DNS of fluid flow with turbulenceProperties as laminar?

vidyadhar · April 28, 2017, 02:52

Hello,

I want to run DNS of fluid flow through a channel.

A tutorial is available for LES.

I am changing the simulation Model in turbulence properties from LESModel to laminar and run the case. Does it become DNS? (Is this correct? OR Does it mean that I am forcing laminar model to be used?)

If it is correct, can I use the same laminar model for running simulations at lower and higher Re? and can I call this as DNS!!

Thanks in advance!!
vidyadhar

piu58 · April 28, 2017, 04:29

"Models" try approximate the turbulence which the core simulation (with it's spatial and temporal resolution) not covers. Laminar is not a model in close sence and does not introduce additional effects: Which is needed for DNS.

To call it DNS you have to use a very high temporal and spatial resolution, down to the Kolmogorov scale.

vidyadhar · April 28, 2017, 05:30

Thank you Pilz for the quick responses!

April 28, 2017, 02:52	DNS of fluid flow with turbulenceProperties as laminar?	#1
vidyadhar Senior Member vidyadhar Join Date: Jul 2016 Posts: 138 Rep Power: 9	Hello, I want to run DNS of fluid flow through a channel. A tutorial is available for LES. I am changing the simulation Model in turbulence properties from LESModel to laminar and run the case. Does it become DNS? (Is this correct? OR Does it mean that I am forcing laminar model to be used?) If it is correct, can I use the same laminar model for running simulations at lower and higher Re? and can I call this as DNS!! Thanks in advance!! vidyadhar

April 28, 2017, 04:29		#2
piu58 Senior Member Uwe Pilz Join Date: Feb 2017 Location: Leipzig, Germany Posts: 744 Rep Power: 15	"Models" try approximate the turbulence which the core simulation (with it's spatial and temporal resolution) not covers. Laminar is not a model in close sence and does not introduce additional effects: Which is needed for DNS. To call it DNS you have to use a very high temporal and spatial resolution, down to the Kolmogorov scale. __________________ Uwe Pilz -- Die der Hauptbewegung überlagerte Schwankungsbewegung ist in ihren Einzelheiten so hoffnungslos kompliziert, daß ihre theoretische Berechnung aussichtslos erscheint. (Hermann Schlichting, 1950)

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April 28, 2017, 05:30		#3
vidyadhar Senior Member vidyadhar Join Date: Jul 2016 Posts: 138 Rep Power: 9	Thank you Pilz for the quick responses!