Abstract: A high energy system comprising a high energy electrical device powered by an electrical generator both of which are cooled by a cryogenic liquid oxidant stored in a storage tank. A power turbine powered by a combustor using fuel and the oxidant drives the electrical generator. A turbopump powered by a portion of exhaust flow from the power turbine pumps the cryogenic liquid oxidant from the storage tank to the generator and the device. In an exemplary embodiment of the system, the electrical device is a directed energy weapon, uses liquid air as the liquid oxidant, and uses a variable geometry turbine nozzle in the power turbine. A reheater may be used between a high pressure turbine and a lower pressure turbine of the power turbine. Compressor bleed from a gas turbine engine may provide air augmentation to the power turbine.

Abstract: An aircraft accessory system includes an aircraft engine powered direct air turbine driven accessory and an air turbine drivingly directly connected by an air turbine shaft to the accessory. The air turbine includes a variable geometry turbine nozzle in selectable direct flow communication with at least two compressed engine air sources. The two compressed engine air sources may be an HPC interstage bleed and an HPC compressor discharge stage bleed. The variable geometry turbine nozzle may be in selectable direct flow communication with a third compressed engine air source such as a bypass duct or an engine inlet duct. The air turbine includes a turbine exit which may be in selectable direct flow communication with at least two relatively lower pressure engine air sinks. The air sinks may be located in the aft end of a bypass duct and in a divergent section of the exhaust nozzle.

Abstract: A coating and method for reducing the tendency for coke and gum deposits of hydrocarbon fluids to form and adhere to a surface at an elevated temperature. The coating enhances surface flow conditions along the surface so as to reduce both surface reaction time and concentration of deposit precursors (radicals and atoms) that provide for polymer growth. The coating has a smooth surface that is free of microscopic pits and scratches, and preferably has a surface roughness not greater than about 16 microinches (about 4 micrometers) R.sub.a. The coating is also preferably resistant to chemical attack from contaminants in the fluid, and inhibits diffusion between the fluid and surface. In addition, the coating has a low surface wettability to hydrocarbons, meaning that the tendency for hydrogen in the fuel to bond with atoms at the coating surface (chemisorption) is reduced or eliminated.

Abstract: A fluid containment article that exhibits a reduced tendency for thermal decomposition products to deposit and adhere to its surface in contact with a hydrocarbon fluid, such as a hydrocarbon fuel, at elevated temperatures. Deposition and adhesion of thermal decomposition products are avoided by tailoring both the composition and surface finish of the surface contacting the hydrocarbon fluid. Preferred characteristics are achieved by appropriately preparing the surface of the article to have a surface roughness characterized by an R.sub.max of up to about 0.4 micrometer, and then depositing an oxide coating on the surface using a deposition process that yields a coating consisting essentially of a metal oxide and the vapors of an organometallic compound used in the deposition process.

Abstract: A system and method for providing clean cooling air to a hot portion of a gas turbine engine is disclosed, where the engine includes a compressor. The system includes a turbocompressor (66) having a compressor section and a turbine section, wherein the compressor and turbine sections each have an inlet and an outlet. The system further includes a heat exchanger (64) having a first inlet and a first outlet for a first fluid flow providing cooling to the heat exchanger, the first inlet being in fluid communication with a low temperature fluid. The heat exchanger (64) also has a second inlet and a second outlet for a second air flow receiving cooling from the heat exchanger, the second inlet being in fluid communication with high temperature air from the engine compressor and the second outlet being in fluid communication with the inlet of the compressor section of the turbocompressor.

Abstract: A gas turbine engine including air cooling and compressing means configured so that, in one embodiment, cool air from the cooling and compressing means is supplied to the combustor for cooling the combustor and then, after cooling at least a portion of the combustor, for mixing with fuel in the fuel injector, is described. In one form, the combustor includes a flowpath in flow communication with cool air supplied by the cooling and compressing means. The air flows through the flowpath from an aft portion to an outlet located at the fuel injector. The cooling air, after having cooled walls of the combustion chamber, mixes with fuel in the fuel injector. Mixing the high pressure air from the cooling and compressing means with the fuel in the fuel injector facilitates dispersion of fuel from the fuel injector into the combustion chamber, and also aids in increasing the fuel/air energy shear gradients.

