Author(s): Michele Catella; Luca Solari
Linked Author(s): Luca Solari
Keywords: Open channels; Unsteady flow; Numerical models; Irregular geometry; Steep channel
Abstract: A numerical model is proposed to compute one-dimensional open channel flows in natural mountain streams involving steep, non-rectangular and non-prismatic channels, and including subcritical, supercritical and transcritical flows. The conservative scheme solves the Saint Venant equations by employing a predictor-corrector finite volume method. A resourceful reformulation of the source terms related to the channel topography allows to precisely balance the mass and momentum fluxes in asymptotically steady conditions. The present method does not require the solution of the Riemann problem at each cell interface, the comprehension of the eigenvalues structure of the conservation laws and don’t need any special additional correction to capture discontinuities in the solution. The resulting scheme has been extensively tested under unsteady flow conditions by reproducing various open channel geometries both ideal and real, with non-uniform grids and without any interpolation of topographic survey data. The proposed model provides a great versatility, stability and robustness moreover capturing transcritical sections and conserving mass.
Year: 2005