a r t i c l e i n f o a b s t r a c t When a buoyant volume of fluid impinges a horizontal boundary, it spreads symmetrically in the Stokes flow limit. We investigate the low Reynolds number spreading of a low-viscosity volume of fluid, hereafter called a " bubble " , in the limit that the fluids are miscible and interfacial tension can be neglected; the symmetry of the bubble's spreading is br...

In flooded evaporators, refrigerants are boiling outside the tubes. This paper focuses on the bubbly two-phase flow characteristics in twisted tube bundles. The quasi 3-D high speed video method and computational fluid dynamics are carried out to understand the effects which angles between the major axis of the cylinder and vertical direction ( ) and bubble diameters have on the motion behavio...

In a previous study M. Hameed et al., J. Fluid Mech. 594, 307 2008 the authors investigated the influence of insoluble surfactant on the evolution of a stretched, inviscid bubble surrounded by a viscous fluid via direct numerical simulation of the Navier–Stokes equations, and showed that the presence of surfactant can cause the bubble to contract and form a quasisteady slender thread connecting...

perturbation of the fluid interface has an exponential growth The Rayleigh–Taylor instability is a gravity driven instability of a contact surface between fluids of different densities. The growth of this instability is sensitive to numerical or physical mass diffusion. h(t) 5 h0e, (1.1) For this reason, high resolution of the contact discontinuity is particularly important. In this paper, we a...

We consider Laplacian growth problems using a field theory approach. In particular we consider the Saffman-Taylor (ST) problem, in which a non-viscous fluid is pumped into the center of a HeleShaw cell filled with a highly viscous fluid generating a bubble of a distinctive fingering fractal pattern. The idealized settings of the problem, with vanishing surface tension between the bubble and the...

The problem of bubble contraction in a Hele-Shaw cell is studied for the case in which the surrounding fluid is of power-law type. A small perturbation of the radially symmetric problem is first considered, focussing on the behaviour just before the bubble vanishes, it being found that for shear-thinning fluids the radially symmetric solution is stable, while for shear-thickening fluids the asp...

In the case of extracorporeal shock wave lithotripsy (ESWL), a shock wave-bubble interaction inevitably occurs near the focusing point of stones, resulting in stone fragmentation and subsequent tissue damage. Because shock wave-bubble interactions are high-speed phenomena occurring in tissue consisting of various media with different acoustic impedance values, numerical analysis is an effective...

Recent observations of growing and collapsing bubbles in flows over axisymmetric headforms have revealed the complexity of the ' micro-fluid-mechanics ' associated with these bubbles (van der Meulen & van Renesse 1989; Briangon-Marjollet et al. 1990; Ceccio & Brennen 1991). Among the complex features observed were the bubble-tobubble and bubble-to-boundary-layer interactions which leads to the ...

A novel computational fluid dynamics-population balance model (CFD-PBM) for the simulation of gas mixing in activated sludge (i.e., an opaque non-Newtonian liquid) in a bubble column is developed and described to solve the problem of measuring the hydrodynamic behavior of opaque non-Newtonian liquid-gas two-phase flow. We study the effects of the inlet position and liquid-phase properties (wate...