Numerical simulation of optimum groyne arrangement for preventing bank erosion (Case study of Ghezel-Ozan River)

This paper will discuss the optimum groyne configuration for preventing bank erosion alongside the Ghezel-Ozan River in Iran through advanced numerical simulations. The research used FLOW3D software to investigate the effects of spacing, lengths, the number, and the orientation of groins on flow patterns and erosion potential. In this regard, some key hydrodynamic parameters, such as Turbulent Kinetic Energy, Overall Flow Velocity, and Froude Number, are analyzed to quantify the efficacy of various groyne arrangements. The study area, belonging to the Eshtibin region of East Azarbaijan Province, is a 3-kilometer segment of the river, with a design flood discharge of 1435 m3/s for a 25-year return period. Coupled with detailed mesh (with 800,000 elements) and bathymetric data, this numerical model is to be used to represent as exactly as possible the morphology of the river. In this study, there are four groyne placement scenarios, showing the effect of number of groynes (4 or 7 units), spacing intervals (2.8 and 3.6 times the groyne length), and angular orientation (perpendicular and 30 degrees downstream). The results indicate that, upon the introduction of groynes, there are prominent changes in flow patterns and velocity distributions; therefore, this offers an avenue for erosion control. The study reveals that the optimal groyne configuration is dependent on site-specific conditions and design objectives, such as 4 number of groynes with 30 degrees orientation, stating tailored approaches are very important in river management strategies.