Laser ignition of a heterogeneous nickel-aluminum system

The ignition of a heterogeneous nickel—aluminum system by laser radiation is investigated experimentally. The ignition characteristics are investigated as a function of the incident flux and the diameter, height, and porosity of the samples. It is established that the ignition of nickel—aluminum composites consisting of highly disperse powder is determined by the solid-phase interaction of the initial reagents. Tomsk Branch, Institute of Structural Macrokinetics, Russian Academy of Sciences, Tomsk. Translated from Fizika Goreniya i Vzryva, Vol. 31, No. 6, pp. 20–27, November–December, 1995.     

Role of the gas phase in the transition of condensed material to combustion on ignition by a radiation flux

A model of ignition and the transition to combustion in condensed material under the action of a pulse of radiant flux is outlined. Chemical reactions on both sides of the phase interface are taken into account. It is shown that taking account of the thermophysical and chemical properties of the phases has a significant effect on the limits of stable ignition. The dynamics of the basic characteristics of the process is studied with pulsed heating of gasifying condensed material.Translated from Fizika Goreniya i Vzryva, Vol. 27, No. 4, pp. 7–12, July–August, 1991.     

Influence of aluminum particle size on ignition and nonstationary combustion of heterogeneous condensed systems

The results of studies of the effect of particle size of aluminum powder in condensed systems on the ignition, nonstationary combustion, and acoustic conductivity of the burning surface are presented. Analysis of the experimental data shows that the ignition delay and the temperature of burning surface of the heterogeneous condensed systems under study decrease with increasing particle size of aluminum powder, and the nature of the dependence of the nonstationary burning rate on the time of depressurization of the combustion chamber for compositions containing micron or ultrafine aluminum powders is in qualitative agreement with the phenomenological theory of nonstationary combustion. Replacement of micron aluminum powder by ultrafine powder in a heterogeneous condensed system increases acoustic conductivity.     

Trends in the ignition and combustion of zirconium

Combustion, Explosion, and Shock Waves -     

Structural transformations in multicomponent system during heterogeneous combustion

Chernogolovka. Translated from Fizika Goreniya i Vzryva, Vol. 26, No. 2, pp. 79–83, March–April, 1990.     

Numerical simulation of syngas combustion with a multi-spark ignition system in a diesel engine adapted to work at the Otto cycle

This work focuses on the construction of a 2D dynamic model, taking into consideration the turbulent flux combustion reactions of syngas inside a combustion chamber and its displacement through the cylinder of a diesel engine model OM 447 LA converted to Otto cycle operation. The engine has a multi-spark ignition system. The geometry of both the chamber and cylinder is symmetric to a radius of 0.064 m and to a length of 0.17595 m. The simulation is carried out on only half of the system, with a premixed supply of the syngas and air. The supply temperature of the mixture is 336 K. The supply relation air/syngas ratio is 1.1:1, and the supply pressure of the mixture is 1 bar. The gaseous phase is modeled as a multi-component mixture comprised of carbon monoxide (CO), hydrogen (H₂), methane (CH₄), nitrogen (N₂), carbon dioxide (CO₂) and oxygen (O₂). The study describes a Computational Fluid Dynamic (CFD) numerical model, in which the conservation of matter, motion and energy equations are solved; in addition, sub-models are used to represent the turbulence intensity and the multiple reactions. The model predicts the profiles of syngas speed, temperature, chemical composition, pressure, and turbulence intensity for the gases when the working parameters and the supply characteristics are modified (air-syngas ratio, initial temperature of the mixture, initial pressure, compression ratio, and engine speed). The equation formulation is elliptic staggered. The result is a simple nonlinear map that resolves combustion time sequences using the commercial code CFD in PHOENICS.     

Effect of radiative heat transfer on the combustion wave propagation in a model of a heterogeneous system

The subject of investigation was the behavior of integral curves of the problem of combustion-wave propagation in a model of a heterogeneous system. The influence of radiative heat transfer on steady combustion regimes was considered. It was shown that for sufficiently large gaps between the plates in the system (when a quasihomogeneous temperature distribution still exists) in the regime of weak retardation by the growing product layer, the radiation can result in a notable acceleration of the combustion wave. In the regime of strong retardation with the remaining conditions being the same, the radiation can be neglected. Translated fromFiz. Goreniya i Vzryva, Vol. 34, No. 3, pp. 69–76, May–June 1998.     

Acoustic emission in the ignition and combustion of energetic materials

Chelyabinsk. Translated from Fizika Goreniya i Vzryva, Vol. 28, No. 6, pp. 39–42, November–December, 1992.     

Kinetic mechanism of propane ignition and combustion in air

A detailed kinetic model of propane ignition and combustion in air is developed. The model includes 599 reactions with 92 species and involves both the high-temperature and low-temperature mechanisms of oxidation. The model is tested against experimental data on the ignition delay time, on propane conversion during low-temperature oxidation, on changes in species concentrations during propane pyrolysis, and on laminar flame propagation velocity. The model is tested in wide ranges of the initial temperature T ₀ = 680–1900 K, pressure p ₀ = 0.17–30 atm, and fuel-air equivalence ratio ϕ = 0.13–2.