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Showing papers on "Turbine published in 1982"


Journal ArticleDOI
S. C. Kacker1, U. Okapuu1
TL;DR: In this paper, a mean line loss system is described, capable of predicting the design point efficiencies of current axial turbines of gas turbine engines, which is a development of the Ainley/Mathieson technique of 1951.
Abstract: A mean line loss system is described, capable of predicting the design point efficiencies of current axial turbines of gas turbine engines. This loss system is a development of the Ainley/Mathieson technique of 1951. The prediction method is tested against the ''Smith's Chart'' and against the known efficiencies of 33 turbines of recent design. It is shown to be able to predict the efficiencies of a wide range of axial turbines of conventional stage loadings to within 1 1/2 percent. 13 refs.

298 citations


01 Jan 1982
TL;DR: In this article, the authors presented experimental fixed pitch wind turbine performance data for both the DOE/NASA Mod-0 and the Danish Gedser wind turbines, and a method for calculating the output power from large fixed-pitch wind turbines is presented.
Abstract: Experimental fixed pitch wind turbine performance data is presented for both the DOE/NASA Mod-0 and the Danish Gedser wind turbines. Furthermore, a method for calculating the output power from large fixed pitch wind turbines is presented. Modifications to classical blade element momentum theory are given that improve correlation with measured data. Improvement is particularly evident in high winds (low tip speed ratios) where aerodynamic stall occurs as the blade experiences high angles of attack.

171 citations


Journal ArticleDOI
TL;DR: In this paper, a simple tip-leakage model is proposed that treats the normal velocity component in terms of discharge coefficient and conserves the tangential velocity (momentum) component.
Abstract: Blade tip losses represent a major efficiency penalty in a turbine rotor. These losses are presently controlled by maintaining close tolerances on tip clearances. This two-part paper outlines a new methodology for predicting and minimizing tip leakage flows. Part I of the paper describes a series of experiments and analyses which indicated a predominantly inviscid nature of tip leakage flow. The experiments were conducted on a series of three water flow rigs in which leakage quantities were measured over simulated blade tips. As a result of the experiments, a simple tip-leakage model is proposed that treats the normal velocity component in terms of discharge coefficient and conserves the tangential velocity (momentum) component. Identification of tip leakage controlled by a normal discharge coefficient suggests an optimum tip-treatment configuration may be designed through discharge testing of candidate configurations. A preliminary design optimization was conducted on the simple discharge rigs, and the results were evaluated on the water table cascade rig and on a turbine stage.

152 citations


Journal ArticleDOI
TL;DR: In this article, the dynamic and stability properties of wind turbine generators connected to power systems are discussed, as well as various schemes for torsional damping such as speed sensitive stabilizer and blade pitch control.
Abstract: This paper describes the dynamic and stability properties of wind turbine generators connected to power systems. Both synchronous and induction generators are considered. A comparison is made between wind turbines, steam, and hydro units. The unusual phenomena associated with wind turbines are emphasized. The general control requirements are discussed, as well as various schemes for torsional damping such as speed sensitive stabilizer and blade pitch control. Interaction between adjacent wind turbines in a "wind farm" is also considered.

143 citations



Patent
19 Nov 1982
TL;DR: In this paper, the potential energy of water is converted to kinetic energy to drive a turbine that is coaxially connected to a generator to produce electricity. But the system is constructed in such a way that it may supply power during peak power demand and be used as a storage system during low power demand.
Abstract: A hydro electric generating system to produce power by changing the potential energy of water to kinetic energy to drive a turbine that is coaxially connected to a generator. Water from the ambient enters the reservoir and is directed by a valve to a conduit to the turbine which turns a generator to produce electricity. The system is constructed in such a matter that it may supply power during peak power demand and be used as a storage system during low power demand.

