Take the extent of the disturbance of the wind in the direction of the incoming wind, i.e. parallel to the axis of the turbine, as πW, where W is the width of the turbine blade. Show that the ratio (R) of the time for the wind to travel a distance πW to the time for one blade to reach the position of the next blade is given by R > 4π/(3λ).
λ = tip-speed ratio = Vtip/u0 = the ratio between the tangential speed of the tip of a blade and the actual speed of the wind.
