Frequency-mistuned light-weight turbomachinery blade rows for increased flutter stability

摘要

The present invention relates to an array of flow directing elements having increased flutter stability for use in turbomachinery devices. The array comprises at least one high frequency flow directing element and at least one low frequency flow directing element. In a preferred embodiment, the array comprises a plurality of alternating high frequency and low frequency flow directing elements. Each high frequency flow directing element has its three lowest frequency vibratory modes at least 2.0% higher in frequency than the three lowest frequency vibratory modes of each low frequency flow directing element. The array of the present invention has particular utility in a turbomachinery device as part of a rotor stage.