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Boris August 22, 2008 11:51

Streamlines end in domain
 
Hello CFX Users,

I am simulating the flow in a Ranque-Hilsch Vortex tube. (Vortex Tube with one Inlet and a Hot and Cold exit) Finally the computation meets the default residual target of 10e-4 and ended normally. When I look at the streamlines starting at the Inlet, they end in the middle of the domain end do not follow to the outlet.

What could be the reason for that?

Thanks, Boris

John S. August 22, 2008 18:23

Re: Streamlines end in domain
 
Make sure you've run enough interations that the flow actually has enough time to advect completely through the domain. I generally set my convergence criteria really low (1e-8) and monitor convergence so I can stop it when I feel it's ready.

Boris August 23, 2008 03:09

Re: Streamlines end in domain
 
Thanks a lot. It was much easier. I have Periodics in my Domain and the default Limit for Max Periods is 20. As I have hundred of turns in my vortex tube I just need to set the limit up ;-)


John S. August 23, 2008 12:23

Re: Streamlines end in domain
 
Ah I see. Also if you don't check the 'cross periodics' option, the streamlines will not cross the periodic boundary and stop.


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