CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > OpenFOAM > OpenFOAM Programming & Development

Sandia Flame D OpenFoam tutorial case - bad result?

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

Like Tree2Likes
  • 1 Post By kerim
  • 1 Post By dlahaye

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   September 5, 2019, 07:31
Default Sandia Flame D OpenFoam tutorial case - bad result?
  #1
New Member
 
Mark
Join Date: Oct 2018
Posts: 18
Rep Power: 6
Brandani is on a distinguished road
Hi there!

I am trying to study combustion modelling within OpenFoam and am currently looking into the Sandia Flame D case - /opt/openfoam6/tutorials/combustion/reactingFoam/RAS/SandiaD_LTS

I copy the case into my own directory and execute provided Allrun script.
The results of the temperature field at the last time step are shown in the first picture (myD).

However (to me) - these results seem to be incorrect. If you google Sandia D flame tutorial in openFoam you get these screenshots that make more sense in terms of results.

For example from the following thesis(http://repozitorij.fsb.hr/9279/1/Del..._diplomski.pdf), page 79 (picture D2) - the results are very different yet according to the information there the conditions are identical to those found in the OpenFoam tutorial case.

Also there is a paper (https://link.springer.com/article/10...494-014-9561-5) looking into Sandia D flames and their OpenFoam simulation looks as follows (D3).

So my question is do I need to work with the case and modify to achieve these more sensible results or is it just a simple question of post-processing -as I assume the in-built openFoam tutorial on this case is correct.

Thank you!
Attached Images
File Type: png myD.png (8.1 KB, 133 views)
File Type: png D2.PNG (53.0 KB, 125 views)
File Type: png D3.PNG (151.9 KB, 135 views)
Brandani is offline   Reply With Quote

Old   September 6, 2019, 11:37
Default
  #2
New Member
 
Mark
Join Date: Oct 2018
Posts: 18
Rep Power: 6
Brandani is on a distinguished road
Update on this -- I installed the most recent dev version of OpenFoam, which contains the updated Sandia Flame D tutorial and produces much better results.
Brandani is offline   Reply With Quote

Old   September 11, 2019, 04:35
Default
  #3
Senior Member
 
Ruiyan Chen
Join Date: Jul 2016
Location: Hangzhou, China
Posts: 162
Rep Power: 8
cryabroad is on a distinguished road
Hi Brandani,

Would it be possible for you to share the updated results you mentioned? We are implementing the flamelet/progress variable approach in OpenFOAM, and obviously Flame D is one of the most used benchmark cases. I wonder what the results look like using the existing solvers in OpenFOAM.

Thanks!
cryabroad is offline   Reply With Quote

Old   September 11, 2019, 06:10
Default
  #4
New Member
 
Mark
Join Date: Oct 2018
Posts: 18
Rep Power: 6
Brandani is on a distinguished road
Quote:
Originally Posted by cryabroad View Post
Hi Brandani,

Would it be possible for you to share the updated results you mentioned? We are implementing the flamelet/progress variable approach in OpenFOAM, and obviously Flame D is one of the most used benchmark cases. I wonder what the results look like using the existing solvers in OpenFOAM.

Thanks!
So just to clarify:

1) What I was saying is that SandiaD flame in OpenFOAM version 6 seemed to produce inaccurate results (I believe there was no ignition with the EDC combustion model - 1st picture in my first post)

2) Then, what I found is that the OpenFOAM development version (https://openfoam.org/version/dev/) + OpenFoam v7 (https://openfoam.org/release/7/) must have had their in-built tutorial on Sandia Flame D updated because there was ignition and results seem to match those pictures (2nd and 3rd) I attached in my first post

3) So install v7 or the dev version of OpenFOAM and you will have a working base case. I did not do any modifications to the case in these versions.

