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1. Relative influence of soot oxidation kinetics and subfilter soot-turbulence interactions on soot evolution in turbulent nonpremixed flames

   https://doi.org/10.1016/j.proci.2022.08.009  

   Duvvuri, Pavan Prakash ; Colmán, Hernando Maldonado ; Mueller, Michael E. ( January 2023 , Proceedings of the Combustion Institute)
2. Propagation of premixed flames in the presence of Darrieus–Landau and thermal diffusive instabilities

   https://doi.org/10.1016/j.combustflame.2020.02.030  

   Creta, Francesco ; Lapenna, Pasquale Eduardo ; Lamioni, Rachele ; Fogla, Navin ; Matalon, Moshe ( June 2020 , Combustion and Flame)
3. A Macroscopic View of Reynolds Scaling and Stretch Effects in Spherical Turbulent Premixed Flames

   https://doi.org/10.2514/6.2022-2115  

   Vinod, Aditya ; Kulkarni, Tejas ; Bisetti, Fabrizio ( January 2022 , AIAA Scitech 2022 Forum. Presented at AIAA Scitech 2022 Forum, San Diego CA & Virtual, Jan 3-7, 2022)

   The burning rate in a spherically turbulent premixed flame is explored using direct numerical simulations, and a model of ordinary differential equations is proposed. The numerical dataset, from a previous work, is obtained from direct numerical simulations of confined spherical flames in isotropic turbulence over a range of Reynolds numbers. We begin the derivation of the model with an equation for the burning rate for the domain under consideration, and using a thin flame assumption and a two-fluid approach, we find the normalized turbulent burning rate to be controlled by the increase in flame surface area due to turbulent wrinkling, and correction factor which is observed to be consistently less than unity. A Reynolds scaling hypothesis for the flame turbulent wrinkling from a previous work using the same numerical dataset is used to model the term controlling the increase in flame surface area. The correction factor is hypothesized to reflect flame stretch effects, and hence this factor is modeled using Markstein theory applied to global averaged quantities. The ordinary differential equations are rewritten to reflect easily observable quantities such as the chamber pressure and mean flame radius, and then expressed in dimensionless form to assess dependence on various dimensionless parameters. The model predictions are found to be in good agreement with the numerical data within expected variances. Additionally, Markstein theory is found to be sufficient in describing the effects of flame stretch in the turbulent premixed flames under consideration. 

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4. Facing the flames: insect responses to megafires and changing fire regimes

   https://doi.org/10.1016/j.cois.2023.101129  

   Dole, Haley E ; Villamarin-Cortez, Santiago ; Richards, Lora A ( December 2023 , Current Opinion in Insect Science)
5. PAHs controlling soot nucleation in 0.101—0.811MPa ethylene counterflow diffusion flames

   https://doi.org/10.1016/j.combustflame.2021.01.015  

   Gleason, Kevin ; Carbone, Francesco ; Gomez, Alessandro ( May 2021 , Combustion and Flame)

   On the heels of a recent study in an atmospheric pressure ethylene diffusion flame in which the transition from parent fuel molecule to Polycyclic Aromatic Hydrocarbons (PAHs) and, eventually, soot was studied by spatially resolved measurements of PAH concentrations and soot quantities, we extended the focus to diffusion flames with self- similar structure in the 0.101–0.811 MPa pressure range. To that end, we complemented pyrometry based measurements of soot volume fraction with light scattering measurements that, once corrected for beam steering, yielded soot particle size and number concentration profiles. A chemistry model, that had been validated for all species up to 3 ring aromatics in one of the flames investigated at each pressure and up to 4-rings for the flame at atmospheric pressure, was used to compare profiles of chemical species to those of soot quantities. Further analysis yielded the assessment of number nucleation rates of soot and their comparison to the dimerization rates of PAHs. Soot nucleation rate is consistent only with the dimerization of one- and two-ring PAHs, an observation that confirms findings in the atmospheric pressure flame. Changes in pressure and temperature have a progressively larger impact on the concentration of aromatics of increasingly larger molecular weight and, even more so, on soot volume fraction and nucleation rate. A four-fold increase in pressure from 0.101 MPa to 0.405 MPa increases the soot nucleation rate and PAH dimerization rate in flames with constant peak temperature, which is primarily a concentration effect on bimolecular collision rates; a similar but less pronounced effect is observed in the higher (0.405–0.811 MPa) pressure range. Changes in pressure and temperature tend to be progressively more consequential on aromatics of increasing molecular weight and soot. 

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