- #1
DaveC426913
Gold Member
- 22,530
- 6,192
Nope. I'm still having trouble. I asked about this before, but it's still not gelling for me.
There's a wind turbine on the "front lawn" of the city of Toronto that I pass every day. Its blades are never more than ~20 degrees from flat, i.e the blades are almost perpendicular to the flow of air. If my model of lift generated by the blades is correct*, that represents a ~70 degree angle of attack. Surely that's beyond stall angle.
What am I missing? Perhaps there's something about 'relative' angle of attack based on slow wind speed and fast blade movement?
* my understanding of wind turbine blades is that you can liken it to a plane, with the turbine shaft as the fuselage and each blade as a wing. The lift generated by each blade is perpendicular to the shaft and is parallel to the plane of the rotor i.e. the lift acts to increase the rotation of the rotor.
There's a wind turbine on the "front lawn" of the city of Toronto that I pass every day. Its blades are never more than ~20 degrees from flat, i.e the blades are almost perpendicular to the flow of air. If my model of lift generated by the blades is correct*, that represents a ~70 degree angle of attack. Surely that's beyond stall angle.
What am I missing? Perhaps there's something about 'relative' angle of attack based on slow wind speed and fast blade movement?
* my understanding of wind turbine blades is that you can liken it to a plane, with the turbine shaft as the fuselage and each blade as a wing. The lift generated by each blade is perpendicular to the shaft and is parallel to the plane of the rotor i.e. the lift acts to increase the rotation of the rotor.