US3873229A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Inlet guide vane configuration for noise control of supersonic fan
Assignee: RTX Corp
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Filing: 1973-12-26
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Granted: 1975-03-25
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Expires: 1993-12-26
Abstract
Abstract The inlet guide vanes positioned adjacent and upstream of a first stage supersonic fan are shaped to reflect virtually all the fan shock wave noise back toward the fan, thereby preventing this shock wave noise from leaving through the engine inlet.
Inventors
- 👤 Alojzy Antoni Mikolajczak
- 👤 Robert Alfred Arnoldi
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-01 01:35
CPC Classifications
F; F04; F04D; F04D29/00; F04D29/66; F04D29/661; F04D29/663; F02; F02C; F02C7/00; F02C7/04; F02C7/045; F04D21/00; F04D29/40; F04D29/52; F04D29/54; F04D29/541; F04D29/542; F04D29/544; Y; Y02; Y02T; Y02T50/00; Y02T50/60
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
125 words
In combination in a gas turbine engine, a casing, a row of stationary inlet guide vanes disposed therein, a supersonic rotor disposed downstream and adjacent said row of guide vanes, each of said guide vanes including a surface facing in a direction opposed to the direction of rotation of said rotor, said surface including a reflecting surface, the chord length of said vanes at each radial location along the span of said reflecting surface being longer than the length of said reflecting surface at said respective radial locations, and a tangent line to each point on said reflecting surface forming a downstream angle of at least 90* with a line parallel to the direction of noise propagaTion at each respective point on said reflecting surface.
Claim 2
Dependent Claim
125 words
In combination in a gas turbine engine, a casing, a row of stationary inlet guide vanes disposed therein, a supersonic rotor disposed downstream and adjacent said row of guide vanes, each of said guide vanes including a surface facing in a direction opposed to the direction of rotation of said rotor, said surface including a reflecting surface, the chord length of said vanes at each radial location along the span of said reflecting surface being longer than the length of said reflecting surface at said respective radial locations, and a tangent line to each point on said reflecting surface forming a downstream angle of at least 90* with a line parallel to the direction of noise propagaTion at each respective point on said reflecting surface.
Claim 3
Dependent Claim
23 words
The combination according to claim 1 wherein the direction of noise propagation is the direction of noise propagation calculated at maximum rotor speed.
Claim 4
Dependent Claim
18 words
The combination according to claim 1 wherein said downstream angle is 90* at each of said respective points.
Claim 5
Dependent Claim
201 words
In combination in a turbofan engine, a hub, an annular casing spaced therefrom and defining therebetween an annular inlet to the turbofan engine, a row of stationary inlet guide vanes circumferentially spaced about the circumference of said hub and extending radially across said annular inlet, a supersonic fan disposed within said casing downstream of said guide vanes, said supersonic fan comprising a disk including a plurality of circumferentially spaced radially extending fan blades attached thereto, said fan blades being spaced downstream and adjacent said guide vanes, each of said guide vanes including a surface facing in a direction opposed to the direction of rotation of said fan blades, said surface including a reflecting surface for reflecting sound waves traveling in the shock wave system created by said fan blades during engine operation, the chord length of said guide vanes at each radial location along the span of said reflecting surface being longer than the length of said reflecting surface at said respective radial locations, and a tangent line to each point on said reflecting surface forming a downstream angle of at least 90* with a line parallel to the direction of noise propagation at each respective point on said reflecting surface.
Claim 6
Dependent Claim
201 words
In combination in a turbofan engine, a hub, an annular casing spaced therefrom and defining therebetween an annular inlet to the turbofan engine, a row of stationary inlet guide vanes circumferentially spaced about the circumference of said hub and extending radially across said annular inlet, a supersonic fan disposed within said casing downstream of said guide vanes, said supersonic fan comprising a disk including a plurality of circumferentially spaced radially extending fan blades attached thereto, said fan blades being spaced downstream and adjacent said guide vanes, each of said guide vanes including a surface facing in a direction opposed to the direction of rotation of said fan blades, said surface including a reflecting surface for reflecting sound waves traveling in the shock wave system created by said fan blades during engine operation, the chord length of said guide vanes at each radial location along the span of said reflecting surface being longer than the length of said reflecting surface at said respective radial locations, and a tangent line to each point on said reflecting surface forming a downstream angle of at least 90* with a line parallel to the direction of noise propagation at each respective point on said reflecting surface.
Claim 7
Dependent Claim
45 words
The combination according to claim 4 wherein said reflecting surface of each vane is defined by a plurality of straight lines, each line being both perpendicular to the spanwise direction of said vane and to the direction of noise propagation at its particular radial location.
Claim 8
Dependent Claim
18 words
The combination according to claim 5 wherein the direction of noise propagation is calculated at maximum rotor speed.
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) | 1978-03-24 | 1978-09-23 | 1979-03-25 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-03-24 | 1982-09-23 | 1983-03-25 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-03-24 | 1986-09-23 | 1987-03-25 | $7700.00 | Window Closed / Lapsed |