Flight-Simulator Study of Airplane Encounters with Perturbed Trailing Vortices

Abstract

This study provides a preliminary, hut concrete, assessment of the potential benefits of causing the breakup of airplane trailing vortices via large-scale instability, resulting in vortex rings. The 737-300 flight simulator is used to model the autopiloted response of an airplane encountering the vortices at different stages in the breakup process. A series of encounters with straight vortices is used to establish a baseline response. For the early stages of the vortex breakup, the vortices are modeled as wavy vortex filaments. For the late stages of the vortex breakup, the vortices are modeled as vortex rings, whose shape is based on experimental observation. The primary results of the study are presented in a collection of contour plots for the maximum bank angle that occurs during an encounter. The bank angles are given as a function of the horizontal and vertical vortex-intercept angles. The results show a significant reduction in the maximum bank angle, experienced by the encountering airplane, as a result of the vortex breakup