Download or read book High pressure Soot Formation and Diffusion Flame Extinction Characteristics of Gaseous and Liquid Fuels written by Ahmet Emre Karatas and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soot Measurements in High Pressure Diffusion Flames of Gaseous and Liquid Fuels written by Gorngrit Intasopa and published by . This book was released on 2011 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: Methane-air, ethane-air, and n-heptane-air over-ventilated co-flow laminar diffusion flames were studied up to pressures of 2.03, 1.52, and 0.51 MPa, respectively, to determine the effect of pressure on flame shape, soot concentration, and temperature. A spectral soot emission optical diagnostic method was used to obtain the spatially resolved soot formation and temperature data. In all cases, soot formation was enhanced by pressure, but the pressure sensitivity decreased as pressure was increased. The maximum fuel carbon conversion to soot, etamax, was approximated by a power law dependence with the pressure exponent of 0.92 between 0.51 and 1.01 MPa, and 0.68 between 1.01 and 2.03 MPa with etamax=9.5% at 2.03 MPa for methane-air flames. For ethane-air flames, the pressure exponent was 1.57 between 0.20 and 0.51 MPa, 1.08 between 0.51 and 1.01 MPa, and 0.58 between 1.01 and 1.52 MPa where etamax=23% at 1.52 MPa. For nitrogen-diluted n-heptane-air flames, etamax=6.5% at 0.51 MPa.
Download or read book The Effect of Elevated Pressure on Soot Formation in a Laminar Jet Diffusion Flame written by and published by . This book was released on 2003 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot volume fraction (f[subscript sv]) is measured quantitatively in a laminar diffusion flame at elevated pressures up to 25 atmospheres as a function of fuel type in order to gain a better understanding of the effects of pressure on the soot formation process. Methane and ethylene are used as fuels; methane is chosen since it is the simplest hydrocarbon while ethylene represents a larger hydrocarbon with a higher propensity to soot. Soot continues to be of interest because it is a sensitive indicator of the interactions between combustion chemistry and fluid mechanics and a known pollutant. To examine the effects of increased pressure on soot formation, Laser Induced Incandescence (LII) is used to obtain the desired temporally and spatially resolved, instantaneous f[subscript sv] measurements as the pressure is incrementally increased up to 25 atmospheres. The effects of pressure on the physical characteristics of the flame are also observed. A laser light extinction method that accounts for signal trapping and laser attenuation is used for calibration that results in quantitative results. The local peak f[subscript sv] is found to scale with pressure as p[superscript 1.2] for methane and p[superscript 1.7] for ethylene.
Download or read book Soot in Combustion Systems and Its Toxic Properties written by J. Lahaye and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 429 pages. Available in PDF, EPUB and Kindle. Book excerpt: Our interest in Mulhouse for carbon black and soot began some 30 years ago when J.B. Donnet developed the concept of surface chemistry of carbon and its involvement in interactions with gas, liquid and solid phases. In the late sixties, we began to study soot formation in pyrolytic systems and later on in flames. The idea of organ1z1ng a meeting on soot formation originated some four or five years ago, through discussions among Professor J.B. Howard, Dr. A. D'Alessio and ourselves. At that time the scientific community was becoming aware of the necessity to strictly control soot formation and emission. Being involved in the study of surface properties of carbon black as well as of formation of soot, we realized that the combustion community was not always fully aware of the progress made by the physical-chemists on carbon black. Reciprocally, the carbon specialists were often ignoring the research carried out on soot in flames. One objective of this workshop was to stimulate discussions between these two scientific communities. During the preparation of the meeting, and especially during the review process by the Material Science Committee of the Scientific Affairs Division of N.A.T.O. the toxicological aspect emerged as being an important component to be addressed during the workshop. To reflect these preoccupations we invited biologists, physical chemists and engineers, all leaders in their field. The final programme is a compromise of the different aspects of the subject and was divided in five sessions.
