Timeline for Is there a limit to the possible altitude for electric jets?
Current License: CC BY-SA 3.0
11 events
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| Feb 11, 2018 at 21:14 | history | edited | Pondlife | CC BY-SA 3.0 |
deleted 14 characters in body; edited title
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| Feb 11, 2018 at 19:50 | comment | added | jamesqf | Isn't the real limitation the amount of thrust you can generate from a fan or propellor? Which is going to depend on the density of the medium: consider the size difference between airplane & boat propellors generating the same thrust. | |
| Feb 11, 2018 at 19:04 | vote | accept | user15864 | ||
| Feb 11, 2018 at 17:54 | history | tweeted | twitter.com/StackAviation/status/962746561955495942 | ||
| Feb 11, 2018 at 16:11 | comment | added | user3528438 | If you remove the limitation of battery the next limitation is probably weight. At high speed and high altitude the engine would probably a jet with high exhaust velocity, where hot jet (e.g. turbo jet, ram jet, and low-bypass turbo fan) has a clear weight advantage over cold jet (e.g electric jet). IMO if you want low carbon super sonic travel implemented with reasonable amount of time and money budget, hyperloop would be slightly more practical, or hydrogen fuel. | |
| Feb 11, 2018 at 14:24 | comment | added | Charles Bretana | Another consideration is that as you go higher, and faster, Lift required decreases due to centrifugal force. Obviously, just outside the atmosphere, 200 miles up, orbital velocity is about 18,000 mph. So airspeeds at some significant percentage of that will garner the benefits of some reduction in required Lift. (to a degree dependent on speed and what direction you travel - with or against the eastward rotation of the earth) | |
| Feb 11, 2018 at 14:18 | comment | added | Charles Bretana | Well, lift is dependent on dynamic pressure to the same degree as drag, so, theoretically, at almost any altitude, as you increase speed to that same dynamic pressure that would produce the drag you have the power (thrust) to overcome, you would have the same amount of Lift, no? | |
| Feb 11, 2018 at 11:33 | answer | added | Peter Kämpf | timeline score: 14 | |
| Feb 11, 2018 at 11:29 | comment | added | Koyovis | Well, you need lift as well, which also reduces with increasing altitude. | |
| Feb 11, 2018 at 10:53 | review | First posts | |||
| Feb 11, 2018 at 11:13 | |||||
| Feb 11, 2018 at 10:52 | history | asked | user15864 | CC BY-SA 3.0 |