Optical and Laser Spectroscopic Study of Microwave Plasma-assisted Combustion

Optical and Laser Spectroscopic Study of Microwave Plasma-assisted Combustion PDF Author: Wei Wu
Publisher:
ISBN:
Category :
Languages : en
Pages : 225

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Book Description
Nonthermal plasma-assisted combustion (PAC) has been demonstrated to be a promising potential method to enhance combustion performance and reduce the pollutant emissions. To better understand the mechanism in PAC, we have conducted a series of studies on the combustion enhancement by plasma using a home-developed PAC platform which employs a nonthermal microwave argon plasma and a suit of optical diagnostic tools including optical imaging, optical emission spectroscopy, and cavity ringdown spectroscopy. A new PAC system in which a continuous atmospheric argon microwave plasma jet is employed to enhance combustion of methane/air mixtures was reported. Reactive species in PAC were characterized in a state-resolved manner including the simultaneously measurements of OH(A) and OH(X) radicals in the PAC flames. Roles of the state-resolved OH(A) and OH(X) radicals in microwave PAC of premixed methane/air mixture were explored. It was concluded that if both OH(A) and OH(X) radicals assisted the ignition and flame stabilization processes, then we may hypothesize that the role of OH(A) was more dominant in the ignition enhancement but the role of OH(X) was more dominant in the flame stabilization. The effect of fuel injection configurations was investigated in the comparative study between PAC of the premixed and nonpremixed methane/air mixtures. It was found that emissions from the CH (A-X) and C2 Swan systems only exist in the nonpremixed PAC which suggest that the reaction pathways are different between premixed and nonpremixed PAC. The PAC of premixed methane/oxygen/argon mixtures was investigated. A Ushaped dual-layer curve of fuel ignition/flame stabilization limit showing the effects of the plasma power on the fuel ignition and flame stabilization was observed and reported. A parametric study of the microwave PAC of the premixed ethylene/air mixtures was conducted. Behavior of the OH, CH, and C2 radicals and their dependence on plasma power, argon flow rate, and total ethylene/air mixture flow rate were also studied.

Optical and Laser Spectroscopic Study of Microwave Plasma-assisted Combustion

Optical and Laser Spectroscopic Study of Microwave Plasma-assisted Combustion PDF Author: Wei Wu
Publisher:
ISBN:
Category :
Languages : en
Pages : 225

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Book Description
Nonthermal plasma-assisted combustion (PAC) has been demonstrated to be a promising potential method to enhance combustion performance and reduce the pollutant emissions. To better understand the mechanism in PAC, we have conducted a series of studies on the combustion enhancement by plasma using a home-developed PAC platform which employs a nonthermal microwave argon plasma and a suit of optical diagnostic tools including optical imaging, optical emission spectroscopy, and cavity ringdown spectroscopy. A new PAC system in which a continuous atmospheric argon microwave plasma jet is employed to enhance combustion of methane/air mixtures was reported. Reactive species in PAC were characterized in a state-resolved manner including the simultaneously measurements of OH(A) and OH(X) radicals in the PAC flames. Roles of the state-resolved OH(A) and OH(X) radicals in microwave PAC of premixed methane/air mixture were explored. It was concluded that if both OH(A) and OH(X) radicals assisted the ignition and flame stabilization processes, then we may hypothesize that the role of OH(A) was more dominant in the ignition enhancement but the role of OH(X) was more dominant in the flame stabilization. The effect of fuel injection configurations was investigated in the comparative study between PAC of the premixed and nonpremixed methane/air mixtures. It was found that emissions from the CH (A-X) and C2 Swan systems only exist in the nonpremixed PAC which suggest that the reaction pathways are different between premixed and nonpremixed PAC. The PAC of premixed methane/oxygen/argon mixtures was investigated. A Ushaped dual-layer curve of fuel ignition/flame stabilization limit showing the effects of the plasma power on the fuel ignition and flame stabilization was observed and reported. A parametric study of the microwave PAC of the premixed ethylene/air mixtures was conducted. Behavior of the OH, CH, and C2 radicals and their dependence on plasma power, argon flow rate, and total ethylene/air mixture flow rate were also studied.

