J.H. Whitelaw – författare

Much has been said and written about the abilities of modern instrumentation to help solve problems of combustion in engines. In the main, however, the design and fabr ication of combustion chambers continues to be based on extrapolation of exper ience gained from use and rig tests, with little input from advanced techniques such as those based on optical diagnotics. At the same time, it has become increasingly difficult to design better combustion chambers without knowledge of the relevant flow processes. Thus, the future must involve improved understanding which, in turn, will require detailed measurements of velocity, temperature and concentration. The need to narrow the gap between current industrial practice and the acquisition and implementation of improved techniques motivated the organization of the Advanced Study Institute upon which this volume is based. This Institute on Instrumentation for Combustion and Flow in Engines was arranged to display the needs of industry and the possibilities made available by modern instrumentation and, at the same time, to make clear the relative advantages of optical and probe techniques. Held at Vimeiro during the period from 13 to 26 September, 1987, the Institute was attended by 120 participants and 16 invited lecturers.

This book consists of papers prepared for and presented at a NATO sponsored Advanced Study Institute which was held in Montechoro, Portugal during the period 16-27 April, 1990. This Institute was attended by approximately ninety delegates from fifteen countries and followed from a related Institute held in Vimeiro, Portugal in 1987 (see the book entitled "Instrumentation for Combustion and Flow in Engines", edited by D. F. G. Dur~o, J. H. Whitelaw and P. O. Witzel. The purposes of the first Institute related closely to instrumentation for use in gas-turbine combustors and the cylinders of internal-combustion engines. These topics were also addressed in the second Institute, though in a manner which was wider ranging and chosen to demonstrate and explain the development and application of measurement methods to combusting flows in general. The papers contained in this boo~ were selected to provide the reader with a comprehensive and up-to-date view of the variety of experimental techniques available to measure in combusting flows. Included are discussions of their range and applicability, potential accuracy and ease of use. Thus, the first paper provides a brief overview and the second an indication of those aspects of combustion which should influence the choice of flow property to be measured and the technique to be used.

This work is divided into three parts: combustion-induced oscillations; internal combustion engines; and experimental techniques and modelling. Part 1 of the book deals with combustion instabilities, pulsed combustors, and active control of unsteady motions, and constitutes a survey of the range of problems central to combustion instabilities. Internal combustion engines will undoubtedly be the prime movers in ground transportation for many years. The major problems in practice are fuel efficiency and the emission of pollutants: all of the papers in Part 2 address these two problems. The third part of the book deals with quite general laser diagnostics and modelling aspects, including computer simulations which hold out the promise of a long and important future.

This volume includes revised and extended versions of selected papers presented at the Tenth International Symposium on Applications of Laser Techniques to Fluid Mechanics held in Lisbon in July 2000.The papers describe instrumentation developments for velocity, scalar and multiphase flows and results of measurements of turbulent flows, and combustion and engines. Focus is placed on laser-Doppler anemometry, particle sizing and other methods for the measurement of velocity and scalars, such as particle image velocimetry and laser induced fluorescence. The application of laser techniques to scientific and engineering fluid flow research was emphasized, but contributions to the theory and practice of laser were also considered where they facilitate new improved fluid mechanic research.

This volume includes revised and extended versions of selected papers presented at the Tenth International Symposium on Applications of Laser Techniques to Fluid Mechanics held in Lisbon in July 2000.The papers describe instrumentation developments for velocity, scalar and multiphase flows and results of measurements of turbulent flows, and combustion and engines. Focus is placed on laser-Doppler anemometry, particle sizing and other methods for the measurement of velocity and scalars, such as particle image velocimetry and laser induced fluorescence. The application of laser techniques to scientific and engineering fluid flow research was emphasized, but contributions to the theory and practice of laser were also considered where they facilitate new improved fluid mechanic research.

