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Damping Time of Bubble Oscillations in Clean Liquids and in Surfactants
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SYSNO ASEP 0341645 Document Type C - Proceedings Paper (int. conf.) R&D Document Type Conference Paper Title Damping Time of Bubble Oscillations in Clean Liquids and in Surfactants Author(s) Vejražka, Jiří (UCHP-M) RID, ORCID, SAI
Vobecká, Lucie (UCHP-M) SAI
Zedníková, Mária (UCHP-M) RID, ORCID, SAI
Orvalho, Sandra (UCHP-M) RID, ORCID, SAI
Tihon, Jaroslav (UCHP-M) RID, ORCID, SAISource Title Fortschritt-berichte VDI, Reihe 3, Nr. 920. - Düsseldorf : VDI Verlag, 2011 / Schindler F. P. - ISSN 0178-9503 - ISBN 978-3-18-392003-7 Pages s. 47-60 Number of pages 14 s. Action International Berlin Workshop on Transport Phenomena with Moving Boundaries /5./ Event date 08.10.2009-09.10.2009 VEvent location Berlin Country DE - Germany Event type EUR Language eng - English Country DE - Germany Keywords bubble shape oscillation ; surface active agent ; interfacial viscosity Subject RIV CI - Industrial Chemistry, Chemical Engineering R&D Projects GA104/08/0428 GA ČR - Czech Science Foundation (CSF) IAA200720801 GA AV ČR - Academy of Sciences of the Czech Republic (AV ČR) CEZ AV0Z40720504 - UCHP-M (2005-2011) Annotation Shape oscillations of bubbles in surfactant solutions are investigated by means of high-speed imaging. Two cases are studied: bubbles attached to a capillary tip, and bubbles freely rising after detachment. The frequency f and the decay time tau of shape oscillations are evaluated, and their dependence on the surfactant concentration and on the bubble size is investigated. If the surfactant is present, tau shortens and a minimum is found for a certain concentration. This observation demonstrates that in the surfactant solutions, the energy dissipation linked to interfacial effects can be much more important than the dissipation due to liquid viscosity. The frequency f increases with increasing concentration of the surfactant first, and then it drops rapidly at concentration, at which tau is minimal. The initial increase of the oscillation frequency suggests that the interfacial elasticity can play an important role in surfactant solutions. Workplace Institute of Chemical Process Fundamentals Contact Eva Jirsová, jirsova@icpf.cas.cz, Tel.: 220 390 227 Year of Publishing 2011
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