Characteristics analysis for turbine film cooling under rotating detonation combustion

Abstract

The integration of rotating detonation combustors into turbine engines has garnered significant attention due to their potential to enhance engine performance. However, the high-frequency pulsations of exhaust flow from rotating detonation combustors create significant challenges for turbine design. The lack of comprehensive analysis of turbine film cooling under rotating detonation inflow conditions has hindered advancements in the cooling strategies for turbine blades. This study aims to fill this gap by conducting numerical simulations to analyze the aerothermal loads and film cooling characteristics of turbine blades under rotating detonation inflow. The results revealed that detonation inflow induces highly uneven spatial and temporal pressure distribution, increasing both pulsation intensity and aerothermal loads on turbine blades. Under these conditions, conventional film cooling experiences periodic cooling air disruption and hot gas backflow, leading to low cooling efficiency. Specifically, during clockwise and counterclockwise detonation wave propagation, the minimum duration of cooling air outflow accounted for only 26 % and 22 % of the total period, with corresponding average cooling efficiencies of 0.53 and 0.46, respectively. To mitigate these limitations, a secondary pressurization strategy was proposed. By increasing the cooling air pressure by 43 %, the cooling performance improved significantly, achieving average cooling efficiencies of 0.77 and 0.79 for clockwise and counterclockwise propagation, respectively.