Abstract: A porous substrate of a fuel cell electrode assembly is formed by producing a fibrous carbon precursor web by means of a conventional wet paper-making process. The precursor web is then dried and saturated with a wet resinous binder which will carbonize when heated. Substantially the entirety of all of the carbon fibers in the web are thus coated with the binder, and substantially all of the inter-fiber junctures in the web will also be coated with the binder. The saturated web is then dried, and heat treated to convert the binder to a glassy carbon which exhibits superior resistance to corrosion.

Abstract: A continuous, pinhole-free thermoplastic polymer coating, which may be a fluoroelastomer, is applied to a porous metal surface in a single coating step by spraying the thermoplastic polymer from a thermal spray gun onto a porous metal surface which is at substantially room temperature to form a semi-fused, highly porous coating. The porous metal surface is then heated to fuse the thermoplastic polymer coating into a well-anchored, continuous film. This method permits the application of a continuous thermoplastic polymer coating with one coating step rather than with the plurality of coating steps currently needed to produce a coating with comparable properties.

Abstract: Optical fibers are used for monitoring the structural integrity of space based or aircraft structures where prompt notification of damage is required to effect rapid repair and thereby maintain safety and operational reliability. A plurality of optical fibers are disposed in an X-Y relationship, with the fibers optimally placed in a pattern comprised of multiple path reversals which provides extensive area coverage with a minimum of fibers thus defining multiple zones wherein damage within a zone is determined by interruption of the light through the damaged fibers.

Abstract: A noble metal ternary alloy catalyst, which has increased mass activity and stability. This catalyst comprises a ternary alloy of platinum, iridium and a metal selected from the group consisting of iron, chromium, cobalt, nickel, vanadium, titanium and manganese.

Abstract: A composition and method for removing deposits (10) from the internal components (24) of a gas turbine engine (18) utilizing a cleaning composition (15) which comprises an aqueous solution of hydroxylamine sulfate, a chelating agent, a compound selected from the group consisting of ammonium sulfamate, ammonium sulfamide, and hydroxylamine-o-sulfonic acid, and, an alkaline pH modifying substance added in an amount sufficient to achieve a pH value of between 6.5 and 14. The method involves contacting the deposits with the cleaning composition, such as in an apply and soak type pattern, chemically dislodging the deposits from the component surfaces. The engine is rinsed to remove the dislodged deposits and residual cleaning composition.

Abstract: Spaced based burst power fuel cells generate large thermal loads in very short time periods. In order to avoid external venting or the use of heavy radiators in space vehicles, such fuel cells must include onboard closed-loop cooling systems. Utilizing subcooled ice as a cooling medium, contactable with either the anode, cathode or coolant recirculating stream provides the fuel cell with a safe, highly efficient and low weight heat absorption capability.

Abstract: A coolable thin metal sheet incorporated in an exhaust nozzle for a gas turbine powered aircraft includes a hot surface, a cool surface and a plurality of triangular sloped depressions which project through the cold gas side of the sheet. Each depression includes a gradually sloped essentially triangular surface which extends gradually in the direction of flow, from a deep, flat faced apex to a flush base, with the apex providing a flat surface perpendicular to the sloped surface. A hole, drilled through the apex admits cooling air which forms a film on the hot gas surface. Utilizing a plurality of such depressions provides precise control of the quantity and direction of cooling gas admitted while allowing use of the thinnest material meeting mechanical requirements, providing optimized film cooling while minimizing nozzle weight.

Abstract: The periodic shedding of vortices produced in a highly sheared gas flow, such as that encountered at the grain transition boundary in a solid propellant rocket motor or at the combustor inlet to a ramjet engine, is a significant source of acoustic instability which may result in unstarting of the ramjet engine or excessive vibration of the rocket motor. By restricting the transition boundary or combustor inlet at the sudden expansion dump plane (5), such as by locating an orifice plate (13) at the dump plane, the gas flow is separated upstream and produces a vena contracta downstream of the orifice, inhibiting the feedback of acoustic pressure to the point of flow separation and preventing the formation of organized oscillations. Incorporation of such a simple thin plate orifice at the dump plane reduces the periodic acoustic oscillations and thereby controls the detrimental oscillatory pressure fluctuations.

Abstract: Spaced based burst power fuel cells generate large thermal loads in very short time periods. In order to avoid external venting or the use of heavy radiators in space vehicles, such fuel cells must include onboard closed-loop cooling systems. Utilizing multiple heat sinks containing subcooled ice as a cooling medium, sequentially contactable with a coolant that passes through the fuel cell, provides a safe, highly efficient and low weight heat absorption capability.

Abstract: High activity sulfur tolerant steam reforming catalysts are described comprising iridium, palladium or platinum supported on lanthanum stabilized alumina or magnesium promoted lanthanum stabilized alumina. The catalysts have improved activity over conventionally used catalysts in the presence of sulfur containing hydrocarbon fuels, particularly in a steam reforming environment. The catalysts have utility in autothermal, tubular, cyclic and adiabatic steam reforming processes.

Abstract: A wire coating oven (2) is disclosed which includes a wire cooling apparatus (1) for cooling a wire (3) passing therethrough, while minimizing gaseous emissions. The cooling apparatus includes a wire cooling passage (10) having a wire entrance end (13) adjacent the oven and a wire exit end open to the atmosphere, with the wire cooling passage defined by a first wall (11) which surrounds the wire passing therethrough. A hot gas passage (15) is defined by a spacing between the first wall and a second wall (14) disposed adjacent thereto with hot gas entering the passage at about the wire exit end and exiting at the oven end. The first wall includes an outwardly tapered surface (19) near the wire entrance end for forming a venturi with the second wall, whereby a hot gas passing therebetween creates a negative pressure within the wire passage, drawing cool air (20) into the wire passage, cooling the wire and drawing any vaporous emissions into the oven.

