Gas-liquid flow regime maps for horizontal pipelines: predicting flow regimes using dimensionless parameter groups

Flow regime maps are essential to gas-liquid flow applications in many industrial processes to accurately identify the flow regimes before estimating multiphase features. Flow regime classifications were originally based on visual observations of two-phase flow experiments. The observations were mapped on two-dimensional plots (called “flow regime maps”) and the boundaries between regimes determined. Over the years, different coordinates have been proposed for the maps (e.g., superficial velocities and momentum fluxes), in search for parameters that are independent of the given experimental set-up. This paper reports a study on developing new flow regime maps with a broader range of applications by using dimensionless parameter groups as the map coordinates. Various flow regime maps were developed with the use of different combinations of these parameter groups, then they were examined and assessed using datasets from published experimental research and the MultiFlowMet II project for validation. This initial feasibility study develops proof-of-concept flow regime maps that demonstrate the potential of dimensionless parameter groups to more accurately characterise multiphase flow in horizontal pipes, with the optimisation of these maps being considered in future works. The analysis revealed that combinations of the mixture Froude number (Frm) versus the ratio of gas superficial velocity to liquid superficial velocity (vSG/vSL), with the liquid phase Froude number (FrL) versus the gas phase Froude number (FrG) show potential for unambiguous identification and mapping of flow regimes, even for datasets with a wider range of operating conditions.