Results 181 to 190 of about 787,947 (227)

Influence of rotational asymmetry on thermoacoustic instabilities in a can-annular lean-premixed combustor

, 2021
Low-frequency combustion instabilities, and ultimately, engine-level dynamics in can-annular gas turbine combustion systems, are driven by acoustic interactions between adjacent combustors through an annular cross-talk section upstream of first stage ...
Kihun Moon, Changjin Yoon, Kyu Tae Kim
semanticscholar   +1 more source

Control of Intrinsic ThermoAcoustic instabilities for methane and hydrogen air flames: DNS and network analysis

Proceedings of the Combustion Institute
Replacing methane by hydrogen in premixed burners is a typical decarbonation scenario. This is usually done by ensuring a constant flame speed, i.e. by using ultra-lean H 2 mixtures. This change can modify the thermoacoustic properties of burners.
Anthony Dupuy, Q. Douasbin, T. Poinsot
semanticscholar   +1 more source

Thermoacoustic Sources and Instabilities

1992
Thermoacoustics deals with the acoustics of flows in which the variation of entropy plays a significant role. A range of processes are thermoacoustic sources. For example, unsteady combustion, diffusion of heat and mass and turbulent two-phase flows all generate sound.
D. G. Crighton, A. P. Dowling, J. E. Ffowcs Williams, M. Heckl, F. G. Leppington   +4 more
openaire   +1 more source

Multivariate Signal Prediction Using Attention Transfer Learning for Early Detection of Thermoacoustic Instabilities

AIAA Journal
The prediction and control of thermoacoustic instability play a crucial role in combustion systems. This paper presents a novel methodology that employs attention transfer learning for the prediction of multivariate thermoacoustic signals, including ...
Zengyi Lyu, Yuanqi Fang, Zhuyin Ren, Gaofeng Wang   +3 more
semanticscholar   +1 more source

Adaptive control for thermoacoustic combustion instabilities

Proceedings of the 2001 American Control Conference. (Cat. No.01CH37148), 2001
Thermoacoustic instabilities in combustion processes involve pressure and velocity limit cycling oscillations that can have adverse effects on system performance. Using a nonlinear state space model for combustion processes that captures the coupling between unsteady combustion and acoustics, a direct adaptive control framework is used to design high ...
N.A. Kablar, T. Hayakawa, W.M. Haddad
openaire   +1 more source

Thermoacoustic instabilities of lean disc flames

Fuel, 2016
Abstract The present work evaluates impinging lean disc flames, stabilized on a Helmholtz resonator, under thermoacoustic oscillations. These unsteady flames were found to oscillate with either one single frequency ( f ) or two simultaneous frequencies ( f , 2 f ).
B.F.C. Cintra, E.C. Fernandes
openaire   +1 more source

Nonlinear saturation of the thermoacoustic instability

The Journal of the Acoustical Society of America, 2000
A weakly nonlinear theory of the thermoacoustic instability in gas-filled tubes is developed in the time domain by exploiting the difference between the instability time scale and the period of standing waves. By carrying the expansion to fourth order in the perturbation parameter, explicit results for the initial growth, nonlinear evolution, and final
Karpov, S., Prosperetti, A.
openaire   +3 more sources

Intrinsic thermoacoustic instability of premixed flames

Combustion and Flame, 2015
Abstract The thermoacoustic stability of velocity sensitive premixed flames is investigated. A causal representation of the flow-flame-acoustic interactions reveals a flame-intrinsic feedback mechanism. The feedback loop may be described as follows: An upstream velocity disturbance induces a modulation of the heat release rate, which in turn ...
Thomas Emmert, Sebastian Bomberg, Wolfgang Polifke   +2 more
openaire   +1 more source

Thermoacoustic instability of a plasma

Soviet Physics Journal, 1988
The possibility of the onset of a self-excited instability in a high-temperature plasma as a result of energy released in thermonuclear interactions between ions is discussed, and the resulting instability conditions are used to investigate the behavior of a linear pinch.
openaire   +1 more source

Thermoacoustic Instabilities in Solid Rocket Motors

45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit, 2009
This work describes an unreported instability in so lid rocket motors found out by numerical simulations. A detailed numerical study s hows that this instability is thermoacoustic and results from a coupling between acoustic velocity and aluminum combustion heat release.
Stany Gallier, Emmanuel Radenac, Franck Godfroy   +2 more
openaire   +1 more source