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1

MHK Technologies/Vortex Induced Vibrations Aquatic Clean Energy VIVACE |  

Open Energy Info (EERE)

Vortex Induced Vibrations Aquatic Clean Energy VIVACE Vortex Induced Vibrations Aquatic Clean Energy VIVACE < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Vortex Induced Vibrations Aquatic Clean Energy VIVACE.jpg Technology Profile Primary Organization Vortex Hydro Energy LLC Project(s) where this technology is utilized *MHK Projects/Marine Hydrodynamics Laboratory at the University of Michigan Technology Resource Click here Current/Tidal Technology Type Click here Reciprocating Device Technology Readiness Level Click here TRL 4: Proof of Concept Technology Description The VIVACE (Vortex Induced Vibrations Aquatic Clean Energy) device is based on the extensively studied phenomenon of Vortex Induced Vibrations (VIV), which was first observed five-hundred years ago by Leonardo DaVinci in the form of 'Aeolian Tones.' VIV results from vortices forming and shedding on the downstream side of a bluff body in a current. Vortex shedding alternates from one side to the other, thereby creating a vibration or oscillation. The VIV phenomenon is non-linear, which means it can produce useful energy at high efficiency over a wide range of current speeds and directions.This converter is unlike any existing technology, as it does not use turbines, propellers, or dams. VIVACE converts the horizontal hydrokinetic energy of currents into cylinder mechanical energy. The latter is then converted to electricity through electric power generators.

2

Low Head, Vortex Induced Vibrations River Energy Converter  

DOE Green Energy (OSTI)

Vortex Induced Vibrations Aquatic Clean Energy (VIVACE) is a novel, demonstrated approach to extracting energy from water currents. This invention is based on a phenomenon called Vortex Induced Vibrations (VIV), which was first observed by Leonardo da Vinci in 1504AD. He called it ‘Aeolian Tones.’ For decades, engineers have attempted to prevent this type of vibration from damaging structures, such as offshore platforms, nuclear fuel rods, cables, buildings, and bridges. The underlying concept of the VIVACE Converter is the following: Strengthen rather than spoil vortex shedding; enhance rather than suppress VIV; harness rather than mitigate VIV energy. By maximizing and utilizing this unique phenomenon, VIVACE takes this “problem” and successfully transforms it into a valuable resource for mankind.

Bernitsas, Michael B.; Dritz, Tad

2006-06-30T23:59:59.000Z

3

Energy harvesting using vortex-induced vibrations of tensioned cables  

E-Print Network (OSTI)

The development of energy harvesting systems based on fluid/structure interactions is part of the global search for innovative tools to produce renewable energy. In this paper, the possibility to harvest energy from a flow using vortex-induced vibrations (VIV) of a tensioned flexible cable is analyzed. The fluid loading on the vibrating solid and resulting dynamics are computed using an appropriate wake-oscillator model, allowing one to perform a systematic parametric study of the efficiency. The generic case of an elastically-mounted rigid cylinder is first investigated, before considering an infinite cable with two different types of energy harvesting : a uniformly spanwise distributed harvesting and then a periodic distribution of discrete harvesting devices. The maximum harvesting efficiency is of the same order for each configuration and is always reached when the solid body and its wake are in a frequency lock-in state.

Grouthier, Clement; de Langre, Emmanuel

2012-01-01T23:59:59.000Z

4

Vortex induced vibration for aquatic clean power (VIVACE)NOTE FROM ACM: It has been determined that the author of this article plagiarized the contents from a previously published paper. Therefore ACM has shut off access to this paper.  

Science Conference Proceedings (OSTI)

NOTE FROM ACM: It has been determined that the author of this article plagiarized the contents from a previously published paper. Therefore ACM has shut off access to this paper. The paper by M. K. Raj and B. G. Muthuraj plagiarizes the ... Keywords: VIVACE, reynolds number, undulations, vortex shedding, vortex vibrations

M. K. Raj; B. G. Muthuraj

2011-02-01T23:59:59.000Z

5

Enhancement of vortex induced forces and motion through surface roughness control  

SciTech Connect

Roughness is added to the surface of a bluff body in a relative motion with respect to a fluid. The amount, size, and distribution of roughness on the body surface is controlled passively or actively to modify the flow around the body and subsequently the Vortex Induced Forces and Motion (VIFM). The added roughness, when designed and implemented appropriately, affects in a predetermined way the boundary layer, the separation of the boundary layer, the level of turbulence, the wake, the drag and lift forces, and consequently the Vortex Induced Motion (VIM), and the fluid-structure interaction. The goal of surface roughness control is to increase Vortex Induced Forces and Motion. Enhancement is needed in such applications as harnessing of clean and renewable energy from ocean/river currents using the ocean energy converter VIVACE (Vortex Induced Vibration for Aquatic Clean Energy).

Bernitsas, Michael M. (Saline, MI); Raghavan, Kamaldev (Houston, TX)

2011-11-01T23:59:59.000Z

6

Case Study of an Orographically Induced Mesoscale Vortex (Denver Cyclone)  

Science Conference Proceedings (OSTI)

Observations taken during the Convection Initiation and Downburst Experiment (CINDE) are used to describe the formation and structure of an orographically induced mesoscale vortex that frequently occurs in northeastern Colorado. This vortex, ...

J. M. Wilczak; T. W. Christian

1990-05-01T23:59:59.000Z

7

Visualization of vibration experienced in offshore platforms  

E-Print Network (OSTI)

In this thesis, I design and evaluate methods to optimize the visualization of vortex-induced vibration (VIV) in marine risers. VIV is vibration experienced by marine risers in offshore drilling platforms due to ocean ...

Patrikalakis, Alexander Marinos Charles

2010-01-01T23:59:59.000Z

8

Blast-induced ground vibration prediction using support vector machine  

Science Conference Proceedings (OSTI)

Ground vibrations induced by blasting are one of the fundamental problems in the mining industry and may cause severe damage to structures and plants nearby. Therefore, a vibration control study plays an important role in the minimization of environmental ... Keywords: Blast vibration, Coefficient of determination, Conventional vibration predictor equations, Mean absolute error, Support vector machine

Manoj Khandelwal

2011-07-01T23:59:59.000Z

9

US LMFBR (Liquid Metal Fast Breeder Reactor): flow induced vibration program (1977-1986): A summary and overview  

SciTech Connect

This paper summarizes the activities and accomplishments under the US LMFBR Flow Induced Vibration Program for the period 1977-1986. Since 1977 represents the date of the last IAEA IWGFR Specialists Meeting on LMFBR Flow Induced Vibration, this paper thus provides an update to the results presented at that meeting. This period also represents a period of substantial change for the US LMFBR program. A major reactor project, the FFTF, was completed and a second major project, the CRBR plant, was terminated. This change adversely impacted the US flow induced vibration program. Nevertheless, base technology activities have continued. In this paper, research in the following areas is summarized: Vibration characteristics and scaling, Turbulent buffeting and vortex shedding, Fluidelastic instabilities of tube bundles in crossflow, and Instabilities induced by leakage flows.

Wambsganss, M.W.; Chen, S.S.; Mulcahy, T.M.; Jendrzejczyk, J.A.

1986-09-01T23:59:59.000Z

10

Control of human induced floor vibrations  

E-Print Network (OSTI)

With the growing demand for open, column-free floor spaces and the advances in material strength, floor vibration serviceability criterion has been of growing importance within the past 20-30 years. All floor systems are ...

Homen, Sean Manuel

2007-01-01T23:59:59.000Z

11

Vibration-Induced Conductance Fluctuation (VICOF) Testing of Soils  

E-Print Network (OSTI)

In this Letter, we propose and experimentally demonstrate a simple method to provide additional information by conductance measurements of soils. While the AC electrical conductance of the soil is measured, it is exposed to a periodic vibration. The vibration-induced density fluctuation implies a corresponding conductivity fluctuation that can be seen as combination frequency components, the sum and the difference of the mean AC frequency and the vibration frequency, in the current response. The method is demonstrated by measurements on two different soil types.

Kish, L B; Kishne, A S; Kish, Laszlo B.; Morgan, Cristine L.S.; Kishne, Andrea Sz.

2005-01-01T23:59:59.000Z

12

Vibration-Induced Conductivity Fluctuation (VICOF) Testing of Soils  

E-Print Network (OSTI)

In this Letter, we propose and experimentally demonstrate a simple method to provide additional in-formation by conductivity measurements of soils. The AC electrical conductance of the soil is measured while it is exposed to a periodic vibration. The vibration-induced density fluctuation implies a corresponding conductivity fluctuation that can be seen as combination frequency components, the sum and the difference of the mean AC frequency and the double of vibration frequency, in the current response. The method is demonstrated by measurements on clayey and sandy soils.

Laszlo B. Kish; Cristine L. S. Morgan; Andrea Sz. Kishne

2005-10-31T23:59:59.000Z

13

Flow-induced vibration of circular cylindrical structures  

SciTech Connect

This report summarizes the flow-induced vibration of circular cylinders in quiescent fluid, axial flow, and crossflow, and applications of the analytical methods and experimental data in design evaluation of various system components consisting of circular cylinders. 219 figs., 30 tabs. (JDB)

Chen, S.S.

1985-06-01T23:59:59.000Z

14

Mooring Vibration as a Source of Current Meter Error and Its Correction  

Science Conference Proceedings (OSTI)

Data from instrumented moorings are used to show that rate underreading of Aanderaa paddle-wheel rotor current meters is a result of mooring vibration induced by vortex shedding from spherical in-line buoyancy. Direct evidence of this mooring ...

James M. Hamilton; George A. Fowler; Donald J. Belliveau

1997-06-01T23:59:59.000Z

15

Flow-induced vibration in LMFBR steam generators: a state-of-the-art review  

SciTech Connect

This state-of-the-art review identifies and discusses existing methods of flow-induced vibration analysis applicable to steam generators, their limitations, and base-technology needs. Also included are discussions of five different LMFBR steam-generator configurations and important design considerations, failure experiences, possible flow-induced excitation mechanisms, vibration testing, and available methods of vibration analysis. The objectives are to aid LMFBR steam-generator designers in making the best possible evaluation of potential vibration in steam-generator internals, and to provide the basis for development of design guidelines to avoid detrimental flow-induced vibration. (auth)

Shin, Y.S.; Wambsganss, M.W.

1975-05-01T23:59:59.000Z

16

Vortex Hydro Energy LLC | Open Energy Information  

Open Energy Info (EERE)

Hydro Energy LLC Hydro Energy LLC Jump to: navigation, search Name Vortex Hydro Energy LLC Address 4870 West Clark Rd Suite 108 Place Ypsilanti Zip 48197 Sector Marine and Hydrokinetic Phone number 734.971.4020 Website http://www.vortexhydroenergy.c Region United States LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This company is listed in the Marine and Hydrokinetic Technology Database. This company is involved in the following MHK Projects: Marine Hydrodynamics Laboratory at the University of Michigan This company is involved in the following MHK Technologies: Vortex Induced Vibrations Aquatic Clean Energy VIVACE This article is a stub. You can help OpenEI by expanding it. Retrieved from "http://en.openei.org/w/index.php?title=Vortex_Hydro_Energy_LLC&oldid=678497

17

VIBRATIONS INDUCED BY THE FLOW OF MAGNET COOLING WATER  

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

Technology Division LS-82 MCTMV 1122 January 30, 1987 In September, 1986, the Mechanics and Vibrations Section of the MCT Division performed a vibration survey of the Phase...

18

Vibration Induced Droplet Generation from a Liquid Layer for Evaporative Cooling in a Heat Transfer Cell .  

E-Print Network (OSTI)

??During this investigation, vibration induced droplet generation from a liquid layer was examined as a means for achieving high heat flux evaporative cooling. Experiments were… (more)

Pyrtle, Frank, III

2005-01-01T23:59:59.000Z

19

Probing the spin polarization of current by soft x-ray imaging of current-induced magnetic vortex dynamics  

SciTech Connect

Time-resolved soft X-ray transmission microscopy is applied to image the current-induced resonant dynamics of the magnetic vortex core realized in a micron-sized Permalloy disk. The high spatial resolution better than 25 nm enables us to observe the resonant motion of the vortex core. The result also provides the spin polarization of the current to be 0.67 {+-} 0.16 for Permalloy by fitting the experimental results with an analytical model in the framework of the spin-transfer torque.

Kasai, Shinya; Fischer, Peter; Im, Mi-Young; Yamada, Keisuke; Nakatani, Yoshinobu; Kobayashi, Kensuke; Kohno, Hiroshi; Ono, Teruo

2008-12-09T23:59:59.000Z

20

vibration  

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

Electronics Testing for Electronics Testing for NANOMETER VIBRATION READING on The Next Linear Collider Project SUMMER INTERN PROJECT Rachel Lansom, Advisor: Josef Frisch, Collaborator: Sara Waugh INTRODUCTION SYNTHESIZER TEST AMPLIFIER TEST THE STATIC ACCELEROMETER TESTING THE CAPACITOR CONCLUSION ACKNOWLEDGEMENTS REFERENCES The NLC when it is completed will consist of two separate beam lines about ten kilometers in length. The beams from these beam lines are expected to converge to a diameter of only a few nanometers just prior to annihilation. One of many problems associated with such small beams is the slight movement of the earth (vibration). These vibrations cause the focusing magnets to move the beams off their collision paths. The earth itself is rather vibrationally quiet, but cars, construction, industries, and human

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Theory and Techniques for Vibration-Induced Conductivity Fluctuation testing of Soils  

E-Print Network (OSTI)

First we present and theoretically analyze the phenomenological physical picture behind Vibration-Induced Conductivity Fluctuations. We identify the relevant tensors characterizing the electromechanical response against the vibrations for both longitudinal and transversal responses. We analyze the conductivity response with acceleration type vibrations and a new scheme, measurements with more advantageous compression type vibrations that are first introduced here. Compression vibrations provide sideband spectral lines shifted by the frequency of the vibration instead of its second harmonics; moreover the application of this method is less problematic with loose electrodes. Concerning geometry and electrodes, the large measurement errors in earlier experiment indicated electrode effects which justify using four-electrode type measurements. We propose and analyze new arrangements for the longitudinal and transversal measurements with both compression vibration and acceleration vibration for laboratory and field conditions.

Hung-Chih Chang; Laszlo B. Kish; Andrea Kishne; Cristine Morgan; Chiman Kwan

2009-01-22T23:59:59.000Z

22

Development of Design Criteria for Fluid Induced Structural Vibrations in Steam Generators and Heat Exchangers  

SciTech Connect

Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers.

Uvan Catton; Vijay K. Dhir; Deepanjan Mitra; Omar Alquaddoomi; Pierangelo Adinolfi

2004-04-06T23:59:59.000Z

23

Time domain 3D finite element modelling of train-induced vibration at high speed  

Science Conference Proceedings (OSTI)

The purpose of this paper is to investigate a 3D finite element (FE) coupled train-track model for the numerical modelling of the ground induced vibration due to the passage of a single high speed train locomotive. The track components such as the sleepers, ... Keywords: Finite elements, Ground vibration, High-speed, Mach cone, Railways

A. El Kacimi; P. K. Woodward; O. Laghrouche; G. Medero

2013-03-01T23:59:59.000Z

24

Structure of a Midtropospheric Vortex Induced by a Mesoscale Convective System  

Science Conference Proceedings (OSTI)

On 9 June 1988 a mesoscale (200-km diameter) convectively generated vortex (MCV) passed through the Colorado wind-profiling network. The generating convective system, which was too small to meet Maddox’s mesoscale convective complex criteria, ...

Diana L. Bartels; John M. Brown; Edward I. Tollerud

1997-02-01T23:59:59.000Z

25

Piezoelectric energy harvesting: vortex induced vibrations in plants, soap films, and arrays of cylinders .  

E-Print Network (OSTI)

??The goal of this project was to develop a wind generator that utilizes the collective oscillating motion of multiple piezoelectric devices. These devices would be… (more)

Hobbs, William Bradford

2010-01-01T23:59:59.000Z

26

Energy harvesting from wind-induced vibration of suspension bridges  

E-Print Network (OSTI)

Recently, an extensive amount of research has been focused on energy harvesting from structural vibration sources for wireless self-powered microsystem applications. One method of energy harvesting is using electromagnetic ...

Shi, Miao, M. Eng. Massachusetts Institute of Technology

2013-01-01T23:59:59.000Z

27

Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis  

E-Print Network (OSTI)

Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified re...

Kishne, Andrea Sz; Chang, Hung-Chih; Kish, Laszlo B

2007-01-01T23:59:59.000Z

28

On the axial dispersion induced by vibrations of a exible D. Brodaya,  

E-Print Network (OSTI)

dispersion of drugs in conduits of the cow's milk system is similar to gas dispersion in airways. Antibiotics that dispersion due to streaming eects in gas-®lled ¯exible tubes which vibrate in a long wave-length radial mode of enhancing dispersion in gas-®lled elastic tubes due to ¯ow induced by vibrations of the tube-walls. We

29

Nanoscale strain-induced pair suppression as a vortex-pinning mechanism in high- temperature superconductors  

SciTech Connect

Boosting large-scale superconductor applications require nanostructured conductors with artificial pinning centres immobilizing quantized vortices at high temperature and magnetic fields. Here we demonstrate a highly effective mechanism of artificial pinning centers in solution-derived high-temperature superconductor nanocomposites through generation of nanostrained regions where Cooper pair formation is suppressed. The nanostrained regions identified from transmission electron microscopy devise a very high concentration of partial dislocations associated with intergrowths generated between the randomly oriented nanodots and the epitaxial YBa{sub 2}Cu{sub 3}O{sub 7} matrix. Consequently, an outstanding vortex-pinning enhancement correlated to the nanostrain is demonstrated for four types of randomly oriented nanodot, and a unique evolution towards an isotropic vortex-pinning behaviour, even in the effective anisotropy, is achieved as the nanostrain turns isotropic. We suggest a new vortex-pinning mechanism based on the bond-contraction pairing model, where pair formation is quenched under tensile strain, forming new and effective core-pinning regions.

Llordes, Anna [ICMAB, Barcelona, Spain; Palau, A. [ICMAB, Barcelona, Spain; Gazquez, J. [Oak Ridge National Laboratory (ORNL); Coll, M. [ICMAB, Barcelona, Spain; Vlad, R. [ICMAB, Barcelona, Spain; Pomar, A. [ICMAB, Barcelona, Spain; Arbiol, Jordi [ICMAB, Barcelona, Spain; Guzman, Roger [ICMAB, Barcelona, Spain; Ye, S. [ICMAB, Barcelona, Spain; Rouco, V [ICMAB, Barcelona, Spain; Sandiumenge, Felip [ICMAB, Barcelona, Spain; Ricart, Susagna [ICMAB, Barcelona, Spain; Puig, Teresa [ICMAB, Barcelona, Spain; Varela del Arco, Maria [ORNL; Chataigner, D. [CRISMAT, Caen, France; Vanacken, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Gutierrez, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Moschalkov, V. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Deutscher, G. [Tel Aviv University; Magen Dominguez, Cesar [ORNL; Obradors, Xavier [ICMAB, Barcelona, Spain

2012-01-01T23:59:59.000Z

30

Effects of Combustion-Induced Vortex Breakdown on Flashback Limits of Syngas-Fueled Gas Turbine Combustors  

DOE Green Energy (OSTI)

Turbine combustors of advanced power systems have goals to achieve very low pollutants emissions, fuel variability, and fuel flexibility. Future generation gas turbine combustors should tolerate fuel compositions ranging from natural gas to a broad range of syngas without sacrificing operational advantages and low emission characteristics. Additionally, current designs of advanced turbine combustors use various degrees of swirl and lean premixing for stabilizing flames and controlling high temperature NOx formation zones. However, issues of fuel variability and NOx control through premixing also bring a number of concerns, especially combustor flashback and flame blowout. Flashback is a combustion condition at which the flame propagates upstream against the gas stream into the burner tube. Flashback is a critical issue for premixed combustor designs, because it not only causes serious hardware damages but also increases pollutant emissions. In swirl stabilized lean premixed turbine combustors onset of flashback may occur due to (i) boundary layer flame propagation (critical velocity gradient), (ii) turbulent flame propagation in core flow, (iii) combustion instabilities, and (iv) upstream flame propagation induced by combustion induced vortex breakdown (CIVB). Flashback due to first two foregoing mechanisms is a topic of classical interest and has been studied extensively. Generally, analytical theories and experimental determinations of laminar and turbulent burning velocities model these mechanisms with sufficient precision for design usages. However, the swirling flow complicates the flashback processes in premixed combustions and the first two mechanisms inadequately describe the flashback propensity of most practical combustor designs. The presence of hydrogen in syngas significantly increases the potential for flashback. Due to high laminar burning velocity and low lean flammability limit, hydrogen tends to shift the combustor operating conditions towards flashback regime. Even a small amount of hydrogen in a fuel blend triggers the onset of flashback by altering the kinetics and thermophysical characteristics of the mixture. Additionally, the presence of hydrogen in the fuel mixture modifies the response of the flame to the global effects of stretch and preferential diffusion. Despite its immense importance in fuel flexible combustor design, little is known about the magnitude of fuel effects on CIVB induced flashback mechanism. Hence, this project investigates the effects of syngas compositions on flashback resulting from combustion induced vortex breakdown. The project uses controlled experiments and parametric modeling to understand the velocity field and flame interaction leading to CIVB driven flashback.

Ahsan Choudhuri

2011-03-31T23:59:59.000Z

31

Development of Design Criteria for Fluid Induced Structural Vibration in Steam Generators and Heat Exchangers  

SciTech Connect

OAK-B135 Flow-induced vibration in heat exchangers has been a major cause of concern in the nuclear industry for several decades. Many incidents of failure of heat exchangers due to apparent flow-induced vibration have been reported through the USNRC incident reporting system. Almost all heat exchangers have to deal with this problem during their operation. The phenomenon has been studied since the 1970s and the database of experimental studies on flow-induced vibration is constantly updated with new findings and improved design criteria for heat exchangers. In the nuclear industry, steam generators are often affected by this problem. However, flow-induced vibration is not limited to nuclear power plants, but to any type of heat exchanger used in many industrial applications such as chemical processing, refrigeration and air conditioning. Specifically, shell and tube type heat exchangers experience flow-induced vibration due to the high velocity flow over the tube banks. Flow-induced vibration in these heat exchangers leads to equipment breakdown and hence expensive repair and process shutdown. The goal of this research is to provide accurate measurements that can help modelers to validate their models using the measured experimental parameters and thereby develop better design criteria for avoiding fluid-elastic instability in heat exchangers. The research is divided between two primary experimental efforts, the first conducted using water alone (single phase) and the second using a mixture of air or steam and water as the working fluid (two phase). The outline of this report is as follows: After the introduction to fluid-elastic instability, the experimental apparatus constructed to conduct the experiments is described in Chapter 2 along with the measurement procedures. Chapter 3 presents results obtained on the tube array and the flow loop, as well as techniques used in data processing. The project performance is described and evaluated in Chapter 4 followed by a discussion of publications and presentations relevant to the project in Chapter 5, while the conclusions and recommendations for future work are presented in Chapter 6.

Catton, Ivan; Dhir, Vijay K.; Alquaddoomi, O.S.; Mitra, Deepanjan; Adinolfi, Pierangelo

2004-03-26T23:59:59.000Z

32

Vibration-Induced Conductivity Fluctuation Measurement for Soil Bulk Density Analysis  

E-Print Network (OSTI)

Soil bulk density affects water storage, water and nutrient movement, and plant root activity in the soil profile. Its measurement is difficult in field conditions. Vibration-induced conductivity fluctuation was investigated to quantify soil bulk density with possible field applications in the future. The AC electrical conductivity of soil was measured using a pair of blade-like electrodes while exposing the soil to periodic vibration. The blades were positioned longitudinally and transversally to the direction of the induced vibration to enable the calculation of a normalized index. The normalized index was expected to provide data independent from the vibration strength and to reduce the effect of soil salinity and water content. The experiment was conducted on natural and salinized fine sand at two moisture conditions and four bulk densities. The blade-shaped electrodes improved electrode-soil contact compared to cylindrical electrodes, and thereby, reduced measurement noise. Simulations on a simplified resistor lattice indicate that the transversal effect increases as soil bulk density decreases. Measurement of dry sand showed a negative correlation between the normalized conductivity fluctuation and soil bulk density for both longitudinal and transversal settings. The decrease in the transversal signal was smaller than expected. The wet natural and salinized soils performed very similarly as hypothesized, but their normalized VICOF response was not significant to bulk density changes.

Andrea Sz. Kishne; Cristine L. S. Morgan; Hung-Chih Chang; Laszlo B. Kish

2007-05-03T23:59:59.000Z

33

Vortex methods and vortex statistics  

SciTech Connect

Vortex methods originated from the observation that in incompressible, inviscid, isentropic flow vorticity (or, more accurately, circulation) is a conserved quantity, as can be readily deduced from the absence of tangential stresses. Thus if the vorticity is known at time t = 0, one can deduce the flow at a later time by simply following it around. In this narrow context, a vortex method is a numerical method that makes use of this observation. Even more generally, the analysis of vortex methods leads, to problems that are closely related to problems in quantum physics and field theory, as well as in harmonic analysis. A broad enough definition of vortex methods ends up by encompassing much of science. Even the purely computational aspects of vortex methods encompass a range of ideas for which vorticity may not be the best unifying theme. The author restricts himself in these lectures to a special class of numerical vortex methods, those that are based on a Lagrangian transport of vorticity in hydrodynamics by smoothed particles (``blobs``) and those whose understanding contributes to the understanding of blob methods. Vortex methods for inviscid flow lead to systems of ordinary differential equations that can be readily clothed in Hamiltonian form, both in three and two space dimensions, and they can preserve exactly a number of invariants of the Euler equations, including topological invariants. Their viscous versions resemble Langevin equations. As a result, they provide a very useful cartoon of statistical hydrodynamics, i.e., of turbulence, one that can to some extent be analyzed analytically and more importantly, explored numerically, with important implications also for superfluids, superconductors, and even polymers. In the authors view, vortex ``blob`` methods provide the most promising path to the understanding of these phenomena.

Chorin, A.J.

1993-05-01T23:59:59.000Z

34

Flow-induced vibration for light-water reactors. Progress report, April 1978-December 1979  

SciTech Connect

Flow-Induced vibration for Light Water Reactors (FIV for LWRs) is a four-year program designed to improve the FIV performance of light water reactors through the development of design criteria, analytical models for predicting behavior of components, general scaling laws to improve the accuracy of reduced-scale tests, and the identification of high FIV risk areas. The program commenced December 1, 1976, but was suspended on September 30, 1978, due to a shift in Department of Energy (DOE) priorities away from LWR productivity/availability. It was reinitiated as of August 1, 1979. This progress report summarizes the accomplishments achieved during the period from April 1978 to December 1979.

Schardt, J. F.

1980-03-01T23:59:59.000Z

35

Research on Vortex Unstablity Caused by Bending Deformation of Drilling Bar in BTA Deep Hole Machining  

Science Conference Proceedings (OSTI)

Vortex and unstability of bending boring bar caused by cutting fluid force are researched, with Timoshenko beam model and mated vibration model, based on which machining quality of BTA deep hole drilling and tools life can be promoted in practice. Linear ... Keywords: deep hole boring, boring bar, Timoshenko beam, mating vibration, vortex motion stability

Zhanqi Hu; Wu Zhao

2009-04-01T23:59:59.000Z

36

Modeling of electromagnetic power output in a vibration-induced micro-generator with a silicon-based helical micro-spring  

Science Conference Proceedings (OSTI)

This paper develops an electromagnetic power output model in a vibration-induced micro-generator with a silicon helical micro-spring to predict the electricity output. The generator consists of a movable ferro-platinum permanent magnet membrane on the ... Keywords: Analytical model, Electromagnetic, Helical micro-spring, Micro-generator, Vibration-induced

W. L. Lu; Y. M. Hwang

2011-02-01T23:59:59.000Z

37

Vibration effects of two-phase cross flow on heat exchangers  

SciTech Connect

Excessive flow-induced vibration in tube bundles causes costly tube failures by fatigue or fretting wear. This is a common condition in many shell-and-tube heat exchangers, such as condensers and reboilers. However, designers can't plan for phenomena that they don't understand. To avoid cross-flow vibration damage, the designer must determine flow-behavior effects on tube bundles under these conditions. And this is very true when discussing two-phase cross-flow vibration. Two-phase cross-flow vibration does cause tube/tube bundle failure. Early research used single-phase flow models, which failed to accurately predict vibration behavior in a two-phase system. Consequently, single-phase models and assumptions don't apply to two-phase systems and don't accurately describe vibration-behavior for exchanger tubes. Improved heat exchanger design requires more emphasis and development on cross-flow vibration parameters. The paper describes tube vibrations; flow conditions; void-fraction effects; vortex-induced vibration; fluid excitation forces; and tube response.

Lian, H.Y.; Kawaji, M. (Univ. of Toronto, Ontario (Canada)); Chan, A.M.C. (Ontario Hydro Research Div., Toronto (Canada))

1993-03-01T23:59:59.000Z

38

Nanoscale strain-induced pair suppression as a source of vortex pinning in high-temperature superconductors  

SciTech Connect

Boosting large-scale superconductor applications require nanostructured conductors with artificial pinning centres immobilizing quantized vortices at high temperature and magnetic fields. Here we demonstrate a highly effective mechanism of artificial pinning centres in solution-derived high-temperature superconductor nanocomposites through generation of nanostrained regions where Cooper pair formation is suppressed. The nanostrained regions identified from transmission electron microscopy devise a very high concentration of partial dislocations associated with intergrowths generated between the randomly oriented nanodots and the epitaxial YBa{sub 2}Cu{sub 3}O{sub 7} matrix. Consequently, an outstanding vortex-pinning enhancement correlated to the nanostrain is demonstrated for four types of randomly oriented nanodot, and a unique evolution towards an isotropic vortex-pinning behaviour, even in the effective anisotropy, is achieved as the nanostrain turns isotropic. We suggest a new vortex-pinning mechanism based on the bond-contraction pairing model, where pair formation is quenched under tensile strain, forming new and effective core-pinning regions.

Llordes, A. [ICMAB, Barcelona, Spain; Palau, A. [ICMAB, Barcelona, Spain; Vlad, R. [ICMAB, Barcelona, Spain; Pomar, A. [ICMAB, Barcelona, Spain; Arbiol, Jordi [ICMAB, Barcelona, Spain; Guzman, Roger [ICMAB, Barcelona, Spain; Gazquez Alabart, Jaume [ORNL; Varela del Arco, Maria [ORNL; Sandiumenge, Felip [ICMAB, Barcelona, Spain; Ricart, Susagna [ICMAB, Barcelona, Spain; Puig, Teresa [ICMAB, Barcelona, Spain; Chataigner, D. [CRISMAT, Caen, France; Vanacken, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Gutierrez, J. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Deutscher, G. [Tel Aviv University; Moschalkov, V. [INPAC-Institute for Nanoscale Physics and Chemistry, Leuven, Belgium; Obradors, Xavier [ICMAB, Barcelona, Spain

2012-01-01T23:59:59.000Z

39

ANL-85-51 ANL-85-51 FLOW-INDUCED VIBRATION OF CIRCULAR CYLINDRICAL STRUCTURES  

Office of Scientific and Technical Information (OSTI)

ANL-85-51 ANL-85-51 ANL-85-51 ANL-85-51 FLOW-INDUCED VIBRATION OF CIRCULAR CYLINDRICAL STRUCTURES by ShoeiSheng Chen BASE TECHNOLOGY ARGONNE NATIONAL LABORATORY, ARGONNE, ILLINOIS Operated by THE UNIVERSITY OF CHICAGO for the U. S. DEPARTMENT OF ENERGY under Contract W-31-109-Eng-38 A major purpose of the Techni- cal information Center is to provide the broadest dissemination possi- ble of information contained in DOE's Research and Development Reports to business, industry, the academic community, and federal, state and local governments. Although a small portion of this report is not reproducible, it is being made available to expedite the availability of information on the research discussed herein. Distribution Category: LMFBR-Components: Base Technology (UC-79k) ANL-85-51 ANL-85-51

40

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

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Flow-induced vibration for light water reactors. Progress report, October 1980-December 1980  

Science Conference Proceedings (OSTI)

Flow-Induced Vibration for Light Water Reactors (FIV for LWRs) is a four-year program designed to improve the FIV performance of light water reactors through the development of design criteria, analytical models for predicting behavior of components, general scaling laws to improve the accuracy of reduced-scale tests, and the identification of high FIV risk areas. The program is managed by the General Electric Nuclear Power Systems Engineering Department and has three major contributors: General Electric Nuclear Power Systems Engineering Department (NPSED), General Electric Corporate Research and Development (CR and D) and Argonne National Laboratory (ANL). The program commenced December 1, 1976. This progress report summarizes the accomplishments achieved during the period from October 1980 to December 1980.

Torres, M.R.

1981-09-01T23:59:59.000Z

42

Vortex Energy | Open Energy Information  

Open Energy Info (EERE)

by expanding it. Vortex Energy is a company located in Germany . References "Vortex Energy" Retrieved from "http:en.openei.orgwindex.php?titleVortexEnergy&oldid352892...

43

Local amplification of deep mining induced vibrations - Part.2: Simulation of the ground motion in a coal basin  

E-Print Network (OSTI)

This work investigates the impact of deep coal mining induced vibrations on surface constructions using numerical tools. An experimental study of the geological site amplification and of its influence on mining induced vibrations has already been published in a previous paper (Part 1: Experimental evidence for site effects in a coal basin). Measurements have shown the existence of an amplification area in the southern part of the basin where drilling data have shown the presence of particularly fractured and soft stratigraphic units. The present study, using the Boundary Element Method (BEM) in the frequency domain, first investigates canonical geological structures in order to get general results for various sites. The amplification level at the surface is given as a function of the shape of the basin and of the velocity contrast with the bedrock. Next, the particular coal basin previously studied experimentally (Driad-Lebeau et al., 2009) is modeled numerically by BEM. The amplification phenomena characteri...

Semblat, Jean-François; Driad-Lebeau, L; Bonnet, Guy; 10.1016/j.soildyn.2010.04.006

2010-01-01T23:59:59.000Z

44

Generation and Propagation of Inertia–Gravity Waves from Vortex Dipoles and Jets  

Science Conference Proceedings (OSTI)

This study investigates gravity wave generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model. Two types of initially balanced and localized jets induced by vortex dipoles are examined here. ...

Shuguang Wang; Fuqing Zhang; Chris Snyder

2009-05-01T23:59:59.000Z

45

Twisted vortex state  

E-Print Network (OSTI)

We study a twisted vortex bundle where quantized vortices form helices circling around the axis of the bundle in a "force-free" configuration. Such a state is created by injecting vortices into rotating vortex-free superfluid. Using continuum theory we determine the structure and the relaxation of the twisted state. This is confirmed by numerical calculations. We also present experimental evidence of the twisted vortex state in superfluid 3He-B.

V. B. Eltsov; A. P. Finne; R. Hanninen; J. Kopu; M. Krusius; M. Tsubota; E. V. Thuneberg

2006-02-28T23:59:59.000Z

46

Generation of laser-induced plasma in supercritical water and vibrational spectroscopic study of accompanying stimulated Raman scattering  

Science Conference Proceedings (OSTI)

We have formed a laser-induced plasma (LIP) in supercritical water (SCW) and studied associated molecular vibrations using spectroscopic methods. The accompanying forward and backward stimulated Raman scattering (SRS) of water molecules showed anisotropic behavior at supercritical conditions (>647 K and >22.1 MPa). The Raman shift of the backward SRS indicated that attractive interactions between water molecules and excess electrons generated by the LIP were dominant in the SCW. The backward SRS spectrum provided a microscopic view of the hydration environment around an excess electron, which is useful for controlling electron-driven chemical reactions and materials processing in SCW.

Yui, Hiroharu [Department of Chemistry, Faculty of Science, Tokyo University of Science, Kagurazaka 1-3, Shinjyuku-ku, Tokyo 162-8601 (Japan); PRESTO-JST, Sanbancho 5, Chiyoda-ku, Tokyo 102-0075 (Japan); Tomai, Takaaki; Sawada, Masayoshi; Terashima, Kazuo [Department of Advanced Materials Science, Graduate School of Frontier Sciences, University of Tokyo, 5-1-5 Kashiwanoha, Kashiwa-shi, Chiba 277-8561 (Japan)

2011-08-29T23:59:59.000Z

47

Improved vortex reactor system  

DOE Patents (OSTI)

An improved vortex reactor system for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor.

Diebold, James P. (Lakewood, CO); Scahill, John W. (Evergreen, CO)

1995-01-01T23:59:59.000Z

48

VORTEX.PDF  

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

vortex generator. Figure 5. The fan in its plenum-a two-speed stove fan mounted in a plywood box. It provides a vacuum at the top of the generator. The ruler is six inches long....

49

Improved vortex reactor system  

DOE Patents (OSTI)

An improved vortex reactor system is described for affecting fast pyrolysis of biomass and Refuse Derived Fuel (RDF) feed materials comprising: a vortex reactor having its axis vertically disposed in relation to a jet of a horizontally disposed steam ejector that impels feed materials from a feeder and solids from a recycle loop along with a motive gas into a top part of said reactor. 12 figs.

Diebold, J.P.; Scahill, J.W.

1995-05-09T23:59:59.000Z

50

Steam Generator Management Program: Benchmark Study of EPRI and EDF Steam Generator Thermal-Hydraulic and Flow Induced Vibration Cod es  

Science Conference Proceedings (OSTI)

Steam generator thermal-hydraulics software codes and flow induced vibration software codes are used for steam generator design, root cause investigations, and assessment of operational changes. Organizations within the steam generator industry develop and maintain such software codes. Capabilities of existing codes are being challenged by current demands for more comprehensive results to troubleshoot ...

2012-12-12T23:59:59.000Z

51

Investigations On Flow And Flow-Induced Vibration Of Candu Fuel Bundles.  

E-Print Network (OSTI)

??Excitations induced by three-dimensional unsteady flows of ordinary water coolant through a string of CANDU fuel bundles in a fuel channel are investigated in this… (more)

Bhattacharya, Alokendu

2013-01-01T23:59:59.000Z

52

Steam Generator Vibration and Wear Protection  

Science Conference Proceedings (OSTI)

This project developed and validated a steam generator flow-induced tube vibration and wear prediction methodology.

1998-03-27T23:59:59.000Z

53

Will water act as a photocatalyst for cluster phase chemical reactions? Vibrational overtone-induced dehydration reaction of methanediol  

Science Conference Proceedings (OSTI)

The possibility of water catalysis in the vibrational overtone-induced dehydration reaction of methanediol is investigated using ab initio dynamical simulations of small methanediol-water clusters. Quantum chemistry calculations employing clusters with one or two water molecules reveal that the barrier to dehydration is lowered by over 20 kcal/mol because of hydrogen-bonding at the transition state. Nevertheless, the simulations of the reaction dynamics following OH-stretch excitation show little catalytic effect of water and, in some cases, even show an anticatalytic effect. The quantum yield for the dehydration reaction exhibits a delayed threshold effect where reaction does not occur until the photon energy is far above the barrier energy. Unlike thermally induced reactions, it is argued that competition between reaction and the irreversible dissipation of photon energy may be expected to raise the dynamical threshold for the reaction above the transition state energy. It is concluded that quantum chemistry calculations showing barrier lowering are not sufficient to infer water catalysis in photochemical reactions, which instead require dynamical modeling.

Kramer, Zeb C.; Takahashi, Kaito; Skodje, Rex T. [Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215 (United States); Vaida, Veronica [Department of Chemistry and Biochemistry, University of Colorado, Boulder, Colorado 80309-0215 (United States); CIRES, University of Colorado, Boulder, Colorado 80309 (United States)

2012-04-28T23:59:59.000Z

54

Impact of a vortex ring on a density interface using a regularized inviscid vortex sheet method  

Science Conference Proceedings (OSTI)

A new, fully three-dimensional, vortex-in-cell method designed to follow the unsteady motion of inviscid vortex sheets with or without small (Boussinesq) density discontinuities is presented. As is common in front-tracking methods, the vortex sheet is ... Keywords: Density discontinuity, Stratified flow, Vortex methods, Vortex sheet dynamics, Vortex-in-cell

Mark J. Stock; Werner J. A. Dahm; Grétar Tryggvason

2008-11-01T23:59:59.000Z

55

Vortex lattices in layered superconductors  

Science Conference Proceedings (OSTI)

We study vortex lattices in a superconductor--normal-metal superlattice in a parallel magnetic field. Distorted lattices, resulting from the shear deformations along the layers, are found to be unstable. Under field variation, nonequilibrium configurations undergo an infinite sequence of continuous transitions, typical for soft lattices. The equilibrium vortex arrangement is always a lattice of isocell triangles, without shear.

Prokic, V. (Department of Physics, University of Belgrade, P.O. Box 368, 11001 Belgrade (Yugoslavia)); Davidovic, D. (Department of Physics and Astronomy, The Johns Hopkins University, Bloomberg Center, Baltimore, Maryland 21218 (United States) Institute of Physics, P.O. Box 57, 11001 Belgrade (Yugoslavia)); Dobrosavljevic-Grujic, L. (Institute of Physics, P.O. Box 57, 11001 Belgrade (Yugoslavia))

1995-03-01T23:59:59.000Z

56

Variable residence time vortex combustor  

DOE Patents (OSTI)

A variable residence time vortex combustor including a primary combustion chamber for containing a combustion vortex, and a plurality of louvres peripherally disposed about the primary combustion chamber and longitudinally distributed along its primary axis. The louvres are inclined to impel air about the primary combustion chamber to cool its interior surfaces and to impel air inwardly to assist in driving the combustion vortex in a first rotational direction and to feed combustion in the primary combustion chamber. The vortex combustor also includes a second combustion chamber having a secondary zone and a narrowed waist region in the primary combustion chamber interconnecting the output of the primary combustion chamber with the secondary zone for passing only lower density particles and trapping higher density particles in the combustion vortex in the primary combustion chamber for substantial combustion.

Melconian, Jerry O. (76 Beaver Rd., Reading, MA 01867)

1987-01-01T23:59:59.000Z

57

VIBRATION COMPACTION  

DOE Patents (OSTI)

A method of compacting a powder in a metal container is described including the steps of vibrating the container at above and below the resonant frequency and also sweeping the frequency of vibration across the resonant frequency several times thereby following the change in resonant frequency caused by compaction of the powder. (AEC)

Hauth, J.J.

1962-07-01T23:59:59.000Z

58

Vortex–Vortex Interactions in the Winter Stratosphere  

Science Conference Proceedings (OSTI)

This paper examines the interaction of oppositely signed vortices in the compressible (non-Boussinesq) quasigeostrophic system, with a view to understanding vortex interactions in the polar winter stratosphere. A series of simplifying ...

R. K. Scott; D. G. Dritschel

2006-02-01T23:59:59.000Z

59

Intense Vortex Motion on the Beta Plane: Development of the Beta Gyres  

Science Conference Proceedings (OSTI)

An analytical theory is presented for the self-induced translation of an intense vortex relative to a uniform background flow on the ? plane. The equivalent barotropic approximation is used to formulate the initial value problem within a polar ...

