Mathematical and numerical investigation of experimental dam breaks in wet-bed channels due to partial sluice gate lifting

Dam failures may result in sudden and catastrophic floods, making the accurate prediction of dam-break wave dynamics crucial for effective flood risk management and disaster mitigation. Dam-breaks are complete if the dam is totally and suddenly removed, or partial if the breach is smaller than the dam. While the behaviour of dam-break waves following the complete structural failure has been extensively studied, research on partial dam break scenarios remains limited. A special partial dam break scenario, consisting of a breach opening at the dam bottom, can be modelled in laboratory experiments with the sudden partial lifting of a sluice gate. Until now, the mathematical and numerical modelling of this partial dam break has received only partial scrutiny, and it is still unclear if the solutions predicted by existing models are those effectively observed in real-world scenarios or laboratory experiments. This study addresses these gaps by confronting the results of the analytical and numerical models proposed by Cozzolino et al. (2023) with recent laboratory experimental data from the literature. The comparison reveals that the inviscid exact solution to the partial dam break problem can reliably predict the type, number, and height of the moving waves developed under both free and submerged flow conditions. The agreement with experimental data is enhanced when applying the numerical model by Cozzolino et al. (2023), owing to the inclusion of dissipative effects through the frictional term. These results advocate extending the existing flow gate equations, usually found in steady flow conditions, to the case of strong transients. The findings further corroborate the application of the Shallow water Equations to the simulation of strong transients in open channels, even in the presence of flow-structure interactions such as those involving sluice gates, bridges, and flood control barrages.