Download or read book Fundamental Studies of Flame Structure Through Laser Plasma Diagnostics written by Wendong Wu and published by . This book was released on 2017 with total page 175 pages. Available in PDF, EPUB and Kindle. Book excerpt: Increasing concerns about air pollution and global climate change are drawing attention to the need for efficiency improvements and emission reductions for combustion processes, which account for more than 85% of energy production in United States. Combustion efficiency and emissions are affected by the mixing and reacting of fuel and oxidizer. Understanding such behavior plays a critical role in flame structure studies and combustion optimization. However, experimentally obtaining mixture fraction, which is a widely used quantity to describe the mixing behavior, has proven to be a challenge, especially for heavier hydrocarbon fuels or fuel rich flames. Moreover, measuring flame temperature simultaneously with mixture fraction adds complexity into the experimental setup. In this dissertation, laser plasma diagnostics techniques were developed to provide a straightforward method to simultaneously obtain composition and temperature measurements. The capability of these novel techniques is applicable to more complex fuels and a broader range of equivalence ratios than has heretofore been possible, and facilitates a better understanding of flame structure.Laser-induced breakdown spectroscopy (LIBS) is proposed as an alternative method of measuring mixture fraction. A back-scattering setup is utilized to mitigate the beam steering effects in non-uniform and unsteady flames. The calibration for the LIBS system was completed in an ethylene-air premixed flame under a broad range of equivalence ratios. The elemental species distributions for H, C, N, O were measured in a counter-flow diffusion flame. The measured mixture fraction compared favorably with the numerical results from OPPDIF flame code. On the basis of LIBS measured elemental species profile, the preferential diffusion effect was analyzed.Utilizing the sound emission from laser-induced plasmas, acoustic-based laser induced breakdown thermometry (LIBT) was developed as a novel method for flame temperature measurement. The established correlation between the optical emission and acoustic emission in a premixed flame demonstrated that the acoustic signal can serve as an internal standard in the gas phase LIBS measurement. The influences of flame temperature and composition on the acoustic signal were investigated independently. The composition effect was found to be second order comparing to the temperature effect. The statistics of the LIBT measurement were also analyzed to better understand the distribution of samples. Furthermore, the temperature and gas density distributions in a counter-flow diffusion flame were measured using LIBT and were found to compare favorably with numerical results. To evaluate the possibility of simultaneous composition and temperature measurement using laser plasma diagnostics, the spatial and temporal resolutions of LIBS and LIBT were carefully examined. The accuracy of LIBT technique was analyzed as a function of sample size from a statistical perspective. The results demonstrated that LIBT has spatial and temporal resolutions comparable to that of LIBS. Finally, a preliminary study using a Burke- Schumann flame and a Hencken burner was performed to understand the influence of turbulent flow.Measuring composition and temperature simultaneously using laser plasma diagnostics provides substantial benefits over traditional measurement technique. However, in exchange for such benefits, information on major species concentrations can no longer be directly measured. To infer the molecular species profile from the elemental species profile, the underlying partial-equilibrium assumption was examined. Among partially-equilibrated reactions, the water-gas shift (WGS) reaction is most often assumed to be in equilibrium because of its important role in the high temperature zone. Thus, the equilibrium domain of WGS reaction was systematically studied in different hydrocarbon flames under varying strain rates to evaluate the validity of partial equilibrium assumption. The underlying mechanism for WGS-equilibrium was also examined. The results suggested that even though the WGS reaction has a broad partial-equilibrium domain in syngas, methane, ethylene and propane flames, the mechanisms responsible for partial equilibrium were very different. In hydrocarbon flames, the water-gas-shift reaction can achieve partial equilibrium even though the two elementary reactions behind it are not equilibrated.
