Engineering topics

Taylor, Allan H.

Publications and source records attributed to Taylor, Allan H..

9 records

NASA NTRS1991

Reusable cryogenic foam insulation for advanced aerospace vehicles

Future high-speed aircraft and aerospace vehicles using cryogenic propellants will require an advanced reusable insulation system for the propellant tank structure. This cryogenic insulation system must be lightweight, structurally and thermally efficient, and capable of multiple reuse without cracking or degraded performance. This paper presents recent progress in the development of a reusable cryogenic foam insulation system having a maximum service temperature of 400 F. The system consists of preshaped, precut blocks of rigid polymethacrylimide foam insulation, wrapped with a high-temperature Kapton and aluminum foil vapor barrier which is adhesively bonded to the propellant tank wall.

Mcauliffe, Patrick S.↗

NASA NTRS1990

Advanced Composite Pistons

New concept involving improved configuration of reinforcing fibers and improved fabrication process proposed to improve thermal and mechanical properties of composite piston structures. Reduces amount of labor necessary to manufacture piston structures, with attendant reductions in costs. Single knitted-carbon-fiber sock used to form external surfaces of piston. Advantages include elimination of heavy dependence on inherently weak interlaminar properties of carbon-carbon; ease of automation to reduce fabrication costs; readily modifiable architecture to vary mechanical properties to desired values; and reduction in number of elements required to fabricate pistons. Advantage of piston structures lies in applications where light weight and high specific performance primary considerations.

Taylor, Allan H.↗

NASA NTRS1990

Advanced Reusable Foam Cryogenic Insulation

Lightweight, reusable cryogenic containers reduce costs of operation of advanced hypersonic airplanes and space launch vehicles. Specimens demonstrated in temperature range of negative 420 to positive 400 degrees F (negative 251 to positive 204 degrees C). Prototype reusable cryogenic foam insulation developed. Consists of two discrete layers of closed-cell polymethacrylimide foam of density 6.9 lb/ft to the 3rd power (111 kg/m to the 3rd power) bonded together with epoxy adhesive. Additionally reinforced with 0.003-in. (0.08-mm)-thick layer of fiberglass cloth. Wrapped with precut and preformed vapor-barrier cover. Such containers useful on Earth in laboratories, factories, and transportation systems.

Taylor, Allan H.↗

NASA NTRS1990

Lightweight piston architecture

The invention is an improvement in a lightweight carbon-carbon composite piston, the improvement uses near-net shape knitted or warp-interlock preforms to improve the structural qualities of the piston. In its preferred embodiment, a one piece, tubular, closed-ended, knitted preform (a sock) of carbon fibers embedded within the matrix of the piston structure forms the crown, side wall, skirt and inner surface of the piston, and wrap-interlock preforms strengthen the piston crown and wrist pin bosses.

Taylor, Allan H.↗

NASA NTRS1988

Cryogenic Insulation System

This invention relates to reusable, low density, high temperature cryogenic foam insulation systems and the process for their manufacture. A pacing technology for liquid hydrogen fueled, high speed aircraft is the development of a fully reusable, flight weight cryogenic insulation system for propellant tank structures. In the invention cryogenic foam insulation is adhesively bonded to the outer wall of the fuel tank structure. The cryogenic insulation consists of square sheets fabricated from an array of abutting square blocks. Each block consists of a sheet of glass cloth adhesively bonded between two layers of polymethacrylimide foam. Each block is wrapped in a vapor impermeable membrane, such as Kapton(R) aluminum Kapton(R), to provide a vapor barrier. Very beneficial results can be obtained by employing the present invention in conjunction with fibrous insulation and an outer aeroshell, a hot fuselage structure with an internal thermal protection system.

Davis, Randall C.↗

NASA NTRS1988

Composite piston

A composite piston structure is disclosed which provides a simple and reliable means for joining a carbon-carbon or ceramic piston cap with a metallic piston body. Attachment is achieved by means of a special geometry which compensates for differences in thermal expansion without complicated mechanical fastening devices. The shape employs a flange created by opposed frustoconical shapes with coincident vertices intersecting on the radial centerline of the piston in order to retain the piston cap. The use of carbon-carbon for the piston cap material allows a close fit between the piston and a cylinder wall, eliminating the need for piston rings. The elimination of extra mechanical parts of previous composite pistons provides a lightweight composite piston capable of extended high temperature operation.

Taylor, Allan H.↗

NASA NTRS1987

Lightweight piston

A lightweight piston composed of carbon-carbon composites is presented. The use of carbon-carbon composites over conventional materials, such as aluminum, reduces piston weight and improves thermal efficiency of the internal combustion reciprocation engine. Due to the negligible coefficient of thermal expansion and unique strength at elevated temperatures of carbon-carbon, the piston-to-cylinder wall clearance is so small as to eliminate the necessity for piston rings. Use of the carbon-carbon composite has the effect of reducing the weight of other reciprocating engine components allowing the piston to run at higher speeds and improving specific engine performance.

Taylor, Allan H.↗

NASA NTRS1987

Reusable High-Temperature/Cryogenic Foam-Insulation System

Flightweight insulation withstands wide temperture cycling. Reusable insulation system for cryogenic containment vessels withstands repeated exposures to thermal environments that span ranges from cryogenic-fluid temperature {-425oF (-254oC)} to maximum use temperature of containment-tank material {+400oF (+204oC)}. System designed for use with high-speed flight vehicles.

Davis, Randall C.↗

NASA NTRS1987

Daze fasteners

A daze fastener system for connecting two or more structural elements wherein the structural elements and fastener parts have substantially different coefficient of thermal expansion physical property characteristics is employed in this invention. By providing frusto-conical abutting surfaces between the structural elements and fastener parts any differences in thermal expansion/contraction between the parts is translated to sliding motion and avoids deleterious thermal stresses in the connection. An essential feature for isotropic homogeneous material connections is that at least two sets of mating surfaces are required wherein each set of mating surfaces has line element extensions that pass through a common point.

Jackson, L. Robert↗