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Showing papers in "Combustion and Flame in 1985"


Journal ArticleDOI
TL;DR: In this article, the aerothermochemistry of premixed turbulent combustion is used to develop a Reynolds stress/flux description of a flow field consisting of constant density regions of either reactants or products and of reaction zones in which density fluctuations arise as a consequence of heat release.

390 citations


Journal ArticleDOI
TL;DR: In this paper, detailed species concentration profiles have been measured using optical and mass spectrometric methods in an atmospheric pressure methane air diffusion flame burning on a Wolfhard-Parker slot burner.

269 citations


Journal ArticleDOI
TL;DR: In this paper, the authors compared and measured cylinder pressure in a reciprocating engine with a pancake combustion chamber and premixed propane/air charges, and concluded that laminar flame processes must be explicitly accounted for in order to reproduce certain elements of premixed charge engine combustion.

262 citations


Journal ArticleDOI
TL;DR: In this paper, the chemistry of knock in internal combustion engines has been examined within the context of a model of autoignition of hydrocarbon air mixtures at high pressure, which has been refined and extended using reactions and rate parameters which are compatible with the expanding body of kinetics information on the type of elementary processes involved.

258 citations


Journal ArticleDOI
TL;DR: In this paper, a general-purpose pyrolysis cell described is capable of attaining rapid heating rates (8-200K s−1) at various gas pressures (0.048-1000 psi, 0.33 KPa-6.8 MPa) and is an attempt to simulate, insofar as possible, combustor conditions.

175 citations


Journal ArticleDOI
TL;DR: In this article, two-dimensional time-dependent numerical simulations have been performed to study the structure and propagation of self-sustained detonations and the evolution of the curvature of the transverse wave appears to be a crucial feature.

172 citations


Journal ArticleDOI
TL;DR: In this paper, the authors measured the soot thresholds in the form of flame heights and fuel mass consumption rates at the smoke points in laminar diffusion flames of 42 pure hydrocarbons using a wick-fed burner.

159 citations


Journal ArticleDOI
TL;DR: The influence of pressure on the occurrence of microexplosion has been experimentally investigated for freely falling miscible multicomponent and water/oil emulsion droplets in hot, oxidizing, high pressure environments up to 5 atm as mentioned in this paper.

151 citations


Journal ArticleDOI
TL;DR: In this paper, two regimes are proposed to define flame quenching: u′ u 1 ⩾0.71R L 0.5 for R L and u′u u 1⩾3.1(R L Le 2 ) 0.25 for RL > 300, where u′ is the rms turbulent velocity, u1 the laminar burning velocity, and RL the turbulent Reynolds number based upon the integral length scale.

150 citations


Journal ArticleDOI
TL;DR: In this paper, fuel-lean flammability limits and burning velocities in a closed vessel were measured for methane-air mixtures burning at earth gravity (oneg) and zero gravity (zero-g) at initial pressures of 50-1500 Torr.

124 citations


Journal ArticleDOI
TL;DR: In this article, an experimental investigation is described of the gasdynamic processes occurring in vented explosions in which two cubical vessels are employed, with internal sides of 18 and 38 cm, repectively.

Journal ArticleDOI
TL;DR: In this article, measurements of time-mean axial velocity and temperature in simulated fires of low height to width ratio were reported, with the flame length scales as Q 2 D 4 and the implications of this on earlier findings of the authors.

Journal ArticleDOI
TL;DR: In this paper, the weight loss of four different woods during vacuum pyrolysis at constant temperature and at constant heating rate is reported. But the model assumes that wood is composed of three major components: cellulose, lignin, and a mixture of hemicellulose and volatiles.

Journal ArticleDOI
TL;DR: In this article, a small thermocouple (TC) bead suddenly immersed in the soot-laden combustion products downstream of a water-cooled premixed flat-flame burner is demonstrated to be dominated by particle thermophoresis, i.e., soot particle drift down the temperature gradient prevailing in the gas thermal boundary layer (BL) surrounding the TC target.

