Aeromechanical Assessment of an Optical Probe Installed in a Two-Stage High-Pressure Gas Turbine

Abstract In recent years, the increasing demand for sustainable energy production has led to the adoption of innovative fuels in Gas Turbine (GT) plants. Among these sustainable fuels, hydrogen is regarded as one of the most promising options. GT combustors have played and continue to play a crucial role in research endeavors aimed at accommodating various fuels while minimizing alterations to turbine design. Consequently, changes in combustor shape and design philosophy necessitate a thorough investigation of High-Pressure Turbine (HPT) operating conditions. In this regard, rigorous experimental procedures and probes must be developed for a detailed flow field characterization. This paper numerically investigates the aeromechanical impact of an intrusive cylindrical probe installed near the Leading Edge (LE) of the second vane row of a commercial HPT module. The investigations are focused on the unsteady forcing acting on the probe to avoid possible resonance issues, as well as on the influence of the probe itself on the stage flow field, as the probe diameter is comparable to the LE radius of the blades. Computational Fluid Dynamics (CFD) has proven to be a powerful and reliable tool for turbomachinery applications over the years. Specifically, the Unstedy Reynolds Averaged Navier Stokes (URANS) approach has demonstrated its ability to accurately predict the forces acting on turbine blade rows. Therefore, both steady-state and unsteady CFD methods are employed in this work to analyze the flow field modification related to the inclusion probe and finally the mechanical response of the probe is investigated using a Finite Element Model (FEM).