Pipeline start-up with entrapped air

A mathematical model for the assessment of the pressure head maxima that ai r pockets within a pipeline can originate on start-up is presented. This mo del is based on a general model addressing the filling of a pipeline with s everal air pockets published by the authors. Here the simulation of the ope ration of a discharge valve in order to control-the peak pressure following the pump start-up is included. Also, in order to correctly model reverse f low through the pump use is made of the dimensionless Suter curves. Water m ovement is modelled through rigid column theory and air - water straight cr oss section moving interfaces are considered. Because of the:huge pressure values that the very rapid compression of the air can cause, and in order t o avoid pipe breaks, practical engineers must lend great attention to this problem.