Patent US4405100A successfully refreshed from Google Patents.
US4405100A
Expired / Lapsed
US
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Turbulence generator for maximizing configuration tolerances of free flight ordnance
Assignee: United States Department of the Navy
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Filing: 1981-02-20
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Granted: 1983-09-20
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Expires: 2001-02-20
Abstract
Abstract A turbulence generator is provided on the forward end of a free flight ornce device to induce a turbulent boundary layer over the surface of the device. The turbulent layer generated is thicker than the normal boundary layer and helps reduce drag disparity between similar ordnance devices.
Inventors
- 👤 Peter Daniels
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 19:24
CPC Classifications
F; F42; F42B; F42B10/00; F42B10/32; F42B10/48; F42B10/52; F42B10/38
Claims Analysis
Total Claims: 2
Claim 1
Independent Claim
172 words
A method of reducing the variations in drag disparity between similar free flight ordnance devices caused by variations in surface roughness and configuration so that each of said devices has substantially the same free flight range and accuracy comprising: providing each device with a raised annular ring means at the same position on the front end of each device, in the laminar flow of air, where the position is on an essentially curved section of the front end wherein the ring means creates turbulent air flow and the ring means is machined to the same close tolerance dimensions on each device, for causing air flow past the device to change from laminar to turbulent at the same position on each device to reduce surface friction on each of said devices, the surface friction on each device being nearly equal due to the introduction of turbulent flow at the same position on each of said devices, thereby reducing the drag disparity therebetween and providing substantially the same free flight range for all devices.
Claim 2
Independent Claim
172 words
A method of reducing the variations in drag disparity between similar free flight ordnance devices caused by variations in surface roughness and configuration so that each of said devices has substantially the same free flight range and accuracy comprising: providing each device with a raised annular ring means at the same position on the front end of each device, in the laminar flow of air, where the position is on an essentially curved section of the front end wherein the ring means creates turbulent air flow and the ring means is machined to the same close tolerance dimensions on each device, for causing air flow past the device to change from laminar to turbulent at the same position on each device to reduce surface friction on each of said devices, the surface friction on each device being nearly equal due to the introduction of turbulent flow at the same position on each of said devices, thereby reducing the drag disparity therebetween and providing substantially the same free flight range for all devices.
References Cited (Backward Citations)
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US3088404A
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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) | 1986-09-19 | 1987-03-21 | 1987-09-20 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1990-09-19 | 1991-03-21 | 1991-09-20 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1994-09-19 | 1995-03-21 | 1995-09-20 | $7700.00 | Window Closed / Lapsed |