Effects of pulse injection on the flow field structure and combustion performance in a kerosene-fueled supersonic combustor

This paper describes the pulse injection of kerosene fuel in a kerosene-fueled supersonic combustor at a Mach number of 3. A high-flow mechanical pulsed injector was utilized to inject kerosene at frequencies ranging from 40 to 212 Hz in experiments. High-speed Schlieren images and wall pressure were employed to analyze the influences of various injection frequencies on the wave family and kerosene combustion performance. Initially, the pulsed injection causes intermittent changes in the wave family after kerosene ignition, leading to combustion instability. However, an optimal injection frequency of 143 Hz stabilizes the wave family. Additionally, pulsed injection reduces the kerosene ignition delay time, with the most notable reduction occurring at 113 Hz. Finally, the average combustion intensity of kerosene with pulse injection is lower than that of steady injection. However, the instantaneous combustion intensity at 143 Hz is similar to steady injection, which constitutes a significant portion of the overall combustion process. In summary, pulse injection of kerosene at 143 Hz could achieve efficient and stable combustion at a Mach number of 3.