Self-similar scaling of pressurised sooting methane/air coflow flames at constant Reynolds and Grashof numbers

Bisetti, Fabrizio; Abdelgadir, Ahmed; Steinmetz, Scott A.; Attili, Antonio; Roberts, William L.

doi:10.1016/j.combustflame.2018.06.023

Cited by 5 publications

(1 citation statement)

References 35 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…-To be more relevant to practical combustion systems like diesel engines and jet engines, counterflow flame experiments must be extended to operate with liquid fuels at high-pressure conditions. Although the counterflow configuration is advantageous for controllable and stable flame operation at elevated pressures (i.e., not sensitive to buoyancy-driven instability, no heat loss through burner rim) [788], it is important to design boundary conditions carefully, so that pressure effects on soot formation can be isolated [537,618,788]. In terms of fuel types, studies on oxygenated fuels with aromatic rings are scarce, but they deserve attention in future research because of their practical uses and potentially different soot growth pathways, as compared to other aliphatic and aromatic fuels.…”

Section: Summary Challenges and Prospectsmentioning

confidence: 99%

Soot formation in laminar counterflow flames

Wang

Chung

2019

Progress in Energy and Combustion Science

359

116

View full text Add to dashboard Cite

Many practical soot-emitting combustion systems such as diesel and jet engines rely on diffusion flames for efficient and reliable operation. Efforts to mitigate soot emissions from these systems are dependent on fundamental understanding of the physicochemical pathways leading from fuel to soot in laminar diffusion flames. Existing diffusion flame−based soot studies focused primarily on overventilated coflow flame where the fuel gas (or vapor) issues from a cylindrical tube into a co-flowing oxidizer, and counterflow flame, where a reacting zone is established between two opposing streams of fuel and oxidizer. As a canonical diffusion flame configuration, laminar counterflow diffusion flames have been widely used as a highly controllable environment for soot research, enabling significant progress in the understanding of soot formation for several decades. In view of the possibility of fuel/oxidizer premixing in practical systems, counterflow partially premixed flames have also been studied. In the present work we intend to provide a comprehensive review of the researches on various aspects of soot formation utilizing counterflow flames. Major processes of soot formation (formation of gas phase soot precursors, soot inception and surface reactions, as well as particle-particle interactions) are examined first, with focus on the most recent (post-2010) research progress. Experimental techniques and associated challenges for the measurement of soot-related properties (some knowledge of which is helpful for full appreciation of the experimental data to be reviewed) are then introduced. This is followed by a detailed description of soot evolution in counterflow flames, which is complemented by a discussion on the similarity and differences of the sooting structures between counterflow and coflow diffusion flames. Parametric studies of the effects of fuel molecular structure, fuel additive, partial-premixing, pressure, temperature, stoichiometric mixture fraction, and residence time on soot formation in counterflow flames will then be addressed in detail. This review concludes with a summary of the knowledge and challenges gathered and demonstrated through decades of research, and an outlook on opportunities for future counterflow flame−based soot research towards a more complete understanding of soot formation and the development of novel techniques for soot mitigation in practical combustion devices.

show abstract