A Simplified Approach for Predicting the Intermittent Behavior of Gas-Liquid Mixtures in Pipes

A new approach to the classical slug flow model is here proposed based on an original correlation for the minimum liquid level in the stratified regions of intermittent horizontal flows. This correlation is obtained by fitting experimental data obtained from a statistical analysis of void fraction signals from ring impedance probes. The new procedure improves the original model in terms of computing time reduction and algorithm simplification. In addition, it is demonstrated that the new closure relationship can be derived with more consistent experimental results, with respect to the slug length, which is employed in the original approach. The predictions of the main flow parameters are presented with reference to the classical and new approach, and all the results are critically compared with literature experimental data. It is demonstrated that the simplified procedure is able to predict the pressure drops and average void fraction values in good agreement with experimental measurements, while only the slug frequency and slug length predictions are affected by poor reliability.