Download or read book Advanced Optical Diagnostics for HF Laser Development written by and published by . This book was released on 2002 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present results from a study that used a non-intrusive diagnostic for mixing, species concentration, optical gain, and spatial beam profile for HF chemical lasers. The instrument is based on hyperspectral imaging using a low order Fabry-Perot interferometer. The basic theory behind this technology is described and several applications to a chemically reacting flow field are presented. We also discuss application of this device to a subsonic HF chemical laser.

Download or read book Development and Application of Advanced Optical Diagnostics for the Study of High Speed Flows in Micro Systems written by and published by . This book was released on 2004 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary goal of this research program is the development and application of laser based flow diagnostics for the study of supersonic micro-nozzles, such as those, which might be employed for flow control and/or small satellite orbit maintenance. In this report we document the significant progress that has been made in FY-02 in the development of Molecular Tagging Velocimetry (MTV), including assessment of experimental accuracy at low (0.10 - 3 torr) static pressure and detailed comparisons between experimental flow field data and computational predictions using the Direct Simulation Monte Carlo (DSMC) method. Progress in the development of micro Planar Doppler Velocimetry (micro PDV) is also described.

Download or read book Application of Advanced Laser and Optical Diagnostics Towards Non Thermochemical Equilibrium Systems written by Andrea Grace Hsu and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The Multidisciplinary University Research Initiative (MURI) research at Texas A and M University is concerned with the experimental characterization of non-thermal and non-chemical equilibrium systems in hypersonic (Mach greater than 5) flowfields using experimental diagnostics, and is an interdisciplinary collaboration between the Chemistry and Aerospace Engineering departments. Hypersonic flight conditions often lead to non-thermochemical equilibrium (NTE) state of air, where the timescale of reaching a single (equilibrium) Boltzmann temperature is much longer than the timescale of the flow, meaning that certain molecular modes such as vibrational modes, may be much more excited than the translational or rotational modes of the molecule leading to thermal-nonequilibrium. A nontrivial amount of energy is therefore contained within the vibrational mode, and this energy cascades into the flow as thermal energy, affecting flow properties through the process of various vibrational-vibrational (V-V) and vibrational-translational (V-T) energy exchanges between the flow species. The research is a fundamental experimental study of these NTE systems and involves the application of advanced laser and optical diagnostics towards hypersonic flowfields. The research is broken down into two main categories: the application and adaptation of existing laser and optical techniques towards characterization of NTE, and the development of new molecular tagging velocimetry techniques which have been demonstrated in an NTE flowfield, but may be extended towards a variety of flowfields.

Download or read book Modern Optical Methods in Gas Dynamic Research written by Darshan Dosanjh and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 303 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is based on material prepared by the contributors to the symposium on "Progress in Gas Dynamic Research by Optical Methods", held on May 25-26, 1970 in the Department of Mechanical and Aerospace Engineering at Syracuse University. The contents focus on experimental and analytical aspects of contemporary op tical methods as applied in modern research on high speed and/or high temperature gaseous flows. State of the art, recent research results and possible research applications of spectroscopy, spectral interferometry, pulse laser holographic interferometry, laser as a diagnostic and plasma generating tool and the analysis of plasma by light scattering constitute part of the subject matter of this vol ume. The emerging importance and impact of recent laser developments on optical diagnostics of gas dynamic and gas-physics phenomena is a recurring theme throughout the volume. Diverse applications of the shock tube to process gases to high temperature equilibrium conditions and the study of important char acteristics of these radiating gases by contemporary spectroscopic methods are discussed in papers by Nicholls, Wurster and Wares, et al. Refractivity index measurements have long been extensively used for investigating gas dynamic and aerodynamic flows. However, the recent availability of the laser as a light source has brought sig nificant improvements in the more conventional optical methods such as schlieren photography and interferometry as reported here in Alcock's paper. More recent laser developments have resulted in several com pletely new optical diagnostic methods.

Download or read book Optical and Laser Diagnostics written by C Arcoumanis and published by CRC Press. This book was released on 2016-04-19 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: From the automotive industry to blood flow monitoring, optical techniques and laser diagnostics are becoming integral parts in engineering and medical instrumentation. Written by leading global experts from industry, academic groups, and laboratories, this volume provides an international perspective on both existing applications and leading-edge r

