The quasi-steady migration and deformation of bubbles rising in a wall-bounded linear shear flow are investigated experimentally in the low-but-finite-Reynolds-number regime. A travelling optical device that follows the bubble is used for this purpose. This apparatus allows us to determine accurately the bubble radius, contour and rising speed, together with the distance between the bubble and ...

A theoretical model for bubble formation and weeping has been developed. Potential #ow theory is used to describe bubble formation at the ori"ce. The in#uence of detached, rising bubbles on liquid pressure at the ori"ce is predicted by Oseen's modi"cation to potential #ow. Model predictions of bubble volumes, weeping #ow rates and weep points agree well with experimental results. ( 2000 Elsevie...

Recently housing price hikes are spreading across America spatially, a reminder of the stock market hikes of the 1990s that ruptured in 2000. The aim of this study were to identify the determinants of housing prices, the differences between housing and stock markets, and whether the housing market can follow the path of the stock market. The aim was also to examine the existence of a housing bu...

We developed a new lattice Boltzmann method that allows the simulation of two-phase flow of viscoelastic liquid mixtures. We used this new method to simulate a bubble rising in a viscoelastic fluid and were able to reproduce the experimentally observed cusp at the trailing end of the bubble.  2000 Elsevier Science B.V. All rights reserved.

Since typical industrial-scale reactors may contain many millions of bubbles, the extension of direct free-surface modelling techniques to resolve every bubble in the vessel would require far more computational power than will be available. A more immediate solution is to couple macro-scale reactor models to micro-scale models of individual bubbles and collections of a small number of bubbles. ...

In this paper we discuss simulation techniques for a rising bubble in viscoelastic fluids via numerical methods based on high order FEM. A level set approach based on the work in [9] is used for interface tracking between the bubble and the surrounding fluid. The two matters obey the Newtonian and the Oldroyd-B constitutive law in the case of a viscoelastic fluid while the flow model is given b...

It has been suggested that rising bubbles in dense fluids resemble an inverted dripping faucet and that they undergo analogous period-doubling bifurcations to chaos. We present experimental results demonstrating that this analogy is weak because the dominant source of instability in the bubble train is inherently different mutual interactions between spatially separated bubbles as opposed to no...

In this work, the rise characteristics of a single H2 bubble, in ellipsoidal regime, (i) water, (ii) electrolyte (2 M, 4.5 M NaCl) solution and (iii) various concentrations mixture (up to 6.4 1:5 weight fraction NaCl-NaClO3), have been studied, at temperatures up 80°C. Our results show that both individual collective effects temperature concentration on velocity bubble shape are purely dependen...