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Note: This page contains sample records for the topic "duct high velocity" from the National Library of EnergyBeta (NLEBeta).
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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

Theoretical Estimates of HVAC Duct Channel Capacity for High-Speed Internet Access  

E-Print Network [OSTI]

Theoretical Estimates of HVAC Duct Channel Capacity for High-Speed Internet Access Ariton E. Xhafa-conditioning (HVAC) ducts based on multi-carrier transmission that uses M-QAM mod- ulation and measured channel- flections in HVAC ducts). Our work also shows that data rates in excess of 300 Mbps are possible over

Stancil, Daniel D.

2

Design and Evaluation of a High Temperature Burner Duct Recuperator System  

E-Print Network [OSTI]

"The Babcock & Wilcox Company (B&W) has completed a program to design, construct, install, and field test a ceramic-based high-temperature burner-duct-recuperator (HTBDR) in an industrial setting. The unit was capable of operating in corrosive, high...

Parks, W. P.; DeBellis, C. L.; Kneidel, K.

3

Particle deposition in ventilation ducts: Connectors, bends anddeveloping flow  

SciTech Connect (OSTI)

In ventilation duct flow the turbulent flow profile is commonly disturbed or not fully developed and these conditions are likely to influence particle deposition to duct surfaces. Particle deposition rates at eight S-connectors, in two 90{sup o} duct bends and in two ducts where the turbulent flow profile was not fully developed were measured in a laboratory duct system with both galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. In the steel duct system, experiments with nominal particle diameters of 1, 3, 5, 9 and 16 {micro}m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition of particles with nominal diameters of 1, 3, 5, 8 and 13 {micro}m was measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces. Deposition at S-connectors, in bends and in straight ducts with developing turbulence was often greater than deposition in straight ducts with fully developed turbulence for equal particle sizes, air speeds and duct surface orientations. Deposition rates at all locations were found to increase with an increase in particle size or air speed. High deposition rates at S-connectors resulted from impaction and these rates were nearly independent of the orientation of the S-connector. Deposition rates in the two 90{sup o} bends differed by more than an order of magnitude in some cases, probably because of the difference in turbulence conditions at the bend inlets. In straight steel ducts where the turbulent flow profile was developing, the deposition enhancement relative to fully developed turbulence generally increased with air speed and decreased with downstream distance from the duct inlet. This enhancement was greater at the duct ceiling and wall than at the duct floor. In insulated ducts, deposition enhancement was less pronounced overall than in steel ducts. Trends that were observed in steel ducts were present, but weaker, in insulated ducts.

Sippola, Mark R.; Nazaroff, William W.

2004-03-01T23:59:59.000Z

4

An insitu borescopic quantitative imaging profiler for the measurement of high concentration sediment velocity  

E-Print Network [OSTI]

of high concentration sediment velocity Edwin A. Cowen •instantaneous velocity in high sediment concentration ?ows,point reveals the sheet ?ow sediment velocities to be highly

Cowen, Edwin A.; Dudley, Russell D.; Liao, Qian; Variano, Evan A.; Liu, Philip L.-F.

2010-01-01T23:59:59.000Z

5

Experimental High Velocity Acid Jetting in Limestone Carbonates  

E-Print Network [OSTI]

Acid jetting is a well stimulation technique that is used in carbonate reservoirs. It typically involves injecting acid down hole at high flow rates through small orifices which cause high velocities of acid to strike the borehole wall...

Holland, Christopher

2014-04-30T23:59:59.000Z

6

High velocity spectroscopic binary orbits from photoelectric radial velocities: BD +30 2129 A  

E-Print Network [OSTI]

The spectroscopic orbit of a high proper motion visual binary system BD +30 2129 component A is determined from 22 CORAVEL-type radial velocity measurements. A period of P = 32.79 days and a moderate eccentricity e = 0.29 are obtained. The visual system AB has a projected spatial separation ~580 AU. The system's barycenter velocity V0 = -35.95 km/s and the transverse velocity Vt = 132.2 km/s. The Galactic spatial velocity components U = +76.7 km/s, V = 110.4 km/s, W = -26.6 km/s, and a large ultraviolet excess give evidence that the star belongs to thick disk population of the Galaxy.

A. Bartkevicius; J. Sperauskas

2007-01-30T23:59:59.000Z

7

High Velocity Spectroscopic Binary Orbits from Photoelectric Radial Velocities: BD +82 565A  

E-Print Network [OSTI]

The spectroscopic orbit of a circumpolar high-proper-motion visual binary BD +82 565 A component is determined from 57 CORAVEL radial velocity measurements. A short period P = 12.69 d and a moderate eccentricity e = 0.30 are obtained. The visual system AB has a projected spatial separation ~830 AU. The system's barycenter velocity V_0 = -86.7 km/s, the transverse velocity V_t = 118.7 km/s and the Galactic spatial velocity components U = -62.6 km/s, V = -84.1 km/s and W = -84.2 km/s give evidence that it belongs to the thick disk of the Galaxy.

A. Bartkevicius; J. Sperauskas

2006-01-10T23:59:59.000Z

8

High-Speed Internet Access via HVAC Ducts: A New Approach Daniel D. Stancil, Ozan K. Tonguz, Ariton Xhafa, Ahmet Cepni, and Pavel Nikitin  

E-Print Network [OSTI]

High-Speed Internet Access via HVAC Ducts: A New Approach Daniel D. Stancil, Ozan K. Tonguz, Ariton conditioning (HVAC) ducts for indoor wireless transmission systems and networks. Mea- surements and system to 100 Mbps should be possible, when HVAC system is used in con- junction with OFDM technology. Keywords

Stancil, Daniel D.

9

MAGNETIZED GAS IN THE SMITH HIGH VELOCITY CLOUD  

SciTech Connect (OSTI)

We report the first detection of magnetic fields associated with the Smith High Velocity Cloud. We use a catalog of Faraday rotation measures toward extragalactic radio sources behind the Smith Cloud, new H I observations from the Robert C. Byrd Green Bank Telescope, and a spectroscopic map of H? from the Wisconsin H-Alpha Mapper Northern Sky Survey. There are enhancements in rotation measure (RM) of ?100 rad m{sup –2} which are generally well correlated with decelerated H? emission. We estimate a lower limit on the line-of-sight component of the field of ?8 ?G along a decelerated filament; this is a lower limit due to our assumptions about the geometry. No RM excess is evident in sightlines dominated by H I or H? at the velocity of the Smith Cloud. The smooth H? morphology of the emission at the Smith Cloud velocity suggests photoionization by the Galactic ionizing radiation field as the dominant ionization mechanism, while the filamentary morphology and high (?1 Rayleigh) H? intensity of the lower-velocity magnetized ionized gas suggests an ionization process associated with shocks due to interaction with the Galactic interstellar medium. The presence of the magnetic field may contribute to the survival of high velocity clouds like the Smith Cloud as they move from the Galactic halo to the disk. We expect these data to provide a test for magnetohydrodynamic simulations of infalling gas.

Hill, Alex S.; McClure-Griffiths, Naomi M. [CSIRO Astronomy and Space Science, Marsfield, NSW (Australia); Mao, S. A. [Department of Astronomy, University of Wisconsin-Madison, Madison, WI (United States); Benjamin, Robert A. [Department of Physics, University of Wisconsin-Whitewater, Whitewater, WI (United States); Lockman, Felix J., E-mail: alex.hill@csiro.au, E-mail: naomi.mcclure-griffiths@csiro.au, E-mail: mao@astro.wisc.edu, E-mail: benjamir@uww.edu, E-mail: jlockman@nrao.edu [National Radio Astronomy Observatory, Green Bank, WV (United States)

2013-11-01T23:59:59.000Z

10

Building Energy Software Tools Directory: Duct Calculator  

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

Duct Calculator Duct Calculator Duct Calculator logo. Provides access to duct calculation and sizing capabilities either as a standalone Windows program or from within the Autodesk Building Mechanical, the new HVAC-oriented version of AutoCAD. Based on the engineering data and procedures outlined in the ASHRAE Fundamentals Handbook Calculation Methods, Duct Calculator features an advanced and fully interactive user interface. Slide controls for air flow, velocity, friction and duct size provide real-time, interactive feedback; as you spin one, the others dynamically respond in real time. When used with Autodesk Building Mechanical, Duct Calculator streamlines the design process by automatically re-sizing whole branches of ductwork. Screen Shots Keywords duct-sizing, design, engineering, calculation

11

High-Velocity Oxygen Fuel Thermal Spray of Fe-Based Amorphous Alloy: a Numerical and Experimental Study  

E-Print Network [OSTI]

High-Velocity Oxygen Fuel Thermal Spray of Fe-Basedusing a high velocity oxygen fuel (HVOF) spray processstructure. [12] High velocity oxygen fuel (HVOF) thermal

Ajdelsztajn, L.; Dannenberg, J.; Lopez, J.; Yang, N.; Farmer, J.; Lavernia, E. J.

2009-01-01T23:59:59.000Z

12

Experimental and numerical studies of high-velocity impact fragmentation  

SciTech Connect (OSTI)

Developments are reported in both experimental and numerical capabilities for characterizing the debris spray produced in penetration events. We have performed a series of high-velocity experiments specifically designed to examine the fragmentation of the projectile during impact. High-strength, well-characterized steel spheres (6.35 mm diameter) were launched with a two-stage light-gas gun to velocities in the range of 3 to 5 km/s. Normal impact with PMMA plates, thicknesses of 0.6 to 11 mm, applied impulsive loads of various amplitudes and durations to the steel sphere. Multiple flash radiography diagnostics and recovery techniques were used to assess size, velocity, trajectory and statistics of the impact-induced fragment debris. Damage modes to the primary target plate (plastic) and to a secondary target plate (aluminum) were also evaluated. Dynamic fragmentation theories, based on energy-balance principles, were used to evaluate local material deformation and fracture state information from CTH, a three-dimensional Eulerian solid dynamics shock wave propagation code. The local fragment characterization of the material defines a weighted fragment size distribution, and the sum of these distributions provides a composite particle size distribution for the steel sphere. The calculated axial and radial velocity changes agree well with experimental data, and the calculated fragment sizes are in qualitative agreement with the radiographic data. A secondary effort involved the experimental and computational analyses of normal and oblique copper ball impacts on steel target plates. High-resolution radiography and witness plate diagnostics provided impact motion and statistical fragment size data. CTH simulations were performed to test computational models and numerical methods.

Kipp, M.E.; Grady, D.E.; Swegle, J.W.

1993-08-01T23:59:59.000Z

13

Velocity alignment leads to high persistence in confined cells  

E-Print Network [OSTI]

Many cell types display random motility on two-dimensional substrates, but crawl persistently in a single direction when confined in a microchannel or on an adhesive micropattern. Does this imply that the motility mechanism of confined cells is fundamentally different from that of unconfined cells? We argue that both free- and confined- cell migration may be described by a generic model of cells as "velocity aligning" active Brownian particles previously proposed to solve a completely separate problem in collective cell migration. Our model can be mapped to a diffusive escape over a barrier and analytically solved to determine the cell's orientation distribution and repolarization rate. In quasi-one-dimensional confinement, velocity-aligning cells maintain their direction for times that can be exponentially larger than their persistence time in the absence of confinement. Our results suggest an important new connection between single- and collective- cell migration: high persistence in confined cells correspo...

Camley, Brian A

2014-01-01T23:59:59.000Z

14

Velocity distribution of high-energy particles and the solar neutrino problem  

E-Print Network [OSTI]

High energy infers high velocity and high velocity is a concept of special relativity. The Maxwellian velocity distribution is corrected to be consistent with special relativity. The corrected distribution reduces to the Maxwellian distribution for small velocities, contains a relatively depleted high-energy tail and vanishes at the velocity of light. This corrected distribution will lower solar neutrino fluxes and change solar neutrino energy spectra but keep solar sound speeds.

Jian-Miin Liu

2001-08-18T23:59:59.000Z

15

The origin of the high-velocity cloud complex C  

E-Print Network [OSTI]

High-velocity clouds consist of cold gas that appears to be raining down from the halo to the disc of the Milky Way. Over the past fifty years, two competing scenarios have attributed their origin either to gas accretion from outside the Galaxy or to circulation of gas from the Galactic disc powered by supernova feedback (galactic fountain). Here we show that both mechanisms are simultaneously at work. We use a new galactic fountain model combined with high-resolution hydrodynamical simulations. We focus on the prototypical cloud complex C and show that it was produced by an explosion that occurred in the Cygnus-Outer spiral arm about 150 million years ago. The ejected material has triggered the condensation of a large portion of the circumgalactic medium and caused its subsequent accretion onto the disc. This fountain-driven cooling of the lower Galactic corona provides the low-metallicity gas required by chemical evolution models of the Milky Way's disc.

Fraternali, F; Armillotta, L; Marinacci, F

2014-01-01T23:59:59.000Z

16

Encapsulated and Buried Ducts  

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

Encapsulated and Buried Ducts Robb Aldrich Steven Winter Associates, Inc. Why Buried Ducts?  Ductwork thermal losses can range from 10-45%  Interior ducts current solution, but may be impractical, expensive, or increase envelope loads Insulation & Air Barrier First Tests - Florida Early Buried Duct Tests (FL) Condensation? Master Bedroom Duct in Attic 10 15 20 25 30 35 40 45 50 55 Duct Top Temp Duct Side Temp Duct Bot. Temp Duct Side Dewpoint Duct Bot. Dewpoint Attic Temp 7/8/2000 7/8/2000 7/8/2000 7/8/2000 7/8/2000 7/8/2000 7/9/2000 0:00 4:00 8:00 12:00 16:00 20:00 0:00 Time California: Much drier, no Problem Implementation Getting it Right... in Florida A Solution for Humid Climates Encapsulated, then Buried Research Questions  What are the effective R-values?

17

High- and low-temperature-stable thermite composition for producing high-pressure, high-velocity gases  

DOE Patents [OSTI]

A high- and low-temperature-stable thermite composition for producing high-pressure and high-velocity gases comprises an oxidizable metal, an oxidizing reagent, and a high-temperature-stable gas-producing additive selected from the group consisting of metal carbides and metal nitrides.

Halcomb, Danny L. (Camden, OH); Mohler, Jonathan H. (Spring Valley, OH)

1990-10-16T23:59:59.000Z

18

Duct joining system  

SciTech Connect (OSTI)

A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

Proctor, John P. (44 Glen Dr., Fairfax, CA 94930); deKieffer, Robert C. (Boulder, CO)

2001-01-01T23:59:59.000Z

19

Duct Joining System  

DOE Patents [OSTI]

A duct joining system for providing an air-tight seal and mechanical connection for ducts and fittings is disclosed. The duct joining system includes a flexible gasket affixed to a male end of a duct or fitting. The flexible gasket is affixed at an angle relative to normal of the male end of the duct. The female end of the other duct includes a raised bead in which the flexible gasket is seated when the ducts are properly joined. The angled flexible gasket seated in the raised bead forms an air-tight seal as well as fastens or locks the male end to the female end. Alternatively, when a flexible duct is used, a band clamp with a raised bead is clamped over the female end of the flexible duct and over the male end of a fitting to provide an air tight seal and fastened connection.

Proctor, John P. (Fairfax, CA)

2001-02-27T23:59:59.000Z

20

Low inlet gas velocity high throughput biomass gasifier  

DOE Patents [OSTI]

The present invention discloses a novel method of operating a gasifier for production of fuel gas from carbonaceous fuels. The process disclosed enables operating in an entrained mode using inlet gas velocities of less than 7 feet per second, feedstock throughputs exceeding 4000 lbs/ft.sup.2 -hr, and pressures below 100 psia.

Feldmann, Herman F. (Worthington, OH); Paisley, Mark A. (Upper Arlington, OH)

1989-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Hollow lensing duct  

DOE Patents [OSTI]

A hollow lensing duct to condense (intensify) light using a combination of focusing using a spherical or cylindrical lens followed by reflective waveguiding. The hollow duct tapers down from a wide input side to a narrow output side, with the input side consisting of a lens that may be coated with an antireflective coating for more efficient transmission into the duct. The inside surfaces of the hollow lens duct are appropriately coated to be reflective, preventing light from escaping by reflection as it travels along the duct (reflective waveguiding). The hollow duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials.

Beach, Raymond J. (Livermore, CA); Honea, Eric C. (Sunol, CA); Bibeau, Camille (Dublin, CA); Mitchell, Scott (Tracy, CA); Lang, John (Pleasanton, CA); Maderas, Dennis (Pleasanton, CA); Speth, Joel (San Ramon, CA); Payne, Stephen A. (Castro Valley, CA)

2000-01-01T23:59:59.000Z

22

Microsoft Word - VitPlantInstallsCrucialDuct_20110209.doc  

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

also known as the "Vit Plant," set a giant heating, ventilation and air-conditioning (HVAC) duct in the High-Level Waste Facility. The nuclear-quality duct is part of the...

23

Flat Oval Spiral Duct Deflection  

E-Print Network [OSTI]

(c) 20 Gauge and 48 inch Flat Span (d) 24 Gauge and 6 inch Flat Span (e) 24 Gauge and 14 inch Flat Span (f) 26 Gauge and 25 inch Flat Span Figure 7.2.: Unreinforced Positive 35 (g) (cont.) 18 Gauge and 63 inch Flat Span (h) (cont.) 20 Gauge and 14.... [18] Ducts can be used in many applications some; applications might be high temperature or even corrosive or abrasive. Ducts are generally used in industrial ventilation, air pollution, and dust collecting systems. Metals can corrode from chemicals...

Daugherty, Matthew

2014-03-10T23:59:59.000Z

24

Hohlraum Designs for High Velocity Implosions on NIF  

SciTech Connect (OSTI)

In this paper, we compare experimental shock and capsule trajectories to design calculations using the radiation-hydrodynamics code HYDRA. The measured trajectories from surrogate ignition targets are consistent with reducing the x-ray flux on the capsule by about 85%. A new method of extracting the radiation temperature as seen by the capsule from x-ray intensity and image data shows that about half of the apparent 15% flux deficit in the data with respect to the simulations can be explained by HYDRA overestimating the x-ray flux on the capsule. The National Ignition Campaign (NIC) point-design target is designed to reach a peak fuel-layer velocity of 370 km/s by ablating 90% of its plastic (CH) ablator. The 192-beam National Ignition Facility laser drives a gold hohlraum to a radiation temperature (T{sub RAD}) of 300 eV with a 20 ns-long, 420 TW, 1.3 MJ laser pulse. The hohlraum x-rays couple to the CH ablator in order to apply the required pressure to the outside of the capsule. In this paper, we compare experimental measurements of the hohlraum T{sub RAD} and the implosion trajectory with design calculations using the code hydra. The measured radial positions of the leading shock wave and the unablated shell are consistent with simulations in which the x-ray flux on the capsule is artificially reduced by 85%. We describe a new method of inferring the T{sub RAD} seen by the capsule from time-dependent x-ray intensity data and static x-ray images. This analysis shows that hydra overestimates the x-ray flux incident on the capsule by {approx}8%.

Meezan, N B; Hicks, D G; Callahan, D A; Olson, R E; Schneider, M S; Thomas, C A; Robey, H F; Celliers, P M; Kline, J K; Dixit, S N; Michel, P A; Jones, O S; Clark, D S; Ralph, J E; Doeppner, T; MacKinnon, A J; Haan, S W; Landen, O L; Glenzer, S H; Suter, L J; Edwards, M J; Macgowan, B J; Lindl, J D; Atherton, L J

2011-10-19T23:59:59.000Z

25

Analysis of particle behavior in High-Velocity Oxy-Fuel thermal spraying process  

Science Journals Connector (OSTI)

This paper analyzes the behavior of coating particle as well as the gas flow both of inside and outside the High-Velocity Oxy-Fuel (HVOF) thermal spraying gun by using quasi-one-dimensional analysis and numerical...

Hiroshi Katanoda; Kazuyasu Matsuo

2003-08-01T23:59:59.000Z

26

Variables Affecting Smooth Particle Hydrodynamics Simulation of High-Velocity Flyer Plate Impact Experiments  

SciTech Connect (OSTI)

This paper describes our work to characterize the variables affecting the smoothed particle hydrodynamics (SPH) method in the LS-DYNA package for simulating high-velocity flyer plate impact experiments. LS-DYNA simulations are compared with one-dimensional experimental data of an oxygen-free high-conductivity (OFHC) copper flyer plate impacting another plate of the same material. The comparison is made by measuring the velocity of a point on the back surface of the impact plate using the velocity interferometer system for any reflector (VISAR) technique.

Somasundaram, Deepak S [UNLV; Trabia, Mohamed [UNLV; O'Toole, Brendan [UNLV; Hixson, Robert S [NSTec

2014-01-23T23:59:59.000Z

27

Moderate Velocity Ball Impact of a Mock High-Explosive  

SciTech Connect (OSTI)

Modeling of thermal and mechanical events in high-explosive materials is complicated by the composite nature of the material, which experiences viscoelastic and plastic deformations and sustains damage in the form of microcracks that can dominate its overall behavior. A mechanical event of interest is projectile interaction with the material, which leads to extreme local deformation and adiabatic heating, which can potentially lead to adverse outcomes in an energetic material. Simulations of such an event predicted large local temperature rises near the path of a spherical projectile, but these were experimentally unconfirmed and hence potentially non-physical. This work concerns the experimental verification of local temperatures both at the surface and in the wake of a spherical projectile penetrating a mock (unreactive) high-explosive at {approx}700 m/s. Fast response thermocouples were embedded radially in a mid-plane of a cylindrical target, which was bonded around the thermocouples with epoxy and recorded by an oscilloscope through a low-pass filter with a bandwidth of 500 Hz. A peak temperature rise of 70 K was measured both at the equator of the projectile and in its wake, in good agreement with the temperature predicted in the minimally distorted elements at those locations by a finite element model in ABAQUS employing the ViscoSCRAM constitutive model. Further work is needed to elucidate the extreme temperature rises in material undergoing crushing or fragmentation, which is difficult to predict with meshed finite element methods due to element distortion, and also challenging to quantify experimentally.

Furmanski, Jevan [Los Alamos National Laboratory; Rae, Philip [Los Alamos National Laboratory; Clements, Bradford E. [Los Alamos National Laboratory

2012-06-05T23:59:59.000Z

28

Velocity of Sound Measurements in High?Pressure, High?Temperature Steam  

Science Journals Connector (OSTI)

Experimental information concerning the acoustic velocity in steam as a function of pressure and temperature is quite limited. Yet it is of particular interest to steam turbine designers who are now planning units as large as 400 000 kw operating at 4500 lb/sq in. and 1200°F so as to increase thermal efficiencies of such units. Apparatus is now in operation for measuring the acoustic velocity up to 2000 lb/sq in. and 750°F using a variable path acoustic interferometer.Measurements are taken at 200?lb/sq in. intervals along a given isotherm using a sound frequency of 750 kc. A special experimental high?pressure boiler is used to generate the steam at the desired pressure and the stem is then increased in temperature by means of a stainless steel superheater before entering the interferometer. The interferometer also of stainless steel is enclosed by an insulated steel vessel maintained at a given constant temperature by another separate steam system. Future work is now being considered up to 6000?lb/sq in. steam pressure based upon results of present experiments.

James Woodburn

1960-01-01T23:59:59.000Z

29

Advanced Duct Sealing Testing  

SciTech Connect (OSTI)

Duct leakage has been identified as a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums or branches in the duct system. At each of these connections a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have typically shown that these seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory has been testing sealant durability for several years. Typical duct tape (i.e. fabric backed tapes with natural rubber adhesives) was found to fail more rapidly than all other duct sealants. This report summarizes the results of duct sealant durability testing of five UL 181B-FX listed duct tapes (three cloth tapes, a foil tape and an Oriented Polypropylene (OPP) tape). One of the cloth tapes was specifically developed in collaboration with a tape manufacturer to perform better in our durability testing. The first test involved the aging of common ''core-to-collar joints'' of flexible duct to sheet metal collars, and sheet metal ''collar-to-plenum joints'' pressurized with 200 F (93 C) air. The second test consisted of baking duct tape specimens in a constant 212 F (100 C) oven following the UL 181B-FX ''Temperature Test'' requirements. Additional tests were also performed on only two tapes using sheet metal collar-to-plenum joints. Since an unsealed flexible duct joint can have a variable leakage depending on the positioning of the flexible duct core, the durability of the flexible duct joints could not be based on the 10% of unsealed leakage criteria. Nevertheless, the leakage of the sealed specimens prior to testing could be considered as a basis for a failure criteria. Visual inspection was also documented throughout the tests. The flexible duct core-to-collar joints were inspected monthly, while the sheet metal collar-to-plenum joints were inspected weekly. The baking test specimens were visually inspected weekly, and the durability was judged by the observed deterioration in terms of brittleness, cracking, flaking and blistering (the terminology used in the UL 181B-FX test procedure).

Sherman, Max H.; Walker, Iain S.

2003-08-01T23:59:59.000Z

30

Duct Tape Durability Testing  

SciTech Connect (OSTI)

Duct leakage is a major source of energy loss in residential buildings. Most duct leakage occurs at the connections to registers, plenums, or branches in the duct system. At each of these connections, a method of sealing the duct system is required. Typical sealing methods include tapes or mastics applied around the joints in the system. Field examinations of duct systems have shown that taped seals tend to fail over extended periods of time. The Lawrence Berkeley National Laboratory (LBNL) has been testing sealant durability for several years using accelerated test methods and found that typical duct tape (i.e., cloth-backed tapes with natural rubber adhesives) fails more rapidly than other duct sealants. This report summarizes the results of duct sealant durability testing over two years for four UL 181B-FX listed duct tapes (two cloth tapes, a foil tape and an Oriented Polypropylene (OPP) tape). One of the cloth tapes was specifically developed in collaboration with a tape manufacturer to perform better in our durability testing. The tests involved the aging of common ''core-to-collar joints'' of flexible duct to sheet metal collars. Periodic air leakage tests and visual inspection were used to document changes in sealant performance. After two years of testing, the flex-to-collar connections showed little change in air leakage, but substantial visual degradation from some products. A surprising experimental result was failure of most of the clamps used to mechanically fasten the connections. This indicates that the durability of clamps also need to be addressed ensure longevity of the duct connection. An accelerated test method developed during this study has been used as the basis for an ASTM standard (E2342-03).

Sherman, Max H.; Walker, Iain S.

2004-04-01T23:59:59.000Z

31

T-method duct design. Part 4: Duct leakage theory  

SciTech Connect (OSTI)

Studies have shown that duct leakage depends on the method of duct fabrication, method of sealing, workmanship, and static pressure differential. An equation that describes leakage as a function of leakage class and static pressure is presented in the Duct Design chapter of the 1993 ASHRAE Handbook. This equation is used to calculate the leakage rate through a unit of duct surface for constant duct static pressure. However, the static pressure of a leaking duct does not remain constant. This process is described by a differential equation. The magnitude of duct leakage for a straight duct depends on internal static pressure and varies uniformly along its length (assumption). Fittings in a system cause sudden changes in static pressure; therefore, duct leakage depends on fitting locations. There are two approaches for duct system leakage calculation: (1) Accurate -- For accurate duct leakage calculations, the duct system is divided into single sections between fittings and the leakage rate and pressure loss for each section calculated by the weighing factor method. (2) Approximate -- For most applications, duct leakage can be calculated by approximate formulas based on the average static pressure in a duct section. Leakage calculation requires dividing the system into sections between each fitting. This paper, the fourth in a series on T-method duct design, discusses the theory of calculating air leakage from/into a single duct to incorporate duct leakage into the optimization and simulation calculation procedures.

Tsal, R.J.; Varvak, L.P. [NETSAL and Associates, Fountain Valley, CA (United States); Behls, H.F. [Behls and Associates, Arlington Heights, IL (United States)

1998-12-31T23:59:59.000Z

32

HIGH-RESOLUTION OBSERVATIONS AND THE PHYSICS OF HIGH-VELOCITY CLOUD A0  

SciTech Connect (OSTI)

The neutral hydrogen structure of high-velocity cloud A0 (at about -180 km s{sup -1}) has been mapped with a 9.'1 resolution. Gaussian decomposition of the profiles is used to separately map families of components defined by similarities in center velocities and line widths. About 70% of the H I gas is in the form of a narrow, twisted filament whose typical line widths are of the order of 24 km s{sup -1}. Many bright features with narrow line widths of the order of 6 km s{sup -1}, clouds, are located in and near the filament. A third category with properties between those of the filament and clouds appears in the data. The clouds are not always co-located with the broader line width filament emission as seen projected on the sky. Under the assumption that magnetic fields underlie the presence of the filament, a theorem is developed for its stability in terms of a toroidal magnetic field generated by the flow of gas along field lines. It is suggested that the axial magnetic field strength may be derived from the excess line width of the H I emission over and above that due to kinetic temperature by invoking the role of Alfven waves that create what is in essence a form of magnetic turbulence. At a distance of 200 pc the axial and the derived toroidal magnetic field strengths in the filament are then about 6 {mu}G while for the clouds they are about 4 {mu}G. The dependence of the derived field strength on distance is discussed.

Verschuur, Gerrit L., E-mail: verschuur@aol.com [Physics Department, University of Memphis, Memphis, TN 38152 (United States)

2013-04-01T23:59:59.000Z

33

Rationale for Measuring Duct Leakage Flows in Large Commercial Buildings  

SciTech Connect (OSTI)

Industry-wide methods of assessing duct leakage are based on duct pressurization tests, and focus on ''high pressure'' ducts. Even though ''low pressure'' ducts can be a large fraction of the system and tend to be leaky, few guidelines or construction specifications require testing these ducts. We report here on the measured leakage flows from ten large commercial duct systems at operating conditions: three had low leakage (less than 5% of duct inlet flow), and seven had substantial leakage (9 to 26%). By comparing these flows with leakage flows estimated using the industry method, we show that the latter method by itself is not a reliable indicator of whole-system leakage flow, and that leakage flows need to be measured.

Wray, Craig P.; Diamond, Richard C.; Sherman, Max H.

2005-07-01T23:59:59.000Z

34

Critical velocities for deflagration and detonation triggered by voids in a REBO high explosive  

SciTech Connect (OSTI)

The effects of circular voids on the shock sensitivity of a two-dimensional model high explosive crystal are considered. We simulate a piston impact using molecular dynamics simulations with a Reactive Empirical Bond Order (REBO) model potential for a sub-micron, sub-ns exothermic reaction in a diatomic molecular solid. The probability of initiating chemical reactions is found to rise more suddenly with increasing piston velocity for larger voids that collapse more deterministically. A void with radius as small as 10 nm reduces the minimum initiating velocity by a factor of 4. The transition at larger velocities to detonation is studied in a micron-long sample with a single void (and its periodic images). The reaction yield during the shock traversal increases rapidly with velocity, then becomes a prompt, reliable detonation. A void of radius 2.5 nm reduces the critical velocity by 10% from the perfect crystal. A Pop plot of the time-to-detonation at higher velocities shows a characteristic pressure dependence.

Herring, Stuart Davis [Los Alamos National Laboratory; Germann, Timothy C [Los Alamos National Laboratory; Jensen, Niels G [Los Alamos National Laboratory

2010-01-01T23:59:59.000Z

35

Experiments measuring particle deposition from fully developed turbulent flow in ventilation ducts  

SciTech Connect (OSTI)

Particle deposition in ventilation ducts influences particle exposures of building occupants and may lead to a variety of indoor air quality concerns. Experiments have been performed in a laboratory to study the effects of particle size and air speed on deposition rates of particles from turbulent air flows in galvanized steel and internally insulated ducts with hydraulic diameters of 15.2 cm. The duct systems were constructed of materials typically found in commercial heating, ventilating and air conditioning (HVAC) systems. In the steel duct system, experiments with nominal particle sizes of 1, 3, 5, 9 and 16 {micro}m were conducted at each of three nominal air speeds: 2.2, 5.3 and 9.0 m/s. In the insulated duct system, deposition rates of particles with nominal sizes of 1, 3, 5, 8 and 13 {micro}m were measured at nominal air speeds of 2.2, 5.3 and 8.8 m/s. Fluorescent techniques were used to directly measure the deposition velocities of monodisperse fluorescent particles to duct surfaces (floor, wall and ceiling) at two straight duct sections where the turbulent flow profile was fully developed. In steel ducts, deposition rates were higher to the duct floor than to the wall, which were, in turn, greater than to the ceiling. In insulated ducts, deposition was nearly the same to the duct floor, wall and ceiling for a given particle size and air speed. Deposition to duct walls and ceilings was greatly enhanced in insulated ducts compared to steel ducts. Deposition velocities to each of the three duct surface orientations in both systems were found to increase with increasing particle size or air velocity over the ranges studied. Deposition rates measured in the current experiments were in general agreement with the limited observations of similar systems by previous researchers.

Sippola, Mark R.; Nazaroff, William W.

2003-08-01T23:59:59.000Z

36

High-Velocity Oxy-Fuel (HVOF) Suspension Spraying of Mullite Coatings  

Science Journals Connector (OSTI)

Mullite coatings (3Al2O3 · 2SiO2) were deposited by suspension thermal spraying of micron-sized (D50...= 1.8 ?m) feedstock powders, using a high-velocity oxy-fuel gun (HVOF) operated on propylene (DJ-2700) and .....

J. Oberste Berghaus; B.R. Marple

2008-12-01T23:59:59.000Z

37

Method and apparatus for optical Doppler tomographic imaging of fluid flow velocity in highly scattering media  

DOE Patents [OSTI]

Optical Doppler tomography permits imaging of fluid flow velocity in highly scattering media. The tomography system combines Doppler velocimetry with high spatial resolution of partially coherent optical interferometry to measure fluid flow velocity at discrete spatial locations. Noninvasive in vivo imaging of blood flow dynamics and tissue structures with high spatial resolutions of the order of 2 to 10 microns is achieved in biological systems. The backscattered interference signals derived from the interferometer may be analyzed either through power spectrum determination to obtain the position and velocity of each particle in the fluid flow sample at each pixel, or the interference spectral density may be analyzed at each frequency in the spectrum to obtain the positions and velocities of the particles in a cross-section to which the interference spectral density corresponds. The realized resolutions of optical Doppler tomography allows noninvasive in vivo imaging of both blood microcirculation and tissue structure surrounding the vessel which has significance for biomedical research and clinical applications.

Nelson, John Stuart (Laguna Niguel, CA); Milner, Thomas Edward (Irvine, CA); Chen, Zhongping (Irvine, CA)

1999-01-01T23:59:59.000Z

38

Simulations of detonation wave propagation in rectangular ducts using a three-dimensional WENO scheme  

SciTech Connect (OSTI)

This paper reports high resolution simulations using a fifth-order weighted essentially non-oscillatory (WENO) scheme with a third-order TVD Runge-Kutta time stepping method to examine the features of detonation front and physics in square ducts. The simulations suggest that two and three-dimensional detonation wave front formations are greatly enhanced by the presence of transverse waves. The motion of transverse waves generates triple points (zones of high pressure and large velocity coupled together), which cause the detonation front to become locally overdriven and thus form ''hot spots.'' The transversal motion of these hot spots maintains the detonation to continuously occur along the whole front in two and three dimensions. The present simulations indicate that the influence of the transverse waves on detonation is more profound in three dimensions and the pattern of quasi-steady detonation fronts also depends on the duct size. For a ''narrow'' duct (4L x 4L where L is the half-reaction length), the detonation front displays a distinctive ''spinning'' motion about the axial direction with a well-defined period. For a wider duct (20L x 20L), the detonation front exhibits a ''rectangular mode'' periodically, with the front displaying ''convex'' and ''concave'' shapes one following the other and the transverse waves on the four walls being partly out-of-phase with each other. (author)

Dou, Hua-Shu; Tsai, Her Mann [Temasek Laboratories, National University of Singapore (Singapore); Khoo, Boo Cheong; Qiu, Jianxian [Department of Mechanical Engineering, National University of Singapore (Singapore)

2008-09-15T23:59:59.000Z

39

Electrical method and apparatus for impelling the extruded ejection of high-velocity material jets  

DOE Patents [OSTI]

A method and apparatus (10, 40) for producing high-velocity material jets provided. An electric current pulse generator (14, 42) is attached to an end of a coaxial two-conductor transmission line (16, 44) having an outer cylindrical conductor (18), an inner cylindrical conductor (20), and a solid plastic or ceramic insulator (21) therebetween. A coxial, thin-walled metal structure (22, 30) is conductively joined to the two conductors (18, 20) of the transmission line (16, 44). An electrical current pulse applies magnetic pressure to and possibly explosively vaporizes metal structure (22), thereby collapsing it and impelling the extruded ejection of a high-velocity material jet therefrom. The jet is comprised of the metal of the structure (22), together with the material that comprises any covering layers (32, 34) disposed on the structure. An electric current pulse generator of the explosively driven magnetic flux compression type or variety (42) may be advantageously used in the practice of this invention.

