Experiments were performed in a three-phase bubble column to study variations of bubble rise velocities. The dynamic gas disengagement (DGD) technique and the fast response pressure transducers were utilized to investigate the bubble rise in the column. The superficial gas velocity of large bubbles and small bubbles, the rise velocities of larger and small bubble fractions were studied consider...

Bubble size measurement using imaging technique is commonly used when visualization is possible. However, overlapped bubble images are commonly found. The absence of internal separating line in overlapped bubble images creates difficulty in automatic algorithm development for accurate bubble size measurement. Common methodologies such as manipulation of pixel connectivity, segmentation by morph...

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 ...

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...