Rotating detonation combustor with regional full-coverage film cooling and variable-shaped hole arrangements

In this study, we conduct a numerical investigation of an annular rotating detonation combustor (RDC) with regional full-coverage film cooling designed for thermal protection. The effects of three different film cooling hole configurations—sequential, interlaced, and front-region circumferential coverage—are examined. We focus on the propagation behavior of the rotating detonation wave (RDW) through the film-cooled regions and evaluate the impact of film cooling jets on detonation wave stability and the overall flow field structure. The results indicate that the RDW can propagate stably across all configurations, though the interaction with film holes generates reflected waves, which propagate and couple with the oblique shock wave (OSW), increasing the OSW pressure and influencing the RDW's propagation velocity and pressure. Sequential and interlaced hole arrangements both demonstrate effective thermal protection: sequential configurations offer superior cooling upstream, while interlaced arrangements enhance cooling downstream. Furthermore, the numerical observations of cooling jet patterns are compared to experimental results from an RDC with full-coverage film cooling using the same interlaced, shaped film holes, and the results demonstrate good consistency. The numerical results demonstrate that film cooling effectiveness improves with increasing injection pressure, as this raises the outflow rate through the film holes and reduces reverse flow in regions affected by the RDW. Additionally, the introduction of a circumferential ring arrangement of film cooling holes at the detonation front forms distinct multi-layered cooling films, offering effective thermal protection to the outer wall of the RDC.