Author(s): J Pekolj; A Bergant; M Perpar; U Ješe

Linked Author(s):

Keywords: Trapped air pockets; Hydraulic pipeline systems; Transient response; Method of characteristics

Abstract: During the operation of water-filled pipelines, air can get trapped in the primary water flow in the form of air trapped pockets or moving bubbles. Consequently, entrained air may change the liquid-filled-pipeline system’s transient response significantly. It could have either a beneficial or a detrimental effect on pressure oscillations. The effect is dependent on the spatial dimensions and other physical properties of the pipeline system, the amount, the location of the air pocket(s), and the nature of the transient excitation. This paper provides an overview of modeling the rigid and elastic water columns in a hydraulic pipeline system with an entrapped air pocket. It presents one-dimensional analytical and numerical solutions for the transient filling of the pipeline system, with the numerical model based on the method of characteristics (MOC). The research aims to analyse the effects of water column elasticity under varying system parameters. Simulation results indicate that higher air pocket pressures are achieved in the rigid column model and that the effects of water column elasticity are most pronounced with a small air length ratio and a high initial pressure difference between the reservoir and the air pocket.

DOI: https://doi.org/10.1088/1755-1315/1483/1/012018

Year: 2023