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更新时间:2017-10-25 20:48:18 来源:纽约时报中文网 作者:佚名

The water speed record that's surprisingly hard to break

On a cold day in October 1991, a team from the Massachusetts Institute of Technology (MIT) led by physicist Mark Drela set a record for the fastest human-powered water craft. Their hydrofoil, Decavitator, reached a speed of 18.5 knots (21.3 mph/34km/h) over a 100-metre (330ft) course on the Charles River that flows through Boston.

1991年10月寒冷的一天,由物理学家马克·德雷拉(Mark Drela)率领的麻省理工学院(MIT)的一个团队创下了人力舰船的最高时速纪录。他们的水翼船"Decavitator"号在流经波士顿的查尔斯河(Charles River)上的一段长100米(330英尺)的河道上达到了18.5节(时速21.3英里/34公里)的速度。

Decavitator didn’t look anything like the hydrofoils that take you to your favourite Greek island. Rather, it was a catamaran with two thin hulls and a giant aeroplane propeller strapped to the back. A cyclist – Drela himself – was suspended between the two hulls, pedalling furiously.


In the spring of 1993, the Decavitator team was awarded the DuPont prize for the fastest human-powered water craft. After its record-breaking journey, the craft was put on display in the entry lobby of Boston’s Museum of Science.

1993年春天,Decavitator团队获得了杜邦人力舰船最高速度奖。在创下纪录的那次航行之后,这艘船在波士顿科学博物馆(Boston's Museum of Science)的入场大厅展出。

Twenty-five years later, despite many attempts, the record remains unbroken.


However, an Oxford University spinout called Animal Dynamics, co-founded by zoologist Adrian Thomas, is spending £200,000 ($260,000) to do just that. Their craft, the Malolo, is a hydrofoil-like Decavitator. Unlike its rival, the Malolo’s design is inspired by the way whales swim through water – instead of a propeller, it has the kind of large, arched tail that you sometimes spot above the water when a whale dives.

不过,由动物学家阿德里安·托马斯(Adrian Thomas)共同创立的牛津大学创业孵化器产物“Animal Dynamics”公司正投入20万英镑(26万美元),希望打破该纪录。他们的Malolo号像Decavitator一样是水翼船。不同之处是Malolo的设计灵感来自于鲸鱼游泳的方式——不是用螺旋桨,而是设计了一条拱形大尾巴,就像鲸鱼潜入水下时,有时会露在水上的尾巴。

Now two years after starting work on the project, the team have begun testing their third prototype off the south coast of England. According to Thomas, they have already reached speeds of about 12 knots (13.8mph/22km/h).


They expect to have to build at least three more prototypes before they really go for the record next year, each one smaller and lighter than the one before.


The question is, can they succeed when other attempts since the Decavitator have failed?


Human-powered vehicles are fueled only by the muscular strength of a human being. For most of us, this means only one thing: bicycles. However, they can also be found flying in the air, diving under the sea and even riding on rails.


Bicycles are an everyday form of transport for many people, but the principle of human-powered vehicles can also be developed as novelty runabout for tourists or to achieve something much more significant like testing new technology – to break a record, win a prize or cement a reputation.


Drela had already been involved in setting records for human-powered planes before his water-speed record attempt – a depth of experience that few teams have been able to rival. His work in human-powered flight culminated in the flight of the dragonfly-like Daedalus from Crete to Santorini in 1988. This trip set the human-powered flight record for speed and endurance.


On its return to the USA, Drela’s team was attracted by the challenge of winning the DuPont Prize for the fastest human-powered water craft, which had been set up in 1988. The prize would be awarded to the first team to break 20 knots (23mph/37km/h) over a 100-metre course, or to the team with the fastest speed on record as of 31 December 1992.


The only way the prize would be theirs, Drela realised, would be by designing a human-powered hydrofoil.


Hydrofoils are part-boat, part-plane. They are often used to connect remote islands or to enable fast commutes. As the boat gains speed, the ski-like foils under the hull lift it up out of the water like aerofoils help raise a plane up into the air.


