Numerical Simulation of Two-Phase Flow Using Eulerian-Eulerian Model With One-Group Interfacial Area Transport Equation

Abstract

Abstract The gas-liquid two-phase flow phenomenon in the vertical circular tube widely exists in a variety of industrial equipment, such as steam generators in the nuclear power plant and the bubble towers. The study of the gas-liquid two-phase flow characteristics, especially the movement characteristics of the gas phase or bubbles is significant. Interfacial area concentration (IAC) is defined as the interfacial area between two phases per unit mixture volume, which is a key parameter to predict the interfacial interaction and transfer terms between two phases. Different IAC represents different flow regime. The IAC changes in various flow regimes are usually modeled by the Interfacial Area Transport Equation (IATE). In this paper, Eulerian-Eulerian two-fluid model (EE) and mixture model with one-group interfacial Area Transport Equation (IATE) are used to numerically simulate the upwardly flowing gas-liquid two-phase flow in a vertical circular tube. Simulation results are compared with the experimental results of adiabatic air-water upward flow in a tube with inner diameter of 2 mm and 1 MPa in steady-state condition (Hibiki et al.2001) for evaluating the two-phase flow model with one-group IATE model. Three experimental cases under various gas and fluid velocity conditions of 0.734–1.39 and 0.512–1.282 are selected, in which case 1 and 2 are typical bubbly flows, and case 3 is in a transition between the bubbly and the slug flow regimes. The characteristics of two-phase flow under different gas and liquid flow rate conditions are analyzed, and the applicability of one-group IATEs is evaluated, and finally the sub-models that can be improved are analyzed. Results show that one-group IATE is only suitable for bubbly flow.