3 ms·

It seems to follow the Stanford Swift aerodynamic philosophy: low taper and winglets. This is different from the recent NASA Prandtl-d aircraft which is of the

It seems to follow the Stanford Swift aerodynamic philosophy: low taper and winglets. This is different from the recent NASA Prandtl-d aircraft which is of the Horten paradigm: lots of taper and no winglets. It's possible the former is a lot easier to build, because of constant chord, especially as a solar powered platform. With batteries you can distribute the weight very well so designing for things like wing root moment might not be the defining thing, instead some re complex aeroelastic design criteria. Very fascinating to see this resurgence of flying wing again, popping up in many other places too.

ktta 10y ago
I have no clue about half of the things you just said. Can you guide us, the ones with less knowledge about aerodynamics-- to some resources which we can watch/read? (preferably online and free, of course :) )
- Gravityloss 10y ago
  See How It Flies at https://www.av8n.com/how/ https://www.av8n.com/how/ seems massive but it's written in a captivating way. Basically in a wing, there's overpressure on the bottom and underpressure at the top. This is all good. But it causes a problem at the wingtip, the air escapes and goes from bottom to top. The tip vortex. Does not contribute to lift, causes drag, so is bad. So you can put a vertical winglet there to diminish the tip vortex, or to extract thrust from it. Or you can extend the wing but make it have a lower angle of attack near the tip, again extracting thrust, basically a horizontal winglet if you will. Then there's the issue of stability. A plane is stable when, if you increase the angle of attack, the rearward lifting surfaces have more increase in negative nose down moment than the positive nose up moment of the forward lifting surfaces. So the aircraft tends to correct itself (move back to lower angle of attack). In an ordinary plane it means a wing near the center of gravity and a tail with a lower angle of set incidence far behind. In a canard, the center of gravity must be between the wings and the front wing must be set in a higher incidence. In a flying wing it means sweepback and twist: the outer portion of the wing must act as a tail. The outer portion must be twisted nose down so it has a lower angle of incidence. Flying wing design is harder since there are more functions it must do than in a more conventional plane. That is a really really short version of it. It didn't mention positive moment airfoils etc.

ktta 10y ago

I have no clue about half of the things you just said. Can you guide us, the ones with less knowledge about aerodynamics-- to some resources which we can watch/read? (preferably online and free, of course :) )

Gravityloss 10y ago
See How It Flies at https://www.av8n.com/how/ https://www.av8n.com/how/ seems massive but it's written in a captivating way. Basically in a wing, there's overpressure on the bottom and underpressure at the top. This is all good. But it causes a problem at the wingtip, the air escapes and goes from bottom to top. The tip vortex. Does not contribute to lift, causes drag, so is bad. So you can put a vertical winglet there to diminish the tip vortex, or to extract thrust from it. Or you can extend the wing but make it have a lower angle of attack near the tip, again extracting thrust, basically a horizontal winglet if you will. Then there's the issue of stability. A plane is stable when, if you increase the angle of attack, the rearward lifting surfaces have more increase in negative nose down moment than the positive nose up moment of the forward lifting surfaces. So the aircraft tends to correct itself (move back to lower angle of attack). In an ordinary plane it means a wing near the center of gravity and a tail with a lower angle of set incidence far behind. In a canard, the center of gravity must be between the wings and the front wing must be set in a higher incidence. In a flying wing it means sweepback and twist: the outer portion of the wing must act as a tail. The outer portion must be twisted nose down so it has a lower angle of incidence. Flying wing design is harder since there are more functions it must do than in a more conventional plane. That is a really really short version of it. It didn't mention positive moment airfoils etc.