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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.


1

Airfoil Vortex Induced Vibration suppression devices  

E-Print Network [OSTI]

Vortex Induced Vibrations (VIV) is a major concern of the offshore oil industry. This problem leads to fatigue failure in the marine risers and causes costly replacement of the risers. Appendages such as helical strakes ...

Lee, Evan J. (Evan Joseph)

2007-01-01T23:59:59.000Z

2

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.

3

A study on passive methods of vortex induced vibrations suppression  

E-Print Network [OSTI]

A number of engineering systems, including those found in offshore operations, are often affected by vortex-induced vibrations (VIV). This phenomenon is caused by the interaction between a structure and shed vortices which ...

Galvao, Richardo A

2008-01-01T23:59:59.000Z

4

Experimental Investigations of Vortex Induced Vibration of A Flat Plate in Pitch Oscillation  

E-Print Network [OSTI]

A bluff structure placed in a flowing fluid, may be subjected to vortex-induced vibrations (VIV). For a flat plate with only rotational degree of freedom, the VIV is rotational oscillation. Based on the experimental investigation, vortex...

Yang, Yi

2012-02-14T23:59:59.000Z

5

CFD Numerical Simulation of Vortex-Induced Vibration of a Stay Cable under a Wind Profile  

Science Journals Connector (OSTI)

VIV (Vortex-induced vibration) of a stay cable subjected to a wind profile is numerically simulated through combining CFD ... numerical model. Under a profile of mean wind speed, unsteady aerodynamic lift coeffic...

Wenli Chen; Hui Li

2009-01-01T23:59:59.000Z

6

Vortex-Induced Vibration of a slender horizontal cylinder in currents and waves  

E-Print Network [OSTI]

Vortex-Induced Vibration (VIV) is a concern when dealing with slender, flexible structural members of deepwater platforms. While much is known about the characteristics of VIV in uniform and sheared current flows, very little is known about...

Chitwood, James Scott

2012-06-07T23:59:59.000Z

7

Application of fiber Bragg grating based strain sensor in pipeline vortex-induced vibration measurement  

Science Journals Connector (OSTI)

The vortex-induced vibrations (VIV) is an important topic of ... of different methods have been applied to the measurement of VIV, especially for the elongated, ... in stainless steel tubes were applied to the measurement

Liang Ren; ZiGuang Jia; Michael Siu Chun Ho…

2014-09-01T23:59:59.000Z

8

Vortex Induced Vibrations of cylinders : experiments in reducing drag force and amplitude of motion  

E-Print Network [OSTI]

Reducing the deleterious effect of Vortex Induced Vibrations (VIV) in marine risers is an important task for ocean engineers; and many competing factors exist in the design of VIV suppression devices. This thesis explores ...

Farrell, David Emmanuel

2007-01-01T23:59:59.000Z

9

Vortex-induced vibration of a circular cylinder with combined in-line and cross-flow motion  

E-Print Network [OSTI]

Deep water, string-like, marine risers subject to strong ocean currents, suffer from vortex-induced vibrations (VIV), where vortex shedding interacts with the structural properties of the riser, resulting in large amplitude ...

Dahl, Jason (Jason Michael)

2008-01-01T23:59:59.000Z

10

VIVDR -Vortex-induced vibration data repository An overview of available riser datasets  

E-Print Network [OSTI]

VIVDR - Vortex-induced vibration data repository An overview of available riser datasets http://oe.mit.edu/VIV H. Mukundan and M. Triantafyllou 20 April 2008 #12;NDP 38m long riser model datasets #12;33 q Rig q Tension applied through spring-supported clump weights NDP 38m long riser model datasets

11

A model for vortex-induced vibration analysis of long-span bridges  

Science Journals Connector (OSTI)

Abstract Long-span structures are susceptible to wind-induced vibrations due to their low oscillation frequency and low mechanical damping. Although many efforts have been made in the past to model vortex-induced vibration of circular cylinders, limited studies can be found for non-circular cross sections representative of long-span bridge decks. A model for vortex-induced vibration analysis of long-span bridge is presented in this paper. The aeroelastic equation of motion of the model, a procedure to extract aeroelastic coefficients from wind tunnel experiments, analysis of full-scale structures incorporating loss of spanwise correlation of aeroelastic forces, and comparison between simulated and full-scale measured responses on a twin deck bridge (Fred Hartman bridge, Baytown, Texas) are discussed. Six bluff sections – Deer Isle bridge, Tsurumi bridge, Fred Hartman bridge, generic rectangular, H shaped, and circular models – were considered in this research program.

Mehedy Mashnad; Nicholas P. Jones

2014-01-01T23:59:59.000Z

12

On the efficiency of energy harvesting using vortex-induced vibrations of cables  

Science Journals Connector (OSTI)

Abstract Many technologies based on fluid–structure interaction mechanisms are being developed to harvest energy from geophysical flows. The velocity of such flows is low, and so is their energy density. Large systems are therefore required to extract a significant amount of energy. The question of the efficiency of energy harvesting using vortex-induced vibrations (VIV) of cables is addressed in this paper, through two reference configurations: (i) a long tensioned cable with periodically-distributed harvesters and (ii) a hanging cable with a single harvester at its upper extremity. After validation against either direct numerical simulations or experiments, an appropriate reduced-order wake-oscillator model is used to perform parametric studies of the impact of the harvesting parameters on the efficiency. For both configurations, an optimal set of parameters is identified and it is shown that the maximum efficiency is close to the value reached with an elastically-mounted rigid cylinder. The variability of the efficiency is studied in light of the fundamental properties of each configuration, i.e. body flexibility and gravity-induced spatial variation of the tension. In the periodically-distributed harvester configuration, it is found that the standing-wave nature of the vibration and structural mode selection plays a central role in energy extraction. In contrast, the efficiency of the hanging cable is essentially driven by the occurrence of traveling wave vibrations.

Clément Grouthier; Sébastien Michelin; Rémi Bourguet; Yahya Modarres-Sadeghi; Emmanuel de Langre

2014-01-01T23:59:59.000Z

13

Airflow induced vibration of the Si-IT prototype  

E-Print Network [OSTI]

In this note we present the results of air-flow induced vibration tests performed on mechanical prototypes of the Si option of the Inner Tracker upgrade. We made a modal analyze where we observed the eigenfrequency of the Si-ladder structure at ?30 Hz as previously measured at CERN. Flowing dry-air to cool the prototypes we do not observe a lock-in state of the vortex induced vibration (VIV). The maximum observed vibration amplitude is calculated. We conclude that the VIV excites the eigenfrequency almost independently from the air-flow speed, and with an amplitude which does not damage the structure.

Dijkstra, H; De Aguiar, V; Rigo, V

2014-01-01T23:59:59.000Z

14

Flow-induced vibration: 1992  

SciTech Connect (OSTI)

A joint program on flow-induced vibration (FIV) as established in July 1988 between Taiwan Power Company (Taipower or TPC) and ANL. The main objectives of the program are to provide a technology transfer program on FIV for Taipower staff and to assist Taipower with various aspects of FIV including evaluation of reports and proposals, review of designs, resolution of design issues, recommendation for design modifications, and selected research studies. During the first two years, the following tasks were accomplished: A technology transfer program on FIV was completed and key Taipower staff members were prepared to handle future problems in the subject area. The modified component cooling water (CCW) heat exchangers were assessed and the basis for a license from the Taiwan Atomic Energy Council (AEC) was established. The seismic reanalysis of Chin Shan spent-fuel racks was assessed and a report was submitted to the Taiwan AEC. Fluid/structure interaction activities were coordinated and provided a list of potential bidders for a fluid transient project and related publications and a recommendation for purchasing technical data on fluid coupling. Flow-induced vibration of tube arrays was reviewed and the needs of Taipower in the area of fluid/structure interaction were identified as were the procedures necessary for Taipower to accomplish its goals. A computer program, ARRAY, was established to compute the added-mass matrices for tube arrays. Taipower expressed interest in extending the joint program so that ANL could provide continuing assistance. The program was extended for several years (May 1, 1991, to June 30, 1994). Work from May 1, 1991, through June 30, 1992, summarized in this report, included technology transfer, assessment of sensing line and valve vibrations, literature survey, and tests on motion-dependent fluid forces acting on tube arrays in crossflow.

Chen, S.S.

1992-09-01T23:59:59.000Z

15

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

16

Vibration-Induced Climbing of Drops  

Science Journals Connector (OSTI)

We report an experimental study of liquid drops moving against gravity, when placed on a vertically vibrating inclined plate, which is partially wetted by the drop. The frequency of vibrations ranges from 30 to 200 Hz, and, above a threshold in vibration acceleration, drops experience an upward motion. We attribute this surprising motion to the deformations of the drop, as a consequence of an up or down symmetry breaking induced by the presence of the substrate. We relate the direction of motion to contact angle measurements. This phenomenon can be used to move a drop along an arbitrary path in a plane, without special surface treatments or localized forcing.

P. Brunet; J. Eggers; R. D. Deegan

2007-10-03T23:59:59.000Z

17

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

SciTech Connect (OSTI)

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

18

Extreme behavior prediction of vortex-induced vibrations  

E-Print Network [OSTI]

new statistical approach that requires knowledge of the correlation structure of the response data. An analytical form of the autocorrelation function is suggested and investigated herein. The behavior of the cylinder in terms of the displacement...

Hariharan, Madhu

2012-06-07T23:59:59.000Z

19

Measurement-Induced Vibrational Dynamics of a Trapped Ion  

Science Journals Connector (OSTI)

Excitation spectra of an individual trapped 138Ba+ ion show sidebands of radial and axial ion vibration in the trap. The second-order sidebands involving radial and axial vibrations would allow swapping these vibrational states; they represent an inverse Raman effect with the role of electronic and vibrational excitation interchanged. Deexcitation sidebands differ from excitation sidebands as the vibrational distribution in the D5/2 level is modified by the ion being reduced to this level in null observations of resonance light. Delayed deexcitation goes along with stochastic cooling that makes the ion collapse into the Fock state |n=1?. Sideband modulation is identified as stroboscopic detection of the light-induced nutation on a vibrational transition with ?n=±1.

B. Appasamy; Y. Stalgies; P. E. Toschek

1998-03-30T23:59:59.000Z

20

Measurement Of Flow Induced Vibration Of Reactor Component  

Science Journals Connector (OSTI)

The effect of flow-induced vibration on class I components in the reactor is a very important design factor for its qualifications worthy of loading inside the core. In this regard, a clear definition of the f...

N. Dharmaraju; K. K. Meher; A. Rama Rao

2008-01-01T23:59:59.000Z

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.


21

Reduction of vortex induced forces and motion through surface roughness control  

DOE Patents [OSTI]

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 decrease/suppress Vortex Induced Forces and Motion. Suppression is required when fluid-structure interaction becomes destructive as in VIM of flexible cylinders or rigid cylinders on elastic support, such as underwater pipelines, marine risers, tubes in heat exchangers, nuclear fuel rods, cooling towers, SPAR offshore platforms.

Bernitsas, Michael M; Raghavan, Kamaldev

2014-04-01T23:59:59.000Z

22

Design and vibration testing of a flexible seal whisker model  

E-Print Network [OSTI]

Harbor seal whiskers have a unique surface structure that dramatically reduces vortex induced vibrations as they move through the water. Concurrently with rigid whisker experiments, this project focuses on the design and ...

Gerber, Christopher D

2013-01-01T23:59:59.000Z

23

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

24

Joule heating induced by vortex motion in a type-II superconductor Z. L. Xiao and E. Y. Andrei  

E-Print Network [OSTI]

Joule heating induced by vortex motion in a type-II superconductor Z. L. Xiao and E. Y. Andrei-II superconductor due to Joule heating induced by vortex motion. The effect of Joule heating is detected s duration, where the Joule heating is negligible and saturates, respectively. The thermometry is based

Andrei, Eva Y.

25

Friction-Induced Vibrations in Railway Transportation Chandra Prakash Sharma  

E-Print Network [OSTI]

Friction-Induced Vibrations in Railway Transportation by Chandra Prakash Sharma B. Tech., Sardar;Abstract Controlling friction at the wheel-rail interface is indispensable for extending track life implementation of friction modifier system consists of a stick-tube assembly, attached through a bracket which

Phani, A. Srikantha

26

Enhanced Seebeck coefficient from carrier-induced vibrational softening  

Science Journals Connector (OSTI)

Through their electron-lattice interactions, localized carriers reduce vibrational stiffness constants in their surroundings. States with a large electronic polarizability (e.g., multiatomic localized states and states of a singlet bipolaron formed of degenerate electronic orbitals) induce exceptionally large softening. This carrier-induced softening augments the Seebeck coefficient of solids whose carriers hop between these localized states through two separate effects. One enhancement is due to a localized carrier inducing an increase in a solid’s vibrational entropy. The other contribution is proportional to the vibrational energy transferred with a carrier as it hops. Both softening contributions are independent of the carrier density. The magnitudes and temperature dependencies of these contributions to the Seebeck coefficient indicate the electronic polarizabilities of the localized states and the vibrational modes to which they are coupled. Measured softening enhancements of Seebeck coefficients are sometimes large enough (e.g., >200 ?V/K measured at 300 K in boron carbides) to significantly increase the efficiency of thermoelectric energy conversion.

David Emin

1999-03-01T23:59:59.000Z

27

Flow-induced vibration of component cooling water heat exchangers  

SciTech Connect (OSTI)

This paper presents an evaluation of flow-induced vibration problems of component cooling water heat exchangers in one of Taipower's nuclear power stations. Specifically, it describes flow-induced vibration phenomena, tests to identify the excitation mechanisms, measurement of response characteristics, analyses to predict tube response and wear, various design alterations, and modifications of the original design. Several unique features associated with the heat exchangers are demonstrated, including energy-trapping modes, existence of tube-support-plate (TSP)-inactive modes, and fluidelastic instability of TSP-active and -inactive modes. On the basis of this evaluation, the difficulties and future research needs for the evaluation of heat exchangers are identified. 11 refs., 19 figs., 3 tabs.

Yeh, Y.S.; Chen, S.S. (Taiwan Power Co., Taipei (Taiwan). Nuclear Engineering Dept.; Argonne National Lab., IL (USA))

1990-01-01T23:59:59.000Z

28

Gravitational Wave Induced Vibrations of Slender Structures in Space  

E-Print Network [OSTI]

This paper explores the interaction of weak gravitational fields with slender elastic materials in space and estimates their sensitivities for the detection of gravitational waves with frequencies between $10^{-4}$ and 1 Hz. The dynamic behaviour of such slender structures is ideally suited to analysis by the simple theory of Cosserat rods. Such a description offers a clean conceptual separation of the vibrations induced by bending, shear, twist and extension and the response to gravitational tidal accelerations can be reliably estimated in terms of the constitutive properties of the structure. The sensitivity estimates are based on a truncation of the theory in the presence of thermally induced homogeneous Gaussian stochastic forces.

R W Tucker; C Wang

2001-12-06T23:59:59.000Z

29

Effects of syngas composition on combustion induced vortex breakdown (CIVB) flashback in a swirl stabilized combustor  

Science Journals Connector (OSTI)

Flame flashback attributed to combustion induced vortex breakdown (CIVB) is a major design challenge for swirl stabilized burner combustors. This paper presents an experimental investigation of combustion induced vortex breakdown (CIVB) flashback propensity for flames yielded from Hydrogen (H2)–Carbon Monoxide (CO) fuel blends and actual synthesized gas (syngas) mixtures. A two-fold experimental approach, consisting of a high definition digital imaging system and a high speed PIV system, was employed. The main emphasis was on the effect of concentration of different constituents in fuel mixtures on flashback limit. In addition, the effect of Swirl Number on flashback propensity was discussed. The percentage of H2 in fuel mixtures played the dominant role when CIVB flashback occurred. For a given air mass flow rate, the mixture containing a higher percentage of H2 underwent flashback at much leaner conditions. Flashback maps for actual syngas fuel compositions showed a distinct behavior when various concentrations of diluents were introduced in the mixture. For the two major diluents tested, carbon dioxide (CO2) and nitrogen dioxide (NO2), CO2 was more dominant. The effect of Swirl Number on the flashback propensity was also tested and showed a decrease with an increase in Swirl Number. The final portion of this paper also provides an analysis of flow field of reacting flames which revealed complex vortex–chemistry interactions leading to vortex breakdown and flashback. Based on the experimental results a parametric model similar to Peclet Number approach was developed employing a flame quenching concept. A value of the quench parameter, Cquench was obtained from the correlation of flow Peclet Number and flame Peclet Number, which was observed to be dominated by the fuel composition rather than Swirl Number.

Bidhan Dam; Gilberto Corona; Mir Hayder; Ahsan Choudhuri

2011-01-01T23:59:59.000Z

30

vibration  

Science Journals Connector (OSTI)

the rapid and promotion of a continuing periodic frequency in a displacement with respect to fixed reference. Lattice vibration .

2009-01-01T23:59:59.000Z

31

Flow Induced Vibration Program at Argonne National Laboratory  

SciTech Connect (OSTI)

Argonne National Laboratory has had a Flow Induced Vibration Program since 1967; the Program currently resides in the Laboratory's Components Technology Division. Throughout its existence, the overall objective of the program has been to develop and apply new and/or improved methods of analysis and testing for the design evaluation of nuclear reactor plant components and heat exchange equipment from the standpoint of flow induced vibration. Historically, the majority of the program activities have been funded by the US Atomic Energy Commission (AEC), Energy Research and Development Administration (ERDA), and Department of Energy (DOE). Current DOE funding is from the Breeder Mechanical Component Development Division, Office of Breeder Technology Projects; Energy Conversion and Utilization Technology (ECUT) Program, Office of Energy Systems Research; and Division of Engineering, Mathematical and Geosciences, Office of Basic Energy Sciences. Testing of Clinch River Breeder Reactor upper plenum components has been funded by the Clinch River Breeder Reactor Plant (CRBRP) Project Office. Work has also been performed under contract with Foster Wheeler, General Electric, Duke Power Company, US Nuclear Regulatory Commission, and Westinghouse.

Not Available

1984-01-01T23:59:59.000Z

32

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

33

vibration  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

34

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

35

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

SciTech Connect (OSTI)

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

36

Friction-induced vibration of a lubricated mechanical system J-J. Sinou*, J. Cayer-Barrioz and H. Berro  

E-Print Network [OSTI]

1 Friction-induced vibration of a lubricated mechanical system J-J. Sinou*, J. Cayer-Barrioz and H that incorporates realistic laws of local friction issued from previous experimental results. The objective or by themselves, such as friction-induced vibrations. In all cases, these vibrations are hardly controllable

Paris-Sud XI, Université de

37

Flow-Induced Sound and Vibration due to the Separated Shear Layer in Backward-Facing Step  

E-Print Network [OSTI]

Flow-Induced Sound and Vibration due to the Separated Shear Layer in Backward-Facing Step of the author. #12;ii Supervisory Committee Flow-Induced Sound and Vibration due to Separated Shear Layer to other equipment. Thus, vibration of the paper sheet and turbulent flow that emerged from a planar curved

Victoria, University of

38

Vibration-induced mobilization of trapped non-aqueous phase liquids in porous media.  

E-Print Network [OSTI]

??Acoustic wave stimulation, such as vibration-induced mobilization, is a promising enhancement approach to remove trapped NAPLs (Non-Aqueous Phase Liquids) usually encountered in multiphase flows through… (more)

Li, Wenqing

2006-01-01T23:59:59.000Z

39

Flow induced vibration of a cantilever column jet: a spectral analysis  

E-Print Network [OSTI]

FLON INDUCED VIBRATION OF A CANTILEVER COLUMN JET ? A SPECTRAL ANALYSIS A Thesis by ROY BRYANT SHILLING III Submitted to the Graduate College of Texas A8M University ir, partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1978 Major Subject: Ocean Engineering FLOW INDUCED VIBRATION OF A CANTILEVER COLUMN JET - A SPECTRAL ANALYSIS A Thesis by ROY BRYANT SHILLING III Approved as to style and content by: (Chairman of Committee) (Head of Department) ember...

Shilling, Roy Bryant

2012-06-07T23:59:59.000Z

40

A survey of ideal fluid propeller theories and a study of the effects of aerodynamic propeller loading on trailing vortex induced velocity and thrust  

E-Print Network [OSTI]

A SURVEY OF IDEAL FLUID PRO~ THEORIES AND A STUIE OP THE EFFECTS OF AERODYNAMIC PRO~ LOADING ON TRAILING VORTEX INDUCED VELOCITY AND THRUST A Thesis EDWARD MADISON ~ Suhmitted to the Graduate College of Texas A&M University in Partial... fulfillment of the requirement for the degree of MASTER OF SCIENCE August 1969 h'h, jor Suhgect: Mechanical Engineering A SURVEY OF IDEAL FLUID PROPELLEB THEORIES AND A STUDY OF THE EFFKTS OF AERODYKVGC PROPELLER LOADING ON TRAILING VORTEX INDUCED...

Kelley, Edward Madison

2012-06-07T23:59:59.000Z

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

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

42

A simple model to predict train-induced vibration: theoretical formulation and experimental validation  

SciTech Connect (OSTI)

No suitable handy tool is available to predict train-induced vibration on environmental impact assessment. A simple prediction model is proposed which has been calibrated for high speed trains. The model input data are train characteristics, train speed and track properties; model output data are soil time-averaged velocity and velocity level. Model results have been compared with numerous vibration data retrieved from measurement campaigns led along the most important high-speed European rail tracks. Model performances have been tested by comparing measured and predicted vibration values.

Rossi, Federico; Nicolini, Andrea

2003-05-01T23:59:59.000Z

43

REDUCTION OF VIBRATION-INDUCED ARTIFACTS IN SYNTHETIC-APERTURE-RADAR IMAGERY USING THE FRACTIONAL FOURIER TRANSFORM  

E-Print Network [OSTI]

REDUCTION OF VIBRATION-INDUCED ARTIFACTS IN SYNTHETIC-APERTURE-RADAR IMAGERY USING THE FRACTIONAL of objects exhibit- ing low-level vibrations are accompanied by localized arti- facts, or ghost targets to the non-stationary nature of the returned signals from vibrating objects. Re- cently, a method based

Santhanam, Balu

44

Measurement and prediction of train-induced vibrations in a full-scale building  

Science Journals Connector (OSTI)

Abstract Buildings located close to transportation corridors experience structure-borne sound and vibration due to passing traffic which can be disruptive to operation of sensitive equipment in manufacturing, and medical facilities. Structure-borne sound and vibrations, when high may also be annoying to human occupants in residential, office, and commercial buildings. Hence, there is a growing need for cost effective sound and vibration predictions to evaluate the need for mitigation. The research focuses on in-situ testing of a full-scale building for verification of a previously developed impedance-based methodology and to create a prediction model to study ground-borne vibrations in the test building. A mitigation methodology was also examined using the verified prediction model. Impedance modeling involves the propagation of axial waves through columns combined with the impedance of the intermediate floor slabs. The vibration transmission in the building was characterized and predicted using a single column model with attached floors. Train-induced floor vibrations in an existing four-story building in Boston were measured and compared with predictions of the impedance model. The impedance model predictions closely matched with the measured floor responses. A previously suggested mitigation method was investigated analytically using the impedance model. A thickened floor referred as the “blocking floor” was used on the lower elevation of the building and the reduction in vibration at the upper floors of the building was compared for various thicknesses of the blocking floor, to study its efficiency. The blocking floor has high impedance and reflects a major portion of the vibration transmitting in the columns preventing it from reaching the upper floors. The blocking floor was found to mitigate the transmission of ground-borne vibrations to upper floors.

Masoud Sanayei; Anish Kayiparambil P.; James A. Moore; Cory R. Brett

2014-01-01T23:59:59.000Z

45

MODELLING THE HUMAN INDUCED VIBRATIONS IN ACABLE-STAYED PEDESTRIAN TIMBER BRIDGE  

E-Print Network [OSTI]

MODELLING THE HUMAN INDUCED VIBRATIONS IN ACABLE-STAYED PEDESTRIAN TIMBER BRIDGE Sara Casciati1 on a pedestrian timber bridge under different "moving" loads configurations are reported and analysed by applying behavior of the bridge under the above loads. A first in situ experimental campaign was carried out

Boyer, Edmond

46

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

SciTech Connect (OSTI)

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

47

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...

Wang, Shuguang

2009-05-15T23:59:59.000Z

48

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

SciTech Connect (OSTI)

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

49

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

50

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

SciTech Connect (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

51

Problems and Challenges Vibrations  

E-Print Network [OSTI]

, but is not necessary for many standard measurements. Mounting all optical components on vibration insulation posts further reduced vibrations. Concerning the suppression of vibration-induced measurement problems58 Problems and Challenges Vibrations: One of the key problems for the bulge tester is vibration

Huston, Dryver R.

52

Chemical reactions of water molecules on Ru(0001) induced by selective excitation of vibrational modes  

SciTech Connect (OSTI)

Tunneling electrons in a scanning tunneling microscope were used to excite specific vibrational quantum states of adsorbed water and hydroxyl molecules on a Ru(0 0 0 1) surface. The excited molecules relaxed by transfer of energy to lower energy modes, resulting in diffusion, dissociation, desorption, and surface-tip transfer processes. Diffusion of H{sub 2}O molecules could be induced by excitation of the O-H stretch vibration mode at 445 meV. Isolated molecules required excitation of one single quantum while molecules bonded to a C atom required at least two quanta. Dissociation of single H{sub 2}O molecules into H and OH required electron energies of 1 eV or higher while dissociation of OH required at least 2 eV electrons. In contrast, water molecules forming part of a cluster could be dissociated with electron energies of 0.5 eV.

Mugarza, Aitor; Shimizu, Tomoko K.; Ogletree, D. Frank; Salmeron, Miquel

2009-05-07T23:59:59.000Z

53

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

54

An energy harvesting system using the wind-induced vibration of a stay cable for powering  

Science Journals Connector (OSTI)

This paper proposes an electromagnetic energy harvesting system, which utilizes the wind-induced vibration of a stay cable, and investigates its feasibility for powering a wireless sensor node on the cable through numerical simulations as well as experimental tests. To this end, the ambient acceleration responses of a stay cable installed in an in-service cable-stayed bridge are measured, and then they are used as input excitations in cases of both numerical simulations and experimental tests to evaluate the performance of the proposed energy harvesting system. The results of the feasibility test demonstrate that the proposed system generates sufficient electricity for operation of a wireless sensor node attached on the cable under the moderate wind conditions.

Hyung-Jo Jung; In-Ho Kim; Seon-Jun Jang

2011-01-01T23:59:59.000Z

55

Reconnection of vortex filaments and Kolmogorov spectrum  

E-Print Network [OSTI]

The energy spectrum of the 3D velocity field, induced by collapsing vortex filaments is studied. One of the aims of this work is to clarify the appearance of the Kolmogorov type energy spectrum $E(k)\\varpropto k^{-5/3}$, observed in many numerical works on discrete vortex tubes (quantized vortex filaments in quantum fluids). Usually, explaining classical turbulent properties of quantum turbulence, the model of vortex bundles, is used. This model is necessary to mimic the vortex stretching, which is responsible for the energy transfer in classical turbulence. In our consideration we do not appeal to the possible "bundle arrangement" but explore alternative idea that the turbulent spectra appear from singular solution, which describe the collapsing line at moments of reconnection. One more aim is related to an important and intensively discussed topic - a role of hydrodynamic collapse in the formation of turbulent spectra. We demonstrated that the specific vortex filament configuration generated the spectrum $E...

Nemirovskii, Sergey K

2014-01-01T23:59:59.000Z

56

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

57

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

SciTech Connect (OSTI)

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

58

Measurement of wall pressure fluctuations in the presence of vibrations induced by a turbulent flow  

Science Journals Connector (OSTI)

A systematic study of the methods of measuring wall pressure fluctuations against a background of intense vibrations is carried out. The method of separating the turbulent signal from noise on the basis of mon...

E. B. Kudashev

2003-03-01T23:59:59.000Z

59

Anharmonic OH vibrations in Mg ( OH ) 2 (brucite): Two-dimensional calculations and crystal-induced blueshift  

Science Journals Connector (OSTI)

A two-dimensional quantum-mechanical vibrational model has been used to calculate the anharmonic OH vibrational frequencies in the layered Mg ( OH ) 2 (brucite) crystal. The underlying potential energy surface was generated by density functional theory(DFT) calculations. The resulting OH frequencies are upshifted (blueshifted) by about + 75 ? cm ? 1 with respect to the gas-phase OH frequency ( + 120 ? cm ? 1 in experiments; the discrepancy is mainly due to inadequacies in the DFT and pseudopotential models). The Raman-IR split is about 50 ? cm ? 1 both in the calculations and in experiments. We find that the blueshift phenomenon in brucite can qualitatively be explained by a parabolalike “OH frequency versus electric field” correlation curve pertaining to an OH ? ion exposed to an electric field. We also find that it is primarily the neighbors within the Mg ( OH ) 2 layer that induce the blueshift while the interlayer interaction gives a smaller (and redshifting) contribution.

Kersti Hermansson; Michael M. Probst; Grzegorz Gajewski; Pavlin D. Mitev

2009-01-01T23:59:59.000Z

60

Longitudinal-optical-vibration-induced high transparency of nominally opaque thin films  

Science Journals Connector (OSTI)

It has been theoretically demonstrated that a presence of a very thin cubic crystal film deposited on a substrate can substantially modify infrared optical properties of the structure. The effect is due to excitation of longitudinal-optical vibrations within the film.

R. Dragila and S. Vukovic

1990-02-15T23:59:59.000Z

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

Temperature dependence of vortex charges in high-temperature superconductors  

Science Journals Connector (OSTI)

Using a model Hamiltonian with d-wave superconductivity and competing antiferromagnetic (AF) interactions, the temperature (T) dependence of the vortex charge in high-Tc superconductors is investigated by numerically solving the Bogoliubov–de Gennes equations. The strength of the induced AF order inside the vortex core is T dependent. The vortex charge could be negative when the AF order with sufficient strength is present at low temperatures. At higher temperatures, the AF order may be completely suppressed and the vortex charge becomes positive. A first-order-like transition in the T-dependent vortex charge is seen near the critical temperature TAF. For an underdoped sample, the spatial profiles of the induced spin-density wave and the charge-density wave orders could have stripelike structures at TTs. As a result, a vortex charge discontinuity occurs at Ts.

Yan Chen; Z. D. Wang; C. S. Ting

2003-06-03T23:59:59.000Z

62

Experimental study on vortex-induced motions of a semi-submersible platform with four square columns, Part I: Effects of current incidence angle and hull appendages  

Science Journals Connector (OSTI)

An experimental study on Vortex-Induced Motion (VIM) of the semi-submersible platform concept with four square columns is presented. Model tests were carried out to check the influence of different headings and hull appendages (riser supports located at the pontoons; fairleads and the mooring stretches located vertically at the external column faces; and hard pipes located vertically at the internal column faces). The results comprise in-line, transverse and yaw motions, as well as combined motions in the XY plane, drag and lift forces and spectral analysis. The main results showed that VIM in the transverse direction occurred in a range of reduced velocity 4.0 up to 14.0 with amplitude peaks around reduced velocities around 7.0 and 8.0. The largest transverse amplitudes obtained were around 40% of the column width for 30° and 45° incidences. Another important result observed was a considerable yaw motion oscillation, in which a synchronization region could be identified as a resonance phenomenon. The largest yaw motions were verified for the 0° incidence and the maxima amplitudes around 4.5°. The hull appendages located at columns had the greatest influence on the VIM response of the semi-submersible.

Rodolfo T. Gonçalves; Guilherme F. Rosetti; André L.C. Fujarra; Allan C. Oliveira

2012-01-01T23:59:59.000Z

63

Vibrational excitation induced by electron beam and cosmic rays in normal and superconductive aluminum bars  

E-Print Network [OSTI]

We report new measurements of the acoustic excitation of an Al5056 superconductive bar when hit by an electron beam, in a previously unexplored temperature range, down to 0.35 K. These data, analyzed together with previous results of the RAP experiment obtained for T > 0.54 K, show a vibrational response enhanced by a factor 4.9 with respect to that measured in the normal state. This enhancement explains the anomalous large signals due to cosmic rays previously detected in the NAUTILUS gravitational wave detector.

M. Bassan; B. Buonomo; G. Cavallari; E. Coccia; S. D'Antonio; V. Fafone; L. G. Foggetta; C. Ligi; A. Marini; G. Mazzitelli; G. Modestino; G. Pizzella; L. Quintieri; F. Ronga; P. Valente; S. M. Vinko

2011-08-02T23:59:59.000Z

64

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 (Author)

2013-01-01T23:59:59.000Z

65

Reconnection of vortex filaments and Kolmogorov spectrum  

E-Print Network [OSTI]

The energy spectrum of the 3D velocity field, induced by collapsing vortex filaments is studied. One of the aims of this work is to clarify the appearance of the Kolmogorov type energy spectrum $E(k)\\varpropto k^{-5/3}$, observed in many numerical works on discrete vortex tubes (quantized vortex filaments in quantum fluids). Usually, explaining classical turbulent properties of quantum turbulence, the model of vortex bundles, is used. This model is necessary to mimic the vortex stretching, which is responsible for the energy transfer in classical turbulence. In our consideration we do not appeal to the possible "bundle arrangement" but explore alternative idea that the turbulent spectra appear from singular solution, which describe the collapsing line at moments of reconnection. One more aim is related to an important and intensively discussed topic - a role of hydrodynamic collapse in the formation of turbulent spectra. We demonstrated that the specific vortex filament configuration generated the spectrum $E(k)$ close to the Kolmogorov dependence and discussed the reason for this as well as the reason for deviation. We also discuss the obtained results from point of view of the both classical and quantum turbulence.

Sergey K. Nemirovskii

2014-04-19T23:59:59.000Z

66

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

67

DSB-SC Phase Demodulation -Application for Vibration Measurement  

Science Journals Connector (OSTI)

A heterodyne interferometry with DSB-SC performance is presented to measure small vibration signal. The vibration induced phase is demodulated by self-mixing without a local...

Teng, Hui-Kang; Lang, Kuo-Chen

68

vibration measurement  

Science Journals Connector (OSTI)

vibration measurement ? Erschütterungsmessung, Schwingungsmessung f [Schwingungsmessungen dienen dazu, die Schwingungsanfälligkeit von Bauwerken realitätsnah zu erfassen

2014-08-01T23:59:59.000Z

69

Vortex dynamics in 4 Banavara N. Shashikanth  

E-Print Network [OSTI]

during the interaction of a pair of counter-rotating vortices Phys. Fluids 24, 014107 (2012) The onset of oblique vortex shedding behind a heated circular cylinder in laminar wake regime Phys. Fluids 24, 011701 fluids Phys. Fluids 23, 115106 (2011) Asymptotic properties of wall-induced chaotic mixing in point

Shashikanth, Banavara N.

70

Vibrational mode analysis of void induced coronene as a possible carrier of the astronomical aromatic infrared bands  

E-Print Network [OSTI]

Void induced di-cation coronene C23H12++ is a possible carrier of the astronomically observed polycyclic aromatic hydrocarbon (PAH). Based on density functional theory, multiple spin state analysis was done for neutral void coronene C23H12. Singlet spin state was most stable (lowest total energy). By the Jahn-Teller effect, there occurs serious molecular deformation. Point group D6h of pure coronene transformed to C2 symmetry having carbon two pentagons. Advanced singlet stable molecules were di-cation C23H12++ and di-anion C23H12- -. Molecular configuration was almost similar with neutral C23H12. However, electric dipole moment of these two charged molecules show reversed direction with 1.19 and 2.63 Debey. Calculated infrared spectrum of C23H12++ show a very likeness to observed one of two astronomical sources of HD44179 and NGC7027. Harmonic vibrational mode analysis was done for C23H12++. At 3.2 micrometer, C-H stretching at pentagons was featured. From 6.4 to 8.7 micrometer, C-C stretching mode was obser...

