Improving hydraulic performance of bank spillways through alternative guide wall designs: a modeling approach

Abstract Recent increases in the magnitude of flash flood have enhanced the need for efficient spillway arrangements capable to safely pass the extreme flood flow. The present study focuses on analyzing the influence of upstream guide wall geometry on spillway approach flow conditions using both physical and numerical modeling techniques. Three guide wall configurations, namely triangular, elliptical, and curved shapes, were evaluated using FLOW-3D simulations. The numerical computations were performed using the Volume of Fluid (VOF) method for free surface tracking together with the RNG turbulence model. Flow patterns, water surface profiles, and velocity distributions in the approach channel were analyzed for each condition. The results showed that the elliptical and curved guide walls reduced cross wave formation and provided a more uniform flow distribution towards the spillway bays compared to the triangular arrangement. The study demonstrates the usefulness of combined CFD and physical model investigations for assessing alternative guide wall layouts and improving spillway hydraulic performances.