BLADE EXCITATION REDUCTION METHOD AND ARRANGEMENT
First Claim
1. A method of reducing stress on an airfoil, comprising:
- a) performing a modal analysis on an airfoil array;
b) selecting a natural frequency of the airfoil array having a primary anti-node within the airfoil array furthest from an air bleed hole location; and
c) selecting a quantity of air-bleed holes corresponding to an engine excitation order frequency closest to the selected natural frequency of the airfoil array.
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Accused Products
Abstract
An impeller shroud is configured to receive an impeller. The impeller shroud establishes a plurality of air-bleed holes configured to communicate air with an impeller. The air-bleed holes are circumferentially distributed about the impeller shroud. The circumferential spacing between some adjacent air-bleed holes within the plurality of air-bleed holes is different than the circumferential spacing between other adjacent air-bleed holes within the plurality of air-bleed holes. A diffuser vane is configured to direct pressurized air to the combustor, the diffuser vanes are circumferentially distributed about the blade exducer. The circumferential spacing between some adjacent diffuser vanes within the plurality of diffuser vanes is different than the circumferential spacing between other adjacent diffuser vanes within the plurality of diffuser vanes.
35 Citations
19 Claims
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1. A method of reducing stress on an airfoil, comprising:
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a) performing a modal analysis on an airfoil array; b) selecting a natural frequency of the airfoil array having a primary anti-node within the airfoil array furthest from an air bleed hole location; and c) selecting a quantity of air-bleed holes corresponding to an engine excitation order frequency closest to the selected natural frequency of the airfoil array. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9)
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10. A method of reducing stress on an airfoil, comprising:
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a) performing a modal analysis on an airfoil array; b) selecting a natural frequency of the airfoil array having a primary anti-node within the airfoil array furthest from the diffuser vane leading edge; and c) selecting a quantity of vanes corresponding to an engine excitation order frequency closest to the above selected natural frequency of the airfoil array. - View Dependent Claims (11, 12, 13, 14, 15)
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16. An impeller shroud, comprising:
an impeller shroud configured to receive an impeller, the impeller shroud establishing a plurality of air-bleed holes configured to communicate air toward the impeller, the air-bleed holes circumferentially distributed about the impeller shroud, wherein the circumferential spacing between some adjacent air-bleed holes within the plurality of air-bleed holes is different than the circumferential spacing between other adjacent air-bleed holes within the plurality of air-bleed holes. - View Dependent Claims (17)
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18. A vane assembly, comprising:
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a base establishing an axis; and a plurality of vanes extending from the base, the vanes circumferentially distributed about the axis, wherein the circumferential spacing between some adjacent vanes within the plurality of vanes is different than the circumferential spacing between other adjacent vanes within the plurality of vanes, wherein the plurality of vanes are configured to influence flow through an impeller of a turbo machine. - View Dependent Claims (19)
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Specification