Why do windmills typically have 4 blades, yet all modern wind turbines have 3?

Question

Why do windmills typically have 4 blades, yet all modern wind turbines have 3?

In: 9124

Answer 1

More blades means more torque in low wind speed. Moreover, an odd number of blades is smoother than an even number in certain applications because of the loss of lift caused by passing in front of structural elements.

Think of a submarine with 4 “fins” just in front of the big spinning propeller. Having a seven bladed propeller means that at any time, only one blade is in front of one of the fins. This reduces vibration and provides smoother propulsion.

Answer 2

More blades means more torque in low wind speed. Moreover, an odd number of blades is smoother than an even number in certain applications because of the loss of lift caused by passing in front of structural elements.

Think of a submarine with 4 “fins” just in front of the big spinning propeller. Having a seven bladed propeller means that at any time, only one blade is in front of one of the fins. This reduces vibration and provides smoother propulsion.