Nonlinear self-excited thermoacoustic oscillations of a ducted premixed flame: bifurcations and routes to chaos

Nonlinear Self-excited Thermoacoustic Oscillations of a Ducted Premixed Flame: Bifurcations and Routes to Chaos

We study the bifurcations of a ducted two-dimensional premixed flame using numerical simulations of the coupled dynamical system. When the flame position in the duct is changed the system undergoes transition to period-1, quasi-periodic, period-2, frequencylocked and chaotic oscillations via different bifurcations. For certain parameter ranges multiple stable solutions exist and the ultimate st...

Nonlinear self-excited oscillations in a thermoacoustic system

Lipika Kabiraj, R. I. Sujith, Pankaj Wahi † ‡ Department of Aerospace Engineering Indian Institute of Technology Madras Chennai 600036, India [email protected], [email protected] Department of Mechanical Engineering Indian Institute of Technology Kanpur Kanpur-208016, India [email protected] ABSTRACT Spontaneous pressure and heat release rate oscillations can get excited in a confined combu...

Behaviour of a Premixed Flame Subjected to Acoustic Oscillations

In this paper, a one dimensional premixed laminar methane flame is subjected to acoustic oscillations and studied. The purpose of this analysis is to investigate the effects of acoustic perturbations on the reaction rates of different species, with a view to their respective contribution to thermoacoustic instabilities. Acoustically transparent non reflecting boundary conditions are employed. T...

Extinction and flame bifurcations of stretched dimethyl-ether premixed flames

Extinction limits and flame bifurcation of lean premixed dimethyl ether-air flames are investigated numerically using the counterflow flame with a reduced chemistry. Emphasis is paid to the combined effect of radiation and flame stretch on the extinction and flammability limits. A method based on the reaction front is presented to predict the Markstein length. The predicted positive Markstein l...

Proper Orthogonal Decomposition Analysis of a Turbulent Swirling Self-Excited Premixed Flame