Experimental Study of Asymmetric Propagation Behavior in Reflective Shuttling Detonation Cycle: Structural Variations Induced by Propagation Direction

The reflective shuttling detonation combustor (RSDC) is a combustor in which a detonation wave propagates back and forth between two reflection walls of a thin combustion chamber. The two-dimensional and no curvature chamber allows for simultaneous pressure measurement and optical visualization. In this study, pressure measurements as well as self-luminescence visualization were performed using a chamber with a reflection wall distance of 90 mm, with ethylene and oxygen. As a result, a single detonation wave was observed to propagate back and forth. Frequency analysis showed that the propagation velocity increased with increasing mass flow rate. Differences in propagation structure depending on the direction of propagation were observed. Using visualization images and high-frequency pressure sensors, the propagation velocities in each direction were calculated. Consequently, it was found that in some cases, the propagation velocity varied depending on the direction. Additionally, an investigation of the relationship between luminance and propagation velocity in each direction revealed that when the luminance varies depending on the propagation direction, the propagation velocity also changes.