Abstract: Nondetonable, or low detonation sensitivity, substantially nontoxic liquid monopropellants are provided. The liquid propellants are formed from aqueous solutions of solid oxidizers in liquid oxidizers and water soluble liquid fuels and formulated to have a freezing point less than ?10° C. Liquid oxidizers may be inorganic or organic aqueous solutions, with hydrogen peroxide being preferred. Preferred solid oxidizers are water soluble nitrates including ammonium dinitramide, aminoguanidine dinitrate, ammonium nitrate, hydroxylamine nitrate, hydrazine nitrate, guanidine nitrate and aminoguanidine nitrate. Preferred liquid fuels are water soluble alcohols, amines and amine nitrates, hydroxyethyl hydrazine, hydroxyethylhydrazine nitrate, cyanoguanidine, guanidines, aminoguanidines, triaminoguanidines, and their nitrate salts, ethanolamine dinitrate, ethylenediamine dinitrate, polyvinyl nitrate, and aziridine.

Abstract: An efficiency enhancing anode-magnetic structure of a Hall effect thruster produces a radially directed magnetic field between inner and outer poles at the exit portion of a gas distribution channel. The field-shaping structure includes magnetic material extending alongside the channel with an associated secondary flux-generating component to create an axially directed magnetic field in the area between the anode of the thruster and the exit portion of the gas distribution channel.

Abstract: Passive venting apparatus and method for a rocket motor or ordnance device containing propellant or explosive material enclosed in a case, which presents an explosion hazard when subjected to external heat. A combustible strip is secured to the exterior surface of the case and is constructed to burn and generate sufficient heat when exposed to predetermined external heat to weaken the adjacent portion of the case and effect rupture of the case to vent interior gases therein prior to autoignition of the propellant or explosive.

Abstract: A fire extinguisher includes a tank and a gas generator breech connected to the tank. The gas generator breech is provided with a hermetically sealed gas generator cartridge. The hermetically sealed gas generator cartridge avoids the need to have a release poppet or burst shims on the gas generator breech. The enclosed space that contains combustion gas pressure is provided by the gas generator cartridge itself and not the gas generator breech. The gas generator cartridge is made from a container that can be the precursor to a beverage can used for carbonated beverages. The beverage can may come in a thickness and material of construction that makes it a suitable, cost-effective container for the gas generator cartridge. However, other containers besides precursors of beverage cans can be used.

Abstract: The present invention provides, inter alia, novel fluorinated polyurethane elastomers (e.g., fluorinated thermoset polyurethane elastomers and fluorinated thermoplastic elastomers) prepared from polyether prepolymers formed from mono-substituted fluorinated oxetane monomers (FOX monomers) and tetrahydrofuran (THF). In addition, the present invention provides methods of making such fluorinated polyurethane elastomers.

Abstract: In a supersonic nozzle incorporating injectors and a combustion chamber as part of an expander cycle rocket engine, the oxidizer is injected in two streams. One of the streams, preferably a small fraction of the total, is injected into an upstream or preburner section of the combustion chamber and the other to a downstream or main section of the chamber. The preburner combustion gas is cooled in a substantially uniform manner to a moderate temperature by cooling the bulk of the gas rather than cooling only the gas in a boundary layer adjacent to the chamber wall. The combustion gas produced in the downstream section is hotter, and heat from that gas is drawn through the chamber wall into a jacket. The limited combustion in the preburner permits the use of a cooling element with highly intimate heat exchange construction, extracting a high level of energy from the preburner gas without damage to the cooling element and an overall improvement in the regenerative cooling.

Abstract: Radial loads and vibrations and axial loads on a rotor are balanced by a fluid bearing controlled by a self-regulating system that supplies fluid flow or pressure to the gap between the rotor and stator in response to signals of imbalance generated in the machinery itself. The resulting balancing force is thus created by fluidics, and in certain embodiments the sensing circuit is fluidics-based as well. This system provides enhanced flexibility and response time relative to conventional fluid bearings.

Abstract: This invention is directed to mono- and bis-substituted oxetane monomers having fluorinated alkoxymethylene side chains, hydroxy-terminated prepolymers derived from these mono- and bis-substituted oxetane monomers and tetrahydrofuran (THF), and polymers produced from these prepolymers, as well as the synthesis processes associated with each, and the use of the monomers, prepolymers and ultimate polymers, both directly and as components of numerous compositions.

Abstract: High temperature incendiary (HTI) devices and methods destroy biological and/or chemical agents. Preferably, such HTI devices include dual modal propellant compositions having low bum rate propellant particles dispersed in a matrix of a high burn rate propellant. Most preferably, the HTI device includes a casing which contains the dual modal propellant and a nozzle through which combustion gases generated by the ignited high burn rate propellant may be discharged thereby entraining ignited particles of the low burn rate propellant. In use, therefore, the high burn rate propellant will be ignited using a conventional igniter thereby generating combustion gases which are expelled through the nozzle of the HTI device. As the ignition face of the propellant composition regresses, the low burn rate particles will similarly become ignited.

Abstract: A convergent-divergent rocket nozzle is formed by joining two coaxially aligned conical sections at a throat plane, each diverging outward from the throat plane. Coolant channels formed in the wall of the nozzle are arranged in spirals around the nozzle axis. Preferably, the conical sections are formed from platelet laminates rolled into conical form with a single spiral seam, and at least one of the conical sections is a composite of two or more component conical sections separately formed and then joined in a nested arrangement with the seams not superimposed. A further preferred construction is one in which the convergent end of one conical section is split radially into strips that are then spread apart to serve as bonding surfaces to bond to the other conical section.

