Q
I'm trying to plot the value of vorticity behind an impeller blade in CFX-5.7.1. I was able to output Vorticity by editing the CEL file, but I found that there is a big "jump" in vorticity values across the rotating frame interface. Is this due to vorticity being defined by velocity gradients rather than stationary frame velocity gradients? Is there a way to get consistent values of vorticity accross the interface?

A
The problem is due to the vorticity being calculated using local-frame velocities. However, there is a variable, vortstn, which is vorticity in the stationary frame. To include this, you should add the following lines to your CCL:

LIBRARY:
VARIABLE: vortstn
Output to Postprocessor = Yes
END
END

You should then find that this is available in CFX-Post.


Q
I'm trying to plot the value of vorticity behind an impeller blade in CFX-5.7.1. I was able to output Vorticity by editing the CEL file, but I found that there is a big "jump" in vorticity values across the rotating frame interface. Is this due to vorticity being defined by velocity gradients rather than stationary frame velocity gradients? Is there a way to get consistent values of vorticity accross the interface?

A
The problem is due to the vorticity being calculated using local-frame velocities. However, there is a variable, vortstn, which is vorticity in the stationary frame. To include this, you should add the following lines to your CCL:

LIBRARY:
VARIABLE: vortstn
Output to Postprocessor = Yes
END
END

You should then find that this is available in CFX-Post.





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