Showing papers in "Combustion and Flame in 1982"

TL;DR: In this paper, the effect of adding simulated combustion products to stoichiometric isooctane-air mixtures was also studied for diluent mass fractions f = 0−0.2.

TL;DR: In this paper, the authors present a review of the main components of calculation methods, based on the solution of conservation equations in differential form, for the velocity, temperature and concentration fields in turbulent combusting flows.

TL;DR: In this paper, the critical tube diameters dc for the successful transformation of a planar to a spherical detonation have been measured in nine gaseous fuels (CH4, C2H2, C 2H4, c2H6, C3H8, C4H10, MAPP and H2) in stoichiometric fuel-oxygen mixtures diluted with nitrogen at atmospheric initial pressure.

TL;DR: In this article, a theoretical model including a detailed chemical kinetic reaction mechanism for hydrocarbon oxidation was used to examine detonation properties for mixtures of fuel, including methane, ethylene, acetylene, and methanol.

TL;DR: In this article, the activation energy asymptotics method was used to describe the behavior and characteristics of adiabatic laminar flamelets involving counterflowing reactants and products as they arise in premixed turbulent flames.

TL;DR: The results of large-scale methane-air explosion tests performed at Raufoss, Norway (July-September 1980) are described and discussed in this paper, where it is observed that even relatively small repeated obstacles of height 0.1 m (blockage ratio 0.16) have a dramatic influence on the violence of the explosion, generating explosion overpressures larger than 1 bar in the tube.

TL;DR: In this paper, detailed one-dimensional calculations have been performed to simulate reflected shock tube experiments in the weak and strong ignition regime in hydrogen-oxygen-argon mixtures, and it is found that the experiments and simulations agree well in the strong ignition case studied.

TL;DR: In this article, the transition from spherical laminar flames to polyhedral and cellular flames was observed in propane-air mixtures ignited at the center of a 260mm-diam constant-volume vessel.

TL;DR: In this article, the ignition delay characteristics of Jet A, JP 4, no. 2 diesel, cetane and an experimental broad specification (ERBS) fuel in air at inlet temperatures up to 1000 K, pressures of 10, 15, 20, 25, 25 and 30 atm, and fuel air equivalence ratios of 0.3, 0.7 and 1.0 were mapped.

TL;DR: In this paper, the authors measured explosion cell dimensions at an initial pressure of ∼10 5 Pa (1 atm) for stoichiometric mixtures with air for hydrogen, acetylene, ethylene, and ethane in a rectangular detonation tube of dimensions 76 mm × 38 mm using the sooted plated technique.

TL;DR: Soot measurements were made in laminar ethylene diffusion flames for various fuel and air flow rates in a Wolfhard-Parker burner as mentioned in this paper, and particle number densities, particle size, and soot volume fraction were obtained.

TL;DR: In this article, the stability of one-dimensional piston-supported gaseous detonations is examined both numerically and analytically, and an approximate linearized stability theory is developed for the case of high activation-energy reactions, and the mechanism of instability is identified.

TL;DR: In this paper, a computer program was developed to solve the boundary layer equations for laminar flow over a heated catalytic plate with H 2 /air combustion, and the results indicated the existence of an initial region near the plate leading edge in which radical concentrations increase with little associated heat release, and a downstream region where heat release due to gas phase combustion results in a significant increase in thermal boundary layer thickness.

TL;DR: In this article, the effects of droplet interaction on the burning of fuel droplet sprays were investigated by both experimental and theoretical methods, and it was shown that the effect of interaction on droplet lifetime depends universally on the droplet spacing and not on fuel type, droplet size or ambient conditions.

TL;DR: In this paper, the influence of surface size, orientation, temperature-time history, stoichiometry, and velocity on the critical surface temperature for ignition has been investigated and a simple correlation is developed among surface ignition temperature, size, pressure, and flow velocity consistent with previous work.

TL;DR: Theoretical numerical solutions of the spread of hot gas kernels under turbulent and laminar conditions are presented in this article, where it is observed that the initiating kernel moves away from the spark gap with a velocity close to the r.m.s.

TL;DR: In this paper, it was shown that the structure of visible fluorescence spectra can be altered dramatically by changes in the flame stabilization conditions and that the structured spectra are caused by recirculation of downstream combustion gases (and particles) into the optically sampled area.

TL;DR: In this article, the effects of sample orientation on auto-ignition delay times and the minimum external radiant flux for autoignition were studied using a CO 2 laser and a gas fired radiant panel as external radiant sources with PMMA and red oak as samples.

TL;DR: In this article, the extinction of flame configurations, flame-front cellular instability, and extinction of propane/air mixtures in the stagnation-point flow were experimentally studied for their dependence on downstream heat loss, preferential diffusion, and flame stretch.

TL;DR: In this article, the authors investigated the structure of premixed laminar flames and calculated flame velocity, which was shown to be greater than the one-dimensional premixed flame speed, and this was attributed to the flame-pressure interaction.

TL;DR: In this article, the experimental results for ignition characterisitcs of a fuel droplet near the ignitable limit were reported, and it was found experimentally that the ignition time increases as the diameter decreases at the region near the ignition limits.

TL;DR: In this paper, a premixed flame located in a counterflow of fresh cold mixture and hot burnt gas, the latter at a temperature close to that of adiabatic deflagration, is examined.

TL;DR: In this paper, a prediction model for turbulent diffusion flames is presented and applied to H 2  air-diffusion flames and in particular to the calculation of mean radical concentrations.

TL;DR: In this article, the authors identify the physical and chemical mechanisms which cause certain mixtures of hydrogen, oxygen, and argon to be very sensitive to sound wave and entropy (temperature) perturbations.

TL;DR: In this paper, the rotational temperature of flat flames was measured with a tunable dye laser and the OH radical nonequilibrium and the associated recombination in the post flame gases were observed for fuel-air equivalence ratios of 0.8, 0.9, 1.0,1.1, and 1.2.

TL;DR: In this paper, the authors studied the nonlinear evolution of a disturbed plane flame front in a hydrodynamic instability regime induced by thermal expansion of a burned gas and showed that spontaneous instability appears in the guise of stationary wide-spaced irregular folds.

TL;DR: In this article, a laser tomographic light scattering technique has been used for the mapping of internal spray structure, which is demonstrated to provide rapid, high-resolution measurements of droplet sizes, concentrations, and vaporization.

TL;DR: In this paper, the concentration profiles of NH and OH were measured in an atmospheric pressure, premixed, laminar CH4/N2O flame over a porous-plug, flat flame burner.

TL;DR: In this article, the rotational temperature of a CH 4 /air flame was estimated from a single v ǫ, J level using a laser, and the resulting fluorescence spectra were measured.

TL;DR: In this article, measurements of the fluctuating temperature, including its probability density function, are reported for a range of burner stabilized, lifted, and nitrogen diluted fully turbulent methane diffusion flames.