Unsteady Methods Applied to a Transonic Aeronautical Gas Turbine Stage

The importance of considering the unsteady effects in aeronautical engine design has brought to the implementation of simplified unsteady CFD models to respect the temporal restrictions of design cycles. A comparison among steady, Non-Linear Harmonic (NLH) and Full-Annulus (FA) methods has been carried out analyzing the transonic turbine stage CT3, experimentally studied at von Karman Institute for Fluid Dynamics. The understanding of the unsteady phenomena is fundamental to increase the engine efficiency and is precluded in steady calculations. As the computational cost of NLH calculations is of the same order of magnitude of steady ones, it represents a valid and competitive option in a turbine design process.