Description
The transition from a supercritical flow to a subcritical flow is called a hydraulic jump. A hydraulic jump is extremely turbulent. It is characterised by the development of large-scale turbulence, surface waves and spray, energy dissipation and air entrainment (Chanson 2004, Chanson and Brattberg 2000). The large-scale turbulence region is usually called the 'roller'. A hydraulic jump is a region of rapidly-varied flow.
The flow within a hydraulic jump is extremely complicated and it is not required usually to consider its fine details. To evaluate the basic flow properties and energy losses in such a region, the momentum principle is used (Chanson 2004).
The video shows a hydraulic jump in a 0.5 m wide channel located in the Gordon McKay Hydraulics Laboratory of the University of Queensland. The waters flow from left to right and the inflow Froude number is about 9 to 10.