Wow, there were a bunch of very interesting designs, Probably telling the winner was a very tradition design, but I love seeing wild stuff being tried.
The kite copter was my favorite, but the large rotor powered by small tip rotors was a close second.
VBprogrammer 2 hours ago [-]
A nearly 4:1 ratio makes a 25kg drone very interesting from a personal mobility perspective. Something you could fly a few miles with and then easily roll around an office. Sadly scaling in aerodynamics is notoriously non-linear.
close04 57 minutes ago [-]
> a conventional single-main-rotor helicopter that weighed 13.3 kg (29.3 pounds) and hauled 51 kg (112.4 pounds)
I think this was the sweet spot for now and we'll need to wait for anything that maintains that ratio at double the carrying capacity.
klntsky 25 minutes ago [-]
What's the problem with connecting two devices together?
VBprogrammer 8 minutes ago [-]
The splodge on the ground when one of them fails is generally the downside.
0-_-0 2 minutes ago [-]
Same is true for 1
bart__ 3 hours ago [-]
Interesting event, annoyingly bad written AI article
camkego 3 hours ago [-]
Slop city, it felt like I was having an LLM chat.
flyinglizard 3 hours ago [-]
This is the honest take.
mattkrause 24 minutes ago [-]
Load-bearing, even.
stubish 38 minutes ago [-]
I assume blimps or lighter than air components where illegal? Or is it just too hard to fly the larger volume around the course?
jml7c5 12 minutes ago [-]
Your assumption is correct, they were prohibited:
>3.7 Heavier than air: The UAS must be a heavier-than-air aircraft. The use of any lighter-than-air gases to provide buoyant lift is strictly prohibited. Teams may use chemically inert gases for subsystem actuation, safety inerting, and component rigidity, provided that there is no buoyant advantage and the gas is contained in components operating at pressures indicative of mechanical function.
Winning $ 1.25 million is great - but I wonder how they feel about not getting the full $ 2.5 million prize because they missed the 4:1 target by 4% ?
Leonard_of_Q 2 hours ago [-]
They probably feel like the athlete who missed breaking a record, like the shipping company which just failed to load the goods in 4 trucks and now needs 5, like the painter who just needed that extra 50 cm on his ladder: "darn, so close".
euroderf 1 hours ago [-]
Whatever happened to "Close enough for gummint work".
rob74 2 hours ago [-]
"Close, but only half the cigar"
lnenad 2 hours ago [-]
They've probably got companies lined up to give them jobs that will pay multiples of those. The runner up is even more interesting, with a slightly larger reason to feel like they should have won it. They did ~3nm (out of 4 iirc) of 4.04:1 ratio.
huflungdung 2 hours ago [-]
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LoganDark 45 minutes ago [-]
Every post on this website looks AI generated but at least most of it doesn't feel like complete fluff.
dyauspitr 2 hours ago [-]
Hunh so for pure lifting our standard helicopter design is apparently the best. How did we stumble on the perfect design half a century ago? Was it sheer luck and constraints or can you actually do the math for this to work it out?
regularfry 2 hours ago [-]
The article makes reference to this being expected from the physics, but I don't think it's particularly intuitive why it should be the case. Unless it's as simple as smaller swept areas needing higher tip speeds for the same lift? That would make the energy loss to drag worse for multirotors.
snovv_crash 2 hours ago [-]
Higher aspect ratio blades are more efficient. It maximises disc area for a given mass of blade (linear-squared relationship). Blade is held straight due to tension not purely from torsional strength, so it can be made from a material with high tension strength like carbon fibre which is light. Also it positions the fastest moving blade area far out from the fuselage where there is less blown-drag.
The downside is that the tail rotor is purely loss.
Potentially a similar efficiency could be achieved with two large rotors, but then you end up needing to use cyclic roll to counter drag-induced cyclic yaw, or adding extra pitch mechanisms on each motor mount to make differential yaw.
cucumber3732842 15 minutes ago [-]
As other commenters say, there's physics reasons one big rotor is most efficient.
The reason the earliest rotary wing aircraft took this configuration is because where was no other choice with the technology of the time. They had to pick the most efficient option for it to be cost effective and have useful capacity.
ballooney 1 hours ago [-]
For a given lift, a larger, lower speed rotor is strictly more efficient than a smaller faster one, all else being equal. So no surprises that when efficiency matters we don’t see quadcopter-type designs. The reason they became ubiquitous is because they are so mechanically simple, all the control can be done with cheap electronics, no need for the great mechanical complexity of a swashplate.
somat 2 hours ago [-]
I am surprised it was not a coaxial design(think the mars copter, but designed for a real atmosphere)
reliablereason 38 minutes ago [-]
I would think coaxial designs suffer as the lower rotor works in more turbulent non laminar air.
whatever1 2 hours ago [-]
We have also achieved optimal teapot design for perfect flow thousands of years ago.
We have some times very good intuition and ideas.
abricq 1 hours ago [-]
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Rendered at 10:21:34 GMT+0000 (Coordinated Universal Time) with Vercel.
The kite copter was my favorite, but the large rotor powered by small tip rotors was a close second.
I think this was the sweet spot for now and we'll need to wait for anything that maintains that ratio at double the carrying capacity.
>3.7 Heavier than air: The UAS must be a heavier-than-air aircraft. The use of any lighter-than-air gases to provide buoyant lift is strictly prohibited. Teams may use chemically inert gases for subsystem actuation, safety inerting, and component rigidity, provided that there is no buoyant advantage and the gas is contained in components operating at pressures indicative of mechanical function.
https://www.darpa.mil/research/challenges/lift/rules
The downside is that the tail rotor is purely loss.
Potentially a similar efficiency could be achieved with two large rotors, but then you end up needing to use cyclic roll to counter drag-induced cyclic yaw, or adding extra pitch mechanisms on each motor mount to make differential yaw.
The reason the earliest rotary wing aircraft took this configuration is because where was no other choice with the technology of the time. They had to pick the most efficient option for it to be cost effective and have useful capacity.
We have some times very good intuition and ideas.