Showing papers on "Propulsion published in 1985"

Turboprop propulsion apparatus

Abstract: A turboprop propulsion system where there is a core engine driving a power turbine that is connected through a planetary drive transmission to first and second counterrotating propellers. One of the propellers is connected to the ring gear, while the other propeller is connected to the planetary carrier, the sun gear being driven from the power turbine. The apparatus is provided with a substantially continuous gaseous flow path from the inlet to the exhaust nozzle of the engine, with the planetary drive transmission being spaced radially from the flow path. In some embodiments, the planetary transmission is positioned radially inwardly of the flow path, while in other embodiments, it is positioned radially outwardly of the flow path. The propellers can be in either the pusher configuration or the tractor configuration.

Antiproton Annihilation Propulsion

Abstract: : Antiproton annihilation propulsion is a new form of space propulsion, where milligrams of antimatter are used to heat tons of reaction fluid to high temperatures. The hot reaction fluid is exhausted from a nozzle to produce high thrust at high specific impulse. This study was to determine the physical, engineering, and economic feasibility of antiproton annihilation propulsion. The conclusion of the study is that antiproton propulsion is feasible, but expensive. Because the low mass of the antimatter fuel more than compensates for its high price, comparative mission studies show that antimatter fuel can be cost effective in space, where even normal chemical fuel is expensive because its mass must be lifted into orbit before it can be used. Antiproton annihilation propulsion is mission enabling, in that it allows missions to be performed that cannot be performed by any other propulsion system. Keywords: Antimatter propulsion; Antiproton; Advanced propulsion.

Convertible turbo-fan, turbo-shaft aircraft propulsion system

Abstract: A composite turbo-fan/turbo-shaft gas turbine engine system is provided wherein the fan is driven through a variable geometry torque coverter whose input is driven by the turbine power shaft supplied through a reduction gear. Actuation of the variable geometry of the torque converter provides a wide variety of operating modes including all power to the power output shaft and combinations in between.

Launch and ascent system

Abstract: This invention uses magnetic levitation in combination with magnetic propulsion (MAGLEV) to accelerate an aircraft of spacecraft--or both crafts as a coupled unit--from standstill along a guideway to the highest possible launch velocity. The acceleration along the guideway is fuel efficient. The craft(s) are brought to launch velocity without using on board fuel. The computer controlled acceleration along the guideway could avoid high g forces to prevent damage to fragile payloads. The guideway may be sectionalized and of any shape. One section, for instance, may be circular to permit a long magnetically accelerated run with a relatively short length guideway. Very heavy crafts and payloads can be launched with superconducting levitation magnets in the guideway which form strong repulsive force fields with superconducting magnets in the MAGLEV vehicle. In another embodiment, the invention includes attraction magnets for the levitation. The invention could operate in an airless environment, such as the moon, to launch rocket powered spacecraft with their payloads. On earth, the invention could launch a rocket powered spacecraft coupled to an aircraft having air breathing engines. The aircraft would power the spacecraft to a staging altitude, where the spacecraft would actuate its own rocket engines for propulsion beyond the atmosphere, and separate from the aircraft. Unlike the space shuttle, all major components of the invention's space launch would be recovered for reuse. The invention may be multipurpose for serving to efficiently launch conventional aircraft. With a circular guideway, takeoff is inherently omnidirectional to take advantage of launch conditions.

Energy efficient engine: Flight propulsion system final design and analysis. Report, November 1978-August 1983

Abstract: The Energy Efficient Engine (E3) is a NASA program to create fuel saving technology for future transport engines. The Flight Propulsion System (FPS) is the engine designed to achieve E3 goals. Achieving these goals required aerodynamic, mechanical and system technologies advanced beyond that of current production engines. These technologies were successfully demonstrated in component rigs, a core engine and a turbofan ground test engine. The design and benefits of the FPS are presented. All goals for efficiency, environmental considerations, and economic payoff were met. The FPS has, at maximum cruise, 10.67 km (35,000 ft), M0.8, standard day, a 16.9 percent lower installed specific fuel consumption than a CF6-50C. It provides an 8.6 percent reduction in direct operating cost for a short haul domestic transport and a 16.2 percent reduction for an international long distance transport.