128 citations


Patent
02 Apr 1982
TL;DR: In this article, a wind turbine is mounted on a tower mounting a wind tower with a control for providing a pitch blade angle reference signal to modulate the pitch of the turbine blades through a pitch change mechanism for constant power.
Abstract: Damping of the primary bending mode of a tower (12) mounting a wind turbine having a control (36) for providing a pitch blade angle reference signal (40) to modulate the pitch of the turbine blades (1) through a pitch change mechanism (38) for constant power is provided by generating the pitch blade angle reference signal as the integral (104) of the summation (266) of a torque/power controlling blade pitch angle reference rate signal (98) with an estimated acceleration signal (255) generated by filtering (250, 252, 254) the blade pitch angle reference signal (40) with the following transfer function ##EQU1##

91 citations


Patent
27 Sep 1982
TL;DR: In this paper, a tethered airship-floated wind turbine is designed for the economical recovery of power at heights of 2,000 feet or more above ground, at which height power density in the wind is typically three times the power density available to a conventionally supported wind turbine.
Abstract: A wind turbine, by use of a tethered airship for support, may be designed for the economical recovery of power at heights of 2,000 feet or more above ground, at which height power density in the wind is typically three times the power density available to a conventionally supported wind turbine. Means can be added to such an airship-floated wind turbine which will permit its generators to be used to meet load demand even during periods of little or no wind. Described to this end is a wind turbine system which combines, among other novel features: (a) a novel tether line system which provides access for men and materials to the supporting airship while in active service, (b) a novel system for providing additional buoyant lift at the nose of the turbine-supporting airship to offset the vertical component of tension induced in the tether line by the downwind force exerted by the turbine blades, (c) a novel bearing assembly at the nose of the supporting airship which permits the airship to rotate as a unit with the turbine it supports without causing a similar rotation of the tether line, (d) a novel turbine airship structure which handles concentrated loads from the turbine efficiently and also permits the safe use of hydrogen for buoyancy, (e) a novel "space frame" structure which supports the turbine blades and greatly reduces blade weight, (f) a novel system for controlling turbine blade angle of incidence and for varying blade incidene in synchrony with blade angular position abut the turbine axis to provide greater control over airship movement, (g) a novel system for locating propellor-driven generators out at the wind turbine perimeter and for using lightweight, high-RPM generators to produce electrical energy at a power line frequency, which greatly reduces the weight required to convert turbine blade torque into useful power, and (h) a novel system for incorporating compressed air storage and combustion turbine components into the wind turbine's generator drive systems to provide a supplementary source of power for driving the wind turbine's generators.

90 citations


Patent
16 Dec 1982
TL;DR: In this paper, a wind machine turns a shaft to activate a multistage pump having intake and discharge means respectively coupled to intake/discharge fluid lines, and power assisted starting can be achieved by reversing the fluid flow through selected stages.
Abstract: A wind machine turns a shaft to activate a multistage pump having intake and discharge means respectively coupled to intake and discharge fluid lines. Control means regulates the operative positions of the intake means or discharge means to remove selected stages from effective pumping while at the same time fluid passes into and from the selected stages. The stages can be of different capacities and selected groups or all of them may be periodically sequentially idled. Torque on the shaft is thereby adjusted to retain the shaft speed in a range for effective wind energy conversion. During starting the stages are idled until an operational speed is reached. Power assisted starting can be achieved by initially reversing the fluid flow through selected stages. Constricting means is located in the common discharge line from all stages and can be additionally located in each discharge line from each stage. Slowing or stalling of the wind rotor is effected against overspeed by constriction of the flow from the stages to increase the torque on the shaft. Pressure downstream of the constricting means is maintained substantially constant without the need for energy accumulation. The discharged fluid drives a turbine coupled to a generator wherein the fluid power is converted into electrical power.

85 citations


Patent
31 Aug 1982
TL;DR: In this article, a plurality of proximity sensors are disposed in a turbine flow guide to measure flow guide-to-turbine blade tip distance at various points around the flow guide.
Abstract: A plurality of proximity sensors are disposed in a turbine flow guide to measure flow guide-to-turbine blade tip distance at various points around the flow guide. The sensor signals are detected and the peak-to-peak voltage of the detected signals provides an indication of the desired distance measurement. The signals are also monitored and if ambient operating conditions causes the signals to exceed predetermined positive or negative thresholds, corrective signals are generated so as to bring the detected signal back into an acceptable range. A proximity sensor is also provided to measure axial movement of the rotor to which the blades are attached so that the other sensor signals can be modified as a function of the measured axial position.

