Accession Number : ADA117849

Title :   A Study of Detonation Structure: The Formation of Unreacted Gas Pockets.

Descriptive Note : Interim rept.,

Corporate Author : NAVAL RESEARCH LAB WASHINGTON DC

Personal Author(s) : Oran,E S ; Young,T R ; Boris,J P ; Picone,J M ; Edwards,D H

PDF Url : ADA117849

Report Date : 26 Jul 1982

Pagination or Media Count : 18

Abstract : Schlieren photographs of detonations in low pressure H2-O2-Ar mixtures and numerical simulations of propagation detonations have revealed the presence of unreacted pockets of gas behind the shock front - Mach stem structure. These pockets are completely surrounded by burned gas, and they in turn burn more slowly, finally giving their energy to the system. Two-dimensional numberical simulations performed to study the development of unburned pockets show that they are peninsulas of cooler material cut off by the collision of two Mach stems or of a Mach stem and the wall. Their presence is observed when there is sufficient decoupling of the reaction zone from the incident shock. These unreacted gas pockets and the associated long induction distance are discussed in terms of possible mechanisms for cell reinitiation, cell generation, and the behavior of detonations near the detonation limits. (Author)

Descriptors :   *Detonations, *Combustion, *Gas dynamics, *Wave propagation, *Mathematical models, Hydrogen peroxide, Argon, Mixtures, Combustion chamber gases, Cavities, Shock waves, Stemming, Mach number, Boundaries, Collisions, Walls, Reaction kinetics, Combustion chambers, Cells, Detonation waves

Subject Categories : Fluid Mechanics
      Combustion and Ignition

Distribution Statement : APPROVED FOR PUBLIC RELEASE