Analysis on Sensitivity of Parameters in Numerical Simulation of Dissolved Gas Supersaturated in Spillway Discharges

High concentration of total dissolved gas (TDG) in the tailrace of high dam may induce gas bubble disease to the fish for lethal effect. Thus, the distribution of the TDG concentration in the plunge pool and immediately in the downstream of dam becomes critical. In order to proves to be effective and convenient, but the determination of the model parameter relies on field observed data and the calibration of the parameter is time-consuming. In this paper, the predictive relationship of the parameter in the TDG transport equation with a source term is developed. Observed field data from six spillways in China were used to fit the source parameter that the predictive relationship needed. The inclusion in the predictive relationship will allow for the estimation of the source parameter representing the mass transfer between bubble/water interfaces and may give an insight into the mitigation of high TDG concentration downstream of spillways.