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Showing papers in "Combustion and Flame in 1980"


Journal ArticleDOI
TL;DR: In this paper, the laminar burning velocity of propane-air mixtures has been measured in the pressure range 0.4 to 40 atm and temperature range 298 to 750 K for equivalence ratios from 0.8 to 1.5.

511 citations


Journal ArticleDOI
TL;DR: In this article, the initial temperature distribution in a reacting mixture enables one to calculate the induction period to the adiabatic explosion in each particle of the mixture, and the inverse gradient of this induction period determines the propagation velocity of the intensive reaction zone.

472 citations


Journal ArticleDOI
TL;DR: In this article, the authors used the Burke and Schumann flame sheet concept to locate the stoichiometric fuel-oxygen interface and, hence, the points of heat release in a laminar methane-air diffusion flame.

251 citations


Journal ArticleDOI
TL;DR: In this article, a turbulent flame propagation model that is dependent on the structure of the turbulent flow field is formulated and applied to combustion in a spark-ignition engine, where combustion is assumed to proceed in a laminar fashion across the microscale.

209 citations


Journal ArticleDOI
TL;DR: In this paper, the influence of obstacles on the propagation of cylindrical flames is investigated and it is found that the flame speed depends critically on the obstacle configuration and flame speeds up to 130 m/sec in stoichiometric methane-air mixtures are readily achieved by placing appropriate turbulence producing obstacles in the flame path.

192 citations


Journal ArticleDOI
TL;DR: In this paper, a numerical model was used to study the propagation of laminar methanol-air flames, which consists of a one-dimensional time-dependent treatment of the conservation equations together with a detailed chemical kinetic oxidation mechanism having 84 elementary chemical reactions involving 26 chemical species.

166 citations


Journal ArticleDOI
TL;DR: In this paper, the consequences of the description of a premixed turbulent flame in terms of an ensemble of laminar flamelets are pursued and lead to new physical insight into the processes occurring in such flames and to new models for use in their analysis.

151 citations


Journal ArticleDOI
TL;DR: For downwardly propagating flames in pyrex tubes at atmospheric pressure and intial temperature of 295°K, measurements were made of the nitrogen dilution required for quenching as a function of the hydrogen-oxygen ratio, as well as of flame temperatures, flame speeds, temperature gradients behind the flame, unburnt hydrogen, and cell sizes as mentioned in this paper.

142 citations


Journal ArticleDOI
TL;DR: In this paper, cross-correlation techniques have been applied to the measurement of mean velocities in simulated fire plumes produced by a gas burner, and analytical expressions for mass, heat, and momentum flux, and for air entrainment ratio from the source to the conventional plume uniquely dependent on height normalized by flame length.

134 citations


Journal ArticleDOI
TL;DR: In this article, the authors show that buoyancy influences the downward spread rate of flames consuming thermally thin fuel beds, and that a small change in orientation with respect to the vertical is equivalent to a change in the magnitude of gravity in the direction of spread.

131 citations


Journal ArticleDOI
TL;DR: In this article, various combustion modes of water-in-oil emulsion droplets are postulated based on the relative volatilities and concentrations of water and oil, the intensity of internal circulation, and the fact that oil and water do not mix.

Journal ArticleDOI
TL;DR: In this article, a quasi-steady approach is used to explain the growth of fires in enclosures. But the authors do not consider the effect of thermal radiative feedback from the enclosure.

Journal ArticleDOI
TL;DR: In this article, it was shown that due to volume effects the amount of fuel vapor in the inner region to the flame during droplet combustion can be substantial, and that the d 2 law yields inaccurate estimates on the rate of chemical heat release from droplet burning.

Journal ArticleDOI
TL;DR: The feasibility of coherent anti-Stokes Raman spectroscopy (CARS) for remote, spatially and temporally resolved, measurements in practical combustion systems is demonstrated in this article.

