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The role of the turbulence in the void fraction distribution in bubbly pipe flow under microgravity condition is evaluated on the basis of numerical simulations using a Eulerian-Eulerian two-fluid model. In microgravity, the average relative velocity is weak and the void fraction distribution is mainly governed by the turbulence. The simulations show that the turbulent contributions of the added mass force play an important role in the phase distribution phenomenon. It is clearly proved that the turbulence acts on the bubbles distribution not only by the pressure term but also by the turbulent correlations obtained by averaging the added mass force.

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in Wiley InterScience (www.interscience.wiley.com).Experimental analysis and numerical simulation of hydrodynamics and mass transfer in a turbulent oxygen-water bubbly shear layer is presented. The experimental data presents the structure of the averaged and fluctuating velocity fields as well as those of the gas volumetric fraction and the local dissolved oxygen concentration. Numerical simulations have been performed using Euler-Euler two-fluid model that provides some specific modeling adapted for gas-liquid bubbly flows and allows a reasonable representation of the two-phase flow structure (fields of average velocities and volumetric fractions of the two phases) as well as the important modulation of the turbulence in the two-phase flow. With the improvements of two-phase flow prediction, the averaged oxygen concentration field is also well predicted. The analysis of these results supports the pertinence of some improvements in two-phase flow modeling and allows some proposals for further progress in the development of more general multiphase models for complex gas-liquid systems.