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Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
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they are not comprehensive nor are they the most current set.
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1

A reduced Blade-Vortex Interaction rotor  

E-Print Network (OSTI)

This research work aims at mapping the BVI azimuthal locations using a model rotor. A model rotor was first developed. An experimental investigation was then carried out to determine the possible BVI locations. The results of the mapping are presented. A qualitative discussion about the nature of the pressure signals obtained is presented. An attempt is made to reduce the BVI strengths using an innovative blade tip device. The results for the rotor with the tip device installed are compared with the results obtained without the tip device installed. The comparisons show the tip device to be fairly effective in reducing the strength of the BVI.

Mani, Somnath

1996-01-01T23:59:59.000Z

2

Methods and apparatus for reduction of asymmetric rotor loads in ...  

A method for reducing load and providing yaw alignment in a wind turbine includes measuring displacements or moments resulting from asymmetric loads on the wind turbine.

3

Separators for flywheel rotors  

DOE Patents (OSTI)

A separator forms a connection between the rotors of a concentric rotor assembly. This separator allows for the relatively free expansion of outer rotors away from inner rotors while providing a connection between the rotors that is strong enough to prevent disassembly. The rotor assembly includes at least two rotors referred to as inner and outer flywheel rings or rotors. This combination of inner flywheel ring, separator, and outer flywheel ring may be nested to include an arbitrary number of concentric rings. The separator may be a segmented or continuous ring that abuts the ends of the inner rotor and the inner bore of the outer rotor. It is supported against centrifugal loads by the outer rotor and is affixed to the outer rotor. The separator is allowed to slide with respect to the inner rotor. It is made of a material that has a modulus of elasticity that is lower than that of the rotors. 10 figs.

Bender, D.A.; Kuklo, T.C.

1998-07-07T23:59:59.000Z

4

Separators for flywheel rotors  

DOE Patents (OSTI)

A separator forms a connection between the rotors of a concentric rotor assembly. This separator allows for the relatively free expansion of outer rotors away from inner rotors while providing a connection between the rotors that is strong enough to prevent disassembly. The rotor assembly includes at least two rotors referred to as inner and outer flywheel rings or rotors. This combination of inner flywheel ring, separator, and outer flywheel ring may be nested to include an arbitrary number of concentric rings. The separator may be a segmented or continuous ring that abuts the ends of the inner rotor and the inner bore of the outer rotor. It is supported against centrifugal loads by the outer rotor and is affixed to the outer rotor. The separator is allowed to slide with respect to the inner rotor. It is made of a material that has a modulus of elasticity that is lower than that of the rotors.

Bender, Donald A. (Dublin, CA); Kuklo, Thomas C. (Oakdale, CA)

1998-01-01T23:59:59.000Z

5

Assessing and Reducing Miscellaneous Electric Loads (MELs) in Lodging  

SciTech Connect

Miscellaneous electric loads (MELs) are the loads outside of a building's core functions of heating, ventilating, air conditioning, lighting, and water heating. This report reviews methods to reduce MELs in lodging.

Rauch, Emily M.

2011-09-01T23:59:59.000Z

6

Bubble deaeration of water at reduced unit loads  

Science Conference Proceedings (OSTI)

Whenever the load is reduced, the parameters of the water and steam being introduced into the deaerator, as well as the pressure, also change. A study was conducted to ascertain the reasons for the improvement in water deaeration whenever the unit load is reduced. The study of the deaerator demonstrated that reducing the load on the turbine produces a reduction in the amount of oxygen contained in the feedwater from 25-30 to 8-12 ..mu..g/kg.

Kondrat'ev, A.D.; Kurnyk, L.N.

1982-11-01T23:59:59.000Z

7

Methods and apparatus for reducing peak wind turbine loads ...  

A method for reducing peak loads of wind turbines in a changing wind environment includes measuring or estimating an instantaneous wind speed and direction at the ...

8

Assessing and Reducing Miscellaneous Electric Loads (MELs) in Banks  

Science Conference Proceedings (OSTI)

Miscellaneous electric loads (MELs) are loads outside of a building's core functions of heating, ventilating, air conditioning, lighting, and water heating. MELs are a large percentage of total building energy loads. This report reviews methods for reducing MELs in Banks. Reducing MELs in a bank setting requires both local and corporate action. Corporate action centers on activities to prioritize and allocate the right resources to correct procurement and central control issues. Local action includes branch assessment or audits to identify specific loads and needs. The worksheet at the end of this guide can help with cataloging needed information and estimating savings potential. The following steps provide a guide to MEL reductions in Bank Branches. The general process has been adapted from a process developed for office buildings the National Renewable Energy Laboratory (NREL, 2011).

Rauch, Emily M.

2012-09-01T23:59:59.000Z

9

Numerical simulation and prediction of loads in marine current turbine full-scale rotor blades.  

E-Print Network (OSTI)

??Marine current turbines are submerged structures and subjected to loading conditions from both the currents and wave effects. The associated phenomena posed significant challenge to… (more)

Senat, Junior.

2011-01-01T23:59:59.000Z

10

Investigation of Stress Indices and Directional Loading of Eccentric Reducers  

SciTech Connect

OAK- B135 Engineering for fatigue is an essential concern in piping systems. Addressing this concern, the ASME Section III and ANSI B31.1 Codes provide stress indices and stress intensification factors (SIFs) to be used in the design and evaluation of Class 1, 2 and 3 systems. In recent research cosponsored by EPRI and the U.S. DOE, new test data have been developed for comparison with the ASME stress indices and SIFs. This report presents the results of fatigue tests on eccentric reducers, taking into account the directionality of the loading. As detailed in the report, the results can help to improve the evaluation of reducers and can help to reduce unnecessary conservatism in piping system design.

R. Carter,E.A. Wais, E.C. Rodabaugh

2003-08-01T23:59:59.000Z

11

Performance and Vibratory Loads Data From a Wind-Tunnel Test of a Model Helicopter MainRotor Blade With a Paddle-Type Tip  

E-Print Network (OSTI)

this report as a "BERP-type" blade. The intent of using these two blade sets was to evaluate the effect of the BERP planform geometry on performance and loads, not to conduct an exhaustive study of the BERP concept. The baseline and paddle-type tip blades were compared with regard to rotor performance, oscillatory pitch-link loads, and 4-per-rev vertical fixed-system loads. Data were obtained in hover and forward flight over a nominal range of advance ratios from 0.15 to 0.425. Results indicate that the paddle-type tip offers no performance improvements in either hover or forward flight. Pitchlink oscillatory loads for the paddle-type tip are higher than for the baseline blade, whereas 4-per-rev vertical fixed-system loads are generally lower.

William T. Yeager, Jr.; Kevin W. Noonan; Jeffrey D. Singleton; Matthew L. Wilbur; Paul H. Mirick

1997-01-01T23:59:59.000Z

12

Direct methanol fuel cells at reduced catalyst loadings  

DOE Green Energy (OSTI)

We focus in this paper on the reduction of catalyst loading in direct methanol fuel cells currently under development at Los Alamos National Laboratory. Based on single-cell DMFC testing, we discuss performance vs. catalyst loading trade-offs and demonstrate optimization of the anode performance. We also show test data for a short five-cell DMFC stack with the average total platinum loading of 0.53 mg cm{sup -2} and compare performance of this stack with the performance of a single direct methanol fuel cell using similar total amount of precious metal.

Zelenay, P. (Piotr); Guyon, F. (Francois); Gottesfeld, Shimshon

2001-01-01T23:59:59.000Z

13

DIRECT METHANOL FUEL CELLS AT REDUCED CATALYST LOADINGS  

DOE Green Energy (OSTI)

We focus in this paper on the reduction of catalyst loading in direct methanol fuel cells currently under development at Los Alamos National Laboratory. Based on single-cell DMFC testing, we discuss performance vs. catalyst loading trade-offs and demonstrate optimization of the anode performance. We also show test data for a short five-cell DMFC stack with the average total platinum loading of 0.53 mg cm{sup {minus}2} and compare performance of this stack with the performance of a single direct methanol fuel cell using similar total amount of precious metal.

P. ZELENAY; F. GUYON; SM. GOTTESFELD

2001-05-01T23:59:59.000Z

14

Investigation of Stress Indices and Directional Loading of Eccentric Reducers  

Science Conference Proceedings (OSTI)

Engineering for fatigue is an essential concern in piping systems. Addressing this concern, the ASME Section III and ANSI B31.1 Codes provide stress indices and stress intensification factors (SIFs) to be used in the design and evaluation of Class 1, 2, and 3 systems. In recent research cosponsored by EPRI and the U.S. Department of Energy (DOE), new test data have been developed for comparison with the ASME stress indices and SIFs. This report presents the results of fatigue tests on eccentric reducers,...

2003-08-11T23:59:59.000Z

15

Guidelines for reducing dynamic loads in two-bladed teetering-hub downwind wind turbines  

DOE Green Energy (OSTI)

A major goal of the federal Wind Energy Program is the rapid development and validation of structural models to determine loads and response for a wide variety of different wind turbine configurations operating under extreme conditions. Such codes are crucial to the successful design of future advanced wind turbines. In previous papers the authors described steps they took to develop a model of a two-bladed teetering-hub downwind wind turbine using ADAMS{reg_sign} (Automatic Dynamic Analysis of Mechanical Systems), as well as comparison of model predictions to test data. In this paper they show the use of this analytical model to study the influence of various turbine parameters on predicted system loads. They concentrate their study on turbine response in the frequency range of six to ten times the rotor rotational frequency (6P to 10P). Their goal is to identify the most important parameters which influence the response of this type of machine in this frequency range and give turbine designers some general design guidelines for designing two-bladed teetering-hub machines to be less susceptible to vibration. They study the effects of such parameters as blade edgewise and flapwise stiffness, tower top stiffness, blade tip-brake mass, low-speed shaft stiffness, nacelle mass momenta of inertia, and rotor speed. They show which parameters can be varied in order to make the turbine less responsive to such atmospheric inputs as wind shear and tower shadow. They then give designers a set of design guidelines in order to show how these machines can be designed to be less responsive to these inputs.

Wright, A.D.; Bir, G.S.; Butterfield, C.D.

1995-06-01T23:59:59.000Z

16

The Potential of Vegetation in Reducing Summer Cooling Loads in Residential Buildings  

Science Conference Proceedings (OSTI)

The potential of trees and other vegetation to reduce building cooling loads has been recorded in a number of studies but the meso- and microclimate changes producing such savings are not well understood. This paper describes a preliminary ...

Y. J. Huang; H. Akbari; H. Taha; A. H. Rosenfeld

1987-09-01T23:59:59.000Z

17

3 Easy Tips to Reduce Your Standby Power Loads | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

3 Easy Tips to Reduce Your Standby Power Loads 3 Easy Tips to Reduce Your Standby Power Loads 3 Easy Tips to Reduce Your Standby Power Loads November 1, 2012 - 3:35pm Addthis Using a power strip to turn off electronics and appliances when they aren't in use ensures that they are truly off and not using extra electricity. | Photo courtesy of ©iStockphoto.com/DonNichols. Using a power strip to turn off electronics and appliances when they aren't in use ensures that they are truly off and not using extra electricity. | Photo courtesy of ©iStockphoto.com/DonNichols. John Chu John Chu Communications Specialist with the Office of Energy Efficiency and Renewable Energy What does this mean for me? Standby power costs the average U.S. household $100 per year. You can reduce your use of standby power by using power strips,

18

3 Easy Tips to Reduce Your Standby Power Loads | Department of Energy  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

3 Easy Tips to Reduce Your Standby Power Loads 3 Easy Tips to Reduce Your Standby Power Loads 3 Easy Tips to Reduce Your Standby Power Loads November 1, 2012 - 3:35pm Addthis Using a power strip to turn off electronics and appliances when they aren't in use ensures that they are truly off and not using extra electricity. | Photo courtesy of ©iStockphoto.com/DonNichols. Using a power strip to turn off electronics and appliances when they aren't in use ensures that they are truly off and not using extra electricity. | Photo courtesy of ©iStockphoto.com/DonNichols. John Chu John Chu Communications Specialist with the Office of Energy Efficiency and Renewable Energy What does this mean for me? Standby power costs the average U.S. household $100 per year. You can reduce your use of standby power by using power strips,

19

Guidelines for Reduced Seismic Loads to Assess Temporary Conditions in Nuclear Power Plants  

Science Conference Proceedings (OSTI)

Utilities do not have uniform guidelines and criteria to treat plant temporary conditions (TCs) or planned changes to safety-related systems. Regulatory review and acceptance criteria and guidelines tend to be overly conservative, leading to costly measures. This report proposes a risk-informed procedure for evaluating TCs using reduced seismic loads and current licensing basis allowables that reduces plant operation and maintenance (O&M) costs, shortens plant outages, and reduces personnel radiation exp...

1998-09-10T23:59:59.000Z

20

Aerodynamic Loads On Rotor Blades.  

E-Print Network (OSTI)

??In the last decade, we have heard more and more about the need of renewable clean energy, but not much has been done. Currently, the… (more)

Abedi, Hamidreza

2011-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Assessing and Reducing Plug and Process Loads in Office Buildings (Brochure)  

SciTech Connect

Plug and process loads (PPLs) in commercial buildings account for almost 5% of U.S. primary energy consumption. Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. PPLs are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the occupants. They use an increasingly large fraction of the building energy use pie because the number and variety of electrical devices have increased along with building system efficiency. Reducing PPLs is difficult because energy efficiency opportunities and the equipment needed to address PPL energy use in office spaces are poorly understood.

Not Available

2011-06-01T23:59:59.000Z

22

Office Buildings: Assessing and Reducing Plug and Process Loads in Office Buildings (Fact Sheet)  

SciTech Connect

Plug and process loads (PPLs) in commercial buildings account for almost 5% of U.S. primary energy consumption. Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. PPLs are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the occupants. They use an increasingly large fraction of the building energy use pie because the number and variety of electrical devices have increased along with building system efficiency. Reducing PPLs is difficult because energy efficiency opportunities and the equipment needed to address PPL energy use in office spaces are poorly understood.

2013-04-01T23:59:59.000Z

23

Retail Buildings: Assessing and Reducing Plug and Process Loads in Retail Buildings (Fact Sheet)  

SciTech Connect

Plug and process loads (PPLs) in commercial buildings account for almost 5% of U.S. primary energy consumption. Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. PPLs are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the occupants. They use an increasingly large fraction of the building energy use pie because the number and variety of electrical devices have increased along with building system efficiency. Reducing PPLs is difficult because energy efficiency opportunities and the equipment needed to address PPL energy use in retail spaces are poorly understood.

2013-04-01T23:59:59.000Z

24

Assessing and Reducing Plug and Process Loads in Retail Buildings (Brochure)  

SciTech Connect

Plug and process loads (PPLs) in commercial buildings account for almost 5% of U.S. primary energy consumption. Minimizing these loads is a primary challenge in the design and operation of an energy-efficient building. PPLs are not related to general lighting, heating, ventilation, cooling, and water heating, and typically do not provide comfort to the occupants. They use an increasingly large fraction of the building energy use pie because the number and variety of electrical devices have increased along with building system efficiency. Reducing PPLs is difficult because energy efficiency opportunities and the equipment needed to address PPL energy use in retail spaces are poorly understood.

Not Available

2011-06-01T23:59:59.000Z

25

Challenges and Potential Solutions for Reducing Climate Control Loads in Conventional and Hybrid Vehicles  

DOE Green Energy (OSTI)

The National Renewable Energy Laboratory, a U.S. Department of Energy national laboratory, is collaborating with U.S. automotive manufacturers to develop innovative techniques to reduce national fuel consumption and vehicle tailpipe emissions by reducing vehicle climate control loads. A new U.S. emissions test, the Supplemental Federal Test Procedure (SFTP), will soon begin measuring tailpipe emissions with the air conditioning system operating. Modeled results show that emissions of oxides of nitrogen (NOx) and carbon monoxide (CO) more than double during the air conditioning part of the SFTP. Reducing the transmittance of the glazing can have a greater impact on the cabin soak temperature than ventilating the vehicle during a hot soak. Reducing the amount of outside air can decrease cooling and heating loads but requires that the recirculated air be cleaned. We discuss a photocatalytic oxidation air-cleaning process for removing volatile organic compounds and bioareosols. We conclude with an example of modeling the thermal comfort of the occupants. An auxiliary load increase of only 400 Watts (W) results in a 0.4 km/L (1 mpg) decrease for a conventional 11.9-L/100-km (28-mpg) vehicle. If every vehicle in the United States were to save only 0.4 km/L (1 mpg), $4 billion (U.S. dollars) would be saved annually in gasoline and oil costs. Further information can be found at http://www.ctts.nrel.gov/auxload.html.

Farrington, R.B., Anderson, R., Blake, D.M., Burch, S.D.; Cuddy, M.R., Keyser, M.A., Rugh, J.P.

1999-01-01T23:59:59.000Z

26

Sweep-twist adaptive rotor blade : final project report.  

DOE Green Energy (OSTI)

Knight & Carver was contracted by Sandia National Laboratories to develop a Sweep Twist Adaptive Rotor (STAR) blade that reduced operating loads, thereby allowing a larger, more productive rotor. The blade design used outer blade sweep to create twist coupling without angled fiber. Knight & Carver successfully designed, fabricated, tested and evaluated STAR prototype blades. Through laboratory and field tests, Knight & Carver showed the STAR blade met the engineering design criteria and economic goals for the program. A STAR prototype was successfully tested in Tehachapi during 2008 and a large data set was collected to support engineering and commercial development of the technology. This report documents the methodology used to develop the STAR blade design and reviews the approach used for laboratory and field testing. The effort demonstrated that STAR technology can provide significantly greater energy capture without higher operating loads on the turbine.

Ashwill, Thomas D.

2010-02-01T23:59:59.000Z

27

Opportunities to Reduce Air-Conditioning Loads Through Lower Cabin Soak Temperatures  

DOE Green Energy (OSTI)

Air-conditioning loads can significantly reduce electric vehicle (EV) range and hybrid electric vehicle (HEV) fuel economy. In addition, a new U. S. emissions procedure, called the Supplemental Federal Test Procedure (SFTP), has provided the motivation for reducing the size of vehicle air-conditioning systems in the United States. The SFTP will measure tailpipe emissions with the air-conditioning system operating. If the size of the air-conditioning system is reduced, the cabin soak temperature must also be reduced, with no penalty in terms of passenger thermal comfort. This paper presents the impact of air-conditioning on EV range and HEV fuel economy, and compares the effectiveness of advanced glazing and cabin ventilation. Experimental and modeled results are presented.

Farrington, R.; Cuddy, M.; Keyser, M.; Rugh, J.

1999-07-12T23:59:59.000Z

28

Design of plywood and paper flywheel rotors  

SciTech Connect

Technical and economic design factors of cellulosic rotors are compared with conventional materials for stationaly flywheel energy storage systems. Wood species, operation in a vacuum, assembly and costs of plywood rotors are evaluated. Wound kraft paper, twine and veneer rotors are examined. Plywood moisture equilibration during manufacture and assembly is critical. Disk shaping and rotor assembly are described. Potential self-centering dynamic balancing methods and equipment are described. High resolution tensile tests were performed while monitoring the acoustic emissions. Reasonable correlations exist between the instantaneous sample stiffness during the test and the accumulated acoustic energy released in fracture of the sample. They indicate promise for short term monitoring of damage during tensile tests. Preliminary duration of load tests were performed on vacuum dried hexagonal Birch plywood. Dynamic and static rotor-hub fatigue equipment were designed. Moisture loss rates while vacuum drying plywood cylinders were measured, and the radial and axial diffusion coefficients were evaluated. Diffusion coefficients of epoxy coated plywood cylinders were also obtained. Economics of cellulosic and conventional rotors were examined. Plywood rotor manufacturing costs were evaluated. The optimum economic shape for laminated rotors is shown to be cylindrical. Vacuum container costs are parametrically derived and based on material properties and costs. Containment costs are significant and are included in comparisons. The optimum design stress and wound rotor configuration are calculated for 17 examples. Plywood rotors appear to be marginally competitive with steel hose wire or E-glass rotors. High performance oriented draft paper rotors potentially provide the lowest energy storage costs in stationary systems.

Hagen, D.L.

1982-01-01T23:59:59.000Z

29

Segmented Ultralight Pre-Aligned Rotor for Extreme-Scale Wind Turbines  

SciTech Connect

To alleviate the mass-scaling issues associated with conventional upwind rotors of extreme-scale turbines, a downwind rotor concept is proposed which employs fixed blade curvature based on force alignment at rated conditions. For a given peak stress constraint, the reduction in downwind cantilever loads allows reduced shell and spar thickness, and thus a reduced blade mass as compared with a conventional upwind rotor, especially as rotor sizes approach extreme-scales. To quantify this mass reduction, a Finite Element Analysis was conducted for a 10 MW rated rotor based on the NREL offshore 5 MW baseline wind turbine. The results show that this 'pre-alignment' yields a net downstream deflection of 32 deg, a downward hub-pitch angle of 6 deg, a 20% increase in blade length (to maintain the same radius as the conventional blade), and a net mass savings of about 50% through decreased shell and spar thicknesses. The pre-alignment may also allow a more straightforward and efficient segmentation of the blade since shear stresses near joints are substantially reduced. Segmenting, in turn, can dramatically reduce costs associated with fabrication, transport and assembly for extreme-scale off-shore systems. The pre-aligned geometric curvature can also help alleviate tower wake effects on the blades since blade tips (where shadow effects can be most problematic) are shifted downstream where the tower wake is weaker. In addition, the portion of the tower that is upstream of the blade tips can be faired with an externally-rotating aerodynamic shroud. Furthermore, the downwind rotor can allow a floating off-shore tri-pod platform to reduce tower weight and yaw-control requirements. A simple economic analysis of the segmented ultralight pre-aligned rotor (SUPAR) concept suggests that the overall system cost savings can be as much as 25%, indicating that more detailed (numerical and experimental) investigations are warranted.

Loth, E.; Steele, A.; Ichter, B.; Selig, M.; Moriarty, P.

2012-01-01T23:59:59.000Z

30

Design of plywood and paper flywheel rotors. Final report  

SciTech Connect

Technical and economic design factors of cellulosic rotors are compared with conventional materials for stationary flywheel energy storage systems. Wood species, operation in a vacuum, assembly and costs of rotors are evaluated. Wound kraft paper, twine and plywood rotors are examined. Two hub attachments are designed. Support stiffness is shown to be constrained by the material strength, rotor configuration and speed ratio. Preliminary duration of load tests was performed on vacuum dried hexagonal birch plywood. Dynamic and static rotor-hub fatigue equipment is designed. Moisture loss rates while vacuum drying plywood cylinders were measured, and the radial and axial diffusion coefficients were evaluated. Diffusion coefficients of epoxy coated plywood cylinders were also obtained. Economics of cellulosic and conventional rotors were examined. Plywood rotor manufacturing costs were evaluated. The optimum economic shape for laminated rotors is shown to be cylindrical. Vacuum container costs are parametrically derived and based on material properties and costs. Containment costs are significant and are included in comparisons. The optimum design stress and wound rotor configuration are calculated for seventeen examples. Plywood rotors appear to be marginally competitive with the steel hose wire or E-glass rotors. High performance oriented kraft paper rotors potentially provide the lowest energy storage costs in stationary systems.

Erdman, A.G.; Hagen, D.L.; Gaff, S.A.

1982-05-01T23:59:59.000Z

31

Using measured equipment load profiles to "right-size" HVAC systems and reduce energy use in laboratory buildings (Pt. 2)  

E-Print Network (OSTI)

load profiles to “right-size” HVAC systems and reduce energyGeorgia. ASHRAE [1999]. HVAC Applications Handbook 1999.Inefficiency of a Common Lab HVAC System,” presented at the

Mathew, Paul; Greenberg, Steve; Frenze, David; Morehead, Michael; Sartor, Dale; Starr, William

2008-01-01T23:59:59.000Z

32

Roof shading and wall glazing techniques for reducing peak building heating and cooling loads. Final report  

SciTech Connect

The roof shading device proved to be effective in reducing peak building cooling loads under both actual testing conditions and in selected computer simulations. The magnitude of cooling load reductions varied from case to case depending on individual circumstances. Key variables that had significant impacts on its thermal performance were the number of months of use annually, the thermal characteristics of the roof construction, hours of building use, and internal gains. Key variables that had significant impacts upon economic performance were the costs of fuel energy for heating and cooling, and heating and cooling equipment efficiency. In general, the more sensitive the building is to climate, the more effective the shading device will be. In the example case, the annual fuel savings ($.05 psf) were 6 to 10% of the estimated installation costs ($.50 to .75 psf). The Trombe wall installation at Roxborough High School proved to be effective in collecting and delivering significant amounts of solar heat energy. It was also effective in conserving heat energy by replacing obsolete windows which leaked large amounts of heat from the building. Cost values were computed for both solar energy contributions and for heat loss reductions by window replacement. Together they amount to an estimated three hundred and ninety dollars ($390.00) per year in equivalent electric fuel costs. When these savings are compared with installation cost figures it is apparent that the Trombe wall installation as designed and installed presents a potentially cost-effective method of saving fuel costs. The study results indicate that improved Trombe wall efficiency can be achieved by making design and construction changes to reduce or eliminate outside air leakage into the system and provide automatic fan control.

Ueland, M.

1981-08-01T23:59:59.000Z

33

Reduced-Order Modeling of Aggregated Thermostatic Loads With Demand Response  

Science Conference Proceedings (OSTI)

Demand Response is playing an increasingly important role in smart grid control strategies. Modeling the behavior of populations of appliances under demand response is especially important to evaluate the effectiveness of these demand response programs. In this paper, an aggregated model is proposed for a class of Thermostatically Controlled Loads (TCLs). The model efficiently includes statistical information of the population, systematically deals with heterogeneity, and accounts for a second-order effect necessary to accurately capture the transient dynamics in the collective response. However, an accurate characterization of the collective dynamics however requires the aggregate model to have a high state space dimension. Most of the existing model reduction techniques require the stability of the underlying system which does not hold for the proposed aggregated model. In this work, a novel model reduction approach is developed for the proposed aggregated model, which can significantly reduce its complexity with small performance loss. The original and the reducedorder aggregated models are validated against simulations of thousands of detailed building models using GridLAB-D, which is a realistic open source distribution simulation software. Index Terms – demand response, aggregated model, ancillary

Zhang, Wei; Lian, Jianming; Chang, Chin-Yao; Kalsi, Karanjit; Sun, Yannan

2012-12-12T23:59:59.000Z

34

Interface structure for hub and mass attachment in flywheel rotors  

DOE Patents (OSTI)

An interface structure is described for hub and mass attachment in flywheel rotors. The interface structure efficiently transmits high radial compression forces and withstands both large circumferential elongation and local stresses generated by mass-loading and hub attachments. The interface structure is comprised of high-strength fiber, such as glass and carbon, woven into an angle pattern which is about 45{degree} with respect to the rotor axis. The woven fiber is bonded by a ductile matrix material which is compatible with and adheres to the rotor material. This woven fiber is able to elongate in the circumferential direction to match the rotor growth during spinning. 2 figs.

Deteresa, S.J.; Groves, S.E.

1998-06-02T23:59:59.000Z

35

Interface structure for hub and mass attachment in flywheel rotors  

DOE Patents (OSTI)

An interface structure for hub and mass attachment in flywheel rotors. The interface structure efficiently transmits high radial compression forces and withstands both large circumferential elongation and local stresses generated by mass-loading and hub attachments. The interface structure is comprised of high-strength fiber, such as glass and carbon, woven into an angle pattern which is about 45.degree. with respect to the rotor axis. The woven fiber is bonded by a ductile matrix material which is compatible with and adheres to the rotor material. This woven fiber is able to elongate in the circumferential direction to match the rotor growth during spinning.

Deteresa, Steven J. (Livermore, CA); Groves, Scott E. (Brentwood, CA)

1998-06-02T23:59:59.000Z

36

Reducing Data Center Loads for a Large-Scale, Net Zero Office Building (Brochure)  

DOE Green Energy (OSTI)

Case study highlighting the design, implementation strategies, and continuous performance monitoring of NREL's Research Support Facility data center. In constructing a new research facility for its campus, the National Renewable Energy Laboratory (NREL) project team identified the opportunity to design a world-class, energy-efficient data center to support its operations. NREL's efforts resulted in a highly efficient data center that demonstrated considerable energy savings in its first 11 months of operations. Using legacy data center performance as a baseline, the new facility cut energy use by nearly 1,450,000 kWh, delivering cost savings of approximately $82,000. The data center's average total load was 165 kW less than the legacy center's average total load, resulting in a 60% reduction in overall power. Finally, the limited use of cooling and fan energy enabled the new data center to achieve a 1.16 average power utilization effectiveness (PUE) rating, compared to the legacy data center's PUE of 2.28. The laboratory had been relying on individual servers with an energy utilization rate of less than 5%. NREL employed building best practices, innovative design techniques and energy-efficient technologies to support its energy goals for the new data center. To counteract the extensive heat generated by data center equipment, the laboratory implemented a cooling system using outdoor air and evaporative cooling to meet most of the center's needs. Inside the data center, NREL replaced much of its legacy equipment with new, energy-efficient technology. By exchanging this infrastructure for virtualized blade servers, NREL reduced its server energy footprint by 96%. Additionally, NREL replaced its 80%-efficient uninterruptible power supply (UPS) with a UPS that is 95% efficient; deployed ultra efficient power distribution units (PDU) to handle higher UPS voltages; and implemented vacancy sensors to drive down lighting loads. Using best practices and energy-efficient technology, NREL was able to successfully design an optimized data center with a minimal energy footprint. At 958,000 kWh, the annual energy use for the RSF data center is approximately 60% less than the legacy data center's annual energy use, surpassing the laboratory's project goal. As specified, the building is equipped with enough onsite renewable energy generation to offset annual energy consumption. The facility has achieved a PUE of 1.16 and ERE of 0.91 in its first 11 months of operation and is using PUE to as a metric to gauge success towards its ultimate goal. Based on the status of its RSF data center project, NREL is advising other government organizations on data center efficiency. The laboratory places great emphasis on the use of key metrics - such as PUE and ERE - to track performance. By carefully monitoring these metrics and making adjustments, NREL is able to continuously improve the performance of its data center operations.

Not Available

2011-12-01T23:59:59.000Z

37

Experimental response of a rotor supported on Rayleigh step gas bearings  

E-Print Network (OSTI)

Gas bearings enable successful applications in high speed oil-free microturbomachinery. This thesis presents analysis and experiments of the dynamic performance of a rotor supported on Rayleigh step gas bearings. Comprehensive experiments demonstrate that Rayleigh step hybrid gas bearings exhibit adequate stiffness and damping capability in a narrow range of shaft speeds, up to ~ 20 krpm. Rotor coastdown responses were performed for two test bearing sets with nominal radial clearance of 25.4 ?m and 38.1 ?m, respectively. A near-frictionless carbon (NFC) coating was applied on the rotor to reduce friction against its bearings at liftoff and touchdown. However, the rotor still experienced dry friction at low shaft speeds (below ~ 4,000 rpm). Experiments show that the supply pressure raises the rotor critical speed and decreases the system damping ratio. The geometry of the Rayleigh steps distributed on the rotor surface generates a time varying pressure field and results in a sizable 4X super synchronous component of bearing transmitted load. The external supply gas pressure affects slightly the onset speed of instability of the rotor-bearing system. The unstable whirl frequencies are nearly fixed at the system natural frequency (~ 120 Hz). Analysis with a finite element model predicts the stiffness and damping force coefficients for the bearing accounting for a purely hydrodynamic operation condition. Predictions show the synchronous stiffness and damping coefficients decrease with shaft speed. Predicted threshold speeds of instability are lower, ~ 50% or less than the measurement due to the analytical model limitations assuming a grooved stator. The predicted synchronous responses to imbalance correlate well with the measurements, however. The Rayleigh step gas bearing shows similar characteristics to the flexure pivot tilting pad bearing (FPTPB) tested in 2003. However, the test Rayleigh step gas bearings exhibit a much reduced stable operating speed range, below 20 krpm. The maximum speed achieved is much lower to that determined with an identical rotor supported on FPTPBs, i.e. rotor dynamically stable up to 100 krpm. The FPTPB is more reliable in high speed oil-free applications due to its excellent stability characteristics.

Zhu, Xuehua

2004-08-01T23:59:59.000Z

38

Flashlamp radiation recycling for enhanced pumping efficiency and reduced thermal load  

DOE Patents (OSTI)

A method for recycling laser flashlamp radiation in selected wavelength ranges to decrease thermal loading of the solid state laser matrix while substantially maintaining the pumping efficiency of the flashlamp.

Jancaitis, K.S.; Powell, H.T.

1986-10-23T23:59:59.000Z

39

Flashlamp radiation recycling for enhanced pumping efficiency and reduced thermal load  

DOE Patents (OSTI)

A method for recycling laser flashlamp radiation in selected wavelength ranges to decrease thermal loading of the solid state laser matrix while substantially maintaining the pumping efficiency of the flashlamp.

Jancaitis, Kenneth S. (Pleasant Hill, CA); Powell, Howard T. (Livermore, CA)

1989-01-01T23:59:59.000Z

40

Multiple piece turbine rotor blade  

DOE Patents (OSTI)

A multiple piece turbine rotor blade with a shell having an airfoil shape and secured between a spar and a platform with the spar including a tip end piece. a snap ring fits around the spar and abuts against the spar tip end piece on a top side and abuts against a shell on the bottom side so that the centrifugal loads from the shell is passed through the snap ring and into the spar and not through a tip cap dovetail slot and projection structure.

Jones, Russell B; Fedock, John A

2013-05-21T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Radial-Radial Single Rotor Turbine  

NLE Websites -- All DOE Office Websites (Extended Search)

Radial-Radial Single Rotor Turbine Radial-Radial Single Rotor Turbine A rotor for use in turbine applications. June 26, 2013 Radial-Radial Single Rotor Turbine A rotor for use in...

42

Rate-optimal multiuser scheduling with reduced feedback load and analysis of delay effects  

Science Conference Proceedings (OSTI)

We propose a feedback algorithm for wireless networks that always collects feedback from the user with the best channel conditions and has a significant reduction in feedback load compared to full feedback. The algorithm is based on a carrier-to-noise ...

Vegard Hassel; Mohamed-Slim Alouini; Geir E. Øien; David Gesbert

2006-04-01T23:59:59.000Z

43

CoolCab: Reducing Thermal Loads in Long-Haul Trucks (Fact Sheet)  

SciTech Connect

This fact sheet describes how the National Renewable Energy Laboratory's CoolCab project tested and modeled the effects of several thermal-load reduction strategies applied to long-haul truck cabs. NREL partnered with two major truck manufacturers to evaluate three long-haul trucks at NREL's outdoor test facility in Golden, Colorado.

Not Available

2010-02-01T23:59:59.000Z

44

Single Rotor Turbine  

DOE Patents (OSTI)

A rotor for use in turbine applications has a centrifugal compressor having axially disposed spaced apart fins forming passages and an axial turbine having hollow turbine blades interleaved with the fins and through which fluid from the centrifugal compressor flows.

Platts, David A. (Los Alamos, NM)

2004-10-26T23:59:59.000Z

45

Main Generator Rotor Maintenance  

Science Conference Proceedings (OSTI)

Main generator rotors are constructed and designed to provide decades of reliable and trouble-free operation. However, a number of incidences have occurred over the years that can adversely impact reliable operation of generator rotors and, ultimately, production of electrical power. This report is a guide for power plant personnel responsible for reliable operation and maintenance of main generators. As a guide, this report provides knowledge and experience from generator experts working at power plants...

2006-11-27T23:59:59.000Z

46

A new field balancing method of rotor systems based on holospectrum and genetic algorithm  

Science Conference Proceedings (OSTI)

Field balancing of flexible rotor system is a key technique to reduce turbine vibration in power plants. Traditional balancing methods are generally based on the information from a unidirectional sensor. In fact, the motion of a rotor system is a complex ... Keywords: Field balancing, Flexible rotor, Genetic algorithm, Holospectrum

Shi Liu; Liangsheng Qu

2008-01-01T23:59:59.000Z

47

Structural testing of the North Wind 250 composite rotor joint  

DOE Green Energy (OSTI)

The North Wind 250 wind turbine is under development at Northern Power Systems (NPS) in Moretown, VT. The turbine uses a unique, flow-through, teetered-rotor design. This design eliminates structural discontinuities at the blade/hub interface by fabricating the rotor as one continuous structural element. To accomplish this, the two blade spars are joined at the center of the rotor using a proprietary bonding technique. Fatigue tests were conducted on the full-scale rotor joint at the National Renewable Energy Laboratory (NREL). Subsequent tests are now underway to test the full-scale rotor and hub assembly to verify the design assumptions. The test articles were mounted in dedicated test fixtures. For the joint test, a constant moment was generated across the joint and parent material. Hydraulic actuators applied sinusoidal loading to the test article at levels equivalent to 90% of the extreme wind load for over one million cycles. When the loading was increased to 112% of the extreme wind load, the joint failed by buckling. Strain levels were monitored at 14 locations inside and outside of the blade joint during the test. The tests were used to qualify this critical element of the rotor for field testing and to provide information needed to improve the structural design of the joint.

Musial, W; Link, H [National Renewable Energy Lab., Golden, CO (United States); Coleman, C [Northern Power Systems, Moretown, VT (United States)

1994-05-01T23:59:59.000Z

48

Application of Sleeper Cab Thermal Management Technologies to Reduce Idle Climate Control Loads in Long-Haul Trucks  

DOE Green Energy (OSTI)

Each intercity long-haul truck in the U.S. idles approximately 1,800 hrs per year, primarily for sleeper cab hotel loads. Including workday idling, over 2 billion gallons of fuel are used annually for truck idling. NREL's CoolCab project works closely with industry to design efficient thermal management systems for long-haul trucks that keep the cab comfortable with minimized engine idling and fuel use. The impact of thermal load reduction technologies on idle reduction systems were characterized by conducting thermal soak tests, overall heat transfer tests, and 10-hour rest period A/C tests. Technologies evaluated include advanced insulation packages, a solar reflective film applied to the vehicle's opaque exterior surfaces, a truck featuring both film and insulation, and a battery-powered A/C system. Opportunities were identified to reduce heating and cooling loads for long-haul truck idling by 36% and 34%, respectively, which yielded a 23% reduction in battery pack capacity of the idle-reduction system. Data were also collected for development and validation of a CoolCalc HVAC truck cab model. CoolCalc is an easy-to-use, simplified, physics-based HVAC load estimation tool that requires no meshing, has flexible geometry, excludes unnecessary detail, and is less time-intensive than more detailed computer-aided engineering modeling approaches.

Lustbader, J. A.; Venson, T.; Adelman, S.; Dehart, C.; Yeakel, S.; Castillo, M. S.

2012-10-01T23:59:59.000Z

49

Using measured equipment load profiles to "right-size" HVAC systems and reduce energy use in laboratory buildings (Pt. 2)  

E-Print Network (OSTI)

Using measured equipment load profiles to “right-size” HVAClighting and occupancy load profiles in all the spaces wereintensity” equipment load profile, while the remaining zones

Mathew, Paul; Greenberg, Steve; Frenze, David; Morehead, Michael; Sartor, Dale; Starr, William

2008-01-01T23:59:59.000Z

50

Whole blood analysis rotor assembly having removable cellular sedimentation bowl  

DOE Patents (OSTI)

A rotor assembly for performing photometric analyses using whole blood samples is described. Following static loading of a gross blood sample within a centrally located, removable, cell sedimentation bowl, the red blood cells in the gross sample are centrifugally separated from the plasma, the plasm displaced from the sedimentation bowl, and measured subvolumes of plasma distributed to respective sample analysis cuvettes positioned in an annular array about the rotor periphery. Means for adding reagents to the respective cuvettes are also described. (auth)

Burtis, C.A.; Johnson, W.F.

1975-08-26T23:59:59.000Z

51

Control for stabilizing the alignment position of the rotor of a synchronous motor  

DOE Patents (OSTI)

A method and apparatus for damping oscillations in the rotor load angle of a synchronous motor to provide stable rotational alignment in high precision applications. The damping method includes sensing the angular position of the rotor and utilizing the position signal to generate an error signal in response to changes in the period of rotation of the rotor. The error signal is coupled to phase shift amplifiers which shift the phase of the motor drive signal in a direction to damp out the oscillations in the rotor load angle.

Donley, Lawrence I. (Lemont, IL)

1988-01-01T23:59:59.000Z

52

Control for stabilizing the alignment position of the rotor of the synchronous motor  

DOE Patents (OSTI)

A method and apparatus is described for damping oscillations in the rotor load angle of a synchronous motor to provide stable rotational alignment in high precision applications. The damping method includes sensing the angular position of the rotor and utilizing the position signal to generate an error signal in response to changes in the period of rotation of the rotor. The error signal is coupled to phase shift amplifiers which shift the phase of the motor drive signal in a direction to damp out the oscillations in the rotor load angle.

Donley, L.I.

1985-03-12T23:59:59.000Z

53

Passive load control for large wind turbines.  

DOE Green Energy (OSTI)

Wind energy research activities at Sandia National Laboratories focus on developing large rotors that are lighter and more cost-effective than those designed with current technologies. Because gravity scales as the cube of the blade length, gravity loads become a constraining design factor for very large blades. Efforts to passively reduce turbulent loading has shown significant potential to reduce blade weight and capture more energy. Research in passive load reduction for wind turbines began at Sandia in the late 1990's and has moved from analytical studies to blade applications. This paper discusses the test results of two Sandia prototype research blades that incorporate load reduction techniques. The TX-100 is a 9-m long blade that induces bend-twist coupling with the use of off-axis carbon in the skin. The STAR blade is a 27-m long blade that induces bend-twist coupling by sweeping the blade in a geometric fashion.

Ashwill, Thomas D.

2010-05-01T23:59:59.000Z

54

Using a collision model to design safer wind turbine rotors for birds  

Science Conference Proceedings (OSTI)

A mathematical model for collisions between birds and propeller-type turbine rotors identifies the variables that can be manipulated to reduce the probability that birds will collide with the rotor. This study defines a safety index--the clearance power density--that allows rotors of different sizes and designs to be compared in terms of the amount of wind energy converted to electrical energy per bird collision. The collision model accounts for variations in wind speed during the year and shows that for model rotors with simple, one-dimensional blades, the safety index increases in proportion to rotor diameter, and variable speed rotors have higher safety indexes than constant speed rotors. The safety index can also be increased by enlarging the region near the center of the rotor hub where the blades move slowly enough for birds to avoid them. Painting the blades to make them more visible might have this effect. Model rotors with practical designs can have safety indexes an order of magnitude higher than those for model rotors typical of the constant speeds rotors in common use today. This finding suggests that redesigned rotors could have collision rates with birds perhaps an order of magnitude lower than today`s rotors, with no reduction in the production of wind power. The empirical data that exist for collisions between raptors, such as hawks and eagles, and rotors are consistent with the model: the numbers of raptor carcasses found beneath large variable speed rotors, relative to the numbers found under small constant speed rotors, are in the proportions predicted by the collision model rather than in proportion to the areas swept by the rotor blades. However, uncontrolled variables associated with these data prevent a stronger claim of support for the model.

