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...

A 3D discrete bubble model is adopted to investigate complex behavior involving hydrodynamics, mass transfer and chemical reactions in a gas–liquid bubble column reactor. In this model a continuum description is adopted for the liquid phase and additionally each individual bubble is tracked in a Lagrangian framework, while accounting for bubble–bubble and bubble–wall interactions via an encount...

Background: The purpose of the present study was to assess the efficacy of non-pharmacological interventions on the anxiety among thalassemic children undergoing venipuncture. Patients and Methods: This was a clinical trial on 60 thalassemic children aged 6-12 years undergoing venipuncture. Children were randomly divided into three groups: control, bubble making and regular breathing exercise....

introduction: there are several methods for evaluating microleakage in dentistry, for example dye or bacterial leakage, electro-chemical methods, radioisotope labeling and fluid filtration. the purpose of this study was to assemble the fluid filtration system for quantitative evaluation of microleakage in dental materials. materials and methods: the roots were connected to a tube filled with an...

INTRODUCTION Bubble columns are widely used in industrial gas-liquid operations (e.g. gas-liquid reactions, fermentations) in chemical and biochemical processes industries, due to their simple construction, low operating cost and high-energy efficiency. In all these processes, gas hold-up and bubble size are important design parameters since they define the gasliquid interfacial area available ...

A free-Lagrange numerical method is implemented to simulate the axisymmetric jetting collapse of air bubbles in water. This is performed for both lithotripter shock-induced collapses of initially stable bubbles, and for free-running cases where the bubble initially contains an overpressure. The code is validated using two test problems (shock-induced bubble collapse using a step shock, and shoc...

Bubble cloud collapse is one of the most destructive forms of cavitation. However, numerical modeling of this phenomenon is challenging and involves strong bubble dynamics, bubble-bubble, and bubble-wall interactions. Here we consider an initially spherical cloud near a rigid wall and treat the cloud bubbly mixture as a continuum and the bubbles in the cloud as discrete singularities. These two...