rms velocity fluctuations

newOFuser · June 21, 2011, 15:37

Hello Foamers,

Does anyone know how we can calculate rms velocity fluctuations (during runtime or during post-processing)?
I am relatively new to using OF, so would appreciate any inputs!

Thanks so much,
ak

gregor · June 22, 2011, 04:01

Hi,

have a look at fieldAverage http://www.cfd-online.com/Forums/ope...ldaverage.html where prime2Mean is the variance (RMS^2)

gregor

newOFuser · June 22, 2011, 14:09

Thanks gregor!

I see that UPrime2Mean has 6 components. Does it correspond to the Reynolds stress tensor?

Thanks,
ak

gregor · June 27, 2011, 09:13

its a part of the reynolds stresses (since you are using only the resolved scales without the modeled stresses to compute it, look for it under src/postProcessing/functionObjects/field/fieldAverage/fieldAverage/fieldAverageTemplates.C)

gregor

June 21, 2011, 15:37	rms velocity fluctuations	#1
newOFuser Member ak Join Date: May 2011 Posts: 64 Rep Power: 15	Hello Foamers, Does anyone know how we can calculate rms velocity fluctuations (during runtime or during post-processing)? I am relatively new to using OF, so would appreciate any inputs! Thanks so much, ak

June 27, 2011, 09:13		#4
gregor Member Gregor Olenik Join Date: Jun 2009 Location: http://greole.github.io/ Posts: 89 Rep Power: 17	its a part of the reynolds stresses (since you are using only the resolved scales without the modeled stresses to compute it, look for it under src/postProcessing/functionObjects/field/fieldAverage/fieldAverage/fieldAverageTemplates.C) gregor tomibraniste, garrison, babakflame and 2 others like this. Last edited by gregor; June 27, 2011 at 11:59.

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June 22, 2011, 04:01		#2
gregor Member Gregor Olenik Join Date: Jun 2009 Location: http://greole.github.io/ Posts: 89 Rep Power: 17	Hi, have a look at fieldAverage http://www.cfd-online.com/Forums/ope...ldaverage.html where prime2Mean is the variance (RMS^2) gregor

June 22, 2011, 14:09		#3
newOFuser Member ak Join Date: May 2011 Posts: 64 Rep Power: 15	Thanks gregor! I see that UPrime2Mean has 6 components. Does it correspond to the Reynolds stress tensor? Thanks, ak