Ota, Norio

2015-01-01T23:59:59.000Z

71

LWBR development program: Flow-induced vibrational wear behavior of zircaloy clad simulated fuel rods in a grid support system  

SciTech Connect (OSTI)

Vibrational wear behavior of flow-tested simulated fuel rods supported in AM-350 stainless steel grids is described. Zircaloy-4 tubes containing copper pellets were tested in 515 and 530/sup 0/F, 1615 and 2000 psia, upward flowing water at various flow rates for periods of 420 to 11,871 hours while supported by normal and off-normal grid conditions. The simulated fuel rods were attached at either top or bottom base plates. Rod wear spots were usually deepest at the free end grid level. Wear spots 9.9 to 17.0 mils deep were produced on several rods for off-normal conditions where the grid closest to the rod free end did not apply spring force to the rod. Expected core conditions are less severe due to a continual shift in rod-grid contact locations as rods lengthen from irradiation induced growth. High wear at free-end grids was most common on top-mounted rods, but it was observed on bottom-mounted rods also.

Galtz, C.S.; Stackhouse, R.M.; Campbell, W.R.

1987-03-01T23:59:59.000Z

72

4 - Friction–vibration interactions  

Science Journals Connector (OSTI)

Abstract: Generally, friction could be treated as a dynamical variable in a dynamical system with a sliding interface. For convenience, the effect of friction on vibrations and the effect of vibrations on friction have been treated separately. The close-loop feedback effects of friction–vibration interactions have rarely been paid attention due to limited engineering applications. Both friction and vibration have been simplified and quantified by order-reduced models. There are many unique dynamic phenomena and underlying mechanisms associated with the vibrations of a system with friction, just to name a few: stick-slip, self-excited vibrations, modal coupling, sprag-slip, loss of contact, parametric resonance, etc. Friction-induced vibrations usually exhibit time-varying, nonlinear and stochastic properties. On the other hand, there are certain underlying mechanisms associated with the effect of vibrations on the friction reductions. This chapter will comprehensively survey varied characteristics of vibrations in systems having friction. Then a detailed consideration of the current understanding of vibration-induced friction reduction will be given. Also the single-degree-of-freedom system, multiple-degree-of-freedom system and continuous system are discussed. Finally, several applications in science and engineering are presented, which include stick-slip associated with earthquakes, friction vibrations of rod in sucker pumping system, and automotive brake vibrations and noise.

2014-01-01T23:59:59.000Z

73

Sediment resuspension and erosion by vortex rings  

Science Journals Connector (OSTI)

Particle resuspension and erosion induced by a vortex ringinteracting with a sediment layer was investigated experimentally using flow visualization (particle image velocimetry) high-speed video and a recently developed light attenuation method for measuring displacements in bed level. Near-spherical sediment particles were used throughout with relative densities of 1.2–7 and diameters ( d ) ranging between 90 and 1600 ? ? m . Attention was focused on initially smooth horizontal bedforms with the vortex ring aligned to approach the bed vertically. Interaction characteristics were investigated in terms of the dimensionless Shields parameter defined using the vortex-ring propagation speed. The critical conditions for resuspension (whereby particles are only just resuspended) were determined as a function of particle Reynolds number (based on the particle settling velocity and d ). The effects of viscous damping were found to be significant for d / ? resuspension volumes are analyzed as a function interaction time impact condition and sediment size.

R. J. Munro; N. Bethke; S. B. Dalziel

2009-01-01T23:59:59.000Z

74

Dynamic decay of a single vortex into vortex-antivortex pairs  

SciTech Connect (OSTI)

A variety of metastable states, including vortices, antivortices, and their combinations, is typical for magnetically soft, thin films and patterned structures. The physics of individual spin vortices in patterned structures has been rather extensively explored. In contrast, there are few studies of the vortex–antivortex–vortex (v-av-v) system, in part because the configuration is rather challenging to obtain experimentally. We demonstrate herein how a recently proposed resonant-spin-ordering technique can be used to induce the dynamic decay of a single vortex into v-av states in elongated elements. The approach is based on first driving the system from the linear regime of constant vortex gyrations to the non-linear regime of vortex-core reversals at a fixed excitation frequency, and then subsequently reducing the excitation field back to the linear regime. This procedure stabilizes the system into a v-av-v state that is completely decoupled from the initialization excitation frequency. The newly acquired state is stable in remanence. The dynamic response of this system is expected to demonstrate a number of collective modes, depending on the combination of the vortex core polarities, and/or the excitation field direction, and, hence, is of interest for future studies.

Lendínez, Sergi [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Universidad Barcelona, Departamento Fisica Fonamental, E-08028 Barcelona (Spain); Jain, Shikha; Novosad, Valentyn, E-mail: novosad@anl.gov; Fradin, Frank Y.; Pearson, John E. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Tejada, Javier [Universidad Barcelona, Departamento Fisica Fonamental, E-08028 Barcelona (Spain); Bader, Samuel D. [Materials Science Division, Argonne National Laboratory, Argonne, Illinois 60439 (United States); Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439 (United States)

2014-05-07T23:59:59.000Z

75

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

76

Field dependence of the vortex structure in d-wave and s-wave superconductors  

Science Journals Connector (OSTI)

We study the vortex structure and its field dependence within the framework of the quasiclassical Eilenberger theory to find the difference between the dx2-y2- and s-wave pairings. We clarify the effect of the dx2-y2-wave nature and the vortex lattice effect on the vortex structure of the pair potential, the internal field and the local density of states. The dx2-y2-wave pairing introduces a fourfold-symmetric structure around each vortex core. With increasing field, their contribution becomes significant to the whole structure of the vortex lattice state, depending on the vortex lattice’s configuration. It is reflected in the form factor of the internal field, which may be detected by small-angle neutron scattering, or the resonance line shape of muon spin resonance and NMR experiments. We also study the induced s- and dxy-wave components around the vortex in dx2-y2-wave superconductors.

Masanori Ichioka; Akiko Hasegawa; Kazushige Machida

1999-04-01T23:59:59.000Z

77

Vortex Characterization for Engineering Applications  

SciTech Connect (OSTI)

Realistic engineering simulation data often have features that are not optimally resolved due to practical limitations on mesh resolution. To be useful to application engineers, vortex characterization techniques must be sufficiently robust to handle realistic data with complex vortex topologies. In this paper, we present enhancements to the vortex topology identification component of an existing vortex characterization algorithm. The modified techniques are demonstrated by application to three realistic data sets that illustrate the strengths and weaknesses of our approach.

Jankun-Kelly, M; Thompson, D S; Jiang, M; Shannahan, B; Machiraju, R

2008-01-30T23:59:59.000Z

78

Mechanical Vibration  

Science Journals Connector (OSTI)

... THE suppression and control of mechanical vibration have assumed great importance in engineering. One consequence of this is that the number ... degree of emphasis is placed on transient oscillation (in addition to steady-State and free vibration). The treatment of this topic is based mainly on phase-plane constructions and it ...

R. E. D. BISHOP

1958-12-06T23:59:59.000Z

79

Vibration Technology  

Science Journals Connector (OSTI)

... AT first sight, one has the impression that this is just another book on vibrations with the same old chapter headings as many others ; it is only when one ... with basic theory of the conventional systems having simple and multi-degrees of freedom and vibration of strings, bars and beams, but the treatment is unusual in that emphasis is ...

E. DOWNHAM

1969-01-18T23:59:59.000Z

80

Nanogenerator as an active sensor for vortex capture and ambient wind-velocity detection  

E-Print Network [OSTI]

and mechanical (wind, water flow, vibration, friction and body movement) energies are common in the ambientNanogenerator as an active sensor for vortex capture and ambient wind-velocity detection Rui Zhang principle, ambient wind-speed measurements with the NG are demonstrated. Due to the simple structure, high

Wang, Zhong L.

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

E-Print Network 3.0 - amplitude mechanical vibrations Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Journal of Mechanics BFluids 23 (2004) 2940 Three-dimensionality of mode transition in vortex-induced Summary: . This significant growth in correlation length occurs...

82

Molecular vibration demonstrations  

Science Journals Connector (OSTI)

Molecular vibration demonstrations ... Two dynamic models that illustrate the normal-mode vibrations of the water and benzene molecules. ...

George Turrell; Robert Demol

1987-01-01T23:59:59.000Z

83

Vortex Formation in a Plasma Interacting with Neutral Flow  

SciTech Connect (OSTI)

Recently, it has been observed that there exists a class of vortices which rotates in the opposite direction to ExB drift (referred to as anti-ExB vortex). This result suggests that a predominant force other than electric field is acting on ions. It is found that momentum transport and resultant force generation through the interaction between ions and neutral flow play an essential role on anti-ExB vortex formation. The existence of inward neutral flow, which drives the ions in the anti-ExB direction, has been confirmed using a newly-developed high-resolution laser induced fluorescence (LIF) spectroscopy system.

Tanaka, M. Y.; Ogiwara, K.; Etoh, S. [Department of High Energy Engineering Science, Kyushu University, Kasuga-koen 6-1, Kasuga 816-8580 (Japan); Aramaki, M. [Department of Electrical Engineering, Nagoya University, Chikusa, Nagoya 464-8603 (Japan); Yoshimura, S. [National Institute for Fusion Science, Oroshi 322-6, Toki 509-5292 (Japan); Varanjes, J. [Center for Plasma Astrophysics, Celestijnenlaan 200 B 3001 Leuven (Belgium)

2008-10-15T23:59:59.000Z

84

Vibrational dynamics of permanently densified GeO{sub 2} glasses: Densification-induced changes in the boson peak  

SciTech Connect (OSTI)

Vitreous GeO{sub 2}, one of the main prototypes of strong glasses, was densified at several pressures up to 6 GPa, achieving more than 20% of densification. The density dependence of the vibrational density of states and of the low temperature properties of these glasses was investigated by means of inelastic neutron scattering and calorimetric measurements. With increasing density, both the boson peak and the bump in c{sub p}/T{sup 3} versus T plot exhibit variations which are stronger than the elastic medium expectation. If one reduces the measured spectra to a common master curve, one finds that this is only possible for the densified samples; the first densification step has an additional effect, similar to other cases in the literature. Nevertheless, the existence of a master curve for the three densified samples proves that the total number of excess modes remains constant on further densification. The experimental data are discussed in the framework of different theoretical models.

Orsingher, L.; Fontana, A. [Dipartimento di Fisica, Universita di Trento, I-38050 Povo Trento (Italy); Research center SOFT-INFM-CNR, Universita di Roma 'La Sapienza', I-00185 Roma (Italy); Gilioli, E. [IMEM-CNR, Area delle Scienze, 43010 Parma (Italy); Carini, G. Jr.; Carini, G.; Tripodo, G. [Dipartimento di Fisica, Universita di Messina, Salita Sperone 31, 98166 S. Agata (Montenegro) (Italy); Unruh, T. [Forschungsneutronenquelle Heinz-Maier-Leibnitz (FRM II), Technische Universitaet Muenchen, 85747 Garching (Germany); Buchenau, U. [Institut fuer Festkoerperforschung, Forschungszentrum Juelich, 52425 Juelich (Germany)

2010-03-28T23:59:59.000Z

85

Wave–vortex interactions in the nonlinear Schrödinger equation  

SciTech Connect (OSTI)

This is a theoretical study of wave–vortex interaction effects in the two-dimensional nonlinear Schrödinger equation, which is a useful conceptual model for the limiting dynamics of superfluid quantum condensates at zero temperature. The particular wave–vortex interaction effects are associated with the scattering and refraction of small-scale linear waves by the straining flows induced by quantized point vortices and, crucially, with the concomitant nonlinear back-reaction, the remote recoil, that these scattered waves exert on the vortices. Our detailed model is a narrow, slowly varying wavetrain of small-amplitude waves refracted by one or two vortices. Weak interactions are studied using a suitable perturbation method in which the nonlinear recoil force on the vortex then arises at second order in wave amplitude, and is computed in terms of a Magnus-type force expression for both finite and infinite wavetrains. In the case of an infinite wavetrain, an explicit asymptotic formula for the scattering angle is also derived and cross-checked against numerical ray tracing. Finally, under suitable conditions a wavetrain can be so strongly refracted that it collapses all the way onto a zero-size point vortex. This is a strong wave–vortex interaction by definition. The conditions for such a collapse are derived and the validity of ray tracing theory during the singular collapse is investigated.

Guo, Yuan, E-mail: yuanguo@cims.nyu.edu; Bühler, Oliver [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)] [Courant Institute of Mathematical Sciences, New York University, New York, New York 10012 (United States)

2014-02-15T23:59:59.000Z

86

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

87

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

88

Vortex lines and transitions in superfluid hydrodynamics  

Science Journals Connector (OSTI)

...Preface to Vortices, dislocations, and line singularities in partial differential equations...Leslie and J. R. Ockendon. Vortex lines and transitions in superfluid hydrodynamics...nature and the motion of qunatized vortex lines. This paper illustrates the transitions...

1997-01-01T23:59:59.000Z

89

The photodissociation and reaction dynamics of vibrationally excited molecules  

SciTech Connect (OSTI)

This research determines the nature of highly vibrationally excited molecules, their unimolecular reactions, and their photodissociation dynamics. The goal is to characterize vibrationally excited molecules and to exploit that understanding to discover and control their chemical pathways. Most recently the author has used a combination of vibrational overtone excitation and laser induced fluorescence both to characterize vibrationally excited molecules and to study their photodissociation dynamics. The author has also begun laser induced grating spectroscopy experiments designed to obtain the electronic absorption spectra of highly vibrationally excited molecules.

Crim, F.F. [Univ. of Wisconsin, Madison (United States)

1993-12-01T23:59:59.000Z

90

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

91

Vortex Structure in Charged Condensate  

E-Print Network [OSTI]

We study magnetic fields in the charged condensate that we have previously argued should be present in helium-core white dwarf stars. We show that below a certain critical value the magnetic field is entirely expelled from the condensate, while for larger values it penetrates the condensate within flux-tubes that are similar to Abrikosov vortex lines; yet higher fields lead to the disruption of the condensate. We find the solution for the vortex lines in both relativistic and nonrelativistic theories that exhibit the charged condensation. We calculate the energy density of the vortex solution and the values of the critical magnetic fields. The minimum magnetic field required for vortices to penetrate the helium white dwarf cores ranges from roughly 10^7 to 10^9 Gauss. Fields of this strength have been observed in white dwarfs. We also calculate the London magnetic field due to the rotation of a dwarf star and show that its value is rather small.

Gabadadze, Gregory

2009-01-01T23:59:59.000Z

92

Vortex Structure in Charged Condensate  

E-Print Network [OSTI]

We study magnetic fields in the charged condensate that we have previously argued should be present in helium-core white dwarf stars. We show that below a certain critical value the magnetic field is entirely expelled from the condensate, while for larger values it penetrates the condensate within flux-tubes that are similar to Abrikosov vortex lines; yet higher fields lead to the disruption of the condensate. We find the solution for the vortex lines in both relativistic and nonrelativistic theories that exhibit the charged condensation. We calculate the energy density of the vortex solution and the values of the critical magnetic fields. The minimum magnetic field required for vortices to penetrate the helium white dwarf cores ranges from roughly 10^7 to 10^9 Gauss. Fields of this strength have been observed in white dwarfs. We also calculate the London magnetic field due to the rotation of a dwarf star and show that its value is rather small.

Gregory Gabadadze; Rachel A. Rosen

2009-05-14T23:59:59.000Z

93

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

94

Flame–vortex interaction in a reacting vortex ring  

Science Journals Connector (OSTI)

Direct numerical simulations are used to study the flame–vortex interaction in a laminar reacting vortex ring. The chemical reaction occurs by a one-step Arrhenius-type reaction that mimics the combustion of typical hydrocarbon and air. The ring is generated by an axisymmetric jet that is impulsed to emit a cold fuel through a nozzle. The fuel enters a quiescent ambient at a much higher temperature. By adjusting the ratio of the ambient and fuel temperatures the ignition either occurs during the formation or post-formation phase of the ring. When ignition occurs during the formation phase of the ring the bulk of combustion is by a flame at the front of the vortex bubble. When ignition is delayed until after the formation phase most of the reaction occurs inside the vortex ring. It is found that premixing the fuel and the oxidizer enhances the amount of product formation. The heat released from the reaction significantly affects production redistribution and diffusion of the vorticity throughout the field. The results of the simulations also reveal that the heat of reaction affects the strain rate fields differently depending on when the ignition of the ring occurs.

J. S. Hewett; C. K. Madnia

1998-01-01T23:59:59.000Z

95

Boundary layer induced by a conical vortex  

Science Journals Connector (OSTI)

......for later convenience. On the other hand, in order to improve the accuracy of the computations as the axis is approached, we rede fi ne the radial coordinate as l =? ln ?, (29) so that the interval 1 ? ? ? 0 is mapped onto 0 ? l < ?. Substituting (26......

R. Fernandez-Feria; J. C. Arrese

2000-11-01T23:59:59.000Z

96

Vibration dissipation mount for motors or the like  

DOE Patents [OSTI]

A vibration dissipation mount which permits the mounting of a motor, generator, or the like such that the rotatable shaft thereof passes through the mount and the mount permits the dissipation of self-induced and otherwise induced vibrations wherein the mount comprises a pair of plates having complementary concave and convex surfaces, a semi-resilient material being disposed therebetween.

Small, Thomas R. (Brookeville, MD)

1987-01-01T23:59:59.000Z

97

Measurement of building foundation and ground-borne vibrations due to surface trains and subways  

Science Journals Connector (OSTI)

Abstract Buildings located near surface trains and subways are subjected to surface train and subway-induced vibrations. Cutting edge technologies in laboratories and precision manufacturing facilities often include operation of vibration sensitive equipment. Human comfort in the form of feelable vibrations and audible noise in residential and office buildings is also a concern. It is thus imperative to reduce these vibrations inside buildings to acceptable levels with the design of an efficient vibration mitigation system. Incorporation of a vibration mitigation system in a building in design phase requires prior understanding and characterization of subway and surface train-induced base excitations of buildings before and after the construction of a structure to meet serviceability criteria. The vibrations measured at the foundation slab of buildings serve as the base excitation for the building and transmit to the to upper floor levels through columns. The focus of this paper is to quantify the amplitudes and frequency contents of vibration level measured at foundation slab and compare these vibration measurements inside the building at foundation level with the open field measurements. In this context, an exploration of ground-borne vibration characteristics was performed at six sites in the Boston area. Three sites were selected for measuring train-induced vibration and another three were considered for subway-induced vibration study. Vibration measurements were performed on the building foundation slab as well as in open fields adjacent to the building. These vibration measurements were quantified and compared. It was found that in the case of surface train-induced building vibrations, open field vibration levels can be conservatively used in the design of buildings. However due to inconsistency in observations, a similar conclusion was not drawn for the case of subway-induced building vibration. This paper also provides the bases that would allow the designer to estimate the vibration levels in sensitive locations within the building. These estimated levels determine the extent to which mitigation is required to meet vibration criteria.

Masoud Sanayei; Pradeep Maurya; James A. Moore

2013-01-01T23:59:59.000Z

98

Novel vortex dynamics in untwinned YBa{sub 2}Cu{sub 3}O{sub 7-{delta}} single crystals  

SciTech Connect (OSTI)

Magnetotransport measurements on a clean, untwinned YBa{sub 2}Cu{sub 3}O{sub 7{minus}{delta}} single crystal show that the vortex dynamics at temperatures just below the vortex lattice melting transition are highly dependent on the type of modulation of the probing current. While in the case of DC current the flux flow is disordered, the {open_quotes}shaking{close_quotes} of the vortex lattice by a square-wave current leads to a more uniform vortex motion. A small asymmetry ({approximately}10%) in the durations of the positive and negative parts of the square-wave period induces periodical oscillations of the voltage response amplitude. The period of oscillations ({approximately}100 s) is the same order of magnitude as the time needed for vortices to cross the sample (transit time). The authors relate the observed voltage oscillations to a periodically ordered vortex motion.

Gordeev, S.N.; Oussena, M.; Pinfold, S.; Langan, R.M. [Univ. of Southampton (United Kingdom)] [and others

1996-12-01T23:59:59.000Z

99

Vortex molecules in Bose-Einstein condensates  

E-Print Network [OSTI]

Stable vortex dimers are known to exist in coherently coupled two component Bose-Einstein condensates (BECs). We construct stable vortex trimers in three component BECs and find that the shape can be controlled by changing the internal coherent (Rabi) couplings. Stable vortex N-omers are also constructed in coherently coupled N-component BECs. We classify all possible N-omers in terms of the mathematical graph theory. Next, we study effects of the Rabi coupling in vortex lattices in two-component BECs. We find how the vortex lattices without the Rabi coupling known before are connected to the Abrikosov lattice of integer vortices with increasing the Rabi coupling. In this process, vortex dimers change their partners in various ways at large couplings. We then find that the Abrikosov lattices are robust in three-component BECs.

Muneto Nitta; Minoru Eto; Mattia Cipriani

2013-07-16T23:59:59.000Z

100

Quantum Kinematics of Bosonic Vortex Loops  

SciTech Connect (OSTI)

Poisson structure for vortex filaments (loops and arcs) in 2D ideal incompressible fluid is analyzed in detail. Canonical coordinates and momenta on coadjoint orbits of the area-preserving diffeomorphism group, associated with such vortices, are found. The quantum space of states in the simplest case of ''bosonic'' vortex loops is built within a geometric quantization approach to the description of a quantum fluid. Fock-like structure and non-local creation and annihilation operators of quantum vortex filaments are introduced.

Goldin, G.A.; Owczarek, R.; Sharp, D.H.

1999-05-06T23:59:59.000Z

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

DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM  

SciTech Connect (OSTI)

The deep hard rock drilling environment induces severe vibrations into the drillstring, which can cause reduced rates of penetration (ROP) and premature failure of the equipment. The only current means of controlling vibration under varying conditions is to change either the rotary speed or the weight-on-bit (WOB). These changes often reduce drilling efficiency. Conventional shock subs are useful in some situations, but often exacerbate the problems. The objective of this project is development of a unique system to monitor and control drilling vibrations in a ''smart'' drilling system. This system has two primary elements: (1) The first is an active vibration damper (AVD) to minimize harmful axial, lateral and torsional vibrations. The hardness of this damper will be continuously adjusted using a robust, fast-acting and reliable unique technology. (2) The second is a real-time system to monitor drillstring vibration, and related parameters. This monitor adjusts the damper according to local conditions. In some configurations, it may also send diagnostic information to the surface via real-time telemetry. The AVD is implemented in a configuration using magnetorheological (MR) fluid. By applying a current to the magnetic coils in the damper, the viscosity of the fluid can be changed rapidly, thereby altering the damping coefficient in response to the measured motion of the tool. Phase I of this program entailed modeling and design of the necessary subsystems and design, manufacture and test of a full laboratory prototype. Phase I of the project was completed by the revised end date of May 31, 2004. The objectives of this phase were met, and all prerequisites for Phase II have been completed.

Martin E. Cobern

2004-08-31T23:59:59.000Z

102

Diaphragm vibrator test rack  

Science Journals Connector (OSTI)

The above diaphragm-type vibrators provide sinusoidal vibrations at an amplitudea of ? 2000–3000 g at four fixed frequencies in the range of 1.5–4.0 kc, with a load not exceeding 100–200 g.

A. P. Pleshko; V. V. Perfil'ev

1961-02-01T23:59:59.000Z

103

Ground Vibration Measurement  

Science Journals Connector (OSTI)

Measurement of ground vibration is important for checking of amplitudes of ... confirmation of efficiency of control measures of ground vibration. The properties of measuring instruments used can affect the resul...

Dr. Milutin Srbulov

2010-01-01T23:59:59.000Z

104

Vortex Hydro Energy Develops Transformational Technology to Harness...  

Energy Savers [EERE]

Vortex Hydro Energy Develops Transformational Technology to Harness Energy from Water Currents Vortex Hydro Energy Develops Transformational Technology to Harness Energy from Water...

105

Vibration Measurement and Monitoring  

Science Journals Connector (OSTI)

Successful vibration measurement and analysis require an intimate familiarity with types of measurement, transducer characteristics and application, plus the...

V. Schlegel

1984-01-01T23:59:59.000Z

106

Heterodyne vibration measurement  

Science Journals Connector (OSTI)

Analytic expressions are derived for the vibration amplitude and frequency in a heterodyne measurement method. The measurement accuracy is estimated.

A. A. Titov

1993-08-01T23:59:59.000Z

107

Vibration Perception by Chaetognaths  

Science Journals Connector (OSTI)

... to locate and attack prey, the prey must be actively moving-that is, producing vibrations and turbulence.

T. K. NEWBURY

1972-04-28T23:59:59.000Z

108

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

2011-09-22T23:59:59.000Z

109

Stability of vortex solitons in a photorefractive optical lattice  

E-Print Network [OSTI]

://www.njp.org/ DOI: 10.1088/1367-2630/6/1/047 Abstract. Stability of on- and off-site vortex solitons with unit stable than off-site ones. Increasing the DC field stabilizes both types of vortex solitons. Contents 1. Introduction 2 2. Off-site vortex solitons 4 3. On-site vortex solitons 9 4. Summary 11 Acknowledgments 11

Yang, Jianke

110

Sediment resuspension and erosion by vortex rings R. J. Munro,1,a  

E-Print Network [OSTI]

Sediment resuspension and erosion by vortex rings R. J. Munro,1,a N. Bethke,2 and S. B. Dalziel2 1; accepted 26 January 2009; published online 8 April 2009 Particle resuspension and erosion induced-ring propagation speed. The critical conditions for resuspension whereby particles are only just resuspended were

Dalziel, Stuart

111

2094 OPTICS LETTERS / Vol. 28, No. 21 / November 1, 2003 Fundamental and vortex solitons in a  

E-Print Network [OSTI]

2094 OPTICS LETTERS / Vol. 28, No. 21 / November 1, 2003 Fundamental and vortex solitons in a two-dimensional optical lattice Jianke Yang Department of Mathematics and Statistics, University of Vermont, Burlington-dimensional optically induced waveguide array are reported. In the strong localization regime the fundamental soliton

Yang, Jianke

112

ORIGINAL ARTICLE BUEVA: a bi-directional ultrasonic elliptical vibration  

E-Print Network [OSTI]

. Surface roughness 1 Introduction Vibration-assisted machining (VAM) and vibration-induced machining (VIM. VAM and VIM applications are quite varied [1­3]. In VAM the former, traditional tools do the cutting, it was not until the early 1990s when many different VAM and VIM designs were introduced which varied in the manner

113

Noise & Vibration Ctrl What's noise and what's vibration?  

E-Print Network [OSTI]

Institut für Technische Akustik Noise & Vibration Ctrl · What's noise and what's vibration? ­ Noise = unwanted sound ­ Vibration = oscillations of structures © Prof. B.A.T. Petersson #12;Institut für Technische Akustik Noise & Vibration Ctrl. · What's Noise & Vibration Control? Genera t ion Transmiss ion

Berlin,Technische Universität

114

Theory of vibrational absorption sidebands in the Coulomb-blockade regime of single-molecule transistors  

E-Print Network [OSTI]

Theory of vibrational absorption sidebands in the Coulomb-blockade regime of single-molecule-driven vibrational nonequilibrium induces vibrational sidebands in single-molecule transistors which arise from.125306 PACS number s : 73.23.Hk, 73.63. b, 85.65. h I. INTRODUCTION Single-molecule junctions and transistors

von Oppen, Felix

115

Fabrication and Optimal Strain Sensor Placement in an Instrumented Disk Drive Suspension for Vibration Suppression  

E-Print Network [OSTI]

for Vibration Suppression Kenn Oldham, Stanley Kon Computer Mechanics Laboratory (CML) University of California drive suspension with vibra- tion sensing strain gages can enhance vibration suppression in hard disk bits. As the industry targets bit densities of 1 terabit per square inch, airflow induced vibration

Horowitz, Roberto

116

Vibration of a Pipeline with Liquid Under Combined Vibration Perturbations  

Science Journals Connector (OSTI)

We study the influence of combined vibration perturbations on the vibration of a pipeline with flowing liquid. The ... nonlinear model of a pipeline whose foundation suffers vibration perturbations in the longitu...

V. O. Limarchenko

2014-09-01T23:59:59.000Z

117

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

118

Vibration Control for Bridge Towers and Field Measurement  

Science Journals Connector (OSTI)

When the tower was under construction, there were some occasions to measure wind-induced response of the tower and also the performance of vibration control devices. Figure 9.8...shows the observed relationship, ...

Yozo Fujino; Kichiro Kimura; Hiroshi Tanaka

2012-01-01T23:59:59.000Z

119

Particle resuspension by an impacting vortex ring  

Science Journals Connector (OSTI)

Coherent vortex structures play a significant and important role in the dynamics of many commonly occurring natural flows, for example turbulent boundary layers and channel flows. One particularly important fe...

Rick J. Munro; Stuart B. Dalziel

2003-01-01T23:59:59.000Z

120

‘Optimal’ vortex rings and aquatic propulsion mechanisms  

Science Journals Connector (OSTI)

...vortex rings and aquatic propulsion mechanisms P. F. Linden...fluid mechanics behind these propulsion mechanisms and show that...over the cycle. 4. FISH PROPULSION BY UNDULATORY SWIMMING Most marine organisms have only discrete...

2004-01-01T23:59:59.000Z

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.


121

Polarization dependent forces in optical vortex pipeline  

Science Journals Connector (OSTI)

We study both, theoretically and in experiments, the dependence of optical forces acting on a spherical particle guided in air with an optical vortex beam, on the light polarization...

Eckerskorn, Niko; Krolikowski, Wieslaw; Shvedov, Vladlen; Rode, Andrei

122

Holographic Vortex Liquids and Superfluid Turbulence  

Science Journals Connector (OSTI)

...of Kelvin waves flowing along vortex strings in 3D quantum turbulence...theory correlators from non-critical string theory . Phys. Lett. B...S. , Emergence of turbulence in an oscillating Bose-Einstein condensate . Phys. Rev...

Paul M. Chesler; Hong Liu; Allan Adams

2013-07-26T23:59:59.000Z

123

Direct Imaging of Antiferromagnetic Vortex States  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

124

Direct Imaging of Antiferromagnetic Vortex States  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

125

Direct Imaging of Antiferromagnetic Vortex States  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

126

Vibration in Engineering  

Science Journals Connector (OSTI)

... THE theory of vibrations has in recent years A become of dominating importance in engineering. It is well ... A become of dominating importance in engineering. It is well known, for example, that vibrations in heavy machinery may be of a destructive nature, causing failures in the machines ...

1935-08-10T23:59:59.000Z

127

Vibration insensitive optical cavity  

Science Journals Connector (OSTI)

An optical cavity is designed and implemented that is insensitive to vibration in all directions. The cavity is mounted with its optical axis in the horizontal plane. A minimum response of 0.1 (3.7)kHz?ms?2 is achieved for low-frequency vertical (horizontal) vibrations.

S. A. Webster; M. Oxborrow; P. Gill

2007-01-09T23:59:59.000Z

128

Vibration in Engineering  

Science Journals Connector (OSTI)

... to be solved have been arranged. Among the subjects chosen for the Cambridge meeting was vibration, a phenomenon which, in this mechanical age, is in daily evidence to every ... concerned with the discomfort (and even, maybe, injury to health), which accompanies continuous vibration. From whichever point of view it is regarded, therefore, ...

1938-10-15T23:59:59.000Z

129

Multiple direction vibration fixture  

DOE Patents [OSTI]

An apparatus for simulating a rocket launch environment on a test item undergoing centrifuge testing by subjecting the item simultaneously or separately to vibration along an axis of centripetal force and along an axis perpendicular to the centripetal force axis. The apparatus includes a shaker motor supported by centrifuge arms and a right angle fixture pivotally connected to one of the shaker motor mounts. When the shaker motor vibrates along the centripetal force axis, the vibrations are imparted to a first side of the right angle fixture. The vibrations are transmitted 90 degrees around the pivot and are directed to a second side of the right angle fixture which imparts vibrations perpendicular to the centripetal force axis. The test item is in contact with a third side of the right angle fixture and receives both centripetal-force-axis vibrations and perpendicular axis vibrations simultaneously. A test item can be attached to the third side near the flexible coupling or near the air bag to obtain vibrations along the centripetal force axis or transverse to the centripetal force axis.

Cericola, Fred (Albuquerque, NM); Doggett, James W. (Albuquerque, NM); Ernest, Terry L. (Albuquerque, NM); Priddy, Tommy G. (Rockville, MD)

1991-01-01T23:59:59.000Z

130

Electron Trapping by Molecular Vibration  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Electron Trapping by Molecular Vibration Electron Trapping by Molecular Vibration Print Wednesday, 27 April 2005 00:00 In photoelectron spectroscopy experiments performed at the...

131

Tunable negligible-loss energy transfer between dipolar-coupled magnetic disks by stimulated vortex gyration  

E-Print Network [OSTI]

structure of magnetic vortex cores. Science 298, 577– Park,Magnetic vortex core observation in circular dots of Permalloy. Science

Jung, Hyunsung

2014-01-01T23:59:59.000Z

132

Spectroscopy and reactions of vibrationally excited transient molecules  

SciTech Connect (OSTI)

Spectroscopy, energy transfer and reactions of vibrationally excited transient molecules are studied through a combination of laser-based excitation techniques and efficient detection of emission from the energized molecules with frequency and time resolution. Specifically, a Time-resolved Fourier Transform Emission Spectroscopy technique has been developed for detecting dispersed laser-induced fluorescence in the IR, visible and UV regions. The structure and spectroscopy of the excited vibrational levels in the electronic ground state, as well as energy relaxation and reactions induced by specific vibronic excitations of a transient molecule can be characterized from time-resolved dispersed fluorescence in the visible and UV region. IR emissions from highly vibrational excited levels, on the other hand, reveal the pathways and rates of collision induced vibrational energy transfer.

Dai, H.L. [Univ. of Pennsylvania, Philadelphia (United States)

1993-12-01T23:59:59.000Z

133

Low-amplitude magnetic vortex core reversal by non-linear interaction between azimuthal spin waves and the vortex gyromode  

SciTech Connect (OSTI)

We show, by experiments and micromagnetic simulations in vortex structures, that an active “dual frequency” excitation of both the sub-GHz vortex gyromode and multi-GHz spin waves considerably changes the frequency response of spin wave mediated vortex core reversal. Besides additional minima in the switching threshold, a significant broadband reduction of the switching amplitudes is observed, which can be explained by non-linear interaction between the vortex gyromode and the spin waves. We conclude that the well known frequency spectra of azimuthal spin waves in vortex structures are altered substantially, when the vortex gyromode is actively excited simultaneously.