Journal ArticleDOI
TL;DR: In this article, an identification of individual PAH responsible for the fluorescence was attempted on the basis of the relative abundance in combustion systems and their spectroscopic properties, namely, excitation and emission spectra and quantum efficiency.

Journal ArticleDOI
TL;DR: The counterflow diffusion flame burner as mentioned in this paper is a tool for the study of the nucleation from the vapor phase of refractory compounds such as SiO2, Al2O3, and other metal oxides.

Journal ArticleDOI
TL;DR: In this paper, a compendium of the various uses and interpretive aspects of sensitivity gradient techniques applied to chemical kinetics is provided through analysis of the frequently studied elementary kinetic mechanism for the CO/H 2 O/O 2 system.

Journal ArticleDOI
TL;DR: In this article, the effects of the nozzle diameter and volume ratio on the structure of the torch jet, ignition process, and subsequent burning process in the main chamber were minutely examined, in both uniform and stratified charges, by measurements of ion current, light emission, OH-emission (306.4 nm), initial torch jet velocity, and main chamber pressure histories and by schlieren photography.

Journal ArticleDOI
TL;DR: In this article, a new Lagrangian sectional approach is used to analyze spray vaporization in a turbulent air jet flow, where the fuel is considered to be in the form of discrete liquid droplets which have an arbitrary range of sizes and differ in their rates of vaporization.

Journal ArticleDOI
TL;DR: In this article, the structure and the mechanism of extinction of partially premixed diffusion flames are analyzed on the basis of a model that uses a one-step irreversible reaction with a large activation energy.

Journal ArticleDOI
TL;DR: In this article, the authors measured minimum ignition energies and flame radii as a function of time for near-limit, limit, and sub-limit fuel-lean methane air mixtures burning at one-g and zero-g.

Journal ArticleDOI
TL;DR: In this paper, an experimental investigation was performed on propane-air flames stabilized by cylindrical rod bluff-bodies when the number and diameter of rods were changed under a constant blockage ratio of 0.4.

Journal ArticleDOI
TL;DR: In this article, a hybrid Eulerian-Lagrangian method is employed to study a laminar unsteady propagating flame through an air/fuel-vapor/fueldroplet mixture in a one-dimensional closed constant volume combustor.

Journal ArticleDOI
TL;DR: In this paper, the evolution of coal nitrogen during devolatilization and the formation of NOx during combustion were studied for two Australian coals in crucible, thermobalance, and rapid heating (drop-tube furnace) experiments.

Journal ArticleDOI
TL;DR: In this paper, a buoyant, turbulent natural gas flame burning on a porous refractory burner, 25 cm in diameter, is compared with numerical predictions using a parabolic formulation, k-ϵ turbulence modeling and a flamelet description for combustion chemistry.

Journal ArticleDOI
TL;DR: In this article, the emittance of a yttrium-beryllium oxide thermocouple coating was determined by an electrical heating method and by sodium line reversal measurements in the overall temperature range 1465-1830K.

Journal ArticleDOI
TL;DR: In this article, a fly ash cloud in p.f. furnaces has been found to have an order of magnitude higher complex refractive index than those of pure silica and alumina mixtures, the major constituents of the fly ash particles.

Journal ArticleDOI
TL;DR: In this paper, the effect of wavelength on the photochemical ignition of hydrogen-air and hydrogen-oxygen mixtures at several equivalence ratios and pressures was investigated, showing that the fuel-lean shift appears typical of photochemical initiation, with the explanation that increased molecular oxygen yields higher atomic oxygen concentration upon irradiation.

Journal ArticleDOI
TL;DR: In this paper, the mechanism of combustion of coal particles in a fluidized bed of sand was studied by injecting small batches of a Montana lignite coal into an electrically heated fluidized ground of sand.

Journal ArticleDOI
TL;DR: In this article, the authors used FTIR spectroscopy to detect gas products from thermolysis at high heating rates (50-170K s −1 ) and various pressures (0.1-1000 psi).