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Gas bubbles in micro capillaries – hydrodynamics and mass transfer
Author(s) -
Lakshmanan Peter,
Ehrhard Peter
Publication year - 2015
Publication title -
pamm
Language(s) - English
Resource type - Journals
ISSN - 1617-7061
DOI - 10.1002/pamm.201510247
Subject(s) - bubble , mass transfer , marangoni effect , mechanics , work (physics) , capillary action , chemistry , mass transfer coefficient , physics , thermodynamics , convection
Process design of multi‐phase unit operations on the micro‐scale relies on the detailed knowledge of the hydrodynamics and mass transfer behavior of discrete disperse fluid particles. The present work examines the hydrodynamics and mass transfer of gas bubbles in vertical capillaries. The hydrodynamic behavior of a single bubble in a capillary including is examined numerically using a modified level‐set method [1]. Additionally, the influence of surface‐active contaminations (‘surfactants’) and the resulting Marangoni effects are taken into account [2]. This enables the differentiation between bubbles with a mobile, i.e. clean, interface and those with a immobile, i.e. contaminated, interface. Based on the hydrodynamics, the mass transfer is examined. In the present work, mass transfer is from the bubble into the bulk fluid. By using a very high mesh resolution, the local concentration field in and around the gas bubble can be resolved, which gives access to the local mass transfer. Results are in good agreement available correlations from literature. (© 2015 Wiley‐VCH Verlag GmbH & Co. KGaA, Weinheim)