Tucker, V.A. [Duke Univ., Durham, NC (United States). Dept. of Zoology

1996-11-01T23:59:59.000Z

55

ROTOR END CAP  

DOE Patents (OSTI)

An improved end cap is described for the cylindrical rotor or bowl of a high-speed centrifugal separator adapted to permit free and efficient continuous counter current flow of gas therethrough for isotope separation. The end cap design provides for securely mounting the same to the hollow central shaft and external wall of the centrifuge. Passageways are incorporated and so arranged as to provide for continuous counter current flow of the light and heavy portions of the gas fed to the centrifuge.

Rushing, F.C.

1959-02-01T23:59:59.000Z

56

Single rotor turbine engine  

SciTech Connect

There has been invented a turbine engine with a single rotor which cools the engine, functions as a radial compressor, pushes air through the engine to the ignition point, and acts as an axial turbine for powering the compressor. The invention engine is designed to use a simple scheme of conventional passage shapes to provide both a radial and axial flow pattern through the single rotor, thereby allowing the radial intake air flow to cool the turbine blades and turbine exhaust gases in an axial flow to be used for energy transfer. In an alternative embodiment, an electric generator is incorporated in the engine to specifically adapt the invention for power generation. Magnets are embedded in the exhaust face of the single rotor proximate to a ring of stationary magnetic cores with windings to provide for the generation of electricity. In this alternative embodiment, the turbine is a radial inflow turbine rather than an axial turbine as used in the first embodiment. Radial inflow passages of conventional design are interleaved with radial compressor passages to allow the intake air to cool the turbine blades.

Platts, David A. (Los Alamos, NM)

2002-01-01T23:59:59.000Z

57

Proposed Update of SAFER-PC Rotor Life Assessment Code  

Science Conference Proceedings (OSTI)

Evaluating the remaining life of power plant turbine and generator rotors is a perennial dilemma facing utility engineers. Extended operation of a critically flawed rotor can result in catastrophic failure. Conversely, premature retirement of equipment burdens a utility financially. With today's pressures to reduce operation and maintenance costs, life extension and maintenance of plant components is receiving considerable attention. Accurate component life assessment is crucial in developing a technical...

1999-12-13T23:59:59.000Z

58

Variable speed operation of generators with rotor-speed feedback in wind power applications  

SciTech Connect

The use of induction generators in wind power applications has been common since the early development of the wind industry. Most of these generators operate at fixed frequency and are connected directly to the utility grid. Unfortunately, this mode of operation limits the rotor speed to a specific rpm. Variable-speed operation is preferred in order to facilitate maximum energy capture over a wide range of wind speeds. This paper explores variable-speed operating strategies for wind turbine applications. The objectives are to maximize energy production, provide controlled start-up and reduce torque loading. This paper focuses on optimizing the energy captured by operating at maximum aerodynamic efficiency at any wind speed. The control strategy we analyze uses rotor speed and generator power as the feedback signals. In the normal operating region, rotor speed is used to compute a target power that corresponds to optimum operation. With power as the control objective, the power converter and generator are controlled to track the target power at any rpm. Thus, the torque-speed characteristic of the generator is shaped to optimize the energy capture. The target power is continuously updated at any rpm. in extreme areas of the operating envelope, during start-up, shutdown, generator overload, or overspeed, different strategies driven by other system considerations must be used.

Muljadi, E.; Butterfield, C.P.; Migliore, P.

1995-11-01T23:59:59.000Z

59

Rotor Noise in Maneuvering Flight.  

E-Print Network (OSTI)

??The objective of this research is to understand the physics of rotor noise in the maneuvering flight. To achieve this objective, an integrated noise prediction… (more)

Chen, Hsuan-nien

2006-01-01T23:59:59.000Z

60

Homopolar motor with dual rotors  

DOE Patents (OSTI)

A homopolar motor has a field rotor mounted on a frame for rotation in a first rotational direction and for producing an electromagnetic field, and an armature rotor mounted for rotation on said frame within said electromagnetic field and in a second rotational direction counter to said first rotational direction of said field rotor. The two rotors are coupled through a 1:1 gearing mechanism, so as to travel at the same speed but in opposite directions. This doubles the output voltage and output power, as compared to a motor in which only the armature is rotated. Several embodiments are disclosed. 7 figs.

Hsu, J.S.

1998-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Reducing Data Center Loads for a Large-scale, Low Energy Office Building: NREL's Research Support Facility (Book), NREL (National Renewable Energy Laboratory)  

NLE Websites -- All DOE Office Websites (Extended Search)

Data Center Loads for a Large- Data Center Loads for a Large- scale, Low-energy Office Building: NREL's Research Support Facility The NREL Approach * December 2011 NREL is a national laboratory of the U.S. Department of Energy, Office of Energy Efficiency and Renewable Energy, operated by the Alliance for Sustainable Energy, LLC. 2 National Renewable Energy Laboratory Reducing Data Center Loads for a Large-Scale, Low-Energy Office Building: NREL's Research Support Facility Michael Sheppy, Chad Lobato, Otto Van Geet, Shanti Pless, Kevin Donovan, Chuck Powers National Renewable Energy Laboratory Golden, Colorado December 2011

62

Recurrent Rotor-Router Configurations  

E-Print Network (OSTI)

We prove the existence of recurrent initial configurations for the rotor walk on many graphs, including Z^d, and planar graphs with locally finite embeddings. We also prove that recurrence and transience of rotor walks are invariant under changes in the starting vertex and finite changes in the initial configuration.

Angel, Omer

2011-01-01T23:59:59.000Z

63

Recurrent Rotor-Router Configurations  

E-Print Network (OSTI)

We prove the existence of recurrent initial configurations for the rotor walk on many graphs, including Z d, and planar graphs with locally finite embeddings. We also prove that recurrence and transience of rotor walks are invariant under changes in the starting vertex and finite changes in the initial configuration.

Omer Angel; Alexander E. Holroyd

2011-01-01T23:59:59.000Z

64

Brake rotor design and comparison using finite element analysis : an investigation in topology optimization  

E-Print Network (OSTI)

and Rotor Figures . . . . . . . . . . . . . . . . . .Appendix D Unsatisfactory RotorAppendix G Supplemental Rotor Symmetrical Instance

Domond, Kenneth

2010-01-01T23:59:59.000Z

65

Reducing Plug and Process Loads for a Large Scale, Low Energy Office Building: NREL's Research Support Facility; Preprint  

SciTech Connect

This paper documents the design and operational plug and process load energy efficiency measures needed to allow a large scale office building to reach ultra high efficiency building goals. The appendices of this document contain a wealth of documentation pertaining to plug and process load design in the RSF, including a list of equipment was selected for use.

Lobato, C.; Pless, S.; Sheppy, M.; Torcellini, P.

2011-02-01T23:59:59.000Z

66

Copper in the Rotor for Lighter, Longer Lasting Motors  

E-Print Network (OSTI)

This paper reviews the advantages of substituting die-cast copper for aluminum in the motor rotor. This advance in motor technology has been long sought by the motor industry but short die life due to the high melting point of copper frustrated attempts to manufacture by pressure die casting. The nickel-base alloy hot die technology developed to solve the manufacturing problem is briefly reviewed. Development work done prior to the present program and commercial motors derived from that work have focused on the increased electrical energy efficiency achievable by using copper with its higher electrical conductivity in the rotor. Performance characteristics of example industrial motors are presented. Modification of the conductor bar shape to control in-rush current and starting torque to accommodate copper in the rotor will be discussed. Modeling by motor manufacturers has shown that by using copper in the rotor, a lighter motor than an aluminum rotor motor at the same efficiency can be built. An example of weight savings calculated for a 15 Hp (11 kW) motor is presented. Data presented here show that motors with copper rotors run cooler. Industry experience shows that cooler operation translates to reduced maintenance costs, improved reliability and longer motor life.

C. Stark; J. G. Cowie; D. T. Peters; E. F. Brush

2005-01-01T23:59:59.000Z

67

CFD analysis of rotating two-bladed flatback wind turbine rotor.  

DOE Green Energy (OSTI)

The effects of modifying the inboard portion of the NREL Phase VI rotor using a thickened, flatback version of the S809 design airfoil are studied using a three-dimensional Reynolds-averaged Navier-Stokes method. A motivation for using such a thicker airfoil design coupled with a blunt trailing edge is to alleviate structural constraints while reducing blade weight and maintaining the power performance of the rotor. The calculated results for the baseline Phase VI rotor are benchmarked against wind tunnel results obtained at 10, 7, and 5 meters per second. The calculated results for the modified rotor are compared against those of the baseline rotor. The results of this study demonstrate that a thick, flatback blade profile is viable as a bridge to connect structural requirements with aerodynamic performance in designing future wind turbine rotors.

van Dam, C.P. (University of California, David, CA); Chao, David D.; Berg, Dale E. (University of California, David, CA)

2008-04-01T23:59:59.000Z

68

Wind turbine rotor aileron  

DOE Patents (OSTI)

A wind turbine has a rotor with at least one blade which has an aileron which is adjusted by an actuator. A hinge has two portions, one for mounting a stationary hinge arm to the blade, the other for coupling to the aileron actuator. Several types of hinges can be used, along with different actuators. The aileron is designed so that it has a constant chord with a number of identical sub-assemblies. The leading edge of the aileron has at least one curved portion so that the aileron does not vent over a certain range of angles, but vents if the position is outside the range. A cyclic actuator can be mounted to the aileron to adjust the position periodically. Generally, the aileron will be adjusted over a range related to the rotational position of the blade. A method for operating the cyclic assembly is also described.

Coleman, Clint (Warren, VT); Kurth, William T. (Warren, VT)

1994-06-14T23:59:59.000Z

69

Optimized Maintenance of Generator Rotors  

Science Conference Proceedings (OSTI)

Generator rotor maintenance options are limited and expensive. The timing and scope of work done requires optimization to obtain the maximum benefits for continued long-term trouble-free operation. This document is a comprehensive guide to the maintenance of large generator rotors of 2 and 4 pole design that are cooled directly or indirectly by air or hydrogen. These include 50 and 60 Hz machines, operating at speeds of 1500, 1800, 3000, and 3600 RPM. The guide does not cover water-cooled rotors. The inf...

2004-12-13T23:59:59.000Z

70

Dynamic Response of a Rotor-air Bearing System Due to Base Induced Periodic Motions  

E-Print Network (OSTI)

Oil-free microturbomachinery (MTM) are inevitably subjected to base or foundation excitations: multiple periodic load excitations from internal combustion (IC) engines in turbochargers, for example. Too large base excitations can produce severe damage, even failure, due to hard collision or rubbing contact between a rotor and its bearings. Therefore, it is paramount to evaluate the reliability of rotor-air bearing systems to withstanding base load excitations. In 2008, intermittent shock excitations, up to 30 g (pk-pk), were introduced to a test rig consisting of a rotor (0.825 kg) supported on two hybrid flexure pivot tilting pad gas bearings (FPTPBs). The experiments demonstrated the reliability of the gas bearings to withstanding external transient load excitations. Presently, a shaker delivers periodic load excitations to the base plate supporting the test rig. The whole system, weighing 48 kg, is supported on two soft coil springs and its lowest natural frequency is ~5 Hz. The rod connecting the shaker to the base plate is not affixed rigidly to the test rig base. The rod merely pushes on the base plate and hence the induced based motions are intermittent with multiple impacts and frequencies. As with most practical conditions, the base motion frequencies (5-12 Hz) are low respective to the operating speed of the rotor-bearing system. Rotor speed coast down tests evidence the rotor-bearing system natural frequency when the gas bearings are supplied with feed pressures increasing from 2.36 to 5.08 bar (ab). Shaker excitation induced rotor response, relative to the bearing housings, contains the main input frequency (5-12 Hz) and its super harmonics; and because of the intermittency of the base motions, it also excites the rotor-bearing system natural frequency, with smaller motion amplitudes than synchronous motion components. The excitation of the system natural frequency does not mean rotordynamic instability. With base induced motions, the rotor motion amplitude at the system natural frequency increases as the gas bearing feed pressure decreases, as the rotor speed increases, and as the shaker input excitation frequency increases (5-12 Hz). Hence, the test rotor-air bearing system is highly sensitive to base motions, intermittent in character, in particular when the gas bearings are supplied with a low feed pressure. Predicted rotor motion responses obtained from XLTRC2 and an analytical rigid rotor model, both including the (measured) periodic base motions, show good correlation with the measurements. The research results demonstrate further the applicability of gas bearings into oil-free high speed MTM.

Niu, Yaying

2009-08-01T23:59:59.000Z

71

Performance of twist-coupled blades on variable speed rotors  

DOE Green Energy (OSTI)

The load mitigation and energy capture characteristics of twist-coupled HAWT blades that are mounted on a variable speed rotor are investigated in this paper. These blades are designed to twist toward feather as they bend with pretwist set to achieve a desirable twist distribution at rated power. For this investigation, the ADAMS-WT software has been modified to include blade models with bending-twist coupling. Using twist-coupled and uncoupled models, the ADAMS software is exercised for steady wind environments to generate C{sub p} curves at a number of operating speeds to compare the efficiencies of the two models. The ADAMS software is also used to generate the response of a twist-coupled variable speed rotor to a spectrum of stochastic wind time series. This spectrum contains time series with two mean wind speeds at two turbulence levels. Power control is achieved by imposing a reactive torque on the low speed shaft proportional to the RPM squared with the coefficient specified so that the rotor operates at peak efficiency in the linear aerodynamic range, and by limiting the maximum RPM to take advantage of the stall controlled nature of the rotor. Fatigue calculations are done for the generated load histories using a range of material exponents that represent materials from welded steel to aluminum to composites, and results are compared with the damage computed for the rotor without twist-coupling. Results indicate that significant reductions in damage are achieved across the spectrum of applied wind loading without any degradation in power production.

Lobitz, D.W.; Veers, P.S.; Laino, D.J.

1999-12-07T23:59:59.000Z

72

Rotor assembly and assay method  

DOE Patents (OSTI)

A rotor assembly for carrying out an assay includes a rotor body which is rotatable about an axis of rotation, and has a central chamber and first, second, third, fourth, fifth, and sixth chambers which are in communication with and radiate from the central chamber. The rotor assembly further includes a shuttle which is movable through the central chamber and insertable into any of the chambers, the shuttle including a reaction cup carrying an immobilized antigen or an antibody for transport among the chambers. A method for carrying out an assay using the rotor assembly includes moving the reaction cup among the six chambers by passing the cup through the central chamber between centrifugation steps in order to perform the steps of: separating plasma from blood cells, binding plasma antibody or antigen, washing, drying, binding enzyme conjugate, reacting with enzyme substrate and optically comparing the resulting reaction product with unreacted enzyme substrate solution. The movement of the reaction cup can be provided by attaching a magnet to the reaction cup and supplying a moving magnetic field to the rotor.

Burtis, Carl A. (Oak Ridge, TN); Johnson, Wayne F. (Loudon, TN); Walker, William A. (Knoxville, TN)

1993-01-01T23:59:59.000Z

73

Rotor walks on general trees  

E-Print Network (OSTI)

The rotor walk on a graph is a deterministic analogue of random walk. Each vertex is equipped with a rotor, which routes the walker to the neighbouring vertices in a fixed cyclic order on successive visits. We consider rotor walk on an infinite rooted tree, restarted from the root after each escape to infinity. We prove that the limiting proportion of escapes to infinity equals the escape probability for random walk, provided only finitely many rotors send the walker initially towards the root. For i.i.d. random initial rotor directions on a regular tree, the limiting proportion of escapes is either zero or the random walk escape probability, and undergoes a discontinuous phase transition between the two as the distribution is varied. In the critical case there are no escapes, but the walker's maximum distance from the root grows doubly exponentially with the number of visits to the root. We also prove that there exist trees of bounded degree for which the proportion of escapes eventually exceeds the escape p...

Angel, Omer

2010-01-01T23:59:59.000Z

74

Hi-Q Rotor - Low Wind Speed Technology  

DOE Green Energy (OSTI)

The project objective was to optimize the performance of the Hi-Q Rotor. Early research funded by the California Energy Commission indicated the design might be advantageous over state-of-the-art turbines for collecting wind energy in low wind conditions. The Hi-Q Rotor is a new kind of rotor targeted for harvesting wind in Class 2, 3, and 4 sites, and has application in areas that are closer to cities, or 'load centers.' An advantage of the Hi-Q Rotor is that the rotor has non-conventional blade tips, producing less turbulence, and is quieter than standard wind turbine blades which is critical to the low-wind populated urban sites. Unlike state-of-the-art propeller type blades, the Hi-Q Rotor has six blades connected by end caps. In this phase of the research funded by DOE's Inventions and Innovation Program, the goal was to improve the current design by building a series of theoretical and numeric models, and composite prototypes to determine a best of class device. Development of the rotor was performed by aeronautical engineering and design firm, DARcorporation. From this investigation, an optimized design was determined and an 8-foot diameter, full-scale rotor was built and mounted using a Bergey LX-1 generator and furling system which were adapted to support the rotor. The Hi-Q Rotor was then tested side-by-side against the state-of-the-art Bergey XL-1 at the Alternative Energy Institute's Wind Test Center at West Texas State University for six weeks, and real time measurements of power generated were collected and compared. Early wind tunnel testing showed that the cut-in-speed of the Hi-Q rotor is much lower than a conventional tested HAWT enabling the Hi-Q Wind Turbine to begin collecting energy before a conventional HAWT has started spinning. Also, torque at low wind speeds for the Hi-Q Wind Turbine is higher than the tested conventional HAWT and enabled the wind turbine to generate power at lower wind speeds. Based on the data collected, the results of our first full-scale prototype wind turbine proved that higher energy can be captured at lower wind speeds with the new Hi-Q Rotor. The Hi-Q Rotor is almost 15% more productive than the Bergey from 6 m/s to 8 m/s, making it ideal in Class 3, 4, and 5 wind sites and has application in the critical and heretofore untapped areas that are closer to cities, 'load centers,' and may even be used directly in urban areas. The additional advantage of the Hi-Q Rotor's non-conventional blade tips, which eliminates most air turbulence, is noise reduction which makes it doubly ideal for populated urban areas. Hi-Q Products recommends one final stage of development to take the Hi-Q Rotor through Technology Readiness Levels 8-9. During this stage of development, the rotor will be redesigned to further increase efficiency, match the rotor to a more suitable generator, and lower the cost of manufacturing by redesigning the structure to allow for production in larger quantities at lower cost. Before taking the rotor to market and commercialization, it is necessary to further optimize the performance by finding a better generator and autofurling system, ones more suitable for lower wind speeds and rpms should be used in all future testing. The potential impact of this fully developed technology will be the expansion and proliferation of energy renewal into the heretofore untapped Class 2, 3, 4, and 5 Wind Sites, or the large underutilized sites where the wind speed is broken by physical features such as mountains, buildings, and trees. Market estimates by 2011, if low wind speed technology can be developed are well above: 13 million homes, 675,000 commercial buildings, 250,000 public facilities. Estimated commercial exploitation of the Hi-Q Rotor show potential increase in U.S. energy gained through the clean, renewable wind energy found in low and very low wind speed sites. This new energy source would greatly impact greenhouse emissions as well as the public sector's growing energy demands.

Todd E. Mills; Judy Tatum

2010-01-11T23:59:59.000Z

75

Rotor for centrifugal fast analyzers  

DOE Patents (OSTI)

The invention is an improved photometric analyzer of the rotary cuvette type, the analyzer incorporating a multicuvette rotor of novel design. The rotor (a) is leaktight, (b) permits operation in the 90/sup 0/ and 180/sup 0/ excitation modes, (c) is compatible with extensively used Centrifugal Fast Analyzers, and (d) can be used thousands of times. The rotor includes an assembly comprising a top plate, a bottom plate, and a central plate, the rim of the central plate being formed with circumferentially spaced indentations. A uv-transmitting ring is sealably affixed to the indented rim to define with the indentations an array of cuvettes. The ring serves both as a sealing means and an end window for the cuvettes.

Lee, N.E.

1984-01-01T23:59:59.000Z

76

Rotor for centrifugal fast analyzers  

DOE Patents (OSTI)

The invention is an improved photometric analyzer of the rotary cuvette type, the analyzer incorporating a multicuvette rotor of novel design. The rotor (a) is leaktight, (b) permits operation in the 90.degree. and 180.degree. excitation modes, (c) is compatible with extensively used Centrifugal Fast Analyzers, and (d) can be used thousands of times. The rotor includes an assembly comprising a top plate, a bottom plate, and a central plate, the rim of the central plate being formed with circumferentially spaced indentations. A UV-transmitting ring is sealably affixed to the indented rim to define with the indentations an array of cuvettes. The ring serves both as a sealing means and an end window for the cuvettes.

Lee, Norman E. (Knoxville, TN)

1985-01-01T23:59:59.000Z

77

Turbomachine rotor with improved cooling  

DOE Patents (OSTI)

A gas turbine rotor has an essentially closed loop cooling air scheme in which cooling air drawn from the compressor discharge air that is supplied to the combustion chamber is further compressed, cooled, and then directed to the aft end of the turbine rotor. Downstream seal rings attached to the downstream face of each rotor disc direct the cooling air over the downstream disc face, thereby cooling it, and then to cooling air passages formed in the rotating blades. Upstream seal rings attached to the upstream face of each disc direct the heated cooling air away from the blade root while keeping the disc thermally isolated from the heated cooling air. From each upstream seal ring, the heated cooling air flows through passages in the upstream discs and is then combined and returned to the combustion chamber from which it was drawn. 5 figs.

Hultgren, K.G.; McLaurin, L.D.; Bertsch, O.L.; Lowe, P.E.

1998-05-26T23:59:59.000Z

78

Turbomachine rotor with improved cooling  

SciTech Connect

A gas turbine rotor has an essentially closed loop cooling air scheme in which cooling air drawn from the compressor discharge air that is supplied to the combustion chamber is further compressed, cooled, and then directed to the aft end of the turbine rotor. Downstream seal rings attached to the downstream face of each rotor disc direct the cooling air over the downstream disc face, thereby cooling it, and then to cooling air passages formed in the rotating blades. Upstream seal rings attached to the upstream face of each disc direct the heated cooling air away from the blade root while keeping the disc thermally isolated from the heated cooling air. From each upstream seal ring, the heated cooling air flows through passages in the upstream discs and is then combined and returned to the combustion chamber from which it was drawn.

Hultgren, Kent Goran (Winter Park, FL); McLaurin, Leroy Dixon (Winter Springs, FL); Bertsch, Oran Leroy (Titusville, FL); Lowe, Perry Eugene (Oviedo, FL)

1998-01-01T23:59:59.000Z

79

Probabilistic analysis of meanline compressor rotor performance  

E-Print Network (OSTI)

This thesis addresses variability in aerodynamic performance of a compressor rotor due to geometric variation. The performance of the rotor is computed using a meanline model that includes the effect of tip clearance ...

Fitzgerald, Nathan Andrew, 1980-

2004-01-01T23:59:59.000Z

80

The Influence of Inversions on Rotors  

Science Conference Proceedings (OSTI)

Rotors are small-scale circulations about a horizontal or quasi-horizontal axis that usually form in conjunction with high-amplitude mountain waves. The moderate to severe turbulence often found within rotors is a hazard to aviation. Observations ...

Rolf F. Hertenstein

2009-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

The Terrain-Induced Rotor Experiment  

Science Conference Proceedings (OSTI)

The Terrain-Induced Rotor Experiment (T-REX) is a coordinated international project, composed of an observational field campaign and a research program, focused on the investigation of atmospheric rotors and closely related phenomena in complex ...

Vanda Grubiši?; James D. Doyle; Joachim Kuettner; Richard Dirks; Stephen A. Cohn; Laura L. Pan; Stephen Mobbs; Ronald B. Smith; C. David Whiteman; Stanley Czyzyk; Simon Vosper; Martin Weissmann; Samuel Haimov; Stephan F. J. De Wekker; Fotini Katopodes Chow

2008-10-01T23:59:59.000Z

82

The fractional symmetric rigid rotor  

E-Print Network (OSTI)

Based on the Riemann fractional derivative the Casimir operators and multipletts for the fractional extension of the rotation group SO(n) are calculated algebraically. The spectrum of the corresponding fractional symmetric rigid rotor is discussed. It is shown, that the rotational, vibrational and $\\gamma$-unstable limits of the standard geometric collective models are particular limits of this spectrum. A comparison with the ground state band spectra of nuclei shows an agreement with experimental data better than 2%. The derived results indicate, that the fractional symmetric rigid rotor is an appropriate tool for a description of low energy nuclear excitations.

Richard Herrmann

2006-10-24T23:59:59.000Z

83

Dielectric anomaly in coupled rotor systems  

E-Print Network (OSTI)

The correlated dynamics of coupled quantum rotors carrying electric dipole moment is theoretically investigated. The energy spectra of coupled rotors as a function of dipolar interaction energy is analytically solved. The calculated dielectric susceptibilities of the system show the peculiar temperature dependence different from that of isolated rotors.

Hiroyuki Shima; Tsuneyoshi Nakayama

2004-07-02T23:59:59.000Z

84

Filter type rotor for multistation photometer  

DOE Patents (OSTI)

A filter type rotor for a multistation photometer is provided. The rotor design combines the principle of cross-flow filtration with centrifugal sedimentation so that these occur simultaneously as a first stage of processing for suspension type fluids in an analytical type instrument. The rotor is particularly useful in whole-blood analysis.

Shumate, II, Starling E. (Knoxville, TN)

1977-07-12T23:59:59.000Z

85

Radial-Radial Single Rotor Turbine  

NLE Websites -- All DOE Office Websites (Extended Search)

Radial-Radial Single Rotor Turbine Radial-Radial Single Rotor Turbine Radial-Radial Single Rotor Turbine A rotor for use in turbine applications. Available for thumbnail of Feynman Center (505) 665-9090 Email Radial-Radial Single Rotor Turbine A rotor for use in turbine applications has a radial compressor/pump having radially disposed spaced apart fins forming passages and a radial turbine having hollow turbine blades interleaved with the fins and through which fluid from the radial compressor/pump flows. The rotor can, in some applications, be used to produce electrical power. U.S. Patent No.: 7,044,718 (DOE S-100,626) Patent Application Filing Date: July 8, 2003 Patent Issue Date: May 16, 2006 Licensing Status: Available for Express Licensing (?). View terms and a sample license agreement.

86

Reducing Data Center Loads for a Large-Scale, Low-Energy Office Building: NREL's Research Support Facility (Book)  

DOE Green Energy (OSTI)

This publication detailing the design, implementation strategies, and continuous performance monitoring of NREL's Research Support Facility data center. Data centers are energy-intensive spaces that facilitate the transmission, receipt, processing, and storage of digital data. These spaces require redundancies in power and storage, as well as infrastructure, to cool computing equipment and manage the resulting waste heat (Tschudi, Xu, Sartor, and Stein, 2003). Data center spaces can consume more than 100 times the energy of standard office spaces (VanGeet 2011). The U.S. Environmental Protection Agency (EPA) reported that data centers used 61 billion kilowatt-hours (kWh) in 2006, which was 1.5% of the total electricity consumption in the U.S. (U.S. EPA, 2007). Worldwide, data centers now consume more energy annually than Sweden (New York Times, 2009). Given their high energy consumption and conventional operation practices, there is a potential for huge energy savings in data centers. The National Renewable Energy Laboratory (NREL) is world renowned for its commitment to green building construction. In June 2010, the laboratory finished construction of a 220,000-square-foot (ft{sup 2}), LEED Platinum, Research Support Facility (RSF), which included a 1,900-ft{sup 2} data center. The RSF will expand to 360,000 ft{sup 2} with the opening of an additional wing December, 2011. The project's request for proposals (RFP) set a whole-building demand-side energy use requirement of a nominal 35 kBtu/ft{sup 2} per year. On-site renewable energy generation will offset the annual energy consumption. To support the RSF's energy goals, NREL's new data center was designed to minimize its energy footprint without compromising service quality. Several implementation challenges emerged during the design, construction, and first 11 months of operation of the RSF data center. This document highlights these challenges and describes in detail how NREL successfully overcame them. The IT settings and strategies outlined in this document have been used to significantly reduce data center energy requirements in the RSF; however, these can also be used in existing buildings and retrofits.

Sheppy, M.; Lobato, C.; Van Geet, O.; Pless, S.; Donovan, K.; Powers, C.

2011-12-01T23:59:59.000Z

87

Analysis of a teetered, variable-speed rotor: final report  

DOE Green Energy (OSTI)

A computer model of a horizontal axis wind turbine (HOOT) with four structural degrees of freedom has been derived and verified. The four degrees of freedom include flapwise motion of the blades, teeter motion, and variable rotor speed. Options for the variable rotor speed include synchronous, induction, and constant-tip speed generator models with either start, stop, or normal operations. Verification is made by comparison with analytical solutions and mean and cyclic ESI-80 data. The Veers full-field turbulence model is used as a wind input for a synchronous and induction generator test case during normal operation. As a result of the comparison, it is concluded that the computer model can be used to predict accurately mean and cyclic loads with a turbulent wind input. 47 refs., 19 figs.

Weber, T.L.; Wilson, R.E.; Walker, S.N. (Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering) [Oregon State Univ., Corvallis, OR (USA). Dept. of Mechanical Engineering

1991-06-01T23:59:59.000Z

88

Rotor walks and Markov chains  

E-Print Network (OSTI)

The rotor walk is a derandomized version of the random walk on a graph. On successive visits to any given vertex, the walker is routed to each of the neighboring vertices in some fixed cyclic order, rather than to a random sequence of neighbors. The concept generalizes naturally to countable Markov chains. Subject to general conditions, we prove that many natural quantities associated with the rotor walk (including normalized hitting frequencies, hitting times and occupation frequencies) concentrate around their expected values for the random walk. Furthermore, the concentration is stronger than that associated with repeated runs of the random walk; the discrepancy is at most C/n after n runs (for an explicit constant C), rather than c / ? n. 1

Alexander E. Holroyd; James Propp

2010-01-01T23:59:59.000Z

89

Rotor Walks and Markov Chains  

E-Print Network (OSTI)

The rotor walk is a derandomized version of the random walk on a graph. On successive visits to any given vertex, the walker is routed to each of the neighboring vertices in some fixed cyclic order, rather than to a random sequence of neighbors. The concept generalizes naturally to Markov chains on a countable state space. Subject to general conditions, we prove that many natural quantities associated with the rotor walk (including normalized hitting frequencies, hitting times and occupation frequencies) concentrate around their expected values for the random walk. Furthermore, the concentration is stronger than that associated with repeated runs of the random walk, with discrepancy at most C/n after n runs (for an explicit constant C), rather than constant/sqrt n.

Holroyd, Alexander E

2009-01-01T23:59:59.000Z

90

Rotor blades for turbine engines  

DOE Patents (OSTI)

A tip shroud that includes a plurality of damping fins, each damping fin including a substantially non-radially-aligned surface that is configured to make contact with a tip shroud of a neighboring rotor blade. At least one damping fin may include a leading edge damping fin and at least one damping fin may include a trailing edge damping fin. The leading edge damping fin may be configured to correspond to the trailing edge damping fin.

Piersall, Matthew R; Potter, Brian D

2013-02-12T23:59:59.000Z

91

A Note on Rotor-Router Aggregation on the Comb  

E-Print Network (OSTI)

We prove a shape theorem for rotor-router aggregation on the comb, for a specific initial rotor configuration and clockwise rotor sequence for all vertices. Furthermore, as an application of rotor-router walks, we describe the harmonic measure for the limiting shape of rotor-router aggregation, which is useful in the study of other growth models on the comb.

Huss, Wilfried

2011-01-01T23:59:59.000Z

92

Reducing Uncertainties in Life Limits of Titanium Alloys in Turbine ...  

Science Conference Proceedings (OSTI)

Presentation Title, Reducing Uncertainties in Life Limits of Titanium Alloys in Turbine Engine Rotors. Author(s), James M. Larsen, Sushant Jha, Christopher J.

93

Gas Turbine Rotor Life: Material Testing  

Science Conference Proceedings (OSTI)

Gas turbine rotor materials are subject to degradation from prolonged hours and multiple start/stop cycles of operation. Periodically, plant operators disassemble the compressor and turbine sections of the rotor system and inspect the components for signs of creep, embrittlement, corrosion, thermal fatigue, and high- and low-cycle fatigue. Beyond limited rotor inspections performed during hot gas path inspections and major overhauls, a more thorough inspection is often required by the equipment ...

2012-12-14T23:59:59.000Z

94

Gas Turbine Rotor Life Assessment Guideline  

Science Conference Proceedings (OSTI)

Gas turbine rotor materials are subject to degradation from prolonged hours and multiple start/stop cycles of operation. Periodically, plant operators disassemble the compressor and turbine sections of the rotor system and inspect the components for signs of creep, embrittlement, corrosion, thermal fatigue, and high- and low-cycle fatigue. Beyond limited rotor inspections performed during hot gas path inspections and major overhauls, a more thorough inspection is often required by the equipment manufactu...

2011-12-14T23:59:59.000Z

95

Negative Sequence Effects on Generator Rotors  

Science Conference Proceedings (OSTI)

Main generator rotors are constructed and designed to provide decades of reliable and trouble-free operation. However, a number of negative sequence and motoring incidences have occurred over the years that can adversely impact reliable operation of generator rotors and, ultimately, production of electrical power. Severe overheating leads to rotor material changes, such as steel hardness, and may if not detected, ultimately lead to catastrophic failure. This report discusses the effects of severe negativ...

2007-12-18T23:59:59.000Z

96

Optical Control of a Quantum Rotor  

E-Print Network (OSTI)

The possibility to coherently control a quantum rotor is investigated theoretically. The rotor is realized by an antiferromagnetic spin-1 Bose-Einstein condensate, trapped in the optical field of a Fabry-Perot resonator. By tuning the pumping field of the resonator, coherent control over the rotor is achieved. The technique is illustrated by the numerical simulation of a protocol that transforms the rotor's ground state into a squeezed state. The detection of the squeezed state via measurement of intensity-correlations of the cavity field is proposed.

Lukas F. Buchmann; H. Jing; C. Raman; P. Meystre

2013-03-04T23:59:59.000Z

97

Rotor interaction in the annulus billiard  

E-Print Network (OSTI)

Introducing the rotor interaction in the integrable system of the annulus billiard produces a variety of dynamical phenomena, from integrability to ergodicity.

Péter Bálint; Serge Troubetzkoy

2004-01-16T23:59:59.000Z

98

BISTABLE DEVICES FOR MORPHING ROTOR BLADES.  

E-Print Network (OSTI)

??This dissertation presents two bistable concepts for morphing rotor blades. These concepts are simple and are composed of bistable devices that act as coupling structures… (more)

Johnson, Terrence

2010-01-01T23:59:59.000Z

99

On the Optimization of Composite Flywheel Rotors.  

E-Print Network (OSTI)

??Energy storing flywheel rotor technology has yet to be fully optimized given the design possibilities. There have been many design approaches that have been published… (more)

Ross, Jacob

2013-01-01T23:59:59.000Z

100

The Intense Lee-Wave Rotor Event of Sierra Rotors IOP 8  

Science Conference Proceedings (OSTI)

A large-amplitude lee-wave rotor event observationally documented during Sierra Rotors Project Intensive Observing Period (IOP) 8 on 24–26 March 2004 in the lee of the southern Sierra Nevada is examined. Mountain waves and rotors occurred over ...

Vanda Grubiši?; Brian J. Billings

2007-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Seismic Loading for FAST: May 2011 - August 2011  

DOE Green Energy (OSTI)

As more wind farms are constructed in seismically active regions, earthquake loading increases in prominence for design and analysis of wind turbines. Early investigation of seismic load tended to simplify the rotor and nacelle as a lumped mass on top of the turbine tower. This simplification allowed the use of techniques developed for conventional civil structures, such as buildings, to be easily applied to wind turbines. However, interest is shifting to more detailed models that consider loads for turbine components other than the tower. These improved models offer three key capabilities in consideration of base shaking for turbines: 1) The inclusion of aerodynamics and turbine control; 2) The ability to consider component loads other than just tower loads; and 3) An improved representation of turbine response in higher modes by reducing modeling simplifications. Both experimental and numerical investigations have shown that, especially for large modern turbines, it is important to consider interaction between earthquake input, aerodynamics, and operational loads. These investigations further show that consideration of higher mode activity may be necessary in the analysis of the seismic response of turbines. Since the FAST code is already capable of considering these factors, modifications were developed that allow simulation of base shaking. This approach allows consideration of this additional load source within a framework, the FAST code that is already familiar to many researchers and practitioners.

Asareh, M. A.; Prowell, I.

2012-08-01T23:59:59.000Z

102

Method for manufacturing a rotor having superconducting coils  

DOE Patents (OSTI)

A method and apparatus for manufacturing a rotor for use with a rotating machine is provided that employs a superconducting coil on the rotor. An adhesive is applied to an outer surface of the rotor body, which may include a groove disposed within an outer surface of the rotor body. A superconducting coil is then mounted onto the rotor body such that the adhesive bonds the superconducting coil to the rotor body.

Driscoll, David I. (South Euclid, OH); Shoykhet, Boris A. (Beachwood, OH)

2001-01-01T23:59:59.000Z

103

Steam Turbine Rotor Life Assessment and Extension: Evaluation of Retired Rotors: Volume 2: Mechanical Properties of Service-Exposed Rotors  

Science Conference Proceedings (OSTI)

Informed run/retire decisions on high and intermediate pressure (HP/IP) rotors require mechanical property data on service-exposed material. This report presents a comprehensive set of mechanical property data, including creep and creep-fatigue crack growth, on a 1950 vintage CrMoV HP/IP rotor retired after more than 160,000 hours of service.

1994-04-01T23:59:59.000Z

104

Blade platform seal for ceramic/metal rotor assembly  

DOE Patents (OSTI)

A combination ceramic and metal turbine rotor for use in high temperature gas turbine engines includes a metal rotor disc having a rim with a plurality of circumferentially spaced blade root retention slots therein to receive a plurality of ceramic blades, each including side platform segments thereon and a dovetail configured root slidably received in one of the slots. Adjacent ones of the platform segments including edge portions thereon closely spaced when the blades are assembled to form expansion gaps in an annular flow surface for gas passage through the blades and wherein the assembly further includes a plurality of unitary seal members on the rotor connected to its rim and each including a plurality of spaced, axially extending, flexible fingers that underlie and conform to the edge portions of the platform segments and which are operative at turbine operating temperatures and speeds to distribute loading on the platform segments as the fingers are seated against the underside of the blade platforms to seal the gaps without undesirably stressing thin web ceramic sections of the platform.

Wertz, John L. (Indianapolis, IN)

1982-01-01T23:59:59.000Z

105

Segmented and self-adjusting wind turbine rotors. Final report  

DOE Green Energy (OSTI)

An investigation was carried out to examine the use of blade aeroelastic properties for providing rotational speed control for a wind turbine generator (WTG). The study was specifically directed at obtaining a rotor configuration that has the capability for maintaining nearly constant torque at constant RPM in the presence of varying wind conditions and is aimed at eliminating the current requirement for mechanical pitch change devices. The approach considered is one in which rotor twist due to aerodynamic loading is used to adjust the blade's pitch as the wind speed changes. The preliminary design concept that has evolved is a flexible rotor blade formed from a series of individual, light, rigid segments that are arranged along the blade spar. Each segment can rotate around the spar but is restricted in pitch by a nonlinear mechanical spring. The results of performance calculations as well as vibration and flutter analyses are presented. Based on these results, the concept appears to provide an attractive solution to the problem of WTG operation in a varying wind field.

Jordan, P.F.; Goldman, R.L.

1976-04-01T23:59:59.000Z

106

Using time-frequency and wavelet analysis to assess turbulence/rotor interactions  

DOE Green Energy (OSTI)

Large loading events on wind turbine rotor blades are often associated with transient bursts of coherent turbulent energy in the turbine inflow. These coherent turbulent structures are identified as peaks in the three-dimensional, instantaneous, turbulent shearing stress field. Such organized inflow structures and the accompanying rotor aeroelastic responses typically have time scales of only a few seconds and therefore do not lend themselves for analysis by conventional Fourier spectral techniques. Time-frequency analysis (and wavelet analysis in particular) offers the ability to more closely study the spectral decomposition of short period events such as the interaction of coherent turbulence with a moving rotor blade. In this paper, the authors discuss the initial progress in the application of time-frequency analysis techniques to the decomposition and interpretation of turbulence/rotor interaction. The authors discuss the results of applying both the continuous and discrete wavelet transforms for their application. Several examples are given of the techniques applied to both observed turbulence and turbine responses and those generated using numerical simulations. They found that the presence of coherent turbulent structures, as revealed by the inflow Reynolds stress field, is a major contributor to large load excursions. These bursts of coherent turbulent energy induce a broadband aeroelastic response in the turbine rotor as it passes through them.

Kelley, N.D.; Osgood, R.M.; Bialasiewicz, J.T.; Jakubowski, A.

2000-01-05T23:59:59.000Z

107

Extension-Twist Coupling Optimization in Composite Rotor Blades .  

E-Print Network (OSTI)

??For optimal rotor performance in a tiltrotor aircraft the difference in the inflow and the rotor speeds between the hover and cruise flight modes suggests… (more)

Ozbay, Serkan

2005-01-01T23:59:59.000Z

108

Signature splitting in $^{173}$W with triaxial particle rotor model  

E-Print Network (OSTI)

A particle rotor model with a quasi-neutron coupled with a triaxially deformed rotor is applied to study signature splitting for bands with intruder orbital $\

B. Qi; S. Q. Zhang; S. Y. Wang; J. Meng

2008-06-15T23:59:59.000Z

109

Signature splitting in $^{173}$W with triaxial particle rotor model  

E-Print Network (OSTI)

A particle rotor model with a quasi-neutron coupled with a triaxially deformed rotor is applied to study signature splitting for bands with intruder orbital $\

Qi, B; Wang, S Y; Meng, J

2008-01-01T23:59:59.000Z

110

Radial-radial single rotor turbine  

SciTech Connect

A rotor for use in turbine applications has a radial compressor/pump having radially disposed spaced apart fins forming passages and a radial turbine having hollow turbine blades interleaved with the fins and through which fluid from the radial compressor/pump flows. The rotor can, in some applications, be used to produce electrical power.

Platts, David A. (Los Alamos, NM)

2006-05-16T23:59:59.000Z

111

Design of Controls to Attenuate Loads in the Controls Advanced Research Turbine: Preprint  

DOE Green Energy (OSTI)

Designing wind turbines to maximize energy production and increase fatigue life is a major goal of the wind industry. To achieve this goal, we must design wind turbines to extract maximum energy and reduce component and system loads. This paper applies modern state-space control design methods to a two-bladed teetering-hub upwind machine located at the National Wind Technology Center*. The design objective is to regulate turbine speed in region 3 (above rated wind speed) and enhance damping in several low-damped flexible modes of the turbine. The controls approach is based on the Disturbance Accommodating Control (DAC) method and provides accountability for wind-speed disturbances. First, controls are designed using the single control input rotor collective pitch to stabilize the first drive-train torsion as well as the tower first fore-aft bending modes. Generator torque is then incorporated as an additional control input. This reduces some of the demand placed on the rotor collective pitch control system and enhances first drive train torsion mode damping. Individual blade pitch control is then used to attenuate wind disturbances having spatial variation over the rotor and effectively reduces blade flap deflections caused by wind shear.

