Abstract: The disclosed technology includes a fluid heating device including a frustoconical combustion chamber and a heat exchanger that can include heating tubes. The combustion chamber can have a first end and a second end that is in fluid communication with the heating tubes. The surface area of the second end of the combustion chamber can be larger than the surface area of the first end of the combustion chamber.

Abstract: A method for inverting a rotation of an impeller driven by a motor of a watercraft is disclosed. In response to sensing that the motor is stopped, a direct linkage is disconnected between the motor and the impeller and a reverse connection is established between the motor and the impeller. The motor is started after sensing that the reverse connection is established. A watercraft propulsion system having an electronic control unit configured to perform the method and a watercraft including the watercraft propulsion system are also disclosed. Reverse operation of the impeller is useful in removing debris from the jet propulsion system.

Abstract: The rocket engine nozzle system comprises a set of individual nozzles distributed in a ring around a central core of axially symmetrical shape that presents a central axis. Each individual nozzle placed at the periphery of the central core comprises a circular section throat for receiving gas from a combustion chamber, and a diverging portion that is tangential to the central core. The diverging portion has an outlet section that presents first and second lateral sides that converge radially towards the central axis of the central core, a curved outer side having its convex side facing outwards, and an inner side situated in the vicinity of the central core.

Abstract: A propulsion system includes a canted multinozzle plate, which has a multitude of small nozzles angled (not perpendicular) to major surfaces of the multinozzle grid plate. The multinozzle plate may be a cylindrical section or plate, and the multitude of nozzles may be substantially axisymmetric about the cylindrical plate. The propulsion system includes a pressurized gas source which may be placed either forward or aft of the multinozzle grid plate. The propulsion system may have a conical insert, an internal flow separator cone, to aid in changing directions of flow from the pressurized gas source, to divert the flow through the multiple nozzles.

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: A continuous fluid circuit electricity generating system for producing relatively expensive electricity without polluting the atmosphere or consuming natural resources. A first turbine submerged in a source of water (e.g., a man-made tank or a naturally-occurring well or larger body of water) supplies water under pressure from the source to a water propulsion turbine. The water propulsion turbine has a rotatable shaft coupled to the shaft of a first generator of electricity and a set of hollow impeller arms coupled to and rotatable with the turbine shaft. The impeller arms of the water propulsion turbine are located in proximity to a rotatable driven rotor having a coupling sleeve surrounding the shaft of a second generator of electricity. Water moving through and expulsed from the hollow impeller arms causes the impeller arms, the shaft of the water propulsion turbine, and the shaft of the first generator to rotate in a first direction.

Abstract: The propulsion device (10) includes a housing (12) having an incoming end cap (14) and an outflowing end cap (16). A tubular bladder (20) within the housing is interconnected to each end cap, thereby varying the volume of both a chamber (22) within the bladder and a chamber (24) between the bladder and the housing during attractive or repulsive movement between end caps (14,16). Check valves control the flowthrough the end caps. The propulsion device is highly efficient and is able to move the vessel through water with little or no cavitation.

Abstract: The inventive apparatus exercises control of the water flow which is discharged from a marine waterjet propulsor. Typical inventive embodiments comprise plural horizontal and plural vertical blade-like structures which together describe an open-ended, box-like rectilinear configuration characterized by at least two adjacent channels. Every vertical blade-like structure includes, at its aft end, a “steering” flap which is pivotable about a vertical axis. Some inventive embodiments advance marine craft reversing by implementing one or more bucket-like devices behind the inventive apparatus.

Abstract: A propulsion system for accelerating and directionally controlling a fluid having a continuous dynamic surface for circulating through a fluid from an entrainment region where fluid is introduced to the dynamic surface to a thrust region where fluid is discharged from the dynamic surface. The dynamic surface accelerates the fluid proximate to the surface so as to produce a layer of accelerated fluid from the entrainment region through the thrust region. A motor is operatively connected to the dynamic surface for driving the dynamic surface. A separator plate is positioned next to the dynamic surface. The separator plate has a leading edge for stripping the layer of accelerated fluid from the dynamic surface, and a substantially flat thrust face adjacent to the leading edge for directing the accelerated fluid in a desired direction.

Abstract: A thrust propulsion mechanism (10) for a boat (12) includes an outlet conduit (22) extending athwartships from a first outlet port (16) to a second outlet port (16') in the hull (18). A paddle-wheel impeller (24) is mounted within the hull for rotation about an axis of rotation (34) by a reversible motor (30). A circumferential paddle (58) portion of the paddle-wheel impeller extends into an aperture (26) defined centrally in the top wall of the outlet conduit. An inlet conduit (20) extends athwartships from a first inlet port (14) to a second inlet port (14'), and intermediate thereof supplies water to the center of the paddle-wheel impeller. Water is discharged from the paddle-wheel impeller through one of the outlet ports, dependent on the direction of rotation of the paddle-wheel impeller, to create thrust by a combined paddle-wheel and centrifugal pump action.

Abstract: An improved thruster system is provided for maneuvering and/or propulsion of a marine vessel, through the use of directionally oriented water jets discharged tangentially from a helical-conical flow chamber. The thruster system includes a high capacity pump for pumping water through a hull intake to the flow chamber with a substantial helical or swirling action. The water exits the flow chamber through one or more of a plurality of tangentially oriented discharge conduits having discharge nozzles for passage of high velocity water jets through the hull, resulting in reaction forces used to maneuver or propel the vessel. Each discharge conduit includes a valve member movable between open and closed positions for respectively permitting or preventing water flow to the associated nozzle.

Abstract: The method of manufacturing a combustion chamber wall, in particular for a rocket engine, includes the following steps:[a] making a corrugated metal inner shell by deforming a first plane or tubular sheet;[b] making a metal outer shell from a second plane or tubular sheet;[c] assembling the corrugated inner shell and the outer shell together and welding them together locally;[d] forming an inner coating on the inside face of the corrugated inner shell by the technique of powder metallurgy using a container for the material that is to constitute the inner coating, the outside face of said container being constituted directly by the inside face of said corrugated inner shell and the inside face of said container being made using removable non-consumable sections or a soluble core that is removed by selective chemical dissolving after the inner coating has been formed by applying a hot isostatic compacting cycle; and[e] forming an outer coating on the outside face of the outer shell.

Abstract: Break-up activity of water by injection of hot propellant gas into channels f a thrust expansion engine is suppressed to prevent rapid cooling of the gas, utilizing one or more methods including injection of a secondary inflow of the propellant gas and/or the water under lower pressures into the channels, injection of a viscosity enhancer and/or surfactant into the inflow stream of the water and restricting outflow of the water from the channels by means of convergent nozzles.

Abstract: A method and apparatus for generating a high plume or "rooster tail" of water behind a water jet propelled marine craft, such as a jet ski, is characterized by the insertion of a water diverting member into the upper regions of the jet of water discharging from the jet propulsion system and diverting a portion of the water from the jet upwardly and outwardly away from the jet to form a tall plume of water above and behind the jet. In its preferred embodiment, the apparatus comprises a lever pivotally mounted on the upper side of the discharge nozzle of the propulsion system and selectively movable at its upstream end through a slot in the nozzle into the interior of the nozzle to divert a portion of the water from the jet stream upwardly and rearwardly away from the nozzle.

Abstract: This disclosure relates to a small craft equipped with a water jet propulsion system and a thrust-reversing device. The thrust-reversing device is supported for movement up and down between an operating position located directly to the rear of the exhaust port of the jet propulsion system and a retracted position located upwardly from the operating position. The thrust-reversing device includes a U-shaped water guide passage which extends laterally; the left and right ends of the water guide passage are shaped into concave ends which curve forwardly; and the bottom of the hull of the craft includes channels aligned with the curved ends of the water guide passage of the thrust-reversing device when the device is at the operating position.

Abstract: This invention is a nozzle system for use on a water craft and in particular a water craft such as a jet ski. A jet ski is a small engine powered surface water craft, usually designed for one person usage, and generally having a small aft deck suitable for standing on by the user. Heretofore, nozzles used on jet skis were pivotally mounted and were used solely to propel or to propel and steer the craft in the water. This invention is for a modified nozzle that additionally produces a small but substantial secondary jet of water directed upwards that breaks through the surface of the water behind the craft and produces a "rooster tail" effect which adds to the safety, excitement and pleasure of the user and produces a spectacular water display that is enjoyed by those observing the craft and its user in action.

Abstract: A wall thruster for surface or submarine vessels that is cavitation resistant and does not require a hull duct. The invention comprises an impeller mounted in a swirl chamber such that seawater is rotated under pressure. The water is then discharged through streamlined nozzles in a direction to minimize mixing with the flow of the water being drawn into the impeller.

Abstract: The marine jet propulsion unit of this invention, in preferred form, has a pair of laterally adjacent blade carriers, each having a vertical outer surface movable in a horizontal orbit and to which blades are fixed that project edgewise outwardly. Each blade has a surface facing in the direction of its orbital movement that is concavely curved along its height. The two blade carriers, at opposite sides of a fore-and-aft extending vertical plane of symmetry, are driven in opposite orbital directions such that each has a driving portion remote from the plane of symmetry that moves rearward in an acceleration channel and has an opposite forwardly moving portion adjacent to the plane wherein its blades are interleaved with those of the other. Water entering a forward intake is guided in two streams, one to the front end of each acceleration channel, and the rear end of each acceleration channel is communicated with a discharging outlet nozzle.

Abstract: A water jet propelled boat hull having an axis of forward motion, a bottom and a centerline. A first and a second water duct are provided, each of which has an exit port discharging rearwardly, the exit ports being laterally spaced from the centerline and on opposite sides of the centerline from each other. Inlet ports are located substantially on the centerline at the bottom of the hull. The ducts interconnect respective inlet ports and respective exit ports. A first and a second water jet propulsion device, such as a pump, is disposed respectively in each of the said first and second ducts to move water from the inlet ports and out the exit ports. Because the inlet ports are on the centerline, both ducts will be provided with water, even when the boat is inclined as a consequence of making sharp turns.

Abstract: A water jet propulsion system for use with boats having an impeller duct which discharges a stream of liquid through a nozzle to propel the vessel in a forward direction. A reversal plate is provided which occludes the rearward jet opening and causes the stream to exit through a pair of reverse movement ports, one disposed on each side of the nozzle to direct the water jet from the impeller duct forwardly and preferably also slanted downwardly when the boat is to be reversed.

Abstract: A propulsion system for a hydrofoil, planing or semi-planing sea-going vessel having a hull having a port pump water inlet formed therethrough on its port side, a starboard pump water inlet formed therethrough on its starboard side and first, second and third outlets formed therethrough, comprises a booster first stage system in the hull coupled to and driven by the motors. The booster first stage system comprises a first axial water jet pump at the port pump water inlet and a second axial water jet pump at the starboard pump water inlet. A second stage water jet system in the hull aft of the first stage system comprises a third axial water jet pump functioning as a turbocharger.

Abstract: The invention pertains to reversing apparatus for hydraulic jet marine drives utilizing a pivoted steering nozzle and a reversing gate adapted to divert a jet of water into a reversing nozzle. The reversing nozzle is rotatably mounted upon the steering nozzle and utilizes orientation apparatus fixed with respect to the axis of the steering nozzle such that rotation of the steering nozzle in one direction produces rotation of the reversing nozzle about its axis in the opposite direction. The relative movements of the steering and reversing nozzles produces force vectors in the nozzles in a common lateral direction with respect to boat movement wherein a high degree of boat control while being reversed is achieved at low pumping capacity.

Abstract: A boat includes a longitudinal water channel along the bottom thereof. A motor driven propeller in the channel circulates water from a forward inlet end thereof to a rear outlet end thereof to advance the boat through the water. Passages are provided which communicate with the channel and which are adapted to discharge water through front and rear openings on the port and starboard sides. Gates are provided for opening these passages. A gate actuating mechanism is provided for opening the front port and rear starboard passages to rotate the boat in one direction about its own vertical axis. Another gate actuating mechanism is provided for opening the front starboard and rear port passages to rotate the boat in the opposite direction about its own vertical axis. Upon being opened, each set of gates serves to block travel of water to the outlet of the channel, and thereby divert all water through the passages.

Abstract: A water jet propulsion system of improved efficiency with a novel boundary ayer water inlet, and having multiple water jet pumps and motors. The inlet has a large width to height ratio. The pumps may be connected to one drive shaft which can be connected to one or more motors by means of clutches.

Abstract: A two-stage axial flow steering and propulsion device has impellers operable by a right-angle reversible drive mounted on a watercraft, and a housing surrounds the blades of the impellers. The housing is mounted for rotation in opposite directions about an axis intersecting with and perpendicular to the blades' rotational axis. The device is therefore capable of a wide range of watercraft steering and propulsion maneuvers. A shroud structure in the form of a venturi-type ring surrounds each of the impellers thereby defining three separate pressure regions of positive pressure ahead of one of the impellers which pulls the fluid when rotating in one direction, a negative pressure between the impellers and a negative pressure behind the other impeller which pushes the fluid when rotating in such one direction.

Abstract: A double suction, double volute pump for propelling a boat having each volute exhaust through a separate jet nozzle. The pump housing defines two intake passageways leading upward to either side of a double suction impeller. The housing further provides double volutes which receive water from each side of the double suction impeller and deliver it to dual nozzles thereby creating twin jets which may be employed to propel and control the boat. The double volutes each extend substantially full circle about the housing and terminate in elbows which lead to the nozzles. The nozzles are placed horizontally equidistant from the centerline of the impeller shaft and are controlled by steering linkages to operate in unison. Reversing control gates may be operated either together for reversing or independently for slow speed steering.

Abstract: A waterjet propulsion system having at least two pumps in series so that low from a hull or other intake is directed through a first waterjet propulsion pump; and then via a two-position diverter valve, either out to a thrust nozzle, or to and through a second waterjet propulsion pump having a thrust nozzle. Subsequent series-pump units and diverter valves may follow to provide as many propulsion stages as required for power requirements. Each pump unit is driven by its own power unit which may be shut down when flow is diverted to the preceding unit's thrust nozzle. Good efficiencies are thereby attained over a wide range of power and speed requirements.

Abstract: A marine jet drive unit includes a continuously running pump. A reversing gate is positioned partially or wholly within the forward jet to establish a corresponding reverse jet. For neutral drive, the gate is positioned such that the reverse jet just balances the forward jet. A remote shift control unit includes a detent means for locating and holding a rotatable shift lever in neutral. The detent means includes a pair of detent pins carried by a plate which is connected to a support wall by a slot and bolt lost motion connection. The pins are located to opposite sides of the lever and the connection permits angular adjustment about the pivot axis of the lever. The plate supports the detent pin in alignment with a circular outer periphery of the lever plate having oppositely located radial detent grooves. The lever is connected by a push-pull cable to the gate. The precise neutral position of the lever may vary for different drive units.