Fully-featured digital twins of in-service high-pressure turbine blades for high-fidelity CFD analyses

The high-pressure turbine blades of modern jet engines are inevitably subject to deformation and deterioration during their service life due to the extreme conditions under which they operate. Their hollow design with multiple internal cavities allows for effective internal and external cooling strategies, helping the component to withstand the increasingly high temperatures produced by modern combustors. Knowledge of the geometric variations experienced by these blades during service is crucial for designers to estimate the residual service life and aerothermal performance of the component. This important task has recently been achieved by running numerical flow simulations on the scanned, digitalized versions of the geometries. For cost effectiveness, time savings, and practical reasons, the scanned geometries do not capture the complex internal channels of the component. This part of the geometry is vital to perform higher-fidelity assessments, such as conjugate heat transfer simulations, which model both internal and external flows. This study proposes the first automatic methodology for reconstructing the internal geometry of a turbine blade scan by linking it to the external deformation field, paving the way for systematic generation of fully-featured digital twins of scanned in-service blade geometries. The internal deformation and reconstruction methodology is first presented in detail, then validated on a simplified test-case, and finally applied to a real high-pressure turbine blade scan from a modern jet engine. The resulting reconstructed geometry is used to assess the residual aerothermal performance of the scanned blade.