Experimental study of kerosene/air valveless air-breathing pulse detonation engines

Detonation initiation of liquid hydrocarbon-air mixtures is critical to the development of the pulsed detonation engine (PDE). This paper focused on investigating the ignition and detonation-initiation performance of kerosene/air based on valveless air-breathing pulse detonation engines (PDEs) with inner diameters of 50mm and 120mm. Because of the poor detonability of kerosene/air mixture, a variety of devices and means were used to promote the detonation initiation. A flash vaporization system was designed and used to heat the kerosene and observed the effect of fuel temperature on ignition-detonation performance of PDE. And the centrifugal nozzle and twin-fluid air-assist atomizer were used to investigate the fuel droplet size effect on detonation-initiation performance. The results indicated that increasing ignition energy and fuel temperature was helpful for quick ignition and flame acceleration although detonation didn't occur when the centrifugal nozzle was used. When air-assisted atomizer was used, detonation was initiated successfully no matter the fuel was heated or not. However, the ignition-detonation times of kerosene/air in air-breathing PDE at several operation frequencies were longer than that of gasoline/air respectively. As the operation frequency increased, the difference between the ignition-detonation times of kerosene/air and gasoline/air decreased. When the PDE inner diameter increased to 120mm, detonation occurred much more difficultly. Detonation was not initiated until the ignition energy increased to 4J and the mixing of kerosene and air was enhanced ulteriorly. And each of the ignition-detonation time at different operation frequency increased as the PDE inner diameter increased.