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-   -   About rigid-body solution? (http://www.cfd-online.com/Forums/cfx/22463-about-rigid-body-solution.html)

billpeace April 17, 2006 21:49

About rigid-body solution?
 
I want to simulate flow in a centrifuge, that was described as a hollow vertical cylinder which rotates very rapidly around its axis. The flow is described by the Navier-Stockes equations and can cfx get a rigid-body solution?

Glenn Horrocks April 18, 2006 17:42

Re: About rigid-body solution?
 
Hi,

What do you mean by a rigid body solution? Do you mean the flow is solid body rotation? If this is the physical solution and you set the simulation correctly up in CFX then it should be able to be done.

Glenn Horrocks

billpeace April 18, 2006 21:01

Re: About rigid-body solution?
 
Yes.The flow have the same azimuthal acceleration with the cylinder.I don't know how to set the simulation with respect to "solid body rotation". Domain motion was set as rotating,heat transfer model was set as total energy,turbulence model was set as none(leminar).

billpeace April 19, 2006 00:05

Re: About rigid-body solution?
 
Sorry for i have a mistake in previous post. "the same azimuthal acceleration" should change to "the same azimuthal velocity per radius"


Glenn Horrocks April 19, 2006 18:26

Re: About rigid-body solution?
 
Hi,

You sound like you are doing a rotating frame of reference simulation. CFX supports this, read the documentation on rotating frame of reference.

Glenn Horrocks

billpeace April 20, 2006 07:50

Re: About rigid-body solution?
 
Hi, en,I am doing a rotating frame of reference simulation. I want to calaulate flow in the vertical cylinder which rotated rapidly around its axis.Assume first that we have a single perfect gas in th rotating cylinder. The result motion of the gas is the well-known isothermal "rigid body rotation" or "wheel flow".The gas rotates as a rigid body with velocity components Vz=0 Vr=0 V(angular)=ωr Can cfx simulate this problem?

Glenn Horrocks April 20, 2006 18:24

Re: About rigid-body solution?
 
Yes.

billpeace April 20, 2006 20:17

Re: About rigid-body solution?
 
Now, The big problem is that how to ensure the gas have the same angular velocity with the cylinder? Can you give me some advice to simulate such problem,thanks

Glenn Horrocks April 23, 2006 18:49

Re: About rigid-body solution?
 
Hi,

Set it as an initial condition and let CFX work it out from there.

Glenn Horrocks


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