Engine exhaust apparatus for water-jet propulsion boat

Abstract: An exhaust apparatus for a water jet propulsion boat having an engine exhaust passage provided inside an impeller shaft. The exhaust passage opens into the water jet at a position rearward of an impeller. Thus, the length of an engine exhaust pipe can be reduced, and it is possible to reduce the space required for installation of the exhaust apparatus. Since the engine exhaust gas is discharged into the water jet at a position to the rear of the impeller, no cavitation occurs at the impeller portion. Further, it is possible to utilize the engine exhaust gas as a gas layer constituting a pneumatic bearing for supporting the impeller shaft.

Advanced Prop-fan Engine Technology (APET) single- and counter-rotation gearbox/pitch change mechanism

Abstract: The preliminary design of advanced technology (1992) prop-fan engines for single-rotation prop-fans, the conceptual design of the entire propulsion system, and an aircraft evaluation of the resultant designs are discussed. Four engine configurations were examined. A two-spool engine with all axial compressors and a three-spool engine with axial/centrifugal compressors were selected. Integrated propulsion systems were designed in conjunction with airframe manufacturers. The design efforts resulted in 12,000 shaft horsepower engines installed in over the installations with in-line and offset gearboxes. The prop-fan powered aircraft used 21 percent less fuel and cost 10 percent less to operate than a similar aircraft powered by turbofan engines with comparable technology.

Advanced Propfan Engine Technology (APET) definition study, single and counter-rotation gearbox/pitch change mechanism design

Abstract: Single-rotation propfan-powered regional transport aircraft were studied to identify key technology development issues and programs. The need for improved thrust specific fuel consumption to reduce fuel burned and aircraft direct operating cost is the dominant factor. Typical cycle trends for minimizing fuel consumption are reviewed, and two 10,000 shp class engine configurations for propfan propulsion systems for the 1990's are presented. Recommended engine configurations are both three-spool design with dual spool compressors and free power turbines. The benefits of these new propulsion system concepts were evaluated using an advanced airframe, and results are compared for single-rotation propfan and turbofan advanced technology propulsion systems. The single-rotation gearbox is compared to a similar design with current technology to establish the benefits of the advanced gearbox technology. The conceptual design of the advanced pitch change mechanism identified a high pressure hydraulic system that is superior to the other contenders and completely external to the gearboxes.

Aerospace vehicle having multiple propulsion systems on a relatively rotatable flying wing

Abstract: An aerospace vehicle having multiple propulsion systems on a relatively rotatable flying wing capable of takeoff and subsequent landing with intermediate space flight in the manner of a conventional aircraft and rocket, respectively, comprising an elongated wing member having internal passenger and crew, cargo and fuel storage compartments. A plurality of propulsion systems are distributed about the wing member for providing thrust and aerodynamic control. The vehicle also includes rotating means for controlling the direction of the thrust of the propulsion systems relative to the longitudinal axis of the wing whereby to rotate the wing member relative to the direction of flight. The vehicle takes off and lands with the longitudinal wing axis being transverse to the direction of thrust and therefore to the flight direction in a manner similar to that of conventional aircraft. In flight as the vehicle approaches space, the rotating means rotates the longitudinal wing axis into alignment with the direction of thrust of the plurality of propulsion systems and therefore to the direction of flight for suborbital, orbital and space flight in the manner similar to that of conventional rockets.