Georgi G. Sutyrin; Glenn R. Flierl

1994-03-01T23:59:59.000Z

60

Drillstring vibrations create crooked holes  

SciTech Connect

Boreholes in hard formations sometimes deviate when the drillstring runs rough or the kelly bounces severely. This article explains how drillstring vibrations produce crooked holes in hard formations. It shows how to reduce dog-leg severity through vibration control. Dog-legs are known to produce cyclic bending-type fatigue loads in drill pipe and collars. Longitudinal and torsional vibrational stresses are additive to rotational bending and further reduce the life of drillstring tubulars. Vibration-induced dog-legs are therefore more damaging to drillstrings than other dog-leg producing mechanisms because total cyclic fatigue loading is the combined effect of bending stress reversal due to rotation plus vibrational stress variations. The vibration-induced dog-leg concept is based on overall vibration response of drillstrings, resultant dynamic displacements of roller cone drill bits, and corresponding dynamic forces between bit and formation. The concept explains how dynamic forces generated by roller cone rock bits might produce helical bore holes in hard homogeneous formations. Dog-legs in hard formations may be due in part to drillstring vibrations. The wellbore deviation concept relates only to roller cone rock bits and is based on dynamically reorienting three-lobed formation pattern hammered out by bottomhole assembly resonance. Analytical studies are needed to determine the effect of bit force impact point location on chip formation and rock removal. Field studies of various bottom hole assemblies operating at critical rotary speeds coupled with directional surveys are needed to test the validity of this theory.

Dareing, D.W.

1984-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Direct Imaging of Antiferromagnetic Vortex States  

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

unique properties for the AFM vortex state. Recently, a research team from Berkeley, Korea, and China has taken the first direct image of an AFM vortex in multilayered magnetic...

62

Gravity waves from vortex dipoles and jets  

E-Print Network (OSTI)

The dissertation first investigates gravity wave generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model. Several initially balanced and localized jets induced by vortex dipoles are examined here. Within these dipoles, inertia-gravity waves with intrinsic frequencies 1-2 times the Coriolis parameter are simulated in the jet exit region. The ray tracing analysis reveals strong variation of wave characteristics along ray paths. The dependence of wave amplitude on the Rossby number is examined through experiments in which the two vortices are initially separated by a large distance but subsequently approach each other and form a vortex dipole with an associated amplifying localized jet. The amplitude of stationary gravity waves in the simulations with a 90-km grid spacing increases nearly linearly with the square of the Rossby number but significantly more rapidly when smaller grid spacing is used. To further address the source mechanism of the gravity waves within the vortex dipole, a linear numerical framework is developed based on the framework proposed by Plougonven and Zhang (2007). Using the nonlinearly balanced fields as the basic state and driven by three types of large scale forcing, the vorticity, divergence and thermodynamic forcing, this linear model is utilized to obtain linear wave responses. The wave packets in the linear responses compare reasonably well with the MM5 simulated gravity waves. It is suggested that the vorticity forcing is the leading contribution to both gravity waves in the jet exit region and the ascent/descent feature in the jet core. This linear model is also adopted to study inertia-gravity waves in the vicinity of a baroclinic jet during the life cycle of an idealized baroclinic wave. It is found that the thermodynamic forcing and the vorticity forcing are equally important to the gravity waves in the low stratosphere, but the divergence forcing is again playing a lesser role. Two groups of wave packets are present in the linear responses; their sources appear to locate either near the surface front or near the middle/upper tropospheric jet.

Wang, Shuguang

2008-08-01T23:59:59.000Z

63

Vortex ice in nanostructured superconductors  

SciTech Connect

We demonstrate using numerical simulations of nanostructured superconductors that it is possible to realize vortex ice states that are analogous to square and kagome ice. The system can be brought into a state that obeys either global or local ice rules by applying an external current according to an annealing protocol. We explore the breakdown of the ice rules due to disorder in the nanostructure array and show that in square ice, topological defects appear along grain boundaries, while in kagome ice, individual defects appear. We argue that the vortex system offers significant advantages over other artificial ice systems.

Reichhardt, Charles [Los Alamos National Laboratory; Reichhardt, Cynthia J [Los Alamos National Laboratory; Libal, Andras J [Los Alamos National Laboratory

2008-01-01T23:59:59.000Z

64

Transformed Eliassen Balanced Vortex Model  

Science Conference Proceedings (OSTI)

We consider the axisymmetric balanced flow occurring in a thermally forced vortex in which the frictional inflow is confined to a thin boundary layer. Above the boundary layer the absolute angular momentum ½fR2=rv+½fr2 is conserved. We refer to R ...

Wayne H. Schubert; James J. Hack

1983-06-01T23:59:59.000Z

65

Vibration dampener for dampening vibration of a tubular member  

DOE Patents (OSTI)

Vibration dampener for dampening vibration of a tubular member, such as an instrumentation tube of the type found in nuclear reactor pressure vessels. The instrumentation tube is received in an outer tubular member, such as a guide thimble tube. The vibration dampener comprises an annular sleeve which is attachable to the inside surface of the guide thimble tube and which is sized to surround the instrumentation tube. Dimples are attached to the interior wall of the sleeve for radially supporting the instrumentation tube. The wall of the sleeve has a flexible spring member, which is formed from the wall, disposed opposite the dimples for biasing the instrumentation tube into abutment with the dimples. Flow-induced vibration of the instrumentation tube will cause it to move out of contact with the dimples and further engage the spring member, which will flex a predetermined amount and exert a reactive force against the instrumentation tube to restrain its movement. The amount by which the spring member will flex is less than the unrestrained amplitude of vibration of the instrumentation tube. The reactive force exerted against the instrumentation tube will be sufficient to return it to its original axial position within the thimble tube. In this manner, vibration of the instrumentation tube is dampened so that in-core physics measurements are accurate and so that the instrumentation tube will not wear against the inside surface of the guide thimble tube.

Obermeyer, Franklin D. (Pensacola, FL); Middlebrooks, Willis B. (Pensacola, FL); DeMario, Edmund E. (Columbia, SC)

1994-01-01T23:59:59.000Z

66

Vibration dampener for dampening vibration of a tubular member  

DOE Patents (OSTI)

Vibration dampener for dampening vibration of a tubular member, such as an instrumentation tube of the type found in nuclear reactor pressure vessels is disclosed. The instrumentation tube is received in an outer tubular member, such as a guide thimble tube. The vibration dampener comprises an annular sleeve which is attachable to the inside surface of the guide thimble tube and which is sized to surround the instrumentation tube. Dimples are attached to the interior wall of the sleeve for radially supporting the instrumentation tube. The wall of the sleeve has a flexible spring member, which is formed from the wall, disposed opposite the dimples for biasing the instrumentation tube into abutment with the dimples. Flow-induced vibration of the instrumentation tube will cause it to move out of contact with the dimples and further engage the spring member, which will flex a predetermined amount and exert a reactive force against the instrumentation tube to restrain its movement. The amount by which the spring member will flex is less than the unrestrained amplitude of vibration of the instrumentation tube. The reactive force exerted against the instrumentation tube will be sufficient to return it to its original axial position within the thimble tube. In this manner, vibration of the instrumentation tube is dampened so that in-core physics measurements are accurate and so that the instrumentation tube will not wear against the inside surface of the guide thimble tube. 14 figs.

Obermeyer, F.D.; Middlebrooks, W.B.; DeMario, E.E.

1994-10-18T23:59:59.000Z

67

Simulations of Dual-Vortex Interaction within Environmental Shear  

Science Conference Proceedings (OSTI)

For over a century it has been known that each vortex in a multiple vortex configuration will move in response to the other vortices. However, despite advances since that time, the complexities of multiple vortex scenarios when sheared ...

Robert E. Hart; Jenni L. Evans

1999-11-01T23:59:59.000Z

68

Hydrogen rotation-vibration oscillator  

DOE Patents (OSTI)

A laser system is described wherein molecular species of hydrogen and hydrogen isotopes are induced to oscillate on rotational-vibrational levels by subjecting the hydrogen to a transverse beam of electrons of a narrowly defined energy between about 1 and 5 eV, thereby producing high intensity and high energy output. (Official Gazette)

Rhodes, C.K.

1974-01-29T23:59:59.000Z

69

Downhole vibration sensing by vibration energy harvesting  

E-Print Network (OSTI)

This thesis outlines the design of a prototype electromagnetic induction vibration energy harvesting device for use in a downhole environment. First order models of the necessary components for a generic vibration energy ...

Trimble, A. Zachary

2007-01-01T23:59:59.000Z

70

Shrouded inducer pump  

DOE Patents (OSTI)

An improvement in a pump is described including a shrouded inducer, the improvement comprising first and second sealing means which cooperate with a first vortex cell and a series of secondary vortex cells to remove any tangential velocity components from the recirculation flow. 3 figs.

Meng, S.Y.

1989-08-08T23:59:59.000Z

71

The idea of vortex energy  

E-Print Network (OSTI)

This work formulates and gives grounds for general principles and theorems that question the energy function doctrine and its quantum version as a genuine law of nature without borders of adequacy. The emphasis is on the domain where the energy of systems is conserved -- I argue that only in its tiny part the energy is in the kinetic, potential and thermal forms describable by a generalized thermodynamic potential, whereas otherwise the conserved energy constitutes a whole linked to vortex forces, and can be a factor of things like persistent currents and dark matter.

V. E. Shapiro

2011-09-12T23:59:59.000Z

72

Polarization radiation of vortex electrons with large orbital angular momentum  

E-Print Network (OSTI)

Vortex electrons, - freely propagating electrons whose wavefunction has helical wavefronts, - could become a novel tool in the physics of electromagnetic radiation. They carry a non-zero intrinsic orbital angular momentum (OAM) $\\ell$ with respect to the propagation axis and, for \\ell \\gg 1, a large OAM-induced magnetic moment, \\mu ~ \\ell \\mu_B (\\mu_B is the Bohr magneton), which influences the radiation of electromagnetic waves. Here, we consider in detail the OAM-induced effects by such electrons in two forms of polarization radiation, namely in Cherenkov radiation and transition radiation. Thanks to the large \\ell, we can neglect quantum or spin-induced effects, which are of the order of \\hbar \\omega/E_e \\ll 1, but retain the magnetic moment contribution \\ell \\hbar \\omega/E_e \\lesssim 1, which makes the quasiclassical approach to polarization radiation applicable. We discuss the magnetic moment contribution to polarization radiation, which has never been experimentally observed, and study how its visibility depends on the kinematical parameters and the medium permittivity. In particular, it is shown that this contribution can, in principle, be detected in azimuthally non-symmetrical problems, for example when vortex electrons obliquely cross a metallic screen (transition radiation) or move nearby it (diffraction radiation). We predict a left-right angular asymmetry of the transition radiation (in the plane where the charge radiation distributions would stay symmetric), which appears due to an effective interference between the charge radiation field and the magnetic moment one. Numerical values of this asymmetry for vortex electrons with E_e = 300keV and \\ell = O(100-1000) are O(0.1-1%), and we argue that this effect could be detected with existing technology. The finite conductivity of the target and frequency dispersion play the crucial roles in these predictions.

Igor P. Ivanov; Dmitry V. Karlovets

2013-05-28T23:59:59.000Z

73

Stable optical vortex solitons in pair plasmas  

Science Conference Proceedings (OSTI)

It is shown that the pair plasmas with small temperature asymmetry can support existence of localized as well as delocalized optical vortex solitons. Coexistence of such solitons is possible due to peculiar form of saturating nonlinearity which has a focusing-defocusing nature--for weak amplitudes being focusing becoming defocusing for higher amplitudes. It is shown that delocalized vortex soliton is stable in entire region of its existence while single- and multicharged localized vortex solitons are unstable for low amplitudes and become stable for relativistic amplitudes.

Berezhiani, V. I.; Shatashvili, N. L. [Plasma Physics Department, Andronikashvili Institute of Physics, Tbilisi 0177 (Georgia); Department of Physics, Faculty of Exact and Natural Sciences, Javakhishvili Tbilisi State University, Tbilisi 0128 (Georgia); Mahajan, S. M. [Institute for Fusion Studies, University of Texas at Austin, Austin, Texas 78712 (United States)

2010-05-15T23:59:59.000Z

74

Vortex Breakdown in Atmospheric Columnar Vortices  

Science Conference Proceedings (OSTI)

Vortex breakdown occurs in tornadoes and waterspouts. This phenomenon may give information on the state and future behavior of those whirlwinds. Because of the rarity of recorded events, archival sources are consulted for qualitative descriptions ...

H. J. Lugt

1989-12-01T23:59:59.000Z

75

Bubble Behavior in a Taylor Vortex  

E-Print Network (OSTI)

We present an experimental study on the behavior of bubbles captured in a Taylor vortex. The gap between a rotating inner cylinder and a stationary outer cylinder is filled with a Newtonian mineral oil. Beyond a critical ...

Deng, Rensheng

76

Barotropic Vortex Evolution on a Beta Plane  

Science Conference Proceedings (OSTI)

A barotropic, primitive equation (shallow water) model is used on the beta plane to investigate the influence of divergence, total relative angular momentum (RAM) and advective nonlinearities on the evolution of a hurricane-like vortex. The ...

Lloyd J. Shapiro; Katsuyuki V. Ooyama

1990-01-01T23:59:59.000Z

77

Vortex Hydro Energy - National Renewable Energy Laboratory  

Vortex Hydro Energy, LLC Michael M. Bernitsas Ph.D., CEO and CTO Gus Simiao MSE, MBA, Dir. of Business Development NREL’s 20th Annual, Industry Growth Forum

78

Vortex-Driven Sensitivity in Deformation Flow  

Science Conference Proceedings (OSTI)

A sensitivity mechanism for the interaction of two vortices in a two-dimensional deformation background flow is explored. A nonlinear model describing the vortex interaction up to a critical merging distance is developed. This model shows that in ...

Zhiyuan Liu; Paul J. Roebber

2008-12-01T23:59:59.000Z

79

Direct Imaging of Antiferromagnetic Vortex States  

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

Direct Imaging of Antiferromagnetic Vortex States Print Direct Imaging of Antiferromagnetic Vortex States Print Magnetic materials are characterized by the ordering of electron spins, with nearest-neighbor spins parallel to each other in ferromagnetic (FM) materials and antiparallel to each other in antiferromagnetic (AFM) materials. As the size of a magnetic system is reduced to micron scale, it has been shown that the spins in an FM microstructure can curl around to form a magnetic vortex state. While there has been intensive activity in the study of vortex states in FM disks, there has been no direct observation of such states in an AFM microstructure, although theory predicts many interesting and unique properties for the AFM vortex state. Recently, a research team from Berkeley, Korea, and China has taken the first direct image of an AFM vortex in multilayered magnetic disk structures using x-ray magnetic linear dichroism (XMLD) and photoemission electron microscopy (PEEM) at ALS Beamlines 4.0.2 and 11.0.1 , respectively. The experiments observed two types of AFM vortices, one of which has no analogue in FM vortices.

80

Direct Imaging of Antiferromagnetic Vortex States  

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

Direct Imaging of Antiferromagnetic Vortex States Print Direct Imaging of Antiferromagnetic Vortex States Print Magnetic materials are characterized by the ordering of electron spins, with nearest-neighbor spins parallel to each other in ferromagnetic (FM) materials and antiparallel to each other in antiferromagnetic (AFM) materials. As the size of a magnetic system is reduced to micron scale, it has been shown that the spins in an FM microstructure can curl around to form a magnetic vortex state. While there has been intensive activity in the study of vortex states in FM disks, there has been no direct observation of such states in an AFM microstructure, although theory predicts many interesting and unique properties for the AFM vortex state. Recently, a research team from Berkeley, Korea, and China has taken the first direct image of an AFM vortex in multilayered magnetic disk structures using x-ray magnetic linear dichroism (XMLD) and photoemission electron microscopy (PEEM) at ALS Beamlines 4.0.2 and 11.0.1 , respectively. The experiments observed two types of AFM vortices, one of which has no analogue in FM vortices.

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Direct Imaging of Antiferromagnetic Vortex States  

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

Direct Imaging of Antiferromagnetic Vortex States Print Direct Imaging of Antiferromagnetic Vortex States Print Magnetic materials are characterized by the ordering of electron spins, with nearest-neighbor spins parallel to each other in ferromagnetic (FM) materials and antiparallel to each other in antiferromagnetic (AFM) materials. As the size of a magnetic system is reduced to micron scale, it has been shown that the spins in an FM microstructure can curl around to form a magnetic vortex state. While there has been intensive activity in the study of vortex states in FM disks, there has been no direct observation of such states in an AFM microstructure, although theory predicts many interesting and unique properties for the AFM vortex state. Recently, a research team from Berkeley, Korea, and China has taken the first direct image of an AFM vortex in multilayered magnetic disk structures using x-ray magnetic linear dichroism (XMLD) and photoemission electron microscopy (PEEM) at ALS Beamlines 4.0.2 and 11.0.1 , respectively. The experiments observed two types of AFM vortices, one of which has no analogue in FM vortices.

82

Mitigation of Wind Turbine/Vortex Interaction Using Disturbance Accommodating Control  

DOE Green Energy (OSTI)

Wind turbines, a competitive source of emission-free electricity, are being designed with diameters and hub heights approaching 100 m, to further reduce the cost of the energy they produce. At this height above the ground, the wind turbine is exposed to atmospheric phenomena such as low-level jets, gravity waves, and Kelvin-Helmholtz instabilities, which are not currently modeled in wind turbine design codes. These atmospheric phenomena can generate coherent turbulence that causes high cyclic loads on wind turbine blades. These fluctuating loads lead to fatigue damage accumulation and blade lifetime reduction. Advanced control was used to mitigate vortex-induced blade cyclic loading. A full-state feedback controller that incorporates more detailed vortex inputs achieved significantly greater blade load reduction. Blade loads attributed to vortex passage, then, can be reduced through advanced control, and further reductions appear feasible.

Hand, M. M.

2003-12-01T23:59:59.000Z

83

OTEC cold water pipe design for problems caused by vortex-excited oscillations  

DOE Green Energy (OSTI)

Vortex-excited oscillations of marine structures result in reduced fatigue life, large hydrodynamic forces and induced stresses, and sometimes lead to structural damage and to diestructive failures. The cold water pipe of an OTEC plant is nominally a bluff, flexible cylinder with a large aspect ratio (L/D = length/diameter), and is likely to be susceptible to resonant vortex-excited oscillations. The objective of this report is to survey recent results pertaining to the vortex-excited oscillations of structures in general and to consider the application of these findings to the design of the OTEC cold water pipe. Practical design calculations are given as examples throughout the various sections of the report. This report is limited in scope to the problems of vortex shedding from bluff, flexible structures in steady currents and the resulting vortex-excited oscillations. The effects of flow non-uniformities, surface roughness of the cylinder, and inclination to the incident flow are considered in addition to the case of a smooth cyliner in a uniform stream. Emphasis is placed upon design procedures, hydrodynamic coefficients applicable in practice, and the specification of structural response parameters relevant to the OTEC cold water pipe. There are important problems associated with in shedding of vortices from cylinders in waves and from the combined action of waves and currents, but these complex fluid/structure interactions are not considered in this report.

Griffin, O. M.

1980-03-14T23:59:59.000Z

84

Low NOx Advanced Vortex Combustor  

SciTech Connect

A lean-premixed advanced vortex combustor (AVC) has been developed and tested. The natural gas fueled AVC was tested at the U.S. Department of Energy’s National Energy Technology Laboratory in Morgantown, WV. All testing was performed at elevated pressures and inlet temperatures and at lean fuel-air ratios representative of industrial gas turbines. The improved AVC design exhibited simultaneous NOx /CO/unburned hydrocarbon (UHC) emissions of 4/4/0 ppmv (all emissions corrected to 15% O2 dry). The design also achieved less than 3 ppmv NOx with combustion efficiencies in excess of 99.5%. The design demonstrated marked acoustic dynamic stability over a wide range of operating conditions, which potentially makes this approach significantly more attractive than other lean-premixed combustion approaches. In addition, the measured 1.75% pressure drop is significantly lower than conventional gas turbine combustors, which could translate into an overall gas turbine cycle efficiency improvement. The relatively high velocities and low pressure drop achievable with this technology make the AVC approach an attractive alternative for syngas fuel applications.

Edmonds, R.G. (Ramgen Power Systems, Inc., Bellevue, WA); Williams, J.T. (Ramgen Power Systems, Inc., Bellevue, WA); Steele, R.C. (EPRI); Straub, D.L.; Casleton, K.H.; Bining, Avtar (California Energy Commission, Sacramento, CA)

2008-05-01T23:59:59.000Z

85

Nonlinear Motion of a Shallow Water Barotropic Vortex  

Science Conference Proceedings (OSTI)

Nonlinear motions of a shallow water barotropic vortex on a ? plane differ substantially from the analogous linear motions. The nonlinear model described here, in which wavenumber 1–3 asymmetries interact with each other and the mean vortex, ...

H. E. Willoughby

1994-12-01T23:59:59.000Z

86

Interactions between a Submesoscale Anticyclonic Vortex and a Front  

Science Conference Proceedings (OSTI)

The evolution of a submesoscale anticyclonic vortex was observed by high-frequency Doppler radio current meters and satellite radiometers. The vortex formed between two large cyclones to the southwest of Oahu, Hawaii. The radius of the core was ...

Cédric Chavanne; Pierre Flament; Klaus-Werner Gurgel

2010-08-01T23:59:59.000Z

87

A Highly Configurable Vortex Initialization Method for Tropical Cyclones  

Science Conference Proceedings (OSTI)

A highly configurable vortex initialization methodology has been constructed in order to permit manipulation of the initial vortex structure in numerical models of tropical cyclones. By using distinct specifications of the flow in the boundary ...

Eric D. Rappin; David S. Nolan; Sharanya J. Majumdar

88

A Highly Configurable Vortex Initialization Method for Tropical Cyclones  

Science Conference Proceedings (OSTI)

A highly configurable vortex initialization methodology has been constructed in order to permit manipulation of the initial vortex structure in numerical models of tropical cyclones. By using distinct specifications of the flow in the boundary ...

Eric D. Rappin; David S. Nolan; Sharanya J. Majumdar

2013-10-01T23:59:59.000Z

89

Heat transfer in a two-pass internally ribbed turbine blade coolant channel with cylindrical vortex generators  

DOE Green Energy (OSTI)

The effect of vortex generators on the mass (heat) transfer from the ribbed passage of a two pass turbine blade coolant channel is investigated with the intent of optimizing the vortex generator geometry so that significant enhancements in mass/heat transfer can be achieved. In the experimental configuration considered, ribs are mounted on two opposite walls; all four walls along each pass are active and have mass transfer from their surfaces but the ribs are non-participating. Mass transfer measurements, in the form of Sherwood number ratios, are made along the centerline and in selected inter-rib modules. Results are presented for Reynolds number in the range of 5,000 to 40,000, pitch to rib height ratios of 10.5 and 21, and vortex generator-rib spacing to rib height ratios of 0.55, and 1.5. Centerline and spanwise averaged Sherwood number ratios are presented along with contours of the Sherwood number ratios. Results indicate that the vortex generators induce substantial increases in the local mass transfer rates, particularly along the side walls, and modest increases in the average mass transfer rates. The vortex generators have the effect of making the inter-rib profiles along the ribbed walls more uniform. Along the side walls, horse-shoe vortices that characterize the vortex generator wake are associated with significant mass transfer enhancements. The wake effects and the levels of enhancement decrease somewhat with increasing Reynolds number and decreasing pitch.

Hibbs, R.; Acharya, S.; Chen, Y. [Louisiana State Univ., Baton Rouge, LA (United States)] [and others

1995-12-31T23:59:59.000Z

90

Stabilization of vortex solitons in nonlocal nonlinear media  

SciTech Connect

We study the evolution of vortex solitons in optical media with a nonlocal nonlinear response. We employ a modulation theory for the vortex parameters based on an averaged Lagrangian, and analyze the azimuthal evolution of both the vortex width and diffractive radiation. We describe analytically the physical mechanism for vortex stabilization due to the long-range nonlocal nonlinear response, the effect observed earlier in numerical simulations only.

Minzoni, Antonmaria A. [Fenomenos Nonlineales y Mecanica (FENOMEC), Department of Mathematics and Mechanics, Instituto de Investigacion en Matematicas Aplicadas y Sistemas, Universidad Nacional Autonoma de Mexico, 01000 Mexico D.F. (Mexico); Smyth, Noel F. [School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); Worthy, Annette L. [School of Mathematics and Applied Statistics, University of Wollongong, Wollongong NSW 2522 (Australia); Kivshar, Yuri S. [Nonlinear Physics Center, Research School of Physical Sciences and Engineering, Australian National University, Canberra ACT 0200 (Australia)

2007-12-15T23:59:59.000Z

91

Vibrational Energy Search  

Science Conference Proceedings (OSTI)

... Search options (step 1) (Back to search). You may search for species based on vibrational energy values in two ways: ... All rights reserved. ...

2013-07-15T23:59:59.000Z

92

vibration_measurements  

Science Conference Proceedings (OSTI)

... information to be furnished by the customer to NIST in order for Vibration ... The magnitude of the latter is set in accordance with the calibration method ...

2013-07-24T23:59:59.000Z

93

A Study of Premixed Propagating Flame Vortex Interaction  

Science Conference Proceedings (OSTI)

Experimental data is presented for the interaction between a propagating flame and a simple vortex flow field structure generated in the wake of solid obstacles. The interaction between gas movement and obstacles creates vortex shedding forming a simple ... Keywords: Combustion, Flame/Vortex, PIV, Visualization

G. K. Hargrave; S. Jarvis

2006-04-01T23:59:59.000Z

94

Entanglement of a Quantum Optical Elliptic Vortex  

E-Print Network (OSTI)

We calculate the entanglement of a generalized elliptical vortex formed by quantized radiation field, using Wigner quasiprobability distribution function for such states. We find a critical squeezing parameter above which the entanglement is less for higher vorticity, which is counter intuitive.

Abir Bandyopadhyay; Shashi Prabhakar; Ravindra Pratap Singh

2010-10-19T23:59:59.000Z

95

Entanglement of Quantum Optical Elliptic Vortex  

E-Print Network (OSTI)

We calculate the entanglement of a generalized elliptical vortex formed by quantized radiation field, using Wigner quasiprobability distribution function for such states. We find a critical squeezing parameter above which the entanglement is less for higher vorticity, which is counter intuitive.

Bandyopadhyay, Abir; Singh, Ravindra Pratap

2010-01-01T23:59:59.000Z

96

Controlled Vortex Breakdown on Modified Delta Wings  

Science Conference Proceedings (OSTI)

This paper studies the effect of perturbation to the breakdown of the leading-edge vortices over delta wings. The passive perturbation in the normal direction is achieved by installing the hemisphere-like bulges on the delta wing along the projection ... Keywords: Bulge perturbation, Delta wing, Vortex breakdown

S. Srigrarom; N. Lewpiriyawong

2007-08-01T23:59:59.000Z

97

The Tornadic Vortex Signature: An Update  

Science Conference Proceedings (OSTI)

A tornadic vortex signature (TVS) is a degraded Doppler velocity signature of a tornado that occurs when the core region of a tornado is smaller than the half-power beamwidth of the sampling Doppler radar. Soon after the TVS was discovered in the ...

Rodger A. Brown; Vincent T. Wood

2012-04-01T23:59:59.000Z

98

Study on the Vibrations in the Discharge Pipe of Oil Flooded Screw Compressor.  

E-Print Network (OSTI)

??Flow induced pulsation in piping are serious concern in refrigeration installations where noise and vibrations are critical factors. This report takes an insight look into… (more)

Ravinath, Vijay

2006-01-01T23:59:59.000Z

99

Numerical and experimental investigations on vibration of simulated CANDU fuel bundles subjected to turbulent fluid flow.  

E-Print Network (OSTI)

??Vibration of simulated CANDU fuel bundles induced by coolant flow is investigated in this thesis through experiments and numerical simulations. Two simulated bundles and a… (more)

Zhang, Xuan

2011-01-01T23:59:59.000Z

100

Vortex operators in gauge field theories  

SciTech Connect

Several related aspects of the 't Hooft vortex operator are studied. The current picture of the vacuum of quantum chromodynamics, the idea of dual field theories, and the idea of the vortex operator are reviewed first. The Abelian vortex operator written in terms of elementary fields and the calculation of its Green's functions are considered. A two-dimensional solvable model of a Dirac string is presented. The expression of the Green's functions more neatly in terms of Wu and Yang's geometrical idea of sections is addressed. The renormalization of the Green's functions of two kinds of Abelian looplike operators, the Wilson loop and the vortex operator, is studied; for both operators only an overall multiplicative renormalization is needed. In the case of the vortex this involves a surprising cancellation. Next, the dependence of the Green's functions of the Wilson and 't Hooft operators on the nature of the vacuum is discussed. The cluster properties of the Green's functions are emphasized. It is seen that the vortex operator in a massive Abelian theory always has surface-like clustering. The form of Green's functions in terms of Feynman graphs is the same in Higgs and symmetric phases; the difference appears in the sum over all tadpole trees. Finally, systems having fields in the fundamental representation are considered. When these fields enter only weakly into the dynamics, a vortex-like operator is anticipated. Any such operator can no longer be local looplike, but must have commutators at long range. A U(1) lattice gauge theory with two matter fields, one singly charged (fundamental) and one doubly charged (adjoint), is examined. When the fundamental field is weakly coupled, the expected phase transitions are found. When it is strongly coupled, the operator still appears to be a good order parameter, a discontinuous change in its behavior leads to a new phase transition. 18 figures.

Polchinski, J.

1980-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

The dependence of chemistry on the inlet equivalence ratio in vortex-flame interactions [Printed LBNL report with title: The effect of stoichiometry on vortex flame interactions  

E-Print Network (OSTI)

of stoichiometry on vortex flame interactions [31] Pember,Rosalik, M . E . , Combust. Flame, 112(3):342-358 (1998).of stoichiometry on vortex flame interactions [15] Mueller,

Tonse, Shaheen R.

2011-01-01T23:59:59.000Z

102

The dependence of chemistry on the inlet equivalence ratio in vortex-flame interactions [Printed LBNL report with title: The effect of stoichiometry on vortex flame interactions  

E-Print Network (OSTI)

of stoichiometry on vortex flame interactions [31] Pember,Rosalik, M . E . , Combust. Flame, 112(3):342-358 (1998).of stoichiometry on vortex flame interactions [15] Mueller,

Bell, John B.; Brown, Nancy J.; Day, Marcus S.; Frenklach, Michael; Grcar, Joseph F.; Tonse, Shaheen R.

1999-01-01T23:59:59.000Z

103

Persistence of Metastable Vortex Lattice Domains in MgB2 in the Presence of Vortex Motion  

Science Conference Proceedings (OSTI)

Recently, extensive vortex lattice metastability was reported in MgB2 in connection with a second-order rotational phase transition. However, the mechanism responsible for these well-ordered metastable vortex lattice phases is not well understood. Using small-angle neutron scattering, we studied the vortex lattice in MgB2 as it was driven from a metastable to the ground state through a series of small changes in the applied magnetic field. Our results show that metastable vortex lattice domains persist in the presence of substantial vortex motion and directly demonstrate that the metastability is not due to vortex pinning. Instead, we propose that it is due to the jamming of counterrotated vortex lattice domains which prevents a rotation to the ground state orientation.

Rastovski, Catherine [University of Notre Dame, IN; Schlesinger, Kimberly [University of Notre Dame, IN; Gannon, William J [Northwestern University, Evanston; Dewhurst, Charles [Institut Laue-Langevin (ILL); Debeer-Schmitt, Lisa M [ORNL; Zhigadlo, Nikolai [ETH Zurich, Switzerland; Karpinski, Janusz [ETH Zurich, Switzerland; Eskildsen, Morten [University of Notre Dame, IN

2013-01-01T23:59:59.000Z

104

2008 Vibrational Spectroscopy  

SciTech Connect

The conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and interfaces. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of systems.

Philip J. Reid

2009-09-21T23:59:59.000Z

105

A Vortex Contactor for Carbon Dioxide Separations  

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

Vortex Contactor for Carbon Dioxide Separations Vortex Contactor for Carbon Dioxide Separations Kevin T. Raterman (ratekt@inel.gov; 208-526-5444) Michael McKellar (mgq@inel.gov; 208-526-1346) Anna Podgorney (poloak@inel.gov; 208-526-0064) Douglas Stacey (stacde@inel.gov; 208-526-3938) Terry Turner (tdt@inel.gov; 208-526-8623) Idaho National Engineering and Environmental Laboratory P.O. Box 1625 Idaho Falls, Idaho 83415-2110 Brian Stokes (bxs9@pge.com; 415-972-5591) John Vranicar (jjv2@pge.com; 415-972-5591) Pacific Gas & Electric Company 123 Mission Street San Francisco, CA 94105 Introduction Many analysts 1,2,3 identify carbon dioxide (CO 2 ) capture and separation as a major roadblock in efforts to cost effectively mitigate greenhouse gas emissions via sequestration. An assessment 4 conducted by the International Energy Agency (IEA)

106

Vortex Dynamics in NanoScale Materials  

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

Into the Vortex: Dynamics in Nanoscale Materials Into the Vortex: Dynamics in Nanoscale Materials Micron and nanosized magnets are of great interest for their potential applications in new electronic devices, such as magnetic random access memories. As the size of magnets is reduced to a 1-micron scale and below, the boundaries (surfaces, perimeters, etc) of the objects begin to profoundly influence both the static and dynamic behavior of the materials. Researchers from Argonne's Materials Science Division (MSD), Center for Nanoscale Materials (CNM), and Advanced Photon Source (APS) have recently examined the dynamics of 3- to 7-micron-diameter NiFe alloy disks with a combination of theoretical calculations and a new time-resolved magnetic imaging technique using synchrotron-based x-ray photoemission electron

107

Vortex formation during rf heating of plasma  

SciTech Connect

Experiments on a test plasma show that the linear theory of waveguide coupling to slow plasma waves begins to break down if the rf power flux exceeds approx. 30 W/cm/sup 2/. Probe measurements reveal that within 30 ..mu..s an undulation appears in the surface plasma near the mouth of the twin waveguide. This surface readjustment is part of a vortex, or off-center convective cell, driven by asymmetric rf heating of the plasma column.

Motley, R.W.

1980-05-01T23:59:59.000Z

108

Vortex flow visualization using tetrahedral cell subdivision  

Science Conference Proceedings (OSTI)

Proposes an effective technique for searching for critical points, which are points at which the velocity vector is zero. The previous method, using tetrahedral-cell subdivision, often generates multiple critical points in a hexahedral cell, and this ... Keywords: Newton's method, critical point searching technique, hexahedral cell, linear interpolation function, multiple critical points, numerical integration scheme, precise position calculation, tetrahedral cell subdivision, trilinear interpolation function, velocity vector, vortex flow visualization, vortices

A. Doi; S. Suzuki; K. Koyamada; S. Sannakanishi

1997-10-01T23:59:59.000Z

109

QCD String as Vortex String in Seiberg-Dual Theory  

E-Print Network (OSTI)

We construct a classical vortex string solution in a Seiberg-dual theory of N=1 supersymmetric SO(N_c) QCD which flows to a confining phase. We claim that this vortex string is a QCD string, as previouly argued by M.Strassler. In SO(N_c) QCD, it is known that stable QCD strings exist even in the presence of dynamical quarks. We show that our vortex strings are stable in the Seiberg-dual theory.

Eto, Minoru; Terashima, Seiji

2007-01-01T23:59:59.000Z

110

Spontaneous Symmetry-Breaking and the Vortex Lattice ...  

Science Conference Proceedings (OSTI)

... The magnetic vortex lattice of Type-II superconductors, as a quasi ... morphology in single-crystals of pure niobium, a 'conventional' superconductor. ...

111

vibrations.dvi  

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

VIBRATIONAL VIBRATIONAL MEASUREMENTS IN 3-ID-B J. Sutter 1 , E. Alp 1 , J. Barraza 2 , D. Shu 2 1 INTRODUCTION We have undertaken a series of vibrational measurements in hutch 3-ID-B. Our motivation was to compare two di erent methods of mounting an interferometer for e ectiveness in vibrational isolation and stability. In addition, we were able to compare the stability of our optical table with and without its eight large bolts inserted. 2 PROCEDURE We used two accelerometers to measure the amplitude of the vibrational acceleration as a function of frequency in steps of 0.0625 Hz from 1 to 25 Hz. The accelerations could then be transformed into displacement amplitudes by the simple harmonic equation of motion x = ,! 2 x, where x is the displacement and ! is the frequency times 2. The accelerometers had been calibrated before our experiment and were found to output a voltage of 7:44G V=g,

112

Vibrational Thermodynamics of Materials  

E-Print Network (OSTI)

Abstract. The literature on vibrational thermodynamics of materials is reviewed. The emphasis is on metals and alloys, especially on the progress over the last decade in understanding differences in the vibrational entropy of different alloy phases and phase transformations. Some results on carbides, nitrides, oxides, hydrides and lithium-storage materials are also covered. Principles of harmonic phonons in alloys are organized into thermodynamic models for unmixing and ordering transformations on an Ising lattice, and extended for non-harmonic potentials. Owing to the high accuracy required for the phonon frequencies, quantitative predictions of vibrational entropy with analytical models prove elusive. Accurate tools for such calculations or measurements were challenging for many years, but are more accessible today. Ab-initio methods for calculating phonons in solids are summarized. The experimental techniques of calorimetry, inelastic neutron scattering, and inelastic x-ray scattering are explained with enough detail to show the issues of using these methods for investigations of vibrational thermodynamics. The explanations extend to methods of data analysis that affect the accuracy of thermodynamic information. It is sometimes possible to identify the structural and chemical origins of the differences in vibrational entropy of materials, and the number of these assessments is growing. There has been

Brent Fultz

2009-01-01T23:59:59.000Z

113

Steam Generator Management Program: Thermal-Hydraulic and Flow-Induced Vibration Analyses of a Representative Model F Steam Generato r  

Science Conference Proceedings (OSTI)

During the Fall 2006 refueling outage of Vogtle 1, circumferential outside-diameter stress corrosion cracking (ODSCC) indications were observed in Model F steam generator tubes on the hot leg near the top of the tubesheet at low-row number, high-column number tubes. Additional ODSCC indications were observed in the same region during the Spring 2008 outage. All tubes with cracklike indications were plugged and stabilized. This report summarizes the comprehensive thermal-hydraulic and flow-induced vibrati...

2009-06-25T23:59:59.000Z

114

Effect of NO on extinction and re-ignition of vortex-perturbed hydrogen flames.  

DOE Green Energy (OSTI)

The catalytic effect of nitric oxide (NO) on the dynamics of extinction and re-ignition of a vortex-perturbed non-premixed hydrogen-air flame is studied in a counterflow burner. A diffusion flame is established with counterflowing streams of nitrogen-diluted hydrogen at ambient temperature and air heated to a range of temperatures that brackets the auto-ignition temperature. Localized extinction is induced by impulsively driving a fuel-side toroidal vortex into the steady flame, and the recovery of the extinguished region is monitored by planar laser-induced fluorescence (PLIF) of the hydroxyl radical (OH). The dynamics of flame recovery depend on the air temperature and fuel concentration, and four different recovery modes are identified. These modes involve combinations of edge-flame propagation and the expansion of an auto-ignition kernel that forms within the extinguished region. The addition of a small amount of NO significantly alters the re-ignition process by shifting the balance between chain-termination and chain-propagation reactions to enhance auto-ignition. The ignition enhancement by this catalytic effect causes a shift in the conditions that govern the recovery modes. In addition, the effects of NO concentration and vortex strength on the flame recovery are examined. Direct numerical simulations of the flame-vortex interaction with and without NO doping show how the small amount of OH produced by NO-catalyzed reactions has a significant impact on the development of an auto-ignition kernel. This joint experimental and numerical study provides detailed insight into the interaction between transient flows and ignition processes.

Yoo, Chun Sang; Chen, Jacqueline H.; Frank, Jonathan H.; Lee, Uen Do (KITECH, Cheonan, Chungnam, South Korea)

2009-01-01T23:59:59.000Z

115

Vibrations from underground blasting  

SciTech Connect

The Bureau of Mines has investigated vibration levels produced by blasting at four underground sites to establish how such factors as type of explosive, delay blasting, charge weight, and geology affect amplitudes of ground motion. A summary of the work is presented and the results of further analysis of the data are discussed. Square root scaling was found applicable to two of the underground sites and could be applied with minor error to all the sites. Comparison of empirical propagation equations in the different rock types indicates that although the site effect is apparent, the combined data may be used as a basis for engineering estimates of vibration amplitudes from subsurface blasting in many different rock types. Recommendations for predicting and minimizing vibration amplitudes from underground blasts are given.

Snodgrass, J.J.; Siskind, D.E.

1964-01-01T23:59:59.000Z

116

Externally tuned vibration absorber  

DOE Patents (OSTI)

A vibration absorber unit or units are mounted on the exterior housing of a hydraulic drive system of the type that is powered from a pressure wave generated, e.g., by a Stirling engine. The hydraulic drive system employs a piston which is hydraulically driven to oscillate in a direction perpendicular to the axis of the hydraulic drive system. The vibration absorbers each include a spring or other resilient member having one side affixed to the housing and another side to which an absorber mass is affixed. In a preferred embodiment, a pair of vibration absorbers is employed, each absorber being formed of a pair of leaf spring assemblies, between which the absorber mass is suspended.

Vincent, Ronald J. (Latham, NY)

1987-09-22T23:59:59.000Z

117

Optical manipulation of intrinsic localized vibrational energy in cantilever arrays  

E-Print Network (OSTI)

Optically-induced real-time impurity modes are used to shepherd intrinsic localized vibrational modes (discrete breathers) along micromechanical arrays via either attractive or replulsive interactions. Adding an electrode to the cantilever array provides control of the sign of lattice anharmonicity, hence allowing both hard and soft nonlinearities to be studied. A number of dynamical effects are demonstrated and explained, including the optical tweezing of localized vibrational energy in a nonlinear lattice.

M. Sato; B. E. Hubbard; A. J. Sievers; B. Ilic; H. G. Craighead

2004-03-16T23:59:59.000Z

118

Magnetic Vortex Core Reversal by Low-Field Excitations  

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

Magnetic Vortex Core Reversal by Magnetic Vortex Core Reversal by Low-Field Excitations Magnetic Vortex Core Reversal by Low-Field Excitations Print Wednesday, 28 March 2007 00:00 In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very strong magnetic fields of around half a tesla (approximately one-third the field of the strongest permanent magnet) were previously thought to be necessary to accomplish this. At the ALS, a team of researchers from Germany, Belgium, and the U.S. has used time-resolved scanning transmission x-ray microscopy (STXM) to observe vortex motion and demonstrate the feasibility of using weak magnetic fields as low as 1.5 millitesla (mT) to reverse the direction of a vortex core. The observed switching mechanism, which can be understood within the framework of micromagnetic theory, gives insights into basic magnetization dynamics and their possible application to data storage technologies.

