Numerical Study of Wake Vortex Behaviour at the Initiation of Jet Transport Airplane Turning Flight

Cruising jet transport wake vortex flight data has been obtained by the NRC, during wake turbulence, emissions and contrails flight research, including NASA ACCESS II, whereupon the wake/contrail generator was the NASA DC-8-72. Generally, such data has been obtained during straight flight. During rate 1 turning flight of Heavy Category wake generators, the immediate onset of wake vortex condensate changes has been generally observed, including meandering, short and long wave, multi-wavelength instability excitation. During wake vortex prediction and verification studies of the data, the non-linear lateral transport behaviour during turning flight was highlighted. In this subsequent numerical study, lifting-line analysis has been conducted, to investigate the existence of an analytical prediction of the changes in characteristics and lateral transport of Heavy jet wake vortex during the initiation of turning flight in cruise. Asymmetry of the full-span lift distribution was introduced by outboard aileron deflection, inducing the turn initiation. The changes to the behaviour downstream of the shed circulation from the wing, compared with that from symmetrical lift distribution, are studied, including developed trailing vortex core radius, circulation, vortex plane tilt, lateral transport, circulation detrainment, and sensitivity to circulation shedding nodal distributions.