Investigation of local scour occured at downstream of the chute channels of spillways

High-speed flows occurring over spillways of dams cause the risk of cavitation along the chute. In many dams, it is necessary to create an additional structure to solve the cavitation problem. The energy at the downstream of the chute dissipates by using stilling basins or flip bucked. If the residual energy at downstream of the chute is excessive, the local scour may be occuring at the stream bed. These local scours have a great danger for dams and their additional structures. Cost of spillway and stilling basin structures arequite high. Therefore, it is very important to prevent these structures from being damaged. In this thesis study, a series of experiments were conducted to estimate the effects of spillway aerators to the scour depth occured downstream of the chute. Atall experiments, three different chute slopes were used. In the experiments, two different types of aerators were taken into consideration. The aerators were used in three different configurations as single, double, and triple. The experiments were made for 30, 40, and 50 chute slopes. In experiments the scouring topographies at the end of the chute and the locations and values of the maximum scour depth were obtained. The findings were discussedand interpreted in detail.