Specific features of unsteady processes in the front regions of streaky structures in the boundary layer on a nonswept wing
V.N. Gorev1, M.M. Katasonov2, V.V. Kozlov3
1 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS Novosibirsk State University, Novosibirsk, Russia, gorev_vasiliy@ngs.ru
2 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS Novosibirsk State University, Novosibirsk, Russia
3 Khristianovich Institute of Theoretical and Applied Mechanics SB RAS Novosibirsk State University, Novosibirsk, Russia
Keywords: boundary layer, laminar-turbulent transition, streaky structures, Tollmien ? Schlichting waves, forerunners, wave packets, ?-structures, wind tunnel
Pages: 415-425
Abstract
Under conditions of a model experiment in nonswept-wing boundary layer, forerunner wave packets were obtained in the flow regions preceding the fronts of streaky structures. A model to describe the formation and development of the fronts is proposed. An external-flow pressure gradient is shown to be a necessary condition for forerunner growth. Besides, the spatial geometry of the forerunners and the evolution of this geometry in the course of downstream development of the wave packet were studied.
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