Thermo-Structural Design of an Air-Cooled Rotating Detonation Combustor for Gas Turbine Integration

Abstract

Abstract. Rotating detonation combustion (RDC) is a promising technology with the potential to significantly enhance thermodynamic efficiency and reduce the footprint of propulsion and power generation systems. However, the inherent fluctuations in flow properties, caused by the motion of the detonation wave, result in strong, unsteady behavior. This dynamic characteristic, combined with the extreme power density of RDCs, leads to a compact combustor size but presents considerable challenges for effective thermal management. The objective of this study is to provide a thorough design methodology for an air-cooled RDC that can be integrated into the Rolls-Royce M250-C40B gas turbine engine. To avoid the unexplored effects of film cooling on detonation physics and combustor operability, a pressure vessel-liner convection cooling architecture was selected. Additionally, a transition duct was integrated to introduce dilution airflow and ensure adequate turbine inlet conditions. A one-dimensional thermal model based on Bartz's Nusselt number correlation was developed to facilitate the rapid evaluation of different materials, temperature profiles, and geometric parameters as well as to estimate the heat fluxes on the combustor walls. The results of the 1D analysis were subsequently used to define boundary conditions for the design and computational assessment of the transition duct, which was carried out using Reynolds-averaged Navier–Stokes simulations. The numerical predictions were compared with the turbine inlet conditions of the M250-C40B engine. Following this, transient thermo-structural finite element analyses were conducted for both the combustor and transition duct components to determine the most suitable materials and cooling designs.