EBookClubs

Read Books & Download eBooks Full Online

EBookClubs

Read Books & Download eBooks Full Online

Book Temperature Oxygen and Soot Volume Fraction Measurements in a Turbulent C2H4 Fueled Jet Flame

Download or read book Temperature Oxygen and Soot Volume Fraction Measurements in a Turbulent C2H4 Fueled Jet Flame written by and published by . This book was released on 2015 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt: We present a detailed set of measurements from a piloted, sooting, turbulent C 2 H 4 - fueled diffusion flame. Hybrid femtosecond/picosecond coherent anti-Stokes Raman scattering (CARS) is used to monitor temperature and oxygen, while laser-induced incandescence (LII) is applied for imaging of the soot volume fraction in the challenging jet-flame environment at Reynolds number, Re = 20,000. Single-laser shot results are used to map the mean and rms statistics, as well as probability densities. LII data from the soot-growth region of the flame are used to benchmark the soot source term for one-dimensional turbulence (ODT) modeling of this turbulent flame. The ODT code is then used to predict temperature and oxygen fluctuations higher in the soot oxidation region higher in the flame.

Book MILD Combustion Modelling Challenges Experimental Configurations and Diagnostic Tools

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:

Book Flow Field and Soot Formation Characteristics in Swirl stabilized Non premixed Turbulent Flames

Download or read book Flow Field and Soot Formation Characteristics in Swirl stabilized Non premixed Turbulent Flames written by Lu-Yin Wang and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot formation and evolution in relation with the flow fields were investigated experimentally in turbulent swirl-stabilized non-premixed flames using three different fuels: methane, ethanol and aviation Jet A-1. The studied flames were confined and stabilized in a model gas turbine combustor with a swirl number of ~0.55. Soot volume fraction, fv, and primary soot particle size, dp, were measured using auto-compensating laser-induced incandescence, and planar three-component velocity fields were measured using stereoscopic particle image velocimetry. Measurements of planar laser-induced fluorescence of OH and OH* chemiluminescence were also made for methane and ethanol flames. The OH* field was further Abel-inverted to qualitatively locate the heat release zone. The flow field for all flames featured pronounced inner and outer recirculation zones (IRZ, ORZ), each bounded by their corresponding inner and outer shear layers (ISL, OSL). Abel-inverted OH* intensity maps showed that primary reaction zones occurred in the vicinity of ISL. The central fuel jet penetrating into the IRZ accompanied by a stagnation zone was observed in all methane flames. Soot measurements showed that the overall dp for methane and Jet A-1 flames ranged between 30 nm and 60 nm without discernible trends. In methane flames, peak time-averaged fv occurred between the central jet penetration and the ISL. The decrease and the final disappearance of time-averaged fv were strongly correlated with elevated OH, demonstrating a dominant oxidative attack of OH on soot. With a ~7% increase in air flow rate, the level of soot volume fraction dropped by nearly threefold due to enhanced turbulence intermittency. The appearance of ethanol spray flames, which lacked a bright yellow color, largely differed from others. The absence of soot was confirmed in the laser-induced incandescence measurements. The isothermal flow field of ethanol flames exhibited a large-scale structure of precessing vortex core which was then suppressed under reacting conditions. In Jet A-1 flames, spray pattern changed from V-shaped hollow cone to semi-solid cone when air flow rate increased by 20%, resulting in a 60% reduction in peak time-averaged fv. In contrast to results obtained from the methane flame, soot was found primarily outside the ISL where fuel existed in abundance.

Book Applied Combustion Diagnostics

Download or read book Applied Combustion Diagnostics written by Katharina Kohse-Hoinghaus and published by CRC Press. This book was released on 2002-04-26 with total page 734 pages. Available in PDF, EPUB and Kindle. Book excerpt: The editors have assembled a world-class group of contributors who address the questions the combustion diagnostic community faces. They are chemists who identify the species to be measured and the interfering substances that may be present; physicists, who push the limits of laser spectroscopy and laser devices and who conceive suitable measuremen

Book Soot Formation In Turbulent Combusting Flows

Download or read book Soot Formation In Turbulent Combusting Flows written by and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of soot formation in turbulent jet flames burning ethylene in air were studied for Reynolds numbers ranging from 4,000 to 23,000. Laser-based techniques were used to measure the soot volume fraction, particle size and number density as well as the temperature and relative concentration of hydroxyl radicals and polycyclic aromatic hydrocarbons. Measurements of the characteristics length scales for the soot and hydroxyl radical fields throughout the turbulent flames were obtained. The maximum soot eddy size was observed to be 7 mm or about three times the size of the diameter of the fuel jet (d= 2.18 mm). The soot eddy size increased linearly along the centerline of the turbulent flame until the mid-point, where it leveled off and finally decreased in the oxidation zone. In contrast, the hydroxyl radical eddy size always increased along the flame with a maximum eddy size of 12 mm for the higher Reynolds number flames. Analysis of the radial dependence of the eddy size was also determined. Relatively little radial dependence in the eddy size was observed for the soot particles indicating that the soot eddies moved off the axis very fast as compared to the mixing rate. However for the hydroxyl radicals, the eddy size was always larger off the axis of the flame except near the flame tip. With respect to the temperature field, temperature probability density functions indicated bimodality at all axially locations. With respect to soot formation, the highest soot formation location and the peak mean temperature were observed on the fuel-rich side of the stoichiometric flame location while the peak hydroxyl radical concentration was on the fuel-lean side.

