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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There is another way to build a greener jet engine: by bypassing the turbine to an even greater extent, with an open rotor.

还有一种制造更为环保的喷气式发动机的方法采用开式转子使得涡轮有更大的旁通。

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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