Development of a Small Scale Rotating Detonation Engine

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 engines mass flow rate. An engine with these design characteristics would reduce hazards associated with previous RDE testing. This research objective resulted in the design of an RDE with an outer diameter sized at 28 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 at mass flow rates of 0.025-0.075 kgs to characterize its operation. Key design parameters were the injection hole diameter, detonation channel gap, detonation channel length, and detonation channel diameter. Detonation was achieved in an RDE of this scale, which proved operability of an engine with these design characteristics was possible.