Experimental data for the bubble mode of breakdown in pipe ows is compared with calculations of the axisymmetric form of the Navier-Stokes equations. The location of breakdown in the calculations is found to be extremely sensitive to the inlet conditions; however, generally good agreement between the experimental and numerical breakdown locations is obtained. Detailed comparisons of the velocit...

A non-spherical model for bubble formation at an ori"ce with liquid cross-#ow has been developed. The interface element approach is applied to describe the dynamics of bubble formation. The e!ect of liquid cross-#ow on the bubble formation process is modelled by a combination of tilting of the bubble axis and liquid pressure analysis of each element on the bubble interface. Model predictions co...

Bubble diameter measurements in a two-dimensional cocurrent bubble column are obtained using a gas−liquid−solid system in which the solid component is a cellulose fiber. Flash X-ray radiography, a noninvasive measurement technique, is used to record bubble size in the opaque slurry at various operating conditions. Results are presented for a range of fiber mass fractions (0 ≤ C ≤ 1.5%), a range...

We draw attention to the fact that the popular but unproven hypothesis of shock-driven sonoluminescence is incompatible with the reported synchronicity of the single bubble sonoluminescence (SBSL) phenomenon. Moreover, it is not a necessary requirement, since we show that the sub-shock dynamic heating in gas bubble cavitation can lead to conditions required to generate intense 100ps light pulse...

The problem of predicting the moments of the distribution of bubble radius in bubbly flows is considered. The particular case where bubble oscillations occur due to a rapid (impulsive or step change) change in pressure is analyzed, and it is mathematically shown that in this case, inviscid bubble oscillations reach a stationary statistical equilibrium, whereby phase cancellations among bubbles ...

in this paper, a cfd model of syngas flow in slurry bubble column was developed. the model is based on an eulerian-eulerian approach and includes three phases: slurry of solid particles suspended in paraffin oil and syngas bubbles. numerical calculations carried out for catalyst particles, bubble coalescence and breakup included bubble-fluid drag force and interfacial area effects. also, the ef...

This paper concerns global existence for arbitrary nonzero surface tension of bubbles in a Hele-Shaw cell that translate in the presence of a pressure gradient. When the cell width to bubble size is sufficiently large, we show that a unique steady translating near-circular bubble symmetric about the channel centerline exists, where the bubble translation speed in the laboratory frame is found a...

In this paper, growth and collapse of a vapour bubble generated due to a local energy input inside a rigid cylinder and in the absence of buoyancy forces is investigated using Boundary Integral Equation Method and Finite Difference Method .The fluid is treated as potential flow and Boundary Integral Equation Method is used to solve Laplace’s equation for velocity potential. Different ratios of ...

The sound produced from a single bubble, oscillating atits breathing mode frequency, and the bubble size distribution are used to model the sound produced by breaking waves. The data of Medwin and Daniel [$. Acoust. Soc. Am. 88, 408-412 ( 1990} ] is used to evaluate the performance ofthe model. The model generates a damped sinusoidal pulse for every bubble formed, as calculated from the bubble ...

Heat transfer associated with a vapor bubble sliding along a downward-facing inclined heater surface was studied experimentally using holographic interferometry. Volume growth rate of the bubbles as well as the rate of heat transfer along the bubble interface were measured to understand the mechanisms contributing to the enhancement of heat transfer during sliding motion. The heater surface was...