High-speed images of bubbly flow coupled with simultaneous passive acoustic measurements were carried out in a bubble column staged with structured fibrous catalysts. Local observations made with a high-speed camera system allow a detailed understanding of the influence of fabric structure on bubble formation processes and the determination of the Sauter bubble diameter. With acoustic measureme...

............................................................................................................................................... 18 INTRODUCTION......................................................................................................................................... 18 EXPERIMENTAL METHODS ...............................................................................

The efficiency of fluidized bed reactors depends on bubble distribution, bubble size and bubble velocity within the reactor. The sizes and size distributions of particles used in the bed may lead to different bubble behaviour. The objective of this work is to study the influence of particle size distribution on bubble behaviour. The results from the experiments will be used for validation of CF...

[1] The evolution of bubbles in a turbulent oceanic boundary layer is simulated using a multi-size multi-gas bubble model coupled with a Large Eddy Simulation model. Bubbles injected by breaking waves are brought into the boundary layer by episodic bubble plumes, and they form near-surface streaks in the convergence zone of Langmuir circulations. The equilibrium bubble distribution decays expon...

Many measurement schemes have been developed to study the resonant characteristics of a bubble near a surface. The desire is to be able to measure the free field characteristics of such a bubble. For experimental investigations, a trade-off must be made between the size of the apparatus and the free field measurement. Thus there is a need to study the effect of surface interference on the reson...

This paper investigates the effect of heat transfer on the motion of a spherical bubble in the vicinity of a rigid boundary. The effects of heat transfer between the bubble and the surrounding fluid, and the resulting loss of energy from the bubble, can be incorporated into the simple spherical bubble model with the addition of a single extra ordinary differential equation. The numerical result...

Bubble point pressure is an important parameter in equilibrium calculations of reservoir fluids and having other applications in reservoir engineering. In this work, an artificial neural network (ANN) and a least square support vector machine (LS-SVM) have been used to predict the bubble point pressure of reservoir fluids. Also, the accuracy of the models have been compared to two-equation stat...

Although CO2 injection is one of the most common methods in enhanced oil recovery, it could alter fluid properties of oil and cause some problems such as asphaltene precipitation. The maximum amount of asphaltene precipitation occurs near the fluid pressure and concentration saturation. According to the description of asphaltene deposition onset, the bubble point pressure has a very special imp...

Two-phase bubble formation coupled with phase change at a submerged nozzle is studied theoretically. The whole bubble consists of a ®apor and a liquid phase. The inner ®apor phase is assumed to be surrounded by a thin condensate layer, in which the ®apor condenses partially as the two-phase bubble grows. The interface element approach is applied to describe the dynamics of bubble formation. The...

The effect of positive and negative pressure on the modes of oscillation of a multielectron bubble in liquid helium is calculated. Already at low pressures of the order of 10-100 mbar, these effects are found to significantly modify the frequencies of oscillation of the bubble. Stabilization of the bubble is shown to occur in the presence of a small negative pressure, which expands the bubble r...