Non-intrusive laser diagnostics for the spatially and temporally resolved measurement of temperature, chemical composition, and flow parameters have emerged over the last few decades as major tools for the study of both fundamental and applied combustion science. Many of the important advances in the field can be attributed to the discussions and ideas emanating from this meeting. This conference, originating in 1981 and held biennially, focuses on laser-based methods for measurement of both macroscopic parameters and the underlying microscale physical and chemical processes. Applications are discussed primarily to elucidate new chemical and physical issues and/or interferences that need to be addressed to improve the accuracy and precision of the various diagnostic approaches or to challenge the community of diagnosticians to invent new measurement techniques. Combustion environments present special challenges to the optical diagnostics community as they address measurements relevant to turbulence, spray and mixture formation, or turbulence/chemistry interactions important in practical combustion systems as well as fundamental chemical reactions in stationary laminar flames. The diagnostics considered may be generally classed as being incoherent, where the signals are radiated isotropically, or coherent, where the signals are generated in a directed, beam-like fashion. Both of the foregoing may employ either electronic or Raman resonance enhancement or a combination of both. Prominent incoherent approaches include laser induced fluorescence (LIF), spontaneous Raman scattering, Rayleigh scattering, laser induced incandescence, molecular flow tagging, and Mie scattering and their two- and three-dimensional imaging variants. Coherent approaches include coherent anti-Stokes Raman scattering (CARS), degenerate four wave mixing (DFWM), polarization spectroscopy (PS), laser induced grating spectroscopy (LIGS) and laser-based absorption spectroscopy. Spectroscopic modelling and validation are key elements to extract accurate parameter measurements and discussions focusing on key energy transfer processes, collisional models, and lineshapes. The properties and behaviour of lasers, optical arrangements and techniques, spectrally-selective and dispersive instruments and detectors are also important determinants of successful measurements and are discussed in detail. Recent developments in the conference have highlighted the application of techniques developed for combustion research that find application in other areas such as biological, atmospheric, chemical engineering or plasma processes.

Studying turbulent combustion at the fundamental level is a primary requirement to construct robust, accurate, efficient models to predict the performance of complex combustion systems. Laser based diagnostics offer significant advantage of probing multiple facets of the combustion processes simultaneously and are capable of providing quantitative information of the highly coupled phenomenon. Design of a vitiated co-flow burner is presented for laser diagnostics of turbulent flames. A foundation was laid to be able to perform Rayleigh scattering, Coherent Ani-Stokes Raman Spectroscopy, Heterodyne velocimetry and Particle scattering. Experiment facilities were developed and tests were performed for feasibility, and performance of test equipment. The present work focused on developing facilities for combined diagnostics of, temperature, species, concentration and velocity measurement. Machine vision cameras were studied for their performance with Rayleigh scattering for temperature, high resolution spectrometer is put to test to resolve rotational/vibrational bands from chemiluminesence for species concentration. An optical design for Narrowband CARS is presented. An experimental setup for multiphase turbulent flow is presented and methods were developed for image analysis in a multiphase turbulent flow. An experimental setup for simultaneous measurement of gas species concentration, particle concentration and particle velocity is presented. The final section discusses analysis of diode lasers and optics to perform seedless Laser Heterodyne Velocimetry. The current work also discusses some of the common problems and solutions for laboratory experiments using laser diagnostics.

This book examines the variety of potential laser diagnostic techniques and presents a considerable theoretical foundation elucidating physics relevant to the laser diagnostics. It explains the Raman-based approaches for major species and temperature measurements.

The increasing concern about CO2 emissions and energy prices has led to new CO2 emission and fuel economy legislation being introduced in world regions served by the automotive industry. In response, automotive manufacturers and Tier-1 suppliers are developing a new generation of internal combustion (IC) engines with ultra-low emissions and high fuel efficiency. To further this development, a better understanding is needed of the combustion and pollutant formation processes in IC engines. As efficiency and emission abatement processes have reached points of diminishing returns, there is more of a need to make measurements inside the combustion chamber, where the combustion and pollutant formation processes take place. However, there is currently no good overview of how to make these measurements. Based on the author’s previous SAE book, Engine Combustion Instrumentation and Diagnostics, this book focuses on laser-based optical techniques for combustion flows and in-cylinder measurements. Included are new chapters on optical engines and optical equipment, case studies, and an updated description of each technique. The purpose of this book is to provide, in one publication, an introduction to experimental techniques that are best suited for in-cylinder engine combustion measurements. It provides sufficient details for readers to set up and apply these techniques to IC engines and combustion flows.