Investigation on Design and Detonation Combustion Characteristics of Liquid-Fuel Initiator for Rotating Detonation Engine

To solve difficulties of ignition and compact structure in liquid-fuel rotating detonation engine, an initiator with liquid aviation kerosene as fuel was designed. It includes centrifugal/pre-film composite fuel atomizing injector, ignition/transmission flame concave cavity and three-branches pipe initiator chamber. The atomization characteristic of the centrifugal/pre-film composite fuel atomizing injector and detonation combustion characteristic of the initiator were experimentally studied with liquid aviation kerosene and pure oxygen. The change rules of atomized particle sizes behind the centrifugal/pre-film composite fuel atomizing injector were obtained. The detonation combustion characteristics such as pressure and flame propagation speed in the initiator were gained. The results show that, the atomization effect improves with increases in fuel pressures and airflow rate. Near the exit of the initiator (location of PCB5), the peak pressure of the detonation waves exceeds 3.80MPa and the maximum velocity reaches 1800m/s. With the increase of equivalence ratio, the positions of the overdriven detonation waves in the initiator are advanced, which are beneficial to shorten the length of the initiator. The research results provide ideas for the design of the initiator using liquid fuel. © 2019, Editorial Department of Journal of Propulsion Technology. All right reserved.