摘要:

We investigate the effect of axial heat conduction in the metal wall of a detonator delay element on the speed of a deflagration wave. An axisymmetric time dependent model is formulated in which the reaction rate is described by a single step kinetic equation. Numerical solutions are obtained and it is found that the flame speed is reduced below its one-dimensional adiabatic value at early times due to heat loss into the cold wall, but exceeds the adiabatic value at later times because the unreacted pyrotechnic ahead of the flame is preheated by radial conduction. These effects happen to almost cancel out for a typical 8s delay element. It is also shown that the wall temperature can exceed the decomposition temperature of the pyrotechnic leading to the onset of a radial flame. A simplified analytical model is presented which allows the wall temperature to be estimated.

ISSN:0010-2202    

DOI:10.1080/00102209408935390

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor

摘要:

Seeking to systemalically identify and organize the physical and chemical properties of biomass particles for combustion in furnaces, an attempt is made here to theoretically describe the temporal change in mass of a burning particle of an organic solid. The development involves a series of simple models to highlight the mechanisms involved, the physical and chemical properties of concern and the expected results. Although many simplifying assumptions are made, the properties identified, the parameters which evolved and the final functional form of the results are expected to becorrect.

ISSN:0010-2202    

DOI:10.1080/00102209408935391

出版商:Taylor & Francis Group    

年代:1994

数据来源: Taylor