Friction Effect on Supercritical Shallow-Water Flows in Straight-Wall Open-Channel Contraction.

In this study, a numerical simulation of supercritical shallow water flows in an open channel contraction is carried out via the two-dimensional depth-averaged shallow water equations. The effect of the friction models (Manning, Chezy, Prandtl, Manning for vertical channel sidewalls) is analyzed on the numerical results. The simulated water depth and velocity obtained by different friction models are compared with experience results. The simulations show that the use of the non-slip boundary conditions and the consideration of the friction effect on the walls do not change the structure and the amplitude of waves but have an important impact on the numerical outcomes mainly on the mean depth flow downstream of the channel. For the Froude number F=3.88, the use of the non-slip boundary conditions and the consideration of friction do not reproduce the transition from flow to the subcritical regime. [ABSTRACT FROM AUTHOR]