High-fidelity digital twins of in-service high-pressure turbine blades

During their service life, film-cooled high-pressure turbine (HPT) blades of modern aero engines experience structural deformations that affect their geometry, including both the external shape and the internal cooling cavity and channels. The accuracy of residual performance assessments through computational fluid dynamics (CFD) simulations of end-of-service blades is limited by traditional scanning techniques, which are usually capable of capturing the outer geometry and not the internal one, requiring approximations such as source terms for the modelling of film cooling. This study presents a novel methodology for reconstructing the internal geometry of end-of-service blades by applying Free Form Deformation (FFD) techniques to the design-intent internal geometry. To enable high-fidelity CFD simulations, including conjugate heat transfer analyses, the deformed internal structure is integrated with the 3D-scanned external surface of the blade, enhancing the accuracy of the geometry representation. The results demonstrate that FFD-based morphing enables the creation of fully-featured digital twins of end-of-service blades.