Showing papers on "Propulsion published in 1990"

Hypersonic vehicle simulation model: Winged-cone configuration

Abstract: Aerodynamic, propulsion, and mass models for a generic, horizontal-takeoff, single-stage-to-orbit (SSTO) configuration are presented which are suitable for use in point mass as well as batch and real-time six degree-of-freedom simulations The simulations can be used to investigate ascent performance issues and to allow research, refinement, and evaluation of integrated guidance/flight/propulsion/thermal control systems, design concepts, and methodologies for SSTO missions Aerodynamic force and moment coefficients are given as functions of angle of attack, Mach number, and control surface deflections The model data were estimated by using a subsonic/supersonic panel code and a hypersonic local surface inclination code Thrust coefficient and engine specific impulse were estimated using a two-dimensional forebody, inlet, nozzle code and a one-dimensional combustor code and are given as functions of Mach number, dynamic pressure, and fuel equivalence ratio Rigid-body mass moments of inertia and center of gravity location are functions of vehicle weight which is in turn a function of fuel flow

Fundamental concepts of vectored propulsion

Abstract: Future fighter aircraft may maneuver, especially in the post-stall (PS) domain, by simultaneousl y directing their jets in the yaw, pitch, and roll coordinates. Consequently, thrust vectoring (TV) may gradually become a key element in helping fighters to survive and win in the close-combat arena. It also provides fighter aircraft with short-takeoff-and-landing (STOL) capabilities. This paper first defines the fundamental concepts associated with pure, or with partial TV powerplants. It then demonstrates that propulsion engineering should be expanded to include such unorthodox engine-design criteria as those of TV maneuverability and controllability. Second, the fundamental concepts of pure vectored propulsion are employed to design, construct, and laboratory test a new type of simultaneous roll-yaw-pitch TV system. Vectored remotely piloted vehicles (RPVs) were then constructed "around" these new propulsion systems. Flight tests of these RPVs since May 1987 have verified the STOL capability and enhanced maneuverability and controllability designable into vectored propulsion systems. They also became the first flight tests of pure vectored propulsion systems. The integrated methodology of laboratory/vectored-RPV-flight tests, as developed for this investigation, has been verified as cost effective and timesaving. Using this methodology a follow-up program was recently launched to help upgrade existing fighter aircraft, such as the F-15, F-16, and F-18, to become partially vectored PS aircraft. Finally, the basic conceptual changes associated with the very introduction of TV engines are summed up in terms of greater emphasis on highly integrated engine/flight-control testing methodologies and on reassessment of conventional concepts.

Oxygen extraction and jet propulsion in cephalopods

Abstract: The ventilatory system of cephalopods has evolved so that the animals minimise the energetic cost of either oxygen extraction or jet propulsion. Optimal design for jet propulsion requires a large s...

Energy absorption from ocean waves: a free ride for cetaceans

Abstract: Flukes of cetaceans are capable of absorbing energy from ocean waves for propulsion. The extent of this energy absorption is demonstrated by considering the flukes of an immature fin whale, Balaenoptera physalus. In a fully developed seaway corresponding to a wind speed of 20 knots (around Beaufort force 5) and at a low swimming speed, of 2.5 m s-1, this whale was able to absorb up to 25% of its required propulsive power in head seas and 33% of propulsive power in following seas. Consequences of wave-energy absorption for energetics of cetacean migrations are discussed.

