|
چکیده
|
Rockfill structures, such as gabion mattresses are widely used in hydraulic engineering applications to mitigate erosion and protect infrastructure. However, these structures are susceptible to erosion processes, both from upstream and downstream directions, which can compromise their integrity and effectiveness. This study employs computational fluid dynamics (CFD) simulations to investigate the complex flow patterns and erosion processes around rockfill structures. The study aims to quantify the effects of various factors, including the gradation of the rockfill material, and the characteristics of the flow passing through and over the structure, on the initiation and extent of bed erosion. The results provide valuable insights into the velocity distribution, turbulence kinetic energy, hydrostatic pressure, and bed morphology changes around these structures over time. Flow characteristics, such as velocity, turbulence intensity, and flow depth, played a crucial role in determining erosion patterns. High-velocity jets and recirculating flow patterns around the structures contributed to localized scour and sediment transport. Higher pressure regions were observed near structure crests, while lower pressure zones existed in the lee of structures. Elevated turbulence kinetic energy levels were found in regions of high flow velocity and intense mixing, enhancing bed erosion and sediment transport. The research emphasizes the critical roles of granulometry in both the rockfill material and the erodible bed, as well as the characteristics of flow passing through and over the structure. The findings underscore the importance of considering both the structural properties of the rockfill and the dynamic nature of the surrounding flow in ensuring the long-term stability and effectiveness of these erosion mitigation measures.
|