High-fidelity aerodynamic and acoustic design and analysis of a heavy-lift eVTOL

Abstract

This work presents the high-fidelity aerodynamic and acoustic modelling processes supporting the preliminary design of a large eVTOL vehicle at the University of Glasgow in collaboration with GKN Aerospace. To support the GKN heavy-lift eVTOL design, known as Skybus, a range of tools of various fidelity levels were adopted and integrated. This paper first presents the conceptual design and initial sizing of the Skybus vehicle. The airframe design was then analysed using high-fidelity methods with parametric variations of wing an/di-hedral designs. By adjusting the interactions between the wings and the airframe, 5∘ front wing anhedral combined with 10∘ aft wing dihedral offered the maximum lift increase. High-fidelity CFD simulations of the complete Skybus vehicle in forward flight with two and four operating propellers were later carried out. The aerodynamic interactions between the propellers and the wings were analysed in detail. In cruise, the four-rotor configuration showed stronger aerodynamic interference effects and hence required more power than the two-rotor counterpart. Near-field acoustics of the vehicle was then extracted directly from the flow solutions and analysed. Far-field noise features were also computed using the FW-H equations and the CFD solutions. The peak noise levels of the heavy-lift vehicle in forward flight at 90 m/s were about 75 dB SPL perceived on the ground 1000 m below. Acoustic features and differences of the two configurations along the flight path and in the lateral directions were presented and discussed.