The first hydrofoil was invented at the end of the 19th Century. We then had to wait until 1955 for German engineer Julius Schuck to present the first human-powered hydrofoil to the public. He called it the Wasserlaufer (water runner).

第一个水翼是在19世纪末发明的。然后,直至1955年,德国工程师朱利叶斯·沙克(Julius Schuck)才向公众展示第一台人力水翼船。他称之为Wasserlaufer(滑水机)。

Since then, many different kinds of one- and even two-seat hydrofoils have been built, with names like AquaSkipper, Foiled Again and Mutiny on the Boundary Layer. They have used propellers under the water, propellers out of the water, flapping wings and even oars to make them go fast enough to take off. The first version of the Flying Fish was even launched from a catapult. Spectacular races have been held in Japan.

从那时起,人们建造了许多不同种类的单座乃至双座水翼船,有的叫AquaSkipper,有的称为Foiled Again,还有叫Mutiny on the Boundary Layer。这些船有的使用水下螺旋桨,有的使用水上螺旋桨,有的会拍打翅膀乃至桨,使它们快到足以起飞。飞鱼号(Flying Fish)的初版甚至是从弹射器上发射的。日本举行了很多壮观的比赛。

The attraction for engineers such as Drela is that human-powered hydrofoils are the fastest human-powered craft on the water. The long, sleek rowing eights made famous by the Oxford and Cambridge Boat Race would still be unable to beat the record set by the Decavitator all those years ago.


“I thought my record would be broken eventually,” says Drela. “But we came to the project with a huge amount of experience of other human-powered projects, and it was still a hard, hard problem.

"我以为我的纪录最终会被打破,"德雷拉说, "我们带着大量其他人力交通工具项目的经验来做这个项目,但这仍然是一个巨大的难题。

“It was much harder problem than building our plane. If you drift up and down in a plane, it’s not a problem, even by a foot. On a hydrofoil, drifting even by a few inches can be a disaster.”


“There have been an awful lot of teams that have tried and failed to break the record because there are only a limited number of people who have the skills to do it, they haven’t got enough time to do it properly, and it’s expensive,” says Adrian Thomas, co-founder of Animal Dynamics. “You need to be able to spend money, do it yourself and make mistakes.”

"有许多团队进行了尝试,但是未能打破纪录,因为有能力做到这一点的人很少,他们没有足够的时间完成,而且成本也很高,"Animal Dynamics的联合创始人阿德里安·托马斯说, "你需要有充足的资金,亲自去试错。"

“It is now at the stage that it is too expensive for hobbyists and needs a whole bunch of different skills to do it,” he adds. “That’s probably why Mike Drela was the one able to do it. He had a fantastic set of skills and was backed by MIT.”


However, some in the small community think that the Decavitator’s victory was down to a tail wind.


“The Dupont Prize rules allowed a small, about 3mph (4.8km/h) tail wind,” says Allan Abbott, co-designer of the rival Flying Fish 20. In 1987 Olympic gold medal cyclist Steve Hegg set a world-record time of 5 min, 48.53 seconds (11.15 knots) over the 2,000-metre Long Beach Marine Stadium Olympic rowing course on the Flying Fish 2 – a record, albeit a less glamorous one, that also still stands today.

"杜邦奖规则允许利用较小的、约每小时3英里(4.8公里)的尾部气流。"对手Flying Fish 20(飞鱼20号)的联合设计师艾伦·阿伯特(Allan Abbott)说。1987年,自行车奥运金牌得主史蒂夫·黑格(Steve Hegg)在长滩海洋体育场2000米的奥林匹克赛道上,通过飞鱼2号创造了世界纪录5分48.54秒(11.15节)。虽然这个纪录并不十分耀眼,但至今仍屹立不倒。

“The Decavitator was designed to take advantage of that rule and utilised an air propeller. A tail wind gives much greater assistance to a craft pushing against the wind, as compared with a craft with its propeller in the water pushing against the water.”


