Intermittent two phase flow in horizontal pipes: Predictive models

TLDR: In this paper, a semi-mechanistic model for two phase gas-liquid slug flow was proposed and extended to apply to the entire intermittent flow regime, which requires the use of empirical correlations for the slug velocity and the in situ liquid volume fraction in the slug.

Abstract: A semi-mechanistic model for two phase gas-liquid slug flow proposed recently by Dukler and Hubbard has been modified and extended to apply to the entire intermittent flow regime. Flow predictions of the model proposed in this paper are compared with detailed experimental data recently obtained for an air-oil system. The model requires the use of empirical correlations for the slug velocity and the in situ liquid volume fraction in the slug. In addition, either the slug frequencies or length corresponding to the given design conditions must be known. However, calculated values of average pressure gradient and in situ liquid volume fraction are relatively insensitive to these latter parameters, and in fact, good results are obtained assuming a constant slug length. The paper includes a discussion of the limitations of the proposed model and the expected direction of further study required to extend its mechanistic aspects.