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Old   July 2, 2009, 01:51
Default Specifying fluid density
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Sanjib Das Sharma
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Hi,

I am new to OpenFoam. I am trying to solve a steady-state, turbulent flow case with water as the fluid. Although I can change the fluid viscosity in the transportProperties file, there is no option for changing the fluid density. As the transportProperties file and the simpleFoam case was developed for air, I suspect my results are wrong as I did not change the fluid density. How do I change the fluid density from the default value?

Thanks in advance,

Sanjib
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Old   July 2, 2009, 02:54
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Mark Olesen
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Quote:
Originally Posted by sanjibdsharma View Post
Although I can change the fluid viscosity in the transportProperties file, there is no option for changing the fluid density.
For incompressible cases, there is no need for the fluid density.
OpenFOAM solvers just use the kinematic viscosity instead of dividing the dynamic viscosity by the fluid density. This saves a few operations and should thus improve the efficiency.
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Old   February 22, 2011, 09:55
Default and in compressible solvers?
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Aldo Iannetti
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Quote:
Originally Posted by olesen View Post
For incompressible cases, there is no need for the fluid density.
OpenFOAM solvers just use the kinematic viscosity instead of dividing the dynamic viscosity by the fluid density. This saves a few operations and should thus improve the efficiency.
Hi, I'm curious about what happens in compressible solvers, I mean:

- In incompressible solvers the pressure solution is to be multiplied by density (constant) in order to give you the real forces on the body.

-does libforces.so give you the real forces without multiplying the pressur e field?

Thanks

Aldo
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