Weingart, Richard C. (Livermore, CA)

1989-01-01T23:59:59.000Z

40

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network [OSTI]

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Lockman, Felix J; Heroux, A J; Langston, Glen I

2008-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Smith's Cloud: A High-velocity Cloud Colliding with the Milky Way  

E-Print Network [OSTI]

New 21cm HI observations made with the Green Bank Telescope show that the high-velocity cloud known as Smith's Cloud has a striking cometary appearance and many indications of interaction with the Galactic ISM. The velocities of interaction give a kinematic distance of 12.4 +/-1.3 kpc, consistent with the distance derived from other methods. The Cloud is >3 x 1 kpc in size and its tip at (l,b)=(39 deg,-13 deg) is 7.6 kpc from the Galactic center and 2.9 kpc below the Galactic plane. It has greater than 10^6 M solar masses in HI. Its leading section has a total space velocity near 300 km/s, is moving toward the Galactic plane with a velocity of 73+/-26 km/s, and is shedding material to the Galaxy. In the absence of drag the Cloud will cross the plane in about 27 Myr. Smith's Cloud may be an example of the accretion of gas by the Milky Way needed to explain certain persistent anomalies in Galactic chemical evolution.

Felix J. Lockman; Robert A. Benjamin; A. J. Heroux; Glen I. Langston

2008-04-25T23:59:59.000Z

42

RATIONALE FOR MEASURING DUCT LEAKAGE FLOWS IN LARGE COMMERCIAL BUILDINGS  

E-Print Network [OSTI]

. Some duct sections operate at high static pressures (e.g., 100 to 2,500 Pa), but other sections leakage flows is to assume that an average duct static pressure applies to every leak. A third important2 ), central HVAC systems continuously supply heated or cooled air to conditioned spaces through

Diamond, Richard

43

Multi-Phase Galaxy Formation: High Velocity Clouds and the Missing Baryon Problem  

E-Print Network [OSTI]

The standard treatment of cooling in Cold Dark Matter halos assumes that all of the gas within a ``cooling radius'' cools and contracts monolithically to fuel galaxy formation. Here we take into account the expectation that the hot gas in galactic halos is thermally unstable and prone to fragmentation during cooling and show that the implications are more far-reaching than previously expected: allowing multi-phase cooling fundamentally alters expectations about gas infall in halos and naturally explains the bright-end cutoff in the galaxy luminosity function. We argue that cooling should proceed via the formation of high-density, 10^4 K clouds, pressure-confined within a hot gas background. The background medium has a low density, and can survive as a stable corona with a long cooling time. The fraction of baryons contained in the residual hot core grows with halo mass because the cooling density increases, and this leads to an upper-mass limit in quiescent, non-merged galaxies of ~10^11 Msun. In this scenario, galaxy formation is fueled by the infall of pressure-supported clouds. For Milky-Way-size systems, clouds of mass ~ 5x10^6 Msun that formed or merged within the last several Gyrs should still exist as a residual population in the halo, with a total mass in clouds of ~ 2 x 10^10 Msun. The mass of the Milky Way galaxy is explained naturally in this model, and is a factor of two smaller than would result in the standard treatment without feedback. We expect clouds in galactic halos to be ~ 1 kpc in size and to extend ~150 kpc from galactic centers. The predicted properties of clouds match well the observed radial velocities, angular sizes, column densities, and velocity widths of High Velocity Clouds around our Galaxy. The clouds also explain high-ion absorption systems at z<1.

Ariyeh H. Maller; James S. Bullock

2004-06-28T23:59:59.000Z

44

Diffusion velocity correlation for nuclear graphite gasification at high temperature and low Reynolds numbers  

SciTech Connect (OSTI)

The safety analysis of High-Temperature and Very High Temperature gas-cooled Reactors requires reliable estimates of nuclear graphite gasification as a function of temperature, among other parameters, in the unlikely event of an air ingress accident. Although the rates of the prevailing chemical reactions increase exponentially with temperature, graphite gasification at high temperatures is limited by the oxygen diffusion through the boundary layer. The effective diffusion velocity depends on the total flow rate and pressure of the bulk air-gas mixture. This paper develops a semi-empirical Sherwood number correlation for calculating the oxygen diffusion velocity. The correlation is based on a compiled database of the results of convective heat transfer experiments with wires and cylinders of different diameters in air, water and paraffin oil at 0.006 {<=} Re {<=} 1,604 and 0.068 {<=} Sc {<=} 35.2, and of mass transfer experiments at 4.8 {<=} Re {<=} 77 and 1,300 {<=} Sc {<=} 2,000. The developed correlation is within {+-} 8% of the compiled database of 567 data points and consistent with reported gasification rate measurements at higher temperatures in experiments using different size specimens of nuclear graphite grades of NBG-18 and NB-25, IG-11, IG-110 and IG-430 in atmospheric air at 0.08 {<=} Re {<=} 30. Unlike the Graetz solution that gives a constant Sh of 3.66 at Re {<=} 1.0, the present correlation shows Sh decreases monotonically to much lower values with decreasing Re. (authors)

El-Genk, M. S. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Mechanical Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States); Tournier, J. M. P. [Inst. for Space and Nuclear Power Studies, Univ. of New Mexico, Albuquerque, NM (United States); Chemical and Nuclear Engineering Dept., Univ. of New Mexico, Albuquerque, NM (United States)

2012-07-01T23:59:59.000Z

45

Seismic Technology Adapted to Analyzing and Developing Geothermal Systems Below Surface-Exposed High-Velocity Rocks  

Broader source: Energy.gov [DOE]

Improved seismic imaging of geology across high-velocity Earth surfaces will allow more rigorous evaluation of geothermal prospects beneath volcanic outcrops. Seismic-based quantification of fracture orientation and intensity will result in optimal positioning of geothermal wells.

46

Numerical modeling of in-flight characteristics of inconel 625 particles during high-velocity oxy-fuel thermal spraying  

Science Journals Connector (OSTI)

A computational fluid dynamics (CFD) model is developed to predict particle dynamic behavior in a high-velocity oxyfuel (HVOF) thermal spray gun in which premixed oxygen and propylene are ... 20 to 40 µm. At a pa...

S. Gu; D. G. McCartney; C. N. Eastwick; K. Simmons

2004-01-01T23:59:59.000Z

47

Turbulent mixing in ducts, theory and experiment application to aerosol single point sampling  

E-Print Network [OSTI]

straight duct, 900 elbow, 450 lateral and a generic mixer are incorporated into a correlation model for predicting the mixing quality for both the velocity and contaminant concentration as functions of such flow geometry, scale, pressure drop and fluid...

Langari, Abdolreza

2012-06-07T23:59:59.000Z

48

A DETAILED KINEMATIC MAP OF CASSIOPEIA A'S OPTICAL MAIN SHELL AND OUTER HIGH-VELOCITY EJECTA  

SciTech Connect (OSTI)

We present three-dimensional (3D) kinematic reconstructions of optically emitting material in the young Galactic supernova remnant Cassiopeia A (Cas A). These Doppler maps have the highest spectral and spatial resolutions of any previous survey of Cas A and represent the most complete catalog of its optically emitting material to date. We confirm that the bulk of Cas A's optically bright ejecta populate a torus-like geometry tilted approximately 30 Degree-Sign with respect to the plane of the sky with a -4000 to +6000 km s{sup -1} radial velocity asymmetry. Near-tangent viewing angle effects and an inhomogeneous surrounding circumstellar material/interstellar medium environment suggest that this geometry and velocity asymmetry may not be faithfully representative of the remnant's true 3D structure or the kinematic properties of the original explosion. The majority of the optical ejecta are arranged in several well-defined and nearly circular ring-like structures with diameters between approximately 30'' (0.5 pc) and 2' (2 pc). These ejecta rings appear to be a common phenomenon of young core-collapse remnants and may be associated with post-explosion input of energy from plumes of radioactive {sup 56}Ni-rich ejecta that rise, expand, and compress non-radioactive material. Our optical survey encompasses Cas A's faint outlying ejecta knots and exceptionally high-velocity NE and SW streams of S-rich debris often referred to as ''jets''. These outer knots, which exhibit a chemical make-up suggestive of an origin deep within the progenitor star, appear to be arranged in opposing and wide-angle outflows with opening half-angles of Almost-Equal-To 40 Degree-Sign.

Milisavljevic, Dan [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA, 02138 (United States); Fesen, Robert A., E-mail: dmilisav@cfa.harvard.edu [6127 Wilder Lab, Department of Physics and Astronomy, Dartmouth College, Hanover, NH 03755 (United States)

2013-08-01T23:59:59.000Z

49

Tips: Air Ducts | Department of Energy  

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

Air Ducts Air Ducts Tips: Air Ducts June 24, 2013 - 7:23pm Addthis Air Ducts: Out of Sight, Out of Mind. The unsealed ducts in your attic and crawlspaces lose air, and uninsulated ducts lose heat -- wasting energy and money. Air Ducts: Out of Sight, Out of Mind. The unsealed ducts in your attic and crawlspaces lose air, and uninsulated ducts lose heat -- wasting energy and money. Your air ducts are one of the most important systems in your home, and if the ducts are poorly sealed or insulated they are likely contributing to higher energy bills. Your home's duct system is a branching network of tubes in the walls, floors, and ceilings; it carries the air from your home's furnace and central air conditioner to each room. Ducts are made of sheet metal, fiberglass, or other materials.

50

The Ultra Luminous X-ray sources in the High Velocity System of NGC 1275  

E-Print Network [OSTI]

We report the results of a study of X-ray point sources coincident with the High Velocity System (HVS) projected in front of NGC 1275. A very deep X-ray image of the core of the Perseus cluster made with the Chandra Observatory has been used. We find a population of Ultra-Luminous X-ray sources (ULX; 7 sources with LX [0.5-7 keV] > 7x10^39 erg/s). As with the ULX populations in the Antennae and Cartwheel galaxies, those in the HVS are associated with a region of very active star formation. Several sources have possible optical counterparts found on HST images, although the X-ray brightest one does not. Absorbed power-law models fit the X-ray spectra, with most having a photon index between 2 and 3.

O. Gonzalez-Martin; A. C. Fabian; J. S. Sanders

2006-01-09T23:59:59.000Z

51

Sealing ducts to save energy  

SciTech Connect (OSTI)

Large amounts of energy are wasted when heat leaks through ductwork located in uninsulated spaces. The Electric Power Research INstitute recently did a study that accurately measured these losses, then substantially reduced them by sealing the leaky ductwork. Six homes in the Pacific Northwest with significant duct leakage to the outside were selected for the study. The homes had electric resistance or heat pump, forced-air heating systems with a major portion of the supply and return ductwork in crawl spaces, attics, garages, etc. Measurements of duct leakage and heating system efficiency were done on all the homes before starting the duct sealing. Retrofitting included finding holes, gaps, cracks and disconnected joints in supply and return ducts as well as in plenums. When necessary, plenums were cut open for repairs. Leaks were sealed with Latex mastic and fiberglass tape. Outside ducts were covered or wrapped with insulation. Unducted returns were sealed with duct board. In some cases, leakage was corrected by merely reconnecting ducts and boots.

Siuru, B.

1996-07-01T23:59:59.000Z

52

An X-ray absorption analysis of the high-velocity system in NGC 1275  

E-Print Network [OSTI]

We present an X-ray absorption analysis of the high-velocity system (HVS) in NGC 1275 using results from a deep 200 ks Chandra observation. We are able to describe the morphology of the HVS in more detail than ever before. We present an HST image for comparison, and note close correspondence between the deepest X-ray absorption and the optical absorption. A column density map of the HVS shows an average column density NH of 1x10^21 cm^-2 with a range from ~5x10^20 to 5x10^21 cm^-2. From the NH map we calculate a total mass for the absorbing gas in the HVS of (1.32+-0.05)x10^9 solar masses at solar abundance. 75 per cent of the absorbing mass is contained in the four regions of deepest absorption. We examine temperature maps produced by spectral fitting and find no direct evidence for shocked gas in the HVS. Using deprojection methods and the depth of the observed absorption, we are able to put a lower limit on the distance of the HVS from the nucleus of 57 kpc, showing that the HVS is quite separate from the body of NGC 1275.

K. Gillmon; J. S. Sanders; A. C. Fabian

2003-10-28T23:59:59.000Z

53

The Smith Cloud: high-velocity accretion and dark-matter confinement  

E-Print Network [OSTI]

The Smith Cloud is a massive system of metal-poor neutral and ionized gas M_gas >= 2x10^6 M_sun) that is presently moving at high velocity (V_GSR ~300 km s^-1) with respect to the Galaxy at a distance of 12 kpc from the Sun. The kinematics of the cloud's cometary tail indicates that the gas is in the process of accretion onto the Galaxy, as first discussed by Lockman et al. (2008). Here, we re-investigate the cloud's orbit by considering the possibility that the cloud is confined by a dark matter halo. This is required for the cloud to survive its passage through the Galactic corona. We consider three possible models for the dark matter halo (NFW, Einasto, Burkert) including the effects of tidal disruption and ram-pressure stripping during the cloud's infall onto and passage through the Galactic disk. For the NFW and Einasto dark-matter models, we are able to determine reasonable initial conditions for the Smith Cloud, although this is only marginally possible with the Burkert model. For all three models, the...

Nichols, M

2009-01-01T23:59:59.000Z

54

Searching for Dark Matter Annihilation in the Smith High-Velocity Cloud  

E-Print Network [OSTI]

Recent observations suggest that some high-velocity clouds may be confined by massive dark matter halos. In particular, the proximity and proposed dark matter content of the Smith Cloud make it a tempting target for the indirect detection of dark matter annihilation. We argue that the Smith Cloud may be a better target than some Milky Way dwarf spheroidal satellite galaxies and use gamma-ray observations from the Fermi Large Area Telescope to search for a dark matter annihilation signal. No significant gamma-ray excess is found coincident with the Smith Cloud, and we set strong limits on the dark matter annihilation cross section assuming a spatially-extended dark matter profile consistent with dynamical modeling of the Smith Cloud. Notably, these limits exclude the canonical thermal relic cross section ($\\sim 3\\times10^{-26}{\\rm cm}^{3}{\\rm s}^{-1}$) for dark matter masses $\\lesssim 30$ GeV annihilating via the $b \\bar b$ or $\\tau^{+}\\tau^{-}$ channels for certain assumptions of the dark matter density profile; however, uncertainties in the dark matter content of the Smith Cloud may significantly weaken these constraints.

Alex Drlica-Wagner; German A. Gomez-Vargas; John W. Hewitt; Tim Linden; Luigi Tibaldo

2014-06-30T23:59:59.000Z

55

detonation velocity  

Science Journals Connector (OSTI)

detonation velocity, detonation rate, velocity of detonation, V.O.D., detonating velocity, rate of detonation, detonating rate, detonation speed, detonating speed, speed of detonation ? Detonationsge...

2014-08-01T23:59:59.000Z

56

Boiling during high-velocity impact of water droplets on a hot stainless steel surface  

Science Journals Connector (OSTI)

...rho, V and p 0 are water density, impact velocity and atmospheric pressure, respectively. Assuming water vapour is a perfect...droplet-on-demand generator. Exp. Fluids. 34...of hot surfaces with water sprays. J. Heat Treating...

2006-01-01T23:59:59.000Z

57

IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 53, NO. 2, FEBRUARY 2005 335 On the Capacity Limits of HVAC Duct Channel for  

E-Print Network [OSTI]

of HVAC Duct Channel for High-Speed Internet Access Ariton E. Xhafa, Member, IEEE, Ozan K. Tonguz, Member and experimental channel-capacity estimates of heating, ventilation, and air condi- tioning (HVAC) ducts based suppressed. Our experimental results also show that even in the case of more complex HVAC duct networks (i

Stancil, Daniel D.

58

Articulated transition duct in turbomachine  

SciTech Connect (OSTI)

Turbine systems are provided. A turbine system includes a transition duct comprising an inlet, an outlet, and a duct passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The duct passage includes an upstream portion and a downstream portion. The upstream portion extends from the inlet between an inlet end and an aft end. The downstream portion extends from the outlet between an outlet end and a head end. The turbine system further includes a joint coupling the aft end of the upstream portion and the head end of the downstream portion together. The joint is configured to allow movement of the upstream portion and the downstream portion relative to each other about or along at least one axis.

Flanagan, James Scott; McMahan, Kevin Weston; LeBegue, Jeffrey Scott; Pentecost, Ronnie Ray

2014-04-29T23:59:59.000Z

59

TWO NEW DUCT LEAKAGE TESTS  

SciTech Connect (OSTI)

Two variations on the tests for duct leakage currently embodied in ASHRAE Standard 152P (Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems) are presented. Procedures are derived for calculating supply and return duct leakage to/from outside using these new variations. Results of these tests are compared with the original ones in Standard 152P on the basis of data collected in three New York State homes.

ANDREWS,J.W.

1998-12-01T23:59:59.000Z

60

High-resolution imaging of velocity-controlled molecular collisions using counterpropagating beams  

E-Print Network [OSTI]

We present ultrahigh-resolution measurements of state-to-state inelastic differential cross sections for NO-Ne and NO-Ar collisions, obtained by combining the Stark deceleration and velocity map imaging techniques. We show that for counterpropagating crossed beam geometries, the effect of the velocity spreads of the reagent beams on the angular resolution of the images is minimized. Futhermore, the counterpropagating geometry results in images that are symmetric with respect to the relative velocity vector. This allows for the use of inverse Abel transformation methods that enhance the resolution further. State-resolved diffraction oscillations in the differential cross sections are measured with an angular resolution approaching 0.3$^\\circ$. Distinct structures observed in the cross sections gauge the quality of recent \\emph{ab initio} potential energy surfaces for NO-rare gas atom collisions with unprecedented precision.

Vogels, Sjoerd N; von Zastrow, Alexander; Groenenboom, Gerrit C; van der Avoird, Ad; van de Meerakker, Sebastiaan Y T

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Characterization and Fabrication of Spoke Cavities for High-Velocity Applications  

SciTech Connect (OSTI)

A 500 MHz, velocity-of-light, two-spoke cavity has been designed and optimized for possible use in a compact light source. Here we present the mechanical analysis and steps taken in fabrication of this cavity at Jefferson Lab.

Hopper, Christopher S. [Old Dominion University, Norfolk, VA (United States); Park, HyeKyoung [Thomas Jefferson National Accelerator Facility, Newport News, VA (United States); Delayen, Jean R. [Old Dominion University, Norfolk, VA (United States)

2014-02-01T23:59:59.000Z

62

ULTRA-COMPACT HIGH VELOCITY CLOUDS AS MINIHALOS AND DWARF GALAXIES  

SciTech Connect (OSTI)

We present dark matter minihalo models for the Ultra-Compact, High-Velocity H I Clouds (UCHVCs) recently discovered in the 21 cm ALFALFA survey. We assume gravitational confinement of 10{sup 4} K H I gas by flat-cored dark-matter subhalos within the Local Group. We show that for flat cores, typical (median) tidally stripped cosmological subhalos at redshift z = 0 have dark-matter masses of ?10{sup 7} M{sub ?} within the central 300 pc (independent of total halo mass), consistent with the 'Strigari mass scale' observed in low-luminosity dwarf galaxies. Flat-cored subhalos also resolve the mass discrepancy between simulated and observed satellites around the Milky Way. For the UCHVCs, we calculate the photoionization-limited hydrostatic gas profiles for any distance-dependent total observed H I mass and predict the associated (projected) H I half-mass radii, assuming the clouds are embedded in distant (d ?> 300 kpc) and unstripped subhalos. For a typical UCHVC (0.9 Jy km s{sup –1}), we predict physical H I half-mass radii of 0.18 to 0.35 kpc (or angular sizes of 0.'6 to 2.'1) for distances ranging from 300 kpc to 2 Mpc. As a consistency check, we model the gas-rich dwarf galaxy Leo T, for which there is a well-resolved H I column density profile and a known distance (420 kpc). For Leo T, we find that a subhalo with M{sub 300} = 8 (± 0.2) × 10{sup 6} M{sub ?} best fits the observed H I profile. We derive an upper limit of P{sub HIM} ?< 150 cm{sup –3} K for the pressure of any enveloping hot intergalactic medium gas at the distance of Leo T. Our analysis suggests that some of the UCHVCs may in fact constitute a population of 21 cm-selected but optically faint dwarf galaxies in the Local Group.

Faerman, Yakov; Sternberg, Amiel [Raymond and Beverly Sackler School of Physics and Astronomy, Tel Aviv University, Ramat Aviv 69978 (Israel); McKee, Christopher F., E-mail: yakovfae@post.tau.ac.il [Department of Physics and Department of Astronomy, University of California at Berkeley, Berkeley, CA 94720 (United States)

2013-11-10T23:59:59.000Z

63

Stochastic simulation for the propagation of high-frequency acoustic waves through a random velocity field  

SciTech Connect (OSTI)

In-service inspection of Sodium-Cooled Fast Reactors (SFR) requires the development of non-destructive techniques adapted to the harsh environment conditions and the examination complexity. From past experiences, ultrasonic techniques are considered as suitable candidates. The ultrasonic telemetry is a technique used to constantly insure the safe functioning of reactor inner components by determining their exact position: it consists in measuring the time of flight of the ultrasonic response obtained after propagation of a pulse emitted by a transducer and its interaction with the targets. While in-service the sodium flow creates turbulences that lead to temperature inhomogeneities, which translates into ultrasonic velocity inhomogeneities. These velocity variations could directly impact the accuracy of the target locating by introducing time of flight variations. A stochastic simulation model has been developed to calculate the propagation of ultrasonic waves in such an inhomogeneous medium. Using this approach, the travel time is randomly generated by a stochastic process whose inputs are the statistical moments of travel times known analytically. The stochastic model predicts beam deviations due to velocity inhomogeneities, which are similar to those provided by a determinist method, such as the ray method.

Lu, B.; Darmon, M.; Leymarie, N.; Chatillon, S.; Potel, C. [CEA, LIST, F-91191 Gif-sur-Yvette (France); Laboratoire d'Acoustique de l'Universite du Maine (LAUM), UMR CNRS 6613, 72085 Le Mans Cedex 9 (France)

2012-05-17T23:59:59.000Z

64

Duct leakage measurement and analysis  

SciTech Connect (OSTI)

Leakage measurements were made on 6-in. (150-mm) and 10-in. (250-mm) round and 14-in. by 6-in. (350-mm by 150-mm) and 22-in. by 8-in. (560-mm by 200-mm) rectangular ducts for both positive and negative internal pressures. The data were found to fit a power law model, with the leakage rate (Q) increasing with a power, n, of static pressure difference ({Delta}p), i.e., Q {proportional_to} ({Delta}p){sup n}. A convenient leakage prediction equation, Q = C ({Delta}p*){sup n}, uses a normalized pressure difference, {Delta}p* = {Delta}p/{Delta}p{sub ref}, with {Delta}p in in. wg (Pa) and a reference pressure difference, {Delta}p{sub ref}, of 1 in. wg (250 Pa). C{sub D}, the recommended design values of C for a repetitive element of a duct system--one duct section and one joint, ranged from 0.01 cfm (0.005 L/s) for a Vanstone flanged joint to 18.5 cfm (8.7 L/s) for an unsealed 22-in. by 8-in (560-mm by 200-mm) duct with a slip-and-drive joint. Most test ducts had C{sub D} values of 6 to 8 cfm (3 to 4 L/s) and had values of n close to 0.58. Joints were found to account for most of the leakage, and thus most of the value of C{sub D}, in unsealed ducts, with seams contributing only 10% to 38% of the total.

Swim, W.B.; Griggs, E.I. [Tennessee Technological Univ., Cookeville, TN (United States). Dept. of Mechanical Engineering

1995-08-01T23:59:59.000Z

65

STATE OF CALIFORNIA DUCT LEAKAGE TEST EXISTING DUCT SYSTEM  

E-Print Network [OSTI]

.g., register boots, air handler, coil, plenums, etc.) if those parts are accessible and they can be sealed 2010 Outside air (OA) ducts for Central Fan Integrated (CFI) ventilation systems, shall not be sealed. Option 3. Reduce leakage by 60% or more, and conduct smoke test to seal all accessible leaks. Option 4

66

Achieving Airtight Ducts in Manufactured Housing  

E-Print Network [OSTI]

correlated with achieving CFM25OUT=3% in mastic sealed systems, but less reliably with taped systems. Cost for achieving duct tightness goals range from $4 to $8 including duct testing on the assembly line...

McIlvaine, J.; Beal, D.; Moyer, N.; Chasar, D.; Chandra, S.

2004-01-01T23:59:59.000Z

67

Reynolds-stress model prediction of 3-D duct flows  

E-Print Network [OSTI]

The paper examines the impact of different modelling choices in second-moment closures by assessing model performance in predicting 3-D duct flows. The test-cases (developing flow in a square duct [Gessner F.B., Emery A.F.: {\\em ASME J. Fluids Eng.} {\\bf 103} (1981) 445--455], circular-to-rectangular transition-duct [Davis D.O., Gessner F.B.: {\\em AIAA J.} {\\bf 30} (1992) 367--375], and \\tsn{S}-duct with large separation [Wellborn S.R., Reichert B.A., Okiishi T.H.: {\\em J. Prop. Power} {\\bf 10} (1994) 668--675]) include progressively more complex strains. Comparison of experimental data with selected 7-equation models (6 Reynolds-stress-transport and 1 scale-determining equations), which differ in the closure of the velocity/pressure-gradient tensor $\\Pi_{ij}$, suggests that rapid redistribution controls separation and secondary-flow prediction, whereas, inclusion of pressure-diffusion modelling improves reattachment and relaxation behaviour.

Gerolymos, G A

2014-01-01T23:59:59.000Z

68

The influence of the Al stabilizer layer thickness on the normal zone propagation velocity in high current superconductors  

E-Print Network [OSTI]

The stability of high-current superconductors is challenging in the design of superconducting magnets. When the stability requirements are fulfilled, the protection against a quench must still be considered. A main factor in the design of quench protection systems is the resistance growth rate in the magnet following a quench. The usual method for determining the resistance growth in impregnated coils is to calculate the longitudinal velocity with which the normal zone propagates in the conductor along the coil windings. Here, we present a 2D numerical model for predicting the normal zone propagation velocity in Al stabilized Rutherford NbTi cables with large cross section. By solving two coupled differential equations under adiabatic conditions, the model takes into account the thermal diffusion and the current redistribution process following a quench. Both the temperature and magnetic field dependencies of the superconductor and the metal cladding materials properties are included. Unlike common normal zon...

Shilon, I; Langeslag, S A E; Martins, L P; Kate, H H J ten

2014-01-01T23:59:59.000Z

69

CALIFORNIA ENERGY Residential Duct Placement  

E-Print Network [OSTI]

CALIFORNIA ENERGY COMMISSION Residential Duct Placement: Market Barriers Market Barriers, Governor #12;#12;CALIFORNIA ENERGY COMMISSION Prepared By: GARD Analytics, Inc. Roger Hedrick, Lead Author DISCLAIMER This report was prepared as the result of work sponsored by the California Energy Commission

70

Assessing the Longevity of Residential Duct Sealants Published in Proc. RILEM 3rd  

E-Print Network [OSTI]

residential buildings [1]. The air distribution systems require some sort of seal between duct sections significant leakage to outside because these spaces are not air sealed. Residential duct systems in the U not usually provide an air seal. High pressure drops in the vicinity of the air handler and associated plenum

71

Design of Flexible-Duct Junction Boxes  

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

Design of Flexible-duct Design of Flexible-duct Junction Boxes Robert Beach, IBACOS Duncan Prahl, IBACOS Design of Flexible-duct Junction Boxes Presentation Outline * Current Standards and Practice * Analysis Methods * Recommendations Design of Flexible-duct Junction Boxes * Detailed report is in peer review anticipated to be published T3 this year. - http://www1.eere.energy.gov/library/default.aspx?page=2&spi d=2. * Measure guide to be part of Building America Solutions Center - http://basc.pnnl.gov/ Design of Flexible-duct Junction Boxes Typical Installations As Plenum As Monster Design of Flexible-duct Junction Boxes Current Standards * ASHRAE 2012 HVAC Systems and Equipment, Box Plenum Systems Using Flexible Duct - Constrains Box Width to 2-3x Entrance Width - Constrains Box Length to 2 x Box Width

72

EVIDENCE OF HOT HIGH VELOCITY PHOTOIONIZED PLASMA FALLING ON ACTIVELY ACCRETING T TAURI STARS  

SciTech Connect (OSTI)

The He II (1640 Å) line and the resonance doublet of N V (UV1) provide a good diagnostic tool to constrain the excitation mechanism of hot (T{sub e} > 40,000 K) atmospheric/magnetospheric plasmas in T Tauri stars (TTSs). Making use of the data available in the Hubble Space Telescope archive, this work shows that there are at least two distinct physical components contributing to the radiation in these tracers: the accretion flow sliding on the magnetosphere and the atmosphere. The N V profiles in most sources are symmetric and at rest with respect to the star. The velocity dispersion of the profile increases from non-accreting (? = 40 km s{sup –1}) to accreting (? = 120 km s{sup –1}) TTSs, suggesting that the macroturbulence field in the line formation region decreases as the stars approach the main sequence. Evidence of the N V line being formed in a hot solar-like wind has been found in RW Aur, HN Tau, and AA Tau. The He II profile has a strong narrow component that dominates the line flux; the dispersion of this component ranges from 20 to 60 km s{sup –1}. Current data suggest that both accretion shocks and atmospheric emission might contribute to the line flux. In some sources, the He II line shows a broad and redward-shifted emission component often accompanied by semiforbidden O III] emission that has a critical electron density of ?3.4 × 10{sup 10} cm{sup 3}. In spite of their different origins (inferred from the kinematics of the line formation region), N V and He II fluxes are strongly correlated, with only the possible exception of some of the heaviest accretors.

Gómez de Castro, Ana Ines [Grupo de Investigación Complutense AEGORA and S.D. Astronomía y Geodesia, Fac. de CC Matemáticas, Universidad Complutense, E-28040 Madrid (Spain)

2013-10-01T23:59:59.000Z

73

High-Frequency Effect Due to the Axial Drift Velocity of a Plasma Column  

Science Journals Connector (OSTI)

The scattering of a plane electromagnetic wave with normal incidence (E field perpendicular to the axis) by a plasma column in the presence of a static magnetic induction B0 has been studied earlier. A heretofore unexplained effect, however, is the existence of a scattered axial field EZ even when B0=0. A mechanism responsible for this coupling between the EZ and the transverse E field, in the absence of B0, is investigated here, namely the role of an axial drift velocity vd. The effect observed is a resonance peak of EZ occurring at the same density for which there exists a resonance of the scattered transverse E field which is well explained by a uniform cold-plasma model. The same model is therefore assumed here. In this approximation the plasma can be described by a surface charge density ? due to the HF polarization which gives rise to a surface current density K=?vd. The boundary conditions then lead to the existence of an EZ which, for B0=0, has a sin? dependence when the exciting field has a cos? dependence. When B0?0, a more complicated theoretical spectrum is obtained. Both the position and the angular dependence of the resonances are in very good agreement with experimental data. The effect predicted by this model is, however, more than an order of magnitude below that observed in a mercury plasma column. This phenomenon can be described as the plasma radio-frequency analog of the static field induced by the Roentgen-Eichenwald current.

A. M. Messiaen and P. E. Vandenplas

1966-09-09T23:59:59.000Z

74

Computer Aided Duct Design  

E-Print Network [OSTI]

is designed with a higher static pressure and greater noise and turbulence than is necessary. A computer model helps to resolve these problems, reducing the fan horsepower needed to deliver the air. Computer optimization also reduces noise and the high rate...

Clark, W. H.

1994-01-01T23:59:59.000Z

75

GALACTIC ALL-SKY SURVEY HIGH-VELOCITY CLOUDS IN THE REGION OF THE MAGELLANIC LEADING ARM  

SciTech Connect (OSTI)

We present a catalog of high-velocity clouds in the region of the Magellanic Leading Arm. The catalog is based on neutral hydrogen (H I) observations from the Parkes Galactic All-Sky Survey. Excellent spectral resolution allows clouds with narrow-line components to be resolved. The total number of detected clouds is 419. We describe the method of cataloging and present the basic parameters of the clouds. We discuss the general distribution of the high-velocity clouds and classify the clouds based on their morphological type. The presence of a significant number of head-tail clouds and their distribution in the region is discussed in the context of Magellanic System simulations. We suggest that ram-pressure stripping is a more important factor than tidal forces for the morphology and formation of the Magellanic Leading Arm and that different environmental conditions might explain the morphological difference between the Magellanic Leading Arm and Magellanic Stream. We also discuss a newly identified population of clouds that forms the LA IV and a new diffuse bridge-like feature connecting the LA II and III complexes.

For, Bi-Qing; Staveley-Smith, Lister [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia)] [International Centre for Radio Astronomy Research, University of Western Australia, 35 Stirling Hwy, Crawley, WA 6009 (Australia); McClure-Griffiths, N. M., E-mail: biqing.for@uwa.edu.au [Australia Telescope National Facility, CSIRO Astronomy and Space Science, PO Box 76, Epping, NSW 1710 (Australia)

2013-02-10T23:59:59.000Z

76

Multi-point, high-speed passive ion velocity distribution diagnostic on the Pegasus Toroidal Experiment  

SciTech Connect (OSTI)

A passive ion temperature polychromator has been deployed on Pegasus to study power balance and non-thermal ion distributions that arise during point source helicity injection. Spectra are recorded from a 1 m F/8.6 Czerny-Turner polychromator whose output is recorded by an intensified high-speed camera. The use of high orders allows for a dispersion of 0.02 A/mm in 4th order and a bandpass of 0.14 A ({approx}13 km/s) at 3131 A in 4th order with 100 {mu}m entrance slit. The instrument temperature of the spectrometer is 15 eV. Light from the output of an image intensifier in the spectrometer focal plane is coupled to a high-speed CMOS camera. The system can accommodate up to 20 spatial points recorded at 0.5 ms time resolution. During helicity injection, stochastic magnetic fields keep T{sub e} low ({approx}100 eV) and thus low ionization impurities penetrate to the core. Under these conditions, high core ion temperatures are measured (T{sub i} Almost-Equal-To 1.2 keV, T{sub e} Almost-Equal-To 0.1 keV) using spectral lines from carbon III, nitrogen III, and boron IV.

Burke, M. G.; Fonck, R. J.; Bongard, M. W.; Schlossberg, D. J.; Winz, G. R. [Department of Engineering Physics, University of Wisconsin, Madison, Wisconsin 53706 (United States)

2012-10-15T23:59:59.000Z

77

Laser-based diagnostics for density, temperature, velocity, and dissociation fraction in high temperature hydrogen flows  

SciTech Connect (OSTI)

This paper is essentially a review of the current state of the art in hydrogen atom and hydrogen molecule diagnostics. This paper contains some of our own results and ideas along with results from many other laboratories. This is not intended to be an exhaustive review; instead it summarizes some techniques which we believe are ideally suited as diagnostics for high temperature hydrogen which are of paramount importance for the Space Exploration Initiative (SEI). 31 refs., 1 fig.

Sappey, A.D.; Funk, D.J.

1991-01-01T23:59:59.000Z

78

Effect of refrigerant charge, duct leakage, and evaporator air flow on the high temerature performance of air conditioners and heat pumps.  

E-Print Network [OSTI]

??An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation… (more)

Rodriguez, Angel Gerardo

2012-01-01T23:59:59.000Z

79

Measure Guideline: Sealing and Insulating of Ducts in Existing Homes  

SciTech Connect (OSTI)

This document begins with a discussion on potential cost and performance benefits of duct sealing and insulating. It continues with a review of typical duct materials and components and the overall procedures for assessing and improving the duct system.

Aldrich, R.; Puttagunta, S.

2011-12-01T23:59:59.000Z

80

Simulated Climatology of Atmospheric Ducts Over the Persian Gulf  

Science Journals Connector (OSTI)

A simulated climatology of ducts in the Persian Gulf area was produced with the MM3 atmospheric ... boundary layer prevented duct formation. Over the Gulf in the season, duct coverage was complete ... from north-...

