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Modelling granular sediment transport over water‐worked gravels
Author(s) -
Hardy Richard J.
Publication year - 2005
Publication title -
earth surface processes and landforms
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.294
H-Index - 127
eISSN - 1096-9837
pISSN - 0197-9337
DOI - 10.1002/esp.1277
Subject(s) - sediment transport , particle (ecology) , geology , sediment , geotechnical engineering , bed load , acceleration , hydraulics , mechanics , porosity , trajectory , geomorphology , engineering , physics , classical mechanics , aerospace engineering , astronomy , oceanography
Abstract This paper reports a numerical model that calculates the transport paths of individual granular particles over a natural water‐worked gravel surface. Surface topography is measured using digital photogrammetry and incorporated into a computational fluid dynamics (CFD) scheme by the application of a porosity algorithm. The predicted hydraulics determine the forces acting on each particle enabling the particle trajectory to be solved by Langrangian transport equations. The methodology demonstrates the importance of including complex topography in the numerical scheme as topographically induced hydraulic acceleration and deceleration affect both the transport mechanism and subsequent trajectory of the particle. Hydraulically induced hops, where the particle is entrained into a localized shear layer around a bed particle, are demonstrated to be important in transporting granular sediment across the bed and in re‐starting sediment transport if the particle has fallen into a hydraulically sheltered region. Copyright © 2005 John Wiley & Sons, Ltd.