Showing papers on "Propulsion published in 1975"

Trifan powered VSTOL aircraft

Abstract: A vertical or short takeoff and landing aircraft (VSTOL) employing three high bypass turbotip fans disposed in the fuselage and faired into the upper surfaces of the wings, and driven by two gas generators to produce vertical lift and transition to cruise flight such that the tripod arrangement for the turbotip fans generates stable powered flight. In the foregoing aircraft the gas generator - turbotip fan is an integrated propulsion system having thrust vectoring devices and gas flow control valved ducts between the two gas generators and the three turbotip fans to provide all lift, control transition and cruise functions, and in which the gas flow system produces variations in bypass ratios for the various modes of operation. Furthermore, in the foregoing aircraft the lift/cruise nacelles are positioned over the wing and blended into the upper wing surface and the adjacent fuselage to achieve high induced lift through supercirculation over the wing to produce stable flight and reduce sensitivity to gust conditions at low air speeds.

Availability and Propulsion

Abstract: The first and second laws applied to steady-flow systems are expressed in forms which emphasize the distinction between energy, which is conserved, and available energy, which is depleted in real processes. These forms are applied to propulsive systems using, as a velocity datum, the propulsion unit itself and, alternatively, the atmosphere at rest. The maximum thrust power obtainable from the combustion of the fuel is shown to be dependent on the composition, state and velocity of the fuel and also on the composition and state of the environment in which the unit works. An illustrative calculation of the losses in a turbojet engine in flight reveals that in this case 16.64 per cent of the fuel's available energy is obtained as thrust power, 54.25 per cent is rejected by the exhaust, 2.33 per cent is dissipated by aerodynamic losses and the remainder (26.78 per cent) is lost by combustion. Available-energy calculations are seen as providing a consistent framework within which losses can be compared within...

Inlet performance of the integrated Langley scramjet module

Abstract: The inlet concept for the Langley Scramjet Module has been developed and proven in Langley wind tunnels over a Mach number range from 2.3 to 6.0 (flight simulation of Mach 2.6 to 7.6). This modular engine concept is designed to integrate with the airframe, which results in precompression of the engine airflow by the vehicle bow shock and additional expansion of the nozzle exhaust gas by the afterbody of the vehicle. With these integration advantages, the inlet can be designed with modest contraction ratios and fixed geometry. Also, the module nozzle exit area can be equal to the capture area, which permits the cowl to be alined with the local flow producing minimum external drag. The inlet leading edges and planar compression surfaces are swept at 48 deg, which provides spillage at low Mach numbers for starting and which reduces the pressure gradient on the top surface to permit ingestion of the vehicle forebody boundary layer into the inlet without separating. Three fuel injection struts provide for the use of a short combustor having low internal cooling requirements. Schedules for mass capture ratio, contraction ratio, and total pressure recovery are well within the acceptable range for a good scramjet propulsion device. The fixed geometry, minimum external drag design has proven to be a practical, high-performance inlet concept.

Electrically propelled vehicle

Abstract: A propulsion system for an electrical vehicle including a linear proportional controller operable in a plurality of modes for operating a dc drive motor via power derived from a propulsion battery Low speed operation is achieved in an armature control mode wherein the controller is interposed between the propulsion battery and the motor armature while the motor field is coupled directly across the battery High speeds are attained in a field control mode wherein the controller is interposed between the battery and motor field while the armature is coupled directly across the propulsion battery, thereby eliminating controller losses from the high current armature circuit Switching between modes is achieved in a manner which minimizes stress on the switching elements The controller is also adapted to operate in a charger mode wherein unregulated dc power is fed to the controller which functions to regulate the charge provided to the battery Overall efficiency is increased by use of a dual chopper as a power modulator element The circuit further includes protection means for controlling or preventing operation under conditions wherein circuit elements might be damaged

Electrically-powered tricycle

Abstract: A tricycle for adults having stable handling characteristics provides pedal drive and electrocmechanical drive for two-speed propulsion, coasting and braking.

Dual motor propulsion and steering control system

Abstract: A propulsion and steering control system for a fishing boat wherein a pair of reversible electric motors are mounted in a fixed angular relationship to each other of from approximately 30° to 120° as defined between the respective axes of rotation of the propellers of such motors. A control device is provided which, in a preferred embodiment, is a substantially flat, foot-actuated pivotally mounted plate which can be rocked in a fore or aft direction as well as a right or left direction for actuating appropriate switches which enable the operator to selectively and independently produce a forward or reverse thrust with any one or both of the angularly oriented motors, thereby enabling the operator to achieve a desired propulsion and steering control for the fishing boat while maintaining the motors in the fixed relationship to each other and without requiring turning of either of the motors.

