Abstract: Slit-type energy dissipator is widely used in hydraulic projects of high water head, large discharge, and narrow river valley due to its simple structure and high efficiency. The water wing caused by shock waves in the contracted section of slit-type energy dissipator may bring about harmful effects, which, however, has not received sufficient attention. In this article, the hydraulic characteristics of slit-type energy dissipator are investigated by means of physical model and theoretical analysis to reveal the internal relation between shock waves and water wings. A correction coefficient is introduced for the application of Ippen’s theory to slit-type energy dissipator. The expression of the coefficient is obtained, and simplified formulas for shock wave angle and water wing scope are theoretically derived, which was verified accurate by experimental data, with the relative error within 5%.

Key words: slit-type energy dissipator, shock wave of flow, water wing, motion characteristics, hydraulic modelling