Finite Volume Method for Transient Pipe Flow with an Air Cushion Surge Chamber Considering Unsteady Friction and Experimental Validation

In various water transmission systems such as long-distance transfer projects and hydropower stations, accurate simulation of hammer is extremely important for safe stable operation the realization intelligent operations. Previous calculations usually consider only steady-state friction, underestimating decay transient pressure. A second-order Finite Volume Method (FVM) considering effect unsteady friction factor developed to simulate dynamic behavior air cushion surge chamber in a pipeline system, while an experimental pipe system conducted validate proposed numerical model. Two models, Brunone TVB were incorporated into equations, which are solved by MUSCL–Hancock method. One virtual boundary method was realize FVM Air Cushion Surge Chamber. Comparisons with results show that, steady model accurately predicts first pressure peak, it seriously underestimates attenuation later stages. Incorporating can better predict entire process; particular, more reproduces peaks whole oscillation periods. For chamber, energy elastic primarily due cushion. The demonstrate that polytropic exponent near 1.0 well reproduce oscillations.