星期三, 十月 17, 2007

朴告:飞行器的设计人保罗·麦克格雷迪

Paul MacCready


Sep 6th 2007

From The Economist print edition

Paul MacCready, designer of flying machines, died on August 28th, aged 81

飞行器的设计人保罗·麦克格雷迪于八月二十八日去世,享年81

ICARUS did it with feathers glued together with wax; he flew too near the sun and plummetted into the sea. Giovanni Battista Danti tried it with pinions of iron and feathers in 15th-century Perugia, hurtling over the piazza and crash-landing on the church. Charles Bernouin in 1672 in Regensburg strapped a rocket to himself, as well as calico wings. His novel jet propulsion merely meant that he broke his neck, rather than his legs.

希腊神话中的伊卡罗斯曾经把蜂蜡和羽毛粘到一起进行飞行,的但是他飞得离太阳太近坠海而亡。15世纪意大利佩鲁贾的乔瓦尼·巴蒂斯·但丁用铁翼和羽毛尝试飞行,他掠过广场摔落在教堂顶上。1672年查尔斯·贝尔努安在雷根斯堡把火箭炮和布质的翅膀绑在自己身尝试飞行。他新奇的喷射推动力只能意味着折断脖子而非双腿。

Paul MacCready's Gossamer Condor, which made the first successful human-powered flight as recently as 1977, was some improvement on these. It was made of aluminium tubing, Mylar and piano wire, with a weird horizontal stabiliser poking from the front like the head of a stork. It weighed 70lb (32kg), with a wingspan of 96 feet (29 metres), and the engine inside it was a lean, determined cyclist called Bryan Allen, pedalling for all he was worth. Sheer perseverance got him five feet off the ground for about a mile (1.6km) round a figure-of-eight course, and won Mr MacCready the first of many prizes.

保罗·麦克格雷迪的“幻影神鹰号”却在飞行领域取得突破,它完成了1977以来首例成功的人力驱动飞行。这个飞行器由铝质管材、聚酯薄膜和钢琴丝制成,前端伸出来一个活象鹳的脑袋的怪异的水平稳定器。它重701(32kg),翼展96英尺(29),内部引擎是踩脚踏车的布赖恩·艾伦,他身材削瘦,被固定在里面,竭尽全力地踩脚踏板。超人的毅力使他离开地面绕了一个八字形的路径,并为麦克格雷迪赢得了首笔大额奖金。

Money was his only motivation, he said later. Because the prize offered for this feat by Henry Kremer, a British industrialist, exactly matched a debt Mr MacCready had to discharge, he had started to think about flying machines and how to make them more efficient. But this offhand explanation was not strictly true. He had been fascinated by wings, and by flying, all his life.

他后来说,奖金是他唯一的动机。麦克格雷迪当时正好有一份债务已到清偿期,而这个由英国实业家亨利·克莱默提供奖金的技艺表演恰好能使他摆脱困境。于是他开始着手研究飞行器并考虑如何使之更有效率。不过这个搪塞的解释并不完全正确。他的一生都为翅膀和飞翔而神魂颠倒。

It began with moths and butterflies. As a boy, he collected them on the Connecticut shore and pored over the exquisite studies of John Henry and Anna Botsford Comstock, two 19th-century naturalists, to explore the evolution and the vein-structure of the wings of lepidoptera. Nerdy already, small and unsporty, he then buried himself in making and flying model aircraft: fixed-wing and flapping-wing, out of a kit or out of his head, propelled with rubber bands or with tiny petrol engines. Again, he won prizes. The boy who posed proudly for the camera with a balsa-wood glider and a silver cup grew naturally into the inventor whose chief joy was to make wings ever lighter and ever larger.

这 个爱好是从对蛾子和蝴蝶的兴趣开始的。孩童时代,他在康涅狄格州的海滨收集这些昆虫,钻研十九世纪博物学家约翰·亨利和安娜·博茨福得·康斯托克精美绝伦 的研究,尝试去探寻鳞翅类生物的翅膀演化规律及其纹理构造。早期形成的书呆子气、矮小的身材,再加上不喜欢运动,这诸多原因使他索性沉浸于制造和试飞定翼 或扑翼飞行模型。这些模型用机械或者手工制造,推动力有橡皮筋也有微型汽油发动机。他又一次赢得了奖励。那个带着轻木滑翔机手拿银杯得意地为照相机摆姿势 的男孩自然而然地长成了一个发明家,他最大的兴趣是制造越来越轻巧、越来越巨大的机翼。

Birds were always his chief instructors. Daydreaming in summer, looking upwards, he noticed that the larger birds, hawks and eagles, could stay aloft for longer, riding thermals with supreme elegance without flapping their wings. When they needed to turn, they would tilt their wings to bank higher, preserving the lift and using almost no energy. Mr MacCready applied the same principles to his human-powered machines. The wider the wingspan, he calculated, the less power would be needed to fly; with wings of 100 feet or so, the 0.3 of horsepower produced by a cyclist would get him airborne and keep him there as long as his legs could last. Another such craft, the Gossamer Albatross, all carbon fibre and polystyrene wrapped in polyester film, flew 22 miles across the English Channel in 1979, barely clearing the waves while Mr MacCready urged it on from a boat.

