Unconfined aluminum particles-air detonation

Zhang, F.; Gerrard, K. B.; Ripley, Robert C.; Tanguay, Vincent

doi:10.1007/978-3-540-85168-4_63

Cited by 6 publications

(6 citation statements)

References 5 publications

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“…In accordance with these experimental facts, a kinetics-diffusion hybrid reaction model is proposed by the authors in the form [26] J p n p d 2 p k p n p d 2…”

Section: Aluminum Reaction Modelmentioning

confidence: 78%

Reaction Mechanism of Aluminum-Particle-Air Detonation

Zhang

Gerrard

Ripley

2009

Journal of Propulsion and Power

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Both in-tube and unconfined experimental evidence showed strong dependence of micrometric aluminum-air detonability on initial pressure and highly nonlinear behavior of abrupt deflagration-to-detonation transition, thus indicating dependence of the aluminum reaction mechanism of the detonation waves on chemical kinetics. On the other hand, the observed aluminum-air detonation manifested itself in a weak transverse wave structure, as revealed by the small-amplitude oscillation that rapidly degenerates behind the shock front in the pressure histories. This suggests a functional dependence that is weaker than the nonlinear Arrhenius kinetic behavior for the later aluminum combustion. Hence, a surface kinetic oxidation and diffusion hybrid reaction model with a degree of condensed detonation products was suggested, and the unsteady two-phase fluid dynamics modeling showed the success of the hybrid reaction model, capable of capturing both the kinetics-limited transient processes of detonation initiation, abrupt deflagration-to-detonation transition and detonation instability, and the diffusion-limited combustion of aluminum in the long reaction zone, supporting the weak transverse wave structure.Nomenclature a e = equilibrium sound speed, m=s a g = phase-frozen sound speed, m=s C = mole concentration, mol=m 3 C D = drag coefficient D = detonation velocity, m=s D g = gas-phase diffusivity, m 2 =s d p = particle diameter, m E = activation energy, J=mol e = specific internal energy, J=kg f p = rate of momentum transfer between the solid and the gas phase, N=m 3 J p = rate of mass transfer between the particles and the gas phase, kg=m 3 s K = diffusion reaction coefficient, s=m 2 k = mass depletion flux, kg=m 2 s k d = rate coefficient of diffusion reaction, kg m=mol s k s = rate coefficient of kinetic reaction, kg m=mol s k 0 = kinetic reaction coefficient, kg m=mol s L b = latent heats of evaporation, J=mol L m = latent heats of melting, J=mol Nu = Nusselt number n p = particle number density, 1=m 3 Pr = gas-phase Prandtl number p = pressure, N=m 2 Q p = rate of heat transfer between the particles and the gas phase, J=m 3 s q p = heat release of particles, J=kg R = universal gas constant, J=mol K Re = two-phase Reynolds number r p = particle radius, m T = temperature, K T ign = particle ignition temperature, K t b = particle burning time, s u = flow velocity, m=s W = molecular weight, g=mol w = species reaction rate, kg=m 3 s x = distance in the shock-propagation direction, m Y = mass fraction of species g = thermal conductivity of the gas phase, W=m K = stoichiometric coefficient = material density, kg=m 3 = partial density or mass concentration, kg=m 3 = volume fraction p = rate of particle number production, 1=m 3 s Subscripts g = gas-phase index oxi = index for oxidizing gases p = particle-phase index s = index for particle surface 0 = initial state

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“…In accordance with these experimental facts, a kinetics-diffusion hybrid reaction model is proposed by the authors in the form [26] J p n p d 2 p k p n p d 2…”

Section: Aluminum Reaction Modelmentioning

confidence: 78%

Reaction Mechanism of Aluminum-Particle-Air Detonation

Zhang

Gerrard

Ripley

2009

Journal of Propulsion and Power

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“…A suspension in air of micron size Al particles supported a detonation wave in tubes [7,8]. Initiation of detonation was investigated in an explosively generated cloud of Al particles (atomized H-2 Al and Àaked Al) using 8 kg C4 explosive and detonation was observed only in the Àaked Al with 4-8 MPa peak pressures [9].…”

Section: Introductionmentioning

confidence: 99%

Dynamic behavior of particulate/porous energetic materials

Nesterenko

Chiu

Braithwaite³

et al. 2012

AIP Conference Proceedings

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Abstract. Dynamic behavior of particulate/porous energetic materials in a broad range of dynamic conditions (low velocity impact and explosively driven expansion of rings) is discussed. Samples of these materials were fabricated using Cold Isostatic Pressing and Hot Isostatic Pressing with and without vacuum encapsulation. The current interest in these materials is due to the combination of their high strength and output of energy under critical conditions of mechanical deformation. They may exhibit high compressive and tensile strength with the ability to undergo bulk distributed fracture resulting in small size reactive fragments. The mechanical properties of these materials and the fragment sizes produced by fracturing are highly sensitive to mesostructure. For example, the dynamic strength of Al-W composites with fine W particles is significantly larger than the strength of composites with coarse W particles at the same porosity. The morphology of W inclusions had a strong effect on the dynamic strength and fracture pattern. Experimental results are compared with numerical data.

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“…The existence of cellular heterogeneous detonation in gas suspensions of metallic or organic particles was validated in experiments [26][27][28][29]. Two-dimensional detonation flows with cellular structures in gas suspensions of aluminum particles were numerically simulated in [24,[29][30][31][32].…”

Section: Cellular Structure In Bidisperse Suspensionsmentioning

confidence: 99%