119

Structure of quantum vortex tangle in He-4 counterflow turbulence  

E-Print Network (OSTI)

The main goal of this paper is to present a comprehensive characterization of well developed vortex tangles in a turbulent counterflow in quantum fluids (with a laminar normal fluid component). We analyze extensive numerical simulations using the vortex filament method, solving the full Biot-Savart equations for the vortex dynamics in a wide range of temperatures and counter-flow velocities. In addition to a detailed analysis of traditional characteristics such as vortex line density, anisotropic and curvature parameters of the vortex tangle, we stress other dynamical and statistical characteristics which are either much less studied or even unstudied. The latter include reconnection rates, mean mutual friction forces, drift velocities and the probability distribution functions of various tangle parameters: the loop length, the line curvature, the mean curvature of loops with a given length, etc. During these studies we compare the three main reconnection procedures which are widely used in the literature, and identify which properties are strongly affected by the choice of the reconnection criteria and which of them are practically insensitive to the reconnection procedure. The conclusion is that the vortex filament method in the framework of the Biot-Savart equation sufficiently robust and well suited for the description of the steady state vortex tangle in a quantum counterflow. The Local-Induction Approximation to this equation may be successfully used to analytically establish relationships between mean characteristics of the stochastic vortex tangle.

Luiza Kondaurova; Victor L'vov; Anna Pomyalov; Itamar Procaccia

2013-06-26T23:59:59.000Z

120

Helicoidal vortex model for wind turbine aeroelastic simulation  

Science Conference Proceedings (OSTI)

The vortex method has been extended to account for blade flexibility, which is a potential source of unsteadiness in the flow past a wind turbine rotor. The code has been validated previously under the assumption of rigid blades. The aerodynamics method ... Keywords: Blade flexibility, Steady and unsteady flows, Tower interference, Vortex model

Jean-Jacques Chattot

2007-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Finned Tube With Vortex Generators For A Heat Exchanger.  

DOE Patents (OSTI)

A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at least one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

Sohal, Monohar S. (Idaho Falls, ID); O' Brien, James E. (Idaho Falls, ID)

2004-09-14T23:59:59.000Z

122

Finned Tube With Vortex Generators For A Heat Exchanger.  

DOE Patents (OSTI)

A system for and method of manufacturing a finned tube for a heat exchanger is disclosed herein. A continuous fin strip is provided with at one pair of vortex generators. A tube is rotated and linearly displaced while the continuous fin strip with vortex generators is spirally wrapped around the tube.

Sohal, Manohar S. (Idaho Falls, ID); O' Brien, James E. (Idaho Falls, ID)

2005-12-20T23:59:59.000Z

123

An Investigation of a Three-Dimensional Asymmetric Vortex  

Science Conference Proceedings (OSTI)

A three-dimensional numerical simulation is presented for the asymmetric vortex motion which occurs in a Ward-type vortex chamber. The initial state is taken to be one of axisymmetric irrotational flow where the flow enters through the sides at ...

Richard Rotunno

1984-01-01T23:59:59.000Z

124

Vibrational and Electronic Energy Level Searches  

Science Conference Proceedings (OSTI)

... options based on vibrational and electronic energies are available: ... the tabulated vibrational and electronic energy level data ... All rights reserved. ...

2013-07-15T23:59:59.000Z

125

Vibration Harvesting using Electromagnetic Transduction  

E-Print Network (OSTI)

wide bandwidth piezoelectric energy harvesting,” Appliedtuning of piezoelectric vibration energy scavengingof electric energy harvesting using piezoelectric windmill,”

Waterbury, Andrew

2011-01-01T23:59:59.000Z

126

Stability of an optical vortex in a circular nematic cell  

SciTech Connect

The stability of an optical vortex in a cell with a circular cross section containing a nematic liquid crystal is studied. A modulation theory based on an averaged Lagrangian formulation is developed to study this stability. It is found that the vortex is stable unless the radius of the cell is very small, nearly the width of the vortex itself. Based on the analysis of a stationary vortex, the stability of a low-amplitude vortex in a large cell under the influence of its orbital angular momentum and the repelling effect of the cell boundary are studied. The predictions of this modulation theory are found to be in excellent agreement with numerical simulations.

Minzoni, Antonmaria A. [Fenomenos Nonlineales y Mecanica (FENOMEC), Departamento de Matematicas y Mecanica, Instituto de Investigacion en Matematicas Aplicadas y Sistemas, Universidad Nacional Autonoma de Mexico, 01000 Mexico D.F. (Mexico); Smyth, Noel F. [School of Mathematics and Maxwell Institute for Mathematical Sciences, University of Edinburgh, Edinburgh EH9 3JZ, Scotland (United Kingdom); Xu Zhiyong [Nonlinear Physics Center, Research School of Physics and Engineering, Australian National University, Canberra ACT 0200 (Australia)

2010-03-15T23:59:59.000Z

127

Nonlinear vibrational microscopy  

SciTech Connect

The present invention is a method and apparatus for microscopic vibrational imaging using coherent Anti-Stokes Raman Scattering or Sum Frequency Generation. Microscopic imaging with a vibrational spectroscopic contrast is achieved by generating signals in a nonlinear optical process and spatially resolved detection of the signals. The spatial resolution is attained by minimizing the spot size of the optical interrogation beams on the sample. Minimizing the spot size relies upon a. directing at least two substantially co-axial laser beams (interrogation beams) through a microscope objective providing a focal spot on the sample; b. collecting a signal beam together with a residual beam from the at least two co-axial laser beams after passing through the sample; c. removing the residual beam; and d. detecting the signal beam thereby creating said pixel. The method has significantly higher spatial resolution then IR microscopy and higher sensitivity than spontaneous Raman microscopy with much lower average excitation powers. CARS and SFG microscopy does not rely on the presence of fluorophores, but retains the resolution and three-dimensional sectioning capability of confocal and two-photon fluorescence microscopy. Complementary to these techniques, CARS and SFG microscopy provides a contrast mechanism based on vibrational spectroscopy. This vibrational contrast mechanism, combined with an unprecedented high sensitivity at a tolerable laser power level, provides a new approach for microscopic investigations of chemical and biological samples.

Holtom, Gary R. (Richland, WA); Xie, Xiaoliang Sunney (Richland, WA); Zumbusch, Andreas (Munchen, DE)

2000-01-01T23:59:59.000Z

128

Magnetic Vortex Core Reversal by Low-Field Excitations  

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

Magnetic Vortex Core Reversal by Low-Field Excitations Print Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very strong magnetic fields of around half a tesla (approximately one-third the field of the strongest permanent magnet) were previously thought to be necessary to accomplish this. At the ALS, a team of researchers from Germany, Belgium, and the U.S. has used time-resolved scanning transmission x-ray microscopy (STXM) to observe vortex motion and demonstrate the feasibility of using weak magnetic fields as low as 1.5 millitesla (mT) to reverse the direction of a vortex core. The observed switching mechanism, which can be understood within the framework of micromagnetic theory, gives insights into basic magnetization dynamics and their possible application to data storage technologies.

129

Magnetic Vortex Core Reversal by Low-Field Excitations  

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

Magnetic Vortex Core Reversal by Low-Field Excitations Print Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very strong magnetic fields of around half a tesla (approximately one-third the field of the strongest permanent magnet) were previously thought to be necessary to accomplish this. At the ALS, a team of researchers from Germany, Belgium, and the U.S. has used time-resolved scanning transmission x-ray microscopy (STXM) to observe vortex motion and demonstrate the feasibility of using weak magnetic fields as low as 1.5 millitesla (mT) to reverse the direction of a vortex core. The observed switching mechanism, which can be understood within the framework of micromagnetic theory, gives insights into basic magnetization dynamics and their possible application to data storage technologies.

130

Magnetic Vortex Core Reversal by Low-Field Excitations  

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

Magnetic Vortex Core Reversal by Low-Field Excitations Print Magnetic Vortex Core Reversal by Low-Field Excitations Print In micrometer-sized magnetic thin films, the magnetization typically adopts an in-plane, circular configuration known as a magnetic vortex. At the vortex core, the magnetization turns sharply out of the plane, pointing either up or down. Magnetic data storage based on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very strong magnetic fields of around half a tesla (approximately one-third the field of the strongest permanent magnet) were previously thought to be necessary to accomplish this. At the ALS, a team of researchers from Germany, Belgium, and the U.S. has used time-resolved scanning transmission x-ray microscopy (STXM) to observe vortex motion and demonstrate the feasibility of using weak magnetic fields as low as 1.5 millitesla (mT) to reverse the direction of a vortex core. The observed switching mechanism, which can be understood within the framework of micromagnetic theory, gives insights into basic magnetization dynamics and their possible application to data storage technologies.

131

Ferroelectric nanostructure having switchable multi-stable vortex states  

DOE Patents (OSTI)

A ferroelectric nanostructure formed as a low dimensional nano-scale ferroelectric material having at least one vortex ring of polarization generating an ordered toroid moment switchable between multi-stable states. A stress-free ferroelectric nanodot under open-circuit-like electrical boundary conditions maintains such a vortex structure for their local dipoles when subject to a transverse inhomogeneous static electric field controlling the direction of the macroscopic toroidal moment. Stress is also capable of controlling the vortex's chirality, because of the electromechanical coupling that exists in ferroelectric nanodots.

Naumov, Ivan I. (Fayetteville, AR); Bellaiche, Laurent M. (Fayetteville, AR); Prosandeev, Sergey A. (Fayetteville, AR); Ponomareva, Inna V. (Fayetteville, AR); Kornev, Igor A. (Fayetteville, AR)

2009-09-22T23:59:59.000Z

132

New developments in IR surface vibrational spectroscopy  

DOE Green Energy (OSTI)

Low frequency dynamics at surfaces, particularly in the region of the adsorbate-substrate vibrational modes is of fundamental importance in areas as varied as sliding friction, catalysis, corrosion and epitaxial growth. This paper reviews the new developments in low frequency Infrared Reflection Absorption Spectroscopy using synchrotron radiation as the source. Absolute changes induced in the far infrared for several adsorbate systems on Cu, including CO and H, are dominated by broadband reflectance changes and dipole forbidden vibrational modes which in some cases are an order of magnitude stronger than the dipole allowed modes. The experimental data can be explained by a theory developed by Persson, in which the dielectric response of the substrate is seen as playing a crucial role in the dynamics. In particular the relationships between the wavelength of the light, the penetration depth and the electron mean-free path, are critical.

Hirschmugl, C.J.; Lamont, C.L.A.; Williams, G.P. [Brookhaven National Lab., Upton, NY (United States). National Synchrotron Light Source

1995-12-31T23:59:59.000Z

133

The Modeling of Vibration Damping in SMA Wires  

SciTech Connect

Through a mathematical and computational model of the physical behavior of shape memory alloy wires, this study shows that localized heating and cooling of such materials provides an effective means of damping vibrational energy. The thermally induced pseudo-elastic behavior of a shape memory wire is modeled using a continuum thermodynamic model and solved computationally as described by the authors in [23]. Computational experiments confirm that up to 80% of an initial shock of vibrational energy can be eliminated at the onset of a thermally-induced phase transformation through the use of spatially-distributed transformation regions along the length of a shape memory alloy wire.

Reynolds, D R; Kloucek, P; Seidman, T I

2003-09-16T23:59:59.000Z

134

Vortex flow around the bases of obstacles  

E-Print Network (OSTI)

.2 The horseshoe . vortex formed by a separating turbulent boundary layer 5.3 Scour around obstacles in an erodible bed 114 116 117 . ·4 References Uf'l() I:!~oLtlecl F,'obL.efl):' Llr:cl ~u.g5el:dto/J~ fer ju.iLt(t' wc"..,I" 11 2 119 Figures (vi... , are shmm in figUre 2.3.4. It can be seen that there is a rather high le,el of turbulence in the tunnel free stream. This is poss:l.bly due to the extra screens placed upstream of the \\'lorking section. At the higher speeds used this turbulence...

Baker, Christopher James

1979-02-06T23:59:59.000Z

135

The multiple vortex nature of tropical cyclogenesis  

E-Print Network (OSTI)

This thesis contains an observational analysis of the genesis of Tropical Storm Allison (2001). Using a paradigm of tropical cyclone formation as the superposition of potential vorticity (PV) anomalies, the importance of different scales of PV merger to various aspects of Allison?s formation is discussed. While only the case of Allison is discussed in great detail, other studies have also documented PV superposition on various scales, and superposition could be important for most tropical cyclones. Preceding Allison?s genesis, PV superposition on the large scale destabilized the atmosphere and increased low-level cyclonic vorticity. This presented a more favorable environment for the formation of MCV-type PV anomalies and smaller, surface-based, meso-?-scale vortices. Although these vortices eventually merged to form a more concentrated vortex with stronger surface pressure gradients, the merger happened well after landfall of Allison and no strengthening ensued. The unstable, vorticity-rich environment was also favorable for the development of even smaller, meso-?-scale vortices that accompanied deep convective cells within one of Allison?s meso-?-scale vortices. The observations herein suggest that the meso-?- scale convective cells and vortices are the respective source of PV production and building blocks for the meso-?-scale vortices. Finally, this thesis discusses issues related to the multiple vortex nature of tropical cyclone formation. For instance, the tracking of developing tropical cyclones is greatly complicated by the presence of multiple vortices. For these cases, the paradigm of a single cyclone center is inappropriate and alternative tracking methods are introduced.

Sippel, Jason Allen

2004-12-01T23:59:59.000Z

136

Argonne CNM Highlight: Biofunctionalized magnetic-vortex microdiscs for  

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

Biofunctionalized magnetic-vortex microdiscs for targeted cancer-cell destruction Biofunctionalized magnetic-vortex microdiscs for targeted cancer-cell destruction Magnetic microdisks Reflection optical microscope image of a dried suspension of the discs prepared via magnetron sputtering and optical lithography. Magnetic spin vortex Model of magnetic-vortex spin distribution in a disc. Users from Argonne's Materials Science Division and University of Chicago's Pritzker School of Medicine, working collaboratively on a user science project with CNM's Nanobio Interfaces Group, have discovered that nanostructured magnetic materials offer exciting avenues for probing cell mechanics, activating mechanosensitive ion channels, and advancing potential cancer therapies. Their new report describes an approach based on interfacing cells with lithographically defined microdiscs (1-micron

137

Magnetic Vortex Core Reversal by Low-Field Excitations  

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

on this binary phenomenon is an intriguing concept, but it would require the ability to flip the vortex cores on demand. Because these structures are highly stable, very strong...

138

Linear Dynamics of the Multiple-Vortex Phenomenon in Tornadoes  

Science Conference Proceedings (OSTI)

The reason for existence of two separate unstable modes, previously described by Gall for flows in vortex simulators, is explored. When the energy equation for an unstable disturbance is considered, it is clear that the most unstable wave must be ...

Robert L. Gall

1985-04-01T23:59:59.000Z

139

Baroclinic Transition of a Long-Lived Mesoscale Convective Vortex  

Science Conference Proceedings (OSTI)

The period 5–15 June 2003, during the field phase of the Bow Echo and Mesoscale Convective Vortex (MCV) Experiment (BAMEX), was noteworthy for the wide variety of mesoscale convective systems (MCSs) that occurred. Of particular interest was a ...

Thomas J. Galarneau Jr.; Lance F. Bosart; Christopher A. Davis; Ron McTaggart-Cowan

2009-02-01T23:59:59.000Z

140

Reexamining the Vertical Development of Tornadic Vortex Signatures in Supercells  

Science Conference Proceedings (OSTI)

Observations from a hybrid phased-array Doppler radar, the Mobile Weather Radar, 2005 X-band, Phased-Array (MWR-05XP), were used to investigate the vertical development of tornadic vortex signatures (TVSs) during supercell tornadogenesis. Data ...

Michael M. French; Howard B. Bluestein; Ivan PopStefanija; Chad A. Baldi; Robert T. Bluth

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Inertia–Gravity Waves Generated within a Dipole Vortex  

Science Conference Proceedings (OSTI)

Vortex dipoles provide a simple representation of localized atmospheric jets. Numerical simulations of a synoptic-scale dipole in surface potential temperature are considered in a rotating, stratified fluid with approximately uniform potential ...

Chris Snyder; David J. Muraki; Riwal Plougonven; Fuqing Zhang

2007-12-01T23:59:59.000Z

142

Ozone Chemistry during the 2002 Antarctic Vortex Split  

Science Conference Proceedings (OSTI)

In September 2002, the Antarctic polar vortex was disturbed, and it split into two parts caused by an unusually early stratospheric major warming. This study discusses the chemical consequences of this event using the Chemical Lagrangian Model of ...

Jens-Uwe Grooß; Paul Konopka; Rolf Müller

2005-03-01T23:59:59.000Z

143

Assimilating Vortex Position with an Ensemble Kalman Filter  

Science Conference Proceedings (OSTI)

Observations of hurricane position, which in practice might be available from satellite or radar imagery, can be easily assimilated with an ensemble Kalman filter (EnKF) given an operator that computes the position of the vortex in the background ...

Yongsheng Chen; Chris Snyder

2007-05-01T23:59:59.000Z

144

Spontaneous Imbalance and Hybrid Vortex–Gravity Structures  

Science Conference Proceedings (OSTI)

After reviewing the background, this article discusses the recently discovered examples of hybrid propagating structures consisting of vortex dipoles and comoving gravity waves undergoing wave capture. It is shown how these examples fall outside ...

Michael E. McIntyre

2009-05-01T23:59:59.000Z

145

Some Aspects of Vortex Structure Related to Tropical Cyclone Motion  

Science Conference Proceedings (OSTI)

Some effect of tropical cyclone structure on the vortex motion are examined in a nondivergent, barotropic numerical model with no basic current. As suggested earlier by DeMaria, the initial maximum wind speed has little effect on the track. ...

Michael Fiorino; Russell L. Elsberry

1989-04-01T23:59:59.000Z

146

MHK Technologies/SeaUrchin Vortex Reaction Turbine | Open Energy  

Open Energy Info (EERE)

SeaUrchin Vortex Reaction Turbine SeaUrchin Vortex Reaction Turbine < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage SeaUrchin Vortex Reaction Turbine.jpg Technology Profile Primary Organization Elemental Energy Technologies Limited ABN 46 128 491 903 Technology Resource Click here Current Technology Type Click here Axial Flow Turbine Technology Readiness Level Click here TRL 4 Proof of Concept Technology Description A revolutionary vortex reaction turbine branded the SeaUrchin an advanced third generation marine turbine technology capable of delivering inexpensive small to large scale baseload or predictable electricity by harnessing the kinetic energy of free flowing ocean currents tides and rivers Technology Dimensions Device Testing Date Submitted 55:15.2

147

Closed cycle steam turbine system with liquid vortex pump  

SciTech Connect

A closed cycle steam generating system is described comprising a steam boiler, and a steam turbine includes a vacuum pump of the liquid vortex type for condensing the exhaust steam from the turbine, a feedwater pump being employed for returning the condensate to the boiler. The tank of the vortex pump is maintained filled with water and the pressure in the tank is regulated automatically to maintain a predetermined value thereof.

Brown, K.D.

1976-08-10T23:59:59.000Z

148

Nonclassicality of vortex Airy beams in the Wigner representation  

Science Conference Proceedings (OSTI)

The Wigner distribution function (WDF) of a vortex Airy beam is calculated analytically. The WDF provides intuitive pictures of the intriguing features of vorticity in phase space. The nonclassical property of the vortex Airy beam and the Airy beam is analyzed through the negative parts of the WDF. The study shows that destructive interference of certain classical waves can mimic nonclassical lights such as those due to quantum effects.

Chen Ruipin [School of Sciences, Zhejiang A and F University, Lin'an, Zhejiang Province 311300 (China); Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia); Ooi, C. H. Raymond [Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

2011-10-15T23:59:59.000Z

149

Vibrational and Electronic Energy Levels  

Science Conference Proceedings (OSTI)

... for the ground-state vibrational fundamentals of larger ... and S. Iwata, Handbook of He I Photoelectron Spectra of Fundamental Organic Molecules ...

2013-07-15T23:59:59.000Z

150

Electron Trapping by Molecular Vibration  

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

Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally...

151

Depinning of a superfluid vortex line by Kelvin waves  

E-Print Network (OSTI)

We measure the interaction of a single superfluid vortex with surface irregularities. While vortex pinning in superconductors usually becomes weaker at higher temperatures, we find the opposite behavior. The pinning steadily increases throughout our measurement range, from 0.15Tc to over 0.5Tc. We also find that moving the other end of the vortex decreases the pinning, so we propose Kelvin waves along the vortex as a depinning mechanism. PACS numbers: 67.40.Vs, 74.60.Ge Pinning sites can trap vortices in a variety of systems. In superconductors, where vortex motion leads to nonzero resistance, a vast amount of work has been devoted to preventing such motion by introducing defects. Experimental work has shown that defects comparable in size to the vortex core make effective pin centers, and that straight [1] or splayed [2] line defects can increase the pin strength. Yet the mechanisms by which vortices interact with pin sites remain unresolved. Experimentally, pinning in superconductors becomes weaker as

L. A. K. Donev; L. Hough; R. J. Zieve

2001-01-01T23:59:59.000Z

152

Turbine blade vibration dampening  

DOE Patents (OSTI)

The present turbine wheel assembly increases component life and turbine engine longevity. The combination of the strap and the opening combined with the preestablished area of the outer surface of the opening and the preestablished area of the outer circumferential surface of the strap and the friction between the strap and the opening increases the life and longevity of the turbine wheel assembly. Furthermore, the mass ``M`` or combined mass ``CM`` of the strap or straps and the centrifugal force assist in controlling vibrations and damping characteristics. 5 figs.

Cornelius, C.C.; Pytanowski, G.P.; Vendituoli, J.S.

1997-07-08T23:59:59.000Z

153

Turbine blade vibration dampening  

DOE Patents (OSTI)

The present turbine wheel assembly increases component life and turbine engine longevity. The combination of the strap and the opening combined with the preestablished area of the outer surface of the opening and the preestablished area of the outer circumferential surface of the strap and the friction between the strap and the opening increases the life and longevity of the turbine wheel assembly. Furthermore, the mass "M" or combined mass "CM" of the strap or straps and the centrifugal force assist in controlling vibrations and damping characteristics.

Cornelius, Charles C. (San Diego, CA); Pytanowski, Gregory P. (San Diego, CA); Vendituoli, Jonathan S. (San Diego, CA)

1997-07-08T23:59:59.000Z

154

A numerical study of steady-state vortex configurations and vortex pinning in type-II superconductors  

E-Print Network (OSTI)

In part I, a numerical study of the mixed states in a mesoscopic type-II superconducting cylinder is described. Steady-state configurations and transient behavior of the magnetic vortices for various values of the applied magnetic field H are presented. Transitions between different multi-vortex states as H is changed is demonstrated by abrupt changes in vortex configurations and jumps in the B vs H plot. An efficient scheme to determine the equilibrium vortex configuration in a mesoscopic system at any given applied field, not limited to the symmetry of the system, is devised and demonstrated. In part II, a superconducting thin film is subject to a non-uniform magnetic field from a vertical magnetic dipole, consisting of two magnetic monopoles of opposite charges. For a film with constant thickness and with no pins, it has been found that the film carries two pairs of vortex-antivortex in the steady state in the imposed flux range of 2.15 < (Phi)+ < 2.90 (in units of flux quantum) and no vortex at all for (Phi)+ <= 2.15. Transitions from a superconducting state with 3 pairs of vortex-antivortex to one with 2 pairs, where a pair of vortex-antivortex annihilates, have been observed in the pseudo-time sequence. With a perturbation with antidots (holes), vortexantivortex pair has been created for lower magnetic fluxes down to (Phi)+ = 1.3. In the sample of size 16(Xi) x 16(Xi), the attraction force between the vortex and antivortex always dominates over the pinning force, so that they eventually come out of pins, move toward each other, and annihilate each other. The annihilation rate, measured with time taken for the annihilation, is reduced noticeably by the increase of the distance between pins, or the increase in the pin size. A simulation of the magnetic vortex pinning in the sample of size 32(Xi) x 32(Xi) suggests we are likely to achieve pinning of the vortex-antivortex pair with the sample size around this and vortex-antivortex separation of 22(Xi). Using this sample as a template, the maximum density of pinned vortices achievable is calculates to be about 7.6 x 10^14 vortices/m2 for (Xi) =~ 1.6A°.

Kim, Sangbum

2004-12-01T23:59:59.000Z

155

Multiple direction vibration fixture - Energy Innovation Portal  

When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture.

156

Barotropic Simulation of Large-Scale Mixing in the Antarctic Polar Vortex  

Science Conference Proceedings (OSTI)

Theory and observations suggest that the Antarctic polar vortex is relatively isolated from midlatitudes, although others have interpreted the observations to indicate that there is substantial mixing from the interior of the vortex into middle ...

Kenneth P. Bowman

1993-09-01T23:59:59.000Z

157

Stratospheric Sudden Warmings as Self-Tuning Resonances. Part I: Vortex Splitting Events  

Science Conference Proceedings (OSTI)

The fundamental dynamics of “vortex splitting” stratospheric sudden warmings (SSWs), which are known to be predominantly barotropic in nature, are reexamined using an idealized single-layer f-plane model of the polar vortex. The aim is to ...

N. Joss Matthewman; J. G. Esler

2011-11-01T23:59:59.000Z

158

A Theory for Mixed Vortex Rossby–Gravity Waves in Tropical Cyclones  

Science Conference Proceedings (OSTI)

Vortex–Rossby waves (VRWs) and inertial gravity waves (IGWs) have been proposed to explain the propagation of spiral rainbands and the development of dynamical instability in tropical cyclones (TCs). In this study, a theory for mixed vortex–...

Wei Zhong; Da-Lin Zhang; Han-Cheng Lu

2009-11-01T23:59:59.000Z

159

Influence of a Strong Bottom Slope on the Evolution of a Surface-Intensified Vortex  

Science Conference Proceedings (OSTI)

The authors investigate the influence of steep bottom topography on the propagation of a vortex in a two-layer quasigeostrophic model. The vortex is intensified in the upper layer and the planetary beta effect is taken into account.

Virginie Thierry; Yves Morel

1999-05-01T23:59:59.000Z

160

Vortex dynamics : a window into the properties of type-II superconductors  

E-Print Network (OSTI)

DIEGO Vortex Dynamics: A Window Into the Properties of Type-DISSERTATION Vortex Dynamics: A Window Into the Propertiesa ?lm deposits on the window through which the laser beam

Taylor, Benjamin Jeremy

2006-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Combining the vortex-in-cell and parallel fast multipole methods for efficient domain decomposition simulations  

Science Conference Proceedings (OSTI)

A new combination of vortex-in-cell and parallel fast multipole methods is presented which allows to efficiently simulate, in parallel, unbounded and half-unbounded vortical flows (flows with one flat wall). In the classical vortex-in-cell (VIC) method, ... Keywords: Incompressible flows, Lagrangian methods, Parallel fast multipole method, Particle methods, Unbounded flows, Unsteady flows, Vortex methods, Vortex-in-cell method, Wall-bounded flows

Roger Cocle; Grégoire Winckelmans; Goéric Daeninck

2008-02-01T23:59:59.000Z

162

Binding sites of quinones in photosynthetic bacterial reaction centers investigated by light-induced FTIR difference spectroscopy: Symmetry of the carbonyl interactions and close equivalence of the Q{sub B} vibrations in Rhodobacter sphaeroides and Rhodopseudomonas viridis probed by isotope labeling  

Science Conference Proceedings (OSTI)

The photoreduction of the secondary quinone acceptor Q{sub B} in reaction centers (RCs) of the photosynthetic bacteria Rhodobacter sphaeroides and Rhodopseudomonas viridis has been investigated by light-induced FTIR difference spectroscopy of RCs reconstituted with several isotopically labeled ubiquinones. The labels used were {sup 18}O on both carbonyls and {sup 13}C either uniformly or selectively at the 1- or the 4-position, i.e., on either one of the two carbonyls. The Q{sub B}{sup {minus}}/Q{sub B} spectra of RCs reconstituted with the isotopically labeled and unlabeled quinones as well as the double differences calculated form these spectra exhibit distinct isotopic shifts for a numer of bands attributed to vibrations of Q{sub B} and Q{sub B}{sup {minus}}. The vibrational modes of the quinone in the Q{sub B} site are compared to those of ubiquinone in vitro, leading to band assignments for the C{double_bond}O and C{double_bond}C vibrations of the neutral Q{sub B} and for the C---O and C---C of the semiquinone. The C{double_bond}O frequency of each of the carbonyls of the unlabeled quinone is revealed at 1641 cm{sup {minus}1} for both species. This demonstrates symmetrical and weak hydrogen bonding of the two C{double_bond}O groups to the protein at the Q{sub B} site. In contrast, the C{double_bond}C vibrations are not equivalent for selective labeling at C{sub 1} or at C{sub 4}, although they both contribute to the {approximately}1611-cm{sup {minus}1} band in the Q{sub B}{sup {minus}}/Q{sub B} spectra of the two species. Compared to the vibrations of isolated ubiquinone, the C{double_bond}C mode of Q{sub B} does not involve displacement of the C{sub 4} carbon atom, while the motion of C{sub 1} is not hindered. Further analysis of the spectra suggests that the protein at the binding site imposes a specific constraint on the methoxy and/or the methyl group proximal to the C{sub 4} carbonyl. 49 refs., 5 figs.

Breton, J.; Berger, G.; Nabedryk, E. [SBE/DBCM and SMM/DBCM, CEA-Saclay (France)] [and others

1995-09-12T23:59:59.000Z

163

Adaptive vibration control using synchronous demodulation with ...  

Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation United States Patent

164

The Data Vortex, an All Optical Path Multicomputer Interconnection Network  

E-Print Network (OSTI)

All optical path interconnection networks employing dense wavelength division multiplexing can provide vast improvements in supercomputer performance. However, the lack of efficient optical buffering requires investigation of new topologies and routing techniques. This paper introduces and evaluates the Data Vortex optical switching architecture which uses cylindrical routing paths as a packet buffering alternative. In addition, the impact of the number of angles on the overall network performance is studied through simulation. Using optimal topology configurations, the Data Vortex is compared to two existing switching architectures—butterfly and omega networks. The three networks are compared in terms of throughput, accepted traffic ratio, and average packet latency. The Data Vortex is shown to exhibit comparable latency and a higher acceptance rate (2x at 50 percent load) than the butterfly and omega topologies.

Cory Hawkins; Benjamin A. Small; D. Scott Wills; Keren Bergman

2007-01-01T23:59:59.000Z

165

Identification of vortexes obstructing the dynamo mechanism in laboratory experiments  

E-Print Network (OSTI)

The magnetohydrodynamic dynamo effect explains the generation of self-sustained magnetic fields in electrically conducting flows, especially in geo- and astrophysical environments. Yet the details of this mechanism are still unknown, e.g., how and to which extent the geometry, the fluid topology, the forcing mechanism and the turbulence can have a negative effect on this process. We report on numerical simulations carried out in spherical geometry, analyzing the predicted velocity flow with the so-called Singular Value Decomposition, a powerful technique that allows us to precisely identify vortexes in the flow which would be difficult to characterize with conventional spectral methods. We then quantify the contribution of these vortexes to the growth rate of the magnetic energy in the system. We identify an axisymmetric vortex, whose rotational direction changes periodically in time, and whose dynamics are decoupled from those of the large scale background flow, is detrimental for the dynamo effect. A compar...

Limone, Angelo; Forest, Cary B; Jenko, Frank

2013-01-01T23:59:59.000Z

166

Shock-compressible-vortex interactions: Computing approximate post-shock fields  

E-Print Network (OSTI)

Shock-compressible-vortex interactions: Computing approximate post-shock fields G.K. O'Reilly and D of the passage of a planar shock through a steady compressible vortex is developed. To compute the approximate post-shock fields, the steady pre-shock vortex is decomposed into a sum of frozen sinusoidal modes

Barr, Al

167

Non-Contact Haptic Feedback Using Air Vortex Rings Sidhant Gupta1,2  

E-Print Network (OSTI)

regions of the human body. Author Keywords Non-contact haptic feedback; air vortex rings ACM1 AirWave: Non-Contact Haptic Feedback Using Air Vortex Rings Sidhant Gupta1,2 , Dan Morris1 feedback into such interaction. In this work, we explore the use of air vortex rings for this purpose

Rajamani, Sriram K.

168

Electron Trapping by Molecular Vibration  

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

Electron Trapping by Molecular Vibration Print Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

169

Electron Trapping by Molecular Vibration  

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

Electron Trapping by Molecular Vibration Print Electron Trapping by Molecular Vibration Print In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

170

What is a lattice vibration?  

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

What is a lattice vibration? The atoms in a crystal are not locked into a rigid pattern but can oscillate around their average position. When a whole group of them does this in a...

171

Vibration of Tethered Microstructure Profilers  

Science Conference Proceedings (OSTI)

Although loosely tethered turbulence profilers have many advantages, they are prone to resonant vibrations at frequencies in the dissipation range when they are falling rapidly or when the tether is strummed. Using the Advanced Microstructure ...

Jack B. Miller; M. C. Gregg; Vernon W. Miller; Gordon L. Welsh

1989-12-01T23:59:59.000Z

172

Wigner function and entanglement of generalized quantum optical vortex  

E-Print Network (OSTI)

We calculate the Wigner quasiprobability distribution function of the quantum elliptical vortex (QEV), produced by coupling squeezed coherent states of two modes . The coupling between the two modes is performed by using beam splitter (BS) or a dual channel directional coupler (DCDC). The quantum interference due to the coupling between the two modes promises the generation of controlled entanglement for quantum computation and quantum tomography. We calculate the entanglement of such generalized elliptical vortex formed by quantized radiation field (QEV), using Wigner quasiprobability distribution function for such states. We find a critical squeezing parameter above which the entanglement is less for higher vorticity, which is counter intuitive.

Bandyopadhyay, Abir; Singh, R P

2011-01-01T23:59:59.000Z

173

Reply to "Comment on 'Vortex-assisted photon counts and their magnetic field dependence in single-photon superconducting detectors'"  

SciTech Connect

The vortex crossing rate in thin current-biased superconducting strips, calculated within the London approach employing the concept of a vortex as a particle, is very sensitive to the cutoff at the vortex core size. To account properly for the vortex core, one needs to use microscopic theory.

Bulaevskii, L.N.; Graf, Matthias; Kogan, Vladimir G.

2012-07-16T23:59:59.000Z

174

On the Onset Vortex of the Summer Monsoon  

Science Conference Proceedings (OSTI)

In this paper we examine the evolution of the low-level flow over the Arabian Sea during the onset of the summer monsoon. A detailed examination of the onset vortex that forms over the Arabian Sea just prior to the commencement of heavy rains ...

T. N. Krishnamurti; Philip Ardanuy; Y. Ramanathan; Richard Pasch

1981-02-01T23:59:59.000Z

175

Blade-Vortex Interactions in High Pressure Steam Turbines  

E-Print Network (OSTI)

A detailed experimental and numerical investigation of the transport of streamwise (passage) vortices in high-pressure axial turbines and their interaction with the downstream blade rows was performed. The results indicate large variations in the downstream flow field, notably the development of the secondary flows. The mechanism of passage vortex transport was studied in two differently configured high-pressure turbine stages. In the first configuration, the blades are radially stacked while the second configuration features three-dimensionally stacked high-pressure steam turbine blading. The stator hub passage vortex is chopped by the downstream blade row in a similar way to the wake. The bowed vortex tube near the inlet to the rotor appeared to develop two counter-rotating legs extending back to the leading edges of the adjacent blades. These were termed the suction side leg and the pressure side leg. The two legs of the incoming passage vortex then convect with the respective velocities on the blade surfaces. The results are discussed for the radially stacked turbine and the 3-D turbine separately.

Venkata Siva Prasad Chaluvadi

2000-01-01T23:59:59.000Z

176

Nielsen-Olesen vortex in varying-alpha theories  

E-Print Network (OSTI)

We consider soliton solutions to Bekenstein's theory, for which the fine structure constant $\\alpha=e^2/(4\\pi\\hbar c)$ is allowed to vary due to the presence of a dielectric field pervading the vacuum. More specifically we investigate the effects of a varying $\\alpha$ upon a complex scalar field with a U(1) electromagnetic gauge symmetry subject to spontaneous symmetry breaking. We find vortex solutions to this theory, similar to the Nielsen-Olesen vortex. Near the vortex core the electric charge is typically much larger than far away from the string, lending these strings a superconducting flavour. In general the dielectric field coats the usual local string with a global string envelope. We discuss the cosmological implications of networks of such strings, with particular emphasis on their ability to generate inhomogeneous recombination scenarios. We also consider the possibility of the dielectric being a charged free field. Even though the vacuum of such a field is trivial, we find that the dielectric arranges itself in the shape of a local string, with a quantized magnetic flux at the core -- presumably borrowing these topological features from the underlying Nielsen-Olesen vortex.

J. Magueijo; H. Sandvik; T. W. B. Kibble

2001-01-15T23:59:59.000Z

177

Diabatically Induced Secondary Flows in Tropical Cyclones. Part II: Periodic Forcing  

Science Conference Proceedings (OSTI)

The linearized equation for the time-varying, axially symmetric circumferential component of the vorticity in a hurricane-like vortex closely resembles the classical Sawyer–Eliassen equation for the quasi-steady, diabatically induced secondary-...

Hugh E. Willoughby

2009-03-01T23:59:59.000Z

178

Strain-Based Turbine Generator Torsional Vibration Monitoring System - Phase 1: Concept Development  

Science Conference Proceedings (OSTI)

Shaft torsional vibration in large steam turbine-generator units is induced by transient grid disturbances and negative sequence currents. If undetected, these vibrations can accumulate fatigue damage in rotor elements such as turbine blades, couplings, and retaining rings. Shaft natural frequencies can be closely aligned with the predominant torsional excitation that occurs at twice the grid frequency, amplifying the resulting vibratory response. Calculation methods have evolved that predict shaft ...

2013-12-20T23:59:59.000Z

179

Spectroscopic probes of vibrationally excited molecules at chemically significant energies  

SciTech Connect

Infrared-optical double resonance is being used to study the unimolecular dissociation dynamics of hydrazoic acid (HN[sub 3]). 6[nu][sub NH] vibrational overtone excitation spectra are given for HN[sub 3]. Work was begun to determine the feasibility of extending the infrared-optical double resonance photofragment spectroscopy to small free radicals, and to be able to monitor atomic dissociation fragments via laser induced fluorescence in the VUV spectrum. 1 fig.

Rizzo, T.R.

1993-04-01T23:59:59.000Z

180

The Nature of Vibrational Softening in ? - Uranium  

Science Conference Proceedings (OSTI)

... The Nature of Vibrational Softening in ? - Uranium. The standard textbook ... B / atom. All experiments used uranium powder. High ...

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Blasting Vibration Forecast Base on Neural Network  

Science Conference Proceedings (OSTI)

The influence of blasting vibration to surroundings around the blasting area can not be ignored, in order to guarantee the safety of surroundings around blasting area, blasting vibration forecasting model based on neural network is established by improved ... Keywords: Blasting vibration, Neural network, Forecast

Haiwang Ye; Fang Liu; Jian Chang; Lin Feng; Yang Wang; Peng Yao; Kai Wu

2010-10-01T23:59:59.000Z

182

Ground Vibration Measurements at LHC Point 4  

Science Conference Proceedings (OSTI)

Ground vibration was measured at Large Hadron Collider (LHC) Point 4 during the winter shutdown in February 2012. This report contains the results, including power and coherence spectra. We plan to collect and analyze vibration data from representative collider halls to inform specifications for future linear colliders, such as ILC and CLIC. We are especially interested in vibration correlations between final focus lens locations.

Bertsche, Kirk; /SLAC; Gaddi, Andrea; /CERN

2012-09-17T23:59:59.000Z

183

Electron Trapping by Molecular Vibration  

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

Electron Trapping by Molecular Electron Trapping by Molecular Vibration Electron Trapping by Molecular Vibration Print Wednesday, 27 April 2005 00:00 In photoelectron spectroscopy experiments performed at the ALS, a group of researchers has found that electronic transitions normally thought to be forbidden can in fact be excited in conjunction with certain types of molecular vibrations. Specifically, they found that when the symmetry of a linear triatomic molecule is broken by asymmetric vibrational modes, photoelectrons can become temporarily trapped by the molecule before ultimately escaping, giving rise to a broad feature in the photoelectron spectrum known as a shape resonance. This process represents a novel type of symmetry-breaking phenomenon that has not been observed previously but appears to be widespread. Such coupling between electronic motion and nuclear motion becomes increasingly important as scientists learn more about the geometry and dynamics of novel chemical structures such as those found in nanodevices and transient chemical species, and the results have implications for studies that use photoelectron spectroscopy as a diagnostic tool.

184

Vibration and noise from blasting  

SciTech Connect

Adverse environmental effects from blasting continue to be a major problem for the mining industry, the public living near mining operations, and the governmental agencies responsible for setting environmental standards. The Bureau of Mines has established a comprehensive blasting research program dealing with the many technical aspects of generation and propagation of ground vibrations and airblast, structure response and damage, and proper instrumentation.

Siskind, D.E.

1982-01-01T23:59:59.000Z

185

Hairpin vortex formation, a case study for unsteady visualization.  

SciTech Connect

To better understand the vortex dynamics of coherent structures in turbulent and transitional boundary layers, we consider direct numerical simulation of the interaction between a flat-plateboundary-layer flow and an isolated hemispherical roughness element. Of principal interest is the evolution of hairpin vortices that form an interlacing pattern in the wake of the hemisphere, lift away from the wall, and are stretched by the shearing action of the boundary layer. Using animations of unsteady three-dimensional representations of this flow, produced by the vtk toolkit and enhanced to operate in a CAVE virtual environment, we identify and study several key features in the evolution of this complex vortex topology not previously observed in other visualization formats.

Fischer, P. F.; Papka, M. E.; Szymanski, M.; Tufo, H. M.

1999-08-10T23:59:59.000Z

186

MHK Technologies/Vortex Oscillation | Open Energy Information  

Open Energy Info (EERE)

Oscillation Oscillation < MHK Technologies Jump to: navigation, search << Return to the MHK database homepage Vortex Oscillation.jpg Technology Profile Primary Organization Vortex Oscillation Technology Ltd Technology Resource Click here Current Technology Type Click here Attenuator Technology Readiness Level Click here TRL 1 3 Discovery Concept Def Early Stage Dev Design Engineering Technology Description If cylinder or another body is fixed on a moving bonding this force can set the body or its separate parts into oscillation e g elastic slat If the system of mechanical energy output is organized correctly this device can be considered as generator Technology Dimensions Device Testing Date Submitted 08:12.7 << Return to the MHK database homepage Retrieved from

187

Observable Vortex Properties in Finite Temperature Bose Gases  

E-Print Network (OSTI)

We study the dynamics of vortices in finite temperature atomic Bose-Einstein condensates, focussing on decay rates, precession frequencies and core brightness, motivated by a recent experiment (Freilich et al. Science 329, 1182 (2010)) in which real-time dynamics of a single vortex was observed. Using the ZNG formalism based on a dissipative Gross-Pitaevskii equation for the condensate coupled to a semi-classical Boltzmann equation for the thermal cloud, we find a rapid nonlinear increase of both the decay rate and precession frequency with increasing temperatures. The increase, which is dominated by the dynamical condensate-thermal coupling is also dependent on the intrinsic thermal cloud collisional dynamics; the precession frequency also varies with the initial radial coordinate. The integrated thermal cloud density in the vortex core is for the most part independent of the position of the vortex (except when it is near the condensate edge) with its value increasing with temperature. This could potentially be used as a variant to the method of Coddington et al. (Phys. Rev. A 70, 063607 (2004)) for experimentally determining the temperature.

