edu.ucar.opensky::articles:14473 UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact 2025-12-26T03:21:44.994764 ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data ISO 19115-2:2009(E) https://n2t.org/ark:/85065/d70r9qd6 Modification of near-wall coherent structures by inertial particles 2014-10-30T00:00:00Z publication https://n2t.org/ark:/85065/d70r9qd6 https://doi.org/10.1063/1.4900583 Richter, D. author Sullivan, Peter P. author UCAR/NCAR - Library publisher Direct numerical simulations are combined with two-way coupled Lagrangian point particles to study the effect of Reynolds number on particle-turbulence interaction. Turbulent planar Couette flow is simulated at a constant dispersed phase mass loading of ϕ m = 0.25 for particle Stokes numbers of St K = [O(1), O(10), O(100)] (based on the Stokes time scale of the particle and the Kolmogorov time scale of the flow) and bulk Reynolds numbers of Re b = [8100, 24000, 72000] (based on the plate velocity difference and separation distance). Statistics of swirling strength \λ ci \ are used to evaluate the impact of particles on near-wall motions which are responsible for turbulent, wall-normal momentum transport. Instantaneously, the number of high-strength swirling motions near the wall decreases significantly in the presence of particles, and this trend is enhanced with increasing Re b . Conditional averages are computed using linear stochastic estimation, providing the average structures responsible for ejection events near the wall. These conditional eddies are weakened substantially by the presence of the dispersed phase, and this effect is again enhanced with increasing Re b . We propose a mechanism where particles, by interfering with the hairpin regeneration process near the wall, can influence turbulent fluxes in a way that increases with Re b despite only having direct interaction with scales on the same order as their small physical size. At the same time, turbulent momentum flux concentrated at higher wavenumbers with increasing Re b allows small particles to be effective agents for altering turbulent transport. UCAR/NCAR - Library OpenSky Support PO Box 3000 Boulder CO 80307-3000 opensky@ucar.edu http://opensky.ucar.edu/ homepage pointOfContact PDF Text theme Resource Type 2016-01-01T00:00:00Z publication Copyright 2014 American Institute of Physics. This article may be downloaded for personal use only. Any other use requires prior permission of the author and the American Institute of Physics. None eng geoscientificInformation