Sproll, Markus; Noske, Matthias; Kammerer, Matthias; Dieterle, Georg; Weigand, Markus; Stoll, Hermann; Schütz, Gisela [Max Planck Institute for Intelligent Systems (formerly MPI for Metals Research), Heisenbergstr. 3, 70569 Stuttgart (Germany)] [Max Planck Institute for Intelligent Systems (formerly MPI for Metals Research), Heisenbergstr. 3, 70569 Stuttgart (Germany); Bauer, Hans; Gangwar, Ajay; Woltersdorf, Georg; Back, Christian H. [Department of Physics, University of Regensburg, Universitätsstr. 31, 93040 Regensburg (Germany)] [Department of Physics, University of Regensburg, Universitätsstr. 31, 93040 Regensburg (Germany)

2014-01-06T23:59:59.000Z

134

Examples of vibration measurements  

Science Journals Connector (OSTI)

A detailed treatment of the vibration measurement techniques, applied in various fields of engineering ... only some of the most widely used modern measurement methods will be briefly presented, as well...

Gheorghe Buzdugan; Elena Mih?ilescu; Mircea Rade?

1986-01-01T23:59:59.000Z

135

2008 Vibrational Spectroscopy  

SciTech Connect (OSTI)

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

136

Vortex reconnections between coreless vortices in binary condensates  

SciTech Connect (OSTI)

Vortex reconnections plays an important role in the turbulent flows associated with the superfluids. To understand the dynamics, we examine the reconnections of vortex rings in the superfluids of dilute atomic gases confined in trapping potentials using Gross-Petaevskii equation. Further more we study the reconnection dynamics of coreless vortex rings, where one of the species can act as a tracer.

Gautam, S. [Indian Institute of Science, Bangalore-560 012 (India); Suthar, K.; Angom, D. [Physical Research Laboratory, Ahmedabad-380 009 (India)

2014-02-11T23:59:59.000Z

137

PHYSICS OF FLUIDS 24, 125108 (2012) Quantum vortex reconnections  

E-Print Network [OSTI]

is continuous, not discrete, and parts of the initial vortical tubes can be left behind as vortex threads, whichPHYSICS OF FLUIDS 24, 125108 (2012) Quantum vortex reconnections S. Zuccher,1 M. Caliari,1 A. W that the minimum distance between vortices scales differently with time before and after the vortex reconnection

Zuccher, Simone

138

Vibrational and Ghost-Vibrational Resonances in A Modified Chua's Circuit Model Equation  

E-Print Network [OSTI]

The role of the number of breakpoints $N$ in the sawtooth form of the characteristic function in the modified Chua's circuit model equation on vibrational and ghost-vibrational resonances is investigated in this paper. To observe vibrational resonance the system should be driven by two periodic forces of frequencies $\\omega$ and $\\Omega$, with $\\Omega\\gg\\omega$. Resonance occurs at the frequency $\\omega$ when the amplitude of the high-frequency force is varied. When the system is subjected to an input signal containing multi-frequencies which are higher-order of a certain (missing) fundamental frequency, then a resonance at the missing fundamental frequency is induced by the high-frequency input signal and is called ghost-vibrational resonance. In both types of resonances, the number of resonances is $N$ and hysteresis occurs in each resonance region. There are some similarities and differences in these two resonance phenomena. We report in detail the influence of the role of number of breakpoints $N$ on the features of vibrational and ghost-vibrational resonances.

K. Abirami; S. Rajasekar; M. A. F. Sanjuan

2014-06-26T23:59:59.000Z

139

Measure the Crack Instead of Construction Vibrations by Charles H. Dowding, Ph.D., P.E.  

E-Print Network [OSTI]

Measure the Crack Instead of Construction Vibrations by Charles H. Dowding, Ph.D., P.E. Figure 1 to address fears of vibration-induced cracking by directly measuring crack response. Relatively inexpensive. HOUSE AND CRACK RESPONSE TO VIBRATIONS Crack measurement concepts are illustrated by the response

140

Resuspension onset and crater erosion by a vortex ring interacting with a particle layer  

Science Journals Connector (OSTI)

This paper presents results from an experimental investigation of the interaction of a vortex ring with a particle layer. The flowdynamics during the onset of particle resuspension are analysed using particle image velocimetry while a light attenuation method provides accurate measurements of the final eroded crater shape. This work is a continuation of the research described in R. J. Munro N. Bethke and S. B. Dalziel “Sediment resuspension and erosion by vortex rings ” Phys. Fluids21 046601 (2009)10.1063/1.3083318 which focussed on the general resuspension onset dynamics and initial crater formation. Here we analyse the velocity induced by the vortex ring on the particle layer surface during the resuspension of particles for different particle sizes and the shape and size of the final craters that are formed by the impact of the vortex ring. We find that the boundary condition is characterised by a quasi-slip velocity at the particle layer surface independent of the particle size. The particle diameter and thus bed permeability is found to have a significant effect on the final crater characteristics.

N. Bethke; S. B. Dalziel

2012-01-01T23:59:59.000Z

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.


141

vibrations.dvi  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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,

142

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

143

Jammed vortex matter Hajime Yoshino1  

E-Print Network [OSTI]

. Abstract: Irrationally frustrated Josephson junction array (JJA), namely JJA with irrational number density point. Figure 1: Josephson junction array (JJA) on a square lattice. The vertexes and bonds represent- not develop usual periodic vortex lattices. 1 Introduction Josephson junction array under mag- netic field

Katsumoto, Shingo

144

Vortex lines in films: Fields and interactions  

Science Journals Connector (OSTI)

General expressions are given for the magnetic field and energy of arbitrary arrangements of straight and curved vortices in an anisotropic superconductor film of finite thickness within anisotropic London theory. As examples we consider the magnetic field and interaction of straight perpendicular vortex lines in films of finite thickness.

Gilson Carneiro and Ernst Helmut Brandt

2000-03-01T23:59:59.000Z

145

Vortex Jitter in Hover Swathi M. Mula  

E-Print Network [OSTI]

78712, USA Abstract The trajectory of the tip vortex of a reduced-scale, 1 m diameter, four-bladed rotor condition of the rotor is at a blade loading of CT / = 0.0645 and a rotational speed of 1240RPM wake dominated by the tip vortices shed from the rotor blades. The complexity of the flow

Tinney, Charles E.

146

The multiple vortex nature of tropical cyclogenesis  

E-Print Network [OSTI]

) __________________________ __________________________ John Nielsen-Gammon Craig Epifanio (Chair of Committee) (Member) __________________________ __________________________ Fuqing Zhang Hongxing Liu (Member) (Member) December 2004 Major Subject: Atmospheric Sciences... iii ABSTRACT The Multiple Vortex Nature of Tropical Cyclogenesis. (December 2004) Jason Allen Sippel, B.S., Texas A&M University Chair of Advisory Committee: Dr. John Nielsen-Gammon This thesis contains an observational analysis...

Sippel, Jason Allen

2005-02-17T23:59:59.000Z

147

Quenching Processes in Flame-Vortex Interactions  

E-Print Network [OSTI]

for Astrophysical Thermonuclear Flashes 1 , Chicago, IL 60637 y Department of Astronomy and Astrophysics, University-vortex interactions in order to understand quenching of thermonuclear ames. The key question is|can a ther- monuclear. If a ame encounters a 1) The Center for Astrophysical Thermonuclear Flashes is supported by the Department

Zingale, Michael

148

Fiber optic vibration sensor  

DOE Patents [OSTI]

A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity.

Dooley, Joseph B. (Harriman, TN); Muhs, Jeffrey D. (Lenoir City, TN); Tobin, Kenneth W. (Harriman, TN)

1995-01-01T23:59:59.000Z

149

Fiber optic vibration sensor  

DOE Patents [OSTI]

A fiber optic vibration sensor utilizes two single mode optical fibers supported by a housing with one optical fiber fixedly secured to the housing and providing a reference signal and the other optical fiber having a free span length subject to vibrational displacement thereof with respect to the housing and the first optical fiber for providing a signal indicative of a measurement of any perturbation of the sensor. Damping or tailoring of the sensor to be responsive to selected levels of perturbation is provided by altering the diameter of optical fibers or by immersing at least a portion of the free span length of the vibration sensing optical fiber into a liquid of a selected viscosity. 2 figures.

Dooley, J.B.; Muhs, J.D.; Tobin, K.W.

1995-01-10T23:59:59.000Z

150

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

151

Vibration by relativistic effects  

E-Print Network [OSTI]

Relativity, time reversal invariance in mechanics and principle of causality can be in the bases of a type of vibration of the extensive objects. It is because, the detailed analysis of the relativistic movement of an extensive body entail that all the objects must have inherent a vibratory movement to their own size. Such effect does not happen when it works with point particles thus is not stranger who happens unnoticed in the traditional studies. Also we can find relation between the form of vibration of the extensive objects and the energy that calculates by quantum considerations.

Enrique Oradaz Romay

2005-12-23T23:59:59.000Z

152

Fundamental discussions on seismic vibrators  

Science Journals Connector (OSTI)

...now ConocoPhillips) with a trailer-mounted swing weight vibrator...an application of a servo-hydraulic vibrator with a peak-force...paper demonstrated the servo-hydraulic vibrator capability to deliver...as indicated in the book, Hydraulic Control Systems (Merritt...

Zhouhong Wei; Thomas F. Phillips; Michael A. Hall

153

2 - Fundamentals of vibrations  

Science Journals Connector (OSTI)

Abstract: An elastic system could exhibit oscillatory motion when external energy is supplied to the system. External energy can be supplied to the system through either an applied force or an imposed motion excitation. The applied force or motion excitation may be harmonic, periodic, nonperiodic, or random in nature. Real engineering systems can be modeled as discrete systems (single or multiple-degree-of-freedom system) or continuous system having an infinite number of degrees of freedom. The discrete system contains discrete masses and springs and even dampers, whereas the continuous system has distributed masses, springs and dampers. A vibration system may experience transient response under suddenly applied non-periodic excitation. The nondeterministic vibration of system under random excitation could be quantified by probabilistic analysis. The dynamical system’s parameters such as stiffness and damping could exhibit salient nonlinearity if the amplitude of motion is relatively large. Nonlinear system exhibit complicated vibrations such as primary resonance, super-and-sub harmonics, combination resonance, bifurcation and chaos. This chapter provides detailed discussion of single- and multiple-degree-of-freedom linear systems under harmonic excitations and random excitations. It will present the vibrations of continuous systems including string, rod and beam. This chapter will also present the methods to treat nonlinear systems, focusing on three kinds of typical nonlinear systems: Duffing equations, Van der Pol equations and Mathieu equations. This chapter will also brief the concept of bifurcation and chaos in nonlinear systems.

2014-01-01T23:59:59.000Z

154

Nonlinear vibrational microscopy  

DOE Patents [OSTI]

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

155

Vibration sensing method and apparatus  

DOE Patents [OSTI]

A method and apparatus for nondestructive evaluation of a structure are disclosed. Resonant audio frequency vibrations are excited in the structure to be evaluated and the vibrations are measured and characterized to obtain information about the structure. The vibrations are measured and characterized by reflecting a laser beam from the vibrating structure and directing a substantial portion of the reflected beam back into the laser device used to produce the beam which device is capable of producing an electric signal containing information about the vibration. 4 figs.

Barna, B.A.

1989-04-25T23:59:59.000Z

156

Vibration sensing method and apparatus  

DOE Patents [OSTI]

A method and apparatus for nondestructive evaluation of a structure is disclosed. Resonant audio frequency vibrations are excited in the structure to be evaluated and the vibrations are measured and characterized to obtain information about the structure. The vibrations are measured and characterized by reflecting a laser beam from the vibrating structure and directing a substantial portion of the reflected beam back into the laser device used to produce the beam which device is capable of producing an electric signal containing information about the vibration.

Barna, Basil A. (Idaho Falls, ID)

1989-04-25T23:59:59.000Z

157

Vibration sensing method and apparatus  

DOE Patents [OSTI]

A method and apparatus for nondestructive evaluation of a structure is disclosed. Resonant audio frequency vibrations are excited in the structure to be evaluated and the vibrations are measured and characterized to obtain information about the structure. The vibrations are measured and characterized by reflecting a laser beam from the vibrating structure and directing a substantial portion of the reflected beam back into the laser device used to produce the beam which device is capable of producing an electric signal containing information about the vibration. 4 figs.

Barna, B.A.

1987-07-07T23:59:59.000Z

158

The Effect of Whole Body Horizontal Vibration in Position Sense and Dynamic Stability of the Spine  

E-Print Network [OSTI]

of kneeling posture [10]. McGill et al. suggested that a fully- flexed spine results in lumbar extensor muscles ineffective to support anterior shear force, which is related to low back injury [11]. Standing and sitting have specific advantages... in flexed and asymmetric posture [79]. In another study, Arashanapalli et al. demonstrated the increased position sense error both during vibration exposure and instant after vibration exposure [76]. In addition, in a recent study of vibration induced...

Lamis, Farhana

2008-06-09T23:59:59.000Z

159

A Vortex Contactor for Carbon Dioxide Separations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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)

160

Vortex Dynamics in NanoScale Materials  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

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

Acceleration and vortex filaments in turbulence  

E-Print Network [OSTI]

We report recent results from a high resolution numerical study of fluid particles transported by a fully developed turbulent flow. Single particle trajectories were followed for a time range spanning more than three decades, from less than a tenth of the Kolmogorov time-scale up to one large-eddy turnover time. We present some results concerning acceleration statistics and the statistics of trapping by vortex filaments.

F. Toschi; L. Biferale; G. Boffetta; A. Celani; B. J. Devenish; A. Lanotte

2005-01-23T23:59:59.000Z

162

Jet?vortex Interaction: A Numerical Study  

Science Journals Connector (OSTI)

The interaction of a vortex and a jet plays an important role for many industrial processes such as Carbon Black formation or combustion in diesel engines. The knowledge of physics of these phenomena is crucial for engineers but also for scientists who wish to reveal many interesting and complex issues hidden there. In this research we numerically investigate cases where a cylindrical reactor is charged with gas injected through five ports. The first one is located along the main axis of the cylinder and this leads to the formation of the main jet. The other four ports are situated along the side walls such that the gas entering the cylinder tangentially through them causes a vortex to be formed. The objective of this paper is to show the fundamental physical phenomena and also how the initial and boundary conditions influence the results. Our most important observation at this stage is that the mixing process is more intense if the vortex is inclined towards x?axis. The results are mainly shown as snapshots of gas velocity.

Catalin G. Ilea; Pawel Kosinski; Alex C. Hoffmann

2009-01-01T23:59:59.000Z

163

Liquid Vortex Shielding for Fusion Energy Applications  

SciTech Connect (OSTI)

Swirling liquid vortices can be used in fusion chambers to protect their first walls and critical elements from the harmful conditions resulting from fusion reactions. The beam tube structures in heavy ion fusion (HIF) must be shielded from high energy particles, such as neutrons, x-rays and vaporized coolant, that will cause damage. Here an annular wall jet, or vortex tube, is proposed for shielding and is generated by injecting liquid tangent to the inner surface of the tube both azimuthally and axially. Its effectiveness is closely related to the vortex tube flow properties. 3-D particle image velocimetry (PIV) is being conducted to precisely characterize its turbulent structure. The concept of annular vortex flow can be extended to a larger scale to serve as a liquid blanket for other inertial fusion and even magnetic fusion systems. For this purpose a periodic arrangement of injection and suction holes around the chamber circumference are used, generating the layer. Because it is important to match the index of refraction of the fluid with the tube material for optical measurement like PIV, a low viscosity mineral oil was identified and used that can also be employed to do scaled experiments of molten salts at high temperature.

Bardet, Philippe M. [University of California, Berkeley (United States); Supiot, Boris F. [University of California, Berkeley (United States); Peterson, Per F. [University of California, Berkeley (United States); Savas, Oemer [University of California, Berkeley (United States)

2005-05-15T23:59:59.000Z

164

Magnetic Vortex Core Reversal by Low-Field Excitations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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...

165

Novel Vortex Generator and Mode Converter for Electron Beams  

Science Journals Connector (OSTI)

A mode converter for electron vortex beams is described. Numerical simulations, confirmed by experiment, show that the converter transforms a vortex beam with a topological charge m=±1 into beams closely resembling Hermite-Gaussian HG10 and HG01 modes. The converter can be used as a mode discriminator or filter for electron vortex beams. Combining the converter with a phase plate turns a plane wave into modes with topological charge m=±1. This combination serves as a generator of electron vortex beams of high brilliance.

P. Schattschneider; M. Stöger-Pollach; J. Verbeeck

2012-08-22T23:59:59.000Z

166

Energy Separation And Lox Separation Studies In Vortex Tubes.  

E-Print Network [OSTI]

??Vortex Tube (VT) is a simple device having no moving mechanical parts, in which compressed gas at high pressure is injected through one or more… (more)

Behera, Upendra

2011-01-01T23:59:59.000Z

167

Vortex motion rectification in Josephson junction arrays with a ratchet potential  

E-Print Network [OSTI]

By means of electrical transport measurements we have studied the rectified motion of vortices in ratchet potentials engineered on over-damped Josephson junction arrays. The rectified voltage as a function of the vortex density shows a maximum efficiency close a matching condition to the period of the ratchet potential indicating a collective vortex motion. Vortex current reversals where detected varying the driving force and vortex density revealing the influence of vortex-vortex interaction in the ratchet effect.

D. E. Shalom; H. Pastoriza

2004-11-19T23:59:59.000Z

168

An application of vortex cancellation to vortex generator techniques in low speed wind tunnels  

E-Print Network [OSTI]

'lugs/ft-sec Axial distance between sets of vortex generators root chord lengths /Y Vertical dimension of duct cross section Tube height/Y in. none ~St i t ()i ()2 (), ( )?q Measured at station g 1 Measured at Station 0 8 Upstream srl... TABLE I II BOUNDARY LAYER PROFILE DATA IN THE VICINITY OF A VORTEX FILAMENT AT STATION 0 7 Tube Number I 2 3 4. 5 6 7 8 9 '10 I 2 3 4 5 6 7 8 9 10 I 2 3 4 5 6 7 8 9 10 Ft-Fs in. H 0 1. 31 1. 31 1. 31 I . 26 1. 20...

Mount, Glynn O., Jr

2012-06-07T23:59:59.000Z

169

Symmetry breaking in the formation of magnetic vortex states in a permalloy nanodisk  

E-Print Network [OSTI]

structure of magnetic vortex cores. Science 298, 6. Fischer,Magnetic Material Center, National Institute for Materials Science (Magnetic vortex core observation in circular dots of Permalloy. Science

Im, Mi-Young

2014-01-01T23:59:59.000Z

170

E-Print Network 3.0 - advanced vortex element Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

method of plasma Summary: with the new simple explanation of the energy separation in vortex tubes described here. Advanced numerical... vortex method of plasma insulation and...

171

E-Print Network 3.0 - accelerated vortex ring Sample Search Results  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

left behind... forces were derived from the vortex rings, assuming all propulsive energy to be compiled in the rings... , ending up in a separate vortex ... Source:...

172

Transverse energy circulation and the edge diffraction of an optical vortex beam  

Science Journals Connector (OSTI)

Edge diffraction of a circular Laguerre–Gaussian beam represents an example of the optical vortex symmetry breakdown in which the hidden “vortex” energy...

Bekshaev, Aleksandr Ya; Mohammed, Kadhim A; Kurka, Ivan A

2014-01-01T23:59:59.000Z

173

Pedestrian-induced vibrations on structural systems  

E-Print Network [OSTI]

Although models have been suggested to describe the loadings caused by pedestrian motion, they do not adequately model pedestrian loading patterns. Therefore the task of describing pedestrian motion was approached from a different direction and a...

McMahan, Anastasia K.

1996-01-01T23:59:59.000Z

174

Vibration damping method and apparatus  

DOE Patents [OSTI]

The present invention provides vibration damping method and apparatus that can damp vibration in more than one direction without requiring disassembly, that can accommodate varying tool dimensions without requiring re-tuning, and that does not interfere with tool tip operations and cooling. The present invention provides active dampening by generating bending moments internal to a structure such as a boring bar to dampen vibration thereof.

Redmond, James M. (Albuquerque, NM); Barney, Patrick S. (Albuquerque, NM); Parker, Gordon G. (Hougton, MI); Smith, David A. (Gainesville, FL)

1999-01-01T23:59:59.000Z

175

Mini genset for vibration measurement.  

E-Print Network [OSTI]

??Detta examensarbete gjordes vid Wärtsilä Service, Vibration Environmental and Measurement Technologies i Runsor, Vasa. Syftet med detta examensarbete var att designa och bygga ett minigenset… (more)

Mann, Dennis

2012-01-01T23:59:59.000Z

176

Electron Trapping by Molecular Vibration  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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...

177

Magnetic Vortex Core Reversal by Low-Field Excitations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

178

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

179

ENERGY LEVEL SPECTROSCOPY OF A BOUND VORTEX-ANTIVORTEX PAIR  

E-Print Network [OSTI]

vortex- antivortex (VAV) state in an annular Josephson junction. The bound VAV pair is formed microwave spectroscopy. Keywords: Macroscopic quantum effects, long Josephson junctions, vortex­9]. Most of the studied systems, such as dc-biased Josephson junctions (JJ), supercon- ducting quantum

Wallraff, Andreas

180

Solvent-side observation on vibrational energy transfer by transient grating spectroscopy: Bridged azulene-anthracene  

E-Print Network [OSTI]

Transient grating acoustic spectroscopy has been applied to studies on the vibrational energy relaxation process of the electronic ground state of azulene, two 1-alkylazulenes, and five bridged azulene-anthracenes in three different solvents: 1,1,1-trichloro-1,2,2-trifluoroethane, acetonitrile, and xenon. The solute molecule was vibrationally excited by the photo-excitation of the auzlenyl group to the S1 state through the fast internal conversion, and the rate of solvent thermalization due to the vibrational energy relaxation was determined. The thermalization rates for 1-alkylazulenes and bridged azulene-anthracenes were faster than that of azulene. Based on the results of the thermalization rates of 1-alkylazulenes, we concluded that the acceleration of the energy dissipation from the azulenyl group induced the faster energy dissipation from the solute to the solvent. The vibrational normal mode analysis suggests that the density of the vibrational modes and anharmonic coupling between the vibrational mode...

Fujiwara, Hiroki

2014-01-01T23:59:59.000Z

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.


181

Dynamics of Magnetized Vortex Tubes in the Solar Chromosphere  

E-Print Network [OSTI]

We use 3D radiative MHD simulations to investigate the formation and dynamics of small-scale (less than 0.5 Mm in diameter) vortex tubes spontaneously generated by turbulent convection in quiet-Sun regions with initially weak mean magnetic fields. The results show that the vortex tubes penetrate into the chromosphere and substantially affect the structure and dynamics of the solar atmosphere. The vortex tubes are mostly concentrated in intergranular lanes and are characterized by strong (near sonic) downflows and swirling motions that capture and twist magnetic field lines, forming magnetic flux tubes that expand with height and which attain magnetic field strengths ranging from 200 G in the chromosphere to more than 1 kG in the photosphere. We investigate in detail the physical properties of these vortex tubes, including thermodynamic properties, flow dynamics, and kinetic and current helicities, and conclude that magnetized vortex tubes provide an important path for energy and momentum transfer from the con...

Kitiashvili, I N; Mansour, N N; Wray, A A

2012-01-01T23:59:59.000Z

182

Apparatus for vibrating a pipe string in a borehole  

SciTech Connect (OSTI)

This patent describes an apparatus for vibrating a drill string having a central axis in a borehole. The apparatus comprising means for generating at a downhole location longitudinally directional vibrations along the central axis of the drill string in response to flow of fluid through the interior of the drill string and a shock absorbing element mounted in the drill string between the apparatus and a drill bit carried by the drill string effective to substantially isolate the drill bit from the vibration induced in the drill string. Also described is a method of feeding a drill string through a mon-vertical section of borehole comprising: generating a downhole location a longitudinally directional vibration along the central axis of the drill string by oscillating a body in a axial direction relative to the drill string in response to flow of fluid through the interior of the drill string. The vibrations preventing frictional sticking of the drill string against the borehole wall; isolating a drill bit at the end of the drill string from the effects of the vibration during drilling operations; and moving the pipe longitudinally in the borehole.

Worrall, R.N.; Stulemeijer, I.P.J.M.

1990-01-02T23:59:59.000Z

183

Vibrations of Sessile Drops of Soft Hydrogels  

E-Print Network [OSTI]

Sessile drops of soft hydrogels were vibrated vertically by subjecting them to a mechanically induced Gaussian white noise. Power spectra of the surface fluctuation of the gel allowed identification of its resonant frequency that decreases with their mass, but increases with its shear modulus. The principal resonant frequencies of the spheroidal modes of the gel of shear moduli ranging from 55 Pa to 290 Pa were closest to the lowest Rayleigh mode of vibration of a drop of pure water. These observations coupled with the fact that the resonance frequency varies inversely as the square root of the mass in all cases suggest that they primarily correspond to the capillary (or a pseudo-capillary) mode of drop vibration. The contact angles of the gel drops also increase with the modulus of the gel. When the resonance frequencies are corrected for the wetting angles, and plotted against the fundamental frequency scale (gamma/mu)^0.5, all the data collapse nicely on a single plot provided that the latter is shifted by a shear modulus dependent factor (1+mu.L/gamma). A length scale L, independent of both the modulus and the mass of the drop emerges from such a fit.

Aditi Chakrabarti; Manoj K. Chaudhury

2014-10-08T23:59:59.000Z

184

Vibration-Rotation Bands of Trideuteromethyl Iodide  

Science Journals Connector (OSTI)

5 October 1965 research-article Vibration-Rotation Bands of Trideuteromethyl...of six parallel and nine perpendicular vibration bands of trideuteromethyl iodide has...constants for the fundamental degenerate vibrations. The values for overtone and combination...

1965-01-01T23:59:59.000Z

185

Modelling vortex-induced fluid–structure interaction  

Science Journals Connector (OSTI)

...Atsavapranee, T Wei, and J McHugh2000The role of turbulent elongational stresses on deflocculation in paper sheet formation. TAPPI J. 83, 70 Sibetheros, I. A., Miskad, R. W., Ventre, A.-V. Lambrakos, K. F. 1994 Flow mapping of the reversing...

2008-01-01T23:59:59.000Z

186

Electromagnetic Behavior of the Vortex Sponge  

Science Journals Connector (OSTI)

In an introductory paper the vortex sponge was shown to be governed in restricted cases by Maxwell's free-space equations. In the present paper analogs to electric and magnetic energies and Poynting's theorem are derived by simple mechanical considerations. Rotational stability suggested originally by MacCullagh as a fundamental property of a luminiferous ether turns out to be a quality of the medium as do the stresses introduced by Faraday and Maxwell to explain the mechanical actions of electric and magnetic fields. A rudimentary model for the electrostatic field is suggested on this basis. A conventional definition of charge and the laws of Coulomb and Biot complete Maxwell's equations for cases including charges and currents. A model of the magnetic field based on the bulk rotation and the Faraday-Maxwell stresses combined with the laws of Coulomb and Biot permits the inference of the Lorentz force. Although numerous gaps occur in the treatment it seems not unlikely that the vortex sponge has the qualities described by the electromagnetic field equations as well as the mechanical attributes required for a model of these fields.

Edward M. Kelly

1964-01-01T23:59:59.000Z

187

Vibration Theory and Engineering Practice  

Science Journals Connector (OSTI)

... INTRICATE vibration phenomena have at all times attracted the attention of the physical investigator, and ... phenomena have at all times attracted the attention of the physical investigator, and vibration theory is a wide field well and fruitfully cultivated by the mathematician. The achievements ...

1929-10-05T23:59:59.000Z

188

Mechanical Impedance Methods in Vibration  

Science Journals Connector (OSTI)

... THE basic theory of linear mechanical vibration has been in existence for many years. Unfortunately, in some respects that theory is ... in some respects that theory is not in a convenient form for use in modern vibration analysis. Much effort has therefore been put into re-casting, tabulating, re-examining ...

R. E. D. BISHOP

1959-12-05T23:59:59.000Z

189

Sum Frequency Generation for Surface Vibrational Spectroscopy...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Sum Frequency Generation for Surface Vibrational Spectroscopy Sum Frequency Generation for Surface Vibrational Spectroscopy This customized SFG-VS spectrometer incorporates unique...

190

Irreversible flow of vortex matter: Polycrystal and amorphous phases Paolo Moretti and M.-Carmen Miguel  

E-Print Network [OSTI]

systems exhibiting this phenomenol- ogy, flux line vortex lattices in type II superconductors rep- resent

Miguel-Lopez, Carmen

191

Potential Flow Model of a Vortex Street Near a Fish-like Body  

E-Print Network [OSTI]

Potential Flow Model of a Vortex Street Near a Fish-like Body Joshua Brulé, University of Maryland to inviscid, irrotational solutions of Navier-Stokes · Vortex potential: "A model of the lateral line of fish for vortex sensing." Ren Z, Mohseni K. 2012 #12;Vortex near a (circular) fish · (Insert your own spherical

Anlage, Steven

192

Vortex-vacancy interactions in two-dimensional easy-plane magnets G. M. Wysin  

E-Print Network [OSTI]

Vortex-vacancy interactions in two-dimensional easy-plane magnets G. M. Wysin Department of Physics of a magnetic vacancy site on a nearby magnetic vortex are analyzed on square, hexagonal and triangular lattices. When the vortex is centered on a vacancy, the critical anisotropies where the stable vortex structure

Wysin, Gary

193

Experimental Analysis of a Piezoelectric Energy Harvesting System for Harmonic, Random, and Sine on Random Vibration  

SciTech Connect (OSTI)

Formal journal article Experimental analysis of a piezoelectric energy harvesting system for harmonic, random, and sine on random vibration Abstract: Harvesting power with a piezoelectric vibration powered generator using a full-wave rectifier conditioning circuit is experimentally compared for varying sinusoidal, random and sine on random (SOR) input vibration scenarios. Additionally, the implications of source vibration characteristics on harvester design are discussed. Studies in vibration harvesting have yielded numerous alternatives for harvesting electrical energy from vibrations but piezoceramics arose as the most compact, energy dense means of energy transduction. The rise in popularity of harvesting energy from ambient vibrations has made piezoelectric generators commercially available. Much of the available literature focuses on maximizing harvested power through nonlinear processing circuits that require accurate knowledge of generator internal mechanical and electrical characteristics and idealization of the input vibration source, which cannot be assumed in general application. In this manuscript, variations in source vibration and load resistance are explored for a commercially available piezoelectric generator. We characterize the source vibration by its acceleration response for repeatability and transcription to general application. The results agree with numerical and theoretical predictions for in previous literature that load optimal resistance varies with transducer natural frequency and source type, and the findings demonstrate that significant gains are seen with lower tuned transducer natural frequencies for similar source amplitudes. Going beyond idealized steady state sinusoidal and simplified random vibration input, SOR testing allows for more accurate representation of real world ambient vibration. It is shown that characteristic interactions from more complex vibrational sources significantly alter power generation and power processing requirements by increasing harvested power, shifting optimal conditioning impedance, inducing significant voltage supply fluctuations and ultimately rendering idealized sinusoidal and random analyses insufficient.

Cryns, Jackson W.; Hatchell, Brian K.; Santiago-Rojas, Emiliano; Silvers, Kurt L.

2013-07-01T23:59:59.000Z

194

Estudo de VIM - Movimentos Induzidos por Vórtices em plataformas do tipo monocoluna: abordagem  numérico-experimental e impactos no sistema de amarração.  

E-Print Network [OSTI]

??The vortex induced vibration VIV is a main subject studied in the offshore engineering, having its name adapted to VIM by the occurrence in Spar… (more)

Marcos Salles Cueva

2011-01-01T23:59:59.000Z

195

CX-011455: Categorical Exclusion Determination | Department of...  

Broader source: Energy.gov (indexed) [DOE]

Exclusion Determination CX-011455: Categorical Exclusion Determination Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters CX(s) Applied: A9, A11 Date: 1105...

196

NETL F 451.1/1-1, Categorical Exclusion Designation Form  

Broader source: Energy.gov (indexed) [DOE]

Laboratory SCNGO FY14-1524 months Gary Covatch Los Alamos, NM Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters Activities include literature...

197

NETL F 451.1/1-1, Categorical Exclusion Designation Form  

Broader source: Energy.gov (indexed) [DOE]

Engineering SCNGO FY14-1524 months Gary Covatch Mountain View, CA Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters Computer modeling. Gary L. Covatch...

198

CX-011456: Categorical Exclusion Determination | Department of...  

Broader source: Energy.gov (indexed) [DOE]

Exclusion Determination CX-011456: Categorical Exclusion Determination Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters CX(s) Applied: A9, A11 Date: 1105...

199

NETL F 451.1/1-1, Categorical Exclusion Designation Form  

Broader source: Energy.gov (indexed) [DOE]

Halkyard & Associates SCNGO FY14-1524 months Gary Covatch Houston, TX Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters Consulting. Gary L. Covatch...

200

CX-011457: Categorical Exclusion Determination | Department of...  

Broader source: Energy.gov (indexed) [DOE]

Exclusion Determination CX-011457: Categorical Exclusion Determination Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters CX(s) Applied: A9, A11 Date: 1105...

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

CX-011454: Categorical Exclusion Determination | Department of...  

Broader source: Energy.gov (indexed) [DOE]

Exclusion Determination CX-011454: Categorical Exclusion Determination Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters CX(s) Applied: A9, A11 Date: 1105...

202

Magnetic Vortex Core Reversal by Low-Field Excitations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

203

Magnetic Vortex Core Reversal by Low-Field Excitations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

204

Magnetic Vortex Core Reversal by Low-Field Excitations  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

205

Vortex configurations of bosons in an optical lattice  

SciTech Connect (OSTI)

The single-vortex problem in a strongly correlated bosonic system is investigated self-consistently within the mean-field theory of the Bose-Hubbard model. Near the superfluid-Mott-insulator transition, the vortex core has a tendency toward the Mott-insulating phase, with the core particle density approaching the nearest commensurate value. If the nearest-neighbor repulsion exists, the charge-density wave order may develop locally in the core. The evolution of the vortex configuration from the strong- to weak-coupling regions is studied. This phenomenon can be observed in systems of rotating ultracold atoms in optical lattices and Josephson-junction arrays.

Wu Congjun; Zhang Shoucheng [Department of Physics, McCullough Building, Stanford University, Stanford, California 94305-4045 (United States); Chen Handong [Department of Applied Physics, McCullough Building, Stanford University, Stanford, California 94305-4045 (United States); Hu Jiangpiang [Department of Physics and Astronomy, University of California, Los Angeles, California 90095-1547 (United States)

2004-04-01T23:59:59.000Z

206

Monopole-Antimonopole Chains and Vortex Rings  

E-Print Network [OSTI]

We consider static axially symmetric solutions of SU(2) Yang-Mills-Higgs theory. The simplest such solutions represent monopoles, multimonopoles and monopole-antimonopole pairs. In general such solutions are characterized by two integers, the winding number m of their polar angle, and the winding number n of their azimuthal angle. For solutions with n=1 and n=2, the Higgs field vanishes at m isolated points along the symmetry axis, which are associated with the locations of m monopoles and antimonopoles of charge n. These solutions represent chains of m monopoles and antimonopoles in static equilibrium. For larger values of n, totally different configurations arise, where the Higgs field vanishes on one or more rings, centered around the symmetry axis. We discuss the properties of such monopole-antimonopole chains and vortex rings, in particular their energies and magnetic dipole moments, and we study the influence of a finite Higgs self-coupling constant on these solutions.

