Numerical modelling of column separation with large pressure pulses

Abstract

Liquid transients involving column separation occur in pipelines when the pressure drops to the vapor pressure of the liquid. The collapse of vapor cavities may result in short duration pressure pulses superimposed on water hammer waves, that exceed the Joukowsky or instantaneous valve closure pressure rise. This paper presents the analytical development of an improved mathematical model for describing column separation in pipelines. The model treats distributed vaporous cavitation regions and localized vapor cavities including intermediate cavities. The results from the numerical model are compared with some experimental results for a reservoir-pipeline-valve system.