83 citations


Patent
02 Apr 1982
TL;DR: In this article, an accelerometer disposed on the support tower of a wind turbine electric generating system in the vicinity of the rotor provides a signal indicative of acceleration of the tower in the direction of the rotational axis.
Abstract: An accelerometer (1) disposed on the support tower (12) of a wind turbine electric generating system in the vicinity of the rotor (10, 16) thereof provides a signal (1) indicative of acceleration of the tower in the direction of the rotor rotational axis. The signal (2) is passed through a band-pass filter (4) for summation (9) with a torque/power controlled (100) blade pitch angle reference rate signal (98), the integral (104) of which provides a blade pitch angle reference signal (40) to control the pitch angle of the rotor blades (10) through a pitch change mechanism (38), thereby to provide additional, positive aerodynamic damping to the tower while modulating blade angle for constant torque/power in response to wind turbulence.

Journal ArticleDOI
Ion Paraschivoiu1
TL;DR: In this paper, the double-multiple-streamtube model was used for determining the aerodynamic blade loads and roto performance on the Darrieus vertical-axis wind turbine with curved blades.
Abstract: The double-multiple-streamtube model was used for determining the aerodynamic blade loads and roto performance on the Darrieus vertical-axis wind turbine with curved blades. This analytical model i capable of predicting the difference in the induced velocities at the upstream and downstream passes. The upwind and downwind interference factors are calculated by a double iteration, one for each half of the rotor and vertical variations in the freestream velocity are accounted for. Under local aerodynamic conditions a closed-form analytical solution is obtained for two functions, one for the upwind and one for the downwind hal of the turbine. Thus the local aerodynamic loads on the blade and the rotor performance are calculated more accurately than by other streamtube methods. Comparison of the analytical results obtained with the doublemultiple-streamtube model and the available field test data for the Sandia 17-m machine shows good agreement. This method can therefore be used for generating a suitable aerodynamic-load model for structural-design analysis of the Darrieus rotor.

Patent
19 Apr 1982
TL;DR: In this article, a turbine blade with a fir tree root flange and a compliant layer is proposed for attachment to the turbine disk without risk of stress fracture or modification of turbine disk.
Abstract: The present invention provides a ceramic turbine blade having a ceramic root flange and a metallic compliant layer which is electroformed to the ceramic root flange and then machine-formed to the geometry required for attachment to the turbine disk. Because of its intimate bond to the surface of the ceramic root flange and because of its compliant nature, the metallic compliant layer serves to uniformly distribute stresses induced by the attachment of the blade to the turbine disk. The present invention also envisions the attachment and use of a fir tree root section to an otherwise complete ceramic blade without risk of stress fracture or modification of the turbine disk.

Patent
09 Feb 1982
TL;DR: A Rankine cycle turbine drives an electric generator and a feed pump, all on a single shaft, and all enclosed within a hermetically sealed case as discussed by the authors, with the turbine exhaust directed downward and the shaft supported on hydrodynamic fluid film bearings using the process fluid as lubricant and coolant.
Abstract: A Rankine cycle turbine drives an electric generator and a feed pump, all on a single shaft, and all enclosed within a hermetically sealed case. The shaft is vertically oriented with the turbine exhaust directed downward and the shaft is supported on hydrodynamic fluid film bearings using the process fluid as lubricant and coolant. The selection of process fluid, type of turbine, operating speed, system power rating, and cycle state points are uniquely coordinated to achieve high turbine efficiency at the temperature levels imposed by the recovery of waste heat from the more prevalent industrial processes.

Patent
19 May 1982
TL;DR: In this paper, a power generating station (20) having a generator (28) driven by solar heat assisted ambient wind is disclosed, where a first plurality of radially extending air passages (32) direct ambient wind to a radial flow wind turbine (34) disposed in a centrally located opening in a substantially disc-shaped structure.
Abstract: A power generating station (20) having a generator (28) driven by solar heat assisted ambient wind is disclosed. A first plurality of radially extending air passages (32) direct ambient wind to a radial flow wind turbine (34) disposed in a centrally located opening (46) in a substantially disc-shaped structure (21). A solar radiation collecting surface having black bodies (40) is disposed above the first plurality of air passages (32) and in communication with a second plurality of radial air passages (44). A cover plate (50) enclosing the second plurality of radial air passages (44) is transparent so as to permit solar radiation to effectively reach the black bodies (40). The second plurality of air passages (44) direct ambient wind and thermal updrafts generated by the black bodies (40) to an axial flow turbine (48) which also derives additional motive power from the air mass exhausted by the radial flow turbine (34). The rotating shaft (26) of the turbines (34) (48) drive the generator (28). The solar and wind driven power generating system operates in electrical cogeneration mode with a fuel powered prime mover (56). The system is particularly adapted to satisfy the power requirements of a relatively small community located in a geographic area having favorable climatic conditions for wind and solar powered power generation.

Patent
24 May 1982
TL;DR: In this paper, a turbojet having a multistage axial compressor with contrarotating blade wheels fitted on inner and outer controllable rotors driven in opposite directions by respective turbine wheels is described.
Abstract: A turbojet having a multistage axial compressor with contrarotating blade wheels fitted on inner and outer contrarotating rotors driven in opposite directions by respective turbine wheels. Each blade wheel (105) of the outer compressor rotor is associated with a rotating shell (86, 81, 82) having relatively few thick spokes for transmitting the drive from the turbine wheel, thereby leaving the blades to transmit aerodynamically induced forces only.

Patent
Peter R. Hull1
23 Jul 1982
TL;DR: In this paper, a cooling airflow modulation system for use on gas turbine engines is presented. The system utilizes one or more circumferential manifolds for collecting and providing a source of high-pressure cooling air to hot turbine parts.
Abstract: The invention is a cooling airflow modulation system for use on gas turbine engines. The system utilizes one or more circumferential manifolds for collecting and providing a source of high-pressure cooling air to hot turbine parts. The cooling air is directed to the manifolds through valved passageways that collect compressor discharge air and direct that air radially inwardly and axially downstream to manifold locations. Multiple passageways aand manifolds provide a means for maintaining pressure in the hot turbine parts while cooling airflow volume is being modulated through selected manifold and passageway combinations.

Journal ArticleDOI
TL;DR: In this article, the rotational sampling effect is quantified using measurements of wind velocity at circular arrays of anemometers and measurements by laser and hotwire anemometer traversing crosswind circular paths.

Patent
24 Mar 1982
TL;DR: In this paper, the authors proposed a light-than-air (LTA) wind energy conversion system (WECS) where the LTA envelope carries a main rotor and electrical generator to take advantage of high wind speeds available at high altitudes.
Abstract: A lighter-than-air (LTA) wind energy conversion system (WECS) wherein the LTA envelope carries a main rotor and electrical generator to take advantage of high wind speeds available at high altitudes. The LTA envelope is adapted to rotate with the main rotor and is tethered to a ground based mooring system designed to provide self-orientation for the LTA envelope. In a preferred embodiment, a hollow bladed main rotor is provided at the midpoint of the rotating envelope. The rotor drives an induction turbine positioned within a substantially linear duct which is, in turn, preferably located along the longitudinal axis of the rotating LTA envelope. The output of the induction turbine is coupled to an electrical generator. In another embodiment, small wind-driven generators are positioned on the tips of the blades of the main rotor. The outputs of both embodiments are transmitted to the ground via the tethering system.

Patent
01 Sep 1982
TL;DR: In this paper, the authors describe a wind machine which includes turbine assemblies arranged in superposed relationship and wherein the turbine assemblies may vary in size and number in accordance with power requirements, together with a plurality of deflector panels or sails associated with the turbine unit of each assembly for directing the wind to selected areas of the driving vanes of each turbine unit and at the same time shielding from the wind other areas of vanes which would tend to interfere with desired rotation of turbine unit.
Abstract: A wind machine which includes turbine assemblies arranged in superposed relationship and wherein the turbine assemblies may vary in size and number in accordance with power requirements, together with a plurality of deflector panels or sails associated with the turbine unit of each assembly for directing the wind to selected areas of the driving vanes of each turbine unit and at the same time shielding from the wind other areas of driving vanes which would tend to interfere with desired rotation of the turbine unit. The deflector panels or sails also accurately controlling the volume of air which bypasses each panel or sail to thereby prevent "stacking" or turbulence adjacent the driving vanes of the turbine unit. The panels also being arranged to recapture the major portion of the bypassed air and direct it back into the turbine unit which increases efficiency of operation.

Patent
12 Mar 1982
TL;DR: In this article, a turbine blade, more particularly a turbine nozzle vane, for a gas turbine engine, consisting of a structural metallic core enveloped at a distance by a ceramic blade jacket, is provided.
Abstract: A turbine blade, more particularly a turbine nozzle vane, for a gas turbine engine, consisting of a structural metallic core enveloped at a distance by a ceramic blade jacket. Through provision a primarily highly heat-resistant, ceramic metal compound structure of the blade, the blade jacket is compressively prestressed spanwise between the blade shrouds in the inoperative condition of the turbine and where said compressive prestressing of the blade jacket, produced during assembly and which exists in the inoperative condition, is at least maintained during the operation condition by selecting for the metallic core of the blade, a material of average coefficient of thermal expansion and for the metallic inner and outer shrouds of the blade, and for the inner and outer metallic, sleeve-like components producing the axial prestress, materials of higher coefficients of thermal expansion, and for the highly thermally stressed ceramic blade jacket, a material of average coefficient of thermal expansion.

Patent
15 Sep 1982
TL;DR: In this paper, a rotor system for horizontal-axis wind turbines with compound coning and a sweep angle was provided to improve the rotor system's yaw responsiveness and stability and reduce vibration and stress.
Abstract: A rotor system for horizontal-axis wind turbines is provided having compound coning and a sweep angle to improve the rotor system's yaw responsiveness and stability and to reduce vibration and stress. To further improve wind turbine performance and rotor durability blades with the load-bearing function and airfoil function separated are disclosed and are particularly useful in rotor systems having compound coning or compound coning and sweepback. The load-bearing function and support function of the rotor hub are separated to improve rotor system durability and to provide a rotor hub for use with a pitch change mechanism for altering the pitch of rotor system blades.

Patent
02 Jul 1982
TL;DR: An improved gas volume calibration method and apparatus for use in respiratory gas analyzers is described in this paper. But this method relies on a control unit that monitors the flow of calibration gas through the analyzer by monitoring the electrical signals produced by a gas turbine and a breath switch.
Abstract: An improved gas volume calibration method and apparatus for use in respiratory gas analyzers. A control unit monitors the flow of calibration gas through the analyzer by monitoring the electrical signals produced by a gas turbine and a breath switch. During calibration, a known volume of calibration gas is repeatedly delivered to the analyzer from a calibration syringe at each of a number of different flow rates. On the basis of the information received from the turbine and the breath switch, the control unit generates and stores a piecewise linear approximation of the nonlinear characteristic of the turbine. This stored turbine characteristic is then made available during subsequent measurements to eliminate those volume errors which are associated with variations in the rate at which the sample gas is delivered, thereby affording measurements of improved accuracy.

Patent
06 Dec 1982
TL;DR: In this paper, the authors make use of the action of ocean waves, converting the water power to electrical energy, by increasing the size of the wave and converting the wave action to hydraulic power using a turbine and a generator.
Abstract: This invention makes use of the action of ocean waves, converting the water power to electrical energy. This is accomplished by increasing the size of the wave and converting the wave action to hydraulic power, using a turbine and a generator. With this method energy can be stored in tanks (under pressure) and used when needed.

Patent
27 Dec 1982
TL;DR: In this article, a turbine generator system for use in a flow line from a water supply to a water usage, treatment or storage system employs a remotely controlled valve for control of the flow of water through the turbine.
Abstract: A turbine generator system for use in a flow line from a water supply to a water usage, treatment or storage system employs a remotely controlled valve for control of the flow of water through the turbine. The system is arranged to shut down upon occurrence of under or over voltage at the generator or loss of pressure at the turbine, disconnecting the generator from the utility line and closing the control valve to stop flow through the turbine. Should failure of the utility line power decrease the generator load to increase turbine speed, restart is prevented until the control valve has closed to stop the turbine. A time delay in the control panel shuts down the system if the control valve does not open within a selected time interval after start up. To accomodate daily variation of flow rate to a water distribution and usage system, a first turbine generator and control valve have a capacity to handle a minimum flow rate and a second turbine generator and control valve, in parallel with the first, automatically come into operation when the flow rate exceeds the capacity of the first turbine generator and control valve.

Patent
18 Jan 1982
TL;DR: In this paper, a fixed pitch wind turbine system utilizing a permanent magnet alternator was proposed to control the load on the stator output armature of the alternator to obtain a substantially optimum output power from the wind turbine.
Abstract: A fixed-pitch wind turbine system utilizing a permanent magnet alternator. Optimum output power is achieved by controlling the load on the stator output armature of the permanent magnet alternator. Energy is stored in the ac utility grid utilizing a synchronous inverter which couples energy from the alternator for storage in the ac utility grid in a controlled manner to regulate the rotational speed of the wind turbine and thereby extract a substantially optimum amount of output power from the wind turbine.

01 Jun 1982
TL;DR: In this article, an active clearance control (ACC) system is used to control the blade tip to shroud clearances for both stages of turbine blades and vanes in a two-stage design system.
Abstract: The high pressure turbine configuration for the Energy Efficient Engine is built around a two-stage design system. Moderate aerodynamic loading for both stages is used to achieve the high level of turbine efficiency. Flowpath components are designed for 18,000 hours of life, while the static and rotating structures are designed for 36,000 hours of engine operation. Both stages of turbine blades and vanes are air-cooled incorporating advanced state of the art in cooling technology. Direct solidification (DS) alloys are used for blades and one stage of vanes, and an oxide dispersion system (ODS) alloy is used for the Stage 1 nozzle airfoils. Ceramic shrouds are used as the material composition for the Stage 1 shroud. An active clearance control (ACC) system is used to control the blade tip to shroud clearances for both stages. Fan air is used to impinge on the shroud casing support rings, thereby controlling the growth rate of the shroud. This procedure allows close clearance control while minimizing blade tip to shroud rubs.

Patent
17 Jun 1982
TL;DR: In this article, the synchronous speed of the generator is selected as a function of the ambient wind speed to make the generator operate more efficiently and without overloading, which can prevent the generator from acting as a motor when connected to a power grid and wasting energy in turning the wind turbine.
Abstract: A wind electric generator employs a freewheeling clutch and an induction generator having several synchronous speeds. By selecting the synchronous speed as a function of the ambient wind speed, the generator can be made to operate more efficiently and without overloading. The freewheeling clutch which connects the generator to the wind turbine prevents the generator from acting as a motor when connected to a power grid, and wasting energy in turning the wind turbine.

Patent
17 Jun 1982
TL;DR: In this article, an overriding clutch mechanically disconnects the generator shaft from the turbine shaft when the wind is too light to permit generation, and the generator is then returned to overriding operation and electrical generation continues until wind speed again becomes too light.
Abstract: A wind electric system intended to provide power to a power grid, for use with a wind turbine which has no starting torque. The generator is one which can function as a motor as well. When the wind is too light to permit generation, an overriding clutch mechanically disconnects the generator shaft from the turbine shaft. The clutch has also the capability of locking the generator shaft to the turbine shaft in response to a control signal. When wind speed is great enough to permit generation and the turbine is stopped, a control signal is issued locking the generator shaft to the turbine shaft. Power from the power grid causes the generator to function as a motor and accelerate the turbine to permit it to be rotated by the wind. The clutch is then returned to overriding operation and electrical generation continues until wind speed again becomes too light.

Patent
06 Apr 1982
TL;DR: In this article, a turbojet turbine stage with air cooling of the turbine wheel disc is described, which has a number of trough-shaped dampers, each of which is inserted in a passage and supported by its edges against the periphery of the disc while its back pushes against the platforms delimiting the passage.
Abstract: A turbojet turbine stage having air cooling of the turbine wheel disc is disclosed which has, on the one hand, devices for blowing in a flow of air A in the direction of the upstream surface of the disc (20) intended in particular to flow into the several passages delimited by the periphery (22) of the disc and by the shanks (14) and platforms (12) of the blade feet (11) of the wheel, and, on the other hand, a number of trough-shaped dampers (30) each of which is inserted in a passage and supported by its edges against the periphery of the disc while its back pushes against the platforms delimiting the passage. The upstream edge of each damper forms a peak (33) which extends beyond the upstream side of the disc.