Showing papers on "Turbine published in 1976"

Noise suppressing exhaust mixer assembly for ducted-fan, turbojet engine

Abstract: To suppress jet noise emanating from a ducted-fan turbojet engine, an improved exhaust mixer assembly is disclosed that is mounted between the engine and the exhaust nozzle and that mixes the flow of high-velocity primary gases (turbine exhaust) with the lower-velocity air from the fan duct in a manner that achieves a significant reduction in the proportion of noise-causing high velocity gases while maintaining approximately the same thrust from the nozzle as other mixer-equipped engines. The mixer assembly includes an annular sleeve, a bulb-shaped plug disposed concentrically within the sleeve, and an annular corregugated mixer duct coaxially positioned between the plug and sleeve wherein these components are arranged so as to receive the primary and fan flows and separately redirect these flows within the assembly so that the flow of primary gases is rearwardly divergent while the flow of fan air is rearwardly convergent. As the primary and fan flows pass through a mixing plane at the aft terminus of the mixer duct, they intersect in a crossing pattern resulting from their divergent-convergent flow paths which yields faster and more complete mixing of the flows before they are discharged from the nozzle. The shaping and dimensioning of the sleeve, plug, and mixer duct are such that optimum mixing, and thus maximum suppression of noise, are achieved without introducing any excessive pressure losses in the mixer assembly and nozzle that otherwise would significantly diminish thrust.

Turbojet engine nozzle for attenuating core and turbine noise

Abstract: Core noise, a low frequency noise component believed to be partly caused by the combustion processes within the engine, and turbine noise, a higher frequency noise component caused by the interaction of high velocity gases with the engine's turbine, are attenuated by noise absorbing structures that are disposed within the engine's nozzle and that in part define the physical geometry of the nozzle duct. The nozzle is formed of an outer sleeve and an inner generally bulb-shaped plug which are coaxially arranged to define an annular nozzle duct that channels the flow of gases rearwardly from the outlet of the engine's turbine. The plug has a hollow interior that is partitioned into a plurality of cavities that communicate with the nozzle duct via perforations provided in an outer wall of the plug. The size, shape and positioning of the interior cavities and outer plug wall perforations are selected so as to absorb noise energy existing in the exhaust gases, both at the relatively low frequencies characteristic of core noise and at the relatively higher frequencies characteristic of turbine noise.

Cleaning and preservation unit for turbine engine

Abstract: A mobile cart-mounted unit for cleaning and preserving turbine engines comprises pressurized reservoirs for holding the solvent, cleaner, preservative and water. Pressurization is achieved by use of an integrally mounted air compressor driven by an internal combustion engine. The engine also powers an alternator which is used to charge a storage battery. The storage battery serves as an energy source to crank the turbine to approximately 10 percent rated speed during the cleaning and preservation servicing sequence. A control console provides the operator with the needed valves, gages and meters with which to operate the unit.

Gas turbine exhaust nozzle for controlled temperature flow across adjoining airfoils

Abstract: An exhaust nozzle for exhausting the effluent of a turbofan gas turbine engine across a portion of the upper surface of an aircraft wing wherein the exhaust nozzle is arranged to establish a temperature profile within the exhausted gases that prevents overheating the wing surface. The nozzle includes a contoured outer housing that longitudinally transists from a circular entrance opening, arranged for interconnection with the rear face of a gas turbine engine, to a semi-elliptical outlet opening located on the upper surface of the aircraft wing. A generally tubular mixer section, of the daisy type, is mounted within the outer housing and coaxially surrounds an engine tail plug. Exhaust gases flowing from the engine fan stage flow through an annular flow duct formed between the inner surface of the forward portion of the outer housing and the outer surface of the mixer section and the high temperature gases flowing from the engine turbine stages flow through an annular duct formed between the tail plug and the inner surface of the mixer section. As the turbine exhaust gases and the fan air flow past the mixer section exit plane, the two fluid streams mix with one another to increase engine thrust and decrease engine noise level. To establish a temperature profile in which the exhaust gases flowing along the aircraft wing do not overheat the wing structure, the outer housing is contoured to have a generally elliptical cross-sectional geometry at the exit plane of the mixer section and the mixer section lobes are of unequal radial dimension such that the mixer section has an asymmetric cross-sectional shape.

Inlet air cleaner assembly for turbine engines

Abstract: An inlet air cleaner assembly is provided for the air intake of gas turbine engines comprising, in combination, an array of vortex air cleaners removing coarse and heavy contaminant particles, but not light and well dispersed contaminant particles, and an array of sheets of filamentary woven or nonwoven material, arranged to receive partially cleaned air from the vortex air cleaner array, and remove light and well dispersed contaminant particles suspended therein.

