Laser Doppler and Phase Doppler Measurement Techniques


Book Description

Providing the first comprehensive treatment, this book covers all aspects of the laser Doppler and phase Doppler measurement techniques, including light scattering from small particles, fundamental optics, system design, signal and data processing, tracer particle generation, and applications in single and two-phase flows. The book is intended as both a reference book for more experienced users as well as an instructional book for students. It provides ample material as a basis for a lecture course on the subject and represents one of the most comprehensive treatments of the phase Doppler technique to date. The book will serve as a valuable reference book in any fluid mechanics laboratory where the laser Doppler or phase Doppler techniques are used. This work reflects the authors' long practical experience in the development of the techniques and equipment, as the many examples confirm.




The Laser Doppler Technique


Book Description




Optical Measurements


Book Description

Increasing possibilities of computer-aided data processing have caused a new revival of optical techniques in many areas of mechanical and chemical en gineering. Optical methods have a long tradition in heat and mass transfer and in fluid dynamics. Global experimental information is not sufficient for developing constitution equations to describe complicated phenomena in fluid dynamics or in transfer processes by a computer program . Furthermore, a detailed insight with high local and temporal resolution into the thermo-and fluiddynamic situations is necessary. Sets of equations for computer program in thermo dynamics and fluid dynamics usually consist of two types of formulations: a first one derived from the conservation laws for mass, energy and momentum, and a second one mathematically modelling transport processes like laminar or turbulent diffusion. For reliably predicting the heat transfer, for example, the velocity and temperature field in the boundary layer must be known, or a physically realistic and widely valid correlation describing the turbulence must be avail able. For a better understanding of combustion processes it is necessary to know the local concentration and temperature just ahead of the flame and in the ignition zone.




Scattering Techniques Applied to Supramolecular and Nonequilibrium Systems


Book Description

This Advanced Study Institute was held at \-lellesley College, Wellesley, MA. , from 3 to 12 August 1980. It followed by four years the second "Capri ~,chool on Photon Correlation Spectroscopy". During the intervening period there had been many new applications of dynamic light scattering techniques to the study of systems whose properties depend either on collective molecular interactions or on the formation or activity of supramo1ecu1ar structures. Con sequently, emphasis at this conference was on light scattering studies of subjects such as dynamical correlations in dense polymer solutions, phase transitions in gels, spinodal decomposition of binary fluids, Benard instabilities in nonequilibrium fluids, the formation of micelles and phospholipid vesicles, and movements of the molecular assemblies of muscle tissue. The instructional pro gramme also included tutorial lectures on two complementary spec troscopic techniques which have benefited from dramatic advances in instrumentation, these being small angle X-ray (SAXS) and small angle neutron (SANS) scattering. Strong cold neutron and synchro tron X-ray sources have become available, and data now can be acquired rapidly with newly developed position-sensitive detectors. Several reviews of recent applications of SAXS and SANS were also provided. The organizers of the ASI hoped to provide a forum for theoreticians and experimentalists to assess advances in fields which, although related, were sufficiently different that a great deal of unfamiliar information could be communicated. The order ing of the papers in this volume closely approximates that of the talks presented at the Advanced Study Institute.




LDA Application Methods


Book Description

This technical book considers the application side of LDA techniques. Starting from the basic theories that are crucial for each LDA user, the main subject of the book is focused on diverse application methods. In details, it deals with universal methodical techniques that have been mostly developed in the last 15 years. The book thus gives for the first time an application reference for LDA users in improving the optical conditions and enhancing the measurement accuracies. It also provides the guidelines for simplifying the measurements and correcting measurement errors as well as for clarifying the application limits and extending the application areas of LDA techniques. Beside the treatments of some traditional optical and flow mechanical features influencing the measurement accuracies, the book shows a broad spectrum of LDA application methods in the manner of measuring the flow turbulence, resolving the secondary flow structures, and quantifying the optical aberrations at measurements of internal flows etc.. Thus, it also supports the further developments of both the hard- and software of LDA instrumentations.




