Darreius problems

DGaden

Hey folks,

I'm having a bugger of a time with a 2D darreius turbine simulation. The solution looks intuitively "okay", except the torque is backwards, predicting power loss instead of power production. Worse yet, I have real experimental data to compare against, and it's almost exactly opposite torque. I've been banging my head on the wall, and triple checked all my calculations. The forces all add up to a backwards torque! There must be a flipped sign in there somewhere, but I can't find it.

Perhaps I don't understand rotating reference frames. How would you do a 2D darrieus turbine? -I created a circular mesh region around the blades and hub -Set it as a rotating domain in the direction the blades should rotate. (When I move timestep forward in post, the mesh moves the way the blades should.) -Set the interface as "Transient rotor / stator"

Am I doing something wrong? Should I do something with a rotating mesh, but not using a "Rotating Reference Frame"? Or is the CFD just that wrong?

-Dave Gaden