M. Zhu; B. W. Atkinson

2005-06-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Observations of Strong Surface Radar Ducts over the Persian Gulf  

Science Journals Connector (OSTI)

Ducting of microwave radiation is a common phenomenon over the oceans. The height and strength of the duct are controlling factors for radar propagation and must be determined accurately to assess propagation ranges. A surface evaporation duct ...

Ian M. Brooks; Andreas K. Goroch; David P. Rogers

1999-09-01T23:59:59.000Z

82

Effect of refrigerant charge, duct leakage, and evaporator air flow on the high temerature performance of air conditioners and heat pumps  

E-Print Network [OSTI]

An experimental study was conducted to quantify the effect of several installation items on the high outdoor ambient temperature performance of air conditioners. These installation items were: improper amount of refrigerant charge, reduced...

Rodriguez, Angel Gerardo

2012-06-07T23:59:59.000Z

83

Velocity determination from velocity spectra  

E-Print Network [OSTI]

. Lithologic and structural information can bc inferred from the interval velocities and thicknesses. Actual seismic exploration data (which are twelvefold sub- surface coverage data taken at Niller County, Arkansas) were used to make the actual velocity...) with decreasing increment of normal incidence time and rms velocity, 2) with in- creasing interval between the initial and final values of time and TRACE NO. & SHOT-GEOPHONE DISTANCE l 2 3 4 3 6 X, X X 4 Xs X~ RMS VELOCITY V ca Jo M A tD M NNO = J o) y...

Yang, Sung Jin

2012-06-07T23:59:59.000Z

84

Buried and Encapsulated Ducts - Building America Top Innovation...  

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

and Encapsulated Ducts - Building America Top Innovation photo of worker blowing insulation on ducts in an attic. Ductwork installed in unconditioned attics can significantly...

85

Integration of HVAC System Design with Simplified Duct Distribution...  

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

Integration of HVAC System Design with Simplified Duct Distribution - Building America Top Innovation Integration of HVAC System Design with Simplified Duct Distribution - Building...

86

Aerosol-Based Duct Sealing Technology  

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

8 8 Aerosol-Based Duct Sealing Technology During the past five years, research has quantified the impacts of residential duct system leakage on HVAC energy consumption and peak electricity demand. A typical house with ducts located in the attic or crawlspace wastes approximately 20% of heating and cooling energy through duct leaks and draws approximately 0.5 KW more electricity during peak cooling periods. A 1991 study indicated that sealing leaks could save close to one Quadrillion Btus per year. (see also Commercializing a New Technology) Because the major cost of sealing leaks in existing air distribution systems is the labor for the location and sealing process, reducing the labor could greatly improve the cost-effectiveness of such a retrofit. Field studies of duct sealing programs performed by HVAC contractors show

87

Tips for specifying active duct silencers  

Science Journals Connector (OSTI)

Low?frequency noise in buildings is receiving greater focus in new noise standards. The extraordinary performance of active duct silencers on these low frequencies provides a powerful new element for fan noise control. Acoustical consultants need to know the most appropriate applications for active duct silencers. The authors have been personally involved in the design and start?up of over 1000 active duct silencers installed in the USA and Europe to silence fans on a variety of HVAC applications. This site experience from office buildings schools hospitals semiconductor manufacturing facilities auditoria sound test chambers and cruise ships—both retrofit and new construction—is summarized to guide acoustical consultants in estimating the performance of active duct silencers. Fan and duct silencer system layouts are reviewed along with performance case histories.

2000-01-01T23:59:59.000Z

88

Acoustical performance testing of duct silencers  

Science Journals Connector (OSTI)

The test method used in North America to evaluate the acoustical performance of duct silencers is ASTM E477. The ASTM standard provides an approved method for measuring the aerodynamic pressure drop dynamic insertion loss and self?generated noise of duct silencers. Unfortunately restrictions on the construction of the test duct in the current standard cause erroneous results in the measurement of insertion loss at low frequencies. These errors are due to acoustic resonances that occur naturally in the empty test duct. It is recommended that the standard be modified to require anechoic terminations at both ends of the test duct. It is also recommended that more specific design criteria for the source chamber be established and that a new section be added to provide for the measurement of the radiated noise from the casing of the test specimen. Specific recommendations relating to all of these issues will be provided.

2002-01-01T23:59:59.000Z

89

INTERIOR DUCT SYSTEM DESIGN, CONSTRUCTION, AND PERFORMANCE  

SciTech Connect (OSTI)

By removing air distribution and conditioning equipment from unconditioned spaces, homeowners stand to benefit substantially with respect to both energy savings and indoor air quality. Duct leakage introduces: Greater heating and cooling loads from air at extreme temperatures and humidity levels; Outside air and air from unconditioned spaces that may contain air borne contaminants, combustion gases, pollen, mold spores, and/or particles of building materials; and Higher whole-house infiltration/exfiltration rates. Exemplary studies conducted since 1990 have demonstrated the prevalence of duct leakage throughout the United States and measured energy savings of approximately 20% during both heating and cooling seasons from leakage reduction. These all dealt with duct leakage to and/or from unconditioned spaces. In the building science community, leakage within the conditioned space is generally presumed to eliminate the negative consequences of duct leakage with the exception of possibly creating pressure imbalances in the house which relates to higher infiltration and/or exfiltration. The practical challenges of isolating ducts and air handlers from unconditioned spaces require builders to construct an air-tight environment for the ducts. Florida Solar Energy Center researchers worked with four builders in Texas, North Carolina, and Florida who build a furred-down chase located either in a central hallway or at the edges of rooms as an architectural detail. Some comparison homes with duct systems in attics and crawl spaces were included in the test group of more than 20 homes. Test data reveals that all of the duct/AHU systems built inside the conditioned space had lower duct leakage to unconditioned spaces than their conventional counterparts; however, none of the homes was completely free of duct leakage to unconditioned spaces. Common problems included wiring and plumbing penetrations of the chase, failure to treat the chase as an air tight space, and misguided fresh air inlet design. Improvements were implemented by the Texas builder and retested in July. Results showed a 36% reduction in duct leakage, significant enough to warrant the builder adopting the new sealing procedure.

Janet E.R. Mcllvaine; David Beal; Philip Fairey

2001-10-10T23:59:59.000Z

90

High frequency sound velocity in the glass former 2Ca(NO3)2?3KNO3: Molecular dynamics simulations  

Science Journals Connector (OSTI)

Molecular dynamics simulations of the fragile glass-forming liquid 2Ca(NO3)2?3KNO3 (CKN) were performed from its molten state at 800K down to its glassy state at 250K. Time correlation functions of mass current fluctuations were calculated in order to investigate sound waves of high wave vectors, 0.18high frequency (THz) sound velocity of CKN was obtained from the slope of the dispersion curve of excitation energy of acoustic modes, ?(k), as a function of temperature across the glass transition. The temperature dependence of the sound velocity of longitudinal acoustic modes is discontinuous in a range that is higher than the glass transition temperature Tg estimated from the T dependence of density and energy. This result demonstrates that the high frequency sound velocity probes the transition from liquidlike to solidlike regimes at a temperature higher than the Tg of the simulated material. The sound velocity of transverse acoustic (TA) modes presents discontinuity at the same value of the thermodynamic derived Tg. It is proposed that the distinct behavior of high frequency TA modes is due to fast reorientational motions of NO3? anions that are able to relieve local shear stresses.

Mauro C. C. Ribeiro

2007-04-06T23:59:59.000Z

91

Aerogel Impregnated Polyurethane Piping and Duct Insulation  

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

Aerogel Impregnated Polyurethane Aerogel Impregnated Polyurethane Piping and Duct Insulation David M. Hess InnoSense LLC david.hess@innosense.us, 310-530-2011 April 4, 2013 2 | Building Technologies Office eere.energy.gov Purpose & Objectives Problem Statement: Develop an efficient insulation system that will adhere to housing duct work and pipe structures while conforming to complex geometries. New insulations must increase the R-value of existing materials and be easy to apply or retrofit to existing structures.

92

Numerical simulation of laminar flow in a curved duct  

SciTech Connect (OSTI)

This paper describes numerical simulations that were performed to study laminar flow through a square duct with a 900 bend. The purpose of this work was two fold. First, an improved understanding was desired of the flow physics involved in the generation of secondary vortical flows in three-dimensions. Second, adaptive gridding techniques for structured grids in three- dimensions were investigated for the purpose of determining their utility in low Reynolds number, incompressible flows. It was also of interest to validate the commercial computer code CFD-ACE. Velocity predictions for both non-adaptive and adaptive grids are compared with experimental data. Flow visualization was used to examine the characteristics of the flow though the curved duct in order to better understand the viscous flow physics of this problem. Generally, moderate agreement with the experimental data was found but shortcomings in the experiment were demonstrated. The adaptive grids did not produce the same level of accuracy as the non-adaptive grid with a factor of four more grid points.

Lopez, A.R.; Oberkampf, W.L.

1995-01-01T23:59:59.000Z

93

Duct injection technology prototype development: Nozzle development Subtask 4. 1, Atomizer specifications for duct injection technology  

SciTech Connect (OSTI)

Babcock Wilcox has conducted a program to identify atomizers appropriate for successful in-duct injection of humidification water and lime slurries. The purpose of this program was to identify and quantify atomizer spray and performance criteria that affect the operations and reliability of the in-duct SO{sub 2} removal process, and compare commercially available atomizers to these criteria.

Not Available

1992-02-01T23:59:59.000Z

94

Evaluation of mixing downstream of tees in duct systems with respect to single point representative air sampling  

E-Print Network [OSTI]

improvement in 3 hydraulic diameters needed to achieve COVs below 10%. Without an air blender, the distance downstream of the T-junction for the COVs below 20% increased as the velocity of the sub duct airflow increased. About 95% of the cases achieved COVs...

Kim, Taehong

2012-06-07T23:59:59.000Z

95

An analysis of fluid flow by electrical analogy as applied to air ducts  

E-Print Network [OSTI]

. 0 10. 0 14. 9 9-4 12. 0 VELOCITY FPM 1600 1460 1570 1300 TOTAL PRESSURE DROP IN. WATER 0 04 0. 10 0 02 o o8 o. o8 TABLE 3 21 PART III ALMQJATING CUHREYZ N. . GAME CALCULATOR APPLIED TO THE TOTAL PiiBSURE DROP METHOD GIVEN... resistance for Section B is then read to be 13. 3$ ohms which gives an R oi' 38 ' 2 ohms. From Figure 4 the velocity is found to be 1400 fpm and duct diameter 14. 9 inches. fhe voltage drop for Section D is read to be 10. 0 volts, giving a total head loss...

Howard, Charles Pinto

2012-06-07T23:59:59.000Z

96

Evaluation of PEGIT duct connection system  

SciTech Connect (OSTI)

Most air duct system components are assembled in the field and are mechanically fastened by sheet metal screws (for sheet metal-to-sheet metal) or by drawbands (for flex duct-to-sheet metal). Air sealing is separate from this mechanical fastening and is usually achieved using tape or mastic products after mechanical fastening. Field observations have shown that mechanical fastening rarely meets code or manufacturers requirements and that sealing procedures are similarly inconsistent. To address these problems, Proctor Engineering Group (PEG) is developing a system of joining ducts (called PEGIT) that combines the mechanical fastening and sealing into a single self-contained procedure. The PEGIT system uses a shaped flexible seal between specially designed sheet metal duct fittings to both seal and fasten duct sections together. Figure 1 shows the inner duct fitting complete with rubber seal. This seal provides the air seal for the completed fitting and is shaped to allow the inner and outer fittings to slide together, and then to lock the fittings in place. The illustration in Figure 2 shows the approximate cross section of the rubber seal that shows how the seal has a lip that is angled backwards. This angled lip allows the joint to be pushed together by folding flat but then its long axis makes it stiff in the pulling apart direction. This study was undertaken to assist PEG in some of the design aspects of this system and to test the performance of the PEGIT system. This study was carried out in three phases. The initial phase evaluated the performance of a preliminary seal design for the PEGIT system. After the first phase, the seal was redesigned and this new seal was evaluated in the second phase of testing. The third phase performed more detailed testing of the second seal design to optimize the production tolerances of the sheet metal fittings. This report summarizes our findings from the first two phases and provides details about the third phase of testing.

Walker, Iain S.; Brenner, Douglas E.; Sherman, Max H.; Dickerhoff, Darryl J.

2003-08-01T23:59:59.000Z

97

Minimizing Energy Losses in Ducts | Department of Energy  

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

Minimizing Energy Losses in Ducts Minimizing Energy Losses in Ducts Minimizing Energy Losses in Ducts June 24, 2012 - 5:45pm Addthis Placing ductwork in conditioned space can help reduce energy losses. | Photo courtesy of ©iStockphoto/SimplyCreativePhotography Placing ductwork in conditioned space can help reduce energy losses. | Photo courtesy of ©iStockphoto/SimplyCreativePhotography In new home construction or in retrofits, proper duct system design is critical. In recent years, energy-saving designs have sought to include ducts and heating systems in the conditioned space. Many existing duct systems lose a lot of energy from leakage and poor insulation, but you can reduce that loss by sealing and insulating your ducts. Existing ducts may also be blocked or may require simple upgrades.

98

Evaluation of a New Ramping Technique for Duct Leakage Testing  

E-Print Network [OSTI]

1 LBNL-61743 Evaluation of a New Ramping Technique for Duct Leakage Testing Iain S. Walker ramping Technique for Duct Leakage Testing Table of contents Introduction......................................................................................................................... 3 DeltaQ ramping testing

99

Potential Flow Calculations of Axisymmetric Ducted Wind Turbines  

E-Print Network [OSTI]

An incompressible potential-flow vortex method has been constructed to analyze the flow field of a ducted

Widnall, Sheila

2009-09-02T23:59:59.000Z

100

Handover Performance of HVAC Duct Based Indoor Wireless Networks  

E-Print Network [OSTI]

Handover Performance of HVAC Duct Based Indoor Wireless Networks A. E. Xhafa, P. Sonthikorn, and O in indoor wireless net- works (IWN) that use heating, ventilation, and air conditioning (HVAC) ducts.e., new call blocking and handover dropping probabilities, of an IWN that uses HVAC ducts are up to 6

Stancil, Daniel D.

Note: This page contains sample records for the topic "duct high velocity" 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

Long Range Passive UHF RFID System Using HVAC Ducts  

E-Print Network [OSTI]

INVITED P A P E R Long Range Passive UHF RFID System Using HVAC Ducts To provide a potential communications channel, HVAC ducts can function as electromagnetic waveguides; a 30-m read range has been-conditioning (HVAC) ducts as a potential communication channel between passive ultrahigh-frequency (UHF) radio

Hochberg, Michael

102

Development of a High Resolution X-Ray Imaging Crystal Spectrometer for Measurement of Ion-Temperature and Rotation-Velocity Profiles in Fusion Energy Research Plasmas  

SciTech Connect (OSTI)

A new imaging high resolution x-ray crystal spectrometer (XCS) has been developed to measure continuous profiles of ion temperature and rotation velocity in fusion plasmas. Following proof-of-principle tests on the Alcator C-Mod tokamak and the NSTX spherical tokamak, and successful testing of a new silicon, pixilated detector with 1 MHz count rate capability per pixel, an imaging XCS is being designed to measure full profiles of Ti and v? on C-Mod. The imaging XCS design has also been adopted for ITER. Ion-temperature uncertainty and minimum measurable rotation velocity are calculated for the C-Mod spectrometer. The affects of x-ray and uclear-radiation background on the measurement uncertainties are calculated to predict performance on ITER.

Hill, K W; Broennimann, Ch; Eikenberry, E F; Ince-Cushman, A; Lee, S G; Rice, J E; Scott, S

2008-01-29T23:59:59.000Z

103

CALIFORNIA ENERGY Homeowners Benefits To Ducts In  

E-Print Network [OSTI]

efficiency is improved through the integrated design, construction, and operation of building systems of Small Commercial HVAC Systems Integrated Design of Commercial Building Ceiling Systems Integrated Design of the Integrated Design of Residential Ducting & Air Flow Systems research project. The reports are a result

104

Reducing Uncertainty for the DeltaQ Duct Leakage Test  

SciTech Connect (OSTI)

The thermal distribution system couples the HVAC components to the building envelope, and shares many properties of the buildings envelope including moisture, conduction and most especially air leakage performance. Duct leakage has a strong influence on air flow rates through building envelopes (usually resulting in much greater flows than those due to natural infiltration) because unbalanced duct air flows and leaks result in building pressurization and depressurization. As a tool to estimate this effect, the DeltaQ duct leakage test has been developed over the past several years as an improvement to existing duct pressurization tests. It focuses on measuring the air leakage flows to outside at operating conditions that are required for envelope infiltration impacts and energy loss calculations for duct systems. The DeltaQ test builds on the standard envelope tightness blower door measurement techniques by repeating the tests with the system air handler off and on. The DeltaQ test requires several assumptions to be made about duct leakage and its interaction with the duct system and building envelope in order to convert the blower door results into duct leakage at system operating conditions. This study examined improvements to the DeltaQ test that account for some of these assumptions using a duct system and building envelope in a test laboratory. The laboratory measurements used a purpose-built test chamber coupled to a duct system typical of forced air systems in US homes. Special duct leaks with controlled air-flow were designed and installed into an airtight duct system. This test apparatus allowed the systematic variation of the duct and envelope leakage and accurate measurement of the duct leakage flows for comparison to DeltaQ test results. This paper will discuss the laboratory test apparatus design, construction and operation, the various analysis techniques applied to the calculation procedure and present estimates of uncertainty in measured duct leakage.

Walker, Iain S.; Sherman, Max H.; Dickerhoff, Darryl J.

2004-05-01T23:59:59.000Z

105

A New Diagnostic for Duct Leakage: DeltaQ  

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

A New Diagnostic for Duct Leakage: DeltaQ A New Diagnostic for Duct Leakage: DeltaQ Speaker(s): Iain Walker Date: February 21, 2002 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Cynthia Tast Duct leakage has been identified as a major contributor to HVAC energy use and building infiltration, particularly in residences. In order to make good estimates of HVAC system energy performance, we need to know how much air leaks between the ducts and outside the building during system operation. Existing methods for determining duct leakage do not perform well due to experimental procedures that produce imprecise results or they require many assumptions to convert measurements into the desired leakage flows. The DeltaQ duct leakage test has been developed by the Energy Performance of Buildings Group at LBNL to determine duct leakage flows by

106

SNM holdup assessment of Los Alamos exhaust ducts. Final report  

SciTech Connect (OSTI)

Fissile material holdup in glovebox and fume hood exhaust ducting has been quantified for all Los Alamos duct systems. Gamma-based, nondestructive measurements were used to quantify holdup. The measurements were performed during three measurement campaigns. The first campaign, Phase I, provided foot-by-foot, semiquantitative measurement data on all ducting. These data were used to identify ducting that required more accurate (quantitative) measurement. Of the 280 duct systems receiving Phase I measurements, 262 indicated less than 50 g of fissile holdup and 19 indicated fissile holdup of 50 or more grams. Seven duct systems were measured in a second campaign, called Series 1, Phase II. Holdup estimates on these ducts ranged from 421 g of {sup 235}U in a duct servicing a shut-down uranium-machining facility to 39 g of {sup 239}Pu in a duct servicing an active plutonium-processing facility. Measurements performed in the second campaign proved excessively laborious, so a third campaign was initiated that used more efficient instrumentation at some sacrifice in measurement quality. Holdup estimates for the 12 duct systems measured during this third campaign ranged from 70 g of {sup 235}U in a duct servicing analytical laboratories to 1 g of {sup 235}U and 1 g of {sup 239}Pu in a duct carrying exhaust air to a remote filter building. These quantitative holdup estimates support the conclusion made at the completion of the Phase I measurements that only ducts servicing shut-down uranium operations contain about 400 g of fissile holdup. No ventilation ducts at Los Alamos contain sufficient fissile material holdup to present a criticality safety concern.

Marshall, R.S.

1994-02-01T23:59:59.000Z

107

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles  

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

2414 2414 1 Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles M. P. Modera, O. Brzozowski ** , F. R. Carrié * , D. J. Dickerhoff, W. W. Delp, W. J. Fisk, R. Levinson, D. Wang Abstract Electricity energy savings potential by eliminating air leakage from ducts in large commercial buildings is on the order of 10 kWh/m 2 per year (1 kWh/ft 2 ). We have tested, in two large commercial buildings, a new technology that simultaneously seals duct leaks and measures effective leakage area of ducts. The technology is based upon injecting a fog of aerosolized sealant particles into a pressurized duct system. In brief, this process involves blocking all of the intentional openings in a duct system (e.g., diffusers). Therefore, when the system is pressurized, the only place for the air carrying the aerosol

108

Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet)  

SciTech Connect (OSTI)

Ductwork installed in unconditioned attics can significantly increase the overall heating and cooling costs of residential buildings. In fact, estimated duct thermal losses for single-family residential buildings with ductwork installed in unconditioned attics range from 10% to 45%. In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes. The BED strategy consists of burying ducts in loose-fill insulation and/or encapsulating them in closed cell polyurethane spray foam (ccSPF) insulation. There are three possible combinations of BED strategies: (1) buried ducts; (2) encapsulated ducts (with ccSPF); and (3) buried and encapsulated ducts. The best solution for each situation depends on the climate, age of the house, and the configuration of the HVAC system and attic. For new construction projects, the team recommends that ducts be both encapsulated and buried as the minimal planning and costs required for this will yield optimal energy savings. The encapsulated/buried duct strategy, which utilizes ccSPF to address condensation concerns, is an approach that was developed specifically for humid climates.

Not Available

2013-11-01T23:59:59.000Z

109

Aerodynamic design considerations for a free-flying ducted propeller  

SciTech Connect (OSTI)

The design philosophy for a free-flying vehicle powered by a ducted propeller is presented from an aerodynamic viewpoint. Airframe design concentrates on duct inlet lip curvature, diffuser angle, and methods of vehicle control. Wind tunnel test results are given to evaluate two inlet designs, two exit designs, and the effect of external appendages such as a camera pod or a forebody. Finally, a simple, analytic method of ducted propeller blade design is presented and the results compared with an existing ducted propeller blade. 14 refs., 28 figs., 2 tabs.

Weir, R.J.

1988-01-01T23:59:59.000Z

110

DOE Challenge Home Technical Training- Ducts in Conditioned Space  

Broader source: Energy.gov [DOE]

A publication of the U.S. Department of Energy Challenge Home program: Design Options for Locating Ducts within Conditioned Space.

111

Flexible metallic seal for transition duct in turbine system  

SciTech Connect (OSTI)

A turbine system is disclosed. In one embodiment, the turbine system includes a transition duct. The transition duct includes an inlet, an outlet, and a passage extending between the inlet and the outlet and defining a longitudinal axis, a radial axis, and a tangential axis. The outlet of the transition duct is offset from the inlet along the longitudinal axis and the tangential axis. The transition duct further includes an interface member for interfacing with a turbine section. The turbine system further includes a flexible metallic seal contacting the interface member to provide a seal between the interface member and the turbine section.

Flanagan, James Scott; LeBegue, Jeffrey Scott; McMahan, Kevin Weston; Dillard, Daniel Jackson; Pentecost, Ronnie Ray

2014-04-22T23:59:59.000Z

112

Performance of high-velocity oxy-fuel-sprayed chromium carbide-nickel chromium coating in an actual boiler environment of a thermal power plant  

SciTech Connect (OSTI)

The present study aims to evaluate the performance of a high-velocity oxy-fuel (HVOF)-sprayed Cr{sub 3}C{sub 2}-NiCr (chromium carbide-nickel chromium) coating on a nickel-based super-alloy in an actual industrial environment of a coal-fired boiler, with the objective to protect the boiler super-heater and reheater tubes from hot corrosion. The tests were performed in the platen super heater zone of a coal-fired boiler for 1,000 h at 900 degrees C under cyclic conditions. The Cr{sub 3}C{sub 2}-NiCr coating imparted the necessary protection to the nickel-based super alloy in the given environment. The dense and flat splat structure of the coating, and the formation of oxides of chromium and nickel and their spinels, might have protected the substrate super alloy from the inward permeation of corrosive species.

Sidhu, T.S.; Prakash, S.; Agrawal, R.D. [Industrial Technology Institute, Roorkee (India)

2007-09-15T23:59:59.000Z

113

Duct Systems in Large Commercial Buildings: Physical  

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

Duct Systems in Large Commercial Buildings: Physical Characterization, Air Leakage, and Heat Conduction Gains William 1. Fisk, Woody Delp, Rick Diamond, Darryl Dickerhoff, Ronnen Levinson, Mark Modera, Matty Nematollahi, Duo Wang Environmental Energy Technologies Division Indoor Environment Department Lawrence Berkeley National Laboratory Berkeley CA 94720 March 30, 1999 This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Building Technology and Community Systems, of the US Department of Energy under Contract No. DE-AC03-76SF00098 and by the California Institute For Energy Efficiency. LBNL-42339

114

CFD simulation of leak in residential HVAC ducts  

Science Journals Connector (OSTI)

A three-dimensional computational fluid dynamics model was used to simulate fluid flow in a duct and its simulated leaks with six different air leak geometries placed respectively on its periphery. The k–? turbulence model for high Reynolds numbers flows was used for that purpose and the Reynolds numbers were varied to simulate a variety of flow conditions between 27,000 and 82,000. The computer code was used to produce pressure drop data and leak flow rates across the holes necessary to compute the pressure loss coefficients, as well as to produce flow field and static pressure plots that offer insight into the physics of the flow field. The flow coefficient and pressure exponent (C and n) were found for different leak geometries by curve fitting the pressure and leak flow data derived from CFD simulations and were compared to available data in the literature.

Samir Moujaes; Radhika Gundavelli

2012-01-01T23:59:59.000Z

115

Compression effects on pressure loss in flexible HVAC ducts  

SciTech Connect (OSTI)

A study was conducted to evaluate the effect of compression on pressure drop in flexible, spiral wire helix core ducts used in residential and light commercial applications. Ducts of 6 inches, 8 inches and 10 inches (150, 200 and 250 mm) nominal diameters were tested under different compression configurations following ASHRAE Standard 120-1999--Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings. The results showed that the available published references tend to underestimate the effects of compression. The study demonstrated that moderate compression in flexible ducts, typical of that often seen in field installations, could increase the pressure drop by a factor of four, while further compression could increase the pressure drop by factors close to ten. The results proved that the pressure drop correction factor for compressed ducts cannot be independent of the duct size, as suggested by ASHRAE Fundamentals, and therefore a new relationship was developed for better quantification of the pressure drop in flexible ducts. This study also suggests potential improvements to ASHRAE Standard 120-1999 and provides new data for duct design.

Abushakra, Bass; Walker, Iain S.; Sherman, Max H.

2002-07-01T23:59:59.000Z

116

E-Print Network 3.0 - advanced bile duct Sample Search Results  

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

the bile ducts, reabsorption in the ileum... inhibitors (9, 50). Bile duct ligated and LCA induced cholestasis animal models (8), and human cholestatic... Regulation of...

117

E-Print Network 3.0 - air duct work Sample Search Results  

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

Duct Sealants Published in Proc. RILEM 3rd Summary: residential buildings 1. The air distribution systems require some sort of seal between duct sections... -40% of the...

118

List of Duct/Air sealing Incentives | Open Energy Information  

Open Energy Info (EERE)

Duct/Air sealing Incentives Duct/Air sealing Incentives Jump to: navigation, search The following contains the list of 580 Duct/Air sealing Incentives. CSV (rows 1-500) CSV (rows 501-580) Incentive Incentive Type Place Applicable Sector Eligible Technologies Active AEP (Central and North) - Residential Energy Efficiency Programs (Texas) Utility Rebate Program Texas Construction Installer/Contractor Multi-Family Residential Building Insulation Caulking/Weather-stripping Comprehensive Measures/Whole Building Custom/Others pending approval Duct/Air sealing Unspecified technologies Yes AEP (Central and SWEPCO) - Coolsaver A/C Tune Up (Texas) Utility Rebate Program Texas Commercial Installer/Contractor Residential Central Air conditioners Custom/Others pending approval Duct/Air sealing

119

Duct injection technology prototype development: Nozzle development Subtask 4.1, Atomizer specifications for duct injection technology. Topical report 8  

SciTech Connect (OSTI)

Babcock & Wilcox has conducted a program to identify atomizers appropriate for successful in-duct injection of humidification water and lime slurries. The purpose of this program was to identify and quantify atomizer spray and performance criteria that affect the operations and reliability of the in-duct SO{sub 2} removal process, and compare commercially available atomizers to these criteria.

Not Available

1992-02-01T23:59:59.000Z

120

Use of Statistical Approach to Design an Optimal Duct System for On-demand Industrial Exhaust Ventilation  

E-Print Network [OSTI]

and noise generated by moving air. 0.0 2.0 4.0 6.0 8.0 10.0 12.0 14.0 16.0 1000 2000 3000 4000 5000 6000 7000 8000 Losses (" w.c. /100 ft) versus Air Velocity (FPM) Fig 1 Fig. 1: friction losses in a circular 6? duct in galva- nized....0 14.0 16.0 1000 2000 3000 4000 5000 6000 7000 8000 Losses?("?w.c.?/100?ft)?versus Air?Velocity?(FPM) ?Range of air velocities = 6500/3,800 = 1.86 ?Maximal practical speed 6,500 FPM ?Minimum transport velocity, for example 3,800 FPM...

Litomisky, A.

2010-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Development of a new duct leakage test: DeltaQ  

SciTech Connect (OSTI)

Duct leakage is a key factor in determining energy losses from forced air heating and cooling systems. Several studies (Francisco and Palmiter 1997 and 1999, Andrews et al. 1998, and Siegel et al. 2001) have shown that the duct system efficiency cannot be reliably determined without good estimates of duct leakage. Specifically, for energy calculations, it is the duct leakage air flow to outside at operating conditions that is required. Existing test methods either precisely measure the size of leaks (but not the flow through them at operating conditions), or measure these flows with insufficient accuracy. The DeltaQ duct leakage test method was developed to provide improved estimates of duct leakage during system operation. In this study we developed the analytical calculation methods and the test procedures used in the DeltaQ test. As part of the development process, we have estimated uncertainties in the test method (both analytically and based on field data) and designed automated test procedures to increase accuracy and reduce the contributions of operator errors in performing field tests. In addition, the test has been evaluated in over 100 houses by several research teams to show that it can be used in a wide range of houses and to aid in finding limits or problems in field applications. The test procedure is currently being considered by ASTM as an update of an existing duct leakage standard.

Walker,I.S.; Sherman,M.H.; Wempen, J.; Wang, D.; McWilliams, J.A.; Dickerhoff, D.J.

2001-08-01T23:59:59.000Z

122

Duct Leakage Impacts on VAV System Performance in Large Commercial  

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

Duct Leakage Impacts on VAV System Performance in Large Commercial Duct Leakage Impacts on VAV System Performance in Large Commercial Buildings Title Duct Leakage Impacts on VAV System Performance in Large Commercial Buildings Publication Type Report LBNL Report Number LBNL-53605 Year of Publication 2003 Authors Wray, Craig P., and Nance Matson Abstract The purpose of this study is to evaluate the variability of duct leakage impacts on air distribution system performance for typical large commercial buildings in California. Specifically, a hybrid DOE-2/TRNSYS sequential simulation approach was used to model the energy use of a low-pressure terminal-reheat variable-air-volume (VAV) HVAC system with six duct leakage configurations (tight to leaky) in nine prototypical large office buildings (representing three construction eras in three California climates where these types of buildings are common). Combined fan power for the variable-speed-controlled supply and return fans at design conditions was assumed to be 0.8 W/cfm. The VAV system that we simulated had perfectly insulated ducts, and maintained constant static pressure in the ducts upstream of the VAV boxes and a constant supply air temperature at the air-handler. Further evaluations of duct leakage impacts should be carried out in the future after methodologies are developed to deal with duct surface heat transfer effects, to deal with airflows entering VAV boxes from ceiling return plenums (e.g., to model parallel fan-powered VAV boxes), and to deal with static pressure reset and supply air temperature reset strategies.

123

Development of a New Duct leakage Test: Delta Q  

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

Development of a New Duct leakage Test: Delta Q Development of a New Duct leakage Test: Delta Q Title Development of a New Duct leakage Test: Delta Q Publication Type Report LBNL Report Number LBNL-47308 Year of Publication 2001 Authors Walker, Iain S., Max H. Sherman, J. Wempen, Duo Wang, Jennifer A. McWilliams, and Darryl J. Dickerhoff Abstract Several studies (Francisco and Palmiter 1997 and 1999, Andrews et al. 1998, and Siegel et al. 2001) have shown that the duct system efficiency cannot be reliably determined without good estimates of duct leakage. Specifically, for energy calculations, it is the duct leakage air flow to outside at operating conditions that is required. Existing test methods either precisely measure the size of leaks (but not the flow through them at operating conditions), or measure these flows with insufficient accuracy. The DeltaQ duct leakage test method was developed to provide improved estimates of duct leakage during system operation. In this study we developed the analytical calculation methods and the test procedures used in the DeltaQ test. As part of the development process, we have estimated uncertainties in the test method (both analytically and based on field data) and designed automated test procedures to increase accuracy and reduce the contributions of operator errors in performing field tests. In addition, the test has been evaluated in over 100 houses by several research teams to show that it can be used in a wide range of houses and to aid in finding limits or problems in field applications. The test procedure is currently being considered by ASTM as an update of an existing duct leakage standard

124

Evaluation of friction loss in flexible and galvanized duct  

E-Print Network [OSTI]

for Friction Loss in Straight Runs of Duct (a'Ipha=0. 10). 21 Ill Static Pressure Data Converted to Equivalent Lengths. 23 IV Duncan's Multiple Range Test of Variability for Equivalent Lengths of 90 Degree Elbows (al pha=0. IO). 26 V Student t Test... because of the higher Friction losses obtained in the first 1. 5 hours of testing. The Investigators concluded that when flex'ible duct was properly installed the Friction losses compared reasonably well with the friction losses in galvanized duct. i...

Zimmermann, Carlos Michael Alberto

2012-06-07T23:59:59.000Z

125

Sensitivity of forced air distribution system efficiency to climate, duct location, air leakage and insulation  

E-Print Network [OSTI]

Location, Air Leakage and Insulation Iain S. Walker Energy4 Duct Insulation, Location and Leakageinsulation

Walker, Iain

2001-01-01T23:59:59.000Z

126

Method and apparatus for duct sealing using a clog-resistant insertable injector  

DOE Patents [OSTI]

A method for forming a duct access region through one side of a previously installed air duct, wherein the air duct has an air flow with an air flow direction by inserting an aerosol injector into a previously installed air duct through the access region. The aerosol injector includes a liquid tube having a liquid tube orifice for ejecting a liquid to be atomized; and a propellant cap. The method is accomplished by aligning the aerosol injector with the direction of air flow in the duct; activating an air flow within the duct; and spraying a sealant through the aerosol injector to seal the duct in the direction of the air flow.

Wang, Duo (Albany, CA); Modera, Mark P. (Piedmont, CA)

2010-12-14T23:59:59.000Z

127

Unitaxial constant velocity microactuator  

DOE Patents [OSTI]

A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment is disclosed. The mechanism includes a flexible coupling having a bore therethrough, and two clamp/pusher assemblies mounted in axial ends of the coupling. The clamp/pusher assemblies are energized by voltage-operated piezoelectrics therewithin to operatively engage the shaft and coupling causing the shaft to move along its rotational axis through the bore. The microactuator is capable of repeatably positioning to sub-nanometer accuracy while affording a scan range in excess of 5 centimeters. Moreover, the microactuator generates smooth, constant velocity motion profiles while producing a drive thrust of greater than 10 pounds. The system is remotely controlled and piezoelectrically driven, hence minimal thermal loading, vibrational excitation, or outgassing is introduced to the operating environment. 10 figs.

McIntyre, T.J.

1994-06-07T23:59:59.000Z

128

Improving Building Envelope and Duct Airtightness of US Dwellings The  

E-Print Network [OSTI]

the building envelope and duct system airtightness of US single-family detached homes, manufactured homes, and multi-family homes, before and after energy retrofits. These data are part of the Residential Improving Building Envelope

129

DOE Zero Energy Ready Home Webinar: Ducts in Conditioned Space  

Broader source: Energy.gov [DOE]

DOE Challenge Home is a blueprint for zero energy ready homes.  When we make that statement – it’s impossible to justify huge thermal losses from ducts in unconditioned spaces.  That’s why one of...

