D-Dalus - an entirely new genre of aircraft arrives
By Mike Hanlon
June 21, 2011
Austrian research company IAT21 has presented a new type of aircraft at the Paris Air Show which has the potential to become aviation's first disruptive technology since the jet engine.
The D-Dalus (a play on Daedalus from Greek mythology) is neither fixed wing or rotor craft and uses four, mechanically-linked, contra-rotating cylindrical turbines, each running at the same 2200 rpm, for its propulsion.
The key to the D-Dalus' extreme maneuverability is the facility to alter the angle of the blades (using servos) to vector the forces, meaning that the thrust can be delivered in your choice of 360 degrees around any of the three axes. Hence D-Dalus can launch vertically, hover perfectly still and move in any direction, and that's just the start of the story.
Like most cars and aircraft these days, it sounds very complex but it's all controlled by computer algorithms, so it's simple joystick control for the user, and far less exacting than a helicopter to fly.
Existing rotary wing aircraft offer VTOL capabilities but have vulnerabilities which make them unsuitable for many applications. They are challenged in bad weather, at long ranges, at high speed and in operating to and from lurching platforms, such as boats in rough weather.
By contrast, D-Dalus is particularly suited for such conditions and can thrust upwards and hence "glue down" on landing, which it can also do on a moving vehicle. Indeed, landing on a moving vehicle is one of the D-Dalus' many party tricks, and it's a natural for landing on watercraft. Not surprisingly, since it initially broke cover at the Royal Aeronautical Society conference a few days ago, it has already attracted a lot of interest from military quarters.
The D-Dalus is also near-silent, and has the dynamic stability to enter buildings and handle rough weather with ease - things which existing rotorcraft simply cannot achieve. The aircraft also has a sense-and-avoid system which, in conjunction with its complete lack of vulnerable external parts (such as rotors), means it can hover in very close proximity to vertical rock faces and walls, making it suitable for search-and-rescue operations, as a surveillance drone with hover-and-stare capabilities and as a proactive tool for urban battlefield situational awareness.
The lack of vulnerable external moving parts will give a small D-Dalus-type drone the ability to fly into buildings through windows, and its unique capabilities also offer 360 degree vision, another aspect lacking in traditional rotor craft which have blind spots due to the rotors, and nowhere near the same maneuverability as the D-Dalus.
IAT21 forsees many applications based on these key new criteria - apart from being able to enter and search buildings, it could conceivably remove radioactive contamination or explosives, extract casualties, or hold and direct water hoses for fire fighters.
As it can lift heavy loads, and becomes even more efficient in doing so as it scales upwards in size, it is also envisaged as a platform for loading and unloading ships when cranes are not available.
The D-Dalus is also so simple mechanically that it needs little maintenance and requires no more maintenance expertise than an auto mechanic. It should be noted that all VTOL aircraft capable of carrying large payloads are complex and very costly to maintain.
Currently, tests are being conducted using a 120 bhp KTM engine and turbines around five feet long - and the capability of lifting a payload of 70 kg. More tests are planned over the coming weeks. IAT21 is now also working with Cranfield University in the U.K. on a larger, more powerful motor, a new hull shape for the craft, and advanced guidance and control systems.
The forces on the blade pivots are understandably huge, and in initial testing it was found that all available bearings failed, so inventor Meinhard Schwaiger, who already has more than 150 patents to his name, knuckled down and invented (and patented) his own, near-frictionless swivel-bearing to cope with the stresses.
The D-Dalus is constructed of carbon fiber, and appears to be scalable for a range of potential applications including maritime search and rescue, freight transport, operating alongside and within buildings during fires - the long term hopes for the platform include a passenger version for public transit.
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