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

janaf warning and printstack error simulating coal gasification by coalchemistryfoam

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

Like Tree1Likes
  • 1 Post By wyldckat

Reply
 
LinkBack Thread Tools Display Modes
Old   June 21, 2015, 09:16
Default janaf warning and printstack error simulating coal gasification by coalchemistryfoam
  #1
New Member
 
ahmad
Join Date: Jun 2015
Posts: 4
Rep Power: 2
akia is on a distinguished road
Hi
I am simulating coal gasification process in fluidized bed with coalchemistryfoam solver in OF 2.3.0. First I start with running itís tutorial (simplified siwek). When i increase the internal field temperature from 400 to 1400, I meet the JANAF warning and printstack error so running had stopped. I changed the tutorial to my case conditions ( 1 inlet for coal and 1 inlet for air with an outlet at top of gasifier ) I have the same problems. I do the following procedures to solve it but it didnít work:
  1. Turning off chemistry and combustion
  2. finer mesh specially near the coal injector and ignition cells
  3. reduce courant number to 0.1
  4. reduce under relaxation factors to 0.5
  5. set many kind of boundary conditions

I want to know it is solverís problem (which itís tutorial has error) or I am doing something wrong?



Please help me and give a solution; my project had stopped for 3 month because of this error


The boundary condition is attached.
Attached Files
File Type: gz 0.tar.gz (1.7 KB, 1 views)
akia is offline   Reply With Quote

Old   June 22, 2015, 02:34
Default out of temprature range(janaf warning) in coalchemistryfoam
  #2
New Member
 
ahmad
Join Date: Jun 2015
Posts: 4
Rep Power: 2
akia is on a distinguished road
Hi freinds

I want to simulate coal gasification process in fluidized bed with coalchemistryfoam solver in OF 2.3.0. use it’s tutorial (simplified siwek) for this purpose but just by increasing the internal field temperature from 400 to 1400, I meet the JANAF warning and printstack error so running had stopped. I do the following procedures to solve it but it didn’t work:
  1. Turning off chemistry and combustion
  2. finer mesh specially near the coal injector and ignition cells
  3. reduce courant number to 0.1
  4. reduce under relaxation factors to 0.5
  5. set many kind of boundary conditions
what else should i do?
akia is offline   Reply With Quote

Old   June 28, 2015, 16:13
Default
  #3
Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 8,488
Blog Entries: 34
Rep Power: 86
wyldckat is just really nicewyldckat is just really nicewyldckat is just really nicewyldckat is just really nice
Quick answer:
  1. Several bugs have been fixed since 2.3.0 was released. Please try upgrading to the latest OpenFOAM 2.4.0.
  2. Don't jump directly from 400K to 1400K. First test what happens when you change to 500K, 600K, and so on, until you find the breaking point.
  3. It's possible that this solver was not designed to work at such high temperatures, since other chemical reactions can occur and possibly explosions can also occur at very high temperatures, which would explain the crash. Therefore, again, this is why I suggest you gradually increase the temperature.
akia likes this.
wyldckat is offline   Reply With Quote

Old   June 29, 2015, 16:23
Default
  #4
New Member
 
ahmad
Join Date: Jun 2015
Posts: 4
Rep Power: 2
akia is on a distinguished road
Dear Bruno Santos

thanks for your answer.
I used OF 2.0.1 - 2.1.0 and 2.3.0 and this error apeare in all of them but i will try in OF 2.4.0 too.
This error occurred after the internal temperature arrive at 900 kelvin, but before and after that any notable thing happened!! I read in other forums that this solver use for gasification that the range of temperature is between 800 to 1500, but i 'm not sure about it.
akia is offline   Reply With Quote

Old   August 20, 2015, 17:20
Default
  #5
Super Moderator
 
Bruno Santos
Join Date: Mar 2009
Location: Lisbon, Portugal
Posts: 8,488
Blog Entries: 34
Rep Power: 86
wyldckat is just really nicewyldckat is just really nicewyldckat is just really nicewyldckat is just really nice
Greetings akia,

So I finally managed to take a look into this and it's a bit disconcerting.
I tested the tutorial "lagrangian/coalChemistryFoam/simplifiedSiwek" with OpenFOAM 2.4.x and the modification you stated, namely of changing the internal temperature from 400 to 1400 K and I ran the case with the Allrun script. There was no crash nor problems with Janaf.
The only issue that occurred were several situations where this output was given:
Code:
--> FOAM Warning : 
    From function seulex::solve(scalar& x, scalarField& y, stepState&
    in file ODESolvers/seulex/seulex.C at line 255
    step size underflow :2.710505431e-20
which seems to be a problem with the ODE solver, which is unable to find a proper solution for the problem.

I have not tested with 2.3.0 no 2.4.0, so either the issue you mentioned is already fixed in 2.4.x, or you omitted important details for reproducing the error.

Best regards,
Bruno
wyldckat 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



All times are GMT -4. The time now is 00:05.