Shock-Tube Studies of High-Temperature Flames Applicable to Next-Generation Energy Systems

Meeting society’s growing energy demands while simultaneously ensuring reliable and equitable energy access and mitigating the role of energy production on exacerbating climate change requires a holistic research and technology-development strategy. The combustion of chemical fuels remains the primary energy conversion technology used in the power generation and transportation sectors and is projected to persist for decades to come, particularly in “hard to electrify” sectors such as commercial aviation and shipping.

Next-generation combustion-based energy systems using sustainable, net-zero-carbon fuels together with advanced thermodynamic cycles to maximize energy conversion efficiency provide a pathway for the continued use of combustion systems while mitigating the adverse effects with which they have historically been associated. This project provides support to the development of next-generation energy systems through fundamental studies of flame behavior at high-temperature conditions relevant to practical combustion applications.

Advanced experimental techniques and high-speed imaging and laser-based diagnostics will provide detailed measurements of flame speeds and structure at the highest temperature conditions ever studied in a controlled laboratory environment. The availability of such measurements will inform the accurate modeling and simulation of combustion processes and shorten the development time required for the deployment of next-generation energy systems with reduced carbon emissions.

The premixed, laminar flame speed represents a fundamental property of a fuel-oxidizer system. Jointly governed by thermal, transport, and chemical-kinetic properties, the laminar flame speed contains information on multiple components of the detailed models commonly compiled to describe combustion events. Experimentally measured flame speeds are widely utilized as performance metrics in all stages of kinetic mechanism development, including tuning the parameters, validating the global performance, and maintaining accuracy as mechanisms are reduced in size for use in detailed simulation of practical combustion systems.

The shock-tube flame speed method has been developed and refined to enable the study of laminar flames at high-temperature, reactive conditions relevant to next-generation energy systems but beyond the capability of experimental study using previous measurement techniques. Activity 1 of this project is to apply the shock-tube flame speed method to perform a survey of laminar flame speed measurements at high temperatures for fuels relevant to current and future energy systems.

These measurements will be collated into a new measurement database to ensure simple and open access of the resulting data. Activity 2 of this project will include the exploratory application of advanced diagnostics to determine the presence of and study novel flame structures and phenomena existing at high temperatures, such as cool, double, and overdriven flames.

Data resulting from this project will serve as the first fundamental experimental measurements of high-temperature flame behavior and are thus expected to significantly advance the understanding of combustion phenomena at conditions relevant to practical energy-conversion systems.

This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.