Multiple bypass-duct turbofan with annular flow plug nozzle and method of operating same

Abstract: A propulsion nozzle having a substantially cylindrical translatable shroud partially defining an outer flow duct and an articulated plug mounted within the shroud to partially define an inner coannular flow duct. A variable position valve comprises the downstream portion of the common wall between the ducts for modulating the relative flow rates between ducts and for creating a favorable static pressure balance therebetween. The shroud and plug cooperate to form a variable area throat for the combined duct flows.

Helicopter yaw and propulsion mechanism

Abstract: A mechanism is provided for controlling the directional heading of a helicopter, particularly during hover and autorotation. In addition the mechanism provides additional thrust which enables the helicopter to increase its maximum velocity. The mechanism includes three nozzles with valves positioned therein, located in the rearward portion of the helicopter fuselage. Two of the nozzles are located on opposite sides of the aircraft fuselage to provide thrust for use in controlling the directional heading of the aircraft. This thrust is also used to counteract the torque generated by the driving of the lifting rotor of the helicopter. The third nozzle is positioned so that the thrust generated by it will increase the forward velocity of the helicopter. A propeller or fan located in the body of the aircraft forces air from intakes through the fuselage to the nozzles. The position of the valves is determined by suitable control linkage.

Scuba divers propulsion unit

Abstract: A battery operated propulsion unit secured to a SCUBA divers air tank consisting of three chambers; the center one containing the propeller drive motor. On each side of the motor is one battery chamber which contains the batteries that supply the power for the propeller drive motor. The propeller is surrounded by a propeller housing. Wired in series with the motor and power supply batteries is the motor control. Wired in parallel or in series depending on the position of the switch and in series with the motor control and motor is a speed control switch.

Compound helicopter drive means

Abstract: Compound helicopters, those having a rotor blade and a small wing, possess rear propulsion propeller adjacent to the tail rotor. The tail gearbox is driven through a drive train coupled to the main rotor drive shaft. In such aircraft the tail rotor is in operation when the propulsion propeller is turning, and vice versa. A mechanism is provided herein for stopping or feathering the tail rotor when driving the propulsion propeller, or for stopping the propulsion propeller when the tail rotor is in operation.

Designing solid propellant pulsed plasma thrusters

Abstract: In this paper fundamental definitions and a few semiempirical correlations of experimental data of solid propellant pulsed plasma thrusters are used to illustrate the design analysis of such propulsion systems. The design analysis presented facilitates the design of a thruster to meet a specific performance level and provides the spacecraft designer with a methodology to select a pulsed plasma propulsion system to meet his mission requirements.

Survey of Electric Propulsion Capability

Abstract: A nearly two decades of research and development, and several recent and ongoing successful tests in space, electric propulsion systems are emerging which are capable of fulfilling the secondary propulsion requirements of initial station acquisition, stationkeeping, attitude control, and modest repositioning, as well as providing primary propulsion for a wide range of interesting missions. Further, system reliability has now advanced sufficiently to project electric propulsion to the threshold of several flights, where it will be an integral part of functioning spacecraft. Many excellent reviews of the historical development and status of electric propulsion have appeared in the literature." The purpose of this paper is to provide the spacecraft designer with sufficient information regarding the recent progress and present capability of the several types of electric propulsion systems to enable him to optimize his selection for a particular mission. To this end, each of four major classes of electric thruster (electrothermal, plasma, colloid, and ion) is briefly described and the distinct programs in each class reviewed. The emphasis is on performance capability, development status, program goals, and technology improvement. Adequate references are provided for a more detailed examination of each thruster program.

Combined generator and boat propulsion system

Abstract: A power system comprising a generator mounted on the propulsion unit of an outboard motor through an interposed adaptor which exposes the drive connection between the generator and propulsion unit to allow access thereto for employment of the drive mechanism for the driving of accessories other than the outboard motor. Clutch means selectively couple the drive means of the generator and the driven means of the propulsion unit for a selective operation of the mounted generator independently of the propulsion unit.

Gas turbine engine geometry control

Abstract: GAS TURBINE ENGINE GEOMETRY CONTROL Abstract of the Disclosure A single-shaft gas turbine engine suited for road vehicle propulsion has variable inlet and outlet guide vanes in the compressor of the engine and a variable turbine nozzle. These variable features are called engine variable geometry (EVG). In normal operation, the areas of the flow paths at the inlet and outlet of the compressor and of the turbine nozzle are varied with desired power level to suit varying air flow through the engine. An actuator increases the areas in response to a request for increased power output. In a braking mode, the compressor variable geometry is decoupled from the actuator and remains at a minimum flow condition while the turbine nozzle is opened as the power request decreases below a particular low value. The opening of the turbine nozzle decreases the engine power output, thus increasing its capacity to absorb power from the vehicle. Logic circuits control the coupling and decoupling of the compressor variable geometry.

