Abstract
The method of complex characteristics is used to describe four kinds of localized disturbances in the boundary layer on a flat plate. The disturbances are those introduced by vibrating ribbon, two-dimensional pulse through a slit parallel to the leading edge, continuous excitement through a small hole on the plate, and an instantaneous jet from the same hole. The corresponding four equation systems are numerically solved to show fundamental properties of these disturbances. It is also intended to estimate quantitative effects of the leading-edge sweep angle and of the boundary-layer nonparallelism on the development of a three-dimensional wave packet.
