摘要 |
A turbomachinery stage comprising two axially spaced blade rows, one of which is rotatable, wherein the blades of the upstream row are contoured to present a leaned wake to the downstream row. In the preferred embodiment, the blades of the upstream row extend radially from a central hub and, at a radius above the hub, are physically curved circumferentially from a radial line through the hub. The physical lean locally complements the inherent aerodynamic lean at each radius such that the integrated acoustic power of the stage is essentially at a minimum, thus maximizing the acoustic attenuation. Preferably, the constraint is imposed that the blade physical curvature is essentially smooth, continuous and without an inflection point.
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