Download or read book Optical Diagnostics for Flow Processes written by L. Lading and published by . This book was released on 1994-12-31 with total page 416 pages. Available in PDF, EPUB and Kindle. Book excerpt: The origin of optical methods for fluid flow investigations appears to be nontraceable. This is no matter for surprise. After all seeing provides the most direct and common way for humans to learn about their environment. But at the same time some of the most sophisticated methods for doing measurements in fluids are also based on light and often laser light. A very large amount of material has been published in this area over the last two decades. Why then another publication? Well, the field is still in a state of rapid development. It is characterised by the use of results and methods developed within very different areas like optical physics, spectroscopy, communication systems, electronics and computer science, mechanical engineering, chemical engineering and, of course, fluid dynamics. We are not aware of a book containing both introductory and more advanced material that covers the same material as presented here. The book is the result of a compilation and expansion of material presented at a summer school on Optical Diagnosticsfor Flow Processes,held at RiS0 National Laboratory and the Technical University of Denmark in September 1993. The aim of the course was to provide a solid background for understanding, evaluating, and using modem optical diagnostic methods, addressing Ph. D. students and researchers active in areas of fluid flow research. The disciplines represented by the participants ranged from atmospheric fluid dynamics to biomedicine.

Download or read book Laser Diagnostics for Reacting Flows written by and published by . This book was released on 2007 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced optical diagnostic techniques relevant to propulsion were investigated. The techniques studied were based on laser spectroscopy, with emphasis on spectrally-resolved absorption and laser-induced fluorescence (LIF). Laser sources included tunable cw near-infrared diode lasers and tunable (or fixed-wavelength) pulsed lasers operated at ultraviolet (UV) or infrared (IR) wavelengths. The cw lasers were spectrally narrow, allowing study of innovative diagnostics based on spectral lineshapes, while the pulsed lasers provided intense bursts of photons needed for techniques based on LIF. Accomplishments of note included: (1) development of a new imaging diagnostic based on infrared planar laser-induced fluorescence (IR PLIF), (2) investigations of quantitative ultraviolet (UV) PLIF of NO and CO2 in high-pressure combustion environments, (3) the development of a new temperature diagnostic using UV absorption of CO2 for high-temperature combustion environments, (4) development of advanced wavelength-multiplexed diode laser absorption sensing of non-uniform temperature distributions, gas temperature in scramjet flows, and tunable mid-IR-based fuel sensing, and (5) further development of quantitative tracers to image fuel distribution using ketones and the aromatic toluene. The full spectrum of results was published in thirty-eight papers in the AIAA and peer reviewed literature, seven PhD theses, and forty-three presentations and invited lectures.

Download or read book Optical Diagnostics of Gas dynamic Flows Using Advanced Laser Measurement Techniques written by Kenneth P. Gross and published by . This book was released on 1985 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Optical Diagnostics in High Speed Flows written by M. Samimy and published by . This book was released on 1999 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Application and Development of Advanced Laser Diagnostics for Flame Measurements written by Sukesh Roy and published by . This book was released on 2002 with total page 272 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Optical Diagnostics of Plasma related Phenomena and Applications written by Yupan Bao and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Optical diagnostics techniques based on coded imaging were developed and applied for plasma-related phenomena and applications. The signal of interest is first encoded with a sinusoid pattern either by structured laser illumination or implement of a diffractive optical element, such as a grating, along the optical path of the signal. The coded signal will then be extracted from the raw data by a lock-in based algorithm, such as frequency recognition algorithm for multiple exposures (FRAME). Two types of non-thermal plasma sources, i.e., gliding arc discharges and nanosecond pulsed discharges, were investigated. Volumetric information of molecular distributions around a gliding arc was captured using laser-induced fluorescence with structured illumination and FRAME. Laser scattering imaging during the formation of a nanosecond pulsed discharge on a at methane-air flame was extracted from luminous plasma emission using structured laser illumination. Furthermore, a technique named periodic shadowing was applied for streak camera measurements, where both higher temporal contrast and effective dynamic range were achieved. The gliding arc plasma discharge was also applied in an industrial prototype burner as plasma-assisted combustion has been proven to be a promising technique to increase energy efficiency as well as reduce environmentally harmful emission. With the help of 0.1% additional energy, the lean blow-out limit of a hundred kilowatt burner was extended from a global equivalence ratio of 0.47 to 0.45.

