Empirical Modelization of Intermittent Gas/Liquid Flow Hydrodynamic Parameters: The Importance of Distinguishing between Plug and Slug Flows

Abstract

Summary Intermittent flow is one of the most complex flow regimes in horizontal pipes. Various studies have classified this regime as two distinct subregimes: plug and slug flow. This classification has been made based on flow observations. In this work, the behavior of several flow parameters that characterize plug and slug flow are presented. Data from eight published works in the open literature were collected and studied to explain the behavior of both regimes. These data include pressure drop, void fraction, and slug frequency, as well as the lengths of liquid slugs and elongated bubbles for slug and plug regimes. It is observed from the evolution and analysis of these parameters that plug and slug flows have several different distinct features and should be considered as two separate regimes for the empirical modelization of the hydrodynamic parameters. The mixture Froude number, and to a lesser extent the liquid superficial velocity to gas superficial velocity ratio, seem to have significant impacts on the plug-to-slug flow transition.

Identifying the intermittent flow sub-regimes using pressure drop time series fluctuations

“…The interesting results observed with the two feature spaces indicate that the mixture Froude number and the gas-to-liquid super cial velocities ratio play a role on the plug-to-LAS ows and LAS-to-HAS ows transitions. Arabi et al (2021a) have highlighted the in uence of these two dimensionless number on the transition from plug to slug ow.…”

Analysis of Horizontal Gas-liquid Intermittent Flow Sub-Regimes Transitions: Physical Mechanisms and Flow Maps

“…This flow regime induces large variations in mass flow rate, pressure, and velocity in both radial and axial directions being inherently unsteady (Ramos et al, 2020). This behavior induces severe consequences for industrial installations as the flow-accelerated corrosion, liquid impact-induced erosion, flow-induced vibration (Arabi et al, 2021a). In addition, the chaotic nature of the intermittent flow, makes the understanding of this flow pattern complicated, and hence to model it.…”