Apparatus for improving aerodynamic flow conditions at the air intake of gas turbine engines

Abstract: Aerodynamic flow conditions at the air intake of gas turbine engines, espally aircraft engines, comprising boundary layer deflectors are improved by movably arranging the boundary layer deflectors so that they may be retracted flush into the aircraft fuselage during take-off and low speed flight, and may be extended to an operating position during high speed flight. A similar retractable boundary layer deflector may be provided for an air intake for an auxiliary engine, which operates intermittently to drive auxiliary devices of an aircraft. When the auxiliary engine operates the air intake is open and the deflector is extended thereby improving the intake air flow conditions. When the auxiliary engine is shut down, the air intake is covered by a control flap and the deflector is retracted flush into the fuselage. These features provide optimal high- and low-speed flow conditions at the air intakes of the primary propulsion plant and of the auxiliary engine of an aircraft, and undesirable drag is eliminated or at least substantially reduced.

Mechanism for maintaining a swinging movement

Abstract: A swinging mechanism for maintaining pendular movement in a swing. A revolving plate is provided which engages a propulsion member on the swing so as to apply torque to the swing during part of the swing cycle, maintaining pendular movement of the swing despite energy loses due to air friction and the like. Switches are provided to activate rotation of the revolving plate when the swing has reached a rear position, and to continue movement of the revolving plate to return it to a neutral or original position in preparation for the next cycle of the swing movement.

Evaluation of propfan propulsion applied to general aviation

Abstract: Propfan propulsion on business aircraft was evaluated. Comparisons, in terms of cost and performance, were made between propfan propulsion systems and conventional turbofan propulsion systems on a typical business aircraft. In addition, configuration and cost sensitivity studies were conducted to further assess the potential of propfan propulsion.

Energy Efficient Engine: Flight propulsion system final design and analysis

Abstract: The Energy Efficient Engine (E3) is a NASA program to create fuel saving technology for future transport engines. The Flight Propulsion System (FPS) is the engine designed to achieve E3 goals. Achieving these goals required aerodynamic, mechanical and system technologies advanced beyond that of current production engines. These technologies were successfully demonstrated in component rigs, a core engine and a turbofan ground test engine. The design and benefits of the FPS are presented. All goals for efficiency, environmental considerations, and economic payoff were met. The FPS has, at maximum cruise, 10.67 km (35,000 ft), M0.8, standard day, a 16.9 percent lower installed specific fuel consumption than a CF6-50C. It provides an 8.6 percent reduction in direct operating cost for a short haul domestic transport and a 16.2 percent reduction for an international long distance transport.

Marine propulsion device hydraulic system

Abstract: A marine propulsion device comprising a propulsion unit adapted to be pivotally mounted on the transom of a boat for pivotal movement relative to the transom about a steering axis, the propulsion unit including a rotatably mounted propeller, an engine including a throttle lever, and a shiftable transmission drivingly connecting the engine to the propeller and including a shift lever, a hydraulic shift assist system connected to the shift lever for actuation thereof, a hydraulic throttle assist system connected to the throttle lever for actuation thereof, a hydraulic fluid reservoir, a pump communicating with the reservoir, a supply conduit communicating between the pump and the shift assist system, a supply conduit communicating between the shift assist system and the throttle assist system, and a return conduit communicating between the throttle assist system and the reservoir.

Design study of an integrated aerobraking orbital transfer vehicle

Abstract: An aerobraking orbital transfer vehicle (AOTV) concept, which has an aerobrake structure that is integrated with the propulsion stage, is discussed. The concept vehicle is to be assembled in space and is space-based. The advantages of aeroassist over an all propulsive vehicle are discussed and it is shown that the vehicle considered is very competitive with inflatable and deployable concepts from mass and performance aspects. The aerobrake geometry is an ellipsoidally blunted, raked-off, elliptical wide-angle cone with a toroidal skirt. Propellant tanks, engines, and subsystems are integrated into a closed, isogrid aerobrake structure which provides rigidity. The vehicle has two side-firing, gimbaled RL-10 type engines and carries 38,000 kg of useable propellant. The trajectory during aerobraking is determined from an adaptive guidance logic, and the heating is determined from engineering correlations as well as 3-D Navier-Stokes solutions. The AOTV is capable of placing 13,500 kg payload into geosynchronous Earth orbit (GEO) or carrying a LEO-GEO-LEO round-trip payload of 7100 kg. A two-stage version considered for lunar missions results in a lunar surface delivery capability of 18,000 kg or a round-trip capability of 6800 kg with 3860 kg delivery-only capability.

