Abstract: A device and method for improving the performance of a pulse detonation engine. The device includes at least one of an exhaust structure and an ejector. The exhaust structure can be configured as a straight, converging or diverging nozzle device, and connected to the engine to control the flow of a primary fluid produced during a detonation reaction. The ejector is fluidly coupled to the engine, using the movement of the primary fluid to promote entrainment of a secondary fluid that can be mixed with the primary fluid. The secondary fluid can be used to increase the mass flow of the primary fluid to increase thrust, as well as be used to cool engine components. Device positioning, sizing, shaping and integration with other engine operating parameters, such as fill fraction, choice of fuel and equivalence ratio, can be used to improve engine performance. In addition to thrust augmentation and enhanced cooling, the disclosed device can be used for engine noise reduction.