关键词: 高速轴流压气机, 转子叶片, 非同步气流激励, 锁频机理, 流固耦合

Abstract: Abstract: To reveal the frequency lock-in mechanism of non-synchronous aerodynamic excitation in high-speed axial compressor rotor blades, a one-way fluid-structure interaction numerical simulation method with forced blade motion was employed to investigate the tip non-synchronous aerodynamic excitation frequency and the evolution of the full-annulus unsteady flow fields under different amplitudes of the first rotor blades in a 1.5-stage compressor. The results indicate that a frequency lock-in phenomenon of non-synchronous aerodynamic excitation occurs under large amplitudes of 2%C and 3%C, with the intensity of non-synchronous aerodynamic excitation increasing with the blade amplitude. On one hand, the increase of blade amplitude reduces the aerodynamic damping of the rotor blades, posing a risk of aeroelastic instability for local blades under large amplitudes. On the other hand, the high-amplitude non-synchronous vibration can result in a decrease in compressor flow instability and intensify the tip flow separation，the induced radial separation vortices are identified as the primary cause of severe pressure fluctuations near the tip region. The flow stability of the compressor and the aeroelastic stability of the rotor blades form a mutually reinforcing relationship under near stall conditions. The findings provide critical insights for analyzing flow-induced vibration failures in multistage axial compressor blades.

Key words: high-speed axial compressor, rotor blade, non-synchronous aerodynamic excitation, frequency lock-in mechanism, fluid-structure interaction