Author(s): Gabriel Echavez
Linked Author(s): Gabriel Echávez
Keywords: Cavitation Damages; Spillway; Aerator
Abstract: A limitation for the dams’ height, that in the 60's seemed insurmountable, was the cavitation damages in the spillways on the zones ofhigh velocity flow. With the aerators, that consist on a groove, ramp or step, perpendicular to the flow, that deflect the water from the floor and allows air suction, supplied by means of lateral chimneys; proposed and tested by the Italians and Soviets, first, and Venezuelans and Americans, later; was possible to inhibit these damages and to continue using high head spillways with water velocities greater than 30 m/s. In Mexico, in the 60’s, the first cavitation damages were presented in the 90 m height tunnel spillways of the "El Infiemillo" Dam, and they were so serious that to study this phenomenon to develop a method to predict its occurrence, and to control it - by means of one or several aerators designed and placed appropriately- became a high-priority issue. To get first hand information some dams with risk of cavitation damages were monitored during several years; specifically, “El Infiernillo” dam on the river Balsas and the “Manuel Moreno Torres” dam in Chicoasen, Chiapas gave valuable information. Other dams, that were exposed to this type of damages, such as: “General Ramon Corona” in Trigomil, Jalisco; “Aguamilpa” in the Santiago river; “Luis Donaldo Colosio” in Huites, Sinaloa; as well the hydroelectric projects “El Cajon” and “Parota”, actually in the first stages of construction and design, respectively; were protected with one or several aerators tested in model. In this work, damages by cavitation that were presented along several years in spillways without aerators are shown, and the observations of the operation of the aerators in other dams, their function as protection devices to avoid damages for cavitation, and two recommendations to locate the first aerator are presented.
Year: 2007