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Showing papers on "Propulsion published in 1971"


Journal ArticleDOI
TL;DR: In this paper, the main features of this undulatory mode of propulsion are discussed for the case of large Reynolds number, based on the principle of energy conservation, and the general problem of a two-dimensional flexible plate, swimming at arbitrary, unsteady forward speeds, is solved by applying the linearized inviscid flow theory.
Abstract: The most effective movements of swimming aquatic animals of almost all sizes appear to have the form of a transverse wave progressing along the body from head to tail. The main features of this undulatory mode of propulsion are discussed for the case of large Reynolds number, based on the principle of energy conservation. The general problem of a two-dimensional flexible plate, swimming at arbitrary, unsteady forward speeds, is solved by applying the linearized inviscid flow theory. The large-time asymptotic behaviour of an initial-value harmonic motion shows the decay of the transient terms. For a flexible plate starting with a constant acceleration from at rest, the small-time solution is evaluated and the initial optimum shape is determined for the maximum thrust under conditions of fixed power and negligible body recoil.

321 citations




Patent
28 Oct 1971
TL;DR: In this article, an outboard motor unit for use on small boats and having a primary propulsion engine connected through a clutch to the propeller shaft and an electric motor aligned with and connected to the prop shaft is described.
Abstract: An outboard motor unit for use on small boats and having a primary propulsion engine connected through a clutch to the propeller shaft and an electric motor aligned with and connected to the propeller shaft. The electric motor is connected to a battery through a switch operatively connected to the engine throttle to complete the power connection for the electric motor when the throttle is at a selected proportion of full throttle. The electric motor operates as a motor when the engine is stopped and as a generator when the engine is running.

38 citations


Patent
18 Jan 1971
TL;DR: In this paper, single and multi-engine versions are described, and eye lid devices which cooperate with the flow-directing means to reduce the loss of liftgas are described.
Abstract: Ground effect vehicles including power means for providing a flow of gas and gimbal mounted flow-directing means for selectively directing the flow of gas into a lift component and a propulsion or control component. The propulsion or control component acts directly from the flow-directing means and is directed over the top of a deck or platform. Single and multiengine versions are disclosed, and eye lid devices which cooperate with the flow-directing means to reduce loss of liftgas are described.

29 citations


Journal ArticleDOI
TL;DR: In this paper, the status of the air-breathing HTOL launch vehicle is assessed in light of recent achievements in propulsion and configuration development, concluding that all major or questions of feasibility, particularly in the area of hypersonic propulsion have been answered favorably by the investigations of several small research engines recently completed.
Abstract: Low-cost transportation to and from Earth orbit with systems characterized by reusability, flexibility, and "airline-type" operations is a prime goal of the space program. The airbreathing HTOL launch vehicle has inherent features which make it a candidate for such a system but, unfortunately, the lack of a developed powerplant implies a procurement cycle length on the order of a decade. The purpose of this paper is to assess the status of the airbreathing launch vehicle in the light of recent achievements in propulsion and configuration development. It is concluded that all maj or questions of feasibility, particularly in the area of hypersonic propulsion, have been answered favorably by the investigations of several small research engines recently completed. The remaining key problems are discussed together with some promising approaches toward their solution. Finally, important steps required to develop an operational air-breathing system by the early eighties are discussed.

27 citations


Patent
Albert N Addie1
02 Aug 1971
TL;DR: In this paper, a bi-modal vehicle, such as a rail car, is provided in a preferred embodiment with a propulsion turbine and an electromechanical transmission arranged to drive the vehicle either from the turbine or from an external source of electrical power.
Abstract: A bi-modal vehicle, such as a rail car, is provided in a preferred embodiment with a propulsion turbine and an electromechanical transmission arranged to drive the vehicle either from the turbine or from an external source of electrical power. The electro-mechanical transmission includes a split torque feature whereby, in the self-propelled mode, some of the turbine torque is delivered mechanically to the output shaft while the remainder passes through an electrical path including a motor and generator combination. In the external electric drive mode, both the generator and motor of the transmission are utilized as drive motors directly driving the output shaft. Numerous additional features are included.

