US4188823A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Detection of the transitional layer between laminar and turbulent flow areas on a wing surface
Assignee: National Aeronautics and Space Administration
•
Filing: 1978-11-27
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Granted: 1980-02-19
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Expires: 1998-11-27
Abstract
Abstract A system is disclosed for detecting the laminar to turbulent boundary layer transition on a surface while simultaneously taking pressure measurements. The system uses an accelerometer for producing electrical signals proportional to the noise levels along the surface and a transducer for producing electrical signals proportional to pressure along the surface. The signals generated by the accelerometer and transducer are sent to a data reduction system for interpretation and storage.
Inventors
- 👤 William R. Hood
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-02 09:54
CPC Classifications
G; G01; G01M; G01M9/00; G01M9/06; Y; Y02; Y02T; Y02T50/00; Y02T50/10
Claims Analysis
Total Claims: 9
Claim 1
Independent Claim
95 words
A device for determining the laminar to turbulent boundary layer transition on a surface the combination comprising: a wing surface having orifices positioned along its surface and subjected to an airflow; noise detecting means for producing audio frequency electrical signals proportional to the noise levels at said orifices along said wing surface caused by said airflow; pressure detecting means for producing electrical signals proportional to the pressures at said orifices upon the wing surface; and acquisition means for automatically collecting and storing the signals produced by said noise detecting means and said pressure detecting means.
Claim 2
Independent Claim
95 words
A device for determining the laminar to turbulent boundary layer transition on a surface the combination comprising: a wing surface having orifices positioned along its surface and subjected to an airflow; noise detecting means for producing audio frequency electrical signals proportional to the noise levels at said orifices along said wing surface caused by said airflow; pressure detecting means for producing electrical signals proportional to the pressures at said orifices upon the wing surface; and acquisition means for automatically collecting and storing the signals produced by said noise detecting means and said pressure detecting means.
Claim 3
Dependent Claim
29 words
A device as in claim 1 wherein said noise detecting means comprises an accelerometer connected to said orifice and an audio amplifier connected to the output of the accelerometer.
Claim 4
Dependent Claim
19 words
A device as in claim 2 wherein said pressure detecting means comprises a pressure transducer connected to said orifices.
Claim 5
Dependent Claim
23 words
A device as in claim 3 including: pneumatic tubes extending from said orifices connecting said orifices to said accelerometer and said pressure transducer.
Claim 6
Dependent Claim
23 words
A device as in claim 4 including: a scanning valve means for selectively connecting said orifices to said accelerometer and said pressure transducer.
Claim 7
Dependent Claim
38 words
A device as in claim 5 wherein said acquisition means comprises a speaker connected to said amplifier for producing an audio output; and a recording means for recording the signals produced by said accelerometer, pressure transducer and amplifier.
Claim 8
Independent Claim
69 words
A method of detecting laminar to turbulent boundary layer transition on a surface subjected to an airflow comprising the steps of: providing orifices at various points along said surface; pneumatically connecting said orifices to a location remote to the environment of said surface; producing audio frequency electrical signals at said remote location that are proportional to the noise levels at said orifices; and recording said audio frequency electrical signals.
Claim 9
Independent Claim
69 words
A method of detecting laminar to turbulent boundary layer transition on a surface subjected to an airflow comprising the steps of: providing orifices at various points along said surface; pneumatically connecting said orifices to a location remote to the environment of said surface; producing audio frequency electrical signals at said remote location that are proportional to the noise levels at said orifices; and recording said audio frequency electrical signals.
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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) | 1983-02-18 | 1983-08-20 | 1984-02-19 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1987-02-18 | 1987-08-20 | 1988-02-19 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1991-02-18 | 1991-08-20 | 1992-02-19 | $7700.00 | Window Closed / Lapsed |