Analysis of transient PIG motion in natural gas pipeline

In this study, the dynamic analysis of Pipeline Inspection Gauge (PIG) flow control in natural gas and liquid pipeline is considered. The basic equations are differential forms of the mass and linear momentum for compressible liquid and gas flows. The fluid flow equations and a linear momentum equation of the PIG are solved simultaneously using an appropriate numerical method. Solution of these nonlinear equations results in a set of diagrams for the variations of the fluid pressure, mass flow rate of the gas and the PIG velocity through the pipeline. Comparing the results of mathematical model for the PIG with the established experimental data in a segment of Ahwaz gas pipeline shows a good agreement between the measurements and computations.