130

Ducts Sealing Using Injected Spray Sealant, Raleigh, North Carolina...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

sealed by hand with mastic. Air handlers were sealed with foil tape or mastic. Duct boots were sealed to floors and ceilings with foil tape or mastic. Lessons Learned *...

131

DOE Zero Energy Ready Home Webinar: Ducts in Conditioned Space...  

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

America research program its and partners have worked out the kinks on a toolkit of duct design strategies. In this session you'll learn the pros and cons of these strategies so...

132

Clutter-Based Evaporation Duct Estimation Performance Using Meteorological Statistics  

E-Print Network [OSTI]

of California, Mediterranean, Persian Gulf, and Coast of Brazil. The effects of the radar frequency (S, C, and X, such as the Mediterranean, Persian Gulf, East China Sea, and California Coast, atmospheric ducts are common occurrences

Gerstoft, Peter

133

Economizer Applications in Dual-Duct Air-Handling Units  

E-Print Network [OSTI]

This paper provides analytical tools and engineering methods to evaluate the feasibility of the economizer for dual-duct air-handling units. The results show that the economizer decreases cooling energy consumption without heating energy penalties...

Joo, I.; Liu, M.

2002-01-01T23:59:59.000Z

134

New and Underutilized Technology: Duct Sealants | Department of Energy  

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

Duct Sealants Duct Sealants New and Underutilized Technology: Duct Sealants October 8, 2013 - 3:01pm Addthis The following information outlines key deployment considerations for duct sealants within the Federal sector. Benefits Aerosol sealant is injected into the ductwork to seal leaks. This can save energy and costs associated with heating, cooling, and fan operation depending on building type. Application Condensing boilers are appropriate for most building applications. Key Factors for Deployment Sealing ductwork should be a standard energy conservation measure evaluated during design, construction, major renovation, or other HVAC projects. Ranking Criteria Federal energy savings, cost-effectiveness, and probability of success are ranked 0-5 with 0 representing the lowest ranking and 5 representing the

135

BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.  

SciTech Connect (OSTI)

This is a series of six guides intended to provide a working knowledge of residential heating and cooling duct systems, an understanding of the major issues concerning efficiency, comfort, health, and safety, and practical tips on installation and repair of duct systems. These guides are intended for use by contractors, system designers, advanced technicians, and other HVAC professionals. The first two guides are also intended to be accessible to the general reader.

ANDREWS,J.

2001-01-01T23:59:59.000Z

136

Measure Guideline: Buried and/or Encapsulated Ducts  

SciTech Connect (OSTI)

Buried and/or encapsulated ducts (BEDs) are a class of advanced, energy-efficiency strategies intended to address the significant ductwork thermal losses associated with ducts installed in unconditioned attics. BEDs are ducts installed in unconditioned attics that are covered in loose-fill insulation and/or encapsulated in closed cell polyurethane spray foam insulation. This Measure Guideline covers the technical aspects of BEDs as well as the advantages, disadvantages, and risks of BEDs compared to other alternative strategies. This guideline also provides detailed guidance on installation of BEDs strategies in new and existing homes through step-by-step installation procedures. This Building America Measure Guideline synthesizes previously published research on BEDs and provides practical information to builders, contractors, homeowners, policy analysts, building professions, and building scientists. Some of the procedures presented here, however, require specialized equipment or expertise. In addition, some alterations to duct systems may require a specialized license. Persons implementing duct system improvements should not go beyond their expertise or qualifications. This guideline provides valuable information for a building industry that has struggled to address ductwork thermal losses in new and existing homes. As building codes strengthen requirements for duct air sealing and insulation, flexibility is needed to address energy efficiency goals. While ductwork in conditioned spaces has been promoted as the panacea for addressing ductwork thermal losses, BEDs installations approach - and sometimes exceed - the performance of ductwork in conditioned spaces.

Shapiro, C.; Zoeller, W.; Mantha, P.

2013-08-01T23:59:59.000Z

137

Integrating ducts into the conditioned space: Successes and challenges  

SciTech Connect (OSTI)

In residential and light commercial construction in the United States, heating and cooling ducts are often located outside the thermal or pressure boundary of the conditioned space. This location is selected for aesthetic and space requirement reasons. Typical duct locations include attics, above dropped ceilings, crawlspaces, and attached garages. A wide body of literature has found that distribution system conduction and air leakage can cause 30-40% energy losses before cooling and heating air reaches the conditioned space. Recent innovative attempts at locating ducts in the conditioned space have had mixed results in terms of improving duct efficiency. Some of these strategies include cathedralizing attics (sealing and insulating at the attic roofline) and locating ducts in interstitial spaces. This paper reviews modeling studies that suggest substantial savings could be realized from these strategies and presents field measurements which reveal that construction planning and execution errors can prevent these strategies from being widely applied or from being effective when they are applied. These types of problems will need to be overcome for effective integration of ducts into the conditioned space.

Siegel, Jeffrey; Walker, Iain

2004-05-01T23:59:59.000Z

138

The Effects of Magnetizer Velocity on Magnetic Flux Leakage Signals  

Science Journals Connector (OSTI)

In many magnetic flux leakage applications, the nondestructive inspection constraints suggest the use of high inspection velocities. However, high inspection velocities can compromise the ability to detect and ch...

J. Bruce Nestleroth; Richard J. Davis

1993-01-01T23:59:59.000Z

139

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant  

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

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles Title Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles Publication Type Journal Article LBNL Report Number LBNL-42414 Year of Publication 2001 Authors Modera, Mark P., Olivier Brzozowski, François Rémi Carrié, Darryl J. Dickerhoff, William W. Delp, William J. Fisk, Ronnen M. Levinson, and Duo Wang Journal Energy & Buildings Volume 34 Start Page Chapter Pagination 705-714 Abstract Electricity energy savings potential by eliminating air leakage from ducts in large commercial buildings is on the order of 10 kWh/m2 per year (1 kWh/ft2). We have tested, in two large commercial buildings, a new technology that simultaneously seals duct leaks and measures effective leakage area of ducts. The technology is based upon injecting a fog of aerosolized sealant particles into a pressurized duct system. In brief, this process involves blocking all of the intentional openings in a duct system (e.g., diffusers). Therefore, when the system is pressurized, the only place for the air carrying the aerosol particles to exit the system is through the leaks. The key to the technology is to keep the particles suspended within the airstream until they reach the leaks, and then to have them leave the airstream and deposit on the leak sites. The principal finding from this field study was that the aerosol technology is capable of sealing the leaks in a large commercial building duct system within a reasonable time frame. In the first building, 66% of the leakage area was sealed within 2.5 hours of injection, and in the second building 86% of the leakage area was sealed within 5 hours. We also found that the aerosol could be blown through the VAV boxes in the second building without impacting their calibrations or performance. Some remaining questions are (1) how to achieve sealing rates comparable to those experienced in smaller residential systems; and (2) what tightness level these ducts systems can be brought to by means of aerosol sealing.

140

LAB #2 Escape Velocity  

E-Print Network [OSTI]

(6) The above calculations ignore the effect of air resistance on the object. We assume that resistance is proportional to velocity and decreases with increasing

2007-02-02T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Hot-film anemometer measurements in adiabatic two-phase flow through a vertical duct  

SciTech Connect (OSTI)

A hot-film anemometer (HFA) probe was used to obtain local measurements of void fraction and bubble frequency in a vertically oriented, high aspect ratio duct containing R-134a under selected adiabatic two-phase flow conditions. Data were obtained along a narrow dimension scan over the range 0.03 {le} {bar Z} {le} 0.80, where {bar Z} is the distance from the wall normalized with the duct spacing dimension. The void fraction profiles displayed large gradients in the near-wall regions and broad maxima near the duct centerline. The trends in the bubble frequency data generally follow those for the local void fraction data. However, the relatively large number of bubbles at higher pressure implies a larger magnitude of the interfacial area concentration, for the same cross-sectional average void fraction. For the two annular flow conditions tested, analysis of the HFA output voltage signal enabled identification of three distinct regions of the flow field; liquid film with dispersed bubbles, interfacial waves, and continuous vapor with dispersed droplets.

Trabold, T.A.; Moore, W.E.; Morris, W.O. [Lockheed Martin Corp., Schenectady, NY (United States)

1997-06-01T23:59:59.000Z

142

Fiberglass Duct Cleaning Safe Work Practices Duct Cleaning -Prior to reaching a decision to clean a duct, an investigation of possible  

E-Print Network [OSTI]

practices for cleaning ducts: · Contact vacuum - Uses a portable vacuum with a HEPA filter. Direct contact filter (HEPA) vacuum or use vacuum equipment that exhausts particles safely outside of the building-insulating any access holes that were made or used so they are airtight. 7. All components of the HVAC system

de Lijser, Peter

143

The Effects of Flux Leakage Magnetizer Velocity on Volumetric Defect Signals  

Science Journals Connector (OSTI)

The inspection requirements of the hundreds of thousands of miles of pipeline worldwide necessitates the use of high inspection velocities. Unfortunately, high inspection velocities can compromise the ability ...

Richard J. Davis; J. Bruce Nestleroth

1995-01-01T23:59:59.000Z

144

Measure Guideline: Optimizing the Configuration of Flexible Duct Junction Boxes  

SciTech Connect (OSTI)

This measure guideline offers additional recommendations to heating, ventilation, and air conditioning (HVAC) system designers for optimizing flexible duct, constant-volume HVAC systems using junction boxes within Air Conditioning Contractors of America (ACCA) Manual D guidance (Rutkowski, H. Manual D -- Residential Duct Systems, 3rd edition, Version 1.00. Arlington, VA: Air Conditioning Contractors of America, 2009.). IBACOS used computational fluid dynamics software to explore and develop guidance to better control the airflow effects of factors that may impact pressure losses within junction boxes among various design configurations (Beach, R., Prahl, D., and Lange, R. CFD Analysis of Flexible Duct Junction Box Design. Golden, CO: National Renewable Energy Laboratory, submitted for publication 2013). These recommendations can help to ensure that a system aligns more closely with the design and the occupants' comfort expectations. Specifically, the recommendations described herein show how to configure a rectangular box with four outlets, a triangular box with three outlets, metal wyes with two outlets, and multiple configurations for more than four outlets. Designers of HVAC systems, contractors who are fabricating junction boxes on site, and anyone using the ACCA Manual D process for sizing duct runs will find this measure guideline invaluable for more accurately minimizing pressure losses when using junction boxes with flexible ducts.

Beach, R.; Burdick, A.

2014-03-01T23:59:59.000Z

145

Duct Chase Sprinkler Replacement Project (4594), 5/31/2012  

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

Duct Chase Sprinkler Replacement Project (4594) Duct Chase Sprinkler Replacement Project (4594) Program or Field Office: Y-12 Site Office Location(s) (Citv/County/State): Oak Ridge, Anderson County, Tennessee Proposed Action Description: The proposed action is provide replacement of corroded and aged sprinkler heads in the plenum duct chases. Categorical Exclusion(s) Applied: 81.3- Routine maintenance Submit by E-mail For the complete DOE National Environmental Policy Act regulations regarding categorical exclusions, including the full text of each categorical exclusion, see Subpart D of I 0 CFR Part 1021. Regulatory Requirements in 10 CFR 1021.410(b): (See full text in regulation) [{Jrhe proposal fits within a class of actions that is listed in Appendix A orB to 10 CFR Part 1021, Subpart D.

146

Our Dog Discovered Our Ducts Have Cats | Department of Energy  

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

Our Dog Discovered Our Ducts Have Cats Our Dog Discovered Our Ducts Have Cats Our Dog Discovered Our Ducts Have Cats January 18, 2010 - 7:30am Addthis Amy Foster Parish Our Australian Shepherd, Matilda, is not the fiercest of protectors. In fact, she's a total coward. She flees in horror from strangers and is terrorized by the vacuum cleaner; even a pair of shoes left in an unaccustomed place can strike fear in her heart. But let her see a cat in the back yard, or even catch the scent of one on a walk, and my cowardly Matilda becomes a superhero ready to save me from the feline menace. So when Matilda started pulling her superhero routine in the house a few weeks ago, running from room to room and growling at the air registers in the floor, I was immediately suspicious. We don't own a cat, and Matilda's

147

CASE STUDY OF DUCT RETROFIT OF A 1985 HOME AND GUIDELINES FOR ATTIC AND CRAWL SPACE DUCT SEALING  

SciTech Connect (OSTI)

The U.S. Department of Energy (DOE) is fully committed to research for developing the information and capabilities necessary to provide cost-effective residential retrofits yielding 50% energy savings within the next several years. Heating, ventilation, and air conditioning (HVAC) is the biggest energy end use in the residential sector, and a significant amount of energy can be wasted through leaky ductwork in unconditioned spaces such as attics and crawl spaces. A detailed duct sealing case study is presented for one house along with nine brief descriptions of other duct retrofits completed in the mixed-humid climate. Costs and estimated energy savings are reported for most of the ten houses. Costs for the retrofits ranged from $0.92/ft2 to $1.80/ft2 of living space and estimated yearly energy cost savings due to the duct retrofits range from 1.8% to 18.5%. Lessons learned and duct sealing guidelines based on these ten houses, as well as close work with the HVAC industry in the mixed-humid climate of East Tennessee, northern Georgia, and south-central Kentucky are presented. It is hoped that the lessons learned and guidelines will influence local HVAC contractors, energy auditors, and homeowners when diagnosing or repairing HVAC duct leakage and will be useful for steering DOE s future research in this area.

Boudreaux, Philip R [ORNL; Christian, Jeffrey E [ORNL; Jackson, Roderick K [ORNL

2012-01-01T23:59:59.000Z

148

Radial velocities of population II binary stars. II  

E-Print Network [OSTI]

Here we publish the second list of radial velocities for 91 Hipparcos stars, mostly high transverse velocity binaries without previous radial velocity measurements. The measurements of radial velocities are done with a CORAVEL-type radial velocity spectrometer with an accuracy better than 1 km/s. We also present the information on eight new radial velocity variables - HD 29696, HD 117466AB, BD +28 4035AB, BD +30 2129A, BD +39 1828AB, BD +69 230A, BD +82 565A and TYC 2267-1300-1 - found from our measurements. Two stars (HD 27961AB and HD 75632AB) are suspected as possible radial velocity variables.

A. Bartkevicius; J. Sperauskas

2006-01-10T23:59:59.000Z

149

ARM - Measurement - Vertical velocity  

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

govMeasurementsVertical velocity govMeasurementsVertical velocity ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Vertical velocity The component of the velocity vector, along the local vertical. Categories Atmospheric State Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System KAZR : Ka ARM Zenith Radar MMCR : Millimeter Wavelength Cloud Radar SODAR : Mini Sound Detection and Ranging

150

Vertical Velocity Focus Group  

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

Velocity Focus Group Velocity Focus Group ARM 2008 Science Team Meeting Norfolk, VA March 10-14 Background Vertical velocity measurements have been at the top of the priority list of the cloud modeling community for some time. Doppler measurements from ARM profiling radars operating at 915-MHz, 35-GHz and 94-GHz have been largely unexploited. The purpose of this new focus group is to develop vertical velocity ARM products suitable for modelers. ARM response to their request has been slow. Most ARM instruments are suitable for cloud observations and have limited capabilities in precipitation Using ARM datasets for evaluating and improving cloud parameterization in global climate models (GCMs) is not straightforward, due to gigantic scale mismatches. Consider this... Looking only vertically drastically limits opportunities

151

Bundle duct interaction studies for fuel assemblies. [LMFBR  

SciTech Connect (OSTI)

It is known that the wire-wrapped rods and duct in an LMFBR are undergoing a gradual structural distortion from the initially uniform geometry under the combined effects of thermal expansion and irradiation induced swelling and creep. These deformations have a significant effect on flow characteristics, thus causing changes in thermal behavior such as cladding temperature and temperature distribution within a bundle. The temperature distribution may further enhance or retard irradiation induced deformation of the bundle. This report summarizes the results of the continuing effort in investigating the bundle-duct interaction, focusing on the need for the large development plant.

Hsia, H.T.S.; Kaplan, S.

1981-06-01T23:59:59.000Z

152

Advanced Strategy Guideline: Air Distribution Basics and Duct Design  

SciTech Connect (OSTI)

This report discusses considerations for designing an air distribution system for an energy efficient house that requires less air volume to condition the space. Considering the HVAC system early in the design process will allow adequate space for equipment and ductwork and can result in cost savings. Principles discussed that will maximize occupant comfort include delivery of the proper amount of conditioned air for appropriate temperature mixing and uniformity without drafts, minimization of system noise, the impacts of pressure loss, efficient return air duct design, and supply air outlet placement, as well as duct layout, materials, and sizing.

Burdick, A.

2011-12-01T23:59:59.000Z

153

TOPIC Brief BUILDING TECHNOLOGIES PROGRAM Residential Duct Insulation and Sealing Requirements TOPIC BRIEF 1  

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

Duct Insulation and Sealing Requirements TOPIC BRIEF 1 Duct Insulation and Sealing Requirements TOPIC BRIEF 1 Residential Duct Insulation and Sealing Requirements Studies show that duct air leakage results in major energy losses. A ll versions of the International Energy Conservation Code (IECC) require ducts, air handlers, filter boxes, and air cavities used as ducts to be sealed, and reference Chapter 16 of the International Residential Code for details on air sealing. This sealing is required on all ducts and other air distribution components regardless of whether they are located inside or outside the conditioned living space. For single-family homes and other low-rise residential buildings, the 2009 and 2012 IECC have duct insulation and sealing requirements in Section 403.2. Both codes require insulation

154

Integration of HVAC System Design with Simplified Duct Distribution- Building America Top Innovation  

Broader source: Energy.gov [DOE]

This Building America Innovations profile describes work by Building America research teams who field tested simplified duct designs in hundreds of homes, confirming the performance of short compact duct runs, with supply registers near interior walls.

155

Sensitivity of Forced Air Distribution System Efficiency to Climate, Duct Location, Air Leakage and Insulation  

E-Print Network [OSTI]

. 94720 This work was supported by the Assistant Secretary for Energy Efficiency and Renewable Energy......................................................... 5 Figure 4. New plastic flexible ducts in an attic.......................................................................... 6 Figure 5. Combination of plastic insulated flexible duct and added open face glass fiber

156

Variable Speed Drive (VSD) Applications in Dual-Duct Constant Volume Systems  

E-Print Network [OSTI]

Models have been developed for static pressure and potential supply fan energy savings by using variable speed drive (VSD) in dual-duct constant volume systems. Experiments have been performed using a full size dual-duct constant volume system...

Joo, I.; Liu, M.; Conger, K.; Wang, G.

2002-01-01T23:59:59.000Z

157

Measure Guideline: Summary of Interior Ducts in New Construction, Including an Efficient, Affordable Method to Install Fur-Down Interior Ducts  

SciTech Connect (OSTI)

This document illustrates guidelines for the efficient installation of interior duct systems in new housing, including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. This document illustrates guidelines for the efficient installation of interior duct systems in new housing. Interior ducts result from bringing the duct work inside a home's thermal and air barrier. Architects, designers, builders, and new home buyers should thoroughly investigate any opportunity for energy savings that is as easy to implement during construction, such as the opportunity to construct interior duct work. In addition to enhanced energy efficiency, interior ductwork results in other important advantages, such as improved indoor air quality, increased system durability and increased homeowner comfort. While the advantages of well-designed and constructed interior duct systems are recognized, the implementation of this approach has not gained a significant market acceptance. This guideline describes a variety of methods to create interior ducts including the fur-up chase method, the fur-down chase method, and interior ducts positioned in sealed attics or sealed crawl spaces. As communication of the intent of an interior duct system, and collaboration on its construction are paramount to success, this guideline details the critical design, planning, construction, inspection, and verification steps that must be taken. Involved in this process are individuals from the design team; sales/marketing team; and mechanical, insulation, plumbing, electrical, framing, drywall and solar contractors.

Beal, D.; McIlvaine , J.; Fonorow, K.; Martin, E.

2011-11-01T23:59:59.000Z

158

Statistical maritime radar duct estimation using hybrid genetic algorithm-Markov chain Monte Carlo method  

E-Print Network [OSTI]

radar ducts over the Persian gulf,” Journal of Appliedas the Mediter- ranean, Persian Gulf, East China Sea, and

Yardim, Caglar; Gerstoft, Peter; Hodgkiss, William S.

2007-01-01T23:59:59.000Z

159

Duct Systems in large commercial buildings: Physical characterization, air leakage, and heat conduction gains  

E-Print Network [OSTI]

connected to a variable frequency drive. + Static pressureSpeed as Frequency of Variable-speed Drive (hz) All Ducts ~

Fisk, W.J.

2011-01-01T23:59:59.000Z

160

Velocity of the electric arc in a plasmatron discharge chamber  

Science Journals Connector (OSTI)

An experimental investigation of the velocity of a high-current arc with air injection in the discharge chamber of a coaxial sectioned plasmatron is described. The experiments showed that the velocity of the c...

A. S. Shaboltas

1969-09-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Velocity distributions in clusters of galaxies  

E-Print Network [OSTI]

We employ a high-resolution dissipationless N-body simulation of a galaxy cluster to investigate the impact of subhalo selection on the resulting velocity distributions. Applying a lower limit on the present bound mass of subhalos leads to high subhalo velocity dispersions compared to the diffuse dark matter (positive velocity bias) and to a considerable deviation from a Gaussian velocity distribution (kurtosis -0.6). However, if subhalos are required to exceed a minimal mass before accretion onto the host, the velocity bias becomes negligible and the velocity distribution is close to Gaussian (kurtosis -0.15). Recently it has been shown that the latter criterion results in subhalo samples that agree well with the observed number-density profiles of galaxies in clusters. Therefore we argue that the velocity distributions of galaxies in clusters are essentially un-biased. The comparison of the galaxy velocity distribution and the sound speed, derived from scaling relations of X-ray observations, results in an average Mach number of 1.24. Altogether 65% of the galaxies move supersonically and 8% have Mach numbers larger than 2 with respect to the intra cluster gas.

A. Faltenbacher; J. Diemand

2006-02-08T23:59:59.000Z

162

RF propagation in an HVAC duct system: impulse response characteristics of the channel  

E-Print Network [OSTI]

RF propagation in an HVAC duct system: impulse response characteristics of the channel Pavel V, the heating, ventilation, and air conditioning (HVAC) duct system in buildings is a complex network of hollow at RF and microwave frequencies of com- mon interest. HVAC ducts can be used as a wireless communication

Stancil, Daniel D.

163

Static Pressure Losses in 6, 8, and 10-inch Non-Metallic Flexible Ducts  

E-Print Network [OSTI]

This study measured airflow static pressure losses through non-metallic flexible ducts in compliance with ASHRAE Standard 120-1999, Methods of Testing to Determine Flow Resistance of HVAC Air Ducts and Fittings (ASHRAE 1999). Duct sizes of 6, 8...

Weaver, K.; Culp, C.

2006-01-01T23:59:59.000Z

164

Improving Control of a Dual-Duct Single-Fan Variable Air Volume Systems  

E-Print Network [OSTI]

cold and hot air duct static pressure set points is presented. The paper also explores the interactions between the cold and hot deck temperatures and duct static pressures, and discusses the impact of non-ideal deck temperature settings on duct static...

Wei, G.; Martinez, J.; Minihan, T.; Brundidge, T.; Claridge, D. E.; Turner, W. D.

2003-01-01T23:59:59.000Z

165

CALIFORNIA ENERGY Residential Duct Placement Field Test and  

E-Print Network [OSTI]

efficiency is improved through the integrated design, construction, and operation of building systems of Small Commercial HVAC Systems Integrated Design of Commercial Building Ceiling Systems Integrated Design of the Integrated Design of Residential Ducting & Air Flow Systems research project. The reports are a result

166

Inertial particle resuspension in a turbulent, square duct flow  

Science Journals Connector (OSTI)

Particle resuspension in a turbulent square duct flow is studied using large eddy simulation combined with Lagrangian particle tracking under conditions of one-way coupling with the particle equation of motion solved with the Stokes drag lift buoyancy and gravitational force terms. Here resuspension is taken to mean the movement of particles in close proximity to the duct walls back in to the mainstream of the flow. The flow considered has a bulk Re = 250 ? k with four particle sizes ranging from 5 to 500 ? ? m examined. The results demonstrate that turbulence-driven secondary flows within the duct play an important role in the resuspension process. In the vertical direction resuspension is promoted by the drag force arising from the secondary flows which is balanced by the gravitational force with this effect increasing with decreasing particle size. In the horizontal direction particle resuspension is promoted by the particle’s inertial force with this effect increasing with increasing particle size. For resuspension in both directions the drag force dominates small particle resuspension while for large particles the lift force is also a contributing factor. In the horizontal direction the effect of the lift force varies with the direction of the secondary flow and becomes more significant when a particle is large or close to the duct wall. The influence of the lift force is also larger in the vertical than in the horizontal direction due to the effects of gravity.

J. Yao; M. Fairweather

2010-01-01T23:59:59.000Z

167

Acoustic transmission in curved ducts with varying cross-sections  

Science Journals Connector (OSTI)

...asymptotically a constant at both ends of the duct, or, more precisely, (u, v) = - + O(ec1u ), u -, (u, v) = + + O(e-c2u ), u , ( 3.2) c1 and c2 being positive constants and - = 1 and + = (b/a)2 . Before we proceed with exploring conformal...

2002-01-01T23:59:59.000Z

168

Duct Thermal Performance Models for Large Commercial Buildings  

E-Print Network [OSTI]

Energy Technologies Division Indoor Environment Department Lawrence Berkeley National Laboratory Berkeley Secretary for Energy Efficiency and Renewable Energy, Building Technologies Program, of the U.S. Department) for his assistance in defining the duct surface heat transfer models described in the body of this report

169

The velocity campaign for ignition on NIF  

SciTech Connect (OSTI)

Achieving inertial confinement fusion ignition requires a symmetric, high velocity implosion. Experiments show that we can reach 95 {+-} 5% of the required velocity by using a 420 TW, 1.6 MJ laser pulse. In addition, experiments with a depleted uranium hohlraum show an increase in capsule performance which suggests an additional 18 {+-} 5 {mu}m/ns of velocity with uranium hohlraums over gold hohlraums. Combining these two would give 99 {+-} 5% of the ignition velocity. Experiments show that we have the ability to tune symmetry using crossbeam transfer. We can control the second Legendre mode (P2) by changing the wavelength separation between the inner and outer cones of laser beams. We can control the azimuthal m = 4 asymmetry by changing the wavelength separation between the 23.5 and 30 degree beams on NIF. This paper describes our 'first pass' tuning the implosion velocity and shape on the National Ignition Facility laser [Moses et al., Phys. Plasmas, 16, 041006 (2009)].

Callahan, D. A.; Meezan, N. B.; Glenzer, S. H.; MacKinnon, A. J.; Benedetti, L. R.; Bradley, D. K.; Celeste, J. R.; Celliers, P. M.; Dixit, S. N.; Doeppner, T.; Dzentitis, E. G.; Glenn, S.; Haan, S. W.; Haynam, C. A.; Hicks, D. G.; Hinkel, D. E.; Jones, O. S.; Landen, O. L.; London, R. A.; MacPhee, A. G. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); and others

2012-05-15T23:59:59.000Z

170

Perspectives on Deposition Velocity  

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

Deposition Deposition Velocity ... Going down the rabbit hole to explain that sinking feeling Brian DiNunno, Ph.D. Project Enhancement Corporation June 6 th , 2012 Discussion Framework  Development of the HSS Deposition Velocity Safety Bulletin  Broader discussion of appropriate conservatism within dispersion modeling and DOE-STD-3009 DOE-STD-3009 Dose Comparison "General discussion is provided for source term calculation and dose estimation, as well as prescriptive guidance for the latter. The intent is that calculations be based on reasonably conservative estimates of the various input parameters." - DOE-STD-3009, Appendix A.3 DOE-STD-3009 Dispersion

171

Velocity pump reaction turbine  

DOE Patents [OSTI]

An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

House, Palmer A. (Walnut Creek, CA)

1982-01-01T23:59:59.000Z

172

Velocity pump reaction turbine  

DOE Patents [OSTI]

An expanding hydraulic/two-phase velocity pump reaction turbine including a dual concentric rotor configuration with an inter-rotor annular flow channel in which the inner rotor is mechanically driven by the outer rotor. In another embodiment, the inner rotor is immobilized and provided with gas recovery ports on its outer surface by means of which gas in solution may be recovered. This velocity pump reaction turbine configuration is capable of potential energy conversion efficiencies of up to 70%, and is particularly suited for geothermal applications.

House, Palmer A. (Walnut Creek, CA)

1984-01-01T23:59:59.000Z

173

MASSIVE AND NEWLY DEAD: DISCOVERY OF A SIGNIFICANT POPULATION OF GALAXIES WITH HIGH-VELOCITY DISPERSIONS AND STRONG BALMER LINES AT z {approx} 1.5 FROM DEEP KECK SPECTRA AND HST/WFC3 IMAGING  

SciTech Connect (OSTI)

We present deep Keck/LRIS spectroscopy and Hubble Space Telescope/WFC3 imaging in the rest-frame optical for a sample of eight galaxies at z {approx} 1.5 with high photometrically determined stellar masses. The data are combined with five Very Large Telescope/X-Shooter spectra. We find that these 13 galaxies have high velocity dispersions, with a median of {sigma} = 301 km s{sup -1}. This high value is consistent with their relatively high stellar masses and compact sizes. We study their stellar populations using the strength of Balmer absorption lines, which are not sensitive to dust absorption. We find a large range in Balmer absorption strength, with many galaxies showing very strong lines indicating young ages. The median H{delta}{sub A} equivalent width, determined directly or inferred from the H10 line, is 5.4 A, indicating a luminosity-weighted age of {approx}1 Gyr. Although this value may be biased toward higher values because of selection effects, high-dispersion galaxies with such young ages are extremely rare in the local universe. Interestingly, we do not find a simple correlation with rest-frame U - V color: some of the reddest galaxies have very strong Balmer absorption lines, which may indicate the importance of multiple bursts of star formation. These results demonstrate that many high-dispersion galaxies at z {approx} 1.5 were recently quenched. This implies that there must be a population of star-forming progenitors at z {approx} 2 with high velocity dispersions or linewidths, which are notoriously absent from CO/H{alpha} selected surveys.

Bezanson, Rachel; Van Dokkum, Pieter [Department of Astronomy, Yale University, New Haven, CT 06520-8101 (United States); Van de Sande, Jesse; Franx, Marijn [Sterrewacht Leiden, Leiden University, NL-2300 RA Leiden (Netherlands); Kriek, Mariska [Department of Astronomy, University of California, Berkeley, CA 94720 (United States)

2013-02-10T23:59:59.000Z

174

Seismic velocity estimation from time migration  

E-Print Network [OSTI]

Seismic images . . . . . . . . . . . . . . . . .Algorithms producing the seismic velocities from thethe Dix velocities and the true seismic velocities in 2D . .

Cameron, Maria Kourkina

2007-01-01T23:59:59.000Z

175

LABORATORY EVALUATION OF THE DELTA Q TEST FOR DUCT LEAKAGE  

SciTech Connect (OSTI)

Using a residential-size duct system in a controlled laboratory setting, the repeatability and accuracy of the Delta Q test for air leakage in residential duct systems have been measured. More than 100 Delta Q tests were performed. These were compared with results using fan pressurization and also with results of a procedure (Delta Q Plus) that uses leakage hole-size information to select the leakage pressures to be used in the Delta Q algorithm. The average error in supply or return leakage for the fan-pressurization test was 6.4% of system fan flow. For the Delta Q test it was 3.4% of fan flow, while for Delta Q Plus it was 1.9% of fan flow.

ANDREWS,J.W.

2003-05-01T23:59:59.000Z

176

Mixed convection flow and heat transfer in entrance region of rectangular ducts rotating about a parallel axis  

SciTech Connect (OSTI)

The objective of the present work is to investigate the laminar mixed convection flow and heat transfer in the entrance region of heated rectangular ducts rotating about a parallel axis. Heating conditions of isothermal and iso-flux are both considered. Boussinesq approximation is invoked to take into account buoyancy effect induced by centrifugal force. Navier-Stokes/Boussinesq system can be cast into a dimensionless form, in which five governing parameters, the Prandtl number Pr, rotational Reynolds number J, rotational Grashof number Gr{sub {Omega}}, aspect ratio {gamma} and the eccentricity E, are involved. Mechanisms of secondary vortex development in the ducts are explored by a theoretical analysis on vorticity transport equation. The values of Pr and E are fixed as 0.7 and 10, respectively. For various combinations of the other thee parameters, a vorticity-velocity method implemented with a marching technique is employed to solve the resultant three-dimensional system for simultaneously developing flow and temperature fields. The emphasis is placed on the rotational effects, including both coriolis force and centrifugal buoyancy; on the non-isothermal flow and the related heat transfer. The results reveal that the friction factors and heat transfer rates can be enhanced by Coriolis and rotation-induced buoyancy effects; and the variations of the local values are closely related to the evolution of the secondary vortices in ducts. The differences in flow behaviors and thermal characteristics for UWT and UHF are also investigated by the present theoretical analysis on secondary flow mechanism as well as the computational results.

Soong, C.Y. [Chung Cheng Inst. of Tech., Taoyuan (Taiwan, Province of China). Dept. of Aeronautical Engineering; Yan, W.M. [Hua Fan Coll. of Humanities and Technology, Taipei (Taiwan, Province of China). Dept. of Mechanical Engineering

1995-12-31T23:59:59.000Z

177

Building America Top Innovations 2013 Profile … Buried and Encapsulated Ducts  

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

match the performance of ducts in conditioned space. match the performance of ducts in conditioned space. For years builders have designed their homes with the HVAC ducts in the attic. There is plenty of space up there to run the ducts, and if the air handler is located in the attic as well, it is not taking up valuable square footage inside the home. The only problem is vented attics can be very hot in the summer and very cold in the winter. Estimated thermal losses through ducts installed in unconditioned attics range from 10% to 45%, contributing significantly to homeowners' heating and cooling costs. The Consortium for Advanced Residential Buildings (CARB), a Building America research team led by Steven Winter Associates, has done extensive research on the feasibility of insulating ducts that are located in the attic and has

178

Building America Top Innovations 2013 Profile … Buried and Encapsulated Ducts  

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

meet the code requirements for ducts in conditioned space. meet the code requirements for ducts in conditioned space. For years builders have designed their homes with the HVAC ducts in the attic. There is plenty of space up there to run the ducts and if the air handler is located in the attic as well, it's not taking up valuable square footage inside the home. The only problem is uninsulated attics can be very hot in the summer and very cold in the winter. Estimated thermal losses through ducts installed in unconditioned attics range from 10% to 45%, contributing significantly to homeowners' heating and cooling costs. The Consortium for Advanced Residential Buildings (CARB), a Building America research team led by Steven Winter Associates, has done extensive research on the feasibility of insulating ducts that are located in the attic and has

179

Building America Top Innovations Hall of Fame Profile … Ducts in Conditioned Space  

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

A duct chase in a dropped hallway ceiling A duct chase in a dropped hallway ceiling provides an affordable way to put ducts in conditioned space, a technique that saves energy and improves indoor air quality. Moving ductwork into the home's conditioned space can save 8%-15% on homeowner air-conditioning bills. Thousands of homes are now applying this important best practice promoted by Building America research. BUILDING AMERICA TOP INNOVATIONS HALL OF FAME PROFILE INNOVATIONS CATEGORY: 1. Advanced Technologies and Practices 1.1 Building Science Solutions: Thermal Enclosure Ducts in Conditioned Space Putting ducts in vented, unconditioned crawlspaces and attics makes almost no sense from a building science standpoint. Building America research has provided proven solutions for locating ducts in conditioned space that are being adopted by

180

Q. For the 2005 Standards there is a new compliance credit for "ducts buried in attic insulation." What must be done to qualify for that credit?  

E-Print Network [OSTI]

Q. For the 2005 Standards there is a new compliance credit for "ducts buried in attic insulation installation of insulation and duct sealing. When taking the buried duct credit, a minimum of R-30 insulation-4.2 duct insulation. Only the portions of duct runs that are directly on or within 3.5 inches

Note: This page contains sample records for the topic "duct high velocity" 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

Characteristics of multimode heat transfer in a differentially-heated horizontal rectangular duct.  

