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Showing 1 to 20 of 38 for “"Turbulent flames"”.
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Simulation of partially premixed turbulent flames
This work numerically investigates the turbulent partially premixed flames, which are ubiquitous in combustion powered devices. This combustion mode involves many physical complexities such as flame propagation in unevenly premixed mixture of fuel and oxidiser, turbulence/flame interaction in …
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A fractal analysis of premixed turbulent flames
… the fractal behavior of lean premixed wrinkled turbulent flames was investigated over a range of turbulence conditions. For this purpose a turbulent combustion rig was designed and built in which the turbulence intensity and scale could be independently varied by means of a set of grids. The …
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Propagation of large scale premixed turbulent flames
We examine premixed turbulent combustion within the context of a hydrodynamic model derived from physical first principles. This is an asymptotic model that exploits the multi-scale nature of the problem, characterized by two disparate length scales: the diffusion length scale representing the …
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Studies of premixed turbulent flames under flamelet assumptions
Turbulent burning velocity is a crucial factor in describing how fast premixed flame can burn, while it is still not well-predictable under various turbulence levels and flame conditions. A clearer definition of turbulent burning velocity based on the reaction rate will help understand the …
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Simulation of turbulent flames relevant to spark-ignition engines
… Navier- Stokes framework, is used to simulate flames relevant to spark-ignition IC engines. A central quantity in the current modelling approach is the scalar dissipation rate, which represents coupling between reaction and diffusion, as well as the flame front dynamics. In the first part of …
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Influences of the Darrieus-Landau instability on premixed turbulent flames
… its inventors. The instability, which prevents flames from being too flat, was thought to lead immediately to turbulent flames. Recent studies, initiated by weakly nonlinear analyses and extended by two-dimensional simulations suggest that this is not the case. It was established that the flame, …
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Simulation of Turbulent Flames at Conditions Related to IC Engines
… framework tools for the prediction of turbulent ow in such conditions. Nonetheless, the combustion submodels commonly used in combustion calculations are developed using insights and results obtained for atmospheric conditions. However, The combustion characteristics and its interaction …
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Flow Field and Soot Formation Characteristics in Swirl-stabilized Non-premixed Turbulent Flames
… flow fields were investigated experimentally in turbulent swirl-stabilized non-premixed flames using three different fuels: methane, ethanol and aviation Jet A-1. The studied flames were confined and stabilized in a model gas turbine combustor with a swirl number of ~0.55. Soot volume fraction, …
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The auto-ignition characteristics of ammonia turbulent flames in a high temperature co-flow
L'abstract è presente nell'allegato / the abstract is in the attachment
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Development and application of a light scattering technique for the study of premixed turbulent flames.
Massachusetts Institute of Technology. Dept. of Chemical Engineering. Thesis. 1966. Ph.D.
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Application of Crossed-Plane Tomography and Stereo Particle Image Velocimetry for Three-Dimensional Analysis of Premixed Turbulent Flames
… flamelet surface normal vectors in premixed turbulent flames to study the wrinkling of flamelet surfaces and the internal structure of the flamelet. CPLT was applied to measure flamelet orientations of premixed turbulent V-flames with increasing downstream distance from the stabilizing rod. …
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Flame Surface Density Measurements and Curvature Statistics for Turbulent Premixed Bunsen Flames
In this work, turbulent premixed combustion was analyzed through CH (methylidyne) planar laser induced fluorescence (PLIF). Flame topography measurements in terms of flame surface density and curvature were calculated based on the flame front detected by the CH PLIF signal. The goal of this work …
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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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Fundamental studies of premixed combustion
… at a point under both laminar and turbulent propagation. Schlieren cine photography has been employed to study laminar flame propagation, while planar mie scattering (PMS) has elucidated important aspects of turbulent flame propagation. Thrbulent flame curvature has also been …
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Reduced Kinetic Mechanisms For Premixedhydrogen-air-cf3br Flames
… reduced the burning velocity of premixed H2/Air flames by depleting the important radical species that are important to sustain chemical reactions. Extending this finding to understand the suppression of more complicated diffusion flames and unsteady three dimension turbulent flames in the …
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Multi-dimensional Flow and Combustion Diagnostics
Turbulent flows and turbulent flames are inherently multi-dimensional in space and transient in time. Therefore, multidimensional diagnostics that are capable of resolving such spatial and temporal dynamics have long been desired; and the purpose of this dissertation is to investigate three such …
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A turbulent combustion noise model
A turbulent combustion noise model based on first principles is developed in this thesis. The model predicts (1) the pressure time series, (2) Sound Pressure Level (SPL) spectrum, (3) Over-All Sound Pressure Level (OASPL), (4) the thermoacoustic efficiency, (5) the peak frequency, and (6) the sound …
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Turbulent flame development in a high-pressure combustion vessel
… of this work was to extend the range of turbulent burning velocities presented in the literature by performing new measurements at elevated pressures over a range of turbulent velocities, u' (r. m. s. deviation from the mean velocity). The influence of equivalence ratio was investigated …
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Flamelet modelling of soot formation in diffusion flames
… been applied to soot formation in laminar and turbulent diffusion flames. The aim was to study how different model parameters affect soot formation in diffusion flames. It was shown that certain assumptions are more crucial in laminar diffusion flames than in turbulent ones. The soot formation …
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Experimental Investigation of Large Scale Aerodynamics on Soot Emissions in Swirling Flows
… Rich-Quench-Lean (RQL) technology that employs turbulent swirling flames with downstream dilution air. These turbulent flames exhibit spatial and temporal fluctuations not present in laminar flames. This adds a level of complexity to turbulent soot studies that is yet to be fully understood. In …
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