Asymptotic and Transient Dynamics of Rotating Detonation Engines

Rotating detonation engines (RDEs) promise a thermodynamic efficiency far exceeding those of conventional deflagration engines. Nevertheless, several knowledge gaps must be surmounted before these gains can be realized. This is most clearly seen in our current inability to predict steady behavior from the operating conditions (mass flow rate, equivalence ratio, etc.) and initial conditions (ignition procedure). The goal of this work, therefore, is to study how both the long-time (asymptotic) and short-time (transient) dynamics of rotating detonations engines depend on initial and operating conditions. To balance the richness and cheapness of data required to understand such phenomena, the proposed work will study the dynamics of a simplified, 2D “unwrapped” computational RDE model. This will be accomplished using a) numerical continuation and bifurcation analysis of asymptotic solutions and b) transient CFD. Together, these tools provide complementary information needed to realize the research goals. Preliminary work has used both tools to study both 1- and 2-dimensional simplified RDE models and has provided striking results in relation to these goals. Future work will build upon these results by assessing their generality as well as seeking and studying various other steady behaviors and the unsteady mechanisms that produce them.