Experimental Research On Unsteady Flow In The Pressure Diversion System Of Hydropower Station

Hydropower station with the pressure diversion system is one of the main arrangement type ofhydropower station. The pressure diversion system usually includes inlet tunnel, surge chamber and penstock etc.. Because of the changes of load on the power units in hydropower station, the flow in the pressure diversion system would change rapidly. The flow variations would generate unsteady flow in the pressure diversion system, the unsteady flow would generate serious effects on operation and safely of the hydropower station. So, the researchers and designers have paid a great attention to the research on the unsteady flow. There are two main methods at present to research the unsteady flow, they are theoretical method and experimental method.By using of experimental method this paper studies the unsteady flow of a hydropower station with the pressure diversion system.. The model can be designed according to the absolute normal model scale or the distorted model scale, in consideration of the conditions of the test site and water supply capacity etc., this experiment designs model in the light of the distorted model scale . The distorted model scale can satisfy the similarity conditions of surge equation and water hammer equation. Through the experimental research, the reasonable parameters of the surge chamber of the hydropower station are obtained. This paper also calculates the unsteady flow of the hydropower station's model by using of the characteristics method, the calculated result is extremely close to the experimental result. The result is useful for the design of the pressure diversion system , and other similar engineerings.