Aerojet-general Corporation

Atlantic Research Corporation

USA As Represented by Secretary of the Navy

Propellant Fracturing & Stimulation, LLC

Guy Bruce Spear

Robert D Lynch

Kenneth J Graham

Edna M Grove

Richard T Brown

Michael Digiacomo

Thomas F Davidson

John P Tiernan

William M Wallace

Mark Peyser Friedlander, Iii

Farid M Khadduri

Timothy L Ludlow

Don Landis

Peikuan Wu

Roger S Snyder

Katherine L Clopeck

Stephen H Tse, Jr

Michael D Allen

Solid propellant systems include a main propellant and a secondary propellant in contact with the first propellant that exhibits autoignition temperatures of at least about 100&#xb0; F. lower than the autoignition temperature of the main propellant. The secondary propellant of the present invention is most advantageously employed with conventional AP-containing solid propellant formulations as the main propellant, especially formulations containing both AP, an energetic solid, and a binder. In especially preferred forms, the secondary propellant will include a nitramine which is at least one selected from nitroguanidine (NQ), cyclotrimethylene trinitramine (RDX) and cyclotetramethylenetetranitramine (HMX), and a binder which is at least one selected from HTPB, HTPE or glycidyl azide polymer (GAP). Most preferably, the secondary propellant will include a combination of nitramines which includes NQ and one of RDX or HMX.

Rocket motors having controlled autoignition propellant systems

Controlled autoignition propellant systems

A fracturing system for wells has a propellant charge having a known surface area for combustion, and a combustion rate as a function of pressure with lower combustion rates at lower pressures and rapidly increasing combustion rates at higher pressures separated by a knee in the combustion rate function. The propellant charge is initially sealed within a vessel as it is inserted into a well. The system also includes means for creating openings in the vessel on ignition of the propellant charge in the well, such that the openings have a known combined flow area selected to create a condition of choked flow of combustion gases from within the vessel and maintain pressures within the vessel below the knee in the combustion rate function.

Propellant fracturing system for wells

A multi-pulse rocket is equipped with a thermally insulating barrier that serves as a rupture disk or a movable plug or plate separating staged propellant grains. When a rupture disk it used, the disk can be equipped with a pyrotechnic actuator to weaken the disk upon command, enabling the propellant grain on the fore side of the disk to burst the disk at a relatively low pressure when ignition of the propellant grain is needed for additional thrust. Rupturing of the disk can also be controlled by attitude maneuvering ports on the fore side of the barrier whose open or closed conditions are controlled by independently operable closures. When a movable plug is used, the plug is movable between a closed position separating rocket chamber into subchambers isolating the propellant grains from each other and an open position allowing the flow of combustion gas between the two subchambers to achieve additional axial thrust. In all cases, the barrier when intact serves to contain both propellant grains regardless of whether one or both is ignited. The propellant grain on the fore side of the barrier can thus be used for either axial thrust augmentation or for attitude maneuvering.

Multi-functional pulse-divided rocket

A piston tank with elongated contact between the piston and the tank bore to prevent piston cocking and preserve alignment is equipped with a compound piston that includes a carriage (or glider) and a barrier that is movable relative to the carriage. The carriage is an elongate ring with sealing and contact sites between the ring and the tank bore and axially spaced apart, and the barrier moves or changes shape in response to pressure differentials across the barrier imposed by a pressurized driving fluid. The barrier and carriage can thus move between a position allowing the full volume of the tank to be occupied by fuel or other functional fluid and a position ejecting all of the fuel or functional fluid out of the tank through an outlet port. Two examples of the barrier are disclosed&#x2014;a plate that is movable within the ring and a diaphragm affixed to the ring and deformable in both directions.

Piston tank with compound piston for high loading and expulsion efficiency

Control apparatus for a nozzle for a rocket or other vehicle having a combustion chamber with a propellant therein in communication with the nozzle, the nozzle having a throat and a pair of bores extending into the throat The bores may be in opposed or any other suitable relation. A pair of plungers are slidably mounted in the bores and are movable between an open position wherein they are disposed outside of the throat and a closed position wherein they extend into the throat to substantially close it. The plungers have a width or diameter substantially the same as the width or diameter of the throat. Actuator devices are provided for moving the plungers independently of each other to control thrust by controlling the flow of combustion gases through the throat and the pressure in the combustion chamber. The movement of the plungers can also be used for thrust vector control.

Nozzle throat area control apparatus and method

A test apparatus and method for a solid propellant, comprising a combustion chamber for the solid propellant, an igniter for igniting propellant in the combustion chamber, and an exhaust housing having a primary exhaust channel extending from the combustion chamber to an exit nozzle. A supplemental exhaust channel is connected to the primary exhaust channel, and a valve controls the size of the supplemental exhaust channel to selectively vary the flow of propellant gases therethrough, thereby to selectively vary the combustion chamber pressure to enable the testing of the burning characteristics of the propellant over a wide pressure range independent of the burning surface area of the propellant. In a further embodiment, an auxiliary exhaust channel closed by a burst disk is connected to the primary exhaust channel. The burst disk is constructed to fail at a predetermined pressure to enable exhaust gases to be vented through the auxiliary exhaust channel in the event the gas pressure in the primary exhaust channel exceeds the predetermined pressure.

Propellant test apparatus and method

A cost effective, efficient thermal insulation composition that will have ng shelf life and withstand severe high temperature and pressure conditions in high temperature solid propellant gas generators can be formed of an ethylene propylene, diene monomer (EPDM)/neoprene rubber binders containing silica powder filler and aramid fibers. The specific chemical constituents include EPDM elastomer, 2 Chlorobutadiene 1,3 elastomer, Silica hydrate, Polymerized Trimethyl Dihydroquinoline, Alkylated Diphenylamines and Diphenyl-p-Phenylendiamene, 40% a,a' Bis (Tert-Butylperoxy), Diisopropylbenzene, Napthenic Process Oil, Synthetic Polyterpene Resin, Aramid Fiber (0.25 inch), and Zinc Oxide, Technical.

Thermal insulation chemical composition and method of manufacture

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Orlean, VA, United States of America

Guy Bruce Spear