Summa Corporation

Northrop Corporation

Hughes Helicopters, Inc.

Robert C Miller

Harold E Lemont

Rudolf J Seemann

The invention provides a system for selective reduction of infrared signature of a vehicle subjected to aerodynamic heating. Liquid coolant under pressure vaporizes in porous sections of the skin of the vehicle to transpiration-cool the skin. Adjacent downstream solid skin sections are film-cooled by the vapor introduced in the boundary layer. Coolant flow control is achieved by pressurizing the liquid coolant, by modulating flow control valves, and, optionally, by configuring the porous section to operate as a cavitating venturi, or combinations of these methods.

Infrared signature reduction of aerodynamic surfaces

A device for shielding a heated surface from infra-red detection through an opening adjacent to the heated surface. The device includes a gas-conducting member, which is adapted to receive heated gases, and has an exterior surface, an interior surface, an inlet for receipt of heated gases from the opening, and an outlet for the discharge of gases. The gas-conducting member has a configuration which blocks the inlet to the member from line-of-sight view through the outlet to the member. Additionally, the device draws cooling air over the exterior surface of the gas-conducting member. The cooling air may then be mixed with the heated gases within the gas conducting member. This provides cooling of the gas-conducting member to prevent the member from being visible to infra-red detection and may also provide cooling of the gases which are discharged from the outlet of the gas-conducting member by mixing of the heated gases with the cooling air.

Radiation shielding and gas diffusion apparatus

A skin construction suitable for use as a high temperature airfoil surface that includes a metallic member having first and second corrugations. The first corrugations have a size and spacing which permits resilient thermal expansion of the member in a direction transverse to the direction of the first corrugations. The second corrugations are positioned in a direction that is substantially transverse to the direction of the first corrugations and the second corrugations have a size and spacing which permits resilient thermal expansion of the member in a direction generally transverse to the direction of the second corrugations. An imperforate metallic surface is integral with the metallic member. Thermal stresses imposed on the skin construction are, thus, absorbed by deformation of the first and second corrugations which act as expansion joints in permitting controlled expansion of the skin construction. In combination, a skin construction, as described, and a support structure for positioning the skin construction in spaced relation to an underlying structure. The upstanding metallic support members are connected to a surface of the metallic member of the skin construction with the support members including a corrugated upstanding surface. In combination, a high temperature skin construction and a support structure, both as described, and an underlying structure with the skin construction supported in spaced relation to the underlying structure. Insulation is placed in the space between the skin construction and the underlying structure. The combination may include means to vent the space between the skin construction and the underlying structure to ambient pressure.

High temperature skin construction

An all metal, low conductivity, high performance and relatively lightweight, composite structure, in the form of an insulation blanket is operably disposed to be exposed to a high temperature zone, e.g., a high temperature fluid, or on a supporting surface exposed to high temperature. The composite includes two metal skin members spaced from each other by a metallic member functioning as a spacing member. The spacing member is preferably deformed to contact the spaced skin sheets at spaced positions, the space between the skin sheets forming a fluid space which defines a zone of substantially reduced heat transfer by convection. When deformed, the spacing member, or an array of spacers, also provides an elongated path for conduction of heat, and defines a plurality of cavities of limited volume forming stagnant gas pockets. The skin sheets may be perforated to vent the cavities and to provide expansion space for absorbing thermal growth by the metal components of the composite. The spacing member also operates as a shield against the transfer of heat by radiation with the effect that the composite has a heat transfer coefficient substantially dictated by the thermal conductivity of the fluid in the space between the skin members. Use of metal components, principally of commercially available materials, permits fabrication of composites having various shapes and structural strengths, e.g., vibration, compaction, fatigue, etc., good chemical stability and easily repaired. Various different forms and alternate arrangements are described.

Insulation system

A thermal insulation composite includes at least a first metallic skin sheet, and a plurality of non-combustible metallic filaments randomly interlocked to form a wool and affixed to said first skin sheet. A second metallic skin sheet may be affixed to said wool and said first sheet, or the second skin sheet may be a surface of the structure to be insulated. A fluid is present in the interstices of the filaments and in the zone between the skin sheets. Each of the filaments has a significant length to cross-sectional diameter ratio to minimize its thermal conductivity. The filaments also preferably have a circular cross section to minimize the area of contact and hence the heat conducted between adjacent filaments. In this manner, the conductivity of the wool is made primarily dependent upon the thermal conductivity of the fluid in the interstices of the filaments. Heat transmission by radiation is inhibited by providing a plurality of radiation shields interposed between multiple layers of the wool. The skin sheets, wool, and radiation shields are bonded by stitches or staples to form an insulation blanket. The interstices of the filaments are of many different sizes so that the insulation has characteristics for absorbing sound waves over a significant band of frequencies. The composite may be used to insulate ducts, airfoil surfaces, fire walls and to form fireproof garments, and has the unique capability of being fabricated into a variety of structural shapes.

A device for shielding a heated surface from infrared detection through an exhaust opening adjacent the heated surface which comprises an exhaust gas conducting member adapted to receive heated exhaust gases from the exhaust opening with the member having a configuration which blocks the exhaust opening from line-of-sight view through the outlet to the member. The exhaust gas conducting member includes apparatus to inhibit heat transfer across its interior surface while promoting heat transfer through the wall of the member. Additionally there is provided a diffusion device for breaking up a main stream of heated exhaust gas into a plurality of smaller streams to reduce infrared radiation from the exhaust gas which includes a body adapted to receive heated exhaust gas with insulation apparatus to maintain the exterior surface of the body at a relatively low temperature. A plurality of openings in the body provide discharge of smaller streams of exhaust gas. The openings may be shaped to provide a cross-sectional configuration for the smaller streams of exhaust gas which promote dissipation of heat and energy and which reduce the emissivity of the gas streams.

Growing community of inventors

Encino, CA, United States of America

Robert C Miller