A. J. Allen; E. Zaremba; C. F. Barenghi; N. P. Proukakis

2012-10-30T23:59:59.000Z

188

Annihilation of vortex dipole in an Oblate Bose-Einstein Condensate  

E-Print Network (OSTI)

We theoretically explore the annihilation of vortex dipole, generated when an obstacle moves through a condensate, in an oblate Bose-Einstein Condensate and the possible reasons for the annihilation. We show that the grey soliton, which results from vortex dipole annihilation, is lower in energy than the vortex dipole. We also investigate the annihilation events numerically and observe annihilation occurs only when the vortex dipole overtake the obstacle. Further more, we find that the adding noise reduces the probability of annihilation events. This may explain the lack of annihilation events in experimental realizations.

Prabhakar, Shashi; Gautam, S; Angom, D

2013-01-01T23:59:59.000Z

189

Vortex formation of a Bose-Einstein condensate in a rotating deep optical lattice  

Science Conference Proceedings (OSTI)

We study the dynamics of vortex nucleation and lattice formation in a Bose-Einstein condensate in a rotating square optical lattice by numerical simulations of the Gross-Pitaevskii equation. Different dynamical regimes of vortex nucleation are found, depending on the depth and period of the optical lattice. We make an extensive comparison with the experiments by R. A. Williams et al.[Phys. Rev. Lett. 104, 050404 (2010)], especially focusing on the issues of the critical rotation frequency for the first vortex nucleation and the vortex number as a function of rotation frequency.

Kato, Akira; Nakano, Yuki; Kasamatsu, Kenichi; Matsui, Tetsuo [Department of Physics, Kinki University, Higashi-Osaka, Osaka 577-8502 (Japan)

2011-11-15T23:59:59.000Z

190

Numerical Simulation of Flame-Vortex Interactions in Natural and Synthetic Gas Mixtures .  

E-Print Network (OSTI)

??The interactions between laminar premixed flames and counter-rotating vortex pairs in natural and synthetic gas mixtures have been computationally investigated through the use of Direct… (more)

Weiler, Justin D.

2004-01-01T23:59:59.000Z

191

VIBRATION DAMPING AND SHOCK MOUNT  

DOE Patents (OSTI)

A shock absorbing mount in which vibrations are damped by an interference fit between relatively movable parts of the mount is described. A pair of generally cup-shaped parts or members have skirt portions disposed in an oppositely facing nesting relationship with the skirt of one member frictionally engaging the skirt of the other. The outermost skirt may be slotted to provide spring-like segments which embrace the inner skirt for effecting the interference fit. Belleville washers between the members provide yieldable support for a load carried by the mount. When a resonant frequency of vibration forces acting upon the moumt attains a certain level the kinetic energy of these forces is absorbed by sliding friction between the parts. (AEC)

Stevens, D.J.; Forman, G.W.

1963-12-10T23:59:59.000Z

192

A low-power circuit for piezoelectric vibration control by synchronized switching on voltage sources  

E-Print Network (OSTI)

In the paper, a vibration damping system powered by harvested energy with implementation of the so-called SSDV (synchronized switch damping on voltage source) technique is designed and investigated. In the semi-passive approach, the piezoelectric element is intermittently switched from open-circuit to specific impedance synchronously with the structural vibration. Due to this switching procedure, a phase difference appears between the strain induced by vibration and the resulting voltage, thus creating energy dissipation. By supplying the energy collected from the piezoelectric materials to the switching circuit, a new low-power device using the SSDV technique is proposed. Compared with the original self-powered SSDI (synchronized switch damping on inductor), such a device can significantly improve its performance of vibration control. Its effectiveness in the single-mode resonant damping of a composite beam is validated by the experimental results.

Shen, Hui; Ji, Hongli; Zhu, Kongjun; Balsi, Marco; Giorgio, Ivan; dell'Isola, Francesco

2010-01-01T23:59:59.000Z

193

Description of Selected Algorithms and Implementation Details of a Concept-Demonstration Aircraft VOrtex Spacing System (AVOSS)  

Science Conference Proceedings (OSTI)

A ground-based system has been developed to demonstrate the feasibility of automating the process of collecting relevant weather data, predicting wake vortex behavior from a data base of aircraft, prescribing safe wake vortex spacing criteria, estimating ...

Hinton David A.

2001-06-01T23:59:59.000Z

194

Cloud-Resolving Simulations of Mesoscale Vortex Intensification and Its Effect on a Serial Mesoscale Convective System  

Science Conference Proceedings (OSTI)

The authors performed numerical simulations of the 27–28 May 1998 mesoscale convective vortex (MCV) and mesoscale convective system (MCS) to understand how the MCV modulated the convection, and how the convection intensified the vortex. The fifth-...

Christopher A. Davis; Stanley B. Trier

2002-12-01T23:59:59.000Z

195

Actively controlled vibration welding system and method  

DOE Patents (OSTI)

A vibration welding system includes a controller, welding horn, an active material element, and anvil assembly. The assembly may include an anvil body connected to a back plate and support member. The element, e.g., a piezoelectric stack or shape memory alloy, is positioned with respect to the assembly. The horn vibrates in a desirable first direction to form a weld on a work piece. The element controls any vibrations in a second direction by applying calibrated response to the anvil body in the second direction. A method for controlling undesirable vibrations in the system includes positioning the element with respect to the anvil assembly, connecting the anvil body to the support member through the back plate, vibrating the horn in a desirable first direction, and transmitting an input signal to the element to control vibration in an undesirable second direction.

Cai, Wayne W.; Kang, Bongsu; Tan, Chin-An

2013-04-02T23:59:59.000Z

196

Solution of linear problems of the uniform motion of a vortex source in a multilayer fluid  

Science Conference Proceedings (OSTI)

A method of solving linear problems of the uniform motion of a vortex source in a multilayer fluid having an arbitrary finite number of layers is proposed. As an example, the problem of the motion of a vortex source of given intensity in a three-layer fluid is solved. Formulas for the complex velocities and hydrodynamic reactions are obtained.

Gorlov, S.I.

1995-11-01T23:59:59.000Z

197

Generalized London free energy for high-Tc vortex lattices Ian Affleck  

E-Print Network (OSTI)

Generalized London free energy for high-Tc vortex lattices Ian Affleck Department of Physics-1829 97 50402-4 The London free energy provides a very simple way of studying the vortex lattice that this effect can arise from additional quartic derivative terms in the Ginzburg-Landau GL free energy4­7 or

Franz, Marcel

198

Combustion in Meso-scale Vortex Chambers Ming-hsun Wu*  

E-Print Network (OSTI)

1 Combustion in Meso-scale Vortex Chambers Ming-hsun Wu* , Yanxing Wang, Vigor Yang and Richard A) #12;2 COMBUSTION IN MESO-SCALE VORTEX CHAMBERS Ming-hsun Wu, Yanxing Wang, Vigor Yang and Richard A with the chemical energy varying from 25 to 174W. For the largest combustion volume, hydrogen and hydrocarbons

Yang, Vigor

199

On a Graphics Hardware-Based Vortex Detection and Visualization System  

Science Conference Proceedings (OSTI)

We present a graphics hardware-based system for interactive denoising, vortex detection, and visualization of vector data. No intermediate results need to be read back by the application once the vector field has been loaded onto the graphics adapter. ... Keywords: Flow visualization, Graphics hardware, Vortex detection

S. Stegmaier; T. Ertl

2005-04-01T23:59:59.000Z

200

High force vibration testing with wide frequency range  

DOE Patents (OSTI)

A shaker assembly for vibration testing includes first and second shakers, where the first shaker includes a piezo-electric material for generating vibration. A support structure permits a test object to be supported for vibration of the test object by both shakers. An input permits an external vibration controller to control vibration of the shakers.

Romero, Edward F.; Jepsen, Richard A.; Gregory, Danny Lynn

2013-04-02T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Wigner distribution function and entanglement of generalized quantum optical vortex  

E-Print Network (OSTI)

We calculate the Wigner (quasi)probability distribution function of the quantum optical elliptical vortex (QEV), generated by coupling squeezed vacuum states of two modes. The coupling between the two modes is performed by using beam splitter (BS) or a dual channel directional coupler (DCDC). The quantum interference due to the coupling between the two modes promises the generation of controlled entanglement for quantum computation and quantum tomography. We compute the entanglement of such QEV formed by non-classical radiation field, using Wigner function. We report a critical squeezing parameter above which the entanglement is less for higher vorticity, which is counter intuitive.

Abir Bandyopadhyay; Shashi Prabhakar; R. P. Singh

2011-01-25T23:59:59.000Z

202

Vortex nozzle for segmenting and transporting metal chips from turning operations  

DOE Patents (OSTI)

Apparatus for collecting, segmenting and conveying metal chips from machining operations utilizes a compressed gas driven vortex nozzle for receiving the chip and twisting it to cause the chip to segment through the application of torsional forces to the chip. The vortex nozzle is open ended and generally tubular in shape with a converging inlet end, a constant diameter throat section and a diverging exhaust end. Compressed gas is discharged through angled vortex ports in the nozzle throat section to create vortex flow in the nozzle and through an annular inlet at the entrance to the converging inlet end to create suction at the nozzle inlet and cause ambient air to enter the nozzle. The vortex flow in the nozzle causes the metal chip to segment and the segments thus formed to pass out of the discharge end of the nozzle where they are collected, cleaned and compacted as needed.

Bieg, L.F.

1993-04-20T23:59:59.000Z

203

Vortex nozzle for segmenting and transporting metal chips from turning operations  

DOE Patents (OSTI)

This invention is comprised of an apparatus for collecting, segmenting and conveying metal chips from machining operations which utilizes a compressed gas driven vortex nozzle for receiving the chip and twisting it to cause the chip to segment through the application of torsional forces to the chip. The vortex nozzle is open ended and generally tubular in shape with a converging inlet end, a constant diameter throat section and a diverging exhaust end. Compressed gas is discharged through angled vortex ports in the nozzle throat section to create vortex flow in the nozzle and through an annular inlet at the entrance to the converging inlet end to create suction at the nozzle inlet and cause ambient air to enter the nozzle. The vortex flow in the nozzle causes the metal chip to segment and the segments thus formed to pass out of the discharge end of the nozzle where they are collected, cleaned and compacted as needed.

Bieg, L.F.

1992-12-31T23:59:59.000Z

204

Erratum: Experimental Vibrational Zero-Point Energies ...  

Science Conference Proceedings (OSTI)

Erratum: Experimental Vibrational Zero-Point Energies: Diatomic Molecules †J ... error in the calculated zero point energy ZPE for ... All rights reserved. ...

2013-04-16T23:59:59.000Z

205

Coal storage hopper with vibrating screen agitator  

DOE Patents (OSTI)

The present invention is directed to a vibrating screen agitator in a coal storage hopper for assuring the uniform feed of coal having sufficient moisture content to effect agglomeration and bridging thereof in the coal hopper from the latter onto a conveyor mechanism. The vibrating screen agitator is provided by a plurality of transversely oriented and vertically spaced apart screens in the storage hopper with a plurality of vertically oriented rods attached to the screens. The rods are vibrated to effect the vibration of the screens and the breaking up of agglomerates in the coal which might impede the uniform flow of the coal from the hopper onto a conveyer.

Daw, Charles S. (Knoxville, TN); Lackey, Mack E. (Oak Ridge, TN); Sy, Ronald L. (Clinton, TN)

1984-01-01T23:59:59.000Z

206

Vibration energy harvesting using piezoelectric materials.  

E-Print Network (OSTI)

??Harvesting environmental energy around a system provides a promising solution to implement self-powered electronic devices, which currently rely on batteries as power supply. Vibration energy… (more)

Tang, Lihua.

2012-01-01T23:59:59.000Z

207

Flame-vortex interaction and mixing behaviors of turbulent non-premixed jet flames under acoustic forcing  

SciTech Connect

This study examines the effect of acoustic excitation using forced coaxial air on the flame characteristics of turbulent hydrogen non-premixed flames. A resonance frequency was selected to acoustically excite the coaxial air jet due to its ability to effectively amplify the acoustic amplitude and reduce flame length and NO{sub x} emissions. Acoustic excitation causes the flame length to decrease by 15% and consequently, a 25% reduction in EINO{sub x} is achieved, compared to coaxial air flames without acoustic excitation at the same coaxial air to fuel velocity ratio. Moreover, acoustic excitation induces periodical fluctuation of the coaxial air velocity, thus resulting in slight fluctuation of the fuel velocity. From phase-lock PIV and OH PLIF measurement, the local flow properties at the flame surface were investigated under acoustic forcing. During flame-vortex interaction in the near field region, the entrainment velocity and the flame surface area increased locally near the vortex. This increase in flame surface area and entrainment velocity is believed to be a crucial factor in reducing flame length and NO{sub x} emission in coaxial jet flames with acoustic excitation. Local flame extinction occurred frequently when subjected to an excessive strain rate, indicating that intense mass transfer of fuel and air occurs radially inward at the flame surface. (author)

Kim, Munki; Choi, Youngil; Oh, Jeongseog; Yoon, Youngbin [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul (Korea)

2009-12-15T23:59:59.000Z

208

Vibrational Spectroscopy of Chromatographic Interfaces  

SciTech Connect

Chromatographic separations play a central role in DOE-supported fundamental research related to energy, biological systems, the environment, and nuclear science. The overall portfolio of research activities in the Separations and Analysis Program within the DOE Office of Basic Energy Sciences includes support for activities designed to develop a molecular-level understanding of the chemical processes that underlie separations for both large-scale and analytical-scale purposes. The research effort funded by this grant award was a continuation of DOE-supported research to develop vibrational spectroscopic methods to characterize the interfacial details of separations processes at a molecular level.

Jeanne E. Pemberton

2011-03-10T23:59:59.000Z

209

Heat Transfer Enhancement in Separated and Vortex Flows  

SciTech Connect

This document summarizes the research performance done at the Heat Transfer Laboratory of the University of Minnesota on heat transfer and energy separation in separated and vortex flow supported by DOE in the period September 1, 1998--August 31, 2003. Unsteady and complicated flow structures in separated or vortex flows are the main reason for a poor understanding of heat transfer under such conditions. The research from the University of Minnesota focused on the following important aspects of understanding such flows: (1) Heat/mass transfer from a circular cylinder; (2) study of energy separation and heat transfer in free jet flows and shear layers; and (3) study of energy separation on the surface and in the wake of a cylinder in crossflow. The current study used three different experimental setups to accomplish these goals. A wind tunnel and a liquid tunnel using water and mixtures of ethylene glycol and water, is used for the study of prandtl number effect with uniform heat flux from the circular cylinder. A high velocity air jet is used to study energy separation in free jets. A high speed wind tunnel, same as used for the first part, is utilized for energy separation effects on the surface and in the wake of the circular cylinder. The final outcome of this study is a substantial advancement in this research area.

Richard J. Goldstein

2004-05-27T23:59:59.000Z

210

Dissipative dynamics of vortex arrays in trapped Bose-condensed gases: neutron stars physics on $?$K scale  

E-Print Network (OSTI)

We develop a theory of dissipative dynamics of large vortex arrays in trapped Bose-condensed gases. We show that in a static trap the interaction of the vortex array with thermal excitations leads to a non-exponential decay of the vortex structure, and the characteristic lifetime depends on the initial density of vortices. Drawing an analogy with physics of pulsar glitches, we propose an experiment which employs the heating of the thermal cloud in the course of the decay of the vortex array as a tool for a non-destructive study of the vortex dynamics.

P. O. Fedichev; A. E. Muryshev

2000-04-17T23:59:59.000Z

211

DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM  

SciTech Connect

The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. Phase I of this program entails modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype. The project continues to advance, but is behind the revised (14-month) schedule. Tasks 1-3 (Modeling, Specification and Design) are all essentially complete. The test bench for the Test and Evaluation (Tasks 4 & 5) and the laboratory prototype were constructed by the end of the period. During assembly, however, several of the key subassemblies became galled together, and had to be cut apart. These parts are being remachined with harder surfaces to prevent recurrence of this problem. One key component, the MR damper mandrel, has been redesigned into a three-piece assembly which will facilitate assembly and reduce the cost of replacement of worn components. The remade parts will be delivered by April 19, and the prototype assembled. Testing will begin during the first week of May and is anticipated to be completed before the revised end date for Phase I, May 31, 2004.

Martin E. Cobern

2004-04-17T23:59:59.000Z

212

Blasting vibrations and their effects on structures  

SciTech Connect

Results of the Bureau of Mines 10-year program to study the problem of air blast and ground vibrations generated by blasting are presented. The program included an extensive field study of ground vibrations; a consideration of air blast effects; an evaluation of instrumentation to measure vibrations; establishment of damage criteria for residential structures; determination of blasting parameters which grossly affected vibrations; empirical safe blasting limits; and the problem of human response. While values of 2.0 in/sec particle velocity and 0.5 psi air blast overpressure are recommended as safe blasting limits not to be exceeded to preclude damage to residential structures, lower limits are suggested to minimize complaints. Millisecond-delay blasting is shown to reduce vibration levels as compared to instantaneous blasting, and electric cap delay blasts offer a slight reduction in vibration levels as compared to Primacord delay blasts. Vibration levels of different blasts may be compared at common scaled distances, where scaled distance is the distance divided by the square root of the maximum charge weight per delay. Geology, rock type, and direction affect vibration level within limits. Empirically, a safe blasting limit based on a scaled distance of 50 ft/lb/sup/sup 1///sub 2// may be used without instrumentation. However, a knowledge of the particle velocity propagation characteristics of a blasting site determined from instrumented blasts at that site are recommended to insure that the safe blasting limit of 2.0 in/sec is not exceeded.

Nicholls, H.R.; Johnson, C.F.; Duvall, W.I.

1971-01-01T23:59:59.000Z

213

Electrostatic Conversion for Vibration Energy Harvesting  

E-Print Network (OSTI)

This chapter focuses on vibration energy harvesting using electrostatic converters. It synthesizes the various works carried out on electrostatic devices, from concepts, models and up to prototypes, and covers both standard (electret-free) and electret-based electrostatic vibration energy harvesters (VEH).

Boisseau, S; Seddik, B Ahmed

2012-01-01T23:59:59.000Z

214

Vibrational analysis of graphene based nanostructures  

Science Conference Proceedings (OSTI)

This paper deals with the molecular mechanics simulations of graphene nanostructures and their vibration behavior for potential applications on nano-electronics and nanocomposites. The fundamental frequencies for CNTs range from 10 to 250GHz and 100 ... Keywords: Carbon nanotubes, Graphene nanosheets, Modal analysis, Molecular mechanics, Vibration

Antonio F. Ávila; Alexandre C. Eduardo; Almir S. Neto

2011-06-01T23:59:59.000Z

215

Observation of coupled vortex gyrations by 70-ps-time and 20-nm-space- resolved full-field magnetic transmission soft x-ray microscopy  

SciTech Connect

We employed time-and space-resolved full-field magnetic transmission soft x-ray microscopy to observe vortex-core gyrations in a pair of dipolar-coupled vortex-state Permalloy (Ni{sub 80}Fe{sub 20}) disks. The 70 ps temporal and 20 nm spatial resolution of the microscope enabled us to simultaneously measure vortex gyrations in both disks and to resolve the phases and amplitudes of both vortex-core positions. We observed their correlation for a specific vortex-state configuration. This work provides a robust and direct method of studying vortex gyrations in dipolar-coupled vortex oscillators.

Jung, Hyunsung; Yu, Young-Sang; Lee, Ki-Suk; Im, Mi-Young; Fischer, Peter; Bocklage, Lars; Vogel, Andreas; Bolte, Markus; Meier, Guido; Kim, Sang-Koog

2010-09-01T23:59:59.000Z

216

Fermilab | Take Five for Goal Zero | Gloves | Anti-Vibration...  

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

Vibration Gloves Anti-Vibration Gloves Description Color Finish USes FNAL Stock Number Pigskin leather palm and fingers Low-profile closure with woven elastic cuff Neoprene knuckle...

217

The Vibrational Spectrometer at SNS | ORNL Neutron Sciences  

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

Vibrational Spectrometer at SNS VISION VISION is best thought of as the neutron analogue of an infrared-Raman spectrometer. It is optimized to characterize molecular vibrations in...

218

Passively damped vibration welding system and method  

DOE Patents (OSTI)

A vibration welding system includes a controller, welding horn, an anvil, and a passive damping mechanism (PDM). The controller generates an input signal having a calibrated frequency. The horn vibrates in a desirable first direction at the calibrated frequency in response to the input signal to form a weld in a work piece. The PDM is positioned with respect to the system, and substantially damps or attenuates vibration in an undesirable second direction. A method includes connecting the PDM having calibrated properties and a natural frequency to an anvil of an ultrasonic welding system. Then, an input signal is generated using a weld controller. The method includes vibrating a welding horn in a desirable direction in response to the input signal, and passively damping vibration in an undesirable direction using the PDM.

Tan, Chin-An; Kang, Bongsu; Cai, Wayne W.; Wu, Tao

2013-04-02T23:59:59.000Z

219

An adaptive mesh method for the simulation of Blade Vortex Interaction  

E-Print Network (OSTI)

An adaptive mesh method for the simulation of parallel ics. Blade Vortex Interaction (BV1) with an active Trailing Edge Flap (TEF) is presented. The two-dimensional 1111-steady problem is solved by a higher order upwind Euler method for an unstructured mesh. A local mesh adaptation technique is employed to maintain vortex strength by capturing the details of the convecting vortex. The computational technique does not require any assumption on the vortex structure, and, therefore is suitable for close interaction of the vortex and the blade. The adaptive method is based on cell subdivisions and allows for frequent mesh adaptation due to its fast speed. To demonstrate the reduction of numerical dissipation of a vortex via mesh adaptation, we first consider a simple case with a convecting vortex in freestream. Finally, we apply tile techniques to examine the effectiveness of an active TEF on BVI in reducing the pressure perturbations at the airfoil leading edge. For the boundary motion due to TEF deployment, a local recessing procedure is utilized to maintain mesh quality by avoiding distorted mesh elements near the flap.

Kim, Kyu-Sup

1998-01-01T23:59:59.000Z

220

Effect of point-like disorder on the vortex phase diagram in Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8-{delta}} in oblique field.  

Science Conference Proceedings (OSTI)

The phase diagram of vortex matter in the layered superconductor Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8-{delta}} exposed to a magnetic field oblique to the crystalline c-axis contains two first order transition (FOT) lines. The first, H{sub FOT}{sup m}, separates the vortex solid from the vortex liquid, the second, H{sub FOT}{sup ct}, separates the combined lattice state in the vortex solid from a tilted lattice state. The angular dependence of H{sub FOT}{sup m} in the tilted lattice region follows the anisotropic Ginzburg-Landau model, allowing for the determination of the anisotropy factor {gamma}{sub eff} and the contribution of magnetic coupling to the mutual interaction of 'pancake' vortices in the crossed lattice limit. The later parameter is directly related to the in-plane penetration depth {lambda}{sub ab}. We investigate the evolution of the phase diagram of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8-{delta}} in oblique fields with point-like disorder, introduced by irradiation with 2.3 MeV electrons. Apart from the depression of T{sub c}, point-like disorder induces an increase of {gamma}{sub eff} and a depression of the superfluid density.

Konczykowski, M.; van der Beek, C. J.; Mosser, V.; Koshelev, A. E.; Li, M.; Kes, P. H. (Materials Science Division); (Ecole Polytechnique); (ITRON); (Leiden Univ.)

2010-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Predicting the Failure of Line Post Insulator Mounting Studs Due to Aeolian Vibrations  

Science Conference Proceedings (OSTI)

This report provides experimental and numerical investigations of the line post insulator stud failures experienced by APS (Arizona Public Service) on its 69kV and 22 kV overhead power lines. The project developed a numerical model conforming to the dynamics of a line post insulator and the coupling between neighboring spans. This model can be used in estimating the dynamic loads induced on a line post insulator from Aeolian (wind-induced) vibration.

2006-06-07T23:59:59.000Z

222

Reduced vibration motor winding arrangement  

DOE Patents (OSTI)

An individual phase winding arrangement having a sixty electrical degree phase belt width for use with a three phase motor armature includes a delta connected phase winding portion and a wye connected phase winding portion. Both the delta and wye connected phase winding portions have a thirty electrical degree phase belt width. The delta and wye connected phase winding portions are each formed from a preselected number of individual coils each formed, in turn, from an unequal number of electrical conductor turns in the approximate ratio of {radical}3. The individual coils of the delta and wye connected phase winding portions may either be connected in series or parallel. This arrangement provides an armature winding for a three phase motor which retains the benefits of the widely known and utilized thirty degree phase belt concept, including improved mmf waveform and fundamental distribution factor, with consequent reduced vibrations and improved efficiency. 4 figs.

Slavik, C.J.; Rhudy, R.G.; Bushman, R.E.

1997-11-11T23:59:59.000Z

223

Energy scavenging from environmental vibration.  

Science Conference Proceedings (OSTI)

The goal of this project is to develop an efficient energy scavenger for converting ambient low-frequency vibrations into electrical power. In order to achieve this a novel inertial micro power generator architecture has been developed that utilizes the bi-stable motion of a mechanical mass to convert a broad range of low-frequency (250 {micro}m) ambient vibrations into high-frequency electrical output energy. The generator incorporates a bi-stable mechanical structure to initiate high-frequency mechanical oscillations in an electromagnetic scavenger. This frequency up-conversion technique enhances the electromechanical coupling and increases the generated power. This architecture is called the Parametric Frequency Increased Generator (PFIG). Three generations of the device have been fabricated. It was first demonstrated using a larger bench-top prototype that had a functional volume of 3.7cm3. It generated a peak power of 558{micro}W and an average power of 39.5{micro}W at an input acceleration of 1g applied at 10 Hz. The performance of this device has still not been matched by any other reported work. It yielded the best power density and efficiency for any scavenger operating from low-frequency (piezoelectric version of the PFIG is currently being developed. This device clearly demonstrates one of the key features of the PFIG architecture, namely that it is suitable for MEMS integration, more so than resonant generators, by incorporating a brittle bulk piezoelectric ceramic. This is the first micro-scale piezoelectric generator capable of <10Hz operation. The fabricated device currently generates a peak power of 25.9{micro}W and an average power of 1.21{micro}W from an input acceleration of 9.8m/s{sup -} at 10Hz. The device operates over a frequency range of 23Hz. The internal volume of the generator is 1.2cm{sup 3}.

Galchev, Tzeno (University of Michigan); Apblett, Christopher Alan; Najafi, Khalil (University of Michigan)

2009-10-01T23:59:59.000Z

224

Axial dipolar dynamo action in the Taylor-Green vortex  

E-Print Network (OSTI)

We present a numerical study of the magnetic field generated by the Taylor-Green vortex. We show that periodic boundary conditions can be used to mimic realistic boundary conditions by prescribing the symmetries of the velocity and magnetic fields. This gives insight in some problems of central interest for dynamos: the possible effect of velocity fluctuations on the dynamo threshold, the role of boundary conditions on the threshold and on the geometry of the magnetic field generated by dynamo action. In particular, we show that an axial dipolar dynamo similar to the one observed in a recent experiment can be obtained with an appropriate choice of the symmetries of the magnetic field. The nonlinear saturation is studied and a simple model explaining the magnetic Prandtl number dependence of the super/sub critical nature of the dynamo transition is given.

Giorgio Krstulovic; Gentien Thorner; Julien-Piera Vest; Stephan Fauve; Marc Brachet

2011-09-19T23:59:59.000Z

225

Vortex flow in the technology of radiation wave cracking (RWC)  

E-Print Network (OSTI)

This article examines the theory of vortex flows in relation to the processes occurring in the radiation-wave cracking of crude oil, when the crude oil is sprayed into the gas stream in the form of a mist and then is fed into the reactor, where it is treated by the accelerated electrons and the UHF radiation. The output of this process are the products with the specified parameters (high-octane petroleum products). This process operates at the ambient pressure and temperature, which makes the process safer for industrial purposes. Besides the process itself, the authors described the equipment used in this process, as well as the parameters of the optimal process.

L. A. Tsoy; V. N. Kolushov; A. G. Komarov; A. N. Tsoy

2012-09-16T23:59:59.000Z

226

Vortex flow in the technology of radiation wave cracking (RWC)  

E-Print Network (OSTI)

This article examines the theory of vortex flows in relation to the processes occurring in the radiation-wave cracking of crude oil, when the crude oil is sprayed into the gas stream in the form of a mist and then is fed into the reactor, where it is treated by the accelerated electrons and the UHF radiation. The output of this process are the products with the specified parameters (high-octane petroleum products). This process operates at the ambient pressure and temperature, which makes the process safer for industrial purposes. Besides the process itself, the authors described the equipment used in this process, as well as the parameters of the optimal process.

Tsoy, L A; Komarov, A G; Tsoy, A N

2012-01-01T23:59:59.000Z

227

Microelectromechanical power generator and vibration sensor  

DOE Patents (OSTI)

A microelectromechanical (MEM) apparatus is disclosed which can be used to generate electrical power in response to an external source of vibrations, or to sense the vibrations and generate an electrical output voltage in response thereto. The MEM apparatus utilizes a meandering electrical pickup located near a shuttle which holds a plurality of permanent magnets. Upon movement of the shuttle in response to vibrations coupled thereto, the permanent magnets move in a direction substantially parallel to the meandering electrical pickup, and this generates a voltage across the meandering electrical pickup. The MEM apparatus can be fabricated by LIGA or micromachining.

Roesler, Alexander W. (Tijeras, NM); Christenson, Todd R. (Albuquerque, NM)

2006-11-28T23:59:59.000Z

228

The Kinematics of a Midlatitude, Continental Mesoscale Convective System and Its Mesoscale Vortex  

Science Conference Proceedings (OSTI)

The authors present a unique, scale-discriminating study of the environment-relative circulations within a mesoscale convective system (MCS) and mesoscale convective vortex (MCV). The MCS, a leading convective line and trailing stratiform region ...

Jason C. Knievel; Richard H. Johnson

2002-07-01T23:59:59.000Z

229

Wave–Current Interaction: A Comparison of Radiation-Stress and Vortex-Force Representations  

Science Conference Proceedings (OSTI)

The vortex-force representation of the wave-averaged effects on currents is compared to the radiation-stress representation in a scaling regime appropriate to coastal and shelf waters. Three-dimensional and vertically integrated expressions for ...

E. M. Lane; J. M. Restrepo; J. C. McWilliams

2007-05-01T23:59:59.000Z

230

Evidence against an Antarctic Stratospheric Vortex Split during the Periods of Pre-IGY Temperature Measurements  

Science Conference Proceedings (OSTI)

Historic upper-air observations from Antarctica are inspected to investigate the uniqueness of the vortex split in the Antarctic spring of 2002. No comprehensive meteorological observations are available prior to the International Geophysical ...

Barbara Naujokat; Howard K. Roscoe

2005-03-01T23:59:59.000Z

231

Midtropospheric Anticyclonic Vortex Street Associated with a Cloud Band near a Cold Front  

Science Conference Proceedings (OSTI)

The characteristics and formation mechanism of an anticyclonic vortex street of meso-? scale, which appeared near a cold front around the Ryukyu Islands, Japan, on 11 April 1995, were examined by an analysis of observational data, a numerical ...

Eizi Toyoda; Hiroshi Niino; Kazuhisa Tsuboki; Ryuji Kimura; Masanori Yoshizaki

1999-08-01T23:59:59.000Z

232

Vortex Ring Dyons of the SU(2) Yang-Mills-Higgs Model  

Science Conference Proceedings (OSTI)

We present an axially symmetric vortex ring dyons solutions of the SU(2) Yang-Mills-Higgs theory. These vortex rings carry electric charges that are determined by a parameter, -1{<=}{eta}{<=}1. They possess vanishing magnetic charge and are located at a ring centered around the z-axis where the Higgs field vanishes. These stationary vortex ring dyon solutions possess finite energy but they do not satisfy the first order Bogomol'nyi equations. In the Bogomol'nyi-Prasad-Sommerfield (BPS) limit where the Higgs field potential is zero, the time component of the gauge field is parallel to the Higgs field in isospace. The total energy, net electric charge and diameter of the vortex ring increase exponentially to infinity when {eta} approaches {+-}1. On the contrary, when {lambda} = 1, all these three values reach their critical value as {eta} approaches {+-}1.

Lim, Kok-Geng; Teh, Rosy; Wong, Khai-Ming [School of Physics, Universiti Sains Malaysia 11800 USM Penang (Malaysia)

2011-03-30T23:59:59.000Z

233

The Splitting of the Stratospheric Polar Vortex in the Southern Hemisphere, September 2002: Dynamical Evolution  

Science Conference Proceedings (OSTI)

The polar vortex of the Southern Hemisphere (SH) split dramatically during September 2002. The large-scale dynamical effects were manifest throughout the stratosphere and upper troposphere, corresponding to two distinct cyclonic centers in the ...

Andrew J. Charlton; Alan O’Neill; William A. Lahoz; Paul Berrisford

2005-03-01T23:59:59.000Z

234

Ensemble Forecasting of Tropical Cyclone Motion Using a Barotropic Model. Part II: Perturbations of the Vortex  

Science Conference Proceedings (OSTI)

In Part I of this study, the technique of ensemble forecasting is applied to the problem of tropical cyclone motion prediction by perturbing the environmental flow. In this part, the focus is shifted to perturbation of the vortex structure. The ...

Kevin K. W. Cheung; Johnny C. L. Chan

1999-11-01T23:59:59.000Z

235

Jovian Dynamics. Part II: The Genesis and Equilibration of Vortex Sets  

Science Conference Proceedings (OSTI)

To extend studies of the dynamics of thin atmospheric layers, the generation and equilibration of multiple anticyclonic vortex sets associated with long solitary baroclinic Rossby waves are examined numerically using a primitive equation model ...

G. P. Williams

2002-04-01T23:59:59.000Z

236

A Vortex-Based Perspective of Eastern Pacific Tropical Cyclone Formation  

Science Conference Proceedings (OSTI)

Tropical cyclone formation over the eastern Pacific during 2005 and 2006 was examined using primarily global operational analyses from the National Centers for Environmental Prediction. This paper represents a “vortex view” of genesis, adding to ...

Christopher Davis; Chris Snyder; Anthony C. Didlake Jr.

2008-07-01T23:59:59.000Z

237

Observations of a Storm Containing Misocyclones, Downbursts, and Horizontal Vortex Circulations  

Science Conference Proceedings (OSTI)

On 30 June 1982, a multicellular storm in Colorado produced four downbursts, three misocyclones, a miso-anticyclone, and horizontal vortex circulations within a relatively small area of the storm. Weather events associated with this storm ...

Cathy J. Kessinger; David B. Parsons; James W. Wilson

1988-10-01T23:59:59.000Z

238

The Role of Vortex and Environment Errors in Genesis Forecasts of Hurricanes Danielle and Karl (2010)  

Science Conference Proceedings (OSTI)

An ensemble of Weather Research and Forecasting Model (WRF) forecasts initialized from a cycling ensemble Kalman filter (EnKF) system is used to evaluate the sensitivity of Hurricanes Danielle and Karl’s (2010) genesis forecasts to vortex and ...

Ryan D. Torn; David Cook

2013-01-01T23:59:59.000Z

239

An Analytic Vortex Initialization Technique for Idealized Tropical Cyclone Studies in AGCMs  

Science Conference Proceedings (OSTI)

The paper discusses the design of idealized tropical cyclone experiments in atmospheric general circulation models (AGCMs). The evolution of an initially weak, warm-core vortex is investigated over a 10-day period with varying initial conditions ...

Kevin A. Reed; Christiane Jablonowski

2011-02-01T23:59:59.000Z

240

The Garden City, Kansas, Storm during VORTEX 95. Part II: The Wall Cloud and Tornado  

Science Conference Proceedings (OSTI)

On 16 May 1995, a supercell storm produced an F1 tornado near Garden City, Kansas, during VORTEX (Verification of the Origins of Rotation in Tornadoes Experiment). This event provided the first opportunity to synthesize data collected by a new ...

Roger M. Wakimoto; Chinghwang Liu

1998-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

The Effect of Tropospheric Jet Latitude on Coupling between the Stratospheric Polar Vortex and the Troposphere  

Science Conference Proceedings (OSTI)

A dry general circulation model is used to investigate how coupling between the stratospheric polar vortex and the extratropical tropospheric circulation depends on the latitude of the tropospheric jet. The tropospheric response to an identical ...

Chaim I. Garfinkel; Darryn W. Waugh; Edwin P. Gerber

2013-03-01T23:59:59.000Z

242

The Role of Multiple Vortex Tornado Structure in Causing Storm Researcher Fatalities  

Science Conference Proceedings (OSTI)

A large and violent tornado/multiple vortex mesocyclone (MVMC) / tornado tracked east and northeastward near El Reno, Oklahoma on 31-May-2013, causing eight fatalities, including storm-chasers/researchers attempting to deploy in-situ instrumentation. Sub-...

Joshua Wurman; Karen Kosiba; Paul Robinson; Tim Marshall

243

A Concentrated Outbreak of Tornadoes, Downbursts and Microbursts, and Implications Regarding Vortex Classification  

Science Conference Proceedings (OSTI)

A remarkable case of severe weather occurred near Springfield, Illinois on 6 August 1977. Aerial and ground surveys revealed that 17 cyclonic vortices an anticyclonic vortex, 10 downbursts and 19 microbursts occurred in a limited (20 km × 40 km) ...

Gregory S. Forbes; Roger M. Wakimoto

1983-01-01T23:59:59.000Z

244

Mesoscale Convective Vortex Formation in a Weakly Sheared Moist Neutral Environment  

Science Conference Proceedings (OSTI)

Idealized simulations of a diabatic Rossby vortex (DRV) in an initially moist neutral baroclinic environment are performed using the fifth-generation National Center for Atmospheric Research–Pennsylvania State University (NCAR–PSU) Mesoscale ...

Robert J. Conzemius; Richard W. Moore; Michael T. Montgomery; Christopher A. Davis

2007-05-01T23:59:59.000Z

245

Interaction of a Baroclinic Vortex with Background Shear: Application to Hurricane Movement  

Science Conference Proceedings (OSTI)

Most extant studies of tropical cyclone movement consider a barotropic vortex on a ? plane. However, observations have shown that real tropical cyclones are strongly baroclinic, with broad anticyclones aloft. Also, the distribution of the large-...

Chun-Chieh Wu; Kerry A. Emanuel

1993-01-01T23:59:59.000Z

246

The Uses and Limitations of Contour Advection as a Technique for Examining Arctic Vortex Dynamics  

Science Conference Proceedings (OSTI)

A contour advection technique, contour advection with surgery (CAS), is applied to the Northern Hemisphere Arctic vortex during several dynamically active periods in midwinter and at several different levels in the stratosphere. The ability of ...

Michael N. Baker; Derek M. Cunnold

2001-08-01T23:59:59.000Z

247

Verification of RUC 0–1-h Forecasts and SPC Mesoscale Analyses Using VORTEX2 Soundings  

Science Conference Proceedings (OSTI)

This study uses radiosonde observations obtained during the second phase of the Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) to verify base-state variables and severe-weather-related parameters calculated from Rapid ...

Michael C. Coniglio

2012-06-01T23:59:59.000Z

248

The Gradient Genesis of Stratospheric Trace Species in the Subtropics and around the Polar Vortex  

Science Conference Proceedings (OSTI)

Mechanisms that control the formation and decay of meridional gradients in stratospheric trace species in the subtropics and around the polar vortex are investigated using a gradient genesis equation that uses mass-weighted isentropic zonal ...

Kazuyuki Miyazaki; Toshiki Iwasaki

2008-02-01T23:59:59.000Z

249

A Mesoscale Vortex Couplet Observed in the Trailing Anvil of a Multicellular Convective Complex  

Science Conference Proceedings (OSTI)

Observations collected during the Oklahoma–Kansas PRE-STORM experiment are used to document the evolution and structure of a mesoscale vortex couplet that developed in the mesoscale convective system that occurred on 16–17 June 1985. The ...

Johannes Verlinde; William R. Cotton

1990-05-01T23:59:59.000Z

250

Parametric Representation of the Primary Hurricane Vortex. Part II: A New Family of Sectionally Continuous Profiles  

Science Conference Proceedings (OSTI)

For applications such as windstorm underwriting or storm-surge forecasting, hurricane wind profiles are often approximated by continuous functions that are zero at the vortex center, increase to a maximum in the eyewall, and then decrease ...

H. E. Willoughby; R. W. R. Darling; M. E. Rahn

2006-04-01T23:59:59.000Z

251

Influence of Balanced Motions on Heavy Precipitation within a Long-Lived Convectively Generated Vortex  

Science Conference Proceedings (OSTI)

The forcing of heavy precipitation within a long-lived convectively generated mesoscale vortex (MCV) is investigated with the aid of diagnoses from Rapid Update Cycle gridded analyses. Organized convection within the MCV followed a distinct ...

Stanley B. Trier; Christopher A. Davis

2002-04-01T23:59:59.000Z

252

Source of Gravity Waves within a Vortex-Dipole Jet Revealed by a Linear Model  

Science Conference Proceedings (OSTI)

This study develops a linear numerical model to address the source mechanism of the gravity waves generated within a vortex dipole simulated in a fully nonlinear nonhydrostatic mesoscale model. The background flow for this linear model is ...

Shuguang Wang; Fuqing Zhang

2010-05-01T23:59:59.000Z

253

Submonthly Polar Vortex Variability and Stratosphere–Troposphere Coupling in the Arctic  

Science Conference Proceedings (OSTI)

A principal component analysis is performed to characterize intraseasonal variability in the boreal stratospheric polar vortex. In contrast to previous studies, the current analysis examines daily zonal-mean variability within a limited spatial ...

Robert X. Black; Brent A. McDaniel

2009-11-01T23:59:59.000Z

254

A New Parametric Model of Vortex Tangential-Wind Profiles: Development, Testing, and Verification  

Science Conference Proceedings (OSTI)

A new parametric model of vortex tangential-wind profiles is presented that is primarily designed to depict realistic-looking tangential wind profiles such as those in intense atmospheric vortices arising in dust devils, waterspouts, tornadoes, ...

Vincent T. Wood; Luther W. White

2011-05-01T23:59:59.000Z

255

Maximum Likelihood Estimates of Vortex Parameters from Simulated Coherent Doppler Lidar Data  

Science Conference Proceedings (OSTI)

The performance of pulsed coherent Doppler lidar in estimating aircraft trailing wake vortices by scanning across the aircraft flight track is evaluated using Monte Carlo lidar simulations of a simple vortex pair in both a nonturbulent and ...

Rod Frehlich; Robert Sharman

2005-02-01T23:59:59.000Z

256

An Observational Study of the Final Breakdown of the Southern Hemisphere Stratospheric Vortex in 2002  

Science Conference Proceedings (OSTI)

The 2002 Southern Hemisphere final warming occurred early, following an unusually active winter and the first recorded major warming in the Antarctic. The breakdown of the stratospheric polar vortex in October and November 2002 is examined using ...

