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Note: This page contains sample records for the topic "load flow analysis" from the National Library of EnergyBeta (NLEBeta).
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1

Load flow analysis: Base cases, data, diagrams, and results  

SciTech Connect

This report describes how an electric utility system is modeled by using load flow techniques to establish a validated power flow case suitable for simulating and evaluating alternative system scenarios. Details of the load flow model are supported by additional technical and descriptive information intended to correlate modeled electrical system parameters with the corresponding physical equipment that makes up the system. Pictures and technical specifications of system equipment from the utility, public, or vendor are provided to support this association for many system components. The report summarizes the load flow model construction, simulation, and validation and describes the general capabilities of an information query system designed to access load flow parameters and other electrical system information.

Portante, E.C.; Kavicky, J.A.; VanKuiken, J.C.; Peerenboom, J.P.

1997-10-01T23:59:59.000Z

2

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

3

ANUDlSiTM-40 Load Flow Analysis: Base Cases, Data, Diagrams, and Results  

Office of Scientific and Technical Information (OSTI)

ANUDlSiTM-40 ANUDlSiTM-40 Load Flow Analysis: Base Cases, Data, Diagrams, and Results by E.C. Portante, J.A. Kavicky, J.C. VanKuiken, and J.P. Peerenboom Decision and Information Sciences Division, Argonne National Laboratory, 9700 South Cass Avenue, Argonne, Illinois 60439 October 1997 Work sponsored by Navy Engineering Logistics Office This report is printed on recycled paper. @ DISCLAIMER This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness. or use- fulness of any information, apparatus, product, or process disclosed, or represents

4

Three Phase Probabilistic Load Flow in Radial Distribution Networks  

SciTech Connect

Probabilistic load flow is a helpful tool in accounting for inconsistent or unknown loads and generation. This is especially true with the push for renewable generation and demand response. This paper proposes an improved version of the probabilistic load flow solution for balanced distribution systems and takes the next step by applying it to unbalanced three phase systems. It is validated by comparing the solutions to that obtained by Monte Carlo simulation. The proposed method provides an accurate and practical way for finding the solution to the stochastic problems occurring in power distribution system analysis today.

Melhorn, Alexander C [ORNL; Dimitrovski, Aleksandar D [ORNL; Tomsovic, Kevin L [ORNL

2012-01-01T23:59:59.000Z

5

A three phase load flow algorithm for Shipboard Power Systems  

E-Print Network (OSTI)

Load Flow (Power Flow) is the determination of the steady state operating conditions for the system. This is a very important tool utilized by many real time applications in power systems. Traditional load flow methods, which incorporate Gauss-Seidel and/or Newton Raphson techniques, were primarily developed for transmission system analysis. Distribution load flow analysis must incorporate its unique characteristics such as unbalanced loads, distributed loads, radial network structure, and one, two, or three phase lines. Also, there are a variety of components included in distribution systems such as switches, transformers, voltage regulators, and distributed generators. Therefore, the traditional methods cannot be directly applied to distribution systems since the assumptions made for transmission systems are not valid for the unique characteristics of distribution systems. A Shipboard Power System (SPS) is a finite inertia electric power system. The generation, transmission, and distribution systems in SPSs are tightly coupled. In reality, the transmission system consists of the lines that interconnect the generator buses in a ring configuration. The distribution system consists of lines, transformers, and loads connected in a radial configuration. When analyzing a SPS, its distinct characteristics must be taken into consideration. Therefore, just as transmission and distribution systems have unique methods of analysis, SPSs also need a unique method of analysis. A load flow algorithm for a SPS must consider its distribution system characteristics as well as the unique characteristics of SPSs. The work presented in this thesis discussed a load flow algorithm developed for Shipboard Power Systems and terrestrial wye and delta connected radial distribution systems. The issues in developing a load flow algorithm for a SPS are addressed and the solution is presented. This solution combines three methods that addressed the issues of multiple sources, ring configuration, and radial load flow. This algorithm was tested on the IEEE 37 Bus Radial Distribution Test Feeder and a simplified Shipboard Power Test System developed by researchers in the Power System Automation Laboratory. The results produced minimal percent error when compared to the actual output results.

Medina-Calder?on, M?onica M

2003-01-01T23:59:59.000Z

6

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

7

Improvements in sparse matrix/vector technique applications for on-line load flow calculation  

Science Conference Proceedings (OSTI)

Sparsity technique is applied to a wide range of problems in power systems analysis. In this paper the authors propose several analytical and computational improvements in sparsity applications. The new partial matrix refactorization method and ordering algorithm are presented. The proposed method is very efficient when applied to various kinds of programs, such as: on-line load flow, optimal power flow and steady-state security analysis. The proposed methodology is applied in a fast decoupled load flow program which include the treatment of tap violations on under-load tap changing (ULTC) transformers and reactive power generation on PV buses. Effects of proposed improvements are well tested and documented on the three networks: 118 bus IEEE test network and two utility networks with 209 and 519 buses, respectively. Keywords: sparsity technique, load flow analysis, security analysis.

Ristanovic, P.; Bjelogrlic, M.; Babic, B.S.

1989-02-01T23:59:59.000Z

8

Load Profiling Based Routing for Guaranteed Bandwidth Flows  

E-Print Network (OSTI)

. To support the stringent Quality of Service (QoS) requirements of real-time (e.g. audio/video) applications in integrated services networks, several routing algorithms that allow for the reservation of the needed bandwidth over a Virtual Circuit (VC), established on one of several candidate routes, have been proposed. Traditionally, such routing is done using the least-loaded concept, and thus results in balancing the load across the set of candidate routes. In this paper, we propose the use of load profiling as an attractive alternative to load balancing for routing guaranteed bandwidth VCs (flows). Load profiling techniques allow the distribution of "available" bandwidth across a set of candidate routes to match the characteristics of incoming VC QoS requests. We thoroughly characterize the performance of VC routing using load profiling and contrast it to routing using load balancing and load packing. We do so both analytically and via extensive simulations of multi-class traffic r...

Ibrahim Matta; Azer Bestavros; Marwan Krunz

1999-01-01T23:59:59.000Z

9

A circuit theory based load flow tracing method considering counter-flow contribution  

Science Conference Proceedings (OSTI)

A new method to trace the power flow based on the converged AC power flow solution is proposed in this paper. The method is formulated by using the transmission network structure, the equivalent-current-injection and the load- equivalent-admittances ... Keywords: equivalent current injection, equivalent load impedance, generator contribution, line loss allocation

Whei-Min Lin; Tung-Sheng Zhan; Cong-Hui Huang

2006-04-01T23:59:59.000Z

10

Test experience with multiterminal HVDC load flow and stability programs  

Science Conference Proceedings (OSTI)

A powerful new set of load flow and stability programs for the study of HVdc systems has recently been completed. During the development of the programs novel applications of multiterminal HVdc systems were investigated, firstly on a large test system and later on actual utility models. This paper describes the test systems used, the HVdc systems studied and some of the interesting system related aspects of the HVdc system performance.

Chapman, D.G.; Davies, J.B. (Manitoba HVDC Research Centre, Winnipeg, Manitoba (CA)); McNichol, J.R. (Manitoba Hydro, Winnipeg, Manitoba (CA)); Gulachenski, E.M.; Doe, S. (New England Power Service Co., Westboro, MA (US)); Balu, N.J. (EPRI, Palo Alto, CA (US))

1988-07-01T23:59:59.000Z

11

Combined transmission distribution load flow model employing system reduction and voltage variable load representation  

SciTech Connect

In the few decades since its introduction the digital computer has found widespread application within the electric power industry. One of the more fruitful areas for its utilization has been in the determination of the steady-state voltage conditions throughout the system. A power system naturally breaks down into two very distinct parts: transmission and distribution, and traditionally, the voltage problem has been separated the same way. In the transmission system it is referred to as a load flow problem, and in the distribution part it is called a voltage profile. In addition, the loads are often treated differently. Transmission loads are usually considered to be constant power, and the equations that result are therefore nonlinear. In the distribution portion the loads, though specified in terms of power, are sometimes handled as constant impedances, with linear equations. This work produced a new model wherein a mesh transmission system is combined with a radial distribution system and they are solved simultaneously. A system reduction technique is used to eliminate part of the transmission system from consideration, and thereby keep the problem at a manageable size. The solution algorithm incorporates a voltage variable load model which approximates the behavior of real loads more nearly than the common representations.

Enouen, P.W.

1985-01-01T23:59:59.000Z

12

Information flow analysis for javascript  

Science Conference Proceedings (OSTI)

Modern Web 2.0 pages combine scripts from several sources into a single client-side JavaScript program with almost no isolation. In order to prevent attacks from an untrusted third-party script or cross-site scripting, tracking provenance of data is ... Keywords: eval, hybrid program analysis, implicit flow, information flow control, unstructured control flow

Seth Just; Alan Cleary; Brandon Shirley; Christian Hammer

2011-10-01T23:59:59.000Z

13

Unbalanced Load Flow for Weakly Meshed Distribution Systems with Distributed Generation  

Science Conference Proceedings (OSTI)

Distributed Generation (DG) can bring support to distribution system, meanwhile, it bring unbalancedness in power source, load and line. Traditional load flow algorithms are not applicable to the weakly meshed distribution system with DGs. First, this ... Keywords: weakly meshed distribution system, distributed generation, unbalanced load flow, sensitivity compensation

Shao-Qiang Hu; Sen-Mao Li

2010-06-01T23:59:59.000Z

14

Reliability analysis of RC containment structures under combined loads  

SciTech Connect

This paper discusses a reliability analysis method and load combination design criteria for reinforced concrete containment structures under combined loads. The probability based reliability analysis method is briefly described. For load combination design criteria, derivations of the load factors for accidental pressure due to a design basis accident and safe shutdown earthquake (SSE) for three target limit state probabilities are presented.

Hwang, H.; Reich, M.; Kagami, S.

1984-01-01T23:59:59.000Z

15

A Simple and Unified Method to Model HVDC Links and FACTS Devices in DC Load Flow  

Science Conference Proceedings (OSTI)

The DC load flow is a rapid and approximate solution method for the determination of lines active power flows in power systems. In this paper, the HVDC (High Voltage Direct Current) links and FACTS (Flexible AC Transmission Systems) devices have been ... Keywords: Flexible AC Transmission Systems, High Voltage Direct Current, linearized load flow

Omid Alizadeh Mousavi; Mohammad Javad Sanjari; G.B. Gharehpetian; R.A. Naghizadeh

2009-02-01T23:59:59.000Z

16

Analysis of parametric transformer with rectifier load  

SciTech Connect

This paper describes a push-pull parametric transformer constructed using a pair of orthogonal-cores. The operating characteristics of the parametric transformer with a rectifier load were analyzed based on SPICE simulations. The analysis results show good agreement with experiment. It was found that the input surge current of the full-wave rectifier circuit with a smoothing capacitor can be compensated by the parametric transformer. Use of the parametric transformer as a power stabilizer is anticipated owing to its various functions such as for voltage regulation and overload protection.

Ichinokura, O.; Jinzenji, T. (Tohoku Univ., Sendai (Japan)); Tajima, K. (Akita Univ. (Japan))

1993-03-01T23:59:59.000Z

17

Miniaturized flow injection analysis system  

DOE Patents (OSTI)

A chemical analysis technique known as flow injection analysis, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38.times.25.times.3 mm, but can be designed for gas analysis and be substantially smaller in construction.

Folta, James A. (Livermore, CA)

1997-01-01T23:59:59.000Z

18

Miniaturized flow injection analysis system  

DOE Patents (OSTI)

A chemical analysis technique known as flow injection analysis is described, wherein small quantities of chemical reagents and sample are intermixed and reacted within a capillary flow system and the reaction products are detected optically, electrochemically, or by other means. A highly miniaturized version of a flow injection analysis system has been fabricated utilizing microfabrication techniques common to the microelectronics industry. The microflow system uses flow capillaries formed by etching microchannels in a silicon or glass wafer followed by bonding to another wafer, commercially available microvalves bonded directly to the microflow channels, and an optical absorption detector cell formed near the capillary outlet, with light being both delivered and collected with fiber optics. The microflow system is designed mainly for analysis of liquids and currently measures 38{times}25{times}3 mm, but can be designed for gas analysis and be substantially smaller in construction. 9 figs.

Folta, J.A.

1997-07-01T23:59:59.000Z

19

Analysis Methodology for Industrial Load Profiles  

E-Print Network (OSTI)

A methodology is provided for evaluating the impact of various demand-side management (DSM) options on industrial customers. The basic approach uses customer metered load profile data as a basis for the customer load shape. DSM technologies are represented as load shapes and are used as a basis for altering the customers existing measured load shape. The impact of load shape changes on the customer is evaluated in terms of a change in the electric bill by using a software analytical tool called LOADEXPERT™. The software calculates the customer's bill for a particular rate structure and a given load shape. The output data from LOADEXPERT™ are used to calculate the rate of return on the DSM technology investment. Other uses of load profile data are provided.

Reddoch, T. W.

1991-06-01T23:59:59.000Z

20

Three-phase power flow analysis in sequence component frame using Hybrid Particle Swarm Optimization  

Science Conference Proceedings (OSTI)

Power flow is an important tool in power system studies. Usually, a power system is assumed to be balanced and the power flow analysis is carried out for the same. Practical power system networks are highly unbalanced and it is required to obtain load ... Keywords: Genetic algorithm, Load flow, Particle Swarm Optimization, Sequence network, Unbalanced power system

K. Gnanambal; N. S. Marimuthu; C. K. Babulal

2011-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Regression Models for Demand Reduction based on Cluster Analysis of Load Profiles  

E-Print Network (OSTI)

on Cluster Analysis of Load Profiles Nobuyuki Yamaguchi,on Cluster Analysis of Load Profiles Nobuyuki Yamaguchi,regressions, using actual load profile data of Pacific Gas

Kiliccote, Sila

2010-01-01T23:59:59.000Z

22

Supplying Renewable Energy to Deferrable Loads: Algorithms and Economic Analysis  

E-Print Network (OSTI)

Supplying Renewable Energy to Deferrable Loads: Algorithms and Economic Analysis Anthony in order to mitigate the unpredictable and non-controllable fluctuation of renewable power supply. We cast for optimally supplying renewable power to time-flexible electricity loads in the presence of a spot market

Oren, Shmuel S.

23

Performance Analysis of Photovoltaic Cell with Dynamic PHEV Loads  

E-Print Network (OSTI)

Performance Analysis of Photovoltaic Cell with Dynamic PHEV Loads F. R. Islam, H. R. Pota, M. S. Rahman and M. S. Ali Abstract--This paper presents the dynamics of photovoltaic (PV) cell with Plug for charging PHEVs with PV cell where PHEVs load are modelled based on third order battery model. System

Pota, Himanshu Roy

24

Finite element analysis of laterally loaded fin piles  

Science Conference Proceedings (OSTI)

A three-dimensional analysis of laterally loaded fin piles is presented. The behaviour of fin piles is difficult to explain using simple pile-soil theories or two dimensional numerical analyses because of the complicated geometry of the piles. In this ... Keywords: 3D finite element models, Capacity of laterally loaded piles, Efficiency of fins, Fin piles, Mohr-Coulomb soil model, Monopiles

J. -R. Peng; M. Rouainia; B. G. Clarke

2010-11-01T23:59:59.000Z

25

Multi-State Load Models for Distribution System Analysis  

Science Conference Proceedings (OSTI)

Recent work in the field of distribution system analysis has shown that the traditional method of peak load analysis is not adequate for the analysis of emerging distribution system technologies. Voltage optimization, demand response, electric vehicle charging, and energy storage are examples of technologies with characteristics having daily, seasonal, and/or annual variations. In addition to the seasonal variations, emerging technologies such as demand response and plug in electric vehicle charging have the potential to send control signals to the end use loads which will affect how they consume energy. In order to support time-series analysis over different time frames and to incorporate potential control signal inputs it is necessary to develop detailed end use load models which accurately represent the load under various conditions, and not just during the peak load period. This paper will build on previous work on detail end use load modeling in order to outline the method of general multi-state load models for distribution system analysis.

Schneider, Kevin P.; Fuller, Jason C.; Chassin, David P.

2011-11-01T23:59:59.000Z

26

Modeling and analysis of unsymmetrical transformer banks serving unbalanced loads  

SciTech Connect

It is a common practice to serve combination three-phase and single-phase loads from an unsymmetrical three-phase transformer bank and a four-wire secondary. Depending upon the loads and company standards, nine different transformer connections can be considered along with either an open four wire or a quadraplex secondary. The selection of the proper connection and transformer ratings can be achieved by the correct modeling and analysis of a system consisting of an equivalent source, transformer bank, secondary, and loads. This paper develops the models for the nine transformer connections, the secondary, and the loads. A computer program has been written that allows the analysis of the system for loading and short-circuit studies. The paper includes several examples of different normal and abnormal operating conditions on some of the transformer connections.

Kersting, W.H. [New Mexico State Univ., Las Cruces, NM (United States). Coll. of Engineering; Phillips, W.H. [WH Power Consultants, Las Cruces, NM (United States)

1996-05-01T23:59:59.000Z

27

Integrated models of distribution transformers and their loads for three-phase power flow analyses  

Science Conference Proceedings (OSTI)

This paper introduces integrated models of distribution transformers and their loads for three-phase power flow analyses. All transformer connections can be easily included, such as single-phase, open wye, open delta and three-phase. For an existing three-phase power flow program without rigorous transformer models, only a slight modification of this program is needed to analyze distribution systems in more detail by using these proposed models. For those with rigorous transformer models, the rigorous transformer models usually make the program converge with difficulty, or even diverge. The convergence characteristics of these program can be dramatically improved if proposed integrated models are used instead of the rigorous transformer models. Moreover, these models can be easily applied by some functions of advanced distribution management systems or automatic mapping and facility management systems, such as transformer load management and feeder load management, to evaluate the individual phase loads along a feeder.

Chen, T.H.; Chang, Y.L. [National Taiwan Inst. of Tech., Taipei (Taiwan, Province of China). Dept. of Electrical Engineering

1996-01-01T23:59:59.000Z

28

The application of load models of electric appliances to distribution system analysis  

SciTech Connect

This paper proposes a methodology to apply the load models of key electric appliances in residential area for distribution system analysis. According to the load models, the transformer hourly loading is estimated during simulation iteration by the bus voltage and ambient temperature. A three phase load flow program is then executed to find the feeder daily profile of power consumption and system loss with the transformer hourly loading derived. Besides, the daily power consumption by each type of key appliances can also be solved. To demonstrate the effectiveness of the proposed method, a distribution feeder of Taipower system is selected for computer simulation to find the potential of energy conservation by controlling the feeder service voltage at substation. Moreover, the load model of air conditioners, which are temperature sensitive appliances, is also considered in the program to find the impact of ambient temperature change to the power consumption of residential distribution feeders. It is concluded that the load models of key electric appliances can provide a useful tool for distribution engineers to enhance the accuracy of system analysis to estimate the operation efficiency of distribution system in a more effective manner.

Chen, C.S.; Wu, T.H.; Lee, C.C.; Tzeng, Y.M. [National Sun Yat-Sen Univ., Kaohsiung (Taiwan, Province of China). Dept. of Electrical Engineering

1995-08-01T23:59:59.000Z

29

Coupling Air Flow Models to Load/Energy Models and Implications for  

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

Coupling Air Flow Models to Load/Energy Models and Implications for Coupling Air Flow Models to Load/Energy Models and Implications for Envelope Component Testing and Modeling Speaker(s): Brent Griffith Date: July 30, 2002 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Dariush Arasteh Air models allow accounting for air temperature variations within a thermal zone or along the surface of an envelope component. A recently completed ASHRAE research project (RP-1222) produced a source code toolkit focused on coupling airflow models to load routines typical of whole building energy simulation. The two modeling domains are computed separately (and iteratively) with relevant temperature boundary conditions passed back and forth. One of the air models in the toolkit is a new contribution to crude/fast airflow modeling that is based on solving the Euler equation

30

Transportation Electrification Load Development For A Renewable Future Analysis: Preprint  

DOE Green Energy (OSTI)

The transition to electricity as a transportation fuel will create a new load for electricity generation. A set of regional hourly load profiles for electrified vehicles was developed for the 2010 to 2050 timeframe. The transportation electrical energy was determined using regional population forecast data, historical vehicle per capita data, and market penetration growth functions to determine the number of plug-in electric vehicles (PEVs) in each analysis region. Market saturation scenarios of 30% and 50% of sales of PEVs consuming on average approx. 6 kWh per day were considered. PEV aggregate load profiles from previous work were combined with vehicle population data to generate hourly loads on a regional basis. A transition from consumer-controlled charging toward utility-controlled charging was assumed such that by 2050 approximately 45% of the transportation energy demands could be delivered across four daily time slices under optimal control from the utility?s perspective. This electrified transportation analysis resulted in an estimate for both the flexible load and fixed load shapes on a regional basis that may evolve under two PEV market penetration scenarios.

Markel, T.; Mai, T.; Kintner-Meyer, M.

2010-12-01T23:59:59.000Z

31

Unsteady Flow Visualization at Part-Load Conditions of a Radial Diffuser Pump: by PIV and CFD  

Science Conference Proceedings (OSTI)

The present study provides flow visualization on complex internal flows in a radial diffuser pump under part-load conditions by using the three-dimensional Navier-Stokes code CFX-10 with Detached Eddy Simulation (DES) turbulence model. Particle Image ... Keywords: CFD, Flow separation, Flow visualization, PIV, Radial pump

J. Feng; F.-K. Benra; H. J. Dohmen

2009-01-01T23:59:59.000Z

32

Transportation Electrification Load Development For a Renewable Future Analysis  

SciTech Connect

Electrification of the transportation sector offers the opportunity to significantly reduce petroleum consumption. The transportation sector accounts for 70% of US petroleum consumption. The transition to electricity as a transportation fuel will create a new load for electricity generation. In support of a recent US Department of Energy funded activity that analyzed a future generation scenario with high renewable energy technology contributions, a set of regional hourly load profiles for electrified vehicles were developed for the 2010 to 2050 timeframe. These load profiles with their underlying assumptions will be presented in this paper. The transportation electrical energy was determined using regional population forecast data, historical vehicle per capita data, and market penetration growth functions to determine the number of plug-in electric vehicles (PEVs) in each analysis region. Two market saturation scenarios of 30% of sales and 50% of sales of PEVs consuming on average {approx}6 kWh per day were considered. Results were generated for 3109 counties and were consolidated to 134 Power Control Areas (PCA) for the use NREL's's regional generation planning analysis tool ReEDS. PEV aggregate load profiles from previous work were combined with vehicle population data to generate hourly loads on a regional basis. A transition from consumer-controlled charging toward utility-controlled charging was assumed such that by 2050 approximately 45% of the transportation energy demands could be delivered across 4 daily time slices under optimal control from the utility perspective. No other literature has addressed the potential flexibility in energy delivery to electric vehicles in connection with a regional power generation study. This electrified transportation analysis resulted in an estimate for both the flexible load and fixed load shapes on a regional basis that may evolve under two PEV market penetration scenarios. EVS25 Copyright.

Markel, Tony; Mai, Trieu; Kintner-Meyer, Michael CW

2010-09-30T23:59:59.000Z

33

Structural analysis of network traffic flows  

Science Conference Proceedings (OSTI)

Network traffic arises from the superposition of Origin-Destination (OD) flows. Hence, a thorough understanding of OD flows is essential for modeling network traffic, and for addressing a wide variety of problems including traffic engineering, traffic ... Keywords: network traffic analysis, principal component analysis, traffic engineering

Anukool Lakhina; Konstantina Papagiannaki; Mark Crovella; Christophe Diot; Eric D. Kolaczyk; Nina Taft

2004-06-01T23:59:59.000Z

34

Repository Reference Disposal Concepts and Thermal Load Management Analysis  

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

Repository Reference Disposal Concepts and Thermal Load Management Repository Reference Disposal Concepts and Thermal Load Management Analysis Repository Reference Disposal Concepts and Thermal Load Management Analysis A disposal concept consists of three parts: waste inventory (7 waste types examined), geologic setting (e.g., clay/shale, salt, crystalline, other sedimentary), and the engineering concept of operations (range of generic operational concepts examined). Two major categories for waste package emplacement modes are identified: 1) "open" where extended ventilation can remove heat for many years following waste emplacement underground; and 2) "enclosed" modes for clay/shale and salt media where waste packages are emplaced in direct or close contact with natural or engineered materials which may have temperature limits that constrain thermal

35

Analysis and Representation of Miscellaneous Electric Loads in NEMS -  

Gasoline and Diesel Fuel Update (EIA)

Analysis and Representation of Miscellaneous Electric Loads in NEMS Analysis and Representation of Miscellaneous Electric Loads in NEMS Release date: January 6, 2014 Miscellaneous Electric Loads (MELs) comprise a growing portion of delivered energy consumption in residential and commercial buildings. Recently, the growth of MELs has offset some of the efficiency gains made through technology improvements and standards in major end uses such as space conditioning, lighting, and water heating. Miscellaneous end uses, including televisions, personal computers, security systems, data center servers, and many other devices, have continued to penetrate into building-related market segments. Part of this proliferation of devices and equipment can be attributed to increased service demand for entertainment, computing, and convenience appliances.

36

Repository Reference Disposal Concepts and Thermal Load Management Analysis  

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

Repository Reference Disposal Concepts and Thermal Load Management Repository Reference Disposal Concepts and Thermal Load Management Analysis Repository Reference Disposal Concepts and Thermal Load Management Analysis A disposal concept consists of three parts: waste inventory (7 waste types examined), geologic setting (e.g., clay/shale, salt, crystalline, other sedimentary), and the engineering concept of operations (range of generic operational concepts examined). Two major categories for waste package emplacement modes are identified: 1) "open" where extended ventilation can remove heat for many years following waste emplacement underground; and 2) "enclosed" modes for clay/shale and salt media where waste packages are emplaced in direct or close contact with natural or engineered materials which may have temperature limits that constrain thermal

37

Water flow calorimetry measurements of heat loads for a volume production H/sup -/ source  

DOE Green Energy (OSTI)

The design of volume-production H/sup -/ sources requires the knowledge of heat loads on the source components. The arc and filament heater power input to a 20 cm diameter x 23 cm long source can be 50 kW or higher, practically all of which is absorbed in the cooling water. Water flow calorimetry measurements were made to determine the heat loads on the bucket walls, grid no. 1, and magnetic filter rods. The measurements are presented for two different filament locations, for three different values of arc power, and for three values of source gas pressure. 1 ref., 4 figs., 2 tabs.

Purgalis, P.; Ackerman, G.; Kwan, J.; Wells, R.P.

1987-10-01T23:59:59.000Z

38

Influence Of Lateral Load Distributions On Pushover Analysis Effectiveness  

SciTech Connect

The effectiveness of two simple load distributions for pushover analysis recently proposed by the authors is investigated through a comparative study, involving static and dynamic analyses of seismic response of eccentrically braced frames. It is shown that in the upper floors only multimodal pushover procedures provide results close to the dynamic profile, while the proposed load patterns are always conservative in the lower floors. They over-estimate the seismic response less than the uniform distribution, representing a reliable alternative to the uniform or more sophisticated adaptive procedures proposed by seismic codes.

Colajanni, P.; Potenzone, B. [Dipartimento di Ingegneria Civile, Universita di Messina, Contrada Di Dio, S. Agata, 98166 Messina (Italy)

2008-07-08T23:59:59.000Z

39

Computer modeling of gas flow and gas loading of rock in a bench blasting environment  

SciTech Connect

Numerical modeling can contribute greatly to an understanding of the physics involved in the blasting process. This paper will describe the latest enhancements to the blast modeling code DMC (Distinct Motion Code) (Taylor and Preece, 1989) and will demonstrate the ability of DMC to model gas flow and rock motion in a bench blasting environment. DMC has been used previously to model rock motion associated with blasting in a cratering environment (Preece and Taylor, 1990) and in confined volume blasting associated with in-situ oil shale retorting (Preece, 1990 a b). These applications of DMC treated the explosive loading as force versus time functions on specific spheres which were adjusted to obtain correct face velocities. It was recognized that a great need in explosives modeling was the coupling of an ability to simulate gas flow with the rock motion simulation capability of DMC. This was accomplished by executing a finite difference code that computes gas flow through a porous media (Baer and Gross, 1989) in conjunction with DMC. The marriage of these two capabilities has been documented by Preece and Knudsen, 1991. The capabilities that have been added recently to DMC and which will be documented in this paper include: (1) addition of a new equation of state for the explosive gases; (2) modeling of gas flow and sphere loading in a bench environment. 8 refs., 5 figs.

Preece, D.S.; Baer, M.R. (Sandia National Labs., Albuquerque, NM (United States)); Knudsen, S.D. (RE/SPEC, Inc., Albuquerque, NM (United States))

1991-01-01T23:59:59.000Z

40

Plug Load Energy Analysis: The Role of Plug Loads in LEED Certification  

E-Print Network (OSTI)

benchmark and is bound to change as the proportion of plug load energy use grows in commercial buildings.

Fuertes, Gwen; Schiavon, Stefano

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

An Analysis of Load Balancing Technology - Comparing LSF with other Load Balancing Software Packages  

E-Print Network (OSTI)

This paper examines what the load balancing needs of organizations are today, the solution LSF (Load Sharing Facility) provides for them, and how other currently available load balancing products compare to LSF. Jean Suplick (suplick@cxsoft.convex.com) CXSOFT Richardson, Texas January 1994 Why clusters?

Jean Suplick

1994-01-01T23:59:59.000Z

42

Onset and Subsequent Transient Phenomena of Liquid Loading in Gas Wells: Experimental Investigation Using a Large Scale Flow Loop  

E-Print Network (OSTI)

Liquid loading in gas wells is generally described as the inability of the well to lift the co-produced liquids up the tubing, which may ultimately kill the well. There is a lack of dedicated models that can mimic the transient features that are typical of liquid loading. Improved characterization of liquid loading in gas wells and enhanced prediction of future well performance can be achieved from the measurements and analyses resulting from this project. An experimental investigation was carried out to study the onset of liquid loading and the subsequent transient phenomena, using a large scale flow loop to visualize two-phase flow regimes, and to measure pressure and liquid holdup along a 42-m long vertical tube. From this investigation, it is possible to conclude that liquid loading should not be characterized based on onset criteria alone, and that it may not be a wellbore-only problem, as it would seem that the reservoir also plays a key role in determining if/when/how liquid loading manifests itself. Additionally, the results from the experimental campaign were used to compare the performance of different wellbore flow simulators. State-of-the-art simulators do not seem to fully capture the nature of liquid loading in vertical tubes. A simplified model is roposed here to evaluate the liquid transport during the transition from one flow regime to another, during the loading sequence.

Waltrich, Paulo

2012-08-01T23:59:59.000Z

43

Analysis of Wind Power and Load Data at Multiple Time Scales  

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

Analysis of Wind Power and Load Data at Multiple Time Scales Title Analysis of Wind Power and Load Data at Multiple Time Scales Publication Type Report Year of Publication 2010...

44

Load Data Analysis and PowerShape Training: Strategic Load Research and Advanced Topics in Load Profiling for Settlements  

Science Conference Proceedings (OSTI)

Load shapes, representing usage patterns in the electric and gas industry, are a key factor in energy company operations and management. In the emerging restructured energy market, retail energy suppliers market energy to final customers and must arrange for electricity generation or gas delivery to meet their customers' needs. EPRI and Primen sponsored a workshop in September 2000 that addressed a range of issues associated with load shapes, including modeling, profiling for retail market settlement, re...

2000-12-20T23:59:59.000Z

45

DOE Hydrogen Analysis Repository: FLOW Model  

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

FLOW Model FLOW Model Project Summary Full Title: Chemical Engineering Process Simulation Platform - FLOW Project ID: 131 Principal Investigator: Juan Ferrada Brief Description: FLOW is a steady-state chemical process simulator. Modules have been developed for supply chain calculations, micro-economic calculations, and other calculations. Purpose Simulate steady-state chemical processes to support hydrogen infrastructure and transition analysis. Performer Principal Investigator: Juan Ferrada Organization: Oak Ridge National Laboratory (ORNL) Address: Bethel Valley 1, Bldg 5700, N217 Oak Ridge, TN 37831-6166 Telephone: 865-574-4998 Email: ferradajj@ornl.gov Sponsor(s) Name: Fred Joseck Organization: DOE Hydrogen Program Telephone: 202-586-7932 Email: Fred.Joseck@ee.doe.gov

46

EPRI/GRI Load Shape Workshop: Load Data Analysis for Gas and Electric Markets  

Science Conference Proceedings (OSTI)

Load shapes, representing usage patterns in the electric and gas industry, are a key factor in energy company operations and management. In the emerging restructured energy market, retail energy suppliers market energy to final customers and must arrange for electricity generation or gas delivery to meet their customers' needs. EPRI and GRI sponsored a two-day workshop in June, 1999 that addressed a range of issues associated with load shapes, including modeling, profiling for retail market settlement, r...

1999-11-10T23:59:59.000Z

47

Infrastructure Analysis Tools: A Focus on Cash Flow Analysis (Presentation)  

DOE Green Energy (OSTI)

NREL has developed and maintains a variety of infrastructure analysis models for the U.S. Department of Energy. Business case analysis has recently been added to this tool set. This presentation focuses on cash flow analysis. Cash flows depend upon infrastructure costs, optimized spatially and temporally, and assumptions about financing and revenue. NREL has incorporated detailed metrics on financing and incentives into the models. Next steps in modeling include continuing to collect feedback on regional/local infrastructure development activities and 'roadmap' dynamics, and incorporating consumer preference assumptions on infrastructure to provide direct feedback between vehicles and station rollout.

Melaina, M.; Penev, M.

2012-09-01T23:59:59.000Z

48

New Technologies and Methods to Improve Computational Speed and Robustness of Power Flow Analysis  

Science Conference Proceedings (OSTI)

The power flow problem consists of determining the steady-state operating point of an electrical transmission network under specific loading conditions. This report describes the development of power flow techniques designed to improve the efficiency and reliability of an electrical power network. Leveraging advancements in computing technologies, data processing, and sophisticated computational methods can improve the performance of power system analysis tools, specifically their accuracy, speed, ...

2013-12-20T23:59:59.000Z

49

Selected Statistical Methods for Analysis of Load Research Data  

Science Conference Proceedings (OSTI)

Applying innovative statistical methods, researchers developed a probabilistic approach that treats loads as random variables. Though preliminary, these findings can lead to a better understanding of load research design and more efficient use of the data. This report is available only to funders of Program 101A or 101.001. Funders may download this report at http://my.primen.com/Applications/DE/Community/index.asp .

1984-05-01T23:59:59.000Z

50

Fluid flow analysis in a rough fracture (type II) using complex networks and lattice Boltzmann method  

E-Print Network (OSTI)

Complexity of fluid flow in a rough fracture is induced by the complex configurations of opening areas between the fracture planes. In this study, we model fluid flow in an evolvable real rock joint structure, which under certain normal load is sheared. In an experimental study, information regarding about apertures of the rock joint during consecutive 20 mm displacements and fluid flow (permeability) in different pressure heads have been recorded by a scanner laser. Our aim in this study is to simulate the fluid flow in the mentioned complex geometries using the lattice Boltzmann method (LBM), while the characteristics of the aperture field will be compared with the modeled fluid flow permeability To characterize the aperture, we use a new concept in the graph theory, namely: complex networks and motif analysis of the corresponding networks. In this approach, the similar aperture profile along the fluid flow direction is mapped in to a network space. The modeled permeability using the LBM shows good correlat...

Ghaffari, H; Sharifzadeh, M; Young, R P

2011-01-01T23:59:59.000Z

51

Elastic sectional stress analysis of variable section piers subjected to three-dimensional loads  

Science Conference Proceedings (OSTI)

The elastic stress analysis of beam-column structures of uniaxial symmetrical variable cross-sections is developed using an extension of Euler-Bernoulli beam theory. The applied loads are general considering axial (P), flexure (M"x-M"y), shear (V"x-V"y), ... Keywords: Elastic sectional analysis, Shear stress, Tapered section, Three-dimensional loads, Variable section, Warping function

Lucian Stefan; Pierre Léger

2012-01-01T23:59:59.000Z

52

Analysis of the Thermal Loads on the KSTAR Cryogenic System  

SciTech Connect

A large-scale helium refrigeration system is one of the key components for the KSTAR (Korea Superconducting Tokamak Advanced Research) device. In the design of the refrigeration system, an estimation of the thermal loads on the cold mass is an important issue according to the operation scenario. The cold mass of the KSTAR device is about 250 tons including 30 superconducting (SC) coils and the magnet structure. In addition to the static thermal loads, pulsed thermal loads to the refrigeration system have been considered in the operation stage. The main pulsed thermal loads on magnet system are AC losses in the SC coils and eddy current losses in the magnet structure that depend on the magnetic field variation rate. The nuclear radiation loss due to plasma pulse operation is also considered. The designed cooling capacity of the refrigeration system is estimated to be about 9 kW at 4.5 K isothermal. In this paper, calculation of the various kinds of thermal loads on KSTAR cryogenic system and design of the large-scale helium refrigeration system are presented.

Kim, Y.S.; Oh, Y.K.; Kim, W.C.; Park, Y.M.; Lee, Y.J.; Jin, S.B.; Sa, J.W.; Choi, C.H.; Cho, K.W.; Bak, J.S.; Lee, G.S. [Korea Basic Science Institute, Yusung-Ku, Daejeon 305-806 (Korea, Republic of)

2004-06-23T23:59:59.000Z

53

Forecasting electricity load demand: analysis of the 2001 rationing period  

E-Print Network (OSTI)

CEPEL e UENF. Abstract. This paper studies the electricity load demand behavior during the 2001 rationing period, which was implemented because of the Brazilian energetic crisis. The hourly data refers to a utility situated in the southeast of the country. We use the model proposed by Soares and Souza (2003), making use of generalized long memory to model the seasonal behavior of the load. The rationing period is shown to have imposed a structural break in the series, decreasing the load at about 20%. Even so, the forecast accuracy is decreased only marginally, and the forecasts rapidly readapt to the new situation. The forecast errors from this model also permit verifying the public response to pieces of information released regarding the crisis.

Leonardo Rocha Souza; Lacir Jorge Soares; Leonardo Rocha Souza; Epge Fundação; Getúlio Vargas; Lacir Jorge Soares

2003-01-01T23:59:59.000Z

54

Regression Models for Demand Reduction based on Cluster Analysis of Load  

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

Regression Models for Demand Reduction based on Cluster Analysis of Load Regression Models for Demand Reduction based on Cluster Analysis of Load Profiles Speaker(s): Nobuyuki Yamaguchi Date: March 26, 2009 - 12:00pm Location: 90-3122 This seminar provides new regression models for demand reduction of Demand Response programs for the purpose of ex ante evaluation of the programs and screening for recruiting customer enrollment into the programs. The proposed regression models employ load sensitivity to outside air temperature and representative load pattern derived from cluster analysis of customer baseline load as explanatory variables. We examined the performance of the proposed models with respect to the validity of explanatory variables and fitness of regressions, using actual load profile data of Pacific Gas and Electric Company's commercial and industrial

55

OTEC cold water pipe: a survey of available shell analysis computer programs and implications of hydrodynamic loadings  

DOE Green Energy (OSTI)

The design and analysis of the cold water pipe (CWP) is one of the most important technological problems to be solved in the OTEC ocean engineering program. Analytical computer models have to be developed and verified in order to provide an engineering approach for the OTEC CWP with regards to environmental factors such as waves, currents, platform motions, etc., and for various structural configurations and materials such as rigid wall CWP, compliant CWP, stockade CWP, etc. To this end, Analysis and Technology, Inc. has performed a review and evaluation of shell structural analysis computer programs applicable to the design of an OTEC CWP. Included in this evaluation are discussions of the hydrodynamic flow field, structure-fluid interaction and the state-of-the-art analytical procedures for analysis of offshore structures. The analytical procedures which must be incorporated into the design of a CWP are described. A brief review of the state-of-the-art for analysis of offshore structures and the need for a shell analysis for the OTEC CWP are included. A survey of available shell computer programs, both special purpose and general purpose, and discussions of the features of these dynamic shell programs and how the hydrodynamic loads are represented within the computer programs are included. The hydrodynamic loads design criteria for the CWP are described. An assessment of the current state of knowledge for hydrodynamic loads is presented. (WHK)

Pompa, J.A.; Allik, H.; Webman, K.; Spaulding, M.

1979-02-01T23:59:59.000Z

56

Multiphase flow analysis of oil shale retorting  

DOE Green Energy (OSTI)

Several multiphase phenomena occur during oil shale retorting. An analysis is presented of two of these processes including condensation of oil shale vapor and oscillations of pressure in oil shale blocks through cracked bedding planes. Energy conservation equations for oil shale retorting, which include the effects associated with condensation of oil, are derived on the basis of two phase flow theory. It is suggested that an effective heat capacity associated with the latent heat of condensation should be included in the modeling of simulated modified in-situ oil shale retorting. A pressure propagation equation for fast transients in oil shale cracks has been derived and examined in view of existing experimental data. For slow processes, a limiting solution for maximum pressure in oil shale rocks has been obtained. Generation of high pressures in rocks by thermal or other means may lead to rock fracture which may be taken advantage of in modified in-situ oil shale processing.

