Comparison of theory and experiment in simulation of dam break in a rectangular channel with a sudden change in cross-sectional area

This paper, presents the results of comparison of theory and laboratory experiment for simulation of the wavy flows resulting from dam break on a sudden change in the rectangular cross-sectional area of a channel whose width is greater upstream than downstream. Exact self-similar solutions containing an heuristic parameter dependent on the total energy of the flow lost on the sudden change in cross-sectional area were obtained using the first approximation of the spatially one-dimensional theory of shallow water. It is shown that theoretical solutions agree quite well with the results laboratory experiments on the possible types of waves, the their propagation velocity, and asymptotic depth values behind their fronts.