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Tim Lieuwen - One of the best experts on this subject based on the ideXlab platform.
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high speed tomo piv oh plif measurements of a transverse turbulent Reacting Fuel jet
Imaging and Applied Optics 2018 (3D AO AIO COSI DH IS LACSEA LS&C MATH pcAOP) (2018) paper LM2C.5, 2018Co-Authors: Benjamin R. Halls, Tim Lieuwen, Naibo Jiang, Josef Felver, Vedanth Nair, Matthew Sirignano, Benjamin Emerson, Sukesh Roy, James R. GordAbstract:High-speed tomographic PIV measurements synchronized with OH-PLIF imaging are used to fully resolve the nine-component velocity-gradient tensor upstream of a turbulent flame front, which is not possible with the traditional stereo-PIV/PLIF technique.
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High-speed Tomo-PIV/OH-PLIF Measurements of a Transverse Turbulent Reacting Fuel Jet
Imaging and Applied Optics 2018 (3D AO AIO COSI DH IS LACSEA LS&C MATH pcAOP), 2018Co-Authors: Benjamin R. Halls, Tim Lieuwen, Naibo Jiang, Josef Felver, Vedanth Nair, Matthew Sirignano, Benjamin Emerson, Sukesh Roy, James R. GordAbstract:High-speed tomographic PIV measurements synchronized with OH-PLIF imaging are used to fully resolve the nine-component velocity-gradient tensor upstream of a turbulent flame front, which is not possible with the traditional stereo-PIV/PLIF technique.
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time averaged characteristics of a Reacting Fuel jet in vitiated cross flow
Combustion and Flame, 2014Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Tim LieuwenAbstract:This paper describes an experimental study of Reacting jets in a high-temperature (1775 K) vitiated crossflow at 6 atm. We present an extensive data set based on high speed chemiluminescence imaging and exhaust gas sampling showing the characteristics of the time-averaged trajectory, width of the flame, flame standoff (or ignition) location, and NOx emissions over a momentum flux ratio range of 0.75 < J < 240. Key observations are: (1) Depending upon ignition times, reaction can initiate uniformly around the jet, initiate on the leeward side of the jet and spread around to the windward side farther downstream, or initiate further downstream. (2) The time-averaged trajectory generally follows nonReacting trajectories, but penetrates further in the far-field than for what would be expected of a nonReacting jet. (3) The width of heat release zone increases monotonically with downstream location, J, and flame flapping amplitude, but seems to be dominated by the size of the counter-rotating vortex pair. (4) The measured ignition locations were of the same order of magnitude as values based on calculated ignition time scales and mean jet exit velocities, but with some additional variability. (5) The incremental NOx emissions were controlled primarily by the global temperature rise associated with burning the jet Fuel (for the fixed crossflow conditions studied here), and the NOx emissions increased roughly linearly with the temperature rise.
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Unsteady flame-wall interactions in a Reacting jet injected into a vitiated cross-flow☆
Proceedings of the Combustion Institute, 2013Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Karthik Periagaram, Tim LieuwenAbstract:This paper describes measurements and analysis of the unsteady characteristics of a turbulent Reacting Fuel jet in a vitiated cross-flow. This problem involves coupling between the hydrodynamic stability of the jet–wall system, combustion induced gas expansion and interactions of the autoigniting jet with the wake flow. Analysis of the unsteady jet motions shows that the Reacting jet flaps in a sinuous manner with an amplitude that increases with downstream distance but is relatively independent of jet-to-cross-flow momentum flux ratio, J. This study particularly focuses on unsteady flame–wall interactions in these systems, showing that even though the time averaged flame trajectory may be well removed from wall regions, its instantaneous trajectory may be very near or even attached to the wall. Specifically, for lower J jets (J < ∼20), the flame intermittently attaches to the wall for some fraction of time that decreases with downstream distance and increasing J. From a practical point of view, intermittent flame–wall interactions cause an increase in the time averaged wall temperature, raising durability concerns. We suggest that this unsteady jet–wall attraction can be understood from analogies to the dynamics of co-flowing jet or wake pairs, as low J jets deflect into the cross-flow direction quickly. Side-by-side jets or wakes are “attracted” toward each other and exhibit global instabilities that are not present when they are isolated. In support of this argument, we show that data taken over the 1.7 < J < 7.2 range and a range of axial locations can be collapsed using the time averaged distance of the Reacting jet from the wall.
Ryan Sullivan - One of the best experts on this subject based on the ideXlab platform.
