KSME International Journal

, Volume 15, Issue 9, pp 1302–1310 | Cite as

Modeling and simulation for PIG with bypass flow control in natural gas pipeline

  • Tan Tien Nguyen
  • Sang Bong Kim
  • Hui Ryong Yoo
  • Yong Woo Rho
Thermal Engineering · Fluid Engineering · Energy and Power Engineering


This paper introduces modeling and simulation results for pipeline inspection gauge (PIG) with bypass flow control in natural gas pipeline. The dynamic behaviour of the PIG depends on the different pressure across its body and the bypass flow through it. The system dynamics includes: dynamics of driving gas flow behind the PIG, dynamics of expelled gas in front of the PIG, dynamics of bypass flow, and dynamics of the PIG. The bypass flow across the PIG is treated as incompressible flow with the assumption of its Mach number smaller than 0.45. The governing nonlinear hyperbolic partial differential equations for unsteady gas flows are solved by method of characteristics (MOC) with the regular rectangular grid under appropriate initial and boundary conditions. The Runge-Kuta method is used for solving the steady flow equations to get initial flow values and the dynamic equation of the PIG. The sampling time and distance are chosen under Courant-Friedrich-Lewy (CFL) restriction. The simulation is performed with a pipeline segment in the Korea Gas Corporation (KOGAS) low pressure system, Ueijungboo-Sangye line. Simulation results show us that the derived mathematical model and the proposed computational scheme are effective for estimating the position and velocity of the PIG with bypass flow under given operational conditions of pipeline.

Key Words

Pipeline Inspection Gauge (PIG) Method Of Characteristics (MOC) Bypass Flow 



Pipe cross section [m2]


Wave speed [m/s]


Linear damping coefficient of the PIG [Ns/m]


Convection heat transfer coefficient [W/m2K]


Internal diameter of pipe [m]


Bypass valve diameter [m]


Braking force [N]


Friction force per unit pipe length [N/m]


Friction force between the PIG and pipeline’s wall including [N]


Static friction force


Dynamic friction force


The PIG driving force [N]


The opening height of valve [m]


Pipe wall roughness [m]


Wear factor per distance travel [N/m]


Sudden constraction loss coefficient


Sudden expansion loss coefficient


Total loss coefficient


Length of the PIG [m]


Hydraulic mean radius of pipe [m]


Weight of the PIG [kg]


Flow pressure [N/m2]


Compound rate of heat inflow per unit area of pipe wall [W/m2]


Perimeter of pipe [m]


Flow temperature [K]


Seabed temperature [K]


Flow velocity [m/s]


Flow velocity through valve [m/s]


Velocity of the PIG [m/s]


Distance from pipe inlet [m]


Position of the PIG [m]


Denote flow parameter values



The ratio of specific heat


Kinetic viscosity of flow [m2/s]


Flow density [kg/m3]


L, R, M, N, S, O, P

Denote the grid points, and

0, l

Denote the points at inlet and outlet of pipeline


Unable to display preview. Download preview PDF.

Unable to display preview. Download preview PDF.


  1. Azevedo, L. F. A., Braga, A. M. B., Nieckele, A. O., Naccache, M. F. and Gomes, M. G. F. M., 1996, “Simple Hydrodynamic Models for the Prediction of Pig Motions in Pipelines,” inProceedings of the 1996 Offshore Technology Conference, TX., USA, pp. 729–739.Google Scholar
  2. Cordell, Jim and Vanzant, Hershel, 1999, “All About Pigging,” On-Stream Systems Limited and Hershel Vanzant & Associates.Google Scholar
  3. Fox, J. A., 1977,Hydraulic Analysis of Unsteady Flow in Pipe Networks, John Wiley & Sons Pub.Google Scholar
  4. Korea Gas Corporation, 2000, “The First Stage of Development of Intelligent PIG for Low Pressure Pipeline.”Google Scholar
  5. Lima, P. C. R., Petrobas, S. A., and Yeoung, H., 1999, “Modeling of Pigging Operations,” inProceedings of SPE Annual Technical Conference and Exhibition, pp. 563–578, TX., USA.Google Scholar
  6. Nguyen, T. T., Yoo, H. R., Rho, Y. W., and Kim, S. B., 2000, “Modelling and Simulation for PIG Flow Control in Natural Gas Pipeline,” inProceedings of the 15th Korea Automatic Control Conference, pp. 448–451, Yong-in, Korea.Google Scholar
  7. Nguyen, T. T., Yoo, H. R., Rho, Y. W., and Kim, S. B., 2001, “Modelling and Simulation for PIG Flow Control in Natural Gas Pipeline,”KSME International Journal, Vol. 15, No. 8, pp. 1165–1173.Google Scholar
  8. Out, J. M. M., 1993, “On the Dynamics of Pigslug Trains in Gas Pipeline,” OMAE, Vol. V,Pipeline Technology, ASME, pp. 395–403.Google Scholar
  9. Sim, W. G. and Park, J. H., 1997, “Transient Analysis for Compressible Fluid Flow in Transmission Line by the Method Of Characteristics,”KSME International Journal, Vol. 11. No. 2, pp. 173–185.Google Scholar
  10. Smith, G. L., 1992, “Pigging Velocities and the Variable-Speed PIG,”Proceedings of Pipeline Pigging and Integrity Monitoring Conference, Amsterdam, Netherlands, 28th September-2nd.Google Scholar
  11. Tannehill, John C., Anderson, Dale A. and Pletcher, Richard H., 1997, “Computational Fluid Mechanics and Heat Transfer,” Taylor & Francis Pub.Google Scholar
  12. White, Frank M., 1999,Fluid Mechanics, McGraw-Hill Pub.Google Scholar
  13. Willson, D. J. and Yokota, J. W., 1994, “Speed Control Research and Development,” Nowsco Pipeline Service.Google Scholar
  14. Wylie, E. Benjamin, Streeter, Victor L. and Suo, Lisheng 1993,Fluid Transients in Systems, Prentice-Hall, Inc.Google Scholar

Copyright information

© The Korean Society of Mechanical Engineers (KSME) 2001

Authors and Affiliations

  • Tan Tien Nguyen
    • 1
  • Sang Bong Kim
    • 1
  • Hui Ryong Yoo
    • 2
  • Yong Woo Rho
    • 2
  1. 1.Department of Mechanical Engineering, College of EngineeringPukyong National UniversityPusanKorea
  2. 2.Korea Gas Corporation (KOGAS)Kyunggi-doKorea

Personalised recommendations