Timeline for How do you maximize lift while keeping span as short as possible?
Current License: CC BY-SA 4.0
18 events
| when toggle format | what | by | license | comment | |
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| Mar 21, 2022 at 9:21 | comment | added | Robert DiGiovanni | Just increasing chord (and reducing weight) would give one something akin to a paraglider with horrible handling in the wind and not as great lifting efficiency. Large square wings (eagles) are useful in strong thermals (have a look at a clipper square rigger), but lack lifting efficiency (have a look at a schooner or an albatross). The "pancake" works at low speeds because it's blown, and at high speeds because of low drag. | |
| Mar 21, 2022 at 9:04 | comment | added | Robert DiGiovanni | @MaxPower Within the low Mach "incompressible" range (circa 1918) Gottingen made some really good low speed wings. V$^2$ has the most powerful effect on lift. For very slow flight, you are right if not changing the airfoil, span should increase with chord, or stack multiwings. Increasing lift coefficient (with more camber) is also useful. | |
| Mar 21, 2022 at 0:09 | comment | added | Max Power | Do you mean low speed as compared to compressible supersonic flow, or just a change in speed within the incompressible speed regime? | |
| Mar 20, 2022 at 23:53 | comment | added | Robert DiGiovanni | @MaxPower the Lift Equation takes care of all that. Unfortunately for the OP, body lift does not work very well at low speeds. | |
| Mar 20, 2022 at 23:46 | comment | added | Max Power | Coefficients are relative, while the common convention is to use horizontal wing area as the reference it is not the only reference that can be plugged into the equation. The only catch is that like must be compared with like, so a frontal reference area coefficient or width based coefficient[this case] could not be numerically compared to a plan-form area coefficient. | |
| Mar 20, 2022 at 23:37 | comment | added | Robert DiGiovanni | @MaxPower we read on then about increasing Coefficient of lift, and my second reference to the DAE 21 (and bird wings). Undercamber is key to increasing Coefficient of Lift. This is really "mission impossible" as seen in the high stall speeds of current designs. (Notice the "pancake" is blown). Let's move on. | |
| Mar 20, 2022 at 22:49 | comment | added | Max Power | My reading comprehension is just fine. "I would like to assume a given airfoil and to exclude modifications to the airfoil itself, i.e. any mechanism that increases lift in pure 2D flow, e.g. camber, slats, flaps, active blowing of the upper surface etc. " | |
| Mar 16, 2022 at 23:54 | comment | added | Robert DiGiovanni | @MaxPower actually, the question specifically says fly slowly. If you want to argue how it's been done for 100 years, be my guest. BTW, the answer does include increasing chord, did you see it? | |
| Mar 16, 2022 at 22:29 | comment | added | Max Power | The question explicitly says not to alter the basic airfoil. Increased cord implies proportional thickness if the airfoil designation is unchanged. | |
| Jan 13, 2022 at 3:08 | comment | added | Michael Hall | "... not very safe" Indeed - don't think about turning in that thing! Ok, maybe 5 degree AOB... | |
| Jan 12, 2022 at 20:36 | comment | added | Jim | Lift is also proportional to S. | |
| Jan 12, 2022 at 19:00 | comment | added | Robert DiGiovanni | Keep in mind some of these "record setting" aircraft may not be very safe to fly | |
| Jan 12, 2022 at 18:27 | history | edited | Robert DiGiovanni | CC BY-SA 4.0 |
Better answer
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| Jan 12, 2022 at 18:21 | history | edited | Robert DiGiovanni | CC BY-SA 4.0 |
Better answer
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| Jan 12, 2022 at 17:46 | history | edited | Robert DiGiovanni | CC BY-SA 4.0 |
Better answer
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| Jan 12, 2022 at 17:37 | history | edited | Robert DiGiovanni | CC BY-SA 4.0 |
Better answer
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| Jan 12, 2022 at 17:32 | history | edited | Robert DiGiovanni | CC BY-SA 4.0 |
Better answer
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| Jan 12, 2022 at 17:26 | history | answered | Robert DiGiovanni | CC BY-SA 4.0 |