Análise comparativa de correlações para a frequência do escoamento intermitente gás-líquido em tubulações

Abstract

Gas-liquid two-phase flows are found in several industrial processes and in nature, which in turn can be classified into three main patterns: dispersed, separated and intermittent. Intermittent flow is characterized as a combination of a separate flow region, elongate gas bubble in parallel with a liquid film, and a dispersed flow region, an aerated liquid piston, thereby constituting a unitary cell, which flows along the liquid flow path with a certain frequency. This frequency is considered a fundamental characteristic of this flow type. Thus, in the present work, it is proposed to carry out a study concerning the models (correlations) available in the literature to estimate the intermittent flow frequency. The frequency correlations analyzed in this study are calculated and compared against experimental data also available in the literature for horizontal, inclined and vertical pipes, in order to verify which are more accurate, as well as their limitations for each application. The results obtained in this analysis showed that although some frequency correlations have satisfactory results, it is not yet possible to apply them comprehensively, taking into account the different experimental configurations that may occur, such as variations in pipe diameters and inclinations as well as fluid properties.