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Old   July 31, 2003, 23:42
Default Momentum source value
  #1
Jackie
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Hello all,

Could anybody Explain how to guess the momentum source value in a tube please.

I'm simulaing the flow in an open end tube which has the momentum source inside. I expect 0.1 m/s velocity at the position adding the momentum . I know the cross section area of the tube and the volume of the 3D region of the source and the unit of the momentum source is kg/m^-2s^-2. Does any body have an idea how to guess it ( equation and method )

I'm looking forward to hear the kindly help soon, @T_T@

Thank you in advance.

Jackie

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Old   August 1, 2003, 15:20
Default Re: Momentum source value
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Robin
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Hi Jackie,

The momentum source basically specifies a pressure gradient, however you can modify modify it to get a specific speed.

The following settings will do the trick:

MOMENTUM SOURCE:

Momentum Source X Component = -C*(u-uspec)

Momentum Source Y Component = -C*(v-vspec)

Momentum Source Z Component = -C*(w-wspec)

Momentum Source Coefficient = -C END

where C is a very large number and uspec, vspec, and wspec, are the specified velocities.

Regards, Robin

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Old   August 1, 2003, 15:57
Default Re: Momentum source value
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Jackie
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How could I know C value Robin.

Jackie,
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Old   August 2, 2003, 10:01
Default Re: Momentum source value
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Robin
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The actual value does not matter, it just has to be a big number.

Robin
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Old   August 3, 2003, 10:07
Default Re: Momentum source value
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Jackie
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Thank you very much Robin.

Jackie
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