Numerical modeling of dam-break flood flows for dry and wet sloped beds

Abstract

Investigation of the effects of sloping dry and wet immobile beds on downstream dam-break flows is of great importance given the destructive power of these flows. Such investigation can lead to the adoption of appropriate measures and timely control strategies. In this study, numerical simulations of experimental wave propagation were carried out using four models, i.e., k-ω-SST-RANS, realizable k-ε-RANS, Smagorinsky-LES, and k-ω-SST-DES on sloped beds, for the first time as its novelty, with respect to upstream water and different downstream tail-water depths. The k-ω-SST-DES exhibited the best performance in the simulation of wave peak patterns and mean velocities. Taylor diagrams showed that all models were similar in estimating the highest R values and lowest centered root-mean-square errors for dry beds. However, for wet beds with higher downstream tail-water depths, the CRMSE were higher. For lower depths, the standard deviations of the models were generally closer to those of the flume experimental measurements conducted by Liu et al. (2020). The present study has shed light on the levels of turbulence models’ accuracy in simulation of dam-break flows on dry and wet sloping beds, and can be taken as a basis for further understanding of the flood flow behavior in future studies.