Download or read book Experimental and Numerical Studies for Soot Formation in Laminar Coflow Diffusion Flames of Jet A 1 and Synthetic Jet Fuels written by Meghdad Saffaripour and published by . This book was released on 2013 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sooting Characteristics of Liquid Pool Diffusion Flames written by Kenneth W. Van Treuren and published by . This book was released on 1978 with total page 111 pages. Available in PDF, EPUB and Kindle. Book excerpt: This investigation deals with a liquid fuel diffusion flame and examines the use of the smoke point test as a means of qualitatively measuring the ability of a fuel to produce soot relative to other fuels. Results indicate the necessity of controlling the initial conditions in order to obtain meaningful measurements. This thesis reports a new technique for the smoke point determination that has proved to be more accurate and reproduceable than previous methods. Recent studies indicate water addition in a premixed flame chemically suppresses soot formation. As a result, addition of water inside a diffusion flame is a likely direction to pursue. Both water in fuel emulsions and direct steam injection were used in the present investigation. The results indicate a dominant thermal effect and a possible secondary chemical effect of water on soot formation. Blending of various fuel types reveals the domination of an aromatic fuel over an aliphatic when determining a combined smoke point of the mixture. Applying this information to alternative hydrocarbon fuels, the oil shale and coal derived fuels, having a higher percentage of aromatics than conventional fuels, produce soot more readily than their petroleum derived counterparts. Testing of oil shale and conventional fuels supplied by the Air Force verifies this result.
Download or read book Soot Formation at High Pressures in Laminar Liquid and Gaseous Fuel Flames written by Adriana Elizabeth Daca 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 Experimental and Numerical Studies on the Soot Formation of Liquid Fuel Relevant Compounds written by Tongfeng Zhang and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In the present thesis, fundamental experimental and numerical studies are performed for the soot formation of liquid fuel relevant compounds. The thesis is composed of four research studies. The first develops an improved data analysis approach for the combined laser extinction and two-angle elastic light scattering diagnostics to relate the various measured optical cross sections to soot aggregate properties. Compared to previously reported studies, the proposed approach can be applied to a wider range of soot sources by removing the assumption made to scattering regime or moment ratio of aggregate size distribution. The second study investigates the effects of n-propylbenzene addition to n-dodecane on soot formation and aggregate structure in a laminar coflow diffusion flame using the combined laser extinction and two-angle elastic light scattering method. It is shown that the relative importance of soot inception and surface growth affected by n-propylbenzene addition is different along the flame wing and centerline, with the aromatic fuel chemistry effect being stronger along the centerline. The third study extends the investigation on the same issue using a numerical model. The simulation results show that mixing n-propylbenzene into the liquid fuel mixture accelerates soot inception, and increases soot surface growth per unit surface area by PAH addition, while soot surface growth per unit surface area by HACA is shown to decrease modestly with n-propylbenzene addition. The fourth and final study investigates the soot formation from jet fuel in a laminar coflow diffusion flame using both numerical and experimental methods. The results demonstrate the robustness of the soot model to changes of fuel and also show that the HyChem model (i.e., lumped fuel breakdown approach, Xu et al., 2017) can be used to predict soot formation from real jet fuel combustion in laminar coflow diffusion flames by adding a PAH growth scheme to the model.
Download or read book Mechanisms Controlling Soot Formation in Diffusion Flames written by and published by . This book was released on 1997 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: Arclength continuation methods were incorporated into a code for predicting the structure of sooting, opposed-jet flames. The code includes complex chemistry, detailed particle dynamics, particle chemistry and radiation. The code was used to predict soot production over a wide variation in strain rates for both ethylene/air and methane/air diffusion flames. Predicted values (both peak and spatial distributions) agree well with experimental measurements in ethylene flames. Particle size distributions are also predicted using the aerosol equations from MAEROS, but no data is available for comparison. Also, the soot dynamical equations were imbedded into a separate code to describe soot production in a coflow, laminar, diffusion flame which includes treatment of detailed, gas phase chemistry. Predictions were compared to measurements made in a methane, coflow flame. Reasonable agreement between the predictions and measurements was obtained, although a factor of three underprediction of the soot volume fractions is likely due to uncertainties in inlet conditions and an inability to match closely bulk flame parameters such as temperature. Predicted peak soot production occurred around 1720K and particle oxidation was dominated by superequilibrium concentrations of hydroxyl radicals. Several PAH-forming sequences were examined and compared to the traditional acetylene-addition sequence. A sequence involving benzyl-propargyl combination was found to compete with the traditional mechanism and it should be included in future analyses. The algorithms for treating sectional soot dynamics and growth/oxidation rates were modified to include effects at high pressure. Continuum effects and limitations to gaseous diffusion were included in the opposed jet code. Predicted variations in soot production due to pressure changes from 4 to 10 atmospheres were made for an ethylene-air.
