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Stabum August 11, 2012 16:37

Simulating a vena contracta
first of all I'm terribly sorry about my poor english. I just hope you'll be able to understand what my problem is. Thanks in advance to all those who will try to help me. I appreciate it so much.
I'm trying to simulate in CFX 13 a nozzle used to accellerate water. Obviously the water jet doesn't have a cilindrical shape right outside the nozzle. I would like to know how I can simulate the water's behaviour when it interacts with the air in order to calculate the coefficient of contraction (Cc).
ANY kind of help will be extremely appreciated.
Bye. :)

ghorrocks August 12, 2012 08:00

So is the flow a free surface simulation? If so, have you done the free surface example tutorrials? They show you how to set up free surface simulations.

Stabum August 12, 2012 13:16

The water flow exits the nozzle and moves through the air reducing its cross section. It means it's a free surface simulation? No, I'm sorry, I've not done any free surface example tutorial. Where can I find them?
Thanks a lot!

ghorrocks August 12, 2012 21:53

Yes, this is a free surface simulation.

For tutorials on this go to the tutorials provided in the CFX documentation. "Free surface flow over a bump" is one you should look into closely.

Stabum August 14, 2012 06:12

There's a lot of new stuff here :eek: But, of course, if I want lo learn to use this amazing program, that's exactly what I need!
Thanks so much for your advices. I have to find the way to study ALL these tutorials.
Thanks again ;)

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