Inner-Outer Interactions in a Turbulent Boundary Layer Overlying Complex Roughness
Abstract eng: Experiments were performed to investigate the modulating influences of the inertial-region large-scale structures, on the small scales near the wall in a turbulent boundary layer. Hot-wire measurements were made in flow over a smooth- and a rough-wall (a multiscale topography), in light of recent studies establishing the phenomena in flows over smooth walls. One-probe measurements capture the streamwise turbulent kinetic energy distribution among various scales and local large-scale–small-scale interactions across the flow. Twoprobe measurements, measuring the large scales in the inertial region and small scales in the near-wall region simultaneously, were then performed to investigate the modulation influences. Amplitude (AM) and frequency modulation (FM) were observed in rough-wall flow, similar in structure to that of the smooth-wall flow. Further, among different spanwise locations investigated in flow over the roughness, it was found that the subtle differences in interactions exist between regions of low-momentum pathways (LMPs) and high-momentum counter parts (HMPs).
Publisher:
International Union of Theoretical and Applied Mechanics, 2016
Conference Title:
Conference Title:
24th International Congress of Theoretical and Applied Mechanics
Conference Venue:
Montreal (CA)
Conference Dates:
2016-08-21 / 2016-08-26
Rights:
Text je chráněný podle autorského zákona č. 121/2000 Sb.
Record appears in:
Record created 2016-11-15, last modified 2016-11-15