Abstract: The gasoline/oxygen-enriched air is used as working medium in ring-array rotating detonation engine (RDE) to study the effect of the central cone position on working process and performance of liquid-fueled RDE. The liquid-fueled RDE was studied through experiment. The one-dimensional thrusts of rotating detonation engine at different positions of central cone and its angles were measured，and the variation tendencies of thrust and fuel specific impulse were analyzed. The experimental results show that the position and angle of central cone have little effect on the propagation mode of rotating detonation wave, and the rotating detonation waves are always in double-wave collision modes. Since the double-wave collision point is affected by the tangential injection hole of the pre-detonator, it cannot be stabilized near the outlet of pre-detonator. The velocity and frequency of detonation wave decrease as the central cone moves forward. For l/L=0% where l is the distance from the equal straight segment end of internal wall surface to the end of external wall surface in combustion chamber, L is the length of external wall surface of combustion chamber and θ=20°, the thrust and fuel specific impulse are 951.6 N and 1 151.8 s, respectively, which are the maximum values under all experimental conditions. As the position l/L or angle θ central cone increases, the axial expansion distance of detonation products becomes shorter, the effect of expansion wave is enhanced at the sudden expansion position of central cone, the constraint effect of central cone surface in external flow field is weakened, and the radial expansion of high temperature gas is enhanced. The axial partial velocity of high temperature gas at outlet decreases gradually, and the thrust and fuel specific impulse decrease gradually. For l/L>25.5% or θ>40°, the lowering speeds of thrust and fuel specific impulse increase due to the re-initiation and expansion wave enhancement.

Key words: rotatingdetonationengine, liquid-fuel, centralcone, double-wavecollisionmode, thrust, specificimpulse