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Showing 1 to 14 of 14 for “"Flame thickness"”.
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Laminar burning velocity measurements of stabilized aluminum dust flames
The laminar burning velocity of a stabilized dust flame is experimentally investigated in the present work. The dust used was aluminum powder with an average particle diameter of approximately 5 microns. Dust flames, in comparison to gas flames, are thicker and brighter, may be influenced by …
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Propagation of spherically expanding premixed flames
The propagation of spherically expanding premixed flames is investigated, in both confined and unconfined scenarios. In the unconfined case, the flame propagates at nearly isobaric conditions and the flame displacement speed eventually reaches a constant value whereas in the confined case there is …
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Propagation of large scale premixed turbulent flames
… the diffusion length scale representing the flame thickness and the hydrodynamic length scale associated with the dimensions of the combustion chamber. It treats the flame as a surface of density discontinuity that separates the burned gas from the fresh combustible mixture and propagates …
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Laminar flame propagation in mixtures with compositional stratification at small length scales
The behavior and structure of laminar hydrocarbon flames which propagate parallel to the direction of a periodic gradient of mixture composition was studied both experimentally, using a specially designed burner, and computationally, using a planar numerical model. The variations in local mixture …
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Equivalence Ratio Gradient Effects on Local Flame Front Topology and Heat Release Rate in Stratified, Iso-Octane/Air Turbulent V-Flames
… premixing on the local behaviour of turbulent flames were investigated using a novel rectangular slot burner that could generate controlled, transverse variations in mixture strength along its exit plane. Turbulent, iso-octane/air V-flames were anchored in reactant mixtures of varying mean …
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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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A fractal analysis of premixed turbulent flames
… 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 relative …
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Mathematical modelling of premixed laminar methane-air flames
… laminar, stationary, axisymmetric methane-air flames, and successfully validated with non-intrusive Coherent Anti-Stokes Raman Spectroscopy (CARS) temperature measurements. With the first model, the heat releaser ate model, volumetric heat release rate was generalised from one-dimensional …
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Physical Insights of Non-Premixed MILD Combustion using DNS
… (DNS) is used to study turbulence, premixed flames and MILD combustion to obtain these additional physical insights. In a first stage, the scale-locality of the energy cascade is analysed by applying a multiscale analysis methodology, called the bandpass filter method, on DNS of homogeneous …
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Fundamental studies of flame propagation in lean-burn natural gas engines
… characteristic time required for steady premixed flame propagation has three components: time for autoignition to occur, time for peak temperature to be achieved following autoignition, and time for steady flame propagation in the premixed fuel/air mixture to be achieved. The autoignition time …
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Reactive flow visualization through high-speed optical laser diagnostics
… resulting in increased emissions and decreased flame stability. Hence, understanding and controlling the coupling between chemical kinetics and turbulence can lead to significant improvements in the design of combustion systems, improving their stability, efficiency and emissions …
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Numerical investigation on the effect of fuel droplets on premixed laminar flames
… with a particular focus on laminar premixed flames containing fuel droplets. Despite their prevalence, these flames have not been extensively studied due to challenges in measuring key parameters and discrepancies in one-dimensional numerical simulations. The present work seeks to enhance our …
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A study on micro-scale combustion
… that the temperature difference between the flame and the internal wall is linear in the axial direction. Making use of the analytical results, an equation for predicting flame temperature has been derived and validated by experiment. Both simulation and experiment show that wall thickness …
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Measurements of the structure of turbulent premixed and stratified methane/air flames
… test cases for existing and emerging turbulent flame models, covering a range of u'/sL from 1 to 10, turbulence intensities from 5% to 60%, and stratification ratios from 1 to 3. Simultaneous Rayleigh/Raman/CO-LIF measurements of temperature and major species concentrations - CH4, CO2, CO, H2, …