Fluid Dynamic Mechanisms and Interactions within Separated Flows

Abstract

Abstract : The significant results of a joint research effort investigating the fundamental fluid dynamic mechanisms and interactions within high-speed separated flows are presented in detail. The results have been obtained through primary emphasis on experimental investigations of missile and projectile base flow-related configurations. The objectives of the research program focus on understanding the component mechanisms and interactions which establish and maintain high-speed separated flow regions. The experimental efforts have considered the development and use of state-of-the-art laser Doppler velocimeter (LDV) and particle image velocimeter (PIV) systems for experiments with axisymmetric and planar, two-dimensional models in subsonic and supersonic flows. The LDV experiments have yielded high quality, well documented mean and turbulence velocity data for a variety of high-speed separated flows including the near-wake region behind a cylindrical afterbody in supersonic flow. The PIV experiments have studied the effect of a base cavity in a two-dimensional, subsonic base flow and the mechanism of drag reduction for this configuration. Another experimental study has considered the interaction occurring when a supersonic stream is separated by means of a second stream impinging the first at an angle (plume-induced separation). The results of these various studies have been carefully documented in a series of journal articles, conference proceedings papers, and theses. The fun text of the papers and thesis abstracts are included as appendices of this report. Separated flow, Transonic flow, Particle image velocimetry, Base flow, Supersonic flow, Subsonic flow, Laser Doppler velocimetry,