Numerical Simulation With Sloping Ceiling Tail Water Tunnels For Right Bank Underground Hydropower Station Of The Three Gorges Project

In recent years, numerical simulation for hydraulic transient process has been a kind of powerful tool in the design of hydraulic and hydropower engineering. It has been applied in hydrodynamics analysis, computing of optimizing parameter and forecasting energy loss and so on for hydropower stations. Consequently a number of model experimentation can be replaced and time, manpower and material resources can be saved.The tail tunnels with sloping ceiling is a new bodily form of pipeline for hydro-power stations. In the specific conditions, it can replace the surge tank of tailrace tunnel .It is applicable specially, if the water lever fluctuates greatly in lower reaches of a river and the length of tailrace tunnel system is between 150m and 600m. Thereby we can save a great deal of engineering quantity and improve the rate of building progress. But, there is the mixed free-surface-pressure flow in the tail tunnels with sloping ceiling and big pressure in the hydraulic transient process. It is bad to hydropower stations of its safe and steady function.To all project practicality, the introduction is given to the operational characteristics, the methods for calculation and the researching actuality of the tail tunnels with sloping ceiling underground hydropower stations the Three Gorges. This paper has discussed in detail the characteristic method being the same with the compressive flow and the Priessmann solution being the same with the free-surface-pressure flow. And how to deal with boundary conditions has been expatiated. Also hydraulic transient process of tremendous load fluctuation in the tail tunnels with sloping ceiling has been numerical simulated and the Fortran program for numerical simulation has been given. The paper gain the maximal press for tail end of the shell, the maximal rising rate of rotational speed of generating set, the maximal vacuum degree for inlet of the tail tunnels and so on under 11 kinds conditions of tremendous load fluctuation. These conditions include the design conditions, the check conditions and the superposition conditions. Finally, the computing results have been analyzed and summarized. The end chapter is the general comment of thewhole-length content and the describing of the intending view of researching.