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December 24, 2014, 18:50 |
ODE Solver: Seulex
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#1 |
New Member
Josh Dawson
Join Date: Oct 2014
Location: Justin, TX
Posts: 19
Rep Power: 12 |
Hello everyone, I am using the seulex ode solver for a hydrogen /air combustion scenario. I received a run time warning:
FOAM Warning : From function seulex::solve(scalar& x, scalarField& y, stepState& in file ODESolvers/seulex/seulex.C at line 255 step size underflow :2.64698e-23. I've searched the internet and the blogs here on this site and I haven't found anything that addresses the cause of this warning. I feel like it is rooted in the concentration gradients or potentially the pressure or temperature which are used to calculate reaction equilibrium rates because it's crashed the simulation due to a floating point exception. Or I should say the warning is expressed rapidly just before the simulation fails. Can anyone help me understand what causes this error please? I would really appreciate the help! I can post any of my files if necessary. |
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December 27, 2014, 13:58 |
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#2 |
New Member
Josh Dawson
Join Date: Oct 2014
Location: Justin, TX
Posts: 19
Rep Power: 12 |
I guess no one knows?
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December 27, 2014, 14:49 |
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#3 |
New Member
Dmitry
Join Date: Dec 2014
Posts: 8
Rep Power: 11 |
hi,
Did you try other ODE solvers? The usual, I use RADAU5 for this staff =) Thx, Dmitry |
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December 27, 2014, 14:52 |
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#4 |
New Member
Josh Dawson
Join Date: Oct 2014
Location: Justin, TX
Posts: 19
Rep Power: 12 |
Thank you Dmitry for your response, I've been searching high and low for information on the ODE solvers within OpenFOAM and there just isn't much information available. It's a fairly stiff system and the only information I was able to find suggested using the Seulex solver for stiff systems.
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December 27, 2014, 14:58 |
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#5 |
New Member
Dmitry
Join Date: Dec 2014
Posts: 8
Rep Power: 11 |
I could suggest to try my solver edcPisoFoam =) which is based on rhoReactingFoam and incorporates the Eddy Dissipation Concept with a detailed chemistry approach for the turbulence-chemistry interaction. I have finished my PhD related to OpenFOAM and turbulent combustion modeling with OpenFOAM this year using this solver, so it has good validation and references =)
edcPisoFoam utilizes the RADAU5 algorithm which is implicit 5th order RK method for stiff chemistry kinetics. You can download it for free from: http://www.edcpisofoam.decgroup.org/ |
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December 29, 2014, 13:41 |
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#6 |
New Member
Josh Dawson
Join Date: Oct 2014
Location: Justin, TX
Posts: 19
Rep Power: 12 |
Thank you very much for your suggestions as well as your offer to use the solver you developed. I just downloaded the solver and will probably spend the next week or so going though it. I like the challenge of creating my own but look forward to learning from the construction of yours. Very much appreciated!
Regards Josh |
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March 2, 2016, 17:52 |
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#7 |
New Member
TN
Join Date: Nov 2015
Location: TN, USA
Posts: 9
Rep Power: 11 |
Hello, JMDag2004.
Did you get a solution to your problem? If yes, I do have the same problem and would appreciate your help. Thank you! |
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November 25, 2016, 10:41 |
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#8 |
Member
Zhiyi Li
Join Date: Mar 2015
Location: Germany
Posts: 43
Rep Power: 11 |
Have you tried to decrease the relative tolerance. I decreased from 0.01 to 0.0001. That warning message doesn't appear then.
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January 13, 2017, 04:40 |
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#9 |
Senior Member
Yan Zhang
Join Date: May 2014
Posts: 120
Rep Power: 12 |
Hi Dmitry,
I cannot dowload the code of edcPisoFoam from www.edcpisofoam.decgroup.org. can you send me a copy of it? my email: zytju@tju.edu.cn Thank you! |
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May 3, 2020, 14:55 |
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#10 |
New Member
Jiaui Zhang
Join Date: Aug 2018
Location: Changsha, China
Posts: 17
Rep Power: 8 |
I have the same warning, but luckily my case does not crash, I just wonder what case this warning and does this warning affect the result?
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August 31, 2021, 06:12 |
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#11 | |
New Member
sanjeev adhikari
Join Date: May 2018
Posts: 13
Rep Power: 8 |
Quote:
webpage is not available to download can you email it ? I am having similar issues with stiff ODE problem. i am looking for RADAU5 email: 071bme435sanjeev@ioe.edu.np |
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October 31, 2022, 22:29 |
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#12 |
New Member
BISSAI NKAA
Join Date: Feb 2022
Posts: 16
Rep Power: 4 |
Hi Dmitry,
I can't download the edcPisoFoam code from www.edcpisofoam.decgroup.org . Can you send me a copy? My email is: santelima8@gmail Thanks! |
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Tags |
combustion, ode, ode solver, reaction, seulex |
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