Power for a space plane.
Power for a space plane.
复制标题
太空飞机的电源。
DOI：
10.1038/scientificamerican0806-56
复制
发表时间：
2006
影响因子：
3
通讯作者：
T. Jackson
中科院分区：
文献类型：
--
作者：
T. Jackson
长期以来，工程师们一直梦想着建造一种可以从跑道上飞到外太空然后再飞回来的飞机--就像《星星大战》电影中卢克·天行者的X翼战斗机那样。但有一件事阻碍了他们：喷气发动机需要氧气来燃烧燃料，而高层大气没有足够的氧气来维持燃烧。因此，飞向太空需要火箭推进，燃料和氧化剂都在飞行器内。即使是在当今使用的最先进的发射系统中，航天飞机，大约一半的发射重量是液态氧和固体氧化剂，它必须将其吊在高处，以保持火箭燃料燃烧到轨道。一个答案可能来自超音速燃烧冲压喷气发动机，被称为超燃冲压发动机，它将从大气中汲取氧气，因为它上升。通过在飞行中捕获空气而不是携带空气来减轻重量意味着每消耗一磅推进剂，超燃冲压发动机可以提供大约四倍于火箭的推力。最后，经过几十年断断续续的发展，实用的超燃冲压发动机似乎准备起飞。
Engineers have long dreamed of building an aircraft that could soar from a runway to outer space and then back again—the way Luke Skywalker’s X-wing fighter does in the Star Wars movies. But one thing has stood in their way: jet engines need oxygen to burn fuel, and the upper atmosphere does not have enough of it to sustain combustion. So flying to space requires rocket propulsion, for which both fuel and oxidizer are carried inside the vehicle. In even the most advanced launch system in use today, the space shuttle, about half the launch weight is the liquid oxygen and solid oxidizer it must lug aloft to keep its rocket fuel burning all the way to orbit. One answer could come from a supersonic combustion ramjet, known as a scramjet, which would scoop oxygen from the atmosphere as it ascends. The weight savings from capturing air in flight instead of carrying it means the scramjet can deliver about four times the thrust of a rocket for every pound of propellant consumed. At last, after decades of intermittent development, practical scramjets appear poised to take wing.