Experimental study on deflagration-to-detonation transition enhancement methods in a PDE

An experimental investigation was carried out to study the performance of a pulse detonation engine platform incorporating commercial, off-the-shelf solenoid valve gas injectors and non-conventional deflagration-to-detonation transition enhancing devices. The study made use of stoichiometric propane-oxygen mixtures with low-energy ignition sources. The gas injectors were observed to be sufficiently robust and operated reliably under the high working temperature and pressure conditions normally associated with pulsed detonation operations provided appropriate preventive measures were taken. One of the major motivations in utilizing these gas injectors lies in the ease and accuracy in controlling their injection operations electronically, which allows for tight integration with auxiliary electronic control and measurement systems. This paper reports on the initial success of integrating these gas injectors into a moderate-frequency pulsed detonation engine system as well as the effectiveness of the deflagration-to-detonation transition enhancing devices which included Shchelkin spiral, circumferential and helical grooves, as well as convergent-divergent throats. Lastly, operational insights in the practical use of gas injectors and the impact on pulse detonation operations are highlighted.