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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Sediment management and morphodynamics : On the threshold of motion of sediment grains: turbulent fluctuation effects
On the threshold of motion of sediment grains: turbulent fluctuation effects
Author : REZA BARATI1, SEYED ALI AKBAR SALEHI NEYSHABOURI2 & GOODARZ AHMADI3
ABSTRACT
Particle movement will occur when the instantaneous fluid force on a particle is just larger than the instantaneous
resisting force. One of the most important issues in this regard is the influence of turbulent fluctuation on threshold of
motion. In this research, a series of numerical experiments was performed for studying the effects of turbulent fluctuation
and turbulence structures on the initiation of sediment grains movement. A 3D Lagrangian numerical model was
developed by considering various hydrodynamic forces such as non-linear drag force, the shear lift force, Magnus force,
the buoyancy force, the added mass force, the history force and torque. The particle-particle interaction and particle-wall
collision were included in the developed model using Discrete Element Method (DEM) and a random process,
respectively. The fluid flow is described by 1D steady flow with 3D turbulent intensities. The validation of the model was
implemented using different particle diameters and flow conditions. The results indicated that threshold of motion of
sediment grains is strongly depends on stream-wise velocity fluctuations.
File Size : 550,766 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Sediment management and morphodynamics
Date Published : 13/08/2015
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