[E391]Ship propulsion
本文音频及原文摘自杂志The Economist 2016年第15期，Science and Technology版块。
We are sailing
Wind power makes another comeback
Apr 9th 2016
OLD technologies can return with a twist, just as airships keep threatening to and windmills and electric cars have already. Fitting ships with sails to assist with propulsion, thus saving fuel and reducing emissions[1], is an idea that has been around for decades. It has now gained renewed interest with a search by the Energy Technologies Institute (ETI), a British public–private partnership that promotes low-carbon[2] uses, for suppliers and a shipowner prepared to undertake a trial of wind-driven rotors on a large cargo vessel[3]. The plan is to gather operating data on whether rotor sails are a worthwhile investment. Depending on the routes, suitably equipped vessels could reduce fuel consumption by 5-12%. As some 90% of the world’s trade travels by sea, such savings would soon add up.
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注释
[1]save fuel节约燃料,省油；
reduce emissions减排
[2]low-carbon低碳
[3]wind-driven rotors风能驱动的转轴/旋翼
cargo vessel 货轮;载货船
生词
▷propulsion [prə'pʌlʃ(ə)n]
a that something
推进；推动力 propulsion 风力推进a propulsion 推进系统
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The type of sail the ETI is interested in is the Flettner rotor[1]. These were demonstrated by Anton Flettner, a German aerospace engineer[2], in the 1920s. When placed on a ship the giant rotating cylinders[3] extract energy from the wind using the Magnus effect[4], a force acting on a spinning body[5] in an airstream to create a pressure difference[6] on either side—the same effect that causes a spinning ball to curve through the air[7]. This force can be used to help push the ship along.
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注释
[1]A rotor ship, or Flettner ship, is a type of ship designed to use the Magnus effect for propulsion.
[2]航空工程师
[3]旋转圆柱体
[4]Magnus effect（马格努斯效应），以他的发现者马格努斯命名，是一个流体力学当中的现象，是一个在流体中转动的物体（如圆柱体）受到的力。——维基百科
[5]旋转体
[6]压力差/差压
[7]在空中弧旋前进
生词
▷curve [kɜːv]
to a curve or in the of a curve
弯曲；成曲线运动The curves round to the . 道路转向左边。
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Rotor sails are most suitable for ships that sail below 15 knots[1] (28kph) on trade routes where the apparent wind[2] (that experienced by an observer in motion[3]) is blowing sideways across the vessel, reckons the ETI. For a rotor sail the higher the ratio of wind speed to ship speed the better. In general, the rotors produce more thrust[4] the windier it is and the slower the ship steams.
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注释
[1]节（英语：knot），单位符号kn或kt，是一个专用于航海的速率单位，后延伸至航空方面，相当于船只或飞机每小时所航行的海里数。(1节的速度为：每小时1海里（nm/h）)
[2]视风;相对风;感觉风
[3]在运动中;在移动中
[4]thrust 牵引力，驱动力
(the driving force produced by, for example, an aircraft engine)
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In 1924 Flettner installed two 18.3-metre rotating metal cylinders on a converted sailing ship, the Buckau, which crossed the North Sea and the Atlantic[1]. Other ship owners have flirted with[2] the technology. In 2010, Enercon, a German windpower specialist, launched E-ship1 with four 2-metre rotor sails to assist its diesel engines[3]. In 2014, Norsepower, a Finnish firm[4], fitted an 18-metre rotor sail to Estraden, a ferry[5] which operates between the Netherlands[6] and Britain. A second rotor was fitted to the ship in 2015. Norsepower reckons they produce a 6% fuel saving on average.
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注释
[1]the North Sea 北海
the Atlantic 大西洋
[2]flirt with sth 不认真地考虑;对…暂时感兴趣
(to consider doing something, but not seriously, or to be interested in something for a short time)
I'm flirting with the idea of taking a year off and travelling round the world.
我心血来潮，想休假一年去周游世界。
[3]diesel engines 柴油引擎
[4]Finnish 芬兰的
[5]ferry 轮渡
[6]Netherlands 荷兰
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This is not a lot to show for more than 90 years of tinkering with the technology. But the arrival of new lightweight composite materials[1] that enable the rotors to spin at higher speeds, together with advanced computer controls that can use sophisticated wind sensors[2] and satellite tracking to constantly adjust the setting of the rotors, holds out greater promise of a return to sail, of a sort.
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注释
[1]新型轻质复合材料
[2]复杂的风传感器/风向风速仪
生词
▷tinker ['tɪŋkə]
to make to something, in an to or it
修补；改进；摆弄He every tinkering (about) with his .他每个周末都在摆弄他的汽车。I the would tinkering with the .我希望政府不要再在公共医疗卫生服务上折腾了。
▷spin [spɪn]
to ( to) around and around,
（使）（尤指快速）旋转The spins on .地球绕地轴旋转。The the spin around/round.玩轮盘赌的玩家们默不作声地注视着轮盘旋转。He was when his a and spun off the .他的车撞在树上甩出路面，他因此而丧生。Spin the (= Make it around and around as you it) and it will when it the .把球旋转起来再抛出去，球触地时就会改变方向。
(of a ) to , or to in a （车辆）疾驰；驾车飞驰We were spinning along, when one of .我们车开得飞快，突然一个轮胎爆了。Chris spun past in a new .克里斯开着辆眩目的新车疾驰而过。
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以上言论不代表本人立场。
原文摘自The economist，仅外语学习之用。
其中生词解释来源于Cambridge Dictionaries
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