Copying Birds May Save Aircraft Fuel
第一段
Both Boeing and Airbus have trumpeted the efficiency of their newest aircraft. The 787 and 350 respectively . Their clever designs and lightweight composites certainly make a difference . But a group of researchers at Stanford University , led by Ilan Kroo , has suggested that airlines could take a more naturalistic approach to cutting jet-fuel use and it would not require them to buy new aircraft.
单词&词组
trumpet v. 大声宣告、大肆宣扬
respectively ad. 分别地
lightweight a. 比通常重量轻的
composite n. 复合材料
make a difference 有作用，有影响
naturalistic a. 自然的
第二段
The answer, says Dr Kroo , lies with birds . Since 1914, scientists have known that birds flying in formation-a V-shape-expend less energy. The air flowing over a bird’s wings curls upwards behind the wingtips . a phenomenon known as upwash. Other birds flying in the upwash experience reduced drag, and spend less energy propelling themselves . Peter Lissaman, an aeronautics expert who was formerly at Caltech and the University of Southern California ,has suggested that a formation of 25 birds might enjoy a range increase of 71%.
单词&词组
formation n. 编队、形成
expend v. 消耗
curl v. 盘绕、缭绕
wingtip n. （鸟或飞机的）翼尖，翼梢
drag n. 负重、累赘
propel v. 推进
第三段
When applied to aircraft, the principles are not substantially different . Dr Kroo and his team modeled what would happen if three passenger jets departing from Los Angeles, San Francisco and I as Vegas were to assemble over Utah, assume an inverted V-formation occasionally change places so all could have a turn in the most favourable positions , and proceed to London. They found that the aircraft consumed as much as 15% less fuel (coupled with a reduction in carbon-dioxide output). Nitrogen-oxide emissions during the cruising portions of the flight fell by around a quarter.
单词&词组
substantially ad. 实质上、大体上
depart v. 出发
assemble v. 集合
inverted a. 倒转的
favorable a. 有利的
proceed v. 继续进行
consume v. 消耗；消费
emission n. 排放
cruise v. （汽车、飞机等）以平稳速度行驶
portion n. 部分
第四段
There are , of course , knots to be worked out . One consideration is safety , or at least the perception of it . Would passengers feel comfortable travelling in companion? Dr Kroo points out that the aircraft could be separated by several nautical miles , and would not be in the intimate groupings favoured by display teams like the Red Arrows , A passenger peering out of the window might not even see the other planes. Whether the separation distances involved would satisfy air-traffic-control regulations is another matter, although a working group at the International Civil Aviation Organisation has included the possibility of formation flying in a blueprint for new operational guidelines.
单词&词组
knot n. 结、疙瘩（文章用以指“问题”）
perception n. 察觉
nautical a. 航海的
intimate a. 亲近的
peer v. 仔细看、盯着看
separation n. 分开
air-traffic-control 空中交通管制
blueprint n. 计划、蓝图
operation a. 操作的
第五段
It remains to be seen how weather conditions affect the air flows that make formation flight more efficient. In zones of increased turbulence, the planes’ wakes will decay more quickly and the effect will diminish. Dr Kroo says this is one of the areas his team will investigate further. It might also be hard for airlines to co-ordinate the departure times and destinations of passenger aircraft in a way that would allow them to gain from formation flight. Cargo aircraft, in contrast, might be easier to reschedule, as might routine military flight.
单词&词组
turbulence n. 湍流、不稳定的强气流
wake n. 航空轨迹
decay v. 消退
diminish v. 变小、减小
investigate v. 调查
co-ordinate v. 协调
destination n. 目的地
reschedule v. 重新计划、重新安排日程
第六段
As it happens, America’s armed forces are on the on case already. Earlier this year the country’s Defence Advanced Research Projects Agency announced plans to pay Boeing to investigate formation flight, though the programme has yet to begin . There are reports that some military aircraft flew in formation when they were low on fuel during the Second World War ,but Dr Lissaman says they are unsubstantiated. “My father was an RAF pilot and my cousin the skipper of a Lancaster lost over Berlin,”he adds. So he should know.
单词&词组
unsubstantiated a. 未经证实的
41. Findings of the Stanford University researchers will promote the sales of new Boeing and Airbus aircraft.
42. The upwash experience may save propelling energy as well as reducing resistance.
43. Formation flight is more comfortable because passengers can not see the other plans.
44. The role that weather plays in formation flight has not yet been clearly defined.
45. It has been documented that during World War Ⅱ, America’s armed forces once tried formation flight to save fuel.
