Chasing eddies and their wall signature in turbulent boundary layers at Mach 3 through 10

We use a direct numerical simulation database of turbulent boundary layers,\footnote{Martin, M.P., JFM, vol. 570, pp. 347- 364, 2006}$^,$\footnote{Martin, M.P., AIAA Paper 2004-2337}$^,$\footnote{Beekman \& Martin, APS DFD08} statistical tools,\footnote{Brown \& Thomas, Phys. Fluids, vol. 20, pp243-251, 1977} scientifically-rooted packet-pattern recognition,\footnote {Ringuette, Wu \& Martin, JFM, vol. 594, pp. 59-69, 2008} and validated visualization algorithms\footnote{O'Farrell, C. Senior Thesis, Princeton University 2008} to identify hairpin packets and their wall signature. We investigate the variation of time scales and length scales associated with coherent structures and the role of hairpin packets on the generation of skin friction, wall-pressure loading and heat transfer.