24 citations


Patent
29 Oct 1971
TL;DR: In this article, a propulsion system for a boat that not only provides forward movement and directional control, but also provides means for controlling the attitude of the boat is presented, by using a novel jet nozzle mounting structure that permits the nozzle to pivot in a horizontal direction and/or in a vertical direction.
Abstract: The present invention relates to a propulsion system for a boat; and more particularly discloses a propulsion system that not only provides forward movement and directional control, but also provides means for controlling the attitude of the boat. The disclosed system accomplishes this dual result by the use of a novel jet nozzle mounting structure that permits the nozzle to pivot in a horizontal direction and/or in a vertical direction. Pivoting in either direction is independent of the other, but may still be combined with the other one when so desired, so that any combination of boat heading and attitude may be provided.

24 citations


Patent
10 Mar 1971
TL;DR: In this paper, a propulsion and control system that includes gas generator means which discharges high energy gases into ducting is connected to at least two thrust units for converting the high-energy gases into propulsive thrusts.
Abstract: A propulsion and control system that includes gas generator means which discharges high energy gases into ducting which is connected to at least two thrust units for converting the high energy gases into propulsive thrusts. A separate pressure controller is associated with each thrust unit for restricting the flow of high energy gases to the thrust unit and thereby increasing back pressure in the ducting upstream from the pressure controllers and at the discharge end of the gas generator means. The two pressure controllers are operable independently of each other and the operation of either one increases the back pressure. Contemporaneously, with the increase in back pressure the gas generator means automatically discharges gases at an even higher energy level and as a result the thrust unit downstream from the pressure controller which is not operated delivers greater thrust, while the thrust unit downstream from the operated pressure controller delivers about the same amount of thrust.

24 citations


Patent
07 Jul 1971
TL;DR: A propulsion device for boats where a boxlike housing is mounted on the transom of a boat is described in this paper, where the bottom of the box-like housing defines an inclined cavity having an inverted U-shaped cross section and a progressively increasing depth toward the rear end.
Abstract: A propulsion device for boats wherein a boxlike housing is mounted on the transom of a boat; the bottom of the boxlike housing defines an inclined cavity having an inverted U-shaped cross section and a progressively increasing depth toward the rear end; there is disposed a propeller in said inverted U-shaped section to increase propulsion efficiency; and a footboard is detachably fitted on the upper portion of the boxlike housing.

22 citations


Patent
30 Dec 1971
TL;DR: In this paper, a propulsion system for high speed planing hulls, employing a tunnel-mounted propeller of the supercavitating type in conjunction with means for causing the propeller to operate partly submerged at planing speeds and, aided by the tunnel, to operate fully-submerged with great effectiveness at low hull speed, was proposed.
Abstract: A propulsion system for high speed planing hulls, employing a tunnel-mounted propeller of the supercavitating type in conjunction with means for causing the propeller to operate partly submerged at planing speeds and, aided by the tunnel, to operate fully-submerged with great effectiveness at low hull speed to enable the propeller to develop ample thrust to drive the craft up to and into planing speed.

Patent
23 Feb 1971
TL;DR: In this article, a linear motor propulsion system for vehicles adapted to travel along a fixed roadway comprising primary and secondary motor elements, one carried by the vehicle and the other of which disposed in a discontinuous fashion along the roadway.
Abstract: A linear motor propulsion system for vehicles adapted to travel along a fixed roadway comprising primary and secondary motor elements, one of which is carried by the vehicle and the other of which is disposed in a discontinuous fashion along the roadway. A constant thrust profile is achieved by arranging the length and spacing of the elements such that a constant area of projected surface coextension exists between the elements irrespective of the vehicle position along the roadway.

01 Jan 1971
TL;DR: In this paper, a study was made to determine the accuracy of dynamic stability derivatives as predicted for the North American Navion by several different sources using the results of flight tests as the norm, estimates from wind tunnel tests and several texts were compared.
Abstract: : For application to a new technique of predicting aerodynamic loads, a study was made to determine the accuracy of dynamic stability derivatives as predicted for the North American Navion by several different sources Using the results of flight tests as the norm, estimates from wind tunnel tests and several texts were compared and found to be accurate to within the order of 20% with a few exceptions It is believed that the results of the study would be typical of single engine light aircraft with straight wing and tail, propeller propulsion, and low power effects

Patent
07 Dec 1971
TL;DR: A ground propulsion system for an aircraft includes a compressor driven by one of the main engines of the aircraft or an auxiliary engine, a turbine driven by the gaseous fluid supplied by the compressor and means including a gearbox coupling the turbine to a wheel of an aircraft as mentioned in this paper.
Abstract: A ground propulsion system for an aircraft includes a compressor driven by one of the main engines of the aircraft or an auxiliary engine, a turbine driven by the gaseous fluid supplied by the compressor and means including a gearbox coupling the turbine to a wheel of the aircraft.

Patent
25 Aug 1971
TL;DR: In this article, the propulsion and steering apparatus for a marine vessel providing for 360* rotation of the propulsion unit about its vertical axis were presented, the propulsion drive shaft, chain drive and double gear shaft are disposed within a vertical housing, the total vertical housing being rotatable through 360* of arc.
Abstract: Propulsion and steering apparatus for a marine vessel providing for 360* rotation of the propulsion unit about its vertical axis. The propulsion drive shaft is coupled to a parallel, double pinion gear by a chain drive, the double pinion and propulsion shaft being in fixed relation with respect to each other. The double pinion gear is engaged by a receiving circular rack gear rotatable about the vertical axis of the chain drive, the receiving rack gear being driven by a power source. The propulsion shaft, chain drive and double gear shaft are disposed within a vertical housing, the total vertical housing being rotatable through 360* of arc.

Journal ArticleDOI
TL;DR: In this article, a conceptual design of a 300 m p h (480 km h −1 ) 100 passenger vehicle was developed for magnetic levitation by means of mutual repulsion between a travelling superconductive magnet and induced eddy currents.

Patent
30 Mar 1971
TL;DR: In this article, a foldable invalid chair, comprising two hingedly connected side frames provided with bearings for the mounting of axles of driving wheels and dirigible wheels, was described.
Abstract: A foldable invalid chair, comprising two hingedly connected side frames provided with bearings for the mounting of axles of driving wheels and dirigible wheels, the driving wheels being in the form of running wheels mounted on the side frames. A detachable propulsion unit, including an electric motor is positioned between the side frames, and is coupled to the axles of both driving wheels.

Proceedings ArticleDOI
01 Jan 1971
TL;DR: A prototype auxiliary propulsion subsystem with isolated single tank propellant feed system and 5 cm-diameter ion thruster is described in this article, along with a 5 cm diameter ion thrusters.
Abstract: Prototype auxiliary propulsion subsystem with isolated single tank propellant feed system and 5-cm-diameter ion thruster


Patent
30 Nov 1971
TL;DR: In this paper, a U-shaped valveless pulse jet engine with an annular scoop adjacent to the lip of the inlet is used to provide fresh air to the rotors of a rotary wing aircraft at increased air velocity.
Abstract: A pulse-jet system for driving rotary wing aircraft. In a first embodiment the tips of the rotors of a rotary wing aircraft are provided with "U"-shaped valveless pulse jet engines having an annular scoop adjacent to the lip of the inlet to provide fresh air thereto at increased air velocity. In a second embodiment a pair of straight, valveless pulse jet engines are mounted perpendicular to the rotor shaft of a rotary wing aircraft so as to rotate therewith. These engines may be contained within a streamlined cowl at the opposite outer ends of which are attached flow augmenters which change the direction and increase the flow of exhaust gases from the engines by 90 DEG and eject the same in a chordwise direction. This forms a propulsion unit. When a cowl is used, air enters the cowl through an inlet disposed along the axis of the rotor shaft. The propulsion unit is adjusted angularly and heightwise with respect to the rotor blades in order to optimize the aerodynamic effects of the flow of exhaust gases over the blades. In both of the embodiments, a first control device primarily governs the engine thrust and consequently the rotor speed while a second control device can be added which supplies fuel to the engines at a frequency differing from the fundamental or resonant frequency of the engines so that engine noise is reduced. Also, in both embodiments, the engines are started by exciting them with bursts of air from a compressed air supply to be carried on the aircraft.

Patent
12 Apr 1971
TL;DR: A control assembly for a boat having a water jet propulsion system in which the jet is discharged successively through a discharge conduit and a nozzle is provided with movable bucket whereby said nozzle and bucket are movable into different positions of adjustment to control the jet for thus controlling the steering, fore and aft movements of the boat as mentioned in this paper.
Abstract: A control assembly for a boat having a water jet propulsion system in which the jet is discharged successively through a discharge conduit and a nozzle. The nozzle, which is movable with respect to the conduit, is provided with movable bucket whereby said nozzle and bucket are movable into different positions of adjustment to control the jet for thus controlling the steering, fore and aft movements, and desired planing of the boat.



01 Jun 1971
TL;DR: Nuclear fusion powered pulsed space propulsion systems with laser initiation are discussed in this paper, where the authors discuss energy conversion to momentum, limitations, vehicle configuration and mission performance, as well as mission performance.
Abstract: Nuclear fusion powered pulsed space propulsion systems with laser initiation, discussing energy conversion to momentum, limitations, vehicle configuration and mission performance

01 Aug 1971
TL;DR: In this paper, the effects of underwing J-85 engine nacelles on F-106 aircraft propulsion system performance were investigated. But they focused on the performance of the underwing engine.
Abstract: Thrust measurement system and aerodynamic drag effects of underwing J-85 engine nacelles on F-106 aircraft propulsion system performance

Patent
10 Sep 1971
TL;DR: In this article, the main wing has an auxiliary wing arranged either above or below in spaced biplane relation with the space between the wings, in combination with suitable end plates, forming a rectangular propulsion duct extending spanwise on each side of a central fuselage.
Abstract: The invention relates to a propulsion system particularly adapted to VTOL and STOL type of aircraft and in which a main wing has an auxiliary wing arranged either above or below in spaced biplane relation with the space between the wings, in combination with suitable end plates, forming a rectangular propulsion duct extending spanwise on each side of a central fuselage. A gas turbine driving an air compressor has the compressed air therefrom delivered through a conduit formed in one of the wings from whence it passes to a series of injection nozzles which inject air into the duct inlet to entrain and mix with atmospheric air drawn into the inlet and which expands in a diffuser portion of the duct to generate an augmented propulsive thrust. The nozzles are housed in streamlined struts or housings extending vertically between the wings and transverse to the duct. One of the wings is provided with an adjustable trailing edge flap for varying the discharge area of the propulsive duct diffuser and the other wing is provided with a flap provided with nozzles at its leading edge and adapted to discharge over the suction surface of the flap and when the flap is depressed downward to cause additional downward deflection of the propulsive duct discharge by "Coanda" effect.


Patent
02 Jul 1971
TL;DR: A propulsion power plant for use in a supersonic aircraft includes an aft-fan engine housed in a first duct which delivers air both to the aft fan and to a further duct for delivery to the gas-generator portion of the engine.
Abstract: A propulsion power plant for use in a supersonic aircraft includes an aft-fan engine housed in a first duct which delivers air both to the aft-fan and to a further duct for delivery to the gas-generator portion of the engine, the intake of the further duct being positioned within the first duct so that it captures the relatively smooth airflow in the middle of the duct for delivery over a relatively short distance to the gas-generator, the relatively turbulent air at the edges of the first duct being delivered o the aft-fan over a relatively longer distance.

Book ChapterDOI
TL;DR: In this article, the authors discuss the plasma problems in electrical propulsion, and present several excellent developments of the rationale for electrical propulsion are available, such as: electric propulsion is concerned with plasma of medium to heavy elements, fairly well ionized, and having electron and ion densities in the range of 10 11 -10 15 /cm 3.
Abstract: Publisher Summary This chapter discusses the plasma problems in electrical propulsion. The involvement of plasma physics and technology in the area of space propulsion has occurred because (1) with the exception of nuclear explosions, the electrical or electromagnetic acceleration of conducting matter is the only feasible way of bringing rocket exhausts to the very high velocities necessary for deep space flight with payloads of men and their support equipment; (2) Ionized gas, or plasma, is the most convenient conducting material to use, as by virtue of its usually low density, it can be brought to the requisite velocities without the expenditure of prohibitive increments of energy. Several excellent developments of the rationale for electrical propulsion are available. The field of electric propulsion is concerned with plasma of medium to heavy elements, fairly well ionized, and having electron and ion densities in the range of 10 11 -10 15 /cm 3 .

DissertationDOI
01 Jan 1971
TL;DR: In this paper, a hydromechanical theory for cycloidal propellers was developed for two limiting modes of operation, i.e., high and low speed modes of propulsion.
Abstract: A hydromechanical theory is developed for cycloidal propellers for two limiting modes of operation wherein U » ΩR and U « ΩR, with U the rectilinear propeller speed (speed of advance) and ΩR the rotational blade speed. A first order theory is developed from the basic principles of the kinematics and dynamics of fluid motion and proceeds from the point of view of unsteady hydrofoil theory. Explicit expressions for the instantaneous forces and moments produced by blade motions are presented. On the basis of these results an optimization procedure is carried out which minimizes the energy loss under the constraint of specified mean thrust. Under optimal conditions the propeller is found to possess high Froude efficiencies in both the high and low speed modes of propulsion. This efficiency is defined as the ratio of the average useful work obtained during one cycle of propeller operation to the average power input required to sustain the motion of the propeller during the cycle.