US4786020A
Expired / Lapsed
US
⏱️ 0.0 years remaining
System for boundary layer control through pulsed heating of a strip heater
Assignee: United States Department of the Air Force
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Filing: 1988-01-29
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Granted: 1988-11-22
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Expires: 2008-01-29
Abstract
Abstract A system is described for controlling the transition of laminar/turbulent flow at a surface which comprises a thin narrow strip heater disposed adjacent the surface and extending substantially transversely of the flow of the air stream thereacross, the heater being resiliently held in tension on or in closely spaced relationship to the surface, and a power source operatively connected to the heater for applying pulsed voltage of preselected amplitude and frequency to the heater.
Inventors
- 👤 Milton E. Franke
- 👤 Lawrence Kudelka
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 21:40
CPC Classifications
B; B64; B64C; B64C23/00
Claims Analysis
Total Claims: 5
Claim 1
Independent Claim
80 words
A system for controlling the transition between laminar and turbulent flow of an air stream across a surface, comprising: (a) a thin narrow strip heater disposed adjacent said surface and extending substantially transversely of the flow of said air stream across said surface; (b) means for resiliently tensioning said heater along the length of said heater; and (c) electrical means operatively connected to the ends of said heater for applying pulsed voltage of preselected amplitude and frequency to said heater.
Claim 2
Independent Claim
80 words
A system for controlling the transition between laminar and turbulent flow of an air stream across a surface, comprising: (a) a thin narrow strip heater disposed adjacent said surface and extending substantially transversely of the flow of said air stream across said surface; (b) means for resiliently tensioning said heater along the length of said heater; and (c) electrical means operatively connected to the ends of said heater for applying pulsed voltage of preselected amplitude and frequency to said heater.
Claim 3
Dependent Claim
38 words
The system as recited in claim 1 wherein said heater comprises a thin metallic strip of preselected length having first and second ends, said thin metallic strip being resiliently tensioned along its length substantially flush against said surface.
Claim 4
Dependent Claim
21 words
The system as recited in claim 1 further comprising means for holding said heater in preselected spaced relationship to said surface.
Claim 5
Dependent Claim
15 words
The system as recited in claim 3 wherein said heater comprises a thin metallic strip.
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) | 1991-11-22 | 1992-05-23 | 1992-11-22 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1995-11-22 | 1996-05-23 | 1996-11-22 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1999-11-22 | 2000-05-23 | 2000-11-22 | $7700.00 | Window Closed / Lapsed |