Ignition and combustion mechanism in aluminum particles

Razdobreev, A. A.; Skorik, A. I.; Frolov, Yu. V.

doi:10.1007/bf00744882

Cited by 10 publications

(3 citation statements)

References 2 publications

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“…A smaller particle and an oxidizer rich mixture were more favorable to the particle ignition. Razdobreev et al [9] attempted microphotography and CO 2 laser heating method. High-resolution images evidenced that the ignition is locally initiated and propagates over the entire particle surface with a velocity which depends on the particle size.…”

Section: Introductionmentioning

confidence: 99%

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: Introductionmentioning

confidence: 99%

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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“…For small sizes and oxygen contents greater than 5 % the limiting temperature is considerably lower than the melting point of oxide. Razdobreev et al [21] evidenced that the ignition is locally initiated and propagates over the entire particle surface with a velocity, which depends on the particle size, under the action of laser radiation by highspeed microcine photography. Marion et al [22] demon-1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 strated that the ignition delay of aluminum particle remains constant with increasing pressure.…”

Section: Introductionmentioning

confidence: 99%

Experiments and Numerical Calculations on Laser‐induced Ignition of Single Micron‐sized Aluminum Fuel Particle

Zhou

2017

Propellants Explo Pyrotec

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This paper presents the experiments and numerical calculations on the laser-induced ignition of single micron-sized aluminum particle in an atmospheric pressure air flow at low Reynolds number. Experimental results demonstrate that the radiation intensity of single micron-sized aluminum particle, during ignition, experiences first sharp rising, stable equilibrium and second steep rising stages. A simplified analytical model was built and numerically solved. Numerical results show that the three distinctive stages represent the heating, melting and evaporation, respectively. Laser radiation mainly contributes to heat aluminum particle, leading to phase transition (melting). The heat released from heterogeneous surface reaction (HSR) domi-nates the temperature rise of the liquid aluminum and accelerate its evaporation. During ignition, the heat loss of natural convection significantly affects the ignition performance of aluminum particle, while the heat loss of radiation toward the surrounding air only affects the evaporation rate. Threshold ignition energy of aluminum particle based on numerical calculations is in good agreement with the experiments, which strongly depends on the particle diameter. Ignition delay time depends on the particle diameter and ignition energy. This study will be beneficial to deeply recognize the ignition mechanism of single micron-sized aluminum particle, especially in the transition region between nanoscale and microscale.

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“…This has led the authors to believe that the cause of aluminum ignition is the increase in the particle oxidation rate as a result of melting of oxide covering aluminum particles. In other ignition studies, [10][11][12][13][14][15] the direct sample temperature measurements and observations showed that aluminum temperature at the ignition moment is lower than the oxide melting point. Also, the disintegration of the aluminum oxide layer was observed before ignition.…”

Section: Introductionmentioning

confidence: 99%

Thermal theory of aluminum particle ignition in continuum, free-molecular, and transition heat transfer regimes

Ermoline

2018

Journal of Applied Physics

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Most studies on nano-and micro-sized aluminum particle ignition have been focused on the processes occurring inside particles. In the current paper, thermal ignition of an aluminum particle in the air is simulated with different heat transfer models: continuum, free-molecular, and Fuchs model. A single parabolic oxidation law is assumed in the particle size range from nano-to millimeter diameters. A particle is considered ignited when it reaches the oxide melting point. The criterion defining the limits of validity for each model is the ratio of continuum and free-molecular heat transfer rates. The dependence of ignition temperature T i on the particle size is in qualitative agreement with the experimental trends: T i can have values in the range of 700-1500 K for nanoparticles due to the dominating contribution of a free-molecular heat transfer, and sharp growth of T i with the particle size in the range of 1-100 lm diameter is due to the transitional character of heat transfer. For small values of the accommodation coefficient, ignition may occur in the critical ignition mode with the thermal runaway. The results suggest the importance of non-continuous heat transfer and, in particular, energy accommodation in ignition of nano-and micro-sized particles. Published by AIP Publishing. https://doi.

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Ignition and combustion mechanism in aluminum particles

Cited by 10 publications

References 2 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

Experiments and Numerical Calculations on Laser‐induced Ignition of Single Micron‐sized Aluminum Fuel Particle

Thermal theory of aluminum particle ignition in continuum, free-molecular, and transition heat transfer regimes

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