Physics Of Buoyant Flows

Gravity pervades the whole universe; hence buoyancy drives fluids everywhere including those in the atmospheres and interiors of planets and stars. Prime examples of such flows are mantle convection, atmospheric flows, solar convection, dynamo process, heat exchangers, airships and hot air balloons. In this book we present fundamentals and applications of thermal convection and stratified flows. Buoyancy brings in extremely rich phenomena including waves and instabilities, patterns, chaos, and turbulence. In this book we present these topics in a systematic manner. First we present a unified treatment of linear theory that yields waves and thermal instability for stably and unstably-stratified flows respectively. We extend this analysis to include rotation and magnetic field. We also describe nonlinear saturation and pattern formation in Rayleigh-Bénard convection. The second half of the book is dedicated to buoyancy-driven turbulence, both in stably-stratified flow and in thermal convection. We describe the spectral theory including energy flux and show that the thermally-driven turbulence is similar to hydrodynamic turbulence. We also describe large-scale quantities like Reynolds and Nusselt numbers, flow anisotropy, and the dynamics of flow structures, namely flow reversals. Thus, this book presents all the major aspects of the buoyancy-driven flows in a coherent manner that would appeal to advanced graduate students and researchers.

Buoyancy is one of the main forces driving flows on our planet, especially in the oceans and atmosphere. These flows range from buoyant coastal currents to dense overflows in the ocean, and from avalanches to volcanic pyroclastic flows on the Earth's surface. This book brings together contributions by leading world scientists to summarize our present theoretical, observational, experimental and modeling understanding of buoyancy-driven flows. Buoyancy-driven currents play a key role in the global ocean circulation and in climate variability through their impact on deep-water formation. Buoyancy-driven currents are also primarily responsible for the redistribution of fresh water throughout the world's oceans. This book is an invaluable resource for advanced students and researchers in oceanography, geophysical fluid dynamics, atmospheric science and the wider Earth sciences who need a state-of-the-art reference on buoyancy-driven flows.

Studies of convection in geophysical flows constitute an advanced and rapidly developing area of research that is relevant to problems of the natural environment. During the last decade, significant progress has been achieved in the field as a result of both experimental studies and numerical modelling. This led to the principal revision of the widely held view on buoyancy-driven turbulent flows comprising an organised mean component with superimposed chaotic turbulence. An intermediate type of motion, represented by coherent structures, has been found to play a key role in geophysical boundary layers and in larger scale atmospheric and hydrospheric circulations driven by buoyant forcing. New aspects of the interaction between convective motions and rotation have recently been discovered and investigated. Extensive experimental data have also been collected on the role of convection in cloud dynamics and microphysics. New theoretical concepts and approaches have been outlined regarding scaling and parameterization of physical processes in buoyancy-driven geophysical flows. The book summarizes interdisciplinary studies of buoyancy effects in different media (atmosphere and hydrosphere) over a wide range of scales (small scale phenomena in unstably stratified and convectively mixed layers to deep convection in the atmosphere and ocean), by different research methods (field measurements, laboratory simulations, numerical modelling), and within a variety of application areas (dispersion of pollutants, weather forecasting, hazardous phenomena associated with buoyant forcing).

Buoyancy Induced Flows and Transport concerns the heat transfer and fluid motions which arise in bodies of fluids. It specifically relates to the natural circulation and other effects which result from density differences and gradients in a fluid region, as a result of a body force, such as gravity. These density differences force a flow. This book covers a wide range of the most important and common flow conditions, as related to more immediate needs and applications. This highly recommended text promises to become the standard reference for those interested in this field. Relevant to any graduate seminar on the subject, it is also an excellent choice for advanced undergraduate study.

The phenomena treated in this book all depend on the action of gravity on small density differences in a non-rotating fluid. The author gives a connected account of the various motions which can be driven or influenced by buoyancy forces in a stratified fluid, including internal waves, turbulent shear flows and buoyant convection. This excellent introduction to a rapidly developing field, first published in 1973, can be used as the basis of graduate courses in university departments of meteorology, oceanography and various branches of engineering. This edition is reprinted with corrections, and extra references have been added to allow readers to bring themselves up to date on specific topics. Professor Turner is a physicist with a special interest in laboratory modelling of small-scale geophysical processes. An important feature is the superb illustration of the text with many fine photographs of laboratory experiments and natural phenomena.

Turbulent transport of momentum, heat and matter dominates many of the fluid flows found in physics, engineering and the environmental sciences. Complicated unsteady motions which mayor may not count as turbulence are found in interstellar dust clouds and in the larger blood vessels. The fascination of this nonlinear, irreversible stochastic process for pure scientists is demonstrated by the contributions made to its understanding by several of the most distinguished mathematical physicists of this century, and its importance to engineers is evident from the wide variety of industries which have contributed to, or benefit from, our current knowledge. Several books on turbulence have appeared in recent years. Taken collectively, they illustrate the depth of the subject, from basic principles accessible to undergraduates to elaborate mathematical solutions representing many years of work, but there is no one account which emphasizes its breadth. For this, a multi-author work is necessary. This book is an introduction to our state of knowledge of turbulence in most of the branches of science which have contributed to that knowledge. It is not a Markovian sequence of unrelated essays, and we have not simply assembled specialized accounts of turbulence problems in each branch; this book is a unified treatment, with the material classified according to phenomena rather than application, and freed as far as possible from discipline-oriented detail. The approach is "applied" rather than "pure" with the aim of helping people who need to under stand or predict turbulence in real life.