Hydraulics & Waterways
394510 - A Coupled 2D and 3D Shallow Water Model for Tidal Flow in Hangzhou Bay
Thursday, June 7
8:30 AM - 10:00 AM
Location: Greenway CD
Weiming Wu, Potsdam – Clarkson University; Zhiguo He, China – Zhejiang University
Flow in the Qiantang River Estuary is affected by the river flow from upstream and ocean flow from the large Hangzhou Bay. To simulate the complex tidal flow at the estuary, a coupled 2D and 3D shallow water model is proposed, taking advantages of the efficiency of 2D model and the accuracy of 3D model. The depth-averaged 2D hydrodynamic model is built on the non-staggered, curvilinear mesh and the 3D shallow water model is built on part of the same horizontal mesh with the sigma coordinate in vertical direction. Both models use implicit finite volume methods with the Rhie and Chow-type momentum interpolation for intercell flux calculations. The 2D and 3D models share the same pressure correction equation based on the hydrostatic pressure assumption. With the solved pressure field in the entire horizontal domain, the velocity components are solved separately in the 2D and 3D sub-domains. The coupled model is advanced in handling large domain using the 2D solver preparing boundary conditions and simulating the local domain with the 3D solver for detailed flow fields. The model is applied to investigate the tidal flow in the Qiantang Estuary and Hangzhou Bay and verified with measured water levels and velocity profiles at several gauging stations. Simulated results show that the coupled model works well in a large ocean domain with special care on local locations near the estuary. It is quite flexible in coastal areas and estuaries with mixed 2D and 3D flow characteristics.