Aircraft propulsion system with flight maneuverable exhaust nozzle

Abstract: An aircraft propulsion system is provided which incorporates a flight maneuverable exhaust nozzle In one embodiment, gas turbine engines are mounted on both sides of an aircraft fuselage, each engine having an exhaust duct partially defining an exhaust stream flow path The duct transists from a substantially cylindrical diffuser section aft of the engine to a relatively high aspect ratio section proximate the trailing edge of the wing Exhaust gases are expelled through a thrust vectorable nozzle which is contoured within the wing and which is adapted to increase wing lift through the concept of supercirculation Maximum aerodynamic advantage is achieved by distributing the exhaust flow over a significant portion of the wing span at the trailing edge Thrust augmentation is provided through use of a long, flat duct burner disposed within the high aspect ratio section proximate the exhaust nozzle thereby minimizing turning losses and cooling air requirements The exhaust nozzle includes an articulated deflector partially defining both the exhaust stream flow path and the wing upper surface Synchronous movement of the two flaps comprising the deflector ensures proper internal area control prior to exhaust gas vectoring The nozzle throat area is varied by a lower flap disposed in general opposition to the articulated deflector Actuators are provided to vary the throat area and produce the proper thrust vector angle by positioning the lower flap and articulated deflector, respectively

Hydraulic jet propulsion system

Abstract: An hydraulic propulsion system for watercraft involving the forming of a parallel-sided, open-ended inlet intake tunnel with a recessed intake screen at the rear of the craft, which tunnel directs the incoming water flow into a single or multi-stage cylindrical axial pump having multi-vaned matched impellers and straighteners for driving the flow into an unobstructed acceleration chamber which converges the flow according to the rule of minimal flow losses, and discharges it as a jet through a cylindrical opening with controls thereat to propel and steer the craft. The intake tunnel and the acceleration chamber may be formed of fiberglass, with the former being laminated or molded into the hull of the craft, and the overall system may be of simplified, light-weight, compact construction while producing at least 15% greater thrust than conventional propulsion systems, and much greater thrust than prior hydraulic jets, of comparable power, installed in the same craft.

Method and apparatus for controlling the speed of a vehicle

Abstract: Apparatus is provided for controlling the speed of a vehicle, especially vehicles of a railway train, wherein acceleration-imparting mechanisms associated with the wheels are adjusted on an individual basis by comparison of tangential speed and desired speed by the use of sensors to maintain the tangential speeds of the wheels equal to each other, and equal to a predetermined value. The technique may be employed in either the braking or the propulsion mode of operation, or in both modes, and allows commanded rates of vehicle acceleration to be realized to the greatest possible extent.

Magnetic levitation and propulsion, 1975

Abstract: A status report on progress toward the development of a magnetic levitation and propulsion system for mass transportation is presented. It summarizes important results and provides a bibliography for further study. Emphasis is placed on various aspects of different magnetic structures which have been proposed for this application.

Distortion-Induced Vibration in Fan and Compressor Blading

Abstract: System of the F-104 Aircraft," WADC TR-1756, 1959, Wright Air Development Center, Wright-Patterson Air Force Base, Ohio. Rudinger, G., Wave Diagrams for Non-Steady Flow In Ducts, Van Nostrand, New York, 1955. ^Marshall, F. L., "Prediction of Inlet Overpressures Resulting From Engine Surge," Journal of Aircraft, Vol. 10, May 1974, pp. 274-278. Kurkov, A. P., Soeder, R. H., and Moss, J. E., "Investigation of the Stall-Induced Shock Wave (Hammershock) at the Inlet to the Engine," TMX-71594, Sept. 1974, NASA. Martin, A. W., "Propulsion System Dynamic Simulation Theory and Equations," CR-928, April 1967, NASA. Martin, A. W., and Wong, H. W., "Propulsion System Dynamic Simulation Users Manual," CR-73113, April 1967, NASA. Martin, A. W., and Kostin, L. C., "Propulsion System Dynamic Test Results," CR-73114, April 1967, NASA. Martin, A. W., "Propulsion System Dynamic Simulation Data," CR-73115, April 1967, NASA. Martin, A. W. and Beaulieu, W. D., "XB-70 Flight Test Data Comparison With Simulation Predictions of Inlet Unstart and Buzz," CR-1631, June 1969, NASA. Johnson, R. H., "B-l Hammershock Estimates," NA 70-38, Aug. 1970, Rockwell International, Los Angeles, Calif. Amin, N. F. and Hall, G. R., "Supersonic Inlet Investigation, Air Induction System Dynamic Simulation Model," AFFDL-TR-121, Vol II, Sept. 1971, Air Force Flight Dynamics Lab., Wright-Patterson Air Force Base, Ohio. Choby, D. A., Burstadt, P. L., and Calogeras, J. E., "Unstart and Stall Interactions Between a Turbojet Engine and an Axisymmetric Inlet With 60-Percent Internal-Area Contraction," TMX-2192, March 1971, NASA. Nugent, J. and Holtzman, J., "Flight-Measured Inlet Pressure Transients Accompanying Engine Compressor Surges on the F-111A Airplane," TND-7696, June 1974, NASA. Barnard, J. D. and Evans, P. J., "Air Induction System EngineStall Loads," Proceedings of Third Structural Loads Workshop for Preliminary Aerospace Design Projects, Aeronautical Systems Division, Wright-Patterson Air Force Base, Sept., 1970, pp.89-127. Randall, L. M., et al., Rockwell Propulsion System Aerodynamics, "B-l Full Scale Inlet-Engine Compatibility Test, AEDC TF 329 and SF 166, Vol. I, Preliminary Summary," NA-74-375, Aug. 1974, Arnold Engineering Development Center, Tullahoma, Tenn.

