-2

Why wind turbine with more blades rotate slower(lower RPM) than turbine with just one or two blades, if both has equal diameter on same wind speed?

Often people say more blades have more drag, but where is aero drag on blades if resultant force is always tilted forward, component in forward direction is thrust, not drag. So what slows down rotation?

Only reasons to slow down are if resultant force has lower magnitude or vector is pointed more backward, then still stay question why this happened at more blades configuration? enter image description heretip speed ratio is ratio between tip speed tangential velocity and wind speed that blows at propeller. So for same wind speed one blade has the highiest RPM...

enter image description here

22flower
  • 249
  • 2
  • 9

1 Answers1

0

Short answer:

enter image description here enter image description here

This should be a good reading material for you. https://www.nmmesa.org/wp-content/uploads/2019/10/Aerodynamics-of-Wind-Turbine-Blades.pdf

Aerodynamics of Wind Turbines: Drag

Both aircraft engineers who build aircraft wings and propellers, and wind turbine engineers who design rotor blades are concerned with aerodynamic drag. Drag is always important when an object moves rapidly through the air. Aircraft should have good fuel economy, and wind turbine rotor blades must have high tip speeds to work efficiently. Therefore it is critical, that both aircraft wings and rotor blades have low aerodynamic drag.

  • Drag Increases with the Area Facing the Wind

  • Drag Depends on the Shape of the Object

  • Drag Increases with the Square of the Wind Speed

and so on... http://www.xn--drmstrre-64ad.dk/wp-content/wind/miller/windpower%20web/en/tour/wtrb/drag.htm

r13
  • 8,333
  • 3
  • 10
  • 29