Modelling of Unsteady Flow in Compound Channels

Abstract

A model based on the St. Venant equations of flow with incorporation of terms to account for the momentum transfer phenomenon, was developed to route unsteady flow in compound channels. For the main channel, the full dynamic equations were used while in the floodplains, a diffusive model was used. Both included mass and momentum transfer terms. The resulting equations called CCDG 1-D model were solved by the characteristic-dissipative-Galerkin (CDG) finite element method. Results from the CCDG 1-D model were compared to observed experimental data. The unsteady results also showed that the CCDG 1-D model showed improvement on discharge prediction when the apparent shear was included in the model.


Journal of Civil Engineering, JKUAT (2001) Vol 6, 45-54