Your forgetting that the cool dense intake air is expanded (greatly) in the engi... | Hacker News

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		seiferteric on Jan 30, 2019 \| parent \| context \| favorite \| on: Boeing 787 Suffers Rare Dual Engine Failure on Lan... Your forgetting that the cool dense intake air is expanded (greatly) in the engine via combustion with fuel, so the volume of air being exhausted is much greater than went in and at much higher pressure, this is where the thrust comes from in the first place. It's not just a big fan :)

alliecat on Jan 30, 2019 | [–]

Modern turbofans are basically ducted fans spun by a smaller turbojet engine, so they are basically huge fans!

cm2187 on Jan 30, 2019 | [–]

But is it the hot air out of the engine being reversed or the air from the big fan? I thought it was the latter.

metalliqaz on Jan 30, 2019 | [–]

It's mostly bypass air.

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