Investigation of the Surface Vortex in a Spillway Tunnel Intake

The surface vortex in a spillway tunnel intake was investigated in a physical model of the Xiluodu hydropower station. The velocity fields were measured using the particle tracking velocimetry technique. The tangential velocity formula of the surface flow field was derived based on the Navier-Stokes equations, and this formula greatly improved the consistency between the numerical and experimental data. Also, the formula has the advantage of describing the tangential velocity more accurately than previous formulas. The current research is based on established engineering practices, and the results provide a valuable reference for actual projects designed to prevent and eliminate surface vortexes.