Results 261 to 270 of about 27,437 (306)

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 ...
Natasa A. Kablar, Tomohisa Hayakawa, Wassim M. Haddad 0001   +2 more
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Fingering instability in combustion: An extended view

Physical Review E, 1999
We detail the experimental situation concerning the fingering instability that occurs when a solid fuel is forced to burn against a horizontal oxidizing wind. The instability appears when the Rayleigh number for convection is below criticality. The focus is on the developed fingering state.
O, Zik, E, Moses
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An adaptive algorithm for control of combustion instability

Automatica, 2004
zbMATH Open Web Interface contents unavailable due to conflicting licenses.
Andrzej Banaszuk, Kartik B. Ariyur, Miroslav Krstic, Clas A. Jacobson   +3 more
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Model-based control of combustion instabilities

Journal of Sound and Vibration, 2005
Model-based control has been successfully implemented on an atmospheric pressure lean premixed combustion rig. The rig incorporated a pressure transducer in the combustor to provide a sensor measurement, with actuation provided by a fuel valve. Controller design was based on experimental measurement of the open loop transfer function. This was achieved
Aimee S. Morgans, Ann P. Dowling
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Instabilities in Gaseous Combustion

2015
By means of high-speed color cinematography, it was shown that the flames in lean Н2–air mixtures at an initial stage propagate symmetrically and the flame radius can be estimated from the frames of speed filming. It is shown that sufficiently strict calculation of cellular structure of the flame front of lean hydrogen mixtures requires consideration ...
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Parametric control of combustion thermo-acoustic instabilities

IEEE Transactions on Control Systems Technology, 2003
In this paper, a theoretical analysis and syntheses of a parametric controller for thermo-acoustic combustion instabilities in a liquid-fueled propulsion system is developed. A generalized wave equation describes the dynamic behavior of second order nonlinear oscillations.
Nidal Al-Masoud, Tarunraj Singh
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Combustion instability studies with plastic propellent

5th Propulsion Joint Specialist, 1969
The eifect of compositional changes on the stability of combustion of plastic propellent, based upon ammonium perchlorate and polyisobutene, is investigated using a 2-in.-diam T burner for the frequencies 0.7-4.0 kHz at 1000 psig. Oxidizer particle size can have a pronounced effect both on the acoustic response and on the maximum pressure amplitude ...
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Combustion Instability Theory

1968
Temporal variations in a combustion system are always present and take varieties of forms and intensity under different environments. A system is stable if a disturbance introduced into the system decreases in amplitude with time and eventually becomes lost in the random fluctuations prevailing in the system.
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Surrogates for Combustion Instabilities in Annular Combustors

2018
While the computational power is still increasing, thus arousing theinterest for high-fidelity simulations, the need of low-order models is also feltto both predict and understand combustion instabilities at low costs. Historicallyapplied to simple systems like longitudinal Rijke tubes to unveil the driven mechanismsleading to instability, they have ...
Bauerheim, Michael, Ndiaye, Aïssatou, Nicoud, Franck   +2 more
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Combustion instability: a distributed-parameter model

Proceedings of the 2003 American Control Conference, 2003., 2004
Two distributed parameter models are suggested as models for thermo-acoustic combustion instability. A standing-wave model exhibits the expected qualitative behavior and is of interest for future stabilization studies.
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