We report experiments on lateral migration of bubbles in a two-dimensional foam sheared in a narrow-gap Couette device. A larger bubble in an otherwise monodisperse bubble raft migrates toward the center of the gap as long as the bubble size ratio and the shear rate are each above a threshold. The migration speed is roughly two orders of magnitude higher than that of a single bubble, and increa...

computational scheme is used to study the bubble trajectories. The 2D averaged Navier stokes equations are solved. The SIMPLEC algorithm is used to relate the pressure to velocity. A one-way coupling is assumed and the effects of the bubbles on carrier flow are neglected. The bubble equation of motion includes the drag, buoyancy, pressure gradient, Saffman lift and bubble volume change forces. ...

Computer simulations of bubble oscillations in water have revealed that characteristics of bubbles depend on types of sonochemical reactors. When the acoustic amplitude is large at 20 kHz, the bubble content when a bubble collapses is mostly water vapor and the temperature inside a bubble at the collapse is relatively low. On the other hand, when the acoustic amplitude is relatively low, the bu...

INTRODUCTION Bubble formation in insulin pump giving sets is a common problem. We studied change in temperature, change in atmospheric pressure, and vibration as potential mechanisms of bubble formation. METHODS 5 Animas 2020 pumps with 2 mL cartridges and Inset II infusion systems, 5 Medtronic Paradigm pumps with 1.8 mL cartridge and Quickset and 3 Roche Accu-chek pumps with 3.15 mL cartridg...

Modifications to a stochastic differential equation (SDE) approach for modeling single and two phase NAPL flow are proposed which are intended to allow SDE modeling of the motion of air bubbles in porous media. Bubble flow and channeling are discussed along with bubble sticking, bubble coalescing, bubble breakup and air sparging.

Most real life bubble dynamics applications involve multiple bubbles, for example, in cavitation erosion prevention, ultrasonic baths, underwater warfare, and medical applications involving microbubble contrast agents. Most scientific dealings with bubble-bubble interaction focus on two similarly sized bubbles. In this study, the interaction between two oscillating differently sized bubbles (ge...

Modeling and measurement of bubble size in a rotating fluidized bed (RFB) were conducted. The model for predicting the bubble growth in RFB has been proposed based on the following concepts: (i) local centrifugal acceleration and excess gas velocity are considered as the parameters in the radial direction, and (ii) bubble volume flow locally changes depending on the radial distance. Bubbling be...

The formation of nanoparticles within the laser-induced cavitation bubble is studied in situ using small angle X-ray scattering with high spatiotemporal resolution. Directly after laser ablation, two different particle fractions consisting of compact primary particles of 8-10 nm size and agglomerates of 40-60 nm size are formed. The abundance of these species is strongly influenced by the dynam...

The wall effects on the axisymmetric rise and deformation of an initially spherical gas bubble released from rest in a liquid-filled, finite circular cylinder are numerically investigated. The bulk and gas phases are considered incompressible and immiscible. The bubble motion and deformation are characterized by the Morton number (Mo), Eötvös number (Eo), Reynolds number (Re), Weber number (We)...

Mechanisms and dynamics of bubble coalescence in silicic magmas 1 Jonathan M. Castro (University of Mainz) 2 Alain Burgisser (ISTO-CNRS) 3 Ian Schipper (ISTO-CNRS) 4 Simona Mancini (ISTO-Université d’Orléans) 5 6 Abstract 7 Bubble coalescence is an important process that strongly affects magmatic degassing. 8 Without coalescence, bubbles remain isolated from one another in the melt, severely 9 ...