Download or read book Laser Diagnostics and Modeling of Combustion written by Kazuo Iinuma and published by Springer. This book was released on 1987 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Advanced Laser Diagnostics of Compressible Flows written by and published by . This book was released on 2003 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advanced laser diagnostics have been developed to study the fundamentals of supersonic flows for scramjet applications. Filtered Rayleigh scattering and planar laser-induced fluorescence (PLIF) techniques were developed and applied for measuring temperature and species in reacting and nonreacting flows. Fundamental studies of a cavity flame-holder in reacting and nonreacting supersonic flows were conducted. Several cavity-configuration and fueling schemes were employed, and combustion performance was documented. Raman scattering was utilized to measure the time-averaged equivalence ratio of cavity fueling. OH-PLIF was used to mark the reaction zone of the combustion and aid the optimization of fueling. An isolator of rectangular cross section with adjustable divergence angles has been evaluated for different inlet Mach numbers. Shock structures and fluctuations of shock position were also identified at various Mach numbers, divergence angles, and pressure ratios. The potential application of a plasma torch as an alternative ignition source for the scramjet combustor was also investigated through experimental and CFD studies. Maintenance and upgrade of the test facility and support of testing were performed.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1986 with total page 812 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Aided Diagnostics of Plasmas and Gases written by K Muraoka and published by CRC Press. This book was released on 2016-04-19 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: Updated and expanded from the original Japanese edition, Laser-Aided Diagnostics of Gases and Plasmas takes a unique approach in treating laser-aided diagnostics. The book unifies the subject by joining applications instead of describing each application as a totally separate system. In taking this approach, it highlights the relative strengths of
Download or read book Laser Diagnostics of Turbulent Flames in High Speed Flows written by Nathan Ryan Grady and published by . This book was released on 2015 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 488 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Laser Diagnostics for Combustion Temperature and Species written by Alan C. Eckbreth and published by CRC Press. This book was released on 1996-10-10 with total page 632 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fossil Energy Update written by and published by . This book was released on 1981 with total page 886 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic and Molecular Spectroscopy written by Sune Svanberg and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 601 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wide-ranging review of modern spectroscopic techniques such as X-ray, photoelectron, optical and laser spectroscopy, and related techniques. The book focuses on physical principles and the impact of spectroscopy on our understanding of the building blocks of matter, while examining applications to chemical analysis, photochemistry, surface characterization, environmental and medical diagnostics, remote sensing, and astrophysics. This Third Edition includes the most up-to-date developments.
Download or read book Combustion Research Program written by and published by . This book was released on 1992 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: This project has comprised laser flame diagnostic experiments, chemical kinetics measurements, and low pressure flame studies. Collisional quenching has been investigated for several systems: the OH radical, by H20 in low pressure flames; the rotational level dependence for NH, including measurements to J=24; and of NH2 at room temperature. Transition probability measurements for bands involving v(prime) = 2 and 3 of the A-X system of OH were measured in a flame. Laser-induced fluorescence of vinyl radicals was unsuccessfully attempted. RRKM and transition state theory calculations were performed on the OH + C2H4 reaction, on the t-butyl radical + HX; and transition state theory has been applied to a series of bond scission reactions. OH concentrations were measured quantitatively in low pressure H2/N2O and H2/O2 flames, and the ability to determine spatially precise flame temperatures accurately using OH laser-induced fluorescence was studied.
Download or read book Government Reports Annual Index written by and published by . This book was released on 1993 with total page 1300 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fusion Energy Update written by and published by . This book was released on 1979 with total page 294 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Basic Research and Technologies for Two Stage to Orbit Vehicles written by Dieter Jacob and published by John Wiley & Sons. This book was released on 2006-03-06 with total page 683 pages. Available in PDF, EPUB and Kindle. Book excerpt: Focusing on basic aspects of future reusable space transportation systems and covering overall design, aerodynamics, thermodynamics, flight dynamics, propulsion, materials, and structures, this report presents some of the most recent results obtained in these disciplines. The authors are members of three Collaborative Research Centers in Aachen, Munich and Stuttgart concerned with hypersonic vehicles. A major part of the research presented here deals with experimental and numerical aerodynamic topics ranging from low speed to hypersonic flow past the external configuration and through inlet and nozzle. Mathematicians and engineers jointly worked on aspects of flight mechanics like trajectory optimization, stability, control and flying qualities. Structural research and development was predominantly coupled to the needs for high temperature resistant structures for space vehicles.
Download or read book AIAA Journal written by American Institute of Aeronautics and Astronautics and published by . This book was released on 2006 with total page 958 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Introduction to Laser Plasma Diagnostics written by Allan A. Hauer and published by . This book was released on 1988 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Diagnostics of the Particle Field in Particle laden DC ARC Plasmas and High Velocity Combustion Jets as Applied to Industrial Thermal Sprays written by Weiduo Yu and published by . This book was released on 1999 with total page 370 pages. Available in PDF, EPUB and Kindle. Book excerpt:
