Agglomeration and ignition mechanism of aluminum particles in solid propellants

Gany, Alon; Caveny, Leonard H.

doi:10.1016/s0082-0784(79)80137-x

Cited by 45 publications

(21 citation statements)

References 5 publications

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“…Combustion of metals using an oxygen flow or jet is also commonly used to cut and process iron and steel, while grinding can produce metal chips and particles that burn as sparks through the air. Only from the middle of the last century did scientific research into metal-combustion phenomena begin in earnest when, due to their exceptionally high energy density, metal powders began to be used as energetic fuel additives in solid rocket motors [87][88][89][90][91], liquid-hydrocarbon slurry fuels [92][93][94], explosives [95,96], and other energetic materials [97][98][99].…”

Section: Combustion Modes Of Single Metal Particles and Metal Fuel Thmentioning

confidence: 99%

“…The study of nano-powder combustion for propulsion applications has demonstrated that the high reactive surface area of nano-particles does not necessarily translate into a proportional increase in their reactivity [146,147]. This poor combustion performance can be explained by the strong tendency of nano-powders to agglomerate during dispersal [56,90,94,[147][148][149]. The combustion of the resulting large particle agglomerates, consisting of hundreds or even thousands of nano-particles, is then equivalent to the combustion of large solid-metal particles of an approximately equivalent size, because the large internal surface area of the agglomerate is irrelevant for a particle burning in a diffusionlimited combustion mode with a micro-flame enveloping it [150].…”

Section: Burning Metals In Internal-combustion Engines (Ices)mentioning

confidence: 99%

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Direct combustion of recyclable metal fuels for zero-carbon heat and power

et al. 2015

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Section: Combustion Modes Of Single Metal Particles and Metal Fuel Thmentioning

confidence: 99%

Section: Burning Metals In Internal-combustion Engines (Ices)mentioning

confidence: 99%

Direct combustion of recyclable metal fuels for zero-carbon heat and power

et al. 2015

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“…Many studies of burning aluminum particles have been conducted [1][2][3][4]. Furthermore, many studies of burning time [5], ignition delay time [6], mechanism of agglomeration, and diameter of agglomerate of aluminum particles [7][8][9][10][11][12][13][14] have been conducted using various procedures, mostly experimental, but also analytical, to clarify the mechanism of agglomeration [15][16][17][18].…”

Section: Introductionmentioning

confidence: 99%

Agglomeration Characteristics of Aluminum Particles in AP/AN Composite Propellants

Takahashi

Oide

Kuwahara

2013

Propellants Explo Pyrotec

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Most solid rockets are powered by ammonium perchlorate (AP) composite propellant including aluminum particles. As aluminized composite propellant burns, aluminum particles agglomerate as large as above 100 μm diameter on the burning surface, which in turn affects propellant combustion characteristics. The development of composite propellants has a long history. Many studies of aluminum particle combustion have been conducted. Optical observations indicate that aluminum particles form agglomerates on the burning surface of aluminized composite propellant. They ignite on leaving the burning surface. Because the temperature gradient in the reaction zone near a burning surface influences the burning rate of a composite propellant, details of aluminum particle agglomeration, agglomerate ignition, and their effects on the temperature gradient must be investigated. In our previous studies, we measured the aluminum particle agglomerate diameter by optical observation and collecting particles. We observed particles on the burning surface, the reaction zone, and the luminous flame zone of an ammonium perchlorate (AP)/ammonium nitrate (AN) composite propellant. We confirmed that agglomeration occurred in the reaction zone and that the agglomerate diameter decreased with increasing the burning rate. In this study, observing aluminum particles in the reaction zone near the burning surface, we investigated the relation between the agglomerates and the burning rate. A decreased burning rate and increased added amount of aluminum particles caused a larger agglomerate diameter. Defining the extent of the distributed aluminum particles before they agglomerate as an agglomerate range, we found that the agglomerate range was constant irrespective of the added amount of aluminum particles. Furthermore, the agglomerate diameter was ascertained from the density of the added amount of aluminum particles in the agglomerate range. We concluded from the heat balance around the burning surface that the product of the agglomerate range and the burning rate was nearly constant irrespective of the added amount of aluminum particles. Moreover, the reduced burning rate increased the agglomerate range.

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“…For nano sized particles, the melting temperature is below 2300 . Here, the ignition temperature is calculated by the following formula [15]: …”

Section: 나노 알루미늄 입자 첨가 추진제에 의한 탄소복합재 노즐의 기계적 삭마 감소 특성 예측 45mentioning

confidence: 99%

“…'  ' is calculated by the force balance between the aluminum particles which are floating on the fluid bed by buoyancy, with the assumption that the fluid bed is in a liquid state [15]:…”

Section: 나노 알루미늄 입자 첨가 추진제에 의한 탄소복합재 노즐의 기계적 삭마 감소 특성 예측 45mentioning

confidence: 99%

Prediction of the Mechanical Erosion Rate Decrement for Carbon-Composite Nozzle by using the Nano-Size Additive Aluminum Particle

Tarey¹,

Kim²,

Levitas³

et al. 2015

Journal of the Korean Society of Propulsion Engineers

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In this study, the influence of Al particle size, as an additive for solid propellant, on the mechanical erosion of the carbon-composite nozzle was evaluated. A new model which can predict the size and distribution of the agglomerated reaction product(Al(l)/Al 2 O 3 (l)) was established, and the size of agglomerate were calculated according to the various initial size of Al in the solid propellant. With predicted results of the model, subsequently, the characteristics of mechanical erosion on the carbon-composite nozzle was estimated using a commercial CFD software, STAR CCM+. The result shows that the smaller the initial Al particles are, in the solid propellant, the lower is the mechanical erosion rate of the composite nozzle wall, especially for the nano-size Al particle.

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Agglomeration and ignition mechanism of aluminum particles in solid propellants

Cited by 45 publications

References 5 publications

Direct combustion of recyclable metal fuels for zero-carbon heat and power

Direct combustion of recyclable metal fuels for zero-carbon heat and power

Agglomeration Characteristics of Aluminum Particles in AP/AN Composite Propellants

Prediction of the Mechanical Erosion Rate Decrement for Carbon-Composite Nozzle by using the Nano-Size Additive Aluminum Particle

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