A Theory of DDT in Unconfined Flames.

Abstract

This paper outlines a theoretical approach for predicting the onset of detonation in unconfined turbulent flames. Two basic assumptions are made (1) the gradient mechanism is the inherent mechanism that leads to DDT in unconfined conditions, and (2) the sole mechanism for preparing the gradient in induction time is by turbulent mixing and local flame quenching. The criterion for DDT is derived in terms of the one-dimensional detonation wave thickness, the laminar flame speed, and the laminar flame thickness in the reactive gas. This approach gives a lower-bound criterion for DDT for conditions where shock preheating, wall effects, and interactions with obstacles are absent. Regions in parameter space where unconfined DDT can and cannot occur are determined.

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Document Details

Document Type
Technical Report
Publication Date
Jun 19, 1996
Accession Number
ADA310467

Entities

People

  • Alexei M. Khokhlov
  • Elaine Oran
  • J. C. Wheeler

Organizations

  • United States Naval Research Laboratory

Tags

Communities of Interest

  • Energy and Power Technologies

DTIC Thesaurus Topics

  • Boundary Layer
  • Chemical Reactions
  • Combustion
  • Detonation Waves
  • Detonations
  • Explosions
  • Fluid Dynamics
  • Fluids
  • Gases
  • Geometry
  • Military Research
  • Mixing
  • Reactive Gases
  • Temperature Gradients
  • Thickness
  • Turbulent Mixing
  • Waves

Readers

  • Combustion Dynamics and Shock Wave Physics.
  • Combustion science or combustion engineering.
  • Theoretical Analysis.

Technology Areas

  • Space
  • Space - Hall-Effect Thruster