Experimental methodology and heat transfer model for identification of ignition kinetics of powdered fuels

Document Type

Article

Publication Date

12-1-2006

Abstract

A methodology for investigating and quantifying the thermal processes leading to ignition of rapidly heated metal powders was developed. The simple experiment involves observing ignition of a powder coated on the surface of an electrically heated filament and is well suited for a variety of powdered fuels. In an experimental case study, the ignition temperature of spherical Mg powder was detected optically at different heating rates. To interpret the results, a heat transfer model was developed for a multilayer powder coating on the heated cylindrical filament. The thermal contact resistance between particles was determined from the measured bulk thermal diffusivity of the powder considering the experimental particle size distribution. An Arrhenius type expression was used to describe the exothermic chemical processes leading to ignition with the pre-exponent as an adjustable parameter. For Mg, a pre-exponent value identified by matching the calculations with the experimental data was found to be 1010 kg/m2 s. The match between the experimental and predicted temperatures and times of ignition was good for different heating rates, which validated the proposed heat transfer model and indicated that the developed methodology is practically useful. © 2006 Elsevier Ltd. All rights reserved.

Identifier

33750366033 (Scopus)

Publication Title

International Journal of Heat and Mass Transfer

External Full Text Location

https://doi.org/10.1016/j.ijheatmasstransfer.2006.05.025

ISSN

00179310

First Page

4943

Last Page

4954

Issue

25-26

Volume

49

Grant

N00014-00-1-0446

Fund Ref

Office of Naval Research

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