Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Variable-swirl burner with optical access Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Cross section of swirler, premixing tube, and combustor Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Swirl number as a function of ratio of axial/tangential momentum Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Normalized axial velocity profiles obtained from LDA measurements for different swirl numbers Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Normalized tangential velocity profiles obtained from LDA measurements for different swirl numbers Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Different flashback mechanisms observed under various test conditions Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / OH* chemiluminescence image sequence of upstream flame propagation caused by CIVB. Image interval = ms, exposure time = 72 μs, swirl number = 0.66, fuel H 2 mole fraction = 0.9, Φ = Φ FB = Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / OH* chemiluminescence image sequence of upstream flame propagation in the boundary layer. Image interval = ms, exposure time = 72 μs, swirl number = 0.0, fuel H 2 mole fraction = 0.9, Φ = Φ FB = Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / OH* chemiluminescence image sequence of flame propagation in the premixing tube caused by auto-ignition. Image interval = ms, exposure time = 72 μs, swirl number = 0.24, fuel H 2 mole fraction = 0.15, Φ = Φ FB = Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / OH* chemiluminescence image sequence of blowout of the flame due to auto-ignition. Image interval = ms, exposure time = 72 μs, swirl number = 0.24, fuel H 2 mole fraction = 0.15, Φ = Φ FB = Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Adiabatic flame temperature at flashback as a function of H 2 mole fraction Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Flame front displacement in the optical section of the premixing tube during the flashback events for various fuel H 2 mole fraction/flashback mechanisms Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Linear approximation of the flame front displacement for various fuel H 2 mole fraction/flashback mechanisms Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / The displacement of the second flame front in the premixing tube obtained in four flashback events caused by auto-ignition under the same condition: swirl number = 0.24, fuel H 2 mole fraction = 0.15, Φ = Φ FB = Figure Legend:

Date of download: 5/28/2016 Copyright © ASME. All rights reserved. Visualization of Different Flashback Mechanisms for H 2 /CH 4 Mixtures in a Variable-Swirl Burner J. Eng. Gas Turbines Power. 2014;137(3): doi: / Equivalence ratio at flashback as a function of total air mass-flow rate (the H 2 mole fraction of the mixtures are presented next to each data point) Figure Legend: