Tip Speed ratio
The tip-speed ratio, λ, or TSR for wind turbines is the ratio between the tangential speed of the tip of a blade and the actual velocity of the wind. (Wind turbine tip speed ratio according to IEC 61400-2).
The tip-speed ratio is related to efficiency, with the optimum varying with blade design. Higher tip speeds result in higher noise levels and require stronger blades due to large centrifugal force.
|λ||Tip speed ratio (dimensionless)|
|Vtip||Local flow velocity at the blade tip (m/s)|
|Vhub||Wind speed at hub height (m/s)|