Inflatable concentrators for solar propulsion and dynamic space power

Abstract: This paper describes the development of an inflatable concentrator for solar propulsion, providing the source of heat to a hydrogen engine aboard the Solar Rocket. The latter is a device designed to carry payloads from a low earth orbit (LEO) to a geosynchronous orbit (GEO) at significant mass savings in comparison to chemical propulsion; it involves two light-weight parabolic reflectors in an off-axis configuration focusing solar radiation into the absorbers of the engine, which causes the emission of a hot hydrogen jet. Each of the reflectors has an elliptical rim with a 40 m major axis, providing heat to the propellant sufficient to produce about 40 lbs. of thrust. The same concentrator concept is contemplated for space power application to focus solar radiation on a conversion device, e.g., a photovoltaic array or the high temperature end of a dynamic engine. Under the present project, a one-fourth scale, 9X7 m off-axis inflatable concentrator has been under development as a pilot for the full-scale flight unit. The reflector component consists of a reflective membrane made of specially designed gores and a geometrically identical transparent canopy. The two form together an inflatable lenslike structure which, upon inflation, assumes the accurate paraboloidal shape. Thismore » inflatable structure is supported along its rim by a strong, bending-resistant torus. The paper describes the development of this system including the analysis leading to determination of the gore shapes, the reflector membrane design and testing, the analysis of the supporting torus, and a discussion of the effects of the space environment.« less

Space transfer vehicle and integrated guidance launch system

Abstract: A space launch system and a space transfer vehicle useable within such system. The space transfer vehicle includes a primary propulsion engine and attitude control system powered by the same storable bipropellant fuel and a guidance system for both the atmospheric launch vehicle and the space transfer vehicle. The space transfer vehicle is fuelable in space and has a primary propulsion engine which is configured for variable thrust burns.

Investigation of very high bypass ratio engines for subsonic transports

Abstract: A study of propulsion system performance for a family of high bypass ratio turbofan engines is presented. The bypass ratio range is from 6 to 17.5, and both bare engine performance and nacelle installation performance have been considered. Geared, variable pitch/variable nozzle engines with bypass ratios of 10.6, 14, and 17.5 have been studied parametrically, and the performance of a fixed pitch, gearless engine of bypass ratio 9.6 has been estimated to represent an advanced engine with conventional mechanical complexity. Nacelle performance data for a bypass 5 engine have also been included as a baseline. Thrust reverser design for these engines is also considered. Results of this study indicate that conventional nacelle installation losses do not reverse the trend of improving engine fuel efficiency with bypass ratio out to at least bypass ratio 17.5. If innovative concepts are used, such as reverse thrust from a reverse fan pitch and a short fan cowl, the installed fuel efficiency for highbypass-ratio engines looks even better. The bypass 9.6 engine shows a lower fuel burn benefit than the bypass 17.5 engine, but it offers the potential of reduced mechanical complexity and lower maintenance cost.

Jet propulsion device for watercraft, aircraft, and circulating pumps

Abstract: A jet propulsion drive element is disclosed for the increasing of the power yield of jet engines, in particular for watercraft, employing a rotary-driven jet propulsion pipe (11). A thrust propulsion element is disposed at the inner jacket of the jet propulsion pipe (11), covers an outer annular face (A), and is formed as a screw (17). The outer edge of the screw (17) is connected to the inner jacket of the jet propulsion pipe (11). The edge screw (17) is furnished with a through borehole, such that a part of the fluid entering into the jet propulsion pipe (11) is not directly accelerated by the edge screw (17). In addition, drive elements such as a screw propeller (18) can be furnished at the outer jacket of the jet propulsion pipe (11). The invention structure can be employed also for circulating pumps in addition to applications in aircrafts.

Self-traveling robotic vehicle with inclinable propulsion units

Abstract: The invention concerns a vehicle (1) with inclinable tracks in which an inclination movement of a propulsion unit (3) about its articulation axis (5) is assisted by reverse propulsion movement of the track (4) of the propulsion unit. The invention is applicable to the nuclear industry in particular.

Multi-purpose underwater propelling device

Abstract: A multi-purpose aquatic propulsion device that may be utilized both with a water craft and separately therefrom. The device has an exhaust conduit including a check valve that permits the device to be utilized underwater. An arrangement is also provided for removably securing the housing under a water craft, whereby the propulsion device drives the craft while submerged.

