Laser Diagnostics for Combustion Temperature and Species


Book Description

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.










Development of Laser Diagnostics Techniques for Combustion


Book Description

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.




Nonlinear Laser Diagnostics for Combustion and Plasma Processes


Book Description

Significant milestones for quantitative laser-based diagnostics of reacting flows were reached on two separate tasks: (1) the extension of laser-based diagnostics to shorter vacuum ultraviolet (vuv) wavelengths and (2) the development of amplified spontaneous emission (ASE) diagnostics for light atoms. For the first task, phase-matching was applied to produce significant increases in vuv laser intensities, producing over 5 mu J at Lyman alpha (121.6 nm) in a mixture of krypton and argon. Factors affecting the long-term stability of vuv powers were studied. The diagnostic potential of two-photon excited ASE of atomic hydrogen and oxygen was explored in a variety of low-pressure flames. Direct ASE gain measurements gave oxygen concentrations. A model of the ASE signal was developed, and a new understanding of both ASE and laser-induced fluorescence of two-photon excited atoms emerged from this model.




Laser Diagnostics for Combustion Temperature and Species


Book Description

Focusing on spectroscopically-based, spatially-precise, laser techniques for temperature and chemical composition measurements in reacting and non-reacting flows, this book makes these powerful and important new tools in combustion research