In this installment of a 13-part series of monthly articles, The Combustion Institute recognizes the 2019 Distinguished Papers selected from among the scientific papers presented during the 37th International Symposium on Combustion. Congratulations to Andrew P. Wandel and R. Peter Lindstedt for their winning paper in the Turbulent Flames colloquium.

The authoritative paper, A mixture-fraction-based hybrid binomial Langevin-multiple mapping conditioning model, has advanced the ability to model the effect of turbulence on chemical (e.g. combustion) processes, which can lead to improved thermal efficiency with lower emissions, especially when renewable fuels (“biofuels”) are used.

Pollution from engines and furnaces (such as smog) can, in principle, be reduced by using less fuel in the mixture. Unfortunately, this also makes it more likely that the fuel does not burn properly (e.g. causes “misfire”) as turbulent flame stability is compromised. Furthermore, biofuels offer an opportunity to reduce greenhouse gas emissions and other pollutants, but because they burn differently to fossil fuels, engines and furnaces have to operate differently. The research of Wandel and Lindstedt provides a novel model that can help engineers anticipate problems and modify designs to combine the best possible efficiency with reduced pollutant emissions.

The research pair used the hybrid model they developed for this paper to simulate a benchmark experiment that deliberately produced a great deal of misfire. The model performed very well, especially when compared to other approaches that have been used to predict this data. They believe their findings will soon lead to the application of the model to power generation and propulsion devices (e.g. gas turbine engines), and ultimately assist in the design of more environmentally-friendly energy conversion systems.

The researchers presented a different form of the model in 2012 at the 34th International Symposium on Combustion. During a two-month sabbatical by Associate Professor Wandel in late 2016, an opportunity arose to explore new ideas and develop a modified form. The final version used in this study was produced in 2017 in conjunction with the completion of their paper.

Research for this paper was conducted at Imperial College, London and the University of Southern Queensland. The study was initiated by funding from the EPSRC (Grant GR/T22766) and the Office of Naval Research (ONR Award N000140710993; Contract monitor Dr. G.D. Roy) while Associate Professor Wandel was working in the UK. [1] [2] The authors wish to express their gratitude to the Australian and New Zealand Section of the Combustion Institute for the award of the inaugural Brian Haynes Regional Travel Grant to Associate Professor Wandel, which enabled continued collaboration across large geographical distances.

Over 1,600 papers were submitted to the 38th Symposium in 13 combustion science colloquia. Those papers were categorized by teams of colloquium coordinators and co-chairs, and then distributed to approximately 1,000 scientific reviewers. One paper in each discipline was awarded the recognition of Distinguished Paper.

The 13 Distinguished Papers undergo committee review for consideration to receive the Silver Combustion Medal that will be awarded during the 38th International Symposium in Adelaide, Australia. A paper selected for this honor exemplifies quality, achievement, and significance to advance a field of combustion science. Distinguished papers are selected biennially from among the scientific papers presented during the International Symposium on Combustion and accepted for publication in the Proceedings of The Combustion Institute.

[1] Wandel, A.P. & Lindstedt, R.P. (2009). Hybrid binomial Langevin-multiple mapping conditioning modeling of a reacting mixing layer. Physics of Fluids 21, 015103.

[2] Wandel, A.P. & Lindstedt, R.P. (2013). Hybrid multiple mapping conditioning modeling of local extinction. Proceedings of The Combustion Institute 34(2), 1365-1372.