SPILLWAY CHUTE AERATION.

Model and prototype measurements of aeration devices installed to prevent cavitation erosion in high velocity spillway flows have been published by various authors. However, the subpressure variation under the jet has often been neglected in the calculation of air entrainment because of the lack of an adequate theory. Especially for physical models, which can reproduce only part of the width of the prototype chute, this simplification can be misleading. Therefore the translation of model to prototype data has often been faulty. This article presents a theory about the subpressure variation and demonstrates the influence of the supply duct arrangement on air entrainment.