Abstract: A superalloy component having a substrate article of a superalloy, and a strengthenable coating covering at least a portion of the substrate article. The coating exhibits thermal barrier characteristics and when cured formed a ceramic material. The component may further include a fiber layer between the substrate article and the coating, and the coating may be reinforced with fiber and the ceramic may be imbedded with inorganic particles. The coating is a foam obtained by reacting an admixture of (a) a silane polymer, (b) a silicone-vinyl resin and (c) a catalyst. The article is preferably a turbine blade. The component is useful as a gas turbine element.

Abstract: Articles for hot hydrocarbon fluid wherein the surface for contacting the fluid is a diffusion barrier material or a catalytic material coated on a metal substrate. The material is either catalytically-inactive tantalum oxide which inhibits the formation of coke in the fluid or catalytically-active zirconium oxide which promotes the formation of a loosely adherent coke in the fluid while inhibiting the formation of gum in the fluid. The coating materials, i.e., the diffusion barrier coating material and the catalytic coating material, are deposited by chemical vapor deposition (CVD), e.g., by effusive chemical vapor deposition of an organometallic compound on the surface without the use of carrier gas, without pre-oxidation of the surface and without thermal decomposition of the diffusion barrier material or the catalytic coating material.

Abstract: A superalloy component having a substrate article of a superalloy, and a strengthenable coating covering at least a portion of the substrate article. The coating exhibits thermal barrier characteristics and when cured formed a ceramic material. The component may further include a fiber layer between the substrate article and the coating, and the coating may be reinforced with fiber and the ceramic may be imbedded with inorganic particles. The coating is a foam obtained by reacting an admixture of (a) a silane polymer, (b) a silicone-vinyl resin and (c) a catalyst. The article is preferably a turbine blade. The component is useful as a gas turbine element.

Abstract: Articles for hot hydrocarbon fluid wherein the surface for contacting the fluid is a metal oxide, amorphous glass or metal fluoride diffusion barrier material coated on a metal substrate. The metal oxide, amorphous glass or metal fluoride is deposited by chemical vapor deposition (CVD), e.g., by effusive CVD of an organometallic compound on the surface without the use of carrier gas, without pre-oxidation of the surface and without thermal decomposition of the diffusion barrier coating material. Examples of coating materials deposited by effusive CVD are SiO.sub.2, TiO.sub.2, spinel and Al.sub.2 O.sub.3. The articles having the coated surfaces find utility in components subjected to high temperatures wherein the components are in contact with hydrocarbon fluids without additives, without special attention to quality control and without the need for special processing.

Abstract: A combustor, for a gas turbine engine, employing regenerative combustor cooling. The combustion gas flow direction extends generally longitudinally aft of the combustor fuel nozzle. A coolant flowpath between the combustor casing and the combustor liner has: 1) a longitudinally aft inlet in fluid communication with a source of compressor-derived cooling air, of lower temperature and higher pressure than diffused air from the combustor diffuser; and 2) a longitudinally forward outlet in fluid communication with the combustor fuel nozzle for "spent" cooling air to be used for combustion.

Abstract: A gas turbine engine cooling system. Hotter engine compressor air is cooled by a heat exchanger using a colder engine fluid (such as fuel or lower pressure (colder) engine compressor air. The cooled air passes through the compressor section of an auxiliary turbocompressor and is used to cool the engine high pressure turbine. Some of the cooled air (or uncooled discharge air from the engine high pressure compressor) is used to drive the turbine section of the turbocompressor. The spent air exiting the turbine section of the turbocompressor is used to help cool the engine low pressure turbine.

Abstract: This invention provides a method to mix a relatively large amount of non-condensable gas with fuel prior to gasification heating thus reducing the residence time of the fuel adjacent to hot surfaces. The non-condensable gas may be air, a cryogenic such as methane, or a chemical fraction of the gasified fuel which by itself does not promote the formation of significant amounts of gums or coke deposits.

