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I've finally got a few minutes to try to answer this. Torque is bad. It's necessary, but it is bad. Ideally, you want the turbine to spin infinitely fast at almost zero torque, not slowly at high torque. To understand why, lets look at how energy is extracted from the air and transferred to the rotor. If we take an earth reference frame aligned to the free ...

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The wind turbines are designed to work under a wide range of wind velocities. They adjust their angle of attack and $C_l$ to the optimal for the existing condition. They use high $C_l$ for when the wind starts to pick up speed and the blades need to use a high torque to accelerate and position themselves at a rotation speed that provides the design angle ...

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One reason I can think of is Because increasing the $c_L$ increases also significantly the coefficient of drag. The increase of drag is a result of increasing flow detachment from the airfoil. Supplement After reading PeteW comment could the situation driving this design decision be the high-wind scenario? I realised that I was only thinking about ...

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to get more power out of the available wind, it is better practice to increase the diameter of the blade disc instead of adding more blades, which greatly increases the size & complexity of the main hub to which the blades are affixed.

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Aside from the efficiency, the blades of wind turbines are basically a wing, aerofoil, the actual upwash and downwash zone are much greater than the wing's cross-section. If the blades are too close they can interfere with each other flow stream and actually create debilitating turbulence. The wind turbines are designed to work in a wide range of winds. The ...

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The function of the wind turbine is to extract as much as possible energy from the moving mass of air. The energy of a mass $m$ of air is $$KE = \frac{1}{2}m v^2$$ and the power is (because the mass rate is $\dot{m} = \rho A v)$ $$P = \frac{1}{2}\dot{m} v^2=\frac{1}{2} \rho A v^3$$ So, the energy in the air is a function of the velocity. As energy is ...

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