User-defined turbulent viscosity - kinematic or dynamic?

tstorm · August 13, 2009, 16:45

The k-e and k-w models have the option for a user-defined turbulent viscosity. Does anyone know if that turbulent viscosity is dynamic viscosity or kinematic viscosity? The difference of course is just a factor of density, which is nearly 1 for air in SI units, so the difference is small. Still, I don't know which it should be.

tstorm · August 13, 2009, 16:50

Sorry, this should have been in the FLUENT section. I'll repost it there.

aatman · August 21, 2009, 02:15

Quote:

Originally Posted by tstorm

The k-e and k-w models have the option for a user-defined turbulent viscosity. Does anyone know if that turbulent viscosity is dynamic viscosity or kinematic viscosity? The difference of course is just a factor of density, which is nearly 1 for air in SI units, so the difference is small. Still, I don't know which it should be.

the question seems strange to me, kinematic and dynamic viscosity are a characteristic of the fluid, instead the turbulent viscosity is a characteristic of the flow, it is defined to close Navier Stokes equation with turbulence model

tstorm · August 21, 2009, 11:16

Yeah, I realized my mistake shortly after posting that thread. Thanks for your response though.

Yogini · January 29, 2010, 11:08

Hello,

Two equations models(k-e and k-w models) are used to find the eddy viscosity(or turbulent viscosity).And the turbulent viscosity is dynamic viscosity.

August 13, 2009, 16:45	User-defined turbulent viscosity - kinematic or dynamic?	#1
tstorm Member Join Date: Apr 2009 Posts: 78 Rep Power: 17	The k-e and k-w models have the option for a user-defined turbulent viscosity. Does anyone know if that turbulent viscosity is dynamic viscosity or kinematic viscosity? The difference of course is just a factor of density, which is nearly 1 for air in SI units, so the difference is small. Still, I don't know which it should be.

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August 13, 2009, 16:50		#2
tstorm Member Join Date: Apr 2009 Posts: 78 Rep Power: 17	Sorry, this should have been in the FLUENT section. I'll repost it there.

August 21, 2009, 11:16		#4
tstorm Member Join Date: Apr 2009 Posts: 78 Rep Power: 17	Yeah, I realized my mistake shortly after posting that thread. Thanks for your response though.

January 29, 2010, 11:08		#5
Yogini New Member Yogini Patel Join Date: Jan 2010 Location: Finland Posts: 15 Rep Power: 16	Hello, Two equations models(k-e and k-w models) are used to find the eddy viscosity(or turbulent viscosity).And the turbulent viscosity is dynamic viscosity.