Author(s): Keisuke Yoshida; Tadaharu Ishikawa
Linked Author(s): Keisuke Yoshida
Keywords: CIP-Soroban scheme; Cylindrical coordinate system; Shallow-water flow model; Meandering river flow; Bank-line tracking
Abstract: A new numerical solver is developed for a shallow-water flow model to simulate meandering river flows. This solver can investigate the flows in the curved river channel, by means of the adaptive CIP-Soroban (CIP-S) scheme in a cylindrical coordinate system. Time development of depth-averaged water velocity and free-surface level is computed in the cylindrical (or orthogonal curvilinear) coordinate system without any transformation of the governing equations, and the advection term is calculated by the high-accuracy CIP scheme. The numerical grid point defined on a waterfront line at river banks is moved and tracked by the kinematic condition, so that the grid point is always located on the line and the rearrangement of the positions is easily conducted by the original CIP-S scheme. The accuracy of this solver was verified by the pure convection test proposed by Zalesak and examined by applying to a virtual meandering river flow. In comparison with the original CIP-S method in a Cartesian coordinate system and with the boundary fitted coordinate (BFC) method, it is shown that the proposed numerical solver presents good performance in dealing with the convection calculation and it can reasonably predict the main flow profile and water surface elevation and will be a promising numerical method as one of the practical solutions.
Year: 2007