Journal ArticleDOI
TL;DR: In this paper, a particle-source-in-cell (PSIN) approach is proposed to predict coal-particle trajectories in a separately computed gas field, where the presence of the particles is made known to the gas field through mass, momentum, etc., by adding a source to the equations governing the gas flow.

Journal ArticleDOI
L. Boyer1
TL;DR: In this article, the authors proposed a method that allows one to obimaging the luminous sheet (xz' plane) on a slit S tain a plane cross section of the flame and to parallel to the z axis.

Journal ArticleDOI
TL;DR: In this article, reflected shock waves were used to heat a variety of formaldehyde mixtures to temperatures of 1600-3000 K at total concentrations near 5 × 1018/cm3.

Journal ArticleDOI
TL;DR: In this article, the initial steps involved in the thermal decomposition of acetylene and diacetylene in the temperature range 1850 to 3000 K have been investigated by monitoring the hydrogen-atom production behind reflected shock waves in highly diluted mixtures of argon (5 −400 ppm, total densities 6 × 10−6 to 2.7 × 10 −5 mol/cm3).

Journal ArticleDOI
TL;DR: In this article, local soot concentrations in polystyrene and polypropylene flames were measured in order to shed light on the position and thus the mechanisms of carbon-particle formation in diffusion flames.

Journal ArticleDOI
TL;DR: In this paper, the behavior of round fuel jets with and without flame was examined experimentally paying attention to the characteristic difference of turbulence due to the existence and nonexistence of flame, and quantitative verification was presented for the facts that the existence of flame suppresses or laminarizes the turbulence.

Journal ArticleDOI
TL;DR: In this article, laser-schlieren profiles of incident shock waves in 2.5, 5, and 10% C 2 H 4 in Ar were recorded for the ranges of shock front conditions 2000 T 2 −6 ϱ −6 mol/cm 3.

Journal ArticleDOI
TL;DR: In this article, an unsteady spherically symmetric formulation of the droplet heat conduction problem with no internal motion and with a time-varying heat flux specified at the surface as a boundary condition is presented.

Journal ArticleDOI
TL;DR: In this article, the thermal structure of turbulent premixed burner flames was investigated, placing emphasis on the influences of equivalence ratio and turbulence intensity. But the results were not consistent with the wrinkled laminar flame model, and the PDF profiles were not influenced by turbulence intensity of the unburnt mixture.

Journal ArticleDOI
TL;DR: In this article, the combustion characteristics of lean hydrogen-air mixtures flowing over a heated catalytic platinum plate were investigated, where boundary-layer density profiles were measured using differential interferometry for flow visualization studies and Rayleigh scattering for point density measurements.

Journal ArticleDOI
TL;DR: In this paper, a modified source function was proposed to find the exact solution of the differential equation, contrary to the nonmodified source function that prohibits the existence of the solution, and a natural answer was given to the old question of how to calculate flame propagation with a smooth source function which is positive at initial temperature.

Journal ArticleDOI
TL;DR: In this paper, the authors employed species-dependent input coefficients for the test case ozone in a one-dimensional model of a premixed, laminar, steady-state flame.

Journal ArticleDOI
TL;DR: In this article, the temperature and composition profiles obtained by probing a confined, axisymmetric-laminar methane-air diffusion flame suggest that a state of partial equilibrium exists in the high-temperature primary reaction zone.

Journal ArticleDOI
TL;DR: The mechanism of pyrolysis of ethane, as expressed by the overall reaction C 2H6 → C2H4 + H2, has been discussed in this article.

Journal ArticleDOI
TL;DR: In this paper, a theoretical model embracing the full kinetic scheme for hydrogen oxidation fits the experimental detonability data and predicts the variation of detonability with concentration over a much wider range.

Journal ArticleDOI
TL;DR: In this article, a combination of single-and multiple-collision studies is used to demonstrate that the continuous aluminum hydrate emission results from the formation of a metal hydrate.