Supercritical flow over a sill in an open channel

Experimental data on typical profiles of free surface and channel bottom pressure for a supercritical flow over a sill are reported. This flow is shown to have, along with the known critical depth, two other characteristic depths, one of which is at the channel exit to the atmosphere and the other determines conditions under which the disturbances propagate well upstream of the sill. The experimental data are compared with calculation results based on a mathematical model that incorporates turbulent mixing upon wave breaking.