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Ask HN: New Jet Engine

2 points by ryanthedev ↗ HN
liquid nitrogen. It’s abundant in our atmosphere, we can cool it using a vacuum.

Replace the jet fuel with a mix of water \ air \ liquid nitrogen.

Creates a lot of dense gas shooting through a nozzle at high velocity.

3 comments

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gus_massa
To make liquid nitrogen, you need an special equipment. Imagine that it's like a refrigerator, but more complex. So to run the equipment you will need a lot of electricity.

You have to do the calculation of how much will it cost in electricity to produce the liquid nitrogen necessary to have the same impulse of the usual fuel.

Also, liquid nitrogen is very cold, mixing it with water will make a lot of ice [1]. The ice is not good for the nozzles or whatever is in the "engine" of the jet.

[1] Liquid nitrogen is quite cheap, something like $3 per gallon. You can get some for free in the laboratory during a major degree in Physics. It's nice to play with it, but be careful and follow the safety instruction. :)

ryanthedev
Liquid nitrogen is actually very easy to make and very easy to melt. You can buy a generator that can make 67 liters a minute of eBay.

The water would be hot though I’m open for debate on another source to rapidly warm the liquid nitrogen.

I wish I had the time or the money and engineering ability to prove it out. Hopefully some other inventor and build on this concept. It will work, my biggest concern would be destroying the atmosphere, but I would predict we would need a lot of nitrogen exhaust to displace enough oxegen.

Thanks for the feedback!

jaclaz
>You can buy a generator that can make 67 liters a minute of eBay.

67 liters per minute?

How much would that cost? I thought that they are in the several tens of thousands dollars for generators that can produse a few tens liters per day.