Preliminary Design of an eVTOL Aircraft

• Autor(a) principal: Rosa, Marcos Filipe Andrade Nunes
• Data de Publicação: 2022
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10400.6/13031
• topic: Asa Fixa; Evtol; Hélice de Passo Variável; Mau; Projecto Preliminar; Uav; Domínio/Área Científica::Engenharia e Tecnologia::Engenharia Aeronáutica

The growing demand for alternative clean energy sources for civil aviation industry, from transport to surveillance, prompts new aircraft configurations for a different range of future applications and replacement of outdated concepts of aircraft still in service. The electrification of aircraft is the future of aviation. The electrical Vertical Take-off and Landing (eVTOL) type of aircraft is growing in demand as an alternative for Urban Air Mobility (UAM), in short to mid-range transportation of goods and passengers. In this dissertation, an eVTOL aircraft concept and preliminary design are proposed. The design is a small UAV optimized for mpay CL CD aiming at longer flight ranges and carrying capacity. An Excel spreadsheet developed to proceed with the parametric study. The parameters considered are: Winspan, mean aerodynamic chord (MAC), and lift coefficient as the main design parameters for the aircraft wing. Multiple parameters combinations were tested and the selection criteria were the objective function and MAC. A compromise between the two criteria was achieved by selecting a wing with a slightly less score in objective function but a mean chord value higher than the optimal chord, which was better for the structure. Prop Selector was used in combination with spreadsheets for the preliminary propeller design, where a variable pitch configuration with the known wing main characteristics was adopted, in hover and cruise conditions to screen the best propeller diameter using the hover lift performance (H) and global efficiency (?global) as the main performance parameters do optimize the propulsion of the aircraft. The selected diameter is studied in the climb condition and the ideal pitch of the propeller is predicted for the relevant flight conditions. The performance parameters such as the rate of climb, cruise speed, and range were estimated, showing promissing results. With XFOIL/XFLR5 software the static longitudinal stability was studied, and Open VSP and CATIA V5 CAD models of the aircraft, and tilt-rotor mechanism were made. Finally, the mission profile is devised, the battery mass fraction, and energy consumption for each flight condition is calculated, thus highlighting the capabilities and limitations of the aircraft.