Laser Doppler Vibrometry


Book Description

This book is a continuous learning tool for experienced technical staff facing laser vibrometry technology for the first time. The book covers both theoretical aspects and practical applications of laser Doppler vibrometry, and is accompanied by a multimedia presentation that allows the audience to browse the content and come as close as possible to performing real experiments. After a brief introduction, Chapter 2 presents supporting theory, providing general information on light sources, light scattering and interference for a better understanding of the rest of the book. Chapter 3 examines the theory of laser vibrometers, explaining interferometers from an optical perspective and in terms of the related electronics. It also addresses options like tracking filters and different signal demodulation strategies, since these have a significant impact on the practical use of vibrometers. Chapter 4 explores the configurations that are encountered in today’s instrumentation, with a focus on providing practical suggestions on the use of laser vibrometers. Lastly, Chapter 5 investigates metrology for vibration and shock measurements using laser interferometry, and analyses the uncertainty of laser vibrometers in depth.




Laser Velocimetry in Fluid Mechanics


Book Description

In fluid mechanics, velocity measurement is fundamental in order to improve the behavior knowledge of the flow. Velocity maps help us to understand the mean flow structure and its fluctuations, in order to further validate codes. Laser velocimetry is an optical technique for velocity measurements; it is based on light scattering by tiny particles assumed to follow the flow, which allows the local fluid flow velocity and its fluctuations to be determined. It is a widely used non-intrusive technique to measure velocities in fluid flows, either locally or in a map. This book presents the various techniques of laser velocimetry, as well as their specific qualities: local measurements or in plane maps, mean or instantaneous values, 3D measurements. Flow seeding with particles is described with currently used products, as well as the appropriate aerosol generators. Post-processing of data allows us to extract synthetic information from measurements and to perform comparisons with results issued from CFD codes. The principles and characteristics of the different available techniques, all based on the scattering of light by tiny particles embedded in the flow, are described in detail; showing how they deliver different information, either locally or in a map, mean values and turbulence characteristics.




Optical Measurement Techniques


Book Description

Devoted to new optical measurement techniques in industry as well as the life sciences, this book has a fresh perspective on the development of modern optical sensors, which are essential for the control of parameters in industrial and biomedical applications.




High Resolution Imaging in Microscopy and Ophthalmology


Book Description

This open access book provides a comprehensive overview of the application of the newest laser and microscope/ophthalmoscope technology in the field of high resolution imaging in microscopy and ophthalmology. Starting by describing High-Resolution 3D Light Microscopy with STED and RESOLFT, the book goes on to cover retinal and anterior segment imaging and image-guided treatment and also discusses the development of adaptive optics in vision science and ophthalmology. Using an interdisciplinary approach, the reader will learn about the latest developments and most up to date technology in the field and how these translate to a medical setting. High Resolution Imaging in Microscopy and Ophthalmology – New Frontiers in Biomedical Optics has been written by leading experts in the field and offers insights on engineering, biology, and medicine, thus being a valuable addition for scientists, engineers, and clinicians with technical and medical interest who would like to understand the equipment, the applications and the medical/biological background. Lastly, this book is dedicated to the memory of Dr. Gerhard Zinser, co-founder of Heidelberg Engineering GmbH, a scientist, a husband, a brother, a colleague, and a friend.




Laser Radar


Book Description

In today's world, the range of technologies with the potential to threaten the security of U.S. military forces is extremely broad. These include developments in explosive materials, sensors, control systems, robotics, satellite systems, and computing power, to name just a few. Such technologies have not only enhanced the capabilities of U.S. military forces, but also offer enhanced offensive capabilities to potential adversaries - either directly through the development of more sophisticated weapons, or more indirectly through opportunities for interrupting the function of defensive U.S. military systems. Passive and active electro-optical (EO) sensing technologies are prime examples. Laser Radar considers the potential of active EO technologies to create surprise; i.e., systems that use a source of visible or infrared light to interrogate a target in combination with sensitive detectors and processors to analyze the returned light. The addition of an interrogating light source to the system adds rich new phenomenologies that enable new capabilities to be explored. This report evaluates the fundamental, physical limits to active EO sensor technologies with potential military utility; identifies key technologies that may help overcome the impediments within a 5-10 year timeframe; considers the pros and cons of implementing each existing or emerging technology; and evaluates the potential uses of active EO sensing technologies, including 3D mapping and multi-discriminate laser radar technologies.