Mechanical behaviors of pipeline inspection gauge (pig) in launching process based on Coupled Eulerian-Lagrangian (CEL) method

Successful launching of the pig is the premise for ensuring the efficiency and accuracy of the pigging operation. This study investigates the effect of the flow field on pig launching by the three-dimensional (3D) fluid-structure interaction (FSI) model based on the Coupled Eulerian-Lagrangian (CEL) method for the first time. Besides, the flow field experiment and the dragging experiment are conducted to verify the reliability of the simulation results. Four parameters as friction force, mandrel flip angle, pig velocity, cup deformation are selected to describe the mechanical behaviors of the pig. Research results indicate that the flow field has a significant effect on contact behaviors between the pig and the pipeline in the pig running-in stage but less effect on that in the steady stage, which presents the necessity of the FSI simulation for investigating the pig launching process. • The Fluid-Structure Interaction (FSI) model was first adopted for simulating the pig launching process. • The comparison between the FSI model and the S–O model analyses were conducted for indicates the necessity of the FSI research. • Based on the FSI model, the mechanical behaviors of the pig during the launching process were analyzed.