Download or read book Soot Analysis in Combustion Environments by Laser induced Incandescence written by R. Wainner 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 Laser induced Incandescence written by and published by . This book was released on 2015 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The understanding of soot formation in combustion processes and the optimization of practical combustion systems require in situ measurement techniques that can provide important characteristics, such as particle concentrations and sizes, under a variety of conditions. Of equal importance are techniques suitable for characterizing soot particles produced from incomplete combustion and emitted into the environment. Also, the production of engineered nanoparticles, such as carbon blacks, may benefit from techniques that allow for online monitoring of these processes.

Download or read book Measurement Characterization Identification and Control of Combustion Produced Soot written by Madhu Singh and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The negative health implications associated with combustion produced soot demand identification of contributing sources, quantification and characterization of their emissions to assess its impact, and control to minimize the imposed hazard. Distinguishing different sources of soot from engines and combustors is challenging, given the morphological and chemical similarity of the emitted soot. Leaner combustion conditions and tighter emission limits challenge traditional filter-based measurements for soot mass. Meanwhile, current after-treatment particulate control strategies are based on regeneration, i.e., soot oxidation which in turn depends upon soot nanostructure and composition (such as in a diesel particulate filter). Presently, effects on human health associated with soot exposure are largely correlative, while controlled lab studies predominantly use varied washings or extracts of soot, but rarely the actual particulate. Given the intertwined nature of these topics this dissertation addresses each in an integrated approach. Laser-induced incandescence (LII) is used to determine soot concentration while Time-resolved LII (TiRe-LII) can be used to estimate soot primary particle size largely by using available and appropriate models. The use of laser diagnostics has been used to experimentally demonstrate prevailing inconsistencies between experimentally measured and model-derived particle diameter values. Discrepancies have been attributed (a) to the empiricism associated with evaluating modeling variables and (b) to the lack of proper accountability of the changes in soot nanostructure upon heating with a pulsed laser. This work uses an experimental approach coupled with microscopy to (a) test the robustness of existing LII models and (b) inform existing models of experimental observations so that these can be accounted for in future models. Specifically, the contribution of changing soot nanostructure on laser heating is known and is shown here again with transmission electron microscopy (TEM). However, the change in soots optical properties because of an altered nanostructure remains unclear. Optical properties change when soot is laser-heated, and this alteration of optical properties upon laser heat treatment has been shown in this work experimentally, by using UV-Vis spectroscopy. Also, the effect of the degree of aggregation on the soots cooling profile is highlighted. This work demonstrates that different degrees of aggregation results in a shift of the time-temperature-history (TTH), thereby resulting in erroneous particle size predictions, which are calculated from the materials TTH. Unfortunately, most models assume point-contacting spheres and aggregation remains unaccounted for. The effect of the thermal accommodation coefficient is similar in that a small change in the value of this mathematical parameter significantly alters particle cooling as simulated here by an open-access simulator, indicating the need to exercise caution when assigning a value to this parameter in the model. While the change in soot nanostructure as a consequence of laser annealing complicates the interpretation from LII measurements, laser heating of soot can reciprocally be used to purposefully study the evolution in soot nanostructure as a function of its chemistry. Soot chemistry varies with its combustion environment, with fuel and combustion conditions specific to each source. Thus, by association, the evolution of soot nanostructure observed upon laser heat treatment can be correlated to its fuel origins and combustion origins, potentially identifying its formation source. Fundamentally, the presence of oxygen in nascent soot is identified here as a key compositional parameter. The increase in oxygen content of the fuel, as diesel is blended with increased proportions of biofuel, is correlated to increased oxygen content in the soot that is generated by the respective fuel. In other words, fuel with a higher oxygen content generates soot which also has oxygen content relatively higher than soot generated by fuel with low oxygen content. This work shows that oxygen dictates the evolution of soot nanostructure when it escapes the material upon laser heat treatment. When laser heated, the nanostructure of soot with a higher oxygen content evolves as hollow-shell like structures while nanostructure of soot with a low oxygen content evolves to show a ribbon-like interior. This divergence in soot nanostructure based on the oxygen content of nascent soot, which in turn is shown to be a function of the fuel composition, could be used to identify the source that generated the soot sample studied. Given the lack of availability of authentic soot samples, the combination of laser heat treatment and TEM of soot to identify fuel or source is powerful when sample quantities are in the range of less than a few nanograms. Being able to identify sources and their contributions using laser derivatization of soot as a diagnostic can help optimize new or existing control measures to reduce the concentration of atmospheric soot. For instance, diesel particulate filters (DPFs) are used to reduce diesel soot emissions. Effective protocols for DPF operation can be developed by understanding soot nanostructure changes as captured soot is oxidized during passive and active DPF regeneration. Typically, O2, NO2 or a combination of the two oxidants are encountered during DPF regeneration. In this work, soot nanostructure has been shown to vary with the order of oxidants to which it is exposed, a significant finding towards optimizing DPF filter regeneration protocols. The study has been performed on authentic diesel soot in a thermogravimetric analyzer under conditions mimicking active and passive regeneration in a DPF. To validate observations with diesel soot, three carbon blacks with varying nanostructure are also subjected to oxidation by O2 and NO2. The intriguing result is that order of oxidation matters, i.e., the oxidation rates are dependent upon nanostructure changes in response to oxidation by O2 alone, or O2 with NO2.Prolonged exposure to particulate matter causes unwanted ill-health, lung dysfunctions, and breathing problems. Most toxicity studies are done using a washing, or an extract of the organic fraction of soot and cells are exposed to this extract. This work tests the adverse effect of soot on human (male) lung cells when these are exposed to surrogate soot as is, i.e., structure and chemistry intact to mimic real-time exposure conditions. The impact of soot chemistry and the presence of acidic functional groups on lung epithelial cells for varying exposure times is demonstrated in our collaborative work with the College of Medicine at Penn State, Hershey, PA. Soot chemistry is shown to directly and adversely impact cell viability and mRNA expressions of the IL-1B and IL-6 cytokines as well as mRNA expression of the TLR4 protein. Specifically, cell viability was shown to reduce significantly after 6- and 24-hours of exposure to carboxylic groups on the soot, thereby demonstrating the health impact of soot surface chemistry in comparison to extracts.In summary, soot measurement, its extensive characterization to identify source contributions and develop practically applicable control strategies has a direct implication on our health and surroundings and can aid in promoting a healthy living environment.

