CFD strategy for the aerodynamic and aeromechanic design and verification of axial compressor for gas turbine engines

This thesis proposes a CFD strategy for the aerodynamic and aeromechanic design and verification of axial compressor for gas turbine engines characterized by a combined use of steady and unsteady numerical simulations in order to significantly increase the design accuracy keeping industrial design time requirements.In particular, the stall margin prediction and the forced response assessment are the key aspects of this procedure. An unsteady analysis of the whole compressor is capable of predicting a stall margin comparable to the measured one and, at the same time, of evaluating the complete blade forcing spectrum on each row from the unsteady solution. The spatial decomposition theory introduced in this thesis applied to the overall unsteady aerodynamic forcing allows to separate the contributions of the different nodal diameters. The proposed improved use of the Interference Diagram is able to detect additional possible resonances in the operating range of turbomachines trying to avoid many unexpected vibrations during compressor validation tests.