Preliminary Noise Assessment of Aircraft with Distributed Electric Propulsion

Abstract

Electric and hybrid-electric propulsion technologies in aviation are becoming more attractive for aviation stakeholders not only due to the resulting reduction or elimination of the dependency on oil, whose availability and price are uncertain, but also because they are more reliable and efficient than traditional internal combustion engines. Moreover, combined with distributed electric propulsion (DEP), these technologies have shown potential in significantly reducing civil aircraft community noise impact and contribute towards delivering the strict mid-to-long-term environmental goals set by organisations worldwide, such as ACARE and NASA. This paper examines the noise impact of a concept tube and wing aircraft that falls in the A320 category and features various DEP systems using different power supply units (turboshaft engines or batteries) and number of electric propulsors. Meanwhile, considerations required for the transition from conventional to electric propulsion are discussed. Estimated Noise-Power-Distance (NPD) curves and noise exposure contour maps are also presented. It is concluded that indeed, the propulsors' number is a key parameter for optimising the environmental performance of DEP aircraft and hence maximising the noise benefits. Also, it is shown that based on the entry into service year (2035) technology, totally electric aircraft tend to have a larger noise footprint than aircraft using hybrid electric propulsion systems.

Numerical Characterisation of the Aeroacoustic Signature of Propeller Arrays for Distributed Electric Propulsion

“…Several concepts of DEP exist in the literature [11][12][13], but most of them are analysed for their applicability in designing BLI configurations [14,15]. Few studies have been conducted so far on the aeroacoustic properties of interacting propellers and are mainly related to counter-rotating propellers [16,17] and drones [18][19][20][21][22], where the distance between rotor hubs is a crucial aspect.…”

Structural Power Performance Targets for Future Electric Aircraft

“…The improvements from propulsor and airframe/wing integration highlight the potential value in exploring energy storage and airframe integration through structural power composites (SPCs). [22,23], HTS = high-temperature superconducting, PMAD = power management and distribution system). (b) An all-electric aircraft with distributed propulsion designed in OpenVSP based on A320 design (adapted from [24]).…”

“…Structural power composites can be further categorized by the type of electrical energy storage device. The two types which receive the greatest attention [22,23], HTS = high-temperature superconducting, PMAD = power management and distribution system). (b) An all-electric aircraft with distributed propulsion designed in OpenVSP based on A320 design (adapted from [24]).…”

Technological, economic and environmental prospects of all-electric aircraft

“…In the present study, the all-electric aircraft NPD curves have been derived from those of a baseline A320-232 aircraft using a novel method, which accounts for both operational and technological variations of the aircraft from the baseline case [46,47,48,49]. The all-electric aircraft airframe and propulsor fans are assumed to behave acoustically in a similar manner to their conventional equivalents.…”