Abstract: A rotating body includes a rotating body core, and a plurality of blades provided at an outer or inner circumference of the rotating body core at equal intervals in a circumferential direction, and connected circumferentially via an annular connection portion provided separately from the rotating body core. A resonance frequency under a two nodal diameter number mode of the rotating body is lower than or equal to a rotational secondary harmonic frequency with respect to a rated rotation speed. Where Nd represents an order of a maximum mistuned component among order components of circumferential distribution of mass, rigidity or natural frequency of the blades, arrangement of the blades satisfies Nd?5, and has order components each having ratio less than 1/2, in which the ratio is obtained by dividing the order component by the magnitude of the component of the order Nd.

Abstract: A rotating body includes a rotating body core, and a plurality of blades provided at an outer or inner circumference of the rotating body core at equal intervals in a circumferential direction, and connected circumferentially via an annular connection portion provided separately from the rotating body core. A resonance frequency under a two nodal diameter number mode of the rotating body is lower than or equal to a rotational secondary harmonic frequency with respect to a rated rotation speed. Where Nd represents an order of a maximum mistuned component among order components of circumferential distribution of mass, rigidity or natural frequency of the blades, arrangement of the blades satisfies Nd?5, and has order components each having ratio less than 1/2, in which the ratio is obtained by dividing the order component by the magnitude of the component of the order Nd.