Passive and Active Control of Massively Separated High-Speed Flows

摘要

This work builds on our previous experimental studies of high-speed separated base flows by performing innovative passive and active flowcontrol experiments on these flowfields. The purpose of these studies is twofold: (1) to effect substantial changes in these base flows that will lead to improved flight vehicle performance; and (2) to further basic understanding of these complex, separated, compressible, turbulent flowfields. The specific passive- control studies that have been conducted consist of inserting splitter plates into the recirculation region to alter the stability characteristics and structure of the near-wake flowfield. The open-loop active control methods that were employed used electric-arc excitation to force or inhibit specific instability modes for these high-speed separated flows. Two electric-arc actuator types were investigated: localized arc-filament plasma actuators and pulsed plasma-jet actuators. In each case, the studies were suggested by our previous experimental investigations that have characterized in detail the uncontrolled flowfields and also by recent DNS/stability studies of other workers. This final report summarizes our progress on both the passive splitter plate and active electric-arc control studies.