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Wings work because of a delta of pressure over surface area. A fire reverses which side of the propeller has the positive pressure, you will see moths and the like get sucked into flames too. I don't think altitude of flight for aircraft really matters at all in this instance. Cruising altitude is pretty high and I believe oxygen becomes the main constraint vs temp.
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Mar 23, 2024 17:50
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Submarine Sandpaper posted:Wings work because of a delta of pressure over surface area. So how does it work for birds? Sorry I am physics-stupid but the commonly accepted explanation is that vultures can soar for so long because using rising air created by heat lets them attain great height with minimal flapping, conserving energy. Their wings are built to maximize glide and keep them aloft for a long time. The circling behavior they display is in fact their process of climbing- circling allows them to stay over the warm air while they rise. Other birds do this too, vultures are just the specialists who are most built to this mode of flight.
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Mar 23, 2024 18:18
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mycatscrimes posted:So how does it work for birds? Sorry I am physics-stupid but the commonly accepted explanation is that vulture's soar for so long because using rising air created by heat lets them attain great height with minimal flapping, conserving energy. Their wings are built to maximize glide and keep them aloft for a long time. The circling behavior they display is in fact their process of climbing- circling allows them to stay over the warm air while they rise. Birds have wings with a lot of surface area relative to their bodies that they spread out to catch the rising hot air. Propellers have very small surface area, so if the air is hot and thin, they aren't catching much and they lose lift.
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Mar 23, 2024 18:20
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Spiders can fly by abusing a glitch in physics and we should build flying machines on the same principle. Just to make physicists mad.
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Mar 23, 2024 18:24
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Byzantine posted:Birds have wings with a lot of surface area relative to their bodies that they spread out to catch the rising hot air. Propellers have very small surface area, so if the air is hot and thin, they aren't catching much and they lose lift. The difference in surface area isn’t really relevant. Birds generate lift by catching hot air rising (or at least, they do when they are gliding), while drones generate lift by pushing down on the air. Drones don’t get a benefit from hot air rising, but they do care about the air being less dense when it’s hot. To maintain lift they need to push down on the same mass of air, which is a larger volume of air when it’s hot. So, they would have to spin faster over hot air, to push that larger volume of air.
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Mar 23, 2024 18:28
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Uh, isn't it due to the change of pressure in flowing hot air rather than warm air being lighter? Bernoulli's effect and all? And that close to the fire there are also sure to be turbulences
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Mar 23, 2024 18:36
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It fell because it flew too close to the sun, melting the wax holding the wings together. Read your classics!
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Mar 23, 2024 18:38
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What if the bonfire was on a treadmill
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Mar 23, 2024 18:41
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The air in thermals is only a few degrees warmer than ambient. The movement of the air provides a lot more upward lift than is lost due to the fractional reduction in density. The air above an open flame is a lot warmer and more turbulent.
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Mar 23, 2024 18:42
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mycatscrimes posted:So how does it work for birds? Sorry I am physics-stupid but the commonly accepted explanation is that vultures can soar for so long because using rising air created by heat lets them attain great height with minimal flapping, conserving energy. Their wings are built to maximize glide and keep them aloft for a long time. The circling behavior they display is in fact their process of climbing- circling allows them to stay over the warm air while they rise. Other birds do this too, vultures are just the specialists who are most built to this mode of flight. Birds have hollow bones and are freakishly light for their size, and the upward thermal pressure literally pushes them (slightly). Gliders can pull this trick off too, they stopped recording 'longest glider flight' because if you're in a good spot for it you're only limited by how many days you can stay awake for. Longest duration glider flight: 70+ hours over Hawaii Longest distance glider flight: 3,000km over the Andes. Helicopters and airplanes want cold, dry, and calm air for best performance.
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Mar 23, 2024 19:15
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Thanks everyone, I feel like I understand better now! nomad2020 posted:Birds have hollow bones and are freakishly light for their size, and the upward thermal pressure literally pushes them (slightly). Gliders can pull this trick off too, they stopped recording 'longest glider flight' because if you're in a good spot for it you're only limited by how many days you can stay awake for. The distinction between gliders and airplanes was particularly helpful. Airplanes seem to have large wings relative to their size if you are a layperson, but if you consider the weight they really don't? I know that's only a small piece of the puzzle, but it's something I was getting stuck on. Like a soaring bird's wings are typically significantly more than 50% of their overall mass, that's not true for planes but it is for lightweight gliders?
