Study on Wave Calculation of an Air Cushion Surge Chamber

To constant flow, the varying rule between gaseous volume and pressure meets Boyle Gas Law. But, in transient process of water diversion system, kinetic characteristic of the gas in air cushion surge chamber has certain complexity when there is great fluctuation in surge chamber. Therefore, when computing surge of air cushion surge chamber, firstly, it is necessary that gaseous volume and pressure meet actual rule and important to establish correct mathematic model. Secondly, initial height and pressure of the chamber should be confirmed correctly. Then the computing method of water level surge of air cushion surge chamber is acquired. The basic equations and boundary conditions of the surge chamber were established in this article. Parameters selection, structure design and surge calculation of the air cushion surge chamber were conducted. The effect of the initial air height and polytrophic exponent n in the chamber on the fluctuations of pressure and changes of water level is discussed. The results are quite important to fluid transient study of the air cushion surge chamber and may promote its use in water power plant.