Inferring the structural properties of eddies in the log layer from spectral statistics

Abstract

The structure of near-wall layers has been the subject of much research over many years, with conceptual descriptions of the Attached Eddy Hypothesis (AEH, henceforth) by Townsend (1980) and Perry & Chong (1982) being key historical fix points. The fact that major efforts have continued unabated over the past two to three decades reflects the exceptional structural complexity of near-wall layers awaiting insight, as well as new opportunities to investigate open questions as a consequence of outstandingly high-quality experimental and DNS data emerging over the past decade (Marusic et al. (2013); Smits et al. (2011); Hultmark et al. (2013); Rosenberg et al. (2013); Jiménez & Hoyas (2008); Lee & Moser (2015)). In particular, the availability of massive amounts of spatially and temporally fully-resolved raw DNS data for fairly high Reynolds numbers has opened new routes to investigating many statistical and structural properties of near-wall layers, with the objective of unravelling a variety of scale-interaction processes.