The Structure and Dynamics of Turbulent, Interacting Flames
Overview
In many modern combustion devices, multiple closely-spaced flames interact with each other. These combustion devices include jet engine combustors and augmentors, power generation gas turbine combustors, and industrial boilers and furnaces. For example, modern gas turbine engines for power generation utilize can-type combustor geometries, where flame-interaction is observed. The development of these practical combustion devices requires a detailed understanding of combustion processes occurring in these devices. Computational fluid dynamics has become a popular tool used in the design process for these devices. However, simulating real flames in these combustors is challenging and the ability to capture all physical processes involved has not yet reached its pinnacle. Flame-flame interaction is one such process that is yet to be completely captured in simulating modern combustors, as this can directly affect these flames by changing the flame structure, flame propagation, flame stability, and emissions production. The interaction between the flow-fields and scalar-fields in these devices changes the structure and dynamics of these flames. Understanding these effects is of crucial importance as it will help in creating a foundational understanding that can enhance the design and operation of combustion devices.
The objective of this research is to understand the impact of flame interactions on flame structure and propagation for the development of turbulent combustion models. To achieve this objective, we are investigating the fundamental understanding of flame interaction events, and the sensitivity of flame interaction behavior to a number of key operational parameters. This will help in characterizing the relative impact of flame interaction events on flame structure and propagation over a wide operating range. The main goals of this project include: 1) better understand flame interactions and how operational parameters – including turbulence intensity, turbulent length scales, turbulence anisotropy, Lewis number, and flame shape – alter flame interaction processes, 2) determine the differences between flame-flame and turbulence-flame interactions, particularly the impact that flame-flame interactions have on key properties that determine flame structure and propagation, including flame area (or flame surface density), flame stretch, flame heat release rate, and combustion efficiency, and 3) describe the relative importance of flame-flame vs. turbulence-flame interaction processes on both local and global flame characteristics as a function of operating parameter to determine in what regimes it is critical to incorporate flame-interaction effects in combustion models. High-speed diagnostic techniques, such as, 10 kHz stereoscopic-particle image velocimetry (S-PIV), OH-planar laser induced fluorescence, and CH* chemiluminescence are utilized to capture the dynamic behavior of these flames.
Funded by the Air Force Office of Scientific Research.
In collaboration with Dr. Isaac Boxx – DLR, German Aerospace Center, Stuttgart, Germany
Publications
Tyagi, A., & O’Connor, J. (2020) “Towards a method of estimating out-of-plane effects on measurements of turbulent flame dynamics,” Combustion and Flame, 216, p. 206-222. Accepted author pre-print available here and supplemental material.
Beseler, K., Tyagi, A., & O’Connor, J. (2020) “Development of a diagnostic Damkohler number for interpreting laser-induced fluorescence data in turbulent flames,” AIAA SciTech, Orlando, FL. Accepted author pre-print available here.
Tyagi, A., Boxx, I., Peluso, S., & O’Connor, J. (2020) “Pocket formation and behavior in turbulent premixed flames,” Combustion and Flame, 211, p. 312-324. Accepted author pre-print available here and supplementary material.
Tyagi, A., Boxx, I., Peluso, S., & O’Connor, J. (2019) “Statistics and topology of local flame-flame interactions in turbulent flames,” Combustion and Flame, 203, p. 92-104, Accepted author pre-print available here and supplementary material.
Tyagi, A., Boxx, I., Peluso, S., & O’Connor, J. (2019) “Statistics of local flame-flame interactions in flame interaction zones of two V-flames,” AIAA SciTech Forum, San Diego, CA. Accepted author pre-print available here.
Tyagi, A., Boxx, I., Peluso, S., & O’Connor, J. (2018). “The role of flow interaction in flame–flame interaction events in a dual burner experiment.” Proceedings of the Combustion Institute, 37(2), p. 3485-2491. Accepted author pre-print available here.
Shupp, R., Tyagi, A., Boxx, I., Peluso, S., O’Connor, J., (2018) “The effects of piloting on turbulent flame structure,” Spring Technical Meeting of the Eastern States Section of the Combustion Institute, State College, PA. Accepted author pre-print available here.
Tyagi, A., Boxx, I., Peluso, S., Shupp, R., O’Connor, J., (2018) “Topology of local flame-flame interaction events in turbulent flames,” Spring Technical Meeting of the Eastern States Section of the Combustion Institute, State College, PA. Author version available here.
Tyagi, A., Boxx, I., Peluso, S., Shupp, R., O’Connor, J., (2018) “Structure of flames in flame interaction zones,” AIAA SciTech, Kissimmee, FL. Accepted author pre-print available here.
Culler, W., A. Tyagi, P. Venkateswararn, J. O’Connor, (2016). “Comparison of Three Interacting V-Flames to a Single Bluff Body Flame at Two Reynolds Numbers,” 2016 AIAA SciTech. San Diego, CA. Accepted author pre-print available here.
Culler, W., J. Crane, R. J. Samarasinghe, M. Meehan, J. O’Connor, (2015) “Effect of Flame Spacing and Flow Velocity on the Dynamics of Three Interacting V-Flames,” in 9th U.S. National Combustion Meeting, Cincinnati, OH. Author version available here.