Hi everyone !

I am working on a modified Darrieus wind turbine (http://en.wikipedia.org/wiki/Darrieus_wind_turbine). The blades have a pitch angle motion in addition to the main rotation of a classical Darrieus.

I want to model this with CFX, but there's a couple of issues :

- Deforming mesh : not possible to simulate several blades (but it does work with one)

- rotating mesh : I wanted to use one domain including the whole turbine (general rotation), and add others domain for each blade that would rotate seperately, in the first rotating coordinate frame.

My issue is that I cannot define a coordinate frame that would rotate during the transient simulation.

Any ideas ???

Try using a rotating domain to account for the main rotation, then use moving mesh within that domain to account for the pitch angle motion. If the pitch angle motion is significant (relative to the rotating domain), then you may need to surround each blade with a GGI interface to avoid the mesh folding. The GGI allows the mesh to slide at the interface - one side of the interface should be stationary (in the rotating domain), the other side can have rotational motion set so that it moves with the blades.

thanks mate, it works very well !!! I've had to go through a pretty nasty trig calculation, but then it works just fine !!