Étude de l’effet de la turbulence homogène sur le transfert de masse en écoulement gaz-liquide à bulles.

Résumé

The second order turbulence closure of bubbly flows model is evaluated on the basis of numerical simulations of uniformly sheared flow over an isolated sphere placed in the production-dissipation equilibrium zone. The analysis of the turbulence statistics on a control volume which size is set based on void fractions, reproduces the experimental results of Lance et al. (1991). Numerical results for a wide range of shear and low void fractions were used in order to analyze the turbulence model proposed by Chahed et al. (2003) in particular with regard to the closure of the transport equation of the turbulent part of the Reynolds stress tensor. The reduction of second order turbulence closure allows defining a dimensionless number characterizing the bubbles effects on turbulence structure. Following a similar approach at the scale of the bubble, we proceed with simulations of mass transfer in transient flow to determine the evolution of the average concentrations of dissolved oxygen in the continuous phase. This flow is supposed to reproduce bubbles in free ascent in a liquid at rest. Simulation results at the local bubble scale have validated the known mass transfer models and showed the effects of the turbulence induced by the shear and the bubble presence on the mass transfer property.

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  • Titre original : Étude de l’effet de la turbulence homogène sur le transfert de masse en écoulement gaz-liquide à bulles.
  • Identifiant de la fiche : 30017662
  • Langues : Français
  • Source : 1st International Refrigeration, Energy and Environment Colloquium. Proceedings: Hammamet, Tunisia, March 24-27, 2016.
  • Date d'édition : 24/03/2016

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