Marine vessel adapted to be powered and steered by a transported land vehicle

Abstract: A marine vessel that is constructed and arranged so that it can accommodate an automobile or other motor vehicle and can simply and efficiently utilize the power drive and steering mechanisms of the motor vehicle for the propulsion and steering of the vessel. The motor vehicle can be carried on the deck of the vessel, and to standardize construction of the vessel, a fixed location for only one supporting element for a steering wheel is provided. The remaining wheels are supported on movable elements that can be located to accommodate a motor vehicle of any width and length. The wheel supporting element that has a fixed location is a turntable which is connected to a rudder, so that the rudder can be controlled by operation of the steering wheel of the motor vehicle. A hydraulic propulsion system is provided which can be driven from a movable supporting element that supports a driving wheel of the motor vehicle.

Means for propelling a wheeled vehicle

Abstract: Electric motors are connected to the front wheels of a vehicle to commence the propulsion of the vehicle. Fluid pressure motors are connected to the rear wheels of the vehicle to propel the vehicle once the electric motors have commenced the propulsion thereof. An electric pump supplies expansible fluid to the fluid pressure motors. Electric heaters expand the fluid in the fluid pressure motors to cause the fluid pressure motors to rotate the rear wheels of the vehicle thereby propelling the vehicle. The electric motors are adapted to act as generators after the fluid pressure motors have commenced the propulsion of the vehicle to recharge a battery that operates the electric motors, the electric pump and the electric heaters.

Semi-submersible, directionally controlled drilling unit

Abstract: A drilling unit is disclosed which incorporates a submersible streamlined hull supporting a streamlined upper hull above the surface of the water by support columns and trusses. The unit is directionally controlled by transverse thrusters and in-line propulsion screws in the submersible hull which are operated by a control system to maintain station keeping over the wellhead at an optimum heading for minimizing the effects of environmental forces such as wind, current and wave action. The control system senses the vessel's heading and surge and sway motions with respect to the wellhead reference and converts this information into error signals. The bow and stern thrusters and in-line propulsion screws are then operated to produce thrust forces which reduce the respective errors. In response to the generation of a stern thrust the control system iteratively calculates a change in the bow target point position on the target circle which will make the stern thrust trend toward zero.

Circuit arrangement for a track-bound propulsion vehicle

Abstract: The invention relates to a circuit arrangement for use with a trackbound propulsion vehicle. The circuit arrangement includes a traveling-field winding which is installed alongside the vehicle roadbed and forms the stator of a linear synchronous motor whose exciter is disposed as a co-movable translator on the vehicle itself. More particularly, in order to be able to accelerate the propulsion vehicle with constant driving power, in accord with the invention, the traveling-field winding is designed such that the number of conductors per pole and phase thereof are inversely proportional to a pre-determined vehicle velocity.

Twin-propeller stern drive

Abstract: Twin-propeller stern drive propulsion unit having automatic thrust alignment trim and retractable hydrofoils for improved shallow water operation. Retention of optimum thrust direction is accomplished automatically by parallel geometry action of a cross-plane trim actuator with a vertical drive shaft housing attached to an underwater unit.

Aircraft with safety tail unit

Abstract: Aircraft having supersonic and subsonic flight capabilities which utilize variable geometry tail units and fixed front planes to generally improve airworthiness and safety of aircraft during takeoff and landing, and which additionally have a reduced air resistance during high-speed flight and thus save propulsion energy.

Factors in the design of spacecraft utilizing multiple electric thrusters

Abstract: An analysis has been performed which describes the electrical interactions between simultaneously operating ion thrusters and between the ion thrusters and a spacecraft bus. The problem is reduced to a relatively simple equivalent circuit including all leakage paths. The influence of the various circuits elements on a spacecraft potential is studied. A thruster grounding scheme is introduced which is designed to minimize the electrical interactions and includes protection for both thrusters and spacecraft from possible damage due to neutralizer failure. The paper includes the results of various experiments which have been conducted to quantitatively define the elements of the equivalent circuit.