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time averaged characteristics of a Reacting Fuel jet in vitiated cross flow
Combustion and Flame, 2014Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Tim LieuwenAbstract:This paper describes an experimental study of Reacting jets in a high-temperature (1775 K) vitiated crossflow at 6 atm. We present an extensive data set based on high speed chemiluminescence imaging and exhaust gas sampling showing the characteristics of the time-averaged trajectory, width of the flame, flame standoff (or ignition) location, and NOx emissions over a momentum flux ratio range of 0.75 < J < 240. Key observations are: (1) Depending upon ignition times, reaction can initiate uniformly around the jet, initiate on the leeward side of the jet and spread around to the windward side farther downstream, or initiate further downstream. (2) The time-averaged trajectory generally follows nonReacting trajectories, but penetrates further in the far-field than for what would be expected of a nonReacting jet. (3) The width of heat release zone increases monotonically with downstream location, J, and flame flapping amplitude, but seems to be dominated by the size of the counter-rotating vortex pair. (4) The measured ignition locations were of the same order of magnitude as values based on calculated ignition time scales and mean jet exit velocities, but with some additional variability. (5) The incremental NOx emissions were controlled primarily by the global temperature rise associated with burning the jet Fuel (for the fixed crossflow conditions studied here), and the NOx emissions increased roughly linearly with the temperature rise.
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Unsteady flame-wall interactions in a Reacting jet injected into a vitiated cross-flow☆
Proceedings of the Combustion Institute, 2013Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Karthik Periagaram, Tim LieuwenAbstract:This paper describes measurements and analysis of the unsteady characteristics of a turbulent Reacting Fuel jet in a vitiated cross-flow. This problem involves coupling between the hydrodynamic stability of the jet–wall system, combustion induced gas expansion and interactions of the autoigniting jet with the wake flow. Analysis of the unsteady jet motions shows that the Reacting jet flaps in a sinuous manner with an amplitude that increases with downstream distance but is relatively independent of jet-to-cross-flow momentum flux ratio, J. This study particularly focuses on unsteady flame–wall interactions in these systems, showing that even though the time averaged flame trajectory may be well removed from wall regions, its instantaneous trajectory may be very near or even attached to the wall. Specifically, for lower J jets (J < ∼20), the flame intermittently attaches to the wall for some fraction of time that decreases with downstream distance and increasing J. From a practical point of view, intermittent flame–wall interactions cause an increase in the time averaged wall temperature, raising durability concerns. We suggest that this unsteady jet–wall attraction can be understood from analogies to the dynamics of co-flowing jet or wake pairs, as low J jets deflect into the cross-flow direction quickly. Side-by-side jets or wakes are “attracted” toward each other and exhibit global instabilities that are not present when they are isolated. In support of this argument, we show that data taken over the 1.7 < J < 7.2 range and a range of axial locations can be collapsed using the time averaged distance of the Reacting jet from the wall.
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Time-Averaged and Unsteady Imaging Analysis of a Reacting Fuel Jet in Vitiated Cross-Flow at Elevated Pressure
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Karthik PeriagaramAbstract:This paper describes an experimental imaging and analysis study of a Reacting CH4/H2/CO jet in a vitiated crossflow. We present an extensive data set showing the variation of the time averaged and unsteady characteristics of the Reacting jet over the momentum flux ratio range of 0.75
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time averaged and unsteady imaging analysis of a Reacting Fuel jet in vitiated cross flow at elevated pressure
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Karthik PeriagaramAbstract:This paper describes an experimental imaging and analysis study of a Reacting CH4/H2/CO jet in a vitiated crossflow. We present an extensive data set showing the variation of the time averaged and unsteady characteristics of the Reacting jet over the momentum flux ratio range of 0.75
David R Noble - One of the best experts on this subject based on the ideXlab platform.
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time averaged characteristics of a Reacting Fuel jet in vitiated cross flow
Combustion and Flame, 2014Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Tim LieuwenAbstract:This paper describes an experimental study of Reacting jets in a high-temperature (1775 K) vitiated crossflow at 6 atm. We present an extensive data set based on high speed chemiluminescence imaging and exhaust gas sampling showing the characteristics of the time-averaged trajectory, width of the flame, flame standoff (or ignition) location, and NOx emissions over a momentum flux ratio range of 0.75 < J < 240. Key observations are: (1) Depending upon ignition times, reaction can initiate uniformly around the jet, initiate on the leeward side of the jet and spread around to the windward side farther downstream, or initiate further downstream. (2) The time-averaged trajectory generally follows nonReacting trajectories, but penetrates further in the far-field than for what would be expected of a nonReacting jet. (3) The width of heat release zone increases monotonically with downstream location, J, and flame flapping amplitude, but seems to be dominated by the size of the counter-rotating vortex pair. (4) The measured ignition locations were of the same order of magnitude as values based on calculated ignition time scales and mean jet exit velocities, but with some additional variability. (5) The incremental NOx emissions were controlled primarily by the global temperature rise associated with burning the jet Fuel (for the fixed crossflow conditions studied here), and the NOx emissions increased roughly linearly with the temperature rise.