Integrated launch and emergency vehicle system

Abstract: A heavy launch vehicle for placing a payload into a spatial Earth orbit including an expendable, multi-container, propellant tank having a plurality of winged booster propulsion modules releasably disposed about one end thereof; and a payload supported by adapter structure at the other end. The preferred payload is an entry module adapted to be docked to a space station and used as a return vehicle for the space station crew, as scheduled, or in emergency situations. Alternately, the payload may include communication satellites, supplies, equipment and/or structural elements for the space station. The winged propulsion modules are released from the expendable propellant tank in pairs and return to Earth in a controlled glide, for safe landing at or near the launch site and prepared for reuse. The rocket engines for each propulsion module are dual-fuel, dual-mode engines and use methane-oxygen and hydrogen-oxygen, respectively, from the multi-containers of the propellant tank. When the propulsion modules are released from the expendable propellant tank, the rocket engines are pivotally moved into the module cargo bay for the return glide flight.

Exhaust Nozzles for Propulsion Systems with Emphasis on Supersonic Cruise Aircraft

Abstract: This compendium summarizes the contributions of the NASA-Lewis and its contractors to supersonic exhaust nozzle research from 1963 to 1985. Two major research and technology efforts sponsored this nozzle research work; the U.S. Supersonic Transport (SST) Program and the follow-on Supersonic Cruise Research (SCR) Program. They account for two generations of nozzle technology: the first from 1963 to 1971, and the second from 1971 to 1985. First, the equations used to calculate nozzle thrust are introduced. Then the general types of nozzles are presented, followed by a discussion of those types proposed for supersonic aircraft. Next, the first-generation nozzles designed specifically for the Boeing SST and the second-generation nozzles designed under the SCR program are separately reviewed and then compared. A chapter on throttle-dependent afterbody drag is included, since drag has a major effect on the off-design performance of supersonic nozzles. A chapter on the performance of supersonic dash nozzles follows, since these nozzles have similar design problems, Finally, the nozzle test facilities used at NASA-Lewis during this nozzle research effort are identified and discussed. These facilities include static test stands, a transonic wind tunnel, and a flying testbed aircraft. A concluding section points to the future: a third generation of nozzles designed for a new era of high speed civil transports to produce even greater advances in performance, to meet new noise rules, and to ensure the continuity of over two decades of NASA research.

Evolutionary use of nuclear electric propulsion

Abstract: Evolving new propulsion technologies through a rational and conscious effort to minimize development costs and program risks while maximizing the performance benefits is intuitively practical. A phased approach to the evolution of nuclear electric propulsion from use on planetary probes, to lunar cargo vehicles, and finally to manned Mars missions with a concomitant growth in technology is considered. Technology levels and system component makeup are discussed for nuclear power systems and both ion and magnetoplasmadynamic thrusters. Mission scenarios are described, which include analysis of a probe to Pluto, a lunar cargo mission, Martian split, all-up, and quick-trip mission options. Evolutionary progression of the use of NEP in such missions is discussed.

Fusion as Electric Propulsion

Abstract: Fusion rocket engines are analyzed as electric propulsion systems, with propulsion thrustpowertoinputpower ratiothe thrustpower "gain," G�� much greater than unity. Gain values of conventionalsolar, fissionelectric propulsion systems are always quite smalle.g., G� < 0.8� . With these, "highthrust" interplanetary flight is not possible, because their system accelerationatcapabili� ties are always less than the local gravitational accelera� tion. In contrast, gain values 50� 100 times higher are found for some fusion concepts, which oer "high� thrust" flight capability. One performance example shows a 53.3 day � 34.4 powered; 18.9 coast� , oneway transit time with 19� payload for a singlestage Earth/ Mars vehicle. Another shows the potential for highac� celerationa� = 0.55 g0� flight in Earth/moon space.

Hybrid internal combustion engine/electrical motor ground vehicle propulsion system

Abstract: A hybrid internal combustion engine/electrical motor ground vehicle propulsion system is disclosed wherein a fluid is first heated in an internal combustion engine cylinder water jacket and then converted to its gaseous phase in a double walled manifold enshrouding the internal combustion engine exhaust manifold. The gas then turns a turbine, exits to a condenser where the gas is condensed into liquid, and then the fluid is returned to a radiator to await the next cycle. The turbine is rotatably connected to a generator which produces electrical energy when the turbine turns. This electrical energy is used to charge a bank of batteries. The bank of batteries is used to supply an electrical motor which may be used as a complementary or alternate source of propulsion for a ground vehicle.

