Application of computational fluid dynamics to evaluate hydraulic performance of spillways in australia

Abstract

In recent years, the design fl ood estimates of a number of dams in Australia have been revised, requiring their spillways to be upgraded to cope with increased fl ood discharges. Traditionally, reduced scale physical models were used in hydraulic laboratories to study spillway hydraulic performance. However, these are prone to problems associated with scaling effects, and cannot readily capture behaviours such as cavitation and air-entrainment effects, which can occur in reality. Nowadays, with the advancement in computing technology, the hydraulic performance of spillways can be investigated numerically. Since 2001, a number of spillway upgrade projects in Australia have been performed using computational fl uid dynamics. This paper provides an overview of how this technology was applied to these projects. The validation process to ensure the numerical model is reliable, and various analysis capabilities allowing better understanding of the fl ow behaviour will be described. Current limitations are also highlighted in order that future research and development can resolve them, thus making this numerical modelling technique more robust for fl ow simulation of not just spillways, but also other hydraulic structures in the future.