This paper describes various manipulations of micro air bubbles using electrowetting on dielectric (EWOD): transporting, splitting, merging and eliminating. First, in order to understand the response of bubbles to EWOD, the contact angle modulation is measured in a capped air bubble and confirmed to be in good agreement with the Lippmann-Young equation until saturation. Based on the contact ang...

This paper reports on an experimental study of the splitting instability of an air bubble a few centimetres in diameter placed in a sealed cylindrical cell filled with liquid and submitted to vertical oscillations. The response of the bubble to the oscillations is observed with a high-speed video camera. It is found that the bubble dynamics is closely associated with the acceleration of the cel...

In the present study the bubble behavior in the narrow space are experimentally and numerically examined as the gap between two parallel walls and the position of bubble induction were changed. The main results are as follows. (1) The effects of two parallel walls can be classified by the ratio of the gap between the walls to the maximum bubble radius. If the ratio>5.0 the bubble shape is almos...

In this paper, we address the relations between the structure, electronic level structure, energetics, and localization dynamics of an excess electron in a bubble in liquid 4He, 3He, and Ne. Our treatment of the dynamics of formation for the electron bubble rests on a quantum mechanical Wigner-Seitz description of the excess electron in conjunction with a hydrodynamic picture for the liquid. Th...

Epstein and Plesset's seminal work on the rate of gas bubble dissolution and growth in a simple liquid is generalized to render it applicable to a gas bubble embedded in a soft elastic solid. Both the underlying diffusion equation and the expression for the gas bubble pressure were modified to allow for the non-zero shear modulus of the medium. The extension of the diffusion equation results in...

This work presents a 3D numerical study of the bubble generation process into a bubble generator obtained with the commercial Computational Fluid Dynamics solver ANSYS Fluent v15.0.7, and its comparison with experimental data reproducing the same conditions [1]. The bubble generator is formed by two perpendicular capillaries in which liquid and gas are injected at perpendicular directions into ...

A simplified approach to the model development and scale-up of a packed bubble column reactor from pilot semi-batch mode to continuous commercial operation has been presented. This is illustrated by choosing the reaction of ethynylation of formaldehyde to 1,4-butynediol for which correct reaction mechanism is difficult to postulate in the compelling safety limitations. The apparent reaction kin...

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...