is 07:55.