Comparison of 2D turbulence models for steady flows computation in a macro-rough channel

A 2D numerical flow model, developed at the Laboratory of Hydrology, Applied Hydrodynamics and Hydraulic Constructions (HACH) at ULg, has been applied to flows in a macro-rough channel using three different approaches to compute the turbulence effects. Both the first and second ones are based on algebraic expressions of the turbulent viscosity, and the third one uses a depth-integrated k- type model involving two additional partial differential equations. Data for the comparison have been provided by experiments conducted at the Laboratory of Hydraulic Constructions (LCH) at EPFL, showing different two-dimensional flow characteristics in varied configurations of large scale cavities in depressions at the side walls of the flume. Despite the strongly different modeling approaches used in the three models to handle the turbulence effects, the numerical models give generally similar and satisfactory agreement between experimental and numerical results regarding backwater curves.