Effective roughness on horizontal rectangular stilling basins

Abstract

Under different flow conditions, hydraulic jump characteristics were investigated experimentally on an artificially roughened bed. Experiments were conducted on horizontal rectangular channel bed using wooden roughness blocks (1.2×1.2×3.0 cm) over fixed length with density ranging from 0 to 20%. The main objectives of this paper are to understand the behavior of such phenomenon when roughness density changed and to obtain the most effective percentage which will give the optimal length of basin from both hydraulic and economic point of view. The analysis and discussion of the present study showed that 12% roughness density provides the optimal length of basin for the flow conditions and roughness arrangement under consideration. Also, empirical formulae were fitted to the experimental data showing good agreement.