Abstract

The finite volume method is applied for solving the conservative Saint-Venant equations in case of a one-dimensional open channel flow with high temporal and spatial variability. A new shock-capturing discretisation scheme is proposed for computation of flow equations with source terms. The proposed scheme, called hybrid, combines adventages of flux-splitting and flux-difference-splitting schemes. Five benchmark tests are used to verify the hybrid scheme. The tests are: (1) Flow in a rectangular cross-section rough channel, (2) instantaneous dambreak over an horizontal, initially dry bed, (3) undercritical flow over a bump, (4) undercritical flow over a bump with change to supercritical flow, and (5) supercritical flow over a bump with hydraulic jump. The quality of the proposed scheme is evaluated and compared with that of well known flux-splitting and flux-difference-splitting schemes,. on the base of the average percentual error. Results show that the hybrid scheme has a good precision for calculation of highly unsteady, varied flow and that the model is able to consider a partially dry bed. The average percentual errors of the computations ranged from 0.0 to 5.4 % for flow depth and from 0.0 to 6.3 % for specific discharge.