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FROZEN ROTOR IN UNST. SIMULATIONS

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Old   May 15, 2008, 11:04
Default FROZEN ROTOR IN UNST. SIMULATIONS
  #1
Spillo
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Hello,

I'd like to know your opinion about using a frozen rotor interface between a rotor and a stator in a unsteady simulations.

Frozen Rotor option does not change the relative position between the rotor and the stator, so that when passing from one domain to the other the boundary condition for the successive domain never changes. Is it correct?

Does it makes sense in a unsteady simulation? In fact in that way I have that in the frozen rotor interface the solution is time independent.

Thanks,

Luca
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Old   May 16, 2008, 04:14
Default Re: FROZEN ROTOR IN UNST. SIMULATIONS
  #2
wayne
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yes,it seems to be,so the relative positon have influnce to the result.
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Old   May 20, 2008, 12:34
Default Re: FROZEN ROTOR IN UNST. SIMULATIONS
  #3
Farid
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Hi, I am also trying to run an unsteady case using frozen rotor. Do I need to set the frame as Rotating frame in Global Initialization?

# I also tried with Transient Rotor Stator model instead of Frozen Rotor model. But in that case it is rotating the rotor domain around the origin(i.e. origin point is the pivot ). But I made the center point of the rotor domain at different location and the pivot should not be the origin in my case.

Is there any suggestion for changing the pivot of the rotor domain?

Thanks

Farid
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Old   May 25, 2008, 23:01
Default Re: FROZEN ROTOR IN UNST. SIMULATIONS
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CycLone
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Spillo: You can use Frozen Rotor in transient, but you would only do so if you weren't interested in the transient effects around the rotating part, otherwise it is advisable to use Transient Rotor-Stator.

Farid: You have chosen the wrong axis of rotation. If your system does not rotate about a primary axis of the global coordinate system, either create a local coordinate system aligned with the device, move the device to the global system, or specify the axis of rotation about two points.

-CycLone
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Old   May 26, 2008, 15:04
Default Re: FROZEN ROTOR IN UNST. SIMULATIONS
  #5
Farid
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Hi Cyclone, Thanks a lot.
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Old   May 31, 2008, 13:32
Default Re: FROZEN ROTOR IN UNST. SIMULATIONS
  #6
Spillo
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Thanks CycLone, what I don't understand is: in all the manuals is said that the relative position between rotor and stator is fixed, but in case I am running an unsteady simulation where the rotor is changing the position at each time step that is not possible since at each instant the position is effectively different...I cannot understand what is going on with frozen rotor interface model...

Cheers
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Old   June 1, 2008, 21:05
Default Re: FROZEN ROTOR IN UNST. SIMULATIONS
  #7
CycLone
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Hi Spillo,

It is fixed if you use a frozen rotor interface, even in transient. However, if you use a transient rotor-stator interface in transient the relative position at the interface will be updated accordingly.

-CycLone
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