Wright, A. D.; Balas, M. J.

2003-11-01T23:59:59.000Z

112

Substantially parallel flux uncluttered rotor machines  

Science Conference Proceedings (OSTI)

A permanent magnet-less and brushless synchronous system includes a stator that generates a magnetic rotating field when sourced by polyphase alternating currents. An uncluttered rotor is positioned within the magnetic rotating field and is spaced apart from the stator. An excitation core is spaced apart from the stator and the uncluttered rotor and magnetically couples the uncluttered rotor. The brushless excitation source generates a magnet torque by inducing magnetic poles near an outer peripheral surface of the uncluttered rotor, and the stator currents also generate a reluctance torque by a reaction of the difference between the direct and quadrature magnetic paths of the uncluttered rotor. The system can be used either as a motor or a generator

Hsu, John S.

2012-12-11T23:59:59.000Z

113

Control system for a wound-rotor motor  

DOE Patents (OSTI)

A load switching circuit for switching two or more transformer taps under load carrying conditions includes first and second parallel connected bridge rectifier circuits which control the selective connection of a direct current load to taps of a transformer. The first bridge circuit is normally conducting so that the load is connected to a first tap through the first bridge circuit. To transfer the load to the second tap, a switch is operable to connect the second bridge circuit to a second tap, and when the second bridge circuit begins to conduct, the first bridge circuit ceases conduction because the potential at the second tap is higher than the potential at the first tap, and the load is thus connected to the second tap through the second bridge circuit. The load switching circuit is applicable in a motor speed controller for a wound-rotor motor for effecting tap switching as a function of motor speed while providing a stepless motor speed control characteristics.

Ellis, J.N.

1981-07-17T23:59:59.000Z

114

Control system for a wound-rotor motor  

DOE Patents (OSTI)

A load switching circuit for switching two or more transformer taps under load carrying conditions includes first and second parallel connected bridge rectifier circuits which control the selective connection of a direct current load to taps of a transformer. The first bridge circuit is normally conducting so that the load is connected to a first tap through the first bridge circuit. To transfer the load to the second tap, a switch is operable to connect the second bridge circuit to a second tap, and when the second bridge circuit begins to conduct, the first bridge circuit ceases conduction because the potential at the second tap is higher than the potential at the first tap, and the load is thus connected to the second tap through the second bridge circuit. The load switching circuit is applicable in a motor speed controller for a wound-rotor motor for effecting tap switching as a function of motor speed while providing a stepless motor speed control characteristic.

Ellis, James N. (Chatsworth, CA)

1983-01-01T23:59:59.000Z

115

Flywheel rotor and containment technology development  

DOE Green Energy (OSTI)

The goals of the project are: to develop an economical and practical composite flywheel having an energy density of 88 Wh/kg at failure, an operational energy density of 44 to 55 Wh/kg, and an energy storage capacity of approximately 1 kWh; to determine the suitability of various manufacturing processes for low-cost rotor fabrication; to investigate flywheel and flywheel-systems dynamics; to test and evaluate prototype rotors for use in transportation and stationary applications; and to develop a fail-safe, lightweight, and low-cost flywheel containment. The following tasks have been accomplished: evaluation and selection of 1-kWh, first-generation, advanced flywheel rotor designs for subsequent development towards the DOE-established energy density goal of 88 Wh/kg at burst; completion of an advanced design concept for a flywheel primary containment structure, capable of containing the failure of a 1-kWh flywheel rotor and targeted for vehicular applications; non-destructive inspection and burst testing of approximately twenty (20) prototype rotors, and initiation of cyclic testing; completion of various activities in the areas of rotor manufacturing processes, dynamic analyses and composite materials design data generation; and initiation of an economic feasibility study to establish a rational costing methodology for composite rotors and containment.

Kulkarni, S.V.

1981-08-11T23:59:59.000Z

116

Antiferromagnetic spinor condensates are quantum rotors  

Science Conference Proceedings (OSTI)

We establish a theoretical correspondence between spin-one antiferromagnetic spinor condensates in an external magnetic field and quantum rotor models in an external potential. We show that the rotor model provides a conceptually clear picture of the possible phases and dynamical regimes of the antiferromagnetic condensate. We also show that this mapping simplifies calculations of the condensate's spectrum and wave functions. We use the rotor mapping to describe the different dynamical regimes recently observed in {sup 23}Na condensates [Phys. Rev. Lett. 102, 125301 (2009); Phys. Rev. Lett. 102, 225301 (2009)]. We also suggest a way to experimentally observe quantum-mechanical effects (collapse and revival) in spinor condensates.

Barnett, Ryan; Sau, Jay D.; Das Sarma, S. [Joint Quantum Institute and Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)

2010-09-15T23:59:59.000Z

117

Rotor apparatus for high strength undiffused brushless ...  

A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a ...

118

Wind turbine rotor hub and teeter joint  

DOE Patents (OSTI)

A rotor hub is provided for coupling a wind turbine rotor blade and a shaft. The hub has a yoke with a body which is connected to the shaft, and extension portions which are connected to teeter bearing blocks, each of which has an aperture. The blocks are connected to a saddle which envelops the rotor blade by one or two shafts which pass through the apertures in the bearing blocks. The saddle and blade are separated by a rubber interface which provides for distribution of stress over a larger portion of the blade. Two teeter control mechanisms, which may include hydraulic pistons and springs, are connected to the rotor blade and to the yoke at extension portions. These control mechanisms provide end-of-stroke damping, braking, and stiffness based on the teeter angle and speed of the blade.

Coleman, Clint (Warren, VT); Kurth, William T. (Warren, VT); Jankowski, Joseph (Stowe, VT)

1994-10-11T23:59:59.000Z

119

Interlayer toughening of fiber composite flywheel rotors  

DOE Patents (OSTI)

An interlayer toughening mechanism is described to mitigate the growth of damage in fiber composite flywheel rotors for long application. The interlayer toughening mechanism may comprise one or more tough layers composed of high-elongation fibers, high-strength fibers arranged in a woven pattern at a range from 0{degree} to 90{degree} to the rotor axis and bound by a ductile matrix material which adheres to and is compatible with the materials used for the bulk of the rotor. The number and spacing of the tough interlayers is a function of the design requirements and expected lifetime of the rotor. The mechanism has particular application in uninterruptable power supplies, electrical power grid reservoirs, and compulsators for electric guns, as well as electromechanical batteries for vehicles. 2 figs.

Groves, S.E.; Deteresa, S.J.

1998-07-14T23:59:59.000Z

120

Interlayer toughening of fiber composite flywheel rotors  

DOE Patents (OSTI)

An interlayer toughening mechanism to mitigate the growth of damage in fiber composite flywheel rotors for long application. The interlayer toughening mechanism may comprise one or more tough layers composed of high-elongation fibers, high-strength fibers arranged in a woven pattern at a range from 0.degree. to 90.degree. to the rotor axis and bound by a ductile matrix material which adheres to and is compatible with the materials used for the bulk of the rotor. The number and spacing of the tough interlayers is a function of the design requirements and expected lifetime of the rotor. The mechanism has particular application in uninterruptable power supplies, electrical power grid reservoirs, and compulsators for electric guns, as well as electromechanical batteries for vehicles.

Groves, Scott E. (Brentwood, CA); Deteresa, Steven J. (Livermore, CA)

1998-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

A carbon nanotube bearing and Stodola rotor  

E-Print Network (OSTI)

A nano-scale rotor supported on a cantilevered multi-wall carbon nanotube (MWNT) shaft (Stodola configuration) is proposed. The nanotube is also expected to function as the bearing, since individual walls of a MWNT are not ...

Cook, Eugene Hightower

2008-01-01T23:59:59.000Z

122

Using measured equipment load profiles to 'right-size' HVACsystems and reduce energy use in laboratory buildings (Pt. 2)  

SciTech Connect

There is a general paucity of measured equipment load datafor laboratories and other complex buildings and designers often useestimates based on nameplate rated data or design assumptions from priorprojects. Consequently, peak equipment loads are frequentlyoverestimated, and load variation across laboratory spaces within abuilding is typically underestimated. This results in two design flaws.Firstly, the overestimation of peak equipment loads results in over-sizedHVAC systems, increasing initial construction costs as well as energy usedue to inefficiencies at low part-load operation. Secondly, HVAC systemsthat are designed without accurately accounting for equipment loadvariation across zones can significantly increase simultaneous heatingand cooling, particularly for systems that use zone reheat fortemperature control. Thus, when designing a laboratory HVAC system, theuse of measured equipment load data from a comparable laboratory willsupport right-sizing HVAC systems and optimizing their configuration tominimize simultaneous heating and cooling, saving initial constructioncosts as well as life-cycle energy costs.In this paper, we present datafrom recent studies to support the above thesis. We first presentmeasured equipment load data from two sources: time-series measurementsin several laboratory modules in a university research laboratorybuilding; and peak load data for several facilities recorded in anational energy benchmarking database. We then contrast this measureddata with estimated values that are typically used for sizing the HVACsystems in these facilities, highlighting the over-sizing problem. Next,we examine the load variation in the time series measurements and analyzethe impact of this variation on energy use, via parametric energysimulations. We then briefly discuss HVAC design solutions that minimizesimultaneous heating and cooling energy use.

Mathew, Paul; Greenberg, Steve; Frenze, David; Morehead, Michael; Sartor, Dale; Starr, William

2005-06-29T23:59:59.000Z

123

LOADED WAVEGUIDES  

DOE Patents (OSTI)

>Loaded waveguides are described for the propagation of electromagnetic waves with reduced phase velocities. A rectangular waveguide is dimensioned so as to cut-off the simple H/sub 01/ mode at the operating frequency. The waveguide is capacitance loaded, so as to reduce the phase velocity of the transmitted wave, by connecting an electrical conductor between directly opposite points in the major median plane on the narrower pair of waveguide walls. This conductor may take a corrugated shape or be an aperature member, the important factor being that the electrical length of the conductor is greater than one-half wavelength at the operating frequency. Prepared for the Second U.N. International ConferThe importance of nuclear standards is duscussed. A brief review of the international callaboration in this field is given. The proposal is made to let the International Organization for Standardization (ISO) coordinate the efforts from other groups. (W.D.M.)

Mullett, L.B.; Loach, B.G.; Adams, G.L.

1958-06-24T23:59:59.000Z

124

Combined Effects of Gravity, Bending Moment, Bearing Clearance, and Input Torque on Wind Turbine Planetary Gear Load Sharing: Preprint  

DOE Green Energy (OSTI)

This computational work investigates planetary gear load sharing of three-mount suspension wind turbine gearboxes. A three dimensional multibody dynamic model is established, including gravity, bending moments, fluctuating mesh stiffness, nonlinear tooth contact, and bearing clearance. A flexible main shaft, planetary carrier, housing, and gear shafts are modeled using reduced degrees-of-freedom through modal compensation. This drivetrain model is validated against the experimental data of Gearbox Reliability Collaborative for gearbox internal loads. Planet load sharing is a combined effect of gravity, bending moment, bearing clearance, and input torque. Influences of each of these parameters and their combined effects on the resulting planet load sharing are investigated. Bending moments and gravity induce fundamental excitations in the rotating carrier frame, which can increase gearbox internal loads and disturb load sharing. Clearance in carrier bearings reduces the bearing load carrying capacity and thus the bending moment from the rotor can be transmitted into gear meshes. With bearing clearance, the bending moment can cause tooth micropitting and can induce planet bearing fatigue, leading to reduced gearbox life. Planet bearings are susceptible to skidding at low input torque.

Guo, Y.; Keller, J.; LaCava, W.

2012-09-01T23:59:59.000Z

125

2274 IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS, VOL. 9, NO. 4, NOVEMBER 2013 Rotor Bar Fault Monitoring Method Based on  

E-Print Network (OSTI)

utilizes the data analysis of the air-gap torque profile in conjunction with a Bayesian classifier, and abrupt load changes, which can produce bearing faults and rotor bar breakages. Meanwhile, electrical Monitoring Method Based on Analysis of Air-Gap Torques of Induction Motors Aderiano M. da Silva, Member, IEEE

Povinelli, Richard J.

126

Voith High Efficiency HM Rotor Energy Data, A Repulper Rotor Design Case Study  

E-Print Network (OSTI)

A recently completed demonstration project, funded partly by the Wisconsin Focus on Energy program and Wisconsin Public Service Corporation, shows the effectiveness of an energy efficient repulper rotor design compared with that of a conventional rotor. We conducted a demonstration to measure the performance and energy consumption of the energy efficient virgin pulp repulper of Wausau Paper in Rhinelander, Wisconsin. This paper describes the demonstration setting, shows the analysis, and discusses the results. Careful monitoring of the batch repulping operation gave us a very good picture of the energy savings. We monitored the energy use and impact on pulp quality under the following three conditions: 1. The existing conventional repulping blade (HOG rotor) 2. A new conventional repulping blade of the same style (spare HOG rotor) 3. A new energy efficient repulping blade (HM rotor) The HM rotor, a tall, swept-back blade design, has been engineered to provide effective turbulence of the fiber suspension and maximum rotor-fiber contact while consuming low horsepower.

Aue, J.; Fineran, B.

2005-01-01T23:59:59.000Z

127

MHK Technologies/Wave Rotor | Open Energy Information  

Open Energy Info (EERE)

Rotor Rotor < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Wave Rotor.jpg Technology Profile Primary Organization Ecofys Subsidiary of Econcern Project(s) where this technology is utilized *MHK Projects/C Energy Technology Resource Click here Wave Technology Type Click here Axial Flow Turbine Technology Readiness Level Click here TRL 5/6: System Integration and Technology Laboratory Demonstration Technology Description The Wave Rotor uses a combined Darrieus-Wells rotor, which is contained on the same vertical axis of rotation. These are respectively omni- and bi-directional rotors that can operate in currents of changing directions. The Wave Rotor is mounted on a platform to allow for the capture of wave energy from circulating water particles created by local currents. Since it uses two types of rotor on a single axis of rotation it is able to convert not only tidal currents, but also waves into electricity.

128

PN Rotor GmbH | Open Energy Information  

Open Energy Info (EERE)

PN Rotor GmbH Jump to: navigation, search Name PN Rotor GmbH Place Lower Saxony, Germany Sector Wind energy Product Germany-based subsidiary of Prokon Nord Energiesysteme GmbH and...

129

Wind turbine rotor hub and teeter joint - Energy Innovation Portal  

A rotor hub is provided for coupling a wind turbine rotor blade and a shaft. The hub has a yoke with a body which is connected to the shaft, and extension portions ...

130

Evaluation of Temper Embrittlement in Turbine Rotor Material  

Science Conference Proceedings (OSTI)

To assess the integrity of in-service steam turbine rotors, utilities need to know their current toughness. This report presents a procedure for nondestructively estimating toughness on the basis of the chemical composition of the rotor steel.

1991-03-01T23:59:59.000Z

131

The cost of noise reduction in commercial tilt rotor aircraft  

E-Print Network (OSTI)

The relationship between direct operating cost and departure noise annoyance was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt rotor aircraft designs to meet various ...

Faulkner, Henry B.

1974-01-01T23:59:59.000Z

132

Testing Controls to Mitigate Fatigue Loads in the Controls Advanced Research Turbine  

Science Conference Proceedings (OSTI)

Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines is nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated three-dimensional (3D) turbulent wind inflow field with imbedded coherent vortices that drive fatigue loads and reduce lifetime. Design of control algorithms for wind turbines must account for multiple control objectives. Future large multi-megawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, maximize energy capture, and add active damping to maintain stability for these dynamically active structures operating in a complex environment. Researchers at the National Renewable Energy Laboratory are designing, implementing, and testing advanced controls to maximize energy extraction and reduce structural dynamic loads. These control designs are based on a linear model of the turbine that is generated by specialized modeling software. This paper describes testing of a control algorithm to mitigate blade, tower, and drivetrain loads using advanced state-space control methods. The controller uses independent blade pitch to regulate the turbine's speed in Region 3, mitigate the effects of shear across the rotor disk, and add active damping to the tower's first fore-aft bending mode. Additionally, a separate generator torque control loop is designed to add active damping to the tower's first side-side mode and the first drivetraintorsion mode. This paper discusses preliminary implementation and field tests of this controller in the Controls Advanced Research Turbine at the National Renewable Energy Laboratory. Also included are preliminary comparisons of the performance of this controller to results from a typical baseline Proportional-Integral-Derivative controller designed with just Region 3 speed regulation as the goal.

Wright, A. D.; Fingersh, L. J.; Stol, K. A.

2009-01-01T23:59:59.000Z

133

Rotor Design and Process Optimization for Rotary Inert Dgeasser  

Science Conference Proceedings (OSTI)

About this Abstract. Meeting, Materials Science & Technology 2012. Symposium, Advances in Metal Casting Technologies. Presentation Title, Rotor Design and ...

134

Encoding many qubits in a rotor  

Science Conference Proceedings (OSTI)

We propose a scheme for encoding many qubits in a single rotor, that is, a continuous and periodic degree of freedom. A key feature of this scheme is its ability to manipulate and entangle the encoded qubits with a single operation on the system. We also show, using quantum error-correcting codes, how to protect the qubits against small errors in angular position and momentum which may affect the rotor. We then discuss the feasibility of this scheme and suggest several candidates for its implementation. The proposed scheme is immediately generalizable to qudits of any finite dimension.

Raynal, Philippe; Kalev, Amir [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 (Singapore); Suzuki, Jun [National Institute of Informatics, 2-1-2 Hitotsubashi, Chiyoda-ku, Tokyo, 101-8430 (Japan); Englert, Berthold-Georg [Centre for Quantum Technologies, National University of Singapore, 3 Science Drive 2, 117543 (Singapore); Department of Physics, National University of Singapore, 2 Science Drive 3, 117542 (Singapore)

2010-05-15T23:59:59.000Z

135

Encoding many qubits in a rotor  

E-Print Network (OSTI)

We propose a scheme for encoding many qubits in a single rotor, that is, a continuous and periodic degree of freedom. A key feature of this scheme is its ability to manipulate and entangle the encoded qubits with a single operation on the system. We also show, using quantum error-correcting codes, how to protect the qubits against small errors in angular position and momentum which may affect the rotor. We then discuss the feasibility of this scheme and suggest several candidates for its implementation. The proposed scheme is immediately generalizable to qudits of any finite dimension.

Kalev, Amir; Suzuki, Jun; Englert, Berthold-Georg

2010-01-01T23:59:59.000Z

136

Kicked rotor quantum resonances in position space  

E-Print Network (OSTI)

We present an approach of the kicked rotor quantum resonances in position-space, based on its analogy with the optical Talbot effect. This approach leads to a very simple picture of the physical mechanism underlying the dynamics and to analytical expressions for relevant physical quantities, such as mean momentum or kinetic energy. The ballistic behavior, which is closely associated to quantum resonances, is analyzed and shown to emerge from a coherent adding of successive kicks applied to the rotor thanks to a periodic reconstruction of the spatial wavepacket.

Maxence Lepers; Véronique Zehnlé; Jean Claude Garreau

2007-11-11T23:59:59.000Z

137

Kicked rotor quantum resonances in position space  

E-Print Network (OSTI)

We present an approach of the kicked rotor quantum resonances in position-space, based on its analogy with the optical Talbot effect. This approach leads to a very simple picture of the physical mechanism underlying the dynamics and to analytical expressions for relevant physical quantities, such as mean momentum or kinetic energy. The ballistic behavior, which is closely associated to quantum resonances, is analyzed and shown to emerge from a coherent adding of successive kicks applied to the rotor thanks to a periodic reconstruction of the spatial wavepacket.

Lepers, Maxence; Garreau, Jean Claude

2007-01-01T23:59:59.000Z

138

Encoding many qubits in a rotor  

E-Print Network (OSTI)

We propose a scheme for encoding many qubits in a single rotor, that is, a continuous and periodic degree of freedom. A key feature of this scheme is its ability to manipulate and entangle the encoded qubits with a single operation on the system. We also show, using quantum error-correcting codes, how to protect the qubits against small errors in angular position and momentum which may affect the rotor. We then discuss the feasibility of this scheme and suggest several candidates for its implementation. The proposed scheme is immediately generalizable to qudits of any finite dimension.

Amir Kalev; Philippe Raynal; Jun Suzuki; Berthold-Georg Englert

2010-03-05T23:59:59.000Z

139

Accelerator dynamics of a fractional kicked rotor  

E-Print Network (OSTI)

It is shown that the Weyl fractional derivative can quantize an open system. A fractional kicked rotor is studied in the framework of the fractional Schrodinger equation. The system is described by the non-Hermitian Hamiltonian by virtue of the Weyl fractional derivative. Violation of space symmetry leads to acceleration of the orbital momentum. Quantum localization saturates this acceleration, such that the average value of the orbital momentum can be a direct current and the system behaves like a ratchet. The classical counterpart is a nonlinear kicked rotor with absorbing boundary conditions.

A. Iomin

2006-09-14T23:59:59.000Z

140

Load attenuating passively adaptive wind turbine blade  

DOE Patents (OSTI)

A method and apparatus for improving wind turbine performance by alleviating loads and controlling the rotor. The invention employs the use of a passively adaptive blade that senses the wind velocity or rotational speed, and accordingly modifies its aerodynamic configuration. The invention exploits the load mitigation prospects of a blade that twists toward feather as it bends. The invention includes passively adaptive wind turbine rotors or blades with currently preferred power control features. The apparatus is a composite fiber horizontal axis wind-turbine blade, in which a substantial majority of fibers in the blade skin are inclined at angles of between 15 and 30 degrees to the axis of the blade, to produces passive adaptive aeroelastic tailoring (bend-twist coupling) to alleviate loading without unduly jeopardizing performance.

Veers, Paul S. (Albuquerque, NM); Lobitz, Donald W. (Albuquerque, NM)

2003-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Computer subroutine for estimating aerodynamic blade loads on Darrieus vertical axis wind turbines. [FORCE code  

DOE Green Energy (OSTI)

An important aspect of structural design of the Darrieus rotor is the determination of aerodynamic blade loads. This report describes a load generator which has been used at Sandia for quasi-static and dynamic rotor analyses. The generator is based on the single streamtube aerodynamic flow model and is constructed as a FORTRAN IV subroutine to facilitate its use in finite element structural models. Input and output characteristics of the subroutine are described and a complete listing is attached as an appendix.

Sullivan, W. N.; Leonard, T. M.

1980-11-01T23:59:59.000Z

142

On the Classification of Universal Rotor-Routers  

E-Print Network (OSTI)

The combinatorial theory of rotor-routers has connections with problems of statistical mechanics, graph theory, chaos theory, and computer science. A rotor-router network defines a deterministic walk on a digraph G in which a particle walks from a source vertex until it reaches one of several target vertices. Motivated by recent results due to Giacaglia et al., we study rotor-router networks in which all non-target vertices have the same type. A rotor type r is universal if every hitting sequence can be achieved by a homogeneous rotor-router network consisting entirely of rotors of type r. We give a conjecture that completely classifies universal rotor types. Then, this problem is simplified by a theorem we call the Reduction Theorem that allows us to consider only two-state rotors. A rotor-router network called the compressor, because it tends to shorten rotor periods, is introduced along with an associated algorithm that determines the universality of almost all rotors. New rotor classes, including boppy ro...

He, Xiaoyu

2011-01-01T23:59:59.000Z

143

A Recurrent Rotor-Router Configuration in Z^3  

E-Print Network (OSTI)

Rotor Router models were first introduced by James Propp in 2002. A recurrent Rotor configuration is the one in which every state is visited infinitely often. In this project we investigated whether there is a recurrent Rotor configuration in Z^d (d>2).

A, Tulasi Ram Reddy

2010-01-01T23:59:59.000Z

144

Rotor bore and turbine rotor wheel/spacer heat exchange flow circuit  

SciTech Connect

In a turbine having closed-circuit steam-cooling passages about the rim of the rotor during steady-state operation, compressor discharge air is supplied to the rotor bore for passage radially outwardly into the wheel space cavities between the wheels and spacers. Communicating slots and channels in the spacers and wheels at circumferentially spaced positions enable egress of the compressor discharge air into the hot gas flow path. At turbine startup, cooling air flows through the closed-circuit steam passages to cool the outer rim of the rotor while compressor discharge air pre-warms the wheels and spacers. At steady-state, cooling steam is supplied in the closed-circuit steam-cooling passages and compressor discharge air is supplied through the bore and into the wheel space cavities to cool the rotor.

Caruso, Philip M. (Selkirk, NY); Eldrid, Sacheverel Quentin (Saratoga Springs, NY); Ladhani, Azad A. (Niskayuna, NY); DeMania, Alan Richard (Niskayuna, NY); Palmer, Gene David (Clifton Park, NY); Wilson, Ian David (Clifton Park, NY); Rathbun, Lisa Shirley (Scotia, NY); Akin, Robert Craig (Schenectady, NY)

2002-01-01T23:59:59.000Z

145

Quantum beats of the rigid rotor  

E-Print Network (OSTI)

The dynamics is investigated of a free particle on a sphere (rigid rotor or rotator) that is initially in a coherent state. The instability of coherent states with respect to the free evolution leads to nontrivial time-development of averages of observables representing the position of a particle on a sphere that can be interpreted as quantum beats.

K. Kowalski; J. Rembieli?ski

2013-09-23T23:59:59.000Z

146

The Evolution of Rotor and Blade Design  

DOE Green Energy (OSTI)

The objective of this paper is to provide a historical perspective of the evolution of rotor and blade design during the last 20 years. This evolution is a balanced integration of economic, aerodynamic, structural dynamic, noise, and aesthetic considerations, which are known to be machine type and size dependent.

Tangler, J.

2000-08-01T23:59:59.000Z

147

Cracked rotor vibrations by multifractal analysis  

E-Print Network (OSTI)

Multifractal analysis has been used to diagnoze cracked and healthy rotors. Is has been shown that the complexity and regularity criteria of the dynamical systems defined by the multiple scaling of the time series can indicate the damages of the rotating shaft.

Grzegorz Litak; Jerzy T. Sawicki

2008-04-15T23:59:59.000Z

148

Quantum beats of the rigid rotor  

E-Print Network (OSTI)

The dynamics is investigated of a free particle on a sphere (rigid rotor or rotator) that is initially in a coherent state. The instability of coherent states with respect to the free evolution leads to nontrivial time-development of averages of observables representing the position of a particle on a sphere that can be interpreted as quantum beats.

Kowalski, K

2013-01-01T23:59:59.000Z

149

Utilization of rotor kinetic energy storage for hybrid vehicles  

DOE Patents (OSTI)

A power system for a motor vehicle having an internal combustion engine, the power system comprises an electric machine (12) further comprising a first excitation source (47), a permanent magnet rotor (28) and a magnetic coupling rotor (26) spaced from the permanent magnet rotor and at least one second excitation source (43), the magnetic coupling rotor (26) also including a flywheel having an inertial mass to store kinetic energy during an initial acceleration to an operating speed; and wherein the first excitation source is electrically connected to the second excitation source for power cycling such that the flywheel rotor (26) exerts torque on the permanent magnet rotor (28) to assist braking and acceleration of the permanent magnet rotor (28) and consequently, the vehicle. An axial gap machine and a radial gap machine are disclosed and methods of the invention are also disclosed.

Hsu, John S. (Oak Ridge, TN)

2011-05-03T23:59:59.000Z

150

Load cell  

DOE Patents (OSTI)

A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components. 16 figs.

Spletzer, B.L.

1998-12-15T23:59:59.000Z

151

Load cell  

DOE Patents (OSTI)

A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs which can be combined to determine any one of the six general load components.

Spletzer, Barry L. (Albuquerque, NM)

2001-01-01T23:59:59.000Z

152

Load cell  

DOE Patents (OSTI)

A load cell combines the outputs of a plurality of strain gauges to measure components of an applied load. Combination of strain gauge outputs allows measurement of any of six load components without requiring complex machining or mechanical linkages to isolate load components. An example six axis load cell produces six independent analog outputs, each directly proportional to one of the six general load components.

Spletzer, Barry L. (Albuquerque, NM)

1998-01-01T23:59:59.000Z

153

Closed continuous-flow centrifuge rotor  

DOE Patents (OSTI)

A blood separation centrifuge rotor having a generally parabolic core disposed concentrically and spaced apart within a housing having a similarly shaped cavity. Blood is introduced through a central inlet and into a central passageway enlarged downwardly to decrease the velocity of the entrant blood. Septa are disposed inside the central passageway to induce rotation of the entrant blood. A separation chamber is defined between the core and the housing wherein the whole blood is separated into red cell, white cell, and plasma zones. The zones are separated by annular splitter blades disposed within the separation chamber. The separated components are continuously removed through conduits communicating through a face seal to the outside of the rotor.

Breillatt, Jr., Julian P. (Oak Ridge, TN); Remenyik, Carl J. (Knoxville, TN); Sartory, Walter K. (Oak Ridge, TN); Thacker, Louis H. (Knoxville, TN); Penland, William Z. (Bethesda, MD)

1976-01-01T23:59:59.000Z

154

Negative Sequence Effects on Generator Rotors  

Science Conference Proceedings (OSTI)

This report is the second part of a study of the effects of severe negative sequence events on round rotor turbine generators. The first part (EPRI report 1014910) introduced simplified models to investigate the thermal and mechanical stresses resulting from unbalanced short circuits and other events. The current report provides documentation on these simplified models. It also describes further studies of the retaining ring and introduces additional models for the pole face and cross-slot regions.

2009-01-16T23:59:59.000Z

155

Rotor assembly and method for automatically processing liquids  

DOE Patents (OSTI)

A rotor assembly for performing a relatively large number of processing steps upon a sample, such as a whole blood sample, and a diluent, such as water, includes a rotor body for rotation about an axis and including a network of chambers within which various processing steps are performed upon the sample and diluent and passageways through which the sample and diluent are transferred. A transfer mechanism is movable through the rotor body by the influence of a magnetic field generated adjacent the transfer mechanism and movable along the rotor body, and the assembly utilizes centrifugal force, a transfer of momentum and capillary action to perform any of a number of processing steps such as separation, aliquoting, transference, washing, reagent addition and mixing of the sample and diluent within the rotor body. The rotor body is particularly suitable for automatic immunoassay analyses.

Burtis, Carl A. (Oak Ridge, TN); Johnson, Wayne F. (Loudon, TN); Walker, William A. (Knoxville, TN)

1992-01-01T23:59:59.000Z

156

Double-ended ceramic helical-rotor expander  

DOE Patents (OSTI)

A ceramic helical rotor expander using a double-ended or tandem herringbone type rotor arrangement with bearing and seal assemblies remote from the hot gas inlets and especially capable of operating at an inlet temperature of above 1100.degree. C. The rotors are solid or hollow and bonded to hollow metal shafts, and mounted in a composite or simple prismatic casing. The rotors, casing and shafts are constructed from low expansivity materials. In the preferred embodiment the rotors are constructed of silicon nitride and the shafts constructed of an molybdenum alloy, with the metal shafts being supported in bearings and secured to synchronizing gears. The rotors and casing may be provided with coolant channels therein, and are constructed to eliminate the problem of end leakages at inlet temperature and pressure, and the need for high temperature bearings and seals.

Mohr, Peter B. (Livermore, CA); Myers, Wendell B. (Livermore, CA)

1995-01-01T23:59:59.000Z

157

Rotor assembly and method for automatically processing liquids  

DOE Patents (OSTI)

A rotor assembly is described for performing a relatively large number of processing steps upon a sample, such as a whole blood sample, and a diluent, such as water. It includes a rotor body for rotation about an axis and includes a network of chambers within which various processing steps are performed upon the sample and diluent and passageways through which the sample and diluent are transferred. A transfer mechanism is movable through the rotor body by the influence of a magnetic field generated adjacent the transfer mechanism and movable along the rotor body, and the assembly utilizes centrifugal force, a transfer of momentum and capillary action to perform any of a number of processing steps such as separation, aliquoting, transference, washing, reagent addition and mixing of the sample and diluent within the rotor body. The rotor body is particularly suitable for automatic immunoassay analyses. 34 figs.

Burtis, C.A.; Johnson, W.F.; Walker, W.A.

1992-12-22T23:59:59.000Z

158

Double-ended ceramic helical-rotor expander  

DOE Patents (OSTI)

A ceramic helical rotor expander is disclosed using a double-ended or tandem herringbone type rotor arrangement with bearing and seal assemblies remote from the hot gas inlets and especially capable of operating at an inlet temperature of above 1,100 C. The rotors are solid or hollow and bonded to hollow metal shafts, and mounted in a composite or simple prismatic casing. The rotors, casing and shafts are constructed from low expansivity materials. In the preferred embodiment the rotors are constructed of silicon nitride and the shafts constructed of an molybdenum alloy, with the metal shafts being supported in bearings and secured to synchronizing gears. The rotors and casing may be provided with coolant channels therein, and are constructed to eliminate the problem of end leakages at inlet temperature and pressure, and the need for high temperature bearings and seals. 3 figs.

Mohr, P.B.; Myers, W.B.

1995-02-28T23:59:59.000Z

159

Escape rates for rotor walks in Z d  

E-Print Network (OSTI)

Rotor walk is a deterministic analogue of random walk. We study its recurrence and transience properties on Z d for the initial configuration of all rotors aligned. If n particles in turn perform rotor walks starting from the origin, we show that the number that escape (i.e., never return to the origin) is of order n in dimensions d ? 3, and of order n / log n in dimension 2. 1

Laura Florescu; Shirshendu Ganguly; Lionel Levine; Yuval Peres

2013-01-01T23:59:59.000Z

160

Geometrical terms in the effective Hamiltonian for rotor molecules  

E-Print Network (OSTI)

An analogy between asymmetric rotor molecules and anisotropic cosmology can be used to calculate new centrifugal distortion terms in the effective potential of asymmetric rotor molecules which have no internal 3-fold symmetry. The torsional potential picks up extra $\\cos\\alpha$ and $\\cos2\\alpha$ contributions, which are comparable to corrections to the momentum terms in methanol and other rotor molecules with isotope replacements.

Moss, Ian G

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

Rotor for processing liquids using movable capillary tubes  

DOE Patents (OSTI)

A rotor assembly for processing liquids, especially whole blood samples, is disclosed. The assembly includes apparatus for separating non-liquid components of whole blood samples from liquid components, apparatus for diluting the separated liquid component with a diluent and apparatus for transferring the diluted sample to an external apparatus for analysis. The rotor assembly employs several movable capillary tubes to handle the sample and diluents. A method for using the rotor assembly to process liquids is also described.

Johnson, Wayne F. (Loudon, TN); Burtis, Carl A. (Oak Ridge, TN); Walker, William A. (Knoxville, TN)

1989-05-30T23:59:59.000Z

162

Rotor for processing liquids using movable capillary tubes  

DOE Patents (OSTI)

A rotor assembly for processing liquids, especially whole blood samples, is disclosed. The assembly includes apparatus for separating non-liquid components of whole blood samples from liquid components, apparatus for diluting the separated liquid component with a diluent and apparatus for transferring the diluted sample to an external apparatus for analysis. The rotor assembly employs several movable capillary tubes to handle the sample and diluents. A method for using the rotor assembly to process liquids is also described. 5 figs.

Johnson, W.F.; Burtis, C.A.; Walker, W.A.

1987-07-17T23:59:59.000Z

163

Rotor for processing liquids using movable capillary tubes  

DOE Patents (OSTI)

A rotor assembly for processing liquids, especially whole blood samples, is disclosed. The assembly includes apparatus for separating non-liquid components of whole blood samples from liquid components, apparatus for diluting the separated liquid component with a diluent and apparatus for transferring the diluted sample to an external apparatus for analysis. The rotor assembly employs several movable capillary tubes to handle the sample and diluents. A method for using the rotor assembly to process liquids is also described.

Johnson, Wayne F. (Loudon, TN); Burtis, Carl A. (Oak Ridge, TN); Walker, William A. (Knoxville, TN)

1989-01-01T23:59:59.000Z

164

Geometrical terms in the effective Hamiltonian for rotor molecules  

E-Print Network (OSTI)

An analogy between asymmetric rotor molecules and anisotropic cosmology can be used to calculate new centrifugal distortion terms in the effective potential of asymmetric rotor molecules which have no internal 3-fold symmetry. The torsional potential picks up extra $\\cos\\alpha$ and $\\cos2\\alpha$ contributions, which are comparable to corrections to the momentum terms in methanol and other rotor molecules with isotope replacements.

Ian G. Moss

2013-03-25T23:59:59.000Z

165

Gas Turbine Rotor Life Evaluation: Siemens V84.2  

Science Conference Proceedings (OSTI)

Gas turbine rotor materials are subject to degradation from prolonged hours and multiple start/stop cycles of operation. Occasionally, plant operators have the compressor and turbine sections of the rotor system disassembled and the components inspected for signs of creep, embrittlement, corrosion, thermal fatigue, and high- and low-cycle fatigue. Inspections of rotor rim areas typically take place more regularly during hot gas path and major maintenance intervals when casings and blades are removed. Thi...

2011-11-10T23:59:59.000Z

166

Summary report on the HFED (High-Uranium-Loaded Fuel Element Development) miniplate irradiations for the RERTR (Reduced Enrichment Research and Test Reactor) Program  

SciTech Connect

An experiment to evaluate the irradiation characteristics of various candidate low-enriched, high-uranium content fuels for research and test reactors was performed for the US Department of Energy Reduced Enrichment Research and Test Reactor Program. The experiment included the irradiation of 244 miniature fuel plates (miniplates) in a core position in the Oak Ridge Research Reactor. The miniplates were aluminum-based, dispersion-type plates 114.3 mm long by 50.8 mm wide with overall plate thicknesses of 1.27 or 1.52 mm. Fuel core dimensions varied according to the overall plate thicknesses with a minimum clad thickness of 0.20 mm. Tested fuels included UAl/sub x/, UAl/sub 2/, U/sub 3/O/sub 8/, U/sub 3/SiAl, U/sub 3/Si, U/sub 3/Si/sub 1.5/, U/sub 3/Si/sub 2/, U/sub 3/SiCu, USi, U/sub 6/Fe, and U/sub 6/Mn/sub 1.3/ materials. Although most miniplates were made with low-enriched uranium (19.9%), some with medium-enriched uranium (40 to 45%), a few with high-enriched uranium (93%), and a few with depleted uranium (0.2 to 0.4%) were tested for comparison. These fuel materials were irradiated to burnups ranging from /approximately/27 to 98 at. % /sup 235/U depletion. Operation of the experiment, measurement of miniplate thickness as the irradiation progressed, ultimate shipment of the irradiated miniplates to various hot cells, and preliminary results are reported here. 18 refs., 12 figs., 7 tabs.

Senn, R.L.

1989-04-01T23:59:59.000Z

167

Electrostatic generator/motor having rotors of varying ...  

Electrostatic generator/motor having rotors of varying thickness and a central stator electrically connected together into two groups United States Patent

168

Mechanical coupling for a rotor shaft assembly of dissimilar materials  

DOE Patents (OSTI)

A mechanical coupling for coupling a ceramic disc member to a metallic shaft includes a first wedge clamp and a second wedge clamp. A fastener engages a threaded end of a tie-bolt to sandwich the ceramic disc between the wedge clamps. An axial spring is positioned between the fastener and the second wedge clamp to apply an axial preload along the longitudinal axis. Another coupling utilizes a rotor shaft end of a metallic rotor shaft as one wedge clamp. Still another coupling includes a solid ceramic rotor disc with a multiple of tie-bolts radially displaced from the longitudinal axis to exert the preload on the solid ceramic rotor disc.

Shi, Jun (Glastonbury, CT); Bombara, David (New Hartford, CT); Green, Kevin E. (Broad Brook, CT); Bird, Connic (Rocky Hill, CT); Holowczak, John (South Windsor, CT)

2009-05-05T23:59:59.000Z

169

Quantum rotor theory of spinor condensates in tight traps  

Science Conference Proceedings (OSTI)

In this work, we theoretically construct exact mappings of many-particle bosonic systems onto quantum rotor models. In particular, we analyze the rotor representation of spinor Bose-Einstein condensates. In a previous work [R. Barnett et al., Phys. Rev. A 82, 031602(R) (2010)] it was shown that there is an exact mapping of a spin-one condensate of fixed particle number with quadratic Zeeman interaction onto a quantum rotor model. Since the rotor model has an unbounded spectrum from above, it has many more eigenstates than the original bosonic model. Here we show that for each subset of states with fixed spin F{sub z}, the physical rotor eigenstates are always those with the lowest energy. We classify three distinct physical limits of the rotor model: the Rabi, Josephson, and Fock regimes. The last regime corresponds to a fragmented condensate and is thus not captured by the Bogoliubov theory. We next consider the semiclassical limit of the rotor problem and make connections with the quantum wave functions through the use of the Husimi distribution function. Finally, we describe how to extend the analysis to higher-spin systems and derive a rotor model for the spin-two condensate. Theoretical details of the rotor mapping are also provided here.

Barnett, Ryan; Hui, Hoi-Yin; Lin, Chien-Hung; Sau, Jay D.; Das Sarma, S. [Joint Quantum Institute and Condensed Matter Theory Center, Department of Physics, University of Maryland, College Park, Maryland 20742-4111 (United States)

2011-02-15T23:59:59.000Z

170

Flight Control Design for Rotorcraft with Variable Rotor Speed.  

E-Print Network (OSTI)

??Flight control design issues for rotorcraft with variable rotor speed are investigated, and new design methodologies are developed to deal with the challenges of variable… (more)

Guo, Wei

2009-01-01T23:59:59.000Z

171

Hawaii Zuteck Rotor Project: Compilation of project reports  

DOE Green Energy (OSTI)

Summarizes project to design and build aileron retrofit blades for a 600 kW upwind, teetered rotor, full-span pitch control, horizontal-axis wind turbine.

Zuteck, M.D.; Miller, M.W.

1999-02-25T23:59:59.000Z

172

Optimal propulsion system design for a micro quad rotor.  

E-Print Network (OSTI)

?? Currently a 50 gram micro quad rotor vehicle is being developed in collaboration with Daedalus Flight Systems. Optimization of the design at this scale… (more)

Harrington, Aaron M.

2011-01-01T23:59:59.000Z

173

Control of wind turbine output power via a variable rotor resistance.  

E-Print Network (OSTI)

??Many utility-scale wind turbine generators use wound-rotor induction machines. By adding an external rotor resistance to the rotor circuit it is possible to control the… (more)

Burnham, David James

2009-01-01T23:59:59.000Z

174

Technical Basis for Generator Rotor Remaining Life Estimation Using Boresonic Inspection Data  

Science Conference Proceedings (OSTI)

Because they operate at much lower temperatures than turbine rotors, generator rotors do not experience the creep or thermal fatigue damage associated with turbine rotors. The major damage mechanism for generator rotors’ near-bore regions is low-cycle fatigue due to startups. However, current practices of generator boresonic inspection do not differentiate between generator rotors and turbine rotors. The current practices also have large variations, ranging from no boresonic inspection to ...

2012-12-12T23:59:59.000Z

175

Turbulence ingestion noise of open rotors  

E-Print Network (OSTI)

liners, which play a crucial role in specific tone reduction for turbofans, cannot of course be used to attenuate noise from these rotors. General Electric (GE) in the US began an in-house ‘UnDucted Fan’ (UDF) research programme in 1983 and also... ), has established ambitious targets for new aircraft entering service in 2020, compared to those entering service in 2000, of a 50% reduction in fuel consumption and CO2 emissions per passenger kilometre (of which 20%, that is just under half...

Robison, Rosalyn Aruna Venner

2012-04-10T23:59:59.000Z

176

Quantum diffusion in the quasiperiodic kicked rotor  

E-Print Network (OSTI)

We study the mechanisms responsible for quantum diffusion in the quasiperiodic kicked rotor. We report experimental measurements of the diffusion constant on the atomic version of the system and develop a theoretical approach (based on the Floquet theorem) explaining the observations, especially the ``sub-Fourier'' character of the resonances observed in the vicinity of exact periodicity, i.e. the ability of the system to distinguish two neighboring driving frequencies in a time shorter than the inverse of the difference of the two frequencies.

Hans Lignier; Jean Claude Garreau; Pascal Szriftgiser; Dominique Delande

2004-12-02T23:59:59.000Z

177

A Numerical Study of Water Injection on Transonic Compressor Rotor Performance.  

E-Print Network (OSTI)

??In this study, numerical simulations of two-phase flow in a transonic compressor rotor (NASA Rotor 37) were performed. Both flow and droplets governing equations were… (more)

Szabo, Istvan

2008-01-01T23:59:59.000Z

178

AN INVESTIGATION OF PERFORMANCE BENEFITS AND TRIM REQUIREMENTS OF A VARIABLE SPEED HELICOPTER ROTOR.  

E-Print Network (OSTI)

??This study primarily examines the main rotor power reductions possible through variation in rotor RPM. Simulations were based on the UH-60 Blackhawk helicopter, and emphasis… (more)

Steiner, Jason

2008-01-01T23:59:59.000Z

179

Refinements and Tests of an Advanced Controller to Mitigate Fatigue Loads in the Controls Advanced Research Turbine: Preprint  

DOE Green Energy (OSTI)

Wind turbines are complex, nonlinear, dynamic systems forced by aerodynamic, gravitational, centrifugal, and gyroscopic loads. The aerodynamics of wind turbines are nonlinear, unsteady, and complex. Turbine rotors are subjected to a complicated 3-D turbulent wind inflow field, with imbedded coherent vortices that drive fatigue loads and reduce lifetime. Design of control algorithms for wind turbines must account for multiple control objectives. Future large multi-megawatt turbines must be designed with lighter weight structures, using active controls to mitigate fatigue loads, while maximizing energy capture. Active damping should be added to these dynamic structures to maintain stability for operation in a complex environment. At the National Renewable Energy Laboratory (NREL), we have designed, implemented, and tested advanced controls to maximize energy extraction and reduce structural dynamic loads. These control designs are based on linear models of the turbine that are generated by specialized modeling software. In this paper, we present field test results of an advanced control algorithm to mitigate blade, tower, and drivetrain loads in Region 3.

Wright, A.; Fleming, P.

2010-12-01T23:59:59.000Z

180

Identification of rotordynamic forces in a flexible rotor system using magnetic bearings  

E-Print Network (OSTI)

Methods are presented for parameter identification of an annular gas seal on a flexiblerotor test rig. Dynamic loads are applied by magnetic bearings (MBs) that support the rotor. MB forces are measured using fiber-optic strain gauges that are bonded to the poles of the MBs. In addition to force and position measurements, a finite element (FE) rotor model is required for the identification algorithms. The FE rotor model matches free-free characteristics of the test rotor. The addition of smooth air seals to the system introduces stiffness and damping terms for identification that are representative of reaction forces in turbomachines. Tests are performed to experimentally determine seal stiffness and damping coefficients for different running speeds and preswirl conditions. Stiffness and damping coefficients are determined using a frequency domain identification method. This method uses an iterative approach to minimize error between theoretical and experimental transfer functions. Several time domain approaches are also considered; however, these approaches do not produce valid identification results. Stiffness coefficients are measured using static test results and an MB current and position based model. Test results produce seal coefficients with low uncertainties for the frequency domain identification method. Static test uncertainties are an order of magnitude larger, and time domain attempts fail to produce sealIn addition to the primary identification research, an investigation of the relationships between MB force, strain, and magnetic field is conducted. The magnetic field of an MB is modeled using commercial FE software. The magnetic field model is used to predict strain measurements for quasi-static test conditions. The strain predictions are compared with experimental strain measurements. Strain predictions agree with experimental measurements, although strain is typically over-predicted. coefficient measurements.

Zutavern, Zachary Scott

2006-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


181

Steam Turbine Rotor Life Assessment: Volumes 1-5  

Science Conference Proceedings (OSTI)

To assess the integrity and residual life of an in-service steam turbine rotor, utilities need to know the rotor's current creep and/or fatigue damage. This series of reports presents procedures for non-destructively estimating this damage using hardness, replication, and X-ray based approaches.

1994-05-21T23:59:59.000Z

182

Intelligent acoustic rotor speed estimation for an autonomous helicopter  

Science Conference Proceedings (OSTI)

Acoustic sensing to gather information about a machine can be highly beneficial, but processing the data can be difficult. In this work, a variety of methodologies have been studied to extract rotor speed information from the sound signature of an autonomous ... Keywords: Acoustic sensing, Adaptive network-based fuzzy inference system, Artificial neural network, Feature selection, Genetic algorithm, Helicopter, Rotor speeds

Benjamin N. Passow; Mario A. Gongora; Adrian A. Hopgood; Sophy Smith

2012-11-01T23:59:59.000Z

183

Disc rotors with permanent magnets for brushless DC motor  

DOE Patents (OSTI)

A brushless dc permanent magnet motor drives an autonomous underwater vehe. In one embodiment, the motor comprises four substantially flat stators in stacked relationship, with pairs of the stators axially spaced, each of the stators comprising a tape-wound stator coil, and first and second substantially flat rotors disposed between the spaced pairs of stators. Each of the rotors includes an annular array of permanent magnets embedded therein. A first shaft is connected to the first rotor and a second, concentric shaft is connected to the second rotor, and a drive unit causes rotation of the two shafts in opposite directions. The second shaft comprises a hollow tube having a central bore in which the first shaft is disposed. Two different sets of bearings support the first and second shafts. In another embodiment, the motor comprises two ironless stators and pairs of rotors mounted on opposite sides of the stators and driven by counterrotating shafts.

Hawsey, Robert A. (Oak Ridge, TN); Bailey, J. Milton (Knoxville, TN)

1992-01-01T23:59:59.000Z

184

Local-to-global principles for rotor walk  

E-Print Network (OSTI)

In rotor walk on a finite directed graph, the exits from each vertex follow a prescribed periodic sequence. Here we consider the case of rotor walk where a particle starts from a designated source vertex and continues until it hits a designated target set, at which point the walk is restarted from the source. We show that the sequence of successively hit targets, which is easily seen to be eventually periodic, is in fact periodic. We show moreover that reversing the periodic patterns of all rotor sequences causes the periodic pattern of the hitting sequence to be reversed as well. The proofs involve a new notion of equivalence of rotor configurations, and an extension of rotor walk incorporating time-reversed particles.

Giacaglia, Giuliano Pezzolo; Propp, James; Zayas-Palmer, Linda

2011-01-01T23:59:59.000Z

185

Small-Scale Aeroelastic Rotor Simulation, Design and Fabrication  

E-Print Network (OSTI)

Efficient, small-scale fixed-pitch rotor blades are essential for miniature rotorcraft. Extremely thin blade sections are required for highly efficient rotor performance that leads to acceptable mission endurance. Such rotor blades are difficult to manufacture from sufficiently rigid material to avoid significant torsional deformation in operating conditions. In practice, it is necessary to trade-off manufacturing simplicity and mechanical rigidity of a blade design against aerodynamic performance. This paper presents a design methodology for this problem, based on development of a simulator for steady-state rotor performance along with a search algorithm to find the ideal taper and twist geometry for a specified motor torque. The approach is demonstrated on the design of rotors for a small scale quad-rotor unmanned aerial vehicle under development at the Australian National University. Experimental thrust tests indicate good correspondence with theoretical predications. Nomenclature A Rotor disc area, m2 AoA Angle of Attack, rad c Blade chord, m cd Non-dimensional drag coefficient cl Non-dimensional lift coefficient cm Non-dimensional moment coefficient

Paul Pounds; Robert Mahony

2005-01-01T23:59:59.000Z

186

User`s Guide for the NREL Teetering Rotor Analysis Program (STRAP)  

DOE Green Energy (OSTI)

The following report gives the reader an overview of instructions on the proper use of the National Renewable Energy Laboratory (formerly the Solar Energy Research Institute, or SERI) teetering Rotor Analysis Program (STRAP version 2.20). STRAP is a derivative of the Force and Loads Analysis program (FLAP). It is intended as a tool for prediction of rotor and blade loads and response for only two-bladed teetering hub wind turbines. The effects of delta-3, undersling, hub mass, and wind turbulence are accounted for. The objectives of the report are to give an overview of the code and also show the methods of data input and correct code execution steps in order to model an example two-bladed teetering hub turbine. A large portion of the discussion (Sections 6.0, 7.0, and 8.0) is devoted to the subject of inputting and running the code for wind turbulence effects. The ability to include turbulent wind effects is perhaps the biggest change in the code since the release of FLAP version 2.01 in 1988. This report is intended to be a user`s guide. It does not contain a theoretical discussion on equations of motion, assumptions, underlying theory, etc. It is intended to be used in conjunction with Wright, Buhl, and Thresher (1988).

Wright, A.D.

1992-08-01T23:59:59.000Z

187

User's Guide for the NREL Teetering Rotor Analysis Program (STRAP). [National Renewable Energy Laboratory (NREL)  

DOE Green Energy (OSTI)

The following report gives the reader an overview of instructions on the proper use of the National Renewable Energy Laboratory (formerly the Solar Energy Research Institute, or SERI) teetering Rotor Analysis Program (STRAP version 2.20). STRAP is a derivative of the Force and Loads Analysis program (FLAP). It is intended as a tool for prediction of rotor and blade loads and response for only two-bladed teetering hub wind turbines. The effects of delta-3, undersling, hub mass, and wind turbulence are accounted for. The objectives of the report are to give an overview of the code and also show the methods of data input and correct code execution steps in order to model an example two-bladed teetering hub turbine. A large portion of the discussion (Sections 6.0, 7.0, and 8.0) is devoted to the subject of inputting and running the code for wind turbulence effects. The ability to include turbulent wind effects is perhaps the biggest change in the code since the release of FLAP version 2.01 in 1988. This report is intended to be a user's guide. It does not contain a theoretical discussion on equations of motion, assumptions, underlying theory, etc. It is intended to be used in conjunction with Wright, Buhl, and Thresher (1988).

Wright, A.D.

1992-08-01T23:59:59.000Z

188

Control coil arrangement for a rotating machine rotor  

DOE Patents (OSTI)

A rotating machine (e.g., a turbine, motor or generator) is provided wherein a fixed solenoid or other coil configuration is disposed adjacent to one or both ends of the active portion of the machine rotor for producing an axially directed flux in the active portion so as to provide planar axial control at single or multiple locations for rotor balance, levitation, centering, torque and thrust action. Permanent magnets can be used to produce an axial bias magnetic field. The rotor can include magnetic disks disposed in opposed, facing relation to the coil configuration.

Shah, Manoj R. (Latham, NY); Lewandowsk, Chad R. (Amsterdam, NY)

2001-07-31T23:59:59.000Z

189

Control Coil Arrangement for a Rotating Machine Rotor  

DOE Patents (OSTI)

A rotating machine (e.g., a turbine, motor or generator) is provided wherein a fixed solenoid or other coil configuration is disposed adjacent to one or both ends of the active portion of the machine rotor for producing an axially directed flux in the active portion so as to provide planar axial control at single or multiple locations for rotor balance, levitation, centering, torque and thrust action. Permanent magnets can be used to produce an axial bias magnetic field. The rotor can include magnetic disks disposed in opposed, facing relation to the coil configuration.

Shah, Manoj R.; Lewandowski, Chad R.

1999-05-05T23:59:59.000Z

190

An experimental study on improvement of a Savonius rotor performance with curtaining  

Science Conference Proceedings (OSTI)

This study introduces a new curtaining arrangement to improve the performance of Savonius wind rotors. The curtain arrangement was placed in front of the rotor preventing the negative torque opposite the rotor rotation. The geometrical parameters of the curtain arrangement were optimized to generate an optimum performance. The rotor with different curtain arrangements was tested out of a wind tunnel, and its performance was compared with that of the conventional rotor. The maximum power coefficient of the Savonius wind rotor is increased to about 38.5% with the optimum curtain arrangement. The experimental results showed that the performance of Savonius wind rotors could be improved with a suitable curtain arrangement. (author)

Altan, Burcin Deda; Atilgan, Mehmet [Department of Mechanical Engineering, Faculty of Engineering, Pamukkale University, Kinikli 20070 Denizli (Turkey); Oezdamar, Aydogan [Department of Mechanical Engineering, Faculty of Engineering, Ege University, Bornova, 35100 Izmir (Turkey)

2008-09-15T23:59:59.000Z

191

Load Control  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Visualization and Controls Peer Review Visualization and Controls Peer Review Load Control for System Reliability and Measurement-Based Stability Assessment Dan Trudnowski, PhD, PE Montana Tech Butte, MT 59701 dtrudnowski@mtech.edu 406-496-4681 October 2006 2 Presentation Outline * Introduction - Goals, Enabling technologies, Overview * Load Control - Activities, Status * Stability Assessment - Activities, Status * Wrap up - Related activities, Staff 3 Goals * Research and develop technologies to improve T&D reliability * Technologies - Real-time load control methodologies - Measurement-based stability-assessment 4 Enabling Technologies * Load control enabled by GridWise technology (e.g. PNNL's GridFriendly appliance) * Real-time stability assessment enabled by Phasor Measurement (PMU) technology 5 Project Overview * Time line: April 18, 2006 thru April 17, 2008

192

Tilt Rotor Aeromechanics Phenomena in Low Speed Flight  

Science Conference Proceedings (OSTI)

This work investigates important aeromechanics phenomena affecting the V-22 tilt rotor in low speed sideward flight or while hovering in quartering or crosswind conditions. These phenomena, such as pitch-up with sideslip and increased power required ...

Mark A. Potsdam; Mark J. Silva

2004-06-01T23:59:59.000Z

193

The Dynamics of Mountain-Wave-Induced Rotors  

Science Conference Proceedings (OSTI)

The development of rotor flow associated with mountain lee waves is investigated through a series of high-resolution simulations with the nonhydrostatic Coupled Ocean–Atmospheric Mesoscale Prediction System (COAMPS) model using free-slip and no-...

James D. Doyle; Dale R. Durran

2002-01-01T23:59:59.000Z

194

Chip-Firing and Rotor-Routing on Directed Graphs  

E-Print Network (OSTI)

We give a rigorous and self-contained survey of the abelian sandpile model and rotor-router model on finite directed graphs, highlighting the connections between them. We present several intriguing open problems.

Holroyd, Alexander E; Meszaros, Karola; Peres, Yuval; Propp, James; Wilson, David B

2008-01-01T23:59:59.000Z

195

Buildings Stock Load Control  

E-Print Network (OSTI)

Researchers and practitioners have proposed a variety of solutions to reduce electricity consumption and curtail peak demand. This research focuses on electricity demand control by applying some strategies in existing building to reduce it during the extreme climate period. The first part of this paper presents the objectives of the study: ? to restrict the startup polluting manufacturing units (power station), ? to limit the environmental impacts (greenhouse emission), ? to reduce the transport and distribution electricity infrastructures The second part presents the approach used to rise the objectives : ? To aggregat the individual loads and to analyze the impact of different strategies from load shedding to reduce peak power demand by: ? Developing models of tertiary buildings stocks (Schools, offices, Shops, hotels); ? Making simulations for different load shedding strategies to calculate potential peak power saving. The third part is dedicated to the description of the developed models: An assembly of the various blocks of the library of simbad and simulink permit to model building. Finally the last part prensents the study results: Graphs and tables to see the load shedding strategies impacts.

Joutey, H. A.; Vaezi-Nejad, H.; Clemoncon, B.; Rosenstein, F.

2006-01-01T23:59:59.000Z

196

Gas Turbine Rotor Life Evaluation: GE 7E/EA  

Science Conference Proceedings (OSTI)

Gas turbine rotor materials are subject to degradation from prolonged hours and multiple start/stop cycles of operation. Periodically, plant operators disassemble the compressor and turbine sections of the rotor system and inspect the components for signs of creep, embrittlement, corrosion, thermal fatigue, and high- and low-cycle fatigue. These inspections typically take place during hot-gas-path and major maintenance intervals when casings are removed. This report provides results of an analysis to est...

2011-10-26T23:59:59.000Z

197

On the Spectrum of the Resonant Quantum Kicked Rotor  

E-Print Network (OSTI)

It is proven that none of the bands in the quasi-energy spectrum of the Quantum Kicked Rotor is flat at any primitive resonance of any order. Perturbative estimates of bandwidths at small kick strength are established for the case of primitive resonances of prime order. Different bands scale with different powers of the kick strength, due to degeneracies in the spectrum of the free rotor.

Italo Guarneri

2009-02-23T23:59:59.000Z

198

On the Spectrum of the Resonant Quantum Kicked Rotor  

E-Print Network (OSTI)

It is proven that none of the bands in the quasi-energy spectrum of the Quantum Kicked Rotor is flat at any primitive resonance of any order. Perturbative estimates of bandwidths at small kick strength are established for the case of primitive resonances of prime order. Different bands scale with different powers of the kick strength, due to degeneracies in the spectrum of the free rotor.

Guarneri, Italo

2009-01-01T23:59:59.000Z

199

Sub-ballistic behaviour of the Quantum Kicked Rotor  

E-Print Network (OSTI)

We study the resonances of the quantum kicked rotor subjected to an excitation that follows an aperiodic Fibonacci prescription. In such a case the secondary resonances show a sub-ballistic behaviour like the quantum walk with the same aperiodic prescription for the coin. The principal resonances maintain the well-known ballistic behaviour. Then the parallelism previusly established between the kicked rotor and the generalized quantum walk is retained only with the secondary resonances.

A. Romanelli; A. Auyuanet; R. Siri; V. Micenmacher

2006-07-20T23:59:59.000Z

200

The Rotor-Router Model on Regular Trees  

E-Print Network (OSTI)

The rotor-router model is a deterministic analogue of random walk. It can be used to define a deterministic growth model analogous to internal DLA. We show that if the initial rotor configuration is acyclic, then the set of occupied sites for rotor-router aggregation on an infinite regular tree is a perfect ball whenever it can be. This is proved by defining the rotor-router group of a graph, which we show is isomorphic to the sandpile group. We also address the question of recurrence and transience: We give two rotor configurations on the infinite ternary tree, one for which chips exactly alternate escaping to infinity with returning to the origin, and one for which every chip returns to the origin. We also characterize the possible "escape sequences" for the ternary tree, that is, binary words $a_1 ... a_n$ for which there exists a rotor configuration so that the $k$-th chip escapes to infinity if and only if $a_k=1$.

Landau, Itamar

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

The Rotor-Router Model on Regular Trees  

E-Print Network (OSTI)

The rotor-router model is a deterministic analogue of random walk. It can be used to define a deterministic growth model analogous to internal DLA. We show that the set of occupied sites for this model on an infinite regular tree is a perfect ball whenever it can be, provided the initial rotor configuration is acyclic (that is, no two neighboring vertices have rotors pointing to one another). This is proved by defining the rotor-router group of a graph, which we show is isomorphic to the sandpile group. We also address the question of recurrence and transience: We give two rotor configurations on the infinite ternary tree, one for which chips exactly alternate escaping to infinity with returning to the origin, and one for which every chip returns to the origin. Further, we characterize the possible “escape sequences ” for the ternary tree, that is, binary words a1... an for which there exists a rotor configuration so that the k-th chip escapes to infinity if and only if ak = 1. 1

Itamar L; Lionel Levine

2008-01-01T23:59:59.000Z

202

The Rotor-Router Model on Regular Trees  

E-Print Network (OSTI)

The rotor-router model is a deterministic analogue of random walk. It can be used to define a deterministic growth model analogous to internal DLA. We show that the set of occupied sites for this model on an infinite regular tree is a perfect ball whenever it can be, provided the initial rotor configuration is acyclic (that is, no two neighboring vertices have rotors pointing to one another). This is proved by defining the rotor-router group of a graph, which we show is isomorphic to the sandpile group. We also address the question of recurrence and transience: We give two rotor configurations on the infinite ternary tree, one for which chips exactly alternate escaping to infinity with returning to the origin, and one for which every chip returns to the origin. Further, we characterize the possible “escape sequences ” for the ternary tree, that is, binary words a1... an for which there exists a rotor configuration so that the k-th chip escapes to infinity if and only if ak = 1.

Itamar Landau; Lionel Levine

2008-01-01T23:59:59.000Z

203

LOADING DEVICE  

DOE Patents (OSTI)

A device is presented for loading or charging bodies of fissionable material into a reactor. This device consists of a car, mounted on tracks, into which the fissionable materials may be placed at a remote area, transported to the reactor, and inserted without danger to the operating personnel. The car has mounted on it a heavily shielded magazine for holding a number of the radioactive bodies. The magazine is of a U-shaped configuration and is inclined to the horizontal plane, with a cap covering the elevated open end, and a remotely operated plunger at the lower, closed end. After the fissionable bodies are loaded in the magazine and transported to the reactor, the plunger inserts the body at the lower end of the magazine into the reactor, then is withdrawn, thereby allowing gravity to roll the remaining bodies into position for successive loading in a similar manner.

Ohlinger, L.A.

1958-10-01T23:59:59.000Z

204

On-line load relief control  

SciTech Connect

This paper describes the results of an investigation concerning the on-line prediction and enhancement of load relief. The effects of voltage fluctuation, system voltage profile control and generator voltage adjustment on load relief and load shedding operations during under-frequency transients are studied. The technique promoted in the paper may be used to reduce system spinning reserve or prospective load shedding.

Jovanovic, S.; Fox, B.; Thompson, J.G. (Queen' s Univ. of Belfast (United Kingdom))

1994-11-01T23:59:59.000Z

205

Wind load reduction for heliostats  

DOE Green Energy (OSTI)

This report presents the results of wind-tunnel tests supported through the Solar Energy Research Institute (SERI) by the Office of Solar Thermal Technology of the US Department of Energy as part of the SERI research effort on innovative concentrators. As gravity loads on drive mechanisms are reduced through stretched-membrane technology, the wind-load contribution of the required drive capacity increases in percentage. Reduction of wind loads can provide economy in support structure and heliostat drive. Wind-tunnel tests have been directed at finding methods to reduce wind loads on heliostats. The tests investigated primarily the mean forces, moments, and the possibility of measuring fluctuating forces in anticipation of reducing those forces. A significant increase in ability to predict heliostat wind loads and their reduction within a heliostat field was achieved.

Peterka, J.A.; Hosoya, N.; Bienkiewicz, B.; Cermak, J.E.

1986-05-01T23:59:59.000Z

206

Building load control and optimization  

E-Print Network (OSTI)

Researchers and practitioners have proposed a variety of solutions to reduce electricity consumption and curtail peak demand. This research focuses on load control by improving the operations in existing building HVAC ...

Xing, Hai-Yun Helen, 1976-

2004-01-01T23:59:59.000Z

207

Measurement in a wind tunnel of the modification of mean wind and turbulence characteristics due to induction effects near wind turbine rotors  

DOE Green Energy (OSTI)

It is the purpose of this report to provide experimental data on the wind field surrounding a single model wind turbine rotor disk. These data should provide an improved physical insight into the induction effects of the air flow as it approaches the wind turbine. This insight should in turn improve an analytical model's predictive capabilities. A scaled model of a horizontal-axis wind turbine (a two-bladed rotor of diameter 53 cm) was placed into the Meteorological Wind Tunnel (MWT) facility at Colorado State University (cross-section width of 183 cm). Four different approach flow conditions were studied: low and moderate turbulence levels (0.1% and 1.5% intensity) at both 6 and 7.6 m/s freestream air velocities. For each of these flow conditions the rotor power coefficient versus tip speed ratio was obtained, and the 3-dimensional velocity field from 3 rotor diameters upwind to 0.5 diameter downwind was tabulated. The power output of the rotor was obtained via a simple prony brake friction device that imparts a torque (measured by the deflection of a spring) to the spinning shaft of the wind turbine. The rotor speed, measured by a strobe light, was observed to vary with load from 900 rpm up to 2100 rpm for the flow conditions described above. The 3-dimensional velocity field was measured via a three-hot-film probe. Details of the measurement techniques are provided. The test program and data results are also given. A short discussion of the implications of this data set is included. 12 refs., 19 figs., 11 tabs.

Neff, D.E.; Meroney, R.N.

1987-08-01T23:59:59.000Z

208

LIDAR Wind Speed Measurement Analysis and Feed-Forward Blade Pitch Control for Load Mitigation in Wind Turbines: January 2010--January 2011  

SciTech Connect

This report examines the accuracy of measurements that rely on Doppler LIDAR systems to determine their applicability to wind turbine feed-forward control systems and discusses feed-forward control system designs that use preview wind measurements. Light Detection and Ranging (LIDAR) systems are able to measure the speed of incoming wind before it interacts with a wind turbine rotor. These preview wind measurements can be used in feed-forward control systems designed to reduce turbine loads. However, the degree to which such preview-based control techniques can reduce loads by reacting to turbulence depends on how accurately the incoming wind field can be measured. The first half of this report examines the accuracy of different measurement scenarios that rely on coherent continuous-wave or pulsed Doppler LIDAR systems to determine their applicability to feed-forward control. In particular, the impacts of measurement range and angular offset from the wind direction are studied for various wind conditions. A realistic case involving a scanning LIDAR unit mounted in the spinner of a wind turbine is studied in depth with emphasis on choices for scan radius and preview distance. The effects of turbulence parameters on measurement accuracy are studied as well. Continuous-wave and pulsed LIDAR models based on typical commercially available units were used in the studies present in this report. The second half of this report discusses feed-forward control system designs that use preview wind measurements. Combined feedback/feed-forward blade pitch control is compared to industry standard feedback control when simulated in realistic turbulent above-rated winds. The feed-forward controllers are designed to reduce fatigue loads, increasing turbine lifetime and therefore reducing the cost of energy. Three feed-forward designs are studied: non-causal series expansion, Preview Control, and optimized FIR filter. The input to the feed-forward controller is a measurement of incoming wind speeds that could be provided by LIDAR. Non-causal series expansion and Preview Control methods reduce blade root loads but increase tower bending in simulation results. The optimized FIR filter reduces loads overall, keeps pitch rates low, and maintains rotor speed regulation and power capture, while using imperfect wind measurements provided by the spinning continuous-wave LIDAR model.

Dunne, F.; Simley, E.; Pao, L.Y.

2011-10-01T23:59:59.000Z

209

Rotor apparatus for high strength undiffused brushless electric machine  

DOE Patents (OSTI)

A radial gap brushless electric machine (30) having a stator (31) and a rotor (32) and a main air gap (34) also has at least one stationary excitation coil (35a, 36a) separated from the rotor (32) by a secondary air gap (35e, 35f, 36e, 36f) so as to induce a secondary flux in the rotor (32) which controls a resultant flux in the main air gap (34). Permanent magnetic (PM) material (38) is disposed in spaces between the rotor pole portions (39) to inhibit the second flux from leaking from the pole portions (39) prior to reaching the main air gap (34). By selecting the direction of current in the stationary excitation coil (35a, 36a) both flux enhancement and flux weakening are provided for the main air gap (34). Improvements of a laminated rotor, an end pole structure, and an arrangement of the PM elements for providing an arrangement of the flux paths from the auxiliary field coil assemblies are also disclosed.

Hsu, John S [Oak Ridge, TN

2006-01-24T23:59:59.000Z

210

Method and apparatus for assembling permanent magnet rotors  

DOE Patents (OSTI)

A permanent magnet assembly for assembly in large permanent magnet motors and generators includes a two-piece carrier that can be slid into a slot in the rotor and then secured in place using a set screw. The invention also provides an auxiliary carrier device with guide rails that line up with the teeth of the rotor, so that a permanent magnet assembly can be pushed first into a slot, and then down the slot to its proper location. An auxiliary tool is provided to move the permanent magnet assembly into position in the slot before it is secured in place. Methods of assembling and disassembling the magnet assemblies in the rotor are also disclosed. 2 figs.

Hsu, J.S.; Adams, D.J.

1999-06-22T23:59:59.000Z

211

Operating Modes of a Teeter-Rotor Wind Turbine  

DOE Green Energy (OSTI)

We examine the operating modes of a two-bladed teetered wind turbine. Because of the gyroscopic asymmetry of its rotor, this turbine's dynamics can be quite distinct from those of a turbine with three or more blades. This asymmetry leads to system equations with periodic coefficients that are solved using the Floquet approach to extract the correct modal parameters. The system equations are derived using a simple analytical model with four degrees of freedom: cacelle yaw, rotor teeter, and flapping associated with each blade. Results confirm that the turbine modes become more dominated by the centrifugal and gyroscopic effects as the rotor speed increases. They gyroscopic effect may also cause dynamic instability. Under certain design conditions, yaw and teeter modal frequencies may coalesce.

Bir, G. S. (National Renewable Energy Laboratory); Stol, K. (University of Colorado at Boulder)

1999-02-25T23:59:59.000Z

212

Rotating Shake Test and Modal Analysis of a Model Helicopter Rotor Blade  

Science Conference Proceedings (OSTI)

Rotating blade frequencies for a model generic helicopter rotor blade mounted on an articulated hub were experimentally determined. Testing was conducted using the Aeroelastic Rotor Experimental System (ARES) testbed in the Helicopter Hover Facility ...

Wilkie W. Keats; Mirick Paul H.; Langston Chester W.

1997-06-01T23:59:59.000Z

213

Rotor Speed Dependent Yaw Control of Wind Turbines Based on Empirical Data  

Science Conference Proceedings (OSTI)

When extracting energy from the wind using horizontal-axis upwind wind turbines, a primary condition for maximum power yield is the ability to align the rotor axis with the dominating wind direction. Attempts have been made to improve yaw alignment by applying advanced measurement techniques such as LIDARs. This study is focused at assessing the current performance of an operating turbine and exploring how the yaw alignment can be improved using existing measurements. By analyzing available turbine and met mast data a correction scheme for the original yaw alignment system is synthesized. The correction scheme is applied and it is seen that with the correction scheme in place, the power yield below rated is raised 1-5 percent. Furthermore, results indicate that blade load variations are decreased when the correction scheme is applied. The results are associated with uncertainties due to the amount of available data and the wind site climate. Further work should be focused at gathering more experimental data.

Kragh, K. A.; Fleming, P. A.

2012-01-01T23:59:59.000Z

214

Load Management: Opportunity or Calamity?  

E-Print Network (OSTI)

After the change in the economics of generating electricity which took place in 1973, many utilities are examining options to hold down their costs. One fact which is clear is that the difference between peak and off peak generating costs is much larger now than prior to 1973. Utilities are examining two options which can be termed load management. One option is to control discretionary loads during peak periods. Cycling of residential water heaters or shutting off industrial electric furnaces during peak periods are both examples of load control which lower the costs borne by the utility. The other option is the use of seasonal surcharges or time-of-day rates to induce customers to alter their usage patterns. Both these load management options focus on reducing utility costs overall without regard to the cost to the consumers affected by the load management options. The issue, then, is whether industrial customers can find opportunities to lower their costs under load management.

Males, R.; Hassig, N.

1981-01-01T23:59:59.000Z

215

Rotor-router aggregation on the layered square lattice  

E-Print Network (OSTI)

In rotor-router aggregation on the square lattice Z^2, particles starting at the origin perform deterministic analogues of random walks until reaching an unoccupied site. The limiting shape of the cluster of occupied sites is a disk. We consider a small change to the routing mechanism for sites on the x- and y-axes, resulting in a limiting shape which is a diamond instead of a disk. We show that for a certain choice of initial rotors, the occupied cluster grows as a perfect diamond.

Kager, Wouter

2010-01-01T23:59:59.000Z

216

Quantum phase transitions in the quasi-periodic kicked rotor  

E-Print Network (OSTI)

We present a microscopic theory of transport in quasi-periodically driven environments (`kicked rotors'), as realized in recent atom optic experiments. We find that the behavior of these systems depends sensitively on the value of Planck's constant $\\tilde h$: for irrational values of $\\tilde h/(4\\pi)$ they fall into the universality class of disordered electronic systems and we derive the microscopic theory of the ensuing localization phenomena. In contrast, for rational values the rotor-Anderson insulator acquires an infinite (static) conductivity and turns into a `super-metal'. Signatures of the corresponding metal/super-metal transition are discussed.

Chushun Tian; Alexander Altland; Markus Garst

2011-01-17T23:59:59.000Z

217

An efficient algorithm for blade loss simulations applied to a high-order rotor dynamics problem  

E-Print Network (OSTI)

In this thesis, a novel approach is presented for blade loss simulation of an aircraft gas turbine rotor mounted on rolling element bearings with squeeze film dampers, seal rub and enclosed in a flexible housing. The modal truncation augmentation (MTA) method provides an efficient tool for modeling this large order system with localized nonlinearities in the ball bearings. The gas turbine engine, which is composed of the power turbine and gas generator rotors, is modeled with 38 lumped masses. A nonlinear angular contact bearing model is employed, which has ball and race degrees of freedom and uses a modified Hertzian contact force between the races and balls and for the seal rub. This combines a dry contact force and viscous damping force. A flexible housing with seal rub is also included whose modal description is imported from ANSYS. Prediction of the maximum contact load and the corresponding stress on an elliptical contact area between the races and balls is made during the blade loss simulations. A finite-element based squeeze film damper (SFD), which determines the pressure profile of the oil film and calculates damper forces for any type of whirl orbit is utilized in the simulation. The new approach is shown to provide efficient and accurate predictions of whirl amplitudes, maximum contact load and stress in the bearings, transmissibility, thermal growths, maximum and minimum damper pressures and the amount of unbalanced force for incipient oil film cavitation. It requires about 4 times less computational time than the traditional approaches and has an error of less than 5 %.

Parthasarathy, Nikhil Kaushik

2003-12-01T23:59:59.000Z

218

WindPACT Turbine Rotor Design, Specific Rating Study; Period of Performance: June 29, 2000--March 1, 2003  

DOE Green Energy (OSTI)

In 2000, the National Renewable Energy Laboratory (NREL) launched the Wind Partnerships for Advanced Component Technologies (WindPACT) program to examine ways in which the cost of wind energy could be reduced a further 30%. One element of the WindPACT program has been a series of design studies aimed at each of the major subsystems of the wind turbine to study the effect of scale and of alternative design approaches. The WindPACT Turbine Rotor Design Study was carried out by Global Energy Concepts, LLC, (GEC) on behalf of NREL, and the final report was delivered in June 2002. The study examined what configuration and design changes in the rotor would reduce the overall cost of energy. The objectives of this report are to use the 1.5-MW baseline configuration from the earlier WindPACT Rotor Design Study to examine the effect of different power ratings and to identify an optimum specific rating; to examine the effect of different maximum tip speeds on overall cost of energy (COE); to examine the role of different wind regimes on the optimum specific rating; and to examine how the optimum specific rating may be affected by introducing more advanced blade designs.

Malcolm, D. J.; Hansen, A. C.

2003-11-01T23:59:59.000Z

219

Unsteady rotor-stator interaction in a low pressure centrifugal compressor  

Science Conference Proceedings (OSTI)

The aim of this paper is to study the unsteady rotor-stator interaction in a low-pressure centrifugal compressor using the finite volume method to solve the Unsteady Reynolds-Averaged Navier-Stokes. In order to understand better, the rotor-stator interaction, ... Keywords: Adamczyk decomposition, CFD, POD, URANS, compressor, unsteady rotor-stator interaction

Mihai Leonida Niculescu; Sterian D?n?il?

2010-04-01T23:59:59.000Z

220

A permanent-magnet rotor for a high-temperature superconducting bearing  

DOE Green Energy (OSTI)

Design, fabrication, and performance, of a 1/3-m dia., 10-kg flywheel rotor with only one bearing is discussed. To achieve low-loss energy storage, the rotor`s segmented-ring permanent-magnet (PM) is optimized for levitation and circumferential homogeneity. The magnet`s carbon composite bands enable practical energy storage.

Mulcahy, T.M.; Hull, J.R.; Uherka, K.L. [Argonne National Lab., IL (United States); Abboud, R.G. [Commonwealth Research Corp., Chicago, IL (United States); Wise, J.H.; Carnegie, D.W. [Pennsylvania State Univ., University Park, PA (United States). Engineering Science

1995-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Modeling and linear function parametric identification for a helicopter main rotor  

Science Conference Proceedings (OSTI)

A model of a helicopter test rotor obtained according to the Euler-Lagrange approach is presented. A simplified linear representation for this model, suitable for control system design, is also proposed. The dynamics of the helicopter test rotor are ... Keywords: helicopter rotors, identification, modeling

José M. Molinar-Monterrubio; Rafael Castro-Linares; Eduardo Licéaga-Castro

2007-05-01T23:59:59.000Z

222

To Design, Build and Test a Wireless Measurement System for Machine Rotor  

Science Conference Proceedings (OSTI)

A wireless measurement system was designed to detect the rotor current of an induction machine. The reason of using wireless technique instead of wire is that it is difficult to connect measured components with wire directly from the rotor which is running ... Keywords: wireless measurement system, machine rotor

Jieyin Zhang; Minxia Zhang

2009-03-01T23:59:59.000Z

223

WREF 2012: THE PAST AND FUTURE COST OF WIND ENERGY  

E-Print Network (OSTI)

A.C. (2006). WindPACT Turbine Rotor Design Study. NREL/SR-growth of turbine nameplate capacity, hub height, and rotorLarger  rotors  with  reduced  turbine  loads  allowed  

Wiser, Ryan

2013-01-01T23:59:59.000Z

224

Reflred - Reduce  

Science Conference Proceedings (OSTI)

... by the monitor count when the data is loaded. ... by which you need to scale the reflectivity curve. ... the Qz values of the specular or background curves. ...

225

A comparison of measured wind park load histories with the WISPER and WISPERX load spectra  

DOE Green Energy (OSTI)

The blade-loading histories from two adjacent Micon 65/13 wind turbines are compared with the variable-amplitude test-loading histories known as the WISPER and WISPERX spectra. These standardized loading sequences were developed from blade flapwise load histories taken from nine different horizontal-axis wind turbines operating under a wide range of conditions in Europe. The subject turbines covered a broad spectrum of rotor diameters, materials, and operating environments. The final loading sequences were developed as a joint effort of thirteen different European organizations. The goal was to develop a meaningful loading standard for horizontal-axis wind turbine blades that represents common interaction effects seen in service. In 1990, NREL made extensive load measurements on two adjacent Micon 65/13 wind turbines in simultaneous operation in the very turbulent environment of a large wind park. Further, before and during the collection of the loads data, comprehensive measurements of the statistics of the turbulent environment were obtained at both the turbines under test and at two other locations within the park. The trend to larger but lighter wind turbine structures has made an understanding of the expected lifetime loading history of paramount importance. Experience in the US has shown that the turbulence-induced loads associated with multi-row wind parks in general are much more severe than for turbines operating individually or within widely spaced environments. Multi-row wind parks are much more common in the US than in Europe. In this paper we report on our results in applying the methodology utilized to develop the WISPER and WISPERX standardized loading sequences using the available data from the Micon turbines. While the intended purpose of the WISPER sequences were not to represent a specific operating environment, we believe the exercise is useful, especially when a turbine design is likely to be installed in a multi-row wind park.

Kelley, N.D.

1995-01-01T23:59:59.000Z

226

Cirriform Rotor Cloud Observed on a Canadian Arctic Ice Cap  

Science Conference Proceedings (OSTI)

A thin rotor cloud was observed on the lee side of Penny Ice Cap in the Canadian Arctic on 21 April 1996. The cloud consisted of thin cirriform layers, so that its motion was clearly observed. By means of time-lapse camera photography, the ...

Hisashi Ozawa; Kumiko Goto-Azuma; Koyuru Iwanami; Roy M. Koerner

1998-06-01T23:59:59.000Z

227

Early Observations of Rotor Clouds by Andrija Mohorovi?i?  

Science Conference Proceedings (OSTI)

This article delivers a short history of the early quantitative documentation of a rotor-type circulation in the bora-type flow on the northern Adriatic by Andrija Mohorovi?i?, an all-around geophysicist and the father of Croatian geophysical ...

Vanda Grubiši?; Mirko Orli?

2007-05-01T23:59:59.000Z

228

Counter Rotating Open Rotor Animation using Particle Image Velocimetry  

E-Print Network (OSTI)

This article describes the two accompanying fluid dynamics videos for the "Counter rotating open rotor flow field investigation using stereoscopic Particle Image Velocimetry" presented at the 64th Annual Meeting of the APS Division of Fluid Dynamics in Baltimore, Maryland, November 20-22, 2011.

Roosenboom, E W M; Geisler, R; Pallek, D; Agocs, J; Neitzke, K -P

2011-01-01T23:59:59.000Z

229

Helical-rotor expander applications for geothermal energy conversion  

DOE Green Energy (OSTI)

The helical-rotor expander is one of numerous candidates for the direct ''total flow'' expansion of geothermal fluids. The potential exists for expansion efficiencies as high as 70 percent. Engine efficiencies will generally be below 70 percent because of an expansion-ratio limitation of 15 and a maximum pressure differential of 110 psi. Single-stage expansion of self-pumped geothermal fluids from reservoirs at 350 to 752/sup 0/F gives engine efficiencies in the range from 57.3 to 43.1 percent. Calculated rotor diameters range from 10.5 to 41.6 ft for a range of outputs of 5 to 40 MW. Two-stage expansion of fluid from the 572/sup 0/F reservoir gives an engine efficiency of 62.3 percent and a 21 percent reduction in the diameter of the larger rotor. Rotor diameters can be held to more reasonable sizes by using the expander in combination with a vapor turbine.

House, P.A.

1976-04-01T23:59:59.000Z

230

Coplanar Doppler Lidar Retrieval of Rotors from T-REX  

Science Conference Proceedings (OSTI)

Dual-Doppler analysis of data from two coherent lidars during the Terrain-Induced Rotor Experiment (T-REX) allows the retrieval of flow structures, such as vortices, during mountain-wave events. The spatial and temporal resolution of this ...

Michael Hill; Ron Calhoun; H. J. S. Fernando; Andreas Wieser; Andreas Dörnbrack; Martin Weissmann; Georg Mayr; Robert Newsom

2010-03-01T23:59:59.000Z

231

Deutsche Rotor und Turm Service GmbH Co KG DRTS | Open Energy Information  

Open Energy Info (EERE)

Rotor und Turm Service GmbH Co KG DRTS Rotor und Turm Service GmbH Co KG DRTS Jump to: navigation, search Name Deutsche Rotor und Turm Service GmbH & Co KG (DRTS) Place Bremen, Germany Zip 28239 Sector Wind energy Product Service company for wind turbine blades and towers. References Deutsche Rotor und Turm Service GmbH & Co KG (DRTS)[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Deutsche Rotor und Turm Service GmbH & Co KG (DRTS) is a company located in Bremen, Germany . References ↑ "Deutsche Rotor und Turm Service GmbH & Co KG (DRTS)" Retrieved from "http://en.openei.org/w/index.php?title=Deutsche_Rotor_und_Turm_Service_GmbH_Co_KG_DRTS&oldid=344202" Categories:

232

Steam Turbine Rotor Life Assessment and Extension: Evaluation of Retired Rotors: Volume 1: Quantification of NDE Uncertainty  

Science Conference Proceedings (OSTI)

In the past, uncertainty in defect sizing during boresonic inspection has been a major source of inaccuracy in assessing the remaining life of steam turbine rotors. This report provides correlations between the boresonically reported defect sizes and the measured metallurgical sizes for

1994-05-14T23:59:59.000Z

233

Plug Load Behavioral Change Demonstration Project  

SciTech Connect

This report documents the methods and results of a plug load study of the Environmental Protection Agency's Region 8 Headquarters in Denver, Colorado, conducted by the National Renewable Energy Laboratory. The study quantified the effect of mechanical and behavioral change approaches on plug load energy reduction and identified effective ways to reduce plug load energy. Load reduction approaches included automated energy management systems and behavioral change strategies.

Metzger, I.; Kandt, A.; VanGeet, O.

2011-08-01T23:59:59.000Z

234

Structural health and prognostics management for offshore wind turbines : case studies of rotor fault and blade damage with initial O&M cost modeling.  

SciTech Connect

Operations and maintenance costs for offshore wind plants are significantly higher than the current costs for land-based (onshore) wind plants. One way to reduce these costs would be to implement a structural health and prognostic management (SHPM) system as part of a condition based maintenance paradigm with smart load management and utilize a state-based cost model to assess the economics associated with use of the SHPM system. To facilitate the development of such a system a multi-scale modeling approach developed in prior work is used to identify how the underlying physics of the system are affected by the presence of damage and faults, and how these changes manifest themselves in the operational response of a full turbine. This methodology was used to investigate two case studies: (1) the effects of rotor imbalance due to pitch error (aerodynamic imbalance) and mass imbalance and (2) disbond of the shear web; both on a 5-MW offshore wind turbine in the present report. Based on simulations of damage in the turbine model, the operational measurements that demonstrated the highest sensitivity to the damage/faults were the blade tip accelerations and local pitching moments for both imbalance and shear web disbond. The initial cost model provided a great deal of insight into the estimated savings in operations and maintenance costs due to the implementation of an effective SHPM system. The integration of the health monitoring information and O&M cost versus damage/fault severity information provides the initial steps to identify processes to reduce operations and maintenance costs for an offshore wind farm while increasing turbine availability, revenue, and overall profit.

Myrent, Noah J. [Purdue Center for Systems Integrity, Lafayette, IN; Kusnick, Joshua F. [Purdue Center for Systems Integrity, Lafayette, IN; Barrett, Natalie C. [Purdue Center for Systems Integrity, Lafayette, IN; Adams, Douglas E. [Purdue Center for Systems Integrity, Lafayette, IN; Griffith, Daniel Todd

2013-04-01T23:59:59.000Z

235

Flywheel rotor and containment technology development, FY83  

DOE Green Energy (OSTI)

The Department of Energy decided to terminate the Flywheel Rotor and Containment Technology Development project during FY 1983. Activities this year included fabrication, inspection, and test evaluation of rotor and containment structures. A peak energy of 700 Wh was stored at an energy density of 70 Wh/kg. In cyclic tests, 10,000 cycles from design speed to half speed were logged without failure. The first test of a lightweight containment structure indicates the need for additional development. In complementary studies, production cost estimates were made for three flywheel designs. In a cooperative program with the University of Wisconsin, work began on construction of a flywheel/continuously variable transmission/heat engine car which promises fuel economy improvements of up to 100%. Suggestions are made for the direction of future work when interest in flywheel system reappears.

Mohr, P.B.; Walter, C.E.

1983-09-12T23:59:59.000Z

236

Aeroacoustics and aerodynamic performance of a rotor with flatback airfoils.  

Science Conference Proceedings (OSTI)

The aerodynamic performance and aeroacoustic noise sources of a rotor employing flatback airfoils have been studied in field test campaign and companion modeling effort. The field test measurements of a sub-scale rotor employing nine meter blades include both performance measurements and acoustic measurements. The acoustic measurements are obtained using a 45 microphone beamforming array, enabling identification of both noise source amplitude and position. Semi-empirical models of flatback airfoil blunt trailing edge noise are developed and calibrated using available aeroacoustic wind tunnel test data. The model results and measurements indicate that flatback airfoil noise is less than drive train noise for the current test turbine. It is also demonstrated that the commonly used Brooks, Pope, and Marcolini model for blunt trailing edge noise may be over-conservative in predicting flatback airfoil noise for wind turbine applications.

Paquette, Joshua A.; Barone, Matthew Franklin; Christiansen, Monica (Pennsylvania State University, State College, PA); Simley, Eric (University of Colorado, Boulder, CO)

2010-06-01T23:59:59.000Z

237

New forms of BRST symmetry in rigid rotor  

E-Print Network (OSTI)

We derive the different forms of BRST symmetry by using the Batalin-Fradkin-Vilkovisky formalism in a rigid rotor. The so called "dual-BRST" symmetry is obtained from usual BRST symmetry by making a canonical transformation in the ghost sector. On the other hand, a canonical transformation in the sector involving Lagrange multiplier and its corresponding momentum leads to a new form of BRST as well as dual-BRST symmetry.

Sumit Kumar Rai; Bhabani Prasad Mandal

2010-01-29T23:59:59.000Z

238

Universality of the Anderson transition with the quasiperiodic kicked rotor  

E-Print Network (OSTI)

We report a numerical analysis of the Anderson transition in a quantum-chaotic system, the quasiperiodic kicked rotor with three incommensurate frequencies. It is shown that this dynamical system exhibits the same critical phenomena as the truly random 3D-Anderson model. By taking proper account of systematic corrections to one-parameter scaling, the universality of the critical exponent is demonstrated. Our result $\

G. Lemarié; B. Grémaud; D. Delande

2009-04-15T23:59:59.000Z

239

Fractional dynamics in the L\\'evy quantum kicked rotor  

E-Print Network (OSTI)

We investigate the quantum kicked rotor in resonance subjected to momentum measurements with a L\\'evy waiting time distribution. We find that the system has a sub-ballistic behavior. We obtain an analytical expression for the exponent of the power law of the variance as a function of the characteristic parameter of the L\\'evy distribution and connect this anomalous diffusion with a fractional dynamics.

Romanelli, Alejandro

2008-01-01T23:59:59.000Z

240

New forms of BRST symmetry in rigid rotor  

E-Print Network (OSTI)

We derive the different forms of BRST symmetry by using the Batalin-Fradkin-Vilkovisky formalism in a rigid rotor. The so called "dual-BRST" symmetry is obtained from usual BRST symmetry by making a canonical transformation in the ghost sector. On the other hand, a canonical transformation in the sector involving Lagrange multiplier and its corresponding momentum leads to a new form of BRST as well as dual-BRST symmetry.

Rai, Sumit Kumar

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Utility of atomic kicked-rotor interferometers for precision measurements  

Science Conference Proceedings (OSTI)

We theoretically investigate a proposed scheme to use an atomic {delta}-kicked rotor resonance for high-precision measurements of accelerations and the photon recoil frequency. Although the technique offers rapid scaling of the measurement sensitivity with pulse number, it also features a high sensitivity to initial atomic momentum. We find that for realistic atom sources, the momentum sensitivity significantly limits the achievable precision. We consider several different variations on the technique, but find similar limitations in all cases.

Horne, R. A.; Leonard, R. H.; Sackett, C. A. [Physics Department, University of Virginia, Charlottesville, Virginia 22904 (United States)

2011-06-15T23:59:59.000Z

242

Suppression of decoherence effects in the quantum kicked rotor  

E-Print Network (OSTI)

We describe a method allowing transient suppression of decoherence effects on the atom-optics realization of the kicked rotor. The system is prepared in an initial state with a momentum distribution concentrated in an interval much sharper than the Brillouin zone; the measure of the momentum distribution is restricted to this interval of quasimomenta: As most of the atoms undergoing decoherence processes fall outside this detection range and thus are not detected, the measured signal is effectively decoherence-free.

Maxence Lepers; Véronique Zehnlé; Jean Claude Garreau

2010-04-15T23:59:59.000Z

243

Fidelity of the near resonant quantum kicked rotor  

E-Print Network (OSTI)

We present a perturbative result for the temporal evolution of the fidelity of the quantum kicked rotor, i.e. the overlap of the same initial state evolved with two slightly different kicking strengths, for kicking periods close to a principal quantum resonance. Based on a pendulum approximation we describe the fidelity for rotational orbits in the pseudo-classical phase space of a corresponding classical map. Our results are compared to numerical simulations indicating the range of applicability of our analytical approximation.

Benedikt Probst; Remy Dubertrand; Sandro Wimberger

2011-04-14T23:59:59.000Z

244

Fractional dynamics in the Lévy quantum kicked rotor  

E-Print Network (OSTI)

We investigate the quantum kicked rotor in resonance subjected to momentum measurements with a L\\'evy waiting time distribution. We find that the system has a sub-ballistic behavior. We obtain an analytical expression for the exponent of the power law of the variance as a function of the characteristic parameter of the L\\'evy distribution and connect this anomalous diffusion with a fractional dynamics.

Alejandro Romanelli

2008-04-15T23:59:59.000Z

245

Preform spar cap for a wind turbine rotor blade  

DOE Patents (OSTI)

A spar cap for a wind turbine rotor blade. The spar cap may include multiple preform components. The multiple preform components may be planar sheets having a swept shape with a first end and a second end. The multiple preform components may be joined by mating the first end of a first preform component to the second end of a next preform component, forming the spar cap.

Livingston, Jamie T. (Simpsonville, SC); Driver, Howard D. (Greer, SC); van Breugel, Sjef (Enschede, NL); Jenkins, Thomas B. (Cantonment, FL); Bakhuis, Jan Willem (Nijverdal, NL); Billen, Andrew J. (Daarlerveen, NL); Riahi, Amir (Pensacola, FL)

2011-07-12T23:59:59.000Z

246

Gas Turbine Rotor Life: General Electric FA Disc Cracking  

Science Conference Proceedings (OSTI)

This report covers the integrated results of the investigation into the occurrence of cooling slot and other rim cracking found in GE 7FA and 9FA gas turbine first and second stage rotor discs. Sections of the report address dimensional characterization, rim temperature measurement, metallurgical results, analytical methods, evaluation of mitigation approaches, and damage tolerance. Structural stress analysis assessed the effectiveness of the blend-polish-peen slot modification and a redesigned ...

2010-12-08T23:59:59.000Z

247

Oxygen-Diffused Titanium as a Candidate Brake Rotor Material  

SciTech Connect

Titanium alloys are one of several candidate materials for the next generation of truck disk brake rotors. Despite their advantages of lightweight relative to cast iron and good strength and corrosion resistance, titanium alloys are unlikely to be satisfactory brake rotor materials unless their friction and wear behavior can be significantly improved. In this study, a surface engineering process oxygen diffusion was applied to titanium rotors and has shown very encouraging results. The oxygen diffused Ti-6Al-4V (OD-Ti) was tested on a sub-scale brake tester against a flat block of commercial brake lining material and benchmarked against several other Ti-based materials, including untreated Ti-6Al-4V, ceramic particle-reinforced Ti composites (MMCs), and a thermal-spray-coated Ti alloy. With respect to friction, the OD-Ti outperformed all other candidate materials under the imposed test conditions with the friction coefficient remaining within a desirable range of 0.35-0.50, even under the harshest conditions when the disk surface temperature reached nearly 600 ?C. In addition, the OD-Ti showed significantly improved wear-resistance over the non-treated one and was even better than the Ti-based composite materials.

Qu, Jun [ORNL; Blau, Peter Julian [ORNL; Jolly, Brian C [ORNL

2009-01-01T23:59:59.000Z

248

Load transfer coupling regression curve fitting for distribution load forecasting  

SciTech Connect

The planning of distribution facilities requires forecasts of future substation and feeder loads. Extrapolation based on a curve fit to past annual peak loads is currently the most popular manner of accomplishing this forecast. Curve fitting suffers badly from data shifts caused by switching as loads are routinely moved from one substation to another during the course of utility operations. This switching contaminates the data, reducing forecast accuracy. A new regression application reduces error due to these transfers by over an order of magnitude. A key to the usefulness of this method is that the amount of the transfer, and its direction (whether it was to or from a substation), is not a required input. The new technique, aspects of computer implementation of it, and a series of tests showing its advantage over normal multiple regression methods are given.

Willis, H.L.; Powell, R.W.

1984-05-01T23:59:59.000Z

249

Active load control techniques for wind turbines.  

DOE Green Energy (OSTI)

This report provides an overview on the current state of wind turbine control and introduces a number of active techniques that could be potentially used for control of wind turbine blades. The focus is on research regarding active flow control (AFC) as it applies to wind turbine performance and loads. The techniques and concepts described here are often described as 'smart structures' or 'smart rotor control'. This field is rapidly growing and there are numerous concepts currently being investigated around the world; some concepts already are focused on the wind energy industry and others are intended for use in other fields, but have the potential for wind turbine control. An AFC system can be broken into three categories: controls and sensors, actuators and devices, and the flow phenomena. This report focuses on the research involved with the actuators and devices and the generated flow phenomena caused by each device.

van Dam, C.P. (University of California, Davis, CA); Berg, Dale E.; Johnson, Scott J. (University of California, Davis, CA)

2008-07-01T23:59:59.000Z

250

A bubble-powered micro-rotor: conception, manufacturing, assembly, and characterization  

E-Print Network (OSTI)

A steady fluid flow, called microstreaming, can be generated in the vicinity of a micro-bubble excited by ultrasound. In this article, we use this phenomenon to assemble and power a microfabricated rotor at rotation speeds as high as 625 rpm. The extractible power is estimated to be on the order of a few femtowatts. A first series of experiments with uncontrolled rotor shapes is presented, demonstrating the possibility of this novel actuation scheme. A second series of experiments with 65 micron rotors micromanufactured in SU-8 resin are presented. Variables controlling the rotation speed and rotor stability are investigated, such as the bubble diameter, the acoustic excitation frequency and amplitude, and the rotor geometry. Finally, an outlook is provided on developing this micro-rotor into a MEMS-based motor capable of delivering tunable, infinitesimal rotary power at the microscale.

Kao, Jonathan; Warren, John; Xu, Jie; Attinger, Daniel; 10.1088/0960-1317/17/12/010

2009-01-01T23:59:59.000Z

251

Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors  

DOE Green Energy (OSTI)

This report describes the adaptation of a wind turbine performance code for use in the development of a general use design code and optimization method for stall-regulated horizontal-axis hydrokinetic turbine rotors. This rotor optimization code couples a modern genetic algorithm and blade-element momentum performance code in a user-friendly graphical user interface (GUI) that allows for rapid and intuitive design of optimal stall-regulated rotors. This optimization method calculates the optimal chord, twist, and hydrofoil distributions which maximize the hydrodynamic efficiency and ensure that the rotor produces an ideal power curve and avoids cavitation. Optimizing a rotor for maximum efficiency does not necessarily create a turbine with the lowest cost of energy, but maximizing the efficiency is an excellent criterion to use as a first pass in the design process. To test the capabilities of this optimization method, two conceptual rotors were designed which successfully met the design objectives.

Sale, D.; Jonkman, J.; Musial, W.

2009-08-01T23:59:59.000Z

252

Preliminary structural design conceptualization for composite rotor for verdant power water current turbine  

DOE Green Energy (OSTI)

Sandia National Laboratories (SNL) and Verdant Power Inc. (VPI) have partnered under a Cooperative Research and Development Agreement (CRADA) to develop a new kinetic hydropower rotor. The rotor features an improved hydrodynamic and structural design which features state-of-the-art technology developed for the wind industry. The new rotor will have higher energy capture, increased system reliability, and reduction of overall cost of energy. This project was divided into six tasks: (1) Composite Rotor Project Planning and Design Specification; (2) Baseline Fatigue Testing and Failure analysis; (3) Develop Blade/Rotor Performance Model; (4) Hydrofoil Survey and Selection; (5) FEM Structural Design; and (6) Develop Candidate Rotor Designs and Prepare Final Report.

Paquette, J. A.

2012-03-01T23:59:59.000Z

253

Periodic load balancing  

Science Conference Proceedings (OSTI)

Multiprocessor load balancing aims to improve performance by moving jobs from highly loaded processors to more lightly loaded processors. Some schemes allow only migration of new jobs upon arrival, while other schemes allow migration of ... Keywords: heavy traffic diffusion approximations, load balancing, periodic load balancing, reflected Brownian motion, resource sharing, transient behavior

Gísli Hjálmtýsson; Ward Whitt

1998-06-01T23:59:59.000Z

254

Metallurgical Guidebook for Steam Turbine Rotors and Discs, Volume 2: Materials Property Database for HP-IP and LP Rotors  

Science Conference Proceedings (OSTI)

As the power plants are aging, many of the components have either surpassed or are nearing their intended design lives. Due to the range of temperatures the steam turbine components areexposed to, material composition, manufacturing and heat treatment methods, and property requirements vary widely. Having the proper knowledge about the vintage, manufacturing history, quality conditions, chemical and mechanical properties, etc., of the rotors and discs become vital when decisions about run, repair, or rep...

2010-12-23T23:59:59.000Z

255

Interruptible load control for Taiwan Power Company  

SciTech Connect

Load management is the planning and implementation of those utility activities designed to influence customer use of electricity in ways that will produce desired changes in the utility's load shape. Interruptible load program is an option of load management which provides incentive rate to customers to interrupt or reduce the power demand during the system peak period or emergency condition. Therefore, how to design a proper incentive rate is the most important issue in implementing this program. This paper describes three alternatives designed for the interruptible load program, one of which was activated by Taiwan Power Company (Taipower) and some preliminary results were obtained. The effect of the interruptible load to the system peak demand reduction and the change of daily load curve for large industrial customers were analyzed. This paper estimates the avoided cost and design more appropriate incentive rate structure for interruptible load program.

Chen, C.S.; Leu, J.T. (Dept. of Electrical Engineering, National Sun Yat-Sen Univ., Kaohsiung (TW))

1990-05-01T23:59:59.000Z

256

Gas Turbine Rotor Life: CrMoV Material Testing, 2013 Status Report  

Science Conference Proceedings (OSTI)

Gas turbine rotor materials are subject to degradation from prolonged hours and multiple start/stop cycles of operation. Periodically, plant operators disassemble the compressor and turbine sections of the rotor system and inspect the components for signs of creep, embrittlement, corrosion, thermal fatigue, and high- and low-cycle fatigue. Beyond limited rotor inspections performed during hot gas path inspections and major overhauls, a more thorough inspection is often required by the equipment ...

2013-12-18T23:59:59.000Z

257

Analytical Parameterization of Rotors and Proof of a Goldberg Conjecture by Optimal Control Theory  

Science Conference Proceedings (OSTI)

Curves which can be rotated freely in an $n$-gon (that is, a regular polygon with $n$ sides) so that they always remain in contact with every side of the $n$-gon are called rotors. Using optimal control theory, we prove that the rotor with minimal area ... Keywords: Noether theorem, Pontryagin maximum principle, bang control, constant width bodies, convexity, optimal control, rotors, shape optimization, support function, switching point

Térence Bayen

2008-11-01T23:59:59.000Z

258

Gas Turbine Rotor Life Evaluation: GE 7FA and 9FA  

Science Conference Proceedings (OSTI)

Gas turbine rotor materials are subject to degradation from prolonged hours and multiple start/stop cycles of operation. Occasionally, plant operators have the compressor and turbine sections of the rotor system disassembled and the components inspected for signs of creep, embrittlement, corrosion, thermal fatigue, and high- and low-cycle fatigue. The inspection of rotor rim areas typically take place more regularly during hot-gas-path and major maintenance intervals when casings and blades are removed. ...

2011-12-19T23:59:59.000Z

259

Gas Turbine Rotor Life Evaluation: Siemens-Westinghouse W501B  

Science Conference Proceedings (OSTI)

Gas turbine rotor materials are subject to degradation from prolonged hours and multiple start/stop cycles of operation. Occasionally, plant operators have the compressor and turbine sections of the rotor system disassembled and the components inspected for signs of creep, embrittlement, corrosion, thermal fatigue, and high- and low-cycle fatigue. The inspection of rotor rim areas typically takes place more regularly during hot-gas-path and major maintenance intervals when casings and blades are removed....

2011-11-14T23:59:59.000Z

260

Modeling And Analysis of Radial Flux Toroidally Wound Twin Rotor Permanent Magnet Motor.  

E-Print Network (OSTI)

??The main objective of current thesis is the study of Radial Flux Twin Rotor Permanent Magnet (RFTWTRPM) motor. The tasks were to review the literature… (more)

Pratapa, Ravi Kishore

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Turning Waste Heat into Power: Ener-G-Rotors and the Entrepreneurial  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Turning Waste Heat into Power: Ener-G-Rotors and the Turning Waste Heat into Power: Ener-G-Rotors and the Entrepreneurial Mentorship Program Turning Waste Heat into Power: Ener-G-Rotors and the Entrepreneurial Mentorship Program March 16, 2011 - 4:55pm Addthis Ener-G-Rotors' 5kW prototype system | courtesy of Ener-G-Rotors Ener-G-Rotors' 5kW prototype system | courtesy of Ener-G-Rotors April Saylor April Saylor Former Digital Outreach Strategist, Office of Public Affairs If you've ever driven by an industrial plant, you've probably noticed big white plumes rising from the tops of the facilities. While it might look like smoke or pollution at first glance, most of the time those white plumes are comprised of steam and heat, or what Ener-G-Rotors CEO Michael Newell calls waste heat. Mike and the researchers of Ener-G-Rotors are finding ways to use this

262

Initial rotor position estimation for low saliency interior permanent-magnet synchronous motor drives.  

E-Print Network (OSTI)

??This work presents an initial rotor position estimation method for low saliency interior permanent-magnet synchronous motor (IPMSM) drives. The method injects signals into the stationary… (more)

Yang, Yan.

2010-01-01T23:59:59.000Z

263

Study on Performance Characteristics of Interior Permanent Magnet Synchronous Motor Due to Rotor Configuration.  

E-Print Network (OSTI)

??This research study was conducted in an effort to understand what effects the rotor configuration has on the performance of a permanent magnet synchronous machine,… (more)

Kettlewell, James

2013-01-01T23:59:59.000Z

264

Tuning thermal mismatch between turbine rotor parts with a thermal medium  

DOE Patents (OSTI)

In a turbine rotor, an aft shaft wheel and the final-stage wheel of the rotor are coupled together, including by a rabbeted joint. During shutdown and startup of the turbine, a thermal mismatch between the aft shaft wheel and final-stage wheel is avoided by respectively heating and cooling the aft shaft wheel to maintain the thermal mismatch within acceptable limits, thereby avoiding opening of the rabbeted joint and the potential for unbalancing the rotor and rotor vibration. The thermal medium may be supplied by piping in the aft bearing cavity into the cavity between the forward closure plate and the aft shaft wheel.

Schmidt, Mark Christopher (Niskayuna, NY)

2001-01-01T23:59:59.000Z

265

Aero-Structural Optimization of a 5 MW Wind Turbine Rotor.  

E-Print Network (OSTI)

??A 5 MW wind turbine rotor blade based on the NREL 5 MW Reference Turbine is optimized for maximum efficiency and minimum flapwise hub bending… (more)

Vesel, Richard W., Jr.

2012-01-01T23:59:59.000Z

266

Inverse Load Calculation of Wind Turbine Support Structures - A Numerical Verification Using the Comprehensive Simulation Code FAST: Preprint (Revised)  

DOE Green Energy (OSTI)

Physically measuring the dynamic responses of wind turbine support structures enables the calculation of the applied loads using an inverse procedure. In this process, inverse means deriving the inputs/forces from the outputs/responses. This paper presents results of a numerical verification of such an inverse load calculation. For this verification, the comprehensive simulation code FAST is used. FAST accounts for the coupled dynamics of wind inflow, aerodynamics, elasticity and turbine controls. Simulations are run using a 5-MW onshore wind turbine model with a tubular tower. Both the applied loads due to the instantaneous wind field and the resulting system responses are known from the simulations. Using the system responses as inputs to the inverse calculation, the applied loads are calculated, which in this case are the rotor thrust forces. These forces are compared to the rotor thrust forces known from the FAST simulations. The results of these comparisons are presented to assess the accuracy of the inverse calculation. To study the influences of turbine controls, load cases in normal operation between cut-in and rated wind speed, near rated wind speed and between rated and cut-out wind speed are chosen. The presented study shows that the inverse load calculation is capable of computing very good estimates of the rotor thrust. The accuracy of the inverse calculation does not depend on the control activity of the wind turbine.

Pahn, T.; Jonkman, J.; Rolges, R.; Robertson, A.

2012-11-01T23:59:59.000Z

267

Decoherence without classicality in the resonant quantum kicked rotor  

E-Print Network (OSTI)

We study the quantum kicked rotor in resonance subjected to an unitary noise defined through Kraus operators, we show that this type of decoherence does not, in general, lead to the classical diffusive behavior. We find exact analytical expressions for the density matrix and the variance in the primary resonances. The variance does not loose its ballistic behavior, however the coherence decays as a power law. The secondary resonances are treated numerically, obtaining a power-law decay for the variance and an exponential law decay for the coherence.

A. Romanelli

2009-05-05T23:59:59.000Z

268

Saturation of fidelity in the atom-optics kicked rotor  

E-Print Network (OSTI)

We show that the quantum fidelity is accessible to cold atom experiments for a large class of evolutions in periodical potentials, properly taking into account the experimental initial conditions of the atomic ensemble. We prove analytically that, at the fundamental quantum resonances of the atom-optics kicked rotor, the fidelity saturates at a constant, time-independent value after a small number of kicks. The latter saturation arises from the bulk of the atomic ensemble, whilst for the resonantly accelerated atoms the fidelity is predicted to decay slowly according to a power law.

Sandro Wimberger; Andreas Buchleitner

2006-03-10T23:59:59.000Z

269

Classical diffusive dynamics for the quasiperiodic kicked rotor  

E-Print Network (OSTI)

We study the classical dynamics of a quasiperiodic kicked rotor, whose quantum counterpart is known to be an equivalent of the 3D Anderson model. Using this correspondence allowed for a recent experimental observation of the Anderson transition with atomic matter waves. In such a context, it is particularly important to assert the chaotic character of the classical dynamics of this system. We show here that it is a 3D anisotropic diffusion. Our simple analytical predictions for the associated diffusion tensor are found in good agreement with the results of numerical simulations.

Gabriel Lemarié; Dominique Delande; Jean Claude Garreau; Pascal Szriftgiser

2010-03-23T23:59:59.000Z

270

Anomalous diffusion in the resonant quantum kicked rotor  

E-Print Network (OSTI)

We study the resonances of the quantum kicked rotor subjected to an excitation that follows a deterministic time-dependent prescription. For the primary resonances we find an analytical relation between the long-time behavior of the standard deviation and the external kick strength. For the secondary resonances we obtain essentially the same result numerically. Selecting the time sequence of the kick allows to obtain a variety of asymptotic wave-function spreadings: super-ballistic, ballistic, sub-ballistic, diffusive, sub-diffusive and localized.

A. Romanelli; Guzmán Hernández

2009-08-31T23:59:59.000Z

271

Neural Network Based Modeling of a Large Steam Turbine-Generator Rotor Body Parameters from On-Line Disturbance Data  

E-Print Network (OSTI)

Neural Network Based Modeling of a Large Steam Turbine-Generator Rotor Body Parameters from On technique to estimate and model rotor- body parameters of a large steam turbine-generator from real time

272

Realizing load reduction functions by aperiodic switching of load groups  

SciTech Connect

This paper investigates the problem of scheduling ON/OFF switching of residential appliances under the control of a Load Management System (LMS). The scheduling process is intended to reduce the controlled appliances` power demand in accordance with a predefined load reduction profile. To solve this problem, a solution approach, based on the methodology of Pulse Width Modulation (PWM), is introduced. This approach provides a flexible mathematical basis for studying different aspects of the scheduling problem. The conventional practices in this area are shown to be special cases of the PWM technique. By applying the PWM-based technique to the scheduling problem, important classes of scheduling errors are identified and analytical expressions describing them are derived. These expressions are shown to provide sufficient information to compensate for the errors. Detailed simulations of load groups` response to switching actions are use to support conclusions of this study.

Navid-Azarbaijani, N. [McGill Univ., Montreal, Quebec (Canada). Dept. of Electrical Engineering; Banakar, M.H. [CAE Electronics Ltd., St. Laurent, Quebec (Canada)

1996-05-01T23:59:59.000Z

273

Battery loading device  

SciTech Connect

A battery loading device for loading a power source battery, built in small appliances having a battery loading chamber for selectively loading a number of cylindrical unit batteries or a one body type battery having the same voltage as a number of cylindrical unit batteries, whereby the one body type battery and the battery loading chamber are shaped similarly and asymmetrically in order to prevent the one body type battery from being inserted in the wrong direction.

Phara, T.; Suzuki, M.

1984-08-28T23:59:59.000Z

274

Neuro-fuzzy modeling tools for estimation of torque in Savonius rotor wind turbine  

Science Conference Proceedings (OSTI)

In the present paper, the ability and accuracy of an adaptive neuro-fuzzy inference system (ANFIS) has been investigated for dynamic modeling of wind turbine Savonius rotor. The main objective of this research is to predict torque performance as a function ... Keywords: ANFIS, ANN, BP, FIS, LSE, MSE, Max, Min, Modeling, Prob, Prod, RBF, RMSE, SD, Savonius rotor, Torque

J. Sargolzaei; A. Kianifar

2010-04-01T23:59:59.000Z

275

Wind Profiler Observations of Mountain Waves and Rotors during T-REX  

Science Conference Proceedings (OSTI)

A network of three boundary layer radar wind profilers is used to study characteristics of mountain waves and rotors and to explore the utility of such a network. The data employed were collected as part of the Terrain-Induced Rotor Experiment (T-...

Stephen A. Cohn; Vanda Grubiši?; William O. J. Brown

2011-04-01T23:59:59.000Z

276

Rotor power feedback control of wind turbine system doubly-fed induction generator  

Science Conference Proceedings (OSTI)

The paper deals with a new system of wind turbine active power vector control. The already familiar cascade regulation with internal vector component feedback of rotor current and external active and reactive power feedbacks control of wind turbine has ... Keywords: DFIG rotor power regulator, doubly-fed induction generator, simulation, vector control

J. Smajo

2006-09-01T23:59:59.000Z

277

The Influence of Support Rods on the Rotation Speed of Savonius Rotors  

Science Conference Proceedings (OSTI)

When a Savonius rotor is used on a current meter as a sensor for fluid speed, it is usually surrounded by a number of support rods. These rods interfere with the flow to the rotor and, depending on their orientation to the flow, can be found to ...

H. D. Pite

1986-09-01T23:59:59.000Z

278

Chirality in odd-$A$ nucleus $^{135}$Nd in particle rotor model  

E-Print Network (OSTI)

A particle rotor model is developed which couples several valence protons and neutrons to a rigid triaxial rotor core. It is applied to investigating the chirality in odd-$A$ nucleus $^{135}$Nd with $\\pi h_{11/2}^2\\otimes\

B. Qi; S. Q. Zhang; J. Meng; S. Y. Wang; S. Frauendorf

2008-12-25T23:59:59.000Z

279

Chirality in odd-$A$ nucleus $^{135}$Nd in particle rotor model  

E-Print Network (OSTI)

A particle rotor model is developed which couples several valence protons and neutrons to a rigid triaxial rotor core. It is applied to investigating the chirality in odd-$A$ nucleus $^{135}$Nd with $\\pi h_{11/2}^2\\otimes\

Qi, B; Meng, J; Wang, S Y; Frauendorf, S

2008-01-01T23:59:59.000Z

280

Fractal Fault Diagnosis of Rotor System Based on Morphological De-nosing  

Science Conference Proceedings (OSTI)

As an experimental tool for analyzing movement of chaos, we intend to introduce the correlation dimension for analyzing vibration signals of rotor system in this paper. For noise corruption existing in field-measured vibration signal, morphological filter ... Keywords: Rotor system, fractal, fault Diagnosis, correlation dimension, morphological filter

Bi-qiang Du; Gui-ji Tang; Song-ling Wang

2008-05-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Typical fault mode determination for rotor test rig based on correlation dimension and Kolmogorov entropy  

Science Conference Proceedings (OSTI)

This paper experimentally investigates the vibration faults of rotor, such as the unbalance, the loosening and the friction, using the rotor test rig. According to the theory of fractal and chaos, the vibration signal series are reconstructed. By the ... Keywords: Kolmogorov entropy, correlation dimension, fractal and chaos, vibration fault

Fengling Zhang; Yanting Ai; Fei Liu

2009-08-01T23:59:59.000Z

282

Computationally fast harmonic balance methods for unsteady aerodynamic predictions of helicopter rotors  

Science Conference Proceedings (OSTI)

A harmonic balance technique for the analysis of unsteady flows about helicopter rotors in forward flight and hover is presented in this paper. The aerodynamics of forward flight are highly nonlinear, with transonic flow on the advancing blade, subsonic ... Keywords: Computational fluid dynamics, Frequency-domain methods, Harmonic balance technique, Helicopter rotors, Unsteady aerodynamics

Kivanc Ekici; Kenneth C. Hall; Earl H. Dowell

2008-06-01T23:59:59.000Z

283

Advanced Flywheel Composite Rotors: Low-Cost, High-Energy Density Flywheel Storage Grid Demonstration  

SciTech Connect

GRIDS Project: Boeing is developing a new material for use in the rotor of a low-cost, high-energy flywheel storage technology. Flywheels store energy by increasing the speed of an internal rotor —slowing the rotor releases the energy back to the grid when needed. The faster the rotor spins, the more energy it can store. Boeing’s new material could drastically improve the energy stored in the rotor. The team will work to improve the storage capacity of their flywheels and increase the duration over which they store energy. The ultimate goal of this project is to create a flywheel system that can be scaled up for use by electric utility companies and produce power for a full hour at a cost of $100 per kilowatt hour.

None

2010-10-01T23:59:59.000Z

284

FINAL PROJECT REPORT LOAD MODELING TRANSMISSION RESEARCH  

E-Print Network (OSTI)

composition: The total load profile obtained from  load individual load types if  load profiles of individual load composition validation: Load profiles generated by the load 

Lesieutre, Bernard

2013-01-01T23:59:59.000Z

285

Evaluation of 2 Percent CrMoWV HP/LP Rotor Gap Forging for Single Cylinder Steam Turbine Use  

Science Conference Proceedings (OSTI)

There has been considerable industry interest in developing a single shaft rotor configuration that uses the same rotor in the high-pressure (HP) as well as the Low Pressure (LP) sections of a steam turbine. This report evaluates an HP/LP rotor forging for single cylinder steam turbines.

1998-11-24T23:59:59.000Z

286

Definition: Reduced Electricity Losses | Open Energy Information  

Open Energy Info (EERE)

Losses Losses Jump to: navigation, search Dictionary.png Reduced Electricity Losses Functions that provide this benefit could help manage peak feeder loads, reduced electricity throughput, locate electricity production closer to the load and ensure that voltages remain within service tolerances, while minimizing the amount of reactive power provided. These actions can reduce electricity losses by making the system more efficient for a given load served or by actually reducing the overall load on the system.[1] Related Terms load, electricity generation, reactive power, smart grid References ↑ SmartGrid.gov 'Description of Benefits' An inl LikeLike UnlikeLike You like this.Sign Up to see what your friends like. ine Glossary Definition Retrieved from "http://en.openei.org/w/index.php?title=Definition:Reduced_Electricity_Losses&oldid=502644

287

WindPACT Turbine Design Scaling Studies Technical Area 2: Turbine, Rotor and Blade Logistics  

SciTech Connect

Through the National Renewable Energy Laboratory (NREL), the United States Department of Energy (DOE) implemented the Wind Partnership for Advanced Component Technologies (WindPACT) program. This program will explore advanced technologies that may reduce the cost of energy (COE) from wind turbines. The initial step in the WindPACT program is a series of preliminary scaling studies intended to determine the optimum sizes for future turbines, help define sizing limits for certain critical technologies, and explore the potential for advanced technologies to contribute to reduced COE as turbine scales increase. This report documents the results of Technical Area 2-Turbine Rotor and Blade Logistics. For this report, we investigated the transportation, assembly, and crane logistics and costs associated with installation of a range of multi-megawatt-scale wind turbines. We focused on using currently available equipment, assembly techniques, and transportation system capabilities and limitations to hypothetically transport and install 50 wind turbines at a facility in south-central South Dakota.

Smith, K.

2001-07-16T23:59:59.000Z

288

Load sensing system  

DOE Patents (OSTI)

A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast

Sohns, Carl W. (Oak Ridge, TN); Nodine, Robert N. (Knoxville, TN); Wallace, Steven Allen (Knoxville, TN)

1999-01-01T23:59:59.000Z

289

Discharge circuits and loads  

SciTech Connect

This will be an overview in which some of the general properties of loads are examined: their interface with the energy storage and switching devices; general problems encountered with different types of loads; how load behavior and fault modes can impact on the design of a power conditioning system (PCS).

Sarjeant, W.J.

1980-10-15T23:59:59.000Z

290

Assembly for facilitating inservice inspection of a reactor coolant pump rotor  

DOE Patents (OSTI)

A reactor coolant pump has an outer casing with an internal cavity holding a coolant and a rotor rotatably mounted in the cavity within the coolant. An assembly for permitting inservice inspection of the pump rotor without first draining the coolant from the casing cavity is attached to an end of the pump. A cylindrical bore is defined through the casing in axial alignment with an end of pump rotor and opening into the internal cavity. An extension attached on the rotor end and rotatable therewith has a cylindrical coupler member extending into the bore. An outer end of the coupler member has an element configured to receive a tool for performance of inservice rotor inspection. A hollow cylindrical member is disposed in the bore and surrounds the coupler member. The cylindrical member is slidably movable relative to the coupler member along the bore between a retracted position wherein the cylindrical member is stored for normal pump operation and an extended position wherein the cylindrical member is extended for permitting inservice rotor inspection. A cover member is detachably and sealably attached to the casing across the bore for closing the bore and retaining the cylindrical member at its retracted position for normal pump operation. Upon detachment of the cover member, the cylindrical member can be extended to permit inservice rotor inspection.

Veronesi, Luciano (O' Hara Township, Allegheny County, PA)

1990-01-01T23:59:59.000Z

291

G&T adds versatile load management system  

SciTech Connect

Wolverine`s load management system was designed in response to the need to reduce peak demand. The Energy Management System (EMS) prepares short term (seven day) load forecasts, based on a daily peak demand forecst, augmented by a similar day profile based on weather conditions. The software combines the similar day profile with the daily peak demand forecast to yield an hourly load forecast for an entire week. The software uses the accepted load forecast case in many application functions, including interchange scheduling, unit commitment, and transaction evaluation. In real time, the computer updates the accepted forecast hourly, based in actual changes in the weather and load. The load management program executes hourly. The program uses impact curves to calculate a load management strategy that reduces the load forecast below a desired load threshold.

Nickel, J.R.; Baker, E.D.; Holt, J.W.; Chan, M.L.

1995-04-01T23:59:59.000Z

292

Demand response can lower electric power load when needed - Today ...  

U.S. Energy Information Administration (EIA)

February 15, 2011 Demand response can lower electric power load when needed . Consumers can play a major role in ensuring reliable electricity supply by reducing ...

293

Reduce Stress!  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

Stress! Stress! x Take a break every hour. Do some relaxation or stretching exercises or talk with someone about topics unrelated to work. Give your body and mind a rest. x Massage your hands and forearms several times a day with a vitamin E lotion. The massage will improve circulation and break up adhesions. Since you can't touch a keyboard until the lotion is absorbed, it also enforces a good break. x Massage the muscles in your neck working your way down from the skull to the shoulders, applying more force to the larger muscles as you go down. x Periodically evaluate your environment for ways to reduce stress. Try to keep your desk uncluttered so you can always find things. Make sure programs are set up correctly on the computer, and see if you can use a macro program to reduce

294

Quantum ether: photons and electrons from a rotor model  

E-Print Network (OSTI)

We give an example of a purely bosonic model -- a rotor model on the 3D cubic lattice -- whose low energy excitations behave like massless U(1) gauge bosons and massless Dirac fermions. This model can be viewed as a ``quantum ether'': a medium that gives rise to both photons and electrons. It illustrates a general mechanism for the emergence of gauge bosons and fermions known as ``string-net condensation.'' Other, more complex, string-net condensed models can have excitations that behave like gluons, quarks and other particles in the standard model. This suggests that photons, electrons and other elementary particles may have a unified origin: string-net condensation in our vacuum.

Michael Levin; Xiao-Gang Wen

2005-07-13T23:59:59.000Z

295

Rigid Rotor as a Toy Model for Hodge Theory  

E-Print Network (OSTI)

We apply the superfield approach to the toy model of a rigid rotor and show the existence of the nilpotent and absolutely anticommuting Becchi-Rouet-Stora-Tyutin (BRST) and anti-BRST symmetry transformations, under which, the kinetic term and action remain invariant. Furthermore, we also derive the off-shell nilpotent and absolutely anticommuting (anti-) co-BRST symmetry transformations, under which, the gauge-fixing term and Lagrangian remain invariant. The anticommutator of the above nilpotent symmetry transformations leads to the derivation of a bosonic symmetry transformation, under which, the ghost terms and action remain invariant. Together, the above transformations (and their corresponding generators) respect an algebra that turns out to be a physical realization of the algebra obeyed by the de Rham cohomological operators of differential geometry. Thus, our present model is a toy model for the Hodge theory.

Saurabh Gupta; R. P. Malik

2009-10-15T23:59:59.000Z

296

Cooling system for a bearing of a turbine rotor  

SciTech Connect

In a gas turbine, a bore tube assembly radially inwardly of an aft bearing conveys cooling steam to the buckets of the turbine and returns the cooling steam to a return. To cool the bearing and thermally insulate the bearing from the cooling steam paths, a radiation shield is spaced from the bore tube assembly by a dead air gap. Additionally, an air passageway is provided between the radiation shield and the inner surface of an aft shaft forming part of the rotor. Air is supplied from an inlet for flow along the passage and radially outwardly through bores in the aft shaft disk to cool the bearing and insulate it from transfer of heat from the cooling steam.

Schmidt, Mark Christopher (Niskayuna, NY)

2002-01-01T23:59:59.000Z

297

Final project report: High energy rotor development, test and evaluation  

DOE Green Energy (OSTI)

Under the auspices of the {open_quotes}Government/Industry Wind Technology Applications Project{close_quotes} [{open_quotes}Letter of Interest{close_quotes} (LOI) Number RC-1-11101], Flo Wind Corp. has successfully developed, tested, and delivered a high-energy rotor upgrade candidate for their 19-meter Vertical Axis Wind Turbine. The project included the demonstration of the innovative extended height-to-diameter ratio concept, the development of a continuous span single-piece composite blade, the demonstration of a continuous blade manufacturing technique, the utilization of the Sandia National Laboratories developed SNLA 2150 natural laminar flow airfoil and the reuse of existing wind turbine and wind power plant infrastructure.

NONE

1996-09-01T23:59:59.000Z

298

Assessment of research needs for wind turbine rotor materials technology  

DOE Green Energy (OSTI)

Wind-driven power systems is a renewable energy technology that is still in the early stages of development. Wind power plants installed in early 1980s suffered structural failures chiefly because of incomplete understanding of wind forces (turbulent), in some cases because of poor product quality. Failures of rotor blades are now somewhat better understood. This committee has examined the experience base accumulated by wind turbines and the R and D programs sponsored by DOE. It is concluded that a wind energy system such as is described is within the capability of engineering practice; however because of certain gaps in knowledge, and the presence of only one major integrated manufacturer of wind power machines in the USA, a DOE R and D investment is still required.

Not Available

1991-01-01T23:59:59.000Z

299

WindPACT Turbine Rotor Design Study: June 2000--June 2002 (Revised)  

SciTech Connect

This report presents the results of the turbine rotor study completed by Global Energy Concepts (GEC) as part of the U.S. Department of Energy's WindPACT (Wind Partnership for Advanced Component Technologies) project. The purpose of the WindPACT project is to identify technology improvements that will enable the cost of energy from wind turbines to fall to a target of 3.0 cents/kilowatt-hour in low wind speed sites. The study focused on different rotor configurations and the effect of scale on those rotors.

Malcolm, D. J.; Hansen, A. C.

2006-04-01T23:59:59.000Z

300

Rotor Spectra, Berry Phases, and Monopole Fields: from Antiferromagnets to QCD  

E-Print Network (OSTI)

The order parameter of a finite system with a spontaneously broken continuous global symmetry acts as a quantum mechanical rotor. Both antiferromagnets with a spontaneously broken $SU(2)_s$ spin symmetry and massless QCD with a broken $SU(2)_L \\times SU(2)_R$ chiral symmetry have rotor spectra when considered in a finite volume. When an electron or hole is doped into an antiferromagnet or when a nucleon is propagating through the QCD vacuum, a Berry phase arises from a monopole field and the angular momentum of the rotor is quantized in half-integer units.

S. Chandrasekharan; F. -J. Jiang; M. Pepe; U. -J. Wiese

2006-12-11T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Guidelines for the Uprate Design of Turbine-Generator Rotor Support Systems  

Science Conference Proceedings (OSTI)

The focus of this guidelines document is the rotor support structure for uprated turbine-generator (T/G) systems. The overall objective of the guidelines is to provide utility personnel with the guidance needed to validate the design of the components prior to a plant uprate/upgrade to ensure that the unit will operate without unplanned and unanticipated issues related to the rotor bearings, bearing support structures, and pedestals. The guidelines are applicable to both nuclear and fossil T/G rotor supp...

2011-12-23T23:59:59.000Z

302

Non-linear dynamic of rotor-stator system with non-linear bearing clearance  

E-Print Network (OSTI)

The study deals with a rotor-stator contact inducing vibration in rotating machinery. A numerical rotor-stator system, including a non-linear bearing with Hertz contact and clearance is considered. To determine the non-linear responses of this system, non-linear dynamic equations can be integrated numerically. However, this procedure is both time consuming and costly to perform. The aim of this Note is to apply the Alternate Frequency/Time Method and the 'path following continuation' in order to obtain the non-linear responses to this problem. Then the orbits of rotor and stator responses at various speeds are investigated.

Jean-Jacques Sinou; Fabrice Thouverez

2008-01-19T23:59:59.000Z

303

Non-linear dynamic of rotor-stator system with non-linear bearing clearance  

E-Print Network (OSTI)

The study deals with a rotor-stator contact inducing vibration in rotating machinery. A numerical rotor-stator system, including a non-linear bearing with Hertz contact and clearance is considered. To determine the non-linear responses of this system, non-linear dynamic equations can be integrated numerically. However, this procedure is both time consuming and costly to perform. The aim of this Note is to apply the Alternate Frequency/Time Method and the 'path following continuation' in order to obtain the non-linear responses to this problem. Then the orbits of rotor and stator responses at various speeds are investigated.

Sinou, Jean-Jacques

2008-01-01T23:59:59.000Z

304

Axial thermal medium delivery tubes and retention plates for a gas turbine rotor  

SciTech Connect

In a multi-stage turbine rotor, tubes are disposed in openings adjacent the rotor rim for flowing a thermal medium to rotor buckets and returning spent thermal medium. The tubes have axially spaced lands of predetermined wall thickness with thin-walled tube sections between the lands and of increasing thickness from the forward to the aft ends of the tubes. A pair of retention plates are carried on the aft end face of the aft wheel and straddle the tube and engage against a shoulder on the tube to preclude displacement of the tube in an aft direction.

Mashey, Thomas Charles (Coxsackie, NY)

2002-01-01T23:59:59.000Z

305

WindPACT Turbine Rotor Design Study: June 2000--June 2002 (Revised)  

DOE Green Energy (OSTI)

This report presents the results of the turbine rotor study completed by Global Energy Concepts (GEC) as part of the U.S. Department of Energy's WindPACT (Wind Partnership for Advanced Component Technologies) project. The purpose of the WindPACT project is to identify technology improvements that will enable the cost of energy from wind turbines to fall to a target of 3.0 cents/kilowatt-hour in low wind speed sites. The study focused on different rotor configurations and the effect of scale on those rotors.

Malcolm, D. J.; Hansen, A. C.

2006-04-01T23:59:59.000Z

306

Advanced Wind Turbine Controls Reduce Loads (Fact Sheet)  

DOE Green Energy (OSTI)

NREL's National Wind Technology Center provides the world's only dedicated turbine controls testing platforms.

Not Available

2012-03-01T23:59:59.000Z

307

The evaluation of a turbulent loads characterization system  

DOE Green Energy (OSTI)

In this paper we discuss an on-line turbulent load characterization system that has been designed to acquire loading spectra from turbines of the same design operating in several different environments and from different turbine designs operating in the same environment. This System simultaneously measures the rainflow-counted alternating and mean loading spectra and the hub-height turbulent mean shearing stress and atmospheric stability associated with the turbulent inflow. We discuss the theory behind the measurement configuration and the results of proof-of-concept testing recently performed at the National Wind Technology Center (NWTC) using a Bergey EXCEL-S 10-kW wind turbine. The on-line approach to characterizing the load spectra and the inflow turbulent scaling parameter produces results that are consistent with other measurements. The on-line approximation of the turbulent shear stress or friction velocity u* also is considered adequate. The system can be used to characterize turbulence loads during turbine deployment in a wide variety of environments. Using the WISPER protocol, we found that a wide-range, variable-speed turbine will accumulate a larger number of stress cycles in the low-cycle, high-amplitude (LCHA) region when compared with a constant speed rotor under similar inflow conditions.

Kelley, N.D.; McKenna, H.E. [National Renewable Energy Lab., Golden, CO (United States)

1996-01-01T23:59:59.000Z

308

A new approach applied to adaptive centralized load shedding scheme  

Science Conference Proceedings (OSTI)

One of major contingencies of an electric power system is due to imbalance between loads and generated power. This leads to instability in the power system and hence to a blackout. A load shedding scheme may be used to avoid such problem by reducing ... Keywords: adaptive load shedding scheme, critical power, power system, threshold power

Hamid Bentarzi; Abderrahmane Ouadi; Nadir Ghout; Farid Maamri; Nikos E. Mastorakis

2009-12-01T23:59:59.000Z

309

Commercial Nonintrusive Load Monitoring System Beta Test Results  

Science Conference Proceedings (OSTI)

Monitoring many different individual loads on customer premises is a costly, complex, and trouble-prone operation. The availability of a single instrument that could plug into the meter socket and measure individual premise loads would greatly simplify and reduce the cost of customer load monitoring. This report provides the test results of such a prototype instrument.

1999-12-15T23:59:59.000Z

310

An Experimental Study of the Sensitivity of Helicopter Rotor Blade Tracking . . .  

E-Print Network (OSTI)

(Maximum 200 words) The sensitivity of blade tracking in hover to variations in root pitch was examined for two rotor configurations. Tests were conducted using a four-bladed articulated rotor mounted on the NASA-Army aeroelastic rotor experimental system (ARES). Two rotor configurations were tested: one consisting of a blade set with flexible fiberglass spars and one with stiffer (by a factor of five in flapwise and torsional stiffnesses) aluminum spars. Both blade sets were identical in planform and airfoil distribution and were untwisted. The two configurations were ballasted to the same Lock number so that a direct comparison of the tracking sensitivity to a gross change in blade stiffness could be made. Experimental results show no large differences between the two sets of blades in the sensitivity of the blade tracking to root pitch adjustments. However, a measurable reduction in in-track coning of the fiberglass spar blades with respect to the aluminum blades is noted at higher...

W. Keats Wilkie; Omb No; Jeffrey D. Singleton; Matthew L. Wilbur; William T. Yeager; Aerostructures Directorate

1991-01-01T23:59:59.000Z

311

The cost of noise reduction for departure and arrival operations of commercial tilt rotor aircraft  

E-Print Network (OSTI)

The relationship between direct operating cost (DOC) and noise annoyance due to a departure and an arrival operation was developed for commercial tilt rotor aircraft. This was accomplished by generating a series of tilt ...

Faulkner, Henry B.

1976-01-01T23:59:59.000Z

312

Chiral bands for quasi-proton and quasi-neutron coupling with a triaxial rotor  

E-Print Network (OSTI)

A particle rotor model (PRM) with a quasi-proton and a quasi-neutron coupled with a triaxial rotor is developed and applied to study chiral doublet bands with configurations of a $h_{11/2}$ proton and a $h_{11/2}$ quasi-neutron. With pairing treated by the BCS approximation, the present quasi-particle PRM is aimed at simulating one proton and many neutron holes coupled with a triaxial rotor. After a detailed analysis of the angular momentum orientations, energy separation between the partner bands, and behavior of electromagnetic transitions, for the first time we find aplanar rotation or equivalently chiral geometry beyond the usual one proton and one neutron hole coupled with a triaxial rotor.

S. Q. Zhang; B. Qi; S. Y. Wang; J. Meng

2007-03-15T23:59:59.000Z

313

Geometric Integration of Non-autonomous Systems with Application to Rotor Dynamics  

E-Print Network (OSTI)

Geometric integration of non-autonomous classical engineering problems, such as rotor dynamics, is investigated. It is shown, both numerically and by backward error analysis, that geometric (structure preserving) integration algorithms are superior to conventional Runge-Kutta methods.

Modin, Klas

2011-01-01T23:59:59.000Z

314

Chirality in odd-$A$ Rh isotopes within triaxial particle rotor model  

E-Print Network (OSTI)

Adopting the fully quantal triaxial particle rotor model, the candidate chiral doublet bands in odd-$A$ nuclei $^{103}$Rh and $^{105}$Rh with $\\pi g_{9/2}^{-1}\\otimes\

B. Qi; S. Q. Zhang; S. Y. Wang; J. Meng; T. Koike

2011-02-11T23:59:59.000Z

315

Observation of coherence revival and fidelity saturation in a delta-kicked rotor potential  

E-Print Network (OSTI)

We experimentally investigate the effect of atomic delta-kicked rotor potentials on the mutual coherence between wavepackets in an atom interferometer. The differential action of the kicked rotor degrades the mutual coherence, leading to a reduction of the interferometry fringe visibility; however, when the repetition rate of the kicked rotor is at or near the quantum resonance, we observe revival of matter-wave coherence as the number of kicks increases, resulting in non-vanishing coherence in the large kick number limit. This coherence saturation effect reflects a fidelity saturation in phase-space displacement echoes in deep quantum regime. The saturation effect is accompanied with an invariant distribution of matter-wave coherence under the kicked rotor perturbations.

Wu, Saijun; Prentiss, Mara G

2008-01-01T23:59:59.000Z

316

Assessment of Slag-Aided Deoxidation Process in 3.5crmov Rotor ...  

Science Conference Proceedings (OSTI)

Presentation Title, Assessment of Slag-Aided Deoxidation Process in 3.5crmov Rotor Steel. Author(s), June-Seong Park, Chang-Woo Seo, Seonhyo Kim.

317

Deflection Shape Reconstructions of a Rotating Five-blade Helicopter Rotor from TLDV Measurements  

Science Conference Proceedings (OSTI)

Helicopters are aircraft machines which are subjected to high level of vibrations, mainly due to spinning rotors. These are made of two or more blades attached by hinges to a central hub, which can make the dynamic behaviour difficult to study. However, they share some common dynamic properties with the ones expected in bladed discs, thereby the analytical modelling of rotors can be performed using some assumptions as the ones adopted for the bladed discs. This paper presents results of a vibrations study performed on a scaled helicopter rotor model which was rotating at a fix rotational speed and excited by an air jet. A simplified analytical model of that rotor was also produced to help the identifications of the vibration patterns measured using a single point tracking-SLDV measurement method.

Fioretti, A.; Castellini, P.; Tomasini, E. P. [Universita Politecnica delle Marche, Dipartimento di Meccanica, Ancona (Italy); Di Maio, D.; Ewins, D. J. [University of Bristol, Aerospace Department, Bristol (United Kingdom)

2010-05-28T23:59:59.000Z

318

Diurnal Variation of Downslope Winds in Owens Valley during the Sierra Rotor Experiment  

Science Conference Proceedings (OSTI)

The impact of diurnal forcing on a downslope wind event that occurred in Owens Valley in California during the Sierra Rotors Project (SRP) in the spring of 2004 has been examined based on observational analysis and diagnosis of numerical ...

Qingfang Jiang; James D. Doyle

2008-10-01T23:59:59.000Z

319

Observation of coherence revival and fidelity saturation in a delta-kicked rotor potential  

E-Print Network (OSTI)

We experimentally investigate the effect of atomic $\\delta$-kicked rotor potentials on the mutual coherence between wavepackets in an atom interferometer. The differential action of the kicked rotor degrades the mutual coherence, leading to a reduction of the interferometry fringe visibility; however, when the repetition rate of the kicked rotor is at or near the quantum resonance, we observe revival of matter-wave coherence as the number of kicks increases, resulting in non-vanishing coherence in the large kick number limit. This coherence saturation effect reflects a saturation of fidelity decay due to momentum displacements in deep quantum regime. The saturation effect is accompanied with an invariant distribution of matter-wave coherence under the kicked rotor perturbations.

Saijun Wu; Alexey Tonyushkin; Mara G. Prentiss

2008-01-03T23:59:59.000Z

320

High-Resolution Doppler Lidar Observations of Transient Downslope Flows and Rotors  

Science Conference Proceedings (OSTI)

The authors present observations of the temporal evolution of downslope windstorms with rotors and internal hydraulic jumps of unprecedented detail and spatiotemporal coverage. The observations were carried out by means of a coherent Doppler lidar ...

Christian Kühnlein; Andreas Dörnbrack; Martin Weissmann

2013-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Rotor and Subrotor Dynamics in the Lee of Three-Dimensional Terrain  

Science Conference Proceedings (OSTI)

The internal structure and dynamics of rotors that form in the lee of topographic ridges are explored using a series of high-resolution eddy-resolving numerical simulations. Surface friction generates a sheet of horizontal vorticity along the lee ...

James D. Doyle; Dale R. Durran

2007-12-01T23:59:59.000Z

322

Effects of rotor tip clearance on an embedded compressor stage performance  

E-Print Network (OSTI)

Compressor efficiency variation with rotor tip gap is assessed using numerical simulations on an embedded stage representative of that in a large industrial gas turbine with Reynolds number being approximately 2 x 106 to ...

Sakulkaew, Sitanun

2012-01-01T23:59:59.000Z

323

Evaluation of the AEA Technology Engineering Services AIS Rotor Bore Ultrasonic Imaging System  

Science Conference Proceedings (OSTI)

Reliable and repeatable boresonic inspections of turbine rotors and generator fields are critical for accurately predicting the remaining life of those components. EPRI's boresonic system evaluation program provides utilities with insight into the capability of commercial boresonic system performance. This report features an evaluation of the Automated Inspection System (AIS) Rotor Bore Ultrasonic Imaging System, a boresonic system owned and operated by AEA Technology Engineering Services.

2006-06-05T23:59:59.000Z

324

Stabilized space---time computation of wind-turbine rotor aerodynamics  

Science Conference Proceedings (OSTI)

We show how we use the Deforming-Spatial-Domain/Stabilized Space---Time (DSD/SST) formulation for accurate 3D computation of the aerodynamics of a wind-turbine rotor. As the test case, we use the NREL 5MW offshore baseline wind-turbine rotor. This class ... Keywords: DSD/SST formulation, Rotating turbulent flow, Space---time variational multiscale method, Torque values, Wind-turbine aerodynamics

Kenji Takizawa; Bradley Henicke; Tayfun E. Tezduyar; Ming-Chen Hsu; Yuri Bazilevs

2011-09-01T23:59:59.000Z

325

Load sensing system  

DOE Patents (OSTI)

A load sensing system inexpensively monitors the weight and temperature of stored nuclear material for long periods of time in widely variable environments. The system can include an electrostatic load cell that encodes weight and temperature into a digital signal which is sent to a remote monitor via a coaxial cable. The same cable is used to supply the load cell with power. When multiple load cells are used, vast inventories of stored nuclear material can be continuously monitored and inventoried of minimal cost. 4 figs.

Sohns, C.W.; Nodine, R.N.; Wallace, S.A.

1999-05-04T23:59:59.000Z

326

Electrical Energy Conservation and Load Management - An Industrial User's Viewpoint  

E-Print Network (OSTI)

Conservation of electrical energy and load management can reduce industry's electric bills, conserves natural resources and reduces the need for new generating plants. In recent years, industry has implemented extensive conservation programs. Some load management has been implemented already. Additional load management is possible; however, optimizing it will require close industry and electric utility company cooperation to develop new incentives and rate structures to make it economically attractive. The limitations of existing rate structures and needed improvements are presented.

Jackson, C. E.

1984-01-01T23:59:59.000Z

327

Structural load combinations  

SciTech Connect

This paper presents the latest results of the program entitled, ''Probability Based Load Combinations For Design of Category I Structures''. In FY 85, a probability-based reliability analysis method has been developed to evaluate safety of shear wall structures. The shear walls are analyzed using stick models with beam elements and may be subjected to dead load, live load and in-plane eqrthquake. Both shear and flexure limit states are defined analytically. The limit state probabilities can be evaluated on the basis of these limit states. Utilizing the reliability analysis method mentioned above, load combinations for the design of shear wall structures have been established. The proposed design criteria are in the load and resistance factor design (LRFD) format. In this study, the resistance factors for shear and flexure and load factors for dead and live loads are preassigned, while the load factor for SSE is determined for a specified target limit state probability of 1.0 x 10/sup -6/ or 1.0 x 10/sup -5/ during a lifetime of 40 years. 23 refs., 9 tabs.

Hwang, H.; Reich, M.; Ellingwood, B.; Shinozuka, M.

1985-01-01T23:59:59.000Z

328

Watershed Mercury Loading Framework  

Science Conference Proceedings (OSTI)

This report explains and illustrates a simplified stochastic framework, the Watershed Mercury Loading Framework, for organizing and framing site-specific knowledge and information on mercury loading to waterbodies. The framework permits explicit treatment of data uncertainties. This report will be useful to EPRI members, state and federal regulatory agencies, and watershed stakeholders concerned with mercury-related human and ecological health risk.

2003-05-23T23:59:59.000Z

329

Definition: Direct Load Control Device | Open Energy Information  

Open Energy Info (EERE)

Load Control Device Load Control Device Jump to: navigation, search Dictionary.png Direct Load Control Device A remotely controllable switch that can turn power to a load or appliance on or off. Such a device could also be used to regulate the amount of power that a load can consume. Direct load control devices can be operated by a utility or third party energy provider to reduce a customer's energy demand at certain times.[1] Related Terms power, load References ↑ https://www.smartgrid.gov/category/technology/direct_load_control_device [[Ca LikeLike UnlikeLike You like this.Sign Up to see what your friends like. tegory: Smart Grid Definitionssmart grid,smart grid, |Template:BASEPAGENAME]]smart grid,smart grid, Retrieved from "http://en.openei.org/w/index.php?title=Definition:Direct_Load_Control_Device&oldid=502631

330

Report on Toyota/Prius Motor Torque-Capability, Torque-Property, No-Load Back EMF, and Mechanical Losses  

SciTech Connect

In today's hybrid vehicle market, the Toyota Prius drive system is currently considered the leader in electrical, mechanical, and manufacturing innovations. It is significant that in today's marketplace, Toyota is able to manufacture and sell the vehicle for a profit. This project's objective is to test the torque capability of the 2004 Prius motor and to analyze the torque properties relating to the rotor structure. The tested values of no-load back electromotive force (emf) and mechanical losses are also presented.

Hsu, J.S.

2004-09-30T23:59:59.000Z

331

load | OpenEI  

Open Energy Info (EERE)

load load Dataset Summary Description This dataset contains hourly load profile data for 16 commercial building types (based off the DOE commercial reference building models) and residential buildings (based off the Building America House Simulation Protocols). This dataset also includes the Residential Energy Consumption Survey (RECS) for statistical references of building types by location. Source Commercial and Residential Reference Building Models Date Released April 18th, 2013 (9 months ago) Date Updated July 02nd, 2013 (7 months ago) Keywords building building demand building load Commercial data demand Energy Consumption energy data hourly kWh load profiles Residential Data Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually

332

Load-management decision  

Science Conference Proceedings (OSTI)

Utilities require baseload, intermediate, and peaking plants to meet fluctuating customer demand. These can be supplemented with off-peak generation and storage and load management, which can take the form of direct utility control over interruptible and deferrable customers or customer incentives that require off-peak demand. Utilities should make a careful analysis of their load profile, their generation mix, their ability to shift loads, and customer attitudes before deciding on a load-management program that fits their individual needs. They should also be aware that load management is only a limited resource with a number of uncertainties. Research programs into customer relations, system reliability, communications devices, and special control switches and meters will help to relieve some of the uncertainties. (DCK)

Lihach, N.; Gupta, P.

1982-05-01T23:59:59.000Z

333

RAMGEN ROTOR CARTRIDGE FOR THE PRE-PROTOTYPE RAMGEN ENGINE  

Science Conference Proceedings (OSTI)

The research and development of a unique combustion engine is presented. The engine converts the thrust from ramjet modules located on the rim of a disk into shaft torque, which in turn can be used for electrical power generation or mechanical drive applications. A test program was undertaken that included evaluation of the pre-prototype engine and incorporation of improvements to the thrust modules and supporting systems. Fuel mixing studies with vortex generators and bluff body flame holders demonstrated the importance of increasing the shear-layer area and spreading angle to augment flame volume. Evaluation of flame-holding configurations (with variable fuel injection methods) concluded that the heat release zone, and therefore combustion efficiency, could be manipulated by judicious selection of bluff body geometry, and is less influenced by fuel injection distribution. Finally, successful operation of novel fuel and cooling air delivery systems have resolved issues of gas (fuel and air) delivery to the individual rotor segments. The lessons learned from the pre-prototype engine are currently being applied to the development of a 2.8MW engine.

Aaron Koopman

2003-09-01T23:59:59.000Z

334

Characteristics of wind power on Savonius rotor using a guide-box tunnel  

Science Conference Proceedings (OSTI)

This study investigates to improve and adjust the output power of Savonius rotor under various wind power and suggests the method of prevention the rotor from strong wind disaster. In this study, as the appropriate device to achieve the purpose of it, a guide-box tunnel is employed. The guide-box tunnel is like a rectangular box as wind passage in which a test rotor is included. The area ratio between the inlet and exit of it is variable to adjust the inlet mass flow rate or input power. At first, the experiment was conducted to find the adequate configuration which would provide the best relative performance. The present experiment, however, does not include the test to retain the guide-box tunnel from the strong wind. The experiments include the static torque test of the fixed rotor at any phase angle and the dynamic torque test at rotation of them. Consequently, it was found that the maximum rotor rotational speed was achieved in the range of the guide-box area ratio between 0.3 and 0.7 and the value of the output power coefficient of the rotor with guide-box tunnel of the area ratio 0.43 increases about 1.5 times with three blades and 1.23 times with two blades greater than that without guide-box tunnel, respectively. It seemed that the performance of Savonius rotor within the guide-box tunnel is comparable enough with other methods for augmentation and control of the output. (author)

Irabu, Kunio; Roy, Jitendro Nath [Faculty of Mechanical Engineering, University of the Ryukyus, Senbaru-1, Nishihara, Okinawa 903-0213 (Japan)

2007-11-15T23:59:59.000Z

335

Designing an H-rotor type Wind Turbine for Operation on Amundsen-Scott South Pole Station.  

E-Print Network (OSTI)

?? This thesis focuses on designing the turbine, tower structure and generator for an H-rotor type wind turbine. The produced power will be used for… (more)

Wahl, Mats

2007-01-01T23:59:59.000Z

336

Detection of Rotor and Load Faults in BLDC Motors Operating Under Stationary and Non-Stationary Conditions .  

E-Print Network (OSTI)

??Brushless Direct Current (BLDC) motors are one of the motor types rapidly gaining popularity. BLDC motors are being increasingly used in critical high performance industries… (more)

Rajagopalan, Satish

2006-01-01T23:59:59.000Z

337

HLW Glass Waste Loadings  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

HLW HLW Glass Waste Loadings Ian L. Pegg Vitreous State Laboratory The Catholic University of America Washington, DC Overview Overview  Vitrification - general background  Joule heated ceramic melter (JHCM) technology  Factors affecting waste loadings  Waste loading requirements and projections  WTP DWPF  DWPF  Yucca Mountain License Application requirements on waste loading  Summary Vitrification  Immobilization of waste by conversion into a glass  Internationally accepted treatment for HLW  Why glass?  Amorphous material - able to incorporate a wide spectrum of elements over wide ranges of composition; resistant to radiation damage  Long-term durability - natural analogs Relatively simple process - amenable to nuclearization at large  Relatively simple process - amenable to nuclearization at large scale  There

338

OpenEI - load  

Open Energy Info (EERE)

are given by a location defined by the Typical Meteorological Year (TMY) for which the weather data was collected. Commercial load data is sorted by the (TMY) site as a...

339

building load data | OpenEI Community  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Load data Image source: NREL...

340

electric load data | OpenEI Community  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Load data Image source: NREL...

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

commercial load | OpenEI Community  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Load data Image source: NREL...

342

residential load | OpenEI Community  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Load data Image source: NREL...

343

Dynamic Rotor Deformation and Vibration Monitoring Using a Non-Incremental Laser Doppler Distance Sensor  

Science Conference Proceedings (OSTI)

Monitoring rotor deformations and vibrations dynamically is an important task for improving the safety and the lifetime as well as the energy efficiency of motors and turbo machines. However, due to the high rotor speed encountered in particular at turbo machines, this requires concurrently a high measurement rate and high accuracy, which can not be fulfilled by most commercially available sensors. To solve this problem, we developed a non-incremental laser Doppler distance sensor (LDDS), which is able to measure simultaneously the in-plane velocity and the out-of-plane position of moving rough solid objects with micrometer precision. In addition, this sensor concurrently offers a high temporal resolution in the microsecond range, because its position uncertainty is in principle independent of the object velocity in contrast to conventional distance sensors, which is a unique feature of the LDDS. Consequently, this novel sensor enables precise and dynamic in-process deformation and vibration measurements on rotating objects, such as turbo machine rotors, even at very high speed. In order to evidence the capability of the LDDS, measurements of rotor deformations (radial expansion), vibrations and wobbling motions are presented at up to 50,000 rpm rotor speed.

Pfister, Thorsten; Guenther, Philipp; Dreier, Florian; Czarske, Juergen [Technische Universitaet Dresden, Faculty of Electrical Engineering and Information Technology, Laboratory for Measurement and Testing Techniques, Helmholtzstrasse 18, D-01062 Dresden (Germany)

2010-05-28T23:59:59.000Z

344

Transient analysis of a flywheel battery containment during a full rotor burst event.  

DOE Green Energy (OSTI)

Flywheels are being developed for use in an Advanced Locomotive Propulsion System (ALPS) targeted for use in high speed passenger rail service. The ALPS combines high performance, high speed gas turbines, motor/generators and flywheels to provide a light-weight, fuel-efficient power system. Such a system is necessary to avoid the high cost of railway electrification, as is currently done for high speed rail service (>100mph) since diesels are too heavy. The light-weight flywheel rotors are made from multilayered composite materials, and are operated at extremely high energy levels. Metal containment structures have been designed to enclose the rotors and provide encapsulation of the rotor during postulated failure events. One such event is a burst mode failure of the rotor in which the composite rim is assumed to burst into debris that impacts against the containment. This paper presents a finite element simulation of the transient structural response of a subscale metal flywheel containment structure to a rotor burst event.

Hsieh, B. J.

1998-04-17T23:59:59.000Z

345

Composite Load Model Evaluation  

Science Conference Proceedings (OSTI)

The WECC load modeling task force has dedicated its effort in the past few years to develop a composite load model that can represent behaviors of different end-user components. The modeling structure of the composite load model is recommended by the WECC load modeling task force. GE Energy has implemented this composite load model with a new function CMPLDW in its power system simulation software package, PSLF. For the last several years, Bonneville Power Administration (BPA) has taken the lead and collaborated with GE Energy to develop the new composite load model. Pacific Northwest National Laboratory (PNNL) and BPA joint force and conducted the evaluation of the CMPLDW and test its parameter settings to make sure that: • the model initializes properly, • all the parameter settings are functioning, and • the simulation results are as expected. The PNNL effort focused on testing the CMPLDW in a 4-bus system. An exhaustive testing on each parameter setting has been performed to guarantee each setting works. This report is a summary of the PNNL testing results and conclusions.

Lu, Ning; Qiao, Hong (Amy)

2007-09-30T23:59:59.000Z

346

Analysis of industrial load management  

SciTech Connect

Industrial Load Management, ILM, has increased the possibilities of changing load profiles and raising load factors. This paper reports on load profile measurements and feasible load management applications that could be implemented in industry e.g. bivalent systems for heating of premises and processes, load priority systems, energy storage and rescheduling processes or parts of processes due to differential electricity rates. Industrial load variations on hourly, daily and seasonal basis are treated as well as the impact by load management on load curves e g peak clipping, valley filling and increased off-peak electricity usage.

Bjork, C.O.; Karlsson, B.G.

1986-04-01T23:59:59.000Z

347

Distribution substation load impacts of residential air conditioner load control  

SciTech Connect

An ongoing experiment to monitor the substation level load impacts of end-use load control is described. An overview of the data acquisition system, experimental procedures and analysis techniques are provided. Results of the 1983 and 1984 experiments demonstrate the value of aggregate load impact monitoring as a means of verifying load research results, calculating the diversity of end-use loads, and predicting the impacts of load management on the transmission and distribution systems.

Heffner, G.C.; Kaufman, D.A.

1985-07-01T23:59:59.000Z

348

Prime movers reduce energy costs  

SciTech Connect

Many industrial plants have found that reciprocating engines used to power generator sets and chiller systems are effective in reducing energy costs as part of a load management strategy, while meeting other plant energy needs. As the trend towards high electric utility costs continues, familiarity with basic analyses used to determine the economic viability of engine-driven systems is essential. A basic method to determine the economic viability of genset or chiller systems is to review the supplying utility`s rate structure, determine approximate costs to install and operate an engine-driven system, and calculate a simple equipment payback period. If the initial analysis shows that significant savings are possible and a quick payback is likely, a thorough analysis should be conducted to analyze a plant`s actual electric load profile. A load profile analysis takes into consideration average loads, peak loads, and peak duration. A detailed study should cover myriad considerations, including local air quality regulations and permitting, space availability, auxiliary system components, and financing options. A basic analysis takes relatively little time and can rule out the need for a detailed study.

Swanson, J.E. [Caterpillar, Inc., Mossville, IL (United States)

1996-01-01T23:59:59.000Z

349

Load Monitoring CEC/LMTF Load Research Program  

SciTech Connect

This white paper addresses the needs, options, current practices of load monitoring. Recommendations on load monitoring applications and future directions are also presented.

Huang, Zhenyu; Lesieutre, B.; Yang, Steve; Ellis, A.; Meklin, A.; Wong, B.; Gaikwad, A.; Brooks, D.; Hammerstrom, Donald J.; Phillips, John; Kosterev, Dmitry; Hoffman, M.; Ciniglio, O.; Hartwell, R.; Pourbeik, P.; Maitra, A.; Lu, Ning

2007-11-30T23:59:59.000Z

350

Load management strategies for electric utilities: a production cost simulation  

SciTech Connect

This paper deals with the development and application of a simulation model for analyzing strategies for managing the residential loads of electric utilities. The basic components of the model are (1) a production-cost model, which simulates daily operation of an electric power system; (2) a load model, which disaggregates system loads into appliance loads and other loads; and (3) a comparison model, which compares the production costs and energy consumption needed to meet a particular load profile to the corresponding costs and energy consumption required for another load profile. The profiles in each pair define alternative ways of meeting the same demand. A method for disaggregating load profiles into appliance components is discussed and several alternative strategies for residential load management for a typical northeastern electric utility are formulated. The method is based on an analysis of the composition of electric loads for a number of classes of residential customers in the model utility system. The effect of alternative load management strategies on the entire residential loadcurve is determined by predicting the effects of these strategies on the specific appliance components of the loadcurve. The results of using the model to analyze alternative strategies for residential load management suggest that load management strategies in the residential sector, if adopted by utilities whose operating and load characteristics are similar to those of the system modeled here, must take into account a wide variety of appliances to achieve significant changes in the total load profile. Moreover, the results also suggest that it is not easy to reduce costs significantly through new strategies for managing residential loads only and that, to be worthwhile, cost-reducing strategies will have to encompass many kinds of appliances.

Blair, P.D.

1979-03-01T23:59:59.000Z

351

Incentivizing Advanced Load Scheduling in Smart Homes  

Science Conference Proceedings (OSTI)

In recent years, researchers have proposed numerous advanced load scheduling algorithms for smart homes with the goal of reducing the grid's peak power usage. In parallel, utilities have introduced variable rate pricing plans to incentivize residential ... Keywords: Battery, Electricity, Energy, Grid

Ye Xu, David Irwin, Prashant Shenoy

2013-11-01T23:59:59.000Z

352

WindPACT Turbine Rotor Design Study: June 2000--June 2002 (Revised)  

NLE Websites -- All DOE Office Websites (Extended Search)

WindPACT Turbine Rotor WindPACT Turbine Rotor Design Study June 2000 - June 2002 D.J. Malcolm Global Energy Concepts, LLC Kirkland, Washington A.C. Hansen Windward Engineering Salt Lake City, Utah Subcontract Report NREL/SR-500-32495 Revised April 2006 WindPACT Turbine Rotor Design Study June 2000 - June 2002 D.J. Malcolm Global Energy Concepts, LLC Kirkland, Washington A.C. Hansen Windward Engineering Salt Lake City, Utah NREL Technical Monitor: A. Laxson Prepared under Subcontract No. YAT-0-30213-01 Subcontract Report NREL/SR-500-32495 Revised April 2006 National Renewable Energy Laboratory 1617 Cole Boulevard, Golden, Colorado 80401-3393 303-275-3000 * www.nrel.gov Operated for the U.S. Department of Energy Office of Energy Efficiency and Renewable Energy by Midwest Research Institute * Battelle

353

Nebulous Art of Using Wind-Tunnel Airfoil Data for Predicting Rotor Performance: Preprint  

DOE Green Energy (OSTI)

The objective of this study was threefold: to evaluate different two-dimensional S809 airfoil data sets in the prediction of rotor performance; to compare blade-element momentum rotor predicted results to lifting-surface, prescribed-wake results; and to compare the NASA Ames combined experiment rotor measured data with the two different performance prediction methods. The S809 airfoil data sets evaluated included those from Delft University of Technology, Ohio State University, and Colorado State University. The performance prediction comparison with NASA Ames data documents shortcomings of these performance prediction methods and recommends the use of the lifting-surface, prescribed-wake method over blade-element momentum theory for future analytical improvements.

Tangler, J. L.

2002-01-01T23:59:59.000Z

354

Axial seal system for a gas turbine steam-cooled rotor  

DOE Patents (OSTI)

An axial seal assembly is provided at the interface between adjacent wheels and spacers of a gas turbine rotor and disposed about tubes passing through openings in the rotor adjacent the rotor rim and carrying a thermal medium. Each seal assembly includes a support bushing for supporting a land of the thermal medium carrying tube, an axially registering seat bushing disposed in the opposed opening and a frustoconical seal between the seal bushing and seat. The seal bushing includes a radial flange having an annular recess for retaining the outer diameter edge of the seal, while the seat bushing has an axially facing annular surface forming a seat for engagement by the inner diameter edge of the seal.

Mashey, Thomas Charles (Anderson, SC)

2002-01-01T23:59:59.000Z

355

Adaptive control using neural network for command following of tilt-rotor airplane in 0°-tilt angle mode  

Science Conference Proceedings (OSTI)

This paper deals with an autonomous flight algorithm design problem for the tilt-rotor airplane under development by Korea Aerospace Research Institute for simulation study. The objective of this paper is to design a guidance and control algorithm to ... Keywords: KARI tilt-rotor airplane, adaptive control, approximate modelbased inversion, command following, neural network

Jae Hyoung Im; Cheolkeun Ha

2009-09-01T23:59:59.000Z

356

An Evaluation of Free- and Fixed-Vane Flowmeters with Curved- and Flat-Bladed Savonius Rotors  

Science Conference Proceedings (OSTI)

Speed and direction performances of flowmeters, designed by the authors for in-house use, employing an Aanderaa-type curved-bladed Savonius rotor and a free vane and an Aanderaa-type flat-bladed Savonius rotor and a fixed vane, are discussed. It ...

Antony Joseph; Ehrlich Desa

1994-04-01T23:59:59.000Z

357

Atmospheric and Wake Turbulence Impacts on Wind Turbine Fatigue Loading: Preprint  

DOE Green Energy (OSTI)

Large-eddy simulations of atmospheric boundary layers under various stability and surface roughness conditions are performed to investigate the turbulence impact on wind turbines. In particular, the aeroelastic responses of the turbines are studied to characterize the fatigue loading of the turbulence present in the boundary layer and in the wake of the turbines. Two utility-scale 5 MW turbines that are separated by seven rotor diameters are placed in a 3 km by 3 km by 1 km domain. They are subjected to atmospheric turbulent boundary layer flow and data is collected on the structural response of the turbine components. The surface roughness was found to increase the fatigue loads while the atmospheric instability had a small influence. Furthermore, the downstream turbines yielded higher fatigue loads indicating that the turbulent wakes generated from the upstream turbines have significant impact.

Lee, S.; Churchfield, M.; Moriarty, P.; Jonkman, J.; Michalakes, J.

2011-12-01T23:59:59.000Z

358

Dehumidification and cooling loads from ventilation air  

SciTech Connect

The importance of controlling humidity in buildings is cause for concern, in part, because of indoor air quality problems associated with excess moisture in air-conditioning systems. But more universally, the need for ventilation air has forced HVAC equipment (originally optimized for high efficiency in removing sensible heat loads) to remove high moisture loads. To assist cooling equipment and meet the challenge of larger ventilation loads, several technologies have succeeded in commercial buildings. Newer technologies such as subcool/reheat and heat pipe reheat show promise. These increase latent capacity of cooling-based systems by reducing their sensible capacity. Also, desiccant wheels have traditionally provided deeper-drying capacity by using thermal energy in place of electrical power to remove the latent load. Regardless of what mix of technologies is best for a particular application, there is a need for a more effective way of thinking about the cooling loads created by ventilation air. It is clear from the literature that all-too-frequently, HVAC systems do not perform well unless the ventilation air loads have been effectively addressed at the original design stage. This article proposes an engineering shorthand, an annual load index for ventilation air. This index will aid in the complex process of improving the ability of HVAC systems to deal efficiently with the amount of fresh air the industry has deemed useful for maintaining comfort in buildings. Examination of typical behavior of weather shows that latent loads usually exceed sensible loads in ventilation air by at least 3:1 and often as much as 8:1. A designer can use the engineering shorthand indexes presented to quickly assess the importance of this fact for a given system design. To size those components after they are selected, the designer can refer to Chapter 24 of the 1997 ASHRAE Handbook--Fundamentals, which includes separate values for peak moisture and peak temperature.

Harriman, L.G. III [Mason-Grant, Portsmouth, NH (United States); Plager, D. [Quantitative Decision Support, Portsmouth, NH (United States); Kosar, D. [Gas Research Inst., Chicago, IL (United States)

1997-11-01T23:59:59.000Z

359

Gamma-soft Analog of the Confined Beta-soft Rotor Model  

E-Print Network (OSTI)

A gamma-soft analog of the confined beta-soft (CBS) rotor model is developed, by using a gamma-independent displaced infinite well beta-potential in the Bohr Hamiltonian, for which exact separation of variables is possible. Level schemes interpolating between the E(5) critical point symmetry (with R(4/2)=E(4)/E(2)= 2.20) and the O(5) gamma-soft rotor (with R(4/2)=2.50) are obtained, exhibiting a crossover of excited 0+ bandheads which leads to agreement with the general trends of first excited 0+ states in this region and is observed experimentally in 128-Xe and 130-Xe.

D. Bonatsos; D. Lenis; N. Pietralla; P. A. Terziev

2006-09-19T23:59:59.000Z

360

Guide to Optimized Nuclear Low-Pressure Turbine Rotor Inspection  

Science Conference Proceedings (OSTI)

In the past few years, the nuclear utility industry has reduced down-time for refueling outages to trim costs and improve overall unit performance. Consequently, this has also reduced the time available for other routine outage work and has often placed turbine maintenance and inspection tasks on the critical path. This report provides a review of the strategies several nuclear utilities have employed at their plants to reduce the time required to perform low-pressure turbine inspections. Included is a r...

1997-12-23T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Mass-Loaded Flows  

E-Print Network (OSTI)

A key process within astronomy is the exchange of mass, momentum, and energy between diffuse plasmas in many types of astronomical sources (including planetary nebulae, wind-blown bubbles, supernova remnants, starburst superwinds, and the intracluster medium) and dense, embedded clouds or clumps. This transfer affects the large scale flows of the diffuse plasmas as well as the evolution of the clumps. I review our current understanding of mass-injection processes, and examine intermediate-scale structure and the global effect of mass-loading on a flow. I then discuss mass-loading in a variety of diffuse sources.

J. M. Pittard

2006-07-13T23:59:59.000Z

362

Cooling load estimation methods  

DOE Green Energy (OSTI)

Ongoing research on quantifying the cooling loads in residential buildings, particularly buildings with passive solar heating systems, is described. Correlations are described that permit auxiliary cooling estimates from monthly average insolation and weather data. The objective of the research is to develop a simple analysis method, useful early in design, to estimate the annual cooling energy required of a given building.

McFarland, R.D.

1984-01-01T23:59:59.000Z

363

LOADING AND UNLOADING DEVICE  

DOE Patents (OSTI)

A device for loading and unloading fuel rods into and from a reactor tank through an access hole includes parallel links carrying a gripper. These links enable the gripper to go through the access hole and then to be moved laterally from the axis of the access hole to the various locations of the fuel rods in the reactor tank.

Treshow, M.

1960-08-16T23:59:59.000Z

364

Multidimensional spectral load balancing  

DOE Patents (OSTI)

A method of and apparatus for graph partitioning involving the use of a plurality of eigenvectors of the Laplacian matrix of the graph of the problem for which load balancing is desired. The invention is particularly useful for optimizing parallel computer processing of a problem and for minimizing total pathway lengths of integrated circuits in the design stage.

Hendrickson, Bruce A. (Albuquerque, NM); Leland, Robert W. (Albuquerque, NM)

1996-12-24T23:59:59.000Z

365

SYSPLAN. Load Leveling Battery System Costs  

SciTech Connect

SYSPLAN evaluates capital investment in customer side of the meter load leveling battery systems. Such systems reduce the customer`s monthly electrical demand charge by reducing the maximum power load supplied by the utility during the customer`s peak demand. System equipment consists of a large array of batteries, a current converter, and balance of plant equipment and facilities required to support the battery and converter system. The system is installed on the customer`s side of the meter and controlled and operated by the customer. Its economic feasibility depends largely on the customer`s load profile. Load shape requirements, utility rate structures, and battery equipment cost and performance data serve as bases for determining whether a load leveling battery system is economically feasible for a particular installation. Life-cycle costs for system hardware include all costs associated with the purchase, installation, and operation of battery, converter, and balance of plant facilities and equipment. The SYSPLAN spreadsheet software is specifically designed to evaluate these costs and the reduced demand charge benefits; it completes a 20 year period life cycle cost analysis based on the battery system description and cost data. A built-in sensitivity analysis routine is also included for key battery cost parameters. The life cycle cost analysis spreadsheet is augmented by a system sizing routine to help users identify load leveling system size requirements for their facilities. The optional XSIZE system sizing spreadsheet which is included can be used to identify a range of battery system sizes that might be economically attractive. XSIZE output consisting of system operating requirements can then be passed by the temporary file SIZE to the main SYSPLAN spreadsheet.

Hostick, C.J. [Pacific Northwest Lab., Richland, WA (United States)

1988-03-22T23:59:59.000Z

366

OpenEI Community - load data  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Utility Rate OpenEI Community...

367

OpenEI Community - electric load data  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Utility Rate OpenEI Community...

368

OpenEI Community - building load  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Utility Rate OpenEI Community...

369

OpenEI Community - residential load  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Utility Rate OpenEI Community...

370

OpenEI Community - commercial load  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Utility Rate OpenEI Community...

371

OpenEI Community - building load data  

Open Energy Info (EERE)

building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Utility Rate OpenEI Community...

372

Extracting Operating Modes from Building Electrical Load Data: Preprint  

Science Conference Proceedings (OSTI)

Empirical techniques for characterizing electrical energy use now play a key role in reducing electricity consumption, particularly miscellaneous electrical loads, in buildings. Identifying device operating modes (mode extraction) creates a better understanding of both device and system behaviors. Using clustering to extract operating modes from electrical load data can provide valuable insights into device behavior and identify opportunities for energy savings. We present a fast and effective heuristic clustering method to identify and extract operating modes in electrical load data.

Frank, S.; Polese, L. G.; Rader, E.; Sheppy, M.; Smith, J.

2012-01-01T23:59:59.000Z

373

LOADED WAVE GUIDES FOR LINEAR ACCELERATORS  

DOE Patents (OSTI)

A periodically loaded waveguide having substantially coaxially arranged elements which provide an axial field for the acceleration of electrons is described. Radiofrequency energy will flow in the space between the inner wall of an outer guide and the peripheries of equally spaced irises or washes arranged coaxially with each other and with the outer guide, where the loading due to the geometry of the irises is such as to reduce the phase velocity of the r-f energy flowing in the guide from a value greater than that of light to the velocity of light or less.

Walkinshaw, W.; Mullett, L.B.

1959-12-01T23:59:59.000Z

374

Impact of Nonlinear Loads on Motor Generator Sets  

Science Conference Proceedings (OSTI)

Using backup generators with loads that create high harmonics can cause power quality problems. This report describes how to calculate voltage distortion based on the different impedance characteristics of a generator and the harmonic current characteristics of loads and discusses options for reducing the harmonics and mitigating their impact.

2001-10-29T23:59:59.000Z

375

Low Wind Speed Technology Phase II: Reducing Cost of Energy Through Rotor Aerodynamics Control; Global Energy Concepts, LLC  

DOE Green Energy (OSTI)

This fact sheet describes a subcontract with Global Energy Concepts to evaluate a wide range of wind turbine configurations and their impact on overall cost of energy (COE).

Not Available

2006-03-01T23:59:59.000Z

376

Motion control for a vertical rigid rotor rotating in electromagnetic bearings  

Science Conference Proceedings (OSTI)

The problems of control of a motion of a rigid rotor in electromagnetic bearings are considered. The main ides of synthesis of the control laws is the approach based on feedback linearization of the original nonlinear mathematical model of the system. ...

D. V. Balandin; M. M. Kogan

2011-10-01T23:59:59.000Z

377

Situational awareness based flight control of a four-rotor type UAV  

Science Conference Proceedings (OSTI)

This paper focuses on a critical component of the situational awareness (SA), the control of autonomous vertical flight for an unmanned aerial vehicle (UAV). With the SA strategy, we proposed a two stage flight control procedure using two autonomous ... Keywords: flight control, four-rotor helicopter, simulation, situational awareness, unmanned aerial vehicle

Igor Astrov; Andrus Pedai

2011-05-01T23:59:59.000Z

378

Soft triaxial rotor in the vicinity of $?=?/6$ and its extensions  

E-Print Network (OSTI)

The collective Bohr hamiltonian is solved for the soft triaxial rotor around $\\gamma_0=\\pi/6$ with a displaced harmonic oscillator potential in $\\gamma$ and a Kratzer-like potential in $\\beta$. The properties of the spectrum are outlined and a generalization for the more general triaxial case with $0<\\gamma<\\pi/6$ is proposed.

L. Fortunato; S. De Baerdemacker; K. Heyde

2004-10-26T23:59:59.000Z

379

Gibbsianness versus Non-Gibbsianness of time-evolved planar rotor models  

E-Print Network (OSTI)

We study the Gibbsian character of time-evolved planar rotor systems on Z^d, d at least 2, in the transient regime, evolving with stochastic dynamics and starting with an initial Gibbs measure. We model the system by interacting Brownian diffusions, moving on circles. We prove that for small times and arbitrary initial Gibbs measures \

A. C. D. van Enter; W. M. Ruszel

2007-11-22T23:59:59.000Z

380

Atom optics kicked rotor: experimental evidence for a pendulum description of the quantum resonance  

E-Print Network (OSTI)

We present measurements of the mean energy for an atom optics kicked rotor ensemble close to quantum resonance. Oscillations in the mean energy in this regime are are shown to be in agreement with a quasi--classical pendulum approximation. The period of the oscillations is shown to scale with a single variable, which depends on the number of kicks.

S. Wayper; M. Sadgrove; W. Simpson; M. D. Hoogerland

2005-04-29T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Prediction and Analysis of Rotor Tip-Clearance Flows using Large-Eddy Simulation  

Science Conference Proceedings (OSTI)

In order to analyze the dynamics of rotor tip-clearance flow and determine the underlying mechanism for the tip-leakage cavitation, a newly developed large-eddy simulation (LES) solver which combines an immersed-boundary method with a generalized curvilinearstructured ...

Donghyun You; Meng Wang; Parviz Moin; Rajat Mittal

2004-06-01T23:59:59.000Z

382

Horizontal-axis wind-system rotor performance model comparison: a compendium  

SciTech Connect

This compendium consists of four reports, the purpose of which is to evaluate performance prediction methods for horizontal-axis wind turbines. The reports were prepared by four separate contractors. Oregon State University, AeroVironment, Inc., Aerospace Systems, Inc., and United Technologies Research Center (UTRC). Three of the four contractors used a blade-element/momentum analysis, while the fourth (UTRC) utilized a lifting line/prescribed wake analysis. These contractors were to apply their prediction methods to two rotors, that of the Enertech 1500 and that of the 1/3-scale UTRC 8 kW turbines. Results from the four prediction methods are compared with actual test data gathered via Controlled Velocity Testing (CVT), carried out by the Rocky Flats Wind Energy Research Center, operated by Rockwell International for the US Department of Energy. The conclusions of the four reports are reviewed in an introduction prepared by Rockwell International. For the Enertech 1500, rotor performance predictions closely agreed with CVT data. Yet, because of the lack of high tip speed ratio data, verification of the Glauert momentum theory was not possible. Predictions regarding the UTRC 1/3 scale 8 kW rotor did not agree well with test results. The reasons cited for the discrepancies center on inadequate airfoil section data and the varying blade pitch angles of the unique UTRC flexbeam rotor.

Not Available

1983-02-01T23:59:59.000Z

383

Dynamic Analysis and Control of an Energy Storage Flywheel Rotor with Active Magnetic Bearings  

Science Conference Proceedings (OSTI)

Flywheel energy storage is a promising technology for providing intermediate energy storage. An energy storage flywheel is supported by active magnetic bearings (AMBs) to achieve high speed running and increase energy efficiency of the energy storage ... Keywords: Flywheel, Energy Storage, Magnetic Bearing, Rotor Dynamics

Zhang Kai; Dai Xingjian; Zhang Xiaozhang

2010-12-01T23:59:59.000Z

384

MPC for Wind Power Gradients --Utilizing Forecasts, Rotor Inertia, and Central Energy Storage  

E-Print Network (OSTI)

MPC for Wind Power Gradients -- Utilizing Forecasts, Rotor Inertia, and Central Energy Storage iterations. We demonstrate our method in simulations with various wind scenarios and prices for energy. INTRODUCTION Today, wind power is the most important renewable energy source. For the years to come, many

385

Report on Toyota/Prius Motor Torque Capability, Torque Property, No-Load Back EMF, and Mechanical Losses, Revised May 2007  

Science Conference Proceedings (OSTI)

In today's hybrid vehicle market, the Toyota/Prius drive system is currently considered the leader in electrical, mechanical, and manufacturing innovations. It is significant that in today's marketplace, Toyota is able to manufacture and sell the vehicle for a profit. This project's objective is to test the torque capability of the 2004 Prius motor and to analyze the torque properties relating to the rotor structure. The tested values of no-load back electromotive force (emf) and mechanical losses are also presented.

Hsu, J.S.; Ayers, C.W.; Coomer, C.L.; Wiles, R.H.; Burress, T.A.; Campbell, S.L.; Lowe, K.T.; Michelhaugh, R.T.

2007-05-31T23:59:59.000Z

386

Load Capacity of Bodies  

E-Print Network (OSTI)

For the stress analysis in a plastic body $\\Omega$, we prove that there exists a maximal positive number $C$, the \\emph{load capacity ratio,} such that the body will not collapse under any external traction field $t$ bounded by $Y_{0}C$, where $Y_0$ is the elastic limit. The load capacity ratio depends only on the geometry of the body and is given by $$ \\frac{1}{C}=\\sup_{w\\in LD(\\Omega)_D} \\frac{\\int_{\\partial\\Omega}|w|dA} {\\int_{\\Omega}|\\epsilon(w)|dV}=\\left\\|\\gamma_D\\right\\|. $$ Here, $LD(\\Omega)_D$ is the space of isochoric vector fields $w$ for which the corresponding stretchings $\\epsilon(w)$ are assumed to be integrable and $\\gamma_D$ is the trace mapping assigning the boundary value $\\gamma_D(w)$ to any $w\\in LD(\\Omega)_D$.

Reuven Segev

2005-11-01T23:59:59.000Z

387

Low Wind Speed Technology Phase II: Sweep-Twist Blade Design and Fabrication with Atmospheric Test Verification  

DOE Green Energy (OSTI)

This fact sheet describes NREL's subcontract with Knight & Carver to develop a sweep-twist adaptive balde to reduce loads and allow a larger more productive rotor.

Not Available

2006-06-01T23:59:59.000Z

388

CX-007538: Categorical Exclusion Determination | Department of...  

Energy.gov (U.S. Department of Energy (DOE)) Indexed Site

is proposing to provide federal funding to Siemens Energy, Inc. (Siemens) to research wind turbine designs that reduce the aeronautical loads turbine rotors experience during...

389

Load responsive hydrodynamic bearing  

Science Conference Proceedings (OSTI)

A load responsive hydrodynamic bearing is provided in the form of a thrust bearing or journal bearing for supporting, guiding and lubricating a relatively rotatable member to minimize wear thereof responsive to relative rotation under severe load. In the space between spaced relatively rotatable members and in the presence of a liquid or grease lubricant, one or more continuous ring shaped integral generally circular bearing bodies each define at least one dynamic surface and a plurality of support regions. Each of the support regions defines a static surface which is oriented in generally opposed relation with the dynamic surface for contact with one of the relatively rotatable members. A plurality of flexing regions are defined by the generally circular body of the bearing and are integral with and located between adjacent support regions. Each of the flexing regions has a first beam-like element being connected by an integral flexible hinge with one of the support regions and a second beam-like element having an integral flexible hinge connection with an adjacent support region. A least one local weakening geometry of the flexing region is located intermediate the first and second beam-like elements. In response to application of load from one of the relatively rotatable elements to the bearing, the beam-like elements and the local weakening geometry become flexed, causing the dynamic surface to deform and establish a hydrodynamic geometry for wedging lubricant into the dynamic interface.

Kalsi, Manmohan S. (Houston, TX); Somogyi, Dezso (Sugar Land, TX); Dietle, Lannie L. (Stafford, TX)

2002-01-01T23:59:59.000Z

390

Real-time rotor bar current measurements using bluetooth technology for a brushless doubly-fed machine (BDFM  

E-Print Network (OSTI)

The Brushless Doubly Fed Machine (BDFM) shows economic promise as a variable speed drive or generator. The optimization of the machine and model-based control strategies both rely on machine models, and the experimental verification of these models. To date, dynamic measurements of rotor quantities have not been possible. The authors present a system of measuring rotor bar currents in real time using a Rogowski coil to detect the current and recently developed Bluetooth wireless technology to transmit the data from the moving rotor to a computer. Experimental data collected from the system are included. 1.

P. C. Roberts; E. Abdi Jalebi; R. A. Mcmahon; T. J. Flack

2004-01-01T23:59:59.000Z

391

Variable loading roller  

DOE Patents (OSTI)

An automatic loading roller for transmitting torque in traction drive devices in manipulator arm joints includes a two-part camming device having a first cam portion rotatable in place on a shaft by an input torque and a second cam portion coaxially rotatable and translatable having a rotating drive surface thereon for engaging the driven surface of an output roller with a resultant force proportional to the torque transmitted. Complementary helical grooves in the respective cam portions interconnected through ball bearings interacting with those grooves effect the rotation and translation of the second cam portion in response to rotation of the first. 14 figs.

Williams, D.M.

1988-01-21T23:59:59.000Z

392

A TIME ACCURATE PREDICTION OF THE VISCOUS FLOW IN A TURBINE STAGE INCLUDING A ROTOR IN MOTION.  

E-Print Network (OSTI)

??AbstractA TIME ACCURATE PREDICTION OF THE VISCOUS FLOW IN A TURBINE STAGE INCLUDING A ROTOR IN MOTIONBy Akamol ShavalikulThe actual flow field in a turbine… (more)

Shavalikul, Akamol

2009-01-01T23:59:59.000Z

393

Building America System Research Plan for Reduction of Miscellaneous Electrical Loads in Zero Energy Homes  

SciTech Connect

This research plan describes the overall scope of system research that is needed to reduce miscellaneous electrical loads (MEL) in future net zero energy homes.

Barley, C. D.; Haley, C.; Anderson, R.; Pratsch, L.

2008-11-01T23:59:59.000Z

394

Designing and Testing Controls to Mitigate Tower Dynamic Loads in the Controls Advanced Research Turbine: Preprint  

DOE Green Energy (OSTI)

This report describes NREL's efforts to design, implement, and test advanced controls for maximizing energy extraction and reducing structural dynamic loads in wind turbines.

Wright, A. D.; Fingersh, L. J.; Stol, K. A.

2007-01-01T23:59:59.000Z

395

Investigation of Peak Load Reduction Strategies in Residential Buildings in Cooling Dominated Climates.  

E-Print Network (OSTI)

??This investigation of peak load reduction strategies in residential buildings contributes to the global international efforts in reducing energy consumption and is related directly to… (more)

Atallah, Fady

2013-01-01T23:59:59.000Z

396

Effect of DC to DC converters on organic solar cell arrays for powering DC loads .  

E-Print Network (OSTI)

??The objective of this research is to determine if it is possible to reduce the number of organic solar cells required to power a load… (more)

Trotter, Matthew S.

2009-01-01T23:59:59.000Z

397

SAFER-PC Version 2.2, Stress and Fracture Evaluation of Rotors - Personal Computer, Version 2.2  

Science Conference Proceedings (OSTI)

The Stress and Fracture Evaluation of RotorsPersonal Computer (SAFER-PC), Version 2.2 software will evaluate the remaining life of steam turbine and generator rotors. Version 2.2 is an upgrade of existing analysis software. SAFER-PC combines transient thermal-elastic finite element stress analysis, fracture mechanics, material property data, and the clustering and linking of surface defects identified from nondestructive examination (NDE) data to assess remaining usable life of steam turbine or generator...

2006-12-22T23:59:59.000Z

398

Metallurgical Guidebook for Steam Turbine Rotors and Discs, Volume 1: Chemistry, Manufacturing, Service Degradation, Life Assessment , and Repair  

Science Conference Proceedings (OSTI)

This guide is a compilation of information concerning steam turbine rotors and discs. Due to the variety of operating temperatures and conditions involved, factors such as material composition, manufacturing and heat treatment condition methods, and property requirements may differ from one steam turbine to another. Specifically, this guide addresses turbine rotor and disc materials used, vintages, manufacturing history, quality conditions, and chemical and mechanical properties, and it provides utility ...

2009-12-23T23:59:59.000Z

399

Dynamic model of power system operation incorporating load control  

SciTech Connect

Load management has been proposed as a means whereby an electric utility can reduce its requirements for additional generation, transmission, and distribution investments, shift fuel dependency from limited to more abundant energy resources, and improve the efficiency of the electric energy system. There exist, however, serious technological and economic questions which must be answered to define the cost trade-offs between initiating a load management strategy or adding additional capacity to meet the load. One aspect of this complex problem is to determine how the load profile might be modified by the load management option being considered. Towards this end, a model has been developed to determine how a power system with an active load control system should be operated to make the best use of its available resources. The model is capable of handling all types of conventional generating sources including thermal, hydro, and pumped storage units, and most appliances being considered for direct control including those with inherent or designed storage characteristics. The model uses a dynamic programming technique to determine the optimal operating strategy for a given set of conditions. The use of the model is demonstrated. Case study results indicate that the production cost savings that can be achieved through the use of direct load control are highly dependent on utility characteristics, load characteristics, storage capacity, and penetration. The load characteristics that produce the greatest savings are: large storage capacity; high coincidence with the system peak; large connected load per point; and moderately high diversity fraction.

Kuliasha, M.A.

1980-10-01T23:59:59.000Z

400

Numerical simulation of VAWT stochastic aerodynamic loads produced by atmospheric turbauence: VAWT-SAL code  

DOE Green Energy (OSTI)

Blade fatigue life is an important element in determining the economic viability of the Vertical-Axis Wind Turbine (VAWT). A principal source of blade fatigue is thought to be the stochastic (i.e., random) aerodynamic loads created by atmospheric turbulence. This report describes the theoretical background of the VAWT Stochastic Aerodynamic Loads (VAWT-SAL) computer code, whose purpose is to numerically simulate these random loads, given the rotor geometry, operating conditions, and assumed turbulence properties. A Double-Multiple-Stream Tube (DMST) analysis is employed to model the rotor's aerodynamic response. The analysis includes the effects of Reynolds number variations, different airfoil sections and chord lengths along the blade span, and an empirical model for dynamic stall effects. The mean ambient wind is assumed to have a shear profile which is described by either a power law or a logarithmic variation with height above ground. Superimposed on this is a full 3-D field of turbulence: i.e., in addition to random fluctuations in time, the turbulence is allowed to vary randomly in planes perpendicular to the mean wind. The influence of flow retardation on the convection of turbulence through the turbine is also modeled. Calculations are presented for the VAWT 34-m Test Bed currently in operation at Bushland, Texas. Predicted time histories of the loads, as well as their Fourier spectra, are presented and discussed. Particular emphasis is placed on the differences between so-called steady-state'' (mean wind only) predictions, and those produced with turbulence present. Somewhat surprisingly, turbulence is found to be capable of either increasing or decreasing the average output power, depending on the turbine's tip-speed ratio. A heuristic explanation for such behavior is postulated, and a simple formula is derived for predicting the magnitude of this effect without the need for a full stochastic simulation. 41 refs., 32 figs., 1 tab.

Homicz, G.F.

1991-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Definition: Reduced Congestion Cost | Open Energy Information  

Open Energy Info (EERE)

Cost Cost Jump to: navigation, search Dictionary.png Reduced Congestion Cost Transmission congestion is a phenomenon that occurs in electric power markets. It happens when scheduled market transactions (generation and load) result in power flow over a transmission element that exceeds the available capacity for that element. Since grid operators must ensure that physical overloads do not occur, they will dispatch generation so as to prevent them. The functions that provide this benefit provide lower cost energy, decrease loading on system elements, shift load to off-peak, or allow the grid operator to manage the flow of electricity around constrained interfaces (i.e. dynamic line capability or power flow control).[1] Related Terms power, transmission lines, load, element, electricity

402

Demonstration of perfect coherence preservation for matter-waves perturbed by a delta-kicked rotor  

E-Print Network (OSTI)

We demonstrate perfect coherence preservation in an atom interferometer perturbed by optical standing wave pulses acting as a kicked rotor. In our experiment we subject a cloud of cold rubidium atoms in a magnetic guide to periodic kicks from a sinusoidal potential created by standing wave pulses of off-resonant laser light propagating along the guiding direction. While, in general, we observed a strong decoherence of matter-waves due to applied perturbations the coherence is perfectly preserved for the conditions similar but not limited to quantum resonances of the quantum kicked rotor. Moreover, these conditions do not depend on the number of kicks applied or require any regularity in the pulse strengths. We show that the narrowing of the width of coherence revival as a function of increasing kick number provides a new method for precise measurement of recoil frequency.

Tonyushkin, A; Prentiss, M

2008-01-01T23:59:59.000Z

403

Delocalized and Resonant Quantum Transport in Nonlinear Generalizations of the Kicked Rotor Model  

E-Print Network (OSTI)

We analyze the effects of a nonlinear cubic perturbation on the delta-Kicked Rotor. We consider two different models, in which the nonlinear term acts either in the position or in the momentum representation. We numerically investigate the modifications induced by the nonlinearity in the quantum transport in both localized and resonant regimes and a comparison between the results for the two models is presented. Analyzing the momentum distributions and the increase of the mean square momentum, we find that the quantum resonances asymptotically are very stable with respect to the nonlinear perturbation of the rotor's phase evolution. For an intermittent time regime, the nonlinearity even enhances the resonant quantum transport, leading to superballistic motion.

Laura Rebuzzini; Sandro Wimberger; Roberto Artuso

2004-10-12T23:59:59.000Z

404

Frequency Dependence of Rotor's Free Falling Acceleration and Inequality of Inertial and Gravity Masses  

E-Print Network (OSTI)

Results of measurements of free falling acceleration of a closed container with a rotor of a mechanical gyroscope placed inside it on the frequency of the rotor rotation are briefly described. Time of separate accelerations measurements is 40 ms, the period of sampling is from 0.5 up to 1.0 minute. In rotation's frequencies range of 20-400 Hz, the negative changes of free falling container acceleration prevail. On individual frequencies the "resonant" maxima and minima of acceleration are observed. The obtained data apparently contradict the equivalence principle of inertial and gravitating masses. The expediency of development of ballistic gravimetry of high time resolution with use of rotating or oscillating test bodies is noted.

Dmitriev, Alexander L

2011-01-01T23:59:59.000Z

405

Frequency Dependence of Rotor's Free Falling Acceleration and Inequality of Inertial and Gravity Masses  

E-Print Network (OSTI)

Results of measurements of free falling acceleration of a closed container with a rotor of a mechanical gyroscope placed inside it on the frequency of the rotor rotation are briefly described. Time of separate accelerations measurements is 40 ms, the period of sampling is from 0.5 up to 1.0 minute. In rotation's frequencies range of 20-400 Hz, the negative changes of free falling container acceleration prevail. On individual frequencies the "resonant" maxima and minima of acceleration are observed. The obtained data apparently contradict the equivalence principle of inertial and gravitating masses. The expediency of development of ballistic gravimetry of high time resolution with use of rotating or oscillating test bodies is noted.

Alexander L. Dmitriev

2011-01-24T23:59:59.000Z

406

The Rotor Model with spectral parameters and enumerations of Alternating Sign Matrices  

E-Print Network (OSTI)

In this paper we study the Rotor Model of Martins and Nienhuis. After introducing spectral parameters, a combined use of integrability, polynomiality of the ground state wave function and a mapping into the fully-packed O(1)-model allows us to determine the sum rule and a family of maximally nested components for different boundary conditions. We see in this way the appearance of 3-enumerations of Alternating Sign Matrices.

Luigi Cantini

2007-03-29T23:59:59.000Z

407

The initial momentum dependence of the quantum resonance in the delta-kicked rotor  

E-Print Network (OSTI)

The influence of an initial momentum on the appearance of "quantum resonances" in the delta-kicked rotor system is explored experimentally. We show that for certain initial momenta, a resonance can be negated entirely, whereas at others a resonance can be made to appear. At a larger number of kicks, all resonances are shown to narrow. We show that as a consequence, the individual "diffraction peaks" may split. We compare our results to numerical simulations as well as analytical theory.

J-A. Currivan; A. Ullah; M. D. Hoogerland

2008-06-18T23:59:59.000Z

408

Short-time quantum correlations in the atom optics kicked rotor  

E-Print Network (OSTI)

We experimentally verify the analytical expressions that exist for the diffusion rate in the quantum delta kicked rotor system for small numbers of kicks. We show development of diffusion resonances from two to five kicks, and of multiple resonances for high kick strengths. Furthermore, we show that, in contrast to classical predictions, the results are purely periodic in the kick period, and reproduce the predicted quantum- and diffusion resonances.

S. A. Wayper; W. Simpson; M. D. Hoogerland

2006-02-08T23:59:59.000Z

409

MTS Table Top Load frame  

NLE Websites -- All DOE Office Websites (Extended Search)

MTS Table Top Load frame MTS Table Top Load frame The Non-destructive Evaluation group operates an MTS Table Top Load frame for ultimate strength and life cycle testing of various ceramic, ceramic-matrix (FGI), carbon, carbon fiber, cermet (CMC) and metal alloy engineering samples. The load frame is a servo-hydraulic type designed to function in a closed loop configuration under computer control. The system can perform non-cyclic, tension, compression and flexure testing and cyclic fatigue tests. The system is comprised of two parts: * The Load Frame and * The Control System. Load Frame The Load Frame (figure 1) is a cross-head assembly which includes a single moving grip, a stationary grip and LVDT position sensor. It can generate up to 25 kN (5.5 kip) of force in the sample under test and can

410

Labyrinth for an ignition distributor cap and rotor assembly with atmospheric purging action  

SciTech Connect

This patent describes an ignition distributor to work with spark plug electrodes, a rotor electrode, a coil electrode and a shaft for an internal combustion engine with cylinders, the ignition distributor comprising: a bowl shaped housing; a distributor cap comprising: a generally dome shape with a generally hollow interior and with a circular shaped bottom to mate with the bowl shaped housing; spark towers equal in number to the number of cylinders of the internal combustion engine, projecting up from the top of the dome shape and slotted to accept spark plug electrodes and allow them to protrude into the distributor cap interior for communication with the rotor electrode; a vent tower projecting up from the top of the dome shape and provided with a vent port through to the distributor cap interior to allow for the outward flow of the atmosphere inside the distributor cap and bowl shaped housing; a coil tower projecting up from the top of the dome shape and slotted to accept a coil electrode and allow it to protrude into the distributor cap interior for communication with the rotor electrode; an inner labyrinth of annular shape on the interior surface of the dome shape surround the coil electrode and protruding into the hollow interior of the dome shape; and an outer labyrinth of annular shape on the interior surface of the dome shape surrounding the inner labyrinth thereby forming an annular channel.

Kronberger, L.J.

1986-12-23T23:59:59.000Z

411

Can quantum fractal fluctuations be observed in an atom-optics kicked rotor experiment?  

E-Print Network (OSTI)

We investigate the parametric fluctuations in the quantum survival probability of an open version of the delta-kicked rotor model in the deep quantum regime. Spectral arguments [Guarneri I and Terraneo M 2001 Phys. Rev. E vol. 65 015203(R)] predict the existence of parametric fractal fluctuations owing to the strong dynamical localisation of the eigenstates of the kicked rotor. We discuss the possibility of observing such dynamically-induced fractality in the quantum survival probability as a function of the kicking period for the atom-optics realisation of the kicked rotor. The influence of the atoms' initial momentum distribution is studied as well as the dependence of the expected fractal dimension on finite-size effects of the experiment, such as finite detection windows and short measurement times. Our results show that clear signatures of fractality could be observed in experiments with cold atoms subjected to periodically flashed optical lattices, which offer an excellent control on interaction times and the initial atomic ensemble.

Andrea Tomadin; Riccardo Mannella; Sandro Wimberger

2005-12-01T23:59:59.000Z

412

Turbine blade platform film cooling with simulated stator-rotor purge flow with varied seal width and upstream wake with vortex  

E-Print Network (OSTI)

The turbine blade platform can be protected from hot mainstream gases by injecting cooler air through the gap between stator and rotor. The effectiveness of this film cooling method depends on the geometry of the slot, the quantity of injected air, and the secondary flows near the platform. The purpose of this study was to measure the effect of the upstream vane or stator on this type of platform cooling, as well as the effect of changes in the width of the gap. Film cooling effectiveness distributions were obtained on a turbine blade platform within a linear cascade with upstream slot injection. The width of the slot was varied as well as the mass flow rate of the injected coolant. Obstacles were placed upstream to model the effect of the upstream vane. The coolant was injected through an advanced labyrinth seal to simulate purge flow through a stator-rotor seal. The width of the opening of this seal was varied to simulate the effect of misalignment. Stationary rods were placed upstream of the cascade in four phase locations to model the unsteady wake formed at the trailing edge of the upstream vane. Delta wings were also placed in four positions to create a vortex similar to the passage vortex at the exit of the vane. The film cooling effectiveness distributions were measured using pressure-sensitive paint (PSP). Reducing the width of the slot was found to decrease the area of coolant coverage, although the film cooling effectiveness close to the slot was slightly increased. The unsteady wake was found to have a trivial effect on platform cooling, while the passage vortex from the upstream vane may significantly reduce the film cooling effectiveness.

Blake, Sarah Anne

2007-05-01T23:59:59.000Z

413

Wind loading on solar collectors  

DOE Green Energy (OSTI)

The present design methodology for the determination of wind loading on the various solar collectors has been reviewed and assessed. The total force coefficients of flat plates of aspect ratios 1.0 and 3.0, respectively, at various angles of attack obtained by using the guidelines of the ANSI A58.1-1982, have been compared with those obtained by using the methodology of the ASCE Task Committee, 1961, and the experimental results of the full-scale test of heliostats by Peglow. The turbulent energy spectra, currently employed in the building code, are compared with those of Kaimal et al., Lumley, and Ponofsky for wind velocities of 20.0 m/s and 40.24 m/s at an elevation of 9.15 m. The longitudinal spectra of the building code overestimates the Kaimal spectra in the frequency range of 0.007 Hz to 0.08 Hz and underestimates beyond the frequency of 0.08 Hz. The peak angles of attack, on the heliostat, stowed in horizontal position, due to turbulent vertical and lateral components of wind velocity, have been estimated by using Daniel's methodology for three wind velocities and compared with the value suggested by the code. The experimental results of a simple test in the laboratory indicate the feasibility of decreasing the drag forces of the flat plate by reducing the solidity ratio.

Bhaduri, S.; Murphy, L.M.

1985-06-01T23:59:59.000Z

414

Transmission and Distribution Benefits of Direct Load Control: Seattle City Light and Snohomish Public Utility District Pilot Project Evaluations  

Science Conference Proceedings (OSTI)

Two residential direct load control programs in the Puget Sound region have reduced peak loads at both the system as well as the local transmission and distribution levels. This report presents program load impact results estimated using metered and disaggregated end-use load data. Included is a detailed description of participants' attitudes toward the programs and their experiences with program implementation.

1994-05-21T23:59:59.000Z

415

Dynamic load balancing in IP-over-WDM optical burst switching networks  

Science Conference Proceedings (OSTI)

In this paper, we consider the problem of dynamic load balancing in wavelength division multiplexing (WDM)-based optical burst switching (OBS) networks. We propose a load balancing scheme based on adaptive alternate routing aimed at reducing burst loss. ... Keywords: Load balancing, Optical burst switching, Traffic engineering, Wavelength division multiplexing

J. Li; G. Mohan; K. C. Chua

2005-02-01T23:59:59.000Z

416

Dynamic load balancing of applications  

DOE Patents (OSTI)

An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated.

Wheat, Stephen R. (Albuquerque, NM)

1997-01-01T23:59:59.000Z

417

Dynamic load balancing of applications  

DOE Patents (OSTI)

An application-level method for dynamically maintaining global load balance on a parallel computer, particularly on massively parallel MIMD computers is disclosed. Global load balancing is achieved by overlapping neighborhoods of processors, where each neighborhood performs local load balancing. The method supports a large class of finite element and finite difference based applications and provides an automatic element management system to which applications are easily integrated. 13 figs.

Wheat, S.R.

1997-05-13T23:59:59.000Z

418

Alaska Village Electric Load Calculator  

DOE Green Energy (OSTI)

As part of designing a village electric power system, the present and future electric loads must be defined, including both seasonal and daily usage patterns. However, in many cases, detailed electric load information is not readily available. NREL developed the Alaska Village Electric Load Calculator to help estimate the electricity requirements in a village given basic information about the types of facilities located within the community. The purpose of this report is to explain how the load calculator was developed and to provide instructions on its use so that organizations can then use this model to calculate expected electrical energy usage.

Devine, M.; Baring-Gould, E. I.

2004-10-01T23:59:59.000Z

419

High-Power Rf Load  

DOE Patents (OSTI)

A compact high-power RF load comprises a series of very low Q resonators, or chokes [16], in a circular waveguide [10]. The sequence of chokes absorb the RF power gradually in a short distance while keeping the bandwidth relatively wide. A polarizer [12] at the input end of the load is provided to convert incoming TE.sub.10 mode signals to circularly polarized TE.sub.11 mode signals. Because the load operates in the circularly polarized mode, the energy is uniformly and efficiently absorbed and the load is more compact than a rectangular load. Using these techniques, a load having a bandwidth of 500 MHz can be produced with an average power dissipation level of 1.5 kW at X-band, and a peak power dissipation of 100 MW. The load can be made from common lossy materials, such as stainless steel, and is less than 15 cm in length. These techniques can also produce loads for use as an alternative to ordinary waveguide loads in small and medium RF accelerators, in radar systems, and in other microwave applications. The design is easily scalable to other RF frequencies and adaptable to the use of other lossy materials.

Tantawi, Sami G. (San Mateo, CA); Vlieks, Arnold E. (Livermore, CA)

1998-09-01T23:59:59.000Z

420

Grid Friendly Appliances – Load-side Solution for Congestion Management  

SciTech Connect

This paper discusses the effectiveness of deploying grid-friendly{trademark} appliances (GFAs) as a load-side solution for congestion management in a competitive electricity market, with the residential house ventilation and air conditioning (HVAC) load used as an example. A GFA is an appliance that can have a sensor and a controller installed to detect price, voltage, or frequency signals and turn on/off according to certain control logic. By using the congestion price as a signal to shift GFA power consumption from high-price periods to low-price periods to reduce load in load pocket areas, transmission line congestion can be successfully mitigated. The magnitude of GFA load reduction and the location of the GFA resources are critical to relieve congestion on targeted lines while not causing other lines to congest. Simulation results are presented and the impact of implementing price-responsive GFAs on the power grid is also studied.

Lu, Ning; Nguyen, Tony B.

2006-05-21T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

End-Use Load Research in a Smart Grid World  

Science Conference Proceedings (OSTI)

In October 2010, EPRI conducted a workshop with EPRI members to identify how broad application of "Smart Grid" or advanced metering infrastructure (AMI) technologies could both increase need for and reduce cost of acquiring high-quality load research data. Representatives from regulated utilities, independent system operators/regional transmission organizations (ISO/RTOs), and industry experts participated. Utility representatives said that they are using "antique" load shape data for forecasting, planni...

2010-12-23T23:59:59.000Z

422

Static identification of delinquent loads  

E-Print Network (OSTI)

The effective use of processor caches is crucial to the performance of applications. It has been shown that cache misses are not evenly distributed throughout a program. In applications running on RISC-style processors, a small number of delinquent load instructions are responsible for most of the cache misses. Identification of delinquent loads is the key to the success of many cache optimization and prefetching techniques. In this paper, we propose a method for identifying delinquent loads that can be implemented at compile time. Our experiments over eighteen benchmarks from the SPEC suite shows that our proposed scheme is stable across benchmarks, inputs, and cache structures, identifying an average of 10 % of the total number of loads in the benchmarks we tested that account for over 90 % of all data cache misses. As far as we know, this is the first time a technique for static delinquent load identification with such a level of precision and coverage has been reported. While comparable techniques can also identify load instructions that cover 90 % of all data cache misses, they do so by selecting over 50 % of all load instructions in the code, resulting in a high number of false positives. If basic block profiling is used in conjunction with our heuristic, then our results show that it is possible to pin down just 1.3 % of the load instructions that account for 82 % of all data cache misses. 1.

Vlad-mihai Panait; Amit Sasturkar Ý

2004-01-01T23:59:59.000Z

423

LOAD FORECASTING Eugene A. Feinberg  

E-Print Network (OSTI)

's electricity price forecasting model, produces forecast of gas demand consistent with electric load. #12Gas demand Council's Market Price of Electricity Forecast Natural GasDemand Electric Load Aggregating Natural between the natural gas and electricity and new uses of natural gas emerge. T natural gas forecasts

Feinberg, Eugene A.

424

building load | OpenEI  

Open Energy Info (EERE)

load load Dataset Summary Description This dataset contains hourly load profile data for 16 commercial building types (based off the DOE commercial reference building models) and residential buildings (based off the Building America House Simulation Protocols). This dataset also includes the Residential Energy Consumption Survey (RECS) for statistical references of building types by location. Source Commercial and Residential Reference Building Models Date Released April 18th, 2013 (9 months ago) Date Updated July 02nd, 2013 (7 months ago) Keywords building building demand building load Commercial data demand Energy Consumption energy data hourly kWh load profiles Residential Data Quality Metrics Level of Review Some Review Comment Temporal and Spatial Coverage Frequency Annually

425

DIELECTRIC-LOADED WAVE-GUIDES  

DOE Patents (OSTI)

This patent presents a particular arrangement for delectric loading of a wave-guide carrying an electromagnetic wave in the E or TM mode of at least the second order, to reduce the power dissipated as the result of conduction loss in the wave-guide walls. To achieve this desirabie result, the effective dielectric constants in the radial direction of adjacent coaxial tubular regions bounded approximateiy by successive nodai surfaces within the electromagnetic field are of two different values alternating in the radial direction, the intermost and outermost regions being of the lower value, and the dielectric constants between nodes are uniform.

Robertson-Shersby-Harvie, R.B.; Mullett, L.B.

1957-04-23T23:59:59.000Z

426

Rotor Design for High Pressure Magic Angle Spinning Nuclear Magnetic Resonance  

Science Conference Proceedings (OSTI)

High pressure magic angle spinning (MAS) nuclear magnetic resonance (NMR) with a sample spinning rate exceeding 2.1 kHz and pressure greater than 165 bar has never been realized. In this work, a new sample cell design is reported, suitable for constructing cells of different sizes. Using a 7.5 mm high pressure MAS rotor as an example, internal pressure as high as 200 bar at a sample spinning rate of 6 kHz is achieved. The new high pressure MAS rotor is re-usable and compatible with most commercial NMR set-ups, exhibiting low 1H and 13C NMR background and offering maximal NMR sensitivity. As an example of its many possible applications, this new capability is applied to determine reaction products associated with the carbonation reaction of a natural mineral, antigorite ((Mg,Fe2+)3Si2O5(OH)4), in contact with liquid water in water-saturated supercritical CO2 (scCO2) at 150 bar and 50 ?C. This mineral is relevant to the deep geologic disposal of CO2, but its iron content results in too many sample spinning sidebands at low spinning rate. Hence, this chemical system is a good case study to demonstrate the utility of the higher sample spinning rates that can be achieved by our new rotor design. We expect this new capability will be useful for exploring solid-state, including interfacial, chemistry at new levels of high-pressure in a wide variety of fields.

Turcu, Romulus VF; Hoyt, David W.; Rosso, Kevin M.; Sears, Jesse A.; Loring, John S.; Felmy, Andrew R.; Hu, Jian Z.

2013-01-01T23:59:59.000Z

427

Load management and the La Vereda passive solar community  

SciTech Connect

Reviewed are preliminary data available from some of the passive solar homes now operational at the La Vereda subdivision in Santa Fe, New Mexico. The major emphasis is Load Management - an electric utility term pertaining to when and how much energy is used by the customer. A customer's home is considered to be Load Managed when its major demands for electricity occur at times during the day when the utility has surplus generation capacity. For most utilities this surplus occurs during the night and is referred to as the off-peak period. Compared to conventional electric homes, the La Vereda passive solar homes are Naturally Load Managed because most of their backup heating requirements occur during the utility's off-peak period. Naturally Load Managed homes like these allow the backup heating system to operate freely whenever the space needs heat. Load data from six La Vereda homes are compared to similar data from 1) a group of nonsolar super-insulated total electric homes, and 2) the utility's winter system peak day load profile. The comparison verifies the Natural Load Management characteristics of the well-designed passive solar home. The free operation of the backup heating system, especially during cloudy or severe weather, can reduce the Natural Load Management characteristics of the La Verda homes. Is it possible to Force Load Management on a home, regardless of weather conditions and still guarantee that all space heating requirements are satisfied with off-peak energy. One home at La Vereda is discussed that has an experimental Forced Load Management backup heating system designed to use energy only during the utility's off-peak period. Load data from this home is presented and compared to other homes at La Verda.

Pyde, S.E.

1981-01-01T23:59:59.000Z

428

O&M First! Actions You Can Take to Reduce Heating Costs  

NLE Websites -- All DOE Office Websites (Extended Search)

Fact Sheet Actions You Can Take to Reduce Heating Costs Heating accounts for a significant energy load and usually presents a number of opportunities to improve performance and...

429

Characterizing Inflow Conditions Across the Rotor Disk of a Utility-Scale Wind Turbine (Poster)  

DOE Green Energy (OSTI)

Multi-megawatt utility-scale wind turbines operate in a turbulent, thermally-driven atmosphere where wind speed and air temperature vary with height. Turbines convert the wind's momentum into electrical power, and so changes in the atmosphere across the rotor disk influence the power produced by the turbine. To characterize the inflow into utility scale turbines at the National Wind Technology Center (NWTC) near Boulder, Colorado, NREL recently built two 135-meter inflow monitoring towers. This poster introduces the towers and the measurements that are made, showing some of the data obtained in the first few months of operation in 2011.

Clifton, A.; Lundquist, J. K.; Kelley, N.; Scott, G.; Jager, D.; Schreck, S.

2012-01-01T23:59:59.000Z

430

Suppression of decoherence-induced diffusion in the quantum kicked rotor  

Science Conference Proceedings (OSTI)

We describe a method that allows transient suppression of spontaneous emission-induced diffusion in the atom-optics realization of the kicked rotor. The system is prepared in an initial state with a momentum distribution concentrated in an interval much sharper than the Brillouin zone; the measure of the momentum distribution is restricted to this interval of quasimomenta. Because most of the atoms undergoing decoherence processes fall outside this detection range and thus are not detected, the measured signal is effectively free of decoherence-induced diffusion effects.

Lepers, Maxence; Zehnle, Veronique; Garreau, Jean Claude [Laboratoire de Physique des Lasers, Atomes et Molecules, Universite Lille 1 Sciences et Technologies, CNRS, F-59655 Villeneuve d'Ascq Cedex (France)

2010-06-15T23:59:59.000Z

431

Blade-forced vibration effects in turbomachinery rotor-stator interaction  

E-Print Network (OSTI)

This thesis presents the effects of blade-forced vibration in turbomachinery rotor-stator interaction. A quasi-three-dimensional multi-row analysis, based on an Euler/Navier-Stokes solver and a parallel computational algorithm, was used to simulate the unsteady flow in a turbine. Results are presented for non-dimensional pressure, velocity, and entropy in the blade passage. The two-stage turbine flow analysis was completed for the case with blade-forced response as well as the case without blade-forced response for comparison.

Collard, Joseph Eugene

2000-01-01T23:59:59.000Z

432

Bushing retention system for thermal medium cooling delivery tubes in a gas turbine rotor  

SciTech Connect

Bushings are provided in counterbores for wheels and spacers for supporting thermal medium cooling tubes extending axially adjacent the rim of the gas turbine rotor. The retention system includes a retaining ring disposed in a groove adjacent an end face of the bushing and which retaining ring projects radially inwardly to prevent axial movement of the bushing in one direction. The retention ring has a plurality of circumferentially spaced tabs along its inner diameter whereby the ring is supported by the lands of the tube maintaining its bushing retention function, notwithstanding operation in high centrifugal fields and rotation of the ring in the groove into other circular orientations.

Mashey, Thomas Charles (Coxsackie, NY)

2002-01-01T23:59:59.000Z

433

The role of quasi-momentum in the resonant dynamics of the atom-optics kicked rotor  

E-Print Network (OSTI)

We examine the effect of the initial atomic momentum distribution on the dynamics of the atom-optical realisation of the quantum kicked rotor. The atoms are kicked by a pulsed optical lattice, the periodicity of which implies that quasi-momentum is conserved in the transport problem. We study and compare experimentally and theoretically two resonant limits of the kicked rotor: in the vicinity of the quantum resonances and in the semiclassical limit of vanishing kicking period. It is found that for the same experimental distribution of quasi-momenta, significant deviations from the kicked rotor model are induced close to quantum resonance, while close to the classical resonance (i.e. for small kicking period) the effect of the quasi-momentum vanishes.

Sandro Wimberger; Mark Sadgrove

2005-05-20T23:59:59.000Z

434

load data | OpenEI Community  

Open Energy Info (EERE)

51 51 Varnish cache server Home Groups Community Central Green Button Applications Developer Utility Rate FRED: FRee Energy Database More Public Groups Private Groups Features Groups Blog posts Content Stream Documents Discussions Polls Q & A Events Notices My stuff Energy blogs 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 2142234851 Varnish cache server load data Home Sfomail's picture Submitted by Sfomail(48) Member 17 May, 2013 - 12:03 Commercial and Residential Hourly Load Data Now Available on OpenEI! building load building load data commercial load data dataset datasets electric load data load data load profile OpenEI residential load TMY3 United States Load data Image source: NREL Files: application/zip icon System Advisor Model Tool for Downloading Load Data

435

Wind Energy Meteorology: Insight into Wind Properties in the Turbine-Rotor Layer of the Atmosphere from High-Resolution Doppler Lidar  

Science Conference Proceedings (OSTI)

Addressing the need for high-quality wind information aloft in the layer occupied by turbine rotors (~30–150 m above ground level) is one of many significant challenges facing the wind energy industry. Without wind measurements at heights within the rotor ...

Robert M. Banta; Yelena L. Pichugina; Neil D. Kelley; R. Michael Hardesty; W. Alan Brewer

2013-06-01T23:59:59.000Z

436

Application of gradient-based optimization methods for a rotor system with static stress, natural frequency,and harmonic response constraints  

Science Conference Proceedings (OSTI)

This paper demonstrates the application of gradient-based optimization methods to the minimal weight design optimization of rotor systems. A nonlinear constrained optimization problem is considered. Design variables are inner radii and wall thicknesses ... Keywords: Gradient projection method, Rotordynamics, Sequential quadratic programming, Sizing optimization, Turbine rotor

Alexander O. Pugachev

2013-06-01T23:59:59.000Z

437

Spinning Reserve from Responsive Load  

SciTech Connect

As power system costs rise and capacity is strained demand response can provide a significant system reliability benefit at a potentially attractive cost. The 162 room Music Road Hotel in Pigeon Forge Tennessee agreed to host a spinning reserve test. The Tennessee Valley Authority (TVA) supplied real-time metering and monitoring expertise to record total hotel load during both normal operations and testing. Preliminary testing showed that hotel load can be curtailed by 22% to 37% depending on the outdoor temperature and the time of day. The load drop was very rapid, essentially as fast as the 2 second metering could detect.

Kueck, John D [ORNL; Kirby, Brendan J [ORNL; Laughner, T [Tennessee Valley Authority (TVA); Morris, K [Tennessee Valley Authority (TVA)

2009-01-01T23:59:59.000Z

438

New analytic solutions of the collective Bohr hamiltonian for a beta-soft, gamma-soft axial rotor  

E-Print Network (OSTI)

New analytic solutions of the quadrupole collective Bohr hamiltonian are proposed, exploiting an approximate separation of the beta and gamma variables to describe gamma-soft prolate axial rotors. The model potential is a sum of two terms: a beta-dependent term taken either with a Coulomb-like or a Kratzer-like form, and a gamma-dependent term taken as an harmonic oscillator. In particular it is possible to give a one parameter paradigm for a beta-soft, gamma-soft axial rotor that can be applied, with a considerable agreement, to the spectrum of 234U.

Lorenzo Fortunato; Andrea Vitturi

2003-12-18T23:59:59.000Z

439

Exponential Quantum Spreading in a Class of Kicked Rotor Systems near High-Order Resonances  

E-Print Network (OSTI)

Long-lasting quantum exponential spreading was recently found in a simple but very rich dynamical model, namely, an on-resonance double-kicked rotor model [J. Wang, I. Guarneri, G. Casati, and J. B. Gong, Phys. Rev. Lett. 107, 234104 (2011)]. The underlying mechanism, unrelated to the chaotic motion in the classical limit but resting on quasi-integrable motion in a pseudoclassical limit, is identified for one special case. By presenting a detailed study of the same model, this work offers a framework to explain long-lasting quantum exponential spreading under much more general conditions. In particular, we adopt the so-called "spinor" representation to treat the kicked-rotor dynamics under high-order resonance conditions and then exploit the Born-Oppenheimer approximation to understand the dynamical evolution. It is found that the existence of a flat-band (or an effectively flat-band) is one important feature behind why and how the exponential dynamics emerges. It is also found that a quantitative prediction of the exponential spreading rate based on an interesting and simple pseudoclassical map may be inaccurate. In addition to general interests regarding the question of how exponential behavior in quantum systems may persist for a long time scale, our results should motivate further studies towards a better understanding of high-order resonance behavior in delta-kicked quantum systems.

Hailong Wang; Jiao Wang; Italo Guarneri; Giulio Casati; Jiangbin Gong

2013-08-16T23:59:59.000Z

440

Mass Transfer Testing of a 12.5-cm Rotor Centrifugal Contactor  

Science Conference Proceedings (OSTI)

TRUEX mass transfer tests were performed using a single stage commercially available 12.5 cm centrifugal contactor and stable cerium (Ce) and europium (Eu). Test conditions included throughputs ranging from 2.5 to 15 Lpm and rotor speeds of 1750 and 2250 rpm. Ce and Eu extraction forward distribution coefficients ranged from 13 to 19. The first and second stage strip back distributions were 0.5 to 1.4 and .002 to .004, respectively, throughout the dynamic test conditions studied. Visual carryover of aqueous entrainment in all organic phase samples was estimated at < 0.1 % and organic carryover into all aqueous phase samples was about ten times less. Mass transfer efficiencies of = 98 % for both Ce and Eu in the extraction section were obtained over the entire range of test conditions. The first strip stage mass transfer efficiencies ranged from 75 to 93% trending higher with increasing throughput. Second stage mass transfer was greater than 99% in all cases. Increasing the rotor speed from 1750 to 2250 rpm had no significant effect on efficiency for all throughputs tested.

D. H. Meikrantz; T. G. Garn; J. D. Law; N. R. Mann; T. A. Todd

2008-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


441

Measured and predicted rotor performance for the SERI advanced wind turbine blades  

DOE Green Energy (OSTI)

Measured and predicted rotor performance for the SERI advanced wind turbine blades were compared to assess the accuracy of predictions and to identify the sources of error affecting both predictions and measurements. An awareness of these sources of error contributes to improved prediction and measurement methods that will ultimately benefit future rotor design efforts. Propeller/vane anemometers were found to underestimate the wind speed in turbulent environments such as the San Gorgonio Pass wind farm area. Using sonic or cup anemometers, good agreement was achieved between predicted and measured power output for wind speeds up to 8 m/sec. At higher wind speeds an optimistic predicted power output and the occurrence of peak power at wind speeds lower than measurements resulted from the omission of turbulence and yaw error. In addition, accurate two-dimensional (2-D) airfoil data prior to stall and a post stall airfoil data synthesization method that reflects three-dimensional (3-D) effects were found to be essential for accurate performance prediction. 11 refs.

Tangler, J.; Smith, B.; Kelley, N.; Jager, D.

1992-02-01T23:59:59.000Z

442

Advanced nonintrusive load monitoring system  

E-Print Network (OSTI)

There is a need for flexible, inexpensive metering technologies that can be deployed in many different monitoring scenarios. Individual loads may be expected to compute information about their power consumption. Utility ...

Wichakool, Warit, 1977-

2011-01-01T23:59:59.000Z

443

OpenEI - building load  

Open Energy Info (EERE)

are given by a location defined by the Typical Meteorological Year (TMY) for which the weather data was collected. Commercial load data is sorted by the (TMY) site as a...

444

Permanent Load Shift Control Strategies  

NLE Websites -- All DOE Office Websites (Extended Search)

of Permanent Load Shifting for HVAC and other storage assets as it relates to summer on-peak demand, how it can be dynamically and autonomously controlled, and its relationship...

445

Load as a reliability resource in restructured electricity markets  

Science Conference Proceedings (OSTI)

Recent electricity price spikes demonstrate the value that demand-side responses could bring to a restructured US electricity system. This report considers how even a modest increase in demand elasticity could dramatically reduce these extremes in price volatility. The report provides a three-part assessment addressing the ability of customer's load to participate in competitive markets and the current and potential future role of customer loads as system reliability resources. The study begins by evaluating the extent to which customer loads might be able to provide electricity reliability or ancillary services and reviewing aspects of a large utility's direct load control program. The second phase of the assessment contains a survey of ways in which load has been used as a system reliability resource focusing on programs triggered by system conditions and a real-time price signal. It reviews the experience of: (1) the California ISO's Demand Relief and Participating Load programs; (2) Interruptible load programs in California; (3) the New England ISO's Load Management program; and (4) a ''mature'' program in New Zealand. The third phase of the assessment examines the status of the underlying metering, communication, and control technologies used to effect customer responses. The final section of the report provides a vision of how the future might look and uses it to outline a program of needed R&D to increase the role of customer loads as system reliability resources. Key elements of this research program include: addressing the needs of system operators, making effective use of load management assets, making use of new program design concepts, the design of end-use technologies, and benefiting from program experiences.

Kueck, J.D.; Kirby, B.J.; Eto, J.; Staunton, R.H.; Marnay, C.; Martinez, A.; Goldman, C.

2001-06-01T23:59:59.000Z

446

Final Report on Control Algorithm to Improve the Partial-Load Efficiency of Surface PM Machines with Fractional-Slot Concentrated Windings  

DOE Green Energy (OSTI)

Surface permanent magnet (SPM) synchronous machines using fractional-slot concentrated windings are being investigated as candidates for high-performance traction machines for automotive electric propulsion systems. It has been shown analytically and experimentally that such designs can achieve very wide constant-power speed ratios (CPSR) [1,2]. This work has shown that machines of this type are capable of achieving very low cogging torque amplitudes as well as significantly increasing the machine power density [3-5] compared to SPM machines using conventional distributed windings. High efficiency can be achieved in this class of SPM machine by making special efforts to suppress the eddy-current losses in the magnets [6-8], accompanied by efforts to minimize the iron losses in the rotor and stator cores. Considerable attention has traditionally been devoted to maximizing the full-load efficiency of traction machines at their rated operating points and along their maximum-power vs. speed envelopes for higher speeds [9,10]. For example, on-line control approaches have been presented for maximizing the full-load efficiency of PM synchronous machines, including the use of negative d-axis stator current to reduce the core losses [11,12]. However, another important performance specification for electric traction applications is the machine's efficiency at partial loads. Partial-load efficiency is particularly important if the target traction application requires long periods of cruising operation at light loads that are significantly lower than the maximum drive capabilities. While the design of the machine itself is clearly important, investigation has shown that this is a case where the choice of the control algorithm plays a critical role in determining the maximum partial-load efficiency that the machine actually achieves in the traction drive system. There is no evidence that this important topic has been addressed for this type of SPM machine by any other authors. This topic takes on even greater significance for fractional-slot concentrated-winding SPM machine designs. In particular, maximizing the torque/power density of this class of SPM machines typically leads to machine designs with high numbers of poles. The resulting high electrical frequencies can easily result in high stator core losses unless special care is taken during the machine design process. The purpose of this report is to discuss a modified vector control algorithm for a fractional-slot concentrated winding SPM machine that has been developed to maximize the machine's partial-load efficiency over a wide range of operating conditions. For purposes of this discussion, a 55 kW (peak) SPM machine designed to meet requirements established in the US FreedomCar program [13] is used as the basis for demonstrating the proposed technique. A combination of closed-form analysis [14] and finite element analysis (FEA) is used during this investigation.

McKeever, John W [ORNL; Reddy, Patel [University of Wisconsin; Jahns, Thomas M [ORNL

2007-05-01T23:59:59.000Z

447

FINAL REPORT ON CONTROL ALGORITHM TO IMPROVE THE PARTIAL-LOAD EFFICIENCY OFSURFACE PM MACHINES WITH FRACTIONAL-SLOT CONCENTRATED WINDINGS  

SciTech Connect

Surface permanent magnet (SPM) synchronous machines using fractional-slot concentrated windings are being investigated as candidates for high-performance traction machines for automotive electric propulsion systems. It has been shown analytically and experimentally that such designs can achieve very wide constant-power speed ratios (CPSR) [1,2]. This work has shown that machines of this type are capable of achieving very low cogging torque amplitudes as well as significantly increasing the machine power density [3-5] compared to SPM machines using conventional distributed windings. High efficiency can be achieved in this class of SPM machine by making special efforts to suppress the eddy-current losses in the magnets [6-8], accompanied by efforts to minimize the iron losses in the rotor and stator cores. Considerable attention has traditionally been devoted to maximizing the full-load efficiency of traction machines at their rated operating points and along their maximum-power vs. speed envelopes for higher speeds [9,10]. For example, on-line control approaches have been presented for maximizing the full-load efficiency of PM synchronous machines, including the use of negative d-axis stator current to reduce the core losses [11,12]. However, another important performance specification for electric traction applications is the machine's efficiency at partial loads. Partial-load efficiency is particularly important if the target traction application requires long periods of cruising operation at light loads that are significantly lower than the maximum drive capabilities. While the design of the machine itself is clearly important, investigation has shown that this is a case where the choice of the control algorithm plays a critical role in determining the maximum partial-load efficiency that the machine actually achieves in the traction drive system. There is no evidence that this important topic has been addressed for this type of SPM machine by any other authors. This topic takes on even greater significance for fractional-slot concentrated-winding SPM machine designs. In particular, maximizing the torque/power density of this class of SPM machines typically leads to machine designs with high numbers of poles. The resulting high electrical frequencies can easily result in high stator core losses unless special care is taken during the machine design process. The purpose of this report is to discuss a modified vector control algorithm for a fractional-slot concentrated winding SPM machine that has been developed to maximize the machine's partial-load efficiency over a wide range of operating conditions. For purposes of this discussion, a 55 kW (peak) SPM machine designed to meet requirements established in the US FreedomCar program [13] is used as the basis for demonstrating the proposed technique. A combination of closed-form analysis [14] and finite element analysis (FEA) is used during this investigation.

Reddy, P.B.; Jahns, T.M.

2007-04-30T23:59:59.000Z

448

Tarazu: optimizing MapReduce on heterogeneous clusters  

Science Conference Proceedings (OSTI)

Data center-scale clusters are evolving towards heterogeneous hardware for power, cost, differentiated price-performance, and other reasons. MapReduce is a well-known programming model to process large amount of data on data center-scale clusters. Most ... Keywords: MapReduce, cluster scheduling, heterogeneous clusters, load imbalance, shuffle

Faraz Ahmad; Srimat T. Chakradhar; Anand Raghunathan; T. N. Vijaykumar

2012-04-01T23:59:59.000Z

449

Building Energy Software Tools Directory: Prophet Load Profiler  

NLE Websites -- All DOE Office Websites (Extended Search)

Prophet Load Profiler Prophet Load Profiler Prophet Load Profiler logo. Internet-enabled software that empowers business energy customers to manage energy and reduce costs. Valuable to facility managers, energy managers and energy service companies, the Prophet web-based service delivers real-time and near-real-time energy information on energy consumption and demand for any size facility. A number of facilities can be managed using consumption data gathered in 15 minute, 30 minute, 60 minute, daily, weekly and monthly intervals. Users can immediately view and analyze data with an eye toward load shedding, cost avoidance strategies, energy budget management, utility cost validation and energy forecasting. All tools are contained within the Prophet Web application and enabled via the internet using a standard web

450

Success stories will crack utility resistance to load management  

SciTech Connect

Advocates of load management see it as a solution to high fuel prices, better system load factors, and high utility earnings. Opposing views are investigated. It is conceded that both views have merit, but with proper attention to rate design, load management holds out hope for utility and customer alike. Westinghouse studies conclude that load management must be developed on a utility-specific basis. Many utilities are concerned that load management systems will reduce energy consumption and thus revenues. Experiences that utilities have had with radio and ripple control are briefly reviewed. Dr. Irwin Stelzer from the National Economic Research Associates says that, giving the customer the right price signal, the load curve will manipulate itself into the shape the customer wants. He advocates charging each customer precisely what it costs to deliver that customer's energy. It is seen that load management could improve the utility's income, possibly help defer the need for capital additions, and potentially help keep energy costs down. (MCW)

Owens, K.

1977-03-01T23:59:59.000Z

451

Reducing waste, Photoby stcvcchan  

E-Print Network (OSTI)

I ' I I t Reducing waste, Photoby stcvcchan AMs President Mike Lee (left to right), Point Grey M U recycling given high priority on campus By GAVIN WILSON UBC is taking stepsto reduce waste and encourageGellatly,Vice-President,Administration and Finance,to develop and recommend university policies on waste recycling. Another task force has submitted

Farrell, Anthony P.

452

Load Reduction, Demand Response and Energy Efficient Technologies and Strategies  

SciTech Connect

The Department of Energy’s (DOE’s) Pacific Northwest National Laboratory (PNNL) was tasked by the DOE Office of Electricity (OE) to recommend load reduction and grid integration strategies, and identify additional demand response (energy efficiency/conservation opportunities) and strategies at the Forest City Housing (FCH) redevelopment at Pearl Harbor and the Marine Corps Base Hawaii (MCBH) at Kaneohe Bay. The goal was to provide FCH staff a path forward to manage their electricity load and thus reduce costs at these FCH family housing developments. The initial focus of the work was at the MCBH given the MCBH has a demand-ratchet tariff, relatively high demand (~18 MW) and a commensurate high blended electricity rate (26 cents/kWh). The peak demand for MCBH occurs in July-August. And, on average, family housing at MCBH contributes ~36% to the MCBH total energy consumption. Thus, a significant load reduction in family housing can have a considerable impact on the overall site load. Based on a site visit to the MCBH and meetings with MCBH installation, FCH, and Hawaiian Electric Company (HECO) staff, recommended actions (including a "smart grid" recommendation) that can be undertaken by FCH to manage and reduce peak-demand in family housing are made. Recommendations are also made to reduce overall energy consumption, and thus reduce demand in FCH family housing.

Boyd, Paul A.; Parker, Graham B.; Hatley, Darrel D.

2008-11-19T23:59:59.000Z

453

Computational study of compressive loading of carbon nanotubes  

Science Conference Proceedings (OSTI)

A reduced-order general continuum method is used to examine the mechanical behavior of single-walled carbon nanotubes (CNTs) under compressive loading and unloading conditions. Quasi-static solutions are sought where the total energy of the system is ... Keywords: carbon nanotube, component, finite element method, mechanical properties

Yang Yang; William W. Liou

2010-03-01T23:59:59.000Z

454

Combining daylighting, personal controls, and load shedding offers  

E-Print Network (OSTI)

systems can enhance occupant comfort and improve organizational productivity. However, even with advances lighting system to respond to available daylight and demand response control · Allows building occupantsCombining daylighting, personal controls, and load shedding offers enormous potential for reducing

455

FINAL PROJECT REPORT LOAD MODELING TRANSMISSION RESEARCH  

E-Print Network (OSTI)

PSLF that incorporates motor  A?C, ZIP, and electronic load the fractions motors A?C, ZIP, and electronic loads.    Usethat incorporates motor  A?C, ZIP, and  electronic load 

Lesieutre, Bernard

2013-01-01T23:59:59.000Z

456

load profile | OpenEI Community  

Open Energy Info (EERE)

load profile Home Sfomail's picture Submitted by Sfomail(48) Member 17 May, 2013 - 13:03 Commercial and Residential Hourly Load Data Now Available on OpenEI building load building...

457

Monthly Crustal Loading Corrections for Satellite Altimetry  

Science Conference Proceedings (OSTI)

Satellite altimeter measurements of sea surface height include a small contribution from vertical motion of the seafloor caused by crustal loading. Loading by ocean tides is routinely allowed for in altimeter data processing. Here, loading by ...

R. D. Ray; S. B. Luthcke; T. van Dam

2013-05-01T23:59:59.000Z

458

WindPACT Rotor Design Study: Hybrid Tower Design; Period of Performance: 29 June 2000 -- 28 February 2004  

DOE Green Energy (OSTI)

The cost of a wind turbine tower can represent as much as 20% of the cost of an entire megawatt-scale horizontal axis wind turbine (HAWT) and as much as 10% of the total cost of energy. The tower is a major cost component, and its design is important: Its structural properties are key to the response of the rotor; its height determines the wind regime that the rotor experiences; it allows access to the turbine nacelle and rotor; and it houses components of the electrical connection and the control and protection systems. Most large wind turbines installed in the United States use self-supporting steel tubular towers. The diameter of these tubes is limited by the size that can be transported by road (approximately 4.3 m). The base dimensions of a truss tower are not restrained by this limit, but trusses may require more maintenance. Guyed tube towers have been used, but they represent additional foundation costs and inconvenience. Addressing these limitations may lead to an alternative that avoids the problems. For this reason, the WindPACT Rotor Design Study was modified to include a study of a hybrid tower to determine the technical and economic feasibility of such a design.

Malcolm, D. J.

2004-04-01T23:59:59.000Z

459

Estimation of rotor angles of synchronous machines using artificial neural networks and local PMU-based quantities  

Science Conference Proceedings (OSTI)

This paper investigates a possibility for estimating rotor angles in the time frame of transient (angle) stability of electric power systems, for use in real-time. The proposed dynamic state estimation technique is based on the use of voltage and current ... Keywords: Electric power systems, Multilayer perceptrons, Phasor measurement units, Transient stability monitoring and control

Alberto Del Angel; Pierre Geurts; Damien Ernst; Mevludin Glavic; Louis Wehenkel

2007-10-01T23:59:59.000Z

460

Steady and Periodic Pressure Measurements on a Generic Helicopter Fuselage Model in the Presence of a Rotor  

Science Conference Proceedings (OSTI)

A wind tunnel test of a generic helicopter fuselage model with an independently mounted rotor has been conducted to obtain steady and periodic pressure data on the helicopter body. The model was tested at four advance ratios and three thrust coefficients. ...

Mineck Raymond E.; Gorton Susan Althoff

2000-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Cost optimization of a hybrid composite flywheel rotor with a split-type hub using combined analytical/numerical models  

Science Conference Proceedings (OSTI)

A procedure to find the optimal design of a flywheel with a split-type hub is presented. Since cost plays a decisive role in stationary flywheel energy storage applications, a trade-off between energy and cost is required. Applying a scaling technique, ... Keywords: Cost optimization, Flywheel energy storage, Flywheel rotors, Multifidelity optimization, Split-type hub, Surrogate-based optimization

Malte Krack; Marc Secanell; Pierre Mertiny

2011-07-01T23:59:59.000Z

462

Wind turbine rotor blade with in-plane sweep and devices using same, and methods for making same  

DOE Patents (OSTI)

A wind turbine includes a rotor having a hub and at least one blade having a torsionally rigid root, an inboard section, and an outboard section. The inboard section has a forward sweep relative to an elastic axis of the blade and the outboard section has an aft sweep.

Wetzel, Kyle Kristopher (Lawrence, KS)

2008-03-18T23:59:59.000Z

463

Peak load management: Potential options  

SciTech Connect

This report reviews options that may be alternatives to transmission construction (ATT) applicable both generally and at specific locations in the service area of the Bonneville Power Administration (BPA). Some of these options have potential as specific alternatives to the Shelton-Fairmount 230-kV Reinforcement Project, which is the focus of this study. A listing of 31 peak load management (PLM) options is included. Estimated costs and normalized hourly load shapes, corresponding to the respective base load and controlled load cases, are considered for 15 of the above options. A summary page is presented for each of these options, grouped with respect to its applicability in the residential, commercial, industrial, and agricultural sectors. The report contains comments on PLM measures for which load shape management characteristics are not yet available. These comments address the potential relevance of the options and the possible difficulty that may be encountered in characterizing their value should be of interest in this investigation. The report also identifies options that could improve the efficiency of the three customer utility distribution systems supplied by the Shelton-Fairmount Reinforcement Project. Potential cogeneration options in the Olympic Peninsula are also discussed. These discussions focus on the options that appear to be most promising on the Olympic Peninsula. Finally, a short list of options is recommended for investigation in the next phase of this study. 9 refs., 24 tabs.

Englin, J.E.; De Steese, J.G.; Schultz, R.W.; Kellogg, M.A.

1989-10-01T23:59:59.000Z

464

Critical analysis of European load management practices. Final report for period January--July 1976  

SciTech Connect

Load management has been practiced in Europe for approximately a quarter century. A critical evaluation of the initial objectives and economic justifications for load management given in Europe may help energy policymakers in the U.S. assess the relevance of load management to meeting their current energy goals. Load management was adopted in Europe primarily to promote a growth in energy sales at a rate greater than the increase in capacity requirements. Utilities were able to improve daily load factors during the winter peak period; however, they may not have been successful in maintaining or improving their financial strength through load management. Increased capital and operating expenditures in the generation and distribution systems became necessary as the power system evolved in response to changing load characteristics. Rates charged to customers did not always produce adequate revenues from managed loads to cover the capital and operating costs to supply those loads. Comprehensive studies of the long-term costs and benefits might have prevented some of the load management problems experienced in Europe. Load management was not introduced in Europe to reduce utility production costs, conserve energy or scarce fuels, improve the environment, or influence summer loads. Accordingly, the European experience with load management may not be relevant to energy policymakers in the U.S. who desire to achieve these objectives.

1977-01-01T23:59:59.000Z

465

Investigation of a high impedance magnetically insulated transmission line oscillator with hollow load  

Science Conference Proceedings (OSTI)

A novel high-impedance magnetically insulated transmission line oscillator (MILO) with greatly restrained power deposition on the anode has been investigated. Methods to increase the MILO impedance and decrease the anode current are discussed. A MILO with impedance of 30 {Omega} and power conversion efficiency of 25% is presented by particle-in-cell simulations. Compared with the previous MILO in our lab, the anode current of the proposed MILO is reduced about 50%, the power conversion efficiency doubles, and the power deposition on anode is reduced nearly one half. Furthermore, considerations for reducing the power deposition on load have also been carried out in MILO design, and the load current is reduced to 4.6 kA, only 17% of the total anode current. Finally, a hollow load was introduced to reduce the power deposition density on the load, without decreasing the power conversion efficiency.

Zhou Heng; Shu Ting; Li Zhiqiang [College of Opto-electric Science and Engineering, National University of Defense Technology, Hunan 410073 (China)

2012-09-15T23:59:59.000Z

466

Building Energy Software Tools Directory: Load Express  

NLE Websites -- All DOE Office Websites (Extended Search)

graphical interface makes Load Express a powerful engineering tool with a very short learning curve. The "rookie" or experienced user can quickly and accurately perform load...

467

Self-aligning biaxial load frame  

DOE Patents (OSTI)

An self-aligning biaxial loading apparatus for use in testing the strength of specimens while maintaining a constant specimen centroid during the loading operation. The self-aligning biaxial loading apparatus consists of a load frame and two load assemblies for imparting two independent perpendicular forces upon a test specimen. The constant test specimen centroid is maintained by providing elements for linear motion of the load frame relative to a fixed cross head, and by alignment and linear motion elements of one load assembly relative to the load frame. 3 figures.

Ward, M.B.; Epstein, J.S.; Lloyd, W.R.

1994-01-18T23:59:59.000Z

468

Decentralized customerlevel under frequency load shedding in...  

Open Energy Info (EERE)

enables the management of large groups of distributed loads under a single innovative control schemes to use the flexibility of electrical loads for power system purposes....

469

Reduce Oil Dependence Costs  

NLE Websites -- All DOE Office Websites (Extended Search)

Reduce Oil Dependence Costs U.S. Petroleum Use, 1970-2010 Nearly 40% of the oil we use is imported, costing us roughly 300 billion annually. Increased domestic oil production from...

470

Reducing Diesel Engine Emissions  

NLE Websites -- All DOE Office Websites (Extended Search)

Reducing Reducing Diesel Engine Emissions 2 0 1 0 Green TransporTaTion TechnoloGies Compared to traditional gasoline engines, diesel engines require less maintenance, generate energy more efficiently, and produce less carbon dioxide emissions. But when uncontrolled, diesel engines churn out harmful emissions like particu- late matter (PM) and nitrogen oxides (NO x ). Researchers at Argonne National Laboratory are currently working to develop

471

Method for loading resin beds  

DOE Patents (OSTI)

An improved method of preparing nuclear reactor fuel by carbonizing a uranium loaded cation exchange resin provided by contacting a H.sup.+ loaded resin with a uranyl nitrate solution deficient in nitrate, comprises providing the nitrate deficient solution by a method comprising the steps of reacting in a reaction zone maintained between about 145.degree.-200.degree. C, a first aqueous component comprising a uranyl nitrate solution having a boiling point of at least 145.degree. C with a second aqueous component to provide a gaseous phase containing HNO.sub.3 and a reaction product comprising an aqueous uranyl nitrate solution deficient in nitrate.

Notz, Karl J. (Oak Ridge, TN); Rainey, Robert H. (Knoxville, TN); Greene, Charles W. (Knoxville, TN); Shockley, William E. (Oak Ridge, TN)

1978-01-01T23:59:59.000Z

472

The Simple Harmonic Rotor with Motion Hinged By of a Helicopter  

E-Print Network (OSTI)

Summary.--In simple harmonic oscillation of the helicopter with hinged blades, the tip-path plane is tilted with respect to the shaft in the plane of oscillation and in the plane perpendicular to it. The angles of tilt can be expressed as functions of angular velocity and acceleration. The influence ' of the acceleration term on the dynamic stability of the helicopter is small. The expressions for angles of tilt due to angular velocity can be simplified to the expressions obtained in previous work under assumptions of quasi-static conditions. 1. I~troductio~.--It has been shown in Ref. 1 that when the rotor shaft of a helicopter tilts with constant pitching velocity, the tip-path plane lags behind the shaft and also tilts Sideways. These angles of lag and sidetilt were found to be proportional to the pitching velocity of the shaft and the following expressions were derived: Oal _. Of yD............. (1)

J. K. Zbrozek; Dipl. Eng; J. K. Zbxoze

1949-01-01T23:59:59.000Z

473

Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors  

NLE Websites -- All DOE Office Websites (Extended Search)

5021 5021 August 2009 Hydrodynamic Optimization Method and Design Code for Stall-Regulated Hydrokinetic Turbine Rotors D. Sale University of Tennessee J. Jonkman and W. Musial National Renewable Energy Laboratory Presented at the ASME 28 th International Conference on Ocean, Offshore, and Arctic Engineering Honolulu, Hawaii May 31-June 5, 2009 NOTICE The submitted manuscript has been offered by an employee of the Alliance for Sustainable Energy, LLC (ASE), a contractor of the US Government under Contract No. DE-AC36-08-GO28308. Accordingly, the US Government and ASE retain a nonexclusive royalty-free license to publish or reproduce the published form of this contribution, or allow others to do so, for US Government purposes. This report was prepared as an account of work sponsored by an agency of the United States government.

474

Rotational damping in a multi-$j$ shell particles-rotor model  

E-Print Network (OSTI)

The damping of collective rotational motion is investigated by means of particles-rotor model in which the angular momentum coupling is treated exactly and the valence nucleons are in a multi-$j$ shell mean-field. It is found that the onset energy of rotational damping is around 1.1 MeV above yrast line, and the number of states which form rotational band structure is thus limited. The number of calculated rotational bands around 30 at a given angular momentum agrees qualitatively with experimental data. The onset of rotational damping takes place gradually as a function of excitation energy. It is shown that the pairing correlation between valence nucleons has a significant effect on the appearance of rotational damping.

Lu Guo; Jie Meng; Enguang Zhao; Fumihiko Sakata

2004-07-25T23:59:59.000Z

475

The influence of crack-imbalance orientation and orbital evolution for an extended cracked Jeffcott rotor  

E-Print Network (OSTI)

Vibration peaks occurring at rational fractions of the fundamental rotating critical speed, here named Local Resonances, facilitate cracked shaft detection during machine shut-down. A modified Jeffcott-rotor on journal bearings accounting for gravity effects and oscillating around nontrivial equilibrium points is employed. Modal parameter selection allows this linear model to represent first mode characteristics of real machines. Orbit evolution and vibration patterns are analyzed, yielding useful results. Crack detection results indicate that, instead of 1x and 2x components, analysis of the remaining local resonances should have priority; this is due to crack-residual imbalance interaction and to 2x multiple induced origins. Therefore, local resonances and orbital evolution around 1/2, 1/3 and 1/4 of the critical speed are emphasized for various crack-imbalance orientations.

Julio Gomez-Mancilla; Jean-Jacques Sinou; V. R. Nosov; Fabrice Thouverez; A. Zambrano

2008-01-19T23:59:59.000Z

476

Observation of high-order quantum resonances in the kicked rotor  

E-Print Network (OSTI)

Quantum resonances in the kicked rotor are characterized by a dramatically increased energy absorption rate, in stark contrast to the momentum localization generally observed. These resonances occur when the scaled Planck's constant hbar=(r/s)*4pi, for any integers r and s. However only the hbar=r*2pi resonances are easily observable. We have observed high-order quantum resonances (s>2) utilizing a sample of low temperature, non-condensed atoms and a pulsed optical standing wave. Resonances are observed for hbar=(r/16)*4pi r=2-6. Quantum numerical simulations suggest that our observation of high-order resonances indicates a larger coherence length than expected from an initially thermal atomic sample.

J. F. Kanem; S. Maneshi; M. Partlow; M. Spanner; A. M. Steinberg

2006-04-15T23:59:59.000Z

477

The effect of imbalance distribution and measurement locations on critical speeds in a turboprop engine rotor  

E-Print Network (OSTI)

The critical speeds of a turbomachine can be defined as the speeds at which synchronous response to imbalance is maximum (Vance,1988). Identifying the proper placement of critical speeds is very important in the design process of turbomachinery. This study examines the influence of imbalance distribution and vibration measurement location on critical speeds for a model turboprop engine rotor. Imbalance response measurements are presented for a full scale model mounted in rolling bearings with squeeze film damper. The measurements were recorded with a Bentley Nevada ADRE 208 Data Acquisition Interface Unit System. These measurements are compared with predictions from a XLROTOR (Spreadsheet for Rotordynamic Analysis) computer model. Measurement imbalance responses show that imbalance location has profound influence on critical speeds. A critical speed variation up to 25 % was found. Comparison between the XLROTOR computer model prediction and measurement shows excellent agreement.

Marin, Manuel

1996-01-01T23:59:59.000Z

478

Wind energy conversion. Volume X. Aeroelastic stability of wind turbine rotor blades  

DOE Green Energy (OSTI)

The nonlinear equations of motion of a general wind turbine rotor blade are derived from first principles. The twisted, tapered blade may be preconed out of the plane of rotation, and its root may be offset from the axis of rotation by a small amount. The aerodynamic center, center of mass, shear center, and area centroid are distinct in this derivation. The equations are applicable to studies of forced response or of aeroelastic flutter, however, neither gravity forcing, nor wind shear and gust forcing are included. The equations derived are applied to study the aeroelastic stability of the NASA-ERDA 100 kW wind turbine, and solved using the Galerkin method. The numerical results are used in conjunction with a mathematical comparison to prove the validity of an equivalent hinge model developed by the Wind Energy Conversion Project at the Massachusetts Institute of Technology.

Wendell, J.

1978-09-01T23:59:59.000Z

479

Rotationally sampled wind characteristics for several rotor sizes using laser anemometer measurements  

DOE Green Energy (OSTI)

The concept of measuring the wind velocity rotationally around crosswind circles using a circle-scanning Doppler laser anemometer is investigated to determine the technique's suitability as an effective, simple, economical, and nonintrusive method for estimation turbulence at a wind turbine rotor. Estimates of wind features obtained using the lidar technique are compared to actual wind measurements obtained using a vertical plane array of anemometers, and to other estimates generated using a single-tower technique. Although the lack of a common data set precludes a firm conclusion regarding the lidar method's accuracy, it appears that the rotationally scanning lidar has the potential of becoming an excellent tool for measuring turbulent wind around the disk of rotation of a turbine blade. 11 refs., 21 figs., 2 tabs.

Connell, J.R.; Morris, V.R.

1989-02-01T23:59:59.000Z

480

NREL: Vehicles and Fuels Research - Vehicle Ancillary Loads Reduction  

NLE Websites -- All DOE Office Websites (Extended Search)

Research Research Search More Search Options Site Map Photo of Advanced Automotive Manikin Reducing fuel consumption by air conditioning systems is the focus of Vehicle Ancillary Loads Reduction (VALR) activities at NREL. About 7 billion gallons of fuel-about 5.5% of total national light-duty vehicle fuel use-are used annually just to cool light-duty vehicles in the United States. That's why our VALR team works with industry to help increase fuel economy and reduce tailpipe emissions by reducing the ancillary loads requirements in vehicles while maintaining the thermal comfort of the passengers. Approaches include improved cabin insulation, advanced window systems, advanced cooling and venting systems, and heat generated cooling. Another focus of the VALR project is ADAM, the ADvanced Automotive Manikin

Note: This page contains sample records for the topic "reduced rotor loading" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

COE Reductions through Active Aerodynamic Control of Rotor Aerodynamics and Geometry  

Science Conference Proceedings (OSTI)

This study investigates potential cost of energy reductions that might be achieved by designing active systems to mitigate loads throughout the wind turbine system.

Griffin, D. A.; McCoy, T. J.

2008-12-01T23:59:59.000Z

482

PRB rail loadings shatter record  

Science Conference Proceedings (OSTI)

Rail transport of coal in the Powder River Basin has expanded, with a record 2,197 trains loaded in a month. Arch Coal's Thunder basin mining complex has expanded by literally bridging the joint line railway. The dry fork mine has also celebrated its safety achievements. 4 photos.

Buchsbaum, L.

2008-09-15T23:59:59.000Z

483

Automatic Electric Load Identification in  

E-Print Network (OSTI)

Abstract — A microgrid is the power system of choice for the electrification of rural areas in developing countries. It should be able to adapt to changing load situations without the need for specialists to change the configuration of the microgrid controller. This paper proposes a self-configuring microgrid management system that is able to adjust both generation and demand of the system, so that also in case of growing electricity demand the grid can still be operable by disconnecting unessential loads. A crucial task for the microgrid controller is to automatically identify the connected loads on the basis of their consumption behaviors. For this, a template-matching algorithm is proposed that is based on Dynamic Time Warping, which is primarily used in speech recognition. It has been found that for load profile analysis, simple signal features such as the number of rising edges or the aggregated energy consumption in a given time window is sufficient to describe the signal. In contrast to speech recognition, frequency domain analysis is not necessary.

Self-configuring Microgrids; Friederich Kupzog; Tehseen Zia; Adeel Abbas Zaidi

2009-01-01T23:59:59.000Z

484

Load Forecasting for Modern Distribution Systems  

Science Conference Proceedings (OSTI)

Load forecasting is a fundamental activity for numerous organizations and activities within a utility, including planning, operations, and control. Transmission and Distribution (T&D) planning and design engineers use the load forecast to determine whether any changes and additions are needed to the electric system to satisfy the anticipated load. Other load forecast users include system operations, financial ...

20