Shear layer control in a free-vortex aerodynamic window

Patent · Tue Dec 17 04:00:00 EST 1985

OSTI ID:5847976

Johnson, B V; Guille, R N

A boundary-controlled aerodynamic window positioned adjacent the exit aperture of a gas laser is transparent to the laser beam emitted from the cavity of the laser. The boundary-controlled aerodynamic window is formed by a high velocity gas flow directed by a duct across the exit aperture for the laser beam isolating the low pressure region of the cavity from the high pressure of the atmosphere. The exit aperture is enlarged and an auxiliary gas flow injected along the sidewall of the duct adjacent the exit aperture to expand the thickness of the boundary layer. In a second embodiment, particulate matter is fixedly attached to the sidewall of the duct to increase the roughness of the wall surface. A third embodiment uses a plurality of nozzles, each injecting gas with a predetermined velocity.

• Assignee: United Technologies Corp.
• Patent Number(s): US 4559628
• OSTI ID: 5847976
• Country of Publication: United States
• Language: English

Related Subjects

42 ENGINEERING
420300* -- Engineering-- Lasers-- (-1989)
AERODYNAMICS
APERTURES
BEAM TRANSPORT
BOUNDARY LAYERS
CONTROL
DESIGN
ELECTROMAGNETIC RADIATION
FLOW RATE
FLUID FLOW
FLUID MECHANICS
GAS FLOW
GAS LASERS
LASER RADIATION
LASERS
LAYERS
MECHANICS
NOZZLES
OPENINGS
PRESSURE CONTROL
RADIATIONS
ROUGHNESS
SURFACE PROPERTIES
WINDOWS