A vibration time-delay method of setting inter-blade phase angle by means of delayed blade vibration and a fluid-structure interaction flutter analysis model for multiple passage blade non-in-phase vibration were developed. The number of passages was twice the passages between adjacent nodal lines; and in the different passages of the cyclic sector

the modal displacement of each blade lagged behind that of the previous blade

and the efficient update of the flow field and blade grids was realized using the fast dynamic mesh algorithm based on pseudo elastic solid. Based on the multiple passage model of Rotor 37

the influences of different inter-blade phase angles on the aerodynamic stability of blades and the flow field characteristics of passages were studied. The results showed that the calculation result of the multiple passage method was basically consistent with the full annulus flutter analysis

and the calculation time of the multiple passage method was 1486% of the full annulus analysis at 18 nodal diameter. Nodal diameter pattern had a significant influence on the aerodynamic damping of blades

and flutter instability occurred at 2 nodal diameter. The inter-blade phase angle led to the changes of the shock wave location and strength and the unsteady pulsation and impact out of phase in the passage

contributing a lot to the flutter.