An investigation of highly pressurized transient fluid flow in pipelines

This paper discusses transient processes in natural gas pipelines. The method of characteristics (MOC) is applied for the analysis of two transient categories, where the governing one-dimensional, hyperbolic conservation equations are linearized and solved without neglecting any of their term. First, we present a parametric study of the pressurized flow encountered when pipelines are utilized for the transportation or the temporary storage of natural gas. The non-ideal compressibility of natural gas is included in the model and its impact on the thermo-hydraulic processes is elucidated. Second, we model the hydrodynamics of a pipeline whose downstream boundary is a periodic discharge rate. The results show that, in response to these boundary conditions, the pressure distribution in the pipeline also undergoes periodic variations. Furthermore, our simulation results confirm the usefulness of MOC for numerical simulation of flow phenomena in pipelines. - Highlights: ► The goal of this work was an investigation of high pressure fluid transients through long pipelines. ► The MOC method was used for the simulation of the hydrodynamic processes in response to transients. ► The first transient type represented the line packing and subsequent pressurization. ► Special attention was given to the effect of non-ideal compressibility of natural gas flow. ► The second type of transients dealt with the effect of periodic downstream boundary conditions.