Asymptotic theory of ignition and failure of self-sustained detonations

Kasimov, Aslan R.; Stewart, D. Scott

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https://hdl.handle.net/2142/681 Copy

Description

Title

Asymptotic theory of ignition and failure of self-sustained detonations

Author(s)

• Kasimov, Aslan R.
• Stewart, D. Scott

Issue Date

2005

Keyword(s)

• Detonation waves
• Ignition failure

Abstract

Based on a general theory of detonation waves with an embedded sonic locus that we have previously developed, we carry out asymptotic analysis of weakly curved slowly varying detonation waves and show that the theory predicts the phenomenon of detonation ignition and failure. The analysis is not restricted to near Chapman– Jouguet detonation speeds and is capable of predicting quasi-steady, normal detonation shock speed versus curvature (D–κ) curves with multiple turning points. An evolution equation that retains the shock acceleration, ˙D, namely a ˙D–D–κ relation is rationally derived which describes the dynamics of pre-existing detonation waves. The solutions of the equation for spherical detonation are shown to reproduce the ignition/failure phenomenon observed in both numerical simulations of blast wave initiation and in experiments. A single-step chemical reaction described by one progress variable is employed, but the kinetics is sufficiently general and is not restricted to Arrhenius form, although most specific calculations are performed for Arrhenius kinetics. As an example, we calculate critical energies of direct initiation for hydrogen– oxygen mixtures and find close agreement with available experimental data.

Publisher

Cambridge University Press

Type of Resource

text

Language

en

Permalink

http://hdl.handle.net/2142/681

DOI

https://doi.org/10.1017/S0022112004002599

Has Version(s)

Also published as: TAM Reports 1042; http://hdl.handle.net/2142/238

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Copyright owned by Cambridge University Press

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