Marine propulsion device oil cooling arrangement

Abstract: A marine propulsion device comprising a propulsion unit adapted to be mounted on the transom of a boat for pivotal movement relative to the transom about a generally vertical steering axis, and about a generally horizontal tilt axis, the propulsion unit including a rotatably mounted propeller, an engine drivingly connected to the propeller, and a wall at least partially defining a cooling water jacket and having therein an opening communicating with the water jacket, and a fluid cooler extending through the opening and including a portion extending internally of the water jacket and having therein a fluid passage adapted to communicate with a source of fluid to be cooled in the fluid cooler.

Laser propulsion for the orbital transfer mission

Abstract: America's space activities in the 1990s and beyond will partly consist of missions involving the transportation of cargo from low earth orbit (LEO) to higher orbits or to an escape trajectory. Such missions are to be performed with the aid of an orbit transfer vehicle (OTV). The operation of the OTV can be based on different propulsion concepts. A chemical OTV is characterized by a high thrust and low specific impulse. The result is a short trip time at the cost of large quantities of propellant. On the other hand, low-thrust systems such as electric propulsion units, consume very little propellant, but would have a long trip time. The present paper is concerned with a compromise between these two extremes. The employed propulsion system utilizes laser thermal propulsion, in which a ground or space-based laser is used to beam energy to a thruster on the OTV. The laser light is absorbed by a propellant. The resulting heating of the propellant causes an expansion of the propellant through a nozzle to produce thrust. Details regarding this propulsion concept are discussed, taking into account operational questions and missions.

Advanced Propfan Engine Technology (APET) and Single-rotation Gearbox/Pitch Change Mechanism

Abstract: The projected performance, in the 1990's time period, of the equivalent technology level high bypass ratio turbofan powered aircraft (at the 150 passenger size) is compared with advanced turboprop propulsion systems. Fuel burn analysis, economic analysis, and pollution (noise, emissions) estimates were made. Three different cruise Mach numbers were investigated for both the turbofan and the turboprop systems. Aerodynamic design and performance estimates were made for nacelles, inlets, and exhaust systems. Air to oil heat exchangers were investigated for oil cooling advanced gearboxes at the 12,500 SHP level. The results and conclusions are positive in that high speed turboprop aircraft will exhibit superior fuel burn characteristics and lower operating costs when compared with equivalent technology turbofan aircraft.

Xenon ion-propulsion subsystem

Abstract: This paper describes an integrated xenon ion propulsion subsystem designed to perform 10 years of northsouth stationkeeping for 2500-kg-class geosynchronous communications satellites. The propulsion subsystem comprises a 25-cm-diam thruster, a power supply, and a propellant tankage and control unit. With a spacecraft bus power of 1400 W, the unit produces 63 mN of thrust at a specific impulse of 2900 s. A propulsion subsystem efficiency of 65% is obtained using a highly efficient ring-cusp discharge chamber equipped with a three-grid ion extraction assembly (thruster efficiency of 70%) and a simplified power supply that operates at 90% efficiency. Results show that the propulsion subsystems can be turned on with a single analog command, reaching its fullthrust level in less than 3 min.