Download or read book Laser Induced Incandescence of Soot for High Pressure Combustion Diagnostics written by Daniel Dennis Emile Cormier and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book An Analytical and Quantitative Analysis of the Laser induced Incandescence of Soot written by Richard Trent Wainner and published by . This book was released on 1999 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Induced Incandescence of Soot at High Pressures written by Sanaz Ghasemi and published by . This book was released on 2012 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Characterization of Soot Particles and Their Precursors by Coupling Laser based Techniques written by Cornelia Irimiea and published by . This book was released on 2017 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combustion impacts many important aspects of our life like the air quality, the local and global climate and the use of energy sources. In the last decades, an outstanding progress towards cleaner combustion has been achieved. However, the reaction pathways leading to the formation of some pollutants, especially particulate matter (soot) resulting from incomplete combustion, are still elusive. In this work, we aim to investigate specific aspects of soot and its precursors formation in laboratory flames for a fundamental understanding of the mechanisms leading from the gas phase up to the mature particulate found in the exhausts. This objective is also pursued in field-campaigns to assess the potential impact of soot surface properties on the environment. Following this approach, experimental techniques like in-situ laser induced incandescence and fluorescence, and ex-situ laser desorption and secondary ion mass spectrometry are used to target specific properties of soot and its precursors. Notably, the evolution of the complex refractive index of soot is measured as a function of soot maturity, and the implications on both the flame physico-chemistry and the analytical techniques applicability are discussed. Additionally, a new detection method for soot and precursors based on simultaneous excitation at one wavelength is developed. In parallel, two campaigns are dedicated to the analysis of the surface chemistry of soot sampled from airplane and car exhausts. Statistical methods as multivariate analysis are used to identify patterns and differences within sets of samples by assessing the influence of the combustion parameters or the role of the fuel.

Download or read book 28th Plasmadynamics and Lasers Conference written by and published by . This book was released on 1997 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Analysis of Laser induced Incandescence and Novel Soot Measurement Approaches written by B. Mewes and published by . This book was released on 1996 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser induced Incandescence for Soot Diagnostics written by and published by . This book was released on 2012 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Laser Diagnostics and Optical Measurement Techniques in Internal Combustion Engines written by Hua Zhao and published by SAE International. This book was released on 2012-07-30 with total page 373 pages. Available in PDF, EPUB and Kindle. Book excerpt: The increasing concern about CO2 emissions and energy prices has led to new CO2 emission and fuel economy legislation being introduced in world regions served by the automotive industry. In response, automotive manufacturers and Tier-1 suppliers are developing a new generation of internal combustion (IC) engines with ultra-low emissions and high fuel efficiency. To further this development, a better understanding is needed of the combustion and pollutant formation processes in IC engines. As efficiency and emission abatement processes have reached points of diminishing returns, there is more of a need to make measurements inside the combustion chamber, where the combustion and pollutant formation processes take place. However, there is currently no good overview of how to make these measurements. Based on the author’s previous SAE book, Engine Combustion Instrumentation and Diagnostics, this book focuses on laser-based optical techniques for combustion flows and in-cylinder measurements. Included are new chapters on optical engines and optical equipment, case studies, and an updated description of each technique. The purpose of this book is to provide, in one publication, an introduction to experimental techniques that are best suited for in-cylinder engine combustion measurements. It provides sufficient details for readers to set up and apply these techniques to IC engines and combustion flows.