Burkhard Kleihaus; Jutta Kunz; Yasha Shnir

2004-05-19T23:59:59.000Z

207

Integrated multi vector vortex beam generator  

E-Print Network [OSTI]

A novel method to generate and manipulate vector vortex beams in an integrated, ring resonator based geometry is proposed. We show numerically that a ring resonator, with an appropriate grating, addressed by a vertically displaced access waveguide emits a complex optical field. The emitted beam possesses a specific polarization topology, and consequently a transverse intensity profile and orbital angular momentum. We propose a combination of several concentric ring resonators, addressed with different bus guides, to generate arbitrary orbital angular momentum qudit states, which could potentially be used for classical and quantum communications. Finally, we demonstrate numerically that this device works as an orbital angular momentum sorter with an average cross-talk of -10 dB between different orbital angular momentum channels.

Sebastian A. Schulz; Taras Machula; Ebrahim Karimi; Robert W. Boyd

2013-03-19T23:59:59.000Z

208

Vibrational relaxation of trapped molecules  

Science Journals Connector (OSTI)

Vibrational relaxation of trapped molecules due to collisions with cold atoms is investigated using the results of quantum-mechanical scattering calculations. Trap loss is analyzed using an exactly solvable kinetic model that includes direct collisional quenching and an indirect process of vibrational predissociation. At low atom density, the relaxation is due primarily to collisional quenching. At high atom density, the relaxation involves additional time scales due to the formation and decay of van der Waals complexes. It is shown that the most weakly bound state of the van der Waals complex for a given diatomic vibrational level controls the relaxation at all atom densities. Possible experiments using trapped molecules are discussed.

R. C. Forrey; V. Kharchenko; N. Balakrishnan; A. Dalgarno

1999-03-01T23:59:59.000Z

209

Semiempirical Model of Vibrational Relaxation for Estimating Absolute Rate Coefficients  

Science Journals Connector (OSTI)

The exchange of vibrational, or thermal, energy between two interacting species is one of the most fundamental properties in chemistry and physics. ... The correlation conforms reasonably well to a linear least-squares fit that is constrained to pass through the origin (dashed line) and supports the validity of the ?1/3 relationship at least for these data. ... They obtained rates for collision-induced population depletion of the initial state by two methods:? (i) the direct measurement of ki from the decay of fluorescence (this rate coefficient is labeled k4 in the notation of CR) and (ii) by a summation of the individual state-to-state rate coefficients (labeled ki = ?kif?, which was labeled ?k4(i) by CR). Figure 2a (upper plot) shows the measured rate coefficients for each vibrational level plotted as a function of vibrational energy. ...

Scott H. Kable; Alan E. W. Knight

2003-11-15T23:59:59.000Z

210

Degassing of molten alloys with the assistance of ultrasonic vibration  

DOE Patents [OSTI]

An apparatus and method are disclosed in which ultrasonic vibration is used to assist the degassing of molten metals or metal alloys thereby reducing gas content in the molten metals or alloys. High-intensity ultrasonic vibration is applied to a radiator that creates cavitation bubbles, induces acoustic streaming in the melt, and breaks up purge gas (e.g., argon or nitrogen) which is intentionally introduced in a small amount into the melt in order to collect the cavitation bubbles and to make the cavitation bubbles survive in the melt. The molten metal or alloy in one version of the invention is an aluminum alloy. The ultrasonic vibrations create cavitation bubbles and break up the large purge gas bubbles into small bubbles and disperse the bubbles in the molten metal or alloy more uniformly, resulting in a fast and clean degassing.

Han, Qingyou (Knoxville, TN); Xu, Hanbing (Knoxville, TN); Meek, Thomas T. (Knoxville, TN)

2010-03-23T23:59:59.000Z

211

Non-equilibrium coherent vortex states and subharmonic giant Shapiro steps in Josephson junction arrays  

E-Print Network [OSTI]

This is a review of recent work on the dynamic response of Josephson junction arrays driven by dc and ac currents. The arrays are modeled by the resistively shunted Josephson junction model, appropriate for proximity effect junctions, including self-induced magnetic fields as well as disorder. The relevance of the self-induced fields is measured as a function of a parameter $\\kappa=\\lambda_L/a$, with $\\lambda_L$ the London penetration depth of the arrays, and $a$ the lattice spacing. The transition from Type II ($\\kappa>1$) to Type I ($\\kappa <1$) behavior is studied in detail. We compare the results for models with self, self+nearest-neighbor, and full inductance matrices. In the $\\kappa=\\infty$ limit, we find that when the initial state has at least one vortex-antivortex pair, after a characteristic transient time these vortices unbind and {\\it radiate} other vortices. These radiated vortices settle into a parity-broken, time-periodic, {\\em axisymmetric coherent vortex state} (ACVS), characterized by alternate rows of positive and negative vortices lying along a tilted axis. The ACVS produces subharmonic steps in the current voltage (IV) characteristics, typical of giant Shapiro steps. For finite $\\kappa$ we find that the IV's show subharmonic giant Shapiro steps, even at zero external magnetic field. We find that these subharmonic steps are produced by a whole family of coherent vortex oscillating patterns, with their structure changing as a function of $\\kappa$. In general, we find that these patterns are due to a break down of translational invariance produced, for example, by disorder or antisymmetric edge-fields. The zero field case results are in good qualitative agreement with experiments

Daniel Domínguez; Jorge V. José

1994-07-11T23:59:59.000Z

212

Rectangular Parallelepiped Vibration in Plane Strain State  

E-Print Network [OSTI]

In this paper we present a vibration spectrum of a homogenous parallelepiped (HP) under the action of volume and surface forces resulting from the exponent displacements entering the Fourier transforms. Vibration under the action of axial surface tractions and the free vibration are described separately. A relationship between the high frequency vibration and boundary conditions (BC) is also considered.

Jerzy Hanckowiak

2004-11-25T23:59:59.000Z

213

Argonne CNM Highlight: Biofunctionalized magnetic-vortex microdiscs for  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

214

Experimental demonstration of vortex pancake in high temperature superconductor  

Science Journals Connector (OSTI)

In order to demonstrate the existence of the vortex pancake in high temperature superconductor experimentally, a configuration in which the current...E-j relation obtained with this electrodes spatial configurati...

Wei-xian Wang; Yu-heng Zhang

2006-09-01T23:59:59.000Z

215

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

216

Electron Trapping by Molecular Vibration  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

217

Electron Trapping by Molecular Vibration  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

218

Vibration Harvesting using Electromagnetic Transduction  

E-Print Network [OSTI]

spectra for (a) a 30 kW water pump motor, and (b) vibrationCondenser water supply Power [kW] Motor #1 and motor #3 were1 Motor # 2 Motor #3 Function Chilled water supply Process

Waterbury, Andrew

2011-01-01T23:59:59.000Z

219

Vibration of Tethered Microstructure Profilers  

Science Journals Connector (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

220

Seismic vibration analysis of fluid-structure interaction in LMFBR piping systems  

SciTech Connect (OSTI)

This paper is a basic study on the vibrational characteristics of an LMFBR piping system containing liquid sodium under one-dimensional seismic excitation. Using Z-shaped piping, the authors formulate coupled equations for the pipe's bending vibration and pressure wave, and transform them into two-degree-of-freedom vibration equations for the first modes of the piping vibration and pressure wave. A numerical study using the vibration model shows that: 1) the coupling effect appears between piping acceleration and liquid pressure for a piping configuration having a natural frequency ratio ..nu.. = about 0.5 to 2.0; 2) the magnitude of seismically induced pressure reaches 0.7 kPa to 1 kPa per gal; and 3) the dead-mass model of liquid gives a nonconservative response depending on the pipe's geometrical configuration, compared to that from the pressure-wave-piping-interaction model.

Hara, F.

1988-05-01T23:59:59.000Z

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

Vibration isolators for oil- and gas-transfer equipment with a low vibration frequency  

Science Journals Connector (OSTI)

The negative effect of vibration on entities used for the transport of ... Systems with quasi-zero stiffness are employed as vibration isolators with a low natural-vibration frequency. The effectiveness of such u...

A. R. Valeev

2011-09-01T23:59:59.000Z

222

Vibration-based structural health monitoring of highway bridges  

E-Print Network [OSTI]

the use of vibration measurement for damage identification.shape extracted from vibration measurements is used as thespatial resolution vibration measurement technique such as

Guan, Hong

2006-01-01T23:59:59.000Z

223

Vibration Phase Based Ordering of Vibration Patterns Acquired With a Shearing Speckle Interferometer and Pulsed Illumination  

Science Journals Connector (OSTI)

Harmonic vibrations of diffusely reflecting objects can be visualized ... period that is relatively long compared to the vibration period, time average interferograms are obtained,...

Peter A. A. M. Somers; Nandini Bhattacharya

2007-01-01T23:59:59.000Z

224

Ultra-Low NOx Advanced Vortex Combustor  

SciTech Connect (OSTI)

An ultra 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 (USDOE NETL) test facility 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/UHC emissions of 4/4/0 ppmv (all emissions are at 15% O2 dry). The design also achieved less than 3 ppmv NOx with combustion efficiencies in excess of 99.5%. The design demonstrated tremendous 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, a pressure drop of 1.75% was measured which is significantly lower than conventional gas turbine combustors. Potentially, this lower pressure drop characteristic of the AVC concept translates into overall gas turbine cycle efficiency improvements of up to one full percentage point. The relatively high velocities and low pressure drops achievable with this technology make the AVC approach an attractive alternative for syngas fuel applications.

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

2006-05-01T23:59:59.000Z

225

ULTRA-LOW NOX ADVANCED VORTEX COMBUSTOR  

SciTech Connect (OSTI)

An ultra 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 (USDOE NETL) test facility 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/UHC emissions of 4/4/0 ppmv (all emissions are at 15% O2 dry). The design also achieved less than 3 ppmv NOx with combustion efficiencies in excess of 99.5%. The design demonstrated tremendous 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, a pressure drop of 1.75% was measured which is significantly lower than conventional gas turbine combustors. Potentially, this lower pressure drop characteristic of the AVC concept translates into overall gas turbine cycle efficiency improvements of up to one full percentage point. The relatively high velocities and low pressure drops achievable with this technology make the AVC approach an attractive alternative for syngas fuel applications.

Ryan G. Edmonds; Robert C. Steele; Joseph T. Williams; Douglas L. Straub; Kent H. Casleton; Avtar Bining

2006-05-01T23:59:59.000Z

226

Measurement of Hyperfine Structure in the Infrared Rotation-Vibration Spectrum of NH-  

Science Journals Connector (OSTI)

Hyperfine structure (hfs) has been observed in the P, Q, and R branches of the fundamental rotation-vibration spectrum of the X?2 electronic state of the molecular anion NH-. A coaxial ion-beam-laser-beam spectrometer is employed in which rotation-vibration transitions are induced by a color-center laser operating near 3000 cm-1. The vibrationally excited ions autodetach, and the fast neutral NH is detected. The structure has been analyzed and the magnetic dipole hfs parameters obtained in both N14H- and N15H-. This is the first analyzed case of hfs in any molecular anion.

Harold C. Miller; Mohammad Al-Za'al; John W. Farley

1987-05-18T23:59:59.000Z

227

WAVE-VORTEX MODE COUPLING IN ASTROPHYSICAL ACCRETION DISKS UNDER COMBINED RADIAL AND VERTICAL STRATIFICATION  

SciTech Connect (OSTI)

We examine accretion disk flow under combined radial and vertical stratification utilizing a local Cartesian (or ''shearing box'') approximation. We investigate both axisymmetric and nonaxisymmetric disturbances with the Boussinesq approximation. Under axisymmetric disturbances, a new dispersion relation is derived. It reduces to the Solberg-Hoieland criterion in the case without vertical stratification. It shows that, asymptotically, stable radial and vertical stratification cannot induce any linear instability; Keplerian flow is accordingly stable. Previous investigations strongly suggest that the so-called bypass concept of turbulence (i.e., that fine-tuned disturbances of any inviscid smooth shear flow can reach arbitrarily large transient growth) can also be applied to Keplerian disks. We present an analysis of this process for three-dimensional plane-wave disturbances comoving with the shear flow of a general rotating shear flow under combined stable radial and vertical rotation. We demonstrate that large transient growth occurs for K{sub 2}/k{sub 1} >> 1 and k{sub 3} = 0 or k{sub 1} {approx} k{sub 3}, where k{sub 1}, K{sub 2}, and k{sub 3} are the azimuthal, radial, and vertical components of the initial wave vector, respectively. By using a generalized ''wave-vortex'' decomposition of the disturbance, we show that the large transient energy growth in a Keplerian disk is mainly generated by the transient dynamics of the vortex mode. The analysis of the power spectrum of total (kinetic+potential) energy in the azimuthal or vertical directions shows that the contribution coming from the vortex mode is dominant at large scales, while the contribution coming from the wave mode is important at small scales. These findings may be confirmed by appropriate numerical simulations in the high Reynolds number regime.

Salhi, A. [Departement de Physique, Faculte des Sciences de Tunis, 1060 Tunis (Tunisia); Lehner, T. [LUTH, UMR 8102 CNRS, Observatoire de Paris-Meudon, 5 place de Janssen, F-92195 Meudon (France); Godeferd, F.; Cambon, C. [Laboratoire de Mecanique des Fluides et d'Acoustique, Ecole Centrale de Lyon, Universite de Lyon, UMR 5509, CNRS, INSA, UCB, F-69134 Ecully Cedex (France)

2013-07-10T23:59:59.000Z

228

Simultaneous two-axis vibration measurement of a nonmetallic cylinder by electromagnetic induction and metallic foil loops  

Science Journals Connector (OSTI)

This work presents a method based on electromagnetic induction for the simultaneous non-contact measurement of two-axis lateral vibrations of a nonmetallic cylinder. The suggested method ... pair of loop is induc...

Soon Woo Han; Jin Ki Kim; Yoon Young Kim

2011-08-01T23:59:59.000Z

229

The Vibration of Bells  

Science Journals Connector (OSTI)

Relative frequencies, nodal meridians, and nodal circles of the bells of the Harkness Memorial Chime.—This is a study of the ten bells of the Harkness Memorial Chime at Yale University. The large size of these bells makes it possible to examine partial tones of higher order than could be studied on smaller bells. For the first ten partials the average values found for the relative frequencies, the numbers of nodal meridians, and the numbers of nodal circles are shown in the following table. Partial12345678910Relative Frequency0.501.001.201.492.002.562.963.283.804.06Nodal Meridians4466881081012Nodal Circles0111122    The nodal circles for the 2d, 3d, 4th, and 5th partials are at levels about 13, ½, 16, and ½ the height of the bell, those for the 6th partial are roughly at 15 and 35, for the 7th at 25 and 45 of the height.Amplitudes of the partials.—Curves showing the vibration in the air near the bells were obtained by a microphone, amplifier, and oscillograph. There is first an irregular motion which may arise from noises in the mechanism by which the bells are struck. The clapper probably strikes after some 0.01 sec. to 0.03 sec., for after this time the amplitude is larger and the curve more regular. Since the partial tones of a bell are not harmonic a Fourier analysis is not directly applicable, but a modified Fourier analysis may be employed. An approximation to the amplitude of each component is obtained by proceeding as if a Fourier analysis were being made, the range of integration for each component being however independently chosen as a whole number of periods of that component. A method is given for obtaining corrections to the approximate amplitudes thus found.The strike note of bells.—The curious phenomenon of the strike note is considered. The hypothesis that the pitch of the strike note is determined by that of the fifth partial, but that it is very generally judged an octave lower, is supported by several facts which have been already known and by the new fact that the fifth partial appears with surprising promptness and vigor. One possible cause for such a misjudging of the octave is the fact that the fifth, seventh, and tenth partials are all brought out well when a bell is struck on the soundbow, and that the relative frequencies of these partials are not far from 2:3:4, thus perhaps giving rise in the ear of the observer to the pitch of the strike note.

Arthur Taber Jones

1928-06-01T23:59:59.000Z

230

UBIQUITOUS SOLAR ERUPTIONS DRIVEN BY MAGNETIZED VORTEX TUBES  

SciTech Connect (OSTI)

The solar surface is covered by high-speed jets transporting mass and energy into the solar corona and feeding the solar wind. The most prominent of these jets have been known as spicules. However, the mechanism initiating these eruption events is still unknown. Using realistic numerical simulations we find that small-scale eruptions are produced by ubiquitous magnetized vortex tubes generated by the Sun's turbulent convection in subsurface layers. The swirling vortex tubes (resembling tornadoes) penetrate into the solar atmosphere, capture and stretch background magnetic field, and push the surrounding material up, generating shocks. Our simulations reveal complicated high-speed flow patterns and thermodynamic and magnetic structure in the erupting vortex tubes. The main new results are: (1) the eruptions are initiated in the subsurface layers and are driven by high-pressure gradients in the subphotosphere and photosphere and by the Lorentz force in the higher atmosphere layers; (2) the fluctuations in the vortex tubes penetrating into the chromosphere are quasi-periodic with a characteristic period of 2-5 minutes; and (3) the eruptions are highly non-uniform: the flows are predominantly downward in the vortex tube cores and upward in their surroundings; the plasma density and temperature vary significantly across the eruptions.

Kitiashvili, I. N.; Kosovichev, A. G. [Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States); Lele, S. K.; Mansour, N. N.; Wray, A. A., E-mail: irinasun@stanford.edu [Center for Turbulence Research, Stanford University, Stanford, CA 94305 (United States)

2013-06-10T23:59:59.000Z

231

Hydrodynamics of vibrated granular monolayer.  

SciTech Connect (OSTI)

We investigate the long-standing puzzle of phase separation in a granular monolayer vibrated from below. Although this system is three dimensional, an interesting dynamics occurs mostly in the horizontal plane, perpendicular to the direction of vibration. Experiments [Olafsen and Urbach, Phys. Rev. Lett. 81 4369 (1998)] demonstrated that for a high amplitude of vibration the system is in the gaslike phase, but when the amplitude becomes smaller than a certain threshold, a phase separation occurs: A solidlike dense condensate of particles forms in the center of the system, surrounded by particles in the gaslike phase. We explain theoretically the experimentally observed coexistence of dilute and dense phases, employing Navier-Stokes granular hydrodynamics. We show that the phase separation is associated with a negative compressibility of granular gas.

Khain, E.; Aranson, I. S. (Materials Science Division); (Oakland Univ.)

2011-01-01T23:59:59.000Z

232

The Vibration of Piezoelectric Plates  

Science Journals Connector (OSTI)

The characteristic frequencies of infinite piezoelectric plates vibrating between the grounded electrodes of a plane parallel condenser have been rigorously investigated. It is found that the frequencies depend on the piezoelectric constants as well as the elastic constants of the crystal. The effective elastic constants for a piezoelectric crystal do not in general satisfy the same symmetry relations as the true elastic constants. For odd harmonics, which are the only modes which can be excited by a uniform electric field, the strain does not vanish at the surface of the plate for a finite gap between the electrodes. Consequently, the frequencies of free vibration also depend on the separation of the electrodes, and the rigorous theory shows this dependence should not be linear as hitherto supposed. The effect of the gap decreases as the square of the harmonic number and hence the higher frequencies of vibration are not exactly harmonics of the fundamental.

A. W. Lawson

1942-07-01T23:59:59.000Z

233

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

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...

234

Generation and Propagation of Inertia Gravity Waves from Vortex Dipoles and Jets Shuguang Wang  

E-Print Network [OSTI]

Generation and Propagation of Inertia Gravity Waves from Vortex Dipoles and Jets Shuguang Wang generation and propagation from jets within idealized vortex dipoles using a nonhydrostatic mesoscale model, moist convection, fronts, upper level jets, geostrophic adjustment and spontaneous generation (Fritts

235

Design of Vibration Absorbers for Step Motions and Step Disturbances  

E-Print Network [OSTI]

Design of Vibration Absorbers for Step Motions and Step Disturbances Joel Fortgang William Singhose or from external disturbances. The technique of adding a vibration ab- sorber has proven useful at eliminating vibrations from external disturbances and rotational imbalances. Traditionally, vibration

Singhose, William

236

Fundamental Vibration of Molecular Hydrogen  

Science Journals Connector (OSTI)

The fundamental ground tone vibration of H2, HD, and D2 is determined to an accuracy of 2×10-4??cm-1 from Doppler-free laser spectroscopy in the collisionless environment of a molecular beam. This rotationless vibrational splitting is derived from the combination difference between electronic excitation from the X1?g+, v=0, and v=1 levels to a common EF1?g+, v=0 level. Agreement within 1? between the experimental result and a full ab initio calculation provides a stringent test of quantum electrodynamics in a chemically bound system.

G. D. Dickenson; M. L. Niu; E. J. Salumbides; J. Komasa; K. S. E. Eikema; K. Pachucki; W. Ubachs

2013-05-08T23:59:59.000Z

237

Method of vibration measurements in heterodyne interferometry  

Science Journals Connector (OSTI)

A novel method is presented for determining the vibration amplitude of a vibrating fringe pattern in the presence of a low-frequency heterodyne phase shift. It consists of counting the...

Stetson, Karl A

1982-01-01T23:59:59.000Z

238

Optical instrumentation for vibration measurement and monitoring  

Science Journals Connector (OSTI)

Monitoring of machine tool vibrations is an important aspect of precision manufacturing ... of a simple and unique instrument for precise vibration measurement that can be used in industry. The ... laboratory. Th...

Devdas Shetty; Ahad Ali; Jonathan Hill

2011-06-01T23:59:59.000Z

239

Comparison of Torsional Vibration Measurement Techniques  

Science Journals Connector (OSTI)

Noise and vibration performance plays an important role in the ... compressors and pumps. The presence of torsional vibrations and other specific phenomena require the dynamic ... of the instrumentation and chall...

Karl Janssens; Laurent Britte

2014-01-01T23:59:59.000Z

240

Windowed defocused photographic speckle vibration measurement  

Science Journals Connector (OSTI)

The out-of-plane vibration of a rough surface causes an in-plane vibration of its speckle pattern when observed with a defocused optical photographic system. If the frequency of the...

Diazdelacruz, Jose

2009-01-01T23:59:59.000Z

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.


241

Interferometric vibration measurement using optical fiber  

Science Journals Connector (OSTI)

The measurement of vibration generally requires the determination of the displacement ... function of time. The aim of the measurement is to determine the amplitude and frequency content of the vibration, or trac...

K. Weir; B. T. Meggitt

1998-01-01T23:59:59.000Z

242

Neuromotor Transmissibility of Horizontal Seatpan Vibration  

E-Print Network [OSTI]

Exposure to occupational whole body vibration (WBV) is associated with low back pain disorders, musculoskeletal disorders, and degeneration of spine. Transmission of vibration to the neuromotor system may play a role in the etiology...

Channamallu, Raghu Ram

2007-12-16T23:59:59.000Z

243

Vibration Transmission through Symmetric Resonant Couplings  

Science Journals Connector (OSTI)

15 March 1994 research-article Vibration Transmission through Symmetric Resonant Couplings D. J. Allwright...Blakemore P. R. Brazier-Smith J. Woodhouse The transmission of vibration through a symmetric junction is considered. The problem is...

1994-01-01T23:59:59.000Z

244

Mutual Chern-Simons gauge theory of spontaneous vortex phase  

Science Journals Connector (OSTI)

We apply the mutual Chern-Simons effective theory [Kou, Qi, and Weng, Phys. Rev. B 71, 235102 (2005)] of the doped Mott insulator to the study of the so-called spontaneous vortex phase in the low-temperature pseudogap region, which is characterized by strong unconventional superconducting fluctuations. An effective description for the spontaneous vortex phase is derived from the general mutual Chern-Simons Lagrangian, based on which the physical properties including the diamagnetism, spin paramagnetism, magnetoresistance, and the Nernst coefficient, have been quantitatively calculated. The phase boundaries of the spontaneous vortex phase, which sits between the onset temperature Tv and the superconducting transition temperature Tc, are also determined within the same framework. The results are consistent with the experimental measurements of the cuprates.

Xiao-Liang Qi and Zheng-Yu Weng

2007-09-07T23:59:59.000Z

245

Ubiquitous Solar Eruptions Driven by Magnetized Vortex Tubes  

E-Print Network [OSTI]

The solar surface is covered by high-speed jets transporting mass and energy into the solar corona and feeding the solar wind. The most prominent of these jets have been known as spicules. However, the mechanism initiating these eruptions events is still unknown. Using realistic numerical simulations we find that small-scale eruptions are produced by ubiquitous magnetized vortex tubes generated by the Sun's turbulent convection in subsurface layers. The swirling vortex tubes (resembling tornadoes) penetrate into the solar atmosphere, capture and stretch background magnetic field, and push surrounding material up, generating quasiperiodic shocks. Our simulations reveal a complicated high-speed flow patterns, and thermodynamic and magnetic structure in the erupting vortex tubes. We found that the eruptions are initiated in the subsurface layers and are driven by the high-pressure gradients in the subphotosphere and photosphere, and by the Lorentz force in the higher atmosphere layers.

Kitiashvili, I N; Lele, S K; Mansour, N N; Wray, A A

2013-01-01T23:59:59.000Z

246

The effect of surface tension on the Moore singularity of vortex sheet dynamics  

E-Print Network [OSTI]

The effect of surface tension on the Moore singularity of vortex sheet dynamics F. de la Hoz , M's singularities by surface tension in the evolution of vortex sheets and its dependence on Weber number (which is inversely proportional to surface tension coefficient). The curvature of the vortex sheet, instead

Fontelos, Marco

247

Traveling Waves from the Arclength Parameterization: Vortex Sheets with Surface Tension  

E-Print Network [OSTI]

Traveling Waves from the Arclength Parameterization: Vortex Sheets with Surface Tension Benjamin for the vortex sheet with surface tension. We use the angle- arclength description of the interface rather than prove that there exist traveling vortex sheets with surface tension bifurcating from equilibrium. We

Wright, J. Douglas

248

Development of vortex state in circular magnetic nanodots: Theory and experiment RID A-9247-2009  

E-Print Network [OSTI]

magnetic vortex. The vortex-core diameter is controlled by competing magnetic energy contributions. For 20-nm-thick Fe dots, the values of the critical diameter (58-60 nm) and the vortex core (16-19 nm) are in very good agreement between the different...

Mejia-Lopez, J.; Altbir, D.; Landeros, P.; Escrig, J.; Romero, A. H.; Roshchin, Igor V.; Li, C-P; Fitzsimmons, M. R.; Batlle, X.; Schuller, Ivan K.

2010-01-01T23:59:59.000Z

249

CALTECH ASCI TECHNICAL REPORT 129 On Velocity Structure Functions and the Spherical Vortex Model for  

E-Print Network [OSTI]

the stretched-spiral vortex has been suc- cessfully applied to the calculation of the energy spectrum,6 and some for larger scales is perhaps questionable. Most quantitative vortex-based models have utilized tube and sheetCALTECH ASCI TECHNICAL REPORT 129 On Velocity Structure Functions and the Spherical Vortex Model

Barr, Al

250

Vortex reconnections in atomic condensates at finite temperature A. J. Allen1  

E-Print Network [OSTI]

, reconnections of stream lines, vortex lines and magnetic flux tubes change the topology of the flowVortex reconnections in atomic condensates at finite temperature A. J. Allen1 , S. Zuccher2 , M (Dated: May 28, 2014) The study of vortex reconnections is an essential ingredient of understanding

Zuccher, Simone

251

Azimuthal Asymmetries and Vibrational Modes in Bubble Pinch-off  

E-Print Network [OSTI]

The pressure-driven inertial collapse of a cylindrical void in an inviscid liquid is an integrable, Hamiltonian system that forms a finite-time singularity as the radius of the void collapses to zero. Here it is shown that when the natural cylindrical symmetry of the void is perturbed azimuthally, the perturbation modes neither grow nor decay, but instead cause constant amplitude vibrations about the leading-order symmetric collapse. Though the amplitudes are frozen in time, they grow relative to the mean radius which is collapsing to zero, eventually overtaking the leading-order symmetric implosion. Including weak viscous dissipation destroys the integrability of the underlying symmetric implosion, and the effect on the stability spectrum is that short-wavelength disturbances are now erased as the implosion proceeds. Introducing a weak rotational flow component to the symmetric implosion dynamics causes the vibrating shapes to spin as the mean radius collapses. The above theoretical scenario is compared to a closely related experimental realization of void implosion: the disconnection of an air bubble from an underwater nozzle. There, the thin neck connecting the bubble to the nozzle implodes primarily radially inward and disconnects. Recent experiments were able to induce vibrations of the neck shape by releasing the bubble from a slot-shaped nozzle. The frequency and amplitude of the observed vibrations are consistent with the theoretical prediction once surface tension effects are taken into account.

Laura E. Schmidt

2011-12-19T23:59:59.000Z

252

Nonlinearity in modal and vibration testing.  

SciTech Connect (OSTI)

This set of slides describes some aspects of nonlinear Vibration analysis thru use of analytical fromulas and Examples from real or simulated test systems . The Systems are drawn from a set of examples based on Years of vibration testing experience . Both traditional and new methods are used to describe nonlinear vibration.

Hunter, N. F. (Norman F.)

2003-01-01T23:59:59.000Z

253

The Vibration of Electrified Water Drops  

Science Journals Connector (OSTI)

4 May 1971 research-article The Vibration of Electrified Water Drops P. R. Brazier-Smith...calculations concerned with charged drops. The vibration of water drops of radius around 2 mm...electrodes. Photographic analysis of the vibrations revealed good agreement between theory...

1971-01-01T23:59:59.000Z

254

Ground Vibration Measurements at LHC Point 4  

SciTech Connect (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

255

Vibration–based structural damage identification  

Science Journals Connector (OSTI)

...N. A. J. Lieven and D. J. Ewins Vibration-based structural damage identification...identification based upon changes in vibration characteristics is one of the few methods...last thirty years is first presented. Vibration-based damage detection is a primary...

2001-01-01T23:59:59.000Z

256

Lattice Vibration and Random Walk Problems  

Science Journals Connector (OSTI)

......1960 research-article Articles Lattice Vibration and Random Walk Problems Ei Teramoto...Mathematical relations between the lattice vibration and the random walk problems are presented...the frequency spectrum of the lattice vibration can be expressed in terms of the transition......

Ei Teramoto

1960-12-01T23:59:59.000Z

257

Laboratory Analysis of Vortex Dynamics For Shallow Tidal Inlets  

E-Print Network [OSTI]

LABORATORY ANALYSIS OF VORTEX DYNAMICS FOR SHALLOW TIDAL INLETS A Thesis by KERRI ANN WHILDEN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree of MASTER OF SCIENCE August 2009... Major Subject: Ocean Engineering LABORATORY ANALYSIS OF VORTEX DYNAMICS FOR SHALLOW TIDAL INLETS A Thesis by KERRI ANN WHILDEN Submitted to the O ce of Graduate Studies of Texas A&M University in partial ful llment of the requirements for the degree...

Whilden, Kerri Ann

2010-10-12T23:59:59.000Z

258

Revival of Classical Vortex Generators Now for Transition Delay  

Science Journals Connector (OSTI)

Classical vortex generators, known for their efficiency in delaying or even inhibiting boundary layer separation, are here shown to be coveted devices for transition to turbulence delay. The present devices are miniature with respect to classical vortex generators but are tremendously powerful in modulating the laminar boundary layer in the direction orthogonal to the base flow and parallel to the surface. The modulation generates an additional term in the perturbation energy equation, which counteracts the wall-normal production term and, hence, stabilizes the flow. Our experimental results show that these devices are really effective in delaying transition, but we also reveal their Achilles’ heel.

Shahab Shahinfar; Sohrab S. Sattarzadeh; Jens H. M. Fransson; Alessandro Talamelli

2012-08-16T23:59:59.000Z

259

Electron Trapping by Molecular Vibration  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

260

Vibrational amplitudes in vitreous silica  

Science Journals Connector (OSTI)

A model structure of vitreous silica, for which the vibrational frequencies and eigenmodes were calculated from first principles, is used to investigate vibrational amplitudes. Calculated mean-square displacements for oxygen and silicon atoms are obtained as a function of temperature. The square displacement tensors of oxygen atoms show a marked anisotropic character, which is related to the local geometry. The displacements of oxygen atoms along the three principal directions can be associated to distinct parts of the vibrational spectrum, as evidenced by their thermal dependence. These anisotropic effects directly affect the elastic and the static structure factors, which are sensitive to the correlation between displacements of different atoms along their connecting direction. This description shows that the observed widths for Si-O and O-O correlations mainly derive from atomic vibrations rather than from structural disorder. Anisotropic correlations between different atoms are shown to be important up to a distance of 4 Å, i.e., involving atoms that belong to corner-sharing tetrahedra. The scattering functions, calculated at finite temperature and in the harmonic approximation, show good agreement with experiment. In particular, the comparison between the static and the elastic structure factors yields a characterization of the correlated displacements in accord with experimental observations. The static structure factor is significantly affected by anisotropic correlations, but shows only a weak dependence on temperature between 0 and 300 K.

Alfredo Pasquarello

2000-02-01T23:59:59.000Z

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.


261

CN vibration–rotation spectrum  

Science Journals Connector (OSTI)

CN vibration–rotation bands for the sequences (1–0) through (4–3) and (2–0) through (4–2) were observed in a King furnace and measured in the spectral regions 1797–2208 and 3740–4156...

Davis, Sumner P; Brault, James W; Abrams, Mark C; Rao, M L P

1991-01-01T23:59:59.000Z

262

Method for enriching a middle isotope using vibration-vibration pumping  

DOE Patents [OSTI]

Method for producing isotopically enriched material by vibration-vibration excitation of gaseous molecules wherein a middle mass isotope of an isotopic mixture including lighter and heavier mass isotopes preferentially populates a higher vibrational mode and chemically reacts to provide a product in which it is enriched. The method can be used for vibration-vibration enrichment of .sup.17 O in a CO reactant mixture.

Rich, Joseph W. (East Aurora, NY); Homicz, Gregory F. (Getzville, NY); Bergman, Richard C. (Corfu, NY)

1989-01-01T23:59:59.000Z

263

Vibration of Nanoparticles in Viscous Fluids  

Science Journals Connector (OSTI)

In this article, we present results of a rigorous finite-element analysis and commensurate scaling theory that enable interpretation and analysis of these experiments, for the extensional vibrational modes of axisymmetric nanoparticles immersed in viscous fluids. ... (51) Vibration of the particle accelerates the fluid, which increases the effective mass of the vibrating particle. ... Using low-frequency Raman scattering, the authors clearly demonstrate that single-domain NCs vibrate differently than their multiply twinned counterparts, through the splitting of the quadrupolar vibrations, which is only obsd. ...

Debadi Chakraborty; Emma van Leeuwen; Matthew Pelton; John E. Sader

2013-03-21T23:59:59.000Z

264

Self-Consistent Electronic Structure of a dx2-y2 and a dx2-y2 + idxy Vortex  

Science Journals Connector (OSTI)

We investigate quasiparticle states associated with an isolated vortex in a d-wave superconductor using a self-consistent Bogoliubov–de Gennes formalism. For a pure dx2-y2 superconductor we find that there exist no bound states in the core; all the states are extended with continuous energy spectrum. This result is inconsistent with the existing experimental data on cuprates. We propose an explanation for this data in terms of a magnetic-field-induced dx2-y2+idxy state recently invoked in connection with the thermal conductivity measurements on Bi2Sr2CaCu2O8.

