Abstract: A pulse combustion device has a number of combustors with upstream bodies and downstream nozzles. Coupling conduits provide communication between the combustors. For each given combustor this includes a first communication between a first location upstream of the nozzle thereof and a first location along the nozzle of another. There is second communication between a second location upstream of the nozzle and a second communication between a second location upstream of the nozzle of a second other combustor and a second nozzle location along the nozzle of the given combustor.

Abstract: A pulse detonation system for a gas turbine engine having a longitudinal centerline axis extending therethrough, the pulse detonation system includes an air inlet duct in flow communication with a source of compressed air, the air inlet duct including at least one port formed therein for permitting compressed air to flow therethrough, a fuel injector mounted to the air inlet duct in circumferentially spaced relation to each port, and a device mounted to the air inlet duct in circumferentially spaced relation to each fuel injector for initiating a detonation wave. A rotatable ring member is also positioned in coaxial relation around a portion of the air inlet duct, with the ring member including at least one stage of detonation disposed therein. Accordingly, a detonation wave is produced in each detonation stage and combustion gases following each detonation wave create a torque which causes the ring member to rotate.

Abstract: A turbine engine has a circumferential array of combustion chamber conduits downstream of the compressor and upstream of the turbine. Means are provided for directing oxygen-containing gas from the compressor to the conduits so as to cyclically feed a gas charge into each conduit through its first port and permit discharge of combustion products of the charge and fuel through both the first and second ports.

Abstract: A pulsed combustion device includes a support structure and a combustor carousel supported by the support structure and rotating relative thereto about an axis. The carousel has a number of combustion conduits in a circumferential array. Each conduit cyclically receives a charge and discharges combustion products of the charge. A venturi effect may help control fuel/air charge leakage from a flowpath spanning the carousel and a stationary manifold.

Abstract: A method enables thrust to be generated from a gas turbine engine using a pulse detonation system is provided. The engine includes an inlet portion and an exhaust portion, and the pulse detonation system includes a multi-staged pulse detonation augmentor including predetonator. The method comprises supplying a less than stoichiometric fuel/air mixture to the pulse detonation system during a first operating stage, detonating the fuel/air mixture with the predetonator to increase the temperature and pressure within the engine and to generate engine thrust, and supplying additional fuel and air to the pulse detonation system during a second operating stage.

Abstract: A pulsejet system and method requires no pulsejet internal moving parts. Each pulsejet includes a combustion chamber having an upstream inlet port joined to an inlet diffuser, boundary layer air ports enveloping the combustion chamber, and a downstream exit port joined to a discharge nozzle. Each pulsejet discharges into an ejector to increase net thrust. Each ejector includes an augmentor cell having side walls and perforated end plates. The perforated end plate between each pair of pulsejets is shared to permit the discharge thrust to equalize across the pulsejet group. Air and fuel mix in the combustion chamber and are detonated by a reflected back-pressure wave. Detonation/deflagration reverse pressure waves compressing boundary layer air flow act as a pneumatic throat to temporarily choke off inlet fresh air at the upstream inlet port. The pneumatic throat replaces the conventional mechanical valve used for this purpose.

Abstract: A shock wave reflector includes a number of reflective units positioned along a longitudinal direction and separated by a gap G. Each reflective unit has a length L. The length L and the gap G are governed by a relationship L+G??. The variable ? characterizes a cell size for a detonation mixture. A detonation chamber includes a receiving end, a discharge end, and a wall extending along a longitudinal direction between the receiving and discharge ends. The detonation chamber further includes a number of reflective units formed in the wall and positioned along the longitudinal direction. The reflective units are separated by a gap G, and each reflective unit has a length L.

Abstract: A method facilitates generating thrust from a gas turbine engine using a pulse detonation system. The method includes introducing fuel and air to the engine, mixing fuel and air in a pulse detonation system deflagration chamber positioned radially outward from an engine exhaust centerbody, and detonating the fuel and air mixture within the pulse detonation system to facilitate increasing the temperature and pressure within the engine and to generate engine thrust.

Abstract: A turbine engine has a circumferential array of combustion chamber conduits downstream of the compressor and upstream of the turbine. Means are provided for directing oxygen-containing gas from the compressor to the conduits so as to cyclically feed a gas charge into each conduit through its first port and permit discharge of combustion products of the charge and fuel through both the first and second ports.

Abstract: A method facilitates generating thrust from a gas turbine engine using a pulse detonation system. The method includes introducing fuel and air to the engine, mixing fuel and air in a pulse detonation system deflagration chamber positioned radially outward from an engine exhaust centerbody, and detonating the fuel and air mixture within the pulse detonation system to facilitate increasing the temperature and pressure within the engine and to generate engine thrust.

Abstract: An engine includes at least one pulse detonation chamber configured to receive and detonate a fuel and an oxidizer. The pulse detonation chamber has an outlet end and includes a porous liner adapted to fit within an inner surface of the pulse detonation chamber within a vicinity of the outlet end. The engine also includes a casing housing the pulse detonation chamber.

Abstract: A method for operating a pulse detonation system. The method includes providing a pulse detonation chamber including a plurality of detonation tubes extending therein, and detonating a mixture of fuel and air within each detonation tube such that at least a first tube is detonated at a different time than at least a second detonation tube.

Abstract: Propellant modules for Micro Pulsed Plasma Thrusters, and techniques for bundling propellant modules and for using a two-stage discharge process to increase MicroPPT propellant throughput, and decrease the output voltage required from the power-processing unit are provided.

Abstract: Distributed initiation (e.g., multipoint or continuous) is utilized to obtain constant volume-like combustion performance in a pulse combustion device in the absence of detonation. A number of such devices may be utilized as turbine engine combustors.

Abstract: A method enables thrust to be generated from a gas turbine engine using a pulse detonation system is provided. The engine includes an inlet portion and an exhaust portion, and the pulse detonation system includes a multi-staged pulse detonation augmentor including predetonator. The method comprises supplying a less than stoichiometric fuel/air mixture to the pulse detonation system during a first operating stage, detonating the fuel/air mixture with the predetonator to increase the temperature and pressure within the engine and to generate engine thrust, and supplying additional fuel and air to the pulse detonation system during a second operating stage.

Abstract: A reciprocating internal combustion engine used a crankshaft to develop rotating motion. A rotary pulse detonation engine can be adapted to rotate a shaft. A combustor portion of the rotary pulse detonation engine is spaced from an axis of the shaft a preestablished distance therebetween in a mass member. An intake portion and an exhaust portion of the combustor portion is positioned in a parameter of the mass member. A combustion portion of the combustor portion is interposed the intake portion and the exhaust portion. The combustion portion has a frustoconical first position which converges to form a deflagration wave and progresses into a detonation. The deflagration to detonation transition occurs in the transition region. A combustible fuel and air mixture is combusted in the combustor portion creating a high speed jet exiting the exhaust portion and rotating the shaft.

Abstract: A pulse detonation engine (10) is provided with an aerovalve (14) for controlling the pressure of injected propellants (Ox, Fuel) in an open-ended detonation chamber (26). The propellants are injected at such pressure and velocity, and in a direction generally toward a forward thrust wall end (16) of the detonation chamber (26), an aerovalve (14) is formed which effectively inhibits or prevents egress of the propellant from the detonation chamber (26). A shock wave (34) formed by the injected propellant acts, after reflection by the thrust wall end (16) and in combination with the aerovalve (14), to compress and conserve, or increase, the pressure of the injected propellant. Carefully timed ignition (28) effects a detonation pulse under desired conditions of maintained, or increased, pressure. Termination of the propellant injection serves to “open” the aerovalve (14), and exhaust of the combusted propellants occurs to produce thrust.

Abstract: A propulsion pod for a twin tube, rotary inlet valve, pulse detonation engine includes a shared, two-dimensional, low aspect ratio wedge nozzle in which each side of the wedge is transitioned into the discharge end of the detonation tubes of the engine. The nozzle design results in a quasi-separate exhaust flow path with two separate nozzle throat areas, one for each detonation tube. Actuation of the center wedge of the nozzle provides pitch vectoring of the exhaust. Actuation of flaps integrated into the side walls of the nozzle provides yaw vectoring. The detonation tubes are cooled by flowing bypass air over cooling means coupled to the detonation tubes.

Abstract: A pulse detonation system for a turbofan engine including a fan assembly and a turbine sub-system, which includes at least one turbine, is configured to create a temperature rise and a pressure rise within the turbofan engine and to generate thrust for the turbofan engine. The pulse detonation system includes a pulse detonation core assembly comprising at least one detonation chamber configured to detonate a fuel mixture. The pulse detonation core assembly is positioned between the fan assembly and the turbine sub-system.

Abstract: A pulsed detonation engine having improved efficiency has a detonation chamber for receiving a detonable mixture, an igniter for igniting the detonable mixture, and an outlet for discharging detonation products. A diverging-converging nozzle is provided at the outlet of the detonation chamber. The geometry of the diverging-converging nozzle is selected to enable a relatively short nozzle to significantly improve efficiency of the pulsed detonation engine.

Abstract: A shaped charge engine includes an annular blast-forming chamber formed by joining inner and outer housings. A central through hole in the inner housing allows exhaust gases to exit. The outer housing comprises a generally round disk with an inner conical concave depression and through holes for the insertion of fuel and ignition. The blast chamber is preferably taper-conical in shape, wider at the base, and gradually decreasing in cross-sectional area as it rises to the apex. This construction forms a circular pinch point or throat toward the apex that produces a primary or first stage compression area. A secondary compression zone is created at the apex of the outer housing, just beyond the throat, producing hypersonic gases as generally opposing exhaust streams collide and are forced to exit the through hole in the inner housing. The collided streams propel a turbine rotor to turn a shaft.

Abstract: A pump augmentation uses a nozzle output which is controlled in pulses to produce vortex rings and is controlled such that 1 F = Formation ⁢   ⁢ Number = m ρ ⁢   ⁢ A ⁢   ⁢ D = U ⁢   ⁢ t D

Abstract: A pulsed detonation engine having improved efficiency has a detonation chamber for receiving a detonable mixture, an igniter for igniting the detonable mixture, and an outlet for discharging detonation products. A diverging-converging nozzle is provided at the outlet of the detonation chamber. The geometry of the diverging-converging nozzle is selected to enable a relatively short nozzle to significantly improve efficiency of the pulsed detonation engine.

Abstract: A rotary inlet flow controller, with one or more open ducts extending therethrough, aerodynamically controls the amount and velocity of the flow of air to combustion chambers of pulse detonation engines, or other engines, without imposing large cyclic airflow transients in the diffuser of the air intake. The ducted rotary inlet flow controller supplies airflow and sealing in synchronization with the cycles of the engine: airflow and fueling supply, sealing, combustion, and re-opening for additional airflow. This controller will supply near-uniform, continuous airflow to the engine. The preferred controller has one or more propeller-like blades that are designed to cyclically and sequentially duct incoming flow to the inlet ports of the combustion chambers, while also providing the capability of sealing the ports during combustion.

Abstract: A shock wave reflector includes a number of reflective units positioned along a longitudinal direction and separated by a gap G. Each reflective unit has a length L. The length L and the gap G are governed by a relationship L+G≧&lgr;. The variable &lgr; characterizes a cell size for a detonation mixture. A detonation chamber includes a receiving end, a discharge end, and a wall extending along a longitudinal direction between the receiving and discharge ends. The detonation chamber further includes a number of reflective units formed in the wall and positioned along the longitudinal direction. The reflective units are separated by a gap G, and each reflective unit has a length L.

Abstract: A rotary inlet flow controller, with one or more open ducts extending therethrough, aerodynamically controls the amount and velocity of the flow of air to combustion chambers of pulse detonation engines, or other engines, without imposing large cyclic airflow transients in the diffuser of the air intake. The ducted rotary inlet flow controller supplies airflow and sealing in synchronization with the cycles of the engine: airflow and fueling supply, sealing, combustion, and re-opening for additional airflow. This controller will supply near-uniform, continuous airflow to the engine. The preferred controller has one or more propeller-like blades that are designed to cyclically and sequentially duct incoming flow to the inlet ports of the combustion chambers, while also providing the capability of sealing the ports during combustion.

Abstract: Flow control in pulse detonation engines is accomplished using magnetohydrodynamic principles. The pulse detonation engine includes a tube having an open forward end and an open aft end and a fuel-air inlet formed in the tube at the forward end. An igniter is disposed in the tube at a location intermediate the forward end and the aft end. A magnetohydrodynamic flow control system is located between the igniter and the fuel-air inlet for controlling detonation in the tube forward of the igniter. The magnetohydrodynamic flow control system utilizes magnetic and electric fields forward of the igniter to dissipate or at least reduce the ignition potential of the forward traveling detonation flame front.

Abstract: A pulse detonation system for a turbofan engine including a fan assembly and a turbine sub-system, which includes at least one turbine, is configured to create a temperature rise and a pressure rise within the turbofan engine and to generate thrust for the turbofan engine. The pulse detonation system includes a pulse detonation core replacement assembly comprising at least one detonation chamber configured to detonate a fuel mixture. The pulse detonation core replacement assembly is positioned between the fan assembly and the turbine sub-system.

Abstract: A method facilitates generating thrust from a gas turbine engine using a pulse detonation system. The method includes introducing fuel and air to the engine, mixing fuel and air in a pulse detonation system deflagration chamber positioned radially outward from an engine exhaust centerbody, and detonating the fuel and air mixture within the pulse detonation system to facilitate increasing the temperature and pressure within the engine and to generate engine thrust.

Abstract: A fuel containing methylacetylene-propadiene, commonly referred to as MAPP gas, produces thrust in a flight vehicle having a pulse detonation engine. The MAPP gas fuel of this invention may be used alone or combined with other conventional fuels such as hydrogen, JP-4, JP-5, JP-10, kerosene or any other suitable hydrocarbon fuel. Such hydrocarbon containing fuel includes, but is not limited to, acetylene, methane, ethylene, propane, butane or liquified petroleum gas. MAPP gas fuel is mixed with an oxidant containing oxygen or air and ignited. The detonation wave created produces thrust for the flight vehicle. A method of powering a flight vehicle having a pulse detonation engine with MAPP gas fuel is also disclosed.

Abstract: A propulsion module including a wave rotor detonation engine having a rotor with a plurality of fluid flow channels. The fluid flow channels extend between an inlet rotor plate, which has a pair of fixed inlet ports, and an outlet rotor plate, which has a pair of fixed outlet ports. The propulsion module includes a pair of inlet ducts have a stowed mode and a deployed mode. The pair of inlet ducts include a fluid flow passageway adapted to convey air to the pair of inlet ports. A fueling system is positioned prior to the inlet ports to deliver fuel into the air introduced through the pair of inlet ducts and into the pair of inlet ports. A pair of ignition chambers are disposed adjacent to the inlet rotor plate.

Abstract: A pulse detonation engine (10) is provided with an aerovalve (14) for controlling the pressure of injected propellants (Ox, Fuel) in an open-ended detonation chamber (26). The propellants are injected at such pressure and velocity, and in a direction generally toward a forward thrust wall end (16) of the detonation chamber (26), an aerovalve (14) is formed which effectively inhibits or prevents egress of the propellant from the detonation chamber (26). A shock wave (34) formed by the injected propellant acts, after reflection by the thrust wall end (16) and in combination with the aerovalve (14), to compress and conserve, or increase, the pressure of the injected propellant. Carefully timed ignition (28) effects a detonation pulse under desired conditions of maintained, or increased, pressure. Termination of the propellant injection serves to “open” the aerovalve (14), and exhaust of the combusted propellants occurs to produce thrust.

Abstract: A fuel containing methylacetylene-propadiene, commonly referred to as MAPP gas, produces thrust in a flight vehicle having a pulse detonation engine. The MAPP gas fuel of this invention may be used alone or combined with other conventional fuels such as hydrogen, JP-4, JP-5, JP-10, kerosene or any other suitable hydrocarbon fuel. Such hydrocarbon containing fuel includes, but is not limited to, acetylene, methane, ethylene, propane, butane or liquified petroleum gas. MAPP gas fuel is mixed with an oxidant containing oxygen or air and ignited. The detonation wave created produces thrust for the flight vehicle. A method of powering a flight vehicle having a pulse detonation engine with MAPP gas fuel is also disclosed.

Abstract: A propulsion module including a wave rotor detonation engine having a rotor with a plurality of fluid flow channels. The fluid flow channels extend between an inlet rotor plate, which has a pair of fixed inlet ports, and an outlet rotor plate, which has a pair of fixed outlet ports. The propulsion module includes a pair of inlet ducts have a stowed mode and a deployed mode. The pair of inlet ducts include a fluid flow passageway adapted to convey air to the pair of inlet ports. A fueling system is positioned prior to the inlet ports to deliver fuel into the air introduced through the pair of inlet ducts and into the pair of inlet ports. A pair of ignition chambers are disposed adjacent to the inlet rotor plate.

Abstract: An aerospike engine has at least one nozzle surface and a plurality of pulse detonation devices mounted to the nozzle surface in place of the more common deflagration-based combustors. Each pulse detonation device is oriented such that its combustion products are directed along the nozzle surface Incorporating pulse detonation devices into the aerospike engine produces the advantage of a more efficient thermodynamic cycle. The pulse detonation aerospike engine is also capable of operating on either air or oxidizer.

Abstract: Flow control in pulse detonation engines is accomplished using magnetohydrodynamic principles. The pulse detonation engine includes a tube having an open forward end and an open aft end and a fuel-air inlet formed in the tube at the forward end. An igniter is disposed in the tube at a location intermediate the forward end and the aft end. A magnetohydrodynamic flow control system is located between the igniter and the fuel-air inlet for controlling detonation in the tube forward of the igniter. The magnetohydrodynamic flow control system utilizes magnetic and electric fields forward of the igniter to dissipate or at least reduce the ignition potential of the forward traveling detonation flame front.

Abstract: A system for propelling a watercraft using hydrogen. The system comprises a combustion chamber, an accumulator system, an ignition system, and a propulsion control system. The combustion chamber defines an upper portion and a lower portion. The accumulator system stores pressurized fluid. A first check valve is arranged to allow water to flow from the exterior of the watercraft into the lower portion of the combustion chamber. A second check valve is arranged to allow water to flow from the lower portion of the combustion chamber to the accumulator system. A propulsion control valve is arranged to control the flow of water from the accumulator system to the exterior of the watercraft. A mixture of hydrogen and oxygen is introduced into the upper portion of the combustion chamber.

Abstract: A propulsion pod for a twin tube, rotary inlet valve, pulse detonation engine includes a shared, two-dimensional, low aspect ratio wedge nozzle in which each side of the wedge is transitioned into the discharge end of the detonation tubes of the engine. The nozzle design results in a quasi-separate exhaust flow path with two separate nozzle throat areas, one for each detonation tube. Actuation of the center wedge of the nozzle provides pitch vectoring of the exhaust. Actuation of flaps integrated into the side walls of the nozzle provides yaw vectoring. The detonation tubes are cooled by flowing bypass air over cooling means coupled to the detonation tubes.

Abstract: A combined cycle pulse combustion/gas turbine engine has a gas turbine engine used in conjunction with a plurality of pulse combustion engines. In one embodiment, the gas turbine engine includes a housing, a bypass fan, a central engine core, and a diffuser section. The diffuser section is used to route bypass air from the bypass fan around the central engine core and out of the housing. The pulse engines are mounted in the diffuser section and receive bypass air from the bypass fan. In a first alternate embodiment, bypass air is routed from the diffuser section through a duct to the pulse engine. A valve is disposed between the bypass fan and the pulse engines for selectively allowing bypass air from the bypass fan to enter the duct. In a second alternate embodiment, a fan mounts to each inlet port. The gas turbine engine has a drive shaft that drives the fan. A clutch selectively disengages the fans.

Abstract: A family of supersonic injectors for use on spaceplanes, rockets and missiles and the like is disclosed and claimed. Each injector maintains a specific constant (uniform) Mach number along its length when used while being minimally intrusive at significantly higher injectant pressure than combustor freestream total pressure. Each injector is substantially non-intrusive when it is not being used. The injectors may be used individually or in a group. Different orientations of the injectors in a group promotes greater penetration and mixing of fuel or oxidizer into a supersonic combustor. The injectors can be made from single piece of Aluminum, investment cast metal, or ceramic or they can be made from starboard and port blocks strapped together to accurately control the throat area. Each injector includes an elongated body having an opening which in cross section is an hour glass (venturi shaped) and the opening diverges in width and depth from the bow section to the stem section of the opening.

Abstract: A pulsed detonation engine having an initiator tube fueled with an enhanced fuel mixture is configured in fluid communication with a detonation chamber via a divergent inflow transition section. The divergent inflow transition section has a diverging contoured shape having a rate of divergence continuously dependent upon the diameter of the tube, the critical diameter of the enhanced fuel mixture within the tube and the cross-sectional area of the detonation chamber. The inflow transition section, which may have a stair-step configuration, includes a plurality of fuel and/or air ports to permit the fuel and air to be injected through the transition section and into the detonation chamber.

Abstract: A turbofan engine includes a pulse detonation system to create a temperature rise and a pressure rise within the engine to generate thrust from the engine. The system includes a pulse detonation augmentor including a shock tube sub-system. The shock tube sub-system includes a plurality of shock tubes which mix air and fuel introduced to the pulse detonation augmentor and detonate the mixture. The detonation creates hot combustion gases which are directed from the engine to produce thrust for the engine. Alternatively, the system includes a pulse detonation augmentation system that replaces a core engine of a turbo-fan engine.

Abstract: A pulse detonation cluster includes a cluster housing and a plurality of pulse detonation engines mounted within the housing. Each pulse detonation engine has an inner tubular housing rigidly and concentrically mounted within a cylindrical bore of an outer tubular housing. The inner housing has a plurality of inner housing ports, and the outer housing has a plurality of outer housing ports. A detonation chamber is formed in the annulus between the inner housing and the outer housing. An outer valve sleeve is rotatably mounted to the outer housing for selectively allowing air to enter the detonation chamber through the outer housing ports. A fuel delivery member is aligned with each inner housing port to deliver fuel to the detonation chamber through the inner housing ports. An inner sleeve is mounted to the inner housing to protect the fuel delivery members during detonation. The air and fuel mixture is detonated by several igniters located in the detonation chamber.

Abstract: A shaped charge engine includes an annular blast-forming chamber formed by joining inner and outer housings. A central through hole in the inner housing allows exhaust gases to exit. The outer housing comprises a generally round disk with an inner conical concave depression and through holes for the insertion of fuel and ignition. The blast chamber is preferably taper-conical in shape, wider at the base, and gradually decreasing in cross-sectional area as it rises to the apex. This construction forms a circular pinch point or throat toward the apex that produces a primary or first stage compression area. A secondary compression zone is created at the apex of the outer housing, just beyond the throat, producing hypersonic gases as generally opposing exhaust streams collide and are forced to exit the through hole in the inner housing. The shaped charge engine may be used in a variety of applications, including as a pulsed direct propulsion device, as a turbine driver, or in a wide array of tools and appliances.

Abstract: Flow control in pulse detonation engines is accomplished using magnetohydrodynamic principles. The pulse detonation engine includes a tube having an open forward end and an open aft end and a fuel-air inlet formed in the tube at the forward end. An igniter is disposed in the tube at a location intermediate the forward end and the aft end. A magnetohydrodynamic flow control system is located between the igniter and the fuel-air inlet for controlling detonation in the tube forward of the igniter. The magnetohydrodynamic flow control system utilizes magnetic and electric fields forward of the igniter to dissipate or at least reduce the ignition potential of the forward traveling detonation flame front.

Abstract: A pulsed detonation engine having an initiator tube fueled with an enhanced fuel mixture is configured in fluid communication with a detonation chamber via a divergent inflow transition section. The divergent inflow transition section has a diverging contoured shape having a rate of divergence continuously dependent upon the diameter of the tube, the critical diameter of the enhanced fuel mixture within the tube and the cross-sectional area of the detonation chamber. The inflow transition section, which may have a stair-step configuration, includes a plurality of fuel and/or air ports to permit the fuel and air to be injected through the transition section and into the detonation chamber.

Abstract: High-power pressure wave source for generating pressure waves that can be repeated by igniting a combustible fluid mixture and by increasing its rate of combustion up to detonation. The high-performance pressure wave source has a channel, which expands toward one of its ends and forms a combustion chamber, a feed means for the components of the fluid mixture, and an igniting means in the area of the narrow end of the channel, a discharge means for the waste gas in the area of the wide end of the channel, and a membrane closing the wide end of the channel on the front side, as well as a plurality of vortex generators distributed over the length of the channel.

Abstract: A pulsed detonation engine having an initiator tube fueled with an enhanced fuel mixture is configured in fluid communication with a detonation chamber via a divergent inflow transition section. The divergent inflow transition section has a diverging contoured shape having a rate of divergence continuously dependent upon the diameter of the tube, the critical diameter of the enhanced fuel mixture within the tube and the cross-sectional area of the detonation chamber. The inflow transition section, which may have a stair-step configuration, includes a plurality of fuel and/or air ports to permit the fuel and air to be injected through the transition section and into the detonation chamber.

Abstract: A pulse detonation engine has an inner tubular housing rigidly and concentrically mounted within a cylindrical bore of an outer tubular housing. The inner housing has a plurality of inner housing ports, and the outer housing has a plurality of outer housing ports. A detonation chamber is formed in the annulus between the inner housing and the outer housing. In one embodiment, an outer valve sleeve is rotatably mounted to the outer housing for selectively allowing air to enter the detonation chamber through the outer housing ports. A movable, inner protective sleeve is mounted to the inner housing for protecting a plurality of fuel injectors that supply liquid fuel to the detonation chamber through the inner housing ports. The air and liquid fuel mixture is detonated by several igniters located in the detonation chamber. In a second embodiment, an inner valve sleeve is rotatably mounted to the inner housing for selectively allowing air to enter the detonation chamber through the inner housing ports.

Abstract: The present invention reveals a method and apparatus for more efficiently injecting a primary fluid flow in a fluid ejector used to pump lower velocity fluid from a secondary source. In one embodiment, the primary fluid flow is a pulsed or unsteady fluid flow contained within an inner nozzle situated within a secondary flow field. This secondary fluid flow is bounded within the walls of an ejector or shroud. The secondary and primary fluid flows meet within the ejector shroud section wherein the secondary fluid flow is entrained by the primary fluid flow. The geometry of the ejector shroud section where the primary and secondary fluids mix is such as to allow the beginning of primary injector pulse to be synchronized with an acoustic wave moving upstream through the ejector initiated by the exiting of the previous pulse from the ejector shroud. The ejector's geometric properties are determined by the acoustic properties, frequency, duty cycle, and amplitude, of the pulsed primary fluid flow.