Enlarge / Artist’s impression of the Ramjet propulsion system proposed in 1960 by physicist Robert W. Bussard (credit score: NASA)
In Poul Anderson’s 1970 novel Tau Zero, a starship crew seeks to journey to the star Beta Virginis in hopes of colonizing a brand new planet. The ship’s mode of propulsion was a so-called “Bussard ramjet,” an precise (although hypothetical) technique of propulsion which had been proposed by physicist Robert W. Bussard only a decade earlier. Now, physicists have revisited this uncommon mechanism for interstellar journey in a brand new paper revealed within the journal Acta Astronautica, and alas, they’ve discovered the ramjet wanting. It is possible from a pure physics standpoint, however the related engineering challenges are at the moment insurmountable, the authors concluded.
A ramjet is mainly a jet engine that “breathes” air. The very best analog for the elemental mechanism is that it exploits the engine’s ahead movement to compress incoming air with out the necessity for compressors, making ramjet engines lighter and easier than their turbojet counterparts. A French inventor named Rene Lorin acquired a patent in 1913 for his idea of ramjet (aka, a flying stovepipe), though he did not construct a viable prototype. Two years later, Albert Fonó proposed a ramjet propulsion unit to extend the vary of gun-launched projectiles and finally was granted a German patent in 1932.
A primary ramjet has three parts: an air consumption, a combustor, and a nozzle. Scorching exhaust from gas combustion flows by the nozzle. The strain of the combustion have to be increased than the strain on the exit of the nozzle with a purpose to keep a gentle move, which a ramjet engine achieves by “ramming” exterior air into the combustor with the ahead pace of no matter automobile is being powered by the engine. There isn’t any want to hold oxygen on board. The draw back is that ramjets can solely produce thrust if the automobile is already transferring, so that they require an assisted takeoff utilizing rockets. As such, ramjets are most helpful as a way of acceleration, akin to for ramjet-powered missiles or for rising the vary of artillery shells.
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