禽 鸟是他的主要灵感来源。在消夏的时候,仰望天空,他注意到大一点的鸟儿,例如鹰和隼,能乘着热气流在高空中不拍打翅膀极其优雅地逗留很久。当它们需要转向 的时候,它们会向一边略高地倾斜翅膀,这几乎不花费能量却能保持高度不变。麦克格雷迪把这个机理运用到了他的人力驱动飞行器上。他通过计算得出结论:翼展 越宽,飞行所需要的动力就越小;在翼展到达100英尺左右的时候,一个踩脚踏车的人产生0.3马力的功率就可以使他飞起来,并在空中呆到他的腿无法再继续支撑的时候。另一个同类飞行器“幻影信天翁”于1979年穿越英吉利海峡飞行了22英里,它由带聚酯膜涂层的碳纤维和聚苯乙烯材料构成。当麦克格雷迪从小船上督促“幻影信天翁”起飞的时候,乎没有激起水面上的任何波纹。

Banking on sunbeams 收集太阳的光芒

There were other ways, too, to fly. Mr MacCready fitted one of his aircraft with an umbrella-panel of leftover photovoltaic cells; they provided 400 watts of extra power. He then produced with DuPont the first plane powered entirely by the sun, the Solar Challenger, which in 1981 flew the 163 miles from Paris to Canterbury at a height of 11,000 feet. “Flying on sunbeams”, he liked to call it. The folk at NASA got interested, and for them he produced giant unmanned solar wings, 200 feet across, which could stay above 50,000 feet for six months at a time to track environmental changes or to spy. Spying could be done, too, with the tiny “drones” he invented, based on bumble bees, with a six-inch (15cm) wingspan and video cameras inside them.

其他的方法同样能进行飞行。麦克格雷迪曾把一个飞行器进行改进,把它和废弃的光电电池伞状配电板装备在一起;那些电池能提供高达400瓦的电源。后来他和杜邦制造了第一架完全由太阳光提供动力的飞机——“日光挑战者”,1981年这架飞行器从巴黎起飞,在11000英尺高空飞行了163英里,最后到达坎特伯雷。他喜欢称那为“日光飞翔”。美国航空航天局的家伙们对此颇有兴趣,对他们来讲,他制造了巨大的无人太阳能机翼。它有200英尺长,能在50000英尺的高空中停留一段时间,对环境变化进行跟踪调查,或者进行高空监视。他还以翁翁叫的蜜蜂为原型发明了微型“雄峰”飞行器,它同样能实施监视任务。这个飞行器只有六英寸翼展(15cm),还内置了一个摄象机。

Realistic, businesslike and, according to friends, with a bit of a Scottish streak, Mr MacCready knew that most of his inventions were impractical. In his mind his company, AeroVironment, which he ran for more than 30 years, was dealing mostly in ideas. People were not going to pedal their planes themselves. Nor were they going to want solar-powered cars, even though Mr MacCready's version, the Sunraycer, won a race of almost 2,000 miles across the Australian desert. The point was to set people thinking about energy efficiency, to inspire the young to take up science, and to experiment for the joy of it.

按照他朋友们的看法,麦克格雷迪是个实事求是的、就事论事的人,有时候还带点苏格兰人的味道。他明白他的大部分发明都不切实际。他自认为,他运营了30多年的公司AeroVironment主要依赖于信念。人们不会去亲自踩动他们的飞机。也不会想要太阳能汽车,即使麦克格雷迪的太阳能汽车“太阳射线”能在穿越澳大利亚沙漠接近2000英里的比赛中获得冠军。他认为关键在于让人们去思考能源效率问题,去激励年轻人从事科学研究,并从中感受到快乐。

At the end of his life, still fascinated by the potential of everything, Mr MacCready began to dream about kites: big kites, kept aloft indefinitely about 1,000 feet up, to extract the “huge energy” from high-altitude winds, to monitor acoustic signals and perhaps even to provide thrust to vehicles on the ground.

在他晚年,仍然迷恋于各式各样的潜能。麦克格雷迪开始对风筝着了魔:使大风筝长期保持在1000英尺的高空,抽取出高空空气中的“巨大能量”,用这些能量控制声波信号,甚至也许能为陆地上的车辆提供推进力。

For him, it was a return to an old delight, soaring and sailing among the clouds. As a student, he had studied the turbulence inside them; as a champion glider in the 1940s and 1950s he had learned to ride on ridges, waves and thermals and had invented a gadget, the MacCready Ring, which showed the optimum speed to fly to avoid losing height between them. After a time, he had found the sport too risky. But at the age of 79 he spryly announced that he would take it up again: still the nearest thing humans have to the carefree flight of birds.穿梭于云间自由的翱翔,对他来讲是重新找回久违的欢乐。学生时代他就研究过内置的涡轮机;19401950年代,他得过滑翔冠军,知道怎样在山脊上空滑翔,懂得如何在波浪与暖流中穿梭,那时候他发明了MacCready圈,这个小装置指示出飞行的最佳速度,以免失去对海拔高度的把握。过了一段时间,他感到这项运动太过冒险。但是在他79岁的时候,他精神抖擞地宣布将要重归这项运动:象鸟一样自由自在的飞翔仍然是人们最希望做的事。

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