부산대학교 도서관

An annulus is a configuration characterizing the cross section of a rotating detonation engine (RDE), and the dimensionless radius is a unique geometric feature of the annulus. The present study examines the effects of the dimensionless radius of the annulus on the detonation wave propagation characteristics in an RDE. The concept of a helical computational domain is introduced for a two-dimensional analogy of the annular cross section of the RDE, and the moving window technique is used to accelerate computation. The results suggest the existence of a critical dimensionless radius (Rcritical) condition, above which stable propagation is feasible. Unstable overdriven detonation is observed for values of the dimensionless radius below the critical value. Based on these investigations, the propagation characteristics of detonation waves in three non-circular cross sections are studied for RDE design flexibility. A track-shaped channel was studied in depth for the transitional phenomena between circular to linear and linear to circular sections. A rounded-square configuration and a star-shaped configuration were also examined, in which the simultaneously curved and linear effects exist and dictate the stability of detonation propagation. In the rounded-square channel, this instability is stabilized only at a high radius of curvature. In the star-shaped channel, the detonation propagates in the critical mode for most cases owing to the small local radius of curvature.