The water flow characteristics over an interval-pooled stepped spillway are investigated by combining the renormalization group (RNG) k-ε turbulence model with the volume of fluid (VOF) interface capture technique in the present study. The results show that the energy dissipation performance of the interval-pooled stepped spillway was generally better than that of the pooled, stepped spillways and the traditional flat-panel stepped spillway. The omega vortex intensity identification method is introduced to evaluate the energy dissipation. Due to the formation of "pseudo-weir", the energy dissipation did not increase with the growth of the pool's height. In addition, the average vortex intensity can characterize the dissipation rate to some extent.
Keywords: energy dissipation; interval-pooled stepped spillway; numerical simulation; omega identification method.