Gidaspow, D.; Lyczkowski, R.W.

1978-09-18T23:59:59.000Z

57

Loads Analysis of Several Offshore Floating Wind Turbine Concepts  

SciTech Connect

This paper presents a comprehensive dynamic-response analysis of six offshore floating wind turbine concepts.

Robertson, A. N.; Jonkman, J. M.

2011-10-01T23:59:59.000Z

58

Load Balancing Technique in SOA -- VN and Performance Analysis  

Science Conference Proceedings (OSTI)

Network Virtualization has helped in achieving the most complex tasks when it comes to Quality-of-Service (QoS) provisioning to all the end-users. In our paper we are trying to show the efficient way to allocate fixed-capacity network services in the ... Keywords: Virtual Network (VN), Load Balancing, Service Oriented Architecture (SOA), Quality-of-Service (QoS), Network Virtualization, Virtual Private Network (VPN)

Aditya Tandon; Dhruv Garg; Kamal Kant; Abhay Bansal

2012-11-01T23:59:59.000Z

59

Analysis of sweeping heat loads on divertor plate materials  

SciTech Connect

The heat flux on the divertor plate of a fusion reactor is probably one of the most limiting constraints on its lifetime. The current heat flux profile on the outer divertor plate of a device like ITER is highly peaked with narrow profile. The peak heat flux can be as high as 30--40 MW/m{sup 2} with full width at half maximum (FWHM) is in the order of a few centimeters. Sweeping the separatrix along the divertor plate is one of the options proposed to reduce the thermomechanical effects of this highly peaked narrow profile distribution. The effectiveness of the sweeping process is investigated parametrically for various design values. The optimum sweeping parameters of a particular heat load will depend on the design of the divertor plate as well as on the profile of such a heat load. In general, moving a highly peaked heat load results in substantial reduction of the thermomechanical effects on the divertor plate. 3 refs., 8 figs.

Hassanein, A.

1991-12-31T23:59:59.000Z

60

Analysis of sweeping heat loads on divertor plate materials  

SciTech Connect

The heat flux on the divertor plate of a fusion reactor is probably one of the most limiting constraints on its lifetime. The current heat flux profile on the outer divertor plate of a device like ITER is highly peaked with narrow profile. The peak heat flux can be as high as 30--40 MW/m{sup 2} with full width at half maximum (FWHM) is in the order of a few centimeters. Sweeping the separatrix along the divertor plate is one of the options proposed to reduce the thermomechanical effects of this highly peaked narrow profile distribution. The effectiveness of the sweeping process is investigated parametrically for various design values. The optimum sweeping parameters of a particular heat load will depend on the design of the divertor plate as well as on the profile of such a heat load. In general, moving a highly peaked heat load results in substantial reduction of the thermomechanical effects on the divertor plate. 3 refs., 8 figs.

Hassanein, A.

1991-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Dynamic Response Analysis of Underground Powerhouse Structures Considering Coupling Effects of Hydraulic Impulse and Dynamic Loads  

Science Conference Proceedings (OSTI)

When accident takes place in hydropower generator units, they transit from normal working condition to accident working condition. During this period, the generator pier structures bear coupling effect of dynamic load from the units and hydraulic impulse ... Keywords: underground powerhouse structure, unit dynamic load, hydraulic impulse, coupling effect, dynamic analysis

Li Xiaoli; Yuan Chaoqing; Li Ke; Li Yujie

2012-05-01T23:59:59.000Z

62

Rotationally Augmented Flow Structures and Time Varying Loads on Turbine Blades: Preprint  

DOE Green Energy (OSTI)

To better understand wind turbine flow physics, time dependent blade surface pressure data were acquired from the NREL Unsteady Aerodynamics Experiment.

Schreck, S. J.

2007-01-01T23:59:59.000Z

63

Regression Models for Demand Reduction based on Cluster Analysis of Load Profiles  

Science Conference Proceedings (OSTI)

This paper provides new regression models for demand reduction of Demand Response programs for the purpose of ex ante evaluation of the programs and screening for recruiting customer enrollment into the programs. The proposed regression models employ load sensitivity to outside air temperature and representative load pattern derived from cluster analysis of customer baseline load as explanatory variables. The proposed models examined their performances from the viewpoint of validity of explanatory variables and fitness of regressions, using actual load profile data of Pacific Gas and Electric Company's commercial and industrial customers who participated in the 2008 Critical Peak Pricing program including Manual and Automated Demand Response.

Yamaguchi, Nobuyuki; Han, Junqiao; Ghatikar, Girish; Piette, Mary Ann; Asano, Hiroshi; Kiliccote, Sila

2009-06-28T23:59:59.000Z

64

Impact of Wind Energy on Hourly Load Following Requirements: An Hourly and Seasonal Analysis; Preprint  

Science Conference Proceedings (OSTI)

The impacts of wind energy on the power system grid can be decomposed into several time scales that include regulation, load following, and unit commitment. Techniques for evaluating the impacts on these time scales are still evolving, and as wind energy becomes a larger part of the electricity supply, valuable experience will be gained that will help refine these methods. Studies that estimated the impact of wind in the load following time scale found differing results and costs, ranging from near zero to approximately $2.50/megawatt-hour (MWh). Part of the reason for these differences is the different interpretation of the impacts that would be allocated to this ancillary service. Because of the low correlation between changes in load and wind, long-term analyses of the load following impact of wind may find low impacts. During the daily load cycle, there is a tremendous variability in load following requirements in systems without wind. When significant levels of wind generation are added to the resource mix, relatively small changes in wind output can complicate the task of balancing the system during periods of large load swings. This paper analyzes the load following impacts of wind by segregating these critical time periods of the day and separating the analysis by season. The analysis compares wind generation at geographically dispersed sites to wind generation based primarily at a single site, and for a large penetration of wind (more than 20% wind capacity to peak load).

Krich, A.; Milligan, M.

2005-05-01T23:59:59.000Z

65

Design of a high-pressure research flow loop for the experimental investigation of liquid loading in gas wells  

E-Print Network (OSTI)

Liquid loading in producing gas wells is the inability of the produced gas to remove produced liquids from the wellbore. A review of existing flow loops worldwide revealed that specialized areas of research such as liquid loading in gas wells are still lacking dedicated test facilities. This project presents the design of a new dedicated facility to be located at the TowerLab at the Richardson building with adequate operating conditions to reproduce the flow regimes encountered prior to and after the onset of liquid loading in gas wells. The facility consists of a compressed air system, pipelines for air and water, a pressure vessel containing glass beads, an injection manifold, and flow control and monitoring devices. Our results show that three compressors working in parallel is the most technical and economic configuration for the TowerLab based on the overall costs provided by the supplier, the footprint but most importantly the flexibility. The design of the pressure vessel required a cylindrical body with top and bottom welded-flat head covers with multiple openings to minimize its weight. The pipelines connecting major equipment and injection manifold located at the pressure vessel were selected based on the superficial velocities for air and water. These values also showed the need for independent injection using two manifolds instead of commingling flow through a tee joint. The use of digital pressure gauges with an accuracy of 0.05 to 25% and coriolis or vortex meters to measure air flowrate is also suggested. For the water line, installation of turbine meters results in the most economic approach.

Fernandez Alvarez, Juan Jose

2008-12-01T23:59:59.000Z

66

Loads Analysis of a Floating Offshore Wind Turbine Using Fully Coupled Simulation: Preprint  

SciTech Connect

This paper presents the use of fully coupled aero-hydro-servo-elastic simulation tools to perform a loads analysis of a 5-MW offshore wind turbine supported by a barge with moorings, one of many promising floating platform concepts.

Jonkman, J. M.; Buhl, M. L., Jr.

2007-06-01T23:59:59.000Z

67

POWER FLOW ANALYSIS OF ELECTROSTRICTIVE ACTUATORS DRIVEN BYSWITCHMODE AMPLIFIERS  

E-Print Network (OSTI)

is within the bandwidth of the amplifier. This analysis also reveals that the electrical power flow through of that energy. We adopt this view in this paper. The analysis in this paper is motivated by the smart skin being Consider the flow of energy through this smart skin. Electrical energy is supplied to the smart skin from

Lindner, Douglas K.

68

Analysis of Loads and Wind Energy Potential for Remote Power Stations in Alaska University of Massachusetts Amherst  

E-Print Network (OSTI)

Analysis of Loads and Wind Energy Potential for Remote Power Stations in Alaska Mia Devine Electric Use (kWh/year) 2,173,400 1,032,800 2,520,500 Average Load 300 kW 140 kW 280 kW Peak Load 600 k load profile. Villages usuall

Massachusetts at Amherst, University of

69

Multiphase Flow Analysis in Hydra-TH  

SciTech Connect

This talk presents an overview of the multiphase flow efforts with Hydra-TH. The presentation begins with a definition of the requirements and design principles for multiphase flow relevant to CASL-centric problems. A brief survey of existing codes and their solution algorithms is presented before turning the model formulation selected for Hydra-TH. The issues of hyperbolicity and wellposedness are outlined, and a three candidate solution algorithms are discussed. The development status of Hydra-TH for multiphase flow is then presented with a brief summary and discussion of future directions for this work.

Christon, Mark A. [Los Alamos National Laboratory; Bakosi, Jozsef [Los Alamos National Laboratory; Francois, Marianne M. [Los Alamos National Laboratory; Lowrie, Robert B. [Los Alamos National Laboratory; Nourgaliev, Robert [Idaho National Laboratory

2012-06-20T23:59:59.000Z

70

Analysis and Synthesis of Load Forecasting Data for Renewable Integration Studies: Preprint  

SciTech Connect

As renewable energy constitutes greater portions of the generation fleet, the importance of modeling uncertainty as part of integration studies also increases. In pursuit of optimal system operations, it is important to capture not only the definitive behavior of power plants, but also the risks associated with systemwide interactions. This research examines the dependence of load forecast errors on external predictor variables such as temperature, day type, and time of day. The analysis was utilized to create statistically relevant instances of sequential load forecasts with only a time series of historic, measured load available. The creation of such load forecasts relies on Bayesian techniques for informing and updating the model, thus providing a basis for networked and adaptive load forecast models in future operational applications.

Steckler, N.; Florita, A.; Zhang, J.; Hodge, B. M.

2013-11-01T23:59:59.000Z

71

Exit blade geometry and part-load performance of small axial flow propeller turbines: An experimental investigation  

Science Conference Proceedings (OSTI)

A detailed experimental investigation of the effects of exit blade geometry on the part-load performance of low-head, axial flow propeller turbines is presented. Even as these turbines find important applications in small-scale energy generation using micro-hydro, the relationship between the layout of blade profile, geometry and turbine performance continues to be poorly characterized. The experimental results presented here help understand the relationship between exit tip angle, discharge through the turbine, shaft power, and efficiency. The modification was implemented on two different propeller runners and it was found that the power and efficiency gains from decreasing the exit tip angle could be explained by a theoretical model presented here based on classical theory of turbomachines. In particular, the focus is on the behaviour of internal parameters like the runner loss coefficient, relative flow angle at exit, mean axial flow velocity and net tangential flow velocity. The study concluded that the effects of exit tip modification were significant. The introspective discussion on the theoretical model's limitation and test facility suggests wider and continued experimentation pertaining to the internal parameters like inlet vortex profile and exit swirl profile. It also recommends thorough validation of the model and its improvement so that it can be made capable for accurate characterization of blade geometric effects. (author)

Singh, Punit; Nestmann, Franz [Institute for Water and River Basin Management (IWG), University of Karlsruhe, Kaiser Str. 12, D 76128 Karlsruhe (Germany)

2010-09-15T23:59:59.000Z

72

Simulation analysis of within-day flow fluctuation effects on trout below flaming Gorge Dam.  

DOE Green Energy (OSTI)

In addition to being renewable, hydropower has the advantage of allowing rapid load-following, in that the generation rate can easily be varied within a day to match the demand for power. However, the flow fluctuations that result from load-following can be controversial, in part because they may affect downstream fish populations. At Flaming Gorge Dam, located on the Green River in northeastern Utah, concern has been raised about whether flow fluctuations caused by the dam disrupt feeding at a tailwater trout fishery, as fish move in response to flow changes and as the flow changes alter the amount or timing of the invertebrate drift that trout feed on. Western Area Power Administration (Western), which controls power production on submonthly time scales, has made several operational changes to address concerns about flow fluctuation effects on fisheries. These changes include reducing the number of daily flow peaks from two to one and operating within a restricted range of flows. These changes significantly reduce the value of the power produced at Flaming Gorge Dam and put higher load-following pressure on other power plants. Consequently, Western has great interest in understanding what benefits these restrictions provide to the fishery and whether adjusting the restrictions could provide a better tradeoff between power and non-power concerns. Directly evaluating the effects of flow fluctuations on fish populations is unfortunately difficult. Effects are expected to be relatively small, so tightly controlled experiments with large sample sizes and long study durations would be needed to evaluate them. Such experiments would be extremely expensive and would be subject to the confounding effects of uncontrollable variations in factors such as runoff and weather. Computer simulation using individual-based models (IBMs) is an alternative study approach for ecological problems that are not amenable to analysis using field studies alone. An IBM simulates how a population responds to environmental changes by representing how the population's individuals interact with their environment and each other. IBMs represent key characteristics of both individual organisms (trout, in this case) and the environment, thus allowing controlled simulation experiments to analyze the effects of changes in the key variables. For the flow fluctuation problem at Flaming Gorge Dam, the key environmental variables are flow rates and invertebrate drift concentrations, and the most important processes involve how trout adapt to changes (over space and time) in growth potential and mortality risk. This report documents simulation analyses of flow fluctuation effects on trout populations. The analyses were conducted in a highly controlled fashion: an IBM was used to predict production (survival and growth) of trout populations under a variety of scenarios that differ only in the level or type of flow fluctuation.

Railsback, S. F.; Hayse, J. W.; LaGory, K. E.; Environmental Science Division; EPRI

2006-01-01T23:59:59.000Z

73

Assessment of seismic resistance of a basilica-type church under earthquake loading: Modelling and analysis  

Science Conference Proceedings (OSTI)

In this paper a finite element methodology for the static and dynamic non-linear analysis of historical masonry structures is described and applied to a case study. A basilica-type masonry church is analysed in order to assess its structural behaviour ... Keywords: Earthquake loading, FE modeling seismic vulnerability, Historical masonry building, Non-linear analysis, Strengthening techniques

Michele Betti; Andrea Vignoli

2008-04-01T23:59:59.000Z

74

Power flow analysis for amplifier design and energy harvesting  

E-Print Network (OSTI)

Power flow analysis for amplifier design and energy harvesting Nikola Vujica, Donald J. Leoa strategies which will provide an electrical energy regeneration. In this case, the power is flowing from to the electrical side which may have the ability to store (regenerate) this energy. The ability of energy storage

Lindner, Douglas K.

75

Energy flow analysis for curved beams  

Science Conference Proceedings (OSTI)

This paper presents an energy model for the medium- and high-frequency analysis of Love–Kirchhoff curved beams. This model introduced by Nefske and Sung [Statistical Energy Analysis NCA 3

A. Le Bot; M. N. Ichchou; L. Jezequel

1997-01-01T23:59:59.000Z

76

The Objective Analysis of Planetary-Scale Flow  

Science Conference Proceedings (OSTI)

Forecast in the medium and longer range requires an accurate forecast of the scale flow. An accurate large-scale forecast requires an accurate, large-scale, initial, objective analysis. The present study examines the accuracy of large objective ...

Roger Daley; Werner Wergen; Gerard Cats

1986-10-01T23:59:59.000Z

77

Statistical Analysis of Baseline Load Models for Non-Residential Buildings  

SciTech Connect

Policymakers are encouraging the development of standardized and consistent methods to quantify the electric load impacts of demand response programs. For load impacts, an essential part of the analysis is the estimation of the baseline load profile. In this paper, we present a statistical evaluation of the performance of several different models used to calculate baselines for commercial buildings participating in a demand response program in California. In our approach, we use the model to estimate baseline loads for a large set of proxy event days for which the actual load data are also available. Measures of the accuracy and bias of different models, the importance of weather effects, and the effect of applying morning adjustment factors (which use data from the day of the event to adjust the estimated baseline) are presented. Our results suggest that (1) the accuracy of baseline load models can be improved substantially by applying a morning adjustment, (2) the characterization of building loads by variability and weather sensitivity is a useful indicator of which types of baseline models will perform well, and (3) models that incorporate temperature either improve the accuracy of the model fit or do not change it.

Coughlin, Katie; Piette, Mary Ann; Goldman, Charles; Kiliccote, Sila

2008-11-10T23:59:59.000Z

78

Forced flow supercritical helium in a closed heat transfer loop subjected to pulsed heat loads  

Science Conference Proceedings (OSTI)

The superconducting magnets of the tokamak JT-60SA are cooled by means of forced flows of supercritical helium at 4.4 K and 0.5 MPa. The closed loops transfer heat from the magnets to the refrigerator through heat exchangers immersed into a saturated liquid helium bath. An experimental loop was designed to represent a 1/20 scaled down mock-up of JT-60SA central solenoid cooling circuits. This design for keeping the same transit times in the helium circuits

2012-01-01T23:59:59.000Z

79

Analysis of the Impurity Flow Reversal Experiment  

DOE Green Energy (OSTI)

Experiments performed on the Impurity Study Experiment (ISX-A) tokamak have shown that poloidally asymmetric injection of hydrogen gas can alter the inward transport of injected impurity atoms. We have compared the observed transport times and the magnitude of the flow reversal effect with a model based on the neoclassical theory of impurity transport and find that the observations are consistent with the theory. However, uncertainities in the radial profiles and the atomic rate coefficients do not permit a truly definitive test of the theory.

Burrell, K.H.; Wong, S.K.; Amano, T.

1979-03-01T23:59:59.000Z

80

Structural analysis of an LMFBR shield assembly duct under thermo-mechanical and seismic loads  

SciTech Connect

This paper describes the stress analysis performed to assess structural adequacy of the Clinch River Breeder Reactor (CRBR) core removable shield assemblies. Removable shield assemblies are located in the peripheral region of the core (between blanket assemblies and the fixed radial shield), and are subjected to severe cross-sectional thermal gradients and seismic loads requiring a relatively complex duct load pad design. For cost-effectiveness, the analysis was conducted in two stages. First, an elasto-plastic seismic stress analysis was performed using a detailed nonlinear finite element model (with gaps) of the load pad configuration. Next, in order to determine the total strain accumulation and the creep-fatigue damage the maximum seismic stresses combined with the ''worst'' thermal stresses from a single assembly model were used to perform a simplified inelastic analysis using two sets of material properties to bound the changing material conditions during reactor operation. This work demonstrated the necessity and applicability of the two simplified analysis techniques in elevated temperature structural design, i.e., the treatment of time-dependent degradation of material properties due to temperature and nuclear irradiation, and the use of time-independent finite element stress analysis results to perform a simplified creep-fatigue analysis.

Malik, S.N.; Sazawal, V.K.

1984-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

A functional analysis of electrical load curve modelling for some households specific electricity end-uses  

E-Print Network (OSTI)

A functional analysis of electrical load curve modelling for some households specific electricity and the way electrical devices are used will evolve significantly. The energy consumption is likely of electrical devices; · integration of decentralized energy production and stocking (PV modules with battery

Paris-Sud XI, Université de

82

Dynamic Analysis of Reinforced Brick Masonry Infilled RC Frames Using 3D Elements under Seismic Loading  

Science Conference Proceedings (OSTI)

Masonry walls are provided basically for the purpose of partitioning and covering but they impart considerable strength and stiffness to the building frame for resisting loads. The strength and stiffness contribution of infill masonry is generally ignored ... Keywords: Masonry, Infill, Frame, Finite Element Analysis

Ramesh S. Manoli; D. S. Prakash

2008-07-01T23:59:59.000Z

83

Stability boundary analysis of the dynamic voltage restorer in weak systems with dynamic loads  

Science Conference Proceedings (OSTI)

In this contribution, a stability analysis for a dynamic voltage restorer (DVR) connected to a weak ac system containing a dynamic load is presented using continuation techniques and bifurcation theory. The system dynamics are explored through the continuation ... Keywords: DVR, Floquet multiplier, active filter, continuation techniques, iterative map, point common coupling, power converter, stability regions, switching process

Juan Segundo-Ramírez; Aurelio Medina; Arindam Ghosh; Gerard Ledwich

2012-06-01T23:59:59.000Z

84

Analysis of Wind Power and Load Data at Multiple Time Scales  

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

Analysis of Wind Power and Load Data at Multiple Time Scales Analysis of Wind Power and Load Data at Multiple Time Scales Title Analysis of Wind Power and Load Data at Multiple Time Scales Publication Type Report LBNL Report Number LBNL-4147E Year of Publication 2010 Authors Coughlin, Katie, and Joseph H. Eto Date Published 12/2010 Publisher LBNL City Berkeley Keywords renewable generation integration Abstract In this study we develop and apply new methods of data analysis for high resolution wind power and system load time series, to improve our understanding of how to characterize highly variable wind power output and the correlations between wind power and load. These methods are applied to wind and load data from the ERCOT region, and wind power output from the PJM and NYISO areas. We use a wavelet transform to apply mathematically well-defined operations of smoothing and differencing to the time series data. This approach produces a set of time series of the changes in wind power and load (or "deltas"), over a range of times scales from a few seconds to approximately one hour. A number of statistical measures of these time series are calculated. We present sample distributions, and devise a method for fitting the empirical distribution shape in the tails. We also evaluate the degree of serial correlation, and linear correlation between wind and load. Our examination of the data shows clearly that the deltas do not follow a Gaussian shape; the distribution is exponential near the center and appears to follow a power law for larger fluctuations. Gaussian distributions are frequently used in modeling studies. These are likely to over-estimate the probability of small to moderate deviations. This in turn may lead to an over-estimation of the additional reserve requirement (hence the cost) for high penetration of wind. The Gaussian assumption provides no meaningful information about the real likelihood of large fluctuations. The possibility of a power law distribution is interesting because it suggests that the distribution shape for of wind power fluctuations may become independent of system size for large enough systems.

85

A new framework for elimination-based data flow analysis using DJ graphs  

Science Conference Proceedings (OSTI)

Keywords: DJ graphs, Tarjan's interval, exhaustive and incremental data flow analysis, irreducible flowgraphs, reducible flowgraphs

Vugranam C. Sreedhar; Guang R. Gao; Yong-Fong Lee

1998-03-01T23:59:59.000Z

86

Model Development and Loads Analysis of a Wind Turbine on a Floating Offshore Tension Leg Platform  

SciTech Connect

This report presents results of the analysis of a 5-MW wind turbine located on a floating offshore tension leg platform (TLP) that was conducted using the fully coupled time-domain aero-hydro-servo-elastic design code FAST with AeroDyn and HydroDyn. Models in this code are of greater fidelity than most of the models that have been used to analyze floating turbines in the past--which have neglected important hydrodynamic and mooring system effects. The report provides a description of the development process of a TLP model, which is a modified version of a Massachusetts Institute of Technology design derived from a parametric linear frequency-domain optimization process. An extensive loads and stability analysis for ultimate and fatigue loads according to the procedure of the International Electrotechnical Commission offshore wind turbine design standard was performed with the verified TLP model. Response statistics, extreme event tables, fatigue lifetimes, and selected time histories of design-driving extreme events are analyzed and presented. Loads for the wind turbine on the TLP are compared to those of an equivalent land-based turbine in terms of load ratios. Major instabilities for the TLP are identified and described.

Matha, D.; Fischer, T.; Kuhn, M.; Jonkman, J.

2010-02-01T23:59:59.000Z

87

Dynamic Analysis and Stability of the Load Frequency Control in Two Area Power System with Steam Turbine  

Science Conference Proceedings (OSTI)

The aim of this paper is to model, analysis and simulation of load frequency control in two area power system and parameters variation effects. State equations of a LFC in two area power system for a steam turbine are proposed. Then by examining some ... Keywords: load frequency control, dynamic analysis, integral controller

Ghazanfar Shahgholian; Serareh Yazdekhasti; Pegah Shafaghi

2009-12-01T23:59:59.000Z

88

Testing and analysis of load-side immersed heat exchangers for solar domestic hot water systems  

DOE Green Energy (OSTI)

This report describes work to determine the performance of load-side heat exchangers for use in residential solar domestic hot water systems. We measured the performance of four heat exchangers: a smooth coil and a finned coil having heat transfer areas of 2.5 m/sup 2/ (26 ft/sup 2/) and those having areas of 1.7 m/sup 2/ (19 ft/sup 2/). A numerical model using the thermal network program MITAS was constructed, and results were compared to the experimental results. Research showed a smooth coil with only 70% of the surface area of a finned coil performed better than the finned coil. Also, load-side heat exchangers can maintain and enhance stratification in storage tanks, permitting the use of control strategies that take advantage of stratified storage tanks to increase system performance. The analytical model, which agreed reasonably well with the experimental results, was used to vary heat exchanger flow rate and area and initial tank temperature for both a smooth- and a finned-coil heat exchanger. Increasing the heat exchanger flow rate and area results in higher heat transfer rates but not necessarily optimal performance. Lower initial tank temperatures resulted in reduced tank stratification. The smooth heat exchanger outperformed the finned heat exchanger with the same outside surface area. 15 refs., 37 figs., 9 tabs.

Farrington, R.B.; Bingham, C.E.

1987-10-01T23:59:59.000Z

89

Evaluation of uncertainties due to hydrogeological modeling and groundwater flow analysis: Steady flow, transient flow, and thermal studies  

SciTech Connect

Starting with regional geographic, geologic, surface and subsurface hydrologic, and geophysical data for the Tono area in Gifu, Japan, we develop an effective continuum model to simulate subsurface flow and transport in a 4 km by 6 km by 3 km thick fractured granite rock mass overlain by sedimentary layers. Individual fractures are not modeled explicitly. Rather, continuum permeability and porosity distributions are assigned stochastically, based on well-test data and fracture density measurements. Lithologic layering and one major fault, the Tsukiyoshi Fault, are assigned deterministically. We conduct three different studies: (1) the so-called base case, in which the model simulates the steady-state groundwater flow through the site, and then stream trace analysis is used to calculate travel times to the model boundary from specified release points; (2) simulations of transient flow during long term pump tests (LTPT) using the base-case model; and (3) thermal studies in which coupled heat flow and fluid flow are modeled, to examine the effects of the geothermal gradient on groundwater flow. The base-case study indicates that the choice of open or closed lateral boundaries has a strong influence on the regional groundwater flow patterns produced by the models, but no field data exist that can be used to determine which boundary conditions are more realistic. The LTPT study cannot be used to distinguish between the alternative boundary conditions, because the pumping rate is too small to produce an analyzable pressure response at the model boundaries. In contrast, the thermal study shows that the temperature distributions produced by the open and closed models differ greatly. Comparison with borehole temperature data may be used to eliminate the closed model from further consideration.

Doughty, Christine; Karasaki, Kenzi

2002-12-11T23:59:59.000Z

90

Flow Analysis on a Limited Volume Chilled Water System  

SciTech Connect

LANL Currently has a limited volume chilled water system for use in a glove box, but the system needs to be updated. Before we start building our new system, a flow analysis is needed to ensure that there are no high flow rates, extreme pressures, or any other hazards involved in the system. In this project the piping system is extremely important to us because it directly affects the overall design of the entire system. The primary components necessary for the chilled water piping system are shown in the design. They include the pipes themselves (perhaps of more than one diameter), the various fitting used to connect the individual pipes to form the desired system, the flow rate control devices (valves), and the pumps that add energy to the fluid. Even the most simple pipe systems are actually quite complex when they are viewed in terms of rigorous analytical considerations. I used an 'exact' analysis and dimensional analysis considerations combined with experimental results for this project. When 'real-world' effects are important (such as viscous effects in pipe flows), it is often difficult or impossible to use only theoretical methods to obtain the desired results. A judicious combination of experimental data with theoretical considerations and dimensional analysis are needed in order to reduce risks to an acceptable level.

Zheng, Lin [Los Alamos National Laboratory

2012-07-31T23:59:59.000Z

91

Simulation-Length Requirements in the Loads Analysis of Offshore Floating Wind Turbines: Preprint  

DOE Green Energy (OSTI)

The goal of this paper is to examine the appropriate length of a floating offshore wind turbine (FOWT) simulation - a fundamental question that needs to be answered to develop design requirements. To examine this issue, a loads analysis of an example FOWT was performed in FAST with varying simulation lengths. The offshore wind system used was the OC3-Hywind spar buoy, which was developed for use in the International Energy Agency Code Comparison Collaborative Project and supports NREL's offshore 5-megawatt baseline turbine. Realistic metocean data from the National Oceanic and Atmospheric Administration and repeated periodic wind files were used to excite the structure. The results of the analysis clearly show that loads do not increase for longer simulations. In regards to fatigue, a sensitivity analysis shows that the procedure used for counting half cycles is more important than the simulation length itself. Based on these results, neither the simulation length nor the periodic wind files affect response statistics and loads for FOWTs (at least for the spar studied here); a result in contrast to the offshore oil and gas industry, where running simulations of at least 3 hours in length is common practice.

Haid, L.; Stewart, G.; Jonkman, J.; Robertson, A.; Lackner, M.; Matha, D.

2013-06-01T23:59:59.000Z

92

Simulation-Length Requirements in the Loads Analysis of Offshore Floating Wind Turbines: Preprint  

SciTech Connect

The goal of this paper is to examine the appropriate length of a floating offshore wind turbine (FOWT) simulation - a fundamental question that needs to be answered to develop design requirements. To examine this issue, a loads analysis of an example FOWT was performed in FAST with varying simulation lengths. The offshore wind system used was the OC3-Hywind spar buoy, which was developed for use in the International Energy Agency Code Comparison Collaborative Project and supports NREL's offshore 5-megawatt baseline turbine. Realistic metocean data from the National Oceanic and Atmospheric Administration and repeated periodic wind files were used to excite the structure. The results of the analysis clearly show that loads do not increase for longer simulations. In regards to fatigue, a sensitivity analysis shows that the procedure used for counting half cycles is more important than the simulation length itself. Based on these results, neither the simulation length nor the periodic wind files affect response statistics and loads for FOWTs (at least for the spar studied here); a result in contrast to the offshore oil and gas industry, where running simulations of at least 3 hours in length is common practice.

Haid, L.; Stewart, G.; Jonkman, J.; Robertson, A.; Lackner, M.; Matha, D.

2013-06-01T23:59:59.000Z

93

Global performance analysis of floating harbor and container ship for loading and offloading operation  

E-Print Network (OSTI)

The feasibility and general performance of a floating harbor system is studied with regard to the relative motion of a floating quay and a container ship. A 350[m]× 160[m] box-type barge is selected as the floating harbor and it is positioned by a dolphin mooring system. The container ship is tied to the land wall by hawsers. The hydrodynamic interactions between floating bodies and a fixed quay wall in close proximity with a side-by-side arrangement are investigated. A three dimensional wave-body diffraction/radiation panel program WAMIT is used for the calculation of hydrodynamic information and response amplitude operators (RAO) of the three bodies in frequency domain. Subsequently, the vessel-mooring coupled dynamic analysis program WINPOST is employed to produce motion time histories in time domain. The frequency-domain RAO is successfully compared with time-domain RAO in case viscous forces are neglected. Compared to Brajesh Kumar’s (2005) study, 12×12 full hydrodynamic interactions between the two floating bodies are included and dynamic wind loading is considered in addition to wave and current loadings. All the relative motion statistics are calculated from the respective motion time histories for a typical operational condition and a typical survival condition. The relative motion between the interacting bodies is small in the operational condition to ensure the efficacy of container loading and offloading operation from both sides of the ship while the loading and offloading operation is not available in the survival condition.

Lim, Sung Ho

2007-12-01T23:59:59.000Z

94

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

22]. Fluid flow and heat-transfer processes in a two-phase,processes associated with multiphase flow and heat transferprocesses has also motivated development of fluid flow and heat transfer

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

95

Dynamic Information Flow Analysis for JavaScript in a Web Browser  

E-Print Network (OSTI)

132 vii Abstract Dynamic Information Flow Analysis forImplementation in Firefox 14 Information Flow Policy VProgramming languages for information security. PhD thesis,

Austin, Thomas Howard

2013-01-01T23:59:59.000Z

96

ANALYSIS OF CHECK VALVE DISC MOTION DURING A FLOW TRANSIENT  

SciTech Connect

An analysis of the dynamics of a check valve disc under the influence of a flow transient is presented. The impact velocities of the disc and the pressure surge resulting from extinguishing a fluid velocity are predicted. This analysis develops the equations of motion of a simple swing disc check valve from Newton's Second Law. Modifications of the analysis necessary for application to other types of valves are described. The developed equations are progiammed for the Philco-2000 digital computer in FORTRAN as the SLAM Code. The Code input consists of the characteristics of the valve and the flow transient. The output of the code includes the dynamics of the valve disc as a function of time and the pressure surge induced by valve closure. (H.G.G.)

Fuls, G.M.

1962-12-01T23:59:59.000Z

97

Analysis of Wind Power and Load Data at Multiple Time Scales  

SciTech Connect

In this study we develop and apply new methods of data analysis for high resolution wind power and system load time series, to improve our understanding of how to characterize highly variable wind power output and the correlations between wind power and load. These methods are applied to wind and load data from the ERCOT region, and wind power output from the PJM and NYISO areas. We use a wavelet transform to apply mathematically well-defined operations of smoothing and differencing to the time series data. This approach produces a set of time series of the changes in wind power and load (or ?deltas?), over a range of times scales from a few seconds to approximately one hour. A number of statistical measures of these time series are calculated. We present sample distributions, and devise a method for fitting the empirical distribution shape in the tails. We also evaluate the degree of serial correlation, and linear correlation between wind and load. Our examination of the data shows clearly that the deltas do not follow a Gaussian shape; the distribution is exponential near the center and appears to follow a power law for larger fluctuations. Gaussian distributions are frequently used in modeling studies. These are likely to over-estimate the probability of small to moderate deviations. This in turn may lead to an over-estimation of the additional reserve requirement (hence the cost) for high penetration of wind. The Gaussian assumption provides no meaningful information about the real likelihood of large fluctuations. The possibility of a power law distribution is interesting because it suggests that the distribution shape for of wind power fluctuations may become independent of system size for large enough systems.

Coughlin, Katie; Eto, J.H.

2010-12-20T23:59:59.000Z

98

End-Use Load and Consumer Assessment Program: Analysis of residential refrigerator/freezer performance  

SciTech Connect

The Bonneville Power Administration (Bonneville) is conducting a large end-use data acquisition program in an effort to understand how energy is utilized in buildings with permanent electric space heating equipment in the Pacific Northwest. The initial portion of effort, known as the End-Use Load and Consumer Assessment Program (ELCAP), was conducted for Bonneville by the Pacific Northwest Laboratory (PNL). The collection of detailed end-use data provided an opportunity to analyze the amount of energy consumed by both refrigerators and separate freezers units located in residential buildings. By obtaining this information, the uncertainty of long- term regional end-use forecasting can be improved and potential utility marketing programs for new appliances with a reduced overall energy demand can be identified. It was found that standby loads derived from hourly averages between 4 a.m. and 5 a.m. reflected the minimum consumption needed to maintain interior refrigerator temperatures at a steady-state condition. Next, an average 24-hour consumption that included cooling loads from door openings and cooling food items was also determined. Later, analyses were conducted to develop a model capable of predicting refrigerator standby loads and 24-hour consumption for comparison with national refrigerator label ratings. Data for 140 residential sites with a refrigeration end-use were screened to develop a sample of 119 residences with pure refrigeration for use in this analysis. To identify those refrigerators that were considered to be pure (having no other devices present on the circuit) in terms of their end-use classification, the screening procedure used a statistical clustering technique that was based on standby loads with 24-hour consumption. 5 refs., 18 figs., 4 tabs.

Ross, B.A.

1991-09-01T23:59:59.000Z

99

Event-plane flow analysis without nonflow effects  

SciTech Connect

The event-plane method, which is widely used to analyze anisotropic flow in nucleus-nucleus collisions, is known to be biased by nonflow effects, especially at high p{sub t}. Various methods (cumulants, Lee-Yang zeros) have been proposed to eliminate nonflow effects, but their implementation is tedious, which has limited their application so far. In this article, we show that the Lee-Yang-zeroes method can be recast in a form similar to the standard event-plane analysis. Nonflow correlations are strongly suppressed by using the information from the length of the flow vector, in addition to the event-plane angle. This opens the way to improved analyses of elliptic flow and azimuthally sensitive observables at the Relativistic Heavy Ion Collider and the Large Hadron Collider.

Bilandzic, Ante; Kolk, Naomi van der [Nikhef, Science Park 105, 1098 XG Amsterdam (Netherlands); Utrecht University, P. O. Box 80000, 3508 TA Utrecht (Netherlands); Ollitrault, Jean-Yves [Institut de Physique Theorique, CEA-Saclay, F-91191 Gif-sur-Yvette cedex (France); Snellings, Raimond [Utrecht University, P. O. Box 80000, 3508 TA Utrecht (Netherlands)

2011-01-15T23:59:59.000Z

100

Utility load management and solar energy. Study background and preliminary market potential analysis  

DOE Green Energy (OSTI)

The large-scale use of electrically assisted solar heating and hot water (solar/electric HHW) systems can have a substantial effect on electric utilities. Under some conditions, peak loads may be increased causing electricity generation costs to rise. However, with appropriate control and thermal storage equipment tied to the HHW system, the timing of the delivery of electricity to the HHW system can be controlled so that it is accomplished during those times of the day when utility supply costs are lowest. In this study various load management schemes for these applications are being investigated to determine their effect on the cost of generating the back-up electric power and on the cost of the required control and storage system. Solar/electric HHW systems are compared to electric-only systems for several utilities and several HHW system designs. The issues underlying the study, the methods of investigation, and the results of the first phase of the study are described. In this phase a preliminary analysis of the maximum market potential for night-time precharge electric-only hot water systems in either utilities was conducted. This analysis indicated that if about 20 to 40 percent of the residential customers used these appliances in a load managed mode, the 10 PM--8 AM valley in the utility load curve would be filled. For combined electric heating and hot water, the corresponding fraction is 6 to 12 percent. It is estimated that in each case, roughly twice the number of residential customers could be accommodated in the valley if solar/electric systems were used instead.

Davitian, H; Bright, R N; Marcuse, W

1978-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

AnalyzeHOLE: An Integrated Wellbore Flow Analysis Tool  

SciTech Connect

Conventional interpretation of flow logs assumes that hydraulic conductivity is directly proportional to flow change with depth. However, well construction can significantly alter the expected relation between changes in fluid velocity and hydraulic conductivity. Strong hydraulic conductivity contrasts between lithologic intervals can be masked in continuously screened wells. Alternating intervals of screen and blank casing also can greatly complicate the relation between flow and hydraulic properties. More permeable units are not necessarily associated with rapid fluid-velocity increases. Thin, highly permeable units can be misinterpreted as thick and less permeable intervals or not identified at all. These conditions compromise standard flow-log interpretation because vertical flow fields are induced near the wellbore. AnalyzeHOLE, an integrated wellbore analysis tool for simulating flow and transport in wells and aquifer systems, provides a better alternative for simulating and evaluating complex well-aquifer system interaction. A pumping well and adjacent aquifer system are simulated with an axisymmetric, radial geometry in a two-dimensional MODFLOW model. Hydraulic conductivities are distributed by depth and estimated with PEST by minimizing squared differences between simulated and measured flows and drawdowns. Hydraulic conductivity can vary within a lithology but variance is limited with regularization. Transmissivity of the simulated system also can be constrained to estimates from single-well, pumping tests. Water-quality changes in the pumping well are simulated with simple mixing models between zones of differing water quality. These zones are differentiated by backtracking thousands of particles from the well screens with MODPATH. An Excel spreadsheet is used to interface the various components of AnalyzeHOLE by (1) creating model input files, (2) executing MODFLOW, MODPATH, PEST, and supporting FORTRAN routines, and (3) importing and graphically displaying pertinent results.

Keith J. Halford

2009-10-01T23:59:59.000Z

102

Non-Darcy flow analysis through tight sand formations  

SciTech Connect

An experimental setup was designed and constructed to measure the flow parameters through tight sand porous media. The two kinds of coreholders being used are Hassler-type and one in which the core sample is encapsulated in layers of epoxy resin and metal alloy. A gas flow measuring system was also developed for accurately measuring very low gas flow rates. Using Darcy's Law as a tool for analysis of the experimental data, we obtained that the gas permeability of the SFE No. 3 (Staged Field Experiment No. 3) core samples is a linear function of reciprocal mean pressure, and decreases with overburden pressure. The water permeability is also decreased with overburden pressure and is about 6 times smaller than gas permeability for the samples that we have tested. No significant hysteresis effect was obtained for dry gas permeability after several two phase flow runs. We successfully tested our encapsulated coreholder and measured gas flow rate through a tight sand core sample at different pressure drops. The results showed that the experimental runs using Hassler-type coreholder at overburden pressures higher than 2000 psig will probably give us the reliable experimental data. The experimental data obtained from the two different types of tight sandstones were analyzed using the Non-Darcy flow equation. The results showed the importance and reliability of the Non-Darcy formulation for describing the flow behavior under different overburden and system pressures. Non-Darcy's velocity for both gas and liquid phase were incorporated into an existing FORTRAN code for simulation of the tight gas reservoirs. The modified program was tested to compare the initial production data of SFE No. 2 well. Our simulation showed in the case of local turbulence and non-uniformities in the tight sand formation, the value of [beta] increases and Non-Darcy effect becomes important.

