@article{marley_danby_roberts_drake_fansler_2008, title={Quantification of transient stretch effects on kernel-vortex interactions in premixed methane-air flames}, volume={154}, ISSN={["0010-2180"]}, DOI={10.1016/j.combustflame.2008.02.003}, abstractNote={Relative flame speeds of time-dependent highly curved premixed methane–air flames (spark-ignited flame kernels) interacting with a laminar vortex have been quantified using high-speed chemiluminescence imaging, particle image velocimetry, and piezoelectric pressure measurements. The goals of this study are to improve fundamental understanding of transient stretch effects on highly curved premixed flames, to provide practical insight into the turbulent growth of spark-ignited flame kernels in internal combustion (IC) engines burning light hydrocarbon fuels, and to provide data for IC engine ignition and combustion model development. Lean and rich CH4–O2–N2 flames were tested (ϕ=0.64, 0.90, and 1.13, with nitrogen dilution to equalize the flame speeds (Sb) in the absence of vortex interaction). Transient stretch rates were varied using three different vortex strengths, and the size of the flame kernel at the start of the vortex interaction controlled by time delay between ignition and vortex generation. Vortex interactions with small (∼5 mm radius) flame kernels were found to increase burning rates for lean (ϕ=0.64) flame kernels substantially. Burning rates for rich (ϕ=1.13) flames were decreased, with total flame kernel extinction occurring in extreme cases. These small flame kernel–vortex interactions are dominated by transient stretch effects and thermodiffusive stability, in agreement with premixed flame theory. However, vortex interactions with larger methane–air flame kernels (∼30 mm radius) led to slight flame speed enhancements for both lean and rich flame kernels, with the flame–vortex process dominated by increased flamefront area generated by vortex-induced flame wrinkling.}, number={1-2}, journal={COMBUSTION AND FLAME}, author={Marley, S. K. and Danby, S. J. and Roberts, W. L. and Drake, M. C. and Fansler, T. D.}, year={2008}, month={Jul}, pages={296–309} }
 @article{marley_roberts_2005, title={Measurements of laminar burning velocity and Markstein number using high-speed chemiluminescence imaging}, volume={141}, ISSN={["1556-2921"]}, DOI={10.1016/j.combustflame.2005.02.011}, abstractNote={A high-speed chemiluminescence imaging diagnostic system has been developed and characterized for measuring species-specific properties of spherically expanding flames, with the objective of obtaining synchronized measurements of multiple flame properties from a single flame experiment. The imaging system comprises a high-speed camera coupled to a high-speed image intensifier and optical filters to isolate emission from desired excited species. This study validates the diagnostic scheme specifically for measuring laminar flame speed and Markstein length from chemiluminescence at three wavelength bands corresponding to OH*, CH*, and total chemiluminescence, respectively. Mixtures of methane-air and methane/ethane-air were tested at initial conditions of atmospheric pressure and room temperature. An under-utilized methodology for computing unburned Markstein length from burned Markstein length was implemented. Flame speed modeling of each mixture was conducted in Chemkin using AramcoMech 2.0. No significant differences were observed between the results derived from the three emission wavelength bands for the flame speeds nor the Markstein lengths. For both of these properties, excellent agreement was observed between the experimental results and the values reported in the literature. Because laminar flame speed and Markstein length show no dependency on the imaging wavelength, the present results imply that multiple flame properties, such as laminar flame speed, Markstein length, flame thickness, and excited-species intensity profiles, can all be acquired simultaneously for the same flame using this method.}, number={4}, journal={COMBUSTION AND FLAME}, author={Marley, SK and Roberts, WL}, year={2005}, month={Jun}, pages={473–477} }
 @article{marley_welle_lyons_2004, title={Combustion structures in lifted ethanol spray flames}, volume={126}, ISSN={["1528-8919"]}, DOI={10.1115/1.1688768}, abstractNote={The development of a double flame structure in lifted ethanol spray flames is visualized using OH planar laser-induced fluorescence (PLIF). While the OH images indicate a single reaction zone exists without co-flow, the addition of low-speed co-flow facilitates the formation of a double flame structure that consists of two diverging flame fronts originating at the leading edge of the reaction zone. The outer reaction zone burns steadily in a diffusion mode, and the strained inner flame structure is characterized by both diffusion and partially premixed combustion exhibiting local extinction and re-ignition events.}, number={2}, journal={JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER-TRANSACTIONS OF THE ASME}, author={Marley, SK and Welle, EJ and Lyons, KM}, year={2004}, month={Apr}, pages={254–257} }
 @article{marley_welle_lyons_roberts_2004, title={Effects of leading edge entrainment on the double flame structure in lifted ethanol spray flames}, volume={29}, DOI={10.1016/j.ecpthermflusci.2004.01.009}, number={1}, journal={Experimental Thermal and Fluid Science}, author={Marley, S. K. and Welle, E. J. and Lyons, K. M. and Roberts, W. L.}, year={2004}, pages={23–31} }