par Wylock, Christophe 
;Colinet, Pierre ;Haut, Benoît
Référence Chemical engineering journal, 207–208, page (851-864)
Publication Publié, 2012-08-02
;Colinet, Pierre ;Haut, Benoît Référence Chemical engineering journal, 207–208, page (851-864)
Publication Publié, 2012-08-02
Article révisé par les pairs
| Résumé : | This work deals with the modeling and the direct numerical simulation of the absorption of a gas component into a spherical liquid droplet in free fall, where the absorbed component takes part to a chemical reaction. This study is realized by computing the flow fields and the concentration fields simultaneously in the gas and liquid phases. The time evolution of the droplet global mass absorption rate is studied for various regimes characterized by the Reynolds and the Hatta numbers. The monitoring of the time evolution of the concentration fields in the droplet enables the understanding of the interactions between the diffusive and convective mass transports and the chemical reaction. The phenomena controlling the mass transfer rate and how they evolve during the mass absorption process can then be identified. In a first stage, the case of the physical absorption is studied. Moreover, analytical expressions are developed to correlate the time evolution of the Sherwood number with the Reynolds number and the absorption time. In a second stage, the influence of the coupling with a chemical reaction is studied. It is observed that several rate-limiting mechanisms successively control the global absorption rate, enlightening the complex interactions between convective and diffusive mass transport and the chemical reaction. |
