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Forces from simpleFoam

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Old   June 26, 2014, 07:47
Default Forces from simpleFoam
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Sture Smidt
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Hi,

This may have been covered before but:
-What is the reference density used by simpleFoam? I am analyzing a sphere in air at 10 m/s, but the stagnation pressure is 20% off. This may indicate that the density is treated as unity (1.0).

Are the simpleFoam results based on a density of unity?
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Old   June 26, 2014, 09:34
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Alexey Matveichev
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Hi,

there's no density in simpleFoam cause equations are divided by constant density and you're using kinematic viscosity. Surely miss in stagnation pressure can mean error in simpleFoam, but it equally (actually more likely) can be the error in your case setup.
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Old   June 28, 2014, 18:00
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Joachim Herb
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Is your medium air (with density 1.2xx kg/m)? In simpleFOAM the pressure used is p/rho, so this might explain the 20 % difference you see?
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Old   August 7, 2014, 14:41
Default Forces from simpleFoam
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How about forces from simpleFoam extracted with functionObjects? Are they normalized with the density like F=f/rho?

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