Abstract: A scramjet engine for powering an aircraft at supersonic velocities is disclosed. The scramjet engine includes supersonic compressed airflow in a combustor along with a fuel for providing combustion. A monopropellant is also supplied adjacent to the airflow and fuel. The monopropellant is effective for expanding in the combustor for mixing the airflow and the fuel for the combustion of the airflow and fuel for generating combustion gases. In a preferred embodiment of the invention, the monopropellant is hydrazine and is effective for obtaining a specific volumetric increase of about 20,000:1.

Abstract: A gas turbine engine cooling system. A first turbocompressor and a heat exchanger are fluidly interconnected and are each in fluid communication to receive air of differing pressures and temperatures. Typically, such air is received from various regions of the engine low pressure compressor and the engine high pressure compressor. The system delivers air through a duct to a portion of the engine for cooling, such as the engine high pressure turbine region, at lower temperatures and higher pressures than if cooling air were directly ducted from the engine compressor to the engine turbine.

Abstract: An endothermic hydrocarbon fuel system to avoid thermally induced coking on the catalytic surfaces of an heat exchanger used as a reactor to dehydrogenate the fuel so that it provides a heat sink for the heat exchanger for cooling parts of high speed aircraft. The invention provides a means to feed an acceptable concentration of hydrogen to the reactor feed stock, wherein the feed stock is a portion of the endothermic hydrocarbon fuel that is catalytically dehydrogenated to provide a heat sink. The preferred embodiment uses Methylcyclohexane as a fuel and provides a return loop to recycle a fraction of the reaction products to provide the hydrogen to the reactor feedstock.

Abstract: A heat exchanger for use in high speed aircraft propulsion engines provides a plurality of heat pipes wherein the evaporator sections of the heat pipes are disposed in a hot fluid flow conduit and the condenser sections are disposed in a cold fluid flow conduit and the flow conduits are separated by a vented cavity and thin heat transfer fins are disposed around the condenser sections. Another embodiment provides a reactor using the heat exchanger and having a metalized, preferably with platinum, carbon fiber supported catalyst in the form of batting woven between the condenser sections of the heat pipes. The batting has platinum in the form of particles or more preferably in the form of small crystallites, typically about 1 to 5 nanometers in size.

Abstract: A heat exchange apparatus to heat hydrocarbon liquid fuel that is particularly useful for a combustion system and method of operation that by fuel in a heat exchanger and avoids undesirable thermal fuel deposits that would otherwise reduce the effectiveness of the heat exchanger. The invention provides a means to mix a relatively large amount of non-condensable gas with the fuel prior to gasification heating thus reducing the residence time of the fuel adjacent to the hot surface. The non-condensable gas may be air, a cryogenic such as methane, or a chemical fraction of the gasified fuel which by itself does of promote the formation of significant amounts of gums or coke deposits.

Abstract: An improved method of operating a scramjet engine for powering an aircraft at supersonic velocity is disclosed. The method includes the steps of providing supersonic compressed airflow in a combustor, supplying fuel to the compressed airflow in the combustor, and providing a monopropellant adjacent to the airflow and the fuel. The monopropellant is effective for expanding in the combustor for mixing the airflow and the fuel for combustion of the airflow and fuel for generating combustion gases. In a preferred embodiment of the invention, the monopropellant is hydrazine and is effective for obtaining a specific volumetric increase of about 20,000:1. An apparatus for carrying out the method of the invention is also disclosed.

Abstract: An aircraft gas turbine engine is provided with a starting air turbine that is directly connected through the starter gearbox to the high pressure (HP) shaft and is provided with an apparatus to extract excess energy from engine compressor bleed air, return it to the engine, and to start the engine with compressed air from starting air sources, and to cool and provide compressed air for powering the Environmental Control System (ECS) and using the bleed air for cabin refreshening. The air turbine may be connected to a nacelle boundary layer bleed compressor to bleed boundary layer air from a forward portion of the nacelle to reduce nacelle surface drag. The ECS may be provided with a wing boundary layer bleed means which uses a cooling air fan in the ECS to draw cooling air through the heat exchangers in the ECS pack from the boundary layer air from a forward portion of the aircraft's wing to reduce its surface drag.