Complex sentence: The ratio between the speed of the blade tips and the speed of the wind is called tip speed ratio.high efficiency 3-blade-turbines have tip speed/wind speed ratios of 6 to 7.
Split into simpler sentences: The ratio between the speed of the blade tips and the speed of the wind is called tip speed ratio. High efficiency 3-blade-turbines have tip speed/wind speed ratios of 6 to 7.