Acoustic Cavitation and Bubble Dynamics


Book Description

This brief explains in detail fundamental concepts in acoustic cavitation and bubble dynamics, and describes derivations of the fundamental equations of bubble dynamics in order to support those readers just beginning research in this field. Further, it provides an in-depth understanding of the physical basis of the phenomena. With regard to sonochemistry, the brief presents the results of numerical simulations of chemical reactions inside a bubble under ultrasound, especially for a single-bubble system and including unsolved problems. Written so as to be accessible both with and without prior knowledge of fundamental fluid dynamics, the brief offers a valuable resource for students and researchers alike, especially those who are unfamiliar with this field. A grasp of fundamental undergraduate mathematics such as partial derivative and fundamental integration is advantageous; however, even without any background in mathematics, readers can skip the equations and still understand the fundamental physics of the phenomena using the book’s wealth of illustrations and figures. As such, it is also suitable as an introduction to the field.




Cavitation and Bubble Dynamics


Book Description

Cavitation and Bubble Dynamics deals with fundamental physical processes of bubble dynamics and cavitation for graduate students and researchers.




Cavitation and Bubble Dynamics


Book Description

Cavitation and Bubble Dynamics: Fundamentals and Applications examines the latest advances in the field of cavitation and multiphase flows, including associated effects such as material erosion and spray instabilities. This book tackles the challenges of cavitation hindrance in the industrial world, while also drawing on interdisciplinary research to inform academic audiences on the latest advances in the fundamentals. Contributions to the book come from a wide range of specialists in areas including fuel systems, hydropower, marine engineering, multiphase flows and computational fluid mechanics, allowing readers to discover novel interdisciplinary experimentation techniques and research results. This book will be an essential tool for industry professionals and researchers working on applications where cavitation hindrance affects reliability, noise, and vibrations. Covers a wide range of cavitation and bubble dynamics phenomena, including shock wave emission, jetting, and luminescence Provides the latest advice about applications including cavitation tunnels, cavitation testing, flow designs to avoid cavitation in pumps and other hydromachinery, and flow lines Describes novel experimental techniques, such as x-ray imaging and new computational techniques




The Acoustic Bubble


Book Description

The Acoustic Bubble describes the interaction of acoustic fields with bubbles in liquid. The book consists of five chapters. Chapter 1 provides a basic introduction to acoustics, including some of the more esoteric phenomena that can be seen when high-frequency high-intensity underwater sound is employed. Chapter 2 discusses the nucleation of cavitation and basic fluid dynamics, while Chapter 3 draws together the acoustics and bubble dynamics to discuss the free oscillation of a bubble and acoustic emissions from such activity. The acoustic probes that are often applied to study the behavior of a bubble when an externally-applied acoustic field drives it into oscillation is deliberated in Chapter 4. The last chapter outlines a variety of effects associated with acoustically-induced bubble activity. The bubble detection, sonoluminescence, sonochemistry, and pulse enhancement are also covered. This publication is a good reference for physics and engineering students and researchers intending to acquire knowledge of the acoustic interactions of acoustic fields with bubbles.




Acoustic Cavitation and Bubble Dynamics


Book Description

The topic of this chapter, acoustic cavitation, is but one of several possible mechanisms through which ultrasound can interact with a liquid medium. Acoustic cavitation can affect a liquid through two possible avenues. The first is the bubble itself. The liquid is disrupted by the inhomogeneous presence of the bubble. The second avenue through which bubbles affect a fluid is through bubble dynamics. The bubble's interior and the liquid immediately surrounding the bubble are regions which undergo continual change. The bubble-liquid interface continually changes shape and size; liquid molecules diffuse into and out of the bubble; the concentration of gas in the surrounding liquid varies; acoustic streaming occurs in the liquid in the vicinity of the bubble often resulting in severe shear stresses; the interior pressure and temperature fluctuate rapidly; the bubble radiates acoustic energy as it oscillates; thermal and viscous damping hinder the bubble oscillations.




