Abstract
The resonant condition by the interaction between the impellers and the stationary parts of the centrifugal compressor has been experimentally investigated. The two types of the diffuser were examined, which is vaneless and vaned diffuser. The 5th nodal diameter mode of the natural frequency was highly excited by the vaned diffuser, which is installed just downstream of the impeller. This resonance can be verified by the interaction theory between the pressure distribution around the impeller and nodal diameter mode of the impeller natural frequency.
The distance between the impeller outlet and leading edge of the diffuser vane is proved to be the critical parameter of the magnitude of the resonance.
