US3907409A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Aerodynamic window
Assignee: RTX Corp
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Filing: 1974-01-28
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Granted: 1975-09-23
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Expires: 1994-01-28
Abstract
Abstract An improved aerodynamic window is provided for laser systems where the pressure in the lasing cavity is lower than ambient pressure. An opening is located in the system to permit a laser beam to pass from the lasing cavity to the exterior thereof. A window is needed in the opening to prevent a flow of air from the ambient pressure into the low pressure in the lasing cavity. The window consists of a multiplicity of inlet ducts on one side of the opening supplied with a high pressure gas with each duct having a Laval nozzle for expanding the gas. The ducts are curved in a manner to provide a prescribed radial variation in velocity and static pressure therein. The pressure and Mach number in the ducts associated therewith provide a centrifugal flow across the opening. An outlet duct on the other side of the opening receives the flow from the inlet ducts after the flow has crossed the opening.
Inventors
- 👤 George F Hausmann
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 01:51
CPC Classifications
H; H01; H01S; H01S3/00; H01S3/02; H01S3/03; H01S3/034; H01S3/0343
Claims Analysis
Total Claims: 3
Claim 1
Independent Claim
436 words
In combination in a system having a region of low pressure, an opening in said region forming an exit, an outlet chamber connected to said system and extending away therefrom around said opening, and an aerodyamic window assembly permitting passage therethrough to a region of higher pressure, and aerodynamic window assembly comprising a plurality of transverse ducts connected to one side of said outlet chamber and terminating at the wall of said chamber, said plurality of said ducts extending in line along the length of said outlet chamber, said plurality of ducts each containing a Laval nozzle to generate a supersonic gas flow, pump means for supplying gas flow to said Laval nozzles, said Laval nozzles each expanding the gas passing therethrough to a supersonic velocity, said plurality of ducts being curved downstream of the Laval nozzles in a manner with said ducts each having an increasing radii of curvature in the direction from the region of low pressure to the region of higher pressure to provide a variation in velocity and static pressure along the axis of the outlet chamber by virtue of the formation of expansion waves on the inner convex surface of each duct and compression waves on the outer concave surface of each duct, said variation of static pressure increasing in magnitude in the direction from the region of low pressure to the region of higher pressure, a duct means being formed on the opposite side of said chamber to receive the flow transverse ducts, said transverse, said Laval nozzles having prescribed expansion ratios to provide a variation of Mach number in each duct such that the Mach numbers in the individual ducts are decreasing in magnitude in the direction from the region of low pressure to the region of higher pressure, said variation in Mach number, velocity and duct curvature being prescribed in a manner such that the static pressure at the intersection of the duct wall and the outlet chamber nearest the region of low pressure is equal to the pressure therein, the static pressure at the intersection of the furthermost duct wall and the outlet chamber is equal to the pressure in the region of higher pressure, and the static pressures at the intersection of each intermediate wall with said outlet chamber are balanced whereby the static pressure along the streamline of the innermost free boundary is equal to the pressure in the region of low pressure, the static pressure along the streamline of the outermost free boundary is equal to the atmospheric pressure and the static pressure along the streamlines emanating from the intermediate duct boundaries are balanced.
Claim 2
Dependent Claim
436 words
In combination in a system having a region of low pressure, an opening in said region forming an exit, an outlet chamber connected to said system and extending away therefrom around said opening, and an aerodyamic window assembly permitting passage therethrough to a region of higher pressure, and aerodynamic window assembly comprising a plurality of transverse ducts connected to one side of said outlet chamber and terminating at the wall of said chamber, said plurality of said ducts extending in line along the length of said outlet chamber, said plurality of ducts each containing a Laval nozzle to generate a supersonic gas flow, pump means for supplying gas flow to said Laval nozzles, said Laval nozzles each expanding the gas passing therethrough to a supersonic velocity, said plurality of ducts being curved downstream of the Laval nozzles in a manner with said ducts each having an increasing radii of curvature in the direction from the region of low pressure to the region of higher pressure to provide a variation in velocity and static pressure along the axis of the outlet chamber by virtue of the formation of expansion waves on the inner convex surface of each duct and compression waves on the outer concave surface of each duct, said variation of static pressure increasing in magnitude in the direction from the region of low pressure to the region of higher pressure, a duct means being formed on the opposite side of said chamber to receive the flow transverse ducts, said transverse, said Laval nozzles having prescribed expansion ratios to provide a variation of Mach number in each duct such that the Mach numbers in the individual ducts are decreasing in magnitude in the direction from the region of low pressure to the region of higher pressure, said variation in Mach number, velocity and duct curvature being prescribed in a manner such that the static pressure at the intersection of the duct wall and the outlet chamber nearest the region of low pressure is equal to the pressure therein, the static pressure at the intersection of the furthermost duct wall and the outlet chamber is equal to the pressure in the region of higher pressure, and the static pressures at the intersection of each intermediate wall with said outlet chamber are balanced whereby the static pressure along the streamline of the innermost free boundary is equal to the pressure in the region of low pressure, the static pressure along the streamline of the outermost free boundary is equal to the atmospheric pressure and the static pressure along the streamlines emanating from the intermediate duct boundaries are balanced.
Claim 3
Dependent Claim
41 words
A combination as set forth in claim 1 wherein throttle valves are provided downstream of the pump means and upstream of the Laval nozzle inlets to provide a means for varying the total pressure in each of the plurality of ducts.
References Cited (Backward Citations)
US3654569A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1978-09-22 | 1979-03-24 | 1979-09-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-09-22 | 1983-03-24 | 1983-09-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-09-22 | 1987-03-24 | 1987-09-23 | $7700.00 | Window Closed / Lapsed |