Numerical Simulation of Pigging Operation in Gas Pipelines

The effect of an axisymmetric constriction is investigated numerically on the operation of an inspection pig taking into account the compressibility of the flowing gas and detailed frictional behavior of the cups of pig. It is shown that the steady-state results obtained using the method-of-characteristics are virtually the same as those obtained using a finitevolume commercial solver (namely, Fluent). At short times, however, their results are realized to be somewhat different. The results show that an anomaly can bring the pig to a complete stop followed by a successive slip-stick behavior which eventually dies down reestablishing the steady state value for the pig velocity provided the pipe is long enough

Keywords:

pig , method of characteristics , compressible natural gas flow , numerical analysis