Dumbbell Model of Bubble Stability

0377664 - ÚCHP 2013 SK eng C - Conference Paper (international conference)
Wichterle, K. - Večeř, M. - Růžička, Marek
Dumbbell Model of Bubble Stability.
Proceedings. Bratislava: AXIMA Graphics Design and Printing Services, 2012 - (Markoš, J.), s. 73. ISBN 978-80-89475-04-9.
[International Conference of Slovak Society of Chemical Engineering /39./. Tatranské Matliare (SK), 21.05.2012-25.05.2012]
R&D Projects: GA ČR GA104/07/1110
Institutional support: RVO:67985858
Keywords : rising bubbles * oscillation * stability
Subject RIV: CI - Industrial Chemistry, Chemical Engineering

When the spherical bubbles are out of a horizontal alignment, the action of gravity and surface tension pumps some gas from the upper sphere to the lower one. As a consequence, the lower sphere rising is accelerated and upper is decelerated. Mathematical model of the process for small perturbations leads to the equation of relative motion in form of 2nd order differential equation. According to this equation, any disturbance is damped for small spheres, while the solution for larger spheres leads to a harmonic oscillation. Limits of stability and frequency of bubble oscillations could be calculated. These predictions have been confronted with our original experimental data for ellipsoidal bubbles and with the data taken from literature. Adequacy of the dumbbell model proves that the oscillation of bubbles is controlled primarily by surface forces, and the vortex shedding plays a secondary role.
Permanent Link: http://hdl.handle.net/11104/0209761