Session: 32-03 CFD Studies

Paper Number: 152944

Aero-Thermal-Structural Optimization of a High-Pressure Turbine Rotor With Robustness Evaluation to In-Service Deterioration 

This paper presents a multi-disciplinary optimization study conducted on the high-pressure turbine rotor of a commercial turbofan engine. For this purpose, the system’s response is studied under the aerodynamic, thermal and structural aspects via high-fidelity numerical simulations. The rotor geometry is parametrized using a total of twelve design parameters, expressing four types of geometric deformations at three constant-span sections along the blade height. 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 conducted by constraining the values of capacity and reaction within a range of respectively ±0.1% and ±0.2% of the datum ones. Among the set of non-dominated points, two designs are selected, respectively achieving a peak stress reduction of 2.6% and peak temperature reduction of 2.1% from the baseline values. For robustness evaluation purposes, the simulations of these optima are repeated after a certain degree of in-service damage is applied. The damage is intended to replicate the deterioration patterns observed on in-serviced blades after different numbers of operational cycles. The aerothermal performance of the optima is confirmed at a higher fidelity by conducting unsteady simulations.

Presenting Author: Mario Carta University of Cagliari

Presenting Author Biography: Postdoctoral research fellow in mechanical and aerospace engineering from the university of Cagliari, Italy.
Working as a research associate for Rolls-Royce plc in the "design engineering - fluid mechanics" team on turbines aerothermal design and optimization

Authors:

Mario Carta University of Cagliari
Roberto Putzu University of Cagliari
Tiziano Ghisu University of Cagliari
Shahrokh Shahpar Rolls-Royce plc