Applicability of horizontal and vertical-downward correlations for two-phase flow in a 90° elbow
Abstract – Two-phase flow is the interactive flow between two phases simultaneously through a channel. In order to predict numerous hydrodynamic parameters of two-phase flow, drift-flux correlations were developed. However, these correlations are only suited for one-directional two-phase flow: either vertically, horizontally, or at an angle. Therefore, this study utilizes current one-directional drift-flux correlations along with data collected from two-phase flow through a 90-degree elbow. By comparing empirical data with predicted data from the correlations, the applicability of two current drift-flux correlations in two-phase flow through a 90-degree elbow was analyzed. Results showed that the correlation by Rassame and Hibiki (2018) shows decent overall predictability (overall 28.74% error), but seems to be inconsistent for bubbly, elongated bubbly flow, and slug flow. The correlation by Rassame and Hibiki (2018) is relatively reliable for void fraction calculation in annular flow for vertical-downward two-phase flow (17.00% error), but unreliable for bubbly, cap-bubbly, slug, and churn-turbulent (overall 33.66% error).