Review of Electrically Powered Propulsion for Aircraft

Abstract

This paper presents a review of the state-of-the-art in aircraft electrical propulsion technology. A comparison is provided of differing propulsion mechanisms such as propellers, open fans, ducted fans, multi-stage rim driven fans and distributed thrust designs and their suitability to particular flight profiles and mission applications. Electrical motor architectures are also reviewed with particular attention being given to synchronous machines, such as Brushless Direct Current (BLDC) and Switched Reluctance Motor (SRM) technologies, and the recent advances that have been made in solid-state switching and High Temperature Superconducting (HTS) material applications. Present day electrical power generation, storage and control technologies are also reviewed including hybrid and fuel cell technologies and regeneration techniques. Electrical storage capabilities with regard to specific power and energy characteristics are discussed and the extent to which existing system technology can be integrated onto a Hybrid-electric and an All Electric Aircraft (AEA) is also investigated. Finally, a conclusion is provided highlighting the current technological challenges facing the development of commercial aircraft in terms of performance, airframe configuration and legislative and operational infrastructural requirements. , all electric aircraft, hybridelectric aircraft, more electric aircraft, unmanned aircraft, rim driven fan, high speed electrical flight, aircraft batteries, fuel Keywords-electrical propulsion cells, PV cells, supercapacitors(3)

Thermal Management of High-Power Density Electric Motors for Electrification of Aviation and Beyond

“…Figure 4d shows a similar cross-section of an axial flux permanent magnet motor, which most often is available in a shaft-drive configuration. Propulsion configurations include fixed pitch propellers, variable pitch propellers, contra-rotating (counter-rotating) fans or propellers, ducted fans, and rim driven fans [13]. Each of these configurations may be compatible with distributed propulsion.…”

The Application of Slotless Skewed Windings to a Rim Driven Fan for Aircraft Electrical Propulsion (AEP)

“…The windings aim is to be incorporated into a motor powering a rim driven fan, therefore the winding sizing is very different from the research done in this field. The sizing requirement is driven by the need for multiple-stage contrarotating fans to maximise the thrust produced [1], [10]. The axial length of the winding should be short and the diameter should be large to accommodate the fan.…”

“…The rising awareness about climate change is leading human activities to engage in a transition toward more environmentally friendly processes. While this change is taking place in many sectors, the aviation industry is tending to evolve through the development of new technologies that could make electric or hybrid flight viable [1]- [3]. In fact, the entire power chain from energy storage and inverters to electromechanical actuators is required to be safe, efficient, and lightweight.…”

Introduction

“…1 If the MEA concept can be viewed as a today reality and the MEP as a challenging but affordable target, the transition to AEA/AEP applications is still far to be concrete, especially for the large transport aircraft category. As highlighted by the data in Table 1.2, the limitation is essentially due to the specific power of batteries: by assuming a Battery-Specific Energy (BSE) of 300 Wh/kg [18] and that the fossil fuel mass on all aircraft contributes to the 30% of the total mass M AC , we have that the Battery Power Coverage (BPC) is roughly given by (1.1):…”