Design and testing of a small-scale laboratory rotating detonation engine running on ethylene-oxygen

A modular laboratory rotating detonation engine (RDE) for combined mass flowrates below 10 g/s has been designed. Since a large chamber diameter to width ratio is used, first tests with stoichiometric ethylene-oxygen mixtures have revealed detonation modes with one, two and three separate detonation heads, depending on mass flow rate. Spectrograms from high-frequency pressure data and high-speed photography are used to confirm successful operation and identify the number of separate detonation fronts reliably. Measurements show that thrust increases by more than a factor 2 can be achieved by placing a constrictor nozzle at the exit of the cylindrical RDE outlet and adding an aerospike nozzle to the overall engine design