A one -dimensional numerical simulation of dam break flows

No Thumbnail Available
Journal Title
Journal ISSN
Volume Title
University of Dar es Salaam
The unsteady flow, produced by a dam breaking across its entire length, is modelled as one-dimensional flows. Such flows are described by a set of quasi-linear, hyperbolic partial differential equations, called the Saint-Venant equations. In this research work the movement of flood waves resulting from a dam break and sudden closure of a gate was investigated based on one-dimensional numerical solution of Saint-Venant equations. Two explicit finite difference numerical schemes with second order accuracy were selected to solve the governing equations written in two different forms. In the first case the MacCormack numerical scheme was employed to solve the system of flow equations written in a conservation form. The actual upstream and downstream boundary conditions of the flow field, i.e., a depth of flow equal to zero at these boundaries and beyond were used for the solution of the flow equations. In the second case the governing equations were arranged in a non-conservative form, known as the characteristic form and compared for the analysis of unsteady free-surface flows. The problem was simulated to an instantaneous closure of a gate in a rectangular channel. The Lambda numerical scheme was used to split the flux vector into positive and negative parts, each of which corresponds to the direction of characteristic, thereby allowing use of proper finite differences for the space derivatives. The depth of flow at the upstream boundary was specified, resembling a constant head reservoir. In both cases the numerical solutions obtained were compared with the experimental data and the analytical solution was found to be satisfactory.
Available in print form
Hydraulic measurements, Hydraulic dynamics
Mohamed, H.G (1994) A one -dimensional numerical simulation of dam break flows, Masters dissertation, University of Dar es Salaam. Available at (