2. 职称英语
  3. 下面你将听到一段关于超音速飞机的讲话。／／ A little airplane has given new meaning to the ter

下面你将听到一段关于超音速飞机的讲话。／／ A little airplane has given new meaning to the ter

游客2025-01-28  28
问题     下面你将听到一段关于超音速飞机的讲话。／／
    A little airplane has given new meaning to the term "going hyper". The Hyper-X recently broke the record for jet planes when it traveled at a hypersonic speed of seven times the speed of sound. That’s about 5,000 miles per hour. At this speed, you’d get around the world — flying along the equator — in less than 5 hours. // The Hyper-X is an unmanned, experimental aircraft just 12 feet long. It achieves hypersonic speed using a special sort of engine known as a scramjet. It may sound like something from a comic book, but engineers have been experimenting with scramjets since the 1960s.  //
    For an engine to burn fuel and produce energy, it needs oxygen. A jet engine, like those on passenger airplanes, gets oxygen from the air. A rocket engine typically goes faster but has to carry its own supply of oxygen. A scramjet engine goes as fast as a rocket, but it doesn’t have to carry its own oxygen supply.  //
    A scramjet’s special design allows it to extract oxygen from the air that flows through the engine. And it does so without letting the fast-moving air put out the combustion flames. However, a scramjet engine works properly only at speeds greater than five times the speed of sound.   //
    A booster rocket carried the Hyper-X to an altitude of about 100, 000 feet for its test flight. The aircraft’s record-beating flight lasted just 11 seconds.  //
    In the future, engineers predict, airplanes equipped with scramjet engines could transport cargo quickly and cheaply to the brink of space. Hypersonic airliners could carry passengers anywhere in the world in just a few hours.  //
选项
答案     一架小型飞机已经赋予“极超音速飞行”以新的含义。“极超一X”最近以7倍于音速的极超音速速度飞行，从而打破了喷气飞机的纪录。其速度约为每小时5千英里。以这样的速度不到5小时便可沿赤道环绕地球飞行。“极超一X”是架长度仅为12英尺的无人实验飞机。它使用的是一种被称为特殊超音速冲压喷气的发动机，以达到极超音速。它听上去像是漫画书上的玩意儿，但工程师们自，20世纪60年代起便一直进行该种发动机的实验。
    发动机要消耗燃料、产生能量这就需要氧气。像客机上的喷气式发动机是从空气中获得氧气的。火箭发动机的特点是速度更快，但它必须自己携带氧气。特殊超音速冲压喷气发动机的速度同火箭一样，但它并不需携带氧气。
    特殊超音速冲压喷气发动机的特殊设计使它能够从流过发动机的空气中提取氧气。而与此同时并不会让快速流动的空气熄灭燃烧火焰。但是，特殊超音速冲压喷气发动机只能在其速度是音速五倍以上的时候才能正常工作。
    在试飞中，一枚助推火箭将“极超一X”送上了约10万英尺的高空。这飞机破纪录的飞行仅仅持续了11秒。
    工程师们预测：在将来，装配了超音速冲压喷气发动机的飞机可以快速而廉价地将货物运往天涯海角。而极超音速客机则可以在几小时之内将旅客送往世界上任何地方。
解析
转载请注明原文地址:http://tihaiku.com/zcyy/3931794.html
相关试题推荐
随机试题
最新回复(0)