Marine jet propulsion unit

Abstract: A jet propulsion unit is provided for marine craft where a stream of water is induced in a converging inlet section and delivered as a steady laminar shaped flow regime to an impeller section whose novel impeller/diffuser vane combination and converging annular volume enables operation of the vessel over a wide range of speeds and sea conditions without cavitation. Acceleration of water energized by the impeller through an interchangeable nozzle provides additional thrust and maneuverability. The propulsion unit additionally incorporates an arm-hole duct in the inlet housing for easy clean-up of any fouling and a bypass valve positioned upstream from the impeller to eliminate balling and drag caused thereby.

Dual motor control and steering system for watercraft

Abstract: A propulsion and steering system for dual motors mounted to a boat, especially of the trolling type, which incorporates a pair of foot pedals which are electrically connected between a battery and the motors and which are operable to independently control the direction of thrust and speed of the motors so that the motors are used to both propel and steer the boat.

Remotely controlled starter for model toy engines

Abstract: A system for remotely starting model toy internal combustion engines, used for propulsion of the model toy, such as an airplane, helicopter, boat, automobile, or other similar vehicles. The starter mechanism being contained in a single case, coupled to a single gear attached to the model engines crankshaft. The starter case being sufficiently small so as to allow it to be mounted directly to the model toys internal combustion engine. An electrical starter motor attached to the starter mechanism case, for cranking the engine, operating from the internal batteries on board the model toy. A remotely controlled servo starting circuit that energizes the engines ignitor plug, allowing sufficient preheat time, and activates the starter motor, from signals provided by the radio receiver on board the model toy vehicle.

An antiproton catalyst for inertial confinement fusion propulsion

Abstract: This paper discusses the concept of an inertial confinement fusion propulsion system involving an antiproton catalyst (for antiproton-induced fission). It is argued that, when the two processes, fusion and antimatter annihilation, are combined into one system, a viable candidate propulsion system for planetary exploration emerges. It is shown that as much as 7.6 GW of power, well within the requrements for interplanetary travel, can be achieved using existing driver technologies and available quantities of antiprotons.

Power unit for vehicles

Abstract: The power unit for a vehicle includes a thermal engine (1) and an electric motor (2). At low speed, the electric motor (2) has a driving torque higher than the thermal engine's (1) load moment. The electric motor (2) is designed to operate without being mechanically disconnected from the thermal engine (1) when the latter is running at its operating speed. In particular, the electric motor makes it possible to replace the starting motor, the alternator, and the flywheel of the thermal engine, and to provide additional or independent propulsion.

Propeller unit with controlled cyclic and collective blade pitch

Abstract: An improved integral marine propulsion unit is disclosed that can generate a thrust vector in any of three degrees of motion. The unit utilizes both collective and cyclic propeller blade pitch angle variation to generate these thrust. This unit obviates the need for control surfaces and rudders for motion control of a marine vessel. Additionally, this unit provides flexibility in external propulsor arrangements on a marine hull. The unit integrates the swash plate mechanism and actuators within the central bore of a ring type prime mover.

Hydrofoil propulsion system.

