Wave Interactions in a Multi-tube Pulsed Detonation Combustor-Turbine Hybrid System

A large-scale, multi-tube pulsed detonation combustor (PDC) with eight tubes arranged in a can-annular configuration was integrated with a single-stage axial turbine nominally rated for 10 lbm/s, 25000 RPM and 1000 hp. This PDC-turbine system was operated using ethylene-air mixtures with each tube firing at 20 Hz. High frequency pressure transducers were installed throughout the flow path to investigate the wave interactions at a range of conditions with three firing patterns: a single tube firing, all tubes firing simultaneously and all tubes firing sequentially. Analysis of these data revealed that wave interactions in the transition plenum between the PDC exit and turbine inlet plane can affect the optimum operation of the multi-tube PDC.