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Unsteady flame-wall interactions in a Reacting jet injected into a vitiated cross-flow☆
Proceedings of the Combustion Institute, 2013Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Karthik Periagaram, Tim LieuwenAbstract:This paper describes measurements and analysis of the unsteady characteristics of a turbulent Reacting Fuel jet in a vitiated cross-flow. This problem involves coupling between the hydrodynamic stability of the jet–wall system, combustion induced gas expansion and interactions of the autoigniting jet with the wake flow. Analysis of the unsteady jet motions shows that the Reacting jet flaps in a sinuous manner with an amplitude that increases with downstream distance but is relatively independent of jet-to-cross-flow momentum flux ratio, J. This study particularly focuses on unsteady flame–wall interactions in these systems, showing that even though the time averaged flame trajectory may be well removed from wall regions, its instantaneous trajectory may be very near or even attached to the wall. Specifically, for lower J jets (J < ∼20), the flame intermittently attaches to the wall for some fraction of time that decreases with downstream distance and increasing J. From a practical point of view, intermittent flame–wall interactions cause an increase in the time averaged wall temperature, raising durability concerns. We suggest that this unsteady jet–wall attraction can be understood from analogies to the dynamics of co-flowing jet or wake pairs, as low J jets deflect into the cross-flow direction quickly. Side-by-side jets or wakes are “attracted” toward each other and exhibit global instabilities that are not present when they are isolated. In support of this argument, we show that data taken over the 1.7 < J < 7.2 range and a range of axial locations can be collapsed using the time averaged distance of the Reacting jet from the wall.
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Time-Averaged and Unsteady Imaging Analysis of a Reacting Fuel Jet in Vitiated Cross-Flow at Elevated Pressure
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Karthik PeriagaramAbstract:This paper describes an experimental imaging and analysis study of a Reacting CH4/H2/CO jet in a vitiated crossflow. We present an extensive data set showing the variation of the time averaged and unsteady characteristics of the Reacting jet over the momentum flux ratio range of 0.75
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time averaged and unsteady imaging analysis of a Reacting Fuel jet in vitiated cross flow at elevated pressure
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Karthik PeriagaramAbstract:This paper describes an experimental imaging and analysis study of a Reacting CH4/H2/CO jet in a vitiated crossflow. We present an extensive data set showing the variation of the time averaged and unsteady characteristics of the Reacting jet over the momentum flux ratio range of 0.75
Benjamin Wilde - One of the best experts on this subject based on the ideXlab platform.
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time averaged characteristics of a Reacting Fuel jet in vitiated cross flow
Combustion and Flame, 2014Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Tim LieuwenAbstract:This paper describes an experimental study of Reacting jets in a high-temperature (1775 K) vitiated crossflow at 6 atm. We present an extensive data set based on high speed chemiluminescence imaging and exhaust gas sampling showing the characteristics of the time-averaged trajectory, width of the flame, flame standoff (or ignition) location, and NOx emissions over a momentum flux ratio range of 0.75 < J < 240. Key observations are: (1) Depending upon ignition times, reaction can initiate uniformly around the jet, initiate on the leeward side of the jet and spread around to the windward side farther downstream, or initiate further downstream. (2) The time-averaged trajectory generally follows nonReacting trajectories, but penetrates further in the far-field than for what would be expected of a nonReacting jet. (3) The width of heat release zone increases monotonically with downstream location, J, and flame flapping amplitude, but seems to be dominated by the size of the counter-rotating vortex pair. (4) The measured ignition locations were of the same order of magnitude as values based on calculated ignition time scales and mean jet exit velocities, but with some additional variability. (5) The incremental NOx emissions were controlled primarily by the global temperature rise associated with burning the jet Fuel (for the fixed crossflow conditions studied here), and the NOx emissions increased roughly linearly with the temperature rise.
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Unsteady flame-wall interactions in a Reacting jet injected into a vitiated cross-flow☆
Proceedings of the Combustion Institute, 2013Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Karthik Periagaram, Tim LieuwenAbstract:This paper describes measurements and analysis of the unsteady characteristics of a turbulent Reacting Fuel jet in a vitiated cross-flow. This problem involves coupling between the hydrodynamic stability of the jet–wall system, combustion induced gas expansion and interactions of the autoigniting jet with the wake flow. Analysis of the unsteady jet motions shows that the Reacting jet flaps in a sinuous manner with an amplitude that increases with downstream distance but is relatively independent of jet-to-cross-flow momentum flux ratio, J. This study particularly focuses on unsteady flame–wall interactions in these systems, showing that even though the time averaged flame trajectory may be well removed from wall regions, its instantaneous trajectory may be very near or even attached to the wall. Specifically, for lower J jets (J < ∼20), the flame intermittently attaches to the wall for some fraction of time that decreases with downstream distance and increasing J. From a practical point of view, intermittent flame–wall interactions cause an increase in the time averaged wall temperature, raising durability concerns. We suggest that this unsteady jet–wall attraction can be understood from analogies to the dynamics of co-flowing jet or wake pairs, as low J jets deflect into the cross-flow direction quickly. Side-by-side jets or wakes are “attracted” toward each other and exhibit global instabilities that are not present when they are isolated. In support of this argument, we show that data taken over the 1.7 < J < 7.2 range and a range of axial locations can be collapsed using the time averaged distance of the Reacting jet from the wall.
