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Old   March 29, 2011, 03:50
Default air - simpleFoam
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Hi,

I want to know, how i can set up the fluid in simpleFoam, for example to set up the fluid as water or as air.

I don't find a file like thermophysical properties like it can be found in chtMulti. I guess that's because of the heat transfer.
But where can I type in the properties of air, for example the molecular weight,...?

I guess that simpleFoam only needs the information newtownian fluid and for every newtonian fluid the result of the simulation with simpleFoam is neraly the same.

Do I guess right? :-)

Best Regards,
tH3f0rC3
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Old   March 29, 2011, 04:00
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Quote:
I guess that simpleFoam only needs the information newtownian fluid and for every newtonian fluid the result of the simulation with simpleFoam is neraly the same.

Do I guess right? :-)

Hi,

in simpleFoam you set the fluid properties via nu in "constant/transportProperties". For example air at 20 °C:

Code:
transportModel  Newtonian;

nu              nu [0 2 -1 0 0 0 0] 1.5e-05;

Regards,
Toni
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Old   March 29, 2011, 05:13
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Thank you for you answer.

So it is meant the dynamic viscosity, isn't it?

More information the solver doesn't need to solve the Navier-Stokes-equaions?!

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tH3f0rC3
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Old   March 29, 2011, 05:27
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Jean El-Hajal
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Hi,

nu is the Kinematic viscosity

nu nu [0 2 -1 0 0 0 0] 1.5e-05;

you can see it in the unit:

nu [0 2 -1 0 0 0 0] --> m²/s , have a look at the user-guide, chapter 4

regards,

Jean
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Old   March 29, 2011, 05:50
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Oh
That was a very stupid question. I know that the units are represented by numbers in these brackets.

Thank you for your answer! :-)


The data below
transportModel Newtonian;

nu nu [..] ...

CROSSPOWERLAWCOEFF...

Are these data also properties of the air or are they speciefic for the solver?

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Old   March 29, 2011, 17:29
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Hi,

nu nu [0 2 -1 0 0 0 0] 1.5e-05; --> kinematic viscosity of the fluid.

Jean
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Old   March 29, 2011, 17:37
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hi dirk,
as far as i know this properties are irrelevant if you are simulating with a newtonian fluid. These entries are only needed if you choose another transport model (like CrossPowerLaw for example).
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Old   March 30, 2011, 02:39
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Ah ok, thank you! :-)
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