ROUGHNESS ELEMENTS AS ENERGY DISSIPATORS OF FREE-SURFACE FLOW IN CIRCULAR PIPES

The report describes experiments on peripheral rings used in smooth, circular pipes, as roughness elements to reduce the velocity of flow. The studies pertain only to culverts flowing under inlet control on steep slopes, that is, pipes functioning as open channels with supercritical flow. Model tests were made to investigate the feasibility of roughness elements as energy dissipators to reduce the kinetic energy of high-velocity, free-surface flows in pipes.