Wang, Ching-Huei.

1992-01-01T23:59:59.000Z

103

Using Load Transformations for the Specification of Arrival Processes in Simulation and Analysis  

Science Conference Proceedings (OSTI)

In this paper the innovative approach of load transformation is used to derive valid load models for secondary loads in computer networks, as they can be observed at lower-layer interfaces of protocol stacks. We apply the technique of load transformation ... Keywords: Markov models, computer networks, load transformation, simulation tools, workload modeling

Stephan Heckmüller; Bernd E. Wolfinger

2009-08-01T23:59:59.000Z

104

The Influence of Proposed Repository Thermal Load on Multiphase Flow and Heat Transfer in the Unsaturated Zone of Yucca Mountain  

E-Print Network (OSTI)

Studies Using the Yucca Mountain Unsaturated Zone Model,Unsaturated Zone at Yucca Mountain, Nevada, to Thermal LoadLarge Block Test at Yucca Mountain, Nevada, Water Resources

Wu, Y.-S.; Mukhopadhyay, Sumit; Zhang, Keni; Bodvarsson, G.S.

2006-01-01T23:59:59.000Z

105

A Monte Carlo Analysis of Gas Centrifuge Enrichment Plant Process Load Cell Data  

Science Conference Proceedings (OSTI)

As uranium enrichment plants increase in number, capacity, and types of separative technology deployed (e.g., gas centrifuge, laser, etc.), more automated safeguards measures are needed to enable the IAEA to maintain safeguards effectiveness in a fiscally constrained environment. Monitoring load cell data can significantly increase the IAEA s ability to efficiently achieve the fundamental safeguards objective of confirming operations as declared (i.e., no undeclared activities), but care must be taken to fully protect the operator s proprietary and classified information related to operations. Staff at ORNL, LANL, JRC/ISPRA, and University of Glasgow are investigating monitoring the process load cells at feed and withdrawal (F/W) stations to improve international safeguards at enrichment plants. A key question that must be resolved is what is the necessary frequency of recording data from the process F/W stations? Several studies have analyzed data collected at a fixed frequency. This paper contributes to load cell process monitoring research by presenting an analysis of Monte Carlo simulations to determine the expected errors caused by low frequency sampling and its impact on material balance calculations.

Garner, James R [ORNL; Whitaker, J Michael [ORNL

2013-01-01T23:59:59.000Z

106

Statistical Analysis of Baseline Load Models for Non-Residential Buildings  

E-Print Network (OSTI)

estimation of the baseline load profile. In this paper, weDemand response, Baseline load profile, Impacts estimationto as the baseline load profile (or baseline) and is key to

Coughlin, Katie

2012-01-01T23:59:59.000Z

107

Dynamic analysis of floating quay and container ship for container loading and offloading operation  

E-Print Network (OSTI)

A floating quay container terminal is used for loading or unloading from container ships from both sides of a floating quay. The side-by-side Liquefied Natural Gas (LNG) offloading operation from floating terminals to LNG carriers is very similar to that from super-container ships to floating quay-walls. The hydrodynamic interaction effects among a fixed quay, container ship and floating quay, which are parallel to one another, are investigated. The three body side-by-side arrangement is compared with the individual freely floating body in the absence/presence of the fixed quay to identify the interaction effects. Hydrodynamic coefficients of the interacting bodies are obtained using a three dimensional constant panel method, WAMIT. Using a vessel-lines coupled dynamic analysis computer program WINPOST, the relative motion between floating quay and container ship is simulated in time domain. It is assumed in the present study that the floating quay is positioned by a dolphin mooring system. This analysis provides the relative motion among container ship, fixed and floating quay to ascertain that container loading and offloading can be performed in the severe wave condition without any problem.

Kumar, Brajesh

2005-12-01T23:59:59.000Z

108

Modeling and Analysis of Load and Time Dependent Software Rejuvenation Policies  

E-Print Network (OSTI)

Due to repeated and potentially faulty usage of continuously running client-server type software systems by many clients, such software "ages" with time and eventually fails. Huang et. al. proposed a technique called "software rejuvenation" [3] in which the software is periodically stopped and then restarted in a "robust" state after proper maintenance. This "renewal " of software prevents, or at least postpones, the crash failure. In this paper, we present a quantitative analysis of two software rejuvenation policies. The first one considers only the ageing behaviour of the system by time, while the second one considers the actual load of the system as well. The behaviour of the system is represented through a Markov Regenerative Stochastic Petri Net (MRSPN) model. Numerical analysis of the system performance regarding the probability of successful service of clients is provided. Keywords: Continuously running client-server software systems, Software rejuvenation, Markov Regenerati...

S. Garg; A. Pfening; A. Puliafito; M. Telek; K. S. Trivedi

1996-01-01T23:59:59.000Z

109

Assessment of Distributed Energy Adoption in Commercial Buildings: Part 1: An Analysis of Policy, Building Loads, Tariff Design, and Technology Development  

E-Print Network (OSTI)

Energy Adoption in Commercial Buildings Part 1: AnAnalysis of Policy, Building loads, Tariff Design, andAdoption in Commercial Buildings Part 1 An Analysis of

Zhou, Nan; Nishida, Masaru; Gao, Weijun; Marnay, Chris

2005-01-01T23:59:59.000Z

110

Distributed Data-Flow for In-Situ Visualization and Analysis at Petascale  

Science Conference Proceedings (OSTI)

We conducted a feasibility study to research modifications to data-flow architectures to enable data-flow to be distributed across multiple machines automatically. Distributed data-flow is a crucial technology to ensure that tools like the VisIt visualization application can provide in-situ data analysis and post-processing for simulations on peta-scale machines. We modified a version of VisIt to study load-balancing trade-offs between light-weight kernel compute environments and dedicated post-processing cluster nodes. Our research focused on memory overheads for contouring operations, which involves variable amounts of generated geometry on each node and computation of normal vectors for all generated vertices. Each compute node independently decided whether to send data to dedicated post-processing nodes at each stage of pipeline execution, depending on available memory. We instrumented the code to allow user settable available memory amounts to test extremely low-overhead compute environments. We performed initial testing of this prototype distributed streaming framework, but did not have time to perform scaling studies at and beyond 1000 compute-nodes.

Laney, D E; Childs, H R

2009-03-13T23:59:59.000Z

111

Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) Data Loading Manual  

Science Conference Proceedings (OSTI)

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) is a software application developed for performing a complete probabilistic risk assessment (PRA) using a personal computer. SAPHIRE is primarily funded by the U.S. Nuclear Regulatory Commission (NRC) and developed by the Idaho National Laboratory. This report is intended to assist the user to enter PRA data into the SAPHIRE program using the built-in MAR-D ASCII-text file data transfer process. Towards this end, a small sample database is constructed and utilized for demonstration. Where applicable, the discussion includes how the data processes for loading the sample database relate to the actual processes used to load a larger PRA models. The procedures described herein were developed for use with SAPHIRE Version 6.0 and Version 7.0. In general, the data transfer procedures for version 6 and 7 are the same, but where deviations exist, the differences are noted. The guidance specified in this document will allow a user to have sufficient knowledge to both understand the data format used by SAPHIRE and to carry out the transfer of data between different PRA projects.

C. L. Smith; K. J. Kvarfordt; S. T. Wood

2008-08-01T23:59:59.000Z

112

Passive load follow analysis of the STAR-LM and STAR-H2 systems.  

E-Print Network (OSTI)

A steady-state model for the calculation of temperature and pressure distributions, and heat and work balance for the STAR-LM and the STAR-H2 systems was developed. The STAR-LM system is designed for electricity production and consists of the lead cooled reactor on natural circulation and the supercritical carbon dioxide Brayton cycle. The STAR-H2 system uses the same reactor which is coupled to the hydrogen production plant, the Brayton cycle, and the water desalination plant. The Brayton cycle produces electricity for the on-site needs. Realistic modules for each system component were developed. The model also performs design calculations for the turbine and compressors for the CO2 Brayton cycle. The model was used to optimize the performance of the entire system as well as every system component. The size of each component was calculated. For the 400 MWt reactor power the STAR-LM produces 174.4 MWe (44% efficiency) and the STAR-H2 system produces 7450 kg H2/hr. The steady state model was used to conduct quasi-static passive load follow analysis. The control strategy was developed for each system; no control action on the reactor is required. As a main safety criterion, the peak cladding temperature is used. It was demonstrated that this temperature remains below the safety limit during both normal operation and load follow.

Moisseytsev, Anton

2003-12-01T23:59:59.000Z

113

Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) Data Loading Manual  

SciTech Connect

The Systems Analysis Programs for Hands-on Integrated Reliability Evaluations (SAPHIRE) is a software application developed for performing a complete probabilistic risk assessment (PRA) using a personal computer. SAPHIRE is primarily funded by the U.S. Nuclear Regulatory Commission (NRC) and developed by the Idaho National Laboratory. This report is intended to assist the user to enter PRA data into the SAPHIRE program using the built-in MAR-D ASCII-text file data transfer process. Towards this end, a small sample database is constructed and utilized for demonstration. Where applicable, the discussion includes how the data processes for loading the sample database relate to the actual processes used to load a larger PRA models. The procedures described herein were developed for use with SAPHIRE Version 6.0 and Version 7.0. In general, the data transfer procedures for version 6 and 7 are the same, but where deviations exist, the differences are noted. The guidance specified in this document will allow a user to have sufficient knowledge to both understand the data format used by SAPHIRE and to carry out the transfer of data between different PRA projects.

C. L. Smith; K. J. Kvarfordt; S. T. Wood

2006-07-01T23:59:59.000Z

114

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

115

Analysis of Wind Power and Load Data at Multiple Time Scales  

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

47E 47E ERNEST ORLANDO LAWRENCE BERKELEY NATIONAL LABORATORY Analysis of Wind Power and Load Data at Multiple Time Scales Katie Coughlin and Joseph H. Eto Environmental Energy Technologies Division December 2010 The work described in this report was funded by the Federal Energy Regulatory Commission, Office of Electric Reliability. The Lawrence Berkeley National Laboratory is operated by the University of California for the U.S. Department of Energy under Contract No. DE-AC02-05CH11231. Disclaimer This document was prepared as an account of work sponsored by the United States Government. While this document is believed to contain correct information, neither the United States Government nor any agency thereof, nor The Regents of the

116

The analysis of an ungrounded Wye-Delta transformer bank serving an induction motor and single-phase lighting loads  

SciTech Connect

This paper documents the detailed analysis of the three-phase ungrounded wye-delta transformer bank serving a combination three-phase induction motor and single-phase lighting load. A 3 x 3 transfer function matrix is developed that makes it possible to determine the load line-to-line voltages with a knowledge of the primary voltages of the transformer bank. Included in the transfer function matrix are the transformer impedances, unsymmetrical secondary impedance matrix, and the impedances of the motor and single-phase lighting load.

Kersting, W.H.; Rathbun, J.S.

2000-02-01T23:59:59.000Z

117

Analysis of Wind Power and Load Data at Multiple Time Scales  

E-Print Network (OSTI)

Minnesota statewide wind integration study. November 2006.of net load vs. load Wind integration studies are generallyIt would be very useful to wind integration studies if this

Coughlin, Katie

2011-01-01T23:59:59.000Z

118

A New Flow Diagramming Scheme For Mapping And Analysis Of Multi-Product Flows In A Facility  

Science Conference Proceedings (OSTI)

The design of layouts for facilities that process a high variety of products requires the analysis of a large number of different product routings and their spatial representation on a planar layout of the facility. Traditionally, the representations ... Keywords: Material flow analysis, cascading flowlines, cluster analysis, facility layout, modified multi-product process chart (MM-PPC), string alignment

Jin Zhou; Shahrukh A. Irani

2003-01-01T23:59:59.000Z

119

Thermomechanical analysis of high-heat-load components for the canted-undulator front end.  

SciTech Connect

With the canted undulators operating at 200 mA at closed gap at the Advanced Photon Source in the future, the front end will receive 20.4 kW of total power and 281 kW/mrad{sup 2} of peak power density. Thermal analysis of the front-end high-heat-load components becomes an essential part of the front-end design. An extensive study has been conducted on the thermal design of the photon shutters and fixed masks. A unique dog-bone-shaped cross-section design for the photon shutters was derived to relieve high stress in the corners. The dual-undulator x-ray beams were simulated at several locations on the fixed mask to ensure the worst possible case is considered. Stress analysis on the fixed mask revealed that the maximum stress occurs when beam hits the intersection between the horizontal surface and the corner surface. The details of the analysis procedure are presented, and the failure criteria are discussed.

Jaski, Y.; Trakhtenberg, E.; Collins, J.; Benson, C.; Brajuskovic, B.; Den Hartog, P.

2002-09-20T23:59:59.000Z

120

An analysis of the potential for shifting electric power demand within daily load requirement  

SciTech Connect

This report analyzes the potential for shifting the electric power demand within the daily load requirements for large industrial and commercial customers of the Philadelphia Electric Company. This shifting of electric power demand would tend to flatten the daily load curve of electricity demand, benefitting both the power industry and the consumer. Data on estimated summer load curves of large commercial and industrial customers are analyzed for load flattening potential. Cost savings to the customers are determined. (GRA)

Lamb, P.G.

1974-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Second law analysis for a variable viscosity plane Poiseuille flow with asymmetric convective cooling  

Science Conference Proceedings (OSTI)

A second-law analysis of a pressure-driven variable viscosity fluid flow through a channel with asymmetric convective cooling at the walls is investigated. Flow is assumed to be steady, laminar and fully-developed. The effect of heat generation due to ... Keywords: Asymmetric convective cooling, Entropy generation analysis, Poiseuille flow, Variable viscosity

O. D. Makinde; A. Aziz

2010-12-01T23:59:59.000Z

122

Sequential Monte Carlo simulation for composite power system reliability analysis with time varying loads  

SciTech Connect

The paper illustrates the development and utilization of an annual chronological load curve for each load bus in a composite generation and transmission system and a sequential Monte Carlo simulation approach for composite system reliability assessment. Antithetic variates as a variance reduction technique has been applied to the simulation model to increase the efficiency of the simulation. An approximate method using a load duration curve of the system load and an enumeration process have been applied to the developed load model and the results are compared in this paper.

Sankarakrishnan, A.; Billinton, R. [Univ. of Saskatchewan, Saskatoon, Saskatchewan (Canada). Power Systems Research Group

1995-08-01T23:59:59.000Z

123

Application of measured loads to wind turbine fatigue and reliability analysis  

DOE Green Energy (OSTI)

Cyclic loadings produce progressive damage that can ultimately result in wind turbine structural failure. There are many issues that must be dealt with in turning load measurements into estimates of component fatigue life. This paper deals with how the measured loads can be analyzed and processed to meet the needs of both fatigue life calculations and reliability estimates. It is recommended that moments of the distribution of rainflow-range load amplitudes be calculated and used to characterize the fatigue loading. These moments reflect successively more detailed physical characteristics of the loading (mean, spread, tail behavior). Moments can be calculated from data samples and functional forms can be fitted to wind conditions, such as wind speed and turbulence intensity, with standard recession techniques. Distributions of load amplitudes that accurately reflect the damaging potential of the loadings can be estimated from the moments at any, wind condition of interest. Fatigue life can then be calculated from the estimated load distributions, and the overall, long-term, or design spectrum can be generated for any particular wind-speed distribution. Characterizing the uncertainty in the distribution of cyclic loads is facilitated by using a small set of descriptive statistics for which uncertainties can be estimated. The effects of loading parameter uncertainty can then be transferred to the fatigue life estimate and compared with other uncertainties, such as material durability.

Veers, P.S. [Sandia National Labs., Albuquerque, NM (United States); Winterstein, S.R. [Stanford Univ., CA (United States)

1997-01-01T23:59:59.000Z

124

Information flow analysis of energy management in a smart grid  

Science Conference Proceedings (OSTI)

Information flow security within the context of multilevel security deals with ways to avoid unwanted information flow from a high level domain to a low level domain. Several confidentiality and information flow properties have been formalized in literature. ... Keywords: bisimulation based non-deducibility on compositions, confidentiality, cyber-physical system, information flow, non-inference, security

Ravi Akella; Bruce M. McMillin

2010-09-01T23:59:59.000Z

125

Dynamic Information Flow Analysis for JavaScript in a Web Browser  

E-Print Network (OSTI)

Flow Analysis for JavaScript in a Web Browser by Thomas H.a central technology of the web, but it is also the sourceinformation flows in javascript web applications. In ACM

Austin, Thomas Howard

2013-01-01T23:59:59.000Z

126

SPECTRAL ANALYSIS OF UNSTEADY FLOW SIMULATION IN A SMALL VAWT  

E-Print Network (OSTI)

The vertical axis wind turbine studied in this paper combine two rotations: one rotating movement of each blade around its own axis and one rotating movement around turbine’s axis. The aim of this paper is to analyse the effect of this two combine movements on fields of pressure and on global forces on each blade with time. Preliminary calculations showed, for some initial blade stagger angles (angle between blade 1 and x axis), that flow is highly unsteady and sometimes hardly periodic. The main goal here is to present spectral analysis of unsteady results like temporal pressure on specific points in the domain and temporal forces on blades and to show the influence of the two combine movements for two different blade stagger angles for elliptic blades.

Annie-claude Bayeul-lainé; Sophie Simonet; Gérard Bois; Leconte P; Rapin M; Szechenyi E; Martin J

2013-01-01T23:59:59.000Z

127

1992 Columbia River Salmon Flow Measures Options Analysis/EIS.  

DOE Green Energy (OSTI)

This Options Analysis/Environmental Impact Statement (OA/EIS) identifies, presents effects of, and evaluates the potential options for changing instream flow levels in efforts to increase salmon populations in the lower Columbia and Snake rivers. The potential actions would be implemented during 1992 to benefit juvenile and adult salmon during migration through eight run-of-river reservoirs. The Corps of Engineers (Corps) prepared this document in cooperation with the Bonneville Power Administration and the Bureau of Reclamation. The US Fish and Wildlife Service (FSWS) is a participating agency. The text and appendices of the document describe the characteristics of 10 Federal projects and one private water development project in the Columbia River drainage basin. Present and potential operation of these projects and their effects on the salmon that spawn and rear in the Columbia and Snake River System are presented. The life history, status, and response of Pacific salmon to current environmental conditions are described.

Not Available

1992-01-01T23:59:59.000Z

128

Power Quality for T&D: Grid IQ Circuit Analysis Using 2030 Load Mix Projections  

Science Conference Proceedings (OSTI)

One of the key sources of harmonic injections into the distribution systems is usage of power electronics in residential and commercial loads, and the proportion of power electronics-based loads can be expected to increase in the future. This expectation is supported by data on projected trends in electricity consumption for different load types in both residential and commercial categories for 2010–2035 published in Annual Energy Outlook 2011 with Projections to 2035 by the U.S. ...

2012-12-06T23:59:59.000Z

129

Regression Models for Demand Reduction based on Cluster Analysis of Load Profiles  

E-Print Network (OSTI)

Methods for Customer and Demand Response Policies SelectionC. McParland,“Open Automated Demand Response Communicationset al, “Estimating Demand Response Load Impacts: Evaluation

Kiliccote, Sila

2010-01-01T23:59:59.000Z

130

An Analysis of a Combined Hardware-software Mechanism for Speculative Loads  

E-Print Network (OSTI)

This paper describes a simple hardware mechanism and related compiler support for softwarecontrolled speculative loads. The compiler issues speculative load instructions based on anticipated data references and the ability of the memory system to hide memory latency in high-performance processors. The architectural support for such a mechanism is simple and minimal, yet handles faults gracefully. We have simulated three speculative load mechanisms based on a MIPS processor and a detailed memory system. The results of scientific kernel loops indicate that speculative load techniques can hide memory latency effectively.

Stefanos Damianakis; Kai Li; Anne Rogers

1994-01-01T23:59:59.000Z

131

Water flows, energy demand, and market analysis of the informal water sector in Kisumu, Kenya  

E-Print Network (OSTI)

Analysis Water flows, energy demand, and market analysis of the informal water sector in Kisumu Available online xxxx Keywords: Informal water sector Water flows Developing countries Water market analysis to cope with popu- lation growth. Informal water businesses fulfill unmet water supply needs, yet little

Elimelech, Menachem

132

Parametric analysis of the electric utility market for advanced load-leveling batteries. Final report  

SciTech Connect

This task examines the market for batteries in utility load-leveling service as a function of the Battery System Cost characteristics in order to give DOE a method of assessing the results of various program alternatives. The sensitivity of the benefits (barrels of oil saved) that might be derived to the timing of the market (i.e. when it begins) is also investigated. (The real cost of fuel is to be assumed to increase 2.4% per year.) How large is the total market for a new technology; how is the relative effectiveness of Battery Storage Systems related to the cost of fuel, the capital cost of the battery, and the perception of the credits associated with batery systems; and how do these vary with time required answers in order to estimate how the market for battery systems might develop. Most of the answers were obtained by studying the data developed by MITRE/METREK for a market assessment of battery systems using lead/acid batteries. MITRE's market analysis considered a large variety of variables; since the resources and time available for the present task were limited, it was not possible to either duplicate or confirm their work in detail. The initial results of this study depend on the assumptions used by MITRE. However, where these assumptions were incomplete, the results are adjusted. The supplementary information was obtained from studies performed by Arthur D. Little, Inc. and by PSE and G.

1979-02-01T23:59:59.000Z

133

Modeling simple trigeneration systems for the distribution of environmental loads  

Science Conference Proceedings (OSTI)

Integration of thermoeconomics and Life Cycle Analysis was carried out within the framework of an Environmental Management Information System. This combined approach identified where environmental loads were generated and tracked environmental loads ... Keywords: CO2, Environmental Management Information System, Environmental costs, Material flow networks, Trigeneration, Umberto software

Monica Carvalho; Miguel A. Lozano; Luis M. Serra; Volker Wohlgemuth

2012-04-01T23:59:59.000Z

134

Proceedings of the North American Power Symposium NAPS, MIT, November 1996, pp.559-565. Bifurcation Analysis of Induction Motor Loads  

E-Print Network (OSTI)

Analysis of Induction Motor Loads for Voltage Collapse Studies Claudio A. Ca~nizares William Rosehart, aggregated loads, induction motor models, voltage collapse. I. Introduction Voltage stability problems- lapse of combined induction motor and impedance loads by means of lab measurements and computer

Cañizares, Claudio A.

135

Puget Sound Area Electric Reliability Plan. Appendix D, Conservation, Load Management and Fuel Switching Analysis : Draft Environmental Impact Statement.  

SciTech Connect

Various conservation, load management, and fuel switching programs were considered as ways to reduce or shift system peak load. These programs operate at the end-use level, such as residential water heat. Figure D-1a shows what electricity consumption for water heat looks like on normal and extreme peak days. Load management programs, such as water heat control, are designed to reduce electricity consumption at the time of system peak. On the coldest day in average winter, system load peaks near 8:00 a.m. In a winter with extremely cold weather, electricity consumption increases fr all hours, and the system peak shifts to later in the morning. System load shapes in the Puget Sound area are shown in Figure D-1b for a normal winter peak day (February 2, 1988) and extreme peak day (February 3, 1989). Peak savings from any program are calculated to be the reduction in loads on the entire system at the hour of system peak. Peak savings for all programs are measured at 8:00 a.m. on a normal peak day and 9:00 a.m. on an extreme peak day. On extremely cold day, some water heat load shifts to much later in the morning, with less load available for shedding at the time of system peak. Models of hourly end-use consumption were constructed to simulate the impact of conservation, land management, and fuel switching programs on electricity consumption. Javelin, a time-series simulating package for personal computers, was chosen for the hourly analysis. Both a base case and a program case were simulated. 15 figs., 7 tabs.

United States. Bonneville Power Administration.

1991-09-01T23:59:59.000Z

136

Analysis of the transient compressible vapor flow in heat pipe  

SciTech Connect

The transient compressible one-dimensional vapor flow dynamics in a heat pipe is modeled. The numerical results are obtained by using the implicit non-iterative Beam-Warming finite difference method. The model is tested for simulated heat pipe vapor flow and actual vapor flow in cylindrical heat pipes. A good comparison of the present transient results for the simulated heat pipe vapor flow with the previous results of a two-dimensional numerical model is achieved and the steady state results are in agreement with the existing experimental data. The transient behavior of the vapor flow under subsonic, sonic, and supersonic speeds and high mass flow rates are successfully predicted. The one-dimensional model also describes the vapor flow dynamics in cylindrical heat pipes at high temperatures.

Jang, J.H.; Faghri, A. [Wright State Univ., Dayton, OH (United States); Chang, W.S. [Wright Research and Development Center, Wright-Patterson, OH (United States)

1989-07-01T23:59:59.000Z

137

Spectral Content and Spatial Scales in Unsteady Rotationally Augmented Flow Fields: Preprint  

DOE Green Energy (OSTI)

This paper describes wind turbine flow fields that effect load predictions for design and analysis and the active aerodynamic control methodologies being considered for wind turbine applications.

Schreck, S. J.

2007-08-01T23:59:59.000Z

138

Post-Contingency Equilibrium Analysis of Power Systems Peter W. Sauer  

E-Print Network (OSTI)

-3]. The static analysis normally relies on load flow as the primary commercial software to predict the post. The third uses a method that takes advantage of existing commercial load flow software to perform the major equations for each generator. Keywords: Dynamic equilibrium, contingency analysis, load flow, steady

139

Regression Models for Demand Reduction based on Cluster Analysis of Load Profiles  

E-Print Network (OSTI)

ESCRIPTIVE S TATISTICS Maximum Demand (kW) Num. of Obs. Meanrate and customer’s maximum demand. C’ i, t : a constant, Arate and customer’s maximum demand. The load sensitivity to

Kiliccote, Sila

2010-01-01T23:59:59.000Z

140

LoadReuse Analysis: Design and Evaluation Rastislav Bodk Rajiv Gupta Mary Lou Soffa  

E-Print Network (OSTI)

are the best hardware defense against the von Neumann memory bottleneck. Capitalizing on data local­ ity hoisting a copy of the load along path p3 . Commonly, the hoisting is formulated as partial redundancy elimination (PRE) [27, 29, 35]. is a2 = a4 along path p2? is a1 = a4 along path p1? is a0 != a4 ? hoist load a

California at Berkeley, University of

Note: This page contains sample records for the topic "load flow analysis" 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

Load-Reuse Analysis: Design and Evaluation Rastislav Bodik Rajiv Gupta Mary Lou Soffa  

E-Print Network (OSTI)

are the best hardware defense against the von Neumann memory bottleneck. Capitalizing on data local- ity hoisting a copy of the load along path p3. Commonly, the hoisting is formulated as partial redundancyelimination (PRE) [27,29,35]. is a2 = a4 along path p2? is a1 = a4 along path p1? is a0 != a4 ? hoist load a4

Gupta, Rajiv

142

Validation of IVA Computer Code for Flow Boiling Stability Analysis  

SciTech Connect

IVA is a computer code for modeling of transient multiphase, multi-component, non-equilibrium flows in arbitrary geometry including flow boiling in 3D nuclear reactors. This work presents part of the verification procedure of the code. We analyze the stability of flow boiling in natural circulation loop. Experimental results collected on the AREVA/FANP KATHY loop regarding frequencies, mass flows and decay ratio of the oscillations are used for comparison. The comparison demonstrates the capability of the code to successfully simulate such class of processes. (author)

Ivanov Kolev, Nikolay [Framatome-ANP, PO Box 3220, D-91058, Erlangen (Germany)

2006-07-01T23:59:59.000Z

143

A Viscoelastic-Viscoplastic Analysis of Fiber Reinforced Polymer Composites Undergoing Mechanical Loading and Temperature Changes  

E-Print Network (OSTI)

This study presents a combined viscoelastic (VE)-viscoplastic (VP) analysis for Fiber Reinforced Polymer (FRP) composites subject to simultaneous mechanical load and conduction of heat. The studied FRP composites consist of unidirectional fibers, which are considered as linearly elastic with regards to their mechanical response, and isotropic polymeric matrix, which shows viscoelastic-viscoplastic response under various stresses and temperatures. Due to the viscoelastic and viscoplastic behavior of the polymeric matrix, the overall FRP composites exhibit a combined time-dependent and inelastic behavior. A simplified micromechanical model, consisting of a unit-cell with four fiber and matrix subcells, is formulated to homogenize the overall heat conduction and viscoelastic-viscoplastic responses of the FRP composites. The micromechanical model is compatible with a displacement based finite element (FE) and is implemented at the Gaussian integration points within the continuum finite elements, which is useful for analyzing the overall time-dependent response of FRP composite structures under various boundary conditions. The Schapery nonlinear integral model combined with the Perzyna viscoplastic model is used to describe the viscoelastic-viscoplastic response of the polymer constituents. An integrated time integration algorithm is formulated at the micromechanics level in order to solve the nonlinear viscoelastic-viscoplastic constitutive model at the matrix subcells and obtain the overall nonlinear response of the FRP. The viscoelastic-viscoplastic micromechanical model is validated usingexperimental data on off-axis glass/epoxy FRP composites available in literature. The overall response of the FRP composites determined from the simplified micromechanical model is also compared with the ones generated from microstructures of FRP with various fiber arrangements dispersed in homogeneous polymer matrix. The microstructural models of the FRP with detailed fiber arrangements are generated using FE. The effects of thermal stresses, due to the mismatches in the coefficient of thermal expansions of the fibers and polymeric matrix, and stress concentrations/discontinuities near the fiber and matrix interfaces on the overall thermo-mechanical deformation of FRP composites are studied using the two micromechanical models discussed above. Finally, an example of structural analysis is performed on a polymeric smart sandwich composite beam, having FRP skins and polymeric foam core with piezoelectric sensors integrated to the FRP skins, undergoing three point bending at an elevated temperature. The creep displacement is compared to experimental data available in literature.

Jeon, Jaehyeuk

2013-08-01T23:59:59.000Z

144

Optical flow image analysis of facial expressions of human emotion: forensic applications  

Science Conference Proceedings (OSTI)

The objective of this study was to induce emotions in individuals to determine if specific facial movements could be detected and analysed by the optical flow technique. This analysis is in the form of motion vector plots. The procedure ascertains if ... Keywords: emotion, facial expression, forensics, image analysis, optical flow, physiological measurement, surveillance

Carmen J. Duthoit; T. Sztynda; S. K. L. Lal; B. T. Jap; J. I. Agbinya

2008-01-01T23:59:59.000Z

145

Novel hybrid approach to data-packet-flow prediction for improving network traffic analysis  

Science Conference Proceedings (OSTI)

Forecast of the flow of data packets between client and server for a network traffic analysis is viewed as a part of web analytics. Thousands of web-smart businesses depend on web analytics to improve website conversions, reduce marketing costs, facilitate ... Keywords: Adaptive neuro-fuzzy inference system, Flow of data packets, Network traffic analysis, Nonlinear generalized autoregressive conditional heteroscedasticity, Quantum minimization

Bao Rong Chang; Hsiu Fen Tsai

2009-06-01T23:59:59.000Z

146

Education, Job Requirements, and Commuting: An Analysis of Network Flows  

E-Print Network (OSTI)

Education, Job Requirements,and Commuting: Analysis of Ne~f,,/ Education, Job Requirements, and Commuting: Analysis ofin Education, Job Requirements, and Commuting: Analysis of

Harsman, Bjorn; Quigley, John M.

1998-01-01T23:59:59.000Z

147

Compiler Analysis for Cache Coherence: Interprocedural Array Data-Flow Analysis and Its Impact on Cache Performance  

Science Conference Proceedings (OSTI)

Abstract¿In this paper, we present compiler algorithms for detecting references to stale data in shared-memory multiprocessors. The algorithm consists of two key analysis techniques, stale reference detection and locality preserving analysis. While the ... Keywords: Compiler, interprocedural analysis, data-flow analysis, cache coherence, shared-memory multiprocessors.

Lynn Choi; Pen-Chung Yew

2000-09-01T23:59:59.000Z

148

Time series power flow analysis for distribution connected PV generation.  

SciTech Connect

Distributed photovoltaic (PV) projects must go through an interconnection study process before connecting to the distribution grid. These studies are intended to identify the likely impacts and mitigation alternatives. In the majority of the cases, system impacts can be ruled out or mitigation can be identified without an involved study, through a screening process or a simple supplemental review study. For some proposed projects, expensive and time-consuming interconnection studies are required. The challenges to performing the studies are twofold. First, every study scenario is potentially unique, as the studies are often highly specific to the amount of PV generation capacity that varies greatly from feeder to feeder and is often unevenly distributed along the same feeder. This can cause location-specific impacts and mitigations. The second challenge is the inherent variability in PV power output which can interact with feeder operation in complex ways, by affecting the operation of voltage regulation and protection devices. The typical simulation tools and methods in use today for distribution system planning are often not adequate to accurately assess these potential impacts. This report demonstrates how quasi-static time series (QSTS) simulation and high time-resolution data can be used to assess the potential impacts in a more comprehensive manner. The QSTS simulations are applied to a set of sample feeders with high PV deployment to illustrate the usefulness of the approach. The report describes methods that can help determine how PV affects distribution system operations. The simulation results are focused on enhancing the understanding of the underlying technical issues. The examples also highlight the steps needed to perform QSTS simulation and describe the data needed to drive the simulations. The goal of this report is to make the methodology of time series power flow analysis readily accessible to utilities and others responsible for evaluating potential PV impacts.

Broderick, Robert Joseph; Quiroz, Jimmy Edward; Ellis, Abraham; Reno, Matthew J. [Georgia Institute of Technology, Atlanta, GA; Smith, Jeff [Electric Power Research Institute, Knoxville, TN; Dugan, Roger [Electric Power Research Institute, Knoxville, TN

2013-01-01T23:59:59.000Z

149

Finite element analysis of the Arquin-designed CMU wall under a dynamic (blast) load.  

Science Conference Proceedings (OSTI)

The Arquin Corporation designed a CMU (concrete masonry unit) wall construction and reinforcement technique that includes steel wire and polymer spacers that is intended to facilitate a faster and stronger wall construction. Since the construction method for an Arquin-designed wall is different from current wall construction practices, finite element computer analyses were performed to estimate the ability of the wall to withstand a hypothetical dynamic load, similar to that of a blast from a nearby explosion. The response of the Arquin wall was compared to the response of an idealized standard masonry wall exposed to the same dynamic load. Results from the simulations show that the Arquin wall deformed less than the idealized standard wall under such loading conditions. As part of a different effort, Sandia National Laboratories also looked at the relative static response of the Arquin wall, results that are summarized in a separate SAND Report.

Lopez, Carlos; Petti, Jason P.

2008-12-01T23:59:59.000Z

150

Coupled Analysis of the Motion and Mooring Loads of a Spar "CONSTITUTION"  

E-Print Network (OSTI)

A truss spar, named as 'Constitution' was installed in Gulf of Mexico located at 90.58' 4.8" West Longitude and 27.17'31.9" North Latitude. Since its installation in October 2006, it has weathered multiple hurricanes. After the installation, British Maritime Technology (BMT) installed an Environmental Platform Response Monitoring System (EPRMS). The EPRMS is an integrated system collecting myriad of data that include the significant wave height and peak period of waves, the magnitude and direction of current and wind in the vicinity of the truss spar, its six-degree of freedom (6-D) motions, and tensions in its mooring lines and Top-Tension Risers. With the permission from Anadarko Petroleum Corporation (APC), these data are available to the Ocean Engineering Program at Texas A&M University (TAMU). In this study, the coupled dynamic analysis of the spar interacting with the mooring and riser systems will be performed using a numerical code, named as 'COUPLE'. 'COUPLE' was developed and is continuously expanded and improved by his former and current graduate students and Professor Jun Zhang at TAMU for the computation of the interaction between a floating structure and its mooring line/riser/tendon system in time domain. The main purpose of this study is to exam the accuracy and efficiency of 'COUPLE' in computing offshore structure motions and mooring line tensions and discuss the main issues of the computation. The numerical results will be compared with the corresponding ones obtained using another commercial software, 'Orcaflex', and the corresponding field measurement during Hurricane Ike which occurred on 12th September of 2008 and a winter storm on 9th November of 2009. The satisfactory agreement between the numerical prediction made using 'COUPLE' and field measurement are observed and presented. The results of the comparisons between 'COUPLE' with 'Orcaflex' and field measurements in this study have verified the accuracy and efficiency of 'COUPLE' in computing offshore structure motions and mooring line tensions due to its nonlinear hybrid wave model which could better estimate the second-order difference-frequency wave loading.

Li, Chengxi

2012-08-01T23:59:59.000Z

151

Throughput-cost analysis of optical flow switching  

E-Print Network (OSTI)

In this paper, we employ a cost model embodying major sources of capital expenditure (CapEx) to compare the throughput-cost tradeoff offered by optical flow switching to that of more traditional optical network architectures.

Chan, Vincent W. S.

152

Instability Analysis of Terrain-Induced Canopy Flows  

Science Conference Proceedings (OSTI)

Tall vegetation and complex terrain create difficult conditions for measuring and modeling net ecosystem–atmosphere exchanges of carbon, water vapor, and pollutants. The instability of canopy flow regimes over complex terrain is critical for ...

Chuixiang Yi

2009-07-01T23:59:59.000Z

153

Application of the pseudolinear flow model to the pressure transient analysis of fractured wells  

SciTech Connect

The theoretical basis for the pseudolinear flow model is established. It is demonstrated by using an analytical model that the linear flow graph (p vs ..sqrt..t) can be extended to the analysis of pressure data of fractured wells intersected by an intermediate or a high conductivity fracture ((k /SUB f/ b /SUB f/ greater than or equal to 15). It appears that the fracture conductivity effect during the pseudolinear flow period can be handled as a pseudo skin pressure drop which is additive to the pressure drop caused by fluid loss damage. The combination of the pseudolinear flow analysis with other interpretation techniques is illustrated through examples of field cases.

Cinco-Ley, H.; Rodriguez, F.; Samaniego, F.

1984-09-01T23:59:59.000Z

154

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

155

Analysis and optimization of service availability in a HA cluster with load-dependent machine availability  

Science Conference Proceedings (OSTI)

Calculations of service availability of a High- Availability (HA) cluster are usually based on the assumption of load-independent machine availabilities. In this paper, we study the issues and show how the service availabilities can be calculated under ... Keywords: High Availability, cluster computing, Markov chains, Markov decision processes, dynamic programming, neuro-dynamic programming

Chee-Wei Ang; Chen-Khong Tham

2007-09-01T23:59:59.000Z

156

Flow Characteristics Analysis of Widows' Creek Type Control Valve for Steam Turbine Control  

Science Conference Proceedings (OSTI)

The steam turbine converts the kinetic energy of steam to mechanical energy of rotor blades in the power conversion system of fossil and nuclear power plants. The electric output from the generator of which the rotor is coupled with that of the steam turbine depends on the rotation velocity of the steam turbine bucket. The rotation velocity is proportional to the mass flow rate of steam entering the steam turbine through valves and nozzles. Thus, it is very important to control the steam mass flow rate for the load following operation of power plants. Among various valves that control the steam turbine, the control valve is most significant. The steam flow rate is determined by the area formed by the stem disk and the seat of the control valve. While the ideal control valve linearly controls the steam mass flow rate with its stem lift, the real control valve has various flow characteristic curves pursuant to the stem lift type. Thus, flow characteristic curves are needed to precisely design the control valves manufactured for the operating conditions of nuclear power plants. OMEGA (Optimized Multidimensional Experiment Geometric Apparatus) was built to experimentally study the flow characteristics of steam flowing inside the control valve. The Widows' Creek type control valve was selected for reference. Air was selected as the working fluid in the OMEGA loop to exclude the condensation effect in this simplified approach. Flow characteristic curves were plotted by calculating the ratio of the measured mass flow rate versus the theoretical mass flow rate of the air. The flow characteristic curves are expected to be utilized to accurately design and operate the control valve for fossil as well as nuclear plants. (authors)

Yoo, Yong H.; Sohn, Myoung S.; Suh, Kune Y. [PHILOSOPHIA, Inc., Seoul National University, San 56-1 Sillim-dong, Gwanak-gu, Seoul, 151-742 (Korea, Republic of)

2006-07-01T23:59:59.000Z

157

Uncertainty Analysis for a Virtual Flow Meter Using an Air-Handling Unit Chilled Water Valve  

SciTech Connect

A virtual water flow meter is developed that uses the chilled water control valve on an air-handling unit as a measurement device. The flow rate of water through the valve is calculated using the differential pressure across the valve and its associated coil, the valve command, and an empirically determined valve characteristic curve. Thus, the probability of error in the measurements is significantly greater than for conventionally manufactured flow meters. In this paper, mathematical models are developed and used to conduct uncertainty analysis for the virtual flow meter, and the results from the virtual meter are compared to measurements made with an ultrasonic flow meter. Theoretical uncertainty analysis shows that the total uncertainty in flow rates from the virtual flow meter is 1.46% with 95% confidence; comparison of virtual flow meter results with measurements from an ultrasonic flow meter yielded anuncertainty of 1.46% with 99% confidence. The comparable results from the theoretical uncertainty analysis and empirical comparison with the ultrasonic flow meter corroborate each other, and tend to validate the approach to computationally estimating uncertainty for virtual sensors introduced in this study.

