A new propulsion system for airships
José Pichel Andrés/DICYT The Centre for Mechanical and Aerospace Science and Technology of the Universidad de Beira Interior, located in Covilhã, has led the Cycloidal Rotors Optimized for Propulsion (CROP) European project with the aim of developing an innovative system for aeronautical propulsion that can be applied to different types of airship such as aeroplanes, helicopters, dirigibles, and other new-generation appliances.
This initiative, which was financed by the European Union, has involved scientists from Italy, the United Kingdom, Germany, and Austria for two years under the coordination of Portugal. The scientific and technological progress of this project mean that in the future aeronautical propulsion can be more ecological and efficient and also paves the way for new airship design.
The system is based on a cycloidal rotor, a set of rectangular blades that rotate on a horizontal axis but also oscillate. “The combination of the rotation on the axis and the oscillation on the centre of each blade allows movement similar to that of a bird beating its wings”, DiCYT was told by José Páscoa, a researcher from the Centre for Mechanical and Aerospace Science and Technology and the director of the project.
This ingenious rotor allows the propulsive force to be exerted 360º in any direction around the rotation axis. In practice this means having greater control over the movements of any airship, reducing the space for taking off and landing to a minimum and gaining considerable manoeuvrability in all flight situations; it can even hold up the appliance in the case of engine failure.
“Current propulsion systems have been optimised to develop a propulsive force in one main direction in the case of aeroplanes or in diagonal directions in the case of helicopters, but some movements are not possible such as making a helicopter turn face downwards in a controlled manner or making an airship, for example a dron, land on a ship in rough seas”, the expert points out. In contrast, “our system allows the development of the propulsive force on the three axes of an airship in a dynamic manner and with quite a fast reaction”.
This innovation may be incorporated to existing airships but also makes us think of future appliances especially adapted to the new system, which would be able to take off vertically, stop at a certain altitude, or turn on themselves bottom-up, always at the same point. A helicopter can only make a circular movement in the air while the new rotor would allow any complete rotation.
On the other hand, a noteworthy aspect of this project is that the new system is designed for airships using electrical propulsion, in such a way that its application would be beneficial to the environment as it would avoid releasing contaminating gases into the atmosphere.
As well as leading the project, the Universidad de Beira Interior has made important scientific and technical contributions in the field of analytical and computational modelling and in the design of the blades. The results obtained on the computer have taken shape in experimental tests with a prototype.
The CROP project has just been completed and will be presented in October at the Aerodays 2015 event to be held in London. Moreover, the partners are continuing to develop this area of research and consider that the new system could reach the market in about 2025.