Aerodynamic Interactions in Formation Flight for Wake Vortex Surfing

Formation flight typically observed in migratory birds allows the trailing aircraft to benefit from surfing the updraft of the wingtip vortices generated by a leading aircraft. This results in higher lift and reduced fuel consumption for the trailing aircraft. However, the formation spacing in longitudinal, lateral, and vertical direction directly impacts the aerodynamics performance of the trailing aircraft. This paper aims to utilize computational fluid dynamics (CFD) tool – OpenFOAM, to capture the wake vortex dynamics from the leading wing using URANS and LES turbulence models. The selected model is then utilized to explore the position of the trailing aircraft in formation and to determine the optimal spacing in terms of aerodynamic improvements in lift and drag.