Simulação numérica do escoamento líquido-gás no padrão de golfadas em baixas razões de massa específica

Abstract

This work presents three-dimensional numerical simulations of liquid–gas flow in the slug flow pattern in horizontal pipelines, using fluids with low density ratios between the phases. The methodology for obtaining slug flow was based on the simulation of a statistically developed slug unit cell, using periodic boundary conditions and initial conditions defined from the average liquid fraction of the unit cell. The study validated the numerical results through quantitative comparison with experimental data from NUEM/UTFPR, analyzing parameters such as gas bubble length, slug frequency, liquid piston translational velocity, and superficial phase velocities. The simulations were conducted using the ANSYS® Fluent® software with the finite volume method. The Homogeneous Model was adopted for the transport equations, the PLIC algorithm for geometric reconstruction of the interface, and the k–ω SST turbulence model. In addition to the quantitative analysis, a qualitative evaluation of the physical phenomena was performed based on phase distribution fields, velocity fields, and turbulent kinetic energy fields. The qualitative results showed that the methodology employed was robust in representing the flow phenomenon for different pressure gradient ranges. In the quantitative analysis, good agreement was obtained for the bubble length, with relative errors compared to experimental values ranging from −5.12% to 17.94%. Larger relative errors were found for the superficial velocities, which consequently affected the relative errors obtained for the other evaluated slug flow parameters.