Communications on Hydraulic and Geotechnical Engineering. Notes on theMathematical Modelling of Alluvial Mountain Rivers

摘要

The dynamics of morphology and hydraulics of mountain rivers must be known whenapplying numerical modeling procedures to mountain rivers. Simplifying a complex, non-uniform geometry significantly affects the behavior of the model at high values of the Froude number. The number and type of boundary conditions to be prescribed at a boundary can change with flow regime. Hydraulic and morphological changes in supercritical flows are coupled and transversal effects are significant. The mathematical models discussed are a single-layer model and a double layer model. With the help of the characteristics, the models are analyzed and compared. Analyzing the characteristic surface yields indispensable insight in the two-dimensional behavior of the mathematical models. To prevent the mathematical model from being elliptical, the thickness of the mixing layer has a maximum. This value is investigated, approximated and evaluated.