LARGE-EDDY SIMULATIONS AND LIDAR MEASUREMENTS OF VORTEX-PAIR BREAKUP IN AIRCRAFT WAKES

Results of large-eddy simulations of an aircraft wake are compared wit h results from ground-based Lidar measurements made at NASA Langley Re search Center during the Subsonic Assessment Near-Field Interaction Fl ight Experiment held tests. Brief reviews of the design of the field t est for obtaining the evolution of wake dispersion behind a Boeing 737 and of the model developed for simulating such wakes are given. Both the measurements and the simulations concentrate on the period from a few seconds to a few minutes after the wake is generated, during which the essentially two-dimensional vortex pair is broken up into a varie ty of three-dimensional eddies. The model and experiment show similar distinctive breakup eddies induced by the mutual interactions of the v ortices, after perturbation by the atmospheric motions.