CFD analysis of flow dynamics around the series of dikes with alternative length layout

In the river system, the deployment of impermeable dikes often leads to significant morphological changes, including scouring due to strong momentum exchanges between the dike field and the main flow. This presents a challenge in managing riverbank erosion effectively. This study aims to analyze the impact of alternative length layouts of dikes on flow dynamics in an open channel, with the focus on minimizing the scour responsible factors around dikes. Employing a Computational Fluid Dynamic approach, this research investigates flow behavior around a series of emerged and a protective dike with varying lengths. The study utilizes the Reynolds Stress Model (RSM) to capture detailed flow characteristics such as velocity, turbulence, and recirculation eye displacement both upstream and downstream of the protective dike. The results showed that employing a protective dike with 0.5L-0.6L (where L represents the dike length) can significantly reduce depth averaged velocity and turbulent kinetic energy near the first dike head by 35% and 41%, respectively. The study recommends constructing protective dikes with optimized dimensions to mitigate the adverse impacts of momentum exchanges, thereby enhancing riverbank protection and reducing erosion risks.