Distinguished Seminar Series in Computational Science and Engineering
November 18, 2021, 12 PM ET
Combustion Dynamics: Predictions and Insight Gained from Simulations and Diagnostic
Ronald C. Crane (1972) Professor
Department of Mechanical Engineering
Massachusetts Institute of Technology
Recorded Seminar YouTube Link:
Combustion is currently used to generate more that 85% of the world primary energy from hydrocarbon fuels and biomass. While the World is on a trajectory to decarbonize, combustion will continue to play a significant role in powering long-distance transportation using alternative fuels, in carbon capture enabled technologies for power and industrial applications, among others. While the technology has evolved to address timely needs, combustion science has enabled quantitative predictions based on multiscale modeling, optical diagnostics and high-performance computing. The talk will demonstrate the effective use of these tools as applied to a problem that has challenged us for many years; namely predicting the onset of combustion instability and elucidating its origin in low-emission systems. Using validated simulations and measurements, we have been able to use concepts from flame theory to scale the onset of critical phenomena in dynamics based on some canonical properties. Observables at the macroscale were shown to be associated with a transition at the microscales, even under uncoupled conditions, that supports the coupling between flame dynamics and the acoustic field. Simulations reveal that the transition in flame structure and associated dynamics is driven by conditions that make the flames survive states that could have led to strain-induced extinction otherwise, explaining the origin of scaling. Simulations results revealed more subtle effects, e.g., the role of helical vortical structures in transitions leading to the onset of dynamics. The applicability of similar scaling rules is demonstrated beyond dynamics, and extended to other critical phenomena captured by high fidelity simulations, and providing further mechanistic support for the origin of scaling. These developments promise to extend the applicability of existing knowledge to new fuels and systems.
Professor Ghoniem is the Ronald C. Crane (’72) professor of Mechanical Engineering and the director of the Center for 21st Century Energy at MIT. He holds B. S. (1973) and M. S. (1975) degrees in Mechanical Engineering from Cairo University in Egypt and a Ph. D. degree from the University of California, Berkeley (1980). He served as a research scientist at Lawrence Berkeley Laboratory from 1980-83. Since 1983 he has been at MIT where he established the Reacting Gas Dynamics Laboratory and has supervised a number of M.S. & Ph.D. students, post-docs and research scientists. He is a fellow of the American Society of Mechanical Engineers and associate fellow of the American Institute of Aeronautics and Astronautics.
His research interest lie in the areas of high performance computing in turbulent reactive flow, computational mathematics, combustion dynamics and active control, modeling and simulation of transport-chemistry interactions in thermochemical and electrochemical systems including high temperature fuel cells, gasification processes and fuel production and analysis of high-performance, zero-emission integrated energy systems with CO2 capture.
Combustion Dynamics: Predictions and Insight Gained from Simulations and Diagnostics
Ahmed Ghoniem, MIT MechE