US3883268A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Blunted leading edge fan blade for noise reduction
Assignee: General Electric Co
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Filing: 1973-08-29
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Granted: 1975-05-13
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Expires: 1993-08-29
Abstract
Abstract A blade of a turbomachinery rotor stage 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 blunting of leading edges of each of a plurality of blades in this way provides significant reduction in noise generated during rotation of the associated turbomachinery rotor state.
Inventors
- 👤 Robert C Evans
- 👤 Donald K Dunbar
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 08:04
CPC Classifications
F; F01; F01D; F01D5/00; F01D5/12; F02; F02C; F02C7/00; F02C7/04; F02C7/045; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 6
Claim 1
Independent Claim
77 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 rotatable disc; and a plurality of turbomachinery rotor blades carried by said disc and having leading edges at least a portion of which include blunting means for reducing the noise generated by the rotation of said blade, and wherein said leading edges of said blades are generally coplanar.
Claim 2
Dependent Claim
77 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 rotatable disc; and a plurality of turbomachinery rotor blades carried by said disc and having leading edges at least a portion of which include blunting means for reducing the noise generated by the rotation of said blade, and wherein said leading edges of said blades are generally coplanar.
Claim 3
Dependent Claim
29 words
The improvement of claim 1 wherein said blunting means comprises a flattened leading edge which extends over at least a portion of the length of each of said blades.
Claim 4
Dependent Claim
20 words
The improvement of claim 2 wherein said flattened leading edge extends along approximately the outer one-third of the blade height.
Claim 5
Dependent Claim
20 words
The improved turbomachinery rotor blade recited in claim 1 wherein said blade comprises a fan blade of a turbofan engine.
Claim 6
Dependent Claim
24 words
The improvement of claim 2 wherein said flattened leading edge is more blunt than that of an aerodynamically ideal blade in a selected application.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-05-12 | 1978-11-11 | 1979-05-13 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-05-12 | 1982-11-11 | 1983-05-13 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-05-12 | 1986-11-11 | 1987-05-13 | $7700.00 | Window Closed / Lapsed |