Numerical simulation of flow on circular crested stepped spillway

Abstract The spillways are one of the most important hydraulic structures used in river engineering, dam construction, irrigation, and drainage engineering projects. Recently, a new type such with circular crest has been proposed. In this paper, properties crested stepped spillway (CCSS) including flow pattern, distribution velocity on pressure, turbulence intensity, discharge coefficient ( $${C}_{d}$$ C d ) energy dissipation ratio (EDR) were investigated numerically. To model free surface volume fluid technique, for modeling flow, k ? ? (RNG) was utilized. Results declared that there is good agreement between laboratory observations numerical simulation. CCSS changes 0.9 1.4 considering range relative upstream head $${h}_{up}/R$$ h up / R 0.33 m 2.67. observation streamlines showed they tangential to curvature no separation from crest. Examination pressure shows just downstream part crest, partially negative. Of course, same partial negative observed edge steps. steps increase maximum intensity by 50%. can dissipate 90 30%, skimming regime, portion each step regardless their position almost identical.