Numerical modeling of transient flows in load pipes with complex geometry

Changes in the system flow of a fluid in a pipe often cause sudden pressure changes and give rise to so-called transient load flows. So, the study of the phenomenon of transient load flows aims to determine whether the pressure in the whole of a system is within the prescribed limits, following a perturbation of the flow. By defining the scope of a water hammer study, an examination is made of variations in velocity or flow and pressure resulting from poor operation of the hydraulic system, its normal operation and emergency operations. This paper introduces a numerical modeling of the phenomenon of transient flows in load pipes with variable geometries which presents a study of the average pressure and the average velocity of the transient flow in the pipe with quasi-steady term friction. The characteristic method is used to solve the governing equations of “Saint-Venant”. Thanks to the AFT Impulse industrial program, we have obtained very interesting and very practical numerical results to describe the phenomenon of transient flows in variable load pipes