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-   -   How to calculate swirl velocity or angular velocity in a in-cylinder flow analysis us (https://www.cfd-online.com/Forums/main/167095-how-calculate-swirl-velocity-angular-velocity-cylinder-flow-analysis-us.html)

tgsankar February 23, 2016 11:07

How to calculate swirl velocity or angular velocity in a in-cylinder flow analysis us
 
I am doing an in-cylinder steady state flow analysis. In that I need to calculate the angular velocity of air rotating
about the cylinder axis. I have been using a custom field function to monitor the velocity. The field function is
given as: (x*Vz-z*Vx)/(x*x+z*z). While using this field function the velocity fluctuates between a maximum and
minimum valve. It does not settle or converge even the solution is converged.

I need to know whether the field function is correct or wrong? Why the value fluctuates?

I really need this explanation which will help me in my project work.
If anybody experienced this same issue, please let me know.
Thanks in advance.

fluid23 February 23, 2016 13:25

Depending on what software you are using, you can probably setup a cylindrical coordinate system and then treat it just like x y z components except get axial, tangential and radial flow velocities.

zkhn April 26, 2017 17:55

Curl of the velocity field
 
You have to calculate \nabla\timesV, i.e curl of the velocity field.


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