distance between two vortex
 

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?

Cheers,

Saeed

I do not understand what you are asking. Are you asking why is a vorticity contour a different distance apart compared to some streamlines?

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?

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?

I think that location of vorticity is where that streamline rotate.


below image of streamlie
Attachment 22516


below image of vorticity contour
Attachment 22518

Your mesh looks very coarse. Have you tried a finer mesh?