E-Print Network [OSTI]

??This study presents the numerical analysis of steady laminar flow heat transfer in a horizontal rectangular duct with differential heating on the vertical walls. Three… (more)

Wangdhamkoom, Panitan

2007-01-01T23:59:59.000Z

182

Duct Remediation Program: Material characterization and removal/handling  

SciTech Connect (OSTI)

Remediation efforts were successfully performed at Rocky Flats to locate, characterize, and remove plutonium holdup from process exhaust ducts. Non-Destructive Assay (NDA) techniques were used to determine holdup locations and quantities. Visual characterization using video probes helped determine the physical properties of the material, which were used for remediation planning. Assorted equipment types, such as vacuum systems, scoops, brushes, and a rotating removal system, were developed to remove specific material types. Personnel safety and material handling requirements were addressed throughout the project.

Beckman, T.d.; Davis, M.M.; Karas, T.M.

1992-11-01T23:59:59.000Z

183

Static Pressure Loss in 12”, 14”, and 16” Non-metallic Flexible Duct  

E-Print Network [OSTI]

This study was conducted to determine the effects of compression on pressure drops in non-metallic flexible duct. Duct sizes of 12”, 14” and 16” diameters were tested at a five different compression ratios (maximum stretch, 4%, 15%, 30% and 45...

Cantrill, David Lee

2013-08-01T23:59:59.000Z

184

Multi-carrier Signal Transmission through HVAC Ducts: Experimental Results for Channel Capacity  

E-Print Network [OSTI]

Multi-carrier Signal Transmission through HVAC Ducts: Experimental Results for Channel Capacity, for the first time, experimental results on channel capacity of heating, ventilation, and air-conditioning (HVAC through a building HVAC duct system demonstrate the ability to transmit with a spectral efficiency of 3

Stancil, Daniel D.

185

Seamless Handover in Buildings Using HVAC Ducts: A New System Architecture  

E-Print Network [OSTI]

Seamless Handover in Buildings Using HVAC Ducts: A New System Architecture Ariton E. Xhafa, Paisarn-- In this paper, we present an innovative solution to the handover problem in multi-story buildings using HVAC of the indoor wireless networks that use the heating, ventilation, and air conditioning (HVAC) ducts

Stancil, Daniel D.

186

96 ASHRAE Transactions: Research Current duct design methods for variable air volume  

E-Print Network [OSTI]

.Hourlyairflowrequirements, part-load fan characteristics, and duct static pressure control are incorporated into the problem airflow. Fan power is also influ- enced if static pressure at the end of the longest duct line for effective, energy-efficient, and comfortable heating, ventilat- ing, and air-conditioning (HVAC) systems

187

Beat phenomenon at the arrival of a guided mode in a semi-infinite acoustic duct  

E-Print Network [OSTI]

. This eigen value problem has an infinite discrete number of solutions N (x, y) with the modal wave numbers NBeat phenomenon at the arrival of a guided mode in a semi-infinite acoustic duct P. Gatignola , M at an initial time in the terminal section of a semi-infinite acoustic duct, will undergo dispersion effects

Paris-Sud XI, Université de

188

Determining Critical Pressure and Duct Leakage in VAV Air-Handling Units  

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

Determining Critical Pressure and Duct Leakage in VAV Air-Handling Units Determining Critical Pressure and Duct Leakage in VAV Air-Handling Units Speaker(s): Clifford Federspiel Date: December 3, 2003 - 12:00pm Location: Bldg. 90 Seminar Host/Point of Contact: Nance Matson Fans for moving air in buildings use a significant amount of energy. It is well known that fan energy use in variable-air-volume (VAV) systems can be reduced by resetting the supply duct pressure. The standard way to reset duct pressure is by controlling the most-open terminal damper to a nearly open position. Most systems can't measure terminal damper positions, so pressures are either not reset at all or use ad hoc resetting strategies that are configured sub-optimally. In this seminar I will describe a new method of determining the critical supply duct pressure for VAV systems.

189

7/11/00-draft copy: do not quote 1 of 30 New Technologies for Residential HVAC Ducts  

E-Print Network [OSTI]

7/11/00-draft copy: do not quote 1 of 30 New Technologies for Residential HVAC Ducts Burke Treidler is not evaluated and HVAC contractors overcome duct system shortcomings by installing oversized equipment Technologies for Residential HVAC Ducts fittings with some use of ductboard. Fittings that snap together were

190

Duct leakage impacts on VAV system performance in California large commercial buildings  

SciTech Connect (OSTI)

The purpose of this study is to evaluate the variability of duct leakage impacts on air distribution system performance for typical large commercial buildings in California. Specifically, a hybrid DOE-2/TRNSYS sequential simulation approach was used to model the energy use of a low-pressure terminal-reheat variable-air-volume (VAV) HVAC system with six duct leakage configurations (tight to leaky) in nine prototypical large office buildings (representing three construction eras in three California climates where these types of buildings are common). Combined fan power for the variable-speed-controlled supply and return fans at design conditions was assumed to be 0.8 W/cfm. Based on our analyses of the 54 simulation cases, the increase in annual fan energy is estimated to be 40 to 50% for a system with a total leakage of 19% at design conditions compared to a tight system with 5% leakage. Annual cooling plant energy also increases by about 7 to 10%, but reheat energy decreases (about 3 to 10%). In combination, the increase in total annual HVAC site energy is 2 to 14%. The total HVAC site energy use includes supply and return fan electricity consumption, chiller and cooling tower electricity consumption, boiler electricity consumption, and boiler natural gas consumption. Using year 2000 average commercial sector energy prices for California ($0.0986/kWh and $7.71/Million Btu), the energy increases result in 9 to 18% ($7,400 to $9,500) increases in HVAC system annual operating costs. Normalized by duct surface area, the increases in annual operating costs are 0.14 to 0.18 $/ft{sup 2}. Using a suggested one-time duct sealing cost of $0.20 per square foot of duct surface area, these results indicate that sealing leaky ducts in VAV systems has a simple payback period of about 1.3 years. Even with total leakage rates as low as 10%, duct sealing is still cost effective. This suggests that duct sealing should be considered at least for VAV systems with 10% or more total duct leakage. The VAV system that we simulated had perfectly insulated ducts, and maintained constant static pressure in the ducts upstream of the VAV boxes and a constant supply air temperature at the airhandler. Further evaluations of duct leakage impacts should be carried out in the future after methodologies are developed to deal with duct surface heat transfer effects, to deal with airflows entering VAV boxes from ceiling return plenums (e.g., to model parallel fan-powered VAV boxes), and to deal with static pressure reset and supply air temperature reset strategies.

Wray, Craig P.; Matson, Nance E.

2003-10-01T23:59:59.000Z

191

DOE Challenge Home Technical Training - Ducts in Conditioned Space  

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

T T h i l T i i 1 | INNOVATION & INTEGRATION: Transforming the Energy Efficiency Market Buildings.Energy.gov Design Options for Locating Ducts within Conditioned Space DOE Challenge Home Bill Zoeller, RA Steven Winter Associates Technical Training Congratulations By designing, constructing, and verifying DOE Challenge Homes, y you are: * in a select group Only the top one percent of builders in the country meets the extraordinary energy efficiency, comfort, health, safety, durability and quality levels associated with the DOE Challenge Home. * providing unprecedented value Your customers receive immediate energy savings of 40-50% easy to adapt to net-zero performance with a small renewable energy system. * differentiated from the competition About 12 in 13 homes sales nationwide are 'used' homes. In addition, the majority of new

192

Unsteady mixed convection in horizontal ducts with applications to chemical vapor deposition processes  

SciTech Connect (OSTI)

Mixed convection in a horizontal rectangular duct of aspect ratio 4 heated from below with cold side walls was studied numerically for a non-Boussinesq fluid. Results are presented for a reduced temperature of 2.33 and a Rayleigh number of 130,700. The resulting flow field at Re = 25 consisted of four steady longitudinal vortices, symmetric about the duct centerline, with a leading transverse roll cell. A reduction to Re = 10 resulted in the introduction of traveling transverse waves. A further reduction Re = 5 resulted in a loss of symmetry about the duct centerline plane. Further work is underway to verify the Re = 5 results.

Spall, R.E. [Univ. of South Alabama, Mobile, AL (United States). Dept. of Mechanical Engineering] [Univ. of South Alabama, Mobile, AL (United States). Dept. of Mechanical Engineering

1996-01-01T23:59:59.000Z

193

Comparative Study: CFD ?P Versus Measured ?P for 30% Flexible Ducts  

E-Print Network [OSTI]

foot-long circular ducts placed on both ends. A CFD model was built and simulations were run under different volumetric air flows. The static pressure drop for those conditions were analyzed and displayed. The final CFD model is tuned until...) computer model. Fluent 6.2.16 CFD software package was used to simulate the static pressure drop inside the flexible duct. 3-D computer model of 6” diameter flexible duct was generated for 30% compression in 5 ft. long. The laboratory data...

Ugursal, A.; Culp, C.

2006-01-01T23:59:59.000Z

194

ARM - Measurement - Hydrometeor fall velocity  

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

fall velocity fall velocity ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Hydrometeor fall velocity Fall velocity of hydrometeors (e.g. rain, snow, graupel, hail). Categories Cloud Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments DISDROMETER : Impact Disdrometer LDIS : Laser Disdrometer WSACR : Scanning ARM Cloud Radar, tuned to W-Band (95GHz) Field Campaign Instruments DISDROMETER : Impact Disdrometer PDI : Phase Doppler Interferometer

195

Augmentation of Power Output of Axisymmetric Ducted Wind Turbines by Porous Trailing Edge Disks  

E-Print Network [OSTI]

This paper presents analytical and experimental results that demonstrated that the power output from a ducted wind turbine can be dramatically increased by the addition of a trailing edge device such as a porous disk. In ...

widnall, sheila

2014-06-30T23:59:59.000Z

196

DOE Zero Energy Ready Home Ducts in Conditioned Space Webinar (Text Version)  

Broader source: Energy.gov [DOE]

Below is a text version of the webinar titled "Design Strategies for Ducts in Conditioned Spaces," originally presented in March 2014 and part of DOE Challenge Home's Tech Training Webinar Series....

197

Building America Technology Solutions for New and Existing Homes: Duct Sealing Using Injected Spray Sealant  

Broader source: Energy.gov [DOE]

In this project, the Raleigh Housing Authority worked with Building America team, the Advanced Residential Integrated Solutions Collaborative to determine the most cost-effective ways to reduce duct leakage in its low-rise housing units.

198

Ultrasonic Inspection of Tendon Ducts in Concrete Slabs Using 3D-SAFT  

Science Journals Connector (OSTI)

The main purpose to use ultrasonic pulse echo techniques for concrete are the following testing B;problems: Injections faults in tendon ducts because they lead to a loss of the...

M. Krause; W. Müller; H. Wiggenhauser

1997-01-01T23:59:59.000Z

199

Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from  

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

Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from Implementing SAV with InCITeTM Title Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from Implementing SAV with InCITeTM Publication Type Report LBNL Report Number LBNL-3525E Year of Publication 2010 Authors Wray, Craig P., and Max H. Sherman Publisher Lawrence Berkeley National Laboratory City Berkeley Keywords airflow, building, duct, energy, energy performance of buildings group, fan, hvac, indoor environment department, other, power, retrofits, simulation, system Abstract This project addressed two significant deficiencies in air-handling systems for large commercial building: duct leakage and duct static pressure reset. Both constitute significant energy reduction opportunities for these buildings. The overall project goal is to bridge the gaps in current duct performance modeling capabilities, and to expand our understanding of air-handling system performance in California large commercial buildings. The purpose of this project is to provide technical support for the implementation of a duct leakage modeling capability in EnergyPlus, to demonstrate the capabilities of the new model, and to carry out analyses of field measurements intended to demonstrate the energy saving potential of the SAV with InCITeTM duct static pressure reset (SPR) technology.A new duct leakage model has been successfully implemented in EnergyPlus, which will enable simulation users to assess the impacts of leakage on whole-building energy use and operation in a coupled manner. This feature also provides a foundation to support code change proposals and compliance analyses related to Title 24 where duct leakage is an issue. Our example simulations continue to show that leaky ducts substantially increase fan power: 10% upstream and 10% downstream leakage increases supply fan power 30% on average compared to a tight duct system (2.5% upstream and 2.5% downstream leakage). Much of this increase is related to the upstream leakage rather than to the downstream leakage. This does not mean, however, that downstream leakage is unimportant. Our simulations also demonstrate that ceiling heat transfer is a significant effect that needs to be included when assessing the impacts of duct leakage in large commercial buildings. This is not particularly surprising, given that "ceiling regain" issues have already been included in residential analyses as long as a decade ago (e.g., ASHRAE Standard 152); mainstream simulation programs that are used for large commercial building energy analyses have not had this capability until now. Our analyses of data that we collected during our 2005 tests of the SAV with InCITeTM duct static pressure reset technology show that this technology can substantially reduce fan power (in this case, by about 25 to 30%). Tempering this assessment, however, is that cooling and heating coil loads were observed to increase or decrease significantly depending on the time window used. Their impact on cooling and heating plant power needs to be addressed in future studies; without translating the coil loads to plant equipment energy use, it is not possible to judge the net impact of this SPR technology on whole-building energy use. If all of the loads had decreased, such a step would not be as necessary.

200

The impacts of duct design on life cycle costs of central residential heating and air-conditioning systems  

Science Journals Connector (OSTI)

Abstract Many central residential HVAC systems in the U.S. operate at high external static pressures due to a combination of system restrictions. Undersized and constricted ductwork are thought to be key culprits that lead to excess external static pressures in many systems, although the magnitude of energy impacts associated with restrictive ductwork and the costs or benefits associated with addressing the problem are not well known. Therefore, this work uses annual energy simulations of two typical new single-family homes in two separate climates in the United States (Austin, TX and Chicago, IL) to predict the impacts of various external static pressure ductwork designs from independent HVAC contractors (using both flexible and rigid sheet metal ductwork materials) on annual space conditioning energy use. Results from the simulations are combined with estimates of the initial installation costs of each duct design made by each contractor to evaluate the total life cycle costs or savings of using lower pressure duct designs in the two homes over a 15-year life cycle. Lower pressure ductwork systems generally yielded life cycle cost savings, particularly in homes with PSC blowers and particularly when making comparisons with constant ductwork materials (i.e., comparing flex only or rigid only).

Brent Stephens

2014-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Determination of hydrogen cluster velocities and comparison with numerical calculations  

SciTech Connect (OSTI)

The use of powerful hydrogen cluster jet targets in storage ring experiments led to the need of precise data on the mean cluster velocity as function of the stagnation temperature and pressure for the determination of the volume density of the target beams. For this purpose a large data set of hydrogen cluster velocity distributions and mean velocities was measured at a high density hydrogen cluster jet target using a trumpet shaped nozzle. The measurements have been performed at pressures above and below the critical pressure and for a broad range of temperatures relevant for target operation, e.g., at storage ring experiments. The used experimental method is described which allows for the velocity measurement of single clusters using a time-of-flight technique. Since this method is rather time-consuming and these measurements are typically interfering negatively with storage ring experiments, a method for a precise calculation of these mean velocities was needed. For this, the determined mean cluster velocities are compared with model calculations based on an isentropic one-dimensional van der Waals gas. Based on the obtained data and the presented numerical calculations, a new method has been developed which allows to predict the mean cluster velocities with an accuracy of about 5%. For this two cut-off parameters defining positions inside the nozzle are introduced, which can be determined for a given nozzle by only two velocity measurements.

Täschner, A.; Köhler, E.; Ortjohann, H.-W.; Khoukaz, A. [Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, D-48149 Münster (Germany)] [Institut für Kernphysik, Westfälische Wilhelms-Universität Münster, D-48149 Münster (Germany)

2013-12-21T23:59:59.000Z

202

Building America Case Study: Duct in Conditioned Space in a Dropped Ceiling or Fur-down, Gainesville, Florida (Fact Sheet)  

SciTech Connect (OSTI)

Forced air distribution systems (duct systems) typically are installed out of sight for aesthetic reasons, most often in unconditioned areas such as an attic or crawlspace. Any leakage of air to or from the duct system (duct leakage) in unconditioned space not only loses energy, but impacts home and equipment durability and indoor air quality. An obvious solution to this problem is to bring the duct system into the interior of the house, either by sealing the area where the ducts are installed (sealed attic or crawlspace) or by building an interior cavity or chase above the ceiling plane (raised ceiling or fur-up chase) or below the ceiling plane (dropped ceiling or fur-down) for the duct system. This case study examines one Building America builder partner's implementation of an inexpensive, quick and effective method of building a fur-down or dropped ceiling chase.

Not Available

2014-09-01T23:59:59.000Z

203

Laboratory and field testing of an aerosol-based duct-sealing technology  

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

Laboratory and field testing of an aerosol-based duct-sealing technology Laboratory and field testing of an aerosol-based duct-sealing technology for large commercial buildings. Title Laboratory and field testing of an aerosol-based duct-sealing technology for large commercial buildings. Publication Type Journal Article LBNL Report Number LBNL-44220 Year of Publication 2002 Authors Carrié, François Rémi, Ronnen M. Levinson, Tengfang T. Xu, Darryl J. Dickerhoff, William J. Fisk, Jennifer A. McWilliams, Mark P. Modera, and Duo Wang Journal ASHRAE Transactions Start Page Chapter Date Published January 2002 Abstract Laboratory and field experiments were performed to evaluate the feasibility of sealing leaks in commercial duct systems with an aerosol sealant. The method involves blowing an aerosol through the duct system to seal the leaks from the inside, the principle being that the aerosol particles deposit in the cracks as they try to escape under pressure. It was shown that the seals created with the current sealant material can withstand pressures far in excess of what is found in commercial-building duct systems. We also performed two field experiments in two large-commercial buildings. The ASHRAE leakage classes of the systems were reduced from 653 down to 103, and from 40 down to 3. Methods and devices specifically devised for this application proved to be very efficient at (a) increasing the sealing rate and (b) attaining state-of-the-art duct leakage classes. Additional research is needed to improve the aerosol injection and delivery processes.

204

Longevity of Duct Tape in Residential Air Distribution Systems: 1-D, 2-D, and 3-D Joints  

E-Print Network [OSTI]

Group (EPB) at Lawrence Berkeley National Laboratory (Abushakra 2002). This study is a continuation of previous studies conducted at LBNL (Walker et al. 1998 and 1999, Walker and Sherman 2000, and Sherman et al. 2000), whose objectives... flexible duct core-to-collar joints. ADC does not provide recommendations for the collar-to-plenum joints. Previous duct sealing tests conducted at LBNL covered two types of joints, core-to-collar, and collar- to-plenum, using sheet metal ducts...

Abushakra, B.

2003-01-01T23:59:59.000Z

205

Velocity Distributions from Nonextensive Thermodynamics  

E-Print Network [OSTI]

There is no accepted mechanism that explains the equilibrium structures that form in collisionless cosmological N-body simulations. Recent work has identified nonextensive thermodynamics as an innovative approach to the problem. The distribution function that results from adopting this framework has the same form as for polytropes, but the polytropic index is now related to the degree of nonextensiveness. In particular, the nonextensive approach can mimic the equilibrium structure of dark matter density profiles found in simulations. We extend the investigation of this approach to the velocity structures expected from nonextensive thermodynamics. We find that the nonextensive and simulated N-body rms-velocity distributions do not match one another. The nonextensive rms-velocity profile is either monotonically decreasing or displays little radial variation, each of which disagrees with the rms-velocity distributions seen in simulations. We conclude that the currently discussed nonextensive models require further modifications in order to corroborate dark matter halo simulations. (adapted from TeX)

Eric I. Barnes; Liliya L. R. Williams; Arif Babul; Julianne J. Dalcanton

2006-10-05T23:59:59.000Z

206

Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from Implementing SAV with InCITeTM  

E-Print Network [OSTI]

the impact of static pressure reset on HVAC system thermalHVAC control system varies the supply fan airflow to maintain a constant duct static pressure

Wray, Craig

2010-01-01T23:59:59.000Z

207

Measurement of velocity field in parametrically excited solitary waves  

E-Print Network [OSTI]

Paramerically excited solitary waves emerge as localized structures in high-aspect-ratio free surfaces subject to vertical vibrations. Herein, we provide the first experimental characterization of the hydrodynamics of thess waves using Particle Image Velocimetry. We show that the underlying velocity field of parametrically excited solitary waves is mainly composed by an oscillatory velocity field. Our results confirm the accuracy of Hamiltonian models with added dissipation in describing this field. Remarkably, our measurements also uncover the onset of a streaming velocity field which is shown to be as important as other crucial nonlinear terms in the current theory. The observed streaming pattern is particularly interesting due to the presence of oscillatory meniscii.

Gordillo, Leonardo

2014-01-01T23:59:59.000Z

208

Normal modes, virtual modes, and alternative representations in the theory of surface?duct sound propagation  

Science Journals Connector (OSTI)

This paper presents a theoretical study of sound propagation in an ocean?surface duct. It deals with several aspects of the theory from a point of view which has not heretofore been taken in the analyses of this problem. The model used to describe a duct assumes the ocean surface to be smooth and the square of the refractive index to be bilinear. Alternative representations of the sound field excited by a point source are derived the two playing the most significant role in this paper being the residue series and the normal?mode representation. It is shown that the depth functions of the residue series do not form a complete set as those of a normal?mode representation must and that the normal?mode spectrum is continuous rather than discrete. The completeness properties of the normal?mode functions are then utilized in a study of the energy?trapping capabilities of the duct. In this connection virtual modes are introduced and shown to lead naturally to the derivation of a leakage coefficient characteristic of the exponential leakage of energy out of the duct with increasing range. In addition a cutoff?frequency criterion useful in determining when a surface duct can trap energy is derived.

Frank M. Labianca

1973-01-01T23:59:59.000Z

209

Aerodynamic Thrust Modelling in Wave Tank Tests of Offshore Floating Wind Turbines Using a Ducted Fan  

Science Journals Connector (OSTI)

Wave tank testing of scaled models is standard practice during the development of floating wind turbine platforms for the validation of the dynamics of conceptual designs. Reliable recreation of the dynamics of a full scale floating wind turbine by a scaled model in a basin requires the precise scaling of the masses and inertias and also the relevant forces and its frequencies acting on the system. The scaling of floating wind turbines based on the Froude number is customary for basin experiments. This method preserves the hydrodynamic similitude, but the resulting Reynolds number is much lower than in full scale. The aerodynamic loads on the rotor are therefore out of scale. Several approaches have been taken to deal with this issue, like using a tuned drag disk or redesigning the scaled rotor. This paper describes the implementation of an alternative method based on the use of a ducted fan located at the model tower top in the place of the rotor. The fan can introduce a variable force that represents the total wind thrust by the rotor. A system controls this force by varying the rpm, and a computer simulation of the full scale rotor provides the desired thrust to be introduced by the fan. This simulation considers the wind turbine control, gusts, turbulent wind, etc. The simulation is performed in synchronicity with the test and it is fed in real time by the displacements and velocities of the platform captured by the acquisition system. Thus, the simulation considers the displacements of the rotor within the wind field and the calculated thrust models the effect of the aerodynamic damping. The system is not able currently to match the effect of gyroscopic momentum. The method has been applied during a test campaign of a semisubmersible platform with full catenary mooring lines for a 6MW wind turbine in scale 1/40 at Ecole Centrale de Nantes. Several tests including pitch free decay under constant wind and combined wave and wind cases have been performed. Data from the experiments are compared with aero-servo-hydro-elastic computations with good agreement showing the validity of the method for the representation of the scaled aerodynamics. The new method for the aerodynamic thrust scaling in basin tests is very promising considering its performance, versatility and lower cost in comparison with other methods.

José Azcona; Faisal Bouchotrouch; Marta González; Joseba Garciandía; Xabier Munduate; Felix Kelberlau; Tor A Nygaard

2014-01-01T23:59:59.000Z

210

BENCAP, LLC: CAPSULE VELOCITY TEST  

SciTech Connect (OSTI)

Ben Cap, LLC, has a technology that utilizes bebtonite to plug wells. The bentonite is encapsulated in a cardboard capsule, droped down to the bottom of the well where it is allowed to hydrate, causing the bentonite to expand and plug the well. This method of plugging a well is accepted in some, but not all states. This technology can save a significant amount of money when compared to cementing methods currently used to plug and abandon wells. The test objective was to obtain the terminal velocity of the capsule delivery system as it drops through a column of water in a wellbore. Once the terminal velocity is known, the bentonite swelling action can be timed not to begin swelling until it reaches the bottom of the well bore. The results of the test showed that an average speed of 8.93 plus or minus 0.12 ft/sec was achieved by the capsule as it was falling through a column of water. Plotting the data revealed a very linear function with the capsules achieving terminal velocity shortly after being released. The interference of the capsule impacting the casing was not readily apparent in any of the runs, but a siginal sampling anomaly was present in one run. Because the anomaly was so brief and not present in any of the other runs, no solid conclusions could be drawn. Additional testing would be required to determine the effects of capsules impacting a fluid level that is not at surface.

Meidinger, Brian

2005-09-07T23:59:59.000Z

211

Stress anisotropy and velocity anisotropy in low porosity shale  

Science Journals Connector (OSTI)

Shales are known for often marked intrinsic anisotropy of many of their properties, including strength, permeability and velocity for example. In addition, it is well known that anisotropic stress fields can also have a significant impact on anisotropy of velocity, even in an isotropic medium. This paper sets out to investigate the ultrasonic velocity response of well-characterised low porosity shales from the Officer Basin in Western Australia to both isotropic and anisotropic stress fields and to evaluate the velocity response to the changing stress field. During consolidated undrained multi-stage triaxial tests on core plugs cut normal to bedding, Vpv increases monotonically with increasing effective stress and Vs1 behaves similarly although with some scatter. Vph and Vsh remain constant initially but then decrease within each stage of the multi-stage test, although velocity from stage to stage at any given differential stress increases. This has the impact of decreasing both P-wave (?) and S-wave anisotropy (?) through application of differential stress within each loading stage. However, increasing the magnitude of an isotropic stress field has little effect on the velocity anisotropies. The intrinsic anisotropy of the shale remains reasonably high at the highest confining pressures. The results indicate the magnitude and orientation of the stress anisotropy with respect to the shale microfabric has a significant impact on the velocity response to changing stress fields.

U. Kuila; D.N. Dewhurst; A.F. Siggins; M.D. Raven

2011-01-01T23:59:59.000Z

212

What are the requirements for duct leakage testing? | Building Energy Codes  

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

requirements for duct leakage testing? requirements for duct leakage testing? Both the 2009 and 2012 IECC require duct tightness to be verified. Verification can take place via either a post-construction test or a rough-in test. For the post-construction test, leakage measurement must be made across the entire system, including the manufacturer's air handler enclosure, with all register boots taped or sealed at a test pressure of 0.1 inches w.g. (25 Pa). The 2009 IECC limits the leakage to outdoors to less than or equal to 8 cfm per 100 ft2 of conditioned floor area or total leakage less than or equal to 12 cfm per 100 ft2 of conditioned floor area. The 2012 IECC only contains a requirement for total leakage of less than or equal to 4 cfm per 100 ft2 of conditioned floor area. For the rough-in test, leakage measurement is made across the system, with

213

Cavitation erosion in blocked flow with a ducted ice-class propeller  

SciTech Connect (OSTI)

Ships that operate in ice often encounter momentary increased propeller cavitation because ice pieces block the flow into the propeller. For ducted propellers, this additional cavitation is more significant than it is for open propellers; ice pieces may become lodged against and within the duct and subject the propeller to longer periods of increased cavitation due to the blocked flow. Associated with this blocked flow is the possibility of cavitation erosion on the propeller. An erosion study, using paint films, was conducted in a cavitation tunnel with a model propeller of the type fitted to the Canadian Marine Drilling Ltd. vessel MV Robert LeMeur. A simulated ice blockage was installed ahead of the propeller model and within the duct. Tests were carried out over a range of advance coefficients for various test conditions. The resulting types of cavitation were documented, the erosion patterns were photographed and comparisons between each test were made.

Doucet, J.M.; Bose, N.; Walker, D. [Memorial Univ. of Newfoundland, St. John`s, Newfoundland (Canada). Ocean Engineering Research Centre; Jones, S.J. [National Research Council of Canada, St. John`s, Newfoundland (Canada). Inst. for Marine Dynamics

1996-12-31T23:59:59.000Z

214

Nuclear reactor fuel assembly duct-tube-to-inlet-nozzle attachment system  

DOE Patents [OSTI]

A reusable system for removably attaching the lower end 21 of a nuclear reactor fuel assembly duct tube to an upper end 11 of a nuclear reactor fuel assembly inlet nozzle. The duct tube's lower end 21 has sides terminating in locking tabs 22 which end in inwardly-extending flanges 23. The flanges 23 engage recesses 13 in the top section 12 of the inlet nozzle's upper end 11. A retaining collar 30 slides over the inlet nozzle's upper end 11 to restrain the flanges 23 in the recesses 13. A locking nut 40 has an inside threaded portion 41 which engages an outside threaded portion 15 of the inlet nozzle's upper end 11 to secure the retaining collar 30 against protrusions 24 on the duct tube's sides.

Christiansen, David W. (Kennewick, WA); Smith, Bob G. (Kennewick, WA)

1982-01-01T23:59:59.000Z

215

Particle Velocity and Deposition Efficiency in the Cold Spray Process  

SciTech Connect (OSTI)

Copper powder was sprayed by the cold-gas dynamic method. In-flight particle velocities were measured with a laser-two-focus system as a function of process parameters such as gas temperature, gas pressure, and powder feed rate. Particle velocities were uniform in a relatively large volume within the plume and agreed with theoretical predictions. The presence of the substrate was found to have no significant effect on particle velocities. Cold-spray deposition efficiencies were measured on aluminum substrates as a function of particle velocity and incident angle of the plume. Deposition efficiencies of up to 95% were achieved. The critical velocity for deposition was determined to be about 640 meters per second. This work investigates both the in-flight characteristics of copper particles in a supersonic cold-spray plume and the build-up of the subsequent coating on aluminum substrates. Velocities were found to be relatively constant within a large volume of the plume. Particle counts dropped off sharply away from the central axis. The presence of a substrate was found to have no effect on the velocity of the particles. A substantial mass-loading effect on the particle velocity was observed; particle velocities begin to drop as the mass ratio of powder to gas flow rates exceeds 3%. The measured variation of velocity with gas pressure and pre-heat temperature was in fairly good agreement with theoretical predictions. Helium may be used as the driving gas instead of air in order to achieve higher particle velocities for a given temperature and pressure. Coating deposition efficiencies were found to increase with particle velocity and decrease with gun- substrate angle. There did not appear to be any dependence of the deposition efficiency on coating thickness. A critical velocity for deposition of about 640 mk appears to fit the data well. The cold-spray technique shows promise as a method for the deposition of materials which are thermally sensitive or may experience rapid oxidation under typical thermal spray conditions. High deposition efficiencies are achievable for certain coating-substrate conditions. Work remains to determine the material and microstructural properties which govern the coating process.

Dykhuizen, R.C.; Gilmore, D.L.; Neiser, R.A.; Roemer, T.J.; Smith, M.F.

1998-11-12T23:59:59.000Z

216

One Component Two Phase Flow in Horizontal and Vertical Ducts: Some Basic Considerations  

SciTech Connect (OSTI)

For a description and analysis of the flow they consider the conservation equations of the two phases separately, but in thermal and mechanical equilibrium, coupled by the itnerface shear forces (two fluid model, drift flux model). Coupling may be weak or strong, depending on Froude and Mach numbers of the flow. The fluid is highly compressible, not because the individual phases move at such speeds that their individual density changes are significant but because evapiration (phase change) results in large density changes of the system at moderate pressure or temperature changes once flashing occurs. The slip between the phases is caused by unequal wall shear stress, acceleration of the fluid or gravitational forces and is hindered by the interface interaction. if they denote by {gamma} the ratio of the liquid density to the vapor density and by {sigma} the ratio of the vapor speed to the liquid speed they find that in horizontal flows {sigma} = {gamma}{sup 1/2} yields the maximum slip (neglecting acceleration effects) that can be reached with no interface force acting (assuming equal friction coefficients for both phases at the wall). If one investigates the conditions of thermodynamic flow similarity between different substances in two phase flow, one finds that the latent heat of vaporization is the principal controlling parameter. Thus, a 5 cm diameter test section in two phase R-114, at room temperature, corresponds to a 30 cm diameter duct in water-steam at boiling conditions at high temperatures such as encountered in geothermal and other power production systems.

Maeder, Paul F.; Dickinson, David A.; Nikitopoulos, Dimitris E.

1983-12-15T23:59:59.000Z

217

RCUT: A Non-Invasive Method for Detection, Location, and Quantification of Radiological Contaminants in Pipes and Ducts - 12514  

SciTech Connect (OSTI)

Radiological Characterization Using Tracers (RCUT) is a minimally invasive method for detection and location of residual radiological contamination in pipes and ducts. The RCUT technology utilizes reactive gaseous tracers that dissociate when exposed to gamma and/or beta radiation emitting from a radiological contaminant in a pipe or duct. Sulfur hexafluoride (SF{sub 6}) was selected as a tracer for this radiological application, because it is a chemically inert gas that is both nonflammable, nontoxic, and breaks down when exposed to gamma radiation. Laboratory tests demonstrated that the tracer pair of SF{sub 6} and O{sub 2} formed SO{sub 2}F{sub 2} when exposed to a gamma or beta radioactive field, which indicated the presence of radiological contamination. Field application of RCUT involves first injecting the reactive tracers into the pipe to fill the pipe being inspected and allowing sufficient time for the tracer to interact with any contaminants present. This is followed by the injection of an inert gas at one end of the pipe to push the reactive tracer at a known or constant flow velocity along the pipe and then out the exit and sampling port at the end of the pipeline where its concentration is measured by a gas chromatograph. If a radiological contaminant is present in the pipe being tested, the presence of SO{sub 2}F{sub 2} will be detected. The time of arrival of the SO{sub 2}F{sub 2} can be used to locate the contaminant. If the pipe is free of radiological contamination, no SO{sub 2}F{sub 2} will be detected. RCUT and PCUT are both effective technologies that can be used to detect contamination within pipelines without the need for mechanical or human inspection. These methods can be used to detect, locate, and/or estimate the volume of a variety of radioactive materials and hazardous chemicals such as chlorinated solvents, petroleum products, and heavy metals. While further optimization is needed for RCUT, the key first step of identification of a tracer compound appropriate for the application of detecting radioactive pipeline contamination through the detection of decomposition products of SF{sub 6} has been demonstrated. Other tracer gases that will also undergo radiolysis will be considered in the future. The next step for the RCUT development process is conducting laboratory scale tests using short pipelines to define analytical requirements, establish performance boundaries, and develop strategies for lower exposure levels. Studies to identify additional analytical techniques using equipment that is more field rugged than a GC/MS would also be beneficial. (authors)

Bratton, Wesley L.; Maresca, Joseph W. Jr.; Beck, Deborah A. [Vista Engineering Technologies, L.L.C., Richland, WA, 99352 (United States)

2012-07-01T23:59:59.000Z

218

Fundamental investigation of Duct/ESP phenomena: 1. 7 MW pilot parametric testing results  

SciTech Connect (OSTI)

Radian Corporation was contracted to investigate duct injection and electrostatic precipitator phenomena in a 1.7-MW pilot plant constructed for this test program. This study was an attempt to resolve previous problems and to answer remaining questions with the technology using an approach which concentrated on the fundamental mechanisms of the process. The goal of the study was to obtain a better understanding of the basic physical and chemical phenomena that control: (1) the desulfurization of flue gas by calcium-based reagent, and (2) the coupling of the duct injection process to an existing ESP particulate collection device. (VC)

McGuire, L.M.; Brown, C.A.

1991-07-22T23:59:59.000Z

219

Investigation of wall friction in noncircular ducts with a rough liner  

E-Print Network [OSTI]

phenomena in circular rough ducts and. these test data are discussed. 2. The test data of this research are similar to that shown by Nikuradse for fluid flow in pipes having artifi- cially roughened, inside surfaces. It is doubtful if Golebrook... in the relative roughness of the duct. The curves of Reynolds number versus friction factor are somewhat similar to those plotted by Nikuradse for fluid flow in artificially roughened round pipe. The shape of the curves is quite similar, but there is a...

