Abstract: A coin handling apparatus having: a first coin position; a second coin position; and a pipe for transporting coins from the first to the second coin position. The pipe is jointed and has a rigid, elongate element having a straight, elongate portion and a curved portion at a first end of the straight, elongate portion. The pipe further includes a rigid, curved element. The curved portion and the curved element are connected to define a continuous passageway through the curved element and the elongate element. The curved element, at least before mounting of the pipe in the coin handling apparatus, is rotatable in relation to the elongate element, such that an angle between a first opening of the curved element and a direction extending along the straight elongate portion is variable.

Abstract: A rocket motor has an electrically operated propellant initiator for a propellant grain that includes an electrode arrangement configured to concentrate an electric field at an ignition electrode for igniting an electrically operated propellant. The rocket motor includes a combustion chamber containing at least one propellant grain and an electrically operated propellant initiator operatively coupled to the propellant grain to initiate combustion of the propellant grain. The electrically operated propellant initiator includes the electrically operated propellant and at least one pair of electrodes configured to ignite the electrically operated propellant. The pair of electrodes includes a ground plane electrode and an ignition electrode. When an electrical input is applied to the electrically operated propellant initiator, the electric field is concentrated at the ignition electrode to ignite the electrically operated propellant at the location where the ignition electrode is arranged.

Abstract: A method and apparatus for simulating icing conditions using a wind tunnel is provided. Water drops are sprayed from a number of nozzles into the wind tunnel. A mist of cryogenic liquid is sprayed into a path of the water drops downwind of the nozzles in the wind tunnel, wherein the mist of cryogenic liquid turns the water drops into ice crystals.

Abstract: Implementations of a combustor assembly yield low emissions, require low power, are suitable for alternate liquid fuels, including highly viscous fuels, and are scalable for various heat release rates. The combustor assembly includes a fuel injector and a swirler. The fuel injector may include a choke portion and a spacer. The choke portion is disposed just upstream of an outlet of a liquid fuel conduit and prevents atomizing gas from interrupting continuous flow of the liquid fuel through the liquid fuel conduit. The spacer is disposed downstream of the outlet to precisely control the gap and thus, bifurcation of atomizing gas flow, between the outlet of liquid fuel conduit and an inlet of an orifice plate. The swirler is disposed radially outwardly and adjacent the fuel injector and includes a plurality of angled vanes.

Abstract: A rotating detonation engine includes an annulus that defines a volume in which a mixture of an oxidizer and a fuel detonate in a rotating fashion, the volume defining a downstream outlet through which detonation exhaust flows. The rotating detonation engine further includes a wave arrestor positioned upstream from a location of detonation and configured to reduce a magnitude of a pressure wave traveling upstream from the location of detonation.

Abstract: The invention relates to the aerospace field, and in particular to the field of vehicles propelled by rocket engines. In particular, the invention relates to a feed circuit (6) for feeding a rocket engine (2) at least with a first liquid propellant, the feed circuit including at least one first heat exchanger (18) suitable for being connected to a cooling circuit (17) for cooling at least one heat source in order to cool said heat source by transferring heat to the first propellant, and, in addition, downstream from said first heat exchanger, a branch passing through a second heat exchanger.

Abstract: The present disclosure relates to an engine having two modes of operation—air breathing and rocket—that may be used in aerospace applications such as in an aircraft, flying machine, or aerospace vehicle. The engine's efficiency can be maximized by using a precooler arrangement to cool intake air in air breathing mode using cold fuel used for the rocket mode. By introducing the precooler and certain other engine cycle components, and arranging and operating them as described, problems such as those associated with higher fuel and weight requirements and frost formation can be alleviated.

Abstract: A system and method of operating an engine anti-ice system includes supplying heat from one or more heat sources to one or more components on or within a gas turbine engine, sensing data representative of one or more parameters related to ice crystal accretion, and based on the data, at least selectively inhibiting at least selected ones of the one or more heat sources from supplying heat to at least selected ones of the one or more components on or within the gas turbine engine.

Abstract: This invention relates to an engine (2) for use in aerial vehicle (1) including a rocket (9) and ram jet engine formed from an intake (8) and a combustion chamber (10). The rocket engine (9) includes an oxidiser combustion chamber (21) which exhausts through the combustion chamber (10). The engine also includes a nozzle (12). Both the intake (8) and nozzle (12) include rectilinear ducts which are defined in part by baffles (16) and panels (33) respectively. Both the baffles (16) and panels (33) are adjustable to adjust the airflow characteristics therethrough.

Abstract: The present invention relates to a reactor for the decomposition of ammonium dinitramide-based liquid monopropellants into hot, combustible gases for combustion in a combustion chamber, and a rocket engine or thruster comprising such reactor, wherein the reactor comprises a heat bed exhibiting catalytic activity.

Abstract: An acoustic resonance igniter uses gas expanding through a nozzle to form a sonic, or under-expanded supersonic, jet directed against the opening of a blind resonance cavity in a central body, setting up a high-frequency sonic resonance which heats the gas within the cavity. A pintle extends coaxially with the nozzle and injects liquid propellant into the jet. The liquid propellant ignites with the heated gas within the resonance cavity forming combustion gases. The combustion gases flow through openings in a flange which supports the resonance cavity into a combustion chamber in the same direction as the gas jet flows. The liquid propellant is injected from within the support flange in the direction of combustion gas flow to film cool the combustion chamber wall and the flange and the central body supported by the flange. The acoustic resonance igniter may form a rocket engine ignition torch or a RCS thruster.

Abstract: Disclosed is a turbo pump in which a pump impeller is connected to one end of a rotary shaft and a turbine is connected to the other end of the rotary shaft. The turbo pump is designed such that an equivalent region, between a turbine efficiency curve obtained on the basis of a conditional expression where the number of rotations of the rotary shaft is maintained constant regardless of a pump flow rate and a turbine efficiency curve of an actual machine, becomes an operation region.

Abstract: Supply of a liquid component in a combustion chamber of a rocket engine is controlled by a feed valve provided with slide valve mobile between an open position and a closed position of at least one supply pipe, which has an inlet that communicates with a tank for containing the liquid component and an outlet that communicates with the combustion chamber. The displacement of the slide valve from its closed position to its open position is triggered by a pressurized fluid supplied to the outlet of the supply pipe.

Abstract: A propellant tank for storing a liquid propellant A and supplying vapor produced by evaporation of part of the liquid propellant A to an external location comprises a tank body for storing the liquid propellant A, a mesh member arranged inside the tank body to cover a liquid surface of the liquid propellant A to divide an interior of the tank body into a liquid propellant storing area LA and a gas storing area GA by utilizing surface tension of the liquid propellant, and a heater arranged to a gas storing area GA side of the tank body to keep the gas storing area GA at higher temperature than temperature in the liquid propellant storing area LA. The tank body has a propellant inlet open into the liquid propellant storing area LA and a gas outlet open into the gas storing area GA.

Abstract: A system and methods are provided for combining systems of an upper stage space launch vehicle for enhancing the operation of the space vehicle. Hydrogen and oxygen already on board as propellant for the upper stage rockets is also used for other upper stage functions to include propellant tank pressurization, attitude control, vehicle settling, and electrical requirements. Specifically, gases from the propellant tanks, instead of being dumped overboard, are used as fuel and oxidizer to power an internal combustion engine that produces mechanical power for driving other elements including a starter/generator for generation of electrical current, mechanical power for fluid pumps, and other uses. The exhaust gas from the internal combustion engine is also used directly in one or more vehicle settling thrusters. Accumulators which store the waste ullage gases are pressurized and provide pressurization control for the propellant tanks.

Abstract: An improved rocket engine system including a rocket engine, a coolant source, and a propellant source. Each of coolant source and propellant source is in operative communication with rocket engine whereby there is independent regulation or control of coolant source flow relative to propellant source flow. The improved rocket engine system may further include one or more of: at least one power source, at least one power source motor, at least one pump, at least one controller, and a propellant pressurizing source. The propellant source preferably includes a fuel source and an oxidizer source. An embodiment includes a cooling system with a coolant source, a fuel system with a fuel source, an oxidizer system with an oxidizer source, a propellant pressurizing system with a propellant pressurizing source, multiple pumps, an assembly of power source and controller, and a main rocket engine assembly.

Abstract: A system and method of cooling a rocket motor component includes injecting a high pressure liquid coolant through an injector nozzle into a cooling chamber. The cooling chamber having a pressure lower than the high pressure liquid coolant. The liquid coolant flashes into a saturated liquid-vapor coolant mixture in the cooling chamber. The saturated liquid-vapor coolant mixture is at equilibrium at the lower pressure of the cooling chamber. Heat from the rocket motor component to be cooled is absorbed by the coolant. A portion of the liquid portion of the saturated liquid-vapor coolant mixture is converted into gas phase, the converted portion being less than 100% of the coolant. A portion of the coolant is released from the cooling chamber and the coolant in the cooling chamber is dynamically maintained at less than 100% gas phase of the coolant as the thrust and heat generated by the rocket motor varies.

Abstract: Disclosed is a liquid-fuel storage vessel for use in a vapor jet system to store liquid fuel, wherein the vapor jet system is adapted to jet the fuel in a state after being vaporized inside the liquid-fuel storage vessel, outside the liquid-fuel storage vessel, to obtain a thrust. The liquid-fuel storage vessel comprises: a hollow tank for storing the liquid fuel, wherein the tank has an ejection port for ejecting the vaporized fuel, outside the liquid-fuel storage vessel therethrough; a heating device for heating the tank; and a porous metal formed to have a plurality of interconnected cells and provided inside the tank, wherein at least a part of the liquid fuel is held in the cells of the porous metal, and heat energy given from the heating device to the tank is transferred to the liquid fuel through the porous metal to cause vaporization of at least a part of the liquid fuel. The liquid-fuel storage vessel of the present invention can obtain a stable thrust level and ensure spacecraft attitude control.

Abstract: A method for determining the optimum inlet geometry of a liquid rocket engine swirl injector includes obtaining a throttleable level phase value, volume flow rate, chamber pressure, liquid propellant density, inlet injector pressure, desired target spray angle and desired target optimum delta pressure value between an inlet and a chamber for a plurality of engine stages. The tangential inlet area for each throttleable stage is calculated. The correlation between the tangential inlet areas and delta pressure values is used to calculate the spring displacement and variable inlet geometry. An injector designed using the method includes a plurality of geometrically calculated tangential inlets in an injection tube; an injection tube cap with a plurality of inlet slots slidably engages the injection tube. A pressure differential across the injector element causes the cap to slide along the injection tube and variably align the inlet slots with the tangential inlets.

Abstract: Disclosed are a method and device for supplying a combustion chamber of a space propulsion engine with cryogenic liquid fuel and oxidizer propellants. The propellants are mixed at constant pressure to produce a propellant mixture, with the propellants being mixed at a location upstream of an orifice of a propellant injector. The propellant mixture is fed to an enclosure of the propellant injector, and from the propellant injector enclosure, the propellant mixture is injected into the combustion chamber. The flow rate of the propellant mixture from the propellant injector enclosure into the combustion chamber is varied by adjustment of the propellant injector, with the injection of the propellant mixture from the propellant injector enclosure into the combustion chamber being at constant pressure.

Abstract: A cryogenic tank for a space launcher, comprising a partition and delimiting top and bottom volumes communicating via at least one free central opening formed in the partition, so as, on the one hand, to allow for the flow of liquid by gravity from the top volume to the bottom volume via the central opening or openings and, on the other hand, to prevent the rising of the fluid from the bottom volume to the top volume via the central opening or openings under the action of acceleration forces, the tank also comprising at least one vent forming separate from the central opening or openings and providing fluid communication between the top and bottom volumes, the vent being configured to favor the migration of vapor from the bottom volume to the top volume and to prevent the rising of liquid from the bottom volume to the top volume.

Abstract: A centrifugal impeller with a single inlet and dual outlets that include a low pressure outlet and a high pressure outlet. The impeller includes low pressure blades with high pressure blades located downstream. The impeller can be shrouded or unshrouded, and can include an inner shroud that forms a flow path for the low pressure fluid and a high pressure flow path for the high pressure fluid. The impeller can include a high pressure volute and a low pressure volute that forms a dual volute with dual diffusers for both fluids.

Abstract: The device for injecting a liquid mono-propellant with a large amount of modulation of its flow rate and disposed at an upstream end of the wall of a combustion chamber of a rocket engine has a feed channel for feeding a mono-propellant from a tank. The device includes a single annular speed-up channel connected to the feed channel and having its outlet opening out via an annular injection section, the speed-up channel and the annular injection section being defined firstly by a first wall forming a stationary surface of revolution situated level with said upstream end, and secondly by a second wall forming a surface of revolution that is on a part that is movable in translation relative to the first wall forming a stationary surface of revolution.

Abstract: A liquid propellant tank for storing a liquid propellant A and supplying vapor produced by evaporation of part of the liquid propellant A to an external location comprises a tank body for storing the liquid propellant A, and a plurality of holder plates arranged inside the tank body, around an axis L of the tank body. The holder plates cause the liquid propellant A to adhere to them by surface tension, thereby establishing, inside the tank body, a liquid propellant holding area LA in which the liquid propellant A is held and a gas accumulation area GA in which vapor produced by evaporation of part of the liquid propellant A accumulates. The tank body has a propellant inlet open into the liquid propellant holding area LA and a gas outlet open into the gas accumulation area GA.

Abstract: A rocket propulsion system having a liquid fuel tank and a liquid oxidizer tank, where a liquid inert gas tank supplies liquid inert gas to a liquid inert gas pump driven by a turbine of the engine to pressurize the liquid inert gas, which is passed through a heat exchanger around the nozzle to vaporize the inert gas, that is then used to pressurize the liquid oxidizer tank so that a liquid oxidizer pump is not needed, or to pressurize both the liquid oxidizer tank and the liquid fuel tank so that a liquid oxidizer pump and a liquid fuel pump are not needed in the rocket engine.

Abstract: A hybrid rocket motor includes a supply of oxidizer, a first solid fuel element positioned around the supply of oxidizer, a second solid fuel element positioned concentrically around the first solid fuel element, and a combustion port positioned between the first and second solid fuel elements. The oxidizer interacts with the first and second solid fuel elements within the combustion port to produce a combustion product. A nozzle is in communication with the combustion port for combustion discharge of the combustion product.

Abstract: A demisable fuel supply system for a satellite includes a pressurized aluminum alloy tank with an aluminum alloy propellant management device therein. The propellant management device (PMD) can have any capillary action surface tension fluid transport features known in the art. Selected inner surfaces of the tank and the PMD are covered with a plasma powder sprayed titanium based coating to guarantee propellant wettability and corrosion resistance of the fuel supply system.

Abstract: A demisable fuel supply system for a satellite includes a pressurized aluminum alloy tank with an aluminum alloy propellant management device therein. The propellant management device (PMD) can have any capillary action surface tension fluid transport features known in the art. Selected inner surfaces of the tank and the PMD are covered with a titanium based coating to guarantee propellant wettability and corrosion resistance of the fuel supply system.

Abstract: The present disclosure generally pertains to a rocket propulsion oxidizer compound that is a solution, is a homogenous and stable liquid at room temperature and includes nitrous oxide and nitrogen tetroxide. In addition, an apparatus is provided for burning a fuel and nitrous oxide/nitrogen tetroxide. The apparatus has a combustor, a catalyst, a nitrous oxide/nitrogen tetroxide supply passage for directing the nitrous oxide/nitrogen tetroxide to a contact position with the catalyst, and a fuel supply passage for supplying the fuel to the combustor. The catalyst acts to facilitate decomposition of the nitrous oxide/nitrogen tetroxide, while the combustor burns the fuel, the decomposed nitrous oxide/nitrogen tetroxide and/or nitrous oxide/nitrogen tetroxide decomposed in the reaction.

Abstract: A dual fuel propulsion system comprising a gas turbine engine configured to generate a propulsive thrust using a cryogenic liquid fuel.

Abstract: A bellows includes a flexible section including a series of convolutions extending between a first end and a second end. The convolutions are formed of a nano-grained aluminum alloy.

Abstract: The fluid and heat transfer theory for regenerative cooling of a rocket combustion chamber with a porous media coolant jacket is presented. This model is used to design a regeneratively cooled rocket or other high temperature engine cooling jacket. Cooling jackets comprising impermeable inner and outer walls, and porous media channels are disclosed. Also disclosed are porous media coolant jackets with additional structures designed to transfer heat directly from the inner wall to the outer wall, and structures designed to direct movement of the coolant fluid from the inner wall to the outer wall. Methods of making such jackets are also disclosed.

Abstract: The electrolytic ignitor comprises an injector constituting a first electrode, a second electrode that is electrically insulated from the injector and that extends downstream beyond the injector, and a distribution channel to deliver a first mono-propellant to a first mono-propellant injector device constituted by at least one injection hole opening out in the vicinity of the second electrode, and an electrical power supply circuit adapted to raise the second electrode to a potential lying in the range 50 V to 1000 V relative to the potential of the first electrode. The electrical power dissipated by ionic conduction in the free jet of the first mono-propellant is suitable for giving rise to spontaneous decomposition of the first mono-propellant and for producing combustion gas that ensures ignition of jets of a second mono-propellant coming from a main injector situated in the vicinity of the second electrode.

Abstract: The electrolytic ignitor comprises an injector constituting a first electrode and including a fuel injector device, an oxidizer injector device, and an electrolyte injector device. A second electrode electrically insulated from the injector extends downstream beyond the injector. An electrolyte distribution channel for delivering electrolyte in the form of free jets through the electrolyte injector device comprises at least one injection hole in the vicinity of the fuel injector device and the oxidizer injector device. An electrical power supply circuit is adapted to raise the second electrode to a potential in the range 50 V to 1000 V relative to the potential of the first electrode. The electrolyte injected through the injection hole is capable of causing ignition of a gaseous mixture in a combustion chamber of an ignitor torch suitable for incorporating in a main injector of a rocket engine.

Abstract: A liquid propellant rocket engine with a propulsion chamber shutter, the rocket engine comprises a combustion chamber, a propellant injector device placed at an upstream first end of the combustion chamber, a nozzle throat disposed at a downstream second end of the combustion chamber remote from the upstream first end, and a diverging portion disposed downstream from the nozzle throat. A selective shutter device for the nozzle throat comprises an axially-symmetrical shutter member placed downstream from the nozzle throat, and axial rod for controlling the shutter member, a first short centering member for the control rod situated at the upstream first end of the combustion chamber level with the propellant injector device, a second short centering member for the control rod situated in the combustion chamber in the vicinity of the nozzle throat and upstream therefrom, and a system for returning the control rod of the selective shutter device for the nozzle throat to the closed position.

Abstract: An apparatus and method to electrocatalytically induce the decomposition of a liquid propellant for propulsion. This is accomplished by providing a reaction chamber filled with catalyst that has a first electrode, such as near the center, and the other electrode disposed away from the first electrode. A charge source that is capable of applying voltage is connected to the electrodes. When the reaction chamber is dosed with a propellant such as an aqueous based amine propellant, such as HAN, an electric current flows between the electrodes and the propellant. This initiates the decomposition of the propellant which is driven to completion by the catalyst bed in order to be used for power generation.

Abstract: A propulsion system may be operated by determining pressure in a cryogenic liquid tank storing a fluid and cooling the cryogenic liquid tank in response to determining that the pressure is greater than a predetermined value. The cryogenic liquid tank may be pressurized by admitting a gaseous form of the fluid into the cryogenic liquid tank in response to determining that the pressure in the cryogenic liquid tank is less than a predetermined value.

Abstract: Propellants flow through specialized mechanical hardware that is designed for effective and safe ignition and sustained combustion of the propellants. By integrating a micro-fluidic porous media element between a propellant feed source and the combustion chamber, an effective and reliable propellant injector head may be implemented that is capable of withstanding transient combustion and detonation waves that commonly occur during an ignition event. The micro-fluidic porous media element is of specified porosity or porosity gradient selected to be appropriate for a given propellant. Additionally the propellant injector head design integrates a spark ignition mechanism that withstands extremely hot running conditions without noticeable spark mechanism degradation.

Abstract: A rocket nozzle includes a dual-bell nozzle and a gas introducing section configured to introduce gas into space surrounded by the dual-bell nozzle. Combustion gas flows in the space. The dual-bell nozzle includes a first stage nozzle bell-shaped and surrounding an upstream portion of the space, and a second stage nozzle bell-shaped and surrounding a downstream portion of the space. The dual-bell nozzle has an inflection point between the first stage nozzle and the second stage nozzle. The gas introducing section includes a gas inlet provided to an inner wall surface of the first stage nozzle. The gas is introduced into the space from the gas inlet.

Abstract: A rocket propulsion oxidizer compound that is a mixture that is a homogenous and stable liquid at room temperature that includes nitrous oxide and nitrogen tetroxide.

Abstract: A cryogenic-propellant rocket engine includes: at least a first tank for a first liquid propellant; a second tank for a second liquid propellant; a third tank for an inert fluid; an axisymmetrical nozzle including a combustion chamber, a device for injecting first and second liquid propellants into the combustion chamber, a nozzle throat, and a divergent section; and a heater device including at least one duct for conveying the inert fluid and arranged outside the nozzle in immediate proximity thereof, but without making contact therewith, to recover energy of thermal radiation emitted when the rocket engine is in operation and to heat the inert fluid.

Abstract: A method of fabrication of a rocket engine nozzle assembly using pressure brazing generally includes initially assembling a rocket engine nozzle liner into a rocket engine nozzle jacket for a rocket engine nozzle assembly. The rocket engine nozzle assembly may then be sealed. Prior to pressure brazing the rocket engine nozzle assembly, pressure brazing parameters may be determined. The pressure brazing may be performed with the determined pressure brazing parameters to complete the fabrication of the rocket engine nozzle. The rocket engine nozzle assembly may include a rocket engine nozzle jacket and a rocket engine nozzle liner having a plurality of channels, with the space between each channel defining a land, and the rocket engine nozzle liner having at least a pair of endlands disposed at each end thereof. The rocket engine nozzle liner is bonded to the rocket engine nozzle jacket by the endlands being bonded to the nozzle jacket and the lands being pressure brazed to the nozzle jacket.

Abstract: A stable and play-free pivot connection of a bicycle derailleur between a parallelogram link and either a base member or a chain cage. The pivot points are formed with first and second bushings that are arranged as far from one another as possible. The parts are connected by pivot pins having a anti-rotation contour for preventing rotation of the pin within an inner pivot part. The axial displacement of the pivot pin is prevented by a securing element or by a deforming element engaging a holding contour on the pivot pin. One of the first and second bushings is protected and arranged in a blind hole and the other of the first and second bushings is covered on the outside by a pin head of the pivot pin.

Abstract: Methods and systems are provided for propelling a vehicle. In an embodiment, by way of example only, a method includes flowing a decomposed hydroxylammonium nitrite (HAN)-based propellant into a chamber, introducing an aspirated non-polar fuel into the chamber, and combusting the decomposed HAN-based propellant and the aspirated non-polar fuel to produce an exhaust gas.

Abstract: Propellant management systems and methods are provided for controlling the delivery of liquid propellants in a space launch vehicle utilizing multiple rockets. The propellant management systems and methods may be configured to enable substantial simultaneous depletion of liquid propellants in each of a plurality of active rockets during operation of various booster stages of the launch vehicle.

Abstract: In some embodiments a propulsion system includes a thrust chamber having an inside wall, an expansion nozzle mounted to the thrust chamber and having an interior and having an exterior, a main propellant injector mounted to the thrust chamber to inject a fluid in the interior of the thrust chamber, the fluid comprising oxidizer, fuel and internal film coolant, the internal film coolant ranging from about 1% to about 5% of the fluid, limited coolant tubing circumscribing the exterior of the expansion nozzle to circulate an external coolant, and an injector mounted to the expansion nozzle to inject the external coolant in the interior of the expansion nozzle, the external convective coolant about 2.5% of the fluid. The system operates at lower temperatures while having conventional amounts of thrust, in which the thrust chamber can be made of thin walls of lower cost conventional metals with simple coolant tube construction.

Abstract: A method for improving interpenetration, mixing, and combustion between a fuel and oxidizer reactant mixture and combustion product gases in engines having a combustor includes the step of providing an engine having a combustor in which the reaction mixture and product gases are subjected to acceleration directed transverse to a direction along which the reactant mixture flows through the combustor during combustion. One or more catalyst elements are positioned within the combustor to generate Rayleigh-Taylor instability and thereby enhance interpenetration of the reactant mixture and product gases within the combustor chamber during combustion.

Abstract: A fuel injector system for combustion engines and motors, such as pulsed bipropellant thrusters, includes noncircular fuel and oxidizer injectors at the ends of respective dribble channels for controlling the mixture ratio of the propellants passing into a combustion chambers for maintaining a desire or ideal mixture ratio as determined by the cross-sectional area of the injectors well suited for pulse combustion fuel injector systems.

Abstract: There is provided a mixture ratio stabilizer for a liquid propellant rocket engine which comprises: a body internally having a chamber and a fuel supply hole communicating with an end of the chamber to receive fuel from a fuel supply pump, an oxidizer inlet, and a fuel outlet; a spool guide in the chamber and including a plurality of first orifices for the fuel outlet and the fuel supply hole to communicate with each other; a bellows in the chamber and having one end adjacent to the spool guide and the other end positioned adjacent to the oxidizer inlet, to expand and contract in accordance with the pressure of an oxidizer which flows into the oxidizer inlet; and a spool having a part placed in the spool guide.

Abstract: An augmented expander cycle rocket engine includes first and second turbopumps for respectively pumping fuel and oxidizer. A gas-generator receives a first portion of fuel output from the first turbopump and a first portion of oxidizer output from the second turbopump to ignite and discharge heated gas. A heat exchanger close-coupled to the gas-generator receives in a first conduit the discharged heated gas, and transfers heat to an adjacent second conduit carrying fuel exiting the cooling passages of a primary combustion chamber. Heat is transferred to the fuel passing through the cooling passages. The heated fuel enters the second conduit of the heat exchanger to absorb more heat from the first conduit, and then flows to drive a turbine of one or both of the turbopumps. The arrangement prevents the turbopumps exposure to combusted gas that could freeze in the turbomachinery and cause catastrophic failure upon attempted engine restart.