Dynamics of Wind Generators on Electric Utility Networks

Abstract: Dynamic interaction of wind-turbine-driven generators on electric utility networks was studied by computer simulation. Nonlinear representations of wind-turbine and various drive train elements and Park equation representations of synchronous and induction generators were implemented. An infinite capacity network was assumed. Time history responses for various system configurations were computed using as the input function severe wind gust data added to cyclical torque variations occurring at turbine blade frequency. Results indicated that severe transient mechanical and electrical stresses can be induced for certain system configurations. Best results were obtained by interposing rate or damped compliant couplings between the wind turbine and a synchronous generator. The induction generator did not appear to require such means. Blade pitch control (or equivalent) was required to limit output above rated wind velocities for wind turbines configured to produce maximum mum specific power. The blade pitch control loop must exhibit high performance to limit transient overshoots. An aerodynamically limited turbine driving an induction generator exhibited good response without the need for blade pitch control, but at the cost of increased turbine rotor diameter. Further work is indicated, taking into account wind-turbine aeroelastic effects, finite capacity networks, and other factors.

Vertical axis wind turbine motor

Abstract: A wind power conversion turbine motor has a body supported to rotate about a vertical axis and carrying a plurality of substantially upright vanes substantially spaced from the vertical axis and circumferentially spaced from one another so that wind thrusting propulsively against outer sides of the vanes can move across the space circumscribed by the vanes and thrust propulsively against inner sides of the vanes on leaving the space, thereby attaining dual power advantage from substantially all wind that strikes the turbine. Each of the plurality of vanes is pivotally carried on the body, with a control means to maintain a substantially constant vane angle of attack to a relative wind vector.

Bearing and drive structure for spinning turbine

Abstract: A bearing and drive structure for the funnel-shaped spinning element of an open-end spinning turbine, composed of a stator with a projecting portion carrying an elastically mounted bearing and a rotor with a cup-shaped portion into which the projecting portion of the stator extends, the rotor being carried by the bearing and having its center of gravity at least approximately in the region defined between the axial ends of the flexible bearing, the stator carrying electrical windings cooperating with the cup-shaped rotor portion to form an electrical drive for the rotor

Fluid pressure actuated clutch for starting multi-stage turbine

Abstract: A fluid pressure actuated clutch for connecting concentric, rotatable shafts in a multi-stage turbine includes a plurality of pivoted pawls mounted on one shaft for engagement with a plurality of gear teeth mounted on the other shaft upon rotation of the pawls by selectively actuatable hydraulic pistons. The pawls are spring biased and/or counterweighted to pivot out of engagement with the gear teeth when the other shaft achieves a rotational speed higher than the one shaft. The device is particularly suited for connecting concentric shafts of high and low pressure stages of turbine plants.

Flexible interstage turbine spacer

Abstract: An interstage spacer for the turbine section of a gas turbine engine is provided with a flexible bellows which absorbs axial growth of the adjacent turbine stages to prevent seizing and binding.

Francis-type hydraulic machine

Abstract: The disclosure concerns a Francis-type hydraulic machine, i.e., a turbine, pump-turbine or pump, having a bladed wheel of large diameter, and in which bearing apparatus for supporting the rotor is arranged in a peripheral region of the bladed wheel spaced radially from the axis.

Blade tip clearance measuring apparatus

Abstract: Apparatus is disclosed for the noncontact measurement of the clearance between the blade tips of a rotating turbine and the surrounding housing. Blade tip clearance is measured by placing a capacitance probe in the housing wall. The probe consists of two metallic conductors insulated one from the other and arranged to form the plates of a capacitor. Passing of a blade tip in close proximity to the two plates of the probe changes its capacitance. Electronic circuitry measures the change in capacitance and hence the clearance between blade tip and probe. Use of a balanced type input avoids the need for a ground return path and enables the use of a long sensor cable without degradation of results.

Variable cycle gas turbine engine

Abstract: A variable cycle air breathing gas turbine engine includes a core engine having a combustor, a high pressure turbine stage and a low pressure stage and wherein the high pressure stage drives a compressor for the core engine and the low pressure stage drives a bypass fan for the engine. The low pressure turbine stage includes a row of tip mounted blades located in a first bypass duct and the engine includes auxiliary inlets and crossover valve means for directing air through the first bypass duct during a first mode of engine operation to cause the tip blades on the low pressure turbine stage to operate as an auxiliary bypass fan while the primary fan is driven during the first mode to produce a bypass ratio in a second bypass duct. During a second engine operating mode crossover valve means are conditioned to communicate the first bypass duct with the primary fan and a second combustor element in the first bypass duct is operated to produce flow of motive fluid across the tip blades to drive the blades as a reaction turbine to produce a high temperature turbojet cycle of engine operation.

Turbine case cooling system

Abstract: Apparatus for reducing the leakage of working medium gases between the rotor and stator assemblies of a gas turbine engine is disclosed. Concepts for maintaining concentric correspondence between a stator outer air seal of a gas turbine engine and the arc circumscribed by blades of the rotor assembly are discussed. Techniques for uniformly distributing the cooling air about the inner circumference of the case to control thermal distortions of the case and techniques for sealing the working medium flow are employed in one embodiment.

Apparatus and process for steam generation by solar energy

Abstract: Steam to be supplied to a turbine is generated in a single pressure chamber reservoir by solar energy concentrated on the head of a conductor mounted in the top wall of the reservoir chamber with its conductive portion extending downward through a head space into the water. Convector surfaces on the conductor in the head space super heats the steam as it flows to the turbine. The solar energy is supplied from a parabolic reflector and directed through a lens system to a focus on the head of the conductor. The focus may be modulated to assure optimum operation without overheating.

Heat storage method and apparatus

Abstract: Method and apparatus for operating power turbomachinery which includes an electromagnetic induction heated, graphite heat storage core adapted to heat compressed fluid for subsequent expansion across a fluid turbine to generate rotary mechanical power output.

Ebullient cooled turbocharger bearing housing

Abstract: A turbocharged internal combustion engine system including a liquid-cooled internal combustion engine, a heat exchanger for cooling the liquid, a pump for pumping cooled liquid from the heat exchanger to the engine, and a turbocharger including a rotary turbine and a rotary compressor, a housing containing the turbine and the compressor, a shaft interconnecting the turbine and the compressor and bearings journalling the shaft within the housing between the turbine and compressor. Exhaust gases from the engine are directed through the turbine to drive the same and air from the compressor is directed to the engine. A liquid passage is located in the turbocharger housing and is operatively interposed between the turbine and the bearing. The passage has a lower inlet and an upper outlet and liquid coolant from the engine is directed to the inlet. Coolant from the output is directed to the heat exchanger or other suitable compartment in the engine coolant system so as to allow flow while the engine is operating and under the following conditions. Thermosiphoning of the coolant will occur through the passage when the engine is not operative, resulting in ebullient cooling of the housing immediately adjacent the bearings when the engine is not operating. As a result, thermal damage to the bearings is prevented and coking of the residual oil on the inside walls of the housing is also prevented.

Steam turbine control system and method of controlling the ratio of steam flow between under full-arc admission mode and under partial-arc admission mode

Abstract: In a steam turbine-generator with means for determining a load demand signal in accordance with a load reference signal, means for determining the valve opening under each admission mode of full-arc and partial-arc in accordance with said load demand signal and means for adjusting the ratio between valve openings under the each admission mode in accordance with a load change the ratio of steam flow under each of the admission modes is controlled in accordance with a load change so as to minimize the thermal stresses and thereby reduce the turbine load changing time.

System and method for operating a steam turbine and an electric power generating plant

Abstract: A programmed digital computer control system determines the turbine steam flow changes required to satisfy the speed and load demand made on the operation of a large electric power stream turbine for which substantially constant throttle pressure steam is generated. Load control is directed to plant electric power generation and it is based on feedforward valve positioning operation with feedback multiplication calibration for plant load and/or turbine speed error. Changes in the turbine operating level are limited by dynamic constraints applied by the computer.

Method for selectively switching motive fluid supply to an aft turbine of a multicycle engine

Abstract: Air breathing gas turbine engine design concepts, and methods and apparatus for providing variable engine cycles are disclosed. The preferred engine embodiments involve two flow control valve systems for internal management of air, each of which have the capacity to cross-over or invert adjacent annular flow patterns, and at least one of which is capable of switching from inverted to straight through flow.

Liquid cooled gas turbine buckets

Abstract: Turbine buckets are designed for use in an environment of ultra-high temperatures by incorporating therein water cooling channels using preformed tubes which are located beneath an outer protective layer. This layer is preferably composed of an inner skin which provides high thermal conductivity and an outer skin which provides protection from hot corrosion.

Flow control valves

Abstract: The disclosure illustrates a flow control bypass valve for a turbine housing. The valve comprises a closure member biased into engagement with a valve seat to block flow and mounted to swing out of engagement with the seat when a given turbine inlet pressure is exceeded thereby bypassing hot gas flow around the turbine. The mounting arrangement for the closure member is insensitive to build up of hot gas deposits and does not significantly increase the overall envelope of the turbine housing.

Heat flow in the stator core of large turbine-generators, by the method of three-dimensional finite elements part II: Temperature distribution in the stator iron

Abstract: The steady state heat flow problem in the atator cores of large turbine-generators is solved using three-dimensional finite elements. The results are compared with those obtained by a thermal resistive network procedure and with factory test data. Three-dimensional plots of core iron isotherms are shown which describe the entire temperature field. Recommendations are made to extend the application of this powerful technique.

Wind turbine with automatic pitch and yaw control

Abstract: A wind turbine having a flexible central beam member supporting aerodynamic blades at opposite ends thereof and fabricated of uni-directional high tensile strength material bonded together into beam form so that the beam is lightweight, and has high tensile strength to carry the blade centrifugal loads, low shear modulus to permit torsional twisting thereof for turbine speed control purposes, and adequate bending stiffness to permit out-of-plane deflection thereof for turbine yard control purposes. A selectively off-set weighted pendulum member is pivotally connected to the turbine and connected to the beam or blade so as to cause torsional twisting thereof in response to centrifugal loading of the pendulum member for turbine speed control purposes.

Axial flow turbine exhaust hood

Abstract: An axial flow turbine incorporating an exhaust hood for receiving exhaust steam from the turbine and directing this exhaust steam through a discharge opening in the hood in a direction essentially normal to the axis of the turbine is disclosed. The exhaust hood includes a first set of guide vanes arranged in an exhaust duct connected to the turbine adjacent the last stage buckets thereof. These vanes are curved to provide a relatively smooth transition of steam flow from an axial direction to a generally radial direction. A guide ring circumferentially surrounds the first set of guide vanes and a plurality of secondary vanes are circumferentially spaced around this guide ring. Steam which is discharged radially from the first set of vanes to the secondary vanes is directed by the secondary vanes to the discharge opening of the exhaust hood. The secondary vanes are substantially equally spaced around the guide ring and are curved at different angles to effect different angles of discharge of steam from these vanes. The angles of discharge are chosen so as to direct the steam toward the discharge opening of the exhaust hood in a manner achieving substantially uniform flow distribution across the exit plane of the last stage buckets and across the plane of the discharge opening. The secondary vanes have an axial length which is a minimum at the inner edges and increases to a maximum at the outer edges.

Overspeed control arrangement for vertical axis wind turbines

Abstract: This invention is an overspeed control arrangement for vertical axis wind turbines employing normally vertically positioned rotor blades, said control arrangement allows the rotor blades to tilt either forward or backwards to form a swept wing configuration, at wind turbine speeds beyond the design rpm. When the rotor blade is in a highly swept wing configuration its high drag and low lift reduces the turbine rotor torque to zero and eliminates excessive overspeeding and structural damage. The rotor blade can tilt about a radial or nearly so, tilt-support arm, mounted on a concentric bearing, the tilting starts at the feathering design rpm which is controlled by the geometric position of the combined center of gravity of both rotor blade and tilt-support arm. The control arrangement is automatic and passive and does not require the use of springs, pulleys or levers.

Turbine engine for automotive vehicles

Abstract: An engine for driving an automotive vehicle has a plurality of turbine rotors mounted on the main drive shaft. Compressed air is supplied to the rotors in succession from a distributing valve which is supplied with compressed air from a main air tank, and compressed air at reduced pressure from the delivery side of each rotor is supplied to a manifold which also supplies the main air tank through a second stage compressor.

Integrated history recorder for gas turbine engines

Abstract: An integrated history recorder for a gas turbine engine includes a number of integrally controlled displays which together provide a comprehensive record of accumulated engine life. The recorder is adapted to interface with an engine contained transducer assembly. Displays indicative of the following parameters are provided: the number of engine starts, engine running time, the number of engine turbine over-temperature occurrences, turbine time-temperature index, and a manually resettable flag which sets on occurrence of a turbine over-temperature event. These integrally controlled displays provide a comprehensive indication of the cumulative duty performed by the gas turbine engine.

Starting an aircraft engine and driving auxiliary, on-board equipment

Abstract: A gear box is provided with three inputs mutually decoupling each other so that neither can drive the other two via the gear box but either can drive secondary power sources such as a pump and a generator. The three inputs are respectively connected to an aircraft engine shaft, a starter-air turbine and a gas turbine, whereby additionally the starter turbine is connected to drive the shaft for starting but not vice versa. The air turbine receives air from the compressor of the gas turbine or otherwise. The shaft can be disconnected from the system.