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Problem with flow simulation / propeller global rotation at high RPM

Question asked by Alexandre Bourrieau on Nov 24, 2015
Latest reply on Dec 2, 2015 by Alexandre Bourrieau
  • Comment • 4

Hi,

 

I am trying to simulate a litle propeler rotation in air: I wan to get the Fy force :

 

 

 

The results are OK with my experiment at slow angular frequency but when w>3000 rad/s there are some errors (see below).

 

I have a warning saying that "there is a lot of supersonics cells... Try to use manual criterium" .... Is that the problem ?

 

Can you help me to avoid this problem please ? (perhaps by adding some initials conditions ??)

 

 

I have add a criterium (F <0.1N) but simulation is very long... and still do not converge to my experiment value...

 

 

Thanks you very much for you help.

 

Regards.

 

Alexandre.

Amit Katz
Amit Katz Dec 1, 2015 4:27 PM
Correct Answer

Global rotation causes every fluid cell in your domain to rotate about the specified axis. If your domain is too large, and the spin is too rapid, then the fluid cells may reach supersonic speeds. In particularly at 3000 rad/s you would need less than 1 meter of distance from your axis to reach Mach 1. I recommend using a local rotating region about the propeller.

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