Abstract: A hydrofoil propulsion system (10) utilizing dual water propellers (16) in combination with dual shrouded air propellers (18) The air propellers (18) and the water propellers (16) are powered by diesel engines (22) mounted in pairs inside the hull (24) of the hydrofoil craft (14) Each water propeller (16) is affixed to an outdrive (35) through a pivotal propeller shaft (28) that permits the propeller shaft (28) and the water propeller (16) to move horizontally and vertically with respect to the hull (24) An air propeller (18) and a water propeller (16) are each coupled to a single pair of engines (22) so that as the craft (14) transistions from the hullborne mode to the foilborne mode, the thrust load is automatically transferred from the water propeller (16) to the air propeller (18)

High-performance dual-mode integral propulsion system

Abstract: A propulsion system in which pure hydrazine is used as the fuel for both a bipropellant rocket engine for high-thrust performance and in multiple monopropellant thrusters for station keeping and attitude control functions. Use of a common fuel for both modes of operation significantly reduces propellant weight and inert propulsion system weight for any given mission requirements, and therefore increases the payload that can be delivered to and maintained in a desired orbit. Further, for station-keeping, the monopropellant thrusters can be augmented in performance by employing either electrothermal or additional direct chemical energy, arc jet operation, or force field acceleration, to provide increased specific impulse values up to 2,000 seconds or higher.

Advanced propulsion options for the Mars cargo mission

Abstract: Several advanced propulsion options for a split-mission piloted Mars exploration scenario are presented. The primary study focus is on identifying concepts that can reduce total initial mass in low earth orbit (IMLEO) for the cargo delivery portion of the mission; in addition, concepts that can reduce the trip time of the piloted option are assessed. The propulsion options considered are nuclear thermal propulsion, solar sails, multimegawatt-class nuclear electric propulsion, solar electric propulsion, magnetic sails, mass drivers, rail guns, solar thermal rockets, beamed-energy propulsion systems, and tethers. For the cargo mission, solar sails are found to provide the greatest mass savings over the baseline chemical system, although they suffer from having very long trip times; a good performance compromise between a low IMLEO and a short trip time can be obtained using multimegawatt-class nuclear electric propulsion systems.

Solid propellant rocket motor with fusible end closure holder

Abstract: A solid propellant rocket motor comprising a motor case, solid propellant and at least one end closure, wherein at least one end closure is connected to the casing by at least one fusible connector which melts at temperatures below those that will cause autoignition of the motor but does not melt during normal propulsion, so that the end closure releases before the antoignition and is retained in place during normal propulsion.

Adaptive lubrication oil system

Abstract: An adaptive oil lubrication system for a marine propulsion system having a variable speed oil pump controlled by a microprocessor The speed of the pump and, thus, the oil flow rate is varied to track the demand for lubrication by the propulsion system A microprocessor monitors the propulsion system and calculates the appropriate speed of the oil pump to generate the oil flow needed by the propulsion system

Jet-propelled aircraft

Abstract: In a jet-propelled aircraft of the type in which the propulsion jets are directed onto a wing so as to achieve an ejector effect, two vertical tail-fin surfaces are provided and extend downwardly beneath the center of gravity of the aircraft to return the aircraft to a correct attitude when it tends to move sideways relative to the direction of flight.

Propulsion device for lng transport vessel

Abstract: PURPOSE: To effectively utilize the energy of the evaporated gas as a portion of the propulsion power by driving a propulsion assisting electric motor by combusting the generated gas generated in an LNG cargo tank in an LNG heavy oil type mixed combustion type auxiliary boiler. CONSTITUTION: A main engine for propelling an LNG transport vessel is an oil-burn type main Diesel engine 1. The evaporated gas generated in an LNG cargo tank is combusted in a mixed combustion type auxiliary boiler 2. When the boiler 2 can not feed LNG, heavy oil combustion is carried out. In a steam turbine power generator 6, a turbine is driven by using the steam generated in the boiler 2, and electric power is generated. The electric power is supplied into all regions of a vessel, and the excessive electric power is supplied into a propulsion assisting electric motor 7 through a controller 8. The controller 8 performs the control for feeding electric power having the cycle suitable for the electric motor 7. The electric motor 7 is directly connected with a main shaft 5, and driven by the electric power generated in the power generator 6, and the load of the main Diesel engine 1 is reduced by the output portion of the electric motor 7. Accordingly, the energy of the evaporated gas is effectively utilized as a portion of the propulsion power. COPYRIGHT: (C)1992,JPO&Japio