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Flame blowout: Transition to an absorbing phase
Vishnu R Unni1, Swetaprovo Chaudhuri2, R I Sujith1
1Department of Aerospace Engineering, Indian Institute of Technology Madras, Chennai 600036, India.
Chaos (Woodbury, N.Y.)
|December 4, 2018
Summary
Flame blowout in gas turbines, driven by lean fuel conditions, is modeled using flamelet population dynamics. This approach reveals blowout as a transition to flame extinction, offering insights for reduced-order models.
Area of Science:
- Combustion science
- Turbulent flows
- Nonlinear dynamics
Background:
- Turbulent flames in gas turbines are prone to extinction at lean fuel conditions, a phenomenon known as flame blowout.
- Traditional views consider blowout as a loss of combustor stability, but pre-blowout dynamics suggest a need for more comprehensive models.
- Understanding these dynamics is crucial for developing reduced-order models for flame behavior.
Purpose of the Study:
- To model the emergent dynamics of flamelet populations in turbulent flames near blowout conditions.
- To investigate flame blowout as a population dynamics process analogous to a contact process.
- To capture the complex dynamics observed in turbulent flames approaching blowout.
Main Methods:
- A cellular automata based model was employed to simulate the population dynamics of flamelets.
- The model treats the turbulent flame as a collection of interacting flamelets.
- Flame blowout is represented as the extinction of the flamelet population.
Main Results:
- The cellular automata model qualitatively captures the dynamics of turbulent flames approaching blowout.
- Flame blowout is demonstrated to be analogous to a threshold-like transition to an absorbing phase.
- The population dynamics of flamelets provide a novel perspective on flame extinguishment.
Conclusions:
- Modeling flamelet population dynamics offers a new framework for understanding turbulent flame blowout.
- The cellular automata approach successfully replicates key pre-blowout flame dynamics.
- Flame blowout exhibits characteristics of a phase transition, suggesting potential for simplified modeling.
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