Visualization of Unsteady Separated Flow About a Pitching Delta Wing.

摘要

Unsteady separated flows produced by three different delta wings driven with constant pitch rates were investigated using high speed flow visualization. The large scale vortices produced were initially similar to those produced above delta wings driven sinusoidally. Subsequently, the vortices either convected away from the wing or were broken up by the complex three-dimensional flow field. Both initiation and development of the leading edge vortices were dependent upon planform geometry and nondimensional pitch rate. Variations in vortex characteristics and duration with spanwise position were also noted. Smoke wire visualization proved a valuable tool in assessing three-dimensional characteristics of the unsteady flow field. Keywords: Pitch motion; Three-dimensional flow; Flow separation; Delta wings. (edc)