Quadrant rotor mistuning for decreasing vibration

• US 6,379,112 B1
• Filed: 11/04/2000
• Issued: 04/30/2002
• Est. Priority Date: 11/04/2000
• Status: Expired due to Term

• Current Assignee: Raytheon Technologies Corporation d/b/a RTX (Rtx Corporation)
• Original Assignee: United Technologies Corporation (Rtx Corporation)
• Inventors: Montgomery, Matthew
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): EDGAR, RICHARD A
• Application Number:
  US09/706,412
• Time in Patent Office: 542 Days
• Field of Search: 415/119, 416/144, 416/175, 416/203, 416/500, 416/145
• US Class Current: 415/119
• CPC Class Codes: F01D 5/10 Anti- vibration means specially adapted for radial flow machines or engines F01D5/04
• CPC Class Codes: F01D 5/145 Means for influencing boundary layers or secondary circulations for compressors F04D29/68
• CPC Class Codes: F01D 5/16 for counteracting blade vibration
• CPC Class Codes: F01D 9/04 forming ring or sector
• CPC Class Codes: F04D 29/542 Bladed diffusers fixing blades to stators F01D9/042
• CPC Class Codes: F04D 29/668 damping or preventing mechanical vibrations
• CPC Class Codes: F05D 2240/12 Fluid guiding means, e.g. vanes
• CPC Class Codes: F05D 2250/30 Arrangement of components
• CPC Class Codes: F05D 2260/961 by mistuning rotor blades or stator vanes with irregular interblade spacing, airfoil shape
• CPC Class Codes: Y02T 50/60 Efficient propulsion technologies, e.g. for aircraft
• CPC Class Codes: Y10S 416/50 Vibration damping features

Abstract

The present invention relates to an array of flow directing elements for use in turbomachinery. The array comprises a plurality of flow directing elements arranged around a disk in a circular pattern having four quadrants. The flow directing elements in each quadrant are different in mass from the flow directing elements in each adjacent quadrant to reduce the tendency of the array to exhibit tuned absorbed behavior. Further, the number of flow directing elements in each quadrant are different from the number of flow directing elements in each adjacent quadrant to reduce stator vibration in the turbomachinery. Still further, centfrigual pull on the disk is equalized by assembling quadrants with lower flow directing element count from heavier flow directing elements.

Claims

1. An array of flow directing elements for use in turbomachinery comprising:

a disk and a plurality of flow directing elements attached to and extending from said disk;

said plurality of flow directing elements being arranged in a circular pattern having four quadrants; and

said flow directing elements in a first one and a second one of said quadrants each having a mass greater than said flow directing elements in a third one and a fourth one of said quadrants.

2. An array according to claim 1, wherein said first one of said quadrants is positioned between said third one and said fourth one of said quadrants and said second one of said quadrants is also positioned between said third one and said fourth one of said quadrants.

3. An array according to claim 1, wherein each of said first and second quadrants contains a number of flow directing elements different from the number of flow directing elements in said third and fourth quadrants.

4. An array according to claim 3, wherein said first and second quadrants each contain N flow directing elements and wherein said third and fourth quadrants each contain N+1 flow directing elements where N is an integer.

5. An array according to claim 3, wherein the ratio of the mass of each individual blade in said first and second quadrants to the mass of each individual blade in said third and fourth quadrants is approximately (N+1):

N.

6. An array according to claim 1, where said flow directing elements comprise a plurality of rotor blades aligned in a row.

7. An array of flow directing elements for use in turbomachinery which comprises:

a plurality of flow directing elements arranged in a circular pattern having four quadrants; and

said flow directing elements in one quadrant having a different count that said flow directing elements in each adjacent quadrant for reducing vibration in adjacent stator rows in said turbomachinery.

8. An array of flow directing elements for use in turbomachinery which comprises:

a plurality of flow directing elements arranged in a circular pattern having four quadrants; and

said flow directing elements in one quadrant each having a mass different from the mass of each flow directing element positioned in two adjacent quadrants to reduce the tendency of the array to exhibit tuned absorbed behavior.

9. An array of flow directing elements for use in turbomachinery which comprises:

a plurality of flow directing elements mounted to a disk;

said flow directing elements being arranged in a circular pattern having four quadrants; and

said flow directing elements in two diametrically opposed quadrants having a lower element count and a greater mass than said flow directing elements in the remaining quadrants so as to equalize centrifugal pull on said disk.