US3844677A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blunted leading edge fan blade for noise reduction
Assignee: General Electric Co
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Filing: 1973-07-05
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Granted: 1974-10-29
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Expires: 1993-07-05
Abstract
Abstract A turbomachinery rotor blade includes a leading edge with a blunted contour over at least a portion of the radial length thereof. The blunting is accomplished in a variety of ways, such as by removing material from a portion of the leading edge, by blowing air into the leading edge or by positioning a mechanical device such as an inflatable boot around a portion of the leading edge. The aerodynamic or mechanical blunting can be utilized during selective portions of flight, such as take-off and landing. The blunted leading edge provides significant reduction in noise generated during rotation of the turbomachinery rotor blade.
Inventors
- 👤 R Evans
- 👤 D Dunbar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-05 10:23
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/12; F01D5/14; F01D5/141; F01D5/145; F02; F02C; F02C7/00; F02C7/04; F02C7/045; F05; F05D; F05D2240/00; F05D2240/20; F05D2240/30; F05D2240/303; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
111 words
In a gas turbine engine of the type which includes rotating turbomachinery, a combustion section, and an exhaust nozzle adapted to provide a propulsive force, the improvement comprising: a turbomachinery rotor blade having a leading edge at least a portion of which includes blunting means for reducing the noise generated by rotation of said blade; wherein said blunting means comprise an inflatable boot which surrounds at least a portion of said leading edge and means for supplying sufficient pressure behind said boot for slightly inflating same; and wherein said boot is expandable, upon inflation, substantially axially of the blade to vary the aerodynamic shape of the blade without varying its camber.
Claim 2
Dependent Claim
111 words
In a gas turbine engine of the type which includes rotating turbomachinery, a combustion section, and an exhaust nozzle adapted to provide a propulsive force, the improvement comprising: a turbomachinery rotor blade having a leading edge at least a portion of which includes blunting means for reducing the noise generated by rotation of said blade; wherein said blunting means comprise an inflatable boot which surrounds at least a portion of said leading edge and means for supplying sufficient pressure behind said boot for slightly inflating same; and wherein said boot is expandable, upon inflation, substantially axially of the blade to vary the aerodynamic shape of the blade without varying its camber.
Claim 3
Dependent Claim
22 words
The improved turbomachinery rotor blade of claim 1 wherein said inflatable boot surrounds approximately the outer one-third of the blade radial height.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1977-10-28 | 1978-04-29 | 1978-10-29 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1981-10-28 | 1982-04-29 | 1982-10-29 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1985-10-28 | 1986-04-29 | 1986-10-29 | $7700.00 | Window Closed / Lapsed |