Quieter, smoother, more fuel efficient – it sounds like the CAFE Foundation’s goals for its Sky Taxis. ACHEON, a Euro-consortium of high-powered academic institutions, is working to bring together the Coanda effect with modern plasma technology to create a much-improved aerial travel experience.
Having explored a few of the many aircraft that have attempted to use the Coanda effect, we now examine the work of the consortium of six organizations: four Universities, one Research and Tech Transfer Organization and one Research intensive SME (Small and Medium Enterprise – Nimbus S.r.l) from four European Countries (Italy, Portugal, the United Kingdom, and Belgium).
The team, committed to exploring and demonstrating the benefits of ACHEON technology, is at work on possible applications for different craft. including:
- Traditional aerial vehicles architecture, which could include aircraft with wing-mounted engines.
- Innovative aerial vehicle designs with localized or distributed propulsion.
- Innovative aircraft optimized for thrust vectoring, even including airship configurations.
One paper, “Investigating the Use of the Coanda Effect to Create Novel Unmanned Aerial Vehicles,” shows potential uses for these technologies in unpiloted aerial vehicles (UAVs) and notes the thrust-multiplying effects of the effect in the Dyson fan. The thrust was there, but getting the pricey fans ($300 for a small desk unit) to operate silently cost $65 million and the efforts of 75 engineers. Similar work on aircraft might be expected to cost even more in blood and treasure. Another discouraging aspect of that research was that the British scientists could not produce sufficient lift to levitate their saucer-like UAV.
Another pointer in the 2010 paper links AESIR, Ltd. to the research, indicating that company was developing a UAV based on the Coanda effect. Their web site today has no links to information other than a phone number and recursive url. Their ship did look very much like a saucer, though.
So, what do the ACHEON researchers have up their sleeves to obtain Dyson fan numbers for thrust while maintaining relative silence and thrust vectoring?
A 2011 Society of Automotive Engineers (SAE) paper, A.C.H.E.O.N.: Aerial Coanda High Efficiency Orienting-jet Nozzle,” by Michele Transcossi and Allesando Dumas, reported on experiments with two model electric turbofans that had their thrust augmented by “a recently patented 2D nozzle, which is able to produce a jet deviation depending on momentums of incoming jets and nozzle geometry. The considered nozzle architecture is a general-purpose fluid dynamic application.” The researchers considered the nozzle’s use “for both shortening takeoff and landing operations if mounted in a vertical plane and for enhancing the horizontal maneuvering if mounted on a horizontal plane.”
With meeting being held by the six major contributors to the ACHEON project, we might expect rapid progress along the two major components of the technology. The group claims two big advantages for their primary technologies.
- HOMER design overcomes the limitations of common Coanda effect Nozzles by the capability of producing a dynamic control of deflection angle based on a patent pending technology developed by the University of Modena and Reggio Emilia.
- PEACE – Plasma Enhanced Actuator for Coanda Effect produces an active precision control of the Coanda adhesion to a surface by means of the BSD technology (Dielectric Barrier Discharge) which allow controlling the adhesion of the synthetic by an active control system.
The application of increased and vectored thrust to different aircraft has a good many positive aspects, and the grandest of these might be in a practical airship. “The Multibody Advanced Airship for Transport (MAAT) project aims to position airships as the solution for future air transportation that is safe, efficient, cheap and environmentally friendly,” according to ACHEON participants at the University of Lincoln. A video wordlessly conveys what such a vehicle might look like. Depicted on a calm day, the dynamics of the “ride” might be more difficult to control, even electronically, on a gustier occasion. Docking the smaller balloon into a special slot for its capture would have to be meticulously executed.
This “feeder and hub system” would also have to overcome issues of weight and stable operation to become successful, but holds a promise of true VTOL flight, reducing the need for airstrips and other support networks.
More conventional aircraft, with distributed thrust such as that on the LEAPTech concept, would benefit from the PEACE actuators that could “amplify” thrust from jet or electric powerplants, and instantly vector thrust in any direction. That might lead to the kind of aircraft Burt Rutan envisioned three decades ago, one on which distributed powerplants took the place of aerodynamic controls. Small electric motors augmented with Coanda technology and vectored by electronic controls would allow nearly-silent operation and a theoretically smoother ride. That would be magic carpet ride indeed.