Then in a head-to-head competition in December 1992 at Puddingstone Reservoir in California where the wind speed was negligible, Decavitator’s speed was slightly slower than the Flying Fish’s.

随后,1992年12月在加利福尼亚州的布丁斯通水库(Puddingstone Reservoir)进行了一场势均力敌的比赛,在风速几乎可以忽略不计的情况下,Decavitator的速度比飞鱼稍慢。

“Top sprint speed records require hydrofoil designs that are designed for high speed,” he says, “and these are inevitably quite impractical in that they won't fly at all with less-than-sprint effort.


“What advice would I have to someone wanting to break it today? Find a sponsor for the project.  It is unlikely that anything marketable will be derived from a top speed competition.”


However, Thomas and Alex Caccia, co-founder and CEO of Animal Dynamics, are confident they are going to smash the record with a speed faster than 20 knots – and that they will have something they can bring to market afterwards.

然而,Animal Dynamics的联合创始人兼首席执行官托马斯和亚历克斯·卡齐亚(Alex Caccia)都有信心将以20节以上的速度打破纪录——而且他们将获得一些能够推向市场的东西。

Animal Dynamics is a hi-tech spinout with a difference. Its technology is inspired by nature. It is developing a pocket-sized drone called the Skeeter for the UK Ministry of Defence, that was inspired by the dragonfly and uses flapping wings to fly. The spinout has just been awarded a contract to develop a prototype of an autonomous paramotor that could help resupply soldiers on the frontline in the future.

Animal Dynamics是一家具有差异优势的高科技公司。其技术灵感来源于大自然。它正在开发一种口袋大小的无人机,被英国国防部称为Skeeter,其灵感来自蜻蜓,并使用扑翼来飞行。该公司刚刚拿下了一项合同,要开发一个自带动力降落伞的原型,未来可以帮助给前线士兵提供补给。

The lessons from this project have, according to Thomas and Caccia, helped to solve the engineering challenges of the Malolo.


“The reason why we have a chance of breaking the record now is that the whale tail as a propulsion mechanism has a 20–30% efficiency gain over a propeller,” says Adrian Thomas. “It’s just hard to do.”


“Various people have looked at it and played with it, but no one has ever actually developed it. I think this is because trying to develop a mechanism to drive it efficiently is difficult.”


The challenge of this design is to convert the circular movement of the cyclist to the up and down flapping movement of the fin without big losses of efficiency.


“There are ways of doing it, and we have various patents in now,” adds Thomas. “But this is the big problem.”

"有一些办法来做尾翼,我们现在有不少专利了,"托马斯补充道, "但这是一个大问题。"

“For many teams, it is easier just to use a propeller and get a guy cycling,” says Caccia.


Thomas and Caccia have their eyes on a prize bigger than setting the record: a technology that will help make the air cleaner and the planet cooler by cleaning up one of the dirtiest industries around – the shipping industry.


Research has shown that just one of the world’s largest container ships can emit as much pollution as about 50 million cars. What’s more, the 16 largest ships emit as much nitrogen oxide and sulphur oxide as the world’s 760 million cars.


“What we are really interested in is using the whale tail as a form of ship propulsion,” says Thomas. “We don’t have to build ships that look like whales; we just need to replace propellers with foils that go up and down.


“The hydrodynamics are the same as on the Malolo and the mechanics are too. The nice thing is that there are already hydraulic mechanisms that work like a whale’s tail that we could use.”


In a water tank near their laboratory in north Oxford they will soon begin testing of an outboard motor propelled by a foil that goes up and down rather than a propeller.


“Whale tail propulsion could offer a 20–30% fuel saving for the shipping industry. The industry is moving to autonomous ships and now is the time to come up with a more efficient propulsion mechanism.


“In the end, we want to break the record because it would be public confirmation of a novel technology,” says Alex Caccia.


Now that would be a prize worth winning.