Experimental study on detonation characteristics of liquid kerosene/air rotating detonation engine

Abstract

Thermal experiments were conducted to investigate the characteristics of rotating detonation waves in a Liquid Kerosene/Air Rotating Detonation Engine featuring gas-liquid two-phase non-premixed injection. The annular combustion chamber for the rotating detonation had inner and outer diameters of 206 mm and 144 mm, respectively. To mitigate pressure back-propagation of detonation waves, a 3 mm high annular gap structure was employed. The fuel injection system utilized an integrated structure for fuel atomization and mixing, which was designed by our research group based on high-speed shear flow and fuel injection principles. The experiment successfully initiated and sustained a single-wave mode rotating detonation wave with tangentially arranged kerosene/air pre-detonators. The frequency of detonation wave propagation ranged from 2.4 kHz to 2.5 kHz, with a detonation wave velocity of up to 1600 m/s. The initiation delay time of the detonation wave varied between 1600 ms and 400 ms. Within the experimental conditions, as the equivalence ratio increased, the detonation wave velocity increased while the stable establishment time of the detonation wave decreased. However, the overall stability of the detonation wave exhibited a decreasing trend. Additionally, a long-term test of the kerosene/air rotating detonation engine was conducted for 4 s, confirming the engine's ability to operate continuously over an extended period. The frequency of the rotating detonation wave obtained during the long-term test differed by only 0.2 % from the results of the short-term experiments, validating the accuracy and universality of the conclusions drawn from the short-term experiments.