ABSTRACT
In the course of the discharge process of Gezhou Dam, high dissolved concentration of gas in the downstream river that can be detrimental to fish. In order to study the influencing factors of the supersaturated gas in the discharge process of Gezhou Dam and provide guidance for reducing the concentration of saturated gas. An investigation of the total dissolved gas (TDG) exchange at Grand Coulee Dam was conducted to simulate the exchange process of TDG using an unsteady three-dimensional (3D) two-phase flow computational fluid dynamics (CFD) model under different conditions such as different water level, discharge flow, discharge patterns and forebay concentration of Grand Coulee Dam. The data obtained by the simulation were compared with the field data, the comparison found that the relative error was less than 4%, indicating that the model had high reliability. On this basis, the discharging data of the typical year of Gezhou Dam were collected, and the saturated gas concentration corresponding to the four classic discharging modes in the downstream of Gezhou Dam was simulated by fitting the observation data and introducing the flow weighting formula and the three-dimensional mathematical model. And through the fitting of the simulation results, the empirical formula of saturated gas pressure under these four discharging modes was obtained, which could provide references for future engineering scheduling optimization.