Microwave Plasma Assisted Ignition and Combustion Diagnostics

Microwave Plasma Assisted Ignition and Combustion Diagnostics PDF Author: Che Amungwa Fuh
Publisher:
ISBN:
Category :
Languages : en
Pages : 148

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Book Description
Plasmas when coupled to the oxidation process of various fuels have been shown to influence the process positively by improving upon flameholding, reduction in ignition delay time, reduced pollutant emission, etc. Despite all this positive effects being known to the science community, the mechanisms through which the plasmas effects all these enhancements are poorly understood. This is often due to the absence of accurate experimental data to validate theoretical mechanisms and the availability of a myriad sources of plasmas having different chemistries. The goal of this thesis is to further narrow the knowledge gap in the understanding of plasma assisted combustion by using a nonthermal microwave plasma to investigate the mechanism through which it enhances the oxidation of several fuel/oxidant combinations. The enhancement metrics used in this studies are minimum ignition energy, flameholding and rotational temperature. A suite of noninvasive optical diagnostics techniques (camera for visual imaging, optical emission spectroscopy and cavity ringdown spectroscopy) are employed to probe the plasma assisted combustion flame and identify the species, obtain rotational temperatures, and identify pathways through which the microwave plasma enhances the combustion process. Initially, the effect of a microwave plasma on the ignition and flameholding of an ethylene/air mixture was investigated. Then, based on observations from that study and previous studies, a novel plasma assisted combustion platform was designed capable of discriminating between the various pathways through which the plasma enhances the combustion of a fuel/air mixture. Using the designed platform, a comparative study was carried out on the roles played by the plasma activated fuel vs. plasma activated oxidizer stream. The roles played by the plasma activated fuel or air molecules in the ignition of the fuel/air mixture was investigated. Data from this study led to the suggestion that there exist a minimum required plasma generated radical pool for ignition to occur with reactive oxygen and nitrogen playing a more important role in the ignition and flameholding effects. Ground state OH(X) number densities were also measured for the first time in the hybrid ignition zone of a plasma assisted combustion reactor using cavity ringdown spectroscopy.

Plasma Spectroscopy

Plasma Spectroscopy PDF Author: Evgeniĭ Aleksandrovich Oks
Publisher: Springer
ISBN:
Category : Science
Languages : en
Pages : 204

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Book Description
Plasma Spectroscopy develops the foundation of spectroscopy for plasmas containing quasi-monochromatic electric fields in the microwaves or optical range. This topic is of major importance for plasma spectroscopy and the diagnostic of technological microwave and radiofrequency discharges, plasma lasers of microwave, optical, and x-ray ranges, pulsed discharges employed as advanced radiation sources, magnetic and laser fusion, and ionospheric and astrophysical plasmas. This monograph presents novel nonlinear-optical methods for theoretical analysis of radiation of quantum systems in media, describes principles for measuring the field and plasma parameters, and discusses their practical applications.

Plasma Spectroscopy

Plasma Spectroscopy PDF Author: Eugene Oks
Publisher:
ISBN: 9783642766718
Category :
Languages : en
Pages : 200

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Book Description
A systematic development of the foundations of spectroscopy for plasmas subjected to quasi-monochromatic electric fields in the microwave or visible range. Of importance are the transverse fields present in the plasmas of tokamaks, laser fusion, and technological microwave discharges. The book describes methods for measuring the field and plasma parameters and discusses their practical application, while also presenting new results on nonpertubative analysis of the interaction of quantum systems with a strong radiation field.

Proceedings of the 37th International MATADOR Conference

Proceedings of the 37th International MATADOR Conference PDF Author: Srichand Hinduja
Publisher: Springer Science & Business Media
ISBN: 1447144805
Category : Technology & Engineering
Languages : en
Pages : 438

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Book Description
Presented here are 97 refereed papers given at the 37th MATADOR Conference held at The University of Manchester in July 2012. The MATADOR series of conferences covers the topics of Manufacturing Automation and Systems Technology, Applications, Design, Organisation and Management, and Research. The Proceedings of this Conference contain original papers contributed by researchers from many countries on different continents. The papers cover the principles, techniques and applications in aerospace, automotive, biomedical, energy, consumable goods and process industries. The papers in this volume reflect: the importance of manufacturing to international wealth creation; the emerging fields of micro- and nano-manufacture; the increasing trend towards the fabrication of parts using lasers; the growing demand for precision engineering and part inspection techniques, and the changing trends in manufacturing within a global environment.