Yvan J. Orsolini; Cora E. Randall; Gloria L. Manney; Douglas R. Allen

2005-03-01T23:59:59.000Z

257

A Subtropical Oceanic Mesoscale Convective Vortex Observed during SoWMEX/TiMREX  

Science Conference Proceedings (OSTI)

This study examines a subtropical oceanic mesoscale convective vortex (MCV) that occurred from 1800 UTC 4 June to 1200 UTC 6 June 2008 during intensive observing period (IOP) 6 of the Southwest Monsoon Experiment (SoWMEX) and the Terrain-...

Hsiao-Wei Lai; Christopher A. Davis; Ben Jong-Dao Jou

2011-08-01T23:59:59.000Z

258

Simulation Research on Coupling Vibration of Tramcar-Track  

Science Conference Proceedings (OSTI)

Tramcar is important railway conveying equipment in acclivitous shaft of mine. During conveying, tramcar and track often vibrate because there are some excitements. Intensive vibration often causes run-away tramcar accident, and causes deformation of ... Keywords: tramcar, track, coupling vibration, vibration control, simulation

Wenhai He

2009-02-01T23:59:59.000Z

259

Vortex Lattice Structures of a Bose-Einstein Condensate in a Rotating Lattice Potential  

E-Print Network (OSTI)

We study vortex lattice structures of a trapped Bose-Einstein condensate in a rotating lattice potential by numerically solving the time-dependent Gross-Pitaevskii equation. By rotating the lattice potential, we observe the transition from the Abrikosov vortex lattice to the pinned lattice. We investigate the transition of the vortex lattice structure by changing conditions such as angular velocity, intensity, and lattice constant of the rotating lattice potential. PACS numbers: 03.75.Lm, 03.75.Kk Quantized vortices are one of the most characteristic manifestations of superfluidity associated with a Bose-Einstein condensate (BEC) in atomic gases. By rotating anisotropic trap potentials, several experimental groups observed formation of triangular Abrikosov lattices of vortices in rotating BECs 1,2,3. Microscopic mechanism of the vortex lattice formation has been extensively studied both analytically and numerically using the Gross-Pitaevskii (GP) equation for the condensate wavefunction 4,5,6,7,8,9,10,11. More recently, the vortex phase diagrams of a BEC in rotating lattice potentials have attracted theoretical attention, since one expects vortex pinning and structural phase transition of vortex lattice structures 12,13,14. Recently, a rotating lattice has been experimentally realized at JILA, makinig use of a laser beam passing through a rotating mask 12. Stimulated by the recent JILA experiment, in this paper, we study vortex lattice structures of a BEC in a rotating triangular lattice potential created by blue-detuned laser beams. We numerically solve the two-dimensional Gross-Pitaevskii (GP) equa-T. Sato, T. Ishiyama and T. Nikuni Fig. 1. Density profile (a) and Structure factor profile (b) of BEC in the lattice potential. The lattice potential geometry is triangular lattice at a/aho = 2.2 and ?/aho = 0.65. tion in a frame rotationg with anguler velocity ?: (i ? ?)¯h ??(r,t)

Toshihiro Sato; Tomohiko Ishiyama; Tetsuro Nikuni

2006-01-01T23:59:59.000Z

260

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

Note: This page contains sample records for the topic "vortex induced vibrations" 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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

262

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Wednesday, 25 November 2009 00:00 Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

263

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

264

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

265

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

266

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

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

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation Print Magnetic thin-film nanostructures can exhibit a magnetic vortex state in which the magnetization vectors lie in the film plane and curl around in a closed loop. At the very center of the vortex, a small, stable core exists where the magnetization points either up or down out of the plane. Three years ago, the discovery of an easy core reversal mechanism at the ALS not only made the possibility of using such systems as magnetic memories much more realistic, it also initiated investigation of the core switching mechanism itself. Now, a Belgian-German-ALS collaboration has used high-resolution, time-resolved, magnetic x-ray microscopy to experimentally reveal the first step of the reversal process: the dynamic deformation of the vortex core. The group also measured a critical vortex velocity above which reversal occurs. Both these observations provide the first experimental support for the postulated reversal mechanism.

267

Vibrational States of the Hydrogen Molecular Ion  

Science Conference Proceedings (OSTI)

The energy levels of H2 + are computed for all vibrational quantum numbers and for rotational quantum numbers up to J=8. The accuracy of the energy of the uppermost levels is estimated to be better than 10?7.

H. Wind

1965-01-01T23:59:59.000Z

268

Electrostatic vibration-to-electric energy conversion  

E-Print Network (OSTI)

Ultra-Low-Power electronics can perform useful functions with power levels as low as 170 nW. This makes them amenable to powering from ambient sources such as vibration. In this case, they can become autonomous. Motivated ...

Mur Miranda, José Oscar, 1972-

2004-01-01T23:59:59.000Z

269

Vibrational Branching Ratios and Asymmetry Parameters in ...  

Science Conference Proceedings (OSTI)

... At energies 2 eV above the threshold, it was not ... into the regions of high vibrational energy, in contrast ... 1] A. Dalgarno and JL Fox, Unimolecular and ...

2010-08-19T23:59:59.000Z

270

MEMS reliability in a vibration environment  

Science Conference Proceedings (OSTI)

MicroElectricalMechanical Systems (MEMS) were subjected to a vibration environment that had a peak acceleration of 120g and spanned frequencies from 20 to 2000 Hz. The device chosen for this test was a surface-micromachined microengine because it possesses many elements (springs, gears, rubbing surfaces) that may be susceptible to vibration. The microengines were unpowered during the test. The authors observed 2 vibration-related failures and 3 electrical failures out of 22 microengines tested. Surprisingly, the electrical failures also arose in four microengines in the control group indicating that they were not vibration related. Failure analysis revealed that the electrical failures were due to shorting of stationary comb fingers to the ground plane.

TANNER,DANELLE M.; WALRAVEN,JEREMY A.; HELGESEN,KAREN SUE; IRWIN,LLOYD W.; GREGORY,DANNY LYNN; STAKE,JOHN R.; SMITH,NORMAN F.

2000-02-03T23:59:59.000Z

271

Harvesting energy from non-ideal vibrations  

E-Print Network (OSTI)

Energy harvesting has drawn significant interest for its potential to power autonomous low-power applications. Vibration energy harvesting is particularly well suited to industrial condition sensing, environmental monitoring ...

Chang, Samuel C

2013-01-01T23:59:59.000Z

272

Near-Surface Vortex Structure in a Tornado and in a Sub-Tornado-Strength, Convective-Storm Vortex Observed by a Mobile, W-Band Radar During VORTEX2  

Science Conference Proceedings (OSTI)

As part of the VORTEX2 field campaign, a very high-resolution, mobile, W-band Doppler radar collected near-surface (?200 m AGL) observations in an EF-0 tornado near Tribune, Kansas on 25 May 2010 and in sub-tornado-strength vortices near Prospect ...

Robin L. Tanamachi; Howard B. Bluestein; Ming Xue; Wen-Chau Lee; Krzysztof A. Orzel; Stephen J. Frasier; Roger M. Wakimoto

273

Modelling the vibration of tyre sidewalls  

E-Print Network (OSTI)

, the exterior component represents an environmental pollutant, while its interior counterpart poses a problem for vehicle manufacturers. In both cases, accurate and effective models of the tyre’s vibration characteristics are needed to improve design... ), and rotational inertia effects appear to be minor at prac- tical vehicle speeds. Keywords: road noise, tyre vibration, tyre model 1. Introduction Noise generated by rolling vehicle tyres is a topic of significant, and growing, concern. From a societal viewpoint...

Graham, W. R.

2013-01-01T23:59:59.000Z

274

Reduced vibration motor winding arrangement  

DOE Patents (OSTI)

The present invention relates generally to an electric motor winding and, more particularly, to a three phase motor armature winding arrangement designed to reduce motor vibration and improve efficiency. An individual phase winding arrangement having a sixty electrical degree phase belt width for use with a three phase motor armature includes a delta connected phase winding portion and a wye connected phase winding portion. Both the delta and wye connected phase winding portions have a thirty electrical degree phase belt width. The delta and wye connected phase winding portions are each formed from a preselected number of individual coils each formed, in turn, from an unequal number of electrical conductor turns in the approximate ratio of {radical}3. The individual coils of the delta and wye connected phase winding portions may either be connected in series or parallel. This arrangement provides an armature winding for a three phase motor which retains the benefits of the widely known and utilized thirty degree phase belt concept, including improved mmf waveform and fundamental distribution factor.

Slavik, C.J.; Rhudy, R.G.; Bushman, R.E.

1995-12-31T23:59:59.000Z

275

ANALYTICAL STUDY OF SOME ASPECTS OF VORTEX TUBES FOR GAS-PHASE FISSION HEATING  

DOE Green Energy (OSTI)

Several problems connected with vortex cavity reactors were studied analytically. They include, the generation of high-strength vortices by utilization of bleed through a porous tube wall to stabilize the shear layer on the wall; the nuclear criticality problem; the suitability of various compounds of plutonium as gaseous fissionable materials; and the problem of retaining the fission fragments within the vortex tube. It is concluded that the shear layer on the vortex tube wall can be stabilized if a mass flow greater than or equal to the vortex through flow is bled through the porous wall, and that the tangential Mach numbers which can be obtained are then slightly more than one-half the inviscid values. Beryllium oxide or graphite-moderated reactors of reasonable size and weight can attain criticality if the product of the hydrogen pressure in the vortex core and the maximum value of the ratio of fissionable gas density to hydrogen density in the tube is greater than about 100 atm. The reactor weights are then in the order of 10,000 lb or less. Of the several compounds of plutonium considered as gaseous fuel carriers, plutonium trifluoride and plutonium tribromide appear to be the most promising. It is probable that they can be held in gaseous form in hydrogen, under the desired concentrations. The rate of loss of fission fragments from the vortex tube can be reduced to a small fraction of the rate of their generation by making the vortex tubes about twice the minimum size that is allowable for satisfactory retention of the fissionable material. (auth)

Kerrebrock, J.L.; Lafyatis, P.G.

1958-07-21T23:59:59.000Z

276

Probing the Vibrational Relaxation of N2 and O2 by Use of CARS Spectroscopy to Model NTE-Turbulence  

E-Print Network (OSTI)

The thermochemical dynamics associated with hypersonic flight and turbulent flow is vital to understanding the effects that hypersonic turbulence has on objects or vehicles traveling at speeds above Mach 5 (~ 1708 m/s). Non-thermochemical equilibrium (NTE) exists downstream of strong shock fronts and encountered in the shear layers from hypersonic flight, and coupled with turbulence, it has significant effects on flow dynamics. NTE, characterized by high vibrational temperatures of N2 and O2, was observed, and the relaxation processes were measured to obtain time-resolved results. By inducing cold-flow NTE via RF-plasma, species in the flow were probed to determine specific vibrational temperatures at particular distances and times following initial NTE-preparation. The detection technique used in the experiment was coherent anti-Stokes Raman spectroscopy (CARS) and variations of this laser-based technique were optimized to maximize accuracy and signal-to-noise in the vibrational relaxation measurements. It was found that the boxCARS variant was most successful in probing the v=1 --> v=0 vibrational transition associated with the measurement. Also a dual pump-beam CARS setup enabled the probing of both N2 and O2 simultaneously; however, in this report only N2 vibrational relaxation was modeled because the lifetime of vibrationally-excited (v=1) O2 was too short and the O2 vibrational temperature was too low to model. The CARS spectra were obtained in a subsonic wind tunnel with a flow velocity of approximately 30 m/s and probing distances from 4.4-39.4 cm downstream the plasma. Five averaged vibrational temperature values were determined and they yielded a decay from 1882 ± 46 K (4.4 cm from plasma) to 1010 ± 16 K (39.4 cm from plasma) showing the relative rate of vibrational relaxation of N2. The vibrational relaxation was also modeled as a function of time after passing through the plasma, and a kinetic simulation was fit to the results. The spectral decay of the v=1 peak relative to v=0 (Iv=1/Iv=0) was found and compared to the decay of the vibrational temperature. Data analysis revealed that the results were in agreement with theory and the observed vibrational relaxation of N2 fit the simulated kinetic model accurately.

Dean, Jacob

2009-06-09T23:59:59.000Z

277

Increase of pinning with temperature for a single vortex line in superfluid helium  

E-Print Network (OSTI)

While vortex pinning in superconductors usually becomes weaker at higher temperatures, we find the opposite behavior for a single vortex line in superfluid 4 He. The pinning steadily increases over our entire measurement range, from 0.15Tc to over 0.5Tc. We propose Kelvin waves along the vortex as a depinning mechanism with the observed temperature behavior. PACS numbers: 67.40.Vs, 74.60.Ge Pinning sites can trap vortices in a variety of systems. In superconductors, where vortex motion leads to non-zero resistance, a vast amount of work has been devoted to preventing such motion by introducing defects. Experimental work has shown that defects comparable in size to the vortex core make effective pin centers, and that straight [1] or splayed [2] line defects can increase the pin strength. Yet the mechanisms by which vortices interact with pin sites remain unresolved. Experimentally, pinning becomes weaker as temperature increases, in accord with the general assumption that depinning

L. A. K. Donev; L. Hough; R. J. Zieve

2000-01-01T23:59:59.000Z

278

Characterization of The Dalles Dam Spillbay 6 Vortex Using Surface Entrained Sensor Fish Device: Preliminary Report  

DOE Green Energy (OSTI)

This document summarizes the pilot study to characterize The Dalles Dam Spillbay 6 vortex using a surface entrained Sensor Fish device. It was conducted by Pacific Northwest National Laboratory (PNNL) on April 13 and 14, 2006. The total spill was controlled at approximately 110 kcfs, the forebay elevation was 157.89 ft, and the discharge of Bay 6 at the tested gate opening of 14 ft was approximately 18 kcfs. The objectives of the full study are to (1) develop baseline conditions for the detailed analysis of Sensor Fish measurements by deploying Sensor Fish in different surface locations in the vortex periphery; (2) observe the entrainment pattern and extract hydraulic data of interest such as acceleration, rotation, pressure, and estimated velocity of Sensor Fish or drogues; (3) integrate the experimental results with companion computational fluid dynamics (CFD) simulations and inertial particle tracking studies. A total of 12 Sensor Fish were released in the surface at upstream edge, left edge, downstream edge, and the core of the vortex at Bay 6. Because of the high discharge, the vortex patterns at the test condition were less consistent than the patterns observed at lower discharges. Compared with the Sensor Fish released at mid-bay at Bay 6, Sensor Fish released from the surface at the vortex experienced higher pressure fluctuations, a larger percentage of severe events, and much more rapid angular velocities.

Deng, Zhiqun; Richmond, Marshall C.; Carlson, Thomas J.

2006-06-22T23:59:59.000Z

279

Enhanced boiling heat transfer by submerged, vibration induced jets .  

E-Print Network (OSTI)

??In this analysis, the efficacy of cavitation jets for heat transfer enhancement was demonstrated. The cavitation jet was formed from a cluster of cavitation bubbles… (more)

Tillery, Steven W.

2005-01-01T23:59:59.000Z

280

Quantum Monte Carlo for vibrating molecules  

SciTech Connect

Quantum Monte Carlo (QMC) has successfully computed the total electronic energies of atoms and molecules. The main goal of this work is to use correlation function quantum Monte Carlo (CFQMC) to compute the vibrational state energies of molecules given a potential energy surface (PES). In CFQMC, an ensemble of random walkers simulate the diffusion and branching processes of the imaginary-time time dependent Schroedinger equation in order to evaluate the matrix elements. The program QMCVIB was written to perform multi-state VMC and CFQMC calculations and employed for several calculations of the H{sub 2}O and C{sub 3} vibrational states, using 7 PES`s, 3 trial wavefunction forms, two methods of non-linear basis function parameter optimization, and on both serial and parallel computers. In order to construct accurate trial wavefunctions different wavefunctions forms were required for H{sub 2}O and C{sub 3}. In order to construct accurate trial wavefunctions for C{sub 3}, the non-linear parameters were optimized with respect to the sum of the energies of several low-lying vibrational states. In order to stabilize the statistical error estimates for C{sub 3} the Monte Carlo data was collected into blocks. Accurate vibrational state energies were computed using both serial and parallel QMCVIB programs. Comparison of vibrational state energies computed from the three C{sub 3} PES`s suggested that a non-linear equilibrium geometry PES is the most accurate and that discrete potential representations may be used to conveniently determine vibrational state energies.

Brown, W.R. [Univ. of California, Berkeley, CA (United States). Chemistry Dept.]|[Lawrence Berkeley National Lab., CA (United States). Chemical Sciences Div.

1996-08-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Vibrational energy transfer in a diesel engine  

Science Conference Proceedings (OSTI)

The paths of vibrational energy transfer in a diesel engine were investigated in order to obtain insight into ways of reducing this transfer to the exterior surfaces and thereby reduce the radiated noise. The engine was tested in a nonrunning condition with simulated internal forces in order to study the different transfer paths separately. Vibration response measurements were made of individual engine components and lumped?parameter models were developed to simulate this response. These models were then used to determine component design changes that would reduce the energy transfer. Two design changes were implemented in the engine and a reduction of the energy transfer was achieved as predicted.

R. G. DeJong; R. H. Lyon

1977-01-01T23:59:59.000Z

282

Characterisation of an Electrostatic Vibration Harvester  

E-Print Network (OSTI)

Harvesting energy from ambient vibration is proposed as an alternative to storage based power supplies for autonomous systems. The system presented converts the mechanical energy of a vibration into electrical energy by means of a variable capacitor, which is polarized by an electret. A lumped element model is used to study the generator and design a prototype. The device has been micromachined in silicon, based on a two-wafer process. The prototype was successfully tested, both using an external polarization source and an electret.

Sterken, T; Fiorini, P; Puers, R

2008-01-01T23:59:59.000Z

283

Structure and Evolution of the Large-Scale Flow and an Embedded Upper-Tropospheric Cyclonic Vortex over Northeast Brazil  

Science Conference Proceedings (OSTI)

Horizontal structure and evolution of large-scale flow and an embedded synoptic-scale cyclonic vortex over northeast Brazil as separate systems and dynamical interaction between them are studied at 200 hPa. A quasi-stationary cyclonic vortex with ...

S. K. Mishra; V. B. Rao; M. A. Gan

2001-07-01T23:59:59.000Z

284

Evidence of small-scale magnetic concentrations dragged by vortex motion of solar photospheric plasma  

E-Print Network (OSTI)

Vortex-type motions have been measured by tracking bright points in high-resolution observations of the solar photosphere. These small-scale motions are thought to be determinant in the evolution of magnetic footpoints and their interaction with plasma and therefore likely to play a role in heating the upper solar atmosphere by twisting magnetic flux tubes. We report the observation of magnetic concentrations being dragged towards the center of a convective vortex motion in the solar photosphere from high-resolution ground-based and space-borne data. We describe this event by analyzing a series of images at different solar atmospheric layers. By computing horizontal proper motions, we detect a vortex whose center appears to be the draining point for the magnetic concentrations detected in magnetograms and well-correlated with the locations of bright points seen in G-band and CN images.

Balmaceda, L; Palacios, J; Cabello, I; Domingo, V

2010-01-01T23:59:59.000Z

285

Vortex combustor for low NOX emissions when burning lean premixed high hydrogen content fuel  

Science Conference Proceedings (OSTI)

A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

Steele, Robert C; Edmonds, Ryan G; Williams, Joseph T; Baldwin, Stephen P

2012-11-20T23:59:59.000Z

286

Vortex combustor for low NOx emissions when burning lean premixed high hydrogen content fuel  

DOE Patents (OSTI)

A trapped vortex combustor. The trapped vortex combustor is configured for receiving a lean premixed gaseous fuel and oxidant stream, where the fuel includes hydrogen gas. The trapped vortex combustor is configured to receive the lean premixed fuel and oxidant stream at a velocity which significantly exceeds combustion flame speed in a selected lean premixed fuel and oxidant mixture. The combustor is configured to operate at relatively high bulk fluid velocities while maintaining stable combustion, and low NOx emissions. The combustor is useful in gas turbines in a process of burning synfuels, as it offers the opportunity to avoid use of diluent gas to reduce combustion temperatures. The combustor also offers the possibility of avoiding the use of selected catalytic reaction units for removal of oxides of nitrogen from combustion gases exiting a gas turbine.

Steele, Robert C. (Woodinville, WA); Edmonds, Ryan G. (Renton, WA); Williams, Joseph T. (Kirkland, WA); Baldwin, Stephen P. (Winchester, MA)

2009-10-20T23:59:59.000Z

287

Electron trapping by a current vortex F. Bentosela, a;b P. Exner, c;d and V.A. Zagrebnov a;b  

E-Print Network (OSTI)

with the magnetic field due to an electric current forming a localized rotationally symmetric vortex. We show simpler example involves a Pauli electron interacting with a flux tube modelling a vortex magnetic field field Ansatz. To illustrate this point we analyze in this letter the situation where the vortex current

288

Measurement of sinusoidal vibration from motion blurred images  

Science Conference Proceedings (OSTI)

Previous vision-based methods usually measure vibration from large sequence of unblurred images recorded by high-speed video or stroboscopic photography. In this paper, we propose a novel method for sinusoidal vibration measurement based on motion blurred ... Keywords: Geometric moment, Motion blur, Motion blurred image, Vibration measurement

Shigang Wang; Baiqing Guan; Guobao Wang; Qian Li

2007-07-01T23:59:59.000Z

289

Testing Technology of Torsional Vibration Spring Static Stiffness  

Science Conference Proceedings (OSTI)

The principle and method of testing static stiffness of torsional vibration spring are put forward based on the structure of dual-mass flywheel with torsional vibration spring, and the test bench is designed for these. The testing data is collected by ... Keywords: LabVIEW, dual-mass flywheel, static stiffness, torsional vibration spring

Zhengfeng Jiang; Shaobo Xu; Lei Chen

2008-10-01T23:59:59.000Z

290

Downhole Vibration Monitoring and Control System  

SciTech Connect

The objective of this program is to develop a system to both monitor the vibration of a bottomhole assembly, and to adjust the properties of an active damper in response to these measured vibrations. The key feature of this system is its use of a magnetorheological fluid (MRF) to allow the damping coefficient to be changed extensively, rapidly and reversibly without the use of mechanical valves, but only by the application of a current. Phase I of this program, which entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype, was completed on May 31, 2004. Much of the effort was devoted to the design and testing of the MRF damper, itself. The principal objectives of Phase II were: more extensive laboratory testing, including the evaluation of different feedback algorithms for control of the damper; design and manufacture of a field prototype system; and, testing of the field prototype in a drilling laboratory. Phase II concluded on January 31, 2006, and a final report was issued. Work on Phase III of the project began during the first quarter, 2006, with the objectives of building precommercial prototypes, testing them in a drilling laboratory and the field; developing and implementing a commercialization plan. All of these have been accomplished. The Downhole Vibration Monitoring & Control System (DVMCS) prototypes have been successfully proven in testing at the TerraTek drilling facility and at the Rocky Mountain Oilfield Test Center (RMOTC.) Based on the results of these tests, we have signed a definitive development and distribution agreement with Smith, and commercial deployment is underway. This current version of the DVMCS monitors and controls axial vibrations. Due to time and budget constraints of this program, it was not possible to complete a system that would also deal with lateral and torsional (stick-slip) vibrations as originally planned; however, this effort is continuing without DOE funding.

Martin E. Cobern

2007-09-30T23:59:59.000Z

291

Study On The Self-Powered Active Vibration Control  

E-Print Network (OSTI)

A method of active vibration control using regenerated vibration energy, i.e., the self-powered active vibration control is proposed. In this system, vibration energy is regenerated with an electric generator ,which is called energy regenerative damper, and is stored in a condenser. An actuator attains active vibration control using the energy stored in the condenser. A variable resistance is used to control output force of the actuator. Since the damping coefficient of the energy regenerative damper is uncertain when it regenerates vibration energy, it is required for the controller to be robust to parameter uncertainty; H control method is applied to the system. Through experiments, the self-powered active control system is proved to have better isolation performance in comparison with that of a semi-active or a passive control system. INTRODUCTION Active vibration control has been applied to several systems. It has better isolation performance than a passive control system. Howe...

Yoshihiro Suda Institute; Yoshihiro Suda; Shigeyuki Nakadai; Kimihiko Nakano

1998-01-01T23:59:59.000Z

292

Force-limited vibration tests aplied to the FORTE` satellite  

SciTech Connect

A force limited random vibration test was conducted on a small satellite called FORTE{prime}. This type of vibration test reduces the over testing that can occur in a conventional vibration test. Two vibration specifications were used in the test: The conventional base acceleration specification, and an interface force specification. The vibration level of the shaker was controlled such that neither the table acceleration nor the force transmitted to the test item exceeded its specification. The effect of limiting the shake table vibration to the force specification was to reduce (or ``notch``) the shaker acceleration near some of the satellite`s resonance frequencies. This paper describes the force limited test conducted for the FORTE{prime} satellite. The satellite and its dynamic properties are discussed, and the concepts of force limiting theory are summarized. The hardware and setup of the test are then described, and the results of the force limited vibration test are discussed.

Stevens, R.R.; Butler, T.A.

1996-02-01T23:59:59.000Z

293

Linear and Nonlinear Vortex Motion in an Asymmetric Balance Shallow Water Model  

Science Conference Proceedings (OSTI)

This work extends asymmetric balance (AB) theory to the beta plane (?-AB). The physical problem examined is the motion of a coherent vortex on a beta plane in a finite depth fluid in the absence of an environmental steering flow. A useful ...

Michael T. Montgomery; J. Dominique Möller; Christopher T. Nicklas

1999-03-01T23:59:59.000Z

294

The Effect of Vorticity-Profile Shape on the Instability of a Two-Dimensional Vortex  

Science Conference Proceedings (OSTI)

A simple linear numerical model is used to study the effect of the shape of the vertical vorticity profile on the stability characteristics of a two-dimensional vortex. In all cases, the basic-state vorticity is confined to an annulus. It is ...

Jerry L. Steffens

1988-01-01T23:59:59.000Z

295

Original articles: Vortex states in axially symmetric superconductors in applied magnetic field  

Science Conference Proceedings (OSTI)

We solve analytically the linearized Ginzburg-Landau (GL) equation in the presence of an uniform magnetic field with cylindrical boundary conditions. The solution of the non-linear GL equation is provided as an expansion in the basis of linearized solutions. ... Keywords: Axial magnetic field, Mesoscopic superconductivity, Nonlinear Ginzburg-Landau equation, Vortex

Andrei Ludu; Milorad V. Miloševi?; Francois M. Peeters

2012-03-01T23:59:59.000Z

296

Stability of a Two-Layer Quasigeostrophic Vortex over Axisymmetric Localized Topography  

Science Conference Proceedings (OSTI)

The stability of a quasigeostrophic vortex over a radially symmetric topographic feature (elevation or depression) in a two-layer ocean on the f plane is examined. This article’s concern is with compensated vortices, that is, those in which the ...

E. S. Benilov

2005-01-01T23:59:59.000Z

297

Indirect Combustion Noise: Experimental Investigation of the Vortex Sound Generation in a Choked  

E-Print Network (OSTI)

Indirect Combustion Noise: Experimental Investigation of the Vortex Sound Generation in a Choked-27 April 2012, Nantes, France 2315 #12;Combustion noise in gas turbines consists of direct noise related to the unsteady combustion process itself and indirect noise. As known, indirect noise is produced when entropy

Paris-Sud XI, Université de

298

Longitudinally Dependent Ozone Increase in the Antarctic Polar Vortex Revealed by Balloon and Satellite Observations  

Science Conference Proceedings (OSTI)

The horizontal structure of processes causing increases in ozone in the Antarctic polar vortex was examined using data measured in 2003 from an ozonesonde observation campaign at Syowa Station (39.6°E, 69.0°S) and from the Improved Limb ...

K. Sato; Y. Tomikawa; G. Hashida; T. Yamanouchi; H. Nakajima; T. Sugita

2009-06-01T23:59:59.000Z

299

Aging memory and glassiness of a driven vortex , Guohong Li1  

E-Print Network (OSTI)

1 Aging memory and glassiness of a driven vortex system. Xu Du1 , Guohong Li1 , Eva Y. Andrei1 , M memory, aging and nonlinear-dynamics. Glasses[1-11], interfaces[12] and fractures are some examples[13 the deviation from equilibrium. After removing the force, the system ages with time and its subsequent response

Andrei, Eva Y.

300

3D-vortex labyrinths in the near field of solid-state microchip laser  

E-Print Network (OSTI)

The spatiotemporal vortex lattices generated in high Fresnel number solid-state microchip lasers are studied in connection with Talbot phenomenon generic to spatially periodic electromagnetic fields. The spatial layout of light field is obtained via dynamical model based on Maxwell-Bloch equations for class-B laser, discrete Fox-Lee map with relaxation of inversion and static model based on superposition of copropagating Gaussian beams. The spatial patterns observed experimentally and obtained numerically are interpreted as nonlinear superposition of vortices with helicoidal phase dislocations. The usage of vortex labyrinths and Talbot lattices as optical dipole traps for neutral atoms is considered for the wavelength of trapping radiation in the range 0.98 $\\div$ 2.79 $\\mu m$. The separable optical trapping potential is mounted as a sum of array of vortex lines and additional parabolic subtrap. The factorization of macroscopic wavefunction have led to analytical solution of Gross-Pitaevski equation for ground state of ensemble of quantum particles trapped in vortex labyrinth and in spatially - periodic array of Gaussian beams.

A. Yu. Okulov

2007-01-21T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Ozone Forecasts of the Stratospheric Polar Vortex–Splitting Event in September 2002  

Science Conference Proceedings (OSTI)

The Southern Hemisphere major warming event in September 2002 has led to a breakup of the vortex in the middle and higher stratosphere and to a corresponding splitting of the ozone hole. Daily 3D ozone forecasts, produced at the Royal Netherlands ...

Henk Eskes; Arjo Segers; Peter van Velthoven

2005-03-01T23:59:59.000Z

302

Genesis of the Goshen County, Wyoming, Tornado on 5 June 2009 during VORTEX2  

Science Conference Proceedings (OSTI)

The genesis of a strong and long-lived tornado observed during the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) in Goshen County, Wyoming, on 5 June 2009 is studied. Mobile radar, mobile mesonet, rawinsonde, and ...

Karen Kosiba; Joshua Wurman; Yvette Richardson; Paul Markowski; Paul Robinson; James Marquis

2013-04-01T23:59:59.000Z

303

Generation and Stability of a Quasi-Permanent Vortex in the Lofoten Basin  

Science Conference Proceedings (OSTI)

In the Nordic seas the Lofoten Basin is a region of high mesoscale activity. The generation mechanism and the conditions for the stability of a quasi-permanent vortex in the center of the Lofoten Basin are studied with a high-resolution ocean ...

Armin Köhl

2007-11-01T23:59:59.000Z

304

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

305

Study of a Heavy Rain Vortex Formed over the Eastern Flank of the Tibetan Plateau  

Science Conference Proceedings (OSTI)

A case of the heavy rain vortex which occurred during the period 14–15 July 1979 is studied using a limited-area mesoscale numerical model. This is a representative example of a group of warm southwest vortices that often form over the eastern ...

Bin Wang; Isidoro Orlanski

1987-07-01T23:59:59.000Z

306

The Final Warming Date of the Antarctic Polar Vortex and Influences on its Interannual Variability  

Science Conference Proceedings (OSTI)

More than 40 years of radiosonde data from two Antarctic stations are examined for changes in the date of the final stratospheric warming that occurs each year as the vortex breaks up in spring/summer. A new measure of this date is derived that ...

Joanna D. Haigh; Howard K. Roscoe

2009-11-01T23:59:59.000Z

307

The Second Verification of the Origins of Rotation in Tornadoes Experiment: VORTEX2  

Science Conference Proceedings (OSTI)

The second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2), which had its field phases in May and June of 2009 and 2010, was designed to explore i) the physical processes of tornadogenesis, maintenance, and demise; ii) the ...

Joshua Wurman; David Dowell; Yvette Richardson; Paul Markowski; Erik Rasmussen; Donald Burgess; Louis Wicker; Howard B. Bluestein

2012-08-01T23:59:59.000Z

308

Water structure and vibrational properties in fibrous clays.  

DOE Green Energy (OSTI)

The behavior of water confined in porous materials influences macroscopic phenomena such as solute and water mobility, ion exchange, and adsorption. While the properties of bulk water are generally understood, that of nanoconfined water remains an active area of research. We used molecular simulation and inelastic neutron scattering (INS) to investigate the effect of local structure on the vibrational behavior of nanoconfined water. We focus specifically on the nanosized pores found in the 2:1 phyllosilicate clay minerals palygorskite and sepiolite. These are charge neutral, Mg-rich trioctahedral clays with idealized formulas Mg{sub 5}Si{sub 8}O{sub 20} (OH){sub 2} {center_dot} 8H{sub 2}O and Mg{sub 8}Si{sub 12}O{sub 30} (OH){sub 2} {center_dot} 12H{sub 2}O for palygorskite and sepiolite, respectively. The regular pattern of inverted phyllosilicate layers results in narrow channels with effective van der Waals dimensions of 3.61 {angstrom} x 8.59 {angstrom} (palygorskite) and 4.67 {angstrom} x 12.29 {angstrom} (sepiolite). These clay minerals represent a unique opportunity to study water adsorbed at 'inner edge' sites of uncoordinated Mg{sup 2+}. INS spectra taken at 90 K reveal a large shift in the water librational edge between palygorskite (358 cm{sup -1}) and sepiolite (536 cm{sup -1}), indicating less restricted water motion in the smaller-pore palygorskite. The librational edge of the reference sample (ice I{sub h}) is similar to sepiolite, which confirms the unique water behavior in palygorskite. We used both classical molecular dynamics (CMD) simulations and more rigorous density functional theory (DFT) calculations to investigate the hydrogen bonding environment and vibrational behavior of structural water, defined as those water molecules coordinated to Mg{sup 2+} along the pore walls. These waters remain coordinated throughout the 1-ns timescale of the CMD simulations, and the resulting vibrational spectra indicate a similar shift in the water librational edges seen in the INS spectra. The DFT-optimized structures indicate differences in hydrogen bonding between palygorskite and sepiolite, which could explain the librational shift. Corner-sharing silicate tetrahedra in palygorskite are tilted with respect to the crystallographic a-axis due to the induced strain of layer inversion. As a result, only two short (1.9 {angstrom}) hydrogen bonds form between each water and the framework. In contrast, the relatively unstrained sepiolite structure, each water forms three hydrogen bonds with the framework, and at greater distances (2.0 {angstrom} - 2.5 {angstrom}).

Ockwig, Nathan W.; Cygan, Randall Timothy; Greathouse, Jeffery A.

2010-06-01T23:59:59.000Z

309

Switching a magnetic vortex by interlayer coupling in epitaxially grown Co/Cu/Py/Cu(001) trilayer disks  

SciTech Connect

Epitaxial Py/Cu/Co/Cu(001) trilayers were patterned into micron sized disks and imaged using element-specific photoemission electron microscopy. By varying the Cu spacer layer thickness, we study how the coupling between the two magnetic layers influences the formation of magnetic vortex states. We find that while the Py and Co disks form magnetic vortex domains when the interlayer coupling is ferromagnetic, the magnetic vortex domains of the Py and Co disks break into anti-parallel aligned multidomains when the interlayer coupling is antiferromagnetic. We explain this result in terms of magnetic flux closure between the Py and Co layers for the antiferromagnetic coupling case.

Wu, J.; Carlton, D.; Oelker, E.; Park, J. S.; Jin, E.; Arenholz, E.; Scholl, A.; Hwang, C.; Bokor, J.; Qiu, Z Q

2010-07-16T23:59:59.000Z

310

Transportation Shock and Vibration Literature Review  

SciTech Connect

This report fulfills the M4 milestone M4FT-13OR08220112, "Report Documenting Experimental Activities." The purpose of this report is to document the results of a literature review conducted of studies related to the vibration and shock associated with the normal conditions of transport for rail shipments of used nuclear fuel from commercial light-water reactors. As discussed in Adkins (2013), the objective of this report is to determine if adequate data exist that would enable the impacts of the shock and vibration associated with the normal conditions of transport on commercial light-water reactor used nuclear fuel shipped in current generation rail transportation casks to be realistically modeled.

Maheras, Steven J.; Lahti, Erik A.; Ross, Steven B.

2013-06-06T23:59:59.000Z

311

Vibrations in jammed solids: Beyond linear response  

E-Print Network (OSTI)

We propose a `phase diagram' for particulate systems that interact via purely repulsive contact forces, such as granular media and colloidal suspensions. We identify and characterize two distinct classes of behavior as a function of the input kinetic energy per degree of freedom $T_0$ and packing fraction deviation above and below jamming onset $\\Delta \\phi=\\phi - \\phi_J$ using numerical simulations of purely repulsive frictionless disks. Iso-coordinated solids (ICS) only occur above jamming for $\\Delta \\phi > \\Delta \\phi_c(T_0)$; they possess average coordination number equal to the isostatic value ($ = z_{\\rm iso}$) required for mechanically stable packings. ICS display harmonic vibrational response, where the density of vibrational modes from the Fourier transform of the velocity autocorrelation function is a set of sharp peaks at eigenfrequencies $\\omega_k^d$ of the dynamical matrix evaluated at $T_0=0$. Hypo-coordinated solids (HCS) occur both above and below jamming onset within the region defined by $\\Delta \\phi > \\Delta \\phi^*_-(T_0)$, $\\Delta \\phi \\Delta \\phi_{cb}(T_0)$. In this region, the network of interparticle contacts fluctuates with $ \\approx z_{\\rm iso}/2$, but cage-breaking particle rearrangements do not occur. The HCS vibrational response is nonharmonic, {\\it i.e} the density of vibrational modes $D(\\omega)$ is not a collection of sharp peaks at $\\omega_k^d$, and its precise form depends on the measurement method. For $\\Delta \\phi > \\Delta \\phi_{cb}(T_0)$ and $\\Delta \\phi < \\Delta \\phi^*_{-}(T_0)$, the system behaves as a hard-particle liquid.

Thibault Bertrand; Carl F. Schreck; Corey S. O'Hern; Mark D. Shattuck

2013-07-01T23:59:59.000Z

312

The High Level Vibration Test Program  

SciTech Connect

As part of cooperative agreements between the United States and Japan, tests have been performed on the seismic vibration table at the Tadotsu Engineering Laboratory of Nuclear Power Engineering Test Center (NUPEC) in Japan. The objective of the test program was to use the NUPEC vibration table to drive large diameter nuclear power piping to substantial plastic strain with an earthquake excitation and to compare the results with state-of-the-art analysis of the problem. The test model was designed by modifying the 1/2.5 scale model of the PWR primary coolant loop. Elastic and inelastic seismic response behavior of the test model was measured in a number of test runs with an increasing excitation input level up to the limit of the vibration table. In the maximum input condition, large dynamic plastic strains were obtained in the piping. Crack initiation was detected following the second maximum excitation run. The test model was subjected to a maximum acceleration well beyond what nuclear power plants are designed to withstand. This paper describes the overall plan, input motion development, test procedure, test results and comparisons with pre-test analysis. 4 refs., 16 figs., 2 tabs.

Hofmayer, C.H.; Curreri, J.R.; Park, Y.J.; Kato, W.Y. (Brookhaven National Lab., Upton, NY (USA)); Kawakami, S. (Nuclear Power Engineering Test Center, Tokyo (Japan))

1989-01-01T23:59:59.000Z

313

Bubble oscillations and motion under vibration  

E-Print Network (OSTI)

Bubbles under vibration can behave in unusual ways, e.g., moving downward against the force of buoyancy. While the bubble downward motion due to the Bjerknes force is well known at acoustic frequencies close to the bubble resonant frequency, these experiments demonstrate that these effects can be observed at relatively low frequencies as well. Experiments were performed in a thin, quasi-two-dimensional rectangular acrylic box partially filled with 20-cSt PDMS silicone oil with overlying ambient air. The apparatus was subjected to sinusoidal axial vibration that produced breakup of the gas-liquid free surface, producing liquid jets into the air, droplets pinching off from these jets, gas cavities in the liquid from impacts of these droplets, and bubble transport below the interface. Vibration conditions for the attached videos are 280 Hz frequency, 15 g acceleration, and 94 micron peak-to-peak displacement. Behaviors shown in the videos include the following. 1. Free surface breakup into jets and droplets, and...

O'Hern, Tim; Torczynski, John

2011-01-01T23:59:59.000Z

314

Tropical Cyclone Initialization with a Spherical High-Order Filter and an Idealized Three-Dimensional Bogus Vortex  

Science Conference Proceedings (OSTI)

A tropical cyclone initialization method with an idealized three-dimensional bogus vortex of an analytic empirical formula is presented for the track and intensity prediction. The procedure in the new method consists of four steps: the separation ...

In-Hyuk Kwon; Hyeong-Bin Cheong

2010-04-01T23:59:59.000Z

315

Observations of a Terrain-Forced Mesoscale Vortex and Canyon Drainage Flows along the Front Range of Colorado  

Science Conference Proceedings (OSTI)

Observations taken during the February 1991 Atmospheric Studies in Complex Terrain (ASCOT) Winter Validation Study are used to describe the wind field associated with a terrain-forced mesoscale vortex and thermally forced canyon drainage flows ...

David H. Levinson; Robert M. Banta

1995-07-01T23:59:59.000Z

316

Convection-Allowing and Convection-Parameterizing Ensemble Forecasts of a Mesoscale Convective Vortex and Associated Severe Weather Environment  

Science Conference Proceedings (OSTI)

An analysis of a regional severe weather outbreak that was related to a mesoscale convective vortex (MCV) is performed. The MCV-spawning mesoscale convection system (MCS) formed in northwest Kansas along the southern periphery of a large cutoff ...

Adam J. Clark; William A. Gallus Jr.; Ming Xue; Fanyou Kong

2010-08-01T23:59:59.000Z

317

A Spatial Filter Approach to Evaluating the Role of Convection on the Evolution of a Mesoscale Vortex  

Science Conference Proceedings (OSTI)

A new spatial filter is proposed that exploits a spectral gap in power between the convective scale and the system (“vortex”) scale during tropical cyclone (TC) genesis simulations. Using this spatial separation, this study analyzes idealized ...

Glenn A. Creighton; Robert E. Hart; Philip Cunningham

2013-07-01T23:59:59.000Z

318

Probabilistic Evaluation of the Dynamics and Predictability of the Mesoscale Convective Vortex of 10–13 June 2003  

Science Conference Proceedings (OSTI)

This study examines the dynamics and predictability of the mesoscale convective vortex (MCV) of 10–13 June 2003 through ensemble forecasting. The MCV of interest developed from a preexisting upper-level disturbance over the southwest United ...

Daniel P. Hawblitzel; Fuqing Zhang; Zhiyong Meng; Christopher A. Davis

2007-04-01T23:59:59.000Z

319

Turbulence process domination under the combined forcings of wind stress, the Langmuir vortex force, and surface cooling  

Science Conference Proceedings (OSTI)

Turbulence in the ocean surface layer is generated by time-varying combinations of destabilizing surface buoyancy flux, wind stress forcing, and wave forcing through a vortex force associated with the surface wave field. Observations of time- and ...

