Conceptual Design Synthesis of Electric VTOL Aircraft for Urban Air Mobility

Abstract

The emerging field of electric vertical take-off and landing (eVTOL) aircraft design lacks the wealth of data that traditional fixed-wing aircraft and rotorcraft design methodologies draw from. Consequently, prior research on the conceptual design of eVTOL aircraft has often been limited to specific eVTOL aircraft configurationsfor which validation data is accessible. This thesis enhances the understanding ofeVTOL conceptual aircraft design by developing a comprehensive database of 70battery-powered eVTOL aircraft concepts. These concepts were filtered from an initial pool of over 500 aircraft concepts announced between 2012 and 2022. Using this database, the thesis introduces a conceptual aircraft design methodology for sizing battery-powered eVTOL aircraft for urban air mobility (UAM) missions.An engineering database and a propulsion-based taxonomy of the reviewed aircraft concepts has been developed. The database establishes a minimum set of performance metrics – range, payload and total mass, required to perform an initial validation of the results of a sizing study in the conceptual design phase. An aircraft mass model for the two primary eVTOL aircraft classes is established – the powered lift class, capable of aerodynamic lift during forward flight, and the wingless class, which lacks this capability. This model synthesises physics-based power modelling from rotorcraft design, with data-driven structural component modelling from fixed-wing aircraft design. To carry out complex eVTOL aircraft sizing studiesefficiently and robustly, two hybrids of classical root-finding algorithms are established, the Bisection Newton-Rapson (Bisection NR) and the Fixed-point Newton-Rapson (Fixed-point NR) algorithms.The results of the multi-mission UAM sizing studies carried out showed a notableagreement between the aircraft mass predicted by the new sizing methodology and eVTOL aircraft performance data derived from the previously established database. The proposed methodology can be applied to powered lift eVTOL aircraft designed for inter-city UAM missions of up to 300-kilometre range with a payload of up to 450 kilograms, and wingless eVTOL aircraft designed for intra-city UAM missions of up to 80-kilometre range with a payload of up to 180 kilograms

Date of Award	Apr 2024
Original language	English
Awarding Institution	Coventry University
Supervisor	Thomas Statheros (Supervisor), Nadjim Horri (Supervisor) & Michael Bromfield (Supervisor)