Download or read book Soot Formation in Ethane air Coflow Laminar Diffusion Flames at Elevated Pressures written by Paul Michael Mandatori and published by . This book was released on 2006 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ethane-air laminar coflow non-smoking diffusion flames have been studied at pressures up to 3.34 MPa to determine the effect of pressure on soot formation, flame temperatures and physical flame properties. The spectral soot emission (SSE) diagnostic was used to obtain spatially resolved (both radially and axially) soot volume fraction and soot temperature measurements at pressures of 0.20 to 3.34 MPa. In general, temperature profiles of a given height were found to decrease with increasing pressure. Pressure was found to enhance soot formation with decreased sensitivity as pressures were increased. A power law relation between maximum soot volume fraction and pressure was found to be fvmax & prop;P 2.39 for 0.20 & le; P & le; 1.52 MPa and fvmax & prop;P 1.10 for 1.52 & le; P & le; 3.34 MPa. The integrated line-of-sight soot volume fraction was found to vary as fvline, max & prop;P 2.32 for 0.20 & le; P & le; 0.51 MPa, fvline, max & prop;P 1.44 for 0.51 & le; P & le; 1.52 MPa and fvline, max & prop;P 0.95 for 1.52 & le; P & le; 3.34 MPa. The variation of maximum carbon conversion to soot, as a percentage of the fuel's carbon, was etas, max & prop; P2.23 for 0.20 & le; P & le; 1.13 MPa, etas, max & prop; P1.12 for 0.51 & le; P & le; 1.52 MPa and etas, max & prop; P0.41 for 1.52 & le; P & le; 3.34 MPa. The maximum value of carbon conversion was found to be eta s, max = 27.61% at P = 3.34 MPa.
Download or read book Soot Formation in Non premixed Laminar Flames at Subcritical and Supercritical Pressures written by Hyun Il Joo and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was conducted using axisymmetric co-flow laminar diffusion flames of methane-air, methane-oxygen and ethylene-air to examine the effect of pressure on soot formation and the structure of the temperature field. A liquid fuel burner was designed and built to observe the sooting behavior of methanol-air and n-heptane-air laminar diffusion flames at elevated pressures up to 50 atm. A non-intrusive, line-of-sight spectral soot emission (SSE) diagnostic technique was used to determine the temperature and the soot volume fraction of methane-air flames up to 60 atm, methane-oxygen flames up to 90 atm and ethylene-air flames up to 35 atm. The physical flame structure of the methane-air and methane-oxygen diffusion flames were characterized over the pressure range of 10 to 100 atm and up to 35 atm for ethylene-air flames. The flame height, marked by the visible soot radiation emission, remained relatively constant for methane-air and ethylene-air flames over their respected pressure ranges, while the visible flame height for the methane-oxygen flames was reduced by over 50 % between 10 and 100 atm. During methane-air experiments, observations of anomalous occurrence of liquid material formation at 60 atm and above were recorded. The maximum conversion of the carbon in the fuel to soot exhibited a strong power-law dependence on pressure. At pressures 10 to 30 atm, the pressure exponent is approximately 0.73 for methane-air flames. At higher pressures, between 30 and 60 atm, the pressure exponent is approximately 0.33. The maximum fuel carbon conversion to soot is 12.6 % at 60 atm. For methane-oxygen flames, the pressure exponent is approximately 1.2 for pressures between 10 and 40 atm. At pressures between 50 and 70 atm, the pressure exponent is about -3.8 and approximately -12 for 70 to 90 atm. The maximum fuel carbon conversion to soot is 2 % at 40 atm. For ethylene-air flames, the pressure exponent is approximately 1.4 between 10 and 30 atm. The maximum carbon conversion to soot is approximately 6.5 % at 30 atm and remained constant at higher pressures.
