Aerodynamic interference and wake characteristics of a multirotor tandem tilt-wing electric vertical take-off and landing aircraft in conversion flight
Jiahao Liu, Gaohua Li, Dechuan Ma, Fuxin Wang
Abstract
Although multirotor tandem tilt-wing (TTW) electric Vertical Take-Off and Landing (eVTOL) aircraft represents a promising class of future air transportation systems, aerodynamic interference during conversion flight remains a critical challenge to both safety and performance. In this study, the associated wake evolution and interference effects are investigated using a high-resolution numerical simulation framework. Two representative layouts are examined in quasi-steady simulation: a single tilt-wing (STW) with two spanwise-mounted rotors and a TTW with each wing carrying a pair of rotors. For the STW configuration, interference effects progressively diminish as the aircraft transitions from helicopter to airplane mode. Compared with a bare tilt-wing, the rotor slipstream increases wing lift by 35.2% while simultaneously amplifying unsteady aerodynamic fluctuations. In addition, the counter-rotating rotors induce a pronounced spanwise uneven distribution of aerodynamic loads, especially between the rotor mounts. For the TTW configuration, the front and rear rotors, rotating in opposite directions, generate substantially different wake structures. Interactions with upstream wake decrease the rear rotors' thrust by 2.1%, while secondary downwash impinging on the rear wing reduces its lift by 27.7% relative to the front wing. This work provides detailed insight into the aerodynamic interactions and wake characteristics of multirotor TTW eVTOL aircraft during conversion flight, thereby deepening the understanding of the underlying flow physics and interference mechanisms.