Timeline for How does the "pendulum effect" affect biplanes?
Current License: CC BY-SA 4.0
13 events
| when toggle format | what | by | license | comment | |
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| Jul 10, 2019 at 13:50 | vote | accept | Jessica Ham | ||
| Jul 8, 2019 at 5:07 | comment | added | Peter Kämpf | @RobertDiGiovanni: A hang glider does not shift the weight, it shifts the wing. Weight shifting is impossible due to the conservation of momentum. | |
| Jul 8, 2019 at 4:05 | history | edited | Koyovis | CC BY-SA 4.0 |
deleted 1 character in body
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| Jul 8, 2019 at 2:52 | comment | added | Koyovis | @quietflyer. Oops, lost in translation, thx. | |
| Jul 8, 2019 at 2:52 | history | edited | Koyovis | CC BY-SA 4.0 |
An = Di
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| Jul 8, 2019 at 2:44 | comment | added | quiet flyer | So why is the caption "anhedral wing in sideslip" attached to an illustration of a dihedral wing? | |
| Jul 8, 2019 at 2:20 | comment | added | Koyovis | @RobertDiGiovanni Yes correct, a hang glider has a wing that can hinge - a hinged wing, not a fixed wing. It can mis-align lift from the CoG. Please note that I'm not proposing using Dutch rolling to control the aircraft, that is what the flight controls are for. A fixed wing has no direct static stability derivative for roll angle, only indirect via sideslip. Dutch roll is a dynamic response in two degrees of freedom. | |
| Jul 8, 2019 at 2:12 | history | edited | Koyovis | CC BY-SA 4.0 |
A bit more detail.
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| Jul 7, 2019 at 23:23 | comment | added | Sophie Swett | @Robert Assuming a roll to the left, the wing is rolled sideways because the left rolling moment created by the right wing is greater than the right rolling moment created by the left wing. Gravity has nothing to do with it; the only effect gravity has on an aircraft is on its linear velocity. | |
| Jul 7, 2019 at 15:10 | comment | added | Robert DiGiovanni | Bingo! And how is that wing rolled sideways??? "Pendulum" is a bit more palatable considering the case of weight ABOVE the wing (destabilizes roll). Dihedral and lower CG are roll stabilizers, sweep and high CG create "Dutch Roll". Shifting CG away from Lift Center (hang glider), or shifting Lift Center away from CG (ailerons), will create roll. | |
| Jul 7, 2019 at 11:36 | comment | added | AEhere supports Monica | @RobertDiGiovanni a hang glider turns by pointing the lift vector sideways, like all aircraft do when they do a banked turn. | |
| Jul 7, 2019 at 11:25 | comment | added | Robert DiGiovanni | Please explain how a hang glider turns. Displacement of lift and center of gravity will create a rolling motion. A side slip must have significant velocity for purely aerodynamic effects to "right" the aircraft. What you propose essentially is an aircraft that must constantly "Dutch Roll" to remain upright. Obviously, this is not a practical mechanism for passenger transportation (although it is theoretically possible). Please review aircraft design. | |
| Jul 7, 2019 at 6:33 | history | answered | Koyovis | CC BY-SA 4.0 |