Pre-Design and Analysis of a Military Hybrid High-Pressure Turbine

Abstract

Increasing aero-engine turbine inlet temperatures and stagnating operational limits of nickel-based superalloys create the need for new material and cooling technologies. Ceramic matrix composites (CMCs) can operate at higher temperatures but restrict the geometrical freedom and thus complexity of the component. Additive manufacturing (AM) facilitates intricate cooling designs but compromises high-temperature mechanical performance. To understand their potential benefit, we investigate a high-pressure turbine concept with different material technologies per turbine row using the DLR pre-design toolkit from engine to airfoil level. Multiple configurations are analysed and promising ones are identified. CMC vanes can lead to benefits in terms of coolant requirements, turbine efficiency, thrust-specific fuel consumption and aircraft maximum take-off mass, whereas AM blades lead to the opposite trend. The pre-design process is discussed and special attention is given to military specific design challenges such as multi-point performance.