Pressure distributions of stepped spillways with different horizontal face angles

Abstract

Stepped spillways are commonly used in hydropower engineering, landscape irrigation and aeration tanks due to their high energy dissipation and superior aeration. This study used the k–ε turbulence model to study the pressure distributions of three types of stepped spillways with different horizontal face angles in fully developed skimming-flow regions. The horizontal surfaces of V-shaped steps exhibited a pressure peak that decreased from both sidewalls to the axial plane, while those of inverted V-shaped steps exhibited the opposite pattern. There was barely any variation from those of traditional stepped spillways. Negative pressures on the vertical surfaces of V-shaped, inverted V-shaped and traditional stepped spillways occurred near the sidewalls, near the axial plane and along the entire cross-section, respectively. For all the stepped spillways studied, the minimum pressure decreased with increasing Froude number and increasing absolute values of the horizontal face angles.