Characterization of Cavitation Bubbles and Sonoluminescence


Book Description

This book presents the latest research on fundamental aspects of acoustic bubbles, and in particular on various complementary ways to characterize them. It starts with the dynamics of a single bubble under ultrasound, and then addresses few-bubble systems and the formation and development of bubble structures, before briefly reviewing work on isolated bubbles in standing acoustic waves (bubble traps) and multibubble systems where translation and interaction of bubbles play a major role. Further, it explores the interaction of bubbles with objects, and highlights non-spherical bubble dynamics and the respective collapse geometries. It also discusses the important link between bubble dynamics and energy focusing in the bubble, leading to sonochemistry and sonoluminescence. The second chapter focuses on the emission of light by cavitation bubbles at collapse (sonoluminescence) and on the information that can be gained by sonoluminescence (SL) spectroscopy, e.g. the conditions reached inside the bubbles or the nature of the excited species formed. This chapter also includes a section on the use of SL intensity measurement under pulsed ultrasound as an indirect way to estimate bubble size and size distribution. Lastly, since one very important feature of cavitation systems is their sonochemical activity, the final chapter presents chemical characterizations, the care that should be taken in using them, and the possible visualization of chemical activity. It also explores the links between bubble dynamics, SL spectroscopy and sonochemical activity. This book provides a fundamental basis for other books in the Molecular Science: Ultrasound and Sonochemistry series that are more focused on applied aspects of sonochemistry. A basic knowledge of the characterization of cavitation bubbles is indispensable for the optimization of sonochemical processes, and as such the book is useful for specialists (researchers, engineers, PhD students etc.) working in the wide area of ultrasonic processing.







Bubble Dynamics and Interface Phenomena


Book Description

This volume contains papers presented at the IUTAM Symposium on Bubble Dynamics and Interface Phenomena held at the University of Birmingham from 6-9 September 1993. In many respects it follows on a decade later from the very successful IUTAM Symposium held at CALTECH in June 1981 on the Mechanics and physics of bubbles in liquids which was organised by the late Milton Plesset and Leen van Wijngaarden. The intervening period has seen major development with both experiment and theory. On the experimental side there have been ad vances with very high speed photography and data recording that provide detailed information on fluid and interface motion. Major developments in both computer hardware and software have also led to extensive improvement in our understand ing of bubble and interface dynamics although development is still limited by the sheer complexity of the laminar and turbulent flow regimes often associated with bubbly flows. The symposium attracts wide and extensive interest from engineers, physical, chemical, biological and medical scientists and applied mathematicians. The sci entific committee sought to achieve a balance between theory and experiment over a range of fields in bubble dynamics and interface phenomena. It was our intention to emphasise both the breadth and recent developments in these various fields and to encourage cross-fertilisation of ideas on both experimental techniques and theo retical developments. The programme, and the proceedings recorded herein, cover bubble dynamics, sound and wave propagation, bubbles in flow, sonoluminescence, acoustic cavitation, underwater explosions, bursting bubbles and ESWL.




Sonochemistry and Sonoluminescence


Book Description

Sonochemistry is studied primarily by chemists and sonoluminescence mainly by physicists, but a single physical phenomenon - acoustic cavitation - unites the two areas. The physics of cavitation bubble collapse, is relatively well understood by acoustical physicists but remains practically unknown to the chemists. By contrast, the chemistry that gives rise to electromagnetic emissions and the acceleration of chemical reactions is familiar to chemists, but practically unknown to acoustical physicists. It is just this knowledge gap that the present volume addresses. The first section of the book addresses the fundamentals of cavitation, leading to a more extensive discussion of the fundamentals of cavitation bubble dynamics in section two. A section on single bubble sonoluminescence follows. The two following sections address the new scientific discipline of sonochemistry, and the volume concludes with a section giving detailed descriptions of the applications of sonochemistry. The mixture of tutorial lectures and detailed research articles means that the book can serve as an introduction as well as a comprehensive and detailed review of these two interesting and topical subjects.