Numerical simulations in hydraulic engineering

The main focus of the chapter is to present various case studies, showing the link between Computational Fluid Dynamics (CFD) and traditional scale model tests in the laboratory. The goal is to illustrate the possibilities and limitations when coupling these two different methods in the context of hydraulic engineering applications. The topics range from hydraulic investigations where numerical simulations are a vital tool for model validation (optimisation and quantification of local head losses, the capacity of a spillway and as a third example impulse waves caused by an avalanche), to modelling of debris flow and log jam processes, including bed load transport issues. The use of such hybrid approaches can contribute to cost-saving and realisation of more complex investigations in shorter time.