Numerical and experimental investigation on the operating characteristics of fan-shaped pulse detonation combustor

The internal flow channel of a turbine engine is typically annular. When circular pulse detonation combustors (PDCs) are installed in this channel, there is a problem with low section utilization rates. To solve this problem, a single-tube fan-shaped PDC test system was developed. The effects of ignition distance on the operating characteristics of the fan-shaped PDC using air and gasoline under different frequencies were studied through both experiment and 3-D numerical simulation. Numerical simulation was also used to investigate the formation and propagation characteristics of detonation waves. The results show that the fan-shaped PDC can operate stably at frequencies ranging from 5 to 25 Hz when the ignition distance is either 2.30 or 2.70 times the equivalent circle diameter from the thrust wall, and it is found to be better to ignite at a distance of 2.30 times the equivalent circle diameter. The blockage ratio of the lower arc surface is larger than that of the other surfaces. This results in more intense collision and reflection. A larger local high pressure area forms near the lower arc surface, which is conducive to the formation of detonation waves. However, the larger blockage ratio makes the flow loss larger, which weakens the intensity of the pressure waves near the lower arc surface. The detonation waves in the fan-shaped PDC travel closer to the upper arc surfaces.