A Lagrangian wave characteristic method for simulating transient water column separation

Abstract

Transient water column separation can create serious consequences for pipeline systems if not properly recognized and addressed by analysis and operational and design modifications (mostly involving the placement of surge‐protection devices). Therefore it is necessary to determine the likelihood of water column separation, evaluate its severity, and estimate its potential effect on the system. This article describes a rigorous Lagrangian method that implements the numerical discrete vapor cavity model for use in simulating transient water column separation in water distribution systems. As the numerical examples considered here demonstrate, results of the proposed method compared closely with the traditional Eulerianbased implementation approach. The method described is both robust and straightforward and will greatly improve the reliability and efficacy of Lagrangian‐based network transient analysis models and the ability of engineers to more accurately predict system transients and properly select and design surge‐protection devices for maximum system protection and safeguarding of public health.