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Mar 23, 2024 19:20
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 This is a good comparison between a stereotypical glider and the sort of thing you might train for your pilots license on. https://www.boldmethod.com/blog/article/2015/02/your-guide-to-glider-flying/ if you want to read more.
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Mar 23, 2024 20:12
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That's pretty cool! Thank you for the link. : )
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Mar 23, 2024 20:17
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Nenonen posted:Spiders can fly by abusing a glitch in physics and we should build flying machines on the same principle. Just to make physicists mad. We did already but it mostly just kills marines.
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Mar 23, 2024 20:25
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iwentdoodie posted:We did already but it mostly just kills marines. 
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Mar 23, 2024 20:45
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nomad2020 posted:
The biggest AR number does not belong to a glider, however. 
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Mar 23, 2024 21:02
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https://i.imgur.com/qIQG5Xf.mp4
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Mar 24, 2024 00:10
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Taint Status: Reaped
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Mar 24, 2024 01:11
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There’s optimism, and then there is whatever this is https://i.imgur.com/3PYpdfw.mp4
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Mar 24, 2024 01:20
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I've loaded some escorts on a small boat before and it was fine
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Mar 24, 2024 01:32
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hold up let me just rock this huge weight back and forth
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Mar 24, 2024 01:34
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Gyroscopic Drones are basically helicopters and benefit from ground effect. While temperature and air density can have an effect their method of flight is similar to a helicopter. The same problems helicopters have, such as vortex ring state—which is most likely what you witness with a drone just falling out of the sky—will be present in drones. There is a chance that a drone can experience receding blade stall but that requires a lot of speed. VRS is probably what you see.
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Mar 24, 2024 01:56
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Ashcans posted:There’s optimism, and then there is whatever this is The amazing biblical parable of Jesus, the Boat, and the Asphalt Roller is still relevant today!
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Mar 24, 2024 01:59
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So what I'm hearing is that helicopters fly by magic, and the flames purify them, removing the enchantment that kept them airborne?
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Mar 24, 2024 02:00
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Actually, yes.
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Mar 24, 2024 02:05
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No but seriously helicopters and gyrocopters are an abomination of physics and human hubris.
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Mar 24, 2024 02:06
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What will really piss you off is knowing that it’s actually a combination of the greek/latin roots helico and pter, and not heli and copter.
dialhforhero has a new favorite as of 02:42 on Mar 24, 2024 |
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Mar 24, 2024 02:08
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helicopt these nuts
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Mar 24, 2024 02:12
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According to all known laws of aviation, there is no way a helicopter should be able to fly.
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Mar 24, 2024 02:13
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Heli cop ter I rest my case
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Mar 24, 2024 02:30
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mycatscrimes posted:According to all known laws of aviation, there is no way a helicopter should be able to fly. They fly much the same way I survive: in spite of those observing
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Mar 24, 2024 02:54
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LifeSunDeath posted:
FTFY
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Mar 24, 2024 03:24
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Ashcans posted:There’s optimism, and then there is whatever this is Can't park there, mate?
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Mar 24, 2024 04:10
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Now how will we roll, roll, roll our boat? 
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Mar 24, 2024 04:25
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Torrannor posted:Yarr, ye can't park there, me matey! Fixed.
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Mar 24, 2024 06:01
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Brawnfire posted:Now how will we roll, roll, roll our boat?
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Mar 24, 2024 06:29
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Ashcans posted:There’s optimism, and then there is whatever this is Man, the live-action adaptation of Stardust Crusaders isn't looking that impressive.
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Mar 24, 2024 06:46
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dialhforhero posted:Gyroscopic Drones are basically helicopters… That’s why they, too, hunger for blood.
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Mar 24, 2024 07:20
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Fun fact: Helicopter is a compound word made from the Greek words Helico and Pter.
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Mar 24, 2024 07:22
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ancient greek name pter
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