Army UAV needed that not only will look at the birds, they need to be able to fly as quiet and maneuverable as the real birds, in other words ornithopters. Will the engineers solve the technical difficulties?
More Zhukovsky claimed that flapping wing by definition a much bigger lift than motionless. But he also added that calculate its aerodynamics are much more difficult. But for a small UAV is inevitable transition to this principle. In order to hang in the air, and then continue to move forward at this time used the aircraft, equipment, helicopter screws. Their fuel efficiency is much worse than the one which is owned aircraft, not to mention the ornithopters. Like all energy-efficient processes, such flights of drones will be accompanied by sufficient sonorous sound, which means that they are almost invisible army intelligence is not applicable.
And one of the principal obstacles to the ornithopter — is the highest hardness of the wing at comparable small mass, which, in principle, is not a problem of micro-UAVs due to the small size and very low requirements for rigidity. Specifically, as is developing "Colibri"From the company Aerovironment. Hummingbird is moved to the title for a reason — swooping, this little bird can proparhat to 400 of its own body length per second. It can fly backwards, not turning around, and has the highest rate of air braking in the middle of a natural or man-made in the middle of the flyers. At Hummingbird weight and wingspan will be '19, respectively, and 16.5 cm weight included weight all flight systems as optional fairing, similar to the body of a hummingbird, which should give the machine similar to a bird of the same name. Naturally, the average colibri somewhat smaller, but everything is dictated by lithium-ion batteries, which are not found in nature that compels to make a drone over a languid.
LA can rapidly accelerate and the brakes, and fly back without turning the body. With all this it sends the video using built-in camera. Moreover, the drone may hang for two minutes a side-wind of 2.1 m / s, with virtually no drift. He can fly through the door at the maximum speed of 18 km / h
But in miniature, and stealth it's still far to the real hummingbird. For example, the smallest hummingbird lead only 2 grams (Cuban variety), which is much less than the mass of the drone. Also lame and drone flight time on a single charge: 8 minutes with active maneuvering, 20 minutes, if the "freeze" on the spot. All this is due to small BATTERY capacity. But not only, velikanskie hummingbird — is the migratory birds that are changing the climate zone without stopping and "refueling". It is clear that she could not do it, if I was such as energy intensive as the drone, which uses its platform. To resolve the issue, Hummingbird wish to ensure the possibility of in-flight refueling.
But it should be noted that these LTH Hummingbird — this is a demo version, so they can grow in the constantly evolving military applets. If we consider the information from the sources in the industry, she said that the military already have a few suggestions for other UAVs from other companies that use different approaches to solving the problem of a flapping wing at mikrodrony.