Download or read book Lizz Roman Dancers Collection written by and published by . This book was released on with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Collection contains clipping and publicity files.

Download or read book On the use of laser induced incandescence for soot diagnostics written by Henrik Bladh and published by . This book was released on 2007 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Using Laser Induced Incandescence to Measure Soot Smoke Concentrations written by and published by . This book was released on 1997 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Soot Formation in Combustion written by Henning Bockhorn and published by Springer Science & Business Media. This book was released on 2013-03-08 with total page 595 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot Formation in Combustion represents an up-to-date overview. The contributions trace back to the 1991 Heidelberg symposium entitled "Mechanism and Models of Soot Formation" and have all been reedited by Prof. Bockhorn in close contact with the original authors. The book gives an easy introduction to the field for newcomers, and provides detailed treatments for the specialists. The following list of contents illustrates the topics under review:

Download or read book Particle Vaporization Velocimetry and Quantitative Soot Concentration Measurement in Sooty Flows written by Ping Yang and published by . This book was released on 2007 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot is a combustion generated pollutant that is both a direct risk to human health and a contributing source to global environmental change. Soot can also be a controlling factor in heat transfer inside combustion systems. Thus there is a growing interest in being able to measure soot and understand its production in practical, turbulent combustion environments. Therefore, the specific objectives of this research work were: (1) developing a way to measure velocity of sooty regions that is compatible with existing methods for measuring temporally and spatially resolved soot concentration fields and (2) using these methods to make quantitative measurements of soot in an unsteady, turbulent-like combustor. The Particle Vaporization Velocimetry (PVV) technique was developed and is compatible with Laser Induced Incandescence (LII), a soot concentration measurement approach. PVV is a flow tagging approach, where a high intensity laser (~2-3 J/cm2) is used to vaporize a small region in the soot field. This approach was demonstrated to produce a long lasting and easily readable flow tag that allows for velocity measurements over a wide range of velocities. LII proved to be the best method for detection the motion of the tag after a fixed delay. PVV and LII were used to measure velocity and two-dimensional soot concentration fields in an acoustically excited burner. In addition, images of soot luminosity were obtained. Both laminar and transitional acetylene diffusion flames were studied. The results reveal that strong acoustic forcing can significantly reduce total flame soot, as well as maximum soot concentrations, while simultaneously increasing the average soot temperature. The influence of acoustically generated vortices on soot formation was studied, and soot and products mixture mostly likely dominant high soot concentration regions. Eventually, these mixtures will be propagated downstream and oxidized as a diffusion flame.

Download or read book Laser Induced Incandescence and Laser Induced Breakdown Spectroscopy Based Sensor Development written by Kemal Efe Eseller and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this doctoral dissertation, two laser-based sensors were evaluated for different applications. Laser Induced Incandescence (LII) is a technique which can provide nonintrusive quantitative measurement of soot and it provides a unique diagnostic tool to characterize engine performance. Since LII is linearly proportional to the soot volume fraction, it can provide in situ, real time measurement of soot volume fraction with high temporal and spatial resolution. LII has the capability to characterize soot formation during combustion. The soot volume fraction from both flames and a soot generator was investigated with LII. The effects of experimental parameters, such as laser fluence, gate delay, gate width and various laser beam focusing, on LII signal was studied. Laser Induced Breakdown Spectroscopy (LIBS), a diagnostic tool for in situ elemental analysis, has been evaluated for on-line, simultaneous, multi-species impurity monitoring in hydrogen. LIBS spectra with different impurity levels of nitrogen, argon, and oxygen were recorded and the intensity of the spectral lines of Ar, O, N, and H observed were used to form calibration plots for impurities in hydrogen measurements. An ungated detection method for LIBS has been developed and applied to equivalence ratio measurements of CH4/air and biofuel/air. LIBS has also been used to quantitatively analyze the composition of a slurry sample. The quenching effect of water in slurry samples causes low LIBS signal quality with poor sensitivity. Univariate and multivariate calibration was performed on LIBS spectra of dried slurry samples for elemental analysis of Mg, Si and Fe. Calibration results show that the dried slurry samples give good correlation between spectral intensity and elemental concentration.