Accession Number:

ADD014075

Title:

Combination Boundary Layer Control System for High Altitude Aircraft.

Descriptive Note:

Patent, Filed 12 Aug 87, patented 28 Feb 89,

Corporate Author:

DEPARTMENT OF THE AIR FORCE WASHINGTON DC

Personal Author(s):

• Brewer, George D.
• Marshall, David P.

Report Date:

1989-02-28

Pagination or Media Count:

5.0

Abstract:

This patent comprises a combination boundary layer control system that uses both suction and cryogenic wall cooling to reduce aircraft drag. The invention is particulary useful in circumstances where liquid hydrogen or other cryogenic fuels are used to operate the aircraft. In the preferred embodiment, a network of D-tube ducts are provided that are fluidly connected to a cryogenic fluid source. These cryogenic fluid ducts are selectively fed cryogenic fluid to reduce aircraft surface temperature and promote adhesion of boundary layer air to the aircraft. An air duct system is also provided to apply suction to the aircraft surface in order to remove the boundary layer at low altitude. The suction is applied by means of a multitude of minute holes in the aircraft skin which are fluidly connected to the air duct system.

Descriptors:

• *BOUNDARY LAYER CONTROL
• *PATENTS
• ADHESION
• AERODYNAMIC DRAG
• AIR
• AIRCRAFT
• BOUNDARY LAYER
• COOLING
• CRYOGENICS
• DRAG REDUCTION
• DUCTS
• FLUIDS
• FUELS
• HIGH ALTITUDE
• LIQUID HYDROGEN
• LOW ALTITUDE
• SKIN(STRUCTURAL)
• SOURCES
• SUCTION
• SURFACE TEMPERATURE
• SURFACES
• WALLS

Subject Categories:

• Hydraulic and Pneumatic Equipment
• Fluid Mechanics

Distribution Statement:

APPROVED FOR PUBLIC RELEASE