Numerical Simulation of Ice Processes for the Middle Route of the South-to-north Water Diversion Project

The middle route of the south-to-north water diversion project, which consists of a long route open channel and various hydraulic constructions is a series-wound water conveyance system. A numerical modeling system of water conveyance in the ice period for such large-scale and long distance water transfer project is developed based on the integration of a river ice model and unsteady flow model with complex inner boundaries. A simplified method which imposed the same flow discharge in the upstream and downstream of the structure by neglecting the storage effect are proposed for dealing with the inner boundaries. To accurately calculate the ice cover progression, a way named artificial fluid method is utilized. According to the measured and design data in winter-spring period, the whole ice process, which includes the formation of ice cover, its development, melting and break up as well as the ice-water dynamic response during the gate operation for the middle route, are simulated. The ice,characters and water conveyance capacity are both analyzed and thus the hydraulic control conditions for safety regulation are presented. At last, the paper provides an operation plan and suggestions for future considerations.