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.

The velocity field in the Wu River at Chongqing was simulated using the shallow water equation implemented on clustered workstations. The parallel computing technique was used to increase the computing power. The shallow water equation was discretized to a linear system of equations with a direct parallel generalized minimum residual algorithm (GMRES) used to solve the linear system. Unlike other parallel GMRES methods, the direct GMRES method does not alter the sequential algorithm, but bases the parallelization on basic operations such as the matrix-vector product. The computed results agree well with observed results. The parallel computing technique significantly increases the solution speed for this large-scale problem.