Detonation Wave Collision Study During Rotating Detonation Rocket Engine Counter-Propagating Modes

The rotating detonation rocket engine (RDRE) is a pressure gain combustion device that exhibits multiple modes of operation. RDRE operational modes are characterized by their number and transient behavior of the detonations that continuously travel around the RDRE chamber annulus. The counter-propagating mode is where detonations travel in both directions of the RDRE chamber, and leads to detonations colliding and interacting with one another. In this study, large eddy simulation (LES) results are analyzed during a detonation wave collision event to investigate its local dynamics in a gaseous methane-oxygen RDRE counter-propagating mode. The corresponding wave collision event is where the relative strengths and speeds between each colliding wave are similar. The results of this research show that a substantial increase in pressure, heat release, and temperature ensue at the point of collision, followed by a recovery phase of the detonation waves and nearby injectors. Additionally, the collision produces a significant increase in coupled pressure and heat release (p'q') that is four times greater than each individual wave prior to colliding, and nearly three times that of a steady, co-rotating detonation wave. Understanding local wave dynamics in the complex flow-field of an RDRE is an important step to understanding steady-state and transient modal transitions during RDRE counter-propagating modes.