Author(s): Wu Jianhua; Ruan Shiping
Linked Author(s): Jianhua Wu
Keywords: Cavity length; Estimation; Aerator; Cavitation
Abstract: It is proved that entrained air is a kind of effective measures for cavitation control for release works of hydropower projects. There are many factors to be considered in designing aerators. One of the most important factors concerns the cavity length behind aerators, which is closely related to the effects of entrained air. It is crucial to determine reasonable real angle Θ for estimation of cavity length. In the present paper the effects of structural and hydraulic parameters, including θ, α1, α2, tr, V0, h and u’, on real angle Θ were analyzed. Four improved expressions presented of real angle Θ with weight w were compared on the basis of error theory. A set of method to estimate cavity length behind aerators was suggested considering comprehensive effects of flow depth h and fluctuating velocity u’. The comparisons of several methods of estimating cavity length showed that the present method is much more reasonable as far as the current methods are concerned, and the mean error of the method is less than 10% .