An extraction of the dominant rotor-stator interaction modes by the use of Proper Orthogonal Decomposition (POD)

Abstract

The Proper Orthogonal Decomposition method is applied to the instantaneous velocity field within the rotor-stator inter-row region of a high-speed high-pressure centrifugal compressor. The processed data come from experiments and numerical simulations. In comparison with a Fourier transform, the POD gives the best modal approximation for both initial fields, in terms of the energy expressed on any given number of modes to be taken into account: to reach 98% of the total energy of the velocity field, the required number of POD modes is up to nine times lower than the number of Fourier harmonics. The individual POD modes are given and show that the unsteady rotor-stator interaction is already present in the very first modes.