English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We have performed direct numerical simulation of turbulent open channel flowover a smooth horizontal wall in the presence of finite-size, heavy particles.The spherical particles have a diameter of approximately 7 wall units, adensity of 1.7 times the fluid density and a solid volume fraction of 0.0005.The value of the Galileo number is set to 16.5, while the Shields parametermeasures approximately 0.2. Under these conditions, the particles arepredominantly located in the vicinity of the bottom wall, where they exhibitstrong preferential concentration which we quantify by means of Voronoianalysis and by computing the particle-conditioned concentration field. Asobserved in previous studies with similar parameter values, the mean streamwiseparticle velocity is smaller than that of the fluid. We propose a newdefinition of the fluid velocity "seen" by finite-size particles based on anaverage over a spherical surface segment, from which we deduce in the presentcase that the particles are instantaneously lagging the fluid only by a smallamount. The particle-conditioned fluid velocity field shows that the particlespreferentially reside in the low-speed streaks, leading to the observedapparent lag. Finally, a vortex eduction study reveals that spanwise particlemotion is significantly correlated with the presence of vortices with thecorresponding sense of rotation which are located in the immediate vicinity ofthe near-wall particles.

DNS of horizontal open channel flow with finite-size, heavy particles at low solid volume fraction