No abstract

In the quest for the reduction of noise pollution, novel hybrid-electric or fully-electric power-trains promise to provide a substantial contribution. Especially closer to airfields, where acceptability issues tend to limit air operations with conventional fuel-burning engines, such novel power-trains allow to fly terminal maneuvers with a dramatically reduced impact on pollution. Considering the General Aviation (GA) field, where such new types of propulsion are more likely to gain a significant market share thanks to their favorable characteristics for this weight category, the reduction of the noise impact on ground may increase the infrastructural value of smaller airfields, often located in densely populated areas. This in turn would help in making novel power-train technologies economically advantageous at a system level. Despite these evident advantages, a methodology to quantify noise emissions of a novel type of power-train has not been identified yet – a fundamental step towards the assessment of the potential contribution of hybrid-electric or fully-electric aircraft to the global scenario of future aviation. This work introduces and discusses a possible procedure to provide such estimation. While mainly focused on the field of propeller-driven GA aircraft, the procedure presented herein can be easily scaled to cope with the specific features of heavier categories.

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The present contribution aims at providing a comprehensive illustration of a new approach to rotorcraft noise abatement, especially during terminal procedures, when the vehicle approaches the ground and the acoustic impact is higher. This approach pursues the development of technologies and tools for real-time, in-flight monitoring of the emitted noise. The effect of the acoustic radiation is presented to the pilot in a condensed, practical form on a new cockpit instrumentation, the Pilot Acoustic Indicator (PAI), to be used for performing quieter maneuvers. The PAI is based on the synergetic composition of pre-calculated acoustic data, which are used in a noise estimation algorithm together with the data gathered by an innovative contactless measurement system, capable of acquiring the main rotor blade motion. The paper reports on the current studies in unsteady and quasi-steady aeroacoustic prediction and tip-path-plane angle of attack and thrust coefficient observation. Results on novel methodologies are discussed, together with the main features of the PAI design and development process

The adoption of hybrid-electric aircraft is expected to have a considerable impact on airport operations, with the need of new infrastructural requirements to support electric-powered fleets. In particular, battery-charging requirements shall play a decisive role. Preliminary investigations useful to perform scenario studies for the future implementation of electric-powered aviation can take advantage of the ARES methodology presented here, which provides the optimal solution to the sizing of airport battery recharging infrastructures. Based on the flight schedule and on the specifications of the aircraft fleet and the charging equipment, the solution assesses the number and type of charging points, the related electrical consumption in terms of energy and power, and further information needed to guarantee the required operational level while minimizing the procurement and operating costs. The method allows considering and comparing two charging strategies: plug-in recharge and battery swapping. Energy price variation in time is also taken into account and a full description of the optimal time scheduling of recharging operations is provided. Application studies to the reconfiguration of two existing aerodromes, a General Aviation airport and a large regional hub, are discussed, showing the potential of the proposed approach.