Figure 11
(Left) Space-time evolution of a 2D QD vortical packet of the mean streamwise vorticity \(\overline{\omega }_x(x,y,t)\) focusing near the wall at B (\(y^+ =13.2\)). Time increases from top to bottom, related animation Movie S4. (Right) hysteresis curve of the peak amplitude \(\eta /\eta _{max}\) as a function of the peak speed \(C/C_{max}\), where \(\eta _{max}\) and \(C_{max}\) are the vorticity and speed maxima. Warmer (cooler) colors denote positive (negative) values of vorticity.
