GEN-BL: Secondary Instability of Saturated CF-Vortices* low-frequency type-III (z)-mode high-frequency type-I (z)-mode us-amplitude in crosscut ws *from a steady mode packet us t-modal amplitude development

GEN-BL: Secondary Instability of Traveling CF-Vortices medium-frequency 'z-y'-mode high-frequency 'y'-mode „steady“ 3-D „steady“ 2-D moving coordinate system

GEN-BL: Transition-Delay by Upstream Flow Deformation With excitation of closer-spaced vortices upstream (UFD) “natural” Wassermann & Kloker (UFD) Saric & al. (DRE) vortices + pulsing UFD „Natural“ scenario

GEN-BL-APG: small-amplitude vortices + T-S-wave: part III Increased initial T-S amplitude breakdown but: - T-S just generates secondary crossflow modes - secondary growth independent of T-S (unlike K-type!) - active control on T-S useless! (see JFM 530, 2005) vortex mode T-S wave t-z-modal amplitude development t-modal amplitude development

GEN-BL: Convective nature of Secondary Instability - DNS t = t0 Switching-off the background pulses  relaxation to steady saturated state t = t0+3T Alle instationären Störungen werden stromab konvektiert Letztendlich wieder stationärer Sättigungszustand mit ausgeprägten Längswirbeln Was sieht man gleich in der Animation Bewies des konvektiven Charakters t = t0+6T Isofläche 2