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Rikio February 25, 2009 20:21

Expressions of cylindrical velocity
 
Dear all,

I want to know the exact expressions of cylindrical velocity components in CFX. Generally speaking, velocity are calculated in cartesian coordinate system. Where I can find it? Thanks for any help...

Rikio

mic March 17, 2009 05:47

Rikio,
I don't know if I exactly understand your question.
Velocities are calculated in the cartesian coordinate system and are u(=vx), v(=vy) and w(=vz).
In the cylindrical coordinate system you have: radial velocity, circumferential velocity and axial velocity. If you're using the "turbo mode" you have to initialise the components and than you can calculate the velocity cylinrical components.
On the users guide the velocities components are explained.
Hope this helps.

rikio March 17, 2009 20:52

Thank you very much, Mic.
I am sorry for the ambiguity of the question. What I want to know is the relationship between cartesian velocity components and cylindrical velocity components, i.e. how to trasfer from cartesian components to cylindrical? Maybe it is more of mathematical, but I just want to know how it works.
Thank you again...

mic March 18, 2009 05:25

Hallo Rikio,
yes, it is more a mathematical issue, than a CFD one.
Have a look at:
http://en.wikipedia.org/wiki/Cylindrical_coordinates

rikio March 18, 2009 20:32

Thank you, mic,

You are very appreciated for kindly help. But the velocity components is more complicated than the coordinate transfer since they are vectors. However, I have derived the formulae. Thank you.


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