M. Franz and Z. Tešanovi?

1998-05-25T23:59:59.000Z

265

Effects of atmospheric conditions and control surface deflections on vortex characteristics  

E-Print Network [OSTI]

I I I i. C iS OF:"-:, ','". : iFII! 2! C CO", Df if Of!S f'-, 'ID CO, ", IROI ':L'll ', CI DI. I I ECT IOIIS O', I 'ilORT:-X ' I~OR;. C I L!If ISTICS 0 Thesis by CALVfl'I L!O'. , 'PRD SIIEIIKIR, JR. Subr~i fis!i to the G! ', 'uete Col ieije...7, SST Ci'rcorde, C-SA, and others, induce 'tr. ailing r, ing iiI! vor'-ic, s ?aiich pr: sent a hazard Lo stnal1er ait craft. In this Itir!Osti(dation such vr. i tex charac'ieristics as I!ave Fornations, r;0!e Ienrgths, b(eak t&1es, and vortex...

Shenkir, Calvin Edward

2012-06-07T23:59:59.000Z

266

Role of the core energy in the vortex Nernst effect  

Science Journals Connector (OSTI)

We present an analytical study of diamagnetism and transport in a film with superconducting phase fluctuations, formulated in terms of vortex dynamics within the Debye-Hückel approximation. We find that the diamagnetic and Nernst signals decay strongly with temperature in a manner that is dictated by the vortex core energy. Using the theory to interpret Nernst measurements of underdoped La2?xSrxCuO4 above the critical temperature regime, we obtain a considerably better fit to the data than a fit based on Gaussian order-parameter fluctuations. Our results indicate that the core energy in this system scales roughly with the critical temperature and is significantly smaller than expected from BCS theory. Furthermore, it is necessary to assume that the vortex mobility is much larger than the Bardeen-Stephen value in order to reconcile conductivity measurements with the same vortex picture. Therefore, either the Nernst signal is not due to fluctuating vortices, or vortices in underdoped La2?xSrxCuO4 have highly unconventional properties.

Gideon Wachtel and Dror Orgad

2014-11-11T23:59:59.000Z

267

New vortex ring configurations for the MAP dyon solutions  

Science Journals Connector (OSTI)

Electrically charged magnetic solutions of SU (2) Yang-Mills-Higgs theory with net zero topological charge has been obtained as axially symmetric saddle-point solutions in Ref. [1]. These solutions are characterized by an integer the winding number n of their azimuthal angle ? and an electric charge parameter 0vortex ring configuration with n=2 ?=0.65 and varying Higgs field strength. Our observations showed that beside the fundamental solution which is an electrically charged MAP solution there also exist two other branches of eclectically charged vortex ring solutions which both appear at ?=20.45. The difference in total energy between these two branches of solution is very small but the difference in diameter of vortex rings of the two branches is quite significant. Finding of a branching phenomena in presence of a fundamental MAP solution has been for the first time. In Ref. [2] new branching solutions occur for the electrically neutral case in presence of fundamental vortex ring solutions but not for the fundamental MAP solution.

2014-01-01T23:59:59.000Z

268

Creation and pinning of vortex-antivortex pairs  

E-Print Network [OSTI]

Computer modeling is reported about the creation and pinning of a magnetic vortex-antivortex (V-AV) pair in a superconducting thin film, due to the magnetic field of a vertical magnetic dipole above the film, and two antidot pins inside the film...

Kim, Sangbum; Hu, Chia-Ren; Andrews, Malcolm J.

2006-01-01T23:59:59.000Z

269

Vortex trimer in three-component Bose-Einstein condensates  

E-Print Network [OSTI]

Vortex trimer is predicted in three-component Bose-Einstein condensates with internal coherent couplings. The molecule is made by three constituent vortices which are bounded by domain walls of the relative phases. We show that the shape and the size of the molecule can be controlled by changing the internal coherent couplings.

Minoru Eto; Muneto Nitta

2012-01-01T23:59:59.000Z

270

High-Resolution Simulations of Parallel BladeVortex Interactions  

E-Print Network [OSTI]

= perturbation pressure coefficient, p ps= 1 2 1U2 1 c = rotor blade chord p = instantaneous airfoil surface­vortex interaction computations Introduction A MAJOR source of rotorcraft noise is generated by the rotor blades on the rotor blades. BVI noise is especially important because it is known to propagate out

Alonso, Juan J.

271

WAVE-VORTEX INTERACTIONS IN THE ATMOSPHERE, AND CLIMATE  

E-Print Network [OSTI]

parcel dynamics, linear modes, balan- ced models, gravity waves, weather and climate prediction Introduction Numerical weather and climate prediction is complicated because only the flow scales larger thanWAVE-VORTEX INTERACTIONS IN THE ATMOSPHERE, AND CLIMATE PREDICTION Onno Bokhove Numerical Analysis

Vellekoop, Michel

272

Modified Black Hole with Polar Jet and Vortex  

E-Print Network [OSTI]

There are many models relating an accretion disk of Black Hole to jet outflow. The herein heuristic model describes the continuation of an external accretion disk to an internal accretion disk for less than Black Hole horizon, and subsequent polar jet outflow along polar axis out of polar vortex wherein the event horizon is no longer descriptive.

T. Tmmalm

2001-12-06T23:59:59.000Z

273

Vortex strings in electric dipole radiation near a mirror  

Science Journals Connector (OSTI)

Abstract The energy flow pattern of the radiation emitted by an oscillating electric dipole near a mirror has a complicated structure, including numerous singularities and vortices. We consider the flow lines of energy in the plane through the surface normal and the oscillation direction of the dipole. It is shown that the vortices are due to the vanishing of the magnetic field at their centers. The locations of the vortices have the appearance of beads on strings, and there are four such strings. The rotation direction of the energy flow for each vortex on a given string is the same. There are two strings with clockwise rotation and two strings with counterclockwise rotation. Field lines of energy flow either start or end at the center of a vortex. For a given string, field lines end at each vortex or field lines start at each vortex. There are two strings on which field lines end at the centers of the vortices, and there are two strings on which field lines start inside the vortices.

Xin Li; Henk F. Arnoldus

2013-01-01T23:59:59.000Z

274

Surveillance and diagnostics of the beam mode vibrations of the Ringhals PWRs  

SciTech Connect (OSTI)

Surveillance of core barrel vibrations has been performed in the Swedish Ringhals PWRs for several years. This surveillance is focused mainly on the pendular motion of the core barrel, which is known as the beam mode. The monitoring of the beam mode has suggested that its amplitude increases along the cycle and decreases after refuelling. In the last 5 years several measurements have been taken in order to understand this behaviour. Besides, a non-linear fitting procedure has been implemented in order to better distinguish the different components of vibration. By using this fitting procedure, two modes of vibration have been identified in the frequency range of the beam mode. Several results coming from the trend analysis performed during these years indicate that one of the modes is due to the core barrel motion itself and the other is due to the individual flow induced vibrations of the fuel elements. In this work, the latest results of this monitoring are presented. (authors)

Martin, C. M. [Applied Physics to Natural Resources Dept., Technical Univ. of Madrid UPM, Rios Rosas 21, 28003 Madrid (Spain); Pazsit, I. [Dept. of Nuclear Engineering, Chalmers Univ. of Technology, SE-412 96 Goeteborg (Sweden); Nylen, H. [Vattenfall Ringhals AB, S-432 85 Vaeroebacka (Sweden)

2012-07-01T23:59:59.000Z

275

Vibration-based damage identification and health monitoring of civil structures  

E-Print Network [OSTI]

from ambient vibration measurements on a bridge. ” Journalmodal parameters from vibration measurements. In classicalshapes) from vibration measurements. These modal parameters

He, Xianfei

2008-01-01T23:59:59.000Z

276

Algebraic methods in vibrational spectroscopy  

SciTech Connect (OSTI)

These lectures review some advances in the algebraic description of molecules from two point of views: structure and dynamics. We start by presenting the basic ideas involved in the traditional description of molecular structure in configuration space, where the Born-Oppenheimer and rotor-rigid approximations are assumed to be valid. We then focus on the vibrational degrees of freedom in order to introduce the traditional algebraic realization in terms of bosonic operators of harmonic oscillators. This analysis allows the algebraic methods based on dynamical unitary groups to be introduced as a anharmonization procedure where the local bosonic operators are translated into operators satisfying the su(2) commutation relations. Some examples of the vibrational spec-troscopic description are presented. Concerned with the dynamical point of view an algebraic model to describe collinear collisions in the semiclassical approximation is presented.

Lemus, Renato [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Apartado Postal 70-543, 04510 Mexico, DF (Mexico)

2011-03-21T23:59:59.000Z

277

Vibration-enhanced quantum transport  

E-Print Network [OSTI]

In this paper, we study the role of collective vibrational motion in the phenomenon of electronic energy transfer (EET) along a chain of coupled electronic dipoles with varying excitation frequencies. Previous experimental work on EET in conjugated polymer samples has suggested that the common structural framework of the macromolecule introduces correlations in the energy gap fluctuations which cause coherent EET. Inspired by these results, we present a simple model in which a driven nanomechanical resonator mode modulates the excitation energy of coupled quantum dots and find that this can indeed lead to an enhancement in the transport of excitations across the quantum network. Disorder of the on-site energies is a key requirement for this to occur. We also show that in this solid state system phase information is partially retained in the transfer process, as experimentally demonstrated in conjugated polymer samples. Consequently, this mechanism of vibration enhanced quantum transport might find applications in quantum information transfer of qubit states or entanglement.

F. L. Semião; K. Furuya; G. J. Milburn

2009-09-09T23:59:59.000Z

278

12 - Vibration Problem-Solving in Grinding  

Science Journals Connector (OSTI)

The first priority in overcoming vibration problems is to recognize the source and nature of the vibrations. Vibrations in grinding lead to surface waviness and loss of workpiece accuracy. Wheel wear is increased and workpiece roughness deteriorates. Sources of machine vibrations are introduced including impulsive vibrations, cyclic forced vibrations and self-excited regenerative vibrations. Regenerative vibrations include work-regenerative and wheel-regenerative vibrations. Dynamic relationships for grinding are discussed including equations of motion, feedback terms and forcing terms. Equations are presented in transfer function form including the depth of cut function, the compliance function and the wheel wear function. General solutions are given. The effect of contact length filtering is explained. Experimental results are presented for typical machine frequency responses. The nature of vibration modes is explained with examples. Theoretical effects of machine stiffness, damping and resonance characteristics are presented. Grinding chatter is explained using graphical stability determination from measured frequency responses. It is shown that the onset of instability depends on the maximum negative real in-phase component of the frequency response. The effect of overlap in traverse grinding is analysed and the benefits of reducing grinding contact stiffness by reducing wheel contact width, by introducing flexibility into the grinding wheel or introducing flexibility at the grinding wheel contact point, are discussed. Other possibilities are suggested to reduce incidence of vibrations. The main techniques for overcoming vibration problems are summarized. It is generally advisable to avoid integer speed ratios between wheel speed and work speed or between wheel speed and dressing roll speed. Chapter 13 includes further analysis of vibrations applied to centreless grinding with emphasis on critical speed relationships.

W. Brian Rowe

2014-01-01T23:59:59.000Z

279

Vortex motion in Josephson-junction arrays near f=0 and f=1/2  

Science Journals Connector (OSTI)

We study vortex motion in two-dimensional Josephson arrays at magnetic fields near zero and one-half flux quanta per plaquette (f=0 and f=1/2). The array is modeled as a network of resistively and capacitively shunted Josephson junctions at temperature T=0. Calculations are carried out over a range of the McCumber-Stewart junction damping parameter ?. Near both f=0 and f=1/2, the I-V characteristics exhibit two critical currents, Ic1(f) and Ic2(f), representing the critical current for depinning a single vortex, and for depinning the entire ground-state phase configuration. Near f=0, single vortex motion just above Ic1(0) leads to Josephson-like voltage oscillations. The motion of the vortex is seemingly overdamped (i.e., nonhysteretic) even when the individual junction parameters are highly underdamped, in agreement with experiments. At sufficiently large ?, and sufficiently high vortex velocity, the vortex breaks up into a row of resistively switched junctions perpendicular to the current. Near f=1/2, the vortex potential, and corresponding vortex trajectories, are more complicated than near f=0. Nevertheless, the vortex is still ‘‘overdamped’’ even when the individual junctions are highly underdamped, and there is still row-switching behavior at large values of ?. A high-energy vortex in a very underdamped array tends to generate resistively switched rows rather than to move ballistically. Some possible explanations for this behavior are discussed.

Wenbin Yu; K. H. Lee; D. Stroud

1993-03-01T23:59:59.000Z

280

GRANULAR MATERIALS UNDER VIBRATION AND THERMAL CYCLES.  

E-Print Network [OSTI]

??We report flow rate measurement of granular materials from a lab size silo with and without sinusoidal vibration, and the flows from a jammed container… (more)

Chen, Ke

2008-01-01T23:59:59.000Z

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.


281

Human response to combined noise and vibration.  

E-Print Network [OSTI]

??The discomfort caused by the noise and vibration in cars is investigated in this thesis to improve understanding of how subjective judgements of noise and… (more)

Huang, Yuan

2012-01-01T23:59:59.000Z

282

Vibration assisted filling of thin section castings.  

E-Print Network [OSTI]

??Understanding of the mechanism of the vibration needed to fill thin section or one with sharp edges in profile shapes and clarifying the dominant control… (more)

Abdul Karem, Waleed

2009-01-01T23:59:59.000Z

283

Effect of vibration exposure duration on discomfort.  

E-Print Network [OSTI]

??The comfort of a seated person exposed to vibration is known to depend on the magnitude, frequency content, and direction of the excitation. A review… (more)

Gallais, Cedric

2008-01-01T23:59:59.000Z

284

Vortex properties in superconducting Nb/Pd multilayers  

Science Journals Connector (OSTI)

We have investigated the upper critical magnetic field Hc2, the critical current density Jc, and the pinning force Fp in sputtered Nb/Pd multilayers, varying the temperatures T, the Pd thicknesses dPd and the magnetic field H orientation (parallel and perpendicular to the plane of the sample). In perpendicular fields, the vortex dynamics was strongly influenced by grain-boundary pinning. In parallel fields, a peak was observed in the Jc(H) curves for samples with Pd thicknesses dPd>100 Å. After comparing the experimental results with the existing theories, we have related the presence of this peak effect to the matching of vortex kinks with the layered artificial structure.

C. Coccorese; C. Attanasio; L. V. Mercaldo; M. Salvato; L. Maritato; J. M. Slaughter; C. M. Falco; S. L. Prischepa; B. I. Ivlev

1998-04-01T23:59:59.000Z

285

Higher Derivative Corrections to Non-Abelian Vortex Effective Theory  

E-Print Network [OSTI]

We give a systematic method to calculate higher derivative corrections to low-energy effective theories of solitons, which are in general non-linear sigma models on the moduli spaces of the solitons. By applying it to the effective theory of a single BPS non-Abelian vortex in U(N) gauge theory with N fundamental Higgs fields, we obtain four derivative corrections to the effective sigma model on the moduli space C \\times CP^{N-1}. We compare them with the Nambu-Goto action and the Faddeev-Skyrme model. We also show that Yang-Mills instantons/monopoles trapped inside a non-Abelian vortex membrane/string are not modified in the presence of higher derivative terms.

Minoru Eto; Toshiaki Fujimori; Muneto Nitta; Keisuke Ohashi; Norisuke Sakai

2012-04-03T23:59:59.000Z

286

Precession of a single vortex line in superfluid B3  

Science Journals Connector (OSTI)

This paper reports the discovery of a new vortex phenomenon in superfluid B3. A single filament of quantized vortex line precesses as a solid body around a wire extending along the axis of a cylinder. The precession frequency equals the angular velocity of the apparatus at which the presence of a single quantum of circulation minimizes the system’s free energy. The period of precession is related to the circulation quantum and the dimensions of the apparatus. Thus a measurement of the precession period is an accurate determination of the quantum unit. We find ?=(1.020±0.03)h/2m3, where m3 is the mass of the He3 atom.

R. J. Zieve; Yu. Mukharsky; J. D. Close; J. C. Davis; R. E. Packard

1992-03-02T23:59:59.000Z

287

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

288

Numerical prediction of interaction between combustion, acoustics and vibration in gas turbines  

Science Journals Connector (OSTI)

The turbulent flame in the lean combustion regime in a gas turbine combustor generates significant thermo?acoustic instabilities. The flame can amplify fluctuations in the released heat and thus in the acoustic field as well. The induced pressure oscillations will drive vibrations of the combustor walls and burner parts. Stronger fluctuating pressure results in stronger fluctuations in the wall structure. Due to fatigue the remaining life time of the hard ware will be reduced significantly. This paper investigates modeling of acoustic oscillations and mechanical vibrations induced by lean premixed natural gascombustion. The mutual interaction of the combustion processes induced oscillating pressure field in the combustion chamber and induced vibration of the liner walls are investigated with numerical techniques. A partitioned procedure is used here: CFX?10 for the CFD analysis and Ansys?10 for the CSD analysis are coupled to give insight into a correlation between acoustic pressure oscillations and liner vibrations. These results will be compared with the available experimental data. The data are gathered in a purpose built 500 kW/5 bar premixed natural gas test rig.

Artur Pozarlik; Jim B. Kok

2008-01-01T23:59:59.000Z

289

Vibration modes of giant gravitons  

Science Journals Connector (OSTI)

We examine the spectrum of small vibrations of giant gravitons when the gravitons expand in anti–de Sitter space and when they expand on the sphere. For any given angular harmonic, the modes are found to have frequencies related to the curvature length scale of the background; these frequencies are independent of radius (and hence angular momentum) of the brane itself. This implies that the holographic dual theory must have, in a given R charge sector, low-lying non-BPS excitations with level spacings independent of the R charge.

Sumit R. Das; Antal Jevicki; Samir D. Mathur

2000-12-21T23:59:59.000Z

290

Vortex energy and 360 Neel walls in thinfilm  

E-Print Network [OSTI]

.Ignat@math.u-psud.fr) Courant Institute, New York University, New York, NY 10012, USA (e-mail: knuepfer@cims.nyu.edu) 1 #12Vortex energy and 360 ­N´eel walls in thin­film micromagnetics Radu Ignat , Hans Kn¨upfer October-section. The model is based on the following energy functional: E2d (m) = Z B2 |m|2 dx + | ln | 2 Z R2 ||-1

291

Coherence Current, Coherence Vortex, and the Conservation Law of Coherence  

Science Journals Connector (OSTI)

Introducing scalar and vector densities for a mutual coherence function, we present a new conservation law for optical coherence of scalar wave fields in the form of a continuity equation. This coherence conservation law provides new insights into topological phenomena for the complex coherence function. Some properties related to the newly introduced coherence vector density, such as a circulating coherence current associated with a coherence vortex, are investigated both theoretically and experimentally for the first time.

Wei Wang and Mitsuo Takeda

2006-06-08T23:59:59.000Z

292

Piping retrofit reduces valve-damaging flow vibration  

SciTech Connect (OSTI)

This article describes how excessive flow-induced vibration was escalating safety relief valve maintenance at an alarming pace until simple piping modifications eliminated the problem. Public Service Co. of Colorado's (PSCO) Cherokee Station Unit 4 had been experiencing excessive hot and cold reheat safety valve maintenance. From 1990 through 1993, expenditures exceeded $150,000, including a complete refurbishing in 1990. Furthermore, from 1990 to 1992 the incurred costs of contracting VR certificate repairs accumulated to more than $50,000. Such exorbitant maintenance costs were unique among PSCO's generating system.

Webb, M.; Ellenberger, P.

1995-01-01T23:59:59.000Z

293

Transient vortex events in the initial value problem for turbulence  

E-Print Network [OSTI]

A vorticity surge event that could be a paradigm for a wide class of bursting events in turbulence is studied to examine how the energy cascade is established and how this event could serve as a new test of LES turbulence models. This vorticity surge event is tied to the formation of the energy cascade in a direct numerical simulation by the traditional signatures of a turbulent energy cascade such as spectra approaching -5/3 and strongly Beltramized vortex tubes. A coherent mechanism is suggested by the nearly simultaneous development of a maximum of the peak vorticity $\\|\\omega\\|_\\infty$, growth of the dissipation, the appearance of a helically aligned local vortex configuration and strong, transient oscillations in the helicity wavenumber spectrum. This coherence is also examined for two LES models, a traditional purely dissipative eddy viscosity model and a modern method (LANS$-\\alpha$) that respects the nonlinear transport properties of fluids. Both LES models properly represent the spectral energy and energy dissipation associated with this vorticity surge event. However, only the model that preserves nonlinear fluid transport properties reproduces the helical properties, including Beltrami-like vortex tubes.

Darryl D. Holm; Robert M. Kerr

2001-10-19T23:59:59.000Z

294

Preliminary Experiment for the Control of Cluster Vibration  

E-Print Network [OSTI]

(= 32.8 nm) to probe the vibration. The absorption of x-ray pulses is measured. We want to find of Cluster Vibration for the Control of Cluster Vibration 99 7 20 1. 15 3 http

295

An Integrated Measurement to Road Vibration Simulation System  

E-Print Network [OSTI]

An Integrated Measurement to Road Vibration Simulation System Charles Birdsong, Ph.D. Dactron Inc for vibrations measured on a Jeep, compensated, and replicated on an electrodynamic shaker. Introduction. Simulation of measured vibrations requires data acquisition, data compensation, and reproduction

Birdsong, Charles

296

VIBRATION OF CERTAIN SQUARE PLATES HAVING SIMILAR ADJACENT EDGES  

Science Journals Connector (OSTI)

......Press 1955 research-article Articles VIBRATION OF CERTAIN SQUARE PLATES HAVING SIMILAR...The fundamental frequencies of flexural vibration are determined for thin uniform elastic...to obtain the approximate solutions. VIBRATION OF CERTAIN SQUARE PLATES HAVING SIMILAR......

HUGH L. COX

1955-01-01T23:59:59.000Z

297

Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting phase  

E-Print Network [OSTI]

In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type-II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied in the mean-field approach at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type I (type II) Nambu-Goldstone modes.

Chernodub, M N; Verschelde, Henri

2014-01-01T23:59:59.000Z

298

Phonon spectrum of QCD vacuum in magnetic-field-induced superconducting phase  

E-Print Network [OSTI]

In the background of a sufficiently strong magnetic field the vacuum was suggested to become an ideal electric conductor (highly anisotropic superconductor) due to an interplay between the strong and electromagnetic forces. The superconducting ground state resembles an Abrikosov lattice state in an ordinary type--II superconductor: it is an inhomogeneous structure made of a (charged vector) quark-antiquark condensate pierced by vortices. In this paper the acoustic (phonon) vibrational modes of the vortex lattice are studied at zero temperature. Using an effective model based on a vector meson dominance, we show that in the infrared limit the longitudinal (transverse) acoustic vibrations of the vortex lattice possess a linear (quadratic) dispersion relation corresponding to type I (type II) Nambu--Goldstone modes.

M. N. Chernodub; Jos Van Doorsselaere; Henri Verschelde

2014-01-01T23:59:59.000Z

299

Electron–Vibration Interaction in Multichannel Single-Molecule Junctions  

Science Journals Connector (OSTI)

The electron-vibration coupling gives rise to small drops in the conductance at voltages corresponding to energies of some of the vibrational modes. ... where only the apex atoms are allowed to vibrate. ... We explore a full range of parameters going from weak to strong electron-vibration coupling, from tunneling to contact, and from 1-vibration description to the need of including all vibrations for a correct description of inelastic effects in transport. ...

Regev Ben-Zvi; Ran Vardimon; Tamar Yelin; Oren Tal

2013-11-19T23:59:59.000Z

300

Coherence Holography and Spatial Frequency Comb for 3-D Coherence Imaging and Coherence Vortex Generation  

Science Journals Connector (OSTI)

The principle and the applications of a recently proposed unconventional holography technique, coherence holography, applied for coherence vortex generation, and a related technique...

Takeda, Mitsuo; Wang, Wei; Duan, Zhihui; Miyamoto, Yoko; Rosen, Joseph

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

Vortex shedding from square plates near a ground plane: an experimental study.  

E-Print Network [OSTI]

??Vortex shedding frequencies were obtained experimentally for square plates near a ground plane in the Texas Tech wind tunnel. These frequencies, in the form of… (more)

Matty, Rosemary Ricohermoso

1979-01-01T23:59:59.000Z

302

Rotational Doppler-effect due to selective excitation of vector-vortex field in optical fiber  

Science Journals Connector (OSTI)

Experimental demonstration of rotational Doppler-effect due to direct and simultaneous excitation of orthogonal elliptically-polarized fundamental and vortex modes in a two-mode...

Inavalli, V V G Krishna; Viswanathan, Nirmal K

2011-01-01T23:59:59.000Z

303

Vibrations of raised access floors  

Science Journals Connector (OSTI)

Raised access floors play a critical role in modern cleanroom design. They have unique mechanical properties that make them respond to dynamic loading in a manner quite different from conventional floors. For example an unbraced floor is much more flexible horizontally than in the vertical direction. Horizontal vibration amplitudes with walker excitation may exceed 100??m/s in an unbraced floor exceeding the sensitivity of 1000× inspection microscopes by as much as an order of magnitude. Issues such as these become important when moderately vibration?sensitive instruments such as optical microscopes are supported on access floors typically the case in cleanrooms. This paper presents results of experimental studies involving a 3?m×3?m segment of floor and a large floor installed in a cleanroom both of which were subjected to dynamic loads using a shaker. Both drive?point and propagation properties were examined. In addition data are presented for variations in bracing and bolting using the 3?m×3?m segment.

2002-01-01T23:59:59.000Z

304

DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM  

SciTech Connect (OSTI)

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, 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. The principal objectives of Phase II are: 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 drilling laboratories and test wells. Work during this quarter centered on the rebuilding of the prototype using the improved valve design described in the last report. Most of the components have been received and assembly has begun. Testing is expected to resume in August. In April, a paper was presented at the American Association of Drilling Engineers National Technical Conference in Houston. The paper was well received, and several oilfield service and supply companies sent inquiries regarding commercial distribution of the system. These are currently being pursued, but none have yet been finalized.

Martin E. Cobern

2005-07-27T23:59:59.000Z

305

Vibration of Glasses containing Effervescing Liquids  

Science Journals Connector (OSTI)

... of the phenomena, he says:—“We must consider what passes in the communication of vibrations through the liquid from one side of the glass to the other. The glass ... it is clear, that if any considerable part of a system be unsusceptible of regular vibration, the whole must be so.” The phenomenon, then, according to this explanation, ...

ALLEN BEAZELEY

1872-07-18T23:59:59.000Z

306

Vibration of Gun-Barrels1  

Science Journals Connector (OSTI)

... THIS research on the vibration of gun-barrels is a continuation of former investigations on the nature of ... of gun-barrels is a continuation of former investigations on the nature of vibrations set up in a gun-barrel when fixed, with a view to discover how ...

F. J.-S

1901-01-17T23:59:59.000Z

307

Operando Raman and Theoretical Vibration Spectroscopy of Non...  

Broader source: Energy.gov (indexed) [DOE]

Operando Raman and Theoretical Vibration Spectroscopy of Non-PGM Catalysts Operando Raman and Theoretical Vibration Spectroscopy of Non-PGM Catalysts Presentation about...

308

Noise and Vibration Control of Combustion Engine Vehicles.  

E-Print Network [OSTI]

??Noise and vibrations have over the last two decades been regarded as significant environmental health problems. Regulations regarding acoustic as well as vibration levels have… (more)

Winberg, Mathias

2005-01-01T23:59:59.000Z

309

Vibration-rotation spectrum of HCl: A physical chemistry experiment  

Science Journals Connector (OSTI)

Vibration-rotation spectrum of HCl: A physical chemistry experiment ... Utilizing a 0.5 cm−1 resolution teaching grade FTIR spectrometer, 15 vibrational ... ...

Fred E. Stafford; C. W. Holt; G. L. Paulson

1963-01-01T23:59:59.000Z

310

Rate Coefficients for Vibrational Relaxation of OH(X2?, v = 1–4) by He  

Science Journals Connector (OSTI)

Rate Coefficients for Vibrational Relaxation of OH(X2?, v = 1–4) by He ... The vibrational levels v = 0–4 of OH were excited via the A2?+–X2? transition with a Nd3+:YAG laser (Spectra Physics GCR-130) pumped dye laser (Lambda Physik LPD3002), and the laser-induced fluorescence (LIF) was detected with a photomultiplier tube (PMT; Hamamatsu R1104) through a UV band-pass filter (Toshiba UV-D35). ... Physical Chemistry Chemical Physics (2007), 9 (31), 4407-4413 CODEN: PPCPFQ; ISSN:1463-9076. ...

Nanase Kohno; Jun Yamashita; Chihiro Kadochiku; Hiroshi Kohguchi; Katsuyoshi Yamasaki

2013-03-21T23:59:59.000Z

311

Release and nonvolatile operation of carbon nanotube nanorelay by resonant vibration  

SciTech Connect (OSTI)

We investigated the release of a stuck carbon nanotube (CNT) cantilever beam in nanorelay applications using a nano-manipulator. Even with strong adhesion induced by electrostatic attraction that is 100 times stronger than the van der Waals interaction, successful release of a nanotube arm from a stuck state was realized by the application of a resonant vibration to the stuck CNT arm. Furthermore, nonvolatile operation of the nanotube nanorelay was demonstrated by the application of the resonant vibration to the stuck CNT arm.

Kagota, Tatsuya; Takei, Kuniharu; Arie, Takayuki; Akita, Seiji, E-mail: akita@pe.osakafu-u.ac.jp [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531 (Japan); Nagataki, Atsuko [Department of Physics and Electronics, Osaka Prefecture University, 1-1 Gakuen-cho, Nakaku, Sakai, Osaka 599-8531 (Japan); Materials Analysis Research Center, KRI, Inc., Osaka 554-0051 (Japan)

2013-11-11T23:59:59.000Z

312

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

313

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 .sqroot.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.

Slavik, Charles J. (Rexford, NY); Rhudy, Ralph G. (Scotia, NY); Bushman, Ralph E. (Lathem, NY)

1997-01-01T23:59:59.000Z

314

Downhole Vibration Monitoring & Control System  

SciTech Connect (OSTI)

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, 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. 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 the Phase II final report was issued. Work on Phase III of the project began during the first quarter, 2006. Efforts the current quarter have continued to focus on the manufacture of the prototype and precommercial parts, field test planning and commercialization. The continued extreme lead times quoted by oilfield machine shops for collar components significantly delayed the deployment of the prototype and precommercial units. All parts have now been received for two units, and all but one for the third. Mechanical assembly of the first two systems is complete and the electronics installation and laboratory testing will be finished in April. We have entered into a Memorandum of Understanding with a major US oilfield equipment supplier, which calls for their assisting with our field tests, in cash and in kind. We are close to signing a definitive agreement which includes the purchase of the three precommercial units. We had also signed a CRADA with the Rocky Mountain Oilfield Test Center (RMOTC), and scheduled a test at their site, The RMOTC drilling schedule continues to slip, and the test cannot begin until the first week of May. Based on these factors, we have requested a no-cost extension to July 31, 2007.

Martin E. Cobern

2007-03-31T23:59:59.000Z

315

DOWNHOLE VIBRATION MONITORING & CONTROL SYSTEM  

SciTech Connect (OSTI)

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, 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. The principal objectives of Phase II are: 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 drilling laboratories and test wells. As a result of the lower than expected performance of the MR damper noted last quarter, several additional tests were conducted. These dealt with possible causes of the lack of dynamic range observed in the testing: additional damping from the oil in the Belleville springs; changes in properties of the MR fluid; and, residual magnetization of the valve components. Of these, only the last was found to be significant. By using a laboratory demagnetization apparatus between runs, a dynamic range of 10:1 was achieved for the damper, more than adequate to produce the needed improvements in drilling. Additional modeling was also performed to identify a method of increasing the magnetic field in the damper. As a result of the above, several changes were made in the design. Additional circuitry was added to demagnetize the valve as the field is lowered. The valve was located to above the Belleville springs to reduce the load placed upon it and offer a greater range of materials for its construction. In addition, to further increase the field strength, the coils were relocated from the mandrel to the outer housing. At the end of the quarter, the redesign was complete and new parts were on order. The project is approximately three months behind schedule at this time.

Martin E. Cobern

2005-04-27T23:59:59.000Z

316

Vibrations in brass instrument bodies: A review.  

Science Journals Connector (OSTI)

The bodies of brass instruments vibrate when played as evident to any player. These vibrations are driven mechanically at the player’s lips and by coupling with the internal acoustic field throughout the instrument. The coupling can equally well allow energy flow in the opposite direction from the body to the player’s lips and to the internal acoustic field. The vibrating shell can also radiate directly into the room. Studies involving human or machine players suggest that the effect of the wall vibrations on the acoustic spectral components is of the order of a few decibels. However for the most part the direct radiation of the wall vibrations is approximately 20 dB below the level of the radiated internal acoustic field. The wall vibrations have a slightly different time envelope though and also have a formant?like region around a few kilohertz. Some of the pieces of this complex puzzle that need further investigation include the interaction between player and instrument the effect of sound level on the coupling the perceptibility of the radiated vibrations by auditors and the variations within the brass family.

Peter L. Hoekje

2010-01-01T23:59:59.000Z

317

van Hove singularities and vortex motion in superconductors B. I. Ivlev,1,2  

E-Print Network [OSTI]

´ 78000, Mexico Received 16 February 2001; published 18 June 2001 When vortices move in a type by an electric current, any peculiarity of the vortex radiation friction due to emission of acoustic waves vortices. When a vortex moves under the action of a transport electric current, an electric field

Kunchur, Milind N.

318

Magnetization reversal via single and double vortex states in submicron Permalloy ellipses P. Vavassori,1  

E-Print Network [OSTI]

Magnetization reversal via single and double vortex states in submicron Permalloy ellipses P University, Ithaca, New York, USA Received December 5, 2003; published 3 June 2004 The magnetization reversal of the magnetic field and to occur via the formation of one or two vortices; the one vortex state is nucleated

Metlushko, Vitali

319

Nucleation-controlled vortex entry in a square-columnar Josephson-junction array  

SciTech Connect (OSTI)

The initial magnetization curve of square-columnar Josephson-junction arrays is calculated from fundamental laws. It is found that the first vortex entry is controlled by vortex nucleation rather than surface depinning and it occurs at a field greater than that predicted by the traditional surface-barrier theory. {copyright} {ital 1997} {ital The American Physical Society}

Chen, D.; Moreno, J.J.; Hernando, A. [Instituto de Magnetismo Aplicado, RENFE-UCM-CSIC, 28230 Las Rozas, Madrid (Spain)] [Instituto de Magnetismo Aplicado, RENFE-UCM-CSIC, 28230 Las Rozas, Madrid (Spain)

1997-08-01T23:59:59.000Z

320

Modeling bubble-vortex interactions Modeling and simulation of multiple bubble entrainment and interactions with two  

E-Print Network [OSTI]

Modeling bubble-vortex interactions Modeling and simulation of multiple bubble entrainment, OR 97331. (Dated: 5 November 2010) 1 #12;Modeling bubble-vortex interactions Simulations of bubble direct numerical simulation whereas motion of subgrid bubbles is modeled using Lagrangian track- ing

Apte, Sourabh V.

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

Generation and Propagation of InertiaGravity Waves from Vortex Dipoles and Jets SHUGUANG WANG*  

E-Print Network [OSTI]

Generation and Propagation of Inertia­Gravity Waves from Vortex Dipoles and Jets SHUGUANG WANG) ABSTRACT This study investigates gravity wave generation and propagation from jets within idealized vortex, geostrophic adjust- ment, and spontaneous generation (Fritts and Alexander 2003, and references therein

322

Windowed defocused photographic speckle vibration measurement  

E-Print Network [OSTI]

The out-of-plane vibration of a rough surface causes an in-plane vibration of its speckle pattern when observed with a defocused optical photographic system. If the frequency of the oscillations is high enough, a time-averaged specklegram is recorded from which the amplitude of the vibration can be estimated. The statistical character of speckle distributions along with the pixel sampling and intensity analog-to-digital conversion inherent to electronic cameras degrade the accuracy of the amplitude measurement to an extent that is analyzed and experimentally tested in this paper. The relations limiting the mutually competing metrological features of a defocused speckle system are also deduced mathematically.

