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Showing 1 to 8 of 8 for “"flame transfer function"”.
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Thermoacoustic Analysis and Experimental Validation of Statistically-Based Flame Transfer Function Extracted from Computational Fluid Dynamics
… the coupling of unsteady heat release from the flame and the acoustic field. One potential driving mechanism for these instabilities arise when velocity fluctuations (u') at the fuel injection location causes perturbations in the local equivalence ratio and is convected to the flame location …
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Spatially Resolved Analysis of Flame Dynamics for the Prediction of Thermoacoustic Combustion Instabilities
… lean premixed combustion, which results in lower flame temperatures and therefore the possibility of significantly reduced nitric oxide emissions. While lean premixed combustion offers reduced environmental impacts, it has been observed to experience increased possibility of the occurrence of …
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Turbulent flame microstructure, dynamics, and thermoacoustic instability in swirl-stabilized premixed combustion : measurements, statistics, and analysis
… and that the frequency-based response of the flame is a function of the flame geometry. In the first part of the thesis, we focus on the flame geometry, identifying several discrete transitions that take place in the swirl-stabilized flame as we adjust the equivalence ratio. By comparing the …
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A method for the numerical analysis of combustion instabilities with an application to afterburner screech
… by acoustic transverse modes at the afterburner flameholder. These vortices trap fresh reactants that burn after a certain time delay, therefore feeding energy into the oscillation. Within a linear approximation, the effect of small amplitude acoustic fluctuations on the flame is studied by …
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Phase Shift Control: Application and Performance Limitations With Respect to Thermoacoustic Instabilities
… in density of the combustion reactants at the flame location. Additionally, the system model is coupled with a model of the control loop and then validated by comparison of simulated results to experimental results using nearly identical controllers.
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A Study of the Dynamics of Laminar and Turbulent Fully and Partially Premixed Flames
… order models for the dynamics of laminar flat flames, swirl stabilized turbulent flames, and in evaluating the effects of the variation in fuel composition on flame dynamics. The laminar flat flame study was conducted on instrument grade methane, propane, and ethane flames for four total flow …
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EXPERIMENTAL INVESTIGATION OF THE RESPONSE OF FLAMES WITH DIFFERENT DEGREES OF PREMIXEDNESS TO ACOUSTIC OSCILLATIONS
… of the response of lean turbulent swirling flames with different degrees of premixedness (i.e. different mixture patterns) to acoustic forcing using the same burner configuration and varying only the fuel injection strategy. Special emphasis was placed on the amplitude dependence of their …
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The Role of Swirl in the Flow Structure and Response of Premixed Flames
… this challenge. Unfortunately, lean premixed flames are often unstable as they may operate close to the flame blow off limit. Therefore, a suitable method of stabilisation is required. Swirlers or bluff bodies help in stabilising the flames, by creating recirculation zones of hot combustion …