Download or read book Development of Instantaneous Temperature Imaging in Sooty Flames written by Qing N. Chan and published by . This book was released on 2011 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This dissertation reports on the single-shot temperature imaging in sooty flames, based on the development of two-line atomic fluorescence (TLAF), with neutral Indium atom as seeded thermometry species. The TLAF technique in the linear excitation regime has previously been demonstrated to be feasible in sooty environments but single-shot imaging, which requires a higher signal-to-noise ratio (SNR), has been elusive. The previous TLAF theory has been extended from the linear excitation into the nonlinear excitation fluence regime. Nonlinear regime two-line atomic fluorescence (NTLAF) provides superior signal, and improves single-shot precision from ~250 K for the linear TLAF to ~100 K for the NTLAF. The NTLAF technique is shown to resolve the temperature profiles across a range of equivalence ratios for natural gas, hydrogen, and ethylene laminar premixed flames, with deviation from radiation-corrected thermocouple measurements not exceeding 100 K, and typically ~30 K. Measurements in lightly sooty flames demonstrate good capacity of the NTLAF technique to exclude interferences that hamper most two-dimensional laser-based thermometry techniques. The developed technique has been further assessed in a laminar nonpremixed flame. The results show the expediency of the technique in the study of the reaction zone, and reveal interesting findings about the Indium formation process. The temperature profile across the reaction zone shows good agreement with laminar flame calculations. Indium fluorescence is observed to be strongest at the flame front, where the temperature exceeds 1000 K. Indium has been typically seeded into flame as Indium Chloride dissolved in distilled water. The feasibility to improve on the signal quality of the developed technique, through the substitution of distilled water with an organic solvent (namely acetone, isopropanol, methanol, and ethanol) as the seeding solution, has been examined. Acetone and methanol are shown to enhance the fluorescence signal intensity the most (approximately threefold to fivefold at stoichiometric flame condition) when used. Acetone and methanol are also shown to improve the fluorescence emission across a range of equivalence ratios, most significantly in the rich combustion region, as well as a twofold enhancement in the SNR. The use of acetone or methanol, has the potential to reduce the precisoin of the measurements down to ~60 K. The use of the NTLAF technique for measurements in flames with high soot loadings was assessed. In particular, the interferences from soot or its precursors on the fluorescence measurements have been evaluated. The findings indicate that interferences, such as spurious scattering and laser-induced incandescence (LII), from soot are not significant. However, interferences from soot precursors, predominantly condensed species (CS) and perhaps polycyclic aromatic hydrocarbons (PAH), are substantial. Potential detection schemes to correct or circumvent these interferences have been identified. The technical feasibility of the NTLAF technique to be used concurrently with the LII technique to provide simultaneous single-shot imaging of temperature and soot concentration has been demonstrated. The joint NTLAF-LII method has been applied to laminar premixed and nonpremixed flames, as well as a wrinkled nonpremixed flame. No significant interference of the two measurement techniques on each other is observed, for the detection and timing schemes employed. The images also reveal that, whilst NTLAF has a limited operating range, this range is sufficient to span all regions with soot. This observation demonstrates the applicability of the joint NTLAF-LII method in assessing the coupled dependency of temperature and soot in flame.

Download or read book Crossed Plane Imaging of Premixed Turbulent Combustion Processes written by and published by . This book was released on 2003 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last several years we have developed and applied advanced imaging methods - crossed-plane laser tomography and crossed-plane laser Rayleigh imaging -- for high-resolution studies of scalar fields in premixed combustion. Laser tomography with micron sized, silicone oil droplets marks 650 K isothermal surfaces, and we have used crossed-plane tomography to measure for the first time in three dimensions the instantaneous orientation of these surfaces and to determine the probability density function of the surface normal vector, a statistical measure of surface wrinkling. Rayleigh scattering from premixed flames can be used for temperature imaging, and we have developed crossed-plane Rayleigh imaging in order to measure with high-resolution instantaneous temperature fields, temperature gradient vectors and isothermal surface densities in premixed reacting flows. Most recently we have combined crossed-plane tomography with stereo particle image velocimetry to measure for the first time reactant flow velocities and the components of this velocity both perpendicular and tangent to the reaction sheet. In this report progress from the inception of Grant number DAAD 19-99-1-0324 is summarized, and relevant information regarding publications and participants in the research is presented.

