此外，由于引擎（发动机）外部运动较慢的空气覆盖了高温燃气排出引擎后部时的噪音，“高旁道比”（高涵道比）飞机的噪音指数下降了80%左右。

They are also some 80% quieter because the mass of slower-moving air shrouds the noisy hot gases coming from the rear of the jet.

youdao

此外，由于引擎（发动机）外部运动较慢的空气覆盖了高温燃气排出引擎后部时的噪音，“高旁道比”（高涵道比）飞机的噪音指数下降了80%左右。

They are also some 80% quieter because the mass of slower-moving air shrouds the noisy hot gases coming from the rear of the jet.

youdao