EVTOL Flys Through Atmospheric Boundary Layer: Unsteady Take-Off and Landing Study via Spatio-Temporal Projection Method

Paper in proceeding, 2024

An electric vertical take-off and landing aircraft (eVTOL) is a variety of vertical take-off aircraft driven by electric power. This work proposed a new boundary condition control method to investigate the take-off and landing process of eVTOL, which is under the conditions of a typical atmospheric boundary layer. The spatial flow field information, especially the height-dependent atmospheric crosswind velocity profile, will be projected on the temporal axis and superimposed with the existing time-dependent unsteady conditions. Taking a 4-axis eVTOL as an example, computational fluid dynamics (CFD) simulations based on unsteady Reynolds-Averaged Navier-Stokes (uRANS) and rigid body motion (RBM) are carried out with proposed unsteady boundary conditions. The loads and surrounding flow field of the aircraft are obtained, while the vortical structures are further identified and discussed. Notably, the impact of atmospheric boundary layer on the aerodynamic force of eVTOL during vertical motions is not distinct. Based on the theoretical basis and results, this boundary condition control method can effectively simplify the simulation process and reduce the computational resource utilization for eVTOLs, or other vertical take-off vehicles. In addition, it also has the potential to empower traditional wind tunnel facilities with full-scale aerodynamic testing capacity for eVTOLs.