Delay detached eddy simulation of hydraulic characteristics after a new sudden lateral enlargement and vertical drop at the end of reversion curve of a spillway

The numerical simulation of hydraulic characteristics is crried out with delay detached eddy simulation (DDES) model and VOF method. The simulation results agree well with experimental date. The flow condition is smooth, the length of lateral cavity gradually increases with the size of lateral enlargement increases, only small water-wing emerges after the lateral cavity and the backwater do not appear in bottom cavity. The research results can provide the reference for design and scientific research.