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 Soot Formation in Non premixed Laminar Flames at Subcritical and Supercritical Pressures written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was conducted using axisymmetric co-flow laminar diffusion flames of methane-air, methane-oxygen and ethylene-air to examine the effect of pressure on soot formation and the structure of the temperature field. A liquid fuel burner was designed and built to observe the sooting behavior of methanol-air and n-heptane-air laminar diffusion flames at elevated pressures up to 50 atm. A non-intrusive, line-of-sight spectral soot emission (SSE) diagnostic technique was used to determine the temperature and the soot volume fraction of methane-air flames up to 60 atm, methane-oxygen flames up to 90 atm and ethylene-air flames up to 35 atm. The physical flame structure of the methane-air and methane-oxygen diffusion flames were characterized over the pressure range of 10 to 100 atm and up to 35 atm for ethylene-air flames. The flame height, marked by the visible soot radiation emission, remained relatively constant for methane-air and ethylene-air flames over their respected pressure ranges, while the visible flame height for the methane-oxygen flames was reduced by over 50 % between 10 and 100 atm. During methane-air experiments, observations of anomalous occurrence of liquid material formation at 60 atm and above were recorded. The maximum conversion of the carbon in the fuel to soot exhibited a strong power-law dependence on pressure. At pressures 10 to 30 atm, the pressure exponent is approximately 0.73 for methane-air flames. At higher pressures, between 30 and 60 atm, the pressure exponent is approximately 0.33. The maximum fuel carbon conversion to soot is 12.6 % at 60 atm. For methane-oxygen flames, the pressure exponent is approximately 1.2 for pressures between 10 and 40 atm. At pressures between 50 and 70 atm, the pressure exponent is about -3.8 and approximately -12 for 70 to 90 atm. The maximum fuel carbon conversion to soot is 2 % at 40 atm. For ethylene-air flames, the pressure exponent is approximately 1.4 between 10 and 30 atm. The maximu.
Download or read book Numerical Modelling of Sooting Laminar Diffusion Flames at Elevated Pressures and Microgravity written by Marc Robert Joseph Charest 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 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 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 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 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 Soot Formation in Propane air Laminar Diffusion Flames at Elevated Pressures microform written by Decio S. (Decio Santos) Bento and published by Library and Archives Canada = Bibliothèque et Archives Canada. This book was released on 2005 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Laminar axisymmetric propane air diffusion flames were studied at pressures 0.1 to 0.725 MPa (1 to 7.25 atm). To investigate the effect of pressure on soot formation, radially resolved soot temperatures and soot volume fractions were deduced from soot radiation emission scans collected at various pressures using spectral soot emission (SSE). Overall flame stability was quite good as judged by the naked eye. Flame heights varied by 15% and flame axial diameters decreased by 30% over the entire pressure range.Analysis of temperature sensitivity to variations in E lambda(m) revealed that a change in E lambda(m) of +/-20% produced a change in local temperature values of about 75 to 100 K or about 5%.Temperatures decreased and soot concentration increased with increased pressure. More specifically, the peak soot volume fraction showed a power law dependence, fv ∝ Pn where n = 2.0 over the entire pressure range. The maximum integrated soot volume fraction also showed a power law relationship with pressure, f ̄v ∝ Pn where n = 3.4 for 1 ≤ P ≤ 2 atm and n = 1.4 for 2 ≤ P ≤ 7.25 atm. The percentage of fuel carbon converted to soot increased with pressure at a rate, etas ∝ Pn where n = 3.3 and n = 1.1 for 1 ≤ P ≤ 2 atm and 2 ≤ P ≤ 7.25 atm respectively.
Download or read book Effects of Elevated Pressure on Soot Formation in Laminar Diffusion Flames written by L. L. McCrain 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 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 Effects of Fuel Doping and Fuel Chemistry on Soot Formation in Co flow Laminar Diffusion Flames at Elevated Pressures written by Silin Yang and published by . This book was released on 2020 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Effects of fuel doping and fuel chemistry on soot formation were studied in laminar diffusion flames at elevated pressures. Soot spectral emission is used to obtain radial temperature, soot volume fraction, and soot yield profiles. This thesis first investigated addition of 0%-40% ethanol in ethylene flames at 3-10 bar. 10% ethanol-doped flames didn't exhibit measurable soot synergy, whereas 20%-40% ethanol displayed lower soot yields. Secondly, 7.5% of benzene, cyclo-hexane and n-hexane was added into methane flames at 1.4-10 bar. Pressure dependence of sooting propensity is lowest for benzene. Thirdly, 3% of m-xylene and n-octane was mixed with methane at 1.4-10 bar. m-Xylene doped methane flames produced highest soot yields but lowest pressure dependency in soot yields. Results indicate that pressure dependence of highly sooting aromatics weakens compared to that of less sooting n-alkanes at high pressures.
