Author(s): Deyou Liu; Ling Zhou; Bryan Karney; Qinfen Zhang; Chuanqi Ou
Keywords: Air pocket; entrapped air; mathematical model; pipe system; pressure surge; transient flow
Abstract: Pressure transients in a rapidly-filling pipe with an entrapped air pocket are investigated analytically. A rigid-plug elastic-water model is developed by applying elastic-water hammer to the majority of the water columns while applying rigid-water analysis to a small portion near the air–water interface. The proposed model is validated by the full elastic-water model and experimental data. It effectively avoids the interpolation error of the method of characteristics reducing its complexity when tracking the air–water interface. Moreover, the current model has the same accuracy as the full elastic-water model.