Analysis on Aerodynamic Stability of Blades by an Efficient Fluid–Structure Coupling Method

Abstract

Poor calculation efficiency is a major issue in the investigation of time-domain aerodynamics of turbomachinery bladings by fluid–structure coupling. In this work, a numerical methodology for 3D time-domain fluid–structure coupling analysis was carried out to investigate aerodynamic stability of blades. Based on an assumptive gross elastic structure, the computational fluid dynamics (CFD) mesh-deformation is generated effectively, while the structural response is calculated using a modal approach. Accuracy of the method is validated by the traditional two-way fluid–structure interaction (FSI) approach on ANSYS Workbench and the literature, while computational efficiency is improved notably. The flutter boundary of the compressor at rotating speeds ranging from 100% to 80% was performed. When the flow rate is low enough, the second-order modal response is more likely to run into surge than the first-order modal response. The aerodynamic characteristics of the blades on two interblade phase angles (IBPAs) were also studied. The results indicate a much more significant increase in aerodynamic stability at 180° IBPA than that at 0° IBPA.