A. E. Gargett; C. E. Grosch

320

Observations of a Squall Line and Its Near Environment Using High-Frequency Rawinsonde Launches during VORTEX2  

Science Conference Proceedings (OSTI)

Rawinsonde data were collected before and during passage of a squall line in Oklahoma on 15 May 2009 during the Second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2). Nine soundings were released within 3 h, allowing ...

George H. Bryan; Matthew D. Parker

2010-11-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Contributions of the wall boundary layer to the formation of the counter-rotating vortex pair in transverse jets  

E-Print Network (OSTI)

Using high-resolution 3-D vortex simulations, this study seeks a mechanistic understanding of vorticity dynamics in transverse jets at a finite Reynolds number. A full no-slip boundary condition, rigorously formulated in ...

Schlegel, Fabrice

322

Variation in the Stratospheric Aerosol Associated with the North Cyclonic Polar Vortex as Measured by the SAM II Satellite Sensor  

Science Conference Proceedings (OSTI)

Aerosol extinction data obtained by the Stratospheric Aerosol Measurement II (SAM II) satellite instrument during the 1979/80 Northern Hemisphere winter season have been analyzed in relation to the cyclonic polar vortex. A synoptic approach has ...

G. S. Kent; C. R. Trepte; U. O. Farrukh; M. P. McCormick

1985-07-01T23:59:59.000Z

323

Argonne CNM Highlight: Damping of acoustic vibrations in gold nanoparticles  

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

Damping of acoustic vibrations in gold nanoparticles Damping of acoustic vibrations in gold nanoparticles Nanopatterning of STO Vibrations in nanostructures offer applications in molecular-scale biological sensing and ultrasensitive mass detection. To approach single-atom sensing, it is necessary to reduce the dimensions of the structures to the nanometer scale while preserving long-lived vibrations. This requires an understanding of how vibrations in nanoscale objects are damped - or lose their energy to the fluid surroundings and within themselves. Researchers have used fast laser pulses to produce and probe high-frequency vibrations in metal nanoparticles. However, significant variations in particle dimensions complicate measurements. By studying bipyramid-shaped gold nanoparticles with highly uniform sizes

324

Vibration Monitoring and Analysis Program Development: Interim Guideline  

Science Conference Proceedings (OSTI)

This report has been prepared by an EPRI team and will serve as an interim guideline to assist the member utilities in the further improvement of maintenance processes by presenting, in detail, the key elements that should be included in a well-organized vibration monitoring and analysis program, as well as conducting comprehensive vibration program evaluations. This report uses the EPRI Monitoring and Diagnostics Center's "Spider Chart" approach to depict graphic representation of the vibration monitori...

2004-12-22T23:59:59.000Z

325

Vibrated Bulk Density (VBD) of Calcined Petroleum Coke and ...  

Science Conference Proceedings (OSTI)

Abstract Scope, Vibrated bulk density (VBD) is a quantitative measurement used in the aluminum industry to evaluate the density of calcined petroleum coke.

326

Vibrated Bulk Density (VBD) of Calcined Petroleum Coke and ...  

Science Conference Proceedings (OSTI)

Presentation Title, Vibrated Bulk Density (VBD) of Calcined Petroleum Coke and Implications of Changes in the ASTM Method D4292. Author(s), Bill Spencer, ...

327

The Nature of Vibrational Softening in ? - Uranium Figure 1  

Science Conference Proceedings (OSTI)

... Back to The Nature of Vibrational Softening in ? - Uranium. Last modified 31-May-2002 by website owner: NCNR (attn: Bill Kamitakahara).

328

The Nature of Vibrational Softening in ? - Uranium -- Figure 2  

Science Conference Proceedings (OSTI)

... Back to The Nature of Vibrational Softening in ? - Uranium. Last modified 31-May-2002 by website owner: NCNR (attn: Bill Kamitakahara).

329

NIST Vibrational and electronic energy levels of polyatomic ...  

Science Conference Proceedings (OSTI)

... The types of measurement surveyed include spectrometer and laser-based ... ground-state vibrational fundamentals, the electronic energy levels, and ...

2010-10-08T23:59:59.000Z

330

Effect of mechanical vibrations on light emitting diode luminaires.  

E-Print Network (OSTI)

??In this work, a LED and two types of Compact fluorescent lamps were investigated for the intensity variation due to mechanical vibrations in the range… (more)

Paladugu, Jayalakshmi

2009-01-01T23:59:59.000Z

331

Coal storage hopper with vibrating-screen agitator  

DOE Patents (OSTI)

The present invention is directed to a vibrating screen agitator in a coal storage hopper for assuring the uniform feed of coal having sufficient moisture content to effect agglomeration and bridging thereof in the coal hopper from the latter onto a conveyer mechanism. The vibrating scrren agitator is provided by a plurality of transversely oriented and vertically spaced apart screens in the storage hopper with a plurality of vertically oriented rods attached to the screens. The rods are vibrated to effect the vibration of the screens and the breaking up of agglomerates in the coal which might impede the uniform flow of the coal from the hopper onto a conveyer.

Daw, C.S.; Lackey, M.E.; Sy, R.L.

1982-04-27T23:59:59.000Z

332

Performance Analysis of Tube-Fin Heat Exchanger under Vibration.  

E-Print Network (OSTI)

??The effects of vibration on the airside heat transfer and pressure drop characteristics are experimented and analyzed. The experiment is conducted on a flat tube… (more)

Kannan, Jayaprakash

2012-01-01T23:59:59.000Z

333

Discrete Element Method Applied to the Vibration Process of Coke ...  

Science Conference Proceedings (OSTI)

In the present work, effects of particle shape and size distribution on vibrated bulk density (VBD) of dry coke samples have been investigated. Discrete Element ...

334

Visualizing Spacetime Curvature via Frame-Drag Vortexes and Tidal Tendexes II. Stationary Black Holes  

E-Print Network (OSTI)

When one splits spacetime into space plus time, the Weyl curvature tensor (which equals the Riemann tensor in vacuum) splits into two spatial, symmetric, traceless tensors: the tidal field $E$, which produces tidal forces, and the frame-drag field $B$, which produces differential frame dragging. In recent papers, we and colleagues have introduced ways to visualize these two fields: tidal tendex lines (integral curves of the three eigenvector fields of $E$) and their tendicities (eigenvalues of these eigenvector fields); and the corresponding entities for the frame-drag field: frame-drag vortex lines and their vorticities. These entities fully characterize the vacuum Riemann tensor. In this paper, we compute and depict the tendex and vortex lines, and their tendicities and vorticities, outside the horizons of stationary (Schwarzschild and Kerr) black holes; and we introduce and depict the black holes' horizon tendicity and vorticity (the normal-normal components of $E$ and $B$ on the horizon). For Schwarzschil...

Zhang, Fan; Nichols, David A; Chen, Yanbei; Lovelace, Geoffrey; Matthews, Keith D; Owen, Robert; Thorne, Kip S

2012-01-01T23:59:59.000Z

335

Tripolar vortex formation in dense quantum plasma with ion-temperature-gradients  

SciTech Connect

We have derived system of nonlinear equations governing the dynamics of low-frequency electrostatic toroidal ion-temperature-gradient mode for dense quantum magnetoplasma. For some specific profiles of the equilibrium density, temperature, and ion velocity gradients, the nonlinear equations admit a stationary solution in the form of a tripolar vortex. These results are relevant to understand nonlinear structure formation in dense quantum plasmas in the presence of equilibrium ion-temperature and density gradients.

Qamar, Anisa; Ata-ur-Rahman [Institute of Physics and Electronics, University of Peshawar, Khyber Pakhtoon Khwa 25000 (Pakistan); National Center for Physics Shahdrah Valley Road, Islamabad 44000 (Pakistan); Mirza, Arshad M. [Theoretical Plasma Physics Group, Physics Department, Quaid-i-Azam University, Islamabad 45320 (Pakistan)

2012-05-15T23:59:59.000Z

336

Numerical evidence of breaking of vortex lines in an ideal fluid  

E-Print Network (OSTI)

Emergence of singularity of vorticity at a single point, not related to any symmetry of the initial distribution, has been demonstrated numerically for the first time. Behavior of the maximum of vorticity near the point of collapse closely follows the dependence 1/(t0-t), where t0 is the time of collapse. This agrees with the interpretation of collapse in an ideal incompressible fluid as of the process of vortex lines breaking.

Kuznetsov, E A; Zheligovsky, V A

2001-01-01T23:59:59.000Z

337

Visualizing Spacetime Curvature via Frame-Drag Vortexes and Tidal Tendexes II. Stationary Black Holes  

E-Print Network (OSTI)

When one splits spacetime into space plus time, the Weyl curvature tensor (which equals the Riemann tensor in vacuum) splits into two spatial, symmetric, traceless tensors: the tidal field $E$, which produces tidal forces, and the frame-drag field $B$, which produces differential frame dragging. In recent papers, we and colleagues have introduced ways to visualize these two fields: tidal tendex lines (integral curves of the three eigenvector fields of $E$) and their tendicities (eigenvalues of these eigenvector fields); and the corresponding entities for the frame-drag field: frame-drag vortex lines and their vorticities. These entities fully characterize the vacuum Riemann tensor. In this paper, we compute and depict the tendex and vortex lines, and their tendicities and vorticities, outside the horizons of stationary (Schwarzschild and Kerr) black holes; and we introduce and depict the black holes' horizon tendicity and vorticity (the normal-normal components of $E$ and $B$ on the horizon). For Schwarzschild and Kerr black holes, the horizon tendicity is proportional to the horizon's intrinsic scalar curvature, and the horizon vorticity is proportional to an extrinsic scalar curvature. We show that, for horizon-penetrating time slices, all these entities ($E$, $B$, the tendex lines and vortex lines, the lines' tendicities and vorticities, and the horizon tendicities and vorticities) are affected only weakly by changes of slicing and changes of spatial coordinates, within those slicing and coordinate choices that are commonly used for black holes. [Abstract is abbreviated.

Fan Zhang; Aaron Zimmerman; David A. Nichols; Yanbei Chen; Geoffrey Lovelace; Keith D. Matthews; Robert Owen; Kip S. Thorne

2012-08-15T23:59:59.000Z

338

Eddy-current system for the vibration-testing of blades  

SciTech Connect

This invention is an improved system for the vibration-testing of cantilevered non-ferrous articles by inducing eddy currents therein. The principal advantage of the system is that relatively little heat is generated in the article being vibrated. Thus, a more accurate measurement of the fatigue characteristics of the article is obtained. Furthermore, the generation of relatively little heat in the blade permits tests to be conducted in low-pressure atmospheres simulating certain actual processes environments. Heat-generation in the vibrated article is minimized by utilizing eddy currents which are generated by an electromagnet whose magnetic field varies but does not change polarity. The typical winding for the electromagnet is excited with pulsating d.c. That is, the winding is alternately charged by connecting it across a d.c. power supply and then discharged by connecting it across a circuit for receiving current generated in the winding by self-induction. Preferably, the discharge circuit is designed so that the waveform of the discharging current approximates that of the charging current.

Jacobs, Martin E. (Chillicothe, OH)

1977-01-01T23:59:59.000Z

339

Vibration Budget for SuperB  

Science Conference Proceedings (OSTI)

We present a vibration budget for the SuperB accelerator. We include ground motion data, motion sensitivity of machine components, and beam feedback system requirements. The SuperB accelerator design attains at least 50 times higher than current B-factories due to smaller beam sizes and a crabbed waist crossing angle scheme at the IP (interaction point). The beam size (1{sigma}) at the IP will be about 10 {micro}m (horizontal) by 40 nm (vertical). These small beam sizes will make the luminosity very sensitive to mechanical vibration and electrical noise. Relative vertical misalignment of the two beams at the IP by only 8 nm will result in a 1% reduction in luminosity. The corresponding horizontal alignment tolerance of is 250x looser (2 {micro}m). The vertical beam angle at the IP for a 1% luminosity loss is fairly loose at 200 {micro}rad, and the horizontal beam angle tolerance is looser still. We will focus on vertical beam position at the IP, since this presents the greatest alignment challenge. The values presented here are for a closed orbit with tunes near a half-integer in the SuperB v.12 lattice.

Bertsche, K; Wittmer, W.; /SLAC; Bolzon, B.; Brunetti, L.; Jeremie, A.; /Annecy, LAPP; Esposito, M.; Tomassini, S.; /Frascati

2011-04-05T23:59:59.000Z

340

Compensated vibrating optical fiber pressure measuring device  

SciTech Connect

A microbending optical fiber is attached under tension to a diaphragm to se a differential pressure applied across the diaphragm which it causes it to deflect. The fiber is attached to the diaphragm so that one portion of the fiber, attached to a central portion of the diaphragm, undergoes a change in tension; proportional to the differential pressure applied to the diaphragm while a second portion attached at the periphery of the diaphragm remains at a reference tension. Both portions of the fiber are caused to vibrate at their natural frequencies. Light transmitted through the fiber is attenuated by both portions of the tensioned sections of the fiber by an amount which increases with the curvature of fiber bending so that the light signal is modulated by both portions of the fiber at separate frequencies. The modulated light signal is transduced into a electrical signal. The separate modulation signals are detected to generate separate signals having frequencies corresponding to the reference and measuring vibrating sections of the continuous fiber, respectively. A signal proportional to the difference between these signals is generated which is indicative of the measured pressure differential across the diaphragm. The reference portion of the fiber is used to compensate the pressure signal for zero and span changes resulting from ambient temperature and humidity effects upon the fiber and the transducer fixture.

Fasching, George E. (Morgantown, WV); Goff, David R. (Christiansburg, VA)

1987-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Adaptive vibration control using synchronous demodulation with machine tool controller motor commutation  

DOE Patents (OSTI)

A control system and method for actively reducing vibration in a spindle housing caused by unbalance forces on a rotating spindle, by measuring the force-induced spindle-housing motion, determining control signals based on synchronous demodulation, and provide compensation for the measured displacement to cancel or otherwise reduce or attenuate the vibration. In particular, the synchronous demodulation technique is performed to recover a measured spindle housing displacement signal related only to the rotation of a machine tool spindle, and consequently rejects measured displacement not related to spindle motion or synchronous to a cycle of revolution. Furthermore, the controller actuates at least one voice-coil (VC) motor, to cancel the original force-induced motion, and adapts the magnitude of voice coil signal until this measured displacement signal is brought to a null. In order to adjust the signal to a null, it must have the correct phase relative to the spindle angle. The feedback phase signal is used to adjust a common (to both outputs) commutation offset register (offset relative to spindle encoder angle) to force the feedback phase signal output to a null. Once both of these feedback signals are null, the system is compensating properly for the spindle-induced motion.

Hopkins, David James (Livermore, CA)

2008-05-13T23:59:59.000Z

342

The Vibration Virtual Environment for Test Optimization (VETO)  

SciTech Connect

A new test simulation tool is being developed to support vibration test design and to evaluate the overall testability of a component or system. This environment, the Vibration Virtual Environment for Test Optimization (VETO), is utilized to optimally place vibration control and response transducers and to investigate the selection of test parameters needed in the design and performance of a vibration experiment. The engineer can investigate the effects of different control parameters prior to performing an actual vibration test. Additionally, new and existing fixture designs can be evaluated through the development of analytical or experimental models that can be integrated into the simulation environment. This test design environment also provides the engineer with the ability to combine analytically or experimentally derived models of the vibration test hardware, instrumentation and equipment into a simulation model that represents the vibration testing capability. Hardware-in-the-loop simulations can be conducted using this model to examine multiple facets of the test design. This paper presents a new tool that will assist test engineers in maximizing the value of vibration tests through the use of hardware-in-the-loop simulations.

Klenke, S.E.; Lauffer, J.P.; Gregory, D.L.; Togami, T.C.

1996-10-01T23:59:59.000Z

343

A longitudinal study of vibration-based water flow sensing  

Science Conference Proceedings (OSTI)

We present a long-term and cross-sectional study of a vibration-based water flow rate monitoring system in practical environments and scenarios. In our earlier research, we proved that a water flow monitoring system with vibration sensors is feasible ... Keywords: Application of sensor networks, adaptive sensor calibration, nonintrusive and spatially distributed sensing, parameter estimation via numerical optimization

Younghun Kim; Heemin Park; Mani B. Srivastava

2012-11-01T23:59:59.000Z

344

SUSPENSION VIBRATION COMPENSATION USING A MEMS MICROACTUATOR IN HARD  

E-Print Network (OSTI)

SUSPENSION VIBRATION COMPENSATION USING A MEMS MICROACTUATOR IN HARD DISK DRIVES Tsung-Lin Chen density and spindle rotation speed in hard disk drives, airflow excited suspension vibration (windage with the MA (Li and Horowitz, 2001a). Several MA designs have been proposed for dual- stage actuation in hard

Horowitz, Roberto

345

Expert system development for vibration analysis in machine condition monitoring  

Science Conference Proceedings (OSTI)

Expert systems can be adapted for machine condition monitoring data interpretation due to the ability to identify systematic reasoning processes. As vibration analysis in condition monitoring is still generally performed by highly trained professionals, ... Keywords: Condition monitoring, Expert system, Vibration analysis

Stephan Ebersbach; Zhongxiao Peng

2008-01-01T23:59:59.000Z

346

Electromagnetic Buckled Beam Oscillator for Enhanced Vibration Energy Harvesting  

Science Conference Proceedings (OSTI)

In this work, a nonlinear vibration energy harvester consisting of a buckled beam and an electromagnetic transducer is proposed. An advantage of this device is that there is no need of permanent magnets to create the bistable potential. Theoretical modeling ... Keywords: Vibration energy harvester (VEH), non linear system, bistability, Duffing oscillator, electromagnetic generators (EMG)

F. Cottone, P. Basset, H. Vocca, L. Gammaitoni

2012-11-01T23:59:59.000Z

347

Exploring the impulsion and vibration effects of tactile patterns  

Science Conference Proceedings (OSTI)

This paper explores the impulsion and vibration properties of different tactile patterns. These properties describe the unique states of the pins for example raised or lowered. The tactile feedback is provided by Braille pins on a finger and is in the ... Keywords: braille cell, impulsion, selection, tactile feedback, tactile patterns, vibration

Muhammad Tahir; Gilles Bailly; Eric Lecolinet

2008-09-01T23:59:59.000Z

348

A Mathematical Model for a Vibrating Human Head  

Science Conference Proceedings (OSTI)

In this paper, a mathematical model has been formulated to study the vibration of the human head. In the mathematical analysis of the model, the skull is considered as an anisotropic spherical shell and brain matter is represented as an inviscid compressible ... Keywords: Anisotropic, Human Head, Laplace Transformation, Skull Vibration, Stress Distribution

J. C. Misra; S. Dandapat; S. Adhikary

2010-04-01T23:59:59.000Z

349

Exact Semiclassical Calculations of Translational-Vibrational Energy Transfer  

SciTech Connect

We present "exact" calculations, by the semiclassical method, of vibrational excitation of a harmonic diatomic molecule A-B, in its ground vibrational state, upon collinear collision with an atom C. Results are compared with those of first-order quantum mechanical time dependent perturbation methods and those of purely classical methods.

Kelley, J. Daniel; Wolfsberg, Max

1966-07-22T23:59:59.000Z

350

Smart Vibration Monitoring System for an Ocean Turbine  

Science Conference Proceedings (OSTI)

This paper describes a Smart Vibration Monitoring System (SVMS) developed as an effective way to reduce equipment losses and enhance safety, efficiency, reliability, availability and long life time duration of an ocean turbine. The system utilizes advanced ... Keywords: Diagnostics, Vibration, Monitoring, Dynamometer, Ocean Turbine

Mustapha Mjit; Pierre-Philippe J. Beaujean; David J. Vendittis

2011-11-01T23:59:59.000Z

351

Spectroscopic probes of vibrationally excited molecules at chemically significant energies. Progress report, August 15, 1992--August 14, 1993  

SciTech Connect

Infrared-optical double resonance is being used to study the unimolecular dissociation dynamics of hydrazoic acid (HN{sub 3}). 6{nu}{sub NH} vibrational overtone excitation spectra are given for HN{sub 3}. Work was begun to determine the feasibility of extending the infrared-optical double resonance photofragment spectroscopy to small free radicals, and to be able to monitor atomic dissociation fragments via laser induced fluorescence in the VUV spectrum. 1 fig.

Rizzo, T.R.

1993-04-01T23:59:59.000Z

352

Analysis of Shear-horizontal Vibrations of Crystal Plates for Acoustic Wave Resonators and Sensors  

E-Print Network (OSTI)

Effects of piezoelectric coupling on energy trapping ofEnergy Trapping in High-Frequency Vibrations of PiezoelectricEnergy Trapping in High-Frequency Vibrations of Piezoelectric

Liu, Bo

2010-01-01T23:59:59.000Z

353

Ground vibration model studies for APS storage ring  

SciTech Connect

An analytical ground vibration model is developed for study of the vibration effects on the beam motion in the Advanced Photon Source (APS) storage ring. The different physical parameters associated with the wave characteristics and the vibration modes needed for the study are taken from the vibration studies carried out at the APS site. The implementation has been carried out using Mathematica{trademark}. The study is carried out for the frequency range 1--35 Hz, with a number of sources changing from one through ten. The program written in Mathematica{trademark}, calculates orbit distortion, beta wave change, tune change, dispersion change, and chromaticity change. However, the main parameter studied for the APS storage ring has been the orbit distortion. The merit factor associated with different modes excited by the vibrations has been calculated.

Koul, R.K.

1994-07-01T23:59:59.000Z

354

2010 GRC VIBRATIONAL SPECTROSCOPY AUGUST 1 - AUGUST 6, 2010  

SciTech Connect

The Vibrational Spectroscopy conference focuses on using vibrational spectroscopy to probe structure and dynamics of molecules in gases, liquids, and at interfaces. The conference explores the wide range of state-of-the-art techniques based on vibrational motion. These techniques span the fields of time-domain, high-resolution frequency-domain, spatially-resolved, nonlinear and multidimensional spectroscopies. The conference highlights the application of these techniques in chemistry, materials, biology, and medicine. The theory of molecular vibrational motion and its connection to spectroscopic signatures and chemical reaction dynamics is the third major theme of the meeting. The goal is to bring together a collection of researchers who share common interests and who will gain from discussing work at the forefront of several connected areas. The intent is to emphasize the insights and understanding that studies of vibrations provide about a variety of molecular systems ranging from small polyatomic molecules to large biomolecules and nanomaterials.

Brooks Pate

2010-08-06T23:59:59.000Z

355

Effect of vibrational excitation on the dynamics of ion-molecule reactions  

DOE Green Energy (OSTI)

A new experimental technique for the study of vibrational effects on ion-molecule reaction cross sections is described. Vibrational and collision energy dependent cross sections are presented for proton and H atom transfer, charge transfer and collision induced dissociation reactions in various isotopic H/sub 2//sup +/ + H/sub 2/ systems. Charge and proton transfer cross sections are presented for the reactions of H/sub 2//sup +/ and D/sub 2//sup +/ with Ar, N/sub 2/, CO, and O/sub 2/. All the reactions are shown to be highly influenced by avoided crossings between the ground and first excited potential energy surfaces. Because of the nature of the crossings, vibrational motion of the systems can cause both adiabatic and non-adiabatic behavior of the system. This makes the vibrational dependences of the various cross sections a very sensitive probe of the dynamics of the collisions particularly, their behavior in the region of the crossings. Evidence is seen for charge transfer between reagents as they approach each other, transition to and in some cases reactions on excited potential energy surfaces, competition between different channels, and strong coupling of proton and charge transfer channels which occurs only for two of the systems studied (H/sub 2//sup +/ + Ar, N/sub 2/). Oscillatory structure is observed in the collision energy dependence of the endoergic H/sub 2//sup +/ (v = 0) + Ar charge transfer reaction for the first time, and a simple model which is commonly used for atom-atom charge transfer is used to fit the peaks. Finally a simple model is used to assess the importance of energy resonance and Franck-Condon effects on molecular charge transfer.

Anderson, S.L.

1981-11-01T23:59:59.000Z

356

Reusable vibration resistant integrated circuit mounting socket  

DOE Patents (OSTI)

This invention discloses a novel form of socket for integrated circuits to be mounted on printed circuit boards. The socket uses a novel contact which is fabricated out of a bimetallic strip with a shape which makes the end of the strip move laterally as temperature changes. The end of the strip forms a barb which digs into an integrated circuit lead at normal temperatures and holds it firmly in the contact, preventing loosening and open circuits from vibration. By cooling the contact containing the bimetallic strip the barb end can be made to release so that the integrated circuit lead can be removed from the socket without damage either to the lead or to the socket components.

Evans, Craig N. (Irwin, PA)

1995-01-01T23:59:59.000Z

357

HDR (Heissdampfreaktor) Phase 2 vibrational experiments  

Science Conference Proceedings (OSTI)

As part of the second phase of vibrational/earthquake investigations at the HDR (Heissdampfreaktor) Test Facility in Kahl/Main, FRG, high-level shaker tests (SHAG) were performed during June and July 1986. The purpose of these experiments is to investigate full-scale structural response, soil-structure interaction, and piping and equipment response under strong excitation conditions. While global safety considerations imposed load limitations, the HDR soil/structure system was nevertheless tested to its capacity limits. The performance of up to seven different multiple support pipe hanger configurations (ranging from flexible to stiff systems) was evaluated in the tests. Data obtained in the tests serve to validate analysis methods.

Malcher, L.; Kot, C.A.

1986-10-01T23:59:59.000Z

358

A vibration model for centrifugal contactors  

Science Conference Proceedings (OSTI)

Using the transfer matrix method, we created the Excel worksheet ``Beam`` for analyzing vibrations in centrifugal contactors. With this worksheet, a user can calculate the first natural frequency of the motor/rotor system for a centrifugal contactor. We determined a typical value for the bearing stiffness (k{sub B}) of a motor after measuring the k{sub B} value for three different motors. The k{sub B} value is an important parameter in this model, but it is not normally available for motors. The assumptions that we made in creating the Beam worksheet were verified by comparing the calculated results with those from a VAX computer program, BEAM IV. The Beam worksheet was applied to several contactor designs for which we have experimental data and found to work well.

Leonard, R.A.; Wasserman, M.O.; Wygmans, D.G.

1992-11-01T23:59:59.000Z

359

Size separation in vibrated granular matter  

E-Print Network (OSTI)

We review recent developments in size separation in vibrated granular materials. Motivated by a need in industry to efficiently handle granular materials and a desire to make fundamental advances in non-equilibrium physics, experimental and theoretical investigations have shown size separation to be a complex phenomena. Large particles in a vibrated granular system invariably rise to the top. However, they may also sink to the bottom, or show other patterns depending on subtle variations in physical conditions. While size ratio is a dominant factor, particle specific properties such as density, inelasticity and friction can play an important role. The nature of the energy input, boundary conditions and interstitial air have been also shown to be significant factors in determining spatial distributions. The presence of convection can enhance mixing or lead to size separation. Experimental techniques including direct visualization and magnetic resonance imaging are being used to investigate these properties. Molecular dynamics and Monte Carlo simulation techniques have been developed to probe size separation. Analytical methods such as kinetic theory are being used to study the interplay between particle size and density in the vibro-fluidized regime, and geometric models have been proposed to describe size separation for deep beds. Besides discussing these studies, we will also review the impact of inelastic collision and friction on the density and velocity distributions to gain a deeper appreciation of the non-equilibrium nature of the system. While a substantial number of studies have been accomplished, considerable work is still required to achieve a firm description of the phenomena.

A. Kudrolli

2004-02-06T23:59:59.000Z

360

Strong-field optical control of vibrational dynamics: Vibrational Stark effect in planar acetylene  

SciTech Connect

We perform quantum mechanical simulations of vibrational excitation of planar (5D) acetylene (HCCH) with linearly polarized, intense but nonionizing, infrared laser pulses, exploring one particular pathway for exciting the HCCH molecule into a CC-stretching state via the fundamental excitation in a two-pulse scheme. We optimize the pulse widths, time centers, and carrier frequencies of the two pulses to achieve the maximal projection onto the target CC-stretching state, (0,3,0,0,0) A{sub 1}, subject to penalties related to peak electric field and pulse duration. The influences of Fermi resonance, the vibrational Stark effect, and avoided crossings on the selective excitation are discussed. Different sizes of {open_quotes}essential-states{close_quotes} representation are used and checked against the underlying 299 475-point discrete variable representation (DVR) basis. We find that an essential-states basis consisting of 362 A{sub 1} and B{sub 2} eigenstates represents the results of a full-grid calculation for the excitation process under study. Moreover, we demonstrate that despite the complications associated with the higher dimensionality of the 5D model, we can nevertheless exert infrared laser control over the vibrational dynamics of selective excitation. {copyright} {ital 1999 American Institute of Physics.}

Liu, L.; Muckerman, J.T. [Chemistry Department, Brookhaven National Laboratory, P.O. Box 5000, Upton, New York,11973-5000 (United States)

1999-02-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Micro manipulator motion control to counteract macro manipulator structural vibrations  

Science Conference Proceedings (OSTI)

Inertial force damping control by micro manipulator modulation is proposed to suppress the vibrations of a micro/macro manipulator system. The proposed controller, developed using classical control theory, is added to the existing control system. The proposed controller uses real-time measurements of macro manipulator flexibility to adjust the motion of the micro manipulator to counteract structural vibrations. Experimental studies using an existing micro/macro flexible link manipulator testbed demonstrate the effectiveness of the proposed approach to suppression of vibrations in the macro/micro manipulator system using micro-manipulator-based inertial active damping control.

Lew, J.Y.; Trudnowski, D.J.; Evans, M.S.; Bennett, D.W.

1995-02-01T23:59:59.000Z

362

System and method for damping vibration in a drill string using a magnetorheological damper  

DOE Patents (OSTI)

A system for damping vibration in a drill string can include a magnetorheological fluid valve assembly having a supply of a magnetorheological fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil for inducing a magnetic field that alters the resistance of the magnetorheological fluid to flow between the first and second chambers, thereby increasing the damping provided by the valve. A remnant magnetic field is induced in one or more components of the magnetorheological fluid valve during operation that can be used to provide the magnetic field for operating the valve so as to eliminate the need to energize the coils during operation except temporarily when changing the amount of damping required, thereby eliminating the need for a turbine alternator power the magnetorheological fluid valve. A demagnetization cycle can be used to reduce the remnant magnetic field when necessary.

Wassell, Mark Ellsworth (Houston, TX); Burgess, Daniel E. (Portland, CT); Barbely, Jason R. (East Islip, NY)

2012-01-03T23:59:59.000Z

363

Principles of equilibrium statistical mechanics revisited: The idea of vortex energy  

E-Print Network (OSTI)

We show that the law of energy conservation with the fact of matter stability imply the existence of energy complementary to that given by the function of states of interacting systems and treated, with the environment, the function of states of interacting extended systems. The complementary energy, we called it vortex, is integral, not quantized, and causes trends contrary to that prescribed by equilibrium statistical mechanics. We formulate its principles and theorems, and question traditional insights in thermodynamics, entropy law, phase transitions, persistent currents, Brownian motion.

V. E. Shapiro

2013-05-21T23:59:59.000Z

364

Interconversion of dark soliton and Josephson vortex in a quasi-1D long Bose Josephson junction  

E-Print Network (OSTI)

Dark soliton (DS) and Josephson vortex (JV) in quasi-1D long Bose Josephson junction (BJJ) can be interconverted by tuning Josephson coupling. Rates of the interconversion as well as of the thermally activated phase-slip effect, resulting in the JV switching its vorticity, have been evaluated. The role of quantum phase-slip in creating superposition of JVs with opposite vorticities as a qubit is discussed as well. Utilization of the JV for controlled and coherent transfer of atomic Bose-Einstein condensate (BEC) is suggested.

V. M. Kaurov; A. B. Kuklov

2003-12-03T23:59:59.000Z

365

System and method of active vibration control for an electro-mechanically cooled device  

SciTech Connect

A system and method of active vibration control of an electro-mechanically cooled device is disclosed. A cryogenic cooling system is located within an environment. The cooling system is characterized by a vibration transfer function, which requires vibration transfer function coefficients. A vibration controller generates the vibration transfer function coefficients in response to various triggering events. The environments may differ by mounting apparatus, by proximity to vibration generating devices, or by temperature. The triggering event may be powering on the cooling system, reaching an operating temperature, or a reset action. A counterbalance responds to a drive signal generated by the vibration controller, based on the vibration signal and the vibration transfer function, which adjusts vibrations. The method first places a cryogenic cooling system within a first environment and then generates a first set of vibration transfer function coefficients, for a vibration transfer function of the cooling system. Next, the cryogenic cooling system is placed within a second environment and a second set of vibration transfer function coefficients are generated. Then, a counterbalance is driven, based on the vibration transfer function, to reduce vibrations received by a vibration sensitive element.

Lavietes, Anthony D. (Hayward, CA); Mauger, Joseph (Livermore, CA); Anderson, Eric H. (Mountain View, CA)

2000-01-01T23:59:59.000Z

366

Magnetic induction systems to harvest energy from mechanical vibrations  

E-Print Network (OSTI)

This thesis documents the design process for magnetic induction systems to harvest energy from mechanical vibrations. Two styles of magnetic induction systems - magnet-through-coil and magnet-across-coils - were analyzed. ...

Jonnalagadda, Aparna S

2007-01-01T23:59:59.000Z

367

Local discriminant bases in machine fault diagnosis using vibration signals  

Science Conference Proceedings (OSTI)

Wavelets and local discriminant bases (LDB) selection algorithm is applied to vibration signals in a single-cylinder spark ignition engine for feature extraction and fault classification. LDB selects a complete orthogonal basis from a wavelet packet ...

R. Tafreshi; F. Sassani; H. Ahmadi; G. Dumont

2005-04-01T23:59:59.000Z

368

Element and system design for active and passive vibration isolation  

E-Print Network (OSTI)

This thesis focusses on broadband vibration isolation, with an emphasis on control of absolute payload motion for ultra-precision instruments such as the MIT/Caltech Laser-Interferometric Gravitational Wave Observatory ...

Zuo, Lei, 1974-

2005-01-01T23:59:59.000Z

369

Modeling and design of a MEMS piezoelectric vibration energy harvester  

E-Print Network (OSTI)

The modeling and design of MEMS-scale piezoelectric-based vibration energy harvesters (MPVEH) are presented. The work is motivated by the need for pervasive and limitless power for wireless sensor nodes that have application ...

Du Toit, Noël Eduard

2005-01-01T23:59:59.000Z

370

A Quantum of Vibration in an Unexpected Place | Advanced Photon...  

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

2004 | 2003 | 2002 2001 | 2000 | 1998 | Subscribe to APS Science Highlights rss feed A Quantum of Vibration in an Unexpected Place OCTOBER 21, 2008 Bookmark and Share Upper panel:...

371

Infrared Probe for Application to Steam Turbine Blade Vibration Detection  

Science Conference Proceedings (OSTI)

Technology for non-contacting steam turbine blade tip vibration measurement has advanced to the point of being a viable tool for risk management in situations where turbine blade high-cycle vibration occurs as a result of operating parameters or blade condition. This report describes the development and prototype testing of a new type of blade tip time-of-arrival sensing system for use with commercial signal processing systems.

2004-12-16T23:59:59.000Z

372

Vibration Model Validation for Linear Collider Detector Platforms  

SciTech Connect

The ILC and CLIC reference designs incorporate reinforced-concrete platforms underneath the detectors so that the two detectors can each be moved onto and off of the beamline in a Push-Pull configuration. These platforms could potentially amplify ground vibrations, which would reduce luminosity. In this paper we compare vibration models to experimental data on reinforced concrete structures, estimate the impact on luminosity, and summarize implications for the design of a reinforced concrete platform for the ILC or CLIC detectors.

Bertsche, Kirk; Amann, J.W.; Markiewicz, T.W.; Oriunno, M.; Weidemann, A.; White, G.; /SLAC

2012-05-16T23:59:59.000Z

373

On the dynamics of flame edges in diffusion-flame/vortex interactions  

Science Conference Proceedings (OSTI)

We analyze the local flame extinction and reignition of a counterflow diffusion flame perturbed by a laminar vortex ring. Local flame extinction leads to the appearance of flame edges separating the burning and extinguished regions of the distorted mixing layer. The dynamics of these edges is modeled based on previous numerical results, with heat release effects fully taken into account, which provide the propagation velocity of triple and edge flames in terms of the upstream unperturbed value of the scalar dissipation. The temporal evolution of the mixing layer is determined using the classical mixture fraction approach, with both unsteady and curvature effects taken into account. Although variable density effects play an important role in exothermic reacting mixing layers, in this paper the description of the mixing layer is carried out using the constant density approximation, leading to a simplified analytical description of the flow field. The mathematical model reveals the relevant nondimensional parameters governing diffusion-flame/vortex interactions and provides the parameter range for the more relevant regime of local flame extinction followed by reignition via flame edges. Despite the simplicity of the model, the results show very good agreement with previously published experimental results. (author)

Hermanns, Miguel; Linan, Amable [Departamento de Motopropulsion y Termofluidodinamica, Universidad Politecnica de Madrid, Pza. Cardenal Cisneros 3, 28040 Madrid (Spain); Vera, Marcos [Area de Mecanica de Fluidos, Universidad Carlos III de Madrid, 28911 Leganes (Spain)

2007-04-15T23:59:59.000Z

374

Combustion of pulverized coal in vortex structures. Final report, October 1, 1993--December 31, 1995  

Science Conference Proceedings (OSTI)

The objectives of the project were: (i) to understand the effects of heating one of the streams on the characteristics of shear layers, (ii) to investigate the changes in the characteristics of large scale vortex structures in the shear layer caused by the introduction of inert solid particles in one of the feed streams; (iii) to understand the effects of pyrolyzing solids on the shear layer behavior; and (iv) to study the effects of combustion of particles and their pyrolysis products on the shear layer structure, heat release rate, and pollutant emission characteristics. An experimental facility for generating two-dimensional shear layers containing vortex structures has been designed and fabricated. The experimental facility is essentially a low speed wind tunnel designed to (i) provide two gas streams, initially with uniform velocity profiles and isotropic turbulence, mixing at the end of a splitter plate, (ii) introduce vorticity by passively perturbing one of the streams, (iii) allow heating of one of the streams to temperatures high enough to cause pyrolysis of coal particles, and (iv) provide a natural gas flame in one of the streams to result in ignition and burning of coal particles.

Gollahalli, S.R.; Butuk, N.

1996-03-01T23:59:59.000Z

375

Tracking Waves and Vortex Nucleation in Excitable Systems with Anomalous Dispersion N. Manz, C.T. Hamik, and O. Steinbock  

E-Print Network (OSTI)

Tracking Waves and Vortex Nucleation in Excitable Systems with Anomalous Dispersion N. Manz, C of the underlying anomalous dispersion relation. DOI: 10.1103/PhysRevLett.92.248301 PACS numbers: 82.40.Ck, 05.45.­a and physicochemical systems [1,2]. Important examples include neuronal and cardiac tissue as well as gas discharge

Steinbock, Oliver

376

Optimizing the WSR-88D Mesocyclone/Tornadic Vortex Signature Algorithm Using WATADS—A Case Study  

Science Conference Proceedings (OSTI)

A tornado outbreak occurred in east-central Minnesota around 0000 UTC 22 July 1995, within 80 km of the KMPX WSR-88D, at the Minneapolis–Chanhassen Weather Service Forecast Office (WSFO). The WSR-88D Mesocyclone/Tornadic Vortex Signature ...

Gregory A. Tipton; Eric D. Howieson; John A. Margraf; Robert R. Lee

1998-06-01T23:59:59.000Z

377

ECMWF Analyses and Forecasts of Stratospheric Winter Polar Vortex Breakup: September 2002 in the Southern Hemisphere and Related Events  

Science Conference Proceedings (OSTI)

Breakup of the polar stratospheric vortex in the Northern Hemisphere is an event that is known to be predictable for up to a week or so ahead. This is illustrated using data from the 45-yr ECMWF Re-Analysis (ERA-40) for the sudden warmings of ...

Adrian Simmons; Mariano Hortal; Graeme Kelly; Anthony McNally; Agathe Untch; Sakari Uppala

2005-03-01T23:59:59.000Z

378

Soliton trains and vortex streets as a form of Cerenkov radiation in trapped Bose-Einstein condensates  

Science Conference Proceedings (OSTI)

We numerically study the nucleation of gray solitons and vortex-antivortex pairs created by a moving impurity in, respectively, 1D and 2D Bose-Einstein condensates (BECs) confined by a parabolic potential. The simulations emulate the motion of a localized ... Keywords: Bose-Einstein condensation, Matter waves, Nucleation, Solitons, Vortices

R. Carretero-González; P. G. Kevrekidis; D. J. Frantzeskakis; B. A. Malomed; S. Nandi; A. R. Bishop

2007-03-01T23:59:59.000Z

379

Vortex Rossby Waves in a Numerically Simulated Tropical Cyclone. Part II: The Role in Tropical Cyclone Structure and Intensity Changes  

Science Conference Proceedings (OSTI)

In Part I, the author analyzed the asymmetric structure in the inner core of a numerically simulated tropical cyclone and found that the asymmetry near the eyewall in the mid–lower troposphere is dominated by wavenumber-1 and -2 vortex Rossby ...

Yuqing Wang

2002-04-01T23:59:59.000Z

380

Hydrogen local vibrational modes in semiconductors  

DOE Green Energy (OSTI)

Following, a review of experimental techniques, theory, and previous work, the results of local vibrational mode (LVM) spectroscopy on hydrogen-related complexes in several different semiconductors are discussed. Hydrogen is introduced either by annealing in a hydrogen ambient. exposure to a hydrogen plasma, or during growth. The hydrogen passivates donors and acceptors in semiconductors, forming neutral complexes. When deuterium is substituted for hydrogen. the frequency of the LVM decreases by approximately the square root of two. By varying the temperature and pressure of the samples, the microscopic structures of hydrogen-related complexes are determined. For group II acceptor-hydrogen complexes in GaAs, InP, and GaP, hydrogen binds to the host anion in a bond-centered orientation, along the [111] direction, adjacent to the acceptor. The temperature dependent shift of the LVMs are proportional to the lattice thermal energy U(T), a consequence of anharmonic coupling between the LVM and acoustical phonons. In the wide band gap semiconductor ZnSe, epilayers grown by metalorganic chemical vapor phase epitaxy (MOCVD) and doped with As form As-H complexes. The hydrogen assumes a bond-centered orientation, adjacent to a host Zn. In AlSb, the DX centers Se and Te are passivated by hydrogen. The second, third, and fourth harmonics of the wag modes are observed. Although the Se-D complex has only one stretch mode, the Se-H stretch mode splits into three peaks. The anomalous splitting is explained by a new interaction between the stretch LVM and multi-phonon modes of the lattice. As the temperature or pressure is varied, and anti-crossing is observed between LVM and phonon modes.

McCluskey, M.D. [Univ. of California, Berkeley, CA (United States). Dept. of Physics]|[Lawrence Berkeley National Lab., CA (United States)

1997-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Settling of loose-fill insulations due to vibration  

SciTech Connect

Vibration and impact testing of loose-fill cellulosic, fiberglass, and rock wool insulations has been carried out to provide a data base for settled density tests. The ratio of final density to initial density for the three materials has been determined for repeated 19-mm (0.75-in.) drops, repeated 152-mm (6.0-in.) drops, and vibrations at frequencies from 10 to 60 Hz with displacements from 0.1 mm (0.004 in.) to 6.35 mm (0.25 in.). Repeated 19-mm or 152-mm drops increased the density ratio for rock wool insulation specimens the most, while the cellulosic insulation specimens were affected the least. Density ratios after 200 19-mm drops averaged 1.75 for loose-fill rock wool, 1.45 for loose-fill fiberglass, and 1.27 for loose-fill cellulosic insulations. Vibration tests for 7200 s at 0.1-mm displacement and 15 Hertz produced negligible changes in the densities of all three loose-fill insulations. An 1800-s vibration test at 2.5 mm (0.1 in.) and 10 Hz resulted in average density ratios of 1.05, 1.11, and 1.18 for specimens of loose-fill cellulosic, rock wool, and fiberglass insulations, respectively. Changes in either frequency of vibration, displacement, or test duration can be used to achieve a wide range of laboratory results. Efforts to correlate laboratory results with in situ density measurements are presented.

Yarbrough, D.W.; McElroy, D.L.; Wright, J.W.

1981-12-01T23:59:59.000Z

382

Settling of loose-fill insulations due to vibration  

SciTech Connect

Vibration and impact testing of loose-fill cellulosic, fiberglass, and rock wool insulations has been carried out to provide a data base for settled density tests. The ratio of final density to initial density for the three materials has been determined for repeated 19-mm (0.75-in.) drops, repeated 152-mm (6.0-in.) drops, and vibrations at frequencies from 10 to 60 Hz with displacements from 0.1 mm (0.004 in.) to 6.35 mm (0.25 in.). Repeated 19-mm or 152-mm drops increased the density ratio for rock wool insulation specimens the most, while the cellulosic insulation specimens were affected the least. Density ratios after 200 19-mm drops averaged 1.75 for loose-fill rock wool, 1.45 for loose-fill fiberglass, and 1.27 for loose-fill cellulosic insulations. Vibration tests for 7200 s at 0.1-mm displacement and 15 Hertz produced negligible changes in the densities of all three loose-fill insulations. An 1800-s vibration test at 2.5 mm (0.1 in.) and 10 Hz resulted in average density ratios of 1.05, 1.11, and 1.18 for specimens of loose-fill cellulosic, rock wool, and fiberglass insulations, respectively. Changes in either frequency of vibration, displacement, or test duration can be used to achieve a wide range of laboratory results. Efforts to correlate laboratory results with in situ density measurements are presented.

Yarbrough, D.W.; Wright, J.H.; McElroy, D.L.; Scanlan, T.F.

1983-01-01T23:59:59.000Z

383

Vibrations of Jammed Disk Packings with Hertzian Interactions  

E-Print Network (OSTI)

Contact breaking and Hertzian interactions between grains can both give rise to nonlinear vibrational response of static granular packings. We perform molecular dynamics simulations at constant energy in 2D of frictionless bidisperse disks that interact via Hertzian spring potentials as a function of energy and measure directly the vibrational response from the Fourier transform of the velocity autocorrelation function. We compare the measured vibrational response of static packings near jamming onset to that obtained from the eigenvalues of the dynamical matrix to determine the temperature above which the linear response breaks down. We compare packings that interact via single-sided (purely repulsive) and double-sided Hertzian spring interactions to disentangle the effects of the shape of the potential from contact breaking. Our studies show that while Hertzian interactions lead to weak nonlinearities in the vibrational behavior (e.g. the generation of harmonics of the eigenfrequencies of the dynamical matrix), the vibrational response of static packings with Hertzian contact interactions is dominated by contact breaking as found for systems with repulsive linear spring interactions.

Carl F. Schreck; Corey S. O'Hern; Mark D. Shattuck

2013-09-03T23:59:59.000Z

384

Method for the detection of a magnetic field utilizing a magnetic vortex  

SciTech Connect

The determination of the strength of an in-plane magnetic field utilizing one or more magnetically-soft, ferromagnetic member, having a shape, size and material whereas a single magnetic vortex is formed at remanence in each ferromagnetic member. The preferred shape is a thin circle, or dot. Multiple ferromagnetic members can also be stacked on-top of each other and separated by a non-magnetic spacer. The resulting sensor is hysteresis free. The sensor's sensitivity, and magnetic saturation characteristics may be easily tuned by simply altering the material, size, shape, or a combination thereof to match the desired sensitivity and saturation characteristics. The sensor is self-resetting at remanence and therefore does not require any pinning techniques.

Novosad, Valentyn (Chicago, IL); Buchanan, Kristen (Batavia, IL)

2010-04-13T23:59:59.000Z

385

Characterization of waste tire incineration in a prototype vortexing fluidized bed combustor  

Science Conference Proceedings (OSTI)

To investigate the characteristics of incinerating waste tires in a prototype vortexing fluidized bed combustor, performance tests were conducted with two sizes of waste tire fragments. The results from the combustion experiments showed that increasing the tire particle size caused less of the volatiles to be burned in the freeboard and thus lowered freeboard temperature. Uniform bed temperature could also be achieved by increasing the size of the tire particles. Variations in the secondary and tertiary air rates simultaneously affected the swirling intensity and the axial gas velocity in the freeboard, and thus resulted in the variations in ash elutriation, combustion efficiency, and pollutant emissions for the combustion systems. 21 refs., 17 figs., 1 tab.

Teng, H.; Chyang, C.S.; Shang, S.H.; Ho, J.A. [Chung Yuan Christian Univ., Chung-Li (Taiwan, Province of China)

1997-01-01T23:59:59.000Z

386

Simulations of 2D magnetic electron drift vortex mode turbulence in plasmas  

E-Print Network (OSTI)

Simulations are performed to investigate turbulent properties of nonlinearly interacting two-dimensional (2D) magnetic electron drift vortex (MEDV) modes in a nonuniform unmagnetized plasma. The relevant nonlinear equations governing the dynamics of the MEDV modes are the wave magnetic field and electron temperature perturbations in the presence of the equilibrium density and temperature gradients. The important nonlinearities come from the advection of the electron fluid velocity perturbation and the electron temperature, as well as from the nonlinear electron Lorentz force. Computer simulations of the governing equations for the nonlinear MEDV modes reveal the generation of streamer-like electron flows, such that the corresponding gradients in the direction of the inhomogeneities tend to flatten out. By contrast, the gradients in an orthogonal direction vary rapidly. Consequently, the inertial range energy spectrum in decaying MEDV mode turbulence exhibits a much steeper anisotropic spectral index. The magn...

Shaikh, Dastgeer

2008-01-01T23:59:59.000Z

387

Effects of surface roughness and vortex generators on the LS(1)-0417MOD airfoil  

DOE Green Energy (OSTI)

An 18-inch constant-chord model of the LS(l)-0417MOD airfoil section was tested under two dimensional steady state conditions ate University 7{times}10 Subsonic Wind Tunnel. The objective was to document section lift and moment characteristics model and air flow conditions. Surface pressure data was acquired at {minus}60{degrees} through + 230{degrees} geometric angles of attack, at a nominal 1 million Reynolds number. Cases with and without leading edge grit roughness were investigated. The leading edge mulated blade conditions in the field. Additionally, surface pressure data were acquired for Reynolds numbers of 1.5 and 2.0 million, with and without leading edge grit roughness; the angle of attack was limited to a {minus}20{degrees} to 40{degrees} range. In general, results showed lift curve slope sensitivities to Reynolds number and roughness. The maximum lift coefficient was reduced as much as 29% by leading edge roughness. Moment coefficient showed little sensitivity to roughness beyond 50{degrees} angle of attack, but the expected decambering effect of a thicker boundary layer with roughness did show at lower angles. Tests were also conducted with vortex generators located at the 30% chord location on the upper surface only, at 1 and 1.5 million Reynolds numbers, with and without leading edge grit roughness. In general, with leading edge grit roughness applied, the vortex generators restored 85 percent of the baseline level of maximum lift coefficient but with a more sudden stall break and at a higher angle of attack than the baseline.

Reuss, R.L.; Hoffman, M.J.; Gregorek, G.M. [Ohio State Univ., Columbus, OH (United States)

1995-12-01T23:59:59.000Z

388

Energy harvesting of random wide-band vibrations with applications to an electro-magnetic rotational energy harvester  

E-Print Network (OSTI)

In general, vibration energy harvesting is the scavenging of ambient vibration by transduction of mechanical kinetic energy into electrical energy. Many mechanical or electro-mechanical systems produce mechanical vibrations. ...

Trimble, A. Zachary

2011-01-01T23:59:59.000Z

389

Lattice vibrations of pure and doped GaSe  

Science Conference Proceedings (OSTI)

The Bridgman method is used to grow especially undoped and doped single crystals of GaSe. Composition and impurity content of the grown crystals were determined using X-ray fluorescence (XRF) method. X-ray diffraction, Raman scattering, photoluminescence (PL), and IR transmission measurements were performed at room temperature. The long wavelength lattice vibrations of four modifications of GaSe were described in the framework of modified one-layer linear-chain model which also takes into consideration the interaction of the selenium (Se) atom with the second nearest neighbor gallium (Ga) atom in the same layer. The existence of an eight-layer modification of GaSe is suggested and the vibrational frequencies of this modification are explained in the framework of a lattice dynamical model considered in the present work. Frequencies and the type of vibrations (gap, local, or resonance) for the impurity atoms were calculated and compared with the experimental results.

Allakhverdiev, K. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey) and Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan)]. E-mail: kerim.allahverdi@mam.gov.tr; Baykara, T. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey); Ellialtioglu, S. [Department of Physics, Middle East Technical University, Ankara 06531 (Turkey); Hashimzade, F. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan); Huseinova, D. [Institute of Physics, Azerbaijan National Academy of Sciences, Baku AZ1143 (Azerbaijan); Kawamura, K. [Institute of Materials Science, University of Tsukuba 305-8573 (Japan); Kaya, A.A. [Materials Institute, Marmara Research Center, TUBITAK, Gebze/Kocaeli 41470 (Turkey); Kulibekov, A.M. [Department of Physics, Mugla University, Mugla 48000 (Turkey); Onari, S. [Institute of Materials Science, University of Tsukuba 305-8573 (Japan)

2006-04-13T23:59:59.000Z

390

Non-linear optical crystal vibration sensing device  

SciTech Connect

A non-linear optical crystal vibration sensing device (10) including a photorefractive crystal (26) and a laser (12). The laser (12 ) produces a coherent light beam (14) which is split by a beam splitter (18) into a first laser beam (20) and a second laser beam (22). After passing through the crystal (26) the first laser beam (20) is counter-propagated back upon itself by a retro-mirror (32), creating a third laser beam (30). The laser beams (20, 22, 30) are modulated, due to the mixing effect within the crystal (26) by vibration of the crystal (30). In the third laser beam (30), modulation is stable and such modulation is converted by a photodetector (34) into a usable electrical output, intensity modulated in accordance with vibration applied to the crystal (26).

Kalibjian, Ralph (Livermore, CA)

1994-01-11T23:59:59.000Z

391

Non-linear optical crystal vibration sensing device  

DOE Patents (OSTI)

The report describes a non-linear optical crystal vibration sensing device including a photorefractive crystal and a laser. The laser produces a coherent light beam which is split by a beam splitter into a first laser beam and a second laser beam. After passing through the crystal the first laser beam is counter-propagated back upon itself by a retro-mirror, creating a third laser beam . The laser beams are modulated, due to the mixing effect within the crystal by vibration of the crystal. In the third laser beam modulation is stable and such modulation is converted by a photodetector into a usable electrical output, intensity modulated in accordance with vibration applied to the crystal.

Kalibjian, R.

1992-12-31T23:59:59.000Z

392

High-vibration detection using motor current signature analysis  

Science Conference Proceedings (OSTI)

Motor current signature analysis (CSA) has been used for several years as a diagnostic tool for electrical problems in ac, induction motors. Personnel at Oak Ridge National Laboratory have found that CSA can also provide information about system vibrations and imbalances similar to the information provided by an accelerometer. As a result, CSA techniques for monitoring the status of the equipment, such as pumps and compressors, driven by induction motors have been developed and used in dedicated monitoring systems. In this work, researchers have found that CSA responds proportionately to imbalances in rotating equipment and can be used to detect the In high-vibration conditions that can result. This report describes how vibration monitoring with CSA can be implemented and presents test data to support that use.

Castleberry, K.N.

1996-08-01T23:59:59.000Z

393

Vibration Combined High Temperature Cycle Tests for Capacitive MEMS Accelerometers  

E-Print Network (OSTI)

In this paper vibration combined high temperature cycle tests for packaged capacitive SOI-MEMS accelerometers are presented. The aim of these tests is to provide useful Design for Reliability information for MEMS designers. A high temperature test chamber and a chopper-stabilized read-out circuitry were designed and realized at BME - DED. Twenty thermal cycles of combined Temperature Cycle Test and Fatigue Vibration Test has been carried out on 5 samples. Statistical evaluation of the test results showed that degradation has started in 3 out of the 5 samples.

Szucs, Z; Hodossy, S; Rencz, M; Poppe, A

2008-01-01T23:59:59.000Z

394

Vibration Combined High Temperature Cycle Tests for Capacitive MEMS Accelerometers  

E-Print Network (OSTI)

In this paper vibration combined high temperature cycle tests for packaged capacitive SOI-MEMS accelerometers are presented. The aim of these tests is to provide useful Design for Reliability information for MEMS designers. A high temperature test chamber and a chopper-stabilized read-out circuitry were designed and realized at BME - DED. Twenty thermal cycles of combined Temperature Cycle Test and Fatigue Vibration Test has been carried out on 5 samples. Statistical evaluation of the test results showed that degradation has started in 3 out of the 5 samples.

Z. Szucs; G. Nagy; S. Hodossy; M. Rencz; A. Poppe

2008-01-07T23:59:59.000Z

395

System and method for damping vibration in a drill string  

DOE Patents (OSTI)

A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)

2011-08-16T23:59:59.000Z

396

System and method for damping vibration in a drill string  

DOE Patents (OSTI)

A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)

2008-05-27T23:59:59.000Z

397

System and method for damping vibration in a drill string  

DOE Patents (OSTI)

A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Wassell, Mark Ellsworth (Kingwood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)

2007-05-22T23:59:59.000Z

398

System and method for damping vibration in a drill string  

Science Conference Proceedings (OSTI)

A system for damping vibration in a drill string can include a valve assembly having a supply of a fluid, a first member, and a second member capable of moving in relation to first member in response to vibration of the drill bit. The first and second members define a first and a second chamber for holding the fluid. Fluid can flow between the first and second chambers in response to the movement of the second member in relation to the first member. The valve assembly can also include a coil or a valve for varying a resistance of the fluid to flow between the first and second chambers.

Wassell, Mark Ellsworth (Kingswood, TX); Turner, William Evans (Durham, CT); Burgess, Daniel E. (Middletown, CT); Perry, Carl Allison (Middletown, CT)

2012-08-14T23:59:59.000Z

399

Satellite Data Assimilation in Numerical Weather Prediction Models. Part II: Uses of Rain-Affected Radiances from Microwave Observations for Hurricane Vortex Analysis  

Science Conference Proceedings (OSTI)

A hybrid variational scheme (HVAR) is developed to produce the vortex analysis associated with tropical storms. This scheme allows for direct assimilation of rain-affected radiances from satellite microwave instruments. In the HVAR, the ...

Fuzhong Weng; Tong Zhu; Banghua Yan

2007-11-01T23:59:59.000Z

400

Non-intrusive vibration monitoring in US Naval and US Coast Guard ships  

E-Print Network (OSTI)

In 2011, the Laboratory for Electromagnetic and Electronic Systems proposed a new type of vibration monitoring system, entitled vibration assessment monitoring point with integrated recovery of energy or VAMPRIE, in their ...

Gerhard, Katherine Leigh

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "vortex induced vibrations" 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

Parameter Identification of Vibration Loads of Hydro Generator Using Neural Networks  

Science Conference Proceedings (OSTI)

Abstract Abstract Abstract Vibrating dynamic characteristics have been a major unknown in the modeling and mechanical analysis of large hydro generators. An identification algorithm for vibrating dynamic characterization by using artificial neural network ...

Lijuan Cao; Shouju Li; Zichang Shangguan

2008-06-01T23:59:59.000Z

402

Analysis of Supercooled Liquid Water Measurements Using Microwave Radiometer and Vibrating Wire Devices  

Science Conference Proceedings (OSTI)

A review is made of the theoretical basis for using a vibrating wire to measure supercooled liquid water in clouds. The device consists of a vibrating wire and associated electronics added to radiosondes. The sensing wire that collects ...

Geoffrey E. Hill

1994-10-01T23:59:59.000Z

403

Vibration and crack detection in gas turbine engine compressor blades using Eddy current sensors  

E-Print Network (OSTI)

(cont.) in the ECS signal, no definitive method for sensing blade vibration using an ECS has yet been developed.

Lackner, Matthew, 1980-

2004-01-01T23:59:59.000Z

404

Free Vibration Analysis of Kirchoff Plates with Damaged Boundaries by the Chebyshev Collocation Method  

E-Print Network (OSTI)

Free Vibration Analysis of Kirchoff Plates with Damaged Boundaries by the Chebyshev Collocation for the free vibration analysis of slender Kirchoff plates with both mixed and damaged boundaries an important role in applications of mechanical, aerospace and civil engineering. Studying the free vibration

Butcher, Eric A.

405

Steam Turbine-Generator Torsional Vibration Interaction With the Electrical Network  

Science Conference Proceedings (OSTI)

This Tutorial Report deals with steam turbine-generator torsional vibration arising from interaction with the electrical systems that connect to the generator. Besides providing background material on torsional vibration and fatigue, it reviews operating experience and machine torsional duty mitigation strategies and provides information on torsional vibration measurement, monitoring, diagnostic procedures, and non-destructive evaluation (NDE).

2005-11-14T23:59:59.000Z

406

Laboratory Calibration of a Vibrating Wire Device for Measuring Concentrations of Supercooled Liquid Water  

Science Conference Proceedings (OSTI)

Laboratory measurements of supercooled liquid water are made by a vibrating-wire sensor whose frequency of vibration varies according to the mass of ice collected on it. The vibrating-wire system is designed to be placed in the humidity duct of ...

Geoffrey E. Hill

1989-12-01T23:59:59.000Z

407

Vibrationally resolved transitions in ion-molecule and atom-molecular ion slow collisions  

DOE Data Explorer (OSTI)

The data tables and interactive graphs made available here contain theoretical integral cross sections for vibrational excitation and vibrationally resolved charge transfer from vibrationally excited states of H2 and H2+ with protons and hydrogen atoms, respectively. [From http://www-cfadc.phy.ornl.gov/h2mol/home.html] (Specialized Interface)

408

Blasting Vibration Signals Based on Hilbert Transformation of the Application  

Science Conference Proceedings (OSTI)

This paper is based on empirical mode decomposition (EMD )of Hilbert-Huang transform (Hilbert-Huang Transformation, HHT) method shall be applied to the blasting vibration signal, first introduced the Hilbert-Huang transform theory and algorithms, then ... Keywords: Blast, Hilbert-Huang transform, seismic wave, frequency spectrogram

Xueping Ren; Dongsheng Hao

2012-04-01T23:59:59.000Z

409

Vibration-Assisted Electron Tunneling in C140 Transistors  

E-Print Network (OSTI)

We measure electron tunneling in transistors made from C140, a molecule with a mass?spring?mass geometry chosen as a model system to study electron-vibration coupling. We observe vibration-assisted tunneling at an energy corresponding to the stretching mode of C140. Molecular modeling provides explanations for why this mode couples more strongly to electron tunneling than to the other internal modes of the molecule. We make comparisons between the observed tunneling rates and those expected from the Franck?Condon model. When electrons travel through molecules, vibrational modes of the molecules can affect current flow. Molecular-vibrationassisted tunneling was first measured in the 1960s using devices whose tunnel barriers contained many molecules. 1 Recently, effects of vibrations in single molecules have been measured using scanning tunneling microscopes, 2 singlemolecule transistors, 3,4 and mechanical break junctions. 5 Theoretical considerations suggest that different regimes may exist depending on whether tunneling electrons occupy resonant energy levels on the molecule, and also on the * Corresponding author.

A. N. Pasupathy; J. Park; C. Chang; A. V. Soldatov; S. Lebedkin; R. C. Bialczak; J. E. Grose; L. A. K. Donev; J. P. Sethna; D. C. Ralph; P. L. Mceuen

2004-01-01T23:59:59.000Z

410

Vibration damping and heat transfer using material phase changes  

SciTech Connect

A method and apparatus wherein phase changes in a material can dampen vibrational energy, dampen noise and facilitate heat transfer. One embodiment includes a method for damping vibrational energy in a body. The method comprises attaching a material to the body, wherein the material comprises a substrate, a shape memory alloy layer, and a plurality of temperature change elements. The method further comprises sensing vibrations in the body. In addition, the method comprises indicating to at least a portion of the temperature change elements to provide a temperature change in the shape memory alloy layer, wherein the temperature change is sufficient to provide a phase change in at least a portion of the shape memory alloy layer, and further wherein the phase change consumes a sufficient amount of kinetic energy to dampen at least a portion of the vibrational energy in the body. In other embodiments, the shape memory alloy layer is a thin film. Additional embodiments include a sensor connected to the material.

Kloucek, Petr (Houston, TX); Reynolds, Daniel R. (Oakland, CA)

2009-03-24T23:59:59.000Z

411

Vibration-based terrain classification for electric powered wheelchairs  

Science Conference Proceedings (OSTI)

Automated terrain classification for electric powered wheelchairs (EPWs) has two primary motivations. First, certain terrains (e.g., sand and gravel) make wheelchair mobility more difficult. To alleviate this problem the wheelchair control system can ... Keywords: advanced wheelchair systems, electric powered wheelchairs, terrain classification, vibrations

Eric Coyle; Emmanuel G. Collins, Jr.; Edmond DuPont; Dan Ding; Hongwu Wang; Rory A. Cooper; Garrett Grindle

2008-04-01T23:59:59.000Z

412

Different Network Topologies for Distributed Electric Damping of Beam Vibrations  

E-Print Network (OSTI)

In this work passive electric damping of structural vibrations by distributed piezoelectric transducers and electric networks is analyzed. Different distributed electric controllers are examined as finite degrees of freedom systems and their performances are compared. Modal reduction is used to optimize the electric parameters

Porfiri, M; dell'Isola, F; Pouget, J

2010-01-01T23:59:59.000Z

413

Different Network Topologies for Distributed Electric Damping of Beam Vibrations  

E-Print Network (OSTI)

In this work passive electric damping of structural vibrations by distributed piezoelectric transducers and electric networks is analyzed. Different distributed electric controllers are examined as finite degrees of freedom systems and their performances are compared. Modal reduction is used to optimize the electric parameters

M. Porfiri; C. Maurini; F. dell'Isola; J. Pouget

2010-09-25T23:59:59.000Z

414

Grinding media oscillation: effect on torsional vibrations in tumble mills  

E-Print Network (OSTI)

Tumble mills are hollow cylindrical shells of large diameter carrying grinding media (a combination of rock/iron ore/chemical flakes and metal balls/rods), which, upon rotation of the mill, will be ground into fine powder. These mills rotate at low speeds using a gear reduction unit and often have vibration problems. These vibration problems result in increased gear wear and occasional catastrophic failures resulting in production loss. The objective of this research is to investigate the effect of oscillation of grinding media on torsional vibrations of the mill. A theoretical model was developed to determine the oscillating frequency of the grinding media. A 12" (0.3 m) diameter tumble mill test rig was built with a 0.5 hp DC motor. The rig is tested with sand and iron bb balls to simulate the industry process application. At low volume levels the grinding media oscillates like a rigid body as compared to higher volumes. It is shown that tumbling action of grinding media causes torsional excitation and hence its effect has to be considered in torsional vibration analysis. At starting, the load on the gears is much higher due to this oscillation.

Toram, Kiran Kumar

2005-08-01T23:59:59.000Z

415

Vibration-based MEMS Piezoelectric Energy Harvester for Power Optimization  

Science Conference Proceedings (OSTI)

The simplicity associated with piezoelectric micro-generators makes them very attractive for MEMS applications in which ambient vibrations are harvested and converted into electric energy. These micro-generators can become an alternative to the battery-based ... Keywords: Piezoelectric materials, Energy conversion, shaped cantilever, MEMS

Othman Sidek, Salem Saadon

2013-04-01T23:59:59.000Z

416

Vortex Diode Analysis and Testing for Fluoride Salt-Cooled High-Temperature Reactors  

SciTech Connect

Fluidic diodes are presently being considered for use in several fluoride salt-cooled high-temperature reactor designs. A fluidic diode is a passive device that acts as a leaky check valve. These devices are installed in emergency heat removal systems that are designed to passively remove reactor decay heat using natural circulation. The direct reactor auxiliary cooling system (DRACS) uses DRACS salt-to-salt heat exchangers (DHXs) that operate in a path parallel to the core flow. Because of this geometry, under normal operating conditions some flow bypasses the core and flows through the DHX. A flow diode, operating in reverse direction, is-used to minimize this flow when the primary coolant pumps are in operation, while allowing forward flow through the DHX under natural circulation conditions. The DRACSs reject the core decay heat to the environment under loss-of-flow accident conditions and as such are a reactor safety feature. Fluidic diodes have not previously been used in an operating reactor system, and therefore their characteristics must be quantified to ensure successful operation. This report parametrically examines multiple design parameters of a vortex-type fluidic diode to determine the size of diode needed to reject a particular amount of decay heat. Additional calculations were performed to size a scaled diode that could be tested in the Oak Ridge National Laboratory Liquid Salt Flow Loop. These parametric studies have shown that a 152.4 mm diode could be used as a test article in that facility. A design for this diode is developed, and changes to the loop that will be necessary to test the diode are discussed. Initial testing of a scaled flow diode has been carried out in a water loop. The 150 mm diode design discussed above was modified to improve performance, and the final design tested was a 171.45 mm diameter vortex diode. The results of this testing indicate that diodicities of about 20 can be obtained for diodes of this size. Experimental results show similar trends as the computational fluid dynamics (CFD) results presented in this report; however, some differences exist that will need to be assessed in future studies. The results of this testing will be used to improve the diode design to be tested in the liquid salt loop system.

Yoder Jr, Graydon L [ORNL; Elkassabgi, Yousri M. [Texas A& M University, Kingsville; De Leon, Gerardo I. [Texas A& M University, Kingsville; Fetterly, Caitlin N. [Texas A& M University, Kingsville; Ramos, Jorge A. [Texas A& M University, Kingsville; Cunningham, Richard Burns [University of Tennessee, Knoxville (UTK)

2012-02-01T23:59:59.000Z

417

Reduced gravity rankine cycle design and optimization with passive vortex phase separation  

E-Print Network (OSTI)

Liquid-metal Rankine power conversion systems (PCS) coupled with a fission reactor remain an attractive option for space power applications because system specific power and efficiency is very favorable for plant designs of 100 kW(e) or higher. Potential drawbacks to the technology in a reduced gravity environment include two-phase fluid management processes such as liquid-vapor phase separation. The most critical location for phase separation is at the boiler exit where only vapor must be sent to the turbine because blade erosion occurs from high velocity liquid droplets entrained by vapor flow. Previous studies have proposed that rotary separators be used to separate the liquid and vapor from a two phase mixture. However these devices have complex turbo machinery, require kilowatts of power and are untested for high vapor flow conditions. The Interphase Transport Phenomena (ITP) laboratory has developed a low-power, passive microgravity vortex phase separator (MVS) which has already proven to be an essential component of two-phase systems operating in low gravity environments. This thesis presents results from flight experiments where a Rankine cycle was operated in a reduced gravity environment for the first time by utilizing the MVS for liquid and vapor phase separation. The MVS was able to operate under saturated conditions and adjust to system transients as it would in the Rankine cycle by controlling the amount of liquid and vapor within the device. A new model is developed for the MVS to predict separation performance at high vapor flow conditions for sizing the separator at the boiler, condenser, and turbine locations within the cycle by using a volume limiting method. This model factors in the following separator characteristics: mass, pumping power, and available buffer volume for system transients. The study is concluded with overall Rankine efficiency and performance changes due to adding vortex phase separation and a schematic of the Rankine cycle with the integration of the MVS is presented. The results from this thesis indicate the thermal to electric efficiency and specific mass of the cycle can be improved by using the MVS to separate the two phases instead of a rotary separator.

Supak, Kevin Robert

2007-12-01T23:59:59.000Z

418

Reduced gravity Rankine cycle system design and optimization study with passive vortex phase separation  

E-Print Network (OSTI)

Liquid-metal Rankine power conversion systems (PCS) coupled with a fission reactor remain an attractive option for space power applications because system specific power and efficiency is very favorable for plant designs of 100 kW(e) or higher. Potential drawbacks to the technology in a reduced gravity environment include two-phase fluid management processes such as liquid-vapor phase separation. The most critical location for phase separation is at the boiler exit where only vapor must be sent to the turbine because blade erosion occurs from high velocity liquid droplets entrained by vapor flow. Previous studies have proposed that rotary separators be used to separate the liquid and vapor from a two phase mixture. However these devices have complex turbo machinery, require kilowatts of power and are untested for high vapor flow conditions. The Interphase Transport Phenomena (ITP) laboratory has developed a low-power, passive microgravity vortex phase separator (MVS) which has already proven to be an essential component of two-phase systems operating in low gravity environments. This thesis presents results from flight experiments where a Rankine cycle was operated in a reduced gravity environment for the first time by utilizing the MVS for liquid and vapor phase separation. The MVS was able to operate under saturated conditions and adjust to system transients as it would in the Rankine cycle by controlling the amount of liquid and vapor within the device. A new model is developed for the MVS to predict separation performance at high vapor flow conditions for sizing the separator at the boiler, condenser, and turbine locations within the cycle by using a volume limiting method. This model factors in the following separator characteristics: mass, pumping power, and available buffer volume for system transients. The study is concluded with overall Rankine efficiency and performance changes due to adding vortex phase separation and a schematic of the Rankine cycle with the integration of the MVS is presented. The results from this thesis indicate the thermal to electric efficiency and specific mass of the cycle can be improved by using the MVS to separate the two phases instead of a rotary separator.

Supak, Kevin Robert

2007-12-01T23:59:59.000Z

419

Engineering Nanocolumnar Defect Configurations for Optimized Vortex Pinning in High Temperature Superconducting Nanocomposite Wires  

SciTech Connect

High temperature superconducting (HTS), coated conductor wires based on nanocomposite films containing self-assembled, insulating BaZrO3 (BZO) nanocolumnar defects have previously been reported to exhibit enhanced vortex pinning. Here, we report on microstructural design via control of BZO nanocolumns density in YBa2Cu3O7- (YBCO)+BZO nancomposite films to achieve the highest critical current density, Jc(H, ,T). X-ray diffraction and microstructural examination shows increasing number density of epitaxial BZO nanocolumns in the highly cube-textured YBCO matrix with increasing nominal BZO additions. Transport property measurement reveals that an increase in BZO content upto 4 vol% is required to sustain the highest pinning and Jc performance as the magnetic field increases. By growing thicker, single-layer nanocomposite films (~4 m) with controlled density of BZO columnar defects, the critical current (Ic) of ~1000 A/cm at 77 K, self-field and the minimum Ic of 455 A/cm at 65 K and 3 T for all magnetic field orientations were obtained. This is the highest Ic reported to date for films on metallic templates which are the basis for the 2nd generation, coated conductor-based HTS wires.

Wee, Sung Hun [ORNL; Zuev, Yuri L [ORNL; Cantoni, Claudia [ORNL; Goyal, Amit [ORNL; Ahuja, Raj [Waukesha Electric Systems Inc.; Abiade, J. [North Carolina A& T State University

2013-01-01T23:59:59.000Z

420

Effects of surface roughness and vortex generators on the NACA 4415 airfoil  

DOE Green Energy (OSTI)

Wind turbines in the field can be subjected to many and varying wind conditions, including high winds with rotor locked or with yaw excursions. In some cases the rotor blades may be subjected to unusually large angles of attack that possibly result in unexpected loads and deflections. To better understand loadings at unusual angles of attack, a wind tunnel test was performed. An 18-inch constant chord model of the NACA 4415 airfoil section was tested under two dimensional steady state conditions in the Ohio State University Aeronautical and Astronautical Research Laboratory (OSU/AARL) 7 x 10 Subsonic Wind Tunnel (7 x 10). The objective of these tests was to document section lift and moment characteristics under various model and air flow conditions. These included a normal angle of attack range of {minus}20{degree} to +40{degree}, an extended angle of attack range of {minus}60{degree} to +230{degree}, applications of leading edge grit roughness (LEGR), and use of vortex generators (VGs), all at chord Reynolds numbers as high as possible for the particular model configuration. To realistically satisfy these conditions the 7 x 10 offered a tunnel-height-to-model-chord ratio of 6.7, suggesting low interference effects even at the relatively high lift and drag conditions expected during the test. Significantly, it also provided chord Reynolds numbers up to 2.0 million. 167 figs., 13 tabs.

Reuss, R.L.; Hoffman, M.J.; Gregorek, G.M. [Ohio State Univ., Columbus, OH (United States)

1995-12-01T23:59:59.000Z

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421

Winding numbers and scaling tilts from random vortex-antivortex pairs  

E-Print Network (OSTI)

I show that random distributions of vortex-antivortex pairs (rather than of individual vortices) lead to scaling of typical winding numbers W trapped inside a loop of circumference C with the square root of C when the expected winding numbers are large. Such scaling is consistent with the Kibble-Zurek mechanism (KZM). By contrast, distribution of individual vortices with randomly assigned topological charges would result in the dispersion of W scaling with the square root of the area inside C. Scaling of the dispersion of W and of the probability of detection of non-zero W with C can be also studied for loops so small that non-zero windings are rare. In this case I show a doubling of the scaling of dispersion with C when compared to the scaling of dispersion in the large W regime. Moreover, probability of trapping of a non-zero W becomes, in this case, proportional to the area subtended by C (hence, to the square of circumference). This quadruples, as compared with large winding numbers regime, the exponent in the power law dependence of the frequency of trapping of W=+1 or W=-1 on C. Such change of the power law exponent by a FACTOR OF FOUR implies quadrupling of the scaling of the frequency of winding number trapping with the quench rate, and is of key importance for experimental tests of KZM.

Wojciech H. Zurek

2013-05-21T23:59:59.000Z

422

Vibrational Stability of SRF Accelerator Test Facility at Fermilab  

Science Conference Proceedings (OSTI)

Recently developed, the Superconducting Radio Frequency (SRF) Accelerator Test Facilities at Fermilab support the International Linear Collider (ILC), High Intensity Neutrino Source (HINS), a new high intensity injector (Project X) and other future machines. These facilities; Meson Detector Building (MDB) and New Muon Lab (NML) have very different foundations, structures, relative elevations with respect to grade level and surrounding soil composition. Also, there are differences in the operating equipment and their proximity to the primary machine. All the future machines have stringent operational stability requirements. The present study examines both near-field and ambient vibration in order to develop an understanding of the potential contribution of near-field sources (e.g. compressors, ultra-high and standard vacuum equipment, klystrons, modulators, utility fans and pumps) and distant noise sources to the overall system displacements. Facility vibration measurement results and methods of possible isolation from noise sources are presented and discussed.

McGee, M.W.; Volk, J.T.; /Fermilab

2009-05-01T23:59:59.000Z

423

Status of vibrational structure in {sup 62}Ni  

Science Conference Proceedings (OSTI)

Measurements consisting of {gamma}-ray excitation functions and angular distributions were performed using the (n,n{sup '{gamma}}) reaction on {sup 62}Ni. The excitation function data allowed us to check the consistency of the placement of transitions in the level scheme. From {gamma}-ray angular distributions, the lifetimes of levels up to {approx}3.8 MeV in excitation energy were extracted with the Doppler-shift attenuation method. The experimentally deduced values of reduced transition probabilities were compared with the predictions of the quadrupole vibrator model and with large-scale shell model calculations in the fp shell configuration space. Two-phonon states were found to exist with some notable deviation from the predictions of the quadrupole vibrator model, but no evidence for the existence of three-phonon states could be established. Z=28 proton core excitations played a major role in understanding the observed structure.

Chakraborty, A.; Orce, J. N.; Ashley, S. F.; Crider, B. P.; Elhami, E.; McEllistrem, M. T.; Mukhopadhyay, S. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Brown, B. A. [National Superconducting Cyclotron Laboratory, Michigan State University, East Lansing, Michigan 48824 (United States); Department of Physics and Astronomy, Michigan State University, East Lansing, Michigan 48824 (United States); Peters, E. E. [Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Singh, B. [Department of Physics and Astronomy, McMaster University, Hamilton, Ontario, L8S 4M1 (Canada); Yates, S. W. [Department of Physics and Astronomy, University of Kentucky, Lexington, Kentucky 40506-0055 (United States); Department of Chemistry, University of Kentucky, Lexington, Kentucky 40506-0055 (United States)

2011-03-15T23:59:59.000Z

424

Vibrational relaxation of matrix-isolated CH/sub 3/F and HCl  

SciTech Connect

Kinetic and spectroscopic studies have been performed on CH/sub 3/F and HCl as a function of host matrix and temperature. Temporally and spectrally resolved infrared fluorescence was used to monitor the populations of both the initially excited state and the lower lying levels which participate in the relaxation process. For CH/sub 3/F, relaxation from any of the levels near 3.5 ..mu.., i.e. the CH stretching fundamentals or bend overtones, occurs via rapid (< 5 ns) V ..-->.. V transfer to 2..nu../sub 3/ with subsequent relaxation of the ..nu../sub 3/ (CF stretch) manifold. Lifetimes of 2..nu../sub 3/ and ..nu../sub 3/ were determined through overtone, ..delta..V = 2, and fundamental fluorescence. These lifetimes show a dramatic dependence on host lattice, an increase of two orders of magnitude in going from Xe and Ar matrices. Lifetimes depend only weakly on temperature. The relaxation of 2..nu../sub 3/ and ..nu../sub 3/ is consistent with a model in which production of a highly rotationally excited guest via collisions with the repulsive wall of the host is the rate limiting step. For HCl, lifetimes of v = 1,2,3 have been determined. In all hosts, the relaxation is non-radiative. For a given vibrational state, v, the relaxation rate increases in the series k(Ar) < k(Kr) < k(Xe). The dependence of the relaxation rate; on v is superlinear in all matrices, the deviation from linearity increasng in the order Ar < Kr < Xe. The relaxation rates become more strongly temperature dependent with increasing vibrational excitation. The results are consistent with a mechanism in which complex formation introduces the anisotropy necessary to induce a near resonant V ..-->.. R transition in the rate limiting step.

Young, L.

1981-08-01T23:59:59.000Z

425

Vibration Fatigue of Small Bore Socket-Welded Pipe Joints  

Science Conference Proceedings (OSTI)

In the course of developing the screening process for the EPRI Fatigue Management Handbook, TR-104534, several areas were identified in which the industry's understanding of socket welds was somewhat lacking and current ASME Code procedures were inadequate to accurately characterize their high-cycle fatigue resistance. The research described in this report is directed at improving the understanding of socket welds and the factors and parameters that affect a socket weld's ability to resist vibration-indu...

1997-06-27T23:59:59.000Z

426

Emergence of Molecular Chirality by Vibrational Raman Scattering  

E-Print Network (OSTI)

In this study, we apply the monitoring master equation describing decoherence of internal states to an optically active molecule prepared in a coherent superposition of nondegenerate internal states interacting with thermal photons at low temperatures. We use vibrational Raman scattering theory up to the first chiral-sensitive contribution, i.e., the mixed electric-magnetic interaction, to obtain scattering amplitudes in terms of molecular polarizability tensors. The resulting density matrix is used to obtain elastic decoherence rates.

Farhad Taher Ghahramani; Afshin Shafiee

2013-11-15T23:59:59.000Z

427

An Automated Home Made Low Cost Vibrating Sample Magnetometer  

E-Print Network (OSTI)

The design and operation of a homemade low cost vibrating sample magnetometer is described here. The sensitivity of this instrument is better than 10-2 emu and found to be very efficient for the measurement of magnetization of most of the ferromagnetic and other magnetic materials as a function of temperature down to 77 K and magnetic field upto 800 Oe. Both M(H) and M(T) data acquisition are fully automated employing computer and Labview software

Kundu, S

2011-01-01T23:59:59.000Z

428

Identification of dynamic properties from ambient vibration measurements  

SciTech Connect

To better understand the dynamic behavior of structures under normal dynamic loads as well as extreme loads such as those caused by seismic events or high winds, it is desirable to measure the dynamic properties (resonant frequencies, mode shapes and modal damping) of these structures. The cross-correlation function between two response measurements made on an ambiently excited structure is shown to have the same form as the system`s impulse response function. Therefore, standard time-domain curve-fitting procedures such as the complex exponential method, which are typically applied to impulse response functions, can now be applied to the cross-correlation functions to estimate the resonant frequencies and modal damping of the structure. A direct comparison of resonant frequencies identified by curve-fitting the cross-correlation functions, using traffic excitation as the ambient vibration source, and modal properties identified by standard forced vibration testing of a highway bridge, after traffic was removed, showed a maximum discrepancy of 3.63%. Similar comparisons for the average modal damping values identified by the two methods showed a 9.82% difference. This experimental verification implies that the proposed method of analyzing ambient vibration data has the potential to accurately assess the dynamic properties of large structures subjected to seismic excitations and small structures that are tested on a shake table.

Farrar, C.R. [Los Alamos National Lab., NM (United States); James, G.H. III [Sandia National Labs., Albuquerque, NM (United States)

1995-09-01T23:59:59.000Z

429

Heat Transfer Enhancement for Finned-Tube Heat Exchangers with Vortex Generators: Experimental and Numerical Results  

Science Conference Proceedings (OSTI)

A combined experimental and numerical investigation is under way to investigate heat transfer enhancement techniques that may be applicable to large-scale air-cooled condensers such as those used in geothermal power applications. The research is focused on whether air-side heat transfer can be improved through the use of finsurface vortex generators (winglets,) while maintaining low heat exchanger pressure drop. A transient heat transfer visualization and measurement technique has been employed in order to obtain detailed distributions of local heat transfer coefficients on model fin surfaces. Pressure drop measurements have also been acquired in a separate multiple-tube row apparatus. In addition, numerical modeling techniques have been developed to allow prediction of local and average heat transfer for these low-Reynolds-number flows with and without winglets. Representative experimental and numerical results presented in this paper reveal quantitative details of local fin-surface heat transfer in the vicinity of a circular tube with a single delta winglet pair downstream of the cylinder. The winglets were triangular (delta) with a 1:2 height/length aspect ratio and a height equal to 90% of the channel height. Overall mean fin-surface Nusselt-number results indicate a significant level of heat transfer enhancement (average enhancement ratio 35%) associated with the deployment of the winglets with oval tubes. Pressure drop measurements have also been obtained for a variety of tube and winglet configurations using a single-channel flow apparatus that includes four tube rows in a staggered array. Comparisons of heat transfer and pressure drop results for the elliptical tube versus a circular tube with and without winglets are provided. Heat transfer and pressure-drop results have been obtained for flow Reynolds numbers based on channel height and mean flow velocity ranging from 700 to 6500.

O'Brien, James Edward; Sohal, Manohar Singh; Huff, George Albert

2002-08-01T23:59:59.000Z

430

Investigation of vortex generators for augmentation of wind turbine power performance  

SciTech Connect

This study focuses on the use of vortex generators (VGs) for performance augmentation of the stall-regulated AWT-26 wind turbine. The goal was to design a VG array which would increase annual energy production (AEP) by increasing power output at moderate wind speeds, without adversely affecting the loads or stall-regulation performance of the turbine. Wind tunnel experiments were conducted at the University of Washington to evaluate the effect of VGs on the AWT-26 blade, which is lofted from National Renewable Energy Laboratory (NREL) S-series airfoils. Based on wind-tunnel results and analysis, a VG array was designed and then tested on the AWT-26 prototype, designated P1. Performance and loads data were measured for P1, both with and without VGs installed. the turbine performance with VGs met most of the design requirements; power output was increased at moderate wind speeds with a negligible effect on peak power. However, VG drag penalties caused a loss in power output for low wind speeds, such that performance with VGs resulted in a net decrease in AEP for sites having annual average wind speeds up to 8.5 m/s. While the present work did not lead to improved AEP for the AWT-2 turbine, it does provide insight into performance augmentation of wind turbines with VGs. The safe design of a VG array for a stall-regulated turbine has been demonstrated, and several issues involving optimal performance with VGs have been identified and addressed. 15 refs., 34 figs., 10 tabs.

Griffin, D.A. [Lynette (R.) and Associates, Seattle, WA (United States)

1996-12-01T23:59:59.000Z

431

Propagation of an arbitrary vortex pair through an astigmatic optical system and determination of its net topological charge  

E-Print Network (OSTI)

We embed a pair of vortices with different topological charges in a Gaussian beam and study its evolution through an astigmatic optical system, a tilted lens. The propagation dynamics is explained by a closed-form analytical expression. Furthermore, we show that a careful examination of the intensity distribution at a predicted position past the lens can provide us with the net charge present in the beam. To the best of our knowledge, our method is the first non-interferometric technique to measure the net charge of an arbitrary vortex pair. Our experimental results are in close agreement with the theoretical predictions.

Reddy, Salla Gangi; Aadhi, A; Banerji, J; Singh, R P

2013-01-01T23:59:59.000Z

432

Methodology for fault detection and diagnostics in an ocean turbine using vibration analysis and modeling.  

E-Print Network (OSTI)

??This thesis describes a methodology for mechanical fault detection and diagnostics in an ocean turbine using vibration analysis and modeling. This methodology relies on the… (more)

Mjit, Mustapha.

2009-01-01T23:59:59.000Z

433

A Possible Pressure-Induced High-Temperature-Superconducting  

Science Conference Proceedings (OSTI)

... Materials Forensics, Three-dimensional Modeling and Fractal Characterization · Vortex Physics in Oxide and Pnictide High Temperature Superconductors.

434

Vibration test plan for a space station heat pipe subassembly  

SciTech Connect

This test plan describes the Sundstrand portion of task two of Los Alamos National Laboratory (LANL) contract 9-x6H-8102L-1. Sundstrand Energy Systems was awarded a contract to investigate the performance capabilities of a potassium liquid metal heat pipe as applied to the Organic Rankine Cycle (ORC) solar dynamic power system for the Space Station. The test objective is to expose the heat pipe subassembly to the random vibration environment which simulates the space shuttle launch condition. The results of the test will then be used to modify as required future designs of the heat pipe.

Parekh, M.B. [Sundstrand Energy Systems, Rockford, IL (United States)

1987-09-29T23:59:59.000Z

435

KNOTS AND RANDOM WALKS IN VIBRATED GRANULAR CHAINS  

Science Conference Proceedings (OSTI)

The authors study experimentally statistical properties of the opening times of knots in vertically vibrated granular chains. Our measurements are in good qualitative and quantitative agreement with a theoretical model involving three random walks interacting via hard core exclusion in one spatial dimension. In particular, the knot survival probability follows a universal scaling function which is independent of the chain length, with a corresponding diffusive characteristic time scale. Both the large-exit-time and the small-exit-time tails of the distribution are suppressed exponentially, and the corresponding decay coefficients are in excellent agreement with the theoretical values.

E. BEN-NAIM; ET AL

2000-08-01T23:59:59.000Z

436

Optimization of Piezoelectric Electrical Generators Powered by Random Vibrations  

E-Print Network (OSTI)

This paper compares the performances of a vibrationpowered electrical generators using PZT piezoelectric ceramic associated to two different power conditioning circuits. A new approach of the piezoelectric power conversion based on a nonlinear voltage processing is presented and implemented with a particular power conditioning circuit topology. Theoretical predictions and experimental results show that the nonlinear processing technique may increase the power harvested by a factor up to 4 compared to the Standard optimization technique. Properties of this new technique are analyzed in particular in the case of broadband, random vibrations, and compared to those of the Standard interface.

Lefeuvre, E; Richard, C; Petit, L; Guyomar, D

2007-01-01T23:59:59.000Z

437

Direct Measurements of Pore Fluid Density by Vibrating Tube Densimetry  

Science Conference Proceedings (OSTI)

The densities of pore-confined fluids were measured for the first time by means of a vibrating tube method. Isotherms of total adsorption capacity were measured directly making the method complementary to the conventional gravimetric or volumetric/piezometric adsorption techniques, which yield the excess adsorption (the Gibbsian surface excess). A custom-made high-pressure, high-temperature vibrating tube densimeter (VTD) was used to measure the densities of subcritical and supercritical propane (between 35 C and 97 C) and supercritical carbon dioxide (between 32 C and 50 C) saturating hydrophobic silica aerogel (0.2 g/cm3, 90% porosity) synthesized inside Hastelloy U-tubes. Additionally, excess adsorption isotherms for supercritical CO2 and the same porous solid were measured gravimetrically using a precise magnetically-coupled microbalance. Pore fluid densities and total adsorption isotherms increased monotonically with increasing density of the bulk fluid, in contrast to excess adsorption isotherms, which reached a maximum at a subcritical density of the bulk fluid, and then decreased towards zero or negative values at supercritical densities. Compression of the confined fluid significantly beyond the density of the bulk liquid at the same temperature was observed at subcritical temperatures. The features of the isotherms of confined fluid density are interpreted to elucidate the observed behavior of excess adsorption. The maxima of excess adsorption were found to occur below the critical density of the bulk fluid at the conditions corresponding to the beginning of the plateau of total adsorption, marking the end of the transition of pore fluid to a denser, liquid-like pore phase. The results for propane and carbon dioxide showed similarity in the sense of the principle of corresponding states. No measurable effect of pore confinement on the liquid-vapor critical point was found. Quantitative agreement was obtained between excess adsorption isotherms determined from VTD total adsorption results and those measured gravimetrically at the same temperature, confirming the validity of the vibrating tube measurements. Vibrating tube densimetry was demonstrated as a novel experimental approach capable of providing the average density of pore-confined fluids.

Gruszkiewicz, Miroslaw {Mirek} S [ORNL; Rother, Gernot [ORNL; Wesolowski, David J [ORNL; Cole, David R [ORNL; Wallacher, Dirk [Helmholtz-Zentrum Berlin

2012-01-01T23:59:59.000Z

438

Magnetic Blockade Mechanism for Quantum Nucleation of Superconducting Vortex-Antivortex Pairs in Zero External Magnetic Field  

E-Print Network (OSTI)

We propose a magnetic dual of the Coulomb blockade effect for quantum nucleation of flux vortex pairs in high-Tc superconducting (HTS) films and grain boundaries in zero applied field. The magnetic blockade instability occurs at {\\theta} = {\\pi}, where {\\theta} is the "vacuum" or theta angle. The {\\theta} term has recently been discussed in the context of several other systems, including charge and spin density waves, topological insulators, the quantum Hall effect, and spontaneous CP violation. Our model predicts a sharp pair creation threshold current at {\\theta} = {\\pi}, analogous to the Coulomb blockade voltage of a tunnel junction, and explains the observed thickness dependence of critical currents in HTS coated conductors. We use the Schr\\"odinger equation to compute the evolving macrostate amplitudes, coupled by a generalized tunneling matrix element. The simulations yield excellent quantitative agreement with measured voltage-current characteristics of bi-crystal and other HTS grain boundary junctions. The model also predicts non-sinusoidal behavior in the voltage oscillations resulting from time-correlated vortex tunneling.

J. H. Miller Jr.; A. I. Wijesinghe

2011-10-12T23:59:59.000Z

439

MOLECULAR BEAM STUDIES OF IR LASER INDUCED MULTIPHOTON DISSOCIATION AND VIBRATIONAL PREDISSOCIATION  

E-Print Network (OSTI)

However, the dissociation rate increases rapidly with thehow the dissociation rate increases with the excess energy (9 the dissociation rate increases faster with excess energy,

Lee, Yuan T.

2013-01-01T23:59:59.000Z

440

A compensated vibrating optical fiber pressure measuring device  

DOE Patents (OSTI)

A microbending optical fiber is attached under tension to a diaphragm to sense a differential pressure applied across the diaphragm which causes it to deflect. The fiber is attached to the diaphragm so that one portion of the fiber, attached to a central portion of the diaphragm, undergoes a change in tension; proportional to the differential pressure applied to the diaphragm while a second portion attached at the periphery of the diaphragm remains at a reference tension. Both portions of the fiber are caused to vibrate at their natural frequencies. Light transmitted through the fiber is attenuated by both portions of the tensioned sections of the fiber by an amount which increases with the curvature of fiber bending so that the light signal is modulated by both portions of the fiber at separate frequencies. The modulated light signal is transduced into an electrical signal. The separate modulation signals are detected to generate separate signals having frequencies corresponding to the reference and measuring vibrating sections of the continuous fiber, respectively. A signal proportional to the difference between these signals is generated which is indicative of the measured pressure differential across the diaphragm. The reference portion of the fiber is used to compensate the pressure signal for zero and span changes resulting from ambient temperature and humidity effects upon the fiber and the transducer fixture.

Fasching, G.E.; Goff, D.R.

1985-12-30T23:59:59.000Z

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


441

Vibration Testing - Reviewing the State of the Art  

Science Conference Proceedings (OSTI)

Vibration testing has advanced significantly over the past several decades. Comparatively speaking, enormous volumes of acceleration data are now available for virtually every vibration test. This data is readily compressed into frequency response functions and modal models. The modal models are compared with corresponding analytical models. Model updating techniques are used to adjust analytical model parameters to minimize the differences between model and test frequencies and mode shapes. These are very positive developments. Model and testing limitations lie in areas other than the direct recording and translation of acceleration data to modal models. Two major limitations of models are the inability to model damping and the limited degree to which nonlinear behavior is incorporated into model construction and model validation. Much more thorough understanding of damping mechanisms in real structures is required. Currently we know enough to bound the range of damping values for some typical structures. A much more thorough understanding of mechanical joints is required to accurately model structural joints. Some studies now underway offer a beginning to such understanding.

Hunter, N.F.

1999-06-23T23:59:59.000Z

442

Combined passive magnetic bearing element and vibration damper  

DOE Patents (OSTI)

A magnetic bearing system contains magnetic subsystems which act together to support a rotating element in a state of dynamic equilibrium and dampen transversely directed vibrations. Mechanical stabilizers are provided to hold the suspended system in equilibrium until its speed has exceeded a low critical speed where dynamic effects take over, permitting the achievement of a stable equilibrium for the rotating object. A state of stable equilibrium is achieved above a critical speed by use of a collection of passive elements using permanent magnets to provide their magnetomotive excitation. In a improvement over U.S. Pat. No. 5,495,221, a magnetic bearing element is combined with a vibration damping element to provide a single upper stationary dual-function element. The magnetic forces exerted by such an element, enhances levitation of the rotating object in equilibrium against external forces, such as the force of gravity or forces arising from accelerations, and suppresses the effects of unbalance or inhibits the onset of whirl-type rotor-dynamic instabilities. Concurrently, this equilibrium is made stable against displacement-dependent drag forces of the rotating object from its equilibrium position.

Post, Richard F. (Walnut Creek, CA)

2001-01-01T23:59:59.000Z

443

Wind Turbine Gearbox Condition Monitoring Round Robin Study - Vibration Analysis  

DOE Green Energy (OSTI)

The Gearbox Reliability Collaborative (GRC) at the National Wind Technology Center (NWTC) tested two identical gearboxes. One was tested on the NWTCs 2.5 MW dynamometer and the other was field tested in a turbine in a nearby wind plant. In the field, the test gearbox experienced two oil loss events that resulted in damage to its internal bearings and gears. Since the damage was not severe, the test gearbox was removed from the field and retested in the NWTCs dynamometer before it was disassembled. During the dynamometer retest, some vibration data along with testing condition information were collected. These data enabled NREL to launch a Wind Turbine Gearbox Condition Monitoring Round Robin project, as described in this report. The main objective of this project was to evaluate different vibration analysis algorithms used in wind turbine condition monitoring (CM) and find out whether the typical practices are effective. With involvement of both academic researchers and industrial partners, the project sets an example on providing cutting edge research results back to industry.

Sheng, S.

2012-07-01T23:59:59.000Z

444

An extraction of the natural frequencies and mode shapes of marine risers by the method of differential transformation  

Science Conference Proceedings (OSTI)

In the offshore oil and gas industry, marine risers are critical conductors connecting platforms to the wellheads at the seabed for drilling, production and transmission, the vortex-induced vibration design of which requires accurate knowledge of the ... Keywords: Differential transformation, Marine risers, Mode shapes, Natural frequencies

Yanfei Chen; Y. H. Chai; Xin Li; Jing Zhou

2009-11-01T23:59:59.000Z

445

Ant Colony Clustering Procedure Used in Vibration Fault Diagnosis of Beam Pumping Unit  

Science Conference Proceedings (OSTI)

The study of vibration fault diagnosis of beam pumping unit is an important task to reasonable production, scientific management and improvement of the oil recovery. The vibration fault diagnosis is a good method with direct result. In view of measurement ... Keywords: ant colony algorithm, clustering procedure, beam pumping unit, fault, diagnosis

Wuguang Li; Shenglai Yang; Ranran Xu; Xiaoxu Sun; Xing Zhang

2011-10-01T23:59:59.000Z

446

Efficient buckling and free vibration analysis of cyclically repeated space truss structures  

Science Conference Proceedings (OSTI)

Eigenproblems play a key role in the stability and free vibration analysis of structures. In large structural models, the solutions of these problems need a considerable computational effort. There are special types of structures whose special properties ... Keywords: Buckling load, Cyclic symmetry, Decomposition, Eigenproblems, Free vibration, Space structures

K. Koohestani; A. Kaveh

2010-10-01T23:59:59.000Z

447

Practical dynamic analysis of structures laterally vibrating in contact with water  

Science Conference Proceedings (OSTI)

This paper proposes a practical formulation to investigate the dynamic response of structures laterally vibrating in contact with water on one or both sides. The proposed technique accounts for structure's flexibility, soil flexibility, varying water ... Keywords: Dynamic analysis, Finite elements, Fluid-structure interaction, Hydrodynamic loads, Simplified formulations, Vibration periods

Benjamin Miquel; Najib Bouaanani

2011-12-01T23:59:59.000Z

448

The Vibration Frequencies of Wind Turbine Steel Tower by Transfer Matrix Method  

Science Conference Proceedings (OSTI)

Large-scale wind turbine structure is simplified as a slender cantilever beam with variable sections subject to complex loads configuration. An analytical procedure to estimate not only natural frequencies but also vibration mode shapes of thin-walled ... Keywords: horizontal axis wind turbine tower, natural frequency, transfer matrix method, free vibration

Wang Meng; Wang Zhangqi

2011-01-01T23:59:59.000Z

449

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

450

A digital vibrating magnetic gyrometer using a control motor DSP TMS320F243  

E-Print Network (OSTI)

A digital vibrating magnetic gyrometer using a control motor DSP TMS320F243 G. Baudoin(1) , O processing system to control a vibrating magnetic gyrometer (VMG). This low cost angular speed sensor has is implemented on a Digital Signal Processor TMS320F243 dedicated to motor control. This DSP is perfectly suited

Baudoin, Geneviève

451

The Resonant Retina: Exploiting Vibration Noise to Optimally Detect Edges in an Image  

Science Conference Proceedings (OSTI)

Abstract¿We show that, far from being a drawback, the ubiquitous presence of random vibrations in vision systems operating from mobile devices can advantageously be used as a fundamental tool for edge detection. Directly inspired by biology, the concept ... Keywords: Edge detection, random vibration of the optical axis, microsaccades, threshold variance estimator, Fisher information, Cramer-Rao inequality, stochastic resonance.

Max-Olivier Hongler; Yuri L. de Meneses; Antoine Beyeler; Jacques Jacot

2003-09-01T23:59:59.000Z

452

Effects of Vibrator Types and Their Placement on Bone?Conduction Threshold Measurements  

Science Conference Proceedings (OSTI)

Monaural bone?conduction threshold measurements in the quiet were obtained for 10 normally hearing young adults at both forehead and mastoid positions using two hearing?aid?type vibrators of different manufacture. Physical calibration data for the vibrators were obtained by other laboratories

Peter B. Weston; Roy W. Gengel; Ira J. Hirsh

1966-01-01T23:59:59.000Z

453

Selective ensemble modeling parameters of mill load based on shell vibration signal  

Science Conference Proceedings (OSTI)

Load parameters inside the ball mill have direct relationships with the optimal operation of grinding process. This paper aims to develop a selective ensemble modeling approach to estimate these parameters. At first, the original vibration signal is ... Keywords: empirical mode decomposition, selective ensemble modeling, soft sensor, vibration frequency spectrum

Jian Tang; Li-Jie Zhao; Jia Long; Tian-you Chai; Wen Yu

2012-07-01T23:59:59.000Z

454

Vibration Reduction Technology for Directional Blasting Demolition of 210m Chimney in Complex Environment  

Science Conference Proceedings (OSTI)

This paper describes the successful experience of the directional control blasting demolition of 210m reinforced concrete chimney, and elucidates the determination of the project scheme, parameter design, electronic digital detonator detonating network ... Keywords: reinforced concrete chimney, directional blasting, electronic digital detonator, blasting vibration, vibration reduction technology

Shunxiang Xu, Dezhi Chen

2013-01-01T23:59:59.000Z

455

Fueled viking generator S/N 106 acceptance vibration test report  

SciTech Connect

The Viking Generator S/N 106 was vibrated to the Teledyne Isotope Flight Acceptance Schedule (Random Only) with no deviation from normal generator functional output. Radiographic analysis and power tests before and after the vibration test indicated no change in the condition of the generator. The work was conducted in the Alpha Fuels Environmental Test Facility at Mound Laboratory.

Anderson, C.; Brewer, C.O.; Abrahamson, S.G.

1976-06-08T23:59:59.000Z

456

Analysis of vibration and pressure pulsation in positive displacement drilling motors  

Science Conference Proceedings (OSTI)

Three, Moineau principle, positive displacement (drilling) motors were tested on a dynamometer using water, air/mist, and foam. In conjunction with a traditional motor performance test, data were collected at 5000 samples per second using an adapted seismic data acquisition system. Shaft speed, torque, pressure, and three-axis vibration data were processed using Seismic Analysis Code (SAC) to obtain energy density spectrums (EDSs). Cascade plots were generated by plotting the EDSs against shaft speed. The cascade plots revealed that pressure pulses and motor vibrations are closely related to the eccentric rotation of the rotor in the power section. Excessive no-load vibrations were not observed in the small motors and test apparatus used; increasing torque usually decreases the amplitude of vibrations observed. Motor vibration amplitudes were as a rule not increased when compressible fluids were substituted for water.

Hamlin, D.B.; Dreesen, D.S.

1998-12-31T23:59:59.000Z

457

Absolute angle-differential vibrational excitation cross sections for electron collisions with diacetylene  

SciTech Connect

Absolute vibrational excitation cross sections were measured for diacetylene (1,3-butadiyne). The selectivity of vibrational excitation reveals detailed information about the shape resonances. Excitation of the C{identical_to}C stretch and of double quanta of the C-H bend vibrations reveals a {sup 2}{Pi}{sub u} resonance at 1 eV (autodetachment width {approx}30 meV) and a {sup 2}{Pi}{sub g} resonance at 6.2 eV (autodetachment width 1-2 eV). There is a strong preference for excitation of even quanta of the bending vibration. Excitation of the C-H stretch vibration reveals {sigma}* resonances at 4.3, 6.8, and 9.8 eV, with autodetachment widths of {approx}2 eV. Detailed information about resonances permits conclusions about the mechanism of the dissociative electron attachment.

Allan, M.; May, O.; Fedor, J.; Ibanescu, B. C.; Andric, L. [Department of Chemistry, University of Fribourg, Chemin du Musee 9, CH-1700 Fribourg (Switzerland); UPMC, Universite Paris 06, LCPMR, 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France) and CNRS, LCPMR (UMR 7614), 11 rue Pierre et Marie Curie, 75231 Paris Cedex 05 (France)

2011-05-15T23:59:59.000Z

458

Comparative Study of Vibration Stability at Operating Light Source Facilities and Lessons Learned in Achieving NSLS II Stability Goals  

E-Print Network (OSTI)

Comparative Study of Vibration Stability at Operating Light Source Facilities and Lessons Learned in Achieving NSLS II Stability Goals

Simos, N; Fallier, M

2008-01-01T23:59:59.000Z

459

Fundamental Vibrational Transitions of HCl Detected in CRL 2136  

E-Print Network (OSTI)

We would like to understand the chemistry of dense clouds and their hot cores more quantitatively by obtaining more complete knowledge of the chemical species present in them. We have obtained high-resolution infrared absorption spectroscopy at 3-4 um toward the bright infrared source CRL 2136. The fundamental vibration-rotation band of HCl has been detected within a dense cloud for the first time. The HCl is probably located in the warm compact circumstellar envelope or disk of CRL 2136. The fractional abundance of HCl is (4.9-8.7)e-8, indicating that approximately 20 % of the elemental chlorine is in gaseous HCl. The kinetic temperature of the absorbing gas is 250 K, half the value determined from infrared spectroscopy of 13CO and water. The percentage of chlorine in HCl is approximately that expected for gas at this temperature. The reason for the difference in temperatures between the various molecular species is unknown.

Goto, Miwa; Geballe, T R; Menten, K M; Indriolo, N; Neufeld, D A

2013-01-01T23:59:59.000Z

460

GAS-PHASE MOLECULAR DYNAMICS: VIBRATIONAL DYNAMICS OF POLYATOMIC MOLECULES  

SciTech Connect

The goal of this research is the understanding of elementary chemical and physical processes important in the combustion of fossil fuels. Interest centers on reactions and properties of short-lived chemical intermediates. High-resolution, high-sensitivity, laser absorption methods are augmented by high-temperature, flow-tube reaction kinetics studies with mass-spectrometric sampling. These experiments provide information on the energy levels, structures and reactivity of molecular free radical species and, in turn, provide new tools for the study of energy flow and chemical bond cleavage in radicals involved in chemical systems. The experimental work is supported by theoretical studies using time-dependent quantum wavepacket calculations, which provide insight into energy flow among the vibrational modes of polyatomic molecules and interference effects in multiple-surface dynamics.

MUCKERMAN,J.T.

1999-06-09T23:59:59.000Z

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


461

Gas-Phase Molecular Dynamics: Vibrational Dynamics of Polyatomic Molecules  

SciTech Connect

The goal of this research is the understanding of elementary chemical and physical processes important in the combustion of fossil fuels. Interest centers on reactions and properties of short-lived chemical intermediates. High-resolution, high-sensitivity, laser absorption methods are augmented by high- temperature, flow-tube reaction kinetics studies with mass-spectrometic sampling. These experiments provide information on the energy levels, structures and reactivity of molecular free radical species and in turn, provide new tools for the study of energy flow and chemical bond cleavage in the radicals involved in chemical systems. The experimental work is supported by theoretical studies using time-dependent quantum wavepacket calculations, which provide insight into energy flow among the vibrational modes of polyatomic molecules and interference effects in multiple-surface dynamics.

Muckerman, J.T.

1999-05-21T23:59:59.000Z

462

An Innovative Transponder-Based Interferometric Radar for Vibration Measurements  

SciTech Connect

Ground-based radar interferometry has recently emerged as an innovative technology of remote sensing, able to accurately measure the static or dynamic displacement of several points of a structure. This technique in the last couple of years has been applied to different types of structures, such as bridges, towers and chimneys. This paper presents a prototype system developed by IDS, originally aimed at measuring the structural vibrations of helicopter rotor blades, based on an interferometric technique and constituted by combination of a radar sensor and a series of transponders installed on the target structure. The main advantages of this solution with respect to conventional interferometric radars, are related to the increased spatial resolution of the system, provided by the possibility to discriminate different transponders installed within the same resolution cell of the radar sensor, and to the reduction of the ambient noise (e.g. multi-path) on the radar measurement. The first feature allows the use of the microwave technology even on target areas with limited dimensions, such as industrial facilities, while the second aspect may extend the use of radar interferometric systems to complex scenarios, where multi-reflections are expected due to the presence of natural targets with high reflectivity to the radar signal. In the paper, the system and its major characteristics are first described; subsequently, application to the measurement of ambient vibration response of a lab set-up is summarized. Then the data acquired on a rotating mock-up are reported and analyzed to identify natural frequencies and mode shapes of the investigated structure.

Coppi, F.; Cerutti, A.; Farina, P.; De Pasquale, G.; Novembrini, G. [IDS Ingegneria dei Sistemi S.p.A., Via Livornese 1019, Pisa (Italy)

2010-05-28T23:59:59.000Z

463

An investigation of the Goshen County, Wyoming, tornadic supercell of 5 June 2009 using EnKF assimilation of mobile mesonet and radar observations collected during VORTEX2. Part I: Experiment design and verification of the EnKF analyses  

Science Conference Proceedings (OSTI)

High-resolution Doppler radar velocities and in situ surface observations collected in a tornadic supercell on 5 June 2009 during the second Verification of the Origins of Rotation in Tornadoes Experiment (VORTEX2) are assimilated into a simulated ...

James Marquis; Yvette Richardson; Paul Markowski; David Dowell; Joshua Wurman; Karen Kosiba; Paul Robinson; Glen Romine

464

Vibration and Structural Response of Hybrid Wind Turbine Blades  

E-Print Network (OSTI)

Renewable energy is a serious alternative to deliver the energy needs of an increasing world population and improve economic activity. Wind energy provides better environmental and economic benefits in comparison with the other renewable energy sources. Wind energy is capable of providing 72 TW (TW = 10^12 W) of electric power, which is approximately four and half times the world energy consumption of 15.8 TW as reported in 2006. Since power output extracted from wind turbines is proportional to the square of the blade length and the cube of the wind speed, wind turbine size has grown rapidly in the last two decades to match the increase in power output. As the blade length increases, so does its weight opening up design possibilities to introduce hybrid glass and carbon fiber composite materials as lightweight structural load bearing alternatives. Herein, we investigate the feasibility of introducing modular composite tubulars as well as hybrid sandwich composite skins in the next generation blades. After selecting a target energy output, 8 MW with 80 m blade, airfoil geometry and the layup for the skin as well as internal reinforcements are proposed. They are incorporated into the computational blade via linear shell elements for the skin, and linear beam elements for the composite tubulars to assess the relationship between weight reduction and structural performance. Computational simulations are undertaken to understand the static and dynamic regimes; specifically, displacements, stresses, and vibration modes. The results showed that the composite layers did not exhibit any damage. However, in the balsa core of the sandwich skin, the von Mises stress exceeded its allowable at wind speeds ranging from 11.0 m/sec to 12.6 m/sec. In the blades with composite tubular reinforcement, two different types of damage are observed: a. Stress concentrations at the tubular-skin attachments, and b. Highest von Mises stress caused by the flapping bending moment. The vibration studies revealed a strong coupling mode, bending and twist, at the higher natural frequencies of the blade with tubular truss configuration. The weight saving measures in developing lighter blades in this study did not detract from the blades structural response for the selected load cases.

Nanami, Norimichi

2010-12-01T23:59:59.000Z

465

LS-4~ GROUND VIBRATION MEASUREMENTS NEAR THE SITE OF THE PROPOSED  

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

~ ~ GROUND VIBRATION MEASUREMENTS NEAR THE SITE OF THE PROPOSED ANL LIGHT SYNCHROTRON RADIATION FACILITY by D.L. McCown and R. Bowen Geoscience and Engineering Energy and Environmental Systems Division January 23, 1986 SUMMARY LS-4'l D. L. McCown/R. Bowen January 23, 1986 GROmm VIBRATION MEASUREMENTS REAR. 'l'IIE SITE OF 'l'IIE PROPOSED ANL LIGHT SYNCHROTRON RADIATION FACILITY Ground surface vibration measurements were conducted near the site of the proposed Light Source Radiation Facility in December, 1985 and early January, 1986 during "busy" and "quiet" periods of site activity. The preliminary analysis of the measurements indicates that ground vibrations (in the vertical) observed at the site are usually at frequencies below 800 Hz.

466

Damping Ditch Effect Analysis of Blasting Vibration Based on Wavelet Transform  

Science Conference Proceedings (OSTI)

This paper researched the propagation laws of blasting seismic wave under the action of damping ditch, with the help of blasting vibration test and wavelet transform method. Blasting seismic wave is short-time non-stationary random signal. According ...

Zhiyang Chen; Xiang Fang; Weiping Zhang; Mingshou Zhong

2009-12-01T23:59:59.000Z

467

Particle Image Velocimetry Study on the Stripe Formation in Vertically Vibrated Granules  

E-Print Network (OSTI)

Recently, granules under vertical vibrations receive many attentions due to their importance in theoretical research and engineering application. In this paper, a two-dimensional Particle Image Velocimetry (PIV) system was ...

Deng, Rensheng

468

Quantum and classical vibrational relaxation dynamics of N-methylacetamide on ab initio potential energy surfaces  

E-Print Network (OSTI)

Employing extensive quantum-chemical calculations at the DFT/B3LYP and MP2 level, a quartic force field of isolated N-methylacetamide is constructed. Taking into account 24 vibrational degrees of freedom, the model is employed to perform numerically exact vibrational configuration interaction calculations of the vibrational energy relaxation of the amide I mode. It is found that the energy transfer pathways may sensitively depend on details of the theoretical description. Moreover, the exact reference calculations were used to study the applicability and accuracy of (i) the quasiclassical trajectory method, (ii) time-dependent second-order perturbation theory, and (iii) the instantaneous normal mode description of frequency fluctuations. Based on the results, several strategies to describe vibrational energy relaxation in biomolecular systems are discussed.

Fujisaki, Hiroshi; Hirao, Kimihiko; Straub, John E; Stock, Gerhard

2008-01-01T23:59:59.000Z

469

Active vibration reduction applied to the compressor of an air?conditioning unit for trams  

Science Conference Proceedings (OSTI)

Within the framework of the European Integrated Project InMAR (intelligent materials for active noise reduction)active vibration control and active structural acoustic control approaches are applied to an HVAC (heating

Joachim Bös; Enrico Janssen; Michael Kauba; Dirk Mayer

2008-01-01T23:59:59.000Z

470

Vertically-Vibrated Gas-Liquid Interfaces: Surface Deformation and Breakup  

E-Print Network (OSTI)

In his pioneering work of 1831, Faraday demonstrated that a vertically vibrated gas-liquid interface exhibits a period-doubling bifurcation from a flat state to a wavy configuration at certain frequencies or amplitudes. Typical experiments performed using thin layers of water produce "Faraday ripples", modest-amplitude nonlinear standing waves. Later experiments by Hashimoto and Sudo (1980) and Jameson (1966) as well as those performed in the present study show that much more dramatic disturbances can be generated at the gas-liquid free surface under certain ranges of vibration conditions. This breakup mechanism was examined experimentally using deep layers of polydimethylsiloxane (PDMS) silicone oils over a range of viscosity and sinusoidal, primarily axial vibration conditions that can produce dramatic disturbances at the gas-liquid free surface. Large-amplitude vibrations produce liquid jets into the gas, droplets pinching off from the jets, gas cavities in the liquid from droplet impact, and bubble transp...

O'Hern, T J; Brooks, C F; Shelden, B; Torczynski, J R; Kraynik, A M; Romero, L A; Benavides, G L

2010-01-01T23:59:59.000Z

471

Solvent and conformation dependence of amide I vibrations in peptides and proteins containing proline  

E-Print Network (OSTI)

We present a mixed quantum-classical model for studying the amide I vibrational dynamics (predominantly CO stretching) in peptides and proteins containing proline. There are existing models developed for determining ...

Roy, Santanu

472

Proceedings of the Fourteenth International Conference on Time-Resolved Vibrational Spectroscopy (TRVS XIV)  

E-Print Network (OSTI)

Abstracts of presentations made at the Fourteenth International Conference on Time-Resolved Vibrational Spectroscopy (TRVS XIV) held May 9-14, 2009 in Meredith, New Hampshire. TRVS is a series of biennial conferences ...

Tokmakoff, Andrei

2011-08-31T23:59:59.000Z

473

Vibration-to-electric energy conversion using a mechanically-varied capacitor  

E-Print Network (OSTI)

Past research in vibration energy harvesting has focused on the use of variable capacitors, magnets, or piezoelectric materials as the basis of energy transduction. How- ever, few of these studies have explored the detailed ...

Yen, Bernard Chih-Hsun, 1981-

2005-01-01T23:59:59.000Z

474

The low frequency 2D vibration sensor based on flat coil element  

SciTech Connect

Vibration like an earthquake is a phenomenon of physics. The characteristics of these vibrations can be used as an early warning system so as to reduce the loss or damage caused by earthquakes. In this paper, we introduced a new type of low frequency 2D vibration sensor based on flat coil element that we have developed. Its working principle is based on position change of a seismic mass that put in front of a flat coil element. The flat coil is a part of a LC oscillator; therefore, the change of seismic mass position will change its resonance frequency. The results of measurements of low frequency vibration sensor in the direction of the x axis and y axis gives the frequency range between 0.2 to 1.0 Hz.

Djamal, Mitra; Sanjaya, Edi; Islahudin; Ramli [Department of Physics, Institut Teknologi Bandung, Jl. Ganesa 10 Bandung 40116 (Indonesia); Department of Physics, Institut Teknologi Bandung, Jl. Ganesa 10 Bandung 40116 (Indonesia) and Department of Physics, UIN Syarif Hidayatullah, Jl. Ir.H. Djuanda 95 Ciputat 15412 (Indonesia); MTs NW Nurul Iman Kembang Kerang, Jl. Raya Mataram - Lb.Lombok, NTB (Indonesia); Department of Physics, Institut Teknologi Bandung, Jl. Ganesa 10 Bandung 40116 (Indonesia) and Department of Physics,Universitas Negeri Padang, Jl. Prof. Hamka, Padang 25132 (Indonesia)

2012-06-20T23:59:59.000Z

475

Vibration mitigation in J-TEXT far-infrared diagnostic systems  

SciTech Connect

Optical structure stability is an important issue for far-infrared (FIR) phase measurements. To ensure good signal quality, influence of vibration should be minimized. Mechanical amelioration and optical optimization can be taken in turn to decrease vibration's influence and ensure acceptable measurement. J-TEXT (Joint Texal Experiment Tokamak, formerly TEXT-U) has two FIR diagnostic systems: a HCN interferometer system for electron density measurement and a three-wave polarimeter-interferometer system (POLARIS) for electron density and Faraday effect measurements. All use phase detection techniques. HCN interferometer system has almost eliminated the influence of vibration after mechanical amelioration and optical optimization. POLARIS also obtained first experimental results after mechanical stability improvements and is expected to further reduce vibration's influence on Faraday angle to 0.1 Degree-Sign after optical optimization.

Li, Q.; Chen, J.; Zhuang, G.; Wang, Z. J.; Gao, L.; Chen, W. [State Key Laboratory of Advanced Electromagnetic Engineering and Technology, Huazhong University of Science and Technology, Wuhan 430074 (China)

2012-10-15T23:59:59.000Z

476

Vibrations of a Hollow Nanosphere with a Porous Thin Shell in Liquid  

E-Print Network (OSTI)

*,, The Open Laboratory of Bond-Selective Chemistry, Departmental of Chemical Physics, University of Science time, Rayleigh3 discussed the flexural vibrations of an open shell or bowl, which is different from

Wu, Chi

477

Disentangling electronic and vibrational coherence in the Phycocyanin-645 light-harvesting complex  

E-Print Network (OSTI)

Energy transfer between chromophores in photosynthesis proceeds with near unity quantum efficiency. Understanding the precise mechanisms of these processes is made difficult by the complexity of the electronic structure and interactions with different vibrational modes. Two-dimensional spectroscopy has helped resolve some of the ambiguities and identified quantum effects that may be important for highly efficient energy transfer. Many questions remain, however, including whether the coherences observed are electronic and/or vibrational in nature and what role they play. We utilise a two-colour four-wave mixing experiment with control of the wavelength and polarization to selectively excite specific coherence pathways. For the light-harvesting complex PC645, from cryptophyte algae, we reveal and identify specific contributions from both electronic and vibrational coherences and determine an excited state structure based on two strongly-coupled electronic states and two vibrational modes. Separation of the cohe...

Richards, Gethin H; Curmi, Paul M G; Davis, Jeffrey A

2013-01-01T23:59:59.000Z

478

Finite-Temperature Hydrogen Adsorption/Desorption Thermodynamics Driven by Soft Vibration Modes  

Science Conference Proceedings (OSTI)

It is widely accepted that room-temperature hydrogen storage on nanostructured or porous materials requires enhanced dihydrogen adsorption. In this work we reveal that room-temperature hydrogen storage is possible not only by the enhanced adsorption, but also by making use of the vibrational free energy from soft vibration modes. These modes exist for example in the case of metallo-porphyrin-incorporated graphenes (M-PIGs) with out-of-plane ( buckled ) metal centers. There, the in-plane potential surfaces are flat because of multiple-orbital-coupling between hydrogen molecules and the buckled-metal centers. This study investigates the finite-temperature adsorption/desorption thermodynamics of hydrogen molecules adsorbed on M-PIGs by employing first-principles total energy and vibrational spectrum calculations. Our results suggest that the current design strategy for room-temperature hydrogen storage materials should be modified by explicitly taking finite-temperature vibration thermodynamics into account.

Woo, Sung-Jae [KAIST, Daejeon, Republic of Korea; Lee, Eui-Sup [KAIST, Daejeon, Republic of Korea; Yoon, Mina [ORNL; Yong-Hyun, Kim [KAIST, Daejeon, Republic of Korea

2013-01-01T23:59:59.000Z

479

Unsteady momentum fluxes in two-phase flow and the vibration of nuclear reactor components  

E-Print Network (OSTI)

The steady and unsteady components of the momentum flux in a twophase flow have been measured at the exit of a vertical pipe. Measured momentum flux data has been machine processed by standard random vibration techniques ...

Yih, Tien Sieh

1968-01-01T23:59:59.000Z

480

The influence of vortex pinning and grain boundary structure on critical currents across grain boundaries in YBa{sub 2}Cu{sub 3}O{sub x}.  

SciTech Connect

We have used studies of single grain boundaries in YBCO thin films and bulk bicrystals to study the influence of vortex pinning along a grain boundary on dissipation. The critical current density for transport across grain boundaries in thin films is typically more than an order of magnitude larger than that measured for transport across grain boundaries in bulk samples. For low disorientation angles, the difference in critical current density within the grains that form the boundary can contribute to the substantial differences in current density measured across the boundary. However, substantial differences exist in the critical current density across boundaries in thin film compared to bulk bicrystals even in the higher angle regime in which grain boundary dissipation dominates. The differences in critical current density in this regime can be understood on the basis of vortex pinning along the boundary.

Miller, D. J.

1998-10-27T23:59:59.000Z

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481

Program on Technology Innovation: Wireless Vibration Measurement of Low-Pressure Steam Turbine Blades  

Science Conference Proceedings (OSTI)

This report describes Phase 2 of a research and development effort to define a turbine blade vibration sensor (TBVS) system for measuring the mechanical vibrational spectrum of large steam turbine blades as they rotate. In Phase 1, the design concept and a number of alternative system components were considered for a wireless electronic device called a mote. In the Phase 2 research covered in this report, the final design of a custom accelerometer capable of operating under very high sustained centrifuga...

2010-12-22T23:59:59.000Z

482

Program on Technology Innovation: Wireless Vibration Measurement of Turbine and Compressor Blades: Phase 3 -- Electronic System  

Science Conference Proceedings (OSTI)

This report describes Phase 3 of a multiphase research and development effort to define a turbine blade vibration sensor (TBVS) system for measuring the vibration spectrum of a complete row of operating large steam turbine or compressor blades. In Phase 1, the design concept and several alternative system components were considered for a wireless electronic device called a mote (see the Electric Power Research Institute [EPRI] report 1020697). In Phase 2, the design of a custom accelerometer capable of o...

2011-12-16T23:59:59.000Z

483

Program on Technology Innovation: Wireless Vibration Measurement of Turbine and Compressor Blades  

Science Conference Proceedings (OSTI)

This report describes Phase 4 of a multiyear research effort to develop a turbine blade vibration sensor (TBVS) system design. The sensor system application is the monitoring of the mechanical vibration spectrum of large steam turbine and compressor blades during operation. In Phase 1, the design concept as well as several alternative system components were considered for a wireless electronic device, called a mote. In Phase 2, the design parameters of a custom microelectromechanical (MEMS) ...

2012-12-12T23:59:59.000Z

484

Low frequency long duration blast vibrations and their effect on residential structures  

Science Conference Proceedings (OSTI)

A study was conducted at a coal mine in India which produces 10 million tonne of coal and 27 million cubic meter of overburden per annum. Detonation of 100 tonnes of explosives in a blasting round is a common practice of the mine. These large sized blasts often led to complaints from the nearby inhabitants regarding ground vibrations and their affects on their houses. Eighteen dragline blasts were conducted and their impacts on nearby structures were investigated. Extended seismic arrays were used to identify the vibration characteristics within a few tens of meters of the blasts and also as modified by the media at distances over 5 km. 10 to 12 seismographs were deployed in an array to gather the time histories of vibrations. A signature blast was conducted to know the fundamental frequency of the particular transmitting media between the blast face and the structures. The faster decay of high frequency components was observed. It was also observed that at distances of 5 km, the persistence of vibrations in the structures was substantially increased by more than 10 seconds. The proximity of the frequency of the ground vibration to the structure's fundamental frequencies produced the resonance in the structures. On the basis of the fundamental frequency of the structures, the delay interval was optimized, which resulted in lower amplitude and reduced persistence of vibration in the structures. 9 refs., 10 figs., 2 tabs.

Roy, M.P.; Sirveiya, A.K.; Singh, P.K. [Central Mining Research Institute, Dhanbad (India). Blasting Dept.

2005-07-01T23:59:59.000Z

485

Interaction of highly vibrationally excited molecules with clean metal surfaces. Final technical report  

DOE Green Energy (OSTI)

The authors present results from a grant funded under the Department of Energy Office of Basic Energy Sciences. A collaboration between Prof. Alec Wodtke of the Department of Chemistry at UCSB and Daniel J. Auerbach of IBM Almaden Research Labs has allowed new experiments on the dynamics of surface chemical reactivity to be successfully executed. High quality data has been generated which provides an excellent test of theoretical mod