Experimental Result of Flow Energy Dissipation on Smooth and Stepped Spillway with and no-Piers

The present work is related with the experimental results obtained on an ogee-crest spillway with smooth and stepped bottom, in order to evaluate the energy dissipation for a discharge range between 20 and 180 l/s. For testing, two classical WES- Creager spillway of 1-m width, 0.57-m high were built. Spillway-1 had a smooth profile and spillway-2 a stepped profile. Spillway-1 and 2 were tested with and no-piers. Besides, flaring gate piers with b/B=0.5 ratio was tested for spillway-1 as well. The results showed that for spillway-1 with no-pier, the energy dissipated decreased from 42.9% to 22% and with piers from 71% to 16%, and from 78% to 24% for flaring gate piers. For spillway-2 with no-piers the energy dissipated decreased from 94.7% to 68.7% and with piers from 94.4% to 72.5%. Therefore the highest rates of flow energy dissipation were obtained for spillway-2 with stepped bottom with and no-piers.