An investigation was carried out for swirling flow in a rotating pipe with highly viscous fluid containing micro-bubbles experimentally and numerically. In the numerical analysis, bubble trajectory of each bubble was calculated using resultant numerical flow field solutions. From experimental results, with an aid of the numerical simulation, data were obtained for the location of a stagnation p...

Bubble column reactors are used in a wide variety of applications such as multiphase bioreactors, catalytic slurry reactors, and absorption processes. The superficial gas velocity-gas holdup relationship and transition point are two important parameters for characterizing the hydrodynamics of a bubble column reactor. In this study, systematic investigation of a nitrogen - water - glass bead...

This paper concerns a relaxation of the assumption of uniform mixture composition in the interior of sonoluminescence bubbles. Intense temperature and pressure gradients within the bubble drive relative mass diffusion which overwhelms diffusion driven by concentration gradients. This thermal and pressure diffusion results in a robust compositional inhomogeneity in the bubble which lasts several...

bubble column reactors are used in a wide variety of applications such as multiphase bioreactors, catalytic slurry reactors, and absorption processes. the superficial gas velocity-gas holdup relationship and transition point are two important parameters for characterizing the hydrodynamics of a bubble column reactor. in this study, systematic investigation of a nitrogen - water - glass beads bu...

This paper presents measurements and model predictions of the density and size distribution of bubbles in the wakes of full scale ships, and the effects of the bubbles on acoustic propagation. The ship wake is primarily a hydrodynamic process, characterized by temporally and spatially varying flow conditions (i.e., local fluid velocity, pressure, turbulent kinetic energy and dissipation, etc.) ...

BACKGROUND Bubble CPAP is frequently used in spontaneously breathing infants with lung disease. Often bubble CPAP systems lack pressure alarms and pressure-release valves. We observed a large volume of condensate in the exhalation limb of a patient circuit and conducted a series of experiments to test the hypothesis that accumulated condensate could affect delivered pressures. METHODS An anat...

A realistic non-spherical model for bubble formation in a co-flowing liquid is presented. In the model, an interfacial element approach is applied to describe the dynamics of bubble formation. The effect of flowing liquid velocity is modeled by a combination of the bubble axis translation and liquid pressure analysis of each interfacial element. The bubble shapes during formation are predicted ...

A high-order accurate shock- and interface-capturing scheme is used to simulate the collapse of a gas bubble in water. In order to better understand the damage caused by collapsing bubbles, the dynamics of the shock-induced and Rayleigh collapse of a bubble near a planar rigid surface and in a free field are analysed. Collapse times, bubble displacements, interfacial velocities and surface pres...

This paper investigates the permeability of several multi-layered, woven filter media using air, water and bubble point methods. Estimated filter efficiencies from the bubble point measurements were then compared to a new sonic challenge test method where precision microspheres are fluidised through the pores. Inconsistencies in the bubble point filter efficiencies were found to be dependent on...

In the collection zone of a flotation column, the air holdup is known to be relatively constant along the column height. The effect of the decrease in hydrostatic pressure with height may need to be taken into consideration, particularly for tall industrial columns. However, this phenomenon is readily ascertained. On the other hand, the changes at the pulp-froth interface, as well as the air fr...