Author(s): Yaoxin Zhang; Yafei Jia; Tingting Zhu
Keywords: Edge gradients; Finite Volume Method; hybrid; hydraulic model; two-dimensional model
Abstract: This paper presents a two-dimensional depth-integrated hydrodynamic flow model using the Finite Volume Method (FVM) on a hybrid unstructured mesh system with a collocated variable arrangement. A new evaluation method for computing the gradients at the cell edges, derived based on the second-order Taylor series expansion, is proposed to improve the solution due to mesh irregularity and non-uniformity. In this method, no interpolation for variables at cell vertices is necessary. The cross-edge flux is evaluated by using the momentum interpolation. The convergence, robustness and accuracy of this model based on the new evaluation method of edge gradients have been demonstrated by several numerical convergence tests and applications to natural rivers with complex geometries and instream structures.