Numerical Investigation of Cavitation on Spillways. A Case Study: Aydoghmush dam

Cavitation is among the most complicated and common damages of spillway structures. This phenomenon is controlled by different parameters including the pressure, flow velocity, spillway surface material, operation time, and air flow content. The cavitation index is calculated along the spillway and compared with its critical value using the measured values of the flow’s hydraulic parameters. The high cost of experimental models for determining hydraulic parameters, the time required for developing experimental models, and the ever-increasing capabilities of computational fluid mechanics (CFD) models have led to the use of numerical simulation in the flow analyses. The present study employs ANSYS FLUENT to simulate the flow on the spillway of Aydoghmush Dam (Iran), calculate flow parameters, and determine the cavitation index at the flow rates of 35, 800, 1500, and 1850 m3/s. The standard k-ε equations were applied to model the turbulent flow, while the volume of fluid (VOF) method was employed to determine the flow’s free surface profile. The results showed acceptable consistency between the FLUENT and physical model results. It was also found that cavitation did not occur at any of the flow rates.