Numerical Analysis and Structural Optimization of a Jet Pig Using a Rifling Structure

Since pigging technology is commonly used to reduce blockage or clogging during the pipeline transportation process, jet pig optimization is essential. This paper proposed a method for incorporating a rifling structure into the inner jet hole wall of a jet pig. Two types of jet pigs with differing jet hole configurations were created using modeling software, one with rifling and one without. The computational fluid dynamics (CFD) method was utilized for the analysis of the flow distribution changes in crude oil pipeline pigs. The contour maps and change curves of the fluid velocity, pressure, and turbulent kinetic energy (TKE) of the two types of pigs were obtained at different bypass fractions and inlet flow velocities. The results demonstrate that a constant inlet fluid velocity and a higher bypass fraction decrease the flow velocity and TKE of the pigs of two types, while the differential pressure values across the pigs decline gradually. The flow velocity, pressure difference, and TKE of the rifling pig exceed those of the nonrifling pig. When the bypass fraction is set at 3%, the rifling pig demonstrates about a 3.4% increase in exit flow velocity compared to its nonrifling pig, while the TKE at the outlet increases by over 13.5%. This indicates that using a rifling structure on the inner jet hole wall of the jet pig improves its dispersal ability.