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Old   June 6, 2013, 06:51
Default distance between two vortex
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saeed
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Hi all

I am attempting to calculate distance between two vortxes behind a submarine by using ansys cfx.

This distance is calculated by vorticity contour (contour of velocity curl in cfx post). Distance between stream lines is also calculated. Why this two distance is different and non equal?

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Saeed
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Old   June 6, 2013, 07:32
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Glenn Horrocks
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I do not understand what you are asking. Are you asking why is a vorticity contour a different distance apart compared to some streamlines?
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Old   June 6, 2013, 17:11
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I am need to obtain distance between two vortexes due to flow over a submarine.
I think that this distance can obtain from vorticity contour or 2D streamline in cfx post that this two value (value from vorticity contour and value from 2D stremline on plane perpendicular to submarine) must be equal. but result from vorticity contour is not equal to 2D streamline. why?
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Old   June 6, 2013, 19:27
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An image would help.

But it seems pretty obvious that the vorticity approach and the streamline approach are defining the distance differently and therefore return different values. Why do you expect them to be the same?
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Old   June 7, 2013, 07:10
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I think that location of vorticity is where that streamline rotate.


below image of streamlie
CFX0.6.jpg


below image of vorticity contour
CFX10.7.jpg
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Old   June 10, 2013, 22:33
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Your mesh looks very coarse. Have you tried a finer mesh?
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