Design of hydraulic structures in supercritical regime with sediments: a mathematical criterion to calculate bottom roughness

Abstract

In some channels with high gradients, heavy scouring and erosion, as well as overflow, is highly common to occur, thus it is required a water flow velocities regulation. An option for achieving this, is to significantly increase the channels’ s bottom roughness through the installation of rapid hydraulic structures. However, in sedimentary density fluids, the change of velocity generates the deposition of solids which could be consolidated by changing the geometric design of these structures. This study aims to estimate the degree of confidence expected when modifications take place to artificial roughness geometries in the bottom of the channel with turbulent flow and sediment flow. This modification requires to transverse ribs into ramps using an experimental mathematical analysis. The study allows us to conclude that the newly generated bottom roughness causes more stable water flows, and it is a way to reduce flow velocities.