Micro-jetting Dynamics in Channel Detonations of High-Activation Energy Mixtures

Highly resolved numerical simulations of irregular detonations are performed for a total of five high activation energy mixtures involving methane/acetylene/hydrogen/oxygen/nitrogen. A single detonation cell cycle is then isolated and observed for each of these mixtures in an attempt to delineate the gas-dynamic and chemical-kinetic effects on micro-jetting, ignition, and their respective contributions to the origins of detonation irregularity. Based on the recent micro-jetting theory centered around the hydrodynamic origins of the cell, the origins of jetting skewness are investigated. The skewness is shown to have a direct link with the ignition dynamics, and consequently the activation energy of the mixture, thereby establishing the direct influence of chemical kinetics on cellular irregularity.