The present book contains papers that have been selected from contributions to the First International Symposium on Turbulent Shear Flows which was held from the 18th to 20th April 1977 at The Pennsylvania State University, University Park, Pennsylvania, USA. Attend­ ees from close to 20 countries presented over 100 contributions at this meeting in which many aspects of the current activities in turbulence research were covered. Five topics received particular attention at the Symposium: Free Flows Wall Flows Recirculating Flows Developments in Reynolds Stress Closures New Directions in Modeling This is also reflected in the five chapters of this book with contributions from research workers from different countries. Each chapter covers the most valuable contributions of the conference to the particular chapter topic. Of course, there were many additional good con­ tributions to each subject at the meeting but the limitation imposed on the length of this volume required that a selection be made. The realization of the First International Symposium on Turbulent Shear Flows was p- sible by the general support of: U. S. Army Research Office U. S. Navy Research Office Continuing Education Center of The Pennsylvania State University The conference organization was carried out by the organizing committee consisting of: F. Durst, Universitat Karlsruhe, Karlsruhe, Fed. Rep. of Germany V. W. Goldschmidt, Purdue University, West Lafayette, Ind. , USA B. E. Launder, University of California, Davis, Calif. , USA F. W. Schmidt, Pennsylvania State University, University Park, Penna.

In the tradition of its predecessors, this volume comprises a selection of the best papers presented at the Ninth International Symposium on Applications of Laser Techniques to Fluid Mechanics, held in Lisbon in July 2000.The papers reflect the state-of-the-art in laser applications of laser techniques in fluid mechanics describing novel ideas for instrumentation, instrumentation developments, results of measurements of wall-bounded flows, free flows and flames and flow and combustion in engines. The papers demonstrate the continuing interest in the development of an understanding of new methodologies and implementation in terms of new instrumentation.

This volume comprises a selection of the best papers presented at the Eighth International Symposium on Applications of Laser Techniques to Fluid Mechanics, held in Lisbon in July 1996.The papers describe novel ideas for instrumentation, instrumentation developments, results of measurements of wall-bounded flows, free flows and flames and flow and combustion in engines. The papers demonstrate the continuing interest in the development of an understanding of new methodologies and implementation in terms of new instrumentation.

The Fourth International Symposium on Turbulent Shear Flows took place at Karlsruhe University in Germany. The papers presented at this Symposium encompassed a similar range to that of the previous meetings, with greater emphasis placed on experimental work, and continued a trend towards the examination of complex flows. Once again, three­ dimensional, recirculating and reacting flows featured strongly in the programme and were complemented by consideration of two-phase flows and discussions of both numerical and experimental techniques. The Symposium brought together some 300 participants from all over the world, and it was evident that there is a need for Turbulent Shear Flows Symposia, in order to obtain and communicate new information useful to researchers in the field of turbulent flows and of interest to engineers who design flow equipment. This volume contains 27 papers selected from more than 100 presentations at the Symposium which have been reviewed and edited before publication. Together they provide an indication of the status of current knowledge on the subjects represented at the Sympo­ sium. They are grouped into four sections, namely: • Fundamentals • Free Flows • Boundary Layers • Reacting Flows As in previous volumes in this series, each section begins with an introductory article con­ sidering the papers which follow in the broader context of available literature and current research.

This volume contains papers selected from contributions made to the Fourth Symposium on "Applications of Laser Anemometry". It is divided into three chapters concerned respectively with single-phase flows, two-phase flows and instrumentation. In the first chapter, the papers are concerned with fundamental investigations of shear flows as well as important applications including the Earth's boundary layer and internal combustion engines. The two-phase flows include applications of amplitude- and phase-based techniques to the sprays of Diesel and gas-turbine engines and to a fluidised bed and slurry flows. The new instrumentation includes miniature and multipoint LDV arrangements, PIDV and photochromic visualisation as well as improved explanations of laser-based systems.

In spite of intensive efforts over many decades, the problem of turbulence remains as challenging as ever and the number of papers, books and conferences on this topic con­ tinues to grow. As experimental techniques and computing power have developed, the breadth of investigations into the structure and development of turbulent flows has in­ creased to encompass many diverse fields of application in engineering, physics, biolo­ gy and so on. As a consequence, it is now very difficult for a single research worker to keep in touch with the many developments that are taking place in turbulence. One of the few opportunities for obtaining some overall view of the subject arises from large international symposia on turbulence and, although they have some drawbacks, it is this opportunity that is one of their main merits. The International Symposium on Turbulent Shear Flows has now been held on three occasions and they seem to be established as a major opportunity for papers on a very diverse range of topics to be presented at a single meeting. This volume is a collec­ tion of papers from the third symposium that was held at the University of California, Davis from 9-11 September 1981. The papers are divided into four sections entitled Wall Flows, Scalar Transport, Recirculating Flows and Fundamentals. This collection represents about a third of the total number of papers presented.

