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Compatibility of gravity and rotating frame

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Old   February 26, 2015, 07:56
Default Compatibility of gravity and rotating frame
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Sangwoo Kim
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Hi all.

I'm simulating an underwater propeller.
Cylindrical region around the propeller is made and it has its own rotating frame. (Tools > Reference Frames(right click) > New > Rotating)
It may be a frozen rotor method.(I'm not sure)

And I want to use gravity for hydrostatic pressure distribution.
Here, can I use gravity and rotating frame at the same time?


I'm going to use multiphase model for cavitation or something.
And there are only 6 boundary conditions available when I activate multiphase model.
wall
symmetry plane
flow-split outlet
velocity inlet
overset mesh
pressure outlet

Which one should I use for the far-field?
Of course, only pressure outlet looks proper, but the calculation diverged if I use it.



I have used other softwares, and began to learn STAR-CCM+ just a week ago.
So any advice or comment(anything!!) will be very helpful.

Thank you.
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Old   February 27, 2015, 05:55
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Sangwoo Kim
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Just FYI, narrow and long cylinder is not a duct, but just multi-block mesh for resolution of a water jet.
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Old   March 1, 2015, 03:56
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Gajendra Gulgulia
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i do not have the software at my disposal, but as far as i remember you need to select 'gravity'model under additional physics model when you set up your physics model, and then align the gravity with specified coordinate axis.
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Old   March 3, 2015, 02:48
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Sangwoo Kim
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Quote:
Originally Posted by ggulgulia View Post
i do not have the software at my disposal, but as far as i remember you need to select 'gravity'model under additional physics model when you set up your physics model, and then align the gravity with specified coordinate axis.
Thank you for reply!

My question was ambiguous. I know how to activate gravity model.

What I asked was the possibility of using both of gravity and rotating frame, because I have experienced with another software that gravity and frozen rotor method cannot be used together; it diverged every time.
(Of course the simulation was carried out very carefully. Gravity model worked well without rotating frame, and vice versa)
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