Tyler, John Charles

2012-06-07T23:59:59.000Z

220

Heat transfer and pressure drop in square duct with two opposite repeated rib-roughened walls  

E-Print Network [OSTI]

HEAT TRANSFER AND PRESSURE DROP IN SQUARE DUCT WITH TWO OPPOSITE REPEATED RIB-ROUGHENED WALLS A Thesis CHIANG-KUO LEI Submitted to the Graduate College of Texas ARM University in partial fulfillment of the requirement for the degree of MASTER... OF SCIENCE December 1983 Major Subject: Mechanical Engineering HEAT TRANSFER AND PRESSURE DROP IN SQUARE DUCT WITH TWO OPPOSITE REPEATED RIB-ROUGHENED WALLS A Thesis by CHIANG-KUO LEI Approved as to style and content by: , ~p= jd~. = e-C in Han...

Lei, Chiang-Kuo

2012-06-07T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Electric coheating as a means to test duct efficiency: A review and analysis of the literature  

SciTech Connect (OSTI)

Recent published literature on electric coheating was reviewed in order to assess its suitability for use in a method of test for the efficiency of residential duct systems. Electric coheating is the research use of electric heaters within the heated space to assess the thermal integrity of the building envelope. Information was sought in two primary areas: (1) experimental methodology and (2) accuracy of the coheating method. A variety of experimental variations was found, and the method was judged, on the basis of published data, to be capable of sufficient accuracy for use in duct testing.

Andrews, J.W.

1995-08-01T23:59:59.000Z

222

Nucleonic analysis of a preliminary design for the ETF neutral-beam-injector duct shielding  

SciTech Connect (OSTI)

A nucleonic analysis of the Engineering Test Facility Neutral-Beam-Injector duct shielding has been made using a hybrid Monte Carlo/discrete-ordinates method. This method used Monte Carlo to determine internal and external boundary surface sources for a subsequent discrete-ordinates calculation of the neutron and gamma-ray transport through the shield. The analysis also included determination of the energy and angular distribution of neutrons and gamma rays entering the duct from the torus plasma chamber. Confidence in the hybrid method and the results obtained were provided through a comparison with three-dimensional Monte Carlo results.

Urban, W.T.; Seed, T.J.; Dudziak, D.J.

1980-01-01T23:59:59.000Z

223

1736 IEEE TRANSACTIONS ON COMMUNICATIONS, VOL. 51, NO. 10, OCTOBER 2003 Impulse Response of the HVAC Duct as a  

E-Print Network [OSTI]

of the HVAC Duct as a Communication Channel Pavel V. Nikitin, Member, IEEE, Daniel D. Stancil, Senior Member (HVAC) ducts in buildings behave as multimode waveguides when excited at radio frequencies and thus, can of a usual indoor propagation channel. In this paper, we describe physical mechanisms which affect the HVAC

Hochberg, Michael

224

Building America Technology Solutions for New and Existing Homes: Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet)  

Broader source: Energy.gov [DOE]

In a study of three single-story houses in Florida, the Building America research team Consortium for Advanced Residential Buildings (CARB) investigated the strategy of using buried and/or encapsulated ducts (BED) to reduce duct thermal losses in existing homes.

225

Property:Maximum Velocity(m/s) | Open Energy Information  

Open Energy Info (EERE)

Velocity(m/s) Velocity(m/s) Jump to: navigation, search Property Name Maximum Velocity(m/s) Property Type String Pages using the property "Maximum Velocity(m/s)" Showing 25 pages using this property. (previous 25) (next 25) A Alden Large Flume + 0.9 + B Bucknell Hydraulic Flume + 2.7 + C Carderock Maneuvering & Seakeeping Basin + 7.2 + Carderock Rotating Arm Tow Tank + 25.8 + Carderock Tow Tank 1 + 9.3 + Carderock Tow Tank 2 + 10.3 + Carderock Tow Tank 3 + 25.8 + Chase Tow Tank + 2.5 + D Davidson Laboratory Tow Tank + 18.3 + H Haynes Tow Tank + 1.8 + I Ice Towing Tank + 0.5 + L Lakefront Tow Tank + 2.7 + M MHL Free Surface Channel + 2 + MHL High Speed Cavitation + 25.9 + MHL Tow Tank + 6.7 + MIT Tow Tank + 1.5 + MMA Tugboat/ Barge/ Vessel + 5.1 + Maine Tow Tank + 3 +

226

Property:Velocity(m/s) | Open Energy Information  

Open Energy Info (EERE)

Velocity(m/s) Velocity(m/s) Jump to: navigation, search Property Name Velocity(m/s) Property Type String Pages using the property "Velocity(m/s)" Showing 21 pages using this property. A Alden Small Flume + >0.9 + B Bucknell Hydraulic Flume + 2.7 + C Carderock 2-ft Variable Pressure Cavitation Water Tunnel + 17 + Carderock 3-ft Variable Pressure Cavitation Water Tunnel + 25.8 + Carderock Circulating Water Channel + 5.2 + Carderock Large Cavitation Tunnel + 18 + Carderock Subsonic Wind Tunnel + 83.8 + D DeFrees Flume 1 + 2 + DeFrees Flume 2 + 2 + DeFrees Flume 3 + 2 + DeFrees Flume 4 + 2 + M MHL Free Surface Channel + 2 + MHL High Speed Cavitation + 25.9 + MHL Student Tunnel + 4.6 + P Penn Large Water Tunnel + 16.8 + Penn Small Water Tunnel + 21 + S SAFL Channel + 6.1 +

227

Optic-microwave mixing velocimeter for superhigh velocity measurement  

SciTech Connect (OSTI)

The phenomenon that a light beam reflected off a moving object experiences a Doppler shift in its frequency underlies practical interferometric techniques for remote velocity measurements, such as velocity interferometer system for any reflector (VISAR), displacement interferometer system for any reflector (DISAR), and photonic Doppler velocimetry (PDV). While VISAR velocimeters are often bewildered by the fringe loss upon high-acceleration dynamic process diagnosis, the optic-fiber velocimeters such as DISAR and PDV, on the other hand, are puzzled by high velocity measurement over 10 km/s, due to the demand for the high bandwidth digitizer. Here, we describe a new optic-microwave mixing velocimeter (OMV) for super-high velocity measurements. By using currently available commercial microwave products, we have constructed a simple, compact, and reliable OMV device, and have successfully obtained, with a digitizer of bandwidth 6 GH only, the precise velocity history of an aluminum flyer plate being accelerated up to 11.2 km/s in a three stage gas-gun experiment.

Weng Jidong; Wang Xiang; Tao Tianjiong; Liu Cangli; Tan Hua [Laboratory for Shock Waves and Detonation Physics Research, Institute of Fluid Physics, P.O. Box 919-102, Mianyang, Sichuan 621900 (China)

2011-12-15T23:59:59.000Z

228

DOE Workshop - Deposition Velocity Status  

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

Delivering DOE's Vision for the Delivering DOE's Vision for the East Tennessee Technology Park Mission Safely Delivering the Department of Energy's Vision for the East Tennessee Technology Park Mission DOE Workshop Deposition Velocity Status Mike Hitchler, Manager Nuclear Facility Safety June 5, 2012 Safely Delivering DOE's Vision for the East Tennessee Technology Park Mission Existing UCOR Analyses * UCOR facilities at East Tennessee Technology Park (ETTP) and Oak Ridge National Laboratory (ORNL) use various plume models depending on when they were developed and by whom. - Some use MACCS or MACCS2 for dispersion evaluation. (~5 locations) - LLLW uses ingestion modeling (multiple locations)

229

Newberry EGS Seismic Velocity Model  

DOE Data Explorer [Office of Scientific and Technical Information (OSTI)]

We use ambient noise correlation (ANC) to create a detailed image of the subsurface seismic velocity at the Newberry EGS site down to 5 km. We collected continuous data for the 22 stations in the Newberry network, together with 12 additional stations from the nearby CC, UO and UW networks. The data were instrument corrected, whitened and converted to single bit traces before cross correlation according to the methodology in Benson (2007). There are 231 unique paths connecting the 22 stations of the Newberry network. The additional networks extended that to 402 unique paths crossing beneath the Newberry site.

Dennise Templeton

230

Newberry EGS Seismic Velocity Model  

SciTech Connect (OSTI)

We use ambient noise correlation (ANC) to create a detailed image of the subsurface seismic velocity at the Newberry EGS site down to 5 km. We collected continuous data for the 22 stations in the Newberry network, together with 12 additional stations from the nearby CC, UO and UW networks. The data were instrument corrected, whitened and converted to single bit traces before cross correlation according to the methodology in Benson (2007). There are 231 unique paths connecting the 22 stations of the Newberry network. The additional networks extended that to 402 unique paths crossing beneath the Newberry site.

Dennise Templeton

2013-10-01T23:59:59.000Z

231

P And S Wave Velocity Determination  

E-Print Network [OSTI]

There are three general methods that can be used to determine formation velocities from full waveform logs. The first approach is to make use of the data from the entire waveform. This type of velocity analysis is performed ...

Willis, M. E.

1983-01-01T23:59:59.000Z

232

IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION, VOL. 51, NO. 5, MAY 2003 945 Propagation Model for the HVAC Duct as a  

E-Print Network [OSTI]

for the HVAC Duct as a Communication Channel Pavel V. Nikitin, Member, IEEE, Daniel D. Stancil, Senior Member (HVAC) ducts in buildings are typically hollow metal pipes which can be used as waveguides to carry such a communication system. This paper presents a propagation model for a straight HVAC duct terminated at both ends

Stancil, Daniel D.

233

A 12-MW-scale pilot study of in-duct scrubbing (IDS) using a rotary atomizer  

SciTech Connect (OSTI)

A low-cost, moderate-removal efficiency, flue gas desulfurization (FGD) technology was selected by the US Department of Energy for pilot demonstration in its Acid Rain Precursor Control Technology Initiative. The process, identified as In-Duct Scrubbing (IDS), applies rotary atomizer techniques developed for lime-based spray dryer FGD while utilizing existing flue gas ductwork and particulate collectors. IDS technology is anticipated to result in a dry desulfurization process with a moderate removal efficiency (50% or greater) for high-sulfur coal-fired boilers. The critical elements for successful application are: (1) adequate mixing of sorbent droplets with flue gas for efficient reaction contact, (2) sufficient residence time to produce a non-wetting product, and (3) appropriate ductwork cross-sectional area to prevent deposition of wet reaction products before particle drying is comple. The ductwork in many older plants, previously modified to meet 1970 Clean Air Act requirements for particulate control, usually meet these criteria. A 12 MW-scale IDS pilot plant was constructed at the Muskingum River Plant of the American Electric Power System. The pilot plant, which operates from a slipstrem attached to the air-preheater outlet duct from the Unit 5 boiler at the Muskingum River Plant (which burns about 4% sulfur coal), is equipped with three atomizer stations to test the IDS concept in vertical and horizontal configurations. In addition, the pilot plant is equipped to test the effect of injecting IDS off- product upstream of the atomizer, on SO{sub 2}and NO{sub x} removals.

Samuel, E.A.; Murphy, K.R.; Demian, A.

1989-11-01T23:59:59.000Z

234

Field Test of Advanced Duct-Sealing Technologies Within the Weatherization Assistance Program  

SciTech Connect (OSTI)

A field test of an aerosol-spray duct-sealing technology and a conventional, best-practice approach was performed in 80 homes to determine the efficacy and programmatic needs of the duct-sealing technologies as applied in the U.S. Department of Energy Weatherization Assistance Program. The field test was performed in five states: Iowa, Virginia, Washington, West Virginia, and Wyoming. The study found that, compared with the best-practice approach, the aerosol-spray technology is 50% more effective at sealing duct leaks and can potentially reduce labor time and costs for duct sealing by 70%, or almost 4 crew-hours. Further study to encourage and promote use of the aerosol-spray technology within the Weatherization Assistance Program is recommended. A pilot test of full production weatherization programs using the aerosol-spray technology is recommended to develop approaches for integrating this technology with other energy conservation measures and minimizing impacts on weatherization agency logistics. In order to allow or improve adoption of the aerosol spray technology within the Weatherization Assistance Program, issues must be addressed concerning equipment costs, use of the technology under franchise arrangements with Aeroseal, Inc. (the holders of an exclusive license to use this technology), software used to control the equipment, safety, and training. Application testing of the aerosol-spray technology in mobile homes is also recommended.

Ternes, MP

2001-12-05T23:59:59.000Z

235

Toward a Better Understanding of Ducted Rotor Antitorque and Directional Control in Forward Flight  

E-Print Network [OSTI]

of the Core Automatic Flight Control System (CAFCS) mode. Figure 1 shows a sustained, large-amplitude 1-Hz yaw ABSTRACT Despite decades of very successful yaw-control and anti-torque applications, the aerodynamics dramatic. From a handling-qualities perspective, the ducted rotor provides the loads capacity required

236

Control of Flow Separation in S-ducts via Flow Injection and Suction  

E-Print Network [OSTI]

with minimum stagnation pressure losses at the compressor face. In some aircraft a straight inletT 1 Research of the curvature of the S-duct centerline lead to cross-stream centrifugal pressure gradients which cause distribution on the engine compressor face. The net effect of the secondary flow and of the diffuser adverse

Debiasi, Marco

237

Improving Building Envelope and Duct Airtightness of US Dwellings - the Current State of Energy Retrofits  

E-Print Network [OSTI]

of different types of multi-family buildings that is not= 6,710 Multi-Family WAP N = 1,340 Figure 1: Whole-buildingbuilding envelope and duct system airtightness of US single-family detached homes, manufactured homes, and multi-

Chan, Wanyu R.

2014-01-01T23:59:59.000Z

238

Study of Gas Solid Flow Characteristics in Cyclone Inlet Ducts of A300Mwe CFB Boiler  

Science Journals Connector (OSTI)

Gas solid flow characteristics in cyclone’s inlet duct of a 300MW CFB boiler were studied in a cold circulating fluidized bed (CFB) experimental setup according to a 410t/h CFB boiler with a scale of 10?1....Figs...

J. Y. Tang; X. F. Lu; J. Lai; H. Z. Liu

2010-01-01T23:59:59.000Z

239

A COMPUTATIONAL AND EXPERIMENTAL ANALYSIS OF A DUCTED FAN USED IN VTOL UAV SYSTEMS  

E-Print Network [OSTI]

conditions. Fan rotor field including secondary flows, tip vortices, blade boundary layers and the wake sys wind tunnel test data. Total pressure measurements and computational predictions of mean flow field shows a significant level of 3D hub separation affecting the overall performance of the ducted fan

Camci, Cengiz

240

Duct System Flammability and Air Sealing Fire Separation Assemblies in the International Residential Code  

SciTech Connect (OSTI)

IBACOS identified two barriers that limit the ability of builders to cost-effectively achieve higher energy efficiency levels in housing. These are (1) the use of duct system materials that inherently achieve airtightness and are appropriately sized for low-load houses and (2) the ability to air seal fire separation assemblies. The issues identified fall into a gray area of the codes.

Rudd, A.; Prahl, D.

2014-12-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

ASU nitrogen sweep gas in hydrogen separation membrane for production of HRSG duct burner fuel  

DOE Patents [OSTI]

The present invention relates to the use of low pressure N2 from an air separation unit (ASU) for use as a sweep gas in a hydrogen transport membrane (HTM) to increase syngas H2 recovery and make a near-atmospheric pressure (less than or equal to about 25 psia) fuel for supplemental firing in the heat recovery steam generator (HRSG) duct burner.

Panuccio, Gregory J.; Raybold, Troy M.; Jamal, Agil; Drnevich, Raymond Francis

2013-04-02T23:59:59.000Z

242

A numerical method for calculation of power output from ducted vertical axis hydro-current turbines  

Science Journals Connector (OSTI)

Abstract This paper investigates effects of ducting on power output from vertical axis hydro-current turbines. A numerical two-dimensional method based on the potential flow theory is developed for calculation of non-dimensional power output from these turbines. In this method, the blades are represented by vortex filaments. The vortex shedding from the blades is modeled by discrete vortices. A boundary element method is used to incorporate the duct shape which is represented by a series of panels with constant distributions of sources and doublets. The aerodynamic loading on the blades are calculated using a quasi-steady modeling. A time-marching scheme is used for implementation of the numerical method. The results of this method are compared with experimental results for a turbine model. A good correlation between the numerical and experimental results is obtained for tip speed ratios equal and higher than 2.25. However due to a lack of dynamic stall modeling, the numerical method is not able to predict power output accurately at lower tip speed ratios wherein effects of dynamic stall are significant. Both numerical and experimental results also showed that the power output from a turbine can increase significantly when it is enclosed within a well-designed duct. The maximum power output of the turbine model investigated in this paper showed a 74% increase when the turbine is operating within the duct relative to the case it is in free-stream conditions.

Mahmoud Alidadi; Sander Calisal

2014-01-01T23:59:59.000Z

243

Duct Leakage Impacts on Airtightness, Infiltration, and Peak Electrical Demand in Florida Homes  

E-Print Network [OSTI]

return leak from the attic can increase cooling electrical demand by 100%. Duct repairs in a typical. electrically heated Florida home reduce winter peak demand by about 1.6 kW per house at about one-sixth the cost of building new electrical generation...

Cummings, J. B.; Tooley, J. J.; Moyer, N.

1990-01-01T23:59:59.000Z

244

Balloon Dilatation of Salivary Duct Strictures: Report on 36 Treated Glands  

SciTech Connect (OSTI)

Purpose: This paper describes the technique for balloon dilatation of salivary duct strictures and evaluates the clinical and radiographic findings in a consecutive series of 36 affected glands. Methods: Thirty-four patients (36 glands) had balloon dilatation of their salivary duct strictures performed under fluoroscopic control. They were evaluated immediately afterwards and at review by sialography. Results: In 36 cases attempted, 33 (92%) strictures were dilated. The immediate post-treatment sialogram was available in 28 cases, of which 23 (82%) demonstrated complete and four (14%) partial elimination of stricture. In one case the appearance was unchanged(4%). Review data (mean 6.8 months) were available on 25 glands: 12 were asymptomatic (48%), 12 (48%) had reduced symptoms and one (4%)failed to improve. Sialographic data were available on 21 glands: in 10(48%) the duct remained patent, in one (5%) the stricture was partially eliminated, in seven (33%) the strictures had returned and in the remaining three (14%) cases there was complete obstruction. Conclusions: Balloon dilatation is an effective treatment of salivary duct stenosis. In half the cases the stricture recurred but symptomatic improvement was achieved and maintained in the majority of cases.

Drage, Nicholas A.; Brown, Jackie E. [Department of Dental Radiology, Guy's Dental Hospital, Guy's and St. Thomas' Hospital Trust, London (United Kingdom); Escudier, Michael P. [Department of Oral Medicine and Pathology, Guy's, King's and St. Thomas' Dental Institute, King's College, London (United Kingdom); Wilson, Ron F. [Dental Clinical Research, Guy's, King's and St. Thomas' Dental Institute, King's College, London (United Kingdom); McGurk, Mark [Department of Oral andMaxillofacial Surgery, Guy's, King's and St. Thomas' Dental Institute, King's College, London (United Kingdom)

2002-10-15T23:59:59.000Z

245

Particle loading rates for HVAC filters, heat exchangers, and ducts Nomenclature  

E-Print Network [OSTI]

Particle loading rates for HVAC filters, heat exchangers, and ducts Nomenclature Afl surface area of floor (m2 ) bf fraction of bypass flow around the filter (dimensionless) Cout outdoor concentration on the filter per volume of air (mg/lm m3 ) Mf,tot total mass deposited on the filter per month of operation (g

Siegel, Jeffrey

246

Cooling air duct and screen arrangement for an air cooled engine  

SciTech Connect (OSTI)

This patent describes a cooling air duct and screen arrangement for an air cooled engine which includes an improved cooling air system for ensuring a supply of relatively clean air for ingestion by the cooling shroud, which consists of: a vertical transverse baffle mounted to the frame and fitting closely against a forward top portion of the shroud and having an edge shaped complementary to and disposed at least closely adjacent the hood. An air duct is mounted to the frame and has an upright rear wall seated against the front of the shroud in an area surrounding the inlet. The air duct further has an upright front wall and a connecting wall joining respective side and bottom edges of the front and rear walls and cooperating therewith to define an upwardly facing opening. A screen is located forwardly of the baffle and has a top and front joined by opposite sides with the top and opposite sides having rear edges mounted against the baffle and with the opposite sides and front having bottom edges engaged with the air duct about the upwardly facing opening wherein the screen is mounted solely to the baffle by connection means including a vertical guide means provided on the forward side of the baffle and flange means formed on the screen and being vertically slidably received in the guide means.

Hoch, J.J.; Stricker, D.K.

1986-03-04T23:59:59.000Z

247

Shielding design of the ITER NBI duct for nuclear and bremsstrahlung radiation  

Science Journals Connector (OSTI)

......evaluated about the nuclear heating rate and surface...representations of these nuclear responses are established...region and that in the vacuum vessel region. These...NBI duct wall in the nuclear fusion reactor. | Japan...Theoretical Particle Accelerators instrumentation Radiation......

S. Sato; H. Iida; M. Yamauchi; T. Nishitani

2005-12-20T23:59:59.000Z

248

Noise pair velocity and range echo location system  

DOE Patents [OSTI]

An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna.

Erskine, David J. (Oakland, CA)

1999-01-01T23:59:59.000Z

249

Noise pair velocity and range echo location system  

DOE Patents [OSTI]

An echo-location method for microwaves, sound and light capable of using incoherent and arbitrary waveforms of wide bandwidth to measure velocity and range (and target size) simultaneously to high resolution is disclosed. Two interferometers having very long and nearly equal delays are used in series with the target interposed. The delays can be longer than the target range of interest. The first interferometer imprints a partial coherence on an initially incoherent source which allows autocorrelation to be performed on the reflected signal to determine velocity. A coherent cross-correlation subsequent to the second interferometer with the source determines a velocity discriminated range. Dithering the second interferometer identifies portions of the cross-correlation belonging to a target apart from clutter moving at a different velocity. The velocity discrimination is insensitive to all slowly varying distortions in the signal path. Speckle in the image of target and antenna lobing due to parasitic reflections is minimal for an incoherent source. An arbitrary source which varies its spectrum dramatically and randomly from pulse to pulse creates a radar elusive to jamming. Monochromatic sources which jigger in frequency from pulse to pulse or combinations of monochromatic sources can simulate some benefits of incoherent broadband sources. Clutter which has a symmetrical velocity spectrum will self-cancel for short wavelengths, such as the apparent motion of ground surrounding target from a sidelooking airborne antenna. 46 figs.

Erskine, D.J.

1999-02-16T23:59:59.000Z

250

Calculation of the Electron Velocity Distribution Function in a Plasma Slab with Large Temperature and Density Gradients  

Science Journals Connector (OSTI)

...velocity. The distribution function for the...calculate the distribution function as a...region of the quiet Sun using several data-sets for temperature and density gradients...high-velocity tail of the distribution function. The...

1990-01-01T23:59:59.000Z

251

Embedded Fiber Optic Probes to Measure Detonation Velocities Using the Photonic Doppler Velocimeter  

SciTech Connect (OSTI)

Detonation velocities for high explosives can be in the 7 to 8 km/s range. Previous work has shown that these velocities may be measured by inserting an optical fiber probe into the explosive assembly and recording the velocity time history using a Fabry-Perot velocimeter. The measured velocity using this method, however, is the actual velocity multiplied times the refractive index of the fiber core, which is on the order of 1.5. This means that the velocimeter diagnostic must be capable of measuring velocities as high as 12 km/s. Until recently, a velocity of 12 km/s was beyond the maximum velocity limit of a homodyne-based velocimeter. The limiting component in a homodyne system is usually the digitizer. Recently, however, digitizers have come on the market with 20 GHz bandwidth and 50 GS/s sample rate. Such a digitizer coupled with high bandwidth detectors now have the total bandwidth required to make velocity measurements in the 12 km/s range. This paper describes measurements made of detonation velocities using a high bandwidth homodyne system.

Hare, D E; Holtkamp, D B; Strand, O T

2010-03-02T23:59:59.000Z

252

Augmented geophysical data interpretation through automated velocity picking in semblance velocity images  

Science Journals Connector (OSTI)

Velocity picking is the problem of picking velocity-time pairs based on a coherence metric between multiple seismic signals. Coherence as a function of velocity and time can be expressed as a 2D color semblance velocity image. Currently, humans pick ...

J. Ross Beveridge; Charlie Ross; Darrell Whitley; Barry Fish

2002-07-01T23:59:59.000Z

253

Low Velocity Boron Micro-Pellet Injector For Edge And Core Impurity Transport Measurements  

E-Print Network [OSTI]

velocities to insure penetration into the cores of high density, high temperature reactor grade plasmas at controlled penetration depths in the edge plasma. Applications involving short penetration distances and;3 required ablation rate. This paper describes a simple Low Velocity Boron Micro-Pellet Injector that has

254

A unified gas kinetic scheme with moving mesh and velocity space adaptation  

Science Journals Connector (OSTI)

There is great difficulty for direct Boltzmann solvers to simulate high Knudsen number flow due to the severe steep slope and high concentration of the gas distribution function in a local particle velocity space. Local mesh adaptation becomes necessary ... Keywords: Adaptive velocity space, Moving mesh, Rarefied gas, Unified gas kinetic scheme

Songze Chen; Kun Xu; Cunbiao Lee; Qingdong Cai

2012-08-01T23:59:59.000Z

255

Ultra-precise particle velocities in pulsed supersonic beams  

SciTech Connect (OSTI)

We describe an improved experimental method for the generation of cold, directed particle bunches, and the highly accurate determination of their velocities in a pulsed supersonic beam, allowing for high-resolution experiments of atoms, molecules, and clusters. It is characterized by a pulsed high pressure jet source with high brilliance and optimum repeatability, a flight distance of few metres that can be varied with a tolerance of setting of 50 {mu}m, and a precision in the mean flight time of particles of better than 10{sup -4}. The technique achieves unmatched accuracies in particle velocities and kinetic energies and also permits the reliable determination of enthalpy changes with very high precision.

Christen, Wolfgang [Institut fuer Chemie, Humboldt-Universitaet zu Berlin, Brook-Taylor-Strasse 2, 12489 Berlin (Germany)

2013-07-14T23:59:59.000Z

256

Cap Bubble Drift Velocity in a Confined Test Section  

SciTech Connect (OSTI)

In the two-group interfacial area transport equation, bubbles are categorized into two groups, i.e., spherical/distorted bubbles as group 1 and cap/slug/churn-turbulent bubbles as group 2. The bubble rise velocities for both groups of bubbles may be estimated by the drift flux model by applying different distribution parameters and drift velocities for both groups. However, the drift velocity for group 2 bubbles is not always applicable (when the wall effect becomes important) as in the current test loop of interest where the flow channel is confined by two parallel flat walls, with a dimension of 200-mm in width and 10-mm in gap. The previous experiments indicated that no stable slug flow existed in this test section, which was designed to permit visualization of the flow patterns and bubble characteristics without the distortion associated with curved surfaces. In fact, distorted cap bubbly and churn-turbulent flow was observed. Therefore, it is essential to developed a correlation for cap bubble drift velocity in this confined flow channel. Since the rise velocity of a cap bubble depends on its size, a high-speed movie camera is used to capture images of cap bubbles to obtain the bubble size information. Meanwhile, the rise velocity of cap and elongated bubbles (called cap bubbles hereafter) is investigated by examining the captured images frame by frame. As a result, the conventional correlation of drift velocity for slug bubbles is modified and acceptable agreements between the measurements and correlation estimation are achieved.

Xiaodong Sun; Seungjin Kim; Mamoru Ishii; Frank W. Lincoln; Stephen G. Beus

2002-10-09T23:59:59.000Z

257

Electromagnetic Energy Velocity in Slow Light  

Science Journals Connector (OSTI)

Group and electromagnetic energy velocities in structural and material slow light are compared. They are equal for structural slow light; the enhancement of linear and nonlinear...

Santagiustina, Marco

258

Reducing Thermal Losses and Gains With Buried and Encapsulated Ducts in Hot-Humid Climates  

SciTech Connect (OSTI)

The Consortium for Advanced Residential Buildings (CARB) monitored three houses in Jacksonville, FL, to investigate the effectiveness of encapsulated and encapsulated/buried ducts in reducing thermal losses and gains from ductwork in unconditioned attics. Burying ductwork beneath loose-fill insulation has been identified as an effective method of reducing thermal losses and gains from ductwork in dry climates, but it is not applicable in humid climates where condensation may occur on the outside of the duct jacket. By encapsulating the ductwork in closed cell polyurethane foam (ccSPF) before burial beneath loose-fill mineral fiber insulation, the condensation potential may be reduced while increasing the R-value of the ductwork.

Shapiro, C.; Magee, A.; Zoeller, W.

2013-02-01T23:59:59.000Z

259

Impacts of Optimized Cold & Hot Deck Reset Schedules on Dual Duct VAV Systems - Theory and Model Simulation  

E-Print Network [OSTI]

Impacts of Optimized Cold & Hot Deck Reset Schedules on Dual Duct VAV Systems - Theory and Model Simulation Mingsheng Liu, Ph.D., P.E. Energy Systems Laboratory Texas A&M University College Station, Texas Abstract Optimal hot and cold deck... rate increased from 30% to 70% of the maximum flow. Introduction Simultaneous heating and cooling can be reduced sigmficantly by optimizing cold and hot deck reset schedules in dual duct constant volume systems [Liu et. a1 1994, 1995, 19961...

Liu, M.; Claridge, D. E.

1998-01-01T23:59:59.000Z

260

Continuous Commissioning® of a Single Fan Dual Duct System in an Office Building  

E-Print Network [OSTI]

Continuous Commissioning ® of a Single Fan Dual Duct System in an Office Building D. Dong M. Liu, Ph.D., P.E Jinrong Wang, P.E Energy Systems Laboratory Energy Systems Laboratory... of AHU control sequences can significantly improve building comfort and reduce HVAC energy cost. REFERENCES 1. Liu, M., Y. Zhu, and D. E. Claridge, “Use of EMCS Recorded Data to Identify Potential Savings Due to Improved HVAC Operations...

Dong, D.; Liu, M.

2005-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Optimize the Supply Air Temperature Reset Schedule for a Single-Duct VAV System  

E-Print Network [OSTI]

Optimize the Supply Air Temperature Reset Schedule for a Single-Duct VAV System Guanghua Wei Mingsheng Liu, Ph.D., P.E. David E. Claridge, Ph.D., P.E. Senior Research Associate Associate Professor Professor Energy Systems Lab Architectural... will occur once the alrflow reaches the minimum and the heating load increases. To minimize this simultaneous cooling and heating, the supply air temperature is often reset based on either return air temperature or outside air temperature. Liu et al...

Wei, G.; Claridge, D. E.; Liu, M.

2000-01-01T23:59:59.000Z

262

Ducts Sealing Using Injected Spray Sealant, Raleigh, North Carolina (Fact Sheet)  

SciTech Connect (OSTI)

In multifamily and attached buildings, traditional duct sealing methods are often impractical or costly and disruptive because of the difficulty in accessing leakage sites. In this project, two retrofit duct sealing techniques - manually-applied sealants and injecting a spray sealant, were implemented in several low-rise multi-unit buildings. An analysis on the cost and performance of the two methods are presented. Each method was used in twenty housing units: approximately half of each group of units are single story and the remainder two-story. Results show that duct leakage to the outside was reduced by an average of 59% through the use of manual methods, and by 90% in the units where the injected spray sealant was used. It was found that 73% of the leakage reduction in homes that were treated with injected spray sealant was attributable to the manual sealing done at boots, returns and the air handler. The cost of manually-applying sealant ranged from $275 to $511 per unit and for the injected spray sealant the cost was $700 per unit. Modeling suggests a simple payback of 2.2 years for manual sealing and 4.7 years for the injected spray sealant system. Utility bills were collected for one year before and after the retrofits. Utility bill analysis shows 14% and 16% energy savings using injected spray sealant system and hand sealing procedure respectively in heating season whereas in cooling season, energy savings using injected spray sealant system and hand sealing were both 16%.

Not Available

2014-03-01T23:59:59.000Z

263

44 Market St - Refurbishment of a Dual Duct Building  

E-Print Network [OSTI]

and West risers with two separate BMS controlled throttling dampers downstream of the fans. While the original intent of the throttling dampers was probably as balancing dampers for the East and West riser, in reality they were resulting in large... of the average floor east group and average floor west group damper positions. This critical static pressure set point reset represents a large energy saving relative to the original fan speed control based on an excessively high static pressure set point...

Bannister, P.; Foo, G.

2013-01-01T23:59:59.000Z

264

Field comparison of the point velocity probe with other groundwater velocity measurement methods  

E-Print Network [OSTI]

Field testing of a new tool for measuring groundwater velocities at the centimeter scale, the point velocity probe (PVP), was undertaken at Canadian Forces Base, Borden, Ontario, Canada. The measurements were performed in ...

Labaky, W.; Devlin, J. F.; Gillham, R. W.

2009-03-14T23:59:59.000Z

265

Impact Velocity (2011) | National Nuclear Security Administration  

National Nuclear Security Administration (NNSA)

Impact Velocity (2011) | National Nuclear Security Administration Impact Velocity (2011) | National Nuclear Security Administration Our Mission Managing the Stockpile Preventing Proliferation Powering the Nuclear Navy Emergency Response Recapitalizing Our Infrastructure Continuing Management Reform Countering Nuclear Terrorism About Us Our Programs Our History Who We Are Our Leadership Our Locations Budget Our Operations Media Room Congressional Testimony Fact Sheets Newsletters Press Releases Speeches Events Social Media Video Gallery Photo Gallery NNSA Archive Federal Employment Apply for Our Jobs Our Jobs Working at NNSA Blog Home > Media Room > Video Gallery > Impact Velocity (2011) Impact Velocity (2011) Impact Velocity (2011) From: NNSANews Views: 388 2 ratings Time: 02:26 More in Science & Technology See video Facebook Twitter

266

Building America Webinar: High Performance Space Conditioning Systems, Part II- Compact Buried Ducts  

Broader source: Energy.gov [DOE]

This presentation is part of the U.S. Department of Energy Building America webinar held on November 18, 2014.

267

Observation of Resonant Behavior in the Energy Velocity of Diffused Light  

SciTech Connect (OSTI)

In this Letter we demonstrate Mie resonances mediated transport of light in randomly arranged, monodisperse dielectric spheres packed at high filling fractions. By means of both static and dynamic optical experiments we show resonant behavior in the key transport parameters and, in particular, we find that the energy transport velocity, which is lower than the group velocity, also displays a resonant behavior.

Sapienza, R.; Garcia, P. D.; Blanco, A.; Lopez, C. [Instituto de Ciencia de Materiales de Madrid (CSIC) and Unidad Asociada CSIC-UVigo, Cantoblanco 28049 Madrid (Spain); Bertolotti, J.; Wiersma, D. S. [European Laboratory for Nonlinear Spectroscopy and INFM-BEC, 50019 Sesto Fiorentino (Florence) (Italy); Martin, M. D.; Vina, L. [Departamento de Fisica de Materiales, Universidad Autonoma de Madrid, Cantoblanco 28049 Madrid (Spain)

2007-12-07T23:59:59.000Z

268

Lowell, Massachusetts, Preserves Historic Home Through Energy...  

Office of Energy Efficiency and Renewable Energy (EERE) Indexed Site

the historic house will receive upgrades that include a high-velocity, small-duct HVAC system, updated storm windows, and attic insulation. These upgrades will reduce...

269

Duct injection for SO{sub 2} control, Design Handbook, Volume 1, Process design and engineering guidelines  

SciTech Connect (OSTI)

PETC developed a comprehensive program of coal-related, acid-rain research and development with a major activity area centering on flue gas cleanup and control of SO{sub 2} emissions. Particular emphasis was placed on the retrofit measures for older coal-fired power plants which predate the 1971 New Source Performance Standards. Candidate emission control technologies fall into three categories, depending upon their point of application along the fuel path (i.e., pre, during, or post combustion). The post-combustion, in-duct injection of a calcium-based chemical reagent seemed promising. Preliminary studies showed that reagent injection between the existing air heater and electrostatic precipitator (ESP) could remove between 50-60% of the SO{sub 2} and produce an environmentally safe, dry, solid waste that is easily disposed. Although SO{sub 2} removal efficiencies were less, the estimated capital costs for duct injection technology were low making the economics of duct injection systems seem favorable when compared to conventional wet slurry scrubbers under certain circumstances. With the promulgation of the Clean Air Act Amendments of 1990 came more incentive for the development of low capital cost flue gas desulfurization (FGD) processes. A number of technical problems had to be resolved, however, before duct injection technology could be brought to a state of commercial readiness. The Duct Injection Technology Development Program was launched as a comprehensive, four-year research effort undertaken by PETC to develop this new technology. Completed in 1992, this Duct Injection Design Handbook and the three-dimensional predictive mathematical model constitute two primary end products from this development program. The aim of this design handbook and the accompanying math model is to provide utility personnel with sufficient information to evaluate duct injection technology against competing SO{sub 2} emissions reduction strategies for an existing plant.

