One way to increase the efficiency of a high-bypass jet engine is to turn the fan into an open rotor, a bit like returning to propellers, but using two rings of stubby counter-rotating blades.

提高高旁通飞机引擎的方法之一就是把风扇变成开放式旋翼，有点回归于螺旋桨的味道，但要使用两圈粗短的反旋桨叶。

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Turn the electric motor shaft if it rotates freely, Measure the air gap between the stator and the rotor.

扳动电动机的转轴是否能自由旋转，测量定子和轴承的空隙。

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Based on the analysis of AC impedance and two poles voltage test data, the reason of turn - to - turn short circuit fault caused by having copper dregs in generator rotor winding was found.

基于交流阻抗和两极电压试验数据的分析，发现发电机转子绕组因存在铜渣而造成匝间短路故障的原因。

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It was three o'clock in the morning when Graham fired up the engine, and as the frost glistened on the young fruit, the giant rotor began to turn.

BBC: Graham Hewitt and his wind machine

One way to increase the efficiency of a high-bypass jet engine is to turn the fan into an open rotor, a bit like returning to propellers, but using two rings of stubby counter-rotating blades.

ECONOMIST: A new way to build a greener jet engine