| 摘要 |
A wind turbine or windmill blade for attachment to a hub of a wind turbine or windmill wherein the angle of the leading edge of the blade is within 20 degrees of an angle of apparent wind and the angle of apparent wind is equal to the arctangent of rotational speed of the blade divided by true wind speed where the speeds are in the same units and a windmill or wind turbine having such blades and having apparatus for controlling rotational speed of the blades so that the angle of apparent wind is within 20 degrees of the angle of the leading edge of the blades. |
