Influence mechanism of axial spacing on rotor blade flutter characteristics

The mechanism of the upstream blade row affecting the flutter characteristics of the rotor blade is studied,using the self-developed unsteady fluid-solid coupling numerical simulation program. The influence coefficient method is used to analyze the effect of axial spacing on the aeroelastic stability of rotor. The results show that the neighboring blade vibration, which adjacent to the certain blade's suction side, determines the value of rotor aerodynamic damping in the tuned cascade, and its effect is even larger than the certain blade vibration itself; in the multi-row environment, inlet guide vanes(IGV) mainly affects the minimum aerodynamic damping of rotor blade, and IGV increases the nodal diameter value of the most unstable point of aeroelasticity; the channel change caused by blade vibration restrains the reflection of IGV on unsteady pressure wave; with the decrease of axial spacing, the range of unsteady influence of blade vibration is obviously increased, since the effect of IGV on the unsteady pressure wave attenuates the circumferential attenuation of unsteady pressure wave; the influence coefficient method needs to measure more blades to obtain more accurate aerodynamic damping in the multi-row environment.