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International Journal of Energetic Materials and Chemical Propulsion

Publicado 6 números por año

ISSN Imprimir: 2150-766X

ISSN En Línea: 2150-7678

The Impact Factor measures the average number of citations received in a particular year by papers published in the journal during the two preceding years. 2017 Journal Citation Reports (Clarivate Analytics, 2018) IF: 0.7 To calculate the five year Impact Factor, citations are counted in 2017 to the previous five years and divided by the source items published in the previous five years. 2017 Journal Citation Reports (Clarivate Analytics, 2018) 5-Year IF: 0.7 The Immediacy Index is the average number of times an article is cited in the year it is published. The journal Immediacy Index indicates how quickly articles in a journal are cited. Immediacy Index: 0.1 The Eigenfactor score, developed by Jevin West and Carl Bergstrom at the University of Washington, is a rating of the total importance of a scientific journal. Journals are rated according to the number of incoming citations, with citations from highly ranked journals weighted to make a larger contribution to the eigenfactor than those from poorly ranked journals. Eigenfactor: 0.00016 The Journal Citation Indicator (JCI) is a single measurement of the field-normalized citation impact of journals in the Web of Science Core Collection across disciplines. The key words here are that the metric is normalized and cross-disciplinary. JCI: 0.18 SJR: 0.313 SNIP: 0.6 CiteScore™:: 1.6 H-Index: 16

Indexed in

INTERFACIAL INSTABILITY INDICATING BORON PARTICLE IGNITION

Volumen 2, Edición 1-6, 1993, pp. 232-247
DOI: 10.1615/IntJEnergeticMaterialsChemProp.v2.i1-6.130
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SINOPSIS

The ignition of boron particles is generally described as a two-stage process. In the first stage, which is described in the present model, a solid boron kernel is covered by a thin layer of liquid B2O3. This layer acts as a diffusional barrier for the oxida-tor transport from the gaseous environment to the BB2O3 − interface, where the reaction occurs. Two competing effects, oxide evaporation at the outer interface and oxide formation at the solid-liquid interface, influence the layer thickness and its temperature. In theoretical models for boron particle ignition, it is generally assumed that the spherical symmetry is not broken during the evolution towards ignition, which is indicated by a vanishing film thickness. In the present model, a nonlinear partial differential equation for the local thickness f of a thin viscous liquid film on a spherical particle in the limit of a vanishing ratio of mean-film thickness and particle diameter is derived. This equation incorporates oxide evaporation and formation depending on the local film thickness and temperature, Marangoni-flow due to a surface temperature gradient and a varying capillary pressure due to a nonuniform curvature. We restrict ourself to the axisymmetric case.
A linear stability analysis of the governing equation shows that a steady, spherical symmetric state becomes unstable with respect to axisymmetric perturbations for certain values of the control parameters. For slightly supercritical parameter values, an adiabatic elimination procedure is used to describe the evolution of the interface. It is shown that this may result in a locally vanishing film, which indicates ignition. Thus boron particle ignition due to interfacial instability is predicted at relatively low ambient temperatures.

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