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Article
Publication date: 7 March 2016

Louis Gagnon, Marco Morandini, Giuseppe Quaranta, Vincenzo Muscarello and Pierangelo Masarati

Few modeling approaches exist for cycloidal rotors because they are a prototypal technology. Thus, the purpose of this study was to develop new models for their analysis and…

Abstract

Purpose

Few modeling approaches exist for cycloidal rotors because they are a prototypal technology. Thus, the purpose of this study was to develop new models for their analysis and validation. These models were used to analyze cycloidal rotors and a helicopter that uses them instead of a tail rotor.

Design/methodology/approach

Three different models were developed to study the aerodynamic response of cycloidal rotors. They are a simplified analytical model resolved algebraically; a multibody model resolved numerically; and an unsteady computational fluid dynamics (CFD) model. The models were validated using data coming from three different experimental sources, each with rotor spans and radii of roughly 1 m. The CFD model was used to investigate the influence of rotor arms. The efficiency and the stability of the rotor in different configurations were studied. An aeroelastic multibody simulation was used to verify the influence of flexibility on the rotor response.

Findings

The analyses suggested that cycloidal rotors can increase the efficiency of a helicopter at high velocities while flexibility reduces it and may lead to instabilities.

Research limitations/implications

These models do not consider the effect of boundary layer friction on the trailing vortices generated by the rotor blades.

Practical implications

These models allow a four-step aerodynamic optimization procedure. First, a range of optimized configurations is obtained by the analytical model. Second, the multibody model refines that range. Third, the CFD model detects eventual problematic blade interactions.

Originality/value

The models presented should serve researchers and industrials looking for a means to measure the performance of cycloidal rotors concepts. The results presented also guide an initial cycloidal rotor design.

Details

Aircraft Engineering and Aerospace Technology: An International Journal, vol. 88 no. 2
Type: Research Article
ISSN: 1748-8842

Keywords

Article
Publication date: 5 September 2016

Meinhard Schwaiger and David Wills

This paper aims to provide the international aeronautical community with details of the development of a new disruptive technology for aircraft propulsion.

573

Abstract

Purpose

This paper aims to provide the international aeronautical community with details of the development of a new disruptive technology for aircraft propulsion.

Design/methodology/approach

This paper describes the results achieved by a small Austrian aeronautical innovations company in developing a cyclogyro propulsion system capable of vertical launch and efficient forward flight. The research team progressed from concept definition and simulation (2004-2006), through experimental validation and concept demonstration (2006), component optimization (2006-2012), full system demonstration (2012-2014) and examination of ability to scale (both larger and smaller) (2015 onwards). This paper provides details of the results of each of these stages.

Findings

The research team proved that cyclogyro propulsion can be used for the vertical launch, and that, in forward flight, it has the potential to achieve efficiency beyond the range of conventional fixed wing and rotorcraft.

Research limitations/implications

This research indicates that the efficiency increases with forward speed within the range achieved in standard wind tunnels (up to 35 m/s). This efficiency appears to be caused by a unique chamber effect within the cyclogyro rotor assembly. Future research should be conducted to analyse this chamber effect in greater detail and to test the cyclogyro rotor for speeds beyond 35 m/s.

Practical implications

This work indicates that cyclogyro propulsion could have the potential to provide vertical launch, high speed and highly efficient aircraft that have reduced wing span, no external rotors and exceptional agility. This technology could therefore be feasible for vertical take-off and landing aircraft that can safely form densely packed swarms.

Social implications

It could be researched as an efficiency increase in forward flight completely different to existing propulsion systems. This could open a way for a more efficient air traffic in future and faster reduction of CO2 and NOX emission an allow an environment-friendlier air travelling.

Originality/value

This paper provides the details of the first cyclogyro aircraft to have flown and will serve the aeronautical community by stimulating the debate on this new disruptive technology.

Details

Aircraft Engineering and Aerospace Technology, vol. 88 no. 5
Type: Research Article
ISSN: 1748-8842

Keywords

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