Diazdelacruz, Jose M

2014-01-01T23:59:59.000Z

323

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

324

Stripe Domains and First-Order Phase Transition in the Vortex Matter of Anisotropic High-Temperature Superconductors  

E-Print Network [OSTI]

Stripe Domains and First-Order Phase Transition in the Vortex Matter of Anisotropic High-Temperature temperature superconductor and reveal a sharp transition in the state of this phase resulting in regular that can subsequently melt at high temperatures to a vortex liquid, a pinned vortex glassy state that can

Alexei, Koshelev

325

Effect of time-dependent piston velocity program on vortex ring formation in a piston/cylinder arrangement  

E-Print Network [OSTI]

Effect of time-dependent piston velocity program on vortex ring formation in a piston An analytical model describing laminar vortex ring formation in a nozzle flow generator piston/ cylinder.1063/1.2188918 I. INTRODUCTION Vortex rings are usually generated in the laboratory by the motion of a piston

Dabiri, John O.

326

arXiv:1206.2498v2[cond-mat.other]19Nov2012 Quantum vortex reconnections  

E-Print Network [OSTI]

, and parts of the initial vortical tubes can be left behind as vortex threads, which then undergo successivearXiv:1206.2498v2[cond-mat.other]19Nov2012 Quantum vortex reconnections S. Zuccher,1 M. Caliari,1 A with time before and after the vor- tex reconnection. We also compute vortex reconnections using the Biot

Caliari, Marco

327

The role of boundary conditions in a simple model of incipient vortex breakdown F. Gallaire and J.-M. Chomaz  

E-Print Network [OSTI]

. In the labora- tory, it is preferentially studied in vortex tubes, where it is seen in many cases to give riseThe role of boundary conditions in a simple model of incipient vortex breakdown F. Gallaire and J of a hairpin vortex in a shear-thinning fluid governed by a power-law model Phys. Fluids 25, 101703 (2013); 10

Boyer, Edmond

328

Quantum dynamics of a vortex in a Josephson junction  

SciTech Connect (OSTI)

We investigate the tunneling character of vortex in an asymmetrical potential well with a finite barrier by using the periodic instanton method. We obtain the total decay rate which is valid for the entire range of temperature and show how it reduces to the appropriate results for the classical thermal activation at high temperatures, the thermally assisted tunneling at intermediate temperatures, and the pure quantum tunneling at low temperature. We can even give the exact definition of the 'crossover' temperature and find experimental data to support our theoretical analysis.

Li Hong; Liu Wuming [Joint Laboratory of Advanced Technology in Measurements, Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100080 (China); Shen Shunqing [Department of Physics, University of Hong Kong, Pokfulam Road, Hong Kong (China); Liang Jiuqing [Institute of Theoretical Physics, Shanxi University, Taiyuan, Shanxi 030006 (China)

2005-07-01T23:59:59.000Z

329

Collective Effects in Vortex Movements in Complex Plasmas  

Science Journals Connector (OSTI)

We study the onset and characteristics of vortices in complex (dusty) plasmas using two-dimensional simulations in a setup modeled after the PK-3 Plus laboratory. A small number of microparticles initially self-arranges in a monolayer around the void. As additional particles are introduced, an extended system of vortices develops due to a nonzero curl of the plasma forces. We demonstrate a shear-thinning effect in the vortices. Velocity structure functions and the energy and enstrophy spectra show that vortex flow turbulence is present that is in essence of the “classical” Kolmogorov type.

Mierk Schwabe, Sergey Zhdanov, Christoph Räth, David B. Graves, Hubertus M. Thomas, and Gregor E. Morfill

2014-03-19T23:59:59.000Z

330

Spontaneous vortex phase and pinning in ferromagnetic-superconducting systems  

E-Print Network [OSTI]

of epsilon10 as a function of rho0lambda for the case when n = 1, lambdaxi = 10,R1 = lambda,R2 = 2lambda and deltam = 10. . . . . . . . . . . . . . . 31 ix FIGURE Page 12 A superconducting thin film pierced by a ferromagnetic nano rod of radius R, length L... circle of radius rho0 that depends on the radii and magnetization per unit area of the annulus, and on the SC pene- tration depth lambda. In section five I focus on pinning and spontaneous vortex creation by a ferromagnetic rod which penetrates...

Kayali, Mohammad Amin

2004-09-30T23:59:59.000Z

331

Roland Kruse, Tiedo Meyer: Vibration platform for the calibration of  

E-Print Network [OSTI]

Overview The project KOLOS Vibration sensor Measurement principle Vibration platform I Concept KOLOS (Cost-Effective Laser Sensor for Optical Vibration Measurements) · Low cost, contactless sensor for measuring the amplitude of in-plane vibrations · Based on the evaluation of the speckle pattern

Vormann, Matthias

332

Water distribution measurement in sand using sound vibration and SLDV  

E-Print Network [OSTI]

Water distribution measurement in sand using sound vibration and SLDV T. Sugimotoa , Y. Nakagawaa vibrator is used as a sound source. SLDV measures the vibration of ground surface. The propagation velocity between vibrator and measuring point is used to estimate the water distribution. Also, the soil

Boyer, Edmond

333

Piezoresistive and Piezoelectric MEMS Strain Sensors for Vibration Detection  

E-Print Network [OSTI]

Piezoresistive and Piezoelectric MEMS Strain Sensors for Vibration Detection Stanley Kona, Kenn and piezoelectric materials are commonly used to detect strain caused by structural vibrations in macro, vibration 1. INTRODUCTION Vibrations are a common phenomena of mechanical structures that can be detrimental

Horowitz, Roberto

334

Vibration?Rotation Spectroscopy of Molecules Trapped inside C60  

Science Journals Connector (OSTI)

The remaining six degrees of freedom correspond to the vibrations and rotations of the diatomic molecule and the rattling vibration of the molecule inside the cage. ... The vibrational frequency and the rotational constant are slightly different. ... Dimerization of I mediated by 4-aminopyridine in a high-speed vibrating mill yields the cyclobutane-contg. ...

R. James Cross

2008-07-04T23:59:59.000Z

335

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 of a prototype MEMS microactuator and vibration sensors, and controller design for suspension vibration. An LQG method is proposed for vibration sensor location and orientation optimization. Strain sensors

Horowitz, Roberto

336

Vibration Analysis of Wiresaw Manufacturing Processes and Wafer Surface Measurements  

E-Print Network [OSTI]

Vibration Analysis of Wiresaw Manufacturing Processes and Wafer Surface Measurements I. Kao (PI), S the yield per crystal and to reduce the cost. In this paper, the vibration model of wiresaw system of vibration indicate the interference of excitation and natural frequencies in the vibration patterns

Kao, Imin

337

PROOF-MASS INERTIAL VIBRATION CONTROL USING A SHUNTED  

E-Print Network [OSTI]

PROOF-MASS INERTIAL VIBRATION CONTROL USING A SHUNTED ELECTROMAGNETIC TRANSDUCER Andrew J. Fleming-mass dampers utilize a suspended mass to reduce the vibration experienced by a host structure. Active vibration vibration absorbtion. An electrical impedance is designed and connected to an electromagnetic coil

Fleming, Andrew J.

338

Interaction of Josephson Junction and Distant Vortex in Narrow Thin-Film Superconducting Strips  

SciTech Connect (OSTI)

The phase difference between the banks of an edge-type planar Josephson junction crossing the narrow thin-film strip depends on wether or not vortices are present in the junction banks. For a vortex close to the junction this effect has been seen by Golod, Rydh, and Krasnov [Phys. Rev. Lett. 104, 227003 (2010)], who showed that the vortex may turn the junction into ? type. It is shown here that even if the vortex is far away from the junction, it still changes the 0 junction to a ? junction when situated close to the strip edges. Within the approximation used, the effect is independent of the vortex-junction separation, a manifestation of the topology of the vortex phase which extends to macroscopic distances of superconducting coherence.

Kogan, V. G. [Ames Laboratory; Mints, R. G. [Tel Aviv University

2014-01-31T23:59:59.000Z

339

Supine human response and vibration-suppression during whole-body vibration.  

E-Print Network [OSTI]

?? Whole-body vibration (WBV) has been identified as a stressor to supine patients with head and spinal injuries during medical transportation. Limited information is available… (more)

Meusch, John Carl

2012-01-01T23:59:59.000Z

340

Harmonic distortion reduction on seismic vibrators  

Science Journals Connector (OSTI)

...amplitude and phase in the fundamental frequency, resulting...accurate control of the fundamental component in the vibrator...a prime mover or a diesel engine to drive the pumps...and intensity of the fundamental force with model 364...

Zhouhong Wei; Thomas F. Phillips

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

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

342

Harmonic distortion reduction on seismic vibrators  

Science Journals Connector (OSTI)

...as well. However, in general, Figure 6 demonstrates...a prime mover or a diesel engine to drive the pumps...vibrator performance. In general, the coupling conditions...rocking motions. In general, the contact area becomes...

Zhouhong Wei; Thomas F. Phillips

343

Journalaf Sound and Vibration (1997) 204(1), 131-158 VIBRATIONS OF OPEN-SECTION CHANNELS  

E-Print Network [OSTI]

Journalaf Sound and Vibration (1997) 204(1), 131-158 ·VIBRATIONS OF OPEN-SECTION CHANNELS 1997) An exact analytical method is presented for the analysis of forced vibrations of uniform, open the flexural and the torsional vibrations are coupled. In the context of this study, the type of any existing

Yaman, Yavuz

344

Method and apparatus for vibrating a substrate during material formation  

DOE Patents [OSTI]

A method and apparatus for affecting the properties of a material include vibrating the material during its formation (i.e., "surface sifting"). The method includes the steps of providing a material formation device and applying a plurality of vibrations to the material during formation, which vibrations are oscillations having dissimilar, non-harmonic frequencies and at least two different directions. The apparatus includes a plurality of vibration sources that impart vibrations to the material.

Bailey, Jeffrey A. (Richland, WA) [Richland, WA; Roger, Johnson N. (Richland, WA) [Richland, WA; John, Munley T. (Benton City, WA) [Benton City, WA; Walter, Park R. (Benton City, WA) [Benton City, WA

2008-10-21T23:59:59.000Z

345

Skyrmion vibration modes within the rational map ansatz  

SciTech Connect (OSTI)

We study the vibration modes of the Skyrme model within the rational map ansatz. We show that the vibrations of the radial profiles and the rational maps are decoupled and we consider explicitly the cases B=1, B=2, and B=4. We then compare our results with the vibration modes obtained numerically by Barnes et al. and show that qualitatively the rational map reproduces the vibration modes obtained numerically but that the vibration frequencies of these modes do not match very well.

Lin, W. T.; Piette, B. [Department of Mathematical Sciences, University of Durham, Durham, DH1 3LE (United Kingdom)

2008-06-15T23:59:59.000Z

346

Skyrmion Vibration Modes within the Rational Map Ansatz  

E-Print Network [OSTI]

We study the vibration modes of the Skyrme model within the rational map ansatz. We show that the vibrations of the radial profiles and the rational maps are decoupled and we consider explicitly the case B=1, B=2 and B=4. We then compare our results with the vibration modes obtained numerically by Barnes et al. and show that qualitatively the rational map reproduces the vibration modes obtained numerically but that the vibration frequencies of these modes do not match very well.

W. T. Lin; B. Piette

2008-04-30T23:59:59.000Z

347

Redesigned recycle valves abate compressor vibration  

SciTech Connect (OSTI)

New recycle valves installed in 1994 on the compressors in the East Brae field in the North Sea corrected the noise and vibration problem that damaged the original valves shortly after commissioning the platform. The original recycle valves, especially on the second-stage compressors, showed severe damage. The paper describes the Brae field, the recycle system, recycle valves, operations, the new valve design, noise and vibration, and valve actuators.

Laing, D.E. [Marathon Oil U.K. Ltd., Aberdeen (United Kingdom); Miller, H.L.; McCaskill, J.W. [Engineering Control Components Inc., Rancho Santa Margarita, CA (United States)

1995-06-05T23:59:59.000Z

348

Active vibration control in a microgravity environment  

E-Print Network [OSTI]

ACTIVE VIBRATION COiVTROL IN A MICROGRAVITY ENVIRONMENT A Thesis MYOUNG SOO PARK Submitted to the Graduate College of Texas A@M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1987 Maior... Subject: Mechanical Engineering ACTIVE VIBRATION CONTROL IN A MICROGRAVITY ENVIRONMENT A Thesis by MYOUNG SOO PARK Approved as to style and content by: Dr. C. H. Gerhold (Chairman of Coxnmit tee) Dr. T ozi (Member) Dr. Y. XVe sman (Member) Dr...

Park, Myoung Soo

2012-06-07T23:59:59.000Z

349

Reduction of aerodynamic forces on a minivan by a pair of vortex generators of a pocket type  

Science Journals Connector (OSTI)

Reduction of the aerodynamic forces on a minivan has been achieved using a pair of pockets at the left and the right sides, respectively, of the rear roof end of the vehicle. The two pockets generate cross-streamwise vortices that cause the turbulent kinetic energy to increase in the boundary layer in the downstream of the two pockets. This increased turbulent kinetic energy induces the flow separation to be delayed further downstream along the vehicle back. Unlike the common Vortex Generators (VGs) of extrusive type, these VGs of a pocket type do not cause any additional drag by themselves. This paper investigates numerically the effects of pockets on the reduction of the aerodynamic forces and the flow field around a minivan.

Inchul Kim; Hualei Chen

2010-01-01T23:59:59.000Z

350

Ultrafast Vibrationally-Induced Dephasing of Electronic Excitations in  

E-Print Network [OSTI]

-3-1 Hongo, Bunkyoku, Tokyo 113-8656, Japan, and Theory DiVision, Los Alamos National Lab, New Mexico 87545 is almost independent of the electronic excitation energy and occurs faster for biexcitons than single solar cells,5 field-effect transis- tors,6 and other nanometer-sized devices. The quasi

351

Correcting vibration-induced performance degradation in enterprise servers  

E-Print Network [OSTI]

achieve performance improvements of up to 73% and energy savings of up to 76% over the state of the art, while meeting thermal constraints and improving the system's resilience to both internal and external and maintain runtime performance, datacenters have high-powered HVAC systems in the buildings and fan

Simunic, Tajana

352

Development of a free vortex wake method code for offshore floating wind turbines  

Science Journals Connector (OSTI)

Offshore floating wind turbines (OFWTs) present unique aerodynamic analysis challenges. Motion–derived velocity perturbations in the wake necessitate higher–fidelity aerodynamic analysis methods than the ubiquitous momentum balance techniques currently in use. A more physically–sound approach is to model the wake generated by a wind turbine rotor as a freely convecting lattice, using the resultant inflow to estimate rotor loads, as it done with a free vortex wake method (FVM). The FVM code Wake Induced Dynamics Simulator (WInDS) was developed at the University of Massachusetts at Amherst to predict the aerodynamic loading and wake evolution of an OFWT to a higher degree of accuracy than is possible via momentum balance methods. A series of validation cases were conducted to provide some basis for applying \\{WInDS\\} to floating wind turbine cases, for which no aerodynamic experimental data is currently available. The results from these tests show that \\{WInDS\\} is able to accurately predict the aerodynamically–derived loads and wake structures generated by various fixed and rotary–wing cases, and may therefore be applied to more complex cases, like OFWTs, with a degree of confidence.

T. Sebastian; M.A. Lackner

2012-01-01T23:59:59.000Z

353

Random center vortex lines in continuous 3D space-time  

E-Print Network [OSTI]

We present a model of center vortices, represented by closed random lines in continuous 2+1- dimensional space- time. These random lines are modeled as being piece-wise linear and an ensemble is generated by Monte Carlo methods. The physical space in which the vortex lines are defined is a cuboid with periodic boundary conditions. Besides moving, growing and shrinking of the vortex configuration, also reconnections are allowed. Our ensemble therefore contains not a fixed, but a variable number of closed vortex lines. This is expected to be important for realizing the deconfining phase transition. Using the model, we study both vortex percolation and the potential V (R) between quark and anti-quark as a function of distance R at different vortex densities, vortex segment lengths, reconnection conditions and at different temperatures. We have found three deconfinement phase transitions, as a function of density, as a function of vortex segment length, and as a function of temperature. The model reproduces the qualitative features of confinement physics seen in SU(2) Yang-Mills theory.

Roman Höllwieser; Derar Altarawneh; Michael Engelhardt

2014-11-26T23:59:59.000Z

354

Terahertz Vibration?Rotation?Tunneling Spectroscopy of the Ammonia Dimer. II. A?E States of an Out-of-Plane Vibration and an In-Plane Vibration  

Science Journals Connector (OSTI)

Terahertz Vibration?Rotation?Tunneling Spectroscopy of the Ammonia Dimer. ... In order to proceed toward the ultimate goal of determining an accurate intermolecular potential surface like what has been done for the water dimer, it is necessary to thoroughly characterize the intermolecular vibrations. ... The ab initio harmonic vibrational frequencies are known to be often too high for the weakly bound systems. ...

Wei Lin; Jia-xiang Han; Lynelle K. Takahashi; Jennifer G. Loeser; Richard J. Saykally

2007-09-07T23:59:59.000Z

355

Self-excited vibrations in turning: cutting moment analysis  

E-Print Network [OSTI]

This work aims at analysing the moment effects at the tool tip point and at the central axis, in the framework of a turning process. A testing device in turning, including a six-component dynamometer, is used to measure the complete torsor of the cutting actions in the case of self-excited vibrations. Many results are obtained regarding the mechanical actions torsor. A confrontation of the moment components at the tool tip and at the central axis is carried out. It clearly appears that analysing moments at the central axis avoids the disturbances induced by the transport of the moment of the mechanical actions resultant at the tool tip point. For instance, the order relation between the components of the forces is single. Furthermore, the order relation between the moments components expressed at the tool tip point is also single and the same one. But at the central axis, two different order relations regarding moments are conceivable. A modification in the rolling moment localization in the (y, z) tool plan is associated to these two order relations. Thus, the moments components at the central axis are particularly sensitive at the disturbances of machining, here the self-excited vibrations.

Olivier Cahuc; Jean-Yves K'Nevez; Alain Gérard; Philippe Darnis; Gaëtan Albert; Claudiu F. Bisu; Céline Gérard

2010-07-06T23:59:59.000Z

356

Vortex and gap generation in gauge models of graphene  

E-Print Network [OSTI]

Effective quantum field theoretical continuum models for graphene are investigated. The models include a complex scalar field and a vector gauge field. Different gauge theories are considered and their gap patterns for the scalar, vector, and fermion excitations are investigated. Different gauge groups lead to different relations between the gaps, which can be used to experimentally distinguish the gauge theories. In this class of models the fermionic gap is a dynamic quantity. The finite-energy vortex solutions of the gauge models have the flux of the "magnetic field" quantized, making the Bohm-Aharonov effect active even when external electromagnetic fields are absent. The flux comes proportional to the scalar field angular momentum quantum number. The zero modes of the Dirac equation show that the gauge models considered here are compatible with fractionalization.

O. Oliveira; C. E. Cordeiro; A. Delfino; W. de Paula; T. Frederico

2010-12-21T23:59:59.000Z

357

Dynamics of nuclear single-particle structure in covariant theory of particle-vibration coupling: From light to superheavy nuclei  

SciTech Connect (OSTI)

The impact of particle-vibration coupling and polarization effects due to deformation and time-odd mean fields on single-particle spectra is studied systematically in doubly magic nuclei from low-mass {sup 56}Ni up to superheavy ones. Particle-vibration coupling is treated fully self-consistently within the framework of the relativistic particle-vibration coupling model. Polarization effects due to deformation and time-odd mean field induced by odd particle are computed within covariant density functional theory. It has been found that among these contributions the coupling to vibrations makes a major impact on the single-particle structure. The impact of particle-vibration coupling and polarization effects on calculated single-particle spectra, the size of the shell gaps, the spin-orbit splittings and the energy splittings in pseudospin doublets is discussed in detail; these physical observables are compared with experiment. Particle-vibration coupling has to be taken into account when model calculations are compared with experiment since this coupling is responsible for observed fragmentation of experimental levels; experimental spectroscopic factors are reasonably well described in model calculations.

Litvinova, E. V.; Afanasjev, A. V. [GSI Helmholtzzentrum fuer Schwerionenforschung, D-64291 Darmstadt, Germany and Institut fuer Theoretische Physik, Goethe-Universitaet, D-60438 Frankfurt am Main (Germany); Department of Physics and Astronomy, Mississippi State University, Mississippi 39762 (United States)

2011-07-15T23:59:59.000Z

358

Dynamics of water probed with vibrational echo correlation spectroscopy John B. Asbury, Tobias Steinel, and Kyungwon Kwak  

E-Print Network [OSTI]

and the time scale for the production of vibrational relaxation induced broken hydrogen bond ``photoproducts infrared experimental methods have been applied to extract information about hydrogen bond dynamics from to the study of water,5,15­19,40 provide a direct method for accessing hydrogen bond dynamics through

Fayer, Michael D.

359

Cylinder Pressures and Vibration in Internal Combustion Engine Condition G O Chandroth, A J C Sharkey and N E Sharkey  

E-Print Network [OSTI]

of sensory information. Inducing several faults in a 4 stroke diesel engine, cylinder pressure (P­stroke high speed diesel engine. The explosion of the hydrocarbon­air mixture within the complex geometryCylinder Pressures and Vibration in Internal Combustion Engine Condition Monitoring G O Chandroth

Sharkey, Amanda

360

Experimental flight test vibration measurements and nondestructive inspection on a USCG HC-130H aircraft  

SciTech Connect (OSTI)

This paper presents results of experimental flight test vibration measurements and structural inspections performed by the Federal Aviation Administration`s Airworthiness Assurance NDI Validation Center (AANC) at Sandia National Laboratories and the US Coast Guard Aircraft Repair and Supply Center (ARSC). Structural and aerodynamic changes induced by mounting a Forward Looking Infrared (FLIR) system on a USCG HC-130H aircraft are described. The FLIR adversely affected the air flow characteristics and structural vibration on the external skin of the aircraft`s right main wheel well fairing. Upon initial discovery of skin cracking and visual observation of skin vibration in flight by the FLIR, a baseline flight without the FLIR was conducted and compared to other measurements with the FLIR installed. Nondestructive inspection procedures were developed to detect cracks in the skin and supporting structural elements and document the initial structural condition of the aircraft. Inspection results and flight test vibration data revealed that the FLIR created higher than expected flight loading and was the possible source of the skin cracking. The Coast Guard performed significant structural repair and enhancement on this aircraft, and additional in-flight vibration measurements were collected on the strengthened area both with and without the FLIR installed. After three months of further operational FLIR usage, the new aircraft skin with the enhanced structural modification was reinspected and found to be free of flaws. Additional US Coast Guard HC-130H aircraft are now being similarly modified to accommodate this FLIR system. Measurements of in-flight vibration levels with and without the FLIR installed, and both before and after the structural enhancement and repair were conducted on the skin and supporting structure in the aircraft`s right main wheel fairing. Inspection results and techniques developed to verify the aircraft`s structural integrity are discussed.

Moore, D.G.; Jones, C.R. [Sandia National Labs., Albuquerque, NM (United States). FAA Airworthiness Assurance NDI Validation Center; Mihelic, J.E.; Barnes, J.D. [Coast Guard Aircraft Repair and Supply Center, Elizabeth City, NC (United States)

1998-08-01T23:59:59.000Z

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.


361

Particle vibrational coupling in covariant density functional theory  

E-Print Network [OSTI]

A consistent combination of covariant density functional theory (CDFT) and Landau-Migdal Theory of Finite Fermi Systems (TFFS) is presented. Both methods are in principle exact, but Landau-Migdal theory cannot describe ground state properties and density functional theory does not take into account the energy dependence of the self-energy and therefore fails to yield proper single-% particle spectra as well as the coupling to complex configurations in the width of giant resonances. Starting from an energy functional, phonons and their vertices are calculated without any further parameters. They form the basis of particle-vibrational coupling leading to an energy dependence of the self-energy and an induced energy-dependent interaction in the response equation. A subtraction procedure avoids double counting. Applications in doubly magic nuclei and in a chain of superfluid nuclei show excellent agreement with experimental data.

P. Ring; E. Litvinova

2010-06-21T23:59:59.000Z

362

Ultrastable lasers based on vibration insensitive cavities  

SciTech Connect (OSTI)

We present two ultrastable lasers based on two vibration insensitive cavity designs, one with vertical optical axis geometry, the other horizontal. Ultrastable cavities are constructed with fused silica mirror substrates, shown to decrease the thermal noise limit, in order to improve the frequency stability over previous designs. Vibration sensitivity components measured are equal to or better than 1.5x10{sup -11}/m s{sup -2} for each spatial direction, which shows significant improvement over previous studies. We have tested the very low dependence on the position of the cavity support points, in order to establish that our designs eliminate the need for fine tuning to achieve extremely low vibration sensitivity. Relative frequency measurements show that at least one of the stabilized lasers has a stability better than 5.6x10{sup -16} at 1 s, which is the best result obtained for this length of cavity.

Millo, J.; Magalhaes, D. V.; Mandache, C.; Le Coq, Y.; English, E. M. L.; Westergaard, P. G.; Lodewyck, J.; Bize, S.; Lemonde, P.; Santarelli, G. [LNE-SYRTE, Observatoire de Paris, CNRS, UPMC, 61 Avenue de l'Observatoire, 75014 Paris (France)

2009-05-15T23:59:59.000Z

363

Mechanical vibration to electrical energy converter  

DOE Patents [OSTI]

Electromechanical devices that generate an electrical signal in response to an external source of mechanical vibrations can operate as a sensor of vibrations and as an energy harvester for converting mechanical vibration to electrical energy. The devices incorporate a magnet that is movable through a gap in a ferromagnetic circuit, wherein a coil is wound around a portion of the ferromagnetic circuit. A flexible coupling is used to attach the magnet to a frame for providing alignment of the magnet as it moves or oscillates through the gap in the ferromagnetic circuit. The motion of the magnet can be constrained to occur within a substantially linear range of magnetostatic force that develops due to the motion of the magnet. The devices can have ferromagnetic circuits with multiple arms, an array of magnets having alternating polarity and, encompass micro-electromechanical (MEM) devices.

Kellogg, Rick Allen (Tijeras, NM); Brotz, Jay Kristoffer (Albuquerque, NM)

2009-03-03T23:59:59.000Z

364

Optimal Excitation of Asymmetric Perturbations on an Axisymmetric Barotropic Vortex: A linear Singular Value Analysis  

Science Journals Connector (OSTI)

Singular vectors on a barotropic circular vortex consisting of three regions of piecewise-constant vorticity are investigated under the L2-norm to reveal the shape and growth rate of possible perturbations that may contribute to the formation of ...

Toshihisa Itano

365

Dynamical mass of a quantum vortex in a Josephson junction array  

SciTech Connect (OSTI)

The real-time response to a small external perturbation of a vortex in a quantum Josephson junction array, with long-range Coulomb interaction between Cooper pairs, is analyzed. While the static damping is zero for vortex velocities below some threshold value v{sub th} (which implies the possibility of ballistic motion), a dynamical friction due to the coupling to the plasma oscillations is always present for frequencies higher than a given threshold {omega}{sub th}. The latter approaches zero when the velocity increases to v{sub th}. However, radiative dissipation of the vortex affects the threshold for ballistic motion. We discuss the conditions under which a mass can be defined for the vortex as a quantum particle. {copyright} {ital 1997} {ital The American Physical Society}

Eckern, U. [Institut fuer Physik, Universitaet Augsburg, D-86135 Augsburg (Germany)] [Institut fuer Physik, Universitaet Augsburg, D-86135 Augsburg (Germany); Luciano, G.; Tagliacozzo, A. [Dipartimento di Scienze Fisiche, Universita di Napoli, Mostra dOltremare Pad. 19, I-80125 Napoli (Italy)] [Dipartimento di Scienze Fisiche, Universita di Napoli, Mostra dOltremare Pad. 19, I-80125 Napoli (Italy); [Istituto Nazionale di Fisica della Materia (INFM), I-16152 Genova (Italy)

1997-12-01T23:59:59.000Z

366

E-Print Network 3.0 - axially-symmetric cyclonic vortex Sample...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

> >> 1 1 APRIL 2002 1213W A N G 2002 American Meteorological Society Summary: and wind fields of the vortex Rossby waves are quasi-balanced, with confluent cyclonic (divergent... ,...

367

Ultraviolet vortex generation using periodically bonded ?-BaB2O4 device  

Science Journals Connector (OSTI)

This paper describes the first demonstration of ultraviolet (266nm) vortex generation using the combination of a frequency-doubled nanosecond green laser, a spiral phase plate, and a...

Sasaki, Yuta; Koyama, Mio; Miyamoto, Katsuhiko; Ariga, Yoshimi; Onda, Tomomi; Shoji, Ichiro; Omatsu, Takashige

2014-01-01T23:59:59.000Z

368

Resonant amplification of vortex-core oscillations by coherent magnetic-field pulses  

E-Print Network [OSTI]

structure of magnetic vortex cores. Science 298, 577–580 (D. A. et al. Magnetic domain-wall logic. Science 309, 1688 (L. Magnetic domain-wall racetrack memory. Science 320, 190–

Yu, Young-Sang

2014-01-01T23:59:59.000Z

369

The Roles of Vortex Rossby Waves in Hurricane Secondary Eyewall Formation  

Science Journals Connector (OSTI)

A high-resolution, full-physics model initiated with an idealized tropical cyclone–like vortex is used to simulate and investigate the secondary eyewall formation. The beta skirt axisymmetrization (BSA) hypothesis previously proposed is examined ...

Xin Qiu; Zhe-Min Tan; Qingnong Xiao

2010-06-01T23:59:59.000Z

370

Vortex life cycles in two-and three-layer quasi-geostrophic models  

E-Print Network [OSTI]

Coherent vortices and their properties were studied in two- and three-layer quasi-geostrophic beta-plane turbulence. Much research has discussed vortex characteristics in a number of applications, but no significant study of vortices in turbulent...

Fox, Amanda Katherine

2012-06-07T23:59:59.000Z

371

Effects of trailing edge flap dynamic deployment on blade-vortex interactions  

E-Print Network [OSTI]

A theoretical and experimental investigation is undertaken to determine the effects of an actively deployable trailing edge flap on the disturbances created during blade-vortex interactions (BVI). The theoretical model consists of an unsteady panel...

Nelson, Carter T.

2012-06-07T23:59:59.000Z

372

Steady-state and equilibrium vortex configurations, transitions, and evolution in a mesoscopic superconducting cylinder  

E-Print Network [OSTI]

that the system passes through nearly metastable intermediate configurations while seeking the final minimum-energy steady state consistent with the square symmetry of the sample. An efficient scheme to determine the equilibrium vortex configuration in a...

Kim, S.; Hu, Chia-Ren; Andrews, MJ.

2004-01-01T23:59:59.000Z

373

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...

Kim, Kyu-Sup

2012-06-07T23:59:59.000Z

374

MEC E 638 VORTEX FLOWS Winter 2014 LARGE-SCALE STRUCTURES IN TURBULENCE PROF L. SIGURDSON  

E-Print Network [OSTI]

to find the characteristic vortex structures; to read the literature, nomenclature, terminology. TOPICS: Professor Lorenz Sigurdson, 5-1B Mech Eng Bldg, lorenz@ualberta.ca, http://websrv.mece.ualberta.ca/intranet

Flynn, Morris R.

375

Visualization of Intricate Flow Structures for Vortex Breakdown Analysis Xavier Tricoche  

E-Print Network [OSTI]

Hansen University of Utah Figure 1: Vortex breakdown bubble in numerical simulation of a cylindrical to study their impact on flight stability. Yet, to fully exploit the huge amount of information contained

Utah, University of

376

Annular Vortex Generation for Inertial Fusion Energy Beam-Line Protection  

SciTech Connect (OSTI)

The use of swirling annular vortex flow inside beam entrance tubes can protect beam-line structural materials in chambers for heavy-ion inertial fusion energy (IFE) applications. An annular wall jet, or vortex tube, is generated by injecting liquid tangent to the inner surface of a tube wall with both axially and azimuthally directed velocity components. A layer of liquid then lines the beam tube wall, which may improve the effectiveness of neutron shielding, and condenses and removes vaporized coolant that may enter the beam tubes. Vortex tubes have been constructed and tested with a thickness of three-tenths the pipe radius. Analysis of the flow is given, along with experimental examples of vortex tube fluid mechanics and an estimate of the layer thickness, based on simple mass conservation considerations.

Pemberton, Steven J.; Abbott, Ryan P.; Peterson, Per F. [University of California (United States)

2003-05-15T23:59:59.000Z

377

Conformational and Vibrational Studies of Triclosan  

Science Journals Connector (OSTI)

The conformational equilibrium of triclosan (5?chloro?2?(2 4?dichlorophenoxy) phenol) have been calculated using density functional theory (DFTe/B3LYP/6?311++G(d p)) method. Four different geometries were found to correspond to energy minimum conformations. The IR spectrum of triclosan was measured in the 4000–400? cm ?1 region. We calculated the harmonic frequencies and intensities of the most stable conformers in order to assist in the assignment of the vibrational bands in the experimental spectrum. The fundamental vibrational modes were characterized depending on their total energy distribution (TED%) using scaled quantum mechanical (SQM) force field method.

Haci Özi?ik; S. Haman Bayari; Semran Sa?lam

2010-01-01T23:59:59.000Z

378

Surrogate Spent Nuclear Fuel Vibration Integrity Investigation  

SciTech Connect (OSTI)

Transportation packages for spent nuclear fuel (SNF) must meet safety requirements under normal and accident conditions as specified by federal regulations. During transportation, SNF experiences unique conditions and challenges to cladding integrity due to the vibrational and impact loading encountered during road or rail shipment. ORNL has been developing testing capabilities that can be used to improve our understanding of the impacts of vibration loading on SNF integrity, especially for high burn-up SNF in normal transportation operation conditions. This information can be used to meet nuclear industry and U.S. Nuclear Regulatory Commission needs in the area of safety of SNF storage and transportation operations.

Wang, Jy-An John [ORNL; Wang, Hong [ORNL; Bevard, Bruce Balkcom [ORNL; Howard, Rob L [ORNL

2014-01-01T23:59:59.000Z

379

High-frequency vortex dynamics and dissipation of high-temperature superconductors  

Science Journals Connector (OSTI)

The high-frequency vortex dynamics of high-temperature superconductors near the flux-line depinning threshold is investigated based on a thermally activated flux-flow (TAFF) model. Dissipation due to vortex motion driven by a microwave electromagnetic field is studied as a function of the frequency, temperature, dc magnetic field, and microwave power. The generalized TAFF model is also compared to the conventional flux-creep theory and is found qualitatively consistent.

N.-C. Yeh

1991-01-01T23:59:59.000Z

380

Effect of a surface boundary layer on an intensifying, downward-propagating vortex  

E-Print Network [OSTI]

EFFECT OF A SURFACE BOUNDARY LAYER ON AN INTENSIFYING, DOWNWARD-PROPAGATING VORTEX A Thesis by VINCENT TUNSTALL WOOD Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE May 1977 Major Subject: Meteorology EFFECT OF A SURFACE BOUNDARY LAYER ON AN INTENSIFYING, DOWNWARD-PROPAGATING VORTEX A Thesis by VINCENT TUNSTALL WOOD Approved as to style and content by: (Chairman of Committee) (Head of Department...

