Author(s): Cem Bingol; Rui Zhu; Eckart Meiburg; Matias Duran-Matute; Herman J. H. Clercx
Linked Author(s): Matias Duran Matute
Keywords: Gravity current; Oscillatory flow; Direct numerical simulation
Abstract: Gravity currents are horizontal flows driven by density differences, and commonly observed in the environment such as the salt wedge forming in estuaries. The denser seawater encounters lighter fresh water from rivers, leading the fresh water to move towards the sea near the surface and saltwater to flow upstream near the bottom, forming the salt wedge. The opposing flow generates significant interfacial shear, promoting instability and turbulent mixing. Improving the knowledge about these processes is crucial to improve the understanding of, for example, nutrient distribution and upstream salt concentration in rivers. Previous research (Geyer and Ralston, 2011) has demonstrated the substantial impact of tidal characteristics on mixing, stratification, and salt intrusion in estuaries, utilizing a hydrostatic numerical ocean model. However, this type of model has limitations since they ignore the impact of non-hydrostatic physics on mixing and salt transport within salt wedges. The present work aims to enhance our understanding of how oscillatory forcing influences the mixing, advection, and front position of gravity currents.
Year: 2024