AbstractsEngineering

On cylindrical detonation waves.

by Benedict Huk Kun. Lee




Institution: McGill University
Department: Department of Mechanical Engineering.
Degree: Master of Engineering.
Year: 1964
Keywords: Mechanical Engineering.
Record ID: 1566348
Full text PDF: http://digitool.library.mcgill.ca/thesisfile116549.pdf


Abstract

A theoretical and experimental investigation of cylindrical detonation waves have been carried out. In the theoretical phase of this investigation, the dynamics of the combustion products behind a cylindrical detonation wave is analysed by extending the Taylor-Zeldovich model of the spherical case. Based on the conservation of mass, it is shown that when the reaction zone thickness is not small compared to the radius, a steady detonation wave cannot exist. A study of the initiation mechanisms of a cylindrical detonation wave shows that it must be initially over-driven and for large radius, the Chapman-Jouguet hypothesis is satisfied. In the experimental phase of this investigation, the detonation velocities in acetylene-oxygen mixtures with different chemical compositions (20% - 60% acetylene by volume) are determined by using ionization probes. The critical energy for spark ignition is also determined. Vertical slit streak photographs and pressure measurements are taken at different radii from the ignition source to verify that the cylindrical detonation wave is initially over-driven. Pressure measurements of the combustion products are also taken and compared with the theoretical values based on the similarity solution. The problem of transition from cylindrical deflagration to detonation, and the phenomena of spinning and pulsations are also investigated. [...]