The Experts below are selected from a list of 6804 Experts worldwide ranked by ideXlab platform
Mitchell D. Smooke - One of the best experts on this subject based on the ideXlab platform.
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SOOT FORMATION IN LAMINAR DIFFUSION FLAMES SOOT FORMATION IN LAMINAR DIFFUSION FLAMES
2020Co-Authors: B C Connelly, Marshall B Long, M B Colket, R J Hall, Mitchell D. SmookeAbstract:Abstract Laminar, sooting, coflow diffusion flames at atmospheric pressure have been studied experimentally and theoretically as a function of Fuel Dilution by inert nitrogen. The flames have been investigated with laser diagnostics. Laser extinction has been used to calibrate the experimental soot volume fractions and an improved gating method has been implemented in the laser-induced incandescence (LII) measurements resulting in differences to the soot distributions reported previously. Numerical simulations have been based on a fully-coupled solution of the flow conservation equations, gas-phase species conservation equations with complex chemistry, and the dynamical equations for soot spheroid growth. The model also includes the effects of radiation reabsorption through an iterative procedure. An investigation of the computed rates of particle inception, surface growth and oxidation, along with a residence time analysis, helps explain the shift in the peak soot volume fraction from the centerline to the wings of the flame as the Fuel fraction increases. The shift arises from changes in the relative importance of inception and surface growth combined with a significant increase in the residence time within the annular soot formation field leading to higher soot volume fractions, as the Fuel fraction increases
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Su Cao, Beth Anne V Bennett, Marshall B Long, Davide Giassi, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted fl...
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Davide Giassi, Beth Anne V Bennett, Marshall B Long, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted flames has been investigated both computationally and experimentally, with pressure ranging from 1.0 to 2.7 atm and CH4 mole fraction ranging from 0.50 to 0.65. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modelled by sectional aerosol equations. The governing equations and boundary conditions were discretised on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton's method. Experimentally, chemiluminescence measurements of CH* were taken to determine its relative concentration profile and the structure of the flame front. A thin-filament ratio pyrometry method using a colo...
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a computational and experimental study of coflow laminar methane air diffusion flames effects of Fuel Dilution inlet velocity and gravity
Proceedings of the Combustion Institute, 2015Co-Authors: Beth Anne V Bennett, Marshall B Long, Davide Giassi, D P Stocker, Fumiaki Takahashi, Mitchell D. SmookeAbstract:Abstract The influences of Fuel Dilution, inlet velocity, and gravity on the shape and structure of laminar coflow CH 4 –air diffusion flames were investigated computationally and experimentally. A series of nitrogen-diluted flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) on board the International Space Station was assessed numerically under microgravity ( μ g) and normal gravity (1 g) conditions with CH 4 mole fraction ranging from 0.4 to 1.0 and average inlet velocity ranging from 23 to 90 cm/s. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modeled by sectional aerosol equations. The governing equations and boundary conditions were discretized on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton’s method. Experimentally, flame shape and soot temperature were determined by flame emission images recorded by a digital color camera. Very good agreement between computation and measurement was obtained, and the conclusions were as follows. (1) Buoyant and nonbuoyant luminous flame lengths are proportional to the mass flow rate of the Fuel mixture; computed and measured nonbuoyant flames are noticeably longer than their 1 g counterparts; the effect of Fuel Dilution on flame shape (i.e., flame length and flame radius) is negligible when the flame shape is normalized by the methane flow rate. (2) Buoyancy-induced reduction of the flame radius through radially inward convection near the flame front is demonstrated. (3) Buoyant and nonbuoyant flame structure is mainly controlled by the Fuel mass flow rate, and the effects from Fuel Dilution and inlet velocity are secondary.
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soot formation in laminar diffusion flames
Combustion and Flame, 2005Co-Authors: Mitchell D. Smooke, Marshall B Long, B C Connelly, M B Colket, R J HallAbstract:Laminar, sooting, coflow diffusion flames at atmospheric pressure have been studied experimentally and theoretically as a function of Fuel Dilution by inert nitrogen. The flames have been investigated with laser diagnostics. Laser extinction has been used to calibrate the experimental soot volume fractions and an improved gating method has been implemented in the laser-induced incandescence (LII) measurements resulting in differences to the soot distributions reported previously. Numerical simulations have been based on a fully coupled solution of the flow conservation equations, gas-phase species conservation equations with complex chemistry, and the dynamical equations for soot spheroid growth. The model also includes the effects of radiation reabsorption through an iterative procedure. An investigation of the computed rates of particle inception, surface growth, and oxidation, along with a residence time analysis, helps to explain the shift in the peak soot volume fraction from the centerline to the wings of the flame as the Fuel fraction increases. The shift arises from changes in the relative importance of inception and surface growth combined with a significant increase in the residence time within the annular soot formation field leading to higher soot volume fractions, as the Fuel fraction increases.