-
Time-Averaged and Unsteady Imaging Analysis of a Reacting Fuel Jet in Vitiated Cross-Flow at Elevated Pressure
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Karthik PeriagaramAbstract:This paper describes an experimental imaging and analysis study of a Reacting CH4/H2/CO jet in a vitiated crossflow. We present an extensive data set showing the variation of the time averaged and unsteady characteristics of the Reacting jet over the momentum flux ratio range of 0.75
-
time averaged and unsteady imaging analysis of a Reacting Fuel jet in vitiated cross flow at elevated pressure
50th AIAA Aerospace Sciences Meeting including the New Horizons Forum and Aerospace Exposition, 2012Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Karthik PeriagaramAbstract:This paper describes an experimental imaging and analysis study of a Reacting CH4/H2/CO jet in a vitiated crossflow. We present an extensive data set showing the variation of the time averaged and unsteady characteristics of the Reacting jet over the momentum flux ratio range of 0.75
Jerry Seitzman - One of the best experts on this subject based on the ideXlab platform.
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time averaged characteristics of a Reacting Fuel jet in vitiated cross flow
Combustion and Flame, 2014Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Tim LieuwenAbstract:This paper describes an experimental study of Reacting jets in a high-temperature (1775 K) vitiated crossflow at 6 atm. We present an extensive data set based on high speed chemiluminescence imaging and exhaust gas sampling showing the characteristics of the time-averaged trajectory, width of the flame, flame standoff (or ignition) location, and NOx emissions over a momentum flux ratio range of 0.75 < J < 240. Key observations are: (1) Depending upon ignition times, reaction can initiate uniformly around the jet, initiate on the leeward side of the jet and spread around to the windward side farther downstream, or initiate further downstream. (2) The time-averaged trajectory generally follows nonReacting trajectories, but penetrates further in the far-field than for what would be expected of a nonReacting jet. (3) The width of heat release zone increases monotonically with downstream location, J, and flame flapping amplitude, but seems to be dominated by the size of the counter-rotating vortex pair. (4) The measured ignition locations were of the same order of magnitude as values based on calculated ignition time scales and mean jet exit velocities, but with some additional variability. (5) The incremental NOx emissions were controlled primarily by the global temperature rise associated with burning the jet Fuel (for the fixed crossflow conditions studied here), and the NOx emissions increased roughly linearly with the temperature rise.
-
Unsteady flame-wall interactions in a Reacting jet injected into a vitiated cross-flow☆
Proceedings of the Combustion Institute, 2013Co-Authors: Ryan Sullivan, Benjamin Wilde, David R Noble, Jerry Seitzman, Karthik Periagaram, Tim LieuwenAbstract:This paper describes measurements and analysis of the unsteady characteristics of a turbulent Reacting Fuel jet in a vitiated cross-flow. This problem involves coupling between the hydrodynamic stability of the jet–wall system, combustion induced gas expansion and interactions of the autoigniting jet with the wake flow. Analysis of the unsteady jet motions shows that the Reacting jet flaps in a sinuous manner with an amplitude that increases with downstream distance but is relatively independent of jet-to-cross-flow momentum flux ratio, J. This study particularly focuses on unsteady flame–wall interactions in these systems, showing that even though the time averaged flame trajectory may be well removed from wall regions, its instantaneous trajectory may be very near or even attached to the wall. Specifically, for lower J jets (J < ∼20), the flame intermittently attaches to the wall for some fraction of time that decreases with downstream distance and increasing J. From a practical point of view, intermittent flame–wall interactions cause an increase in the time averaged wall temperature, raising durability concerns. We suggest that this unsteady jet–wall attraction can be understood from analogies to the dynamics of co-flowing jet or wake pairs, as low J jets deflect into the cross-flow direction quickly. Side-by-side jets or wakes are “attracted” toward each other and exhibit global instabilities that are not present when they are isolated. In support of this argument, we show that data taken over the 1.7 < J < 7.2 range and a range of axial locations can be collapsed using the time averaged distance of the Reacting jet from the wall.