Book The Measurement of Mixture Fraction and Scalar Dissipation Rate in Turbulent Jet Flames

Download or read book The Measurement of Mixture Fraction and Scalar Dissipation Rate in Turbulent Jet Flames written by Jeffrey Alan Muss and published by . This book was released on 1997 with total page 746 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Soot Production and Thermal Radiation from Turbulent Jet Diffusion Flames

Download or read book Soot Production and Thermal Radiation from Turbulent Jet Diffusion Flames written by and published by . This book was released on 1910 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The aim of this study is to advance the present capability for modelling soot production and thermal radiation from turbulent jet diffusion flames. Turbulent methane / air jet diffusion flames at atmospheric and elevated pressure are studied experimentally to provide data for subsequent model development and validation. Methane is only lightly sooting at atmospheric pressure whereas at elevated pressure the soot yield increases greatly. This allows the creation of an optically thick, highly radiating flame within a laboratory scale rig. Essential flame properties needed for model validation are measured at 1 and 3 atm. These are mean mixture fraction, mean temperature, mean soot volume fraction, and mean and instantaneous spectrally resolved radiation intensity. These two flames are modelled using the parabolic CFD code GENMIX. The combustion / turbulence interaction is modelled using the conserved scalar / laminar flamelet approach. The chemistry of methane combustion is modelled using a detailed chemistry laminar flame code. The combustion model accommodates the non-adiabatic nature of the flames through the use of multiple flamelets for each scalar. The flamelets are differentiated by the amount of radiative heat loss that is included. Flamelet selection is carried out through the solution of a balance equation for enthalpy, which includes a source term for the radiative heat loss. A new soot model has been developed and calibrated by application to a laminar flame calculation. Within the turbulent flame calculations the soot production is fully coupled to the radiative loss. This is achieved through the use of multiple flamelets for the soot source terms and the inclusion of the radiative loss from the soot (as well as the gases) in the enthalpy source. Spectral radiative emission from the flames has been modelled using the RADCAL code. Mean flame properties from the GENMIX calculations are used as an input to RADCAL.

Book Optical Measurements of Soot in Premixed Flames

Download or read book Optical Measurements of Soot in Premixed Flames written by Valerie Jean Lyons and published by . This book was released on 1988 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Turbulent Premixed Flames

Download or read book Turbulent Premixed Flames written by Nedunchezhian Swaminathan and published by Cambridge University Press. This book was released on 2011-04-25 with total page 447 pages. Available in PDF, EPUB and Kindle. Book excerpt: A work on turbulent premixed combustion is important because of increased concern about the environmental impact of combustion and the search for new combustion concepts and technologies. An improved understanding of lean fuel turbulent premixed flames must play a central role in the fundamental science of these new concepts. Lean premixed flames have the potential to offer ultra-low emission levels, but they are notoriously susceptible to combustion oscillations. Thus, sophisticated control measures are inevitably required. The editors' intent is to set out the modeling aspects in the field of turbulent premixed combustion. Good progress has been made on this topic, and this cohesive volume contains contributions from international experts on various subtopics of the lean premixed flame problem.

Book Soot Modeling of a Turbulent Non premixed Methane air Flame

Download or read book Soot Modeling of a Turbulent Non premixed Methane air Flame written by Michael I. B. Chai and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soot is an important air pollutant. Its formation must be modeled accurately to assist designers in development of low soot emission combustors. This study was concerned with the semi-empirical modeling of soot. The models considered inception, coagulation, agglomeration, and oxidation of the soot particles. Since inception is a key process in the development of soot it was studied in great detail. Two approaches to modeling inception were investigated: acetylene and phenyl. For a methane/air coflow diffusion flame at a pressure of one atmosphere both approaches showed good agreement with experimentally observed trends. Furthermore, the acetylene route under predicted the magnitude of the soot volume fraction while the phenyl route over predicted the magnitude of the soot volume fraction. However, it is believed that the phenyl model will perform better with more complex fuels such as kerosene and with improved laminar flamelet libraries that are optimized for C6 species.

Book Quantifying Soot Concentrations in Turbulent Non Premixed Jet Flames

Download or read book Quantifying Soot Concentrations in Turbulent Non Premixed Jet Flames written by and published by . This book was released on 2016 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book A Study on the Effect of Temperature on Soot Formation in a Jet Stirred Combustor

Download or read book A Study on the Effect of Temperature on Soot Formation in a Jet Stirred Combustor written by Hiroki Satō and published by . This book was released on 1989 with total page 432 pages. Available in PDF, EPUB and Kindle. Book excerpt: