Energy dissipation of hydraulic jump in gradually expanding channel after free overfall

This study derived equations for examining the energy dissipation characteristics of a hydraulic jump after free overfall. Comparison of energy dissipation characteristics was further made between hydraulic flows occurring in a prismatic channel of constant cross-sectional width and that in an expanding channel with gradual increase in width along the length. Results calculated using the derived equations show that the conjugate depth ratio relative energy loss and energy dissipation efficiency ( ) are not only influenced by the pre-jump Froude number and the relative height of the weir but also by pre- and post-jump cross-sectional width ratio. In addition, energy dissipation of hydraulic jump after free overfall is greater in an expanding channel than in a prismatic channel. Hence, future design of stilling basins should consider having a gradually expanding channel so as to achieve lower level of tailwater.