Eulerian prediction of a turbulent bubbly flow downstream of a sudden pipe expansion

A two-fluid model for turbulent dispersed two-phase flow is presented and applied to a turbulent bubbly flow downstream of a sudden pipe expansion. Turbulence fields in the continuous phase are predicted by means of a q[sup 2]-epsilon eddy viscosity model with additional terms which account for the interaction between the two phases. The modeling of the dispersed phase fluctuating motion is achieved by an extended approach of the Tchen's theory for the dispersion of discrete particles suspended in an homogeneous fluid turbulence. Special attempts are made to account for the turbulent correlations in the average interfacial momentum transfer terms. The comparison of numerical predictions and experimental data shows a satisfactory agreement for those cases tested but the void fraction distribution is found to be very sensitive to the closure hypothesis used for the fluid pressure/void fraction correlation in the average interfacial momentum transfer. (orig.)