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US4727751A
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Crossflow vorticity sensor
Assignee: United States, ADMINISTRATOR OF NASA, Secretary of
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Filing: 1987-01-15
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Granted: 1988-03-01
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Expires: 2007-01-15
Abstract
Abstract A crossflow vorticity sensor is provided for the detection of crossflow vorticity characteristics. The crossflow vorticity sensor is comprised of crossflow sensors (10) which are non-invasively adhered to swept wing laminar surface (12) either singularly, in multi-element strips (11), in polar patterns (40), or orthogonal patterns (41). These crossflow sensors (10) are comprised of hot-film sensor elements (18) which operate as a constant temperature anemometer circuit to detect heat transfer rate changes. Accordingly, crossflow vorticity characteristics are determined via cross-correlation. In addition, the crossflow sensors (10) have a thickness which does not exceed a maximum value h in order to avoid contamination of downstream crossflow sensors (10).
Inventors
- 👤 Bruce J. Holmes
- 👤 Debra L. Carraway
- 👤 Harlan K. Holmes
- 👤 Thomas C. Moore
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 12:34
CPC Classifications
G; G01; G01M; G01M9/00; G01M9/06; G01M9/065; G01P; G01P5/00; G01P5/10; G01P5/12
Claims Analysis
Total Claims: 10
Claim 1
Independent Claim
72 words
A crossflow sensor for measuring the behavior of crossflow vorticity over a laminar surface comprising: a plurality of crossflow sensors; a means for non-invasively adhering said crossflow sensors to said laminar surface; a means for sensing heat transfer rate changes caused by crossflow vorticity in said crossflow sensors; a means for arranging said crossflow sensors on said laminar surface to measure crossflow vorticity as a function of said heat transfer rate changes.
Claim 2
Dependent Claim
72 words
A crossflow sensor for measuring the behavior of crossflow vorticity over a laminar surface comprising: a plurality of crossflow sensors; a means for non-invasively adhering said crossflow sensors to said laminar surface; a means for sensing heat transfer rate changes caused by crossflow vorticity in said crossflow sensors; a means for arranging said crossflow sensors on said laminar surface to measure crossflow vorticity as a function of said heat transfer rate changes.
Claim 3
Dependent Claim
18 words
The device of claim 1 wherein said crossflow sensors comprise hot-film sensors mounted on a thermoplastic film sheet.
Claim 4
Dependent Claim
20 words
The device of claim 2 wherein said hot-film sensors comprise a metal heat sensor mounted on a polyimide film sheet.
Claim 5
Dependent Claim
14 words
The device of claim 3 wherein said metal heat sensor is constructed of nickel.
Claim 6
Dependent Claim
67 words
The device of claim 1 wherein said means for arranging said crossflow sensors on said laminar surface is a multi-element strip which in non-invasively adhered to said laminar surface, said multi-element strip having said crossflow sensors affixed thereto in an arrayed pattern, said affixed crossflow sensors being oriented in the direction of a freestream to detect relative changes in downstream crossflow vorticity amplitude in the downstream direction.
Claim 7
Dependent Claim
51 words
The device of claim 1 wherein the thickness of said crossflow sensor is less than h, where h is defined by the following equation: ##EQU2## where R' is the unit Reynolds number of the freestream, whereby a local turbulence transition is avoided and no contamination of downstream crossflow vorticity measurements occurs.
Claim 8
Dependent Claim
20 words
The device of claim 1 wherein said means for sensing heat transfer rate changes is a constant temperature anemometer circuit.
Claim 9
Dependent Claim
51 words
The device of claim 1 wherein said means for arranging said crossflow sensors on said laminar surface is a multi-element strip which is non-invasively adhered to said laminar surface and has said crossflow sensors affixed thereto in a polar pattern to determine the frequency and wave angles of moving crossflow vortices.
Claim 10
Dependent Claim
51 words
The device of claim 1 wherein said means for arranging said crossflow sensor on said laminary surface is a multi-element strip which is non-invasively adhered to said laminar surface and has said crossflow sensors affixed thereto in an orthogonal pattern to determine the frequency and wave angles of moving crossflow vortices.
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) | 1991-03-01 | 1991-08-31 | 1992-03-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-03-01 | 1995-08-31 | 1996-03-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-03-01 | 1999-08-31 | 2000-03-01 | $7700.00 | Window Closed / Lapsed |