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The article mainly mentions kerosene-powered engines. Is diesel more efficient on a per-kilo basis than kerosene? I always thought kerosene packs a bigger punc
by bayesian_horse 7y ago
The article mainly mentions kerosene-powered engines.
Is diesel more efficient on a per-kilo basis than kerosene? I always thought kerosene packs a bigger punch so you can carry less of it for the same distance.
Also if the plane is intended to fly both that high/slow and that low/slow that probably informs the wing choice. Less air resistance and lift up there.
- walrus01 7y agoAccording to this, diesel is 45.6MJ/kg Jet fuel is 43MJ/kg https://en.m.wikipedia.org/wiki/Energy_density https://en.m.wikipedia.org/wiki/Energy_density A big part of it has to be how much is lost to heat, an internal combustion engine is far from efficient... But then again neither is a turbine.
- dsfyu404ed 7y agoKerosene, diesel, jp8, etc. are all basically the same from a power density point of view. It's what you burn them in and how you burn them that matters.
- dusbajd 7y agoHydrocarbons have very similar energy/mole and therefore energy/volume, energy/mass ratios. This relationship breaks down for very short HC (methane, basic alcohols). Differences in effective energy density result from the combustion cycle used: Otto is better than Diesel for the same compression ratio, but you can’t easily get high compression ratio w/ Otto. Therefore Diesels are, typically, more efficient. However, if you use methane (high compression) in an Otto cycle with turbo compounding, you’ll probably beat diesel. But then you have NOx emissions
- dusbajd 7y agoHydrocarbons have very similar energy/mole and therefore energy/volume, energy/mass ratios. This relationship breaks down for very short HC (methane, basic alcohols). Differences in effective energy density result from the combustion cycle used: Otto is better than Diesel for the same compression ratio, but you can’t easily get high compression ratio