what is passive species in converge?

Weiqiang Liu · August 24, 2020, 06:10

Hi all,

I am a new learner of converge. when I tried to follow sample case set up step by step, I came across some species type named passive species.

I can understand what passive species mean. Can anybody give me some suggesiotns?

Best regards

MFGT · August 24, 2020, 06:36

hi,

you can consider it as a label. For example, everthing in the cylinder is labeled by the "CYLINDER" passive at the start of the simulation, so after the gas exchange you can trace these and see e.g. 5% still remaining in the cylinder.

Weiqiang Liu · August 24, 2020, 09:26

Quote:

Originally Posted by MFGT

hi,

you can consider it as a label. For example, everthing in the cylinder is labeled by the "CYLINDER" passive at the start of the simulation, so after the gas exchange you can trace these and see e.g. 5% still remaining in the cylinder.

So is it equivalent to a user defined species?

MFGT · August 24, 2020, 10:24

somehow yes, yet its not a species like o2, n2 etc...

The n2 species in the intake port are labeled INTAKE and the n2 species in cylinder with CYLINDER. So if these mix, you can see in postprocessing where the old gas from previous cycle is now, or see in passive.out how much fresh gas went into the cylinder, or maybe even scavenged through the engine if you find INTAKE passive labeled species in the exhaust system.

Weiqiang Liu · August 24, 2020, 21:12

Quote:

Originally Posted by MFGT

somehow yes, yet its not a species like o2, n2 etc...

The n2 species in the intake port are labeled INTAKE and the n2 species in cylinder with CYLINDER. So if these mix, you can see in postprocessing where the old gas from previous cycle is now, or see in passive.out how much fresh gas went into the cylinder, or maybe even scavenged through the engine if you find INTAKE passive labeled species in the exhaust system.

hi ,

Thanks very much for your anwser!

Best regards

Xiao Ren · August 25, 2020, 18:26

Weiqiang,

CONVERGE now is giving on-line training for new users every month. If you are interested in such training, please go to our website www.convergecfd.com and register for the upcoming trainings.

Best,

Weiqiang Liu · August 25, 2020, 21:58

Quote:

Originally Posted by Xiao Ren

Weiqiang,

CONVERGE now is giving on-line training for new users every month. If you are interested in such training, please go to our website www.convergecfd.com and register for the upcoming trainings.

Best,

Hi,

I've registered for the online training. Thanks for sharing

Best

August 24, 2020, 06:10	what is passive species in converge?	#1
Weiqiang Liu Senior Member Weiqiang Liu Join Date: Feb 2018 Posts: 278 Rep Power: 9	Hi all, I am a new learner of converge. when I tried to follow sample case set up step by step, I came across some species type named passive species. I can understand what passive species mean. Can anybody give me some suggesiotns? Best regards

August 25, 2020, 18:26		#6
Xiao Ren New Member Xiao Join Date: Aug 2020 Posts: 25 Rep Power: 5	Weiqiang, CONVERGE now is giving on-line training for new users every month. If you are interested in such training, please go to our website www.convergecfd.com and register for the upcoming trainings. Best, __________________ Xiao Ren, PhD Senior Research Engineer, Applications Convergent Science

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Modelling Biomass Combustion via Species Transport	Racheal	FLUENT	39	January 8, 2022 07:42
Combine Flux/Concentration BC in Electrochemical Species Model	Anodos	STAR-CCM+	0	May 4, 2020 15:03
Passive scalar-concentration of species	itsme_kit	STAR-CCM+	6	December 8, 2018 06:06
Site Species	Diger	FLUENT	6	May 3, 2016 05:36
A question about species box of species transport model	tjushang	FLUENT	2	June 25, 2014 07:56

August 24, 2020, 06:36		#2
MFGT Senior Member Tobias Join Date: May 2016 Location: Germany Posts: 265 Rep Power: 10	hi, you can consider it as a label. For example, everthing in the cylinder is labeled by the "CYLINDER" passive at the start of the simulation, so after the gas exchange you can trace these and see e.g. 5% still remaining in the cylinder.

August 24, 2020, 10:24		#4
MFGT Senior Member Tobias Join Date: May 2016 Location: Germany Posts: 265 Rep Power: 10	somehow yes, yet its not a species like o2, n2 etc... The n2 species in the intake port are labeled INTAKE and the n2 species in cylinder with CYLINDER. So if these mix, you can see in postprocessing where the old gas from previous cycle is now, or see in passive.out how much fresh gas went into the cylinder, or maybe even scavenged through the engine if you find INTAKE passive labeled species in the exhaust system.