Problem diverges: Scalar/Species transport equation

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 August 27, 2016, 09:01 Problem diverges: Scalar/Species transport equation #1 New Member   saeid Join Date: Aug 2016 Posts: 1 Rep Power: 0 Hi my calculation becomes diverged at 720 CA. This is the problem ===> Problem diverges: Scalar/Species transport equation, variable I changed scalar and species transport equation terms in under relaxation factors but still doesn't work. How can I fix it?

 September 22, 2016, 06:18 #2 New Member   nieman Join Date: Sep 2016 Posts: 1 Rep Power: 0 Did you use general gas phase reactions module for simulation?

August 13, 2018, 05:28
#3
New Member

iman pourmousavi
Join Date: Sep 2013
Location: iran
Posts: 5
Rep Power: 9
Quote:
 Originally Posted by firemann Did you use general gas phase reactions module for simulation?
Hello
Im using GGPR and i face this error .could you help me?
Iman

 October 5, 2018, 06:44 What happens at 720° #4 New Member   Stephan Werner Join Date: Sep 2018 Posts: 6 Rep Power: 4 Hey Iman, maybe I could help You. Where do You start simulating, at 0°CA or 180°CA (or maybe even somewhere else)? I had a divergence right when the exhaust valve opened at some point and could solve it with using a smoothening function. maybe that's the case with Yours as well, does the intake valve open at 720° and cause the diversion?

 October 8, 2018, 05:33 #5 New Member   iman pourmousavi Join Date: Sep 2013 Location: iran Posts: 5 Rep Power: 9 Hi Stephan Actually the simulation started at -145.3 CA.

 October 8, 2018, 06:13 #6 New Member   Stephan Werner Join Date: Sep 2018 Posts: 6 Rep Power: 4 So you start at -145.3° CA at TDC (?), at 574.7° CA you have another TDC and an intake stroke starts. Maybe the intake valve closes at 720°? Did you Use any special functions around 0° like a smoothener for pressure/temperature? Why do You simulate more than 4 strokes? iman.pourmousavi likes this.

 November 20, 2018, 06:39 #7 New Member   Dennis Niemann Join Date: Oct 2018 Location: Germany Posts: 4 Rep Power: 4 I have a similar problem. My simulation is diverged around 760CA (intake stroke 526CA - 772CA). I have already set a smoothing function (100 iterations) for temperature and pressure. How can I solve this problem? Increase the iterations of the smoothing function? Best regards