University of Illinois Urbana-Champaign

Hydrodynamic mechanisms of pulsating detonation wave instability

Short, Mark; Kapila, Ashwani K.; Quirk, James J.

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https://hdl.handle.net/2142/112596

Description

Title
Hydrodynamic mechanisms of pulsating detonation wave instability
Author(s)
  • Short, Mark
  • Kapila, Ashwani K.
  • Quirk, James J.
Issue Date
1998-09
Keyword(s)
Pulsating Detonation Wave Instability
Abstract
The hydrodynamic mechanisms behind the instability and failure of a one-dimensional pulsating detonation wave driven by a three-step chain-branching reaction are revealed by direct numerical simulation. Two types of pulsating instability observed experimentallv are explained. The first involves regular oscillations of the detonation front, where the instability is driven by low-frequencv. finite-amplitude compression and expansion waves in the chain-branching induction zone between the main reaction layer and the detonation shock. For irregular oscillations of the front. the instability mechanism first involves a decoupling between the shock and main reaction layer. Subsequently, the main reaction layer accelerates, drives a compression wave ahead of it, and undergoes a transition to detonation. This internal detonation wave overtakes the lead detonation shock, generating a new high-pressure detonation. which rapidly decays. A smaller amplitude pressure oscillation occurs during the decay with a mechanism reminiscent of that observed for the previous regular oscillation. before the detonation and main reaction layer once again decouple and the instability cycle is repeated. For failure scenarios. the shock temperature is observed to drop to the cross-over temperature for the chain-branching reaction, causing the main reaction layer to decouple and retreat indefinitely from the detonation shock.
Publisher
Department of Theoretical and Applied Mechanics. College of Engineering. University of Illinois at Urbana-Champaign
Series/Report Name or Number
  • TAM R 889
  • 1998-6015
ISSN
0073-5264
Type of Resource
text
Language
eng
Permalink
http://hdl.handle.net/2142/112596
Sponsor(s)/Grant Number(s)
Air Force Office of Scientific Research; National Science Foundation; Los Alamos National Laboratory F49620-96-1-0260
Copyright and License Information
Copyright 1998 Board of Trustees of the University of Illinois

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Technical Reports - Theoretical and Applied Mechanics (TAM) PRIMARY
TAM technical reports include manuscripts intended for publication, theses judged to have general interest, notes prepared for short courses, symposia compiled from outstanding undergraduate projects, and reports prepared for research-sponsoring agencies.