Experimental and numerical investigation of the dam-break wave propagation over movable bed

In this study, a dam-break flood wave propagating in mobile bed and inclined channel conditions was investigated experimentally and numerically. The upstream section was arranged to consist of water, while the downstream section was consisted of sediment and the sudden dam-break was simulated by removing the plate representing the dam. The experiments were recorded on video and the experimental data were obtained by image processing. For numerical analyses, the open source DualSPHysics software, which uses the Smoothed Particle Hydrodynamics (SPH) method based on the Lagrangian approach, was used. The numerical and experimental data were examined in three groups as time dependent water surface level probe, time dependent point water-sediment interface level probe and water-sediment profiles. The numerical and experimental data were compared and interpreted using level-time curves. In the numerical model, three different distance of particles (dp) and five different cohesion (c) values were used to investigate the agreement with the experimental results. Time dependent water-sediment interface probe curves were analyzed in terms of mean absolute percentage error and an ideal c/dp ratio that will be valid within the limitations and conditions of the current study was obtained. The results showed that, the c/dp ratio is related to the complexity of the problem. It was determined that, continuously decreasing the dp value in the model was not the most accurate method, as there is an optimum dp value. It has been concluded that the sediment solution module of DualSPHysics, which is still under development, is generally successful. It was concluded that image processing can be used as a numerical data acquisition tool for determining some post-analysis outputs that the software does not provide by default.