Optimization of a multiple pulse detonation engine-crossover system

•A four PDE-crossover array is operated continuously, in a sequential pattern.•Combustion is initiated by a shock wave transferred from the previous PDE.•Increasing skin temperature decreases deflagration-to-detonation run-up length.•Increasing frequency decreases deflagration-to-detonation run-up length. A University of Cincinnati experimental study is conducted on a Pulse Detonation Engine (PDE)-Crossover System to investigate the feasibility of repeated, shock-initiated combustion as a means to generate detonation within an annular array of detonation tubes. An optimization study of the system finds that reducing driver PDE length increases auto-ignition failures in the driver PDE due to undesirable feedback of hot products from the driven PDE. Initiation performance in the driven PDE is strongly dependent on initial driven PDE skin temperature in the shock wave reflection region. The optimum initiation performance is achieved within the driven PDE by filling the driver PDE with reactants past the crossover tube entrance. Increasing operating frequency negates the detrimental effect of increased nitrogen dilution. An array of detonation tubes connected with crossover tubes is developed using optimized parameters. Successful operation utilizing shock-initiated combustion through shock wave reflection is achieved and sustained. Results from this array show that if initially driven PDE tubes are operating successfully, all subsequently driven PDE tubes also operate successfully.