Download or read book High Pressure Soot Formation in Non smoking Methane air Laminar Diffusion Flames from 1 5 MPa to 6 0 MPa written by Marie Emma Vaillancourt and published by . This book was released on 2006 with total page 190 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of soot concentration, flame temperature and flame geometry have been recorded for non-smoking methane-air laminar diffusion flames at pressures from P = 1.5 MPa to P = 6.0 MPa. Soot concentration and temperature profiles were obtained using the spectral soot emission diagnostic method and the Abel inversion deconvolution technique. Visual inspection and measurement of the flame revealed a slight increase in height and decrease in cross-section with increasing pressure. Soot volume fraction increased with pressure according to fv max & prop; P1.4 for 1.5 & le; P & le; 5.0 MPa. The maximum carbon conversion to soot was related to pressure following the relationship eta s, max & prop; P0.55 for 1.5 & le; P & le; 5.0 MPa. The maximum value of carbon converted to soot was etas, max = 10.1% at P = 5.0 MPa. The maximum soot concentration was always found at a height approximately half way between the burner and the flame tip. The temperature was lower in high soot loading regions of the flame. For the same height in the flame, temperature decreased with increasing pressure.
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 Detailed Modeling of Soot Formation oxidation in Laminar Coflow Diffusion Flames written by Qingan Zhang and published by . This book was released on 2009 with total page 388 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first goal of this thesis is to develop and validate a modeling tool into which fundamental combustion chemistry and aerosol dynamics theory are implemented for investigating soot formation/oxidation in multi-dimensional laminar coflow diffusion flames taking into account soot polydispersity and fractal-like aggregate structure. The second goal is to use the tool to study soot aggregate formation/oxidation in experimentally studied laminar coflow diffusion flames to advance the understanding of soot aggregate formation/oxidation mechanism.The first part of the thesis deals with the large CPU time problem when detailed models are coupled together. Using the domain decomposition method, a high performance parallel flame code is successfully developed. An advanced sectional aerosol dynamics model which can model fractal-like aggregate structure is successfully implemented into the parallel flame code. The performance of the parallel code is demonstrated through its application to the modeling of soot formation/oxidation in a laminar coflow CH4/air diffusion flame. The parallel efficiency reaches as high as 83%.In the third part of the thesis, the effects of oxidation-driven soot aggregate fragmentation on aggregate structure and soot oxidation rate are studied. Three fragmentation models with different fragmentation patterns are developed and implemented into the sectional aerosol dynamics model. The implementation of oxidation-driven aggregate fragmentation significantly improves the prediction of soot aggregate structure in the soot oxidation region.The second part of the thesis numerically explores soot aggregate formation in a laminar coflow C2H4/air diffusion flame using detailed PAH-based combustion chemistry and a PAH-based soot formation/oxidation model. Compared to the measured data, flame temperature, axial velocity, C2 H2 and OH concentrations, soot volume fraction, the average diameter and the number density of primary particles are reasonably well predicted. However, it is very challenging to predict effectively the average degree of particle aggregation. To do so, particle-particle and fluid-particle interactions that may cause non-unitary soot coagulation efficiency need to be considered. The original coagulation model is enhanced in this thesis to accommodate soot coagulation efficiency. Different types of soot coagulation efficiency are numerically investigated. It is found that a simple adjustment of soot coagulation efficiency from 100% to 20% provides good predictions on soot aggregate structure as well as flame properties.
Download or read book A Computational Study of Soot Formation and Flame Structure of Coflow Laminar Methane air Diffusion Flames Under Microgravity and Normal Gravity written by and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