Abstract: Heat is extracted from the combustion gas in a rocket engine combustion chamber by diverting portions of the gas through channels in the nozzle wall. The channels are layered between channels of coolant, which in expander cycle rocket engines is uncombusted fuel, to achieve intimate heat exchange between the combustion gas and the fuel. The combustion gas channels are relatively short, returning combustion gas thus cooled to the chamber interior. By drawing combustion gas from the chamber interior into the chamber wall, the cooling process no longer relies on the combustion gas boundary layer for heat transfer as in the prior art.

Abstract: In a supersonic nozzle incorporating injectors and a combustion chamber as part of an expander cycle rocket engine, the oxidizer is injected in two streams. One of the streams, preferably a small fraction of the total, is injected into an upstream or preburner section of the combustion chamber and the other to a downstream or main section of the chamber. The preburner combustion gas is cooled in a substantially uniform manner to a moderate temperature by cooling the bulk of the gas rather than cooling only the gas in a boundary layer adjacent to the chamber wall. The combustion gas produced in the downstream section is hotter, and heat from that gas is drawn through the chamber wall into a jacket. The limited combustion in the preburner permits the use of a cooling element with highly intimate heat exchange construction, extracting a high level of energy from the preburner gas without damage to the cooling element and an overall improvement in the regenerative cooling.

Abstract: A convergent-divergent rocket nozzle is formed by joining two coaxially aligned conical sections at a throat plane, each diverging outward from the throat plane. Coolant channels formed in the wall of the nozzle are arranged in spirals around the nozzle axis. Preferably, the conical sections are formed from platelet laminates rolled into conical form with a single spiral seam, and at least one of the conical sections is a composite of two or more component conical sections separately formed and then joined in a nested arrangement with the seams not superimposed. A further preferred construction is one in which the convergent end of one conical section is split radially into strips that are then spread apart to serve as bonding surfaces to bond to the other conical section.

Abstract: High temperature incendiary (HTI) devices and methods destroy biological and/or chemical agents. Preferably, such HTI devices include dual modal propellant compositions having low burn rate propellant particles dispersed in a matrix of a high burn rate propellant. Most preferably, the HTI device includes a casing which contains the dual modal propellant and a nozzle through which combustion gases generated by the ignited high burn rate propellant may be discharged thereby entraining ignited particles of the low burn rate propellant. In use, therefore, the high burn rate propellant will be ignited using a conventional igniter thereby generating combustion gases which are expelled through the nozzle of the HTI device. As the ignition face of the propellant composition regresses, the low burn rate particles will similarly become ignited.

Abstract: Heat is extracted from the combustion gas in a rocket engine combustion chamber by diverting portions of the gas through channels in the nozzle wall. The channels are layered between channels of coolant, which in expander cycle rocket engines is uncombusted fuel, to achieve intimate heat exchange between the combustion gas and the fuel. The combustion gas channels are relatively short, returning combustion gas thus cooled to the chamber interior. By drawing combustion gas from the chamber interior into the chamber wall, the cooling process no longer relies on the combustion gas boundary layer for heat transfer as in the prior art.

Abstract: A stack of very thin metal plates provides high surface area for catalytic decomposition of a fluid flowing axially from upstream to downstream through the stack. Each plate has flow-through passages of selected size and location to promote uniform flow and good surface contact with a catalyst surface on the plates. The downstream surface of each plate is etched to provide gaps between plates for lateral fluid flow. The plates are divided into groups separated by metering plates that promote more uniform flow from group to group.

Abstract: A discharge valve element seals the outlet of a fire extinguisher vessel holding a fire suppressant. A source of gas pressurizes the suppressant at least when the extinguisher vessel is in a discharging condition. When the pressure acting on the element exceeds the threshold, the force resisting opening the element is overcome and substantially eliminated, whereupon the suppressant discharges through the outlet.

Abstract: A system for uniformly distributing propellant gas in a Hall-effect thruster (10) (HET) includes an anode (42, 42′) and a porous material gas distributor (60, 89) (PMGD). The porous material (120) may be porous metal or porous ceramic. Propellant gas is directed from a supply to the PMGD for distribution into a gas discharge region (16) of the HET (10). The gas flows through the porous material (120) of the PMGD and out of the PMGD's exit surface (71) into the annular gas discharge region (16). The PMGD has an average pore size, pore density and thickness that are optimized to control the flow of the gas at the desired flow rate and distribution uniformity at a relatively short distance downstream from the PMGD. This feature allows HET to be short, significantly decreasing susceptibility to vibration problems encountered during vehicle launch. The PMGD can include a shield (79, 80) for preventing contaminants from traveling upstream from the gas discharge region from adhering to the porous metal.

Abstract: An apparatus for fire suppression may include a flexible container, a gas generant or other suppressant, initially located within the flexible container, and an initiator. A propagating member may be located within the container to permit the initiator to initiate the generant or expel the other suppressant upon triggering of the initiator to extinguish the fire. A sustainer may be provided to sustain the suppression and may be positioned within a generator housing upstream of the propagating member or at or adjacent the downstream end of the propagating member.

Abstract: This invention is directed to mono- and bis-substituted oxetane monomers having fluorinated alkoxymethylene side chains, hydroxy-terminated prepolymers derived from these mono- and bis-substituted oxetane monomers and tetrahydrofuran (THF), and polymers produced from these prepolymers, as well as the synthesis processes associated with each, and the use of the monomers, prepolymers and ultimate polymers, both directly and as components of numerous compositions.