Timeline for Are wings any more efficient at creating lift, versus orienting the engine's thrust downwards?
Current License: CC BY-SA 3.0
36 events
| when toggle format | what | by | license | comment | |
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| Jun 22, 2021 at 18:27 | answer | added | Phil Crowther | timeline score: 0 | |
| May 4, 2017 at 14:01 | answer | added | Koyovis | timeline score: 0 | |
| Apr 23, 2017 at 2:39 | comment | added | Ross Millikan | The very simple answer is to observe that commercial airliners have wings, which weigh and cost. Commercial airliners are designed to minimize the cost, so if they could reasonably get rid of the wings they would. | |
| Apr 21, 2017 at 20:34 | comment | added | yshavit | I asked a similar question on Physics.SE a while back: physics.stackexchange.com/questions/122102/… . The tl;dr: energy goes up as v^2, while momentum goes up a v. For the same momentum, you can either move a little air quickly, or a lot of air slowly; the first of those requires more energy, because of that ^2. Engines do the first option, and wings translate that energy it into the latter (and thus get more momentum for the energy). | |
| Apr 20, 2017 at 14:40 | history | protected | fooot | ||
| Apr 20, 2017 at 14:31 | answer | added | NoAnswer | timeline score: 2 | |
| S Apr 19, 2017 at 23:18 | history | edited | Ryan Mortensen | CC BY-SA 3.0 |
Better wording
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| S Apr 19, 2017 at 23:18 | history | suggested | sixtyfootersdude | CC BY-SA 3.0 |
Better wording
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| Apr 19, 2017 at 22:37 | comment | added | Superbest | Some intuition: Flying machines that are entirely wingless exist. These are called rockets. They typically have a lot of problems with endurance and terrible loiter time. Also, on the other extreme, you have things like engineless gliders which can fly despite having no engine at all - so nothing to point down. | |
| Apr 19, 2017 at 21:36 | answer | added | Redja | timeline score: 2 | |
| Apr 19, 2017 at 21:11 | review | Suggested edits | |||
| S Apr 19, 2017 at 23:18 | |||||
| Apr 19, 2017 at 18:34 | answer | added | skua | timeline score: 0 | |
| Apr 19, 2017 at 17:37 | comment | added | jamesqf | @el.pescado: And what is the fuel burn when your F-15 is at full throttle, vs normal cruise? Or a Harrier doing a vertical takeoff (or hovering) vs maintaining altitude with wings AND overcoming the drag needed to cruise at several hundred knots? | |
| Apr 19, 2017 at 14:51 | answer | added | Trevor_G | timeline score: 29 | |
| Apr 19, 2017 at 14:40 | answer | added | coteyr | timeline score: 2 | |
| Apr 19, 2017 at 8:37 | comment | added | el.pescado - нет войне | Very few aircraft have thrust-to-weight ratio larger than 1, i.e. have engines powerful enough to lift aircraft weight alone. For example, F-15 has thrust-to-weight "barely" 1.07 and most airliners are closer to 0.2 | |
| Apr 19, 2017 at 6:18 | comment | added | Xen2050 | By power required & energy, are you essentially asking about fuel efficiency (over distance / time)? So which uses less fuel, a regular jet vs a Harrier? Or a regular plane vs a helicopter? | |
| Apr 19, 2017 at 6:03 | comment | added | jwenting | Technically, downward thrust does not create lift. It does of course have the same effect as lift in that it counters the force of gravity, but it's not lift :) | |
| Apr 19, 2017 at 5:31 | vote | accept | user9037 | ||
| Apr 19, 2017 at 4:32 | comment | added | jamesqf | Re "...shouldn't it require exactly the same amount of power...": Yes, and bumblebees shouldn't be able to fly :-) Nevertheless, we observe bumblebees flying, and winged aircraft using much less power than would be needed to keep the aircraft aloft through thrust. Even VTOL aircraft transition to using wings for lift once they're off the ground. | |
| Apr 18, 2017 at 21:20 | answer | added | Boog Dow | timeline score: 0 | |
| Apr 18, 2017 at 19:37 | answer | added | supercat | timeline score: 1 | |
| Apr 18, 2017 at 19:05 | answer | added | Dmitry Grigoryev | timeline score: 4 | |
| Apr 18, 2017 at 16:51 | comment | added | Todd Wilcox | @FreeMan I should have written, "you can't use the same engine as effectively for forward motion." Meaning, it's not as efficient for traveling quickly in a horizontal direction. When you use a gimbaled engine system the aircraft basically becomes fixed wing in flight. | |
| Apr 18, 2017 at 16:16 | comment | added | user9037 | Thanks a lot for all the interest and contributions! I'll check out the answers and comment on them, but right now I think the question still lacks closure as far as the underlying physics is concerned. | |
| Apr 18, 2017 at 15:44 | answer | added | user21228 | timeline score: 4 | |
| Apr 18, 2017 at 15:13 | comment | added | FreeMan | weeeelllll... @ToddWilcox, helicopters do move forward, they just angle their wings in the direction they want to go. Gimbaled engines (or exhaust) would do the same thing. | |
| Apr 18, 2017 at 14:07 | answer | added | Suncat2000 | timeline score: 0 | |
| Apr 18, 2017 at 13:43 | comment | added | Todd Wilcox | Note that a helicopter is like a prop plane with no wings and a huge prop pointed down. So yes, you can create useful lift by just pointing an engine straight down, but then you can't use the same engine as well for forward motion. This is assuming your want your aircraft to take you somewhere besides just up. Compare with rockets used for spaceflight. | |
| Apr 18, 2017 at 13:19 | answer | added | David K | timeline score: 29 | |
| Apr 18, 2017 at 12:37 | history | tweeted | twitter.com/StackAviation/status/854312936638214144 | ||
| Apr 18, 2017 at 11:54 | comment | added | FreeMan | Pretty darn good for a first question! Welcome! | |
| Apr 18, 2017 at 10:26 | answer | added | Martin | timeline score: 54 | |
| Apr 18, 2017 at 10:23 | answer | added | xxavier | timeline score: -4 | |
| Apr 18, 2017 at 9:24 | review | First posts | |||
| Apr 18, 2017 at 9:37 | |||||
| Apr 18, 2017 at 9:15 | history | asked | user9037 | CC BY-SA 3.0 |