Download or read book Flame Temperature Imaging of a Low NOx Burner Via Laser Rayleigh Scattering written by Nicholas A. Smith and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Federal and global legislation are requiring increasingly stringent emission regulation on household appliances and in particular water heater burners. Emissions like NOx (NO and NO2) are a growing concern due to their adverse health effects and contribution to tropospheric ozone, acid rain, and smog formation. As NOx is more closely controlled, appliance manufacturers are developing low emission burners for use in water heaters. Flame temperature is strongly correlated to NOx production. Hence, characterizing flame temperatures in new burners is a key part of improving upon burners used today and the development of future burners. Temperature measurements applied to a new, radiant, ultralow-NOx burner are thus the focus of this research. Laser Rayleigh scattering allows us to make near-instantaneous, 2-D measurements using an unobtrusive technique. The application of this technique resulted in flame temperature images in three locations, above and across the burner surface ranging from 800-1600 K in general with an uncertainty of 9.6%. The fluctuation of the flame temperature was also found ranging from 200-800 K, indicating the presence of large scale hot and cold gas mixing. Other temperature measuring techniques were applied to the burner as well. A type-K thermocouple 5 cm above the center of the burner measured a point gas temperature of 1508 K after an estimated radiative correction was applied. This measurement was within 5.3% of the laser Rayleigh scattering measurement of 1428 K at the same location. An IR camera did not provide quantitative temperature measurements, but the videos indicated similar flame structure and mixing behavior when compared to a series of single-shot laser Rayleigh scattering images. It was concluded that the large amount of excess air (equivalence ratio of 0.725) was primarily responsible for reducing the flame temperature by 436 K in comparison with the adiabatic flame temperature under stoichiometric conditions. The radiative emission by the burner was estimated from the thermocouple and laser Rayleigh scattering measurements to decrease the temperature further by an average of 420 K relative to the stoichiometric adiabatic flame temperature.

Download or read book MILD Combustion Modelling Challenges Experimental Configurations and Diagnostic Tools written by Alessandro Parente and published by Frontiers Media SA. This book was released on 2021-11-26 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantitative NO LIF Temperature Imaging in High pressure Flames written by T. Lee and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Instantaneous Temperature Imaging with Single wavelength Aceton PLIF written by M. C. Thurber and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Quantitative Imaging of In Cylinder Processes by Multispectral Methods written by and published by . This book was released on 1997 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the objective of achieving better investigation of engines-fuels by obtaining instantaneous quantitative imaging of in-cylinder processes, several steps have been taken for some years at Rutgers University. They are: (1) Construction of a new Multispectral high-speed infrared (IR) digital imaging system; (2) Development of spectrometric analysis methods; (3) Application of the above to real-world in-cylinder engine environments and simple flames. This paper reports some of results from these studies. The one-of-a-kind Rutgers IR imaging system was developed in order to simultaneously capture four geometrically (pixel-to-pixel) identical images in respective spectral bands of IR radiation issued from a combustion chamber at successive instants of time and high frame rates. In order to process the raw data gathered by this Rutgers system, three new spectrometric methods have been developed to date: (1) dual-band mapping method; (2) new band-ratio method; and (3) three-band iteration method. The former two methods were developed to obtain instantaneous distributions of temperature and water vapor concentrations, and the latter method is to simultaneously find those of temperature, water vapor and soot in gaseous mixtures, i.e., to achieve quantitative imaging. Applications of these techniques were made to both SI and CI engine combustion processes as well as bench-top burner flames. Discussion is made on the methods and new results.

Download or read book Development of Quantitative Optical Techniques for Microgravity Combustion and Sooty Flame Characterization written by Bin Ma and published by . This book was released on 2013 with total page 372 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Joint Meeting of the U S Sections of the Combustion Institute Western States Central States Eastern States written by and published by . This book was released on 1999 with total page 954 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 994 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Species and Temperature Imaging in Liquid fueled Spray Flames written by Mark G. Allen and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book High speed Imaging Studies of Flames in a Shock Tube written by Adam Joseph Susa and published by . This book was released on 2022 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Developed through the combination of two preexisting methods - a shock tube acting as an impulse heater and a flame speed measurement from a spherically expanding flame - the shock-tube flame speed method brought significant promise to enable fundamental laminar flame speed measurements at previously inaccessible temperature conditions. Nevertheless, early applications of the method, as originally devised, encountered challenges associated with flame stability and structure that limited its ability to fulfill its full potential. In this dissertation, a series of efforts undertaken to characterize and optimize the shock-tube flame speed method are reported; the newly refined methods are subsequently validated and applied to demonstrate flame speed measurements at extreme unburned-gas temperatures, up to and exceeding 1,000 K, for the first time. After introducing the fundamentals of shock tubes, spherically expanding flames, and their combination in the first-generation shock-tube flame speed method, three investigations extending the original methods are described. First, the development of a technique for performing side-wall emission imaging through a small diagnostic port allowed for the identification of axial flame distortion in shock tube experiments. Then, the side-wall imaging was again leveraged in the development of the [laser-induced] flame image velocimetry ([LI]FIV) technique as a seedless, single-point velocimetry method for combustion environments, which was used in the first systematic investigation of core-gas velocities in the post-reflected-shock environment. Finally, a meta-analysis to identify conditions producing stable flames was performed on a collection of ten groups of experiments performed using variations of the first-generation method. In the resulting binary-classifier model, the unburned-gas ratio of specific heats and the ignition location were found to most strongly affect stability, guiding the optimal selection of an oxygen-argon oxidizer mixture for future experiments and motivating the need for additional experimental flexibility. Inspired by the significant insight gained through the application of side-wall imaging to shock-tube flame experiments, and seeking to realize the flexibility required to perform optimized flame speed experiments, a novel side-wall imaging flame test section (SWIFT) was designed and procured. The SWIFT features first-of-their-kind side-wall windows designed as cemented-doublet cylindrical lenses in order to provide large field-of-view, schlieren-compatible optical access through the curved side walls of the shock tube. Together with an enhanced suite of instrumentation, the implementation of the SWIFT enabled what would become the second-generation of the shock-tube flame speed method through the studies that followed. Making use of the new schlieren capabilities, the effect of the axial position on the stability of flames was reevaluated, both using static experiments to quantify the effect of asymmetric end-wall confinement and through post-reflected-shock experiments performed near 650 K and 1 atm to observe the effect of the post-shock flow field, reaffirming the presence of significant axial distortion at a certain (6.4-cm) axial location. Then, based on the need for a model capable of extracting laminar flame data from experiments exhibiting aspherical flames, an area-averaged formulation of the linear-curvature extrapolation model (the AA-LC model) was derived for use in shock-tube flame experiments. Applied to the static and 650 K experiments at different ignition locations, the model was demonstrated to yield precise and repeatable measurements, even in cases in which flame distortion was observed. The SWIFT, side-wall schlieren, and AA-LC model were finally applied in laminar flame speed measurements of propane, norm-heptane, and iso-octane at highest-ever-reported unburned-gas temperatures, up to and exceeding 1,000 K.

