Performance of Multiple Stream Pulsed Jet Combustion Systems

In the course of our studies on pulsed jet combustion (PJC) a series of tests were carried out to determine the performance of multi-stream systems. This included multi-jet efflux, as well as dual-generator aggregates. The essential performance indicator of a PJC system is the pressure transducer record, yielding, in particular, data on the rise time and amplitude of the pressure pulse, as well as the rate of pressure rise. Concomitantly with pressure measurements, a sequence of schlieren records were obtained to reveal the salient features of the fluid mechanical phenomena of the PJC process. Elucidated thereby are the effects of entrainment induced by large scale vortex structures of turbulent jet plumes, and their decisive role in governing the process of combustion, as influenced by their particular configuration. Our tests demonstrated the capability of multiple stream PJC systems to shorten the rise time and increase the amplitude of the pressure pulse, both effects of obvious potential benefit to engine performance.