British Start-Up Tests Flying Saucers

Sabre Runner writes to mention that a new British start-up, Aesir, has acquired the assets of a defunct drone company and is working on evolving a working model from several prototypes of "flying saucer" drones. "Aesir's first prototype, named 'Embler' [...] demonstrates the so-called 'Coanda effect,' where air speeds up as it 'sticks' to a curved surface. Aesir's drones take advantage of the Coanda effect to direct air down, away from the drone, boosting lift. Aesir doesn't appear to have any paying customers yet — and is reportedly bankrolled by a single investor."

Comments

could it be ...

[neonprimetime]

Aesir doesn't appear to have any paying customers yet -- and is reportedly bankrolled by a single investor

CSG?

Sigh

[Kell Bengal]

I see a lot of these sorts of start-ups - people who design a VTOL UAV using some fancy lift generation device. Entecho entecho.com.au immediately springs to mind (if only because a friend works there). What these people aren't getting is that the problem with VTOL UAVs isn't the form of the lift production, it's the energy density of its power source. Think about it, the power needed to lift a mass is inversely proportional to the square root of the rotor area - that is, the more area, the less power. Things like this use a much smaller area to accelerate air than an equivalently sized helicopter rotor. Yes, they can bump into things, but their flight time will be slashed.

It's hard to make a more efficient rotor, and it's hard to make a duct light weight at large enough sizes to compete on power. So, unless I'm missing something these guys are using the same petrol/kerosine/lipo power sources as everyone else, except with higher power consumption. It's the same problem quadrotors and jet VTOLs have - they simply can't compete with helicopters on hover efficiency.

That's bad news for startups, though, because the helicopter space is already crowded with heavy hitters like Sikorski and the like.

Where does this leave UAVs? It leaves us with incremental improvements (my PhD involved making freaky aeroelastic UAV rotors that were fiercly optimised for the hover regime, just to squeeze out more flight time) with no real long-term flight performance in sight.

Why do these start-ups appear and disappear so quickly? Because they're trying to 'solve' a hard laws-of-physics style problem that isn't bounded by UAV technology, but rather power technology.

YIAAUHETYVM (Yes I Am A UAV Helicopter Engineer, Thank You Very Much)

Re:Sigh

[interval1066]

Ah. I see that I got caught up in Steorn's doublespeak. If you read the wikipedia article on the company what actually happened was that they finally showed the technology to some independent scientists who were completely unimpressed with what they were shown. In other words; Orbo does not work.

Re:Sigh

[Kell Bengal]

Yes and no. We understand a lot about how fluids work in idealised cases. We know a lot about how individual molecules of air work. We know a lot about how turbulent flow works on a probablistic scale.

What we don't know well is how to estimate unsteady fluid flows with no a priori global knowledge of fluid conditions (same problem the climate modelers have on a much smaller scale). If we knew where every molecule was, how much energy it had and what the forces acting on them were at initial conditions I think we could do a pretty decent job working out what blade profile would work best for that condition; but it's a trick question because conditions can change dramatically across the flight envelope of a helicopter.

As I understand it, aerodynamics design these days is mostly simulation anyway. Blade design is still an art as much of a science, requiring careful consideration of trade-offs involved. I do not believe we're going to see any revolutionary performance gains until a truly novel lift device is invented (ie. something that doesn't use air as a working fluid).

Oh!

[actionbastard]

It's only a model.

Re:Oh!

[geekoid]

Shh

Echo from 2007

[codegen]

Looks a lot like:
http://www.dailymail.co.uk/sciencetech/article-447317/The-flying-saucer-snapped-US-army.html;jsessionid=646AE8D297BA42F4A5BDDD6223D5FA58
from the slashdot story back in 2007:
http://science.slashdot.org/story/07/04/09/1723218/Combined-Hovercraft-and-Helicopter?art_pos=4
In fact, the 'first' prototype looks like the prototype from 2007 (even the same yellow body!!)

I know who it is?

[IonOtter]

Aesir doesn't appear to have any paying customers yet â" and is reportedly bankrolled by a single investor.

John Bigboote
CEO/CFO Yoyodyne Corporation Intl
1938 Yoyodyne Way, Lot 49
San Narciso, CA 92129-3064

Re:Avrocar anyone?

[Hal_Porter]

No. This saucer company is named after Æsir, the True Norse Gods and will make drones that will be used to hunt down and KILL! Taliban and other Islamists in Afghanistan, Iraq and Malmö.

According to Norse theology those killed will then suffer forever in Hellheim. Soon the survivors will burn down their mosques and begin sacrficing to Odin to stop the attacks. Then it will be time to deal with the Christians. Eventually Ásatrú will dominate the world.

The Truth About the Coanda Effect

[thepainguy]

The point of the Coanda effect is NOT that the flow speeds up. Rather, and as Wikipedia correctly points out, the point of the Coanda effect is that the flow stays attached to the curved surface, which allows you to redirect it...

The CoandÄf effect is the tendency of a fluid jet to stay attached to an adjacent curved surface of a specific radius. The principle was named after Romanian aerodynamics pioneer Henri CoandÄf, who was the first to recognize the practical application of the phenomenon in aircraft development.

FYI, the Coanda effect is what makes leafless gutter systems work. It allows the water to turn the corner and enter the gutter while the leaves shoot over the side.