NONE

1995-09-01T23:59:59.000Z

270

Energy Savings and Peak Demand Reduction of a SEER 21 Heat Pump vs. a SEER 13 Heat Pump with Attic and Indoor Duct Systems  

SciTech Connect (OSTI)

This report describes results of experiments that were conducted in an unoccupied 1600 square foot house--the Manufactured Housing (MH Lab) at the Florida Solar Energy Center (FSEC)--to evaluate the delivered performance as well as the relative performance of a SEER 21 variable capacity heat pump versus a SEER 13 heat pump. The performance was evaluated with two different duct systems: a standard attic duct system and an indoor duct system located in a dropped-ceiling space.

Cummings, J.; Withers, C.

2014-03-01T23:59:59.000Z

271

Modeling velocity dispersion In Gypsy site, Oklahoma  

E-Print Network [OSTI]

Discrepancies in interval velocities estimated from vertical well measurements made with different source central frequencies at Gypsy site could be primarily explained in terms of intrinsic attenuation. Four intervals ...

Alsaadan, Sami Ibrahim

2010-01-01T23:59:59.000Z

272

Acoustic measurement of potato cannon velocity  

E-Print Network [OSTI]

This article describes measurement of potato cannon velocity with a digitized microphone signal. A microphone is attached to the potato cannon muzzle and a potato is fired at an aluminum target about 10 m away. The potato's flight time can be determined from the acoustic waveform by subtracting the time in the barrel and time for sound to return from the target. The potato velocity is simply the flight distance divided by the flight time.

Courtney, M; Courtney, Amy; Courtney, Michael

2006-01-01T23:59:59.000Z

273

Finite element analysis of laminar mixed convection in the entrance region of horizontal annular ducts  

SciTech Connect (OSTI)

The laminar mixed convection in the entrance region of horizontal straight ducts of an annular cross section is studied by means of a generally applicable finite element procedure based on the parabolized simplification of the Navier-Stokes and energy equations and on the Boussinesq approximation of the buoyancy term. The procedure is validated through comparisons of computed results with available data from the literature. New results concern annuli with radius ratios equal to 0.25, 0.5, and 0.75 subjected to the fundamental boundary condition of the second and the third kinds, for Prandtl numbers equal to 0.7 and 7, and different values of Grashof number.

Nonino, C.; Giudice, S. del [Univ. di Udine (Italy). Dipt. di Energetica e Macchine

1996-02-23T23:59:59.000Z

274

Building America Case Study: Raised Ceiling Interior Duct System, New Smyrna, Florida (Fact Sheet)  

SciTech Connect (OSTI)

One of BA-PIRC's longtime Habitat for Humanity partners, S.E. Volusia CO (SEVHFH), was interested in building a home to the new Challenge Home standards. SEVHFH routinely builds ENERGY STAR V3.1 homes. The only modification to their design needed to comply with the Challenge Home criteria was the interior duct requirement. Unwilling to incur the added costs of a foam roof deck or wall heights above 8 feet to accommodate a fur-down chase SEVHFH opted to build a fur-up or raised ceiling chase.

Not Available

2014-09-01T23:59:59.000Z

275

An advanced economizer controller for dual-duct air-handling systems -- with a case application  

SciTech Connect (OSTI)

A heating penalty is expected when economizers are applied to dual-duct air-handling systems. The heating penalty can be even higher than the cooling savings when the hot airflow is higher than the cold airflow. To avoid the excessive heating penalty, advanced economizers are developed in this paper. The application of the advanced economizer has resulted in savings of $7,000/yr in one 95,000-ft{sup 2} (8,800-m{sup 2}) school building since 1993. The impacts of cold and hot deck settings on the energy consumption are also discussed.

Liu, M.; Claridge, D.E. [Texas A and M Univ., College Station, TX (United States). Mechanical Engineering Dept.; Park, B.Y. [Engineering Education Inst., Inchon (Korea, Republic of). Dept. of Architectural Engineering

1997-12-31T23:59:59.000Z

276

Numerical experiments of fracture-induced velocity and attenuation anisotropy  

Science Journals Connector (OSTI)

......Plata, La Plata, Argentina 4 Department of...phase velocities, energy velocities (wavefronts...112-200801-00952 (CONICET, Argentina). Appendix Appendix...qSV or v SH. The energy-velocity vector...phase velocities, energy velocities (wavefronts...de Buenos Aires Argentina 1179 1191 Geophysical......

J. M. Carcione; S. Picotti; J. E. Santos

2012-12-01T23:59:59.000Z

277

Nuclear reactor fuel assembly duct-tube-to-handling-socket attachment system  

DOE Patents [OSTI]

A reusable system for removably attaching the upper end 10of a nuclear reactor duct tube to the lower end 30 of a nuclear reactor fuel assembly handling socket. A transition ring 20, fixed to the duct tube's upper end 10, has an interior-threaded section 22 with a first locking hole segment 24. An adaptor ring 40, fixed to the handling socket's lower end 30 has an outside-threaded section 42 with a second locking hole segment 44. The inside 22 and outside 42 threaded sections match and can be joined so that the first 24 and second 44 locking hole segments can be aligned to form a locking hole. A locking ring 50, with a locking pin 52, slides over the adaptor ring 40 so that the locking pin 52 fits in the locking hole. A swage lock 60 or a cantilever finger lock 70 is formed from the locking cup collar 26 to fit in a matching groove 54 or 56 in the locking ring 50 to prevent the locking ring's locking pin 52 from backing out of the locking hole.

Christiansen, David W. (Kennewick, WA); Smith, Bob G. (Kennewick, WA)

1982-01-01T23:59:59.000Z

278

The use of ducts to improve the control of supply air temperature rise in UFAD systems: CFD and lab study  

Science Journals Connector (OSTI)

Abstract Cool supply air flowing through the underfloor plenum is exposed to heat gain from both the concrete slab (conducted from the warm return air on the adjacent floor below the slab) and the raised floor panels (conducted from the warmer room above). The magnitude of this heat gain can be quite high, resulting in undesirable loss of control of the supply air temperature from the plenum into the occupied space. These warmer supply air temperatures can make it more difficult to maintain comfort in the occupied space (without increasing airflow rates), particularly in perimeter zones where cooling loads reach their highest levels. How to predict plenum thermal performance is one of the key design issues facing practicing engineers – evidence from completed projects indicates that excessive temperature rise in the plenum can be a problem. One of the recommended strategies for addressing temperature rise in UFAD systems is the use of ductwork (flexible or rigid) within the underfloor plenum to deliver cool air preferentially to perimeter zones or other critical areas of high cooling demand. Several experiments were carried out in a full-scale underfloor plenum test facility, in order to characterize all the phenomena that take place in an underfloor plenum equipped with a fabric or metal duct. Experimental data were collected for validation of a computational fluid dynamics (CFD) model of the plenum. This paper describes the first part of a more comprehensive work, whose aim is to use the validated CFD plenum model to conduct simulations of a broader range of plenum design and operational parameters. This work proves that using ductwork within the underfloor plenum reduce the temperature rise in the plenum.

Wilmer Pasut; Fred Bauman; Michele De Carli

2014-01-01T23:59:59.000Z

279

Radial velocities and binarity of southern SIM grid stars  

E-Print Network [OSTI]

We present analysis of precision radial velocities (RV) of 1134 mostly red giant stars in the southern sky, selected as candidate astrometric grid objects for the Space Interferometry Mission (SIM). Only a few (typically, 2 or 3) spectroscopic observations per star have been collected, with the main goal of screening binary systems. The estimated rate of spectroscopic binarity in this sample of red giants is 32% at the 0.95 confidence level, and 46% at the 0.75 confidence. The true binarity rate is likely to be higher, because our method is not quite sensitive to very wide binaries and low-mass companions. The estimated lower and upper bounds of stellar RV jitter for the entire sample are 24 and 51 m/s, respectively; the adopted mean value is 37 m/s. A few objects of interest are identified with large variations of radial velocities, implying abnormally high mass ratios.

Makarov, Valeri V

2014-01-01T23:59:59.000Z

280

Small Arteriovenous Malformation of the Common Bile Duct Causing Hemobilia in a Patient with Hereditary Hemorrhagic Telangiectasia  

SciTech Connect (OSTI)

We report a 54-year-old male patient with arteriovenous malformation located at the common bile duct and hereditary hemorrhagic telangiectasia. The patient was treated as gallstone pancreatitis at first. Three days after endoscopic nasobiliary drainage (ENBD) for biliary drainage to subside gallstone pancreatitis, hemobilia was drained from the ENBD tube and the serum hemoglobin level gradually decreased. Cholangioscopy and angiography revealed that hemobilia was due to a small arteriovenous malformation located at the common bile duct. Subsequently, the patient was successfully treated by endovascular intervention.

Hayashi, Sadao, E-mail: hayashi@m.kufm.kagoshima-u.ac.jp; Baba, Yasutaka; Ueno, Kazuto; Nakajo, Masayuki [Kagoshima University Graduate School of Medical and Dental Sciences, Department of Radiology (Japan)

2008-07-15T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Cross spectra between temperature and pressure in a constant area duct downstream of a hydrogen fueled combustor  

Science Journals Connector (OSTI)

It was shown in a recent paper [J. H. Miles and E. A. Krejsa J. Acoust. Soc. Am. 72 2008–2019 (1982)] that knowledge of pressure?temperature auto spectra and cross spectra could be used in a model for sound propagation in a variable duct having acoustic and convected entropy fluctuations. The present exploratory study investigates the measurement of pressure?temperature cross spectra and coherence and temperature cross spectra and coherence at well separated points in a combustion rig. Data obtained near the inlet and the exit of a 6.44?m?long duct attached to a J?47 combustor fueled with hydrogen are presented.

J. H. Miles; C. A. Wasserbauer; E. A. Krejsa

1983-01-01T23:59:59.000Z

282

Faster-Than-Light Group Velocities and Causality Violation  

Science Journals Connector (OSTI)

...research-article Faster-Than-Light Group Velocities and Causality...group velocities in excess of the speed of light does not imply causality violation...phase velocity shall exceed the speed of light. Application of the theorem leads...

1970-01-01T23:59:59.000Z

283

Pneumatic cleaning of sugarcane utilizing a high velocity air jet  

E-Print Network [OSTI]

- oped to cope with the increased amount of trash present in unburned sugarcane. This research involved the testing and computer simulation of a chopper air jet nozzle assembly. The experimental test setup included a two-stage conveyor. This conveyor... of cleaning produced by the system and the amount of momentum produced by the air jet. When unburned, untopped sugarcane was fed. into the chopper air jet nozzle assembly, a result of 9/~ trash in the bottom conveyor was achieved, A value of 14/ trash...

Fisher, John Ray

2012-06-07T23:59:59.000Z

284

Relation between plasma plume density and gas flow velocity in atmospheric pressure plasma  

SciTech Connect (OSTI)

We have studied atmospheric pressure plasma generated using a quartz tube, helium gas, and copper foil electrode by applying RF high voltage. The atmospheric pressure plasma in the form of a bullet is released as a plume into the atmosphere. To study the properties of the plasma plume, the plasma plume current is estimated from the difference in currents on the circuit, and the drift velocity is measured using a photodetector. The relation of the plasma plume density n{sub plu}, which is estimated from the current and the drift velocity, and the gas flow velocity v{sub gas} is examined. It is found that the dependence of the density on the gas flow velocity has relations of n{sub plu} ? log(v{sub gas}). However, the plasma plume density in the laminar flow is higher than that in the turbulent flow. Consequently, in the laminar flow, the density increases with increasing the gas flow velocity.

Yambe, Kiyoyuki; Taka, Shogo; Ogura, Kazuo [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)] [Graduate School of Science and Technology, Niigata University, Niigata 950-2181 (Japan)

2014-04-15T23:59:59.000Z

285

ARM - Evaluation Product - Convective Vertical Velocity  

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

ProductsConvective Vertical Velocity ProductsConvective Vertical Velocity Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Evaluation Product : Convective Vertical Velocity 2011.04.25 - 2011.05.23 Site(s) SGP General Description Convective processes play an important role in Earth's energy balance by distributing heat and moisture throughout the atmosphere. In particular, vertical air motions associated with these processes are inherently linked to the life cycle of these convective systems and are therefore directly tied to their energy budget. However, direct measurements of vertical air motions (e.g., in situ aircraft observations) are sparse, making it difficult to compare them with numerical model output, which relies on convective parameterization schemes that have yet to be extensively

286

Sound velocity bound and neutron stars  

E-Print Network [OSTI]

It has been conjectured that the velocity of sound in any medium is smaller than the velocity of light in vacuum divided by $\\sqrt{3}$. Simple arguments support this bound in non-relativistic and/or weakly coupled theories. The bound has been demonstrated in several classes of strongly coupled theories with gravity duals and is saturated only in conformal theories. We point out that the existence of neutron stars with masses around two solar masses combined with the knowledge of the equation of state of hadronic matter at "low" densities is in strong tension with this bound.

Paulo F. Bedaque; Andrew W. Steiner

2015-01-25T23:59:59.000Z

287

Augmented Geophysical Data Interpretation Through Automated Velocity Picking in Semblance Velocity Images  

E-Print Network [OSTI]

University Fort Collins, CO 80523 ross@cs.colostate.edu Barry Fish Sun Microsystems (Previously at Landmark Graphics) Denver, CO Barry.Fish@central.sun.com Abstract Velocity Picking is the problem of picking velocity-time pairs based on a coherence metric between multiple seismic signals. Coherence as a function

Whitley, Darrell

288

Velocity Shear Stabilization of Centrifugally Confined Plasma  

Science Journals Connector (OSTI)

A magnetized, centrifugally confined plasma is subjected to a 3D MHD stability test. Ordinarily, the system is expected to be grossly unstable to “flute” interchanges of field lines. Numerical simulation shows though that the system is stable on account of velocity shear. This allows consideration of a magnetically confined plasma for thermonuclear fusion that has a particularly simple coil configuration.

Yi-Min Huang and A. B. Hassam

2001-11-16T23:59:59.000Z

289

LATTICE BOLTZMANN SCHEMES WITH RELATIVE VELOCITIES  

E-Print Network [OSTI]

LATTICE BOLTZMANN SCHEMES WITH RELATIVE VELOCITIES FRANÃ?OIS DUBOIS, TONY FEVRIER, AND BENJAMIN GRAILLE Abstract. In this contribution, a new class of lattice Boltzmann schem- es is introduced is then performed to derive the equivalent equations up to third order accuracy. Introduction The lattice Boltzmann

Boyer, Edmond

290

Localized velocity anomalies in the lower mantle  

Science Journals Connector (OSTI)

......projection centred on the Argentina source region. The location...approximately 80" from the Argentina source region. S-waves...Bolivia are dominated by SV energy, and large Sp precursors...closer to the stations than Argentina. Lower mantle velocity anomalies......

Thorne Lay

1983-02-01T23:59:59.000Z

291

Bulk flow velocities in the solar corona  

Science Journals Connector (OSTI)

......bin. In a small but significant number of images the data are defective, largely owing to telemetry drop outs. These images are easily...velocity-height curves. We perform a five-point running-box-car straight-line fit with appropriate weighting and this rate......

D. J. Lewis; G. M. Simnett

2000-10-01T23:59:59.000Z

292

VELOCITY AND MAGNETIC FIELD DISTRIBUTION IN A FORMING PENUMBRA  

SciTech Connect (OSTI)

We present results from the analysis of high-resolution spectropolarimetric and spectroscopic observations of the solar photosphere and chromosphere, obtained shortly before the formation of a penumbra in one of the leading polarity sunspots of NOAA active region 11490. The observations were performed at the Dunn Solar Telescope of the National Solar Observatory on 2012 May 28, using the Interferometric Bidimensional Spectrometer. The data set is comprised of a 1 hr time sequence of measurements in the Fe I 617.3 nm and Fe I 630.25 nm lines (full Stokes polarimetry) and in the Ca II 854.2 nm line (Stokes I only). We perform an inversion of the Fe I 630.25 nm Stokes profiles to derive magnetic field parameters and the line-of-sight (LOS) velocity at the photospheric level. We characterize chromospheric LOS velocities by the Doppler shift of the centroid of the Ca II 854.2 nm line. We find that, before the formation of the penumbra, an annular zone of 3''-5'' width is visible around the sunspot. In the photosphere, we find that this zone is characterized by an uncombed structure of the magnetic field although no visible penumbra has formed yet. We also find that the chromospheric LOS velocity field shows several elongated structures characterized by downflow and upflow motions in the inner and outer parts of the annular zone, respectively.

Romano, P.; Guglielmino, S. L. [INAF-Osservatorio Astrofisico di Catania, Via S. Sofia 78, I-95125 Catania (Italy); Frasca, D.; Zuccarello, F. [Dipartimento di Fisica e Astronomia-Sezione Astrofisica, Universita di Catania, Via S. Sofia 78, I-95125 Catania (Italy); Ermolli, I. [INAF-Osservatorio Astronomico di Roma, Via Frascati 33, I-00040 Monte Porzio Catone (Italy); Tritschler, A.; Reardon, K. P., E-mail: prom@oact.inaf.it [National Solar Observatory/Sacramento Peak, P.O. Box 62, Sunspot, NM 88349-0062 (United States)

2013-07-01T23:59:59.000Z

293

Water Velocity Measurements on a Vertical Barrier Screen at the Bonneville Dam Second Powerhouse  

SciTech Connect (OSTI)

Fish screens at hydroelectric dams help to protect rearing and migrating fish by preventing them from passing through the turbines and directing them towards the bypass channels by providing a sweeping flow parallel to the screen. However, fish screens may actually be harmful to fish if they become impinged on the surface of the screen or become disoriented due to poor flow conditions near the screen. Recent modifications to the vertical barrier screens (VBS) at the Bonneville Dam second powerhouse (B2) intended to increase the guidance of juvenile salmonids into the juvenile bypass system (JBS) have resulted in high mortality and descaling rates of hatchery subyearling Chinook salmon during the 2008 juvenile salmonid passage season. To investigate the potential cause of the high mortality and descaling rates, an in situ water velocity measurement study was conducted using acoustic Doppler velocimeters (ADV) in the gatewell slot at Units 12A and 14A of B2. From the measurements collected the average approach velocity, sweep velocity, and the root mean square (RMS) value of the velocity fluctuations were calculated. The approach velocities measured across the face of the VBS varied but were mostly less than 0.3 m/s. The sweep velocities also showed large variances across the face of the VBS with most measurements being less than 1.5 m/s. This study revealed that the approach velocities exceeded criteria recommended by NOAA Fisheries and Washington State Department of Fish and Wildlife intended to improve fish passage conditions.

Hughes, James S.; Deng, Zhiqun; Weiland, Mark A.; Martinez, Jayson J.; Yuan, Yong

2011-11-22T23:59:59.000Z

294

Procedure and Application for Determining the Cold Deck and Hot Deck Airflow in a Dual-Duct System  

E-Print Network [OSTI]

This paper introduces an innovative method to determine the cold and hot airflow through a dual-duct variable air volume (VAV) system. The actual building load can be identified based on the calculated airflow and temperature for both the cold...

Liu, G.; Mingsheng, L.

2006-01-01T23:59:59.000Z

295

Orthogonality relations for fluid-structural waves in a three-dimensional, rectangular duct with flexible walls  

Science Journals Connector (OSTI)

...ventilation and air conditioning (HVAC), provide ideal channels for...such systems do not satisfy standard orthogonality conditions, such...however, exist albeit of non-standard form, and Lawrie Abrahams...particular relevance to the HVAC industry because many HVAC ducts...

2009-01-01T23:59:59.000Z

296

Exploring Maximum Humidity Control and Energy Conservation Opportunities with Single Duct Single Zone Air-Handling Units  

E-Print Network [OSTI]

Humidity control for single-duct single-zone (SDSZ) constant volume air handling units is known to be a challenge. The operation of these systems is governed by space temperature only. Under mild weather conditions, discharge air temperature can get...

Zhou, J.; Wei, G.; Turner, W. D.; Deng, S.; Claridge, D.

2006-01-01T23:59:59.000Z

297

Influence of Tip Clearance and Inlet Flow Distortion on Ducted Fan Performance in VTOL UAVs Graduate Research Assistant  

E-Print Network [OSTI]

(Pa) CpTotal = Total pressure coefficient = Rotational speed (radian/sec) r = Radial distance measured military tasks, they can continuously transmit surveillance data and act as a relay station. Although to study the flow characteristics of ducted fans. Abrego and Bulaga [1] performed wind tunnel tests

Camci, Cengiz

298

A MAGNETIC CALIBRATION OF PHOTOSPHERIC DOPPLER VELOCITIES  

SciTech Connect (OSTI)

The zero point of measured photospheric Doppler shifts is uncertain for at least two reasons: instrumental variations (from, e.g., thermal drifts); and the convective blueshift, a known correlation between intensity and upflows. Accurate knowledge of the zero point is, however, useful for (1) improving estimates of the Poynting flux of magnetic energy across the photosphere, and (2) constraining processes underlying flux cancellation, the mutual apparent loss of magnetic flux in closely spaced, opposite-polarity magnetogram features. We present a method to absolutely calibrate line-of-sight (LOS) velocities in solar active regions (ARs) near disk center using three successive vector magnetograms and one Dopplergram coincident with the central magnetogram. It exploits the fact that Doppler shifts measured along polarity inversion lines (PILs) of the LOS magnetic field determine one component of the velocity perpendicular to the magnetic field, and optimizes consistency between changes in LOS flux near PILs and the transport of transverse magnetic flux by LOS velocities, assuming that ideal electric fields govern the magnetic evolution. Previous calibrations fitted the center-to-limb variation of Doppler velocities, but this approach cannot, by itself, account for residual convective shifts at the limb. We apply our method to vector magnetograms of AR 11158, observed by the Helioseismic and Magnetic Imager aboard the Solar Dynamics Observatory, and find clear evidence of offsets in the Doppler zero point in the range of 50-550 m s{sup -1}. In addition, we note that a simpler calibration can be determined from an LOS magnetogram and Dopplergram pair from the median Doppler velocity among all near-disk-center PIL pixels. We briefly discuss shortcomings in our initial implementation, and suggest ways to address these. In addition, as a step in our data reduction, we discuss the use of temporal continuity in the transverse magnetic field direction to correct apparently spurious fluctuations in resolution of the 180 Degree-Sign ambiguity.

Welsch, Brian T.; Fisher, George H. [Space Sciences Laboratory, University of California, Berkeley, CA 94720-7450 (United States); Sun, Xudong [W. W. Hansen Experimental Physics Laboratory, Stanford University, Stanford, CA 94305 (United States)

2013-03-10T23:59:59.000Z

299

Three-dimensional P and S waves velocity structures of the Coso geothermal  

Open Energy Info (EERE)

P and S waves velocity structures of the Coso geothermal P and S waves velocity structures of the Coso geothermal area, California, from microseismic travel time data Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Three-dimensional P and S waves velocity structures of the Coso geothermal area, California, from microseismic travel time data Details Activities (1) Areas (1) Regions (0) Abstract: High precision P and S wave travel times for 2104 microearthquakes with focus <6 km are used in a non-linear inversion to derive high-resolution three-dimensional compressional and shear velocity structures at the Coso Geothermal Area in eastern California. Block size for the inversion is 0.2 km horizontally and 0.5 km vertically and inversions are investigated in the upper 5 km of the geothermal area.

300

Characterization of Pipes, Drain Lines, and Ducts using the Pipe Explorer System  

Office of Scientific and Technical Information (OSTI)

MC/30172-97/C0803 MC/30172-97/C0803 Title: Characterization of Pipes, Drain Lines, and Ducts Using the Pipe Explorer System TM Authors: C.D. Cremer D.T. Kendrick E. Cramer Contractor: Science and Engineering Associates, Inc. 6100 Uptown Blvd, NE Albuquerque, NM 87100 Contract Number: DE-AC21-93MC30172 Conference: Industry Partnerships to Deploy Environmental Technology Conference Location: Morgantown, West Virginia Conference Dates: October 22-24, 1996 Conference Sponsor: Morgantown Energy Technology Center Disclaimer This report was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor any agency thereof, nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any

Note: This page contains sample records for the topic "duct high velocity" 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

Impact of Ducting on Heat Pump Water Heater Space Conditioning Energy Use and Comfort  

SciTech Connect (OSTI)

Increasing penetration of heat pump water heaters (HPWHs) in the residential sector will offer an important opportunity for energy savings, with a theoretical energy savings of up to 63% per water heater and up to 11% of residential energy use (EIA 2009). However, significant barriers must be overcome before this technology will reach widespread adoption in the Pacific Northwest region and nationwide. One significant barrier noted by the Northwest Energy Efficiency Alliance (NEEA) is the possible interaction with the homes’ space conditioning system for units installed in conditioned spaces. Such complex interactions may decrease the magnitude of whole-house savings available from HPWH installed in the conditioned space in cold climates and could lead to comfort concerns (Larson et al. 2011; Kresta 2012). Modeling studies indicate that the installation location of HPWHs can significantly impact their performance and the resultant whole-house energy savings (Larson et al. 2012; Maguire et al. 2013). However, field data are not currently available to validate these results. This field evaluation of two GE GeoSpring HPWHs in the PNNL Lab Homes is designed to measure the performance and impact on the Lab Home HVAC system of a GE GeoSpring HPWH configured with exhaust ducting compared to an unducted GeoSpring HPWH during heating and cooling season periods; and measure the performance and impact on the Lab Home HVAC system of the GeoSpring HPWH with both supply and exhaust air ducting as compared to an unducted GeoSpring HPWH during heating and cooling season periods. Important metrics evaluated in these experiments include water heater energy use, HVAC energy use, whole house energy use, interior temperatures (as a proxy for thermal comfort), and cost impacts. This technical report presents results from the PNNL Lab Homes experiment.

Widder, Sarah H.; Petersen, Joseph M.; Parker, Graham B.; Baechler, Michael C.

2014-07-21T23:59:59.000Z

302

Preliminary Estimates of Specific Discharge and TransportVelocities near Borehole NC-EWDP-24PB  

SciTech Connect (OSTI)

This report summarizes fluid electrical conductivity (FEC)and thermal logging data collected in Borehole NC-EWDP-24PB, locatedapproximately 15 km south of the proposed repository at Yucca Mountain.Preliminary analyses of a small fraction of the FEC and temperature dataindicate that relatively large, localized fluid fluxes are likely toexist at this location. The implication that considerable flow is inducedby small gradients, and that flow is highly localized, is significant forthe estimation of groundwater transport velocities and radionuclidetravel times. The sensitivity of the data to potential perturbationsduring testing (i.e., internal wellbore flow in the case of FEC data, andbuoyancy effects in the case of thermal logging data) make it difficultto conclusively derive fluid fluxes and transport velocities without adetailed analysis of all data and processes involved. Such acomprehensive analysis has not yet been performed. However, thepreliminary results suggest that the ambient component of the estimatedflow rates is significant and on the order of liters per minute, yieldinggroundwater transport velocities in the range of kilometers per year. Oneparticular zone in the Bullfrog tuff exhibits estimated velocities on theorder of 10 km/yr. Given that the preliminary estimates of ambient flowrates and transport velocities are relatively high, and considering thepotential impact of high rates and velocities on saturated-zone flow andtransport behavior, we recommend that a comprehensive analysis of all theavailable data be performed. Moreover, additional data sets at otherlocations should be collected to examine whether the current data set isrepresentative of the regional flow system near YuccaMountain.

Freifeld, Barry; Doughty, Christine; Finsterle, Stefan

2006-06-21T23:59:59.000Z

303

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer  

E-Print Network [OSTI]

3D REGULARIZED VELOCITY FROM 3D DOPPLER RADIAL VELOCITY X. Chen, J.L. Barron, R.E. Mercer Dept, Ontario, M3H 5T4 Paul.Joe@ec.gc.ca ABSTRACT The recent availability of sequences of 3D Doppler radial velocity datasets provides sufficient information to estimate the 3D velocity of Doppler storms. We present

Barron, John

304

In-depth survey report: Control technology for small business: Evaluation of a flexible duct ventilation system for radiator repair, at A-1 Radiator, Reno, Nevada  

SciTech Connect (OSTI)

An engineering control evaluation was conducted at a radiator repair shop which operated at a very high level of production. The shop had the potential for high exposures to lead (7439921) because of the high volume of work, the number of radiator repair stations, and repairs to huge radiators for mining equipment. Local exhaust ventilation which utilized adjustable arm elephant trunk exhaust hoods had been installed 18 months prior to the visit. The objective of the study was to evaluate the effectiveness of the local exhaust ventilation (LEV) system to control lead exposures during work operations. Time weighted average personal exposures for lead were at or below the OSHA permissible exposure level for ten of 15 mechanics during a high level of production. The elephant trunk ventilation system was capable of controlling lead fumes while shop doors were open, except at one tank in a corner. Work practices were found to be a source of excessive lead exposure. Emissions from a worker's own soldering and from soldering activity upwind of the worker were a major source of lead exposure. Collapse of flexible portions of ducts could reduce exhaust volume. Dampers also showed a tendency to close automatically.

Sheehy, J.W.; Cooper, T.C.; Hall, R.M.; Meier, R.M.

1990-02-01T23:59:59.000Z

305

Buried and Encapsulated Ducts, Jacksonville, Florida (Fact Sheet), Building America Case Study: Technology Solutions for New and Existing Homes, Building Technologies Office (BTO)  

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

Buried and Encapsulated Ducts Buried and Encapsulated Ducts Jacksonville, Florida PROJECT INFORMATION Project Name: Buried and Encapsulated Ducts Location: Jacksonville, FL Partners: BASF http://www.basf.com Consortium for Advanced Residential Buildings www.carb-swa.com Building Component: Ductwork and Attic Insulation Application: New and/or Retrofit; Single-Family Year Tested: 2010-2011 Applicable Climate Zone(s): All Climates in IECC Moisture Regime A. PERFORMANCE DATA Cost of Energy-Efficiency Measure (including labor): $2,439 Projected Energy Savings: 34% cooling and heating savings Projected Energy Cost Savings: $11/month or $135/year Ductwork installed in unconditioned attics can significantly increase the overall

306

high  

Gasoline and Diesel Fuel Update (EIA)

0 0 Summary Our short-term outlook for a wide array of energy prices has been adjusted upward as international and domestic energy supply conditions have tightened. We think that crude oil prices are as likely as not to end the year $2 to $3 per barrel higher than our previous projections. Thus, we think that the probability of West Texas Intermediate costing an average of $30 per barrel or more at midwinter is about 50 percent. On their current track, heating oil prices are likely to be about 30 percent above year-ago levels in the fourth quarter. Prices for Q1 2001 seem more likely now to match or exceed the high level seen in Q1 2000. Tight oil markets this year and an inherent propensity for high gas utilization in incremental power supply have resulted in rising North American natural gas

307

Frictional behaviour of halite/muscovite fault gouge analogues: Effects of sliding velocity and of stepwise acceleration from sub- to co-seismic slip rates.  

E-Print Network [OSTI]

??Investigating the (transient) frictional behaviour of fault rock from low to high velocities is required in experimental research on the stability of faults and earthquake… (more)

Buijze, A.J.L.

2010-01-01T23:59:59.000Z

308

Laser-driven acceleration of a dense matter up to 'thermonuclear' velocities  

Science Journals Connector (OSTI)

The results of theoretical studies and numerical simulations of laser-driven acceleration of a flat foil up to ultrahigh velocity of the order of 1000?km?s?1, which corresponds to the achievement of thermonuclear temperatures due to kinetic energy transition into thermal energy at an inelastic impact, are reported. The behavior of a foil accelerated to such high velocities, in particular, the distribution of foil density, which defines thermonuclear reaction intensity, has been studied. The calculation results are compared with the results of the experiments performed on the Gekko/HIPER laser, where a laser-driven projectile achieved record-breaking velocity. The laser pulse and foil parameters responsible for acceleration of the projectile up to 'thermonuclear' velocities in a dense state have been determined.

S Yu Gus'kov; H Azechi; N N Demchenko; V V Demchenko; I Ya Doskoch; M Murakami; H Nagatomo; V B Rozanov; S Sakaiya; R V Stepanov; N V Zmitrenko

2007-01-01T23:59:59.000Z

309

Building America Technology Solutions for New and Existing Homes: New Insights for Improving the Designs of Flexible Duct Junction Boxes (Fact Sheet)  

Broader source: Energy.gov [DOE]

IBACOS explored the relationships between pressure and physical configurations of flexible duct junction boxes by using computational fluid dynamics simulations to predict individual box parameters and total system pressure, thereby ensuring improved HVAC performance.

310

high  

Gasoline and Diesel Fuel Update (EIA)

0 0 Highlights International Oil Markets Prices. We have raised our world oil price projection by about $2 per barrel for this month because of assumed greater compliance by OPEC to targeted cuts, especially for the second quarter of 2000 (Figure 1). The expected decline in world petroleum inventories continues (Figure 2), and, given the generally stiff resolve of OPEC members to maintain production cuts, any sign of a turnaround in stocks may be postponed until later this year than previously assumed (Q3 instead of Q2). Our current estimate for the average import cost this past January is now $25 per barrel, a nearly $15-per-barrel increase from January 1999. Crude oil prices are expected to remain at relatively high levels for the first half of 2000, but

311

In situ remediation of plutonium from glovebox exhaust ducts at the Department of Energy`s Rocky Flats Plant  

SciTech Connect (OSTI)

Plutonium and other miscellaneous hold-up materials have been accumulating in the glovebox exhaust ducts at the Rocky Flats Plant over the 40 years of weapons production at the site. The Duct Remediation Project was undertaken to assess the safety impacts of this material, and to remove it from the ductwork. The project necessitated the development of specialized tools, equipment and methods to remediate the material from continuously operating ventilation systems. Special engineered access locations were also required to provide access to the ductwork, and to ensure that safety and system operability were not degraded as a result of the remediation efforts. Operations personnel underwent significant training and development, and became an important asset to the success of the project. In total, the project succeeded in removing over 40 kilograms of plutonium-bearing material from one of the major weapons production buildings at the plant.

Dugdale, J.S.; Humiston, T.J.; Omer, G.E.

1993-10-01T23:59:59.000Z

312

Residual turbulence from velocity shear stabilized interchange instabilities  

SciTech Connect (OSTI)

The stabilizing effect of velocity shear on the macroscopic, broad bandwidth, ideal interchange instability is studied in linear and nonlinear regimes. A 2D dissipative magnetohydrodynamic (MHD) code is employed to simulate the system. For a given flow shear, V Prime , linear growth rates are shown to be suppressed to below the shear-free level at both the small and large wavelengths. With increasing V Prime , the unstable band in wavenumber-space shrinks so that the peak growth results for modes that correspond to relatively high wavenumbers, on the scale of the density gradient. In the nonlinear turbulent steady state, a similar turbulent spectrum obtains, and the convection cells are roughly circular. In addition, the density fluctuation level and the degree of flattening of the initial inverted density profile are found to decrease as V Prime increases; in fact, unstable modes are almost completely stabilized and the density profile reverts to laminar when V Prime is a few times the classic interchange growth rate. Moreover, the turbulent particle flux diminishes with increasing velocity shear such that all the flux is carried by the classical diffusive flux in the asymptotic limit. The simulations are compared with measurements of magnetic fluctuations from the Maryland Centrifugal Experiment, MCX, which investigated interchange modes in the presence of velocity shear. The experimental spectral data, taken in the plasma edge, are in general agreement with the numerical data obtained in higher viscosity simulations for which the level of viscosity is chosen consistent with MCX Reynolds numbers at the edge. In particular, the residual turbulence in both cases is dominated by elongated convection cells. Finally, concomitant Kelvin-Helmholtz instabilities in the system are also examined. Complete stability to interchanges is obtained only in the parameter space wherein the generalized Rayleigh inflexion theorem is satisfied.

