Numerical investigation of the rotating detonation engine with cat-ear-shaped film cooling holes under varying operating modes

Abstract

The advancement of implementing the rotating detonation engine (RDE) in practical applications necessitates overcoming the challenges arising from severe heating and high-frequency thermal loads caused by the rotating detonation wave (RDW). As an important means of thermal protection, film cooling is widely used in modern gas turbines. In this numerical study, film cooling holes with a cat-ear-shaped configuration are arranged on the outer wall of the RDE, which operates in various modes with a different number of RDWs. It is shown that as the number of RDWs increases in the flow field, the intensity of each RDW gradually decreases but the interactions between the cooling air (secondary flow) and the RDWs become more frequent. These phenomena can lead to noticeable differences in the characteristics of the secondary flow and the corresponding film cooling performance across different operating modes. Specifically, the analysis reveals the influence of the number of RDWs on the development and oscillation of the secondary flow jet. A comprehensive assessment of the effectiveness of the cat-ear-shaped and cylindrical film holes is also conducted in terms of the film cooling efficiency, i.e., the overall efficiency and the variation of the cooling efficiency along the axial direction, the coverage of cooling air on the wall surface, and the fluctuation of the secondary flow under the periodic influence of the high-pressure RDW.