Investigation of pressure variations over stepped spillways using smooth particle hydrodynamics

• We examine skimming flow over moderately sloped, stepped spillways.
• We report numerical simulations made using smoothed particle hydrodynamics methods.
• Good agreement is obtained against published laboratory experiments.
• We find negative pressures on the vertical step faces near the inception point.
• Suggesting that cavitation can occur on stepped spillways in the absence of aeration.

In this paper the smoothed particle hydrodynamics, (SPH), technique is used to investigate the pressure distribution on steps located in the non-aerated flow region of a stepped spillway for different discharges typical of skimming flow conditions. The open source code 2D SPHysics has been employed after being validated against the laboratory model studies of flow over broad crested weirs and flow over stepped spillways. The numerical results, in terms of the water surface and velocity profiles at different sections, are in good agreement with the corresponding experimental results. The code is then applied to determine the pressure distribution on the vertical and horizontal step faces. Also, the aspects of the pressure pattern are described and the positions/magnitudes of the maximum and minimum pressure values are presented.