Interaction of Very Large Scale Motion of Coherent Structures with Sediment Particle Exposure

• Main Authors: Sencer Yücesan, Daniel Wildt, Philipp Gmeiner, Johannes Schobesberger, Christoph Hauer, Christine Sindelar, Helmut Habersack, Michael Tritthart
• Format: Article
• Language: English
• Published: MDPI AG 2021-01-01
• Series: Water
• Subjects: coherent structures; hairpin-vortex packets; hydrodynamic forces; particle entrainment; very-large-scale motions; turbulent channel flow
• Online Access: https://www.mdpi.com/2073-4441/13/3/248

A systematic variation of the exposure level of a spherical particle in an array of multiple spheres in a high Reynolds number turbulent open-channel flow regime was investigated while using the Large Eddy Simulation method. Our numerical study analysed hydrodynamic conditions of a sediment particle based on three different channel configurations, from full exposure to zero exposure level. Premultiplied spectrum analysis revealed that the effect of very-large-scale motion of coherent structures on the lift force on a fully exposed particle resulted in a bi modal distribution with a weak low wave number and a local maximum of a high wave number. Lower exposure levels were found to exhibit a uni-modal distribution.