Thrust Chamber Dynamics and Propulsive Performance of Multitube Pulse Detonation Engines

Our earlier work on single-tube airbreathing pulse detonation engines (PDEs) is extended to explore the chamber dynamics and propulsive performance of multitube PDEs with repetitive operations. Detailed flow evolution in the entire chamber for two different configurations is examined over a broad range of operating parameters, and loss mechanisms are quantified. Emphasis is placed on the interactions between detonation tubes and their collective influence on the nozzle flowfield. The benefits of precompression of refilled fresh reactants by shock waves originating from other tubes are demonstrated. Compared with single-tube designs, multitube PDEs improve propulsive performance, reduce axial-flow oscillation, and offer a wider operation range in terms of valve timing. They can, however, cause thrust variation in the transverse direction. The convergent part of the nozzle helps preserve the chamber pressure and consequently improve the engine performance. The free volume between the detonation tubes and the common nozzle might render in performance degradation because of the existence of complicated shock structures and recirculating flows.