Wood, Vincent Tunstall

2012-06-07T23:59:59.000Z

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

Explicit mean-field radius for nearly parallel vortex filaments in statistical equilibrium  

E-Print Network [OSTI]

Geophysical research has focused on flows, such as ocean currents, as two dimensional. Two dimensional point or blob vortex models have the advantage of having a Hamiltonian, whereas 3D vortex filament or tube systems do not necessarily have one, although they do have action functionals. On the other hand, certain classes of 3D vortex models called nearly parallel vortex filament models do have a Hamiltonian and are more accurate descriptions of geophysical and atmospheric flows than purely 2D models, especially at smaller scales. In these ``quasi-2D'' models we replace 2D point vortices with vortex filaments that are very straight and nearly parallel but have Brownian variations along their lengths due to local self-induction. When very straight, quasi-2D filaments are expected to have virtually the same planar density distributions as 2D models. An open problem is when quasi-2D model statistics behave differently than those of the related 2D system and how this difference is manifested. In this paper we study the nearly parallel vortex filament model of Klein, Majda, Damodaran in statistical equilibrium. We are able to obtain a free-energy functional for the system in a non-extensive thermodynamic limit that is a function of the mean square vortex position $R^2$ and solve \\emph{explicitly} for $R^2$. Such an explicit formula has never been obtained for a non-2D model. We compare the results of our formula to a 2-D formula of \\cite{Lim:2005} and show qualitatively different behavior even when we disallow vortex braiding. We further confirm our results using Path Integral Monte Carlo (Ceperley (1995)) \\emph{without} permutations and that the Klein, Majda, Damodaran model's asymptotic assumptions \\emph{are valid} for parameters where these deviations occur.

Timothy D. Andersen; Chjan C. Lim

2006-11-19T23:59:59.000Z

382

Tactile Icon Design Using a Vibration Actuator in Mobile Devices  

Science Journals Connector (OSTI)

This study presents three attributes for composing vibration patterns: Rhythm, intensity difference, and continuous variation in intensity. The intervals and the duration of the vibrations offer the elements of r...

Meng-Dar Shieh; Zheng-Bin Wu

2008-01-01T23:59:59.000Z

383

Apparatus and method of preloading vibration-damping bellows  

DOE Patents [OSTI]

An improved vibration damping bellows mount or interconnection is disclosed. In one aspect, the bellows is compressively prestressed along its length to offset vacuum-generated tensile loads and thereby improve vibration damping characteristics.

Cutburth, Ronald W. (Tracy, CA)

1988-01-01T23:59:59.000Z

384

Whole body vibration alters proprioception in the trunk  

E-Print Network [OSTI]

Occupational whole body vibration has long been associated with low back injuries. However, the mechanism of these injuries is not well understood. In this paper, the effect of whole body vibration on proprioception and dynamic stability...

Li, Lu; Lamis, Farhana; Wilson, Sara E.

2008-01-01T23:59:59.000Z

385

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

386

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

387

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

388

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

389

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

390

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

391

X-Ray Imaging of the Dynamic Magnetic Vortex Core Deformation  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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.

392

High-speed digital holographic interferometry for vibration measurement  

Science Journals Connector (OSTI)

A system based on digital holographic interferometry for the measurement of vibrations is presented. A high-power continuous laser

Pedrini, Giancarlo; Osten, Wolfgang; Gusev, Mikhail E

2006-01-01T23:59:59.000Z

393

NETL F 451.1/1-1, Categorical Exclusion Designation Form  

Broader source: Energy.gov (indexed) [DOE]

AC26-07NT42677 RPSEA FE Houston Offshore Engineering SCNGO FY14-1524 months Gary Covatch Houston, TX Vortex Induced Vibration Study for Deep Draft Column Stabilized Floaters...

394

The effect of non-uniform damping on flutter in axial flow and energy-harvesting strategies  

Science Journals Connector (OSTI)

...vortex induced vibration aquatic clean energy): a new concept in generation of clean and renewable energy from fluid flow. J. Offshore Mech. Arct...Chebyshev and Fourier spectral methods. New York, NY: Dover Publications. Boyer, F...

2012-01-01T23:59:59.000Z

395

Phase slippage and self-trapping in a self-induced bosonic Josephson junction  

SciTech Connect (OSTI)

A dipolar condensate confined in a toroidal trap constitutes a self-induced Josephson junction when the dipoles are oriented perpendicularly to the trap symmetry axis and the s-wave scattering length is small enough. The ring-shaped double-well potential coming from the anisotropic character of the mean-field dipolar interaction is robust enough to sustain self-trapping dynamics, which takes place when the initial population imbalance between the two wells is large. We show that, in this system, the self-trapping regime is directly related to a vortex-induced phase-slip dynamics. A vortex and antivortex are spontaneously nucleated in the low-density regions before a minimum of the population imbalance is reached and then cross the toroidal section in opposite directions through the junctions. This vortex dynamics yields a phase slip between the two weakly linked condensates causing an inversion of the particle flux.

Abad, M.; Guilleumas, M.; Mayol, R.; Pi, M. [Departament d'Estructura i Constituents de la Materia, Facultat de Fisica, Universitat de Barcelona, E-08028 Barcelona (Spain); Jezek, D. M. [IFIBA-CONICET and Departamento de Fisica, FCEN-UBA Pabellon 1, Ciudad Universitaria, 1428 Buenos Aires (Argentina)

2011-09-15T23:59:59.000Z

396

Phase-slippage and self-trapping in a self-induced bosonic Josephson junction  

E-Print Network [OSTI]

A dipolar condensate confined in a toroidal trap constitutes a self-induced Josepshon junction when the dipoles are oriented perpendicularly to the trap symmetry axis and the s-wave scattering length is small enough. The ring-shaped double-well potential coming from the anisotropic character of the mean-field dipolar interaction is robust enough to sustain self-trapping dynamics, which takes place when the initial population imbalance between the two wells is large. We show that in this system the self-trapping regime is directly related to a vortex-induced phase-slip dynamics. A vortex and antivortex are spontaneously nucleated in the low density regions, before a minimum of the population imbalance is reached, and then cross the toroidal section in opposite directions through the junctions.This vortex dynamics yields a phase slip between the two weakly linked condensates causing an inversion of the particle flux.

Abad, M; Mayol, R; Pi, M; Jezek, D M

2011-01-01T23:59:59.000Z

397

VIBRATION AMPLITUDE -DEPENDENT NATURAL FREQUENCY AND DAMPING RATIO OF REPAIRED PIER MODEL  

E-Print Network [OSTI]

by measuring its vibration. Therefore, so far, vibration measurements have been carried out to various bridge of vibration can be verified by this method, in some cases, vibration measurement of existing bridges of vibration measurement methods without the need of vibration devices were founded [8]. The main purpose

Paris-Sud XI, Université de

398

Experimental Study of Active Vibration Control of a Cantilever Beam  

Science Journals Connector (OSTI)

The modern technology demands the system to be light and reliable. However, with the conventional vibration control techniques it is difficult to keep the system light with all the damping mechanisms. This work deals with the Active Vibration Control ... Keywords: Active Vibration Control, cantilever, classical controller, piezoelectric transducers

S. M. Khot, Nitesh P. Yelve, Shoaib Shaik

2013-12-01T23:59:59.000Z

399

POLE ASSIGNMENT FOR A VIBRATING SYSTEM WITH AERODYNAMIC EFFECT #  

E-Print Network [OSTI]

POLE ASSIGNMENT FOR A VIBRATING SYSTEM WITH AERODYNAMIC EFFECT # J. N. WANG + , S. H. CHOU # , Y. C­input state feedback control arising from a one­dimensional vibrating system with aerodynamic e real axis. Key words. vibrating system, aerodynamic e#ect, state feedback control, pole assignment AMS

Chou, So-Hsiang

400

POLE ASSIGNMENT FOR A VIBRATING SYSTEM WITH AERODYNAMIC EFFECT  

E-Print Network [OSTI]

POLE ASSIGNMENT FOR A VIBRATING SYSTEM WITH AERODYNAMIC EFFECT J. N. WANG, S. H. CHOU, Y. C. CHEN feedback control arising from a one-dimensional vibrating system with aerodynamic effect. On the practical real axis. Key words. vibrating system, aerodynamic effect, state feedback control, pole assignment AMS

Lin, Wen-Wei

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

Active Automobile Engine Vibration Analysis Technical Report Number 1  

E-Print Network [OSTI]

Active Automobile Engine Vibration Analysis Technical Report Number 1 Page 1 of 26 DISTRIBUTION STATEMENT: Distribution authorized to all. Active Automobile Engine Vibration Analysis Technical Report at the University of Southern California #12;Active Automobile Engine Vibration Analysis Technical Report Number 1

Levi, Anthony F. J.

402

Particle Sizing using Passive Ultrasonic Measurement of Vessel Wall Vibrations  

E-Print Network [OSTI]

Particle Sizing using Passive Ultrasonic Measurement of Vessel Wall Vibrations Gillian Carson for particle sizing using an ultrasonic transducer to measure vessel wall vibrations and 1 #12;considers in a stirred vessel, its subse- quent impact with the vessel wall, and the resulting flexural vibrations

Mottram, Nigel

403

LINEAR COLLIDER FINAL DOUBLET CONSIDERATIONS: ATF2 VIBRATION MEASUREMENTS*  

E-Print Network [OSTI]

LINEAR COLLIDER FINAL DOUBLET CONSIDERATIONS: ATF2 VIBRATION MEASUREMENTS* B. Bolzon# , N. Geffroy to measure medium frequency vibrations in vertical axis. First, ground motion was measured for 72 hours vibrations (with their supports) were measured to evaluate their rigidity. The correlation of QD0 and QF1

Paris-Sud XI, Université de

404

ACTIVE VIBRATION CONTROL OF A SMART BEAM Yavuz Yaman1  

E-Print Network [OSTI]

1 ACTIVE VIBRATION CONTROL OF A SMART BEAM Yavuz Yaman1 , Tarkan Ã?alikan1 , Volkan Nalbantolu2, Collingwood, Ontario, Canada ABSTRACT This study presents an active vibration control technique applied this reduced model, presents the design of an active vibration controller which effectively suppresses

Yaman, Yavuz

405

Vibration-Rotation Bands of Allene-1. 1-d$_{2}$  

Science Journals Connector (OSTI)

24 February 1959 research-article Vibration-Rotation Bands of Allene-1. 1-d...the perpendicular bands to particular vibrations, some characteristic details of their...Coriolis interaction between B and B class vibrations, and the results are in general accord...

1959-01-01T23:59:59.000Z

406

Vibration-Rotation Bands of Acetylene and the Molecular Dimensions  

Science Journals Connector (OSTI)

4 December 1956 research-article Vibration-Rotation Bands of Acetylene and the...constants in the isotopic acetylenes, some vibration-rotation bands of acetylene have been...The values for each of the molecular vibrations have been re-determined, taking into...

1956-01-01T23:59:59.000Z

407

Vibration–mediated interactions in a host–parasitoid system  

Science Journals Connector (OSTI)

22 February 1997 research-article Vibration-mediated interactions in a host-parasitoid...was to obtain behavioral evidence of vibration mediated interactions between the apple...their respective responses to the leaf vibrations produced by the other party. We analysed...

1997-01-01T23:59:59.000Z

408

THE VIBRATION OF A CONDUCTING WIRE IN A MAGNETIC FIELD  

Science Journals Connector (OSTI)

......1963 research-article Articles THE VIBRATION OF A CONDUCTING WIRE IN A MAGNETIC FIELD...Polytechnic Institute of Brooklyn. The vibration of a perfectly flexible, stretched...inpedance of the wire is discuassed. THE VIBRATION OF A CONDUCTING WIRE IN A MAGNETIC FIELD......

M.A. LEIBOWITZ; R.C. ACKERBERG

1963-11-01T23:59:59.000Z

409

Vibration of spinning discs and powder formation in centrifugal atomization  

Science Journals Connector (OSTI)

...research-article Research articles 1006 121 117 Vibration of spinning discs and powder formation...liquid film. In this paper, the vibration of an atomizing disc excited by...melt is analysed and the role of vibration in the disintegration of the melt...

2011-01-01T23:59:59.000Z

410

Vibration Control of Multi-Mode Rotor-Bearing Systems  

Science Journals Connector (OSTI)

8 March 1983 research-article Vibration Control of Multi-Mode Rotor-Bearing...least-squares method to minimize the vibration of any general rotor-bearing system...to implement the open-loop adaptive vibration control strategies outlined in the paper...

1983-01-01T23:59:59.000Z

411

Titel des Moduls : Geruschbekmpfung/ Noise and Vibration Control  

E-Print Network [OSTI]

Titel des Moduls : Geräuschbekämpfung/ Noise and Vibration Control LP (nach ECTS): 6 Interne Kurzbe) Pflicht(P) / Wahl(W) Wahlpflicht(WP) Semester (WiSe/SoSe) Noise & Vibration Control VL 2 3 WP Wi. Springer-Verlag Berlin. ISBN 3-540-54473-9. 2. L.L. Beranek (ed.), 1971. Noise and Vibration Control. Mc

Berlin,Technische Universität

412

Variational Structure of Inverse Problems in Wave Propagation and Vibration  

E-Print Network [OSTI]

Variational Structure of Inverse Problems in Wave Propagation and Vibration James G. Berryman in wave propagation (traveltime tomography) and two examples in vibration (the plucked string and free.'' For vibrating systems, the apparently very complex behavior of an excited string, drumhead, or the Earth can

413

Vibration Proof Construction of 1000kV Electron Microscope  

Science Journals Connector (OSTI)

......University Press 1970 other ORIGINAL Vibration Proof Construction of 1000kV Electron...with the center of gravity. That is, a vibration proof hanging console was made as a method...protecting a 1000kV Electron Microscope from vibration, and this allowed the whole instrument......

Yoshio SAKITANI; Susumu OZASA

1970-01-01T23:59:59.000Z

414

Vibration-Assisted Electron Tunneling in C140 Transistors  

Science Journals Connector (OSTI)

Vibration-Assisted Electron Tunneling in C140 Transistors ... When electrons travel through molecules, vibrational modes of the molecules can affect current flow. ... 1 Recently, effects of vibrations in single molecules have been measured using scanning tunneling microscopes,2 single-molecule transistors,3,4 and mechanical break junctions. ...

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

2005-01-07T23:59:59.000Z

415

Development of Flexural Vibration Inspection Techniques to Rapidly  

E-Print Network [OSTI]

Development of Flexural Vibration Inspection Techniques to Rapidly Assess the Structural Health conditions at supports #12;Phase II Activities !! Develop an automated testing system !! Conduct vibration testing on bridge sections during construction !! Conduct load and vibration testing of in-service spike

Minnesota, University of

416

Active Vibration Suppression of a Smart Beam Cem ONAT+,*  

E-Print Network [OSTI]

1 Active Vibration Suppression of a Smart Beam via PI Dµ Control Cem ONAT+,* , Melin SAHIN* , Yavuz controller was designed for the active vibration suppression of a smart beam equipped with PZT (Lead successfully suppressed the vibration levels of the smart beam for the first two flexural modes. Keywords

Yaman, Yavuz

417

Vibration-Free Pulse Tube Cryocooler System for Gravitational Wave Detectors, Part I: Vibration-Reduction Method and Measurement  

Science Journals Connector (OSTI)

We developed a vibration-free cryocooler system based on a 4 K pulse tube (PT) cryocooler for a cryogenic interferometric gravitational wave detector. In this system, we incorporated a vibration-reduction syst...

T. Tomaru; T. Suzuki; T. Haruyama; T. Shintomi; N. Sato; A. Yamamoto…

2005-01-01T23:59:59.000Z

418

HYDROGEN LOCAL VIBRATIONAL MODES IN COMPOUND SEMICONDUCTORS  

E-Print Network [OSTI]

HYDROGEN LOCAL VIBRATIONAL MODES IN COMPOUND SEMICONDUCTORS M.D. MCCLUSKEY* University) spectroscopy of hydrogen and deuterium in GaP, AlSb, ZnSe, and GaN has provided important information about the structures of dopant- hydrogen complexes and their interaction with the host lattice. In GaN:Mg, for example

McCluskey, Matthew

419

Noise and Vibration Reduction in Felt Mountings  

Science Journals Connector (OSTI)

Resonant curves of loaded felt pads in compressional vibration give values for the damping and dynamic stiffness which show that felt in vibration is quite different from an equivalent perfect spring with viscous damping. The un?symmetrical resonance curves and the fact that within experimental error the stiffness is inversely proportional to the square root of the thickness indicate a decrease in stiffness with increasing amplitude. The increase in stiffness with pressure is so large that the ratio of dynamic elastic modulus to pressure (stiffness over mass) does not vary greatly between pressures of three to one hundred pounds per square inch. In this range the natural frequency of a mass on a felt pad is determined by the thickness of the pad rather than by its area and static load. An analysis of the performance of felt in reducing vibration transmission shows that its effectiveness is limited in most cases to frequencies above forty cycles per second. Practical installations have been studied and tables drawn up to give the acoustical engineer “handbook” information for the solution of problems in vibration reduction.

H. C. Hardy; F. G. Tyzzer

1946-01-01T23:59:59.000Z

420

Model for characterization of a vortex pair formed by shock passage over a light-gas inhomogeneity  

SciTech Connect (OSTI)

This work investigates the two-dimensional flow of a shock wave over a circular light-gas inhomogeneity in a channel with finite width. The pressure gradient from the shock wave interacts with the density gradient at the edge of the inhomogeneity to deposit vorticity around the perimeter, and the structure rolls up into a pair of counter-rotating vortices. The aim of this study is to develop an understanding of the scaling laws for the flow field produced by this interaction at times long after the passage of the shock across the inhomogeneity. Numerical simulations are performed for various initial conditions and the results are used to guide the development of relatively simple algebraic models that characterize the dynamics of the vortex pair, and that allow extrapolation of the numerical results to conditions more nearly of interest in practical situations. The models are not derived directly from the equations of motion but depend on these equations and on intuition guided by the numerical results. Agreement between simulations and models is generally good except for a vortex-spacing model which is less satisfactory. A practical application of this shock-induced vortical flow is rapid and efficient mixing of fuel and oxidizer in a SCRAMJET combustion chamber. One possible injector design uses the interaction of an oblique shock wave with a jet of light fuel to generate vorticity which stirs and mixes the two fluids and lifts the burning jet away from the combustor wall. Marble proposed an analogy between this three-dimensional steady flow and the two-dimensional unsteady problem of the present investigation. Comparison is made between closely corresponding three-dimensional steady and two-dimensional unsteady flows, and a mathematical description of Marble`s analogy is proposed. 17 refs.

Yang, J.; Kubota, T.; Zukoski, E.E. [California Inst of Technology, Pasadena, CA (United States)

1994-01-01T23:59:59.000Z

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.


421

Relaxation jumps of strong vibration  

Science Journals Connector (OSTI)

A nonperturbative theory of two-phonon relaxation of a strongly excited local mode is developed, whereby the mode is considered classically and phonons, quantum mechanically. The relaxation mechanism is analogous to that of black hole emission proposed by Hawking: it consists of linear transformation of phonon operators in time, which is induced by the classical subsystem (mode). Due to this transformation the number of phonons increases while the energy of the local mode decreases in time. It is found that there exist some critical energies of the local mode when relaxation rate is strongly enhanced. Thereby relaxation jumps take place, which are accompanied by generation of bursts of phonons. The values of the critical energies do not depend on temperature. The final stage of relaxation is exponential, in agreement with perturbation theory. Numerical calculations of the relaxation jumps are presented.

V. Hizhnyakov

1996-06-01T23:59:59.000Z

422

Downhole Vibration Monitoring and Control System  

SciTech Connect (OSTI)

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

423

Crack propagation induced heating in crystalline energetic materials W. Holmes,a)  

E-Print Network [OSTI]

Crack propagation induced heating in crystalline energetic materials W. Holmes,a) R. S. Francis of the heating of molecular vibrations and the possible initiation of chemical reaction from heat dissipated that vibrational temperatures can reach 800 K in 55 ps and exceed 550 K for 1 ns after the initial heating

Fayer, Michael D.

424

Numerical simulation of a viscous vortex ring interaction with a density interface  

SciTech Connect (OSTI)

When a vortex-dominated flow interacts with a sharp density interface, the dynamics are characterized by the interaction of baroclinically generated vorticity with the already existing vorticity field. This can be seen in many natural and technology settings; examples are the interaction of a ship or submarine wake with a thermocline, the collision of a buoyant thermal with a temperature inversion, and the interaction of a vortex flow with a flame front. This problem also serves as a generic model for turbulent mixing and entrainment processes across sharp density interfaces. The interaction between vortices and a free surface, with corresponds to the case where the density jump is very large, has been studied fairly extensively, both experimentally and computationally. By comparison, the literature for the more general case of vortex pairs and rings interacting with sharp density interfaces is relatively sparse. Experiments and numerical studies have been performed, but the numerical simulations were confined primarily to vortex pairs, restricted to the inviscid case, and the effect of density variation modeled under the Boussinesq approximation. The experiments were also confined to the Boussinesq regime. In this paper, we study the motion of a vortex ring in a sharply stratified, viscous fluid via a numerical solution of the full Navier-Stokes equations with finite-amplitude density variation. both Boussinesq and non-Boussinesq flow regimes will be studied, the effect of viscosity on the interaction will be examined, and three-dimensional aspects of the motion will be addressed, such as Widnall instability of the vortex ring and vortex reconnection at the interface.

Marcus, D.L.; Bell, J.B.

1990-10-01T23:59:59.000Z

425

Magnetorotational instability, current relaxation, and current-vortex sheet  

SciTech Connect (OSTI)

The conjugate effect of current relaxation and of current-vortex sheet formation on the magnetorotational instability is explored in a conducting fluid. It is found that the relative amplification of the magnetic viscosity from marginal stability to the instability determined by the maximum growth rate is around 924% when resistive effects dominate, while the corresponding quantity is around 220% in the ideal limit. This shows that the conjugate influence is much more efficient to amplify the magnetic viscosity than just the effect due to the standard magnetic tension. It is also found that the magnitude of the magnetic viscosity is effectively enhanced by the conjugate influence. The results presented here may contribute to the understanding of the various processes that play a significant role in the mechanism of anomalous viscosity observed in Keplerian disks. It is argued that the new effect shall be relevant in thin accretion disks. It is also mentioned that the proposed formulation may be of interest for some theories of magnetic reconnection. Possible extensions of this work are suggested.

Silveira, F. E. M. [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adélia, 166, CEP 09210-170, Bairro Bangu, Santo André, SP (Brazil)] [Centro de Ciências Naturais e Humanas, Universidade Federal do ABC, Rua Santa Adélia, 166, CEP 09210-170, Bairro Bangu, Santo André, SP (Brazil); Galvão, R. M. O. [Instituto de Física, Universidade de São Paulo, Rua do Matão, Travessa R, 187, CEP 05508-090, Cidade Universitária, São Paulo, SP (Brazil)] [Instituto de Física, Universidade de São Paulo, Rua do Matão, Travessa R, 187, CEP 05508-090, Cidade Universitária, São Paulo, SP (Brazil)

2013-08-15T23:59:59.000Z

426

Vortex Dynamics for the Ginzburg-Landau-Schrödinger Equation  

E-Print Network [OSTI]

The initial value problem for the Ginzburg-Landau-Schr\\"odinger equation is examined in the $\\epsilon \\rightarrow 0$ limit under two main assumptions on the initial data $\\phi^\\epsilon$. The first assumption is that $\\phi^\\epsilon$ exhibits $m$ distinct vortices of degree $\\pm 1$; these are described as points of concentration of the Jacobian $[J\\phi^\\epsilon]$ of $\\phi^\\epsilon$. Second, we assume energy bounds consistent with vortices at the points of concentration. Under these assumptions, we identify ``vortex structures'' in the $\\epsilon \\rightarrow 0$ limit of $\\phi^\\epsilon$ and show that these structures persist in the solution $u^\\epsilon(t)$ of $GLS_\\epsilon$. We derive ordinary differential equations which govern the motion of the vortices in the $\\epsilon \\rightarrow 0$ limit. The limiting system of ordinary differential equations is a Hamitonian flow governed by the renormalized energy of Bethuel, Brezis and H\\'elein. Our arguments rely on results about the structural stability of vortices which are proved in a separate paper.

James Ellis Colliander; Robert L. Jerrard

1997-12-12T23:59:59.000Z

427

Adjustable Nonlinear Springs to Improve Efficiency of Vibration Energy Harvesters  

E-Print Network [OSTI]

Vibration Energy Harvesting is an emerging technology aimed at turning mechanical energy from vibrations into electricity to power microsystems of the future. Most of present vibration energy harvesters are based on a mass spring structure introducing a resonance phenomenon that allows to increase the output power compared to non-resonant systems, but limits the working frequency bandwidth. Therefore, they are not able to harvest energy when ambient vibrations' frequencies shift. To follow shifts of ambient vibration frequencies and to increase the frequency band where energy can be harvested, one solution consists in using nonlinear springs. We present in this paper a model of adjustable nonlinear springs (H-shaped springs) and their benefits to improve velocity-damped vibration energy harvesters' (VEH) output powers. A simulation on a real vibration source proves that the output power can be higher in nonlinear devices compared to linear systems (up to +48%).

S. Boisseau; G. Despesse; B. Ahmed Seddik

2012-07-19T23:59:59.000Z

428

Vibration?Pseudorotation Coupling in Symmetric Triatomic Molecules  

Science Journals Connector (OSTI)

For each type of molecule, the vibration?rotation coupling energy and vibrational structures of wave functions were examined up to the levels of high energy, about 15?000?20?000 cm-1 above the bottom of the well. ... The dynamics of polyatomic vibrations and vibration?rotation interaction in highly excited states have been the subject of many theoretical and experimental studies for the past decade. ... 11-13 Since the angular momentum of the system can also be generated by simultaneous vibrations as well as rotation of the molecule, there exists a coupling between vibration and rotation even for the states with zero total angular momentum (J = 0) which would be nonnegligible in some highly excited vibrational levels. ...

Jae Shin Lee

1996-02-01T23:59:59.000Z

429

Increasing liquid hydrocarbon recovery from natural gas: Evaluation of the vortex-tube device  

SciTech Connect (OSTI)

The vortex-tube device provides a useful addition to the range of equipment available to the gas industry. It has been shown that the use of vortex-tube equipment permits improved separation in comparison with a Joule-Thomson system, without entering into the cost and complexity of a true isentropic system such as a turbo-expander unit. The comparative advantage of the vortex tube depends upon the inlet conditions of the gas and the pressure drop that is available. An optimum pressure drop of 25--35% of the inlet gas pressure has been confirmed in practice. Although not yet tested on operating plant, it is expected that a loss of performance of vortex-tube units will occur for inlet liquid-to-gas ratios of greater than 20%. Units with up to 5% liquid at the inlet have been successfully operated showing that a single phase gas at the unit inlet is not essential. It is expected that future application of vortex tube units will be concentrated where performance improvements over Joule-Thomson units, at low capital cost, are required.

Hajdik, B. [CBS Engineering, Houston, TX (United States); Steinle, J. [BEB Erdoel and Erdgas GmbH, Hannover (Germany); Lorey, M. [Filtan Analgenbau GmbH, Langenselbold (Germany); Thomas, K. [Falk and Thomas Engineering GmbH, Wettenberg (Germany)

1997-12-31T23:59:59.000Z

430

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

SciTech Connect (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

431

Numerical Simulation of the Meso-? Scale Structure and Evolution of the 1977 Johnstown Flood. Part II: Inertially Stable Warm-Core Vortex and the Mesoscale Convective Complex  

Science Journals Connector (OSTI)

A mesoscale warm-core vortex associated with the mesoscale convective complex (MCC) that produced the 1977 Johnstown flood is examined using a three-dimensional nested-grid model simulation of the flood episode. In the simulation, the vortex ...

Da-Lin Zhang; J. Michael Fritsch

1987-09-01T23:59:59.000Z

432

Vibration welding system with thin film sensor  

DOE Patents [OSTI]

A vibration welding system includes an anvil, a welding horn, a thin film sensor, and a process controller. The anvil and horn include working surfaces that contact a work piece during the welding process. The sensor measures a control value at the working surface. The measured control value is transmitted to the controller, which controls the system in part using the measured control value. The thin film sensor may include a plurality of thermopiles and thermocouples which collectively measure temperature and heat flux at the working surface. A method includes providing a welder device with a slot adjacent to a working surface of the welder device, inserting the thin film sensor into the slot, and using the sensor to measure a control value at the working surface. A process controller then controls the vibration welding system in part using the measured control value.

Cai, Wayne W; Abell, Jeffrey A; Li, Xiaochun; Choi, Hongseok; Zhao, Jingzhou

2014-03-18T23:59:59.000Z

433

Automatic monitoring of vibration welding equipment  

DOE Patents [OSTI]

A vibration welding system includes vibration welding equipment having a welding horn and anvil, a host device, a check station, and a robot. The robot moves the horn and anvil via an arm to the check station. Sensors, e.g., temperature sensors, are positioned with respect to the welding equipment. Additional sensors are positioned with respect to the check station, including a pressure-sensitive array. The host device, which monitors a condition of the welding equipment, measures signals via the sensors positioned with respect to the welding equipment when the horn is actively forming a weld. The robot moves the horn and anvil to the check station, activates the check station sensors at the check station, and determines a condition of the welding equipment by processing the received signals. Acoustic, force, temperature, displacement, amplitude, and/or attitude/gyroscopic sensors may be used.

Spicer, John Patrick; Chakraborty, Debejyo; Wincek, Michael Anthony; Wang, Hui; Abell, Jeffrey A; Bracey, Jennifer; Cai, Wayne W

2014-10-14T23:59:59.000Z

434

Localized Surface Plasmons in Vibrating Graphene Nanodisks  

E-Print Network [OSTI]

Localized surface plasmons are confined collective oscillations of electrons in metallic nanoparticles. When driven by light, the optical response is dictated by geometrical parameters and the dielectric environment and plasmons are therefore extremely important for sensing applications. Plasmons in graphene disks have the additional benefit to be highly tunable via electrical stimulation. Mechanical vibrations create structural deformations in ways where the excitation of localized surface plasmons can be strongly modulated. We show that the spectral shift in such a scenario is determined by a complex interplay between the symmetry and shape of the modal vibrations and the plasmonic mode pattern. Tuning confined modes of light in graphene via acoustic excitations, paves new avenues in shaping the sensitivity of plasmonic detectors, and in the enhancement of the interaction with optical emitters, such as molecules, for future nanophotonic devices.

Wang, Weihua; Mortensen, N Asger; Christensen, Johan

2015-01-01T23:59:59.000Z

435

Active vibration control of civil structures  

SciTech Connect (OSTI)

This is a final report of a one year, Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL). Active vibration control (AVC) of structural and mechanical systems is one of the rapidly advancing areas of engineering research. The multifaceted nature of AVC covers many disciplines, such as sensors and instrumentation, numerical modeling, experimental mechanics, and advanced power systems. This work encompassed a review of the literature on active control of structures focusing both on active control hardware and on control algorithms, a design of an isolation systems using magneto-rheological fluid-filled (MRF) dampers and numerical simulations to study the enhanced vibration mitigation effects of this technology.

Farrar, C.; Baker, W.; Fales, J.; Shevitz, D.

1996-11-01T23:59:59.000Z

436

Vibration of submillimeter-size supported droplets  

Science Journals Connector (OSTI)

We study the fundamental vibration mode of supported submillimeter-size droplets. Using an analogy with a simple oscillator we derive a semianalytical expression for the eigenfrequency and the scaling law of the energy dissipation within the droplet. The experimental results obtained for mercury drops deposited on glass are compared with the model. The agreement is satisfactory for the eigenfrequencies on the whole range of size we considered (from 0.04 to 0.9mm). The scaling law for the dissipation is recovered for radii larger than 0.1mm but fails for smaller droplets. We finally discuss possible applications related to the use of vibrations to effectively reduce the hysteresis of the wetting angle and therefore increase the mobility of the supported droplets.

Franck Celestini and Richard Kofman

2006-04-07T23:59:59.000Z

437

Vibrational Superposition States Without Rotating Wave Approximation  

E-Print Network [OSTI]

We propose a scheme to generate superpositions of coherent states for the vibrational motion of a laser cooled trapped-ion. It is based on the interaction with a standing wave making use of the counter-rotating terms, i.e. not applying the rotating wave approximation. We also show that the same scheme can be exploited for quantum state measurement, i.e. with the same scheme non-classical states may be reconstructed

Mancini, S; Tombesi, P

2000-01-01T23:59:59.000Z

438

Vibrational sum frequency study on biological interfaces  

E-Print Network [OSTI]

) ............................................................................................................. 11 3 Vibrating capacitive probe ................................................................................. 16 4 Molecular structure of human plasma fibrinogen (FRN)................................... 19 5 Displacement of Alexa 594...-labeled fibrinogen from a silica surface by a 5% human plasma solution ............................................................ 24 6 AFM images of a single FRN molecule adsorbed at the silica/buffer interface (a) at pH 8.0 and (b) at pH 8.0 after...

Lim, Soon Mi

2009-06-02T23:59:59.000Z

439

Vibrational States of the Hydrogen Molecular Ion  

Science Journals Connector (OSTI)

The eigenvalues and eigenfunctions of the vibrational states belonging to the ground electronic state of the hydrogen molecular ion have been calculated. The calculations have been done for the J=0, 2, 4, and 7 rotational states. Included is a discussion of the dependence of the eigenvalues as a function of the lowest-order dynamic corrections to the internuclear potential. Also, a calculation has been done to determine the number of bound states of the D2+ system.

Stanley Cohen, John R. Hiskes, and Robert J. Riddell, Jr.

1960-08-01T23:59:59.000Z

440

Theoretical rotation-vibration spectrum of thioformaldehyde  

SciTech Connect (OSTI)

We present a variational calculation of the first comprehensive T = 300 K rovibrational line list for thioformaldehyde, H{sub 2}CS. It covers 41?809 rovibrational levels for states up to J{sub max} = 30 with vibrational band origins up to 5000 cm{sup ?1} and provides the energies and line intensities for 547?926 transitions from the ground vibrational state to these levels. It is based on our previously reported accurate ab initio potential energy surface and a newly calculated ab initio dipole moment surface. Minor empirical adjustments are made to the ab initio equilibrium geometry to reduce systematic errors in the predicted intra-band rotational energy levels. The rovibrational energy levels and transition intensities are computed variationally by using the methods implemented in the computer program TROVE. Transition wavelengths and intensities are found to be in excellent agreement with the available experimental data. The present calculations correctly reproduce the observed resonance effects, such as intensity borrowing, thus reflecting the high accuracy of the underlying ab initio surfaces. We report a detailed analysis of several vibrational bands, especially those complicated by strong Coriolis coupling, to facilitate future laboratory assignments.

