Aerothermal–Structural Optimization of a High-Pressure Turbine Rotor With Robustness Evaluation to in-Service Deterioration

Abstract This article presents a multidisciplinary optimization conducted on the high-pressure turbine rotor of a commercial turbofan engine. The rotor geometry is parametrized using a compact orthogonal design space, and the system's response is studied under the aerodynamic, thermal, and structural aspects via high-fidelity numerical simulations. The analysis is conducted using proprietary Rolls-Royce flow and structural solvers. The objective functions considered for the aerodynamic, thermal, and structural disciplines are, respectively, high-pressure stage isentropic efficiency, peak near-wall gas temperature, and peak von Mises stress on the rotor. The optimization is constrained by rotor capacity and high-pressure stage reaction degree. On the final three-dimensional Pareto front, two designs are selected, achieving a peak stress reduction of 17.5 MPa and a peak temperature reduction of 27.5 K, respectively. The sensitivity of these optimal designs to in-service degradation is then evaluated by applying various degrees of deterioration to the nominal designs. This deterioration is intended to replicate the erosion and deformation patterns observed on in-service blades after different numbers of operational cycles. The aerothermal performance of the optima is verified at a higher fidelity by conducting unsteady simulations.