Author(s): Joao Leal; Rui Ferreira; Antonio Cardoso
Keywords: 2D Dam-break waves; Mobile bed; Wave-front; Free-surface profile
Abstract: The propagation of 2D dam-break flows under dry mobile bed was investigated, experimentally and numerically. The experiments were made in a flume with a sudden enlargement. The bed was mobile in the upstream reach. Two types of sediments were used: sand and pumice. This allows for studying the effect of sediment mobility on dam-break flow propagation. The tests were recorded with video cameras and flow depths were evaluated at thirteen points using pressure transducers. A 2D conceptual model was developed. The model was based on Leal et al. (2003a) 1D conceptual model that incorporates two transport layers. The conservation equations are solved using a TVD version of MacCormack’s scheme. The computational domain was discretized with an equally sized square mesh. The numerical results show good agreement with the experimental ones. Some discrepancies were found in the wave-front location. The pumice bed test show higher flow depths and slower wave-front propagation than the sand bed test, indicating that the sediment mobility plays an important rule in the process.