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-   -   CFX: Transient sim with fluid-fluid domain interface (http://www.cfd-online.com/Forums/cfx/74561-cfx-transient-sim-fluid-fluid-domain-interface.html)

 farzola April 3, 2010 11:44

CFX: Transient sim with fluid-fluid domain interface

Hello all,
I'm simulating a Kaplan hydraulic turbine. I got a good convergence in steady state, but I'm studying unsteady flows and of course is needed to carry out transient simulations.

I'm using a fifth part of runner subdomain and a complete draft tube geometry (the water conduit to the exit), this is equivalent to said a pitch angle for side one equal to 72 degrees and a pitch angle for side two equal to 360 degrees. Then I can see a very good behavior of oscillations due to blade passage frequency in the outlet of the runner but it didn't pass to the draft tube subdomain :(. So, what's happens? From the draft tube point of view it's as the fifth part of runner is a total water passage way.

Someone can give me a recommendation to try to solve it.

 ghorrocks April 4, 2010 07:34

Sorry, I don't understand your question.

 brunoc April 6, 2010 12:05

Fidel,
Did you remember to check the pitch change on the rotor-draft tube interface? That seems to be the problem.

 brunoc April 6, 2010 12:07

Fidel,
From what you said you have two domain interfaces. Did you check the pitch change on both of them?

 farzola April 7, 2010 15:08

Quote:
 Originally Posted by brunoc (Post 253367) Fidel, Did you remember to check the pitch change on the rotor-draft tube interface? That seems to be the problem.
I'm setted a pitch change between rotor and draft tube equal to 72°/360° and a pitch change between distributor and rotor equal to 15°/72°. Is that correct?

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