Song, Li; Wang, Gang; Brambley, Michael R.

2013-04-28T23:59:59.000Z

158

Performance assessment of mass flow rate measurement capability in a large scale transient two-phase flow test system  

SciTech Connect

Mass flow is an important measured variable in the Loss-of-Fluid Test (LOFT) Program. Large uncertainties in mass flow measurements in the LOFT piping during LOFT coolant experiments requires instrument testing in a transient two-phase flow loop that simulates the geometry of the LOFT piping. To satisfy this need, a transient two-phase flow loop has been designed and built. The load cell weighing system, which provides reference mass flow measurements, has been analyzed to assess its capability to provide the measurements. The analysis consisted of first performing a thermal-hydraulic analysis using RELAP4 to compute mass inventory and pressure fluctuations in the system and mass flow rate at the instrument location. RELAP4 output was used as input to a structural analysis code SAPIV which is used to determine load cell response. The computed load cell response was then smoothed and differentiated to compute mass flow rate from the system. Comparison between computed mass flow rate at the instrument location and mass flow rate from the system computed from the load cell output was used to evaluate mass flow measurement capability of the load cell weighing system. Results of the analysis indicate that the load cell weighing system will provide reference mass flows more accurately than the instruments now in LOFT.

Nalezny, C.L.; Chapman, R.L.; Martinell, J.S.; Riordon, R.P.; Solbrig, C.W.

1979-01-01T23:59:59.000Z

159

Evaluation of Counter-Based Dynamic Load Balancing Schemes for Massive Contingency Analysis on Over 10,000 Cores  

SciTech Connect

Contingency analysis studies are necessary to assess the impact of possible power system component failures. The results of the contingency analysis are used to ensure the grid reliability, and in power market operation for the feasibility test of market solutions. Currently, these studies are performed in real time based on the current operating conditions of the grid with a set of pre-selected contingency list, which might result in overlooking some critical contingencies caused by variable system status. To have a complete picture of a power grid, more contingencies need to be studied to improve grid reliability. High-performance computing techniques hold the promise of being able to perform the analysis for more contingency cases within a much shorter time frame. This paper evaluates the performance of counter-based dynamic load balancing schemes for a massive contingency analysis program on 10,000+ cores. One million N-2 contingency analysis cases with a Western Electricity Coordinating Council power grid model have been used to demonstrate the performance. The speedup of 3964 with 4096 cores and 7877 with 10240 cores are obtained. This paper reports the performance of the load balancing scheme with a single counter and two counters, describes disk I/O issues, and discusses other potential techniques for further improving the performance.

Chen, Yousu; Huang, Zhenyu; Rice, Mark J.

2012-12-27T23:59:59.000Z

160

Numerical analysis of vapor flow in a micro heat pipe  

E-Print Network (OSTI)

The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two-dimensional flow were solved using the SIMPLE method. The results indicate that the pressure, shear stress, and friction factor under linear heat flux boundary conditions are considerably smoother, and hence, more closely approximate the real situation. As the heat flux increases, the pressure drop increases, but the friction factor demonstrates only a slight change for different heat flux conditions. The size and shape of the micro heat pipe vapor space was shown to have a significant influence on the vapor flow behavior for micro heat pipes. When the vapor space area decreases, the pressure drop, shear stress, and friction factor all significantly increase.

Liu, Xiaoqin

1996-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Analysis and performance of radial flow rotary dessicant dehumidifiers  

SciTech Connect

A model is developed to predict the steady periodic performance of a radial flow desiccant wheel. The model is expressed in terms of the same dimensionless parameters that are commonly used in modeling of the conventional axial flow desiccant wheel. In addition a dimensionless geometrical ratio of the volume of the matrix to the volume of the wheel core is found to affect the performance of the wheel. A finite difference technique on staggered grid is used to discretize the governing dimensionless equations. The discretized equations are solved to predict the performance of the desiccant wheel at given values of operation parameters. A sensitivity study is carried out to investigate the effect of changing any of these parameters on the performance of the wheel. The performance of the radial flow desiccant wheel having the same values of the operation parameters.

Elsayed, M.M.; Chamkha, A.J. [Kuwait Univ., Safat (Kuwait). Mechanical and Industrial Engineering Dept.

1997-02-01T23:59:59.000Z

162

Estimating Air Conditioner Loads Using Available Billing and Weather Data: An Exploratory Analysis  

Science Conference Proceedings (OSTI)

In limited testing, an innovative statistical technique for estimating the effects of residential air conditioners on system loads under various weather conditions produced encouraging results. The simple technique, which uses standard utility billing records and readily available weather data, could offer an inexpensive alternative to household monitoring. This report is available only to funders of Program 101A or 101.001. Funders may download this report at http://my.primen.com/Applications/DE/Commun...

1985-10-25T23:59:59.000Z

163

Combination of job oriented simulation with ecological material flow analysis as integrated analysis tool for business production processes  

Science Conference Proceedings (OSTI)

This paper outlines the application of a special Environmental Management Information System (EMIS) as combination of discrete event simulation with ecological material flow analysis for a selected production process. The software tool serves as decision ...

Philip Joschko; Bernd Page; Volker Wohlgemuth

2009-12-01T23:59:59.000Z

164

Stochastic analysis of unsaturated flow with probabilistic collocation method  

E-Print Network (OSTI)

with probabilistic collocation method, Water Resour. Res., 45, W08425, doi:10.1029/2008WR007530. 1. Introduction [2, the vadose zone has received increasing attention in recent years. Because of the coexis- tence of water to study the effect of spatial variability on flow in unsaturated zone [Jury, 1982; Yeh et al., 1985a, 1985

Lu, Zhiming

165

Complexity analysis of the turbulent environmental fluid flow time series  

E-Print Network (OSTI)

We have used the Kolmogorov complexities, sample and permutation entropies to quantify the randomness degree in river flow time series of two mountain rivers in Bosnia and Herzegovina, representing the turbulent environmental fluid, for the period 1926-1990. In particular, we have examined the monthly river flow time series from two rivers (Miljacka and Bosnia) in mountain part of their flow and then calculated the Kolmogorov Complexity (KL) based on the Lempel-Ziv Algorithm (LZA) (Lower - KLL and Upper - KLU), Sample Entropy (SE) and Permutation Entropy (PE) values for each time series. The results indicate that the KLL, KLU, SE and PE values in two rivers are close to each other regardless of the amplitude differences in their monthly flow rates. We have illustrated the changes in mountain river flow complexity by experiments using (i) the data set for the Bosnia River and (ii) anticipated human activities and projected climate changes. We have explored the sensitivity of considered measures in dependence on the length of time series. In addition, we have divided the period 1926-1990 into three sub-intervals: (a) 1926-1945, (b)1946-1965 and (c)1966-1990, and calculated the KLL, KLU, SE and PE values for the various time series in these sub-intervals. It is found that during the period 1946-1965, there is a decrease in their complexities, and corresponding changes in the SE and PE, in comparison to the period 1926-1990. This complexity loss may be primarily attributed to (i) human interventions, after Second World War, on these rivers because of their use for water consumption and (ii) climate change in recent time.

Dragutin T. Mihailovic; Emilija Nikolic-Djoric; Nusret Dreskovic; Gordan Mimic

2013-01-10T23:59:59.000Z

166

The Interaction of Katabatic Flow and Mountain Waves. Part II: Case Study Analysis and Conceptual Model  

Science Conference Proceedings (OSTI)

Via numerical analysis of detailed simulations of an early September 1993 case night, the authors develop a conceptual model of the interaction of katabatic flow in the nocturnal boundary layer with mountain waves (MKI). A companion paper (Part I)...

Gregory S. Poulos; James E. Bossert; Thomas B. McKee; Roger A. Pielke Sr.

2007-06-01T23:59:59.000Z

167

Analysis of Chemically Reacting Gas Flow and Heat Transfer in Methane Reforming Processes  

Science Conference Proceedings (OSTI)

This paper presents simulation and analysis of gas flow and heat transfer affected by chemical reactions relating to steam reforming of methane in a compact reformer. The reformer conditions such as the combined thermal boundary conditions on solid walls, ...

Guogang Yang; Danting Yue; Xinrong Lv; Jinliang Yuan

2009-10-01T23:59:59.000Z

168

1486 IEEE TRANSACTIONS ON COMPUTER-AIDED DESIGN OF INTEGRATED CIRCUITS AND SYSTEMS, VOL. 25, NO. 8, AUGUST 2006 Modeling and Analysis of Loading Effect on Leakage  

E-Print Network (OSTI)

, AUGUST 2006 Modeling and Analysis of Loading Effect on Leakage of Nanoscaled Bulk-CMOS Logic Circuits geometry and the doping profile) and at the circuit level (through the node voltages). Due to the circuit. In this paper, the effect of loading on a leakage of a circuit is analyzed for the first time. The authors have

Bhunia, Swarup

169

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

170

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

171

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

172

Analysis of a flow metering device for low-quality steam-water flows. Final report  

DOE Green Energy (OSTI)

The goal of this project is to investigate the potential of the meter configuration consisting of a sharp-edged contraction section followed by an extended length of constant area duct and finally a diffuser section for pressure recovery. This and two other configurations were tested. These configurations and the reasons underlying their selection are described and discussed. It is concluded that Murdock's correlation for steam/water flow through orifices and sudden contraction sections at low qualities is invalid and the metering scheme based on it is inoperative. (MHR)

Crowe, C.T.

1979-06-26T23:59:59.000Z

173

Nonlinear finite-element analysis of a reinforced-concrete Mark III containment under pressure and gravity loads. [BWR  

DOE Green Energy (OSTI)

An analysis of a Mark III reactor containment vessel subjected to a uniformly increasing internal pressure and gravity loads is carried out in order to ascertain the load carrying capacity of the structure under hydrogen burn. The analysis is conducted by using a nonlinear finite element model that includes nonlinearities in the strain-displacement relations as well as in the material constitutive equations. In this analysis, the nonlinear behavior of the liner and reinforcement steels is described by a von Mises elastic-plastic model with isotropic hardening. A recently developed elastic-plastic-fracture model that includes both the cracking and crushing limit states is used for the plain concrete. Consistent smearing and de-smearing procedures are then used to represent the composite material properties of the reinforced concrete by an anisotropic and locally homogeneous continuum. Results pertaining to the critical regions of the containment where cracking of the concrete, yielding of the reinforcement bars, and substantial straining of the liner take place are discussed.

Sharma, S.; Reich, M.; Shteyngart, S.; Chang, T.Y.

1983-01-01T23:59:59.000Z

174

HANFORD DOUBLE SHELL TANK THERMAL AND SEISMIC PROJECT SUMMARY OF COMBINED THERMAL AND OPERATING LOADS WITH SEISMIC ANALYSIS  

SciTech Connect

This report summarizes the results of the Double-Shell Tank Thermal and Operating Loads Analysis (TaLA) combined with the Seismic Analysis. This combined analysis provides a thorough, defensible, and documented analysis that will become a part of the overall analysis of record for the Hanford double-shell tanks (DSTs). The bases of the analytical work presented herein are two ANSYS{reg_sign} finite element models that were developed to represent a bounding-case tank. The TaLA model includes the effects of temperature on material properties, creep, concrete cracking, and various waste and annulus pressure-loading conditions. The seismic model considers the interaction of the tanks with the surrounding soil including a range of soil properties, and the effects of the waste contents during a seismic event. The structural evaluations completed with the representative tank models do not reveal any structural deficiencies with the integrity of the DSTs. The analyses represent 60 years of use, which extends well beyond the current date. In addition, the temperature loads imposed on the model are significantly more severe than any service to date or proposed for the future. Bounding material properties were also selected to provide the most severe combinations. While the focus of the analyses was a bounding-case tank, it was necessary during various evaluations to conduct tank-specific analyses. The primary tank buckling evaluation was carried out on a tank-specific basis because of the sensitivity to waste height, specific gravity, tank wall thickness, and primary tank vapor space vacuum limit. For this analysis, the occurrence of maximum tank vacuum was classified as a service level C, emergency load condition. The only area of potential concern in the analysis was with the buckling evaluation of the AP tank, which showed the current limit on demand of l2-inch water gauge vacuum to exceed the allowable of 10.4 inches. This determination was based on analysis at the design waste temperature of 350 F and the full 60-year corrosion allowance on the tank wall of 0.060 inch. However, analysis at a more realistic temperature of 250 F or corrosion allowance of 0.025 inch results in an acceptable demand/capacity ratio according to the ASME code criteria. Thus, buckling of the primary tank is judged to be unlikely for the current lack of corrosion in the tanks, and the expectation that the maximum waste temperature will not exceed 210 F. The reinforced concrete structure was evaluated as specified by the American Concrete Institute (ACI) code requirements for nuclear safety-related structures (ACI-349). The demand was demonstrated to be lower than the capacity at all locations. Revision 1 is being issued to document changes to the anchor bolt evaluation. RPP-RPT-32237 Rev. 1, Hanford Double-Shell Tank Thermal and Seismic Project-Increased Liquid Level Analysis for 241AP Tank Farms, described changes to the anchor bolt modeling and evaluation which were implemented in response to the independent reviewer's comments. Similar changes have been made in the bounding tank analysis and are documented in RPP-RPT-28968 Rev. 1. The conclusions of the previous releases of this report remain unchanged.

MACKEY TC; DEIBLER JE; RINKER MW; JOHNSON KI; ABATT FG; KARRI NK; PILLI SP; STOOPS KL

2009-01-15T23:59:59.000Z

175

A Flow-Channel Analysis for the Mars Hopper  

DOE Green Energy (OSTI)

The Mars Hopper is an exploratory vehicle designed to fly on Mars using carbon dioxide from the Martian atmosphere as a rocket propellant. The propellent gasses are thermally heated while traversing a radioisotope ther- mal rocket (RTR) engine’s core. This core is comprised of a radioisotope surrounded by a heat capacitive material interspersed with tubes for the propellant to travel through. These tubes, or flow channels, can be manu- factured in various cross-sectional shapes such as a special four-point star or the traditional circle. Analytical heat transfer and computational fluid dynamics (CFD) anal- yses were performed using flow channels with either a circle or a star cross- sectional shape. The nominal total inlet pressure was specified at 2,805,000 Pa; and the outlet pressure was set to 2,785,000 Pa. The CO2 inlet tem- perature was 300 K; and the channel wall was 1200 K. The steady-state CFD simulations computed the smooth-walled star shape’s outlet temper- ature to be 959 K on the finest mesh. The smooth-walled circle’s outlet temperature was 902 K. A circle with a surface roughness specification at 0.01 mm gave 946 K and at 0.1 mm yielded 989 K. The The effects of a slightly varied inlet pressure were also examined. The analytical calculations were based on the mass flow rates computed in the CFD simulations and provided significantly higher outlet temperature results while displaying the same comparison trends. Research relating to the flow channel heat transfer studies was also done. Mathematical methods to geometrically match the cross-sectional areas of the circle and star, along with a square and equilateral triangle, were derived. A Wolfram Mathematica 8 module was programmed to analyze CFD results using Richardson Extrapolation and calculate the grid convergence index (GCI). A Mathematica notebook, also composed, computes and graphs the bulk mean temperature along a flow channel’s length while the user dynam- ically provides the input variables, allowing their effects on the temperature to be more easily observed.

W. Spencer Cooley

2013-02-01T23:59:59.000Z

176

Analysis and design of axisymmetric transonic flow with linearized three-dimensional flow prediction  

E-Print Network (OSTI)

The primary goal of this thesis is the application of the proven stream-surface based Newton method to analysis/design of an axisymmetric nacelle with the actuator disk modeling of a fan. And to further utilize the benefits ...

Ahn, Jon

177

In situ stress, fracture, and fluid flow analysis in Well 38C-9: an  

Open Energy Info (EERE)

In situ stress, fracture, and fluid flow analysis in Well 38C-9: an In situ stress, fracture, and fluid flow analysis in Well 38C-9: an enhanced geothermal system in the Coso geothermal field Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: In situ stress, fracture, and fluid flow analysis in Well 38C-9: an enhanced geothermal system in the Coso geothermal field Abstract Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the U.S. Geological Survey are cooperating in a multi-year study to develop an Enhanced Geothermal System (EGS) in the Coso Geothermal Field. Key to the creation of an EGS is an understanding of the relationship among natural fracture distribution, fluid flow, and the ambient tectonic stresses that exist within the resource in order to design

178

IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED  

Open Energy Info (EERE)

FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED GEOTHERMAL SYSTEM IN THE COSO GEOTHERMAL FIELD Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: IN SITU STRESS, FRACTURE, AND FLUID FLOW ANALYSIS IN WELL 38C-9:AN ENHANCED GEOTHERMAL SYSTEM IN THE COSO GEOTHERMAL FIELD Details Activities (2) Areas (1) Regions (0) Abstract: Geoscientists from the Coso Operating Company, EGI-Utah, GeoMechanics International, and the U.S. Geological Survey are cooperating in a multi-year study to develop an Enhanced Geothermal System (EGS) in the Coso Geothermal Field. Key to the creation of an EGS is an understanding of the relationship among natural fracture distribution, fluid flow, and the ambient tectonic stresses that exist within the resource in order to design

179

Strength Estimation of Self-Piercing Rivets using Lower Bound Limit Load Analysis  

DOE Green Energy (OSTI)

This paper summarizes the authors' work on strength and failure mode estimation of self-piercing rivets (SPR) for automotive applications. First, the static cross tension strength of an SPR joint is estimated using a lower bound limit load based strength estimator. Failure mode associated with the predicted failure strength can also be identified. It is shown that the cross tension strength of an SPR joint depends on the material and gage combinations, rivet design, die design and riveting direction. The analytical rivet strength estimator is then validated by experimental rivet strength measurements and failure mode observations from nine SPR joint populations with various material and gage combinations. Next, the estimator is used to optimize rivet strength. Two illustrative examples are presented in which rivet strength is improved by changing rivet length and riveting direction from the original manufacturing parameters.

Sun, Xin; Khaleel, Mohammad A.

2005-08-01T23:59:59.000Z

180

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

Note: This page contains sample records for the topic "load flow analysis" 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

Analysis of performance capabilities of redox-flow storage batteries  

SciTech Connect

Major physical performance parameters and economic factors of a generalized redox-flow storage battery system are analyzed. The system is divided into power-related and energy-related subsystems. The economic factors include plant capital (and other) costs, electrical energy lost by the storage-cycle inefficiency, and a penalty term for failures. Relationships are formulated for the overall system efficiency and system performance parameters (voltages, current density, state-of-charge of the storage liquid, and parasitic losses). Equations for sizing and costing of the battery and the storage tank subsystems are given. Directions for needed research are indicated.

Roy, A.S.; Kaplan, S.I.

1978-01-01T23:59:59.000Z

182

Turbulent Flow Analysis and Coherent Structure Identification in Experimental Models with Complex Geometries  

E-Print Network (OSTI)

Turbulent flows and coherent structures emerging within turbulent flow fields have been extensively studied for the past few decades and a wide variety of experimental and numerical techniques have been developed for measurement and analysis of turbulent flows. The complex nature of turbulence requires methods that can accurately estimate its highly chaotic spatial and temporal behavior. Some of the classical cases of turbulent flows with simpler geometries have been well characterized by means of the existing experimental techniques and numerical models. Nevertheless, since most turbulent fields are of complex geometries; there is an increasing interest in the study of turbulent flows through models with more complicated geometries. In this dissertation, characteristics of turbulent flows through two different facilities with complex geometries are studied applying two different experimental methods. The first study involves the investigation of turbulent impinging jets through a staggered array of rods with or without crossflow. Such flows are crucial in various engineering disciplines. This experiment aimed at modeling the coolant flow behavior and mixing phenomena within the lower plenum of a Very High Temperature Reactor (VHTR). Dynamic Particle Image Velocimetry (PIV) and Matched Index of Refraction (MIR) techniques were applied to acquire the turbulent velocity fields within the model. Some key flow features that may significantly enhance the flow mixing within the test section or actively affect some of the structural components were identified in the velocity fields. The evolution of coherent structures within the flow field is further investigated using a Snapshot Proper Orthogonal Decomposition (POD) technique. Furthermore, a comparative POD method is proposed and successfully implemented for identification of the smaller but highly influential coherent structures which may not be captured in the full-field POD analysis. The second experimental study portrays the coolant flow through the core of an annular pebble bed VHTR. The complex geometry of the core and the highly turbulent nature of the coolant flow passing through the gaps of fuel pebbles make this case quite challenging. In this experiment, a high frequency Hot Wire Anemometry (HWA) system is applied for velocity measurements and investigation of the bypass flow phenomena within the near wall gaps of the core. The velocity profiles within the gaps verify the presence of an area of increased velocity close to the outer reflector wall; however, the characteristics of the coolant flow profile is highly dependent on the gap geometry and to a less extent on the Reynolds number of the flow. The time histories of the velocity are further analyzed using a Power Spectra Density (PSD) technique to acquire information about the energy content and energy transfer between eddies of different sizes at each point within the gaps.

Amini, Noushin

2011-12-01T23:59:59.000Z

183

ATR LEU Monothlic and Dispersed with 10B Loading Minimization Design – Neutronics Performance Analysis  

SciTech Connect

The Advanced Test Reactor (ATR), currently operating in the United States, is used for material testing at very high neutron fluxes. Powered with highly enriched uranium (HEU), the ATR has a maximum thermal power rating of 250 MWth. Because of the large test volumes located in high flux areas, the ATR is an ideal candidate for assessing the feasibility of converting HEU driven reactor cores to low-enriched uranium (LEU) cores. The present work investigates the optimized LEU Monolithic and Dispersed fuel with 10B loading minimization design and evaluates the subsequent neutronics operating effects of these optimized fuel designs. The MCNP ATR 1/8th core model was used to optimize the 235U and minimize the 10B loading in the LEU core, such that the differences in K-eff and heat flux profiles between the HEU and LEU cores were minimized. The fuel depletion methodology MCWO was used to calculate K eff versus effective full power days (EFPD) in this paper. The MCWO-calculated results for the optimized LEU Monolithic and Dispersed fuel cases demonstrated adequate excess reactivity such that the K-eff versus EFPD plot is similar to the ATR reference HEU case study. Each HEU fuel element contains 19 fuel plates with a fuel meat thickness of 0.508 mm (20 mil). In this work, the proposed LEU Monolithic (U-10Mo) core conversion case with nominal fuel meat thickness of 0.330 mm (13 mil) and 235U enrichment of 19.7 wt% is used to optimize the radial heat flux profile by varying the fuel meat thickness. The proposed LEU fuel meat varies from 0.203 mm (8.0 mil) to 0.254 mm (10.0 mil) at the inner four fuel plates (1-4) and outer four fuel plates (16-19). In addition, an optimized LEU dispersed (U7Mo) case with all the fuel meat thickness of 0.635 mm (25 mil) was also proposed. Then, for both Monolithic and dispersed cases, a burnable absorber – 10B, was added in the inner and outer plates to reduce the initial excess reactivity, and the higher to average ratio of the inner/outer heat flux more effectively. The final minimized 10B loading for LEU case studies will have 0.635 g in the LEU fuel meat at the inner 2 fuel plates (1-2) and outer 2 fuel plates (18-19), which can achieve peak to average ratios similar to those for the ATR reference HEU case study. The investigation of this paper shows the optimized LEU Monolithic (U-10Mo) and Dispersed (U7Mo) cases can all meet the LEU conversion objectives.

G. S. Chang

2001-10-01T23:59:59.000Z

184

Application of the pseudolinear-flow model to the pressure-transient analysis of fractured wells  

SciTech Connect

The theoretical basis for the pseudolinear-flow model is established. In this paper it is demonstrated by use of an analytical model that the linear-flow graph (rho vs. {Lambda}tau) can be extended to the analysis of pressure data of fractured wells intersected by an intermediate- or high-conductivity fracture (C/sub fD/ > 5{pi}). It appears that the fracture-conductivity effect during the pseudolinear-flow period can be handled as pseudoskin pressure drop that adds to the pressure drop caused by fluid-loss damage. The combination of the pseudolinear-flow analysis with other interpretation techniques is illustrated through examples of field cases.

Cinco-Ley, H.; Samanlego, V.F. (Univ. of Mexico/Pemex (MX)); Rodriguez, F. (Univ. of Mexico/IMP (MX))

1989-09-01T23:59:59.000Z

185

Analysis of Supercritical Stratified Tidal Flow in a Scottish Fjord  

Science Conference Proceedings (OSTI)

The baroclinic tidal regime of the fjord Loch Etive (Scotland) is studied. Analysis is performed on the basis of both in situ data and numerical simulations, with the use of a fully nonlinear nonhydrostatic fine-resolution model. It was found ...

Nataliya Stashchuk; Mark Inall; Vasiliy Vlasenko

2007-07-01T23:59:59.000Z

186

Nonlinear vibration analysis of actively loaded sandwich piezoelectric beams with geometric imperfections  

Science Conference Proceedings (OSTI)

Modal analysis is developed for linear and nonlinear vibrations of deformed sandwich piezoelectric beams with initial imperfections. The beam is subjected to axial displacement and active voltage generated by the top and the bottom piezoelectric layers. ... Keywords: Control, Nonlinear, Piezoelectric, Sandwich, Stability, Vibration

L. Azrar; S. Belouettar; J. Wauer

2008-12-01T23:59:59.000Z

187

A Novel Power Flow Method for Long Term Frequency Stability Analysis  

E-Print Network (OSTI)

This thesis presents a novel approach for a power system to find a practical power flow solution when all the generators in the system have hit their real power output limits, such as some generator units shutting down or load outages. The approach assumes the frequency of the system is unable to be kept at the rated value (usually 60 or 50 Hz) and accordingly, the generator real power outputs are affected by the system frequency deviation. The modification aims to include the system frequency deviation as a new state variable in the power flow so that the power system can be described in a more precise way when the generation limits are hit and the whole system is not operated under the normal condition. A new mathematical formulation for power flow is given by modified the conventional power flow mismatch equation and Jacobian matrix. The Newton – Raphson method is particularly chose to be modified because Newton – Raphson method is most widely used and it is a fast convergent and accurate method. The Jacobian matrix will be augmented by adding a column and a row. Matlab is used as a programming tool to implement the Power Flow for Long Term Frequency Stability (PFLTFS) method for a simple 4-bus system and the IEEE 118-bus system. And PSS/E Dynamic simulation is used to verify the steady state solution from PFLTFS is reasonable. The PSS/E Dynamic Simulation plots are used to analyze the long term frequency response. The PFLTFS method provides a technique for solving an abnormal state system power flow. From the results we can conclude that the PFLTFS method is reasonable for solving power flow of a real power unbalanced system.

Yan, Wenjin

2013-05-01T23:59:59.000Z

188

SINGLE-SHELL TANK INTEGRITY PROJECT ANALYSIS OF RECORD-PRELIMINARY MODELING PLAN FOR THERMAL AND OPERATING LOADS  

SciTech Connect

This document is a Phase I deliverable for the Single-Shell Tank Analysis of Record effort. This document is not the Analysis of Record. The intent of this document is to guide the Phase II detailed modeling effort. Preliminary finite element models for each of the tank types were developed and different case studies were performed on one or more of these tank types. Case studies evaluated include thermal loading, waste level variation, the sensitivity of boundary effects (soil radial extent), excavation slope or run to rise ratio, soil stratigraphic (property and layer thickness) variation at different farm locations, and concrete material property variation and their degradation under thermal loads. The preliminary analysis document reviews and preliminary modeling analysis results are reported herein. In addition, this report provides recommendations for the next phase of the SST AOR project, SST detailed modeling. Efforts and results discussed in this report do not include seismic modeling as seismic modeling is covered by a separate report. The combined results of both static and seismic models are required to complete this effort. The SST AOR project supports the US Department of Energy's (DOE) Office of River Protection (ORP) mission for obtaining a better understanding of the structural integrity of Hanford's SSTs. The 149 SSTs, with six different geometries, have experienced a range of operating histories which would require a large number of unique analyses to fully characterize their individual structural integrity. Preliminary modeling evaluations were conducted to determine the number of analyses required for adequate bounding of each of the SST tank types in the Detailed Modeling Phase of the SST AOR Project. The preliminary modeling was conducted in conjunction with the Evaluation Criteria report, Johnson et al. (2010). Reviews of existing documents were conducted at the initial stage of preliminary modeling. These reviews guided the topics that were explored in the SST preliminary modeling. The reviews determined the level of detail necessary to perform the analyses of the SSTs. To guide the Phase II detailed modeling effort, preliminary finite element models for each of the tank types were developed and different case studies were performed on one or more of these tank types. Case studies evaluated include thermal loading, waste level variation, the sensitivity of boundary effects (soil radial extent), excavation slope or run to rise ratio, soil stratigraphic (property and layer thickness) variation at different farm locations, and concrete material property variation and their degradation under thermal loads. Conclusions were derived from case studies on one of the tank types when no additional runs of similar cases on other types of tanks were found necessary to derive those conclusions. The document reviews provided relatively complete temperature histories for Type IV tanks. The temperature history data for Type I, II, and III tanks was almost nonexistent for years prior to 1975. Document reviews indicate that there might be additional useful data in the US Department of Energy, Richland Operations Office (DOE-RL) records in Seattle, WA, and these records need to be reviewed to extract data that might have been disregarded during previous reviews. Thermal stress analyses were conducted using different temperature distribution scenarios on Type IV tanks. Such studies could not be carried out for other tank types due to lack of temperature history data. The results from Type IV tank analyses indicate that factors such as temperature distribution in the tank waste and rate of rise in waste temperature have a significant impact on the thermal stresses in the tank structures. Overall, the conclusion that can drawn from the thermal stress analyses is that these studies should be carried out for all tank types during the detailed analysis phase with temperature values that are reasonably close to the typical temperature histories of the respective tank types. If and/or when additional waste temperature data

RAST RS; RINKER MW; BAPANAALLI SK; DEIBLER JE; GUZMAN-LEONG CE; JOHNSON KI; KARRI NK; PILLI SP; SANBORN SE

2010-10-22T23:59:59.000Z

189

Criticality Analysis for Proposed Maximum Fuel Loading in a Standardized SNF Canister with Type 1a Baskets  

SciTech Connect

This document represents a summary version of the criticality analysis done to support loading SNF in a Type 1a basket/standard canister combination. Specifically, this engineering design file (EDF) captures the information pertinent to the intact condition of four fuel types with different fissile loads and their calculated reactivities. These fuels are then degraded into various configurations inside a canister without the presence of significant moderation. The important aspect of this study is the portrayal of the fuel degradation and its effect on the reactivity of a single canister given the supposition there will be continued moderation exclusion from the canister. Subsequent analyses also investigate the most reactive ‘dry’ canister in a nine canister array inside a hypothetical transport cask, both dry and partial to complete flooding inside the transport cask. The analyses also includes a comparison of the most reactive configuration to other benchmarked fuels using a software package called TSUNAMI, which is part of the SCALE 5.0 suite of software.

Chad Pope; Larry L. Taylor; Soon Sam Kim

2007-02-01T23:59:59.000Z

190

Real-Time Forcast Model Analysis of Daily Average Building Load for a Thermal Storage System Control  

E-Print Network (OSTI)

Thermal storage systems were originally designed to shift the on-peak cooling production to off-peak cooling production to reduce the on-peak demand. Based on the current electricity charging structure, the reduction of both on-peak and off-peak demands is becoming an exceedingly important issue. Reduction of both on-peak and off-peak demands can also extend the life span and defer or eliminate the replacement of power transformers due to potential shortage of building power capacity with anticipated equipment load increases. The next day daily average electricity demand is a critical set point to operate chillers and associated pumps at the appropriate time. For this paper, a mathematic analysis was conducted for annual daily average cooling of a building and three real-time building load forecasting models were developed. They are first-order autogressive model, random walk model and linear regression model. Finally, the comparison of results show the random walk model provides the best forecast.

Song, L.; Joo, I. S.; Guwana, S.

2009-11-01T23:59:59.000Z

191

An Energy and Peak Loads Analysis of the TYC/TRC Building – Final Report  

E-Print Network (OSTI)

The energy use of the Texas Youth Commission/Texas Rehabilitation Commission (TYC/TRC) Building at Austin, Texas, was analyzed using the DOE 2.IB building energy simulation program. An analysis was made for the building as specified in the building plans and the specifications provided by the State Purchasing and General Services Commission. Operating schedules for occupancy, lighting, office equipment, and infiltration were assumed. The energy consumption of the TYC/TRC Building can be reduced with certain modifications.

Katipamula, S.; O'Neal, D. L.

1987-01-01T23:59:59.000Z

192

IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO  

Open Energy Info (EERE)

IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO GEOTHERMAL FIELD Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: IN SITU STRESS, FRACTURE AND FLUID FLOW ANALYSIS-EAST FLANK OF THE COSO GEOTHERMAL FIELD Details Activities (1) Areas (1) Regions (0) Abstract: High rock temperatures, a high degree of fracturing, high tectonic stresses, and low permeability are the combination of qualities that define an ideal candidate-Enhanced Geothermal System (EGS) reservoir. The Coso Geothermal Field is an area where fluid temperatures exceeding 300°C have been measured at depths less than 10,000 feet and the reservoir is both highly fractured and tectonically stressed. Some of the wells within this portion of the reservoir are relatively impermeable,

193

UNDERSTANDING FLOW OF ENERGY IN BUILDINGS USING MODAL ANALYSIS METHODOLOGY  

SciTech Connect

It is widely understood that energy storage is the key to integrating variable generators into the grid. It has been proposed that the thermal mass of buildings could be used as a distributed energy storage solution and several researchers are making headway in this problem. However, the inability to easily determine the magnitude of the building’s effective thermal mass, and how the heating ventilation and air conditioning (HVAC) system exchanges thermal energy with it, is a significant challenge to designing systems which utilize this storage mechanism. In this paper we adapt modal analysis methods used in mechanical structures to identify the primary modes of energy transfer among thermal masses in a building. The paper describes the technique using data from an idealized building model. The approach is successfully applied to actual temperature data from a commercial building in downtown Boise, Idaho.

John Gardner; Kevin Heglund; Kevin Van Den Wymelenberg; Craig Rieger

2013-07-01T23:59:59.000Z

194

Depletion Analysis of Modular High Temperature Gas-cooled Reactor Loaded with LEU/Thorium Fuel  

SciTech Connect

Thorium based fuel has been considered as an option to uranium-based fuel, based on considerations of resource utilization (Thorium is more widely available when compared to Uranium). The fertile isotope of Thorium (Th-232) can be converted to fissile isotope U-233 by neutron capture during the operation of a suitable nuclear reactor such as High Temperature Gas-cooled Reactor (HTGR). However, the fertile Thorium needs a fissile supporter to start and maintain the conversion process such as U-235 or Pu-239. This report presents the results of a study that analyzed the thorium utilization in a prismatic HTGR, namely Modular High Temperature Gas-Cooled Reactor (MHTGR) that was designed by General Atomics (GA). The collected for the modeling of this design come from Chapter 4 of MHTGR Preliminary Safety Information Document that GA sent to Department of Energy (DOE) on 1995. Both full core and unit cell models were used to perform this analysis using SCALE 6.1 and Serpent 1.1.18. Because of the long mean free paths (and migration lengths) of neutrons in HTRs, using a unit cell to represent a whole core can be non-trivial. The sizes of these cells were set to match the spectral index between unit cell and full core domains. It was found that for the purposes of this study an adjusted unit cell model is adequate. Discharge isotopics and one-group cross-sections were delivered to the transmutation analysis team. This report provides documentation for these calculations

Sonat Sen; Gilles Youinou

2013-02-01T23:59:59.000Z

195

Quantitative Analysis of Flow Processes in a Sand Using Synchrotron-Based X-ray Microtomography  

Science Conference Proceedings (OSTI)

Pore-scale multiphase flow experiments were developed to nondestructively visualize water flow in a sample of porous material using X-ray microtomography. The samples were exposed to similar boundary conditions as in a previous investigation, which examined the effect of initial flow rate on observed dynamic effects in the measured capillary pressure-saturation curves; a significantly higher residual saturation and higher capillary pressures were found when the sample was drained fast using a high air-phase pressure. Prior work applying the X-ray microtomography technique to pore-scale multiphase flow problems has been of a mostly qualitative nature and no experiments have been presented in the existing literature where a truly quantitative approach to investigating the multiphase flow process has been taken, including a thorough image-processing scheme. The tomographic images presented here show, both by qualitative comparison and quantitative analysis in the form of a nearest neighbor analysis, that the dynamic effects seen in previous experiments are likely due to the fast and preferential drainage of large pores in the sample. Once a continuous drained path has been established through the sample, further drainage of the remaining pores, which have been disconnected from the main flowing water continuum, is prevented.

Wildenschild, D.; Hopmans, J.W.; Rivers, M.L.; Kent, A.J.R. (OSU); (UCD); (UC)

2010-07-20T23:59:59.000Z

196

Human Factors Aspects of Power System Flow Animation  

E-Print Network (OSTI)

, engineering analysis and EMS (energy management system) software will need to be modified in a number of ways not provide a clear advantage in the visualization of transmission line flows for uncomplicated analysis tasks listings showing the exact power flows and percentage loadings can be crucial. But for medium to large

197

CFD simulation of neutral ABL flows Xiaodong Zhang  

E-Print Network (OSTI)

in the atmosphere, prediction of wind load on structure, analysis of wind flow patterns in urban area flow field over different terrains employing Fluent 6.3 software. How accurate the simulation could.2 Problem analysis 18 3.3 User-defined wall functions 18 3.4 Results from different model settings 19 3

198

Analysis and Design Significance of A-11 Flow-Induced Vibration Test, Phases I and III  

SciTech Connect

Comparisons of the experimental data on seal pressure distributions obtained from the A-11 Flow Induced Vibration Test, Phases I and III, with analytical results including porous flow through the unimpregnated inner reflector cylinder for the same operating conditions show generally very good agreement. The principal deviations between analysis and experiment occurs when high pressure ratios exist across the last seal. Additional investigation, both in the relationship used in the analytical model and in the experimental area, are required to determine the cause of the deviation found between analysis and experiment when the pressure ratio across the last seal is near critical. As a result of this comparison, it appears that the analytical methods and assumtions made in predicting unheated seal pressure distributions are resonable, and may be used with confidence in the test prediction of the NRX-A1 cold flow test.

1964-01-01T23:59:59.000Z

199

Randomized flow model and centrality measure for electrical power transmission network analysis  

E-Print Network (OSTI)

1 Randomized flow model and centrality measure for electrical power transmission network analysis. Centrality measures can then be coherently defined. An example of application to an electrical power transmission system is presented. Acknowledgements This work has been partially funded by the Foundation pour

200

Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1  

E-Print Network (OSTI)

Analysis of granular flow in a pebble-bed nuclear reactor Chris H. Rycroft,1 Gary S. Grest,2 James February 2006; published 24 August 2006 Pebble-bed nuclear reactor technology, which is currently being States, the Modular Pebble Bed Reactor MPBR 4,8 is a candidate for the next generation nuclear plant

Bazant, Martin Z.

Note: This page contains sample records for the topic "load flow analysis" 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

CFD analysis of the effect of elbow radius on pressure drop in multiphase flow  

Science Conference Proceedings (OSTI)

Computational fluid dynamics (CFD) analysis was performed in four different 90 degree elbows with air-water two-phase flows. The inside diameters of the elbows were 6.35mm and 12.7mm with radius to diameter ratios (r/D) of 1.5 to 3. The pressure drops ...

Quamrul H. Mazumder

2012-01-01T23:59:59.000Z

202

A Linear Analysis on the Acceleration of Zonal Flow by Baroclinic Instability. Part I. Terrestrial Atmosphere  

Science Conference Proceedings (OSTI)

A mechanism which accelerates the midlatitude zonal-mean wind is investigated by means of linear stability analysis for the wave-zonal flow interaction. Two kinds of models are analyzed: In the first, the basic state consists of an unstable zonal-...

T. Sasamori; K. Droegemeier

1983-10-01T23:59:59.000Z

203

Gridded retarding pressure sensor for ion and neutral particle analysis in flowing plasmas  

E-Print Network (OSTI)

configuration can be used to measure the ion energy distribution. Preliminary data from this probe were takenGridded retarding pressure sensor for ion and neutral particle analysis in flowing plasmas Lyon B. Kinga) and Alec D. Gallimoreb) Plasmadynamics and Electric Propulsion Laboratory, Department

King, Lyon B.

204

Definition: Dispersed Load By Substations | Open Energy Information  

Open Energy Info (EERE)

By Substations Jump to: navigation, search Dictionary.png Dispersed Load By Substations Substation load information configured to represent a system for power flow or system...

205

Energetical factors in power systems with nonlinear loads  

Science Conference Proceedings (OSTI)

Based on the volt-ampere charac- teristic of the nonlinear load, an equivalent circuit, containing linear elements, can be determined. In this way, load-flow and.

206

Use of Residential Smart Appliances for Peak-Load Shifting and Spinning Reserves Cost/Benefit Analysis  

Science Conference Proceedings (OSTI)

In this report, we present the results of an analytical cost/benefit study of residential smart appliances from a utility/grid perspective in support of a joint stakeholder petition to the ENERGY STAR program within the Environmental Protection Agency (EPA) and Department of Energy (DOE). The goal of the petition is in part to provide appliance manufacturers incentives to hasten the production of smart appliances. The underlying hypothesis is that smart appliances can play a critical role in addressing some of the societal challenges, such as anthropogenic global warming, associated with increased electricity demand, and facilitate increased penetration of renewable sources of power. The appliances we consider include refrigerator/freezers, clothes washers, clothes dryers, room air-conditioners, and dishwashers. The petition requests the recognition that providing an appliance with smart grid capability, i.e., products that meet the definition of a smart appliance, is at least equivalent to a corresponding five percent in operational machine efficiencies. It is then expected that given sufficient incentives and value propositions, and suitable automation capabilities built into smart appliances, residential consumers will be adopting these smart appliances and will be willing participants in addressing the aforementioned societal challenges by more effectively managing their home electricity consumption. The analytical model we utilize in our cost/benefit analysis consists of a set of user-definable assumptions such as the definition of on-peak (hours of day, days of week, months of year), the expected percentage of normal consumer electricity consumption (also referred to as appliance loads) that can shifted from peak hours to off-peak hours, the average power rating of each appliance, etc. Based on these assumptions, we then formulate what the wholesale grid operating-cost savings, or benefits, would be if the smart capabilities of appliances were invoked, and some percentage of appliance loads were shifted away from peak hours to run during off-peak hours, and appliance loads served power-system balancing needs such as spinning reserves that would otherwise have to be provided by generators. The rationale is that appliance loads can be curtailed for about ten minutes or less in response to a grid contingency without any diminution in the quality of service to the consumer. We then estimate the wholesale grid operating-cost savings based on historical wholesale-market clearing prices (location marginal and spinning reserve) from major wholesale power markets in the United States. The savings derived from the smart grid capabilities of an appliance are then compared to the savings derived from a five percent increase in traditional operational machine efficiencies, referred to as cost in this report, to determine whether the savings in grid operating costs (benefits) are at least as high as or higher than the operational machine efficiency credit (cost).

Sastry, Chellury; Pratt, Robert G.; Srivastava, Viraj; Li, Shun

2010-12-01T23:59:59.000Z

207

Rock matrix and fracture analysis of flow in western tight gas sands: 1986 annual report  

SciTech Connect

This report presents progress for the second year of a five-year project concerned with the pore structure and flow properties of low permeability gas sands. The main objective of work during the first year was to carry out advanced core analysis on cores recovered from the Multi-Well Field Experiment. In Phase 2, the properties of both fractured and non-fractured samples (hereafter referred to as matrix) have been studied. Special attention was given to the combined effect of overburden pressure and water saturation on gas flow. 11 refs., 18 figs., 4 tabs.

Morrow, N.R.; Buckley, J.S.; Cather, S.M.; Brower, K.R.; Dandge, V.; Graham, M.; Gonzales, B.

1987-02-01T23:59:59.000Z

208

Analysis and testing the performance of a centrifugal two phase flow separator  

DOE Green Energy (OSTI)

Analysis and testing the performance of an 8 in., 1.72 ft high centrifugal cyclone separator for flows up to 4.0 lbs/s and pressures ranging from 10 to 60 psig. Conclusions drawn are based on inlet steam qualities of 23 to 27 percent (x% = m/sub s//m /sub t/) .99% and better steam quality is achieved up to 3 lbs/s under 50 and 60 psig. Breakdown flow rate is found to be a linear function of separator pressure.

Mirza-Moghadam, A.V.

209

Model Development and Loads Analysis of an Offshore Wind Turbine on a Tension Leg Platform with a Comparison to Other Floating Turbine Concepts: April 2009  

DOE Green Energy (OSTI)

This report presents results of the analysis of a 5-MW wind turbine located on a floating offshore tension leg platform (TLP) that was conducted using the fully coupled time-domain aero-hydro-servo-elastic design code FAST with AeroDyn and HydroDyn. The report also provides a description of the development process of the TLP model. The model has been verified via comparisons to frequency-domain calculations. Important differences have been identified between the frequency-domain and time-domain simulations, and have generated implications for the conceptual design process. An extensive loads and stability analysis for ultimate and fatigue loads according to the procedure of the IEC 61400-3 offshore wind turbine design standard was performed with the verified TLP model. This report compares the loads for the wind turbine on the TLP to those of an equivalent land-based turbine. Major instabilities for the TLP are identified and described.

Matha, D.

2010-02-01T23:59:59.000Z

210

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

211

Hydrodynamic design loads for the OTEC cold water pipe  

DOE Green Energy (OSTI)

Ocean current and/or plant motion crossflows induce time dependent hydrodynamic loads on the OTEC cold water pipe due to vortex shedding. Design criteria were established for mean and fluctuating loads based on a review of the literature, analysis of test data acquired by SAI under a previous experimental program and an analytical extension of test results to higher Reynolds number. Baseline loads were specified for rigid cylinders in uniform flows. Modifications to the loads by current shear, stratification and cylinder motion, were investigated and final design criteria established. Limited structural response calculations were performed to demonstrate the use of the design criteria and to investigate briefly the possible structural response mode. Comparisons were made with alternate hydrodynamic loads, and recommendations were made for experimental verification.

Hove, D.; Shih, W.; Albano, E.

1978-09-01T23:59:59.000Z

212

Compilation of Diversity Factors and Schedules for Energy and Cooling Load Calculations, Phase II Report - Identified Relevant Data Sets, Methods, and Variability Analysis  

E-Print Network (OSTI)

This is the second report of the ASHRAE 1093-RP project that reports on the progress during the scheduled Phase II effort. In this report, we present: (1) the data sets identified and acquired required for the analysis; (2) the method adopted for classifying the Office building categories; (3) the relevant methods for daytyping necessary for creating the typical load shapes for energy and cooling load calculation; (4) the relevant robust variability (uncertainty) analysis; (5) typical load shapes reported in the literature; (6) a test to assure the non-weather dependency (seasonal variation) of the lighting and equipment data sets; and (7) a proposed occupancy surrogate variable. The results obtained during Phase II will enable us to proceed with Phase III, as planned. Phase III will cover: (1) developing the typical load shapes for the acquired data sets, using the proposed method, for both energy and cooling load calculations; (2) developing the tool-kit for deriving the new diversity factors and general guidelines for their use; and (3) developing illustrative examples of the use of the diversity factors in the DOE-2 and BLAST simulation programs.

Abushakra, B.; Haberl, J. S.; Claridge, D. E.

1999-01-01T23:59:59.000Z

213

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

214

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

215

FAST 1.0 - Flow Path Analysis for Steam Turbines, Version 1.0  

Science Conference Proceedings (OSTI)

FAST Software Flow Analysis of Steam Turbines is a tool for performance engineers, designers and financial analysts. This tool is for industry use by utilities and manufacturers to evaluate thermal performance characteristics of existing and proposed turbine steam-path modifications/upgrades. Description The FAST software diagnoses performance problems and facilitates the economic evaluation of steam-path upgrade options. FAST software is used primarily by the thermal performance engineer in both fossil ...

2007-05-30T23:59:59.000Z

216

ANALYSIS OF TWO-PHASE FLOW MODELS WITH TWO MOMENTUM EQUATIONS.  

SciTech Connect

An analysis of the standard system of differential equations describing multi-speed flows of multi-phase media is performed. It is proved that the Cauchy problem, as posed in most best-estimate thermal-hydraulic codes, results in unstable solutions and potentially unreliable description of many physical phenomena. A system of equations, free from instability effects, is developed allowing more rigorous numerical modeling.

KROSHILIN,A.E.KROSHILIN,V.E.KOHUT,P.

2004-03-15T23:59:59.000Z

217

Assessment of HTGR Helium Compressor Analysis Tool Based on Newton-Raphson Numerical Application to Through-flow Analysis  

SciTech Connect

This study describes the development of a computer program for analyzing the off-design performance of axial flow helium compressors, which is one of the major concerns for the power conversion system of a high temperature gas-cooled reactor (HTGR). The compressor performance has been predicted by the aerodynamic analysis of meridional flow with allowances for losses. The governing equations have been derived from Euler turbomachine equation and the streamline curvature method, and then they have been merged into linearized equations based on the Newton-Raphson numerical method. The effect of viscosity is considered by empirical correlations to introduce entropy rises caused by primary loss sources. Use of the method has been illustrated by applying it to a 20-stage helium compressor of the GTHTR300 plant. As a result, the flow throughout the stages of the compressor has been predicted and the compressor characteristics have been also investigated according to the design specification. The program results show much better stability and good convergence with respect to other through-flow methods, and good agreement with the compressor performance map provided by JAEA. (authors)

Ji Hwan Kim; Hyeun Min Kim; Hee Cheon NO [Korea Advanced Institute of Science and Technology, 335 Gwahangno - 373-1 Guseong-dong, Yuseong-gu, Daejeon 305-701 (Korea, Republic of)

2006-07-01T23:59:59.000Z

218

A finite element analysis modeling tool for solid oxide fuel cell development: coupled electrochemistry, thermal and flow analysis in MARC®  

Science Conference Proceedings (OSTI)

A 3D simulation tool for modeling solid oxide fuel cells is described. The tool combines the versatility and efficiency of a commercial finite element analysis code, MARC{reg_sign}, with an in-house developed robust and flexible electrochemical (EC) module. Based upon characteristic parameters obtained experimentally and assigned by the user, the EC module calculates the current density distribution, heat generation, and fuel and oxidant species concentration, taking the temperature profile provided by MARC{reg_sign} and operating conditions such as the fuel and oxidant flow rate and the total stack output voltage or current as the input. MARC{reg_sign} performs flow and thermal analyses based on the initial and boundary thermal and flow conditions and the heat generation calculated by the EC module. The main coupling between MARC{reg_sign} and EC is for MARC{reg_sign} to supply the temperature field to EC and for EC to give the heat generation profile to MARC{reg_sign}. The loosely coupled, iterative scheme is advantageous in terms of memory requirement, numerical stability and computational efficiency. The coupling is iterated to self-consistency for a steady-state solution. Sample results for steady states as well as the startup process for stacks with different flow designs are presented to illustrate the modeling capability and numerical performance characteristic of the simulation tool.

Khaleel, Mohammad A.; Lin, Zijing; Singh, Prabhakar; Surdoval, Wayne; Collin, D

2004-05-03T23:59:59.000Z

219

Load Transfer Analysis in Short Carbon Fibers with Radially-Aligned Carbon Nanotubes Embedded in a Polymer Matrix  

E-Print Network (OSTI)

A novel shortfiber composite in which the microscopic advanced fiber reinforcements are coated with radially aligned carbon nanotubes (CNTs) is analyzed in this study. A shear-lag model is developed to analyze the load ...

Ray, M. C.

220

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

Note: This page contains sample records for the topic "load flow analysis" 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

Information flow metrics analysis in object oriented programming and metrics validation process by RAA algorithm  

Science Conference Proceedings (OSTI)

Transparent data flow metrics and control flow metrics had no main concern which to be handled by a compiler. Nowadays similar hardware and multithreaded coding is increased. Consequently, both data flow and control flow become more important in analyses ... Keywords: Ant colony algorithm, Information flow metrics, Object oriented information flow, Object oriented programming, Rule accuracy algorithm, Rule induction

Abdul Jabbar; Subramani Sarala

2012-12-01T23:59:59.000Z

222

228 POWER FLOW ANALYSIS parties, it is crucial to recognize the inherently subjective nature of OPF. Power flow  

E-Print Network (OSTI)

about the duration of an outage; in particular, one day in ten years does not mean the load between outage cost and duration. Here, outage cost is expressed in terms of dollars per kilowatt-hour (k of the outage period. Such a cost might be derived, for example, from the lost revenues of a business during

Kammen, Daniel M.

223

Shear-slip analysis in multiphase fluid-flow reservoir engineeringap plications using TOUGH-FLAC  

DOE Green Energy (OSTI)

This paper describes and demonstrates the use of the coupledTOUGH-FLAC simulator for geomechanical shear-slip (failure) analysis inmultiphase fluid-flow reservoir-engineering applications. Two approachesfor analyzing shear-slip are described, one using continuum stress-strainanalysis and another using discrete fault analysis. The use of shear-slipanalysis in TOUGH-FLAC is demonstrated on application examples related toCO2 sequestration and geothermal energy extraction. In the case of CO2sequestration, the shear-slip analysis is used to evaluate maximumsustainable CO2-injection pressure under increasing reservoir pressure,whereas in the case of geothermal energy extraction, the shear-slipanalysis is used to study induced seismicity during steam productionunder decreasing reservoir pressure and temperature.

Rutqvist, Jonny; Birkholzer, Jens; Cappa, Frederic; Oldenburg,Curt; Tsang, Chin-Fu

2006-01-15T23:59:59.000Z

224

Repository Reference Disposal Concepts and Thermal Load Management...  

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

Repository Reference Disposal Concepts and Thermal Load Management Analysis Repository Reference Disposal Concepts and Thermal Load Management Analysis A disposal concept consists...

225

Building Energy Software Tools Directory: Prophet Load Profiler  

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

Shots Keywords energy analysis, load profiling, cost comparison, energy budgeting, rate analysis, data collection, real-time monitoring, load shedding ValidationTesting NA...

226

Uncertainty Analysis Framework - Hanford Site-Wide Groundwater Flow and Transport Model  

Science Conference Proceedings (OSTI)

Pacific Northwest National Laboratory (PNNL) embarked on a new initiative to strengthen the technical defensibility of the predictions being made with a site-wide groundwater flow and transport model at the U.S. Department of Energy Hanford Site in southeastern Washington State. In FY 2000, the focus of the initiative was on the characterization of major uncertainties in the current conceptual model that would affect model predictions. The long-term goals of the initiative are the development and implementation of an uncertainty estimation methodology in future assessments and analyses using the site-wide model. This report focuses on the development and implementation of an uncertainty analysis framework.

Cole, Charles R.; Bergeron, Marcel P.; Murray, Christopher J.; Thorne, Paul D.; Wurstner, Signe K.; Rogers, Phillip M.

2001-11-09T23:59:59.000Z

227

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

228

ESF Subsurface Standby Generator Analysis  

Science Conference Proceedings (OSTI)

The purpose of this analysis is to outline and recommend two standby generator systems. These systems shall provide power during a utility outage to critical Alcove No.5's thermal test loads and to subsurface flow through ventilation loads. Critical loads that will be supported by these generator systems will be identified and evaluated. Additionally, other requirements from the Exploratory Studies Facilities Design Requirements (ESFDR) document will be evaluated. Finally, the standby generator systems will be integrated into the existing ESF subsurface distribution system. The objective of this analysis is to provide design inputs for an efficient and reliable standby generator systems which will provide power for critical loads during a power outage; specifically, Alcove No.5's thermal test loads and the subsurface flow through ventilation loads. Additionally, preliminary one-line diagrams will be developed using this analysis as a primary input.

L. Fernandez

1998-04-17T23:59:59.000Z

229

Carbon flow and ecosystem dynamics in the Mississippi River plume described by inverse analysis  

E-Print Network (OSTI)

Planktonic ecosystem dynamics in the buoyant Mississippi River plume were investigated using inverse analysis, a technique that incorporates data describing ecosystem processes and calculates rates of unknown trophic flows and sedimentation in the plume ecosystem. The waters receiving the Mississippi River were divided into four subregions connected by water flow to discretize the gradient of ecosystem properties as river water mixed with ocean water. Each subregion was represented by eight interconnected compartments that were linked to adjacent subregions by advective carbon flow. Models were produced for 4 seasons. Solutions for three seasons (spring, summer, and fall) showed a small region of net autotrophy associated with mid-salinity waters (15-29 psu), surrounded by a larger region of net heterotrophic waters where production did not meet respiratory carbon demand. In addition to moving more than 20% of total plume primary productivity out of the study region, westward water flow moved excess organic carbon from autotrophic regions to heterotrophic regions. In contrast, the winter result indicated a plume that was net-heterotrophic in all 4 subregions with high aerobic bacterial respiration and relatively low primary production that did not meet respiratory demand. Inputs of riverine DOC and carbon from resuspended sediments were required to make up the deficit. Sedimentation of organic carbon was linked to primary production in the mid-salinity regions of the plume, with strongest sedimentation from the productive mid-salinity regions during most of the year. Sedimentation was enhanced beneath less productive, higher salinity areas, due to inputs of organic carbon advected from mid-salinity regions. During winter organic carbon sedimentation was calculated to be zero. The models indicated that a dynamic relationship between primary production and sedimentation exists and provide a good starting point for future development of models which directly address the relationships between nutrient inputs, primary production, sedimentation, and hypoxia in the economically and environmental important regions of the Louisiana Shelf.

Breed, Greg Allen

2002-01-01T23:59:59.000Z

230

MATPOWER's Extensible Optimal Power Flow Architecture  

E-Print Network (OSTI)

of MATPOWER's extensible OPF architecture. Index Terms--Load flow analysis, Optimization methods, Power-compiled solvers. A software object is used to encapsulate the definition of the problem formulation, manage tasks. The software design has the advantage of minimizing the coupling between variables, constraints

Tesfatsion, Leigh

231

Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis  

E-Print Network (OSTI)

The thimble delivery heat-transfer (TDHT) system is one of the primary modes to utilize the energy of urban sewage. Given the schematic diagram of TDHT system, introducing the definition of equivalent fouling roughness height, and using the Niklaus semi-rational resistance coefficient formula in rough region, the calculation methods of the sewage flow resistance are explained. Through the resistance contrastive analysis of sewage and pure mediate water, the results indicate that the mediate water sub-system is the primary design point of the TDHT system. The economical ratio of flux and velocity is determined by optimization analysis of investment and operating cost in the technical feasible range. The paper will provide reference for pipe design and pump selection of urban sewage cool or heat source applied delivery heat transfer methods.

Zhang, C.; Wu, R.; Li, G.; Li, X.; Huang, L.; Sun, D.

2006-01-01T23:59:59.000Z

232

Computational analysis of fluid flow and zonal deposition in ferrocyanide single-shell tanks. Ferrocyanide Safety Program  

SciTech Connect

Safety of single-shell tanks containing ferrocyanide wastes is of concern. Ferrocyanide in the presence of an oxidizer such as NaNO{sub 3} or NaNO{sub 2} is explosively combustible when concentrated and heated. Evaluating the processes that could affect the fuel content of waste and distribution of the tank heat load is important. Highly alkaline liquid wastes were transferred in and out of the tanks over several years. Since Na{sub 2}NiFe(CN){sub 6} is much more soluble in alkaline media, the ferrocyanide could be dispersed from the tank more easily. If Cs{sub 2}NiFe(CN){sub 6} or CsNaNiFe(CN){sub 6} are also soluble in alkaline media, solubilization and transport of {sup 137}Cs could also occur. Transporting this heat generating radionuclide to a localized area in the tanks is a potential mechanism for generating a ``hot spot.`` Fluid convection could potentially speed the transport process considerably over aqueous diffusion alone. A stability analysis was performed for a dense fluid layer overlying a porous medium saturated by a less dense fluid with the finding that the configuration is unconditionally unstable and independent of the properties of the porous medium or the magnitude of the fluid density difference. A parametric modeling study of the buoyancy-driven flow due to a thermal gradient was combusted to establish the relationship between the waste physical and thermal properties and natural convection heat transfer. The effects of diffusion and fluid convection on the redistribution of the {sup 137}Cs were evaluated with a 2-D coupled heat and mass transport model. The maximum predicted temperature rise associated with the formation of zones was only 5{degrees}C and thus is of no concern in terms of generating a localized ``hot spot.``

McGrail, B.P.; Trent, D.S.; Terrones, G.; Hudson, J.D.; Michener, T.E.

1993-10-01T23:59:59.000Z

233

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

234

Compressible Shear Flow Transition and Turbulence: Enhancement of GKM Numerical Scheme and Simulation/Analysis of Pressure Effects on Flow Stabilization  

E-Print Network (OSTI)

Despite significant advancements in the understanding of fluid flows, combustion and material technologies, hypersonic flight still presents numerous technological challenges. In hypersonic vehicles turbulence is critical in controlling heat generation in the boundary layer, mixing inside the combustor, generation of acoustic noise, and mass flow in the intake. The study of turbulence in highly compressible flows is challenging compared to incompressible due to a drastic change in the behavior of pressure and a relaxation of the incompressibility constraint. In addition fluid flow inside a flight vehicle is complicated by wall-effects, heat generation and complex boundary conditions. Homogeneous shear flow contains most of the relevant physics of boundary and mixing layers without the aforementioned complicating effects. In this work we aim to understand and characterize the role of pressure, velocity-pressure interaction, velocity-thermodynamics interaction in the late-stage transition-to-turbulence regime in a high speed shear dominated flow by studying the evolution of perturbations in in a high Mach number homogeneous shear flow. We use a modal-analysis based approach towards understanding the statistical behavior of turbulence. Individual Fourier waves constituting the initial flow field are studied in isolation and in combination to understand collective statistical behavior. We demonstrate proof of concept of novel acoustic based strategies for controlling the onset of turbulence. Towards this goal we perform direct numerical simulations (DNS) in three studies: (a) development and evaluation of gas kinetic based numerical tool for DNS of compressible turbulence, and perform detailed evaluation of the efficacy of different interpolation schemes in capturing solenoidal and dilatational quantities, (b) modal investigation in the behavior of pressure and isolation of linear, non-linear, inertial and pressure actions, and (c) modal investigation in the possible acoustic based control strategies in homogeneously sheared compressible flows. The findings help to understand the manifestation of the effects of compressibility on transition and turbulence via the velocity-pressure interactions and the action of individual waves. The present study helps towards the design of control mechanisms for compressible turbulence and the development of physically consistent pressure strain correlation models.

Kumar, Gaurav 1984-

2012-12-01T23:59:59.000Z

235

Building waste management core indicators through Spatial Material Flow Analysis: Net recovery and transport intensity indexes  

Science Conference Proceedings (OSTI)

Highlights: Black-Right-Pointing-Pointer Sustainability and proximity principles have a key role in waste management. Black-Right-Pointing-Pointer Core indicators are needed in order to quantify and evaluate them. Black-Right-Pointing-Pointer A systematic, step-by-step approach is developed in this study for their development. Black-Right-Pointing-Pointer Transport may play a significant role in terms of environmental and economic costs. Black-Right-Pointing-Pointer Policy action is required in order to advance in the consecution of these principles. - Abstract: In this paper, the material and spatial characterization of the flows within a municipal solid waste (MSW) management system are combined through a Network-Based Spatial Material Flow Analysis. Using this information, two core indicators are developed for the bio-waste fraction, the Net Recovery Index (NRI) and the Transport Intensity Index (TII), which are aimed at assessing progress towards policy-related sustainable MSW management strategies and objectives. The NRI approaches the capacity of a MSW management system for converting waste into resources through a systematic metabolic approach, whereas the TII addresses efficiency in terms of the transport requirements to manage a specific waste flow throughout the entire MSW management life cycle. Therefore, both indicators could be useful in assessing key MSW management policy strategies, such as the consecution of higher recycling levels (sustainability principle) or the minimization of transport by locating treatment facilities closer to generation sources (proximity principle). To apply this methodological approach, the bio-waste management system of the region of Catalonia (Spain) has been chosen as a case study. Results show the adequacy of both indicators for identifying those points within the system with higher capacity to compromise its environmental, economic and social performance and therefore establishing clear targets for policy prioritization. Moreover, this methodological approach permits scenario building, which could be useful in assessing the outcomes of hypothetical scenarios, thus proving its adequacy for strategic planning.

Font Vivanco, David, E-mail: font@cml.leidenuniv.nl [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d'Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain); Institute of Environmental Sciences (CML), Leiden University, P.O. Box 9518, 2300 RA Leiden (Netherlands); Puig Ventosa, Ignasi [ENT Environment and Management, Carrer Sant Joan 39, First Floor, 08800 Vilanova i la Geltru, Barcelona (Spain); Gabarrell Durany, Xavier [Institut de Ciencia i Tecnologia Ambientals (ICTA), Departament d'Enginyeria Quimica, Universitat Autonoma de Barcelona (UAB), 08193 Bellaterra, Barcelona (Spain)

2012-12-15T23:59:59.000Z

236

Detailed analysis of the wake and free-flow characteristics at the Goodnoe Hills MOD-2 site  

DOE Green Energy (OSTI)

Wind data collected at nine meteorological towers at the Goodnoe Hills MOD-2 wind turbine site were analyzed to characterize the wind flow over the site both in the absence and presence of wind turbine wakes. Although previous studies have examined the wake and free-flow characteristics at the site, data collected in 1985 from nine towers permitted a much more detailed and accurate analysis than was previously possible. 13 refs., 25 figs., 7 tabs.

Elliott, D.L.; Barnard, J.C.

1989-07-01T23:59:59.000Z

237

Assessment of Distributed Energy Adoption in Commercial Buildings:Part 1: An Analysis of Policy, Building Loads, Tariff Design, andTechnology Development  

Science Conference Proceedings (OSTI)

Rapidly growing electricity demand brings into question theability of traditional grids to expand correspondingly while providingreliable service. An alternative path is the wider application ofdistributed energy resource (DER) that apply combined heat and power(CHP). It can potentially shave peak loads and satiate its growing thirstfor electricity demand, improve overall energy efficiency, and lowercarbon and other pollutant emissions. This research investigates a methodof choosing economically optimal DER, expanding on prior studies at theBerkeley Lab using the DER design optimization program, the DistributedEnergy Resources Customer Adoption Model (DER-CAM). DER-CAM finds theoptimal combination of installed equipment from available DERtechnologies, given prevailing utility tariffs, site electrical andthermal loads, and a menu of available equipment. It provides a globaloptimization, albeit idealized, that shows how the site energy loads canbe served at minimum cost by selection and operation of on-sitegeneration, heat recovery, and cooling. Utility electricity and gastariffs are key factors determining the economic benefit of a CHPinstallation, however often be neglected. This paper describespreliminary analysis on CHP investment climate in the U.S. and Japan. DERtechnologies, energy prices, and incentive measures has beeninvestigated.

Zhou, Nan; Nishida, Masaru; Gao, Weijun; Marnay, Chris

2005-12-31T23:59:59.000Z

238

Coupled hydrodynamic-structural analysis of an integral flowing sodium test loop in the TREAT reactor  

SciTech Connect

A hydrodynamic-structural response analysis of the Mark-IICB loop was performed for the TREAT (Transient Reactor Test Facility) test AX-1. Test AX-1 is intended to provide information concerning the potential for a vapor explosion in an advanced-fueled LMFBR. The test will be conducted in TREAT with unirradiated uranium-carbide fuel pins in the Mark-IICB integral flowing sodium loop. Our analysis addressed the ability of the experimental hardware to maintain its containment integrity during the reference accident postulated for the test. Based on a thermal-hydraulics analysis and assumptions for fuel-coolant interaction in the test section, a pressure pulse of 144 MPa maximum pressure and pulse width of 1.32 ms has been calculated as the reference accident. The response of the test loop to the pressure transient was obtained with the ICEPEL and STRAW codes. Modelling of the test section was completed with STRAW and the remainder of the loop was modelled by ICEPEL.

Zeuch, W.R.; A-Moneim, M.T.

1979-01-01T23:59:59.000Z

239

Uncertainty analysis of an IGCC system with single-stage entrained-flow gasifier  

Science Conference Proceedings (OSTI)

Integrated Gasification Combined Cycle (IGCC) systems using coal gasification is an attractive option for future energy plants. Consequenty, understanding the system operation and optimizing gasifier performance in the presence of uncertain operating conditions is essential to extract the maximum benefits from the system. This work focuses on conducting such a study using an IGCC process simulation and a high-fidelity gasifier simulation coupled with stochastic simulation and multi-objective optimization capabilities. Coal gasifiers are the necessary basis of IGCC systems, and hence effective modeling and uncertainty analysis of the gasification process constitutes an important element of overall IGCC process design and operation. In this work, an Aspen Plus{reg_sign} steady-state process model of an IGCC system with carbon capture enables us to conduct simulation studies so that the effect of gasification variability on the whole process can be understood. The IGCC plant design consists of an single-stage entrained-flow gasifier, a physical solvent-based acid gas removal process for carbon capture, two model-7FB combustion turbine generators, two heat recovery steam generators, and one steam turbine generator in a multi-shaft 2x2x1 configuration. In the Aspen Plus process simulation, the gasifier is represented as a simplified lumped-parameter, restricted-equilibrium reactor model. In this work, we also make use of a distributed-parameter FLUENT{reg_sign} computational fluid dynamics (CFD) model to characterize the uncertainty for the entrained-flow gasifier. The CFD-based gasifer model is much more comprehensive, predictive, and hence better suited to understand the effects of uncertainty. The possible uncertain parameters of the gasifier model are identified. This includes input coal composition as well as mass flow rates of coal, slurry water, and oxidant. Using a selected number of random (Monte Carlo) samples for the different parameters, the CFD model is simulated to observe the variations in the output variables (such as syngas composition, gas and ash flow rates etc.). The same samples are then used to conduct simulations using the Aspen Plus IGCC model. The simulation results for the high-fidelity CFD-based gasifier model and the Aspen Plus equilibrium reactor model for selected uncertain parameters are then used to perform the estimation. Defining the ratio of CFD based results to the Aspen Plus result as the uncertainty factor (UF), the work quantifies the extent of uncertainty and then uses uniform* distribution to characterize the uncertainty factor distribution. The characterization and quantification of uncertainty is then used to conduct stochastic simulation of the IGCC system in Aspen Plus. The CAPE-OPEN compliant stochastic simulation capability allows one to conduct a rigorous analysis and generate the feasible space for the operation of the IGCC system. The stochastic simulation results can later be used to conduct multi-objective optimization of the gasifier using a set of identified decision variables. The CAPE-OPEN compliant multi-objective capability in Aspen Plus can be used to conduct the analysis. Since the analysis is based on the uncertainty modeling studies of the gasifier, the optimization accounts for possible uncertainties in the operation of the system. The results for the optimized IGCC system and the gasifier, obtained from the stochastic simulation results, are expected to be more rigorous and hence closer to those obtained from CFD-based rigorous modeling.

Shastri, Y.; Diwekar, U.; Zitney, S.

2008-01-01T23:59:59.000Z

240

Multifractal detrended fluctuation analysis of combustion flames in four-burner impinging entrained-flow gasifier  

E-Print Network (OSTI)

On a laboratory-scale testing platform of impinging entrained-flow gasifier with four opposed burners, the flame images for diesel combustion and gasification process were measured with a single charge coupled device (CCD) camera. The two-dimensional multifractal detrended fluctuation analysis was employed to investigate the multifractal nature of the flame images. Sound power-law scaling in the annealed average of detrended fluctuations was unveiled when the order $q>0$ and the multifractal feature of flame images were confirmed. Further analyses identified two multifractal parameters, the minimum and maximum singularity $\\alpha_{\\min}$ and $\\alpha_{\\max}$, serving as characteristic parameters of the multifractal flames. These two characteristic multifractal parameters vary with respect to different experimental conditions.

Niu, Miao-Ren; Yan, Zhuo-Yong; Guo, Qing-Hua; Liang, Qin-Feng; Wang, Fu-Chen; Yu, Zun-Hong

2007-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Flow cytometric analysis of respiratory tract cells exposed to oil shale and silica particulates. [Hamsters  

SciTech Connect

Flow cytometric techniques were used to measure the cytological and biochemical damage to respiratory tract cells in animals exposed to particulates. Hamsters were exposed to raw and spent oil shale particulates and silica by intratracheal instillation. Exfoliated lung cells were obtained by sacrificing the animals and lavaging the respiratory tract posterior to the trachea with saline. Cell samples were fixed in ethanol and stained with mithramycin for fluorescence analysis of DNA content. DNA content distributions from hamsters exposed to spent oil shale and silica particulates showed atypical changes 28 to 35 days later. Cell counts and total numbers of macrophages, leukocytes, and epithelial cells in the lavage fluid also showed marked changes related to time after exposure.

Steinkamp, J.A.; Wilson, J.S.

1979-01-01T23:59:59.000Z

242

An Analysis of the Kinetic Energy Budget for Two Extratropical Cyclones: The Vertically Averaged Flow and the Vertical Shear Flow  

Science Conference Proceedings (OSTI)

An analysis of the kinetic energy budget is made for two intensely developing cyclones over North America. The principal kinetic energy source for the first cyclone is the net horizontal transport of kinetic energy across the boundaries of the ...

Jordan C. Alpert

1981-06-01T23:59:59.000Z

243

Rock Joint Surfaces Measurement and Analysis of Aperture Distribution under Different Normal and Shear Loading Using GIS  

E-Print Network (OSTI)

Geometry of the rock joint is a governing factor for joint mechanical and hydraulic behavior. A new method of evaluating aperture distribution based on measurement of joint surfaces and three dimensional characteristics of each surface is developed. Artificial joint of granite surfaces are measured,processed, analyzed and three dimensional approaches are carried out for surface characterization. Parameters such as asperity's heights, slope angles, and aspects distribution at micro scale,local concentration of elements and their spatial localization at local scale are determined by Geographic Information System (GIS). Changes of aperture distribution at different normal stresses and various shear displacements are visualized and interpreted. Increasing normal load causes negative changes in aperture frequency distribution which indicates high joint matching. However, increasing shear displacement causes a rapid increase in the aperture and positive changes in the aperture frequency distribution which could be ...

Sharifzadeh, Mostafa; Esaki, Tetsuro

2009-01-01T23:59:59.000Z

244

Analysis of Mass Flow and Enhanced Mass Flow Methods of Flashing Refrigerant-22 from a Small Vessel  

E-Print Network (OSTI)

The mass flow characteristics of flashing Refrigerant-22 from a small vessel were investigated. A flash boiling apparatus was designed and built. It was modeled after the flashing process encountered by the accumulator of air-source heat pump systems. Three small pyrex glass vessels were used to hold the refrigerant and allow for visualization studies of the flashing process. Baseline experiments were run varying initial pressure, initial refrigerant amount, orifice diameter, and vessel geometry. Three sets of experiments were run using two passive enhancement methods (the addition of steel balls and the addition of small amounts of oil) and one active enhancement method (the addition of an immersion heater). Furthermore, a lumped-parameter analytical model was developed from basic thermodynamic principles that predicted the rate of depressurization for the flashing refrigerant. The study showed that the initial refrigerant amount and the orifice size had the greatest influence on the mass flow and pressure characteristics during each sixty second test. The initial pressure and vessel volume had less of an impact under the conditions tested. Two of the enhancement methods consistently increased the amount of refrigerant flashed during the tests as compared to the baseline data for the same initial conditions. The addition a 1 cm layer of 3.6 mm steel balls to the base of the vessel increased the amount flashed from 21% to 81% and the addition of the 215-watt flat-spiral immersion heater the increased the amount flashed from 47% to 111 %. Foaming at the vapor-liquid interface was observed with the refrigerant-oil mixture experiments as two of the eight test conditions averaged an increase while six averaged a decrease, ranging from a 21% increase to a 27% decrease. The analytical depressurization model predicted general pressure and mass flux trends, and revisions to the model improved pressure predictions to within ±11%.

Nutter, Darin Wayne

1994-12-01T23:59:59.000Z

245

Analysis of Gravity Waves Generated at the Top of a Drainage Flow  

Science Conference Proceedings (OSTI)

Drainage or katabatic flows are common mesoscale circulations established as a result of differential radiative cooling of near-surface air masses in sloping terrain. The initial irruption of these flows, with sudden shifts in wind speed and ...

Samuel Viana; Enric Terradellas; Carlos Yagüe

2010-12-01T23:59:59.000Z

246

An Integrated Modeling Analysis of Unsaturated Flow Patterns in Fractured Rock  

E-Print Network (OSTI)

study, heat flow simulations use a 3-D thermal model grid (model grid, which is used for gas flow and ambient heat-flowgrid showing a smaller model domain, used for modeling gas and heat

Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua; Bodvarsson, Gudmundur S.

2008-01-01T23:59:59.000Z

247

Capacity fade analysis of a battery/super capacitor hybrid and a battery under pulse loads full cell studies  

E-Print Network (OSTI)

words: capacity fade, interfacial impedance, lithium ion battery/supercapacitor hybrid, pulse discharge amplitude, rate capability Abstract A detailed analysis of the capacity fade of a battery/supercapacitor

Popov, Branko N.

248

Asymptotic and numerical analysis of an inviscid bounded vortex flow at low Mach number  

Science Conference Proceedings (OSTI)

The inviscid low Mach number compressible flow developing from a plane incompressible vortex with constant density in a bounded domain is studied. A reference solution for this model flow is obtained by two-time scale asymptotic development in the zero ... Keywords: Asymptotic development, Compressible low Mach number flow, Explicit Roe scheme, Implicit scheme, WENO and high-order-compact schemes

Anne Cadiou; Lionel Le Penven; Marc Buffat

2008-09-01T23:59:59.000Z

249

Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects  

SciTech Connect

Preliminary Analysis of Grande Ronde Basalt Formation Flow Top Transmissivity as it Relates to Assessment and Site Selection Applications for Fluid/Energy Storage and Sequestration Projects

Spane, Frank A.

2013-04-29T23:59:59.000Z

250

CFD Analysis of Core Bypass Flow and Crossflow in the Prismatic Very High Temperature Gas-cooled Nuclear Reactor  

E-Print Network (OSTI)

Very High Temperature Rector (VHTR) had been designated as one of those promising reactors for the Next Generation (IV) Nuclear Plant (NGNP). For a prismatic core VHTR, one of the most crucial design considerations is the bypass flow and crossflow effect. The bypass flow occurs when the coolant flow into gaps between fuel blocks. These gaps are formed as a result of carbon expansion and shrinkage induced by radiations and manufacturing and installation errors. Hot spots may appear in the core if the large portion of the coolant flows into bypass gaps instead of coolant channels in which the cooling efficiency is much higher. A preliminary three dimensional steady-state CFD analysis was performed with commercial code STARCCM+ 6.04 to investigate the bypass flow and crossflow phenomenon in the prismatic VHTR core. The k-? turbulence model was selected because of its robustness and low computational cost with respect to a decent accuracy for varied flow patterns. The wall treatment used in the present work is two-layer all y+ wall treatment to blend the wall laws to estimate the shear stress. Uniform mass flow rate was chose as the inlet condition and the outlet condition was zero gauge pressure outlet. Grid independence study was performed and the results indicated that the discrepancy of the solution due to the mesh density was within 2% of the bypass flow fraction. The computational results showed that the bypass flow fraction was around 12%. Furthermore, the presence of the crossflow gap resulted in a up to 28% reduction of the coolant in the bypass flow gap while mass flow rate of coolant in coolant channels increased by around 5%. The pressure drop at the inlet due to the sudden contraction in area could be around 1kpa while the value was about 180 Pa around the crossflow gap region. The error analysis was also performed to evaluate the accumulated errors from the process of discretization and iteration. It was found that the total error was around 4% and the variation for the bypass flow fraction was within 1%.

Wang, Huhu 1985-

2012-12-01T23:59:59.000Z

251

CFD Analysis for Flow Behavior Characteristics in the Upper Plenum during low flow/low pressure transients for the Gas Cooled Fast Reactor (GCFR)  

Science Conference Proceedings (OSTI)

Gas coolant at low pressure exhibits poor heat transfer characteristics. This is an area of concern for the passive response targeted by the Generation IV GCFR design. For the first 24 hour period, the decay heat removal for the GCFR design is dependent on an actively powered blower, which also would reduce the temperature in the fuel during transients, before depending on the passive operation. Natural circulation cooling initiates when the blower is stopped for the final phase of the decay heat removal, as under forced convection the core decay heat is adequately cooled by the running blower. The ability of the coolant to flow in the reverse direction or having recirculation, when the blowers are off, necessitates more understanding of the flow behavior characteristics in the upper plenum. The work done here focuses primarily on the period after the blower has been turned off, as the core is adequately cooled when the blowers are running, thus there was no need to carry out the analysis for the first 24 hours. In order to understand the plume behavior for the GCFR upper plenum several cases were run, with air, helium and helium-air mixture. For each case, the FLUENT was used to characterize the steady state velocity vectors and corresponding temperature in the upper plenum under passive decay heat removal conditions. This study will provide better insight into the plume interaction in the upper plenum at low flow and low pressure conditions.

Piyush Sabharwall; Theron Marshall; Kevan Weaver; Hans Gougar

2007-05-01T23:59:59.000Z

252

Enhancement of Watershed Analysis Risk Management Framework (WARMF) for Mercury Watershed Management and Total Maximum Daily Loads (TMDLs)  

Science Conference Proceedings (OSTI)

This report documents the enhancement of EPRI's Watershed Analysis Risk Management Framework (WARMF) to enable it to simulate the biogeochemical cycling and fish accumulation of mercury in the environment. This report should be of value to the power sector, industry, environmental organizations, government, and public agencies concerned about environmental mercury.

2006-03-13T23:59:59.000Z

253

Acceleration of Plasma Flows in the Solar Atmosphere Due to Magnetofluid Coupling - Simulation and Analysis  

E-Print Network (OSTI)

Within the framework of a two-fluid description possible pathways for the generation of fast flows (dynamical as well as steady) in the lower solar atmosphere is established. It is shown that a primary plasma flow (locally sub-Alfv\\'enic) is accelerated when interacting with emerging/ambient arcade--like closed field structures. The acceleration implies a conversion of thermal and field energies to kinetic energy of the flow. The time-scale for creating reasonably fast flows ($\\gtrsim 100$ km/s) is dictated by the initial ion skin depth while the amplification of the flow depends on local $\\beta $. It is shown, for the first time, that distances over which the flows become "fast" are $\\sim 0.01 R_s$ from the interaction surface; later the fast flow localizes (with dimensions $\\lesssim 0.05 R_S$) in the upper central region of the original arcade. For fixed initial temperature the final speed ($\\gtrsim 500 km/s$) of the accelerated flow, and the modification of the field structure are independent of the time-duration (life-time) of the initial flow. In the presence of dissipation, these flows are likely to play a fundamental role in the heating of the finely structured Solar atmosphere.

Swadesh M. Mahajan; Nana L. Shatashvili; Solomon V. Mikeladze; Ketevan I. Sigua

2005-02-17T23:59:59.000Z

254

A Database and Meta-Analysis of Ecological Responses to Flow in the South Atlantic Region  

Science Conference Proceedings (OSTI)

Generalized and quantitative relationships between flow and ecology are pivotal to developing environmental flow standards based on socially acceptable ecological conditions. Informing management at regional scales requires compiling sufficient hydrologic and ecological sources of information, identifying information gaps, and creating a framework for hypothesis development and testing. We compiled studies of empirical and theoretical relationships between flow and ecology in the South Atlantic region (SAR) of the United States to evaluate their utility for the development of environmental flow standards. Using database searches, internet searches, and agency contacts, we gathered 186 sources of information that provided a qualitative or quantitative relationship between flow and ecology within states encompassing the SAR. A total of 109 of the 186 sources had sufficient information to support quantitative analyses. Ecological responses to natural changes in flow magnitude, frequency, and duration were highly variable regardless of the direction and magnitude of changes in flow. In contrast, the majority of ecological responses to anthropogenic-induced flow alterations were negative. Fish consistently showed negative responses to anthropogenic flow alterations whereas other ecological groups showed somewhat variable responses (e.g. macroinvertebrates and riparian vegetation) and even positive responses (e.g. algae). Fish and organic matter had sufficient sample sizes to stratify natural flow-ecology relationships by specific flow categories (e.g. high flow, baseflows) or by region (e.g. coastal plain, uplands). After stratifying relationships, we found that significant correlations existed between changes in natural flow and ecological responses. In addition, a regression tree explained 57% of the variation in fish responses to anthropogenic and natural changes in flow. Because of some ambiguity in interpreting the directionality in ecological responses, we utilized ecological gains or losses, where each represents a benefit or reduction to ecosystem services, respectively. Variables explained 49% of the variation in ecological gains and losses for all ecological groups combined. Altogether, our results suggested that the source of flow change and the ecological group of interest played primary roles in determining the direction and magnitude of ecological responses. Furthermore, our results suggest that developing broadly generalized relationships between ecology and changes in flow at a regional scale is unlikely unless relationships are placed within meaningful contexts, such as environmental flow components or by geomorphic setting.

McManamay, Ryan A [ORNL; Orth, Dr. Donald J [Virginia Polytechnic Institute and State University (Virginia Tech); Davis, Dr, Mary [Southeastern Aquatic Resources Partnership; Kauffman, John [John Kauffman LLC.

2013-01-01T23:59:59.000Z

255

Rock matrix and fracture analysis of flow in western tight gas sands  

SciTech Connect

Advanced core analysis includes measurements on the matrix properties of the rock. Matrix properties are important even in fractured wells since it is these properties which determine the rate of gas flow into the fractures. Cores are being tested from the fluvial, coastal, and paludal zones of the Mesaverde. At least two cores from each of these zones from all three wells will be analyzed. Properties measured include permeability as a function of confining pressure over the range of 500 to 5000 psi. A minimum of two Klinkenberg permeabilities are being determined from at least five data points. Interpretation includes estimates of pore size from gas slippage. Water adsorption and desorption isotherms will be determined for selected samples with data points being obtained at the following relative humidities: 0, 20, 40, 60, 75, 90, 92, 95 and 98. Porosity measurements from both thin section examination and volumetric measurements are being made. These results will be compared with the porosities of the cored internals determined from logs.

Morrow, N.R.; Brower, K.R.; Ward, J.S.

1985-01-01T23:59:59.000Z

256

1992 Columbia River Salmon Flow Measures Options Analysis/EIS : Appendices.  

DOE Green Energy (OSTI)

This Options Analysis/Environmental Impact Statement (OA/EIS) identifies, presents effects of, and evaluates the potential options for changing instream flow levels in efforts to increase salmon populations in the lower Columbia and Snake rivers. The potential actions would be implemented during 1992 to benefit juvenile and adult salmon during migration through eight run-of-river reservoirs. The Corps of Engineers (Corps) prepared this document in cooperation with the Bonneville Power Administration and the Bureau of Reclamation. The US Fish and Wildlife Service (FWS) is a participating agency. The text and appendices of the document describe the characteristics of 10 Federal projects and one private water development project in the Columbia River drainage basin. Present and potential operation of these projects and their effects on the salmon that spawn and rear in the Columbia and Snake River System are presented. The life history, status, and response of Pacific salmon to current environmental conditions are described. The document concludes with an evaluation of the potential effects that could result from implementing proposed actions. The conclusions are based on evaluation of existing data, utilization of numerical models, and application of logical inference. This volume contains the appendices.

Not Available

1992-01-01T23:59:59.000Z

257

Use of vertical slip flow and flooding models in LOCA analysis  

SciTech Connect

Vertical slip flow and flooding models, which have been incorporated in a version of the RELAP4 computer code by Aerojet Nuclear Company have led to significant improvements in modeling nuclear reactor coolant system phenomena during postulated large and small break loss-of-coolant accidents. The vertical slip flow model computes the separated fluid component velocities and directions at vertical flow junctions. Use of the slip model allows the energy transfer between volumes to be based on individual liquid and vapor component flows rather than on the net junction flow. Continuity and momentum equations are unaffected by the addition of slip. The vertical flow slip model logic is based on the assumption that gravity forces dominate causing slip between phases. 7 references (auth)

Fischer, S.R.

1975-01-01T23:59:59.000Z

258

Acceleration of plasma flows in the closed magnetic fields: Simulation and analysis  

Science Conference Proceedings (OSTI)

Within the framework of a two-fluid description, possible pathways for the generation of fast flows (dynamical as well as steady) in the closed magnetic fields are established. It is shown that a primary plasma flow (locally sub-Alfvenic) is accelerated while interacting with ambient arcade-like closed field structures. The time scale for creating reasonably fast flows (> or approx. 100 km/s) is dictated by the initial ion skin depth, while the amplification of the flow depends on local plasma {beta}. It is shown that distances over which the flows become 'fast' are {approx}0.01R{sub 0} from the interaction surface (R{sub 0} being a characteristic length of the system); later, the fast flow localizes (with dimensions or approx. 500 km/s) of the accelerated flow and the modification of the field structure are independent of the time duration (lifetime) of the initial flow. In the presence of dissipation, these flows are likely to play a fundamental role in the heating of the finely structured stellar atmospheres; their relevance to the solar wind is also obvious.

Mahajan, Swadesh M.; Shatashvili, Nana L.; Mikeladze, Solomon V.; Sigua, Ketevan I. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States); Plasma Physics Department, Tbilisi State University, Tbilisi 0128 and Georgia Abdus Salam International Centre for Theoretical Physics, 34014 Trieste (Italy); Andronikashvili Institute of Physics, Georgian Academy of Sciences, Tbilisi 0177 (Georgia)

2006-06-15T23:59:59.000Z

259

Experimental Analysis of the Flow, Pressure, Speed, and Torque Characteristics of Two Eaton Geroler Hydraulic Motors.  

E-Print Network (OSTI)

??This paper presents data collected examining the flow, pressure, speed, and torque characteristics of two Eaton Geroler hydraulic motors. A test installation was designed and… (more)

Cazaban, Philip M.

2011-01-01T23:59:59.000Z

260

Purged window apparatus. [On-line spectroscopic analysis of gas flow systems  

DOE Patents (OSTI)

A purged window apparatus is described which utilizes tangentially injected heated purge gases in the vicinity of electromagnetic radiation transmitting windows and a tapered external mounting tube to accelerate these gases to provide a vortex flow on the window surface and a turbulent flow throughout the mounting tube thereby preventing backstreaming of flowing gases under investigation in a chamber to which a plurality of similar purged apparatus is attached with the consequent result that spectroscopic analyses can be undertaken for lengthy periods without the necessity of interrupting the flow for cleaning or replacing the windows due to contamination.

Ballard, E.O.

1982-04-05T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

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

262

An Auto-Adaptive Multidomain Spectral Technique for Linear Stability Analysis: Application to Viscous Compressible Flows  

Science Conference Proceedings (OSTI)

An auto-adaptive multidomain pseudo-spectral technique is considered in order to solve the linear stability problem of viscous compressible flows. Both the locations of the interfaces and the parameters of the mappings in each subdomain are adapted by ... Keywords: Rayleigh–Taylor instability, compressible viscous flows, spectral multidomain method

Eric Serre; Serge Gauthier

2002-12-01T23:59:59.000Z

263

Acceleration of Plasma Flows in the Solar Atmosphere Due to Magnetofluid Coupling - Simulation and Analysis  

E-Print Network (OSTI)

Within the framework of a two-fluid description possible pathways for the generation of fast flows (dynamical as well as steady) in the lower solar atmosphere is established. It is shown that a primary plasma flow (locally sub-Alfv\\'enic) is accelerated when interacting with emerging/ambient arcade--like closed field structures. The acceleration implies a conversion of thermal and field energies to kinetic energy of the flow. The time-scale for creating reasonably fast flows ($\\gtrsim 100$ km/s) is dictated by the initial ion skin depth while the amplification of the flow depends on local $\\beta $. It is shown, for the first time, that distances over which the flows become "fast" are $\\sim 0.01 R_s$ from the interaction surface; later the fast flow localizes (with dimensions $\\lesssim 0.05 R_S$) in the upper central region of the original arcade. For fixed initial temperature the final speed ($\\gtrsim 500 km/s$) of the accelerated flow, and the modification of the field structure are independent of the time-d...

Mahajan, S M; Mikeladze, S V; Sigua, K I; Mahajan, Swadesh M.; Shatashvili, Nana L.; Mikeladze, Solomon V.; Sigua, Ketevan I.

2005-01-01T23:59:59.000Z

264

Global Stability Analysis of Fluid Flows using Sum-of-Squares  

E-Print Network (OSTI)

flow is globally stable, if the flow does remain globally stable for Reynolds numbers at least ... ?v1,v2 · ?v3? = ??v3,v2 · ?v1?,. (2) ... Note that the nonlinear term u·?u in (4a) does not feature in the energy equation ...... Transactions on Automatic Control, 54(5):1007–1011, May 2009. ... Handbook of semidefinite program-.

265

Properly Evaluating load-following products  

SciTech Connect

The authors briefly survey the jurisdictions where load-following products have been successfully used, examine the characteristics of the load-following products, and explain the shortcomings and inaccurate conclusions of previous analyses. A more thorough analysis reveals that the load-following products fulfill the public policy objectives for which they have been designed and do not adversely impact wholesale electricity markets.

Cavicchi, Joseph; Lemon, Andrew

2009-01-15T23:59:59.000Z

266

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

267

Estimating Demand Response Load Impacts: Evaluation of Baseline Load Models for Non-  

E-Print Network (OSTI)

, and the Office of Electricity Delivery and Energy Reliability, Permitting, Siting and Analysis of the ULBNL-63728 Estimating Demand Response Load Impacts: Evaluation of Baseline Load Models for Non .............................................................................................................. 9 4. Baseline Profile (BLP) Models

268

Drift-flux analysis of two-phase flow in microgravity  

E-Print Network (OSTI)

As NASA programs such as the International Space Station, the Space Shuttle, the Space Nuclear Power Initiative, and other future spacecraft become more demanding, two-phase (gas-liquid) systems for advanced life support and thermal management are highly advantageous over single-phase systems. Two-phase fluid loops provide significant thermal transport advantages over their single-phase counterparts and are able to carry more energy per unit mass than single-phase systems. They are also able to transport more energy per unit pumping power than single-phase systems. These two advantages alone offer great reductions in both mass and volume, which are two primary design parameters for space-based systems. Unfortunately, the ability to predict two-phase phenomena such as flow regime transitions and void fraction at microgravity conditions is greatly limited and its development is still in its infancy. A Texas A&M University two-phase flow loop was tested aboard NASA's KC-135 aircraft to collect two-phase microgravity data for dichlorodifluoromethane (R-12). A wide variety of flow rates were tested and many different flow regimes were observed. Data produced by the two-phase microgravity experiment were analyzed in accordance with the drift-flux model to calculate the distribution parameter, C?, and the drift-velocity, V[gj], of the two-phase mixture. The C?and V[gj] found for each flow regime were compared with other microgravity and a one-g upflow data. The C? for the slug flow regime was greater than that of the transition and annular flow regimes respectively for the microgravity data and correlated well with other R-12 microgravity data for the slug flow regime. The V[gj] for slug flow was found to be negative, which was unexpected, but the drift velocities for the transition and annular flow regimes provided expected results. The V[gj] for the annular flow regime in microgravity was less than that of the one-g upflow system due to the lower superficial velocities required in microgravity. Similarly, the C? for the R-12 microgravity data was higher than for a one-g upflow system due to its lower void fraction. A common C? and V[gj] can be used to predict void fraction for the transition and annular flow regimes for R-12 for the same pipe diameter and operating conditions.

Braisted, Jonathan David

2004-01-01T23:59:59.000Z

269

LES Analysis of the Aerodynamic Surface Properties for Turbulent Flows over Building Arrays with Various Geometries  

Science Conference Proceedings (OSTI)

This paper describes aerodynamic roughness properties for turbulent flows over various building arrays that represent realistic urban surface geometries. First, building morphological characteristics such as roughness density ?f and building ...

Hiromasa Nakayama; Tetsuya Takemi; Haruyasu Nagai

2011-08-01T23:59:59.000Z

270

Instability of Non-Zonal Baroclinic Flows: Multiple-Scale Analysis  

Science Conference Proceedings (OSTI)

The linear instability of a non-zonal flow can be reduced to an eigenvalue-eigenfunction problem, governed by a nonseparable partial differential equation (Niehaus, 1980). Approximate solutions, found by the method of multiple scales, are derived ...

Margaret C. W. Niehaus

1981-05-01T23:59:59.000Z

271

Propagation of a Tropical Cyclone in a Meridionally Varying Zonal Flow: An Energetics Analysis  

Science Conference Proceedings (OSTI)

Tropical cyclone propagation (the beta drift) is driven by a secondary circulation associated with axially asymmetric gyres (beta gyres) in the vicinity of the cyclone center. In the presence of the beta effect, the environmental flow may ...

Bin Wang; Xiaofan Li

1995-05-01T23:59:59.000Z

272

Rheo-PIV Analysis of the Yielding and Flow of Model Waxy Crude Oils  

E-Print Network (OSTI)

Waxes are a commonly encountered precipitate that can result in the gelation of crude oils and cessation of flow in pipelines. In this work, we develop a model wax–oil system that exhibits rheological behavior similar to ...

Dimitriou, Christopher J.

273

Synoptic Analysis of the GUFMEX Return-Flow Event of 10–12 March 1988  

Science Conference Proceedings (OSTI)

Return flow is the moist southerly wind that develops over the Gulf of Mexico after an outbreak of polar air. Surface, aircraft, and special rawinsonde data collected during the Gulf of Mexico Experiment (GUFMEX) are used to describe the return-...

Robert T. Merrill

1992-08-01T23:59:59.000Z

274

Multifractal Analysis of Line-Source Plume Concentration Fluctuations in Surface-Layer Flows  

Science Conference Proceedings (OSTI)

A codimension multifractal methodology was used to analyze and to model scalar concentration fluctuations within sulfur hexafluoride tracer gas plumes from a line source in atmospheric surface-layer flows. Correspondence was exhibited between the ...

D. Finn; B. Lamb; M. Y. Leclerc; S. Lovejoy; S. Pecknold; D. Schertzer

2001-02-01T23:59:59.000Z

275

Modeling, Analysis and Simulation of Multiscale Preferential Flow - 8/05-8/10 - Final Report  

SciTech Connect

The research agenda of this project are: (1) Modeling of preferential transport from mesoscale to macroscale; (2) Modeling of fast flow in narrow fractures in porous media; (3) Pseudo-parabolic Models of Dynamic Capillary Pressure; (4) Adaptive computational upscaling of flow with inertia from porescale to mesoscale; (5) Adaptive modeling of nonlinear coupled systems; and (6) Adaptive modeling and a-posteriori estimators for coupled systems with heterogeneous data.

Ralph Showalter; Malgorzata Peszynska

2012-07-03T23:59:59.000Z

276

Mathematical modelling, analysis and computation of some complex and nonlinear flow problems.  

E-Print Network (OSTI)

???This thesis consists of two parts: (I) modelling, analysis and computation of sweat transport in textile media; (II) unconditional convergence and optimal error analysis of… (more)

Li, Buyang (???)

2012-01-01T23:59:59.000Z

277

Assessment of Distributed Energy Adoption in Commercial Buildings: Part 1: An Analysis of Policy, Building Loads, Tariff Design, and Technology Development  

E-Print Network (OSTI)

DER technologies, Japanese energy tariffs, and prototypicalon DER project costs, energy tariff reductions, or utilitypower, building energy efficiency, tariff, building loads,

Zhou, Nan; Nishida, Masaru; Gao, Weijun; Marnay, Chris

2005-01-01T23:59:59.000Z

278

Analysis Of Residence Time Distribution Of Fluid Flow By Axial Dispersion Model  

Science Conference Proceedings (OSTI)

Radioactive tracer {sup 82}Br in the form of KBr-82 with activity {+-} 1 mCi has been injected into steel pipeline to qualify the extent dispersion of water flowing inside it. Internal diameter of the pipe is 3 in. The water source was originated from water tank through which the water flow gravitically into the pipeline. Two collimated sodium iodide detectors were used in this experiment each of which was placed on the top of the pipeline at the distance of 8 and 11 m from injection point respectively. Residence time distribution (RTD) curves obtained from injection of tracer are elaborated numerically to find information of the fluid flow properties. The transit time of tracer calculated from the mean residence time (MRT) of each RTD curves is 14.9 s, therefore the flow velocity of the water is 0.2 m/s. The dispersion number, D/uL, for each RTD curve estimated by using axial dispersion model are 0.055 and 0.06 respectively. These calculations are performed after fitting the simulated axial dispersion model on the experiment curves. These results indicated that the extent of dispersion of water flowing in the pipeline is in the category of intermediate.

Sugiharto [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia); Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Su'ud, Zaki; Kurniadi, Rizal; Waris, Abdul [Centre for Applications of Isotopes and Radiation Technology-National Nuclear Energy Agency, Jl. Lebak Bulus Raya No. 49, Jakarta 12440 (Indonesia); Abidin, Zainal [Department of Physics, Faculty of Mathematics and Natural Sciences, Bandung Institute of Technology, Jl. Ganesha 10, Bandung 40132 (Indonesia)

2010-12-23T23:59:59.000Z

279

An Integrated Modeling Analysis of Unsaturated Flow Patterns inFractured Rock  

Science Conference Proceedings (OSTI)

Characterizing percolation patterns in unsaturated zones hasposed a greater challenge to numerical modeling investigations thancomparable saturated zone studies, because of the heterogeneous nature ofunsaturated media as well as the great number of variables impactingunsaturated zone flow. This paper presents an integrated modelingmethodology for quantitatively characterizing percolation patterns in theunsaturated zone of Yucca Mountain, Nevada, a proposed undergroundrepository site for storing high-level radioactive waste. It takes intoaccount the multiple coupled processes of air, water, heat flow andchemical isotopic transport in Yucca Mountain s highly heterogeneous,unsaturated fractured tuffs. The modeling approach integrates a widevariety of moisture, pneumatic, thermal, and isotopic geochemical fielddata into a comprehensive three-dimensional numerical model for modelinganalyses. Modeling results are examined against different types offield-measured data and then used to evaluate different hydrogeologicalconceptual models and their results of flow patterns in the unsaturatedzone. In particular, this integration model provides a much clearerunderstanding of percolation patterns and flow behavior through theunsaturated zone, both crucial issues in assessing repositoryperformance. The integrated approach for quantifying Yucca Mountain sflow system is also demonstrated to provide a comprehensive modeling toolfor characterizing flow and transport processes in complex subsurfacesystems.

Wu, Yu-Shu; Lu, Guoping; Zhang, Keni; Pan, Lehua; Bodvarsson,Gudmundur S.

2005-03-21T23:59:59.000Z

280

1994 Pacific Northwest Loads and Resources Study.  

Science Conference Proceedings (OSTI)

The 1994 Pacific Northwest Loads and Resources Study presented herein establishes a picture of how the agency is positioned today in its loads and resources balance. It is a snapshot of expected resource operation, contractual obligations, and rights. This study does not attempt to present or analyze future conservation or generation resource scenarios. What it does provide are base case assumptions from which scenarios encompassing a wide range of uncertainties about BPA`s future may be evaluated. The Loads and Resources Study is presented in two documents: (1) this summary of Federal system and Pacific Northwest region loads and resources and (2) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. This analysis updates the 1993 Pacific Northwest Loads and Resources Study, published in December 1993. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The Federal system and regional analyses for medium load forecast are presented.

United States. Bonneville Power Administration.

1994-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Development and performance analysis of a standard orifice flow calibration system  

Science Conference Proceedings (OSTI)

An orifice flow system has been developed indigenously which is a primary standard for the calibration of high vacuum gauges in the range of 10{sup -3}-10{sup -6} mbar. It consists of a constant-volume flow meter, designed to generate a known flow rate of a particular gas to the vacuum chamber. This chamber is partitioned into two parts by a plate with an orifice of calculable conductance. The pressures, generated by this standard system, are compared with those of secondary standard, namely, spinning rotor gauge. Different uncertainties and correction factors are calculated. The maximum percentage deviation is from 1.16% to 0.97%. The combined uncertainties over the entire calibration range of the standard system are in the range of 4.0x10{sup -6} mbar.

Akram, H. M.; Maqsood, M.; Rashid, H. [NINVAST, National Centre for Physics Complex, Shahdara Valley Road, P.O. Box 3125, Islamabad (Pakistan)

2009-07-15T23:59:59.000Z

282

The application of AM/FM system to distribution contingency load transfer  

SciTech Connect

In this paper, one of the geographic information management system (GIS) is applied to perform the automated mapping and facility management (AM/FM) of power distribution systems for contingency load transfer. Three phase load flow analysis is used to calculate the current flows of line switches by retrieving the network topology and facility attributes which have been stored in the AM/FM database. The current flows solved are then stored in the database as the attributes of line switches for load transfer analysis. When a system contingency such as fault or overload occurs, the load transfer is then executed to find the switches to be operated by the heuristic search method while subjected to the system operation rules. By the proposed method, the network topology can be easily updated and displayed in the computers by connectivity trace routine according to the switching operations. Since all the system facilities are stored in the AM/FM database according to the actual spatial coordinates, it provides practical information for the system operators and crews to allocate and operate the switches easily. To demonstrate the effectiveness of the integrated AM/FM system with application programs for distribution operation, a distribution system of Taiwan Power Company (Taipower) in Kaohsiung downtown area is selected for case study. It is found that contingency load transfer for distribution system operation can be enhanced significantly with the application of AM/FM systems significantly with the application of AM/FM systems to determine the switches to be operated and the corresponding spatial locations of the switches. The impact of load transfer to the system voltage profile and the feeder loading can also be analyzed to provide valuable information for the system operators.

Lee, T.E.; Chen, C.S.; Tzeng, Y.M.; Kang, M.S.; Lee, C.C. [National Sun Yat-Sen Univ., Kaohsiung (Taiwan, Province of China). Dept. of Electrical Engineering; Wu, J.S. [National Kaohsiung Institute of Technology (Taiwan, Province of China); Liu, T.S.S.; Chen, Y.M. [Taiwan Power Co., Taipei (Taiwan, Province of China)

1995-04-01T23:59:59.000Z

283

Flow reference method testing and analysis: Field test plan, Texas Utilities Decordova Steam Electric Station  

SciTech Connect

This report describes the experimental design and test plan for the first of three field tests that the US Environmental Protection Agency (EPA) conducted in 1997 as part of a major study to evaluate potential improvements to Method 2, EPA`s test method for measuring flue gas volumetric flow in stacks. The experimental design involved four test teams taking concurrent in-stack measurements with velocity sensing probes. Seven types of probes were included in the study. Three test matrices were used to gather data for inter-probe and inter-team comparisons and to assess the impact of velocity decline near the stack wall on volumetric flow measurements.

Lieberman, E.; Werner, A.S.

1997-05-30T23:59:59.000Z

284

Perturbative analysis of sheared flow Kelvin-Helmholtz instability in a weakly relativistic magnetized electron fluid  

Science Conference Proceedings (OSTI)

In the interaction of intense lasers with matter/plasma, energetic electrons having relativistic energies get created. These energetic electrons can often have sheared flow profiles as they propagate through the plasma medium. In an earlier study [Phys. Plasmas 17, 022101 (2010)], it was shown that a relativistic sheared electron flow modifies the growth rate and threshold condition of the conventional Kelvin-Helmholtz instability. A perturbative analytic treatment for the case of weakly relativistic regime has been provided here. It provides good agreement with the numerical results obtained earlier.

Sundar, Sita; Das, Amita; Kaw, Predhiman [Institute for Plasma Research, Bhat, Gandhinagar-382428 (India)

2012-05-15T23:59:59.000Z

285

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

286

Simulation Analysis of Within-Day Flow Fluctuation Effects on Trout below Flaming Gorge Dam  

Science Conference Proceedings (OSTI)

This report demonstrates the use of an individual-based model for studying the impact of river flow fluctuations resulting from hydroelectric project operation on a tailwater trout fishery. The study was conducted at the Flaming Gorge Hydroelectric Project on the Green River in Utah.

2006-04-20T23:59:59.000Z

287

Secured CAD Back-End Flow for Power-Analysis-Resistant Cryptoprocessors  

Science Conference Proceedings (OSTI)

This article presents a comprehensive back-end design flow that enables the realization of constant-power cryptoprocessors, natively protected against side-channel attacks exploiting the instant power consumption. The proposed methodology is based on ... Keywords: robust hardware, back-end design automation, power-constant architectures, side-channel attacks, mitigation, DFM, DFY

Sylvain Guilley; Florent Flament; Philippe Hoogvorst; Renaud Pacalet; Yves Mathieu

2007-11-01T23:59:59.000Z

288

AIAA Paper 2006-0102 Analysis of Jet Effects on Co-Flow Jet Airfoil  

E-Print Network (OSTI)

.-C. Zha, C. Paxton, A. Conley, A. Wells, and B. Carroll, "Effect of Injection Slot Size on High in this paper to analyze the jet effect on co-flow jet airfoil with injection and suction and the airfoil with injection only. The ducts reaction forces formulations to be included for lift and drag calculation

Zha, Gecheng

289

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

290

Non-uniform isentropic gas flow analysis of explosion in fractured solid media  

Science Conference Proceedings (OSTI)

This paper presents a new formulation of non-uniform isentropic gas flow during an explosion in solid media. The present form takes into account additional effects of variations in geometries of voids and crack openings. Variations of mass, density, ... Keywords: Blast, Combined finite/discrete element method, Explosion, Gas-solid interaction

S. Mohammadi; A. Pooladi

2007-04-01T23:59:59.000Z

291

A Network-Flow-Based Scheduler: Design, Performance History, and Experimental Analysis  

Science Conference Proceedings (OSTI)

We describe a program that schedules physician attending teams at Denver Health Medical Center. The program uses network flow techniques to prune an exponentially sized search space. We describe the program design, its performance history at the hospital, ... Keywords: graphs, matroids, scheduling

Harold Gabow; Tadayoshi Kohno

2001-12-01T23:59:59.000Z

292

Model-based analysis of flow-mediated dilation and intima-media thickness  

Science Conference Proceedings (OSTI)

We present an end-to-end system for the automatic measurement of flow-mediated dilation (FMD) and intima-media thickness (IMT) for the assessment of the arterial function. The video sequences are acquired from a B-mode echographic scanner. A spline model ...

G. Bartoli; G. Menegaz; M. Lisi; G. Di Stolfo; S. Dragoni; T. Gori

2008-01-01T23:59:59.000Z

293

Enhancing Cross-Correlation Analysis with Artificial Neural Networks for Nuclear Power Plant Feedwater Flow Measurement  

Science Conference Proceedings (OSTI)

One of the primary cost-saving objectives of the power plant industry, including the nuclear industry, has long been the efficient operation of plant systems. Since the maximum operating thermal power of any nuclear plant is bounded by the specific licensing ... Keywords: flow measurement, neural networks, nuclear power plant

Davide Roverso; Da Ruan

2004-05-01T23:59:59.000Z

294

Columbia University flow instability experimental program: Volume 2. Single tube uniformly heated tests -- Part 2: Uncertainty analysis and data  

Science Conference Proceedings (OSTI)

In June 1988, Savannah River Laboratory requested that the Heat Transfer Research Facility modify the flow excursion program, which had been in progress since November 1987, to include testing of single tubes in vertical down-flow over a range of length to diameter (L/D) ratios of 100 to 500. The impetus for the request was the desire to obtain experimental data as quickly as possible for code development work. In July 1988, HTRF submitted a proposal to SRL indicating that by modifying a facility already under construction the data could be obtained within three to four months. In January 1990, HTFR issued report CU-HTRF-T4, part 1. This report contained the technical discussion of the results from the single tube uniformly heated tests. The present report is part 2 of CU-HTRF-T4 which contains further discussion of the uncertainty analysis and the complete set of data.

Dougherty, T.; Maciuca, C.; McAssey, E.V. Jr.; Reddy, D.G.; Yang, B.W.

1990-05-01T23:59:59.000Z

295

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

296

1993 Pacific Northwest Loads and Resources Study.  

SciTech Connect

The Loads and Resources Study is presented in three documents: (1) this summary of Federal system and Pacific Northwest region loads and resources; (2) a technical appendix detailing forecasted Pacific Northwest economic trends and loads, and (3) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. In this loads and resources study, resource availability is compared with a range of forecasted electricity consumption. The forecasted future electricity demands -- firm loads -- are subtracted from the projected capability of existing and {open_quotes}contracted for{close_quotes} resources to determine whether Bonneville Power Administration (BPA) and the region will be surplus or deficit. If resources are greater than loads in any particular year or month, there is a surplus of energy and/or capacity, which BPA can sell to increase revenues. Conversely, if firm loads exceed available resources, there is a deficit of energy and/or capacity, and additional conservation, contract purchases, or generating resources will be needed to meet load growth. The Pacific Northwest Loads and Resources Study analyzes the Pacific Northwest`s projected loads and available generating resources in two parts: (1) the loads and resources of the Federal system, for which BPA is the marketing agency; and (2) the larger Pacific Northwest regional power system, which includes loads and resource in addition to the Federal system. The loads and resources analysis in this study simulates the operation of the power system under the Pacific Northwest Coordination Agreement (PNCA) produced by the Pacific Northwest Coordinating Group. This study presents the Federal system and regional analyses for five load forecasts: high, medium-high, medium, medium-low, and low. This analysis projects the yearly average energy consumption and resource availability for Operating Years (OY) 1994--95 through 2003--04.

United States. Bonneville Power Administration.

1993-12-01T23:59:59.000Z

297

Neutron formation temperature gauge and neutron activation analysis brine flow meter. Final report, October 1, 1976--March 31, 1978  

DOE Green Energy (OSTI)

Feasibility studies of nuclear techniques applicable to the determination of geothermal formation temperature and two-phase brine flow downhole have been performed. The formation temperature gauging technique involves injection of fast neutrons into the formation and analysis of the moderated slow neutron energy distribution by appropriately filtered neutron detectors. The scientific feasibility of the method has been demonstrated by analytical computational and experimental evaluation of the system response. A data analysis method has been developed to determine unambiguously the temperature, neutron absorption cross section and neutron moderating power of an arbitrary medium. The initial phase of a program to demonstrate the engineering feasibility of the technique has been performed. A sonde mockup was fabricated and measurements have been performed in a test stand designed to simulate a geothermal well. The results indicate that the formation temperature determined by this method is independent of differences between the temperature in the borehole fluid and the formation, borehole fluid density, and borehole fluid salinity. Estimates of performance specifications for a formation temperature sonde have been made on the basis of information obtained in this study and a conceptual design of a logging system has been developed. The technique for the determination of fluid flow in a well is based on neutron activation analysis of elements present in the brine. An analytical evaluation of the method has been performed. The results warrant further, experimental evaluation.

Vagelatos, N.; Steinman, D.K.; John, J.

1978-03-31T23:59:59.000Z

298

Analysis of Granular Flow in a Pebble-Bed Nuclear Reactor  

E-Print Network (OSTI)

Pebble-bed nuclear reactor technology, which is currently being revived around the world, raises fundamental questions about dense granular flow in silos. A typical reactor core is composed of graphite fuel pebbles, which drain very slowly in a continuous refueling process. Pebble flow is poorly understood and not easily accessible to experiments, and yet it has a major impact on reactor physics. To address this problem, we perform full-scale, discrete-element simulations in realistic geometries, with up to 440,000 frictional, viscoelastic 6cm-diameter spheres draining in a cylindrical vessel of diameter 3.5m and height 10m with bottom funnels angled at 30 degrees or 60 degrees. We also simulate a bidisperse core with a dynamic central column of smaller graphite moderator pebbles and show that little mixing occurs down to a 1:2 diameter ratio. We analyze the mean velocity, diffusion and mixing, local ordering and porosity (from Voronoi volumes), the residence-time distribution, and the effects of wall friction and discuss implications for reactor design and the basic physics of granular flow.

Chris H. Rycroft; Gary S. Grest; James W. Landry; Martin Z. Bazant

2006-02-16T23:59:59.000Z

299

Estimation of fracture flow parameters through numerical analysis of hydromechanical pressure pulses  

Science Conference Proceedings (OSTI)

The flow parameters of a natural fracture were estimated by modeling in situ pressure pulses. The pulses were generated in two horizontal boreholes spaced 1 m apart vertically and intersecting a near-vertical highly permeable fracture located within a shallow fractured carbonate reservoir. Fracture hydromechanical response was monitored using specialized fiber-optic borehole equipment that could simultaneously measure fluid pressure and fracture displacements. Measurements indicated a significant time lag between the pressure peak at the injection point and the one at the second measuring point, located 1 m away. The pressure pulse dilated and contracted the fracture. Field data were analyzed through hydraulic and coupled hydromechanical simulations using different governing flow laws. In matching the time lag between the pressure peaks at the two measuring points, our hydraulic models indicated that (1) flow was channeled in the fracture, (2) the hydraulic conductivity tensor was highly anisotropic, and (3) the radius of pulse influence was asymmetric, in that the pulse travelled faster vertically than horizontally. Moreover, our parametric study demonstrated that the fluid pressure diffusion through the fracture was quite sensitive to the spacing and orientation of channels, hydraulic aperture, storativity and hydraulic conductivity. Comparison between hydraulic and hydromechanical models showed that the deformation significantly affected fracture permeability and storativity, and consequently, the fluid pressure propagation, suggesting that the simultaneous measurements of pressure and mechanical displacement signals could substantially improve the interpretation of pulse tests during reservoir characterization.

Cappa, F.; Guglielmi, Y.; Rutqvist, J.; Tsang, C.-F.; Thoraval, A.

2008-03-16T23:59:59.000Z

300

Analysis of granular flow in a pebble-bed nuclear reactor  

Science Conference Proceedings (OSTI)

Pebble-bed nuclear reactor technology, which is currently being revived around the world, raises fundamental questions about dense granular flow in silos. A typical reactor core is composed of graphite fuel pebbles, which drain very slowly in a continuous refueling process. Pebble flow is poorly understood and not easily accessible to experiments, and yet it has a ma jor impact on reactor physics. To address this problem, we perform full-scale, discrete-element simulations in realistic geometries, with up to 440,000 frictional, viscoelastic 6cm-diameter spheres draining in a cylindrical vessel of diameter 3.5m and height 10m with bottom funnels angled at 30? or 60? . We also simulate a bidisperse core with a dynamic central column of smaller graphite moderator pebbles and show that little mixing occurs down to a 1:2 diameter ratio. We analyze the mean velocity, diffusion and mixing, local ordering and porosity (from Voronoi volumes), the residence-time distribution, and the effects of wall friction and discuss implications for reactor design and the basic physics of granular flow.

C. H. Rycroft; Gary S. Grest; James W. Landry; Martin Z. Bazant

2006-04-17T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Numerical analysis of temperature and flow effects in a dry, one-dimensional aquifer used for compressed air energy storage  

DOE Green Energy (OSTI)

A detailed description of the method of analysis and the results obtained for an investigation of the hydrodynamic and thermodynamic response of a model of a dry porous media reservoir used for compressed air energy storage (CAES) is presented. Results were obtained from a one-dimensional simulation of the cycling of heated air to and from a radial flow field surrounding a single well in a porous rock. It was assumed that the performance of the bulk of the reservoir could be characterized by the performance of a single well.

Smith, G.C.; Wiles, L.E.; Loscutoff, W.V.

1979-02-01T23:59:59.000Z

302

Wind flow modeling for wind energy analysis of the Nellis Dunes area in Nevada.  

E-Print Network (OSTI)

??A wind energy analysis of the Nellis Dunes area in Nevada was conducted. A DEM file which contains the elevation data was used to generate… (more)

Rangegowda, Upendra

2010-01-01T23:59:59.000Z

303

Classification and forecasting of load curves Nolwen Huet  

E-Print Network (OSTI)

on up to stabilisation of the clusters. Finally, the load profiles are predicted by covariance analysis of electricity customer uses. This load curve is only available for customers with automated meter readingClassification and forecasting of load curves Nolwen Huet Abstract The load curve, which gives

Cuesta, Juan Antonio

304

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

305

Protected Loss of Flow Transient Simulation (Quicktime format, High  

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

Engineering Analysis > Videos Engineering Analysis > Videos Engineering Analysis: Protected Loss of Flow Transient Simulation Quicktime format Quicktime Format - High Bandwidth | Size: 25.94 MB | Bit Rate: 1148 kbps Keywords: flow transient, plot, EBR-II, SAS4A, SASSYS-1, passive safety, protected loss of flow, PLOF, shutdown heat removal test, SHRT-17, SHRT17 Elevation plot showing detailed top of core temperatures in experimental assembly XX09 during a protected loss of flow transient in EBR-II. Surrounding assemblies are depicted using fuel average temperatures. Results show excellent decay heat removal capability of sodium through natural circulation and exceptionally low transient temperatures with metallic fuel. :: Please wait until video loads completely :: Closed Captioning Transcript

306

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

307

Panorama: capturing system-wide information flow for malware detection and analysis  

Science Conference Proceedings (OSTI)

Malicious programs spy on users' behavior and compromise their privacy. Even software from reputable vendors, such as Google Desktop and Sony DRM media player, may perform undesirable actions. Unfortunately, existing techniques for detecting malware ... Keywords: dynamic taint analysis, malware analysis, malware detection, spyware

Heng Yin; Dawn Song; Manuel Egele; Christopher Kruegel; Engin Kirda

2007-10-01T23:59:59.000Z

308

CFD Analysis of Turbulent Flow Phenomena in the Lower Plenum of a Prismatic Gas-Cooled Reactor  

Science Conference Proceedings (OSTI)

This paper is concerned with the implementation of a computational model of turbulent flow in a section of the lower plenum of Very High Temperature Reactor (VHTR). The proposed model has been encoded in a state-of-the-art CFD code, NPHASE. The results of NPHASE predictions have been compared against the experimental data collected using a scaled model of a sub-region in the lower plenum of a modular prismatic gas-cooled reactor. It has been shown that the NPHASE-based model is capable of predicting a three-dimensional velocity field in a complex geometrical configuration of VHTR lower plenum. The current and future validations of computational predictions are necessary for design and analysis of new reactor concepts, as well as for safety analysis and licensing calculations.

T. Gallaway; S.P. Antal; M.Z. Podowski; D.P. Guillen

2007-09-01T23:59:59.000Z

309

Estimation of steady-state unbalanced system conditions combining conventional power flow and fault analysis software  

Science Conference Proceedings (OSTI)

In real three-phase power systems the voltages and currents are not fully symmetrical. A method has been developed to estimate the effects of slight unbalanced network conditions for steady-state operation. A conventional power flow is followed by a linear incremental calculation using a three-phase model of the network. The unbalanced condition is handled like a multiple unbalanced fault. The process is illustrated for the case of a transformer bank with non-identical single phase units. The results show the effects of different transformer reactances and different voltage ratios, respectively.

Reichelt, D.; Ecknauer, E. [Nordostschweizerische Kraftwerke AG, Baden (Switzerland); Glavitsch, H. [Swiss Federal Inst. of Tech., Zurich (Switzerland)

1996-02-01T23:59:59.000Z

310

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

311

Trends in electric utility load duration curves  

SciTech Connect

This report documents the development and analysis of annual and quarterly load duration curves for each of the 10 Federal regions. The report describes analyses performed to test for changes in load duration curve shapes over time. These analyses are intended to aid the electric utility analyses and modeling activities of the Energy Information Administration (EIA) by expanding the understanding of current and expected load duration curve shapes. 7 figs., 13 tabs.

1984-12-01T23:59:59.000Z

312

Loads, capacity, and failure rate modeling  

SciTech Connect

Both failure rate and load capacity (stress-strength) interferenece methodologies are employed in the reliability analysis at nuclear facilities. Both of the above have been utilized in a heuristic failure rate model in terms of load capacity inference. Analytical solutions are used to demonstrate that infant mortality and random aging failures may be expressed implicity in terms of capacity variability, load variability, and capacity deterioration, and that mode interactions play a role in the formation of the bathtub curve for failure rates.

Lewis, E.E.; Chen, Hsin-Chieh

1994-12-31T23:59:59.000Z

313

NORMAL LOAD BEARING BY SITE SPECIFIC CANISTER  

Science Conference Proceedings (OSTI)

The overall purpose of this calculation is to perform a preliminary analysis of the Site Specific Canister/Basket, subject to static gravity loads that include the self weight of the Canister Shell, the Basket, the Spent Nuclear Fuel, the Shield Plug and the related hardware, so that the loads are approximately known for sizing purposes. Based on these loads the stress levels in various components of the Site Specific Canister/Basket are evaluated.

NA

2005-03-23T23:59:59.000Z

314

Analysis of Fault Permeability Using Mapping and Flow Modeling, Hickory Sandstone Aquifer, Central Texas  

Science Conference Proceedings (OSTI)

Reservoir compartments, typical targets for infill well locations, are commonly created by faults that may reduce permeability. A narrow fault may consist of a complex assemblage of deformation elements that result in spatially variable and anisotropic permeabilities. We report on the permeability structure of a km-scale fault sampled through drilling a faulted siliciclastic aquifer in central Texas. Probe and whole-core permeabilities, serial CAT scans, and textural and structural data from the selected core samples are used to understand permeability structure of fault zones and develop predictive models of fault zone permeability. Using numerical flow simulation, it is possible to predict permeability anisotropy associated with faults and evaluate the effect of individual deformation elements in the overall permeability tensor. We found relationships between the permeability of the host rock and those of the highly deformed (HD) fault-elements according to the fault throw. The lateral continuity and predictable permeability of the HD fault elements enhance capability for estimating the effects of subseismic faulting on fluid flow in low-shale reservoirs.

Nieto Camargo, Jorge E., E-mail: jorge.nietocamargo@aramco.com; Jensen, Jerry L., E-mail: jjensen@ucalgary.ca [University of Calgary, Department of Chemical and Petroleum Engineering (Canada)

2012-09-15T23:59:59.000Z

315

Design, build and test of an axial flow hydrokinetic turbine with fatigue analysis  

E-Print Network (OSTI)

OpenProp is an open source propeller and turbine design and analysis code that has been in development since 2007 by MIT graduate students under the supervision of Professor Richard Kimball. In order to test the performance ...

Ketcham, Jerod W

2010-01-01T23:59:59.000Z

316

Breaks in presence in virtual environments: An analysis of blood flow velocity responses  

Science Conference Proceedings (OSTI)

One of the techniques used to monitor variations in presence during a virtual reality experience is the analysis of breaks in presence (BIPs). Previous studies have monitored peripheral physiological responses during BIPs in order to find a characteristic ...

Beatriz Rey; Vera Parkhutik; Mariano Alcañiz

2011-06-01T23:59:59.000Z

317

Stochastic Finite Element Analysis for Multiphase Flow in Heterogeneous Porous Media  

E-Print Network (OSTI)

. This study is concerned with developing a two-dimensional multiphase model that simulates the movement of NAPL in heterogeneous aquifers. Heterogeneity is dealt with in a probabilistic sense by modeling the intrinsic permeability of the porous medium as a stochastic process. The deterministic finite element method is used to spatially discretize the multiphase flow equations. The intrinsic permeability is represented in the model via its Karhunen-Loeve expansion (Ghanem and Spanos, 1991). This is a computationally expedient representation of stochastic processes by means of a discrete set of random variables. Further, the nodal unknowns, water phase saturations and water phase pressures, are represented by their stochastic spectral expansions. This representation involves an orthogonal basis in the space of random variables. The basis consists of orthogonal polynomial chaoses of consecutive orders. The relative permeabilities of water and oil phases, and the capillary pressure are ex...

R. Ghanem; S. Dham

1998-01-01T23:59:59.000Z

318

Validation Analysis of the Groundwater Flow and Transport Model of the Central Nevada Test Area  

Science Conference Proceedings (OSTI)

The Central Nevada Test Area (CNTA) is a U.S. Department of Energy (DOE) site undergoing environmental restoration. The CNTA is located about 95 km northeast of Tonopah, Nevada, and 175 km southwest of Ely, Nevada (Figure 1.1). It was the site of the Faultless underground nuclear test conducted by the U.S. Atomic Energy Commission (DOE's predecessor agency) in January 1968. The purposes of this test were to gauge the seismic effects of a relatively large, high-yield detonation completed in Hot Creek Valley (outside the Nevada Test Site [NTS]) and to determine the suitability of the site for future large detonations. The yield of the Faultless underground nuclear test was between 200 kilotons and 1 megaton (DOE, 2000). A three-dimensional flow and transport model was created for the CNTA site (Pohlmann et al., 1999) and determined acceptable by DOE and the Nevada Division of Environmental Protection (NDEP) for predicting contaminant boundaries for the site.

A. Hassan; J. Chapman; H. Bekhit; B. Lyles; K. Pohlmann

2006-09-30T23:59:59.000Z

319

Variable Selection for Five-Minute Ahead Electricity Load Forecasting  

Science Conference Proceedings (OSTI)

We use autocorrelation analysis to extract 6 nested feature sets of previous electricity loads for 5-minite ahead electricity load forecasting. We evaluate their predictive power using Australian electricity data. Our results show that the most important ... Keywords: very short-term electricity load forecasting, prediction, variable selection, autocorrelation analysis

Irena Koprinska; Rohen Sood; Vassilios Agelidis

2010-08-01T23:59:59.000Z

320

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

Note: This page contains sample records for the topic "load flow analysis" 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

Data flow analysis for anomaly detection and identification toward resiliency in extreme scale systems  

Science Conference Proceedings (OSTI)

The increased complexity and scale of high performance computing and future extreme-scale systems have made resilience a key issue, since it is expected that future systems will have various faults during critical operations. It is also expected that ... Keywords: Anomaly, Data analysis, Fault detection and identification, Resilience

Byoung Uk Kim

2012-07-01T23:59:59.000Z

322

Optimizing urban traffic flow using Genetic Algorithm with Petri net analysis as fitness function  

Science Conference Proceedings (OSTI)

This paper describes a new methodology adopted for urban traffic stream optimization. By using Petri net analysis as fitness function of a Genetic Algorithm, an entire urban road network is controlled in real time. With the advent of new technologies ... Keywords: Genetic Algorithm, Optimization, Petri net, Urban traffic

Henrique Dezani, Regiane D. S. Bassi, Norian Marranghello, Luís Gomes, Furio Damiani, Ivan Nunes Da Silva

2014-01-01T23:59:59.000Z

323

A Robust Four-Fluid Transient Flow Simulator as an Analysis and Decision Making Tool for Dynamic Kill Operation  

E-Print Network (OSTI)

The worst scenario of drilling operation is blowout which is uncontrolled flow of formation fluid into the wellbore. Blowouts result in environmental damage with potential risk of injuries and fatalities. Although not all blowouts result in disaster, outcomes of blowouts are unknown and should be studied before starting an operation. Plans should be available to prevent blowouts or provide safe and secure ways of controlling the well before the drilling operation starts. The plan should include procedures in case of any blowout incident as a proactive measure. A few commercial softwares are available in the industry for dynamic kill and transient modeling. All models are proprietary and very complex which reduces the flexibility of the program for specific cases. The purpose of this study is to develop a pseudo transient hydraulic simulator for dynamic kill operations. The idea and concept is to consider the flow of each phase as a single phase flow. The summation of hydrostatic and frictional pressure of each phase determines the bottomhole pressure during the dynamic kill operation. The simulator should be versatile and capable of handling special cases that may encounter during blowouts. Some of the main features of the proposed dynamic kill simulator include; quick and robust simulation, fluid properties are corrected for pressure and temperature, sensitivity analysis can be performed through slide bars, and capable of handling variety of wellbore trajectories. The results from the proposed simulator were compared to the result of commercial software, OLGA ABC. The results were in agreement with each other. It is recommended to apply the simulator for operations with required kill fluid volumes of one to two wellbore volumes.

Haghshenas, Arash

2013-05-01T23:59:59.000Z

324

Load relaxation studies of a metallic glass  

SciTech Connect

Experimental results of load relaxation studies of a commercial metallic glass as a function of temperature are reported. The data suggest that metallic glasses exhibit deformation behavior with flow laws similar to those governing plastic deformation in crystalline solids. The lack of appreciable work hardening in annealed material and the identification of an anelastic component are also indicated by the experimental observations. (GHT)

Hadnagy, T.D.; Krenisky, D.J.; Ast, D.G.; Li, C.Y.

1977-01-01T23:59:59.000Z

325

Image analysis algorithms for estimating porous media multiphase flow variables from computed microtomography data: a validation study  

Science Conference Proceedings (OSTI)

Image analysis of three-dimensional microtomographic image data has become an integral component of pore scale investigations of multiphase flow through porous media. This study focuses on the validation of image analysis algorithms for identifying phases and estimating porosity, saturation, solid surface area, and interfacial area between fluid phases from gray-scale X-ray microtomographic image data. The data used in this study consisted of (1) a two-phase high precision bead pack from which porosity and solid surface area estimates were obtained and (2) three-phase cylindrical capillary tubes of three different radii, each containing an air-water interface, from which interfacial area was estimated. The image analysis algorithm employed here combines an anisotropic diffusion filter to remove noise from the original gray-scale image data, a k-means cluster analysis to obtain segmented data, and the construction of isosurfaces to estimate solid surface area and interfacial area. Our method was compared with laboratory measurements, as well as estimates obtained from a number of other image analysis algorithms presented in the literature. Porosity estimates for the two-phase bead pack were within 1.5% error of laboratory measurements and agreed well with estimates obtained using an indicator kriging segmentation algorithm. Additionally, our method estimated the solid surface area of the high precision beads within 10% of the laboratory measurements, whereas solid surface area estimates obtained from voxel counting and two-point correlation functions overestimated the surface area by 20--40%. Interfacial area estimates for the air-water menisci contained within the capillary tubes were obtained using our image analysis algorithm, and using other image analysis algorithms, including voxel counting, two-point correlation functions, and the porous media marching cubes. Our image analysis algorithm, and other algorithms based on marching cubes, resulted in errors ranging from 1% to 20% of the analytical interfacial area estimates, whereas voxel counting and two-point correlation functions overestimated the analytical interfacial area by 20--40%. In addition, the sensitivity of the image analysis algorithms on the resolution of the microtomographic image data was investigated, and the results indicated that there was little or no improvement in the comparison with laboratory estimates for the resolutions and conditions tested.

Porter, Mark L.; Wildenschild, Dorthe; (Oregon State U.)

2010-09-03T23:59:59.000Z

326

Profile Guided Load Marking for Memory Renaming  

E-Print Network (OSTI)

Memory operations remain a significant bottleneck in dynamically scheduled pipelined processors, due in part to the inability to statically determine the existence of memory address dependencies. Hardware memory renaming techniques have been proposed which predict which stores a load might be dependent upon. These prediction techniques can be used to speculatively forward a value from a predicted store dependency to a load through a value prediction table; however, these techniques require large and time-consuming hardware tables. In this paper we propose a software-guided approach for identifying dependencies between store and load instructions and the Load Marking (LM) architecture to communicate these dependencies to the hardware. Compiler analysis and profiles are used to find important store/load relationships, and these relationships are identified during execution via hints or an n-bit tag. For those loads that are not marked for renaming, we then use additional profiling inform...

Glenn Reinman; Brad Calder; Dean Tullsen; Gary Tyson; Todd Austin

1998-01-01T23:59:59.000Z

327

Regional load-curve models: QUERI's model long-run forecasts and sensitivity analysis. Volume 4. Final report. [Hourly demand in 32 US regions  

SciTech Connect

This report presents detailed forecasts of the hourly demand for electricity in 32 regions of the US through the year 2000. The forecasts are generated by a load curve model estimated by QUERI and described in Volume II of this report. Two primary sets of input assumptions for this model are utilized: one based on DRI's macro, regional and sectoral models is called the Baseline Scenario while the other, which is a projection of historical trends, is the Extrapolation Scenario. Under both assumptions, the growth rates of electricity are forecast to slow from historical levels. Load factors are generally projected to continue to decline; most regions are forecast to remain Summer peaking but this is rather sensitive to the choice of scenario. By considering other scenarios which are small perturbations of the Baseline assumptions, elasticities of average, peak and hourly loads are calculated. Different weather assumptions are also examined for the sensitivity of the load shapes to changes in the weather.

Engle, R.F.; Granger, C.W.J.; Ramanathan, R.

1981-09-01T23:59:59.000Z

328

Analysis of fluid flow and heat transfer in a rib grit roughened surface solar air heater using CFD  

SciTech Connect

This paper presents the study of fluid flow and heat transfer in a solar air heater by using Computational Fluid Dynamics (CFD) which reduces time and cost. Lower side of collector plate is made rough with metal ribs of circular, square and triangular cross-section, having 60 inclinations to the air flow. The grit rib elements are fixed on the surface in staggered manner to form defined grid. The system and operating parameters studied are: e/D{sub h} = 0.044, p/e = 17.5 and l/s = 1.72, for the Reynolds number range 3600-17,000. To validate CFD results, experimental investigations were carried out in the laboratory. It is found that experimental and CFD analysis results give the good agreement. The optimization of rib geometry and its angle of attack is also done. The square cross-section ribs with 58 angle of attack give maximum heat transfer. The percentage enhancement in the heat transfer for square plate over smooth surface is 30%. (author)

Karmare, S.V. [Department of Mechanical Engineering, Government College Engineering, Karad 415 124, Maharashtra (India); Shivaji University, Kolhapur, Maharashtra (India); Tikekar, A.N. [Department of Mechanical Engineering, Walchand College of Engineering, Sangli (India); Shivaji University, Kolhapur, Maharashtra (India)

2010-03-15T23:59:59.000Z

329

Analysis of char-slag interaction and near-wall particle segregation in entrained-flow gasification of coal  

SciTech Connect

The fate of carbon particles during entrained-flow gasification of coal in the slagging regime is analyzed. More specifically, the study addresses the relevance of segregation of carbon particles in a near-wall region of the gasifier to coal conversion. Segregation of carbon particles is analyzed considering the effects of turbulence- and swirl-promoted particle migration toward the wall, interaction of the impinging particles with the wall ash layer, coverage of the slag layer by refractory carbon particles, accumulation of carbon particles in a dense-dispersed phase near the wall of the gasifier. Operating conditions of the gasifier and slag properties may be combined so as to give rise to a variety of conversion regimes characterized by distinctively different patterns of carbon particles segregation. A simple 1D model of an entrained-flow gasifier has been developed based on the conceptual framework of carbon particle segregation. The model aims at providing a general assessment of the impact of the different patterns of carbon particle segregation on the course and extent of carbon gasification. A sensitivity analysis with reference to selected model parameters is performed to identify key processes controlling carbon segregation and their impact on the gasifier performance. (author)

Montagnaro, Fabio [Dipartimento di Chimica, Universita degli Studi di Napoli Federico II, Complesso Universitario del Monte di Sant'Angelo, 80126 Napoli (Italy); Salatino, Piero [Dipartimento di Ingegneria Chimica, Universita degli Studi di Napoli Federico II and Istituto di Ricerche sulla Combustione, CNR, Piazzale Vincenzo Tecchio 80, 80125 Napoli (Italy)

2010-05-15T23:59:59.000Z

330

Flow microfluorometric and spectrophotofluorometric analysis of DNA staining in mammalian cells  

SciTech Connect

The effects of pH, ionic strength, stain concentration, and magnesium concentration on DNA staining with the antibiotics mithramycin, chromomycin A3, and olivomycin were examined with DNA in solution and in mammalian cells. Ethanol-fixed Chinese hamster cells (line CHO) stained with mithramycin solution in the pH range 4.0 to 10.0 and analyzed by flow microfluorometry (FMF) showed only a slight increase in fluorescence intensity from pH 4.0 to 8.0. Above this range, there was a more dramatic increase in intensity of stained cells, and at pH 10.0 the flouorescence intensity was 1-1/2 times greater than cells stained at pH 4.5. The resolution in DNA distribution patterns also improved as a function of increasing pH, corresponding with a marked decrease in the coefficient of variation (CV). However, the distribution of cells in various phases of the cell cycle remained essentially the same over the pH ranges tested.

Crissman, H.A.; Stevenson, A.; Kissane, R.J.

1977-01-01T23:59:59.000Z

331

Flow analysis of metals in a municipal solid waste management system  

Science Conference Proceedings (OSTI)

This study aimed to identify the metal flow in a municipal solid waste (MSW) management system. Outputs of a resource recovery facility, refuse derived fuel (RDF) production facility, carbonization facility, plastics liquefaction facility, composting facility, and bio-gasification facility were analyzed for metal content and leaching concentration. In terms of metal content, bulky and incombustible waste had the highest values. Char from a carbonization facility, which treats household waste, had a higher metal content than MSW incinerator bottom ash. A leaching test revealed that Cd and Pb in char and Pb in RDF production residue exceeded the Japanese regulatory criteria for landfilling, so special attention should be paid to final disposal of these substances. By multiplying metal content and the generation rate of outputs, the metal content of input waste to each facility was estimated. For most metals except Cr, the total contribution ratio of paper/textile/plastics, bulky waste, and incombustible waste was over 80%. Approximately 30% of Cr originated from plastic packaging. Finally, several MSW management scenarios showed that most metals are transferred to landfills and the leaching potential of metals to the environment is quite small.

Jung, C.H. [Laboratory of Solid Waste Disposal Engineering, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan); Matsuto, T. [Laboratory of Solid Waste Disposal Engineering, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan)]. E-mail: matsuto@eng.hokudai.ac.jp; Tanaka, N. [Laboratory of Solid Waste Disposal Engineering, Graduate School of Engineering, Hokkaido University, Kita 13 Nishi 8, Kita-ku, Sapporo 060-8628 (Japan)

2006-07-01T23:59:59.000Z

332

Disaggregating regional energy supply/demand and flow data to 173 BEAs in support of export coal analysis. Final report  

SciTech Connect

This report documents the procedures and results of a study sponsored jointly by the US Department of Transportation and the US Department of Energy. The study was conducted to provide, Bureau of Economic Analysis (BEA)-level production/consumption data for energy materials for 1985 and 1990 in support of an analysis of transportation requirements for export coal. Base data for energy forecasts at the regional level were obtained from the Department of Energy, Energy Information Administration. The forecasts selected for this study are described in DOE/EIA's 1980 Annual Report to Congress, and are: 1985 Series, B, medium oil import price ($37.00/barrel); and 1990 Series B, medium oil import price ($41.00/barrel). Each forecast period is extensively described by approximately forty-three statistical tables prepared by EIA and made available to TERA for this study. This report provides sufficient information to enable the transportation analyst to appreciate the procedures employed by TERA to produce the BEA-level energy production/consumption data. The report presents the results of the procedures, abstracts of data tabulations, and various assumptions used for the preparation of the BEA-level data. The end-product of this effort was the BEA to BEA energy commodity flow data by more which serve as direct input to DOT's transportation network model being used for a detailed analysis of export coal transportation.

1981-06-01T23:59:59.000Z

333

Analysis of a Window-Based Flow Control Mechanism based on TCP Vegas in Heterogeneous Network Environment  

E-Print Network (OSTI)

Another version of TCP called TCP Vegas has been proposed and studied in the literature. It can achieve better performance than the current TCP Reno. In our previous studies, steady-state behavior of a windowbased flow control mechanism based on TCP Vegas has been analyzed for a simple network topology. In this paper, we extend our analysis to a generic network topology where multiple bottleneck links exist. We first derive equi- librium values of a window size of a TCP connection and the number of packets waiting in a router's buffer in steady state. We also derive throughput of each TCP connection in steady state, and investigate the effect of control parameters of TCP Vegas on fairness among TCP connections. We then present several numerical examples, showing how control parameters of TCP Vegas should be configured for achieving both stability and better transient performance.

Keiichi Takagaki; Hiroyuki Ohsaki; Masayuki Murata

2001-01-01T23:59:59.000Z

334

1991 Pacific Northwest Loads and Resources Study.  

SciTech Connect

This study establishes the Bonneville Power Administration's (BPA) planning basis for supplying electricity to BPA customers. The Loads and Resources Study is presented in three documents: (1) this summary of federal system and Pacific Northwest region loads and resources; (2) a technical appendix detailing forecasted Pacific Northwest economic trends and loads, and (3) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. This analysis updates our 1990 study. BPS's long-range planning incorporates resource availability with a range of forecasted electrical consumption. The forecasted future electrical demands-firm loads--are subtracted from the projected capability of existing resources to determine whether BPA and the region will be surplus or deficit. If resources are greater than loads in any particular year or month, there is a surplus of energy and/or capacity, which BPA can sell to increase revenues. Conversely, if firm loads exceed available resources, there is a deficit of energy and/or capacity, then additional conservation, contract purchases, or generating resources will be needed to meet load growth. This study analyzes the Pacific Northwest's projected loads and available generating resources in two parts: (1) the loads and resources of the federal system, for which BPA is the marketing agency; and (2) the larger Pacific Northwest regional profile, which includes loads and resources in addition to the federal system. This study presents the federal system and regional analyses for five load forecasts: high, medium-high, medium, medium-low, and low. This analysis projects the yearly average energy consumption and resource availability for 1992- 2012.

United States. Bonneville Power Administration.

1991-12-01T23:59:59.000Z

335

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

336

Analysis and identification of vortices within a turbulent channel boundary layer flow  

E-Print Network (OSTI)

Vortical structures are regarded as the dominant organized patterns in wall turbulence. They play a key role in physical phenomena of practical importance such as energy and momentum transport, combustion, mixing, and noise and drag production. Considerable investigations have been performed in drag and noise phenomena studies, with a main purpose of controlling and reducing them. Various techniques to control the drag reduction have been studied for over last five decades; however, the detailed understanding of the drag reduction mechanism is still lacking. Vortices play an important role in turbulence structure. Nevertheless, the identification of vortices is still unclear, not even a universal definition of a vortex is accepted. In the present study, several vortex feature extraction schemes are implemented. The methods are applied to analyze instantaneous two-dimensional velocity fields obtained by particle tracking Velocimetry (PTV) measurements of a turbulent channel flow with and without microbubble injection within the boundary layer. Microbubble injection is one of the drag reduction techniques, first studied in early 1970s, that has undergone extensive research in past years, and the generated information has aided into drag reduction understanding. As a general rule, vortex extraction methods can be either a simple visualization scheme or more sophisticated identification tools. The Reynolds decomposition and its variants are suitable due to their capacity to mark vortices advecting at different velocities. In the case of identification techniques, which yield a scalar field calculated from either the velocity vector field or the velocity gradient tensor, both the modified swirling strength ?ci or the ?2 criteria were found to be well suited for vortex identification.

Maroni Veiga, Adrian Gaston

2005-05-01T23:59:59.000Z

337

2012 CERTS LAAR Program Peer Review - Integration and Extension of Direct Load Management of Smart Loads - Anna Scaglioni, UC Davis  

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

Integration and Extension of Direct Integration and Extension of Direct Load Management of Smart Loads Anna Scaglione, UC Davis GRA: Mahnoosh Alizadeh Project objective  Invent methods to "store" load demand for * Real-time "generation following" * Integration of load reserves as dispatchable assets in the Energy Market  Architecture for virtual "reserves" (queues) of electrical load demand * Watts to Job mapping (analysis)  Captures digitally the service requirements - Equal service type = Equal queue * Job to Watts mapping (synthesis)  Allows to optimally schedule the load profile Major technical accomplishments  Centralized model: Digital Direct Load Scheduling (DDLS) - Year 1-Year 2

338

1998 Pacific Northwest Loads and Resources Study: The White Book.  

DOE Green Energy (OSTI)

The Pacific Northwest Loads and Resources Study (White Book) is published annually by BPA and establishes the planning basis for supplying electricity to customers. It serves a dual purpose. First, the White Book presents projections of regional and Federal system load and resource capabilities, along with relevant definitions and explanations. Second, the White Book serves as a benchmark for annual BPA determinations made pursuant to the 1981 regional power sales contracts. Specifically, BPA uses the information in the White Book for determining the notice required when customers request to increase or decrease the amount of power purchased from BPA. The White Book compiles information obtained from several formalized resource planning reports and data submittals, including those from the Northwest Power Planning Council (Council) and the Pacific Northwest Utilities Conference Committee (PNUCC). The White Book is not an operational planning guide, nor is it used for inventory planning to determine BPA revenues. Operation of the Federal Columbia River Power System (FCRPS) is based on a set of criteria different from that used for resource planning decisions. Operational planning is dependent upon real-time or near-term knowledge of system conditions, including expectations of river flows and runoff, market opportunities, availability of reservoir storage, energy exchanges, and other factors affecting the dynamics of operating a power system. The 1998 White Book is presented in two documents: (1) this summary of Federal system and Pacific Northwest region loads and resources; and (2) a technical appendix detailing the loads and resources for each major Pacific Northwest generating utility. This analysis updates the December 1997 Pacific Northwest Loads and Resources Study.

United States. Bonneville Power Administration.

1998-12-01T23:59:59.000Z

339

Calculations of slurry pump jet impingement loads  

SciTech Connect

This paper presents a methodology to calculate the impingement load in the region of a submerged turbulent jet where a potential core exits and the jet is not fully developed. The profile of the jet flow velocities is represented by a piece-wise linear function which satisfies the conservation of momentum flux of the jet flow. The adequacy of the of the predicted jet expansion is further verified by considering the continuity of the jet flow from the region of potential core to the fully developed region. The jet impingement load can be calculated either as a direct impingement force or a drag force using the jet velocity field determined by the methodology presented.

Wu, T.T.

1996-03-04T23:59:59.000Z

340

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

Note: This page contains sample records for the topic "load flow analysis" 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

The End-Use Technology Assessment Project: A Load-Shape Analysis of Ground Source Heat Pumps and Good Cents Homes  

Science Conference Proceedings (OSTI)

Interest is growing in end-use technology applications that promote overall energy efficiency through increased electricity use. This study will help utilities understand the impacts of such applications by providing load-shape information on ground source heat pumps as well as energy-efficient appliances promoted through Good Cents Homes programs. This report is available only to funders of Program 101A or 101.001. Funders may download this report at http://my.primen.com/Applications/DE/Community/index...

1995-05-27T23:59:59.000Z

342

Statistical analysis of cascading failures in power grids  

SciTech Connect

We introduce a new microscopic model of cascading failures in transmission power grids. This model accounts for automatic response of the grid to load fluctuations that take place on the scale of minutes, when optimum power flow adjustments and load shedding controls are unavailable. We describe extreme events, caused by load fluctuations, which cause cascading failures of loads, generators and lines. Our model is quasi-static in the causal, discrete time and sequential resolution of individual failures. The model, in its simplest realization based on the Directed Current description of the power flow problem, is tested on three standard IEEE systems consisting of 30, 39 and 118 buses. Our statistical analysis suggests a straightforward classification of cascading and islanding phases in terms of the ratios between average number of removed loads, generators and links. The analysis also demonstrates sensitivity to variations in line capacities. Future research challenges in modeling and control of cascading outages over real-world power networks are discussed.

Chertkov, Michael [Los Alamos National Laboratory; Pfitzner, Rene [Los Alamos National Laboratory; Turitsyn, Konstantin [Los Alamos National Laboratory

2010-12-01T23:59:59.000Z

343

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

344

Self-Organized Network Flows  

E-Print Network (OSTI)

A model for traffic flow in street networks or material flows in supply networks is presented, that takes into account the conservation of cars or materials and other significant features of traffic flows such as jam formation, spillovers, and load-dependent transportation times. Furthermore, conflicts or coordination problems of intersecting or merging flows are considered as well. Making assumptions regarding the permeability of the intersection as a function of the conflicting flows and the queue lengths, we find self-organized oscillations in the flows similar to the operation of traffic lights.

Helbing, D; Lämmer, S; Helbing, Dirk; Siegmeier, Jan; L\\"{a}mmer, Stefan

2007-01-01T23:59:59.000Z

345

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

346

How and why distribution loads vary  

SciTech Connect

Because the maximum-use rates of gas customers having differing appliance combinations do not coincide, a distribution system's peak-hour flow rate depends on the relative proportions of the load contributed by the appliances of all the different types of residential, commercial, and industrial customers. The maximum load on Central Hudson's distribution system coincides with the maximum hourly gas flow rate for all residential space-heating purposes; however, Central Hudson analyzes the peak-hour load of its commercial and industrial customers individually. The gas-system sendout presented as a sendout-duration curve is a convenient way to show how these various loads determine gas requirements and to compare the economics of alternative supply methods. The sendout-duration curve consists of long-term weather data plotted against time intervals of 1-365 days. If the threshold temperature and the heating load per degree-day are known, the curve allows the calculation of both normal and design annual peakshaving quantities.

Haber, D.P.

1980-01-01T23:59:59.000Z

347

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

348

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...

349

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...

350

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...

351

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...

352

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...

353

Dynamic modelling of metals - Time scales and target loads  

Science Conference Proceedings (OSTI)

Over the past decade steady-state methods have been developed to assess critical loads of metals avoiding long-term risks in view of food quality and eco-toxicological effects on organisms in soils and surface waters. However, dynamic models are needed ... Keywords: Critical loads, Delay times, Dynamic modelling, Metals, Scenario analysis, Target loads

Maximilian Posch; Wim de Vries

2009-01-01T23:59:59.000Z

354

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

355

Plasma flow switch experiment on Procyon  

SciTech Connect

This report presents the results obtained from a series of plasma flow switch experiments done on the Procyon explosive pulse power generator. These experiments involved switching into a fixed inductance dummy load and also into a dynamic implosion load. The results indicated that the switch did fairly well at switching current into the load, but the results for the implosion are more ambiguous. The results are compared to calculations and the implications for future plasma flow switch work are discussed.

Benage, J.F. Jr.; Bowers, R.; Peterson, D. [and others

1995-09-01T23:59:59.000Z

356

Analysis of environmental issues related to small-scale hydroelectric development. V. Instream flow needs for fishery resources  

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

45b 45b 0554033 I . . ~ ...... . . . . . . . . _ . . _ ~ ~~ ~~ - . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . - . . . , O R N U T M - 7 8 6 1 Distribution Category UC-97e 0. W-7405-eng-26 ANALYSIS OF ENVIRO RELATED TO SMALL-SCALE HYDROELECTRIC DEVELOPMENT. V. INSTREAM FLOW NEE S FOR FISHERY RESOURCES James M. Loar Michael J. Sale TAL SCIENCES D r v r S - I o N Pub1 i c a t i on No. 1829 Prepared f o r U. S. Department o f Energy, A s s i s t a n t Secretary f o r Conservation and Renewable Energy, D i v i s i o n o f H y d r o e l e c t r i c Resource Development Date Pub1 i shed: October 1981 L Tennessee 37830 UNION CARBIDE ~ O ~ ~ ~ R A T I O N f o r the ENT OF ENERGY 3 445b 0554033 B ACKNOWLEDGMENTS W e thank W i l l i a m Knapp (1I.S. F i s h and W i l d l i f e Service, Region 5) and Mark Robinson (Federal Energy Regulatory Commission) for h

357

Demodulation circuit for AC motor current spectral analysis  

DOE Patents (OSTI)

A motor current analysis method for the remote, noninvasive inspection of electric motor-operated systems. Synchronous amplitude demodulation and phase demodulation circuits are used singly and in combination along with a frequency analyzer to produce improved spectral analysis of load-induced frequencies present in the electric current flowing in a motor-driven system.

Hendrix, Donald E. (Oak Ridge, TN); Smith, Stephen F. (Knoxville, TN)

1990-12-18T23:59:59.000Z

358

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

359

PASSIVE DETECTION OF VEHICLE LOADING  

SciTech Connect

The Digital Imaging and Remote Sensing Laboratory (DIRS) at the Rochester Institute of Technology, along with the Savannah River National Laboratory is investigating passive methods to quantify vehicle loading. The research described in this paper investigates multiple vehicle indicators including brake temperature, tire temperature, engine temperature, acceleration and deceleration rates, engine acoustics, suspension response, tire deformation and vibrational response. Our investigation into these variables includes building and implementing a sensing system for data collection as well as multiple full-scale vehicle tests. The sensing system includes; infrared video cameras, triaxial accelerometers, microphones, video cameras and thermocouples. The full scale testing includes both a medium size dump truck and a tractor-trailer truck on closed courses with loads spanning the full range of the vehicle's capacity. Statistical analysis of the collected data is used to determine the effectiveness of each of the indicators for characterizing the weight of a vehicle. The final sensing system will monitor multiple load indicators and combine the results to achieve a more accurate measurement than any of the indicators could provide alone.

Garrett, A.

2012-01-03T23:59:59.000Z

360

Two-phase jet loads. [PWR  

Science Conference Proceedings (OSTI)

Two-phase jets are currently being studied to improve engineering models for the prediction of loads on pipes and structures during LOCAs. Multi-dimensional computer codes such as BEACON/MOD2, CSQ, and TRAC-P1A are being employed to predict flow characteristics and flow-structure loading. Our ultimate goal is to develop a new approximate engineering model which is superior to the F.J. Moody design model. Computer results are compared with data obtained from foreign sources, and a technique for using the TRAC-P1A vessel component as a containment model is presented. In general, good agreement with the data is obtained for saturated stagnation conditions; however, difficulties are encountered for subcooled stagnation conditions, possibly due to nucleation delay and non-equilibrium effects.

Tomasko, D.

1980-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Load diagram for a perforated plate tray  

E-Print Network (OSTI)

1 decimals noggrannhet c. Upprita i x,y-diagrammet q-linjen och bestäm (grafiskt, eller med must be produced. The feed stream F is a saturated liquid, i.e. q = 1, while the reflux ratio R = 1Load diagram for a perforated plate tray vG, vL: velocities G, L: densities QL, QG: volume flows H

Zevenhoven, Ron

362

3He Top Loading Cryostat  

Science Conference Proceedings (OSTI)

... flow meter measure a flow rate and close the ... The recommended flow rate is approximately 1,000cc per minute and the charcoal adsorption pump ...

2007-11-05T23:59:59.000Z

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

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

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

Building Energy Software Tools Directory: HAP System Design Load  

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

HAP System Design Load HAP System Design Load HAP System Design Load logo. Provides the load estimating and system design features found in its popular cousin � Carrier�s Hourly Analysis Program (HAP). By focusing on system design features, the HAP System Design Load program serves as a simpler, more efficient tool for those users only interested in system design; energy simulation features are omitted. Like the HAP program, HAP System Design Load provides the ease of use of a Windows-based graphical user interface and the computing power of modern 32-bit software. HAP System Design Load uses a system-based approach to HVAC load estimating. This approach tailors sizing procedures and results to the specific type of system being considered. A wide variety of equipment types

373

Estimation of structural reliability under combined loads. [PWR; BWR  

DOE Green Energy (OSTI)

For the overall safety evaluation of seismic category I structures subjected to various load combinations, a quantitative measure of the structural reliability in terms of a limit state probability can be conveniently used. For this purpose, the reliability analysis method for dynamic loads, which has recently been developed by the authors, was combined with the existing standard reliability analysis procedure for static and quasi-static loads. The significant parameters that enter into the analysis are: the rate at which each load (dead load, accidental internal pressure, earthquake, etc.) will occur, its duration and intensity. All these parameters are basically random variables for most of the loads to be considered. For dynamic loads, the overall intensity is usually characterized not only by their dynamic components but also by their static components. The structure considered in the present paper is a reinforced concrete containment structure subjected to various static and dynamic loads such as dead loads, accidental pressure, earthquake acceleration, etc. Computations are performed to evaluate the limit state probabilities under each load combination separately and also under all possible combinations of such loads.

Shinozuka, M.; Kako, T.; Hwang, H.; Brown, P.; Reich, M.

1983-01-01T23:59:59.000Z

374

Electrical and Production Load Factors  

E-Print Network (OSTI)

Load factors are an important simplification of electrical energy use data and depend on the ratio of average demand to peak demand. Based on operating hours of a facility they serve as an important benchmarking tool for the industrial sector. The operating hours of small and medium sized manufacturing facilities are analyzed to identify the most common operating hour or shift work patterns. About 75% of manufacturing facilities fall into expected operating hour patterns with operating hours near 40, 80, 120 and 168 hours/week. Two types of load factors, electrical and production are computed for each shift classification within major industry categories in the U.S. The load factor based on monthly billing hours (ELF) increases with operating hours from about 0.4 for a nominal one shift operation, to about 0.7 for around-the-clock operation. On the other hand, the load factor based on production hours (PLF) shows an inverse trend, varying from about 1.4 for one shift operation to 0.7 for around-the-clock operation. When used as a diagnostic tool, if the PLF exceeds unity, then unnecessary energy consumption may be taking place. For plants operating at 40 hours per week, the ELF value was found to greater than the theoretical maximum, while the PLF value was greater than one, suggesting that these facilities may have significant energy usage outside production hours. The data for the PLF however, is more scattered for plants operating less than 80 hours per week, indicating that grouping PLF data based on operating hours may not be a reasonable approach to benchmarking energy use in industries. This analysis uses annual electricity consumption and demand along with operating hour data of manufacturing plants available in the U.S. Department of Energy’s Industrial Assessment Center (IAC) database. The annual values are used because more desirable monthly data are not available. Monthly data are preferred as they capture the load profile of the facility more accurately. The data there come from Industrial Assessment Centers which employ university engineering students, faculty and staff to perform energy assessments for small to medium-sized manufacturing plants. The nation-wide IAC program is sponsored by the U.S. Department of Energy.

Sen, Tapajyoti

2009-12-01T23:59:59.000Z

375

Stability analysis of a phase-field model of gravity-driven unsaturated flow through porous media  

E-Print Network (OSTI)

The formation of preferential flow paths during infiltration of water into homogeneous, dry soil is an important phenomenon whose explanation and prediction have remained elusive under the standard theories of multiphase ...

Cueto-Felgueroso, Luis

376

Stochastic Analysis of Transient Flow in Heterogeneous, Variably Saturated Porous Media: The van GenuchtenMualem Constitutive Model  

E-Print Network (OSTI)

of the van Genuchten­Mualem constitu- (e.g., Yeh et al., 1985a,b; Russo, 1993, 1995a,b; Yang ettive-textured soils with a shallow water table. More the pressure head variance. It is found that the pressure head­saturatedbe ignored. flow (Li and Yeh, 1998; Ferrante and Yeh, 1999; Zhang and Lu, 2002). To describe unsaturated flow

Lu, Zhiming

377

Automatic Detection of Unsafe Component Loadings  

E-Print Network (OSTI)

Dynamic loading of software components (e.g., libraries or modules) is a widely used mechanism for improved system modularity and flexibility. Correct component resolution is critical for reliable and secure software execution, however, programming mistakes may lead to unintended or even malicious components to be resolved and loaded. In particular, dynamic loading can be hijacked by placing an arbitrary file with the specified name in a directory searched before resolving the target component. Although this issue has been known for quite some time, it was not considered serious because exploiting it requires access to the local file system on the vulnerable host. Recently such vulnerabilities started to receive considerable attention as their remote exploitation became realistic; it is now important to detect and fix these vulnerabilities. In this paper, we present the first automated technique to detect vulnerable and unsafe dynamic component loadings. Our analysis has two phases: 1) apply dynamic binary instrumentation to collect runtime information on component loading (online phase); and 2) analyze the collected information to detect vulnerable component loadings (offline phase). For evaluation, we implemented our technique to detect vulnerable and unsafe DLL loadings in popular Microsoft Windows software. Our results show that unsafe DLL loading is prevalent and can lead to serious security threats. Our tool detected more than 1,700 unsafe DLL loadings in 28 widely used software and discovered serious attack vectors for remote code execution. Microsoft has opened a Microsoft Security Response Center (MSRC) case on our reported issues and is working with us and other affected software vendors to develop necessary patches.

Taeho Kwon; Zhendong Su

2010-01-01T23:59:59.000Z

378

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

379

Calculation of Extreme Wave Loads on Coastal Highway Bridges  

E-Print Network (OSTI)

Coastal bridges are exposed to severe wave, current and wind forces during a hurricane. Most coastal bridges are not designed to resist wave loads in such extreme situations, and there are no existing analytical methods to calculate wave loads on coastal highway bridges. This study focuses on developing a new scheme to estimate the extreme wave loads on bridges for designing purpose. In order to do this, a 2D wave velocity potential model (2D Model) is set up for the deterministic analysis of wave force on bridge decks. 2D Model is a linear wave model, which has the capability of calculating wave velocity potential components in time domain based on wave parameters such as wave height, wave period and water depth, and complex structural geometries. 2D Model has Laplace equation as general equation. The free surface boundary, incoming and outgoing wave boundary conditions are linearized, decomposed first, and then solved by the finite difference method. Maximum wave forces results calculated by the linear 2D Model are compared with results from CFD software Flow3D that is using Navier Stokes theory up to the 5th order; and 2D Model is validated by comparing results with experiment data. A case study is conducted for calculating extreme wave forces on I-10 Bridge across Escambia Bay, Florida during Hurricane Ivan in September 2004.SWAN model is adapted to investigate the parameters of wave heights and wave periods around bridge sites. SWAN model has the capability of predicting or hindcasting significant wave heights and wave periods as long as the domain and input parameters are given. The predicted significant wave heights are compared with measurements by Buoy Station 42039 and 42040 nearest to Escambia Bay. A new prediction equation of maximum uplift wave forces on bridge decks is developed in terms of wave height, wave period, water depth, bridge width, water clearance and over top water load. To develop the equations, the relationship is investigated between maximum uplift wave forces and wave parameters, water clearance, green water effects and bridge width. 2D Model is used for up to 1886 cases with difference parameters. Flow3D model is adopted to determine coefficients of water clearance and green water effects, which cannot be calculated by 2D Model.

Meng, Bo

2008-12-01T23:59:59.000Z

380

A three-phase converter model for harmonic analysis of HVDC systems  

Science Conference Proceedings (OSTI)

An equivalent circuit model is presented to model bridge converters for three-phase HVDC harmonic power flow analysis. The validity and accuracy of the model are verified by comparing simulation results against field test results. The model is interfaced with a multiphase harmonic load flow program to investigate the generation of non-characteristic harmonics from HVDC links and the flow of HVDC harmonics in a real system.

Xu, W.; Drakos, J.E.; Mansour, Y.; Chang, A. (B.C. Hydro, Burnaby, British Columbia (Canada))

1994-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

Momentum Balance of Gravity Flows  

Science Conference Proceedings (OSTI)

A unified scale analysis of the momentum balance of downslope gravity flows is developed to organize previous theories for the case of negligible ambient flow and fixed temperature deficit scale. The values of several nondimensional parameters ...

L. Mahrt

1982-12-01T23:59:59.000Z

382

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

383

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

384

Stochastically scalable flow control  

Science Conference Proceedings (OSTI)

Recent advances in the mathematical analysis of flow control have prompted the creation of the Scalable TCP (STCP) and Exponential RED (E-RED) algorithms. These are designed to be scalable under the popular deterministic delay ...

Thomas Voice

2009-10-01T23:59:59.000Z

385

NEW EXPERIMENTAL DATA AND ANALYSIS FOR TWO-PHASE FLOW-INDUCED VIBRATION OF TUBE BUNDLES: PRELIMINARY RESULTS  

E-Print Network (OSTI)

that the void fraction increases through the tube array due to the pressure drop through the bundle. At high.4.2. Fully flexible array 64 4. Results: Air-water two-phase flow 73 4.1. Void fraction measurement 74 4) visual observations and (b) strain gauge signal 71 4.1: Comparison of measured void fraction

Dhir, Vijay

386

A two-mesh coupled gas flow-solid interaction model for 2D blast analysis in fractured media  

Science Conference Proceedings (OSTI)

A 2D coupled two-mesh interaction model for blast gas flow through fractured and fragmented solid media is presented. It is mainly designed to solve blast problems where a complicated set of wide difficult phenomena are involved: shock waves, progressive ... Keywords: Blast, Combined finite/discrete element method, Cracking, Explosion, Fragmentation, Gas-solid interaction

S. Mohammadi; A. Pooladi

2012-03-01T23:59:59.000Z

387

Fluid-based analysis of a network of AQM routers supporting TCP flows with an application to RED  

Science Conference Proceedings (OSTI)

In this paper we use jump process driven Stochastic Differential Equations to model the interactions of a set of TCP flows and Active Queue Management routers in a network setting. We show how the SDEs can be transformed into a set of Ordinary Differential ...

Vishal Misra; Wei-Bo Gong; Don Towsley

2000-08-01T23:59:59.000Z

388

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

389

Loading capacity of various filters for lithium fire generated aerosols  

Science Conference Proceedings (OSTI)

The lithium aerosol loading capacity of a prefilter, HEPA filters and a sand and gravel bed filter was determined. The test aerosol was characterized and was generated by burning lithium in an unlimited air atmosphere. Correlation to sodium aerosol loading capacities were made to relate existing data to lithium aerosol loadings under varying conditions. This work is being conducted in support of the fusion reactor safety program. The lithium aerosol was generated by burning lithium pools, up to 45 kgs, in a 340 m/sup 3/ low humidity air atmosphere to supply aerosol to recirculating filter test loops. The aerosol was sampled to determine particle size, mass concentrations and chemical species. The dew point and gas concentrations were monitored throughout the tests. Loop inlet aerosol mass concentrations ranged up to 5 gr/m/sup 3/. Chemical compounds analyzed to be present in the aerosol include Li/sub 2/O, LiOH, and Li/sub 2/CO/sub 3/. HEPA filters with and without separators and a prefilter and HEPA filter in series were loaded with 7.8 to 11.1 kg/m/sup 2/ of aerosol at a flow rate of 1.31 m/sec and 5 kPa pressure drop. The HEPA filter loading capacity was determined to be greater at a lower flow rate. The loading capacity increased from 0.4 to 2.8 kg by decreasing the flow rate from 1.31 to 0.26 m/sec for a pressure drop of 0.11 kPa due to aerosol buildup. The prefilter tested in series with a HEPA did not increase the total loading capacity significantly for the same total pressure drop. Separators in the HEPA had only minor effect on loading capacity. The sand and gravel bed filter loaded to 0.50 kg/m/sup 2/ at an aerosol flow rate of 0.069 m/sec and final pressure drop of 6.2 kPa. These loading capacities and their dependence on test variables are similar to those reported for sodium aerosols except for the lithium aerosol HEPA loading capacity dependence upon flow rate.

Jeppson, D.W.; Barreca, J.R.

1980-10-23T23:59:59.000Z

390

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

391

Statistical Review of UK Residential Sector Electrical Loads  

E-Print Network (OSTI)

This paper presents a comprehensive statistical review of data obtained from a wide range of literature on the most widely used electrical appliances in the UK residential load sector. It focuses on individual appliances and begins by consideration of the electrical operations performed by the load. This approach allows for the loads to be categorised based on the electrical characteristics, and also provides information on the reactive power characteristics of the load, which is often neglected from standard consumption statistics. This data is particularly important for power system analysis. In addition to this, device ownership statistics and probability distribution functions of power demand are presented for the main residential loads. Although the data presented is primarily intended as a resource for the development of load profiles for power system analysis, it contains a large volume of information which provides a useful database for the wider research community.

Tsagarakis, G; Kiprakis, A E

2013-01-01T23:59:59.000Z

392

Measuring the CO2 flux at the air/water interface in lakes using flow injection analysis  

E-Print Network (OSTI)

, close to the sampling points, in order to allow in situ analysis. O´ leo Lake, a waterflood basin

Jardim, Wilson de Figueiredo

393

NREL: Vehicle Ancillary Loads Reduction - Integrated Modeling  

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

Integrated Modeling Integrated Modeling NREL's Vehicle Ancillary Loads Reduction (VALR) team predicts the impact of advanced vehicle cooling technologies before testing by using an integrated modeling process. Evaluating the heat load on a vehicle under real world conditions is a difficult task. An accepted method to evaluate passenger compartment airflow and heat transfer is computational fluid dynamics. (CFD). Combining analytical models with CFD provides a powerful tool to assist industry both on current vehicles and on future design studies. Flow chart showing the vehicle integrated modeling process which considers solar radiation, air conditioning, and vehicles with CAD, glazing, cabin thermal/fluid, and thermal comfort modeling tools. Results are provided for fuel economy, tailpipe emissions and occupant thermal comfort.

394

Matching equipment size to the cooling load  

SciTech Connect

This article presents a heat extraction rate analysis method, using ASHRAE algorithms that enables HVAC system designers to optimally size cooling equipment. The final stage of the cooling load calculation process determines the heat extraction rate required to achieve design conditions. Put another way, this stage determines the equipment capacity required to match the cooling load profile, and it does so in a manner that predicts the resulting space temperature profile, and it does so in a manner that predicts the resulting space temperature profile. It is a stage in the design process that, in practice, may not be given the attention it deserves.

Bloom, B. (Harvey Toub Engineering, Atlanta, GA (United States))

1993-10-01T23:59:59.000Z

395

Demand-Side Response from Industrial Loads  

Science Conference Proceedings (OSTI)

Through a research study funded by the Department of Energy, Smart Grid solutions company ENBALA Power Networks along with the Oak Ridge National Laboratory (ORNL) have geospatially quantified the potential flexibility within industrial loads to leverage their inherent process storage to help support the management of the electricity grid. The study found that there is an excess of 12 GW of demand-side load flexibility available in a select list of top industrial facilities in the United States. Future studies will expand on this quantity of flexibility as more in-depth analysis of different industries is conducted and demonstrations are completed.

Starke, Michael R [ORNL; Alkadi, Nasr E [ORNL; Letto, Daryl [Enbala Power Networks; Johnson, Brandon [University of Tennessee, Knoxville (UTK); Dowling, Kevin [University of Tennessee, Knoxville (UTK); George, Raoule [Enbala Power Networks; Khan, Saqib [University of Texas, Austin

2013-01-01T23:59:59.000Z

396

Probabilistic Rating and Equipment Temperature Tracking During Emergency Load Events  

Science Conference Proceedings (OSTI)

This report concerns a possible extension of the Electric Power Research Institute's (EPRI's) Dynamic Thermal Circuit Rating (DTCR) and Increased Power Flow (IPF) technologies. In most applications of dynamic rating and real-time monitoring to date, the purpose is to enhance the use of existing power equipment by calculating power flow limits based on real-time weather and load data, rather than using worst-case” assumptions. The goal of these enhancements has been to allow additional economic transfers ...

2008-02-25T23:59:59.000Z

397

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

398

NREL: Vehicle Ancillary Loads Reduction - Physiological Model  

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

Physiological Model Physiological Model The Vehicle Ancillary Loads Reduction team developed a three-dimensional model to simulate human internal thermal physiological systems (muscle, blood, etc.) and thermoregulatory responses such as metabolic heat generation. The model was developed with ANSYS, a finite element software which computes heat flow by conduction, convection, and mass transport of the blood. A human tissue system model represents the human body, including the physiological and thermal properties of the tissues. The arms and legs consist of bone, muscle, fat, and skin. There are additional lung, abdominal, and brain tissues in the torso and head zones. The model calculates the conduction heat transfer based on the temperature gradients between the tissue nodes. Blood flow is modeled with a network of supply

399

Part-Load Flow and Hydraulic Stability of Centrifugal Pumps  

Science Conference Proceedings (OSTI)

Replacement energy costs for outages of large plants caused by feedpump problems amount to more than $400 million annually. Laboratory tests were performed to increase understanding of the physical mechanisms responsible for unstable performance curves and hydraulic excitation forces that can lead to failure. Tentative guidelines have been established for the selection of hydraulic design parameters.Background The size and number of fossil-fired generating ...

1992-03-01T23:59:59.000Z

400

Designing Axial Flow Fan for Flow and Noise  

E-Print Network (OSTI)

A comprehensive finite element methodology is developed to predict the compressible flow performance of a non-symmetric 7-blade axial flow fan, and to quantify the source strength and sound pressure levels at any location in the system. The acoustic and flow performances of the fan are predicted simultaneously using a computational aero-acoustic technique combining transient flow analysis and noise propagation. The calculated sound power levels compare favorably with the measured sound power data per AMCA 300-96 code.

Subrata Roy; Phillip Cho; Fred Périé; International Off-highway

1999-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

TYBO/BENHAM: Model Analysis of Groundwater Flow and Radionuclide Migration from Underground Nuclear Tests in Southwestern Pahute Mesa, Nevada  

Science Conference Proceedings (OSTI)

Recent field studies have led to the discovery of trace quantities of plutonium originating from the BENHAM underground nuclear test in two groundwater observation wells on Pahute Mesa at the Nevada Test Site. These observation wells are located 1.3 km from the BENHAM underground nuclear test and approximately 300 m from the TYBO underground nuclear test. In addition to plutonium, several other conservative (e.g. tritium) and reactive (e.g. cesium) radionuclides were found in both observation wells. The highest radionuclide concentrations were found in a well sampling a welded tuff aquifer more than 500m above the BENHAM emplacement depth. These measurements have prompted additional investigations to ascertain the mechanisms, processes, and conditions affecting subsurface radionuclide transport in Pahute Mesa groundwater. This report describes an integrated modeling approach used to simulate groundwater flow, radionuclide source release, and radionuclide transport near the BENHAM and TYBO underground nuclear tests on Pahute Mesa. The components of the model include a flow model at a scale large enough to encompass many wells for calibration, a source-term model capable of predicting radionuclide releases to aquifers following complex processes associated with nonisothermal flow and glass dissolution, and site-scale transport models that consider migration of solutes and colloids in fractured volcanic rock. Although multiple modeling components contribute to the methodology presented in this report, they are coupled and yield results consistent with laboratory and field observations. Additionally, sensitivity analyses are conducted to provide insight into the relative importance of uncertainty ranges in the transport parameters.

Andrew Wolfsberg; Lee Glascoe; Guoping Lu; Alyssa Olson; Peter Lichtner; Maureen McGraw; Terry Cherry; Guy Roemer

2002-09-01T23:59:59.000Z

402

Analysis of mass loss of a coal particle during the course of burning in a flow of inert material  

SciTech Connect

This paper is an attempt to explain the role of erosion during the process of coal combustion in a circulating fluidized bed. Different kinds of carbon deposits found in Poland, both bituminous as well as lignite with the particle of 10 mm in diameter were the subject of the research. According to many publications it is well known that erosion plays a significant role in coal combustion, by changing its mechanism as well as generating an additional mass loss of the mother particle. The purpose of this research was to determine the influence of an inert material on an erosive mass loss of a single coal particle burning in a two-phase flow. The determination of the influence of a coal type, the rate of flow of inert material and the temperature inside the furnace on the erosive mass loss of burning coal particle was also taken into consideration. The results obtained indicate that the velocity of the erosive mass loss depends on the chemical composition and petrographic structure of burning coal. The mechanical interaction of inert and burning coal particles leads to the shortening of the period of overall mass loss of the coal particle by even two times. The increase in the rate of flow of the inert material intensifies the generation of mass loss by up to 100%. The drop in temperature which slows down the combustion process, decreases the mass loss of the coal particle as the result of mechanical interaction of the inert material. As was observed, the process of percolation plays a significant role by weakening the surface of the burning coal. (author)

Pelka, Piotr [Czestochowa University of Technology, Department of Boilers and Thermodynamics, Armii Krajowej 19c, Czestochowa, Silesia 42-200 (Poland)

2009-08-15T23:59:59.000Z

403

The influence of the time delay of information flow on an economy evolution. The stock market analysis  

E-Print Network (OSTI)

The decision process requires information about the present state of the system, but in economy acquiring data and processing them is an expensive and time consuming process. Therefore the state of the system is measured and announced at the end of the well defined time intervals. The model of a stock market coupled with an economy is investigated and the role of the length of the time delay of information flow investigated. It is shown that increasing the time delay leads to collective behavior of agents and oscillations of autocorrelations in absolute log-returns.

Miskiewicz, Janusz

2007-01-01T23:59:59.000Z

404

Research | Children’s Health Substance Flow Analysis: A Case Study of Fluoride Exposure through Food and Beverages in Young Children Living in Ethiopia  

E-Print Network (OSTI)

Con t e x t: Dental and skeletal fluorosis is endemic in the Ethiopian Rift Valley. Children are especially vulnerable to excessive fluoride intake because their permanent teeth are still being formed. Strategies to reduce the total fluoride intake by children are thus warranted. Case presentation: By combining the results of field studies in Ethiopia, the relevant pathways for fluoride intake have been identified in 28 children 2–5 years of age living in two villages on the Wonji Shoa Sugar Estate in the Ethiopian Rift Valley. The focus of the present study was to simulate the fluoride intake of the children using the methods of material flow analysis (MFA) and substance flow analysis. Discussion: With a model based on MFA, we quantified the potential reduction in total fluoride intake given different scenarios—for example, by reducing the fluoride intake from drinking water and cooking water. The results show clearly that only by removing fluoride completely from both drinking and cooking water does the probability of remaining below the daily tolerable upper intake level exceed 50%. Both prepared food and food ingredients must be taken into consideration when assessing the total fluoride intake by children living in high-fluoride areas. Relevance: This knowledge will help health personnel, the government, and the food authorities to give scientifically based advice on strategies for reducing the total fluoride intake by children living in high-fluoride areas in the Ethiopian Rift Valley.

Marian Kjellevold Malde; Ruth Scheidegger; Kåre Julshamn; Hans-peter Bader

2010-01-01T23:59:59.000Z

405

Flow instabilities in the core and the coolant circuit of advances low-boiling light water reacto: classification of causes and development of simulator for the future analysis  

E-Print Network (OSTI)

The coolant flow instability, apparent in the coolant mass flow fluctuations in the separate parallel heating channels and also in a closed loop of the primary circuit under some operating conditions, is observed in the core fuel assemblies of light water reactors. In some ways this phenomenon is identical with the fluctuations in the once-through steam generators pipes, and changes of the coolant mass flows and length of flow patterns are initiating this phenomenon. The parameters at the core output and the secondary circuit parameters have influence on each other. These parameter changes have significant influences on the operating processes, operating and control algorithms, operating and control system design, and reliability of the operating power plant's machines and equipment. Changes of heating surface temperatures, displacement borders of the flow patterns, and critical heat flux entail changes of the coolant flow parameters, finally causing changes of the initial primary system parameters due to closed loop system feedback. In turn, these cause over-circuit instability in the reactor. Core power generation changes are carried out by means of influencing the nuclear fission process through changing the multiplication factor. Additionally, these local side-to-side power irregularities in sub-zones may appear due to the influence of various hydrodynamic instabilities. The local side-to-side power in these sub-zones may differ significantly from each other. The aforesaid arguments are correct for the both light water reactor types. But, as is shown by our investigations and operational practice of low-boiling reactors, behavior of the core-circuit hydrodynamic system is significantly different from its behavior in the boiling or pressurized reactors with pumping circulation. The coolant flow regimes in typical reactors are defined through pump operating regimes and are not adjustable inside a certain power range. The objective of this thesis is to understand more precisely the influence and the nature of these phenomena. After analyzing the problem from different points of view and showing the necessity of its comprehensive understanding, we present recommendations for engineering solutions and plans for further investigations. We will try to determine limits of their reliable practical application with modern low-to-medium power reactor design and investigate this dynamic system behavior. Finally, it is necessary to take into consideration not separate phenomena, but their complex influence on the whole primary system (i.e. a kind of macro-system is examined without being separated into its individual elements). But, the analysis of every phenomenon is fulfilled separately and a process of formation of a block-scheme, consisting of several sub-systems, is given in this thesis. The final block-scheme is presented as a simulator model, taking into consideration design components chosen for the analysis of system dynamics as the first step of model development.

Rezvyi, Aleksey

2002-01-01T23:59:59.000Z

406

Ice Loads on a Lattice Tower Estimated by Weather Station Data  

Science Conference Proceedings (OSTI)

Atmospheric ice loads are a major design criterion of tall structures in cold regions. In this paper the possibility to derive the design ice loads using analysis of meteorological observations made routinely at a weather station is studied. Ice ...

Eva Sundin; Lasse Makkonen

1998-05-01T23:59:59.000Z

407

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

408

Load Model Data Processing and Parameter Derivation (LMDPPD) Version 2.1  

Science Conference Proceedings (OSTI)

The tool allows the user to find optimum values of parameters for two load model structures developed as part of the load modeling project using system disturbance data. Description It is important to represent the dynamic behavior of system load for system planning studies and analysis. Developing load models is a challenging task due to the varying nature of loads and uncertainty in the load information. The Load Model Data Processing and Parameter Derivation (LMDPPD) Version 2.1 software tool is a sim...

2009-09-02T23:59:59.000Z

409

Thermal-fluid and electrochemical modeling and performance study of a planar solid oxide electrolysis cell : analysis on SOEC resistances, size, and inlet flow conditions.  

DOE Green Energy (OSTI)

Argonne National Laboratory and Idaho National Laboratory researchers are analyzing the electrochemical and thermal-fluid behavior of solid oxide electrolysis cells (SOECs) for high temperature steam electrolysis using computational fluid dynamics (CFD) techniques. The major challenges facing commercialization of steam electrolysis technology are related to efficiency, cost, and durability of the SOECs. The goal of this effort is to guide the design and optimization of performance for high temperature electrolysis (HTE) systems. An SOEC module developed by FLUENT Inc. as part of their general CFD code was used for the SOEC analysis by INL. ANL has developed an independent SOEC model that combines the governing electrochemical mechanisms based on first principals to the heat transfer and fluid dynamics in the operation of SOECs. The ANL model was embedded into the commercial STAR-CD CFD software, and is being used for the analysis of SOECs by ANL. The FY06 analysis performed by ANL and reported here covered the influence of electrochemical properties, SOEC component resistances and their contributing factors, SOEC size and inlet flow conditions, and SOEC flow configurations on the efficiency and expected durability of these systems. Some of the important findings from the ANL analysis are: (1) Increasing the inlet mass flux while going to larger cells can be a compromise to overcome increasing thermal and current density gradients while increasing the cell size. This approach could be beneficial for the economics of the SOECs; (2) The presence of excess hydrogen at the SOEC inlet to avoid Ni degradation can result in a sizeable decrease in the process efficiency; (3) A parallel-flow geometry for SOEC operation (if such a thing be achieved without sealing problems) yields smaller temperature gradients and current density gradients across the cell, which is favorable for the durability of the cells; (4) Contact resistances can significantly influence the total cell resistance and cell temperatures over a large range of operating potentials. Thus it is important to identify and avoid SOEC stack conditions leading to such high resistances due to poor contacts.

Yildiz, B.; Smith, J.; Sofu, T.; Nuclear Engineering Division

2008-06-25T23:59:59.000Z

410

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

411

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

412

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

413

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

414

The International Heat Flow Commission | Open Energy Information  

Open Energy Info (EERE)

The International Heat Flow Commission The International Heat Flow Commission Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: The International Heat Flow Commission Details Activities (1) Areas (1) Regions (0) Abstract: Unavailable Author(s): A. E. Beck, V. Cermak Published: Geothermics, 1989 Document Number: Unavailable DOI: Unavailable Source: View Original Journal Article Data Acquisition-Manipulation (Beck & Cermak, 1989) Unspecified Retrieved from "http://en.openei.org/w/index.php?title=The_International_Heat_Flow_Commission&oldid=387748" Category: Reference Materials What links here Related changes Special pages Printable version Permanent link Browse properties 429 Throttled (bot load) Error 429 Throttled (bot load) Throttled (bot load) Guru Meditation: XID: 1863774514

415

Network flow model analysis of the impact of chlorofluorocarbon phaseout on acid-grade fluorspar. Information circular/1994  

SciTech Connect

Chlorofluorocarbons (CFC`s) are being phased out and eventually banned under extensive international agreements because the chlorine in CFC`s is thought to deplete the Earth`s ozone layer. As a result, the fluorspar mining industry, which is the source of fluorine in fluorocarbons through intermediate hydrofluoric acid, is being affected. Concern for this impact has led the U.S. Bureau of Mines to employ its capabilities to analyze various scenarios in the evolution of CFC replacements and substitutes to determine their effect on fluorspar mining. This report utilizes a network flow model to examine the effects of proposed replacements for CFC`s, in terms of fluorine content, on fluorspar operations worldwide and on hydrofluoric acid plants in North America and Europe.

Slatnick, J.A.; Fulton, R.B.

1994-12-31T23:59:59.000Z

416

A Control Scheme of Enhanced Reliability for Multiple Chiller Plants Using Mergerd Building Cooling Load Measurements  

E-Print Network (OSTI)

This paper presents a control scheme which utilizes the enhanced instantaneous cooling load measurements to improve the reliability of chiller sequencing control. The enhanced measurement is obtained by merging two different measurements of building cooling load using data fusion technique. One is the direct cooling load measurement, which is obtained directly using the differential water temperature and water flow rate measurements. The other is the indirect cooling load measurement, which estimates the cooling load using chiller models based on the instantaneous chiller electrical power input and condition measured variables. The control performance of the proposed scheme is validated in this paper.

Wang, S.; Sun, Y.; Huang, G.; Zhu, N.

2008-10-01T23:59:59.000Z

417

Mathematical Model for Efficient Water Flow Curic Vladimir  

E-Print Network (OSTI)

Industry, Mathematical and Computer Modelling, 39, pp. 1353- 1374, 2004 [6] Jeppson R. Analysis of flow

Krejiæ, Nata�a

418

Unloading using auger tool and foam and experimental identification of liquid loading of low rate natural gas wells  

E-Print Network (OSTI)

Low-pressure, low-producing natural gas wells commonly encounter liquid loading during production. Because of the decline in the reservoir pressure and the flow capacity, wells can fall below terminal velocity. Identifying and predicting the onset of liquid loading allows the operators to plan and prepare for combating the liquid loading hence saving valuable reserves and downtime. The present industrial applications of artificial lift, wellhead pressure reduction by compressor installation at the wellheads and reduction in tubing size are costly and often intermittent. The thesis examines the above aspects to generate a workflow for identifying and predicting the liquid loading conclusively and also assessing the application of Auger Tool and foam combination towards achieving a cost effective and more efficient solution for liquid unloading. In chapters I-IV, I describe the process of using production surveillance software of Halliburton Digital Consulting Services, named DSS (Dynamic Surveillance Software), to create a workflow of identifying the liquid loaded wells based on well data on daily basis for field personnel and engineers. This workflow also decides the most cost effective solution to handle it. Moreover, it can perform decline analysis to predict the conditions of liquid loading. In chapters V-VIII of the thesis, I describe the effort of handling the problem of liquid loading in a cost effective manner by introduction of an inexpensive Auger Tool in the bottomhole assembly and using WhiteMax surfactant soapstick from J&J Solutions. Four different combinations of well completion and fluid were tested for performance in respect to liquid hold up, pressure loss in the tubing, unloading efficiency and critical flow requirement. The test facilities and instruments, along with the operational methods, are discussed in chapter VI. Except for the reduction of the operational envelope with the inclusion of Auger Tool, the performance improved with the insertion of Auger Tool. The best combination of Auger and foam system could be a result of flow modification by the Auger Tool caused by reduced pressure loss and increase in drag coefficient and also by reduced density and surface tension of foam.

Bose, Rana

2003-05-01T23:59:59.000Z

419

A new generation of load sharing algorithms: the semi-adaptive load sharing algorithm  

E-Print Network (OSTI)

Distributed systems have become a popular computing environment. Due to their high potentials in improving performance and resource sharing, the evolution and maturing of technologies such as networks and computer hardware, have led to more realizations of distributed computing capabilities. One of the key factors that impacts the system's performance is how load sharing is handled. Most of the work done in load sharing algorithms focused on either one of two approaches: the static approach, or the dynamic approach. Static load sharing is characterized with its simplicity and minimal overhead induced on the system when performing load distribution. This is attributed to the fact that their load sharing decisions do not require any information exchange between nodes. However, static algorithms are not capable of adapting to traffic changes. Hence, this will affect the distributed system adaptability and stability features against load alteration. The second approach in load sharing algorithums is the dynamic approach. In this approach, nodes base their sharing decisions on the knowledge of the status on other nodes. This knowledge enables nodes to make improved decisions when selecting a remote execution site. Therefore, these algorithms provide the distributed system with adaptability and stability. Nevertheless, information exchange between nodes has proven to be expensive. The problem lies in the communication and processing overheads which these algorithms impose on the system. This research work presents a Semi-Adaptive load sharing approach that attempts to lay a common ground between the dynamic and the static approaches. This approach provides the system with adaptability features at are supplied with tools to control the level of adaptability and information exchange in the system. It is argued that this approach is adaptable, scalable, stable, fault tolerant, and will generate low and controlled system overheads. Two implementations of the Semi-Adaptive approach are presented: The Controller Load Sharing Protocol (CLSP) and The Pool Load Sharing Protocol (PLSP). The study of CLSP and PLSP include simulating their performance under various conditions. The simulation include comparing the performance of these two protocols against two load sharing algorithms representing the static and dynamic families. Furthermore, the properties of CLSP and PLSP are investigated. Finally, based on the study and analysis of both protocols, the research work proposes possible areas of improvement in the final conclusion.

Morsy, Hazem Kamal

1997-01-01T23:59:59.000Z

420

Prediction of loaded airfoil unsteady aerodynamic gust response by a locally analytical method  

Science Conference Proceedings (OSTI)

A complete first order model is formulated to analyze the effects of steady loading on the incompressible unsteady aerodynamics generated by a two-dimensional gust convected with the steady mean flow past an arbitrary airfoil at finite nonzero angle ...

Hsiao-Wei D. Chiang; Sanford Fleeter

1988-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "load flow analysis" 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

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

422

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.

423

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

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

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

426

Probability based load combinations for design of category I structures  

SciTech Connect

This paper discusses a reliability analysis method and a procedure for developing the load combination design criteria for category I structures. For safety evaluation of category I concrete structures under various static and dynamic loads, a probability-based reliability analysis method has been developed. This reliability analysis method is also used as a tool for determining the load factors for design of category I structures. In this paper, the load combinations for design of concrete containments, corresponding to a target limit state probability of 1.0 x 10/sup -6/ in 4 years, are described. A comparison of containments designed using the ASME code and the proposed design criteria is also presented.

Reich, M.; Hwang, H.

1985-01-01T23:59:59.000Z

427

AN INVESTIGATION TO RESOLVE THE INTERACTION BETWEEN FUEL CELL, POWER CONDITIONING SYSTEM AND APPLICATION LOADS  

SciTech Connect

Solid-Oxide Fuel Cell (SOFC) stacks respond quickly to changes in load and exhibit high part- and full-load efficiencies due to its rapid electrochemistry. However, this is not true for the thermal, mechanical, and chemical balance-of-plant subsystem (BOPS), where load-following time constants are, typically, several orders of magnitude higher. This dichotomy diminishes the reliability and performance of the electrode with increasing demand of load. Because these unwanted phenomena are not well understood, the manufacturers of SOFC use conservative schemes (such as, delayed load-following to compensate for slow BOPS response or expensive inductor filtering) to control stack responses to load variations. This limits the applicability of SOFC systems for load-varying stationary and transportation applications from a cost standpoint. Thus, a need exists for the synthesis of component- and system-level models of SOFC power-conditioning systems and the development of methodologies for investigating the system-interaction issues (which reduce the lifetime and efficiency of a SOFC) and optimizing the responses of each subsystem, leading to optimal designs of power-conditioning electronics and optimal control strategies, which mitigate the electrical-feedback effects. Equally important are ''multiresolution'' finite-element modeling and simulation studies, which can predict the impact of changes in system-level variables (e.g., current ripple and load-transients) on the local current densities, voltages, and temperature (these parameters are very difficult or cumbersome, if not impossible to obtain) within a SOFC cell. Towards that end, for phase I of this project, sponsored by the U.S. DOE (NETL), we investigate the interactions among fuel cell, power-conditioning system, and application loads and their effects on SOFC reliability (durability) and performance. A number of methodologies have been used in Phase I to develop the steady-state and transient nonlinear models of the SOFC stack subsystem (SOFCSS), the power-electronics subsystem (PES), and the BOPS. Such an approach leads to robust and comprehensive electrical, electrochemical, thermodynamic, kinetic, chemical, and geometric models of the SOFSS, PES and application loads, and BOPS. A comprehensive methodology to resolve interactions among SOFCSS, PES and application loads and to investigate the impacts of the fast- and slow-scale dynamics of the power-conditioning system (PCS) on the SOFCSS has been developed by this team. Parametric studies on SOFCSS have been performed and the effects of current ripple and load transients on SOFC material properties are investigated. These results are used to gain insights into the long-term performance and reliability of the SOFCSS. Based on this analysis, a novel, efficient, and reliable PES for SOFC has been developed. Impacts of SOFC PCS control techniques on the transient responses, flow parameters, and current densities have also been studied and a novel nonlinear hybrid controller for single/parallel DC-DC converter has been developed.

Sudip K. Mazumder; Chuck McKintyre; Dan Herbison; Doug Nelson; Comas Haynes; Michael von Spakovsky; Joseph Hartvigsen; S. Elangovan

2003-11-03T23:59:59.000Z

428

AN INVESTIGATION TO RESOLVE THE INTERACTION BETWEEN FUEL CELL, POWER CONDITIONING SYSTEM AND APPLICATION LOADS  

DOE Green Energy (OSTI)

Solid-Oxide Fuel Cell (SOFC) stacks respond quickly to changes in load and exhibit high part- and full-load efficiencies due to its rapid electrochemistry. However, this is not true for the thermal, mechanical, and chemical balance-of-plant subsystem (BOPS), where load-following time constants are, typically, several orders of magnitude higher. This dichotomy diminishes the reliability and performance of the electrode with increasing demand of load. Because these unwanted phenomena are not well understood, the manufacturers of SOFC use conservative schemes (such as, delayed load-following to compensate for slow BOPS response or expensive inductor filtering) to control stack responses to load variations. This limits the applicability of SOFC systems for load-varying stationary and transportation applications from a cost standpoint. Thus, a need exists for the synthesis of component- and system-level models of SOFC power-conditioning systems and the development of methodologies for investigating the system-interaction issues (which reduce the lifetime and efficiency of a SOFC) and optimizing the responses of each subsystem, leading to optimal designs of power-conditioning electronics and optimal control strategies, which mitigate the electrical-feedback effects. Equally important are ''multiresolution'' finite-element modeling and simulation studies, which can predict the impact of changes in system-level variables (e.g., current ripple and load-transients) on the local current densities, voltages, and temperature (these parameters are very difficult or cumbersome, if not impossible to obtain) within a SOFC cell. Towards that end, for phase I of this project, sponsored by the U.S. DOE (NETL), we investigate the interactions among fuel cell, power-conditioning system, and application loads and their effects on SOFC reliability (durability) and performance. A number of methodologies have been used in Phase I to develop the steady-state and transient nonlinear models of the SOFC stack subsystem (SOFCSS), the power-electronics subsystem (PES), and the BOPS. Such an approach leads to robust and comprehensive electrical, electrochemical, thermodynamic, kinetic, chemical, and geometric models of the SOFSS, PES and application loads, and BOPS. A comprehensive methodology to resolve interactions among SOFCSS, PES and application loads and to investigate the impacts of the fast- and slow-scale dynamics of the power-conditioning system (PCS) on the SOFCSS has been developed by this team. Parametric studies on SOFCSS have been performed and the effects of current ripple and load transients on SOFC material properties are investigated. These results are used to gain insights into the long-term performance and reliability of the SOFCSS. Based on this analysis, a novel, efficient, and reliable PES for SOFC has been developed. Impacts of SOFC PCS control techniques on the transient responses, flow parameters, and current densities have also been studied and a novel nonlinear hybrid controller for single/parallel DC-DC converter has been developed.

Sudip K. Mazumder; Chuck McKintyre; Dan Herbison; Doug Nelson; Comas Haynes; Michael von Spakovsky; Joseph Hartvigsen; S. Elangovan

2003-11-03T23:59:59.000Z

429

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

430

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

431

A new aggregation method for determining composite load characteristics  

SciTech Connect

A new aggregation method for determining load characteristics for representation in computer simulations is proposed. In support of the new method, a mathematical derivation is presented. Also, results are compared with models obtained by using the EPRI/University of Texas at Arlington method and field tests. The application of the proposed method is simpler than existing methods in that it does not require field tests or the use of curve fitting techniques. The procedure should be of primary interest to transmission system planners involved in load flow and dynamic stability simulations of power systems.

Rideiro, J.R.; Lange, F.J.

1982-08-01T23:59:59.000Z

432

A linearized formulation of triphasic mixture theory for articular cartilage, and its application to indentation analysis  

E-Print Network (OSTI)

to complicated loading profiles, e.g., indentation or other multi-dimensional configurations. In this study to indentation analysis Xin L. Lu, Leo Q. Wan, X. Edward Guo, Van C. Mow n Department of Biomedical Engineering the deformational, electrical, and flow behaviors inside the articular cartilage under indentation. The calculated

Linhardt, Robert J.

433

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

434

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...

435

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...

436

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

437

Failure Loads and Deformation in 6061-T6 Aluminum Alloy Spot ...  

Science Conference Proceedings (OSTI)

Presentation Title, Failure Loads and Deformation in 6061-T6 Aluminum Alloy ... Application of Neutron Diffraction in Analysis of Residual Stress Profile in the ...

438

Application of direct-fitting, mass-integral, and multi-ratemethods to analysis of flowing fluid electric conductivity logs fromHoronobe, Japan  

Science Conference Proceedings (OSTI)

The flowing fluid electric conductivity (FFEC) loggingmethod is an efficient way to provide information on the depths,salinities, and transmissivities of individual conductive featuresintercepted by a borehole, without the use of specialized probes. Usingit in a multiple-flow-rate mode allows, in addition, an estimate of theinherent "far-field" pressure heads in each of the conductive features.The multi-rate method was successfully applied to a 500-m borehole in agranitic formation and reported recently. The present paper presents theapplication of the method to two zones within a 1000-m borehole insedimentary rock, which produced, for each zone, three sets of logs atdifferent pumping rates, each set measured over a period of about oneday. The data sets involve a number of complications, such as variablewell diameter, free water table decline in the well, and effects ofdrilling mud. To analyze data from this borehole, we apply varioustechniques that have been developed for analyzing FFEC logs:direct-fitting, mass-integral, and the multi-rate method mentioned above.In spite of complications associated with the tests, analysis of the datais able to identify 44 hydraulically conducting fractures distributedover the depth interval 150-775 meters below ground surface. Thesalinities (in FEC), and transmissivities and pressure heads (indimensionless form) of these 44 features are obtained and found to varysignificantly among one another. These results are compared with datafrom eight packer tests with packer intervals of 10-80 m, which wereconducted in this borehole over the same depth interval. They are foundto be consistent with these independent packer-test data, thusdemonstrating the robustness of the FFEC logging method under non-idealconditions.

Doughty, C.; Tsang, C.-F.; Hatanaka, K.; Yabuuchi, S.; Kurikami, H.

2007-08-01T23:59:59.000Z

439

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

440

Water Energy Load Profiling (WELP) Tool | Open Energy Information  

Open Energy Info (EERE)

Water Energy Load Profiling (WELP) Tool Water Energy Load Profiling (WELP) Tool Jump to: navigation, search Tool Summary Name: Water Energy Load Profiling (WELP) Tool Agency/Company /Organization: California Public Utilities Commission (CPUC) Sector: Energy, Water Focus Area: Energy Efficiency, - Embodied Energy, Water Conservation Phase: Determine Baseline, "Evaluate Effectiveness and Revise" is not in the list of possible values (Bring the Right People Together, Create a Vision, Determine Baseline, Evaluate Options, Develop Goals, Prepare a Plan, Get Feedback, Develop Finance and Implement Projects, Create Early Successes, Evaluate Effectiveness and Revise as Needed) for this property. Topics: GHG inventory, Policies/deployment programs, Resource assessment, Background analysis

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