Numerical Simulation Study On Water Flow Characteristics Of Different Aerators In Jingping-? Hydropower Project

Cavitation reduction is important aspect for the safe operation of the overflow dam and the tunnel spillway.In this paper,different numerical simulations on water flow characteristics using different aerators types in Jingping-1 hydropower projects have been performed.The study can be summarized into two parts.In first part of the study,the mathematical model of the cavitation reduction in the spillway was established by using the k-? turbulence model and combining the two phase flow interface tracking method i.e.Volume of Fluid(VOF)method.Four different simulations were done by introducing different aeration types in the tunnel spillway.The hydraulic features were studied performing four different numerical simulations i.e.without aerators,offset only,with aerators combining deflector and offset and combining the aerators with offset,deflector and groove.The hydraulic characteristics of the flows like surface water flows,pressures distributions,cavitation,aeration cavities and velocity profiles from different simulation were obtained.In second part of the study,comparative study and analysis of the results from different simulations with experimental results were done.The numerical simulation with the combination of aerators deflector and offset was found to be more reliable and effective than other aerators.There was no any chance of cavitation damages inside the spillway of aerator with deflector and offset as the least cavitation number was obtained more than 0.2 in all the section.The stable aeration cavity length without backwater effect was obtained.The mean flow velocity and bottom pressures inside the tunnel in different sections were near with that of experimental results.