Considerations of the Butterfly Kick Based on Hydrodynamical Experiments

Abstract: In recent years the consideration of the propulsion in competitive swimming has been focused on the contribution by the upper limbs. A comprehensive overview of the force production by hands and arms has been worked out, since COUNSILMAN (1971) applied the “Bernoulli or Lift Principle” to human propulsion in water. Based on this principle the understanding of the swimming techniques increased, resulting in different learning steps and better swimming results. Moreover, the introduction of the lift force into the biomechanics of swimming permitted a more realistic assumption of the forces produced by the hands. SCHLEIHAUF (1979) and WOOD (1979) presented figures of hydrodynamical coefficients on which calculations have been based (SCHLEIHAUF, 1984).

Space station propulsion: The advanced development program at Lewis

Abstract: A reference configuration was established for the initial operating capability (IOC) station. The reference configuration has assumed hydrazine fueled thrusters as the propulsion system. This was to establish costing and as a reference for comparison when other propulsion systems are considered. An integral part of the plan to develop the Space Station is the advanced development program. The objective of this program is to provide advanced technology alternatives for the initial and evolutionary Space Station which optimize the system's functional characteristics in terms of performance, cost, and utilization. The portion of the Advanced Development Program that is concerned with auxiliary propulsion and the research and programmatic activities conducted are discussed.

Integrated flight/propulsion control - Adaptive engine control system mode

Abstract: The adaptive engine control system mode (ADECS) which is developed and tested on an F-15 aircraft with PW1128 engines, using the NASA sponsored highly integrated digital electronic control program, is examined. The operation of the ADECS mode, as well as the basic control logic, the avionic architecture, and the airframe/engine interface are described. By increasing engine pressure ratio (EPR) additional thrust is obtained at intermediate power and above. To modulate the amount of EPR uptrim and to prevent engine stall, information from the flight control system is used. The performance benefits, anticipated from control integration are shown for a range of flight conditions and power settings. It is found that at higher altitudes, the ADECS mode can increase thrust as much as 12 percent, which is used for improved acceleration, improved turn rate, or sustained turn angle.

Power system containing generator and battery for driving a vehicle or vessel

Abstract: The power system consists of a combustion engine 1 driving a generator 2 which charges a battery 3 and also drives a propulsion motor 4 when the car or vessel is in motion. The control unit 5 sets the parameters of the engine and generator in such a way as to achieve their maximum efficiency coefficient. When the battery is discharged the control unit switches on the engine and generator. After the battery is charged the engine will switched off by the control unit and the motor will be driven by the battery. When the car or vessel is standing the battery can be charged from a.c, mains and this way it can be used for short trips without using the combustion engine.

Small-sized marine craft with shell construction having hand grips

Abstract: A small-sized marine craft has a shell with a deck, an engine room formed in the bow portion of the hull, an engine mounted in the engine room, a propulsion device on the stern of the hull, a steering handle device on the top wall of the engine room, a rear part of the deck provides a seat for a rider, and a grip at the rear wall of the engine room for easy gripping and pulling by a rider climbing up the marine craft or by a fellow rider during a tandem ride.

Thermal arcjet technology for space propulsion

Abstract: Advanced space propulsion systems are required to meet projected Air Force needs through the year 2000 Most of these missions require a large, on-orbit impulse capability High specific impulse (I sub sp) electric engines can provide this impulse while consuming relatively little propellant An arcjet engine system, which operates in the range of 800 to 2000 s I sub sp, is a promising candidate to meet these projected Air Force mission needs This electric propulsion system is ideally suited to missions currently under consideration, such as the Space-based Radar and other space platforms, because sufficient power is already installed for other functions on the spacecraft Also, arcjet systems are attractive for NASA near-term, low-cost Mariner Mark II missions to Saturn and Uranus Development of arcjet engines was an Air Force and NASA-sponsored activity that proceeded vigorously from its inception during the late 1950's up to the mid-1960's when the programs were terminated This paper describes thermal arcjet technology as it was developed over two decades ago and points to the direction this technology development should proceed in the future In particular, operation with storable propellants such as ammonia and hydrazine are considered The performance, applicability and advantages of these systems in terms of increased payload and/or decreased trip times are discussed