Where does this come from, and can I check it?

A large fan pushes air past the engine core, and modern airliners move several times more of it than the core burns. The figure is taken from NASA Glenn Research Center, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.

Is this really a technology fact?

Yes. It sits on the Technology shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.

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The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.

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Most of a turbofan's thrust comes from cold air

A large fan pushes air past the engine core, and modern airliners move several times more of it than the core burns In a high bypass turbofan the fan is turned by the core turbine, but most of the air it moves goes around the combustor rather than through it. Moving a large mass of air slowly is quieter and more efficient than accelerating a small mass to high speed. Early jet engines had bypass ratios near zero, while modern civil engines reach ten to one. It sits in Mondo's technology collection, one of 200 facts that each trace back to the reference below.

Where this comes from

NASA Glenn Research Center

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Tags: jet-engines, aviation, propulsion

Most of a turbofan's thrust comes from cold air: the short answers

Where does this come from, and can I check it?: A large fan pushes air past the engine core, and modern airliners move several times more of it than the core burns. The figure is taken from NASA Glenn Research Center, which is linked in full on this page. Every fact on Mondo Knows names its source rather than repeating an unsourced claim.
Is this really a technology fact?: Yes. It sits on the Technology shelf, one of 2,600 sourced facts grouped into space, animals, the human body, history, science and more. Category pages collect every fact in the same field.
What else can I read about it?: The links under the fact point to a quiz, game, puzzle or calculator on the same subject, and the shelf below shows related facts. The wording here is original, and quoted phrases are marked as quotations.