Yachmenev, Andrey [Department of Physics and Astronomy, University College London, London, WC1E 6BT (United Kingdom)] [Department of Physics and Astronomy, University College London, London, WC1E 6BT (United Kingdom); Polyak, Iakov; Thiel, Walter [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D–45470 Mülheim an der Ruhr (Germany)] [Max-Planck-Institut für Kohlenforschung, Kaiser-Wilhelm-Platz 1, D–45470 Mülheim an der Ruhr (Germany)

2013-11-28T23:59:59.000Z

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

A parametric study of the circulation and updwelling induced by an axially-symmetric atmospheric vortex  

E-Print Network [OSTI]

5 hours, u and v in Model I and II are nearly identical LFig. (4)], but then f striking differences soon develop. In Model II for I t & 5 h"s. , u and v are everywhere greater than in Model I. Note in particular the slope of the v curves... for t & 12 hours. Fluid veloci- ti. es u and v are for t & 5 hours everywhere increased with v becoming significantly greater for t & 12 hours. Both the rate and the extent of upwelling of the initial layer depth, h , has increased for t & 6 hours, and 0...

Knowles, C. Ernest

2012-06-07T23:59:59.000Z

442

Method for the assessment of airborne off-target pesticide spray concentrations due to aircraft wing-tip vortex  

E-Print Network [OSTI]

that spherical spray droplets are transported by a two dimensional parametric representation of a spray-engulfing aircraft wing-tip vortex pair. Two distinctive flow regions were considered for the spray-vortex dynamics. The first occurs in the vicinity...

Oliva, Sergio Eduardo

2012-06-07T23:59:59.000Z

443

Counter-rotating vortex patches in shear: a model of the effect of wind shear on aircraft trailing vortices  

Science Journals Connector (OSTI)

...significantly a following passenger-containing aircraft and cause an accident. For example, the vortex wake of a Boeing 747 can rotate a Boeing 737 through 45 . This problem is called the trailing-vortex hazard, and since the trailing vortices can...

2002-01-01T23:59:59.000Z

444

Slowing of vortex rings by development of Kelvin waves Robert E. Hershberger, Diogo Bolster, and Russell J. Donnelly*  

E-Print Network [OSTI]

of existence, their duration a problem of stability and if there are several we have a problem of vortex mecha- nism is that the bubble loses impulse as the radius of the ring grows due to viscous decay of circulation 6 . A further theory suggests that the vortex bubble the ambient fluid car- ried along

Bolster, Diogo

445

Observation of Hybrid Soliton Vortex-Ring Structures in Bose-Einstein Condensates Naomi S. Ginsberg,1,* Joachim Brand,2  

E-Print Network [OSTI]

-Einstein condensates. We examine both their creation via soliton-vortex collisions and their subsequent development into vortex rings (VRs) [7,8] via the Kadomtsev-Petviashvili, or ``snake,'' instability [9]. In this Letter frequencies !z 2 21 Hz and !x !y 3:0!z in our 4-Dee magnetic trap [14]. We work at temperatures well below

Hau, Lene Vestergaard

446

Polarization-selective vortex-core switching by tailored orthogonal Gaussian-pulse currents  

SciTech Connect (OSTI)

We experimentally demonstrate low-power-consumption vortex-core switching in magnetic nanodisks using tailored rotating magnetic fields produced with orthogonal and unipolar Gaussian-pulse currents. The optimal width of the orthogonal pulses and their time delay are found, from analytical and micromagnetic numerical calculations, to be determined only by the angular eigenfrequency {omega}{sub D} for a given vortex-state disk of polarization p, such that {sigma}=1/{omega}{sub D} and ?{Delta}t={pi}/2 p/{omega}{sub D} . The estimated optimal pulse parameters are in good agreement with the experimental results. This work lays a foundation for energy-efficient information recording in vortex-core cross-point architecture.

Jung, H.; Choi, Y. -S.; Yoo, M. -W.; Im, M. -Y.; Kim, S. -K.

2010-10-13T23:59:59.000Z

447

Experimental study of vortex generators effects on low Reynolds number airfoils in turbulent flow  

Science Journals Connector (OSTI)

In the present work, we study the aerodynamic effects of triangular vortex generators, as passive flow control devices, placed on the upper surface of an airfoil submitted to a low Reynolds number turbulent flow. In the experiments, different configurations of those devices have been studied. An Eppler 387 airfoil was used. The tests were performed in a turbulent boundary layer wind tunnel using a two component aerodynamic balance and flow visualisation systems. Turbulent flow characterisation was made by means of hot wire anemometry. Calculations of local turbulent intensity as well as temporal and spatial turbulent scales were made. Vortex generators were located at 10% and 20% of the airfoil chord from the leading edge, modifying its angle of incidence refereed to the free stream. The results show changes in the aerodynamic section coefficients, C1, Cd and C1, for the different vortex generator configurations. Neither hysteresis effects, nor leading edge bubbles were found in the experiments.

Juan Sebastián Delnero; Julio Marañon Di Leo; Mauricio Ezequiel Camocardi; Mariano A. Martinez; Jorge L. Colman Lerner

2012-01-01T23:59:59.000Z

448

A Vibrating Wire System For Quadrupole Fiducialization  

SciTech Connect (OSTI)

A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization step of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method of choice. We then give an overview of the measurement system showing how the vibrating wire is positioned onto the quadrupole axis, how the wire position detectors locate the wire relative to tooling balls without touching the wire, and how the tooling ball positions are all measured. The novel feature of this system is the vibrating wire which we discuss in depth. We analyze the wire dynamics and calculate the expected sensitivity of the system. The note should be an aid in debugging the system by providing calculations to compare measurements to.

Wolf, Zachary

2010-12-13T23:59:59.000Z

449

Lower pseudogap phase of Mott insulators: A spin/vortex liquid state  

Science Journals Connector (OSTI)

The pseudogap phase is considered to be a new state of matter in the phase string model of the doped Mott insulator, which is composed of two distinct regimes known as the upper and lower pseudogap phases, respectively. The former corresponds to the formation of spin-singlet pairing, the magnetic characterizations of which have been recently studied [Phys. Rev. B 72, 104520 (2005)]. The latter, as a low-temperature regime of the pseudogap phase, is systematically explored in this work, which is characterized by the formation of the Cooper pair amplitude and described by a generalized Ginzburg-Landau theory. Elementary excitation in this phase is a charge-neutral object carrying spin-1?2 and locking with a supercurrent vortex, known as a spinon-vortex composite. Such a lower pseudogap phase can be regarded as a vortex liquid state due to the presence of free spinon vortices. Here thermally excited spinon vortices destroy the phase coherence and are responsible for the nontrivial Nernst effect and diamagnetism. The transport entropy and core energy associated with a spinon vortex are determined by the spin degrees of freedom. Such a spontaneous vortex liquid phase can be also considered as a spin liquid with a finite correlation length and gaped S=1?2 excitations, where a resonancelike nonpropagating spin mode emerges at the antiferromagnetic wavevector (?,?) with a doping-dependent characteristic energy. The superconducting phase is closely related to the lower pseudogap phase by a topological transition with spinon vortices and antivortices forming bound pairs and the emergence of fermionic quasiparticles as holon-spinon-vortex bound objects. A quantitative phase diagram in the parameter space of doping, temperature, and magnetic field is determined. Comparisons with experiments are also made.

Zheng-Yu Weng and Xiao-Liang Qi

2006-10-26T23:59:59.000Z

450

Argonne CNM Highlight: Damping of acoustic vibrations in gold nanoparticles  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (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

451

Phase-locking of driven vortex lattices with transverse ac force and periodic pinning  

SciTech Connect (OSTI)

For a vortex lattice moving in a periodic array we show analytically and numerically that a new type of phase locking occurs in the presence of a longitudinal dc driving force and a transverse ac driving force. This phase locking is distinct from the Shapiro step phase locking found with longitudinal ac drives. We show that an increase in critical current and a fundamental phase-locked step width scale with the square of the driving ac amplitude. Our results should carry over to other systems such as vortex motion in Josephson-junction arrays.

Reichhardt, Charles; Kolton, Alejandro B.; Dominguez, Daniel; Gronbech-Jensen, Niels

2001-10-01T23:59:59.000Z

452

Low-temperature vortex dynamics in a high-temperature superconductor  

Science Journals Connector (OSTI)

Magnetic-field gradients in the mixed state of a type-II superconductor are studied using Tl205 nuclear magnetic resonance (NMR) on Tl2Ba2Ca2Cu3O10+?. An anomalous peak was observed in the temperature dependence of the transverse relaxation rate at T/Tc?0.25. We attribute this behavior to magnetic-field flucutations from vortex dynamics. We interpret this behavior as a crossover of the principal time scale for vortex dynamics with that of the NMR experiment, approximately 100 ?s. The temperature dependence of this time scale is discussed.

Y.-Q. Song; S. Tripp; W. P. Halperin; L. Tonge; T. J. Marks

1994-12-01T23:59:59.000Z

453

The effects of a jet on vortex breakdown over a sharp leading-edge delta wing  

E-Print Network [OSTI]

THE EFFECTS OF A JET ON VORTEX BREAKDOWN OVER A SHARP LEADING-EDGE DELTA WING A Thesis Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 1985... Major Subject: Aerospace Engineering THE EFFECTS OF A JET ON VORTEX BREAKDOWN OVER A SHARP LEADING-EDGE DELTA WING A Thesis by IAN KENNETH MAYNARD Approved as to style and content by: Cyrus Ostowar (Chairman of Committee) Stan J Miley (M er...

Maynard, Ian Kenneth

2012-06-07T23:59:59.000Z

454

Active Vibration Control on A 3-DOF Parallel Platform Based on Kane's Dynamics Method  

E-Print Network [OSTI]

- 2783 - Active Vibration Control on A 3-DOF Parallel Platform Based on Kane's Dynamics Method Yuan be impossible without a careful isolation of the instrument from the vibration sources. To reduce the vibration low remaining vibration level. This paper is concerned with the development of a vibration isolation

Li, Yangmin

455

An experimental study of torsional vibration measurement / b  

E-Print Network [OSTI]

major problem. In some studies of torsional vibration [6] [7], vibration has been detected by a pair of matched accelerometers mounted on a disk, dia- metrically opposed to each other at equal radii. Summing the outputs of the pair increases... under consideration is the Vibration Envelope Detector Model 223A (VED), manufactured by Shaker Research Corp. To perform envelope detection, or amplitude demodu- lation, it is necessary only to build an amplitude demodulation circuit with one or two...

French, Robert Sheldon

1981-01-01T23:59:59.000Z

456

Classroom demonstration of the vibration of a bowed string  

Science Journals Connector (OSTI)

An overhead projector has been modified for stroboscopic illumination for the purpose of demonstrating the vibration of a string excited by a violinbow. The vibrational pattern is clearly delineated as are differences caused by insufficient or excessive bow force. A regime of oscillation is noted at high bow force and low speed in which alternate waves are reflected from the bow and the bridge so that the vibration transmitted to the bridge is about an octave below the fundamental frequency of the string.

E. Brock Dale

1976-01-01T23:59:59.000Z

457

Self Excited Vibration in a Specialised Electric Propulsion System  

Science Journals Connector (OSTI)

Special marine propulsion applications demand efficient manoeuvrability under extreme conditions. ... , vibration resonance and radiated noise from the propulsion shafting system must be kept to a ... purpose ves...

Don Chool Lee; Ronald D. Barro

2014-09-01T23:59:59.000Z

458

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

459

Bending vibration measurement on rotors by laser vibrometry  

Science Journals Connector (OSTI)

A new technique is proposed for noncontact measurement of bending vibration directly from a rotating component. This notoriously difficult and previously unattained measurement is a...

Miles, Toby; Lucas, Margaret; Rothberg, Steve

1996-01-01T23:59:59.000Z

460

Photorefractive holography for 2D mechanical vibrations measurement  

Science Journals Connector (OSTI)

We report an efficient holographic setup for the real time measurement of 2D mechanical vibration modes in surfaces, based on the time-average holographic interferometry technique...

de Oliveira, Ivan; Frejlich, Jaime

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

Transient full-field vibration measurement using spectroscopical stereo photogrammetry  

Science Journals Connector (OSTI)

Contrasted with other vibration measurement methods, a novel spectroscopical photogrammetric approach is proposed. Two colored light filters and a CCD color camera are used to...

Yue, Kaiduan; Li, Zhongke; Zhang, Ming; Chen, Shan

2010-01-01T23:59:59.000Z

462

Optical fiber sensor for membrane submicrometer vibration measurement  

Science Journals Connector (OSTI)

This paper presents an optical fiber sensor for membrane submicrometer vibration measurement. The sensor is designed ultimately for low-cost medical audiometric applications such as...

Prokopczuk, Krzysztof; Rozwadowski, Krzysztof; Aleksandra Starzy?ska, M D; Doma?ski, Andrzej W

2014-01-01T23:59:59.000Z

463

Smart Sensor Nodes for Vibration Measurement of Large Civil Infrastructure  

Science Journals Connector (OSTI)

Dynamic characteristics of large civil infrastructures have been monitored for safe operation and efficient maintenance of the structures. To measure vibration data, the conventional system uses cables which ... ...

Jong-Jae Lee; Young-Soo Park; Won-Tae Lee…

2014-01-01T23:59:59.000Z

464

Vibration measurement using phase-shifting speckle-pattern interferometry  

Science Journals Connector (OSTI)

Digital speckle-pattern interferometries for the measurement of a vibration amplitude are presented, based on phase shifting of a speckle interferogram. The calculation of the square...

Nakadate, Suezou

1986-01-01T23:59:59.000Z

465

Predicting the vibration discomfort of standing passengers in transport.  

E-Print Network [OSTI]

??It has previously been assumed that the vibration discomfort of standing people can be estimated using the same procedures developed from for seated people. In… (more)

Thuong, O.

2011-01-01T23:59:59.000Z

466

Minimax design of parallel multi-mass dynamic vibration absorbers.  

E-Print Network [OSTI]

?? This thesis discusses the design of multi-mass dynamic vibration absorbers in parallel configuration subject to uncertainties in the forcing frequency. A minimax parameter optimization… (more)

Kee, Kerk Cheng

2011-01-01T23:59:59.000Z

467

Analytical and numerical development on vibration of shells.  

E-Print Network [OSTI]

??The subject of free vibration analysis of thin cylindrical shells is one that extends well back into the last century. In general, the computational methods… (more)

Zhang, Lei

2005-01-01T23:59:59.000Z

468

Capturing inhomogeneous broadening of the -CN stretch vibration...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

Capturing inhomogeneous broadening of the -CN stretch vibration in a Langmuir monolayer with high-resolution spectra and Capturing inhomogeneous broadening of the -CN stretch...

469

APS Protocol for Reporting Construction Vibration Issues for...  

Broader source: All U.S. Department of Energy (DOE) Office Webpages (Extended Search)

in the online version. Advanced Photon Source APS Protocol for Reporting Construction Vibration Issues for Beamlines Section where used: This procedure describes the process for...

470

VIBRATION CONTROL OF DISTRIBUTED PARAMETER SYSTEMSAND FLUIDIC FLEXIBLE MATRIX COMPOSITES.  

E-Print Network [OSTI]

??Vibration degrades the performance of many mechanical systems, reducing the qualityof manufactured products, producing noise, introducing fatigue in mechanical compo-nents, and generating an uncomfortable environment… (more)

Lotfi Gaskarimahalle, Amir

2009-01-01T23:59:59.000Z

471

Correlated vortex pinning in slightly orthorhombic twinned Ba(Fe1-xCox)2As2 single crystals: Possible shift of the vortex-glass/liquid transition  

SciTech Connect (OSTI)

The interest in twin-boundary (TB) planes as a source of vortex pinning has been recently renewed with the discovery of the new iron-arsenide pnictide superconductors. In the family of compounds Ba(Fe1-xCox)2As2 a structural transition from a tetragonal to orthorhombic lattice takes place for compounds with xvortex cores. In this work we investigate the changes in anisotropy produced by subtle differences in the Co doping level, in the neighborhood of the structural transition, in good-quality single crystals. Using a scaling approach we are able to determine the angular regions where correlated or uncorrelated disorder prevails. In the tetragonal samples (x>xcr) there is no twinning and we find good agreement with the expected scaling function under uncorrelated disorder, with small anisotropy values similar to those reported in the literature. We show that in the orthorhombic samples (xvortex liquid-glass transition temperature.

Bermudez, M. Marziali [Universidad de Buenos Aires; Pasquini, G. [Universidad de Buenos Aires; Budko, Sergey L. [Ames Laboratory; Canfield, Paul C. [Ames Laboratory

2013-02-28T23:59:59.000Z

472

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

473

Noise control versus shock and vibration engineering  

Science Journals Connector (OSTI)

Noise control and shock and vibration engineering have many fundamentals in common and many analogous practical constraints. Yet in many respects they tend to be opposite in methodology philosophy and past history. The present discussion is an attempt to present the point of view of the practicing engineer in either field who has some perspective on the historical origins of his art. It focuses on aspects that epitomize the practical objectives of such engineers plus any administrators lawyers etc. who may also be involved in team efforts. For noise control the aspects chosen are establishment of regulations monitoring and design or other actions intended to bring about compliance with regulations. For shock and vibration engineering they are establishment of environmental specifications to ensure reliability environmental testing in accordance with these and design or redesign to bring about compliance with test requirements and also (we hope) to bring about reliability without severe penalties in weight schedule or cost. This is not to say that these aspects in their barest sense represent all the technology or methodology that is pertinent or even that these limited aspects will be treated comprehensively. It is almost self?evident that the Acoustical Society of America should and does maintain beneficial relationship with medical psychological mechanical engineering and other societies that report their particular developing lore of fundamentals and some practical information from their particular viewpoint. The Acoustical Society is an important part of this spectrum by virtue of its interdisciplinary coverage extending through materials dynamics sound instrumentation and electronics to speech and hearing. But it is also worthwhile for the ASA by whatever means are available to sample the flavor of various disciplines as unified and value?weighted in accordance with typical practical objectives. For this reason the developing beneficial relationships with the Institute of Noise Control (INCE) and the Shock and Vibration Information Center (SVIC) will become increasingly important.

Charles T. Morrow

1974-01-01T23:59:59.000Z

474

Chemical reaction versus vibrational quenching in low energy collisions of vibrationally excited OH with O  

SciTech Connect (OSTI)

Quantum scattering calculations are reported for state-to-state vibrational relaxation and reactive scattering in O + OH(v = 2 ? 3, j = 0) collisions on the electronically adiabatic ground state {sup 2}A?? potential energy surface of the HO{sub 2} molecule. The time-independent Schrödinger equation in hyperspherical coordinates is solved to determine energy dependent probabilities and cross sections over collision energies ranging from ultracold to 0.35 eV and for total angular momentum quantum number J = 0. A J-shifting approximation is then used to compute initial state selected reactive rate coefficients in the temperature range T = 1 ? 400 K. Results are found to be in reasonable agreement with available quasiclassical trajectory calculations. Results indicate that rate coefficients for O{sub 2} formation increase with increasing the OH vibrational level except at low and ultralow temperatures where OH(v = 0) exhibits a slightly different trend. It is found that vibrational relaxation of OH in v = 2 and v = 3 vibrational levels is dominated by a multi-quantum process.

Pradhan, G. B.; Juanes-Marcos, J. C.; Balakrishnan, N., E-mail: naduvala@unlv.nevada.edu [Department of Chemistry, University of Nevada Las Vegas, Las Vegas, Nevada 89154 (United States); Kendrick, Brian K. [Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)] [Theoretical Division (T-1, MS B221), Los Alamos National Laboratory, Los Alamos, New Mexico 87545 (United States)

2013-11-21T23:59:59.000Z

475

Surface Vibrations in a Model Hcp Crystal  

E-Print Network [OSTI]

-1973. R. E. Allen, G. P. Alldredge, and F. W. de Wette, Phys. Rev. B 4, 1661 (3.971). 2R. E. Allen and F. W. de Wette, Phys. Rev. 179, 873 0.969). ..., and F. W. de Wette, Phys. Rev. B4, 1661 (1971). PHYSICA L RE VIE W 8 VOLUME 6, NUMBE R 2 15 JULY 1972 Surface Vibrations in a Model hcp Crystal R. E. Allen Department of Physics, Texas A @ M University, College Station, Texas 77843 and G. P...

Allen, Roland E.; Alldredg, GP; DEWITTE, FW.

1972-01-01T23:59:59.000Z

476

Lattice Vibrations and Superconductivity in Layered Structures  

E-Print Network [OSTI]

PHYSICAL REVIEW B VOLUME 2, NUMBER 7 1 OCTOB ER, 1970 Lattice Vibrations and Superconductivity in Layered Structures* B. E. Allen, G. P. Alldredge, and F. W. de bette DePartment of Physics, University of Texas, Austin, Texas 78712 (Received 18... monolayers of identical particles, stacked atop one another to form a 21-layer slab. A side view of this system is shown in Fig. 1. The films alternately have atomic masses m and M, with m corresponding to the outermost films. The crys- tal structure...

Allen, Roland E.; Alldredg, GP; WETTE, FWD.

1970-01-01T23:59:59.000Z

477

Vibrating sample magnetometer with a step motor  

Science Journals Connector (OSTI)

A new version of the low-frequency (3.6 Hz) vibrating sample magnetometer was built. Its mechanical part consists of a crank transducer with a step motor driven by a microcontroller. Step durations are programmed in such a way that the signal from pick-up coils is perfectly sinusoidal as a function of time. The signal is narrow-band amplified, digitized at each of 400 steps of one period and lock-in detected by a computer. The magnetometer has low noise and may be used not only with superconducting but with water-cooled magnets.

V I Nizhankovskii; L B Lugansky

2007-01-01T23:59:59.000Z

478

Uncertainty quantification in vibration-based structural health monitoring for enhanced decision-making capability  

E-Print Network [OSTI]

time series measurements from vibration-based experiments.measurements, Journal of Sound and Vibration, 314(2008) 343–measurement of coherence function and input/output quantities, Journal of Sound and Vibration,

Mao, Zhu

2012-01-01T23:59:59.000Z

479

Measurement, evaluation, and assessment of peripheral neurological disorders caused by hand-transmitted vibration  

Science Journals Connector (OSTI)

Regular exposure to hand-transmitted vibration can result in symptoms and signs of ... other disorders collectively known as the hand-arm vibration syndrome. The measurement of the effects of hand-transmitted vibration

Michael J. Griffin

2008-04-01T23:59:59.000Z

480

Integration of Piezoelectric Sensing and Control for Nano-Scale Vibration Suppression in Hard Disk Drives  

E-Print Network [OSTI]

Time trace of vibration measurements from LDV (top) andTime trace of vibration measurements from LDV (top) and3.13: Time trace of vibration measurements from LDV (top)

Felix, Sarah Helen

2010-01-01T23:59:59.000Z

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.


481

Vibration Spectra of Hydrocarbon Molecules. II. Skeletal Frequencies in Certain Branched Paraffins  

Science Journals Connector (OSTI)

25 October 1949 research-article Vibration Spectra of Hydrocarbon Molecules. II...characteristic frequencies should be assigned as vibrations of the carbon skeleton of these structural...problem of the interpretation of the vibration spectra of hydrocarbons is considered...

1949-01-01T23:59:59.000Z

482

Vibration of an infinite membrane supported by an array of posts  

Science Journals Connector (OSTI)

...Copyright 2000 Article Vibration of an infinite membrane supported...East Lansing, MI 48824, USA The vibration of an infinite membrane supported...an asymptotic formula. membrane, vibration| IMA Journal of Applied Mathematics......

CY Wang

2000-06-01T23:59:59.000Z

483

Boundary layer transition as a source of noise and vibration  

Science Journals Connector (OSTI)

When laminar flow over a rigid or flexible surface becomes unstable an intermittent flow state occurs. This intermittent flow regime called the transition region is where turbulent spots are created and then grow as they convect downstream at a velocity typically equal to 0.7 times the free?stream velocity. The spots eventually coalesce to form the beginning of the fully developed turbulent boundary layer. The statistics of the velocity or pressure fluctuations in the transition region are essentially stationary in time but nonhomogeneous in the streamwise direction. Fundamentally it has been argued that this region is capable of creating monopole sound radiation e.g. Lauchle [J. Acoust. Soc. Am. 69 665–671 (1981)] and Sornette and Lagier [Acustica 55 255–267 (1984)]. Also it has been suspected that a transitional boundary layer can induce wall vibrations. These issues have been under study for some time. We have completed a set of measurements on the. space?time statistics of turbulent spots in a naturally occurring transition zone and from them developed an analytical model for the wavenumber?frequency spectrum of the pressure fluctuations. Based on this model it appears that the transition zone wall pressure is less intense than that of a fully developed turbulent layer by a factor equal approximately to the intermittency factor. This presentation will review the current research findings on wall pressure fluctuations and radiated sound caused by boundary layer transition. [Work supported by Applied Research Laboratory under NAVSEA contract.

Gerald C. Lauchle; M. A. Josserand

1986-01-01T23:59:59.000Z

484

Tropical cyclone genesis efficiency: mid-level versus bottom vortex Xuyang Ge and Tim Li  

E-Print Network [OSTI]

;4 1. Introduction Tropical cyclone (TC) genesis is the least understood phase in a TC life cycle is cyclogenesis in an environment with a mid-level vortex (EMV). An analysis of the WNP TC genesis in 2000 the QuikSCAT-derived surface wind observations, there was no sign

Li, Tim

485

Cherenkov resonances in vortex dissipation in superconductors B. I. Ivlev and S. Mejia-Rosales  

E-Print Network [OSTI]

, Mexico M. N. Kunchur Department of Physics and Astronomy, University of South Carolina, Columbia, South-two superconductors the magnetic flux is carried by vortices. If the transport electric current greatly exceeds in the crystal the dissipa- tion increases due to Cherenkov emission of sound waves. Each moving vortex creates

Kunchur, Milind N.

486

DETECTION OF VORTEX TUBES IN SOLAR GRANULATION FROM OBSERVATIONS WITH SUNRISE  

SciTech Connect (OSTI)

We have investigated a time series of continuum intensity maps and corresponding Dopplergrams of granulation in a very quiet solar region at the disk center, recorded with the Imaging Magnetograph eXperiment (IMaX) on board the balloon-borne solar observatory SUNRISE. We find that granules frequently show substructure in the form of lanes composed of a leading bright rim and a trailing dark edge, which move together from the boundary of a granule into the granule itself. We find strikingly similar events in synthesized intensity maps from an ab initio numerical simulation of solar surface convection. From cross sections through the computational domain of the simulation, we conclude that these granular lanes are the visible signature of (horizontally oriented) vortex tubes. The characteristic optical appearance of vortex tubes at the solar surface is explained. We propose that the observed vortex tubes may represent only the large-scale end of a hierarchy of vortex tubes existing near the solar surface.

Steiner, O.; Franz, M.; Bello Gonzalez, N.; Nutto, Ch.; Rezaei, R.; Schmidt, W. [Kiepenheuer-Institut fuer Sonnenphysik, Schoeneckstrasse 6, 79104 Freiburg (Germany); Martinez Pillet, V.; Bonet Navarro, J. A. [Instituto de Astrofisica de Canarias, 38200, La Laguna, Tenerife (Spain); Del Toro Iniesta, J. C. [Instituto de Astrofisica de Andalucia (CSIC), Apdo. de Correos 3004, 18080 Granada (Spain); Domingo, V. [Grupo de Astronomia y Ciencias del Espacio, Universidad de Valencia, 46980 Paterna, Valencia (Spain); Solanki, S. K.; Barthol, P.; Gandorfer, A. [Max-Planck-Institut fuer Sonnensystemforschung, 37191 Katlenburg-Lindau (Germany); Knoelker, M., E-mail: steiner@kis.uni-freiburg.d [High Altitude Observatory, National Center for Atmospheric Research (NCAR), Boulder, CO 80307-3000 (United States)

2010-11-10T23:59:59.000Z

487

ADVANCES IN ATMOSPHERIC SCIENCES, VOL. 27, NO. 2, 2010, 243252 Mesoscale Barotropic Instability of Vortex Rossby  

E-Print Network [OSTI]

ADVANCES IN ATMOSPHERIC SCIENCES, VOL. 27, NO. 2, 2010, 243­252 Mesoscale Barotropic Instability of Vortex Rossby Waves in Tropical Cyclones ZHONG Wei1 ( Í), LU Han-Cheng1 (ö ), and Da-Lin ZHANG2 1 Institute of Meteorology, PLA University of Science and Technology, Nanjing 211101 2 Department

Zhang, Da-Lin

488

Particle resuspension by an impacting vortex ring RICK J. MUNRO & STUART B. DALZIEL  

E-Print Network [OSTI]

Particle resuspension by an impacting vortex ring RICK J. MUNRO & STUART B. DALZIEL Department results from a set of visualization experiments conducted to analyse the hydrodynamic resuspension of particles from a thick horizontal sediment layer. The mechanism employed to produce the resuspension

Dalziel, Stuart

489

Vortex Ring Interaction with a Particle Layer: Implications for Sediment Transport  

E-Print Network [OSTI]

resuspension has been studied much less. This is an important mechanism, however, as it represents an integral conducted to study particle resuspension by vortex rings colliding with a particle bed. The dynamics at the resuspension onset are investigated, showing that the deformable particle bed resembles a free slip boundary

Dalziel, Stuart

490

Resuspension onset and crater erosion by a vortex ring interacting with a particle layer  

E-Print Network [OSTI]

Resuspension onset and crater erosion by a vortex ring interacting with a particle layer N. Bethke://pof.aip.org/features/most_downloaded Information for Authors: http://pof.aip.org/authors #12;PHYSICS OF FLUIDS 24, 063301 (2012) Resuspension onset layer. The flow dynamics during the onset of particle resuspension are analysed using particle image

Dalziel, Stuart

491

Tip Vortex Field Resolution Using an Adaptive Dual-Mesh Computational Nathan Hariharan  

E-Print Network [OSTI]

for the aforementioned unsteady, vortical fields. 1. Introduction 1.1 Background Vortical wakes introduce important AMR in an unstructured Euler solver. Potsdam[3] also applied unstructured AMR to wind turbine wake1 Tip Vortex Field Resolution Using an Adaptive Dual-Mesh Computational Paradigm Nathan Hariharan

Steffen, Michael

492

First-order disorder-driven transition and inverse melting of the vortex lattice  

E-Print Network [OSTI]

`inverse' melting behavior. � 2001 Published by Elsevier Science B.V. Keywords: Type-II superconductivity-order transition (FOT) [1±5] whereas at low temperatures the ordered vortex lattice transforms into a disordered open questions in the phase diagram of HTS is the thermodynamic nature of the disorder-dri- ven

Zeldov, Eli

493

Computational Analysis of a Tip Vortex Structure Shed from a Bioinspired Blade  

E-Print Network [OSTI]

design for this purpose. Different rotor blade designs and relevant insect wings are under study Computational Analysis of a Tip Vortex Structure Shed from a Bioinspired Blade Sebastian was generated with SolidWorks CAD software from measurements performed on a wing sample obtained from

Maccabe, Barney

494

Effect of asymmetric axial strain on the behavior of the juncture vortex system  

E-Print Network [OSTI]

The objective of this research was to investigate the behavior of the vortex formed in a wing-body juncture in a water tunnel flow. The wing-body juncture was created by mounting a symmetrical airfoil with an elliptical leading edge normal to a flat...

Trosper, Jeffrey Randall

2012-06-07T23:59:59.000Z

495

Neutron Scattering Studies of Vortex Matter in Type-II Superconductors  

SciTech Connect (OSTI)

The proposed program is an experimental study of the fundamental properties of Abrikosov vortex matter in type-II superconductors. Most superconducting materials used in applications such as MRI are type II and their transport properties are determined by the interplay between random pinning, interaction and thermal fluctuation effects in the vortex state. Given the technological importance of these materials, a fundamental understanding of the vortex matter is necessary. The vortex lines in type-II superconductors also form a useful model system for fundamental studies of a number of important issues in condensed matter physics, such as the presence of a symmetry-breaking phase transition in the presence of random pinning. Recent advances in neutron scattering facilities such as the major upgrade of the NIST cold source and the Spallation Neutron Source are providing unprecedented opportunities in addressing some of the longstanding issues in vortex physics. The core component of the proposed program is to use small angle neutron scattering and Bitter decoration experiments to provide the most stringent test of the Bragg glass theory by measuring the structure factor in both the real and reciprocal spaces. The proposed experiments include a neutron reflectometry experiment to measure the precise Q-dependence of the structure factor of the vortex lattice in the Bragg glass state. A second set of SANS experiments will be on a shear-strained Nb single crystal for testing a recently proposed theory of the stability of Bragg glass. The objective is to artificially create a set of parallel grain boundaries into a Nb single crystal and use SANS to measure the vortex matter diffraction pattern as a function of the changing angle between the applied magnetic field to the grain boundaries. The intrinsic merits of the proposed work are a new fundamental understanding of type-II superconductors on which superconducting technology is based, and a firm understanding of phases and phase transitions in condensed matter systems with random pinning. The broader impact of the program includes the training of future generation of neutron scientists, and further development of neutron scattering and complementary techniques for studies of superconducting materials. The graduate and undergraduate students participating in this project will learn the state-of-the-art neutron scattering techniques, acquire a wide range of materials research experiences, and participate in the frontier research of superconductivity. This should best prepare the students for future careers in academia, industry, or government.

Xinsheng Ling

2012-02-02T23:59:59.000Z

496

Modelling vibrations caused by tram movement on slab track line  

Science Journals Connector (OSTI)

The recent growth in the use of the railway and particularly that of the tram in urban areas highlights the need to investigate and mitigate the harmful effects associated with these means of transport. The vibrations caused by passing vehicles can be ... Keywords: Fourier Transform, Ground vibrations, Slab track, Timoshenko beam, Tram

Julia Real; Pablo MartíNez; Laura MontalbáN; Antonio Villanueva

2011-07-01T23:59:59.000Z

497

Vibration Combined High Temperature Cycle Tests for Capacitive MEMS  

E-Print Network [OSTI]

Vibration Combined High Temperature Cycle Tests for Capacitive MEMS Accelerometers Z. Szcs, G. Nagy|nagyg|hodossy|rencz|poppe>@eet.bme.hu Abstract - In this paper vibration combined high temperature cycle tests for packaged capacitive SOI- MEMS designed and realized at BME ­ DED. Twenty thermal cycles of combined Temperature Cycle Test and Fatigue

Boyer, Edmond

498

Vibrational Signature of Water Molecules in Asymmetric Hydrogen Bonding Environments  

E-Print Network [OSTI]

Vibrational Signature of Water Molecules in Asymmetric Hydrogen Bonding Environments Chao Zhang contributions of each of the two hydrogen atoms to the vibrational modes 1 and 3 of water molecules the early works on the molecular structure of water, it has been accepted that a water molecule

Guidoni, Leonardo

499

Stator Vibration Analysis of Bearingless Switched Reluctance Motors  

Science Journals Connector (OSTI)

Radial magnetic force acts on the motor stator cause large vibration and acoustic noise, that have limit the application of switched reluctance motors (SRMs). They can be aggravated when there is unbalanced force due to rotor eccentricity. This paper ... Keywords: switched reluctance motors, bearingless technique, vibration, magnetic fore, mathematic model

Yang Yan; Deng Zhiquan; Zhang Qianying; Wang Xiaolin

2010-06-01T23:59:59.000Z

500

Vibrational Raman Spectroscopy of High-temperature Superconductors  

E-Print Network [OSTI]

Vibrational Raman Spectroscopy of High-temperature Superconductors C. Thomsen and G. Kaczmarczyk after the discovery of high- critical-temperature Tc superconductors:2 while reports on Raman scattering Wiley & Sons Ltd, Chichester, 2002 #12;Vibrational Raman Spectroscopy of High-temperature

Nabben, Reinhard