Marshall B Long - One of the best experts on this subject based on the ideXlab platform.
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SOOT FORMATION IN LAMINAR DIFFUSION FLAMES SOOT FORMATION IN LAMINAR DIFFUSION FLAMES
2020Co-Authors: B C Connelly, Marshall B Long, M B Colket, R J Hall, Mitchell D. SmookeAbstract:Abstract Laminar, sooting, coflow diffusion flames at atmospheric pressure have been studied experimentally and theoretically as a function of Fuel Dilution by inert nitrogen. The flames have been investigated with laser diagnostics. Laser extinction has been used to calibrate the experimental soot volume fractions and an improved gating method has been implemented in the laser-induced incandescence (LII) measurements resulting in differences to the soot distributions reported previously. Numerical simulations have been based on a fully-coupled solution of the flow conservation equations, gas-phase species conservation equations with complex chemistry, and the dynamical equations for soot spheroid growth. The model also includes the effects of radiation reabsorption through an iterative procedure. An investigation of the computed rates of particle inception, surface growth and oxidation, along with a residence time analysis, helps explain the shift in the peak soot volume fraction from the centerline to the wings of the flame as the Fuel fraction increases. The shift arises from changes in the relative importance of inception and surface growth combined with a significant increase in the residence time within the annular soot formation field leading to higher soot volume fractions, as the Fuel fraction increases
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Su Cao, Beth Anne V Bennett, Marshall B Long, Davide Giassi, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted fl...
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Davide Giassi, Beth Anne V Bennett, Marshall B Long, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted flames has been investigated both computationally and experimentally, with pressure ranging from 1.0 to 2.7 atm and CH4 mole fraction ranging from 0.50 to 0.65. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modelled by sectional aerosol equations. The governing equations and boundary conditions were discretised on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton's method. Experimentally, chemiluminescence measurements of CH* were taken to determine its relative concentration profile and the structure of the flame front. A thin-filament ratio pyrometry method using a colo...
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a computational and experimental study of coflow laminar methane air diffusion flames effects of Fuel Dilution inlet velocity and gravity
Proceedings of the Combustion Institute, 2015Co-Authors: Beth Anne V Bennett, Marshall B Long, Davide Giassi, D P Stocker, Fumiaki Takahashi, Mitchell D. SmookeAbstract:Abstract The influences of Fuel Dilution, inlet velocity, and gravity on the shape and structure of laminar coflow CH 4 –air diffusion flames were investigated computationally and experimentally. A series of nitrogen-diluted flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) on board the International Space Station was assessed numerically under microgravity ( μ g) and normal gravity (1 g) conditions with CH 4 mole fraction ranging from 0.4 to 1.0 and average inlet velocity ranging from 23 to 90 cm/s. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modeled by sectional aerosol equations. The governing equations and boundary conditions were discretized on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton’s method. Experimentally, flame shape and soot temperature were determined by flame emission images recorded by a digital color camera. Very good agreement between computation and measurement was obtained, and the conclusions were as follows. (1) Buoyant and nonbuoyant luminous flame lengths are proportional to the mass flow rate of the Fuel mixture; computed and measured nonbuoyant flames are noticeably longer than their 1 g counterparts; the effect of Fuel Dilution on flame shape (i.e., flame length and flame radius) is negligible when the flame shape is normalized by the methane flow rate. (2) Buoyancy-induced reduction of the flame radius through radially inward convection near the flame front is demonstrated. (3) Buoyant and nonbuoyant flame structure is mainly controlled by the Fuel mass flow rate, and the effects from Fuel Dilution and inlet velocity are secondary.
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soot formation in laminar diffusion flames
Combustion and Flame, 2005Co-Authors: Mitchell D. Smooke, Marshall B Long, B C Connelly, M B Colket, R J HallAbstract:Laminar, sooting, coflow diffusion flames at atmospheric pressure have been studied experimentally and theoretically as a function of Fuel Dilution by inert nitrogen. The flames have been investigated with laser diagnostics. Laser extinction has been used to calibrate the experimental soot volume fractions and an improved gating method has been implemented in the laser-induced incandescence (LII) measurements resulting in differences to the soot distributions reported previously. Numerical simulations have been based on a fully coupled solution of the flow conservation equations, gas-phase species conservation equations with complex chemistry, and the dynamical equations for soot spheroid growth. The model also includes the effects of radiation reabsorption through an iterative procedure. An investigation of the computed rates of particle inception, surface growth, and oxidation, along with a residence time analysis, helps to explain the shift in the peak soot volume fraction from the centerline to the wings of the flame as the Fuel fraction increases. The shift arises from changes in the relative importance of inception and surface growth combined with a significant increase in the residence time within the annular soot formation field leading to higher soot volume fractions, as the Fuel fraction increases.
Beth Anne V Bennett - One of the best experts on this subject based on the ideXlab platform.
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Davide Giassi, Beth Anne V Bennett, Marshall B Long, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted flames has been investigated both computationally and experimentally, with pressure ranging from 1.0 to 2.7 atm and CH4 mole fraction ranging from 0.50 to 0.65. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modelled by sectional aerosol equations. The governing equations and boundary conditions were discretised on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton's method. Experimentally, chemiluminescence measurements of CH* were taken to determine its relative concentration profile and the structure of the flame front. A thin-filament ratio pyrometry method using a colo...
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Su Cao, Beth Anne V Bennett, Marshall B Long, Davide Giassi, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted fl...
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a computational and experimental study of coflow laminar methane air diffusion flames effects of Fuel Dilution inlet velocity and gravity
Proceedings of the Combustion Institute, 2015Co-Authors: Beth Anne V Bennett, Marshall B Long, Davide Giassi, D P Stocker, Fumiaki Takahashi, Mitchell D. SmookeAbstract:Abstract The influences of Fuel Dilution, inlet velocity, and gravity on the shape and structure of laminar coflow CH 4 –air diffusion flames were investigated computationally and experimentally. A series of nitrogen-diluted flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) on board the International Space Station was assessed numerically under microgravity ( μ g) and normal gravity (1 g) conditions with CH 4 mole fraction ranging from 0.4 to 1.0 and average inlet velocity ranging from 23 to 90 cm/s. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modeled by sectional aerosol equations. The governing equations and boundary conditions were discretized on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton’s method. Experimentally, flame shape and soot temperature were determined by flame emission images recorded by a digital color camera. Very good agreement between computation and measurement was obtained, and the conclusions were as follows. (1) Buoyant and nonbuoyant luminous flame lengths are proportional to the mass flow rate of the Fuel mixture; computed and measured nonbuoyant flames are noticeably longer than their 1 g counterparts; the effect of Fuel Dilution on flame shape (i.e., flame length and flame radius) is negligible when the flame shape is normalized by the methane flow rate. (2) Buoyancy-induced reduction of the flame radius through radially inward convection near the flame front is demonstrated. (3) Buoyant and nonbuoyant flame structure is mainly controlled by the Fuel mass flow rate, and the effects from Fuel Dilution and inlet velocity are secondary.
Davide Giassi - One of the best experts on this subject based on the ideXlab platform.
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Davide Giassi, Beth Anne V Bennett, Marshall B Long, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted flames has been investigated both computationally and experimentally, with pressure ranging from 1.0 to 2.7 atm and CH4 mole fraction ranging from 0.50 to 0.65. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modelled by sectional aerosol equations. The governing equations and boundary conditions were discretised on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton's method. Experimentally, chemiluminescence measurements of CH* were taken to determine its relative concentration profile and the structure of the flame front. A thin-filament ratio pyrometry method using a colo...
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effects of pressure and Fuel Dilution on coflow laminar methane air diffusion flames a computational and experimental study
Combustion Theory and Modelling, 2018Co-Authors: Su Cao, Beth Anne V Bennett, Marshall B Long, Davide Giassi, Mitchell D. SmookeAbstract:In this study, the influence of pressure and Fuel Dilution on the structure and geometry of coflow laminar methane–air diffusion flames is examined. A series of methane-Fuelled, nitrogen-diluted fl...
