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.

Related formulas


λTip speed ratio (dimensionless)
VtipLocal flow velocity at the blade tip (m/s)
VhubWind speed at hub height (m/s)