ABSTRACT
The stability of structures can be endangered due to scour or geotechnical processes. Scouring occurs when the local flow velocity or turbulence characteristics exceed the critical values. Geotechnical instability is the result of various phenomena such as flow slides and shear slides and groundwater flow. In the early 1990s, a morphological model of the development of scour holes behind hydraulic structures was developed. Reynolds-Averaged Navier–Stokes models offer the most economic approach for computing complex turbulent flows. Direct Numerical Simulation (DNS) and Large-Eddy Simulation are alternative approaches for reproducing the turbulence in a better way. Typically, the flow in a scour hole is computed by using a turbulence model. LES is a mathematical model for turbulence used in computational fluid mechanics and is currently applied in a wide variety of engineering applications. DNS is a simulation in computational fluid dynamics in which the Navier–Stokes equations are numerically solved without any turbulence model.
