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Electric Aircraft Propeller Design
Published in Ranjan Vepa, Electric Aircraft Dynamics, 2020
Electric motors have vastly different performance features and characteristics when compared with conventional fossil fuel-powered motors, including incredibly higher efficiencies, much smaller volumes, lower mass, fewer moving parts, independence of motor shaft power with air density and scalability over wide range power requirements. Electric motors are relatively easily controllable and thus facilitate the incorporation of distributed propulsion with a multiplicity of smaller motors driving highly efficient but smaller propellers to deliver large levels of thrust to the aircraft. This is the basis of a new and emerging strategy generally called distributed electric propulsion (DEP) so as to facilitate full propulsion control of an aircraft. DEP requires two types of propellers, low-speed, high-lift propellers used during low-speed maneuvering of the aircraft and high-speed, low-lift propellers used during cruising. The requirement is that they generate a higher axial induced velocity for the same level of thrust force generated. The high-lift propeller system is defined by selecting the number of propellers, the propeller disc diameter, the shape of the blade, including the twist distribution and chordwise blade section profile, and the number of blades. The blade section lift coefficient is an important parameter that should generally be higher. Patterson [35] and Patterson, Derlaga and Borer [36] have considered and proposed suitable methods for the design of such propeller systems, wherein they give due importance to propeller—wing interactions.
Environmental challenges and the aerospace industry
Published in Wesley Spreen, The Aerospace Business, 2019
Nonetheless, aircraft powered by electric motors have inherent efficiency advantages. The motors themselves tend to be lightweight, and they can easily be made in a range of sizes. It is comparatively easy to mount multiple small motors at various aircraft locations in what is known as distributed electric propulsion. Distributed propulsion can yield greater aerodynamic efficiency than a smaller number of larger conventional engines.
Exploring the User Acceptance of Urban Air Mobility: Extending the Technology Acceptance Model with Trust and Service Quality Factors
Published in International Journal of Human–Computer Interaction, 2023
Young Woo Kim, Cherin Lim, Yong Gu Ji
UAM vehicle, also known as a vertical takeoff and landing (VTOL) aircraft, is a key technology that enables air travel within the urban areas (Straubinger et al., 2021). UAM vehicles will be capable of carrying out vertical takeoff and landing but are distinguishable from existing urban aerial vehicles such as helicopters by their technical structures. VTOL aircrafts adopt an electrical distributed propulsion system that can improve the stability of aircraft through independent control of several motors (Holden & Goel, 2016). Porsche Consulting proposed three vertical mobility concepts that employ either a multirotor system, a lift-and-cruise combination, and a tilt-X system, each with a travel speed ranging between 70 and 300 km/h (Grandl et al., 2018). The EHang 216 is composed of multiple motors and coaxial propellers and can travel a short-to-medium ranged distance (3–100 km) at a flight elevation of under 800 m (Xu, 2020).