School of Engineering, The University of Queensland
Abstract
Pigs are utilized in pipelines to perform operations such as dewatering, cleaning and internal inspection for damages. Transient motion of pigs through gas pipelines has been simulated numerically in order to help engineers predict the variables related to pig motion such as estimating its speed, required driving pressure, and the amount of fluid bypass through the pig. In this paper, the continuity and linear momentum equations for compressible gas flows were discretized by finite difference method based on moving and staggered grids. These equations were solved together with dynamic equation for pig movement and the equation for modelling bypass flow. Besides, gas was considered both ideal and real. Test cases representing typical pigging operations in pipelines with or without flanges and branches were studied using the numerical model developed. The fluid flow and pig behaviour predicted by the model have a reasonable behaviour
