Dynamics Of Ignition Observed Through High Speed Imaging Inside A Shock Tube

Understanding the experimental data from shock tubes can be complicated when non-idealities such as bifurcations are present. This paper examines the affects of CO2 dilution in methane mixtures using high speed imaging along with traditional methods to measure ignition delay times. Experiments were performed for temperatures between 1600 to 2000 K near 1 atm. The resuls show that the global reactivity is captured well by the chemical kinetic mechanisms through the accurate modeling of the ignition delay times. The imaging shows that the ignition process is no longer homogeneous as a result of the CO2 dilution. This work shows that there is coupled fluid and chemical effects that are occurring during the experiments