Hope this helps!
Brandani is offline   Reply With Quote

Old   September 11, 2019, 06:14
Default
  #5
New Member
 
Mark
Join Date: Oct 2018
Posts: 18
Rep Power: 6
Brandani is on a distinguished road
Quote:
Originally Posted by Brandani View Post
So just to clarify:

1) What I was saying is that SandiaD flame in OpenFOAM version 6 seemed to produce inaccurate results (I believe there was no ignition with the EDC combustion model - 1st picture in my first post)

2) Then, what I found is that the OpenFOAM development version (https://openfoam.org/version/dev/) + OpenFoam v7 (https://openfoam.org/release/7/) must have had their in-built tutorial on Sandia Flame D updated because there was ignition and results seem to match those pictures (2nd and 3rd) I attached in my first post

3) So install v7 or the dev version of OpenFOAM and you will have a working base case. I did not do any modifications to the case in these versions.

Hope this helps!
This is the T field at last time step produced by the in-built case in the dev version.
Attached Images
File Type: png Selection_357.png (17.1 KB, 95 views)
Brandani is offline   Reply With Quote

Old   August 27, 2021, 02:48
Default
  #6
Member
 
Join Date: Apr 2014
Location: N/A
Posts: 47
Rep Power: 10
FluentStarter is on a distinguished road
Does anyone have an explanation for the results in v6? One gets actually the same "bad" result in v2106.
FluentStarter is offline   Reply With Quote

Old   January 7, 2022, 12:41
Default
  #7
Member
 
Amirreza Niazmehr
Join Date: Nov 2018
Posts: 40
Rep Power: 6
Amirreza_pro is on a distinguished road
Hi dear Brandani
I would appreciate if you could answer my question.
Actually I'm using SandiaD_LTS test case, but the time unite which OpenFOAM is using does not make sense me at all. Is the unite of time in second? Because in the default setting, 'end time' is set to 1500, but this time for combustion (injection) is not a reasonable value ! In combustion the time is ususallly in millisecond scale.
Do you have probably any Idea about time units in Openfoam, specially by using this start time and end time and also Delta T.
In attachment you can also find the picture of the ControlDict.orig file.

Thanks alot in advance
Attached Images
File Type: jpg Screenshot (561).jpg (81.2 KB, 15 views)
Amirreza_pro is offline   Reply With Quote

Old   January 18, 2022, 02:10
Default Sandia Flame D OpenFoam tutorial case - bad result?
  #8
Senior Member
 
abdikerim kurbanaliev
Join Date: Jun 2010
Location: Kyrgyzstan, Osh
Posts: 109
Rep Power: 14
kerim is on a distinguished road
All quantities in OpenFOAM should be in SI system of unit.
Amirreza_pro likes this.
kerim is offline   Reply With Quote

Old   January 18, 2022, 14:29
Default
  #9
Senior Member
 
Domenico Lahaye
Join Date: Dec 2013
Posts: 517
Blog Entries: 1
Rep Power: 14
dlahaye is on a distinguished road
End time 1500 here refers to the maximal number of time steps (intended as number of iterations).

The value to the time step (or time increment) in controlled by the PIMPLE dictionary inside system/fvSolution
Amirreza_pro likes this.
dlahaye is offline   Reply With Quote

Reply

Tags
combustion, reactingfoam, sandiad

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
Frequently Asked Questions about Installing OpenFOAM wyldckat OpenFOAM Installation 1 June 24, 2021 21:34
[DesignModeler] DesignModeler Scripting: How to get Full Command Access ANT ANSYS Meshing & Geometry 53 February 16, 2020 16:13
fluxRequired OpenFoam Versions SimpleFoam Taylor Couette flow tutorial mörli OpenFOAM Running, Solving & CFD 0 April 9, 2019 12:50
Free surface boudary conditions with SOLA-VOF Fan Main CFD Forum 10 September 9, 2006 13:24
Problems of Duns Codes! Martin J Main CFD Forum 8 August 15, 2003 00:19


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