Speaker 1: Welcome to Brainstuff from house stuff Works dot com where
Speaker 1: smart happens. Hi Am Marshall Brain with today's question, how
Speaker 1: does an afterburner work on a jet engine? A jet engine,
Speaker 1: like a rocket engine, is a reaction engine. It works
Speaker 1: by throwing mass in one direction and taking advantage of
Speaker 1: the reaction in the opposite direction. In the case of
Speaker 1: a jet engine, the engine bird's fuel like kerosene with
Speaker 1: error from the atmosphere. The burning fuel heats and expands
Speaker 1: the air, and this hot air shoots out the exhaust
Speaker 1: end of the engine to create thrust. Most modern jet
Speaker 1: engines use a turbine to improve the efficiency of the
Speaker 1: engine and allow the engine to work at low speeds.
Speaker 1: One part of the turbine sucks in airror and compresses
Speaker 1: it before the fuel is injected. The back portion of
Speaker 1: the turbine acts like a windmill, extracting entered from the
Speaker 1: exhaust gases and using the energy to spin the compressor portion.
Speaker 1: A modern turbine engine is extremely efficient and there's still
Speaker 1: a lot of oxygen available in the exhaust stream. The
Speaker 1: idea behind an afterburner is to inject fuel directly into
Speaker 1: that exhaust stream and burn it using the remaining oxygen.
Speaker 1: This heats and expands the exhaust gases further, and it
Speaker 1: can increase the thrust of a jet engine by fifty
Speaker 1: or more. The big advantage of an afterburner is that
Speaker 1: you can significantly increase the thrust of the engine without
Speaker 1: adding much weight or complexity to the engine. And afterburner
Speaker 1: is nothing but a set of fuel injectors, a tube
Speaker 1: and flame holder that the fuel burns in, and an
Speaker 1: adjustable nozzle. A jet engine with an afterburner needs that
Speaker 1: adjustable nozzle so that it can work with and without
Speaker 1: the afterburners on the disadvantage of an afterburner is that
Speaker 1: it uses a ton of fuel for the power it generates. Therefore,
Speaker 1: most planes use afterburners sparingly. For example, a military jet
Speaker 1: would use its afterburners when taking off from a short
Speaker 1: runway on an aircraft carrier or during a high speed
Speaker 1: maneuver in a dog fight. Do you have any ideas
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Speaker 1: an email at podcast at how stuff works dot com.
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