For this sixth volume 01 proceedings stemming lrom a Symposium on the Applications 01 Laser Techniques to Fluid Techniques, we have selected thirty one papers which are presented in live chapters. They represent some 01 the best papers presented at the Sixth Symposium which was again held at the Calouste Gulbenkian Foundation in Lisbon, this time lrom 20 to 23 July 1992. The total number of papers at the Symposium was slightly larger than in 1990 and was selected from a much increased number of abstracts, with a considerably smaller of accepted manuscripts. Thus, this volume represents some 01 the best 01 the best. The topics we have chosen to include are Laser Anemometer Optics and Processing, Two-Phase Flow Instrumentation, Whole-Field Velocimetry, Complex Flow Applications and Engine and Combusting Flows, and they show that there continues to be a healthy interest in the development 01 understanding of the methodology and its implementation in terms 01 new instrumentation, and this is emphasised by the increasing number 01 companies which have attended the Symposium in recent years in order to demonstrate their range 01 products. At the same time, it is clear that there is an increasing range of applications 01 the corresponding laser techniques and this is represented, in part, by the chapters concerned with Complex and Engine and Combusting Flows. In general, we are very pleased with the way the application 01 laser techniques has grown and hope that this se ries 01 Symposia has played its part.

This book consists of papers prepared for and presented at a NATO sponsored Advanced Study Institute which was held in Montechoro, Portugal during the period 16-27 April, 1990. This Institute was attended by approximately ninety delegates from fifteen countries and followed from a related Institute held in Vimeiro, Portugal in 1987 (see the book entitled "Instrumentation for Combustion and Flow in Engines", edited by D. F. G. Dur~o, J. H. Whitelaw and P. O. Witzel. The purposes of the first Institute related closely to instrumentation for use in gas-turbine combustors and the cylinders of internal-combustion engines. These topics were also addressed in the second Institute, though in a manner which was wider ranging and chosen to demonstrate and explain the development and application of measurement methods to combusting flows in general. The papers contained in this boo~ were selected to provide the reader with a comprehensive and up-to-date view of the variety of experimental techniques available to measure in combusting flows. Included are discussions of their range and applicability, potential accuracy and ease of use. Thus, the first paper provides a brief overview and the second an indication of those aspects of combustion which should influence the choice of flow property to be measured and the technique to be used.

This book contains selected papers prepared for the NATO Advanced Study Institute on "Unsteady Combustion", which was held in Praia da Granja, Portugal, 6-17 September 1993. Approximately 100 delegates from 14 countries attended. The Institute was the most recent in a series beginning with "Instrumentation for Combustion and Flow in Engines", held in Vimeiro, Portugal 1987 and followed by "Combusting Flow Diagnostics" conducted in Montechoro, Portugal in 1990. Together, these three Institutes have covered a wide range of experimental and theoretical topics arising in the research and development of combustion systems with particular emphasis on gas-turbine combustors and internal combustion engines. The emphasis has evolved roughly from instrumentation and experimental techniques to the mixture of experiment, theory and computational work covered in the present volume. As the title of this book implies, the chief aim of this Institute was to provide a broad sampling of problems arising with time-dependent behaviour in combustors. In fact, of course, that intention encompasses practically all possibilities, for "steady" combustion hardly exists if one looks sufficiently closely at the processes in a combustion chamber. The point really is that, apart from the excellent paper by Bahr (Chapter 10) discussing the technology of combustors for aircraft gas turbines, little attention is directed to matters of steady performance. The volume is divided into three parts devoted to the subjects of combustion-induced oscillations; combustion in internal combustion engines; and experimental techniques and modelling.