The thesis is part of a research project carried out by AvioAero Ge in collaboration with academic research groups and Morfo Design Srl, with the purpose of improving the investigation of Low-Pressure Turbine (LPT) cascades performances through high fidelity CFD simulation. In particular, the aim of this work is to highlight the power of Large Eddy Simulation (LES) of a complex environment such as a LPT cascade with unsteady incoming wakes by introducing and developing new techniques of postprocessing that can be placed within the framework of a preliminary design. The main topic regards the developing of a Python tool to compute the Proper Orthogonal Decomposition (POD) on unsteady LES data able to evaluate unsteady losses due to larger and smaller flow structures carried by the wakes in different parts of the cascade.