Abstract: The lag-torsion flexure portion (16) of a flexbeam (10) having segregated lag-torsion flexure portions (16) and flap flexure portions has multiple longitudinal lobes (98A-98G, 100A-100G) formed by multiple grooves (90A-90F, 92A-92F) extending from the upper (94) and lower (96) surfaces of the lag-torsion flexure portion to a central planar portion (102) thereof. The bases of the grooves are radiused (r) for favorable stress distribution while allowing for torsional and lead/lag softness in the lag-torsion flexure portion. The preferred number of grooves is an even number, such as six, resulting in an odd number of lobes. The lobes may decrease in height from the central lobe to the edgemost lobes (FIG. 12A). The lobes may be radiused at the upper and lower surfaces of the lag-torsion flexure portions (FIG. 12B). The lobes may be formed of alternate layers of unidirectional longitudinal fiber (32) extending the length of the flexbeam and elastomeric material (112) (FIG. 12D).

Abstract: A cooled highly twisted airfoil (1) includes an integrally formed continuous warped wall (12) defined as a surface of revolution about an axis (13) with the axis determined such that the axis intersects the plane of a section along a desired centerline. Such an internal wall structure separates adjacent cooling cavities (10) and (11) and includes relatively precisely aligned impingement holes (14) for directing cooling air to the leading edge (6) of a highly twisted airfoil. Such a structure minimizes the complexity of the ceramic core and die inserts required to cast such an airfoil, thereby decreasing manufacturing costs while increasing the overall cooling efficiency of the blade.

Abstract: A plastic composite sabot (1) includes an integrally molded rearwardly located deformable shoulder (6) which engages the grooves (10) in a rifled barrel (7). The sabot also includes mid and forward sections (4) and (5) which engage the lands (11) in the rifled barrel, and, an axially disposed projectile retaining chamber (13). An obturator (17), attached by pins to the sabot, drives the sabot and projectile through the barrel on firing. Utilizing a unitary plastic composite sabot substantially lessens manufacturing costs and increases projectile stability while reducing overall weight, thereby optimizing projectile velocity and accuracy while minimizing costs.

Abstract: A workholder (6) has a contoured bonding surface (7), which essentially matches a contoured surface (4) of an airfoil (1). A plurality of studs (8) are disposed within a plurality of tapped holes (9) located about the workholder bonding surface. In operation, the studs are extended outwardly from the surface, and both the studs and bonding surface are contacted with a release agent (10). A curable resinous material (11) is applied to the bonding surface and studs, and an airfoil positioned next to the bonding surface, sandwiching the resinous material therebetween. After curing, a plurality of tapped holes (13) are formed in resin layer (11), with the extended studs fixably positioning the airfoil relative to the workholder. Removing the studs provides heatless release of the airfoil from the workholder.

Abstract: A coated nickel base superalloy single crystal turbine airfoil blade (1), which is subject to gas turbine engine operation, can crack during refurbishment by a stress corrosion mechanism when exposed to certain corrosive media. The rapid thermal cycling that occurs during typical gas turbine engine operation results in high, non-uniform stresses across the airfoil, producing large localized residual strains in the article at ambient temperatures. Exposure to a corrosive environment, such as during coating removal or agressive cleaning, can produce chordwise cracks in a large number of the airfoils exposed. Such cracking is avoided by subjecting the articles to a preliminary stress relieving heat treatment which reduces the residual strains to a level below which cracking will not occur, prior to exposure to the corrosive media.

Abstract: A gas turbine vane (1) is subject to distortion and wear during operation or repair which results in an increase in the spacing between successive vanes (6 and 7) which define nozzle gas flow areas (8 and 9). During refurbishment, the nozzle spacing must be returned to the original dimension to insure optimum turbine performance. A build up of alloy in the wear area is accomplished by controllably applying layers of a tape (12) of uniform thickness to the vane. The tape includes a mixture of a binder and an alloy powder, which is compatible with the substrate alloy, with the mixture formed into a sheet of uniform thickness and having an adhesive backing. After applying the tape in layers to a desired thickness, the vane is heated to a temperature at which the binder and adhesive decompose and the alloy in the tape diffusion bonds with the substrate alloy. Utilization of this process reduces the cost of refurbishing used turbine vanes and avoids hot forming or bending processes which could damage the vanes.

Abstract: A ram cannon (1) has an extendable barrel (2) slidably disposed over a starter cannon barrel (7). Such an extendable barrel is fully retractable during transport of the cannon and extendable at the time of firing. The barrel is also partially extendable, thereby providing a means to vary the muzzle velocity of a projectile (6) without varying the ratio of the fuel to the oxidizer in the propellant mixture. Utilizing an extendable barrel allows adapting a ram cannon to mobile artillery weapons, providing ease in transport, setup and firing, with a precise and rapid range adjustment capability.

Abstract: A composition and method for removing deposits (10) from the internal components (24) of a gas turbine engine (18) utilizing a cleaning composition (15) which comprises an aqueous solution of hydroxylamine sulfate, a chelating agent, a compound selected from the group consisting of ammonium sulfamate, ammonium sulfamide, and hydroxylamine-o-sulfonic acid, and, an alkaline pH modifying substance added in an amount sufficient to achieve a pH value of between 6.5 and 14. The method involves contacting the deposits with the cleaning composition, such as in an apply and soak type pattern, chemically dislodging the deposits from the component surfaces. The engine is rinsed to remove the dislodged deposits and residual cleaning composition.