Ignition and combustion of powdered aluminum in high-temperature gaseous media and in a composition of heterogeneous condensed systems

Frolov, Yu. V.; Pokhil, P. F.; Logachev, V. S.

doi:10.1007/bf00740445

Cited by 27 publications

(21 citation statements)

References 5 publications

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“…1(a)). Similar to the ignition of a magnesium particle, the ignition may be initiated after the cracking of oxide film [32,33], but the removal of the oxide film concurrent with the oxide melting would be more probable cause for the particle ignition [3,34] when the particle size is a few hundreds of microns in particular.…”

Section: Oxide Film Removal and Ignitionmentioning

confidence: 97%

Modeling of aluminum particle combustion with emphasis on the oxide effects and variable transport properties

Yang

Yoon

2010

J Mech Sci Technol

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A simplified analytical modeling of single aluminum particle combustion was conducted. Ignition and quasi-steady combustion (QSC) were separately formulated and integrated. Both the heat transfer from the hot ambient gas and the enthalpy of heterogeneous surface reaction (HSR) served to cause the particle ignition. Conservation equations were solved for QSC parameters in conjunction with conserved scalar formulation and Shvab-Zeldovich function. Limit temperature postulate was formulated by a sink term pertinent to the dissociation of the aluminum oxide near the flame zone. Effective latent heat of vaporization was modified for the thermal radiation. Ignition and QSC of the aluminum particle were predicted and discussed with emphasis on the effect of the aluminum oxide and variable properties. The model was validated with the experiments regarding ignition delay time, burning rate, residue particle size, flame temperature, QSC duration, and stand-off distance of the envelop flame. Agreement was satisfactory and the prediction errors were limited within 10%.

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Section: Oxide Film Removal and Ignitionmentioning

confidence: 97%

Modeling of aluminum particle combustion with emphasis on the oxide effects and variable transport properties

Yang

Yoon

2010

J Mech Sci Technol

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“…The considerable change in the size is probably related to a change in the effective density of the agglomerates [35].…”

Section: Tablementioning

confidence: 99%

“…We give some data of [24], where the evolution of burning agglomerates of a propellant consisting of 49.5% AP, 21.4% of RDX, 12% HTPB, and 17% Al was studied using a sampling bomb with a rotated drum [35]. In [24], the sample diameter was 6.28 mm, the sample length was 10 mm, and the experiments were performed with changes in pressure (2.3 or 7 MPa), aluminum particle size (7, 17 or 30 µm), and particle quenching distance (7, 17, .…”

Section: Tablementioning

confidence: 99%

Condensed combustion products of aluminized propellants. IV. Effect of the nature of nitramines on aluminum agglomeration and combustion efficiency

Глотов

2006

Combust Explos Shock Waves

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The condensed combustion products of two model propellants consisting of ammonium perchlorate, aluminum, nitramine, and an energetic binder were studied by a sampling method. One of the propellants contained HMX with a particle size D 10 ≈ 490 µm, and the other RDX with a particle size D 10 ≈ 380 µm. The particle-size distribution and the content of metallic aluminum in particles of condensed combustion products with a particle size of 1.2 µm to the maximum particle size in the pressure range of 0.1-6.5 MPa were determined with variation in the particle quenching distance from the burning surface to 100 mm. For agglomerates, dependences of the incompleteness of aluminum combustion on the residence time in the propellant flame were obtained. The RDX-based propellant is characterized by more severe agglomeration than the HMX-based propellant -the agglomerate size and mass are larger and the aluminum burnout proceeds more slowly. The ratio of the mass of the oxide accumulated on the agglomerates to the total mass of the oxide formed is determined. The agglomerate size is shown to be the main physical factor that governs the accumulation of the oxide on the burning agglomerate.

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“…Parallel activities on aluminum combustion evolved in USSR, and the early experimental work was summarized in [9,10]. Kudryavtsev et al [8] and Gremyachkin et al [11,12] developed models for describing the burning rate of metals in general, but focused on aluminum.…”

Section: Introductionmentioning

confidence: 99%

Numerical Simulation of Single Aluminum Particle Combustion (Review)

Beckstead

Liang

Pudduppakkam

2005

Combust Explos Shock Waves

137

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A two-dimensional, unsteady-state, kinetic-diffusion-vaporization-controlled numerical model for aluminum particle combustion is presented. The model solves the conservation equations, while accounting for species generation and destruction with a 15-reaction kinetic mechanism. Two of the major phenomena that differentiate aluminum combustion from hydrocarbon-droplet combustion, namely, condensation of the aluminum-oxide product and subsequent deposition of part of the condensed oxide onto the particle, are accounted for in detail with a submodel for each phenomenon. The effect of the oxide cap in the distortion of the species and temperature profiles around the particle is included into the model. The results obtained from the model, which include two-dimensional species and temperature profiles, are analyzed and compared with experimental data. The combustion process is found to approach a diffusion-controlled process for the oxidizers (O 2 , CO 2 , and H 2 O) and conditions treated. The flame-zone location and thickness are found to vary with the oxidizer. The result shows that the exponent of the particle-diameter dependence of the burning time is not a constant and changes from ≈1.2 for smaller-diameter particles to ≈1.9 for larger-diameter particles. Owing to deposition of the aluminum oxide onto the particle surface, the particle velocity oscillates. The effect of pressure is analyzed for a few oxidizers. Key words: aluminum particle, two-dimensional unsteady-state numerical model, kinetic mechanism, effect of the nature of the gaseous oxidizer, condensed oxide, oxide dissociation, oxide cap, burning time, species and temperature fields INTRODUCTIONAluminum has been added to propellants for many years as an extra energy source for the propellant. Thus, research on the combustion mechanism of burning aluminum has been an ongoing effort. A very significant effort was expended in the 1960s and 1970s shortly after the effects of aluminum were first conceived. In an early study, Glassman [1] and Brzustowski and Glassman [2] recognized that metal combustion would be analogous to hydrocarbon-droplet combustion, that the D 2 law ought to be applied, and that ignition and combustion ought to depend on the melting and boiling points of the metal and the oxide. Glassman speculated that ig-

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Ignition and combustion of powdered aluminum in high-temperature gaseous media and in a composition of heterogeneous condensed systems

Cited by 27 publications

References 5 publications

Modeling of aluminum particle combustion with emphasis on the oxide effects and variable transport properties

Modeling of aluminum particle combustion with emphasis on the oxide effects and variable transport properties

Condensed combustion products of aluminized propellants. IV. Effect of the nature of nitramines on aluminum agglomeration and combustion efficiency

Numerical Simulation of Single Aluminum Particle Combustion (Review)

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