3D Lagrangian modelling of saltating particles diffusion in turbulent water flow

Robert J. Bialik, Vladimir Nikora, Pawel M. Rowinski

Research output: Contribution to journalArticlepeer-review

47 Citations (Scopus)

Abstract

Abstract
A 3D Lagrangian model of the saltation of solid spherical particles on the bed of an open channel flow, accounting for turbulence-induced mechanisms, is proposed and employed as the key tool of the study. The differences between conventional 2D models and a proposed 3D saltation model are discussed and the advantages of the 3D model are highlighted. Particularly, the 3D model includes a special procedure allowing generation of 3D flow velocity fields. This procedure is based on the assumption that the spectra of streamwise, vertical and transverse velocity components are known at any distance from the bed. The 3D model was used to identify and quantify effects of turbulence on particle entrainment and saltation. The analysis of particle trajectories focused on their diffusive nature, clarifying: (i) the effect of particle mobility parameter; (ii) the effect of bed topography; and (iii) the effect of turbulence. Specifically, the results of numerical simulations describing the abovementioned effects on the change in time of the variance are presented. In addition, the change in time of the skewness and kurtosis, which are likely to reflect the turbulence influence on the spread of particles, are also shown. Two different diffusion regimes (local and intermediate) for each of the investigated flow conditions are confidently identified.
Original languageEnglish
Pages (from-to)1639-1660
Number of pages22
JournalActa Geophysica
Volume60
Issue number6
DOIs
Publication statusPublished - Dec 2012

Keywords

  • Lagrangian approach
  • particle diffusion
  • particle entrainment
  • saltating particle trajectories
  • sediment transport
  • turbulence-particle interaction

Fingerprint Dive into the research topics of '3D Lagrangian modelling of saltating particles diffusion in turbulent water flow'. Together they form a unique fingerprint.

Cite this