Analysis of slug tracking model for gas–liquid flows in a pipe

This work focuses on the physical representativeness of slug tracking models. The numerical analyses are supported by a detailed experimental campaign in a horizontal test section with 900 pipe diameters long. The analyses address: (a) the model’s performance in predicting averaged slug flow properties, (b) the bubble overtaking mechanism and the slug flow sensitivity to the wake function, (c) the slug flow sensitivity to the slug insertion process, (d) the capture of the slug’s evolution in flows with distinct slug formation processes and (e) the inclusion of the advection term and the induced slug oscillations. The work presents a compressible, one-dimensional slug tracking model satisfying the mass and momentum equations. The equations are presented in a unified fashion to handle horizontal and inclined gas–liquid flows. The model embodies all terms introduced by the previous models and includes the advection term, so far neglected. The analyses, despite of being supported by the present numerical model, are not constrained to this model, but apply to slug tracking models in general.