Classification and Simulation of Anomalous Events in Turbulent Combustion

In practical combustion systems, the high nonlinearity of the turbulent combustion process can result in unexpected behavior even for nominal operating conditions. This includes flame flashback in premixed gas turbines, engine unstart in scramjets, and failure of engines to ignite at high altitudes. Many of these events have catastrophic consequences. Hence, understanding the nature of such irregular excursions of combustion systems is important to ensure robust operation. The focus of this work is to identify the sources of such rare excursions from a dynamical systems perspective. Specifically, such anomalous behavior can be explained in terms of three different classes based on the trajectories that the system traverses in its phase-space. For each class, computational algorithms and validation exercises are briefly discussed.