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.