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auxiliary sweep

Posted 10 avr. 2014, 09:16 UTC−4 Fluid & Heat, Computational Fluid Dynamics (CFD), Chemical Reaction Engineering, Studies & Solvers Version 4.4 2 Replies

Miriam Vogt
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Hello everyone,

I am simulating a reacting flow with a rather fast reaction. This problem does not converge, and I found out that I should try an auxiliary sweep with a parameter in front of the reaction rate that is increased step by step using last steps solution as initial guess.
For the first step this is working perfectly, I get a good solution for 1/1000 of the reaction rate. But after the first step the study stops and does not continue with the next step. Anybody has an idea what I am doing wrong?

Here is what I entered so far:
I checked auxiliary sweep in my stationary solution and added the parameter (which i before defined in global definitions as 1[1].) I chose Specified combinations, gave a range of 4 steps and chose run continuation for last parameter (but it is the same for no parameter and then reuse solution yes)
under solver - stationary solver - parametric I did not change anything.

Any idea/help/hint? Thanks in advance!
Best regards,
Miriam
2 Replies Last Post 22 oct. 2014, 09:29 UTC−4
Pu
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Posted: 1 decade ago 10 avr. 2014, 09:50 UTC−4
Interesting approach, curious to see the solution...

--
Pu, ZHANG
DTU Fotonik
Interesting approach, curious to see the solution... -- Pu, ZHANG DTU Fotonik
Mathieu Boidot
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Posted: 1 decade ago 22 oct. 2014, 09:29 UTC−4
Hi,

I have also tried recently to use auxiliary sweep with stationary studies to get good convergence.
After discussing with support, you can try to tweek a parameter in the solver configuration.

In the model tree, go to Study->Solver configurations->Solver->StationarySolver->Parametric and in the settings window, look for the continuation panel.

Set the predictor to constant for enhancing convergence (instead of automatic (which choses linear by default))

Tell us if it works.

Best regards.

Hi, I have also tried recently to use auxiliary sweep with stationary studies to get good convergence. After discussing with support, you can try to tweek a parameter in the solver configuration. In the model tree, go to Study->Solver configurations->Solver->StationarySolver->Parametric and in the settings window, look for the continuation panel. Set the predictor to constant for enhancing convergence (instead of automatic (which choses linear by default)) Tell us if it works. Best regards.

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