Download or read book A Nonintrusive Diagnostics Technique for Flame Soot Based on Near infrared Emission Spectrometry written by Işil Ayranci Kilinç and published by . This book was released on 2007 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: A novel nonintrusive soot diagnostics methodology was developed, validated and applied for in-situ determination of temperature, volume fraction and refractive index of soot aggregates formed inside flames by using near-infrared emission spectrometry. Research was conducted in three main parts, first one addressing development and validation of a comprehensive direct model for simulation of line-of-sight radiative emission from axisymmetric sooty flames by coupling sub-models for radiative transfer, radiative properties and optical constants. Radiative property for soot agglomerates was investigated by experimentally validating DDA method against microwave measurements and using it as a reference to assess applicability of simpler RDG-FA approximation. Part two concerns experimental investigation of an axisymmetric ethylene/air diffusion flame by Fourier Transform Near-Infrared spectroscopy. Measurement of line-of-sight emission intensity spectra was performed along with analyses on calibration, noise, uncertainty and reproducibility. Final part focuses on development, evaluation and application of an inversion methodology that inputs spectral emission intensity measurements from optically thin flames, removes noise, identifies soot refractive index from spectral gradients and retrieves soot temperature and volume fraction fields by tomographic reconstruction. Validation with simulated data and favourable application to measurements indicate that proposed methodology is a promising option for nonintrusive soot diagnostics in flames.

Download or read book A Gallery of Combustion and Fire written by Charles E. Baukal, Jr. and published by Cambridge University Press. This book was released on 2020-09-03 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: A Gallery of Combustion and Fire is the first book to provide a graphical perspective of the extremely visual phenomenon of combustion in full color. It is designed primarily to be used in parallel with, and supplement existing combustion textbooks that are usually in black and white, making it a challenge to visualize such a graphic phenomenon. Each image includes a description of how it was generated, which is detailed enough for the expert but simple enough for the novice. Processes range from small scale academic flames up to full scale industrial flames under a wide range of conditions such as low and normal gravity, atmospheric to high pressures, actual and simulated flames, and controlled and uncontrolled flames. Containing over 500 color images, with over 230 contributors from over 75 organizations, this volume is a valuable asset for experts and novices alike.

Download or read book Temporal and Spatial Temperature Measurements of Combustion Flames written by James D. Winefordner and published by . This book was released on 1980 with total page 165 pages. Available in PDF, EPUB and Kindle. Book excerpt: Five methods have been developed theoretically from steady state rate theory and four have been verified experimentally for the measurement of spatial flame temperatures. All of the methods have potential use on a 'single' pulse (time period less than 1 micron) basis for the measurements of flame temperatures. All of the methods involve the use of one or two closely spaced (in time) dye laser pulses to excited atomic fluorescence of probe atoms (e.g., T1, In, Ga, etc.) introduced as an aerosol into the flames. Several experimental difficulties have resulted in initial barriers to the measurement of flame temperatures in hydrocarbon flames as well as the use of an available SIT detector for height profiles of flame temperatures. Other studies have included the theoretical development nad experimental implementation of absolute concentration measurements of atom probes in flame as well as study of saturation broadening of atomic lines. (Author).

Download or read book Development and Application of a Time and Space Resolved Optical Diagnostic for Soot Temperature and Concentration in a Spark ignited Direct injection Engine written by Boris Dragomir Stojkovic and published by . This book was released on 2003 with total page 302 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Determination of the Heat Release Distribution in Turbulent Flames by Chemiluminescence Imaging written by Martin Rolf Werner Lauer and published by . This book was released on 2011 with total page 204 pages. Available in PDF, EPUB and Kindle. Book excerpt: