Experimental Analysis of Operating Frequency Enhancement and Pressure Characteristics in a Pulsed Detonation Combustor

Abstract This research explores the improvement of operating frequency and pressure characteristics in a Pulsed Detonation Combustor (PDC) through aerodynamic tuning achieved by geometric adjustments. PDC technology is a promising approach for high-efficiency propulsion and energy systems, leveraging pressure gain combustion to improve performance. The study presents a detailed experimental analysis of a hydrogen-fueled PDC prototype, focusing on the effects of modifying the Hartmann-Sprenger resonator length and exhaust pipe length. High-speed pressure sensors are employed to record the detonation cycle characteristics, enabling an assessment of cycle frequency and pressure metrics. The results demonstrate that cycle frequencies can be increased up to 300 Hz for Hydrogen/Air and 400 Hz for Hydrogen/Oxygen mixtures, surpassing the spark plug ignition frequency of 100 Hz. Notably, a previously unreported phenomenon is observed in the pressure profiles at high operating frequencies, which can be interpreted as an aerodynamic Shchelkin spiral. This pattern suggests a self-sustaining mechanism influencing vortex dynamics and detonation wave propagation, offering new insights into pressure oscillations in high-frequency pulsed detonation systems. These findings highlight the significance of geometric optimization in achieving higher operating frequencies without additional active control systems. Different resonatorexhaust pipe length combinations enhance various performance metrics, contributing to the advancement of pressure gain combustion technology and informing future aerospace propulsion designs.