Quadrant and probability density function analyses in high-reynolds number turbulent channel flows based on high-resolution DNS database

Abstract

Direct Numerical Simulations (DNS) resolved Kolmogolov scales were employed to investigate large-scale structure in fully developed turbulent channel flows. Quadrant and probability density function analyses were conducted over a decoupled range of Reynolds numbers (Rex), 150, 400, 1000, and 2000, based on the friction velocity and channel half-width The quadrant analysis has proved a larger contribution of sweep event to the Reynolds shear stress with increasing Reynolds number at each location from the wall to the channel center. This suggests that energy transfer increased on large-scale structure from outer region to inner region. In contrast, at each location from the wall, the PDF profiles of turbulent velocities and pressure have the analogous them uninfluenced by increasing Reynolds number. In near log-law region, Kullaback-Leibler divergence profiles of the streamwise turbulent velocity have the V-shaped them in cases of Reτ > 400. © 2012 The Japan Society of Mechanical Engineers.