Effects of Turbulence Parameterization on Hydrodynamics and Sediment Transport in Tidal Channels: A Case Study of Yamen Channel in the Northern South China Sea

• Published in: Journal of marine science and application 2023-06, Vol.22 (2), p.284-295
• Main Authors: Yang, Yi, Liu, Jingui, Li, Yichun, Zhang, Chunhua
• Format: Article
• Language: English
• Subjects: Boundary conditions; Brackishwater environment; Continuity (mathematics); Deltas; Electrical Machines and Networks; Engineering; Environmental management; Environmental protection; Estuaries; Geotechnical Engineering & Applied Earth Sciences; Hydrodynamics; Kinetic energy; Machinery and Machine Elements; Mathematical analysis; Mathematical models; Numerical models; Offshore Engineering; Outfalls; Parameterization; Power Electronics; Research Article; Rivers; Sediment; Sediment concentration; Sediment dynamics; Sediment transport; Sediment-water interface; Sediments; Spatial variations; Stability; Surface layers; Suspended sediments; Tidal inlets; Turbulence; Turbulent flow; Vertical profiles; Viscosity
• ISSN: 1671-9433; 1993-5048
• DOI: 10.1007/s11804-023-00327-9

In this study, we conducted numerical experiments to examine the effects of turbulence parameterization on temporal and spatial variations of suspended sediment dynamics. Then, we applied the numerical model to the Yamen Channel, one of the main eight outfalls in the Pearl River Delta. For the field application, we implemented the k−ε scheme with a reasonable stability function using the continuous deposition formula during the erosion process near the water-sediment interface. We further validated and analyzed the temporal-spatial suspended sediment concentrations (SSCs). The experimental results show that under specified initial and boundary conditions, turbulence parameterization with stability functions can lead to different vertical profiles of the velocity and SSC. The k−ε predicts stronger mixing with a maximum value of approximately twice the k−kl. The k−kl results in smaller SSCs near the surface layer and a larger vertical gradient than the k−ε. In the Yamen Channel, though the turbulent dissipation, turbulent viscosity and turbulence kinetic energy exhibit similar trends, SSCs differ significantly between those at low water and high water due to the tidal asymmetry and settling lag mechanisms. The results can provide significant insights into environmental protection and estuarine management in the Pearl River Delta.