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level June 10, 2012 14:46

advice on wind turbine simulation?
 
3 Attachment(s)
Hello CFD community,
i am a bit clueless with my wind turbine simulation which i have to do for a universityproject... After reading a lot in the Ansys documentation and on the internet (and this forum in particularly) i created a simlation as follows (see also first picture):
- 2 domains, one stationary and one rotational
- the blade is cut out of the inner domain and the generated faces are defined as wall
- inner domain is rotating to get a realistic airvelocity at the rotating blade (increasing to the tip)
- domains are connected with a frozen rotor interface
- the rotational periodicity is generated as a rotational periodicity interface

The results i get are a bit confusing and i guess that i made a general designmistake. If you look at the results (picture 2 and 3) you can notice a very abrupt change of the velocity between the two domains. I would have expected a steady distribution in the whole designspace.
Can you give me an advice how i have to change the flow analysis to get a realistic solution? :confused:

My first guess is that i made a mistake in geometry. My blade is also rotating, because it is a part of the inner domain. Actually i wanted to create a stationary blade and a rotating domain round this airfoil to get the velocitydistribution. Should i use 2 domains and a rigid body (blade) which overlaps the inner domain??! I tried this approach, but i couldn't create a mesh with a prism layer because of the overlap of the domain and blade...

Your help is apprecited a lot! :)

k.vafiadis June 10, 2012 18:53

Try to plot the velocity in stn frame. This variable (velocity) is the relative velocity caused by the rotation of the rotating domain relative to a stationary observer.

level June 11, 2012 04:31

Ahh! :D Thanks, that explains a lot!


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