Experience in developing methods for preventing cavitation in excess flow release structures

Conclusions

• 1. Selection of the method of preventing cavitation erosion in excess flow control structures or their individual elements should be made with consideration of the topographical, geological, and hydrological conditions and purpose of the hydrostation on the basis of a technicoeconomic comparison of variants. It is necessary to take into account not only the effect of the spillway on adjacent structures and the environment but also factors acting in the reverse.

• 2. The concrete surfaces of excess-flow structures exposed to a high-velocity flow should be made in conformity with recommendations in Table 1 for heads up to 50–60 m. For higher heads it is recommended to use other methods of protection from cavitation erosion.

• 3. It is expedient to develop effective protective polymer compositions to increase their reliability, durability, and technological effectiveness.

• 4. Aeration of the descending flow economically prevents cavitation erosion on surface asperities and on elements of excess flow structures. The given types of aerators and air-conducting systems can be used effectively on overflow spillways, tunnel spillways, and dewatering outlets.