Application of UQ for Turbine Blade CHT Computations

Abstract

A HPT blade is affected by different operational uncertainties in the process of actual engine work: probabilistic fluctuations of inlet parameters and difference in operational parameters for manufactured engines. The combination of these factors makes the task of uncertainty quantification and robust optimization of the HPT blade relevant. At the same time, working of the HPT blade at the real gas turbine engines shows strong influence of the operational uncertainties that appear from the differences in real engines characteristics (e.g., differences in HPC efficiency from the manufacture tolerances) on blade temperature distribution and aerodynamic efficiency. Deviations in operational parameters result in oscillations in temperature and pressure distributions at the inlet of the blade hot gas channel and in cooling air pressure under the blade. Aforementioned operational and geometrical uncertainties have an influence to the blade temperature distribution and aerodynamic efficiency. In spite of all uncertainties, the turbine blade should provide stable cooling effectiveness of the leading edge, blade tip, other regions, and high aerodynamic effectiveness. High-pressure turbine blade from industrial gas turbine engine is considered as the object of the investigation. HPT blade must provide necessary level of aerodynamic efficiency and necessary temperature distribution of the blade. Due to high temperatures in the hot gas path, the blade was designed with internal cooling air passages and film-cooling holes. UQ and RDO of the conjugate heat transfer (CHT) were carried out for a cooled turbine blade using surrogate models (Approx) and IOSO NM software. The CHT test case under consideration is the IC-05 test case, with operational uncertainties. The problem definition covers internal and external aerodynamics, blade heat conduction, and heat transfer, while the optimization parameters to be considered.