2017/06/30 by Myoungkyu Lee, Robert D. Moser · 94 citations
Computer Science · Engineering · Physics and Astronomy · #Biomimetic flight and propulsion mechanisms #Couette flow #Direct numerical simulation #Fluid Dynamics and Turbulent Flows #Nonlinear Dynamics and Pattern Formation #Plane (geometry) #Reynolds number #Reynolds stress equation model #Taylor–Couette flow #Turbulence #Vortex #physics.flu-dyn
paper · pdf · doi:10.1017/jfm.2018.131
published in Journal of Fluid Mechanics 842, 128-145 (Cambridge University Press) · Accepted manuscript in the Journal of Fluid Mechanics
openalex created_date 2017/07/14 · arxiv created 2018/01/29 · openalex publication_date 2018/03/06 · arxiv updated 2018/04/04 · openalex updated_date 2026/08/05
We study the large-scale motions in turbulent plane Couette flows at moderate friction Reynolds number up to Re_\unicode[STIX]x1D70F=500 . Direct numerical simulation (DNS) domains were as large as 100\unicode[STIX]x03C0\unicode[STIX]x1D6FF× 2\unicode[STIX]x1D6FF× 5\unicode[STIX]x03C0\unicode[STIX]x1D6FF , where \unicode[STIX]x1D6FF is half the distance between the walls. The results indicate that there are streamwise vortices filling the space between the walls that remain correlated over distances in the streamwise direction and that increase strongly with the Reynolds number, so that for the largest Reynolds number studied here, they are correlated across the entire 100\unicode[STIX]x03C0\unicode[STIX]x1D6FF length of the domain. The presence of these very long structures is apparent in the spectra of all three velocity components and the Reynolds stress. In DNS using a smaller domain, the large structures are constrained, eliminating the streamwise variations present in the larger domain. Near the centre of the domain, these large-scale structures contribute as much as half of the Reynolds shear stress.