Study of the effect of the gas phase on the structure of turbulent flow and friction in the stream of a water-gas mixture in a vertical pipe

The results of numerical simulation of the structure of a two-phase flow of a gas-liquid bubble mixture in a vertical ascending flow in a pipe are presented. The mathematical model is based on the use of the two-fluid Eulerian approach taking into account the inverse influence of bubbles on averaged characteristics and turbulence of the carrying phase. The turbulent kinetic energy of a liquid is calculated using equations for the transfer of Reynolds stresses. To describe the dynamics of bubble size distribution, the equations of particle number conservation for individual groups of bubbles with different constant diameters for each fraction are used taking into account the processes of breakup and coalescence. The influence of changes in the degree of dispersion of the gas phase, volume flow gas content and the velocity of the dispersed phase on the local structure and surface friction in the two-phase flow is numerically investigated. Comparison of simulation results with experimental data has shown that the developed approach allows an adequate description of turbulent gas-liquid flows in a wide range of changes in gas content and initial bubble sizes.