Development of a Small Scale Rotating Detonation Engine
Joseph R. Dechert, Marc D. Polanka, Frederick R. Schauer, Stephen A. Schumaker, Brian Sell, Matthew Fotia
Abstract
The Rotating Detonation Engine (RDE) has been researched extensively in recent years, but the minimum size limits of an RDE have not been well investigated. The goal of this research was to build an RDE small enough to produce a detonation frequency above 20 kHz with a single detonation wave while also reducing the engine’s mass flow rate. This research objective resulted in the design of an RDE with an outer diameter sized at 25-30 mm using ethylene and nitrous oxide as a fuel and oxidizer. The engine was tested over a range of equivalence ratios between 0.5-1.5 and mass flow rates between 0.025-0.075 kg/s to characterize its operation. Key design parameters were the injection hole diameter, detonation channel gap, detonation channel length, and detonation channel diameter. These parameters effected the rate at which the reactants could be refreshed in the detonation channel as well as the detonation’s stability. High speed imaging in conjunction with a microphone were used to monitor engine operation. Current testing efforts have been unable to produce a detonation, but an axial acoustic mode was observed. The ignition scheme was suspected to be the primary reason for unsuccessful operation.