Download or read book Application of Advanced Laser Diagnostics to Hypersonic Wind Tunnels and Combustion Systems written by and published by . This book was released on 2009 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: This LDRD was a Sandia Fellowship that supported Andrea Hsu's PhD research at Texas A & M University and her work as a visitor at Sandia's Combustion Research Facility. The research project at Texas A & M University is concerned with the experimental characterization of hypersonic (Mach>5) flowfields using experimental diagnostics. This effort is part of a Multidisciplinary University Research Initiative (MURI) and is a collaboration between the Chemistry and Aerospace Engineering departments. Hypersonic flight conditions often lead to a non-thermochemical equilibrium (NTE) state of air, where the timescale of reaching a single (equilibrium) Boltzmann temperature is much longer than the timescale of the flow. Certain molecular modes, such as vibrational modes, may be much more excited than the translational or rotational modes of the molecule, leading to thermal-nonequilibrium. A nontrivial amount of energy is therefore contained within the vibrational mode, and this energy cascades into the flow as thermal energy, affecting flow properties through vibrational-vibrational (V-V) and vibrational-translational (V-T) energy exchanges between the flow species. The research is a fundamental experimental study of these NTE systems and involves the application of advanced laser and optical diagnostics towards hypersonic flowfields. The research is broken down into two main categories: the application and adaptation of existing laser and optical techniques towards characterization of NTE, and the development of new molecular tagging velocimetry techniques which have been demonstrated in an underexpanded jet flowfield, but may be extended towards a variety of flowfields. In addition, Andrea's work at Sandia National Labs involved the application of advanced laser diagnostics to flames and turbulent non-reacting jets. These studies included quench-free planar laser-induced fluorescence measurements of nitric oxide (NO) and mixture fraction measurements via Rayleigh scattering.

Download or read book Optical Diagnostics Toolbox for Laser Interstitial Thermal Therapy written by Lee Chin and published by . This book was released on 2007 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laser interstitial thermal therapy (LITT) shows promise as an alternative to radiation therapy and/or invasive surgery. While LITT has shown promise in a number of clinical trials, widespread implementation of LITT requires the development of practical on-line monitoring techniques for ensuring complete coagulation of the tumour volume while sparing healthy surrounding tissues. The first half of this thesis focuses on providing a better understanding of the optical signal dynamics that occur during LITT for the purpose of developing monitoring strategies that utilize optical measurements. Based on diffuse light model results and phantom experiments we develop a novel strategy for determining the location of the coagulation boundary using temporally measured changes in optical signal intensity. The strategy is evaluated in ex vivo bovine liver and shown to localize the thermal damage boundary location to within & sim; 1 mm. The second half of this thesis examines the utility of radiance measurements for in vivo optical property determination and spectroscopic assessment of tissue state that can be applied for on-site treatment planning and pre/post treatment evaluation of tissue malignancy or thermal damage zones, respectively. A novel radiance-based technique is presented for separating the absorption and scattering properties of turbid media under realistic noise conditions and typical experimental uncertainty. We demonstrate that the technique is able to experimentally quantify optical properties to within & sim; 10% for transport albedos greater or equal to 0.5. Finally, we develop a novel spectroscopic method that can quantify chromophore concentrations, interstitially, at a single sensor position. The technique is verified experimentally in tissue simulating phantoms and shown to recover chromophore concentrations to within & sim; 10%. The results of this thesis provide a potential interstitial optical toolkit for monitoring and evaluation of LITT.

Download or read book Development of High speed Laser Diagnostics for the Study of Advanced Propulsion Systems written by Stephen Daniel Hammack and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Development of Laser Spectroscopic Diagnostics to Support Advanced Compound Semiconductor Deposition Techniques written by and published by . This book was released on 1990 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: This program constructed and demonstrated an apparatus for the development of laser diagnostics for the gas phase molecules involved in semiconductor fabrication techniques, particularly the organometallic chemical vapor deposition of compound semiconductors like gallium arsenide. Work in this apparatus, a flow tube with mirrors for long path tunable infrared diode laser absorption and electrodes for a radio frequency glow discharge, culminated in observations designed to assess the importance of arsenic hydride radicals in the decomposition of organoarsenic compounds. Preliminary observations of fluorocarbon and methane plasmas produced observations of several species which could be compared with models and other observations and which added to knowledge of these systems with their important applications in silicon etching an diamond deposition. The program also resulted in band strength measurements for the methyl and difluorocarbene radicals, using tunable diode laser, dye laser, and fast flow reactor techniques.

Download or read book Advanced Laser Diagnostics Development and Application written by D. F. Grosjean and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Experimental and numerical investigations on gas-turbine combustion processes and jet-fuel thermal stability were undertaken. Advanced laser-based diagnostic techniques were developed and applied to the experimental study of combustion processes (jet diffusion flames and research combustors) and jet-fuel thermal-stability processes (autoxidation, global chemistry, and fuel-additive effects). In addition, numerical computational fluid dynamics with chemistry (CFDC) models detailing both the fluid dynamics and chemistry were developed to simulate realistic environments. The development, calibration, and evaluation of the numerical models employing fundamental combustion and fuel experiments was the ultimate goal of this research program.

Download or read book 36th AIAA Plasmadynamics and Lasers Conference 05 5037 05 5390 written by and published by . This book was released on 2005 with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: