ID#: 174
Abstract Title: Sensitization of Hydrocarbon-Oxygen Mixtures to DDT via Cool Flame Oxidation
Session Title: DDT
Session Date: 7/31/01
Session Start Time: 8:30 AM
Contributing Author: Romano, M.P.
Organization: McGill University
Country: Canada
Authors: Massimiliano P. Romano, Andrew J. Higgins, John H.S. Lee, Stephen M. Murray
Short Abstract: нннн Experiments in a heated Pyrex tube have examined the effect of cool flame oxidation on the run up distance to detonation in pentane-oxygen mixtures. From fundamental considerations it is known that the introduction of free radicals into a combustible mixture would make it more sensitive to detonation by reducing its induction time. One of the interesting features of hydrocarbon oxidation is the existence of a temperature range that leads to a two-stage ignition mechanism. The first stage follows a low temperature dissociation reaction that leads to formation of free peroxide radicals and onset of a chemiluminescent phenomenon referred to as cool flame. The second stage is controlled by the high temperature dissociation of hydroperoxides. нннн In the present study, an attempt it is made to measure the run up distance for deflagration to detonation transition (DDT) in a pentane-oxygen mixture when it is spark ignited while undergoing cool flame oxidation. Particular attention was given to determine the conditions for the onset of cool flame to be able to predict the instant of appearance of the chemiluminescence. The pentane-oxygen mixture was spark ignited at different moments before and after the onset of cool flame and run up distances to detonation were compared. The results show a decrease in run up distance when the mixture is spark ignited prior to the onset of cool flame.