Effects of asymmetric vane spacing on rotor blade vibration

The effects of asymmetric vane spacing on the aerodynamic force on the surface and the dynamic response level of the downstream rotor blade were analyzed using the fluid-structure interaction method in the time-domain. Two different types of asymmetric vane spacing, variation of the flow angle and variation of the vane spacing were studied. The results show that the vibration of the rotor blade is forced response under the wake excitation from upstream. The single-frequency of high amplitude of blade vibration is changed to the multi-frequency of low amplitude due to the upstream asymmetric vane spacing. The reduction of the dynamic response level under variation of the vane spacing is more advantageous, and the effect is optimal when vane spacing variation of two segments is between 4%~5%. In this model, case 4 is optimal because of the reduction of 28% on the amplitude of the vane passing frequency.