Timeline for How are pitching and rolling moments transferred from rotor to the body?
Current License: CC BY-SA 4.0
11 events
| when toggle format | what | by | license | comment | |
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| May 21, 2020 at 12:00 | history | tweeted | twitter.com/StackAviation/status/1263439464090697728 | ||
| May 7, 2020 at 14:48 | comment | added | quiet flyer | @JanHudec -- thanks for the note; not being that knowledgeable about helicopters perhaps I placed too much reliance on that linked answer | |
| May 7, 2020 at 5:53 | comment | added | Jan Hudec | @quietflyer, the link certainly is related, but it answers a different question of ‘what ensures the tilt between rotor and body does not exceed some reasonable range’ (with, basically, ‘the way cyclic is rigged’). | |
| May 7, 2020 at 5:16 | comment | added | Jan Hudec | @quietflyer, yes, I disagree with that. The aerodynamic coupling in case of teetering rotor (it exists for every rotor anyway) is from body to rotor only, because the actual force is between rotor and air and the body position only affects cyclic. Of course the effect of rotor tilt on the body is there, but the discussion is now what effects there are besides that. And it does have practical implication too: teetering rotor loses all control effectiveness when unloaded, hinged or flexible maintains some. | |
| May 6, 2020 at 18:00 | comment | added | quiet flyer | @JanHudec -- so you disagree with the following? (Highly condensed from the link above) -- (With hinged rotors) "As soon as the rotor plane changes as a result of cyclic stick input, the resulting rotor hinge moment will change fuselage angle accordingly, providing the desired feedback cue." "With teetering rotors, there is an indirect aerodynamic coupling between fuselage and rotor shaft. This provides the same cues as the hinge offset solution but at a slower rate." | |
| May 6, 2020 at 15:25 | comment | added | Jan Hudec | @quietflyer, that answer was (the answer is deleted now) already linked below. I already read it, and it definitely does not say that. What it does say is that when the body tilts, it will make the rotor tilt too. That is clearly important to prevent the rotor hitting the body, but because the moment is between the rotor and air, it does not create any moment on the body. The body does actually “dangle freely” (on teetering rotor), though that's not really a good term, because it evokes a fixed mount, which the rotor definitely isn't. | |
| May 6, 2020 at 12:20 | comment | added | quiet flyer | Related - - aviation.stackexchange.com/questions/38859/… --even with a teetering system, the helicopter does not just dangle freely from the rotor disk -- see last paragraph for detailed explanation. | |
| May 5, 2020 at 14:02 | vote | accept | Jan Hudec | ||
| May 5, 2020 at 1:13 | comment | added | John K | A good way to think of it is with a teetering system, you fly the rotor disc here and there and the machine itself is just slung under it like a ball on a string that follows wherever the forces take it. Articulating rotor is a bit like the body is connected to the rotor disc by a flexible rod instead of a string, it still tilts and flies around as you command it, but it also imparts some of its tilt to the body. Articulating masts and the transmission mounts have to take bending as well as lift loads, whereas teetering sees no bending loads, unless you get into mast bumping, and you're dead. | |
| May 5, 2020 at 0:17 | answer | added | Mat | timeline score: 1 | |
| May 4, 2020 at 6:50 | history | asked | Jan Hudec | CC BY-SA 4.0 |