Hung, C. P.; Hassam, A. B. [University of Maryland at College Park, College Park, Maryland 20742 (United States)

2013-01-15T23:59:59.000Z

313

Innovative Carbon Dioxide Sequestration from Flue Gas Using an In-Duct Scrubber Coupled with Alkaline Clay Mineralization  

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

Innovative Carbon Dioxide Sequestration Innovative Carbon Dioxide Sequestration from Flue Gas Using an In-Duct Scrubber Coupled with Alkaline Clay Mineralization Background The United States Department of Energy (DOE) is leading an effort to find novel approaches to reduce carbon dioxide (CO 2 ) emissions from industrial sources. The Industrial Carbon Capture and Sequestration (ICCS) program is funded by the American Recovery and Reinvestment Act (ARRA) to encourage development of processes that

314

?Thermo-Hydraulic Performance of a Roughened Square Duct Having Inclined Ribs with a Gap on Two Opposite Walls  

E-Print Network [OSTI]

Abstract:- Experimentation has been carried out to find the influence of a gap provided in ribs on thermohydraulic performance of a square duct roughened with discrete inclined ribs. The two opposite walls of the square duct are roughened with ribs having attack angle (?) of 45 0 and a gap on its length. The investigation has been performed for relative roughness pitch (p/e) of 10, relative roughness height (e/Dh) of 0.060 and Reynolds number is varied in the range of 5000-40,000. The other rib parameters; relative gap position (d/W) and relative gap width (g/e) is varied in the range of 1/4 – 2/3(4 steps) and 0.5 – 1.5 (3 steps) respectively. The comparative study of various cases shows that the ribs with a gap considerably enhance the value of thermohydraulic performance for the range of parameters taken for the present investigation. Presence of inclined ribs with a gap yields about 2.1-fold enhancements in thermo-hydraulic performance as compared to smooth duct. The maximum value of thermo-hydraulic performance parameter has been observed for relative gap width of 1.0 and the relative gap position of 1/3. Keywords:- Relative gap width, Relative gap position, Reynolds number, Thermo-hydraulic performance. I.

unknown authors

315

Numerical inverse method predicting acoustic spinning modes radiated by a ducted fan from free-field test dataa)  

Science Journals Connector (OSTI)

Spinning modes generated by a ducted turbofan at a given frequency determine the acoustic free-field directivity. An inverse method starting from measured directivity patterns is interesting in providing information on the noise sources without requiring tedious spinning-mode experimental analyses. According to a previous article equations are based on analytical modal splitting inside a cylindrical duct and on a Rayleigh or a Kirchhoff integral on the duct exit cross section to get far-field directivity. Equations are equal in number to free-field measurement locations and the unknowns are the propagating mode amplitudes (there are generally more unknowns than equations). A MATLAB procedure has been implemented by using either the pseudoinverse function or the backslash operator. A constraint comes from the fact that squared modal amplitudes must be positive which involves an iterative least squares fitting. Numerical simulations are discussed along with several examples based on tests performed by Rolls–Royce in the framework of a European project. It is assessed that computation is very fast and it well fits the measured directivities but the solution depends on the method and is not unique. This means that the initial set of modes should be chosen according to any known physical property of the acoustic sources.

Serge Lewy

2008-01-01T23:59:59.000Z

316

Sound attenuation in ducts using locally resonant periodic flush mounted flexible silicon aerogel patches  

Science Journals Connector (OSTI)

In recent years low frequency noise has become an important factor especially in the Aircraft HVAC and Automotive industries. In order to reduce this low frequency noise noise attenuation by the classical Helmholtz resonators has size limitations due to the large wavelengths. Promising noise reductions with flush mounted Silicon Aerogel patches can be obtained implementing attenuation due to local resonance and that too without any size constraints. The objective of the current paper is to introduce locally resonant Silicon Aerogel patches flush mounted to an acoustic duct walls aiming at creating frequency stop bands at the low frequency zone (below 500 Hz). Green’s Function is used under the framework of interface response theory to predict the degree of attenuation of the local resonant patches. Realistic techniques for expanding the stop bandwidth have been introduced and difference between the Bragg scattering and the locally resonant mechanism was demonstrated using mathematical models. The effect of the arrays of patches on the effective dynamic density and bulk modulus has also been investigated. It is also shown that the numbers and periodicity of these local resonators also plays role in determining the depth and width of the acoustic band gap.

Maaz Farooqui; Wael Akl

2013-01-01T23:59:59.000Z

317

Characterization of pipes, drain lines, and ducts using the pipe explorer system  

SciTech Connect (OSTI)

As DOE dismantles its nuclear processing facilities, site managers must employ the best means of disposing or remediating hundreds of miles of potentially contaminated piping and duct work. Their interiors are difficult to access, and in many cases even the exteriors are inaccessible. Without adequate characterization, it must be assumed that the piping is contaminated, and the disposal cost of buried drain lines can be on the order of $1,200/ft and is often unnecessary as residual contamination levels often are below free release criteria. This paper describes the program to develop a solution to the problem of characterizing radioactive contamination in pipes. The technical approach and results of using the Pipe Explorer {trademark} system are presented. The heart of the system is SEA`s pressurized inverting membrane adapted to transport radiation detectors and other tools into pipes. It offers many benefits over other pipe inspection approaches. It has video and beta/gamma detection capabilities, and the need for alpha detection has been addressed through the development of the Alpha Explorer{trademark}. These systems have been used during various stages of decontamination and decommissioning of DOE sites, including the ANL CP-5 reactor D&D. Future improvements and extensions of their capabilities are discussed.

Cremer, C.D.; Kendrick, D.T.; Cramer, E.

1997-05-01T23:59:59.000Z

318

IR diagnostics of embedded jets: velocity resolved observations of the HH34 and HH1 jets  

E-Print Network [OSTI]

We present VLT-ISAAC medium resolution spectroscopy of the HH34 and HH1 jets. Our aim is to derive the kinematics and the physical parameters and to study how they vary with jet velocity. We use several important diagnostic lines such as [FeII] 1.644um, 1.600um and H2 2.122um. In the inner jet region of HH34 we find that both the atomic and molecular gas present two components at high and low velocity. The [FeII] LVC in HH34 is detected up to large distances from the source (>1000 AU), at variance with TTauri jets. In H2 2.122um, the LVC and HVC are spatially separated. We detect, for the first time, the fainter red-shifted counterpart down to the central source. In HH1, we trace the jet down to ~1" from the VLA1 driving source: the kinematics of this inner region is again characterised by the presence of two velocity components, one blue-shifted and one red-shifted with respect to the source LSR velocity. In the inner HH34 jet region, ne increases with decreasing velocity. Up to ~10" from the driving source, and along the whole HH1 jet an opposite behaviour is observed instead, with ne increasing with velocity. In both jets the mass flux is carried mainly by the high-velocity gas. A comparison between the position velocity diagrams and derived electron densities with models for MHD jet launching mechanisms has been performed for HH34. While the kinematical characteristics of the line emission at the jet base can be, at least qualitatively, reproduced by both X-winds and disc-wind models, none of these models can explain the extent of the LVC and the dependence of electron density with velocity that we observe. It is possible that the LVC in HH34 represents gas not directly ejected in the jet but instead denser ambient gas entrained by the high velocity collimated jet.

R. Garcia Lopez; B. Nisini; T. Giannini; J. Eisloeffel; F. Bacciotti; L. Podio

2008-05-19T23:59:59.000Z

319

On Approximating the Translational Velocity of Vortex Rings  

E-Print Network [OSTI]

from this configuration and the system scaling. Here, the accuracy of this approximation is presented orifice in a flat plate contain a converging radial component of velocity. For both configurations. By this definition, the piston velocity is the average jet velocity passing through the orifice independent

Mohseni, Kamran

320

LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL  

E-Print Network [OSTI]

1 LAMINAR BURNING VELOCITY OF GASOLINES WITH ADDITION OF ETHANOL P. Dirrenberger1 , P.A. Glaude*1 (2014) 162-169" DOI : 10.1016/j.fuel.2013.07.015 #12;2 LAMINAR BURNING VELOCITY OF GASOLINES, Sweden Abstract The adiabatic laminar burning velocities of a commercial gasoline and of a model fuel (n

Boyer, Edmond

Note: This page contains sample records for the topic "duct high velocity" 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

Observations of Velocity Conditions near a Hydroelectric Turbine Draft Tube Exit using ADCP Measurements  

SciTech Connect (OSTI)

Measurement of flow characteristics near hydraulic structures is an ongoing challenge because of the need to obtain rapid measurements of time-varying velocity over a relatively large spatial domain. This paper discusses use of an acoustic Doppler current profiler (ADCP) to measure the rapidly diverging flow exiting from an operating hydroelectric turbine draft tube exit. The resolved three-dimensional velocity vectors show a highly complex and helical flow pattern developed near to and downstream of the exit. Velocity vectors were integrated across the exit and we computed an uneven percentage of flow (67%/33%) passing through the two draft tube barrels at a mid-range turbine discharge, consistent with physical model results. In addition to the three-dimensional velocity vectors, the individual one-dimensional velocities measured by each of the four ADCP beams can be separately used as calibration and validation datasets for numerical and physical models. This technique is demonstrated by comparing along-beam ADCP velocity measurements to data collected in a scaled physical model.

Cook, Christopher B.; Richmond, Marshall C.; Serkowski, John A.

2007-10-01T23:59:59.000Z

322

Relative velocity of dark matter and baryons in clusters of galaxies and measurements of their peculiar velocities  

Science Journals Connector (OSTI)

......Salpeter initial mass function...fixed to get a wind velocity of 1. More...Synthetic maps of observables...call peculiar velocity the mean (and mass-weighted...maximum circular velocity (e.g. mass) of galaxies...kinetic SZ map directly produced......

K. Dolag; R. Sunyaev

2013-01-01T23:59:59.000Z

323

Filament velocity scaling laws for warm ions  

SciTech Connect (OSTI)

The dynamics of filaments or blobs in the scrape-off layer of magnetic fusion devices are studied by magnitude estimates of a comprehensive drift-interchange-Alfvén fluid model. The standard blob models are reproduced in the cold ion case. Even though usually neglected, in the scrape-off layer, the ion temperature can exceed the electron temperature by an order of magnitude. The ion pressure affects the dynamics of filaments amongst others by adding up to the interchange drive and the polarisation current. It is shown how both effects modify the scaling laws for filament velocity in dependence of its size. Simplifications for experimentally relevant limit regimes are given. These are the sheath dissipation, collisional, and electromagnetic regime.

Manz, P. [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany) [Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany); Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Carralero, D.; Birkenmeier, G.; Müller, H. W.; Scott, B. D. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany)] [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Müller, S. H. [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States)] [Center for Momentum Transport and Flow Organization, University of California at San Diego, San Diego 92093 (United States); Fuchert, G. [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany)] [Insitut für Grenzflächenverfahrenstechnik und Plasmatechnologie, Universität Stuttgart, 70569 Stuttgart (Germany); Stroth, U. [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany) [Max-Planck-Institut für Plasmaphysik, EURATOM Assoziation, Boltzmannstr. 2, 85748 Garching (Germany); Physik-Department E28, Technische Universität München, James-Franck-Str. 1, 85748 Garching (Germany)

2013-10-15T23:59:59.000Z

324

Single-mode fiber, velocity interferometry  

SciTech Connect (OSTI)

In this paper, we describe a velocity interferometer system based entirely on single-mode fiber optics. This paper includes a description of principles used in developing the single-mode velocity interferometry system (SMV). The SMV design is based on polarization-insensitive components. Polarization adjusters are included to eliminate the effects of residual birefringence and polarization dependent losses in the interferometers. Characterization measurements and calibration methods needed for data analysis and a method of data analysis are described. Calibration is performed directly using tunable lasers. During development, we demonstrated its operation using exploding-foil bridge-wire fliers up to 200 m/s. In a final test, we demonstrated the SMV in a gas gun experiment up to 1.2 km/sec. As a basis for comparison in the gas gun experiment, we used another velocimetry technique that is also based on single-mode fiber optics: photonic Doppler velocimetry (PDV). For the gas gun experiment, we split the light returned from a single target spot and performed a direct comparison of the homodyne (SMV) and heterodyne (PDV) techniques concurrently. The two techniques had a negligible mean difference and a 1.5% standard deviation in the one-dimensional shock zone. Within one interferometer delay time after a sudden Doppler shift, a SMV unencumbered by multimode-fiber dispersion exhibits two color beats. These beats have the same period as PDV beats--this interference occurs between the ''recently'' shifted and ''formerly unshifted'' paths within the interferometer. We believe that recognizing this identity between homodyne and heterodyne beats is novel in the shock-physics field. SMV includes the conveniences of optical fiber, while removing the time resolution limitations associated with the multimode delivery fiber.

Krauter, K. G.; Jacobson, G. F.; Patterson, J. R.; Nguyen, J. H.; Ambrose, W. P. [Lawrence Livermore National Laboratory, 7000 East Ave., Livermore California 94551 (United States)

2011-04-15T23:59:59.000Z

325

Time-synchronized continuous wave laser-induced fluorescence axial velocity measurements in a diverging cusped field thruster  

Science Journals Connector (OSTI)

Measurements are presented of time-synchronized axial ion velocities at three positions in the discharge channel and plume of a diverging cusped field thruster operating on xenon. Xenon axial ion velocities for the thruster are derived from laser-induced fluorescence measurements of the 5d[4]7/2–6p[3]5/2 xenon ion excited state transition centred at ? = 834.72 nm. The thruster is operated in a high-current mode, where the anode discharge current is shown to oscillate quasi-periodically. A sample-hold scheme is implemented to correlate ion velocities to phases along the current cycle. These time-synchronized measurements show that median axial ion velocities decrease as discharge current increases, and that the widths of ion velocity distributions increase with increases in discharge current for positions at the exit plane and outside the thruster channel.

N A MacDonald; M A Cappelli; W A Hargus Jr

2014-01-01T23:59:59.000Z

326

Refinement in the ultrasonic velocity data and estimation of the critical parameters for molten uranium dioxide  

E-Print Network [OSTI]

the reactor and its vicinity. A reliable equation of state for the nuclear fuel, therefore, necessitates, reliable data on the sound prop- agation velocity in molten uranium dioxide have been obtained. An equation reserved. 1. Introduction The analysis of hypothetical and undesirable yet highly improbable accidents

Azad, Abdul-Majeed

327

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.

328

Coherence, Strain, and Phase Velocity of Strong Ground Motions in the Mississippi Charles A. Langston  

E-Print Network [OSTI]

ground motions in the deep, unconsolidated Mississippi embayment sediments since there are no comparable within the thick, unconsolidated sedimentary column, the high velocity basement rocks, and small is the existence of thick, unconsolidated sediments that blanket the area and attain thicknesses of up to kilometer

Langston, Charles A.

329

Radial velocity measurements of white dwarfs  

E-Print Network [OSTI]

We present 594 radial velocity measurements for 71 white dwarfs obtained during our search for binary white dwarfs and not reported elsewhere. We identify three excellent candidate binaries, which require further observations to confirm our preliminary estimates for their orbital periods, and one other good candidate. We investigate whether our data support the existence of a population of single, low mass (<~0.5 solar masses) white dwarfs (LMWDs). These stars are difficult to explain in standard models of stellar evolution. We find that a model with a mixed single/binary population is at least ~20 times more likely to explain our data than a pure binary population. This result depends on assumed period distributions for binary LMWDs, assumed companion masses and several other factors. Therefore, the evidence in favour of the existence of a population of single LMWDs is not sufficient, in our opinion, to firmly establish the existence of such a population, but does suggest that extended observations of LMWDs to obtain a more convincing result would be worthwhile .

P. F. L. Maxted; T. R. Marsh; C. K. J. Moran

2000-07-11T23:59:59.000Z

330

True Masses of Radial-Velocity Exoplanets  

E-Print Network [OSTI]

We explore the science power of space telescopes used to estimate the true masses of known radial-velocity exoplanets by means of astrometry on direct images. We translate a desired mass accuracy (+/10% in our example) into a minimum goal for the signal-to-noise ratio, which implies a minimum exposure time. When the planet is near a node, the mass measurement becomes difficult if not impossible, because the apparent separation becomes decoupled from the inclination angle of the orbit. The combination of this nodal effect with considerations of solar and anti-solar pointing restrictions, photometric and obscurational completeness, and image blurring due to orbital motion, severely limits the observing opportunities, often to only brief intervals in a five-year mission. We compare the science power of four missions, two with external star shades, EXO-S and WFIRST-S, and two with internal coronagraphs, EXO-C and WFIRST-C. The star shades out-perform the coronagraph in this science program by about a factor of th...

Brown, Robert A

2015-01-01T23:59:59.000Z

331

Shake Table for Calibration of Velocity Pickups  

Science Journals Connector (OSTI)

A Shake Table was developed and built by the Engineering Research Institute to calibrate low?frequency (0 to 200 cps) velocity pickups. The platform that supports the pickup to be tested is 6 in. in diameter and will support a load of approximately 30 lb. This makes the use of a table limited by force it can deliver except at very low frequencies. The table will operate with a 10 lb load to a frequency of 150 cps. The platform displacement is 0.125 in. peak?to?peak. The platform and its load are supported by air bellows. This is an improvement over a spring support due to the fact that it has greater damping and it is more easily adjusted to different loads. The adjustment consists of just putting more air in the bellows. The table is driven by a dc push?pull power amplifier. This delivers a current to a tapped coil on the Shake Table that is located in a magnetic field. The field is set up by a coil energized by 24 volts. The power amplifier can be driven by any convenient source delivering about 1 volt. (Parts of this research were supported by Tri?service Contract No. DA?36?039?sc?52654.)

J. W. Wescott; J. H. Prout; W. H. Follett

1957-01-01T23:59:59.000Z

332

Natural discharge after pulse and cooperative electrodes to enhance droplet velocity in digital microfluidics  

SciTech Connect (OSTI)

Digital Microfluidics (DMF) is a promising technology for biological/chemical micro-reactions due to its distinct droplet manageability via electronic automation, but the limited velocity of droplet transportation has hindered DMF from utilization in high throughput applications. In this paper, by adaptively fitting the actuation voltages to the dynamic motions of droplet movement under real-time feedback monitoring, two control-engaged electrode-driving techniques: Natural Discharge after Pulse (NDAP) and Cooperative Electrodes (CE) are proposed. They together lead to, for the first time, enhanced droplet velocity with lower root mean square voltage value.

Chen, Tianlan; Dong, Cheng; Gao, Jie; Jia, Yanwei; Mak, Pui-In, E-mail: pimak@umac.mo; Vai, Mang-I; Martins, Rui P. [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)] [State Key Laboratory of Analog and Mixed-Signal VLSI and FST-ECE, University of Macau, Macao (China)

2014-04-15T23:59:59.000Z

333

Two-dimensional Imaging Velocity Interferometry: Technique and Data Analysis  

SciTech Connect (OSTI)

We describe the data analysis procedures for an emerging interferometric technique for measuring motion across a two-dimensional image at a moment in time, i.e. a snapshot 2d-VISAR. Velocity interferometers (VISAR) measuring target motion to high precision have been an important diagnostic in shockwave physics for many years Until recently, this diagnostic has been limited to measuring motion at points or lines across a target. We introduce an emerging interferometric technique for measuring motion across a two-dimensional image, which could be called a snapshot 2d-VISAR. If a sufficiently fast movie camera technology existed, it could be placed behind a traditional VISAR optical system and record a 2d image vs time. But since that technology is not yet available, we use a CCD detector to record a single 2d image, with the pulsed nature of the illumination providing the time resolution. Consequently, since we are using pulsed illumination having a coherence length shorter than the VISAR interferometer delay ({approx}0.1 ns), we must use the white light velocimetry configuration to produce fringes with significant visibility. In this scheme, two interferometers (illuminating, detecting) having nearly identical delays are used in series, with one before the target and one after. This produces fringes with at most 50% visibility, but otherwise has the same fringe shift per target motion of a traditional VISAR. The 2d-VISAR observes a new world of information about shock behavior not readily accessible by traditional point or 1d-VISARS, simultaneously providing both a velocity map and an 'ordinary' snapshot photograph of the target. The 2d-VISAR has been used to observe nonuniformities in NIF related targets (polycrystalline diamond, Be), and in Si and Al.

Erskine, D J; Smith, R F; Bolme, C; Celliers, P; Collins, G

2011-03-23T23:59:59.000Z

334

Waveinduced velocities inside a model seagrass bed Mitul Luhar,1  

E-Print Network [OSTI]

. By damping nearbed water velocities, seagrasses reduce local resuspension and promote the retention the seabed. Reduced resuspension improves water clarity, leading to greater light penetration and increased

Nepf, Heidi M.

335

Pseudostress-velocity formulation for incompressible Navier-Stokes ...  

E-Print Network [OSTI]

Velocity profiles and streamline portraits for Re=100 with h = 1. 128 and different . Circles in ... of meshes generated by a refining process. The error between ...

2009-05-29T23:59:59.000Z

336

Crusius, John, and Rik Wanninkhof, Gas transfer velocities ...  

Science Journals Connector (OSTI)

Jun 29, 2000 ... 2003, by the American Society of Limnology and Oceanography, Inc. Gas transfer velocities measured at low wind speed over a lake.

2003-05-02T23:59:59.000Z

337

Multipole-specific, model-independent, velocity-change spectra of collisionally perturbed P13-state Yb174 atoms  

Science Journals Connector (OSTI)

Coherent transient (echo) techniques have been employed in a high-precision study of collisional velocity thermalization in a sample of (6s6p)P13, excited-state, Yb174 atoms perturbed by He or Ar. This work probes the comparative response of aligned and oriented atoms to both depolarizing and to weak, nondepolarizing and/or velocity-changing collisions. By direct inversion of our time-domain echo relaxation data, we also provide a model-independent determination of velocity-change spectra (collision kernels) for nondepolarizing collisions.

A. G. Yodh; T. W. Mossberg; J. E. Thomas

1986-12-01T23:59:59.000Z

338

High-Current Accelerators  

E-Print Network [OSTI]

F i g . 13 F i g . 14 A 48 ACCELERATOR F i g . 25 F i g . 16supply. Extrapolation of accelerator energy and current9 . A-48 high-current accelerator, low-velocity end. Fig.

Lawrence, Ernest O.

1955-01-01T23:59:59.000Z

339

Building America Webinar: High Performance Space Conditioning Systems, Part II- Design Options for Locating Ducts within Conditioned Space  

Broader source: Energy.gov [DOE]

This presentation was delivered at the U.S. Department of Energy Building America webinar on November 18, 2014.

340

Control Humidity With Single-Duct, Single-Zone, Constant Air Volume System  

E-Print Network [OSTI]

for the AHLJ after Adjusted Conditions I I Return Fan: off; Return Damper: closed; Outside Air Damper: closed (signal) I 7- 14-99 9:44 AM AHU Dimensions Total Air Flow (CW Average Velocity (FPM) Temperature ("F) Humidity (% RH) Dew Point (OF... (FPM) Humidity (% RH) 1 83.0 -... r------ L -/ Dew Point (OF) Static Pressure supply 24" x 24" 4450 1180 Outside Air N/ A 2490 N/ A Mix Air 20" x 36" 4530 1091 T~mnrmt~w~ (OF) I 67.6 1 73.0 I 72.1 I 85.7 I . - 62.9 10.75 Return Air...

Chen, H.; Deng, S.; Bruner, H. L.; Claridge, D. E.

2000-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Free–energy landscape and the critical velocity of superfluid films  

Science Journals Connector (OSTI)

...P. Boon and P. V. Coveney Free-energy landscape and the critical velocity...superfluids shedding light on the free-energy landscape, the critical velocity...critical velocity|vortex| Free-energy landscape and the critical velocity...

2004-01-01T23:59:59.000Z

342

Cleanup and Dismantling of Highly Contaminated Ventilation Systems Using Robotic Tools - 13162  

SciTech Connect (OSTI)

The UP1 plant reprocessed nearly 20,000 tons of used natural uranium gas cooled reactor fuel coming from the first generation of civil nuclear reactors in France. Following operating incidents in the eighties, the ventilation system of the continuous dissolution line facility was shut down and replaced. Two types of remote controlled tool carriers were developed to perform the decontamination and dismantling operations of the highly contaminated ventilation duct network. The first one, a dedicated small robot, was designed from scratch to retrieve a thick powder deposit within a duct. The robot, managed and confined by two dedicated glove boxes, was equipped for intervention inside the ventilation duct and used for carrying various cleanup and inspection tools. The second type, consisting of robotic tools developed on the base of an industrial platform, was used for the clean-up and dismantling of the ventilation duct system. Depending on the type of work to be performed, on the shape constraints of the rooms and any equipment to be dismantled, different kinds of robotic tools were developed and installed on a Brokk 40 carrier. After more than ten years of ventilation duct D and D operations at the UP1 plant, a lot of experience was acquired about remote operations. The three main important lessons learned in terms of remote controlled operation are: characterizing the initial conditions as much as reasonably possible, performing non-radioactive full scale testing and making it as simple and modular as possible. (authors)

Chambon, Frederic [AREVA FEDERAL SERVICES, Columbia MD (United States)] [AREVA FEDERAL SERVICES, Columbia MD (United States); CIZEL, Jean-Pierre [AREVA BE/NV, Marcoule (France)] [AREVA BE/NV, Marcoule (France); Blanchard, Samuel [CEA DEN/DPAD, Marcoule (France)] [CEA DEN/DPAD, Marcoule (France)

2013-07-01T23:59:59.000Z

343

Velocity of Second Sound in NaF  

Science Journals Connector (OSTI)

The velocity of drifting second sound and the heat capacity per unit volume are calculated for NaF for temperatures from 0 to 40 °K. The velocity of second sound decreases by 24% as the temperature is increased from 10 to 30 °K, because of the dispersion of the phonon frequency spectrum.

Robert J. Hardy and S. S. Jaswal

1971-06-15T23:59:59.000Z

344

Hydrocarbon saturation determination using acoustic velocities obtained through casing  

DOE Patents [OSTI]

Compressional and shear velocities of earth formations are measured through casing. The determined compressional and shear velocities are used in a two component mixing model to provides improved quantitative values for the solid, the dry frame, and the pore compressibility. These are used in determination of hydrocarbon saturation.

Moos, Daniel (Houston, TX)

2010-03-09T23:59:59.000Z

345

Comparing Glider Observed Velocities and Geostrophic Currents Regina Yopak  

E-Print Network [OSTI]

offshore and brings cold, deep water to fill it's place. The upwelling regime creates a unique coastal. This project endeavors to compare calculated geostrophic velocities to the water velocities measured which the net vertical volume of water is transferred 90° to the right which forces warm, surface waters

Kurapov, Alexander

346

On the Structure of the Low Velocity Zone  

Science Journals Connector (OSTI)

......large nuclear explosions at the Nevada Test Site have been used to model the P-velocity...1961. Crustal structure from Nevada Test Site to Kingman, Arizona from seismic...large nuclear explosions at the Nevada Test Site have been used to model the P-velocity......

Donald V. Helmberger

1973-11-01T23:59:59.000Z

347

Tsallis Entropy Based Velocity Distribution in Open Channel Flows  

E-Print Network [OSTI]

............................................................. 94 32 Dimensionless velocity distribution and parameter M ............................... 96 33 um/ umax versus various M ........................................................................... 99 34 Upper Tiber River basin with location... velocity distribution with different m ... 68 9 Computation of M, ?1 and ?V based on um and umax measured on the Po river (Italy) for different verticals at Pontelagoscuro gauged section during flood event that occurred on February 2, 1985...

Luo, Hao

2010-07-14T23:59:59.000Z

348

Tracking moving radar targets with parallel, velocity-tuned filters  

DOE Patents [OSTI]

Radar data associated with radar illumination of a movable target is processed to monitor motion of the target. A plurality of filter operations are performed in parallel on the radar data so that each filter operation produces target image information. The filter operations are defined to have respectively corresponding velocity ranges that differ from one another. The target image information produced by one of the filter operations represents the target more accurately than the target image information produced by the remainder of the filter operations when a current velocity of the target is within the velocity range associated with the one filter operation. In response to the current velocity of the target being within the velocity range associated with the one filter operation, motion of the target is tracked based on the target image information produced by the one filter operation.

Bickel, Douglas L.; Harmony, David W.; Bielek, Timothy P.; Hollowell, Jeff A.; Murray, Margaret S.; Martinez, Ana

2013-04-30T23:59:59.000Z

349

Discrimination of porosity and fluid saturation using seismic velocity analysis  

DOE Patents [OSTI]

The method of the invention is employed for determining the state of saturation in a subterranean formation using only seismic velocity measurements (e.g., shear and compressional wave velocity data). Seismic velocity data collected from a region of the formation of like solid material properties can provide relatively accurate partial saturation data derived from a well-defined triangle plotted in a (.rho./.mu., .lambda./.mu.)-plane. When the seismic velocity data are collected over a large region of a formation having both like and unlike materials, the method first distinguishes the like materials by initially plotting the seismic velocity data in a (.rho./.lambda., .mu./.lambda.)-plane to determine regions of the formation having like solid material properties and porosity.

Berryman, James G. (Danville, CA)

2001-01-01T23:59:59.000Z

350

Detection of electron velocity in graphene by Doppler effect  

Science Journals Connector (OSTI)

Abstract Electron velocity in a two-dimensional electron gas can be measured by Doppler shift. Thus, we construct the Doppler shift of light and apply it to the motion of electrons in a graphene sheet to estimate the electron velocity. Here, a laser beam with initial frequency is incident on the graphene sheet in a parallel direction, and then the frequency of the emitted light can be measured by spectroscopy after detecting the electron velocity. Then, the ratio of frequency shift from the Doppler effect is described in terms of the electron velocity, as well as the incident and the detection angle of laser beam. The thermal broadening of detected frequency as a function of velocity is also shown for different temperatures.

Heetae Kim; Chang-Soo Park; Hak Dong Cho

2014-01-01T23:59:59.000Z

351

Precision Measuring of Velocities via the Relativistic Doppler Effect  

E-Print Network [OSTI]

Just as the ordinary Doppler effect serves as a tool to measure radial velocities of celestial objects, so can the relativistic Doppler effect be implemented to measure a combination of radial and transverse velocities by using recent improvements in observing techniques. A key element that makes a further use of this combination feasible is the periodicity in changes of the orbital velocity direction for the source. Two cases are considered: (i) a binary star; and (ii) a solitary star with the planetary companion. It is shown that, in case (i), several precision Doppler measurements employing the gas absorption cell technique would determine both the total orbital velocity and the inclination angle of the binary orbit disentangled from the peculiar velocity of the system. The necessary condition for that is the measured, at least with a modest precision, proper motion and distance to the system.

Leonid M. Ozernoy

1997-12-26T23:59:59.000Z

352

Inversion of azimuthally dependent NMO velocity in transversely isotropic media with a tilted axis of symmetry  

SciTech Connect (OSTI)

Just as the transversely isotropic model with a vertical symmetry axis (VTI media) is typical for describing horizontally layered sediments, transverse isotropy with a tilted symmetry axis (TTI) describes dipping TI layers (such as tilted shale beds near salt domes) or crack systems. P-wave kinematic signatures in TTI media are controlled by the velocity V{sub PO} in the symmetry direction, Thomsen's anisotropic coefficients {xi} and {delta}, and the orientation (tilt {nu} and azimuth {beta}) of the symmetry axis. Here, the authors show that all five parameters can be obtained from azimuthally varying P-wave NMO velocities measured for two reflectors with different dips and/or azimuths (one of the reflectors can be horizontal). The shear-wave velocity V{sub SO} in the symmetry direction, which has negligible influence on P-wave kinematic signatures, can be found only from the moveout of shear waves. Using the exact NMO equation, the authors examine the propagation of errors in observed moveout velocities into estimated values of the anisotropic parameters and establish the necessary conditions for a stable inversion procedure. Since the azimuthal variation of the NMO velocity is elliptical, each reflection event provides them with up to three constraints on the model parameters. Generally, the five parameters responsible for P-wave velocity can be obtained from two P-wave ellipses, but the feasibility of the moveout inversion strongly depends on the tilt {nu}. While most of the analysis is carried out for a single layer, the authors also extend the inversion algorithm to vertically heterogeneous TTI media above a dipping reflector using the generalized Dix equation. A synthetic example for a strongly anisotropic, stratified TTI medium demonstrates a high accuracy of the inversion.

Grechka, V.; Tsvankin, I.

2000-02-01T23:59:59.000Z

353

Ultrasonic velocity measurements for synthetic gas?hydrate samples  

Science Journals Connector (OSTI)

Laboratory ultrasonic methods offer a way of studying acoustic velocity of a gas?hydrate bearing formation. By measuringultrasonic velocities of the gas?hydrate samples in various temperature and pressure conditions more effective inversion techniques can be developed to quantitatively evaluate gas?hydrate concentration and distributions. Low?temperature laboratory measurements of compressional velocities in compacted samples are conducted. These gas?hydrate samples are synthesized by using various densities at various pressures and temperatures. At ?10°C the compressional velocities of the compacted gas?hydrate samples are from 2440 to 3570 m/s with the density range from 475 to 898 kg/m3. Compressional velocity measurements are made where the temperature and pressure can be controlled. When the pore pressure increases from 10 to 40 MPa the compressional velocities of the sample increases from 2340 to 2600 m/s at 1.5°C. When the temperature decreases from 10° to ?13°C the compressional velocity will increase from 3600 to 3800 m/s at a pore pressure of 6 MPa. Our experimental results are qualitatively in agreement with those of weighted average model and the Biot?Gassmanns model when the gas?hydrate concentration in a sediment bearing sand is about 20%. [Work supported by National Natural Science Fundation of China No. 10534040.

2006-01-01T23:59:59.000Z

354

Two-stream instability with time-dependent drift velocity  

DOE Public Access Gateway for Energy & Science Beta (PAGES Beta)

The classical two-stream instability driven by a constant relative drift velocity between two plasma components is extended to the case with time-dependent drift velocity. A solution method is developed to rigorously define and calculate the instability growth rate for linear perturbations relative to the time-dependent unperturbed two-stream motions. Stability diagrams for the oscillating two-stream instability are presented over a large region of parameter space. It is shown that the growth rate for the classical two-stream instability can be significantly reduced by adding an oscillatory component to the relative drift velocity.

Qin, Hong [PPPL; Davidson, Ronald C. [PPPL

2014-01-01T23:59:59.000Z

355

Building America Technology Solutions for New and Existing Homes: Duct in Conditioned Space in a Dropped Ceiling or Fur-down, Gainesville, Florida (Fact Sheet)  

Broader source: Energy.gov [DOE]

This case study examines a Building America builder partner’s implementation of an inexpensive, quick and effective method of building a fur-down or dropped ceiling chase, which brings the duct system into the interior of the house to reduce air leakage and improve durability and indoor air quality

356

In Proc. 1996 ACEEE Summer Study, August 1996, Asilomar, CA Field Measurements of Efficiency and Duct Retrofit Effectiveness in Residential Forced air  

E-Print Network [OSTI]

% and a corresponding average decrease in HVAC energy use of 18%. This paper summarizes the pre- and post to large energy bills for home owners and to large peak demands for utilities. Some previous studies have% reduction in heating energy consumption. · Cummings et al. performed pre- and post-duct retrofit

357

Seismic Velocity And Attenuation Structure Of The Geysers Geothermal Field,  

Open Energy Info (EERE)

Velocity And Attenuation Structure Of The Geysers Geothermal Field, Velocity And Attenuation Structure Of The Geysers Geothermal Field, California Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Seismic Velocity And Attenuation Structure Of The Geysers Geothermal Field, California Details Activities (1) Areas (1) Regions (0) Abstract: The Geysers geothermal field is located in northern California and is one of the world's largest producers of electricity from geothermal energy. A key resource management issue at this field is the distribution of fluid in the matrix of the reservoir rock. In this paper, we interpret seismic compressional-wave velocity and quality quotient (Q) data at The Geysers in terms of the geologic structure and fluid saturation in the reservoir. Our data consist of waveforms from approximately 300

358

Y-12 Site Experience with Deposition Velocity Issues  

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

Site Experience with Site Experience with Deposition Velocity Issues Douglas Clark Analyst B&W Technical Services Y-12 May 9, 2012 Y-12 Site Experience with Deposition Velocity Issues Y-12 Specific Issues Y-12 Site Experience with Deposition Velocity Issues Windspeed - Calm Wind Conditions at Y-12 Site Y-12 Site Experience with Deposition Velocity Issues Windspeed - Stability Class Determinations * NRC RG 1.23 ΔT-only method * EPA-454/R-99-005 solar- radiation-delta-temperature (SRDT) method * Hybrid SR - DT method * wind direction standard deviation [sigma-theta (σ θ )] * elevation angle standard deviation [sigma-phi (σ φ )] * vertical wind speed standard deviation [sigