Cp-TSR curve in a VS-FP stall regulated small turbine

Wind & Water Rotor Aerodynamics
2

Dear Alvaro,

I can’t comment about your specific 10-kW turbine in particular, but here are my answers to your questions in general:

  1. A wind turbine may operate at a TSR higher than optimal at low wind speeds when it produces power because one often limits the variable-speed range to avoid resonances; in this case, the controller may have the rotor spin faster at low wind/rotor speeds than it would for optimal power.

  2. I agree. The impact of the Reynolds number likely depends on the airfoil (some airfoils are more Reynolds number sensitive than others). We discussed this recently in a related forum topic: Variable Speed Fixed Pitch WT blade design - #2 by Jason.Jonkman.

Best regards,