Interactions of row blades of a marine compressor based on POD analysis

Abstract

The complex internal flow of the marine low-pressure compressor (LPC) is characterized by a series of unsteady flow structures, presenting extensive temporal and spatial features that pose challenges to direct data analysis. This paper employs the Unsteady Reynolds-averaged Navier Stokes (URANS) method to simulate a marine 1.5-stage LPC with full-channel configuration. Validation of the compressor’s overall characteristics and the unsteady pressure is achieved through comparison with experimental data. Additionally, the Proper Orthogonal Decomposition (POD) method is applied to decompose the velocity and pressure fields in various computational regions. The results demonstrate that the combined use of URANS and POD facilitates detailed insights into blade interactions. The consistency between time-averaged variables and POD modes underscores the practical physical significance of the POD modes. Furthermore, the study reveals that the Rotor-Stator interaction significantly outweighs the Inlet Guide Vane (IGV)-Rotor interaction. The coherent modal pairs generated by different interferences exhibit diverse characteristics within the computational domain, with distinct frequencies observed for the same interference reaction in the upstream and downstream regions. Notably, the POD modes of the rotor pressure field unveil a separation bubble structure.