Atomic and Molecular Spectroscopy

Atomic and Molecular Spectroscopy PDF Author: Sune Svanberg
Publisher: Springer Nature
ISBN: 3031047761
Category : Science
Languages : en
Pages : 698

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Book Description
A wide-ranging review of modern spectroscopic techniques such as X-ray, photoelectron, optical and laser spectroscopy, and radiofrequency and microwave techniques. On the fundamental side the book focuses on physical principles and the impact of spectroscopy on our understanding of the building blocks of matter, while in the area of applications particular attention is given to those in chemical analysis, photochemistry, surface characterisation, environmental and medical diagnostics, remote sensing and astrophyscis. The Fourth Edition also provides the reader with an update on laser cooling and trapping, Bose-Einstein condensation, ultra-fast spectroscopy, high-power laser/matter interaction, satellite-based astronomy and spectroscopic aspects of laser medicine.

Laser Spectroscopy of Solids

Laser Spectroscopy of Solids PDF Author: W. M. Yen
Publisher: Springer Science & Business Media
ISBN: 3662122138
Category : Science
Languages : en
Pages : 321

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Book Description
In this volume we have attempted to present a concise survey of the spectroscopic properties of insulators as derived from the application of tunable laser spectro scopic techniques. As has been the case in gaseous atomic spectroscopy, the use of tunable lasers has allowed the extension and the refmement of optical measure ments in the condensed phases to unprecedented resolutions in the frequency and temporal domains. In turn, this firmer base of empirical fmdings has led to a more sophisticated theoretical understanding of the spectroscopy of optically excited states with major modifications being apparent in the area of their dynamic be havior. Yet the revivalistic nature of these advances implies that additional advan ces are to be expected as the techniques and developments outlined in this volume are put to widespread use. Regardless, it is our hope and that of our distinguished colleagues in this venture that the reviews presented here will be useful to neo phytes and veterans to this field alike - to the former as a laissez-passer into solid-state spectroscopy, to the latter as a useful synopsis and reference of recent developments. We have also attempted to expose the reader to the concept that optically active materials, be they organic or inorganic, as universality would require, be have in a like manner and, though terminology may vary in detail, the outline and general features of all insulators remain constant.

An Experimental Study of Microwave Plasma-enhance Combustion

An Experimental Study of Microwave Plasma-enhance Combustion PDF Author: Chandra Lynn Romel
Publisher:
ISBN:
Category : Combustion
Languages : en
Pages : 278

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Book Description


Laser Induced Plasma Spectroscopy and Applications

Laser Induced Plasma Spectroscopy and Applications PDF Author:
Publisher:
ISBN:
Category : Medical
Languages : en
Pages : 258

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Book Description


Nonlinear Laser Spectroscopy

Nonlinear Laser Spectroscopy PDF Author: V. S. Letokhov
Publisher: Springer
ISBN: 9783662134870
Category : Technology & Engineering
Languages : en
Pages : 466

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Book Description
The laser as a source of coherent optical radiation has made it possible to investigate nonlinear interaction of optical radiation with atoms and mole cules. Its availability has given rise to new research fields, such as non linear optics, laser spectroscopy, laser photochemistry, that lie at the boundary between quantum electronics and physical optics, optical spectros copy and photochemistry, respectively. The use of coherent optical radiation in each of these fields has led to the discovery of qualitatively ne\~ effects and possibilities; in particular, some rather subtle effects of interaction between highly monochromatic light and atoms and molecules, in optical spec troscopy, have formed the bases for certain methods of so-called nonlinear, laser Doppler-free spectroscopy. These methods have made it possible to in 5 6 crease the resolution of spectroscopic studies from between 10 and 10 , lim 11 ited by Doppl er 1 i ne broadeni ng up, to about 10 ; at present some 1 abor atories are developing new techniques that have even higher resolution. The discovery and elaboration of the methods of nonlinear laser spectroscopy have resulted largely from contributions by scientists from many countries, in particular from the USA (Massachusetts Institute of Technology, Stanford Uni versity, National Bureau of Standards in Boulder, Harvard University, etc. ), the USSR (P. N. Levedev Institute of Physics, Institute of Semiconductor Phys ics in Novosibirsk, Institute of Spectroscopy, etc.