Download or read book A Fundamental Study of Soot Formation in Diffusion Flames written by Richard L. Axelbaum and published by . This book was released on 1988 with total page 510 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effect of Elevated Pressure on Soot Formation in a Laminar Jet Diffusion Flame written by Laura Lynne McCrain and published by . This book was released on 2003 with total page 69 pages. Available in PDF, EPUB and Kindle. Book excerpt: Keywords: diffusion flame, high pressure, soot formation.
Download or read book Soot Formation in Gaseous Laminar Diffusion Flames written by Changlie Wey and published by . This book was released on 1984 with total page 386 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamic Effects on Soot Formation in Laminar Hydrocarbon fueled Diffusion Flames written by Guozheng Lin and published by . This book was released on 1996 with total page 568 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fuel Structure and Pressure Effects on the Formation of Soot Particles in Diffusion Flames written by Robert J. Santoro and published by . This book was released on 1990 with total page 67 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies emphasizing the effects of fuel concentration and operating pressure on the formation of soot particles have been conducted in a series of laminar diffusion flames. These experiments have shown that fuel concentration has a measurable effect on the amount of soot formed in the flame. However, a simple, constant proportionality between the fuel concentration and soot volume fraction has not been found to apply for the range of flow conditions studied. This observation is believed to be a result of flame residence time and diffusion effects which mitigate the consequences of reduced initial fuel concentration. Comparisons with simple laminar diffusion flame models are currently being used to investigate the relationship between initial fuel concentration and local flame concentration fields. Similar studies of soot formation in laminar diffusion flames as a function of operating pressure have also been completed for ethene, ethane and propene fuel species. Keywords: Soot formation, Soot particles, Diffusion flames. (JES).
Download or read book Chemical Mechanistic Approaches for the Suppression of Soot Formation in the Combustion of High Energy Density Fuels written by and published by . This book was released on 1996 with total page 54 pages. Available in PDF, EPUB and Kindle. Book excerpt: Significant advantages can be gained by the use of high energy density fuels in volume limited applications. However, excessive soot formation that accompanies the combustion of these fuels presently limits their application. Fuel additive approaches prove attractive as they require minimal modifications to already existing equipment. In the present study, a variety of flame configurations were used to study the additive effects on soot formation. Through tests conducted on laminar diffusion flames carbon disulfide (CS2) and methanol (CH3OH) were found to be the most effective soot suppressants. Chemical interaction by either additive was found to far surpass the physical influences. However, the exact nature of the chemical action could not be established with the current set of experiments. Additionally, both of these additives were found to reduce soot formation in at least one high energy density fuel - quadricyclane (C7H8). To further validate this approach, studies were conducted using droplet flames and high-pressure spray flames.
Download or read book Combustion Measurements written by Norman Chigier and published by CRC Press. This book was released on 1991-04-01 with total page 556 pages. Available in PDF, EPUB and Kindle. Book excerpt: The book begins with an introduction to the general problems of making measurements in high temperature and a presentation of chemically reacting flow systems. It describes each instrument with the various diagnostic techniques and discusses measurements that have been made in furnaces, flames, and rocket engines. The detailed measurement techniques described in this book cover a wide spectrum of applications in combustion systems, including gas turbine, rocket measurement techniques that were developed in laboratories. Information obtained on detailed temperature, velocity, particle size, and gas concentration distribution is leading to improve understanding of the chemical combustion process and to design imporvements in combustors.
Download or read book High pressure flame system for pollution studies with results for methane air diffusion flames written by Irvin M. Miller and published by . This book was released on 1977 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt:
