Author: Steven George HallPublisher:
ISBN:
Category :
Languages : en
Pages : 224
Book Description
In-situ Measurement of Line-of-sight Soot Volume Fraction by Laser Light Extinction in a Combustion Wind Tunnel
Author: Steven George HallSoot Volume Fraction and Temperature Measurement in a Slot Burner Utilizing Laser Extinction and Emission
Author: Jimmy Jean DaghlianPublisher:
ISBN:
Category : Combustion engineering
Languages : en
Pages : 198
Book Description
Sensitivity of Flame Structure and Particulate Matter Emissions to the Operating Configurations of a Combustion Wind Tunnel
Author: Soot Volume Fraction Imaging
Author: National Aeronautics and Space Adm NasaPublisher:
ISBN: 9781729005460
Category :
Languages : en
Pages : 26
Book Description
A new technique is described for the full-field determination of soot volume fractions via laser extinction measurements. This technique differs from previously reported point-wise methods in that a two-dimensional array (i.e., image) of data is acquired simultaneously. In this fashion, the net data rate is increased, allowing the study of time-dependent phenomena and the investigation of spatial and temporal correlations. A telecentric imaging configuration is employed to provide depth-invariant magnification and to permit the specification of the collection angle for scattered light. To improve the threshold measurement sensitivity, a method is employed to suppress undesirable coherent imaging effects. A discussion of the tomographic inversion process is provided, including the results obtained from numerical simulation. Results obtained with this method from an ethylene diffusion flame are shown to be in close agreement with those previously obtained by sequential point-wise interrogation. Greenberg, Paul S. and Ku, Jerry C. Glenn Research Center NAG3-1265...
Soot Fformation in Co-flow and Counterflow Laminar Diffusion Flames of Fuel Mixtures
Author: Ahmet Emre KaratasPublisher:
ISBN:
Category :
Languages : en
Pages : 0
Book Description
In the formation process of soot in the flames of even-carbon-numbered fuels, acetylene and its derivatives are suspected to be dominant. The addition of an odd-carbon-numbered fuel into these flames introduces methyl radicals and/or C3 chemistries, which are believed to (de)activate certain chemical pathways towards the production of soot. The resultant soot formation rate of the mixture could be higher than the sum of the respective rates of the mixture components, i.e., synergistic eff ect. In this work, the mixtures of butane isomers, ethylene-butane isomers, and propane-butane isomers were studied on a co-flow and a counterflow burner. Chemical effects were isolated from those of thermal and dilution by mixing isomers and comparing the mixtures including one isomer to those including the counterpart. Line of sight attenuation (LOSA) and laser-light extinction techniques were used for measuring soot volume fraction. The results provide information on synergistic effects in soot formation for the fuels used.
Laser Transmission Measurements of Soot Extinction Coefficients in the Exhaust Plume of the X-34 60k-lb Thrust Fastrac Rocket Engine
Author: C. C. DobsonPublisher:
ISBN:
Category : Argon lasers
Languages : en
Pages : 40
Book Description
Computational and Experimental Study of Laminar Flames
Author: Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
During the past three years, our research has centered on an investigation of the effects of complex chemistry and detailed transport on the structure and extinction of hydrocarbon flames in coflowing axisymmetric configurations. We have pursued both computational and experimental aspects of the research in parallel on both steady-state and time-dependent systems. The computational work has focused on the application of accurate and efficient numerical methods for the solution of the steady-state and time-dependent boundary value problems describing the various reacting systems. Detailed experimental measurements were performed on axisymmetric coflow flames using two-dimensional imaging techniques. Previously, spontaneous Raman scattering, chemiluminescence, and laser-induced fluorescence were used to measure the temperature, major and minor species profiles. Particle image velocimetry (PIV) has been used to investigate velocity distributions and for calibration of time-varying flames. Laser-induced incandescence (LII) with an extinction calibration was used to determine soot volume fractions, while soot surface temperatures were measured with three-color optical pyrometry using a color digital camera. A blackbody calibration of the camera allows for determination of soot volume fraction as well, which can be compared with the LII measurements. More recently, we have concentrated on a detailed characterization of soot using a variety of techniques including time-resolved LII (TiRe-LII) for soot primary particles sizes, multi-angle light scattering (MALS) for soot radius of gyration, and spectrally-resolved line of sight attenuation (spec-LOSA). Combining the information from all of these soot measurements can be used to determine the soot optical properties, which are observed to vary significantly depending on spatial location and fuel dilution. Our goal has been to obtain a more fundamental understanding of the important fluid dynamic and chemical interactions in these flames so that this information can be used effectively in combustion modeling.
Optical Measurements of Soot in Premixed Flames
Author: Valerie Jean LyonsLaser Diagnostics for Combustion Temperature and Species
Author: Alan C. EckbrethPublisher: CRC Press
ISBN: 9789056995324
Category : Technology & Engineering
Languages : en
Pages : 636
Book Description
Focusing on spectroscopically-based, spatially-precise, laser techniques for temperature and chemical composition measurements in reacting and non-reacting flows, this book makes these powerful and important new tools in combustion research
Author: Dale Reif Tree