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a computational and experimental study of coflow laminar methane air diffusion flames effects of Fuel Dilution inlet velocity and gravity
Proceedings of the Combustion Institute, 2015Co-Authors: Beth Anne V Bennett, Marshall B Long, Davide Giassi, D P Stocker, Fumiaki Takahashi, Mitchell D. SmookeAbstract:Abstract The influences of Fuel Dilution, inlet velocity, and gravity on the shape and structure of laminar coflow CH 4 –air diffusion flames were investigated computationally and experimentally. A series of nitrogen-diluted flames measured in the Structure and Liftoff in Combustion Experiment (SLICE) on board the International Space Station was assessed numerically under microgravity ( μ g) and normal gravity (1 g) conditions with CH 4 mole fraction ranging from 0.4 to 1.0 and average inlet velocity ranging from 23 to 90 cm/s. Computationally, the MC-Smooth vorticity–velocity formulation was employed to describe the reactive gaseous mixture, and soot evolution was modeled by sectional aerosol equations. The governing equations and boundary conditions were discretized on a two-dimensional computational domain by finite differences, and the resulting set of fully coupled, strongly nonlinear equations was solved simultaneously at all points using a damped, modified Newton’s method. Experimentally, flame shape and soot temperature were determined by flame emission images recorded by a digital color camera. Very good agreement between computation and measurement was obtained, and the conclusions were as follows. (1) Buoyant and nonbuoyant luminous flame lengths are proportional to the mass flow rate of the Fuel mixture; computed and measured nonbuoyant flames are noticeably longer than their 1 g counterparts; the effect of Fuel Dilution on flame shape (i.e., flame length and flame radius) is negligible when the flame shape is normalized by the methane flow rate. (2) Buoyancy-induced reduction of the flame radius through radially inward convection near the flame front is demonstrated. (3) Buoyant and nonbuoyant flame structure is mainly controlled by the Fuel mass flow rate, and the effects from Fuel Dilution and inlet velocity are secondary.
Steven Zabarnick - One of the best experts on this subject based on the ideXlab platform.
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pseudo detailed chemical kinetic modeling of antioxidant chemistry for jet Fuel applications
Energy & Fuels, 1998Co-Authors: Steven ZabarnickAbstract:Chemical kinetic modeling was used to simulate the autoxidation of jet Fuel including the chemistry of peroxy radical inhibiting antioxidants and hydroperoxide decomposing species. Recent experimental measurements of oxygen concentration during autoxidation of model hydrocarbon solvents were used to “calibrate” the rate parameters of the mechanism. The model showed good agreement with oxygen profiles of static measurements at 140 °C. At this temperature, the model predicts large increases in oxidation rate upon peroxy radical inhibiting antioxidant consumption to below 1 × 10-5 M. At 185 °C we have shown that peroxy radical inhibiting antioxidants and hydroperoxide decomposers both slow and/or delay oxidation, but the resulting oxygen profiles display different characteristics. We have shown that comparison of these profiles with Fuel blending and Fuel Dilution measurements has the potential to differentiate between the two types of oxidation-slowing species. The modeling predicts that the presence of bot...
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jet Fuel deposition and oxidation Dilution materials oxygen and temperature effects
Journal of Engineering for Gas Turbines and Power-transactions of The Asme, 1996Co-Authors: Steven Zabarnick, Paula Zelesnik, Rebecca R. GrinsteadAbstract:Quartz crystal microbalance (QCM) and pressure measurements are used for determination of jet Fuel thermal stability in a batch reactor. The QCM is able to monitor extremely small amounts of deposition in situ, while the pressure measurements provide qualitative data on the oxidation process. The dependence of the deposition amount was monitored as a function of the oxygen availability for two Fuels. Also, the effect of QCM electrode materials was investigated. Deposition and oxidation were compared for the following electrode materials: gold, aluminum, silver, and platinum. The authors also studied the effect of Dilution on oxidation and deposition. Jet Fuel was diluted with increasing amounts of hydrocarbon solvent. It was observed that this Dilution procedure can help characterize a Fuel`s effective antioxidant concentration. Fuel Dilution is also shown to be a good technique for improving thermal stability characteristics of poor Fuels. Additionally they have studied the temperature effect on deposition for two Fuels over the range 140 to 180 C.
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Jet Fuel Deposition and Oxidation: Dilution, Materials, Oxygen, and Temperature Effects
Volume 3: Coal Biomass and Alternative Fuels; Combustion and Fuels; Oil and Gas Applications; Cycle Innovations, 1995Co-Authors: Steven Zabarnick, Paula Zelesnik, Rebecca R. GrinsteadAbstract:The quartz crystal microbalance (QCM) and pressure measurements are used for determination of jet Fuel thermal stability in a batch reactor. The QCM is able to monitor extremely small amounts of deposition in situ, while the pressure measurements provide qualitative data on the oxidation process. The dependence of the deposition amount was monitored as a function of the oxygen availability for two Fuels. Also, the effect of QCM electrode materials was investigated. Deposition and oxidation were compared for the following electrode materials: gold, aluminum, silver, and platinum. We also studied the effect of Dilution on oxidation and deposition. Jet Fuel was diluted with increasing amounts of hydrocarbon solvent. It was observed that this Dilution procedure can help characterize a Fuel’s effective antioxidant concentration. Fuel Dilution is also shown to be a good technique for improving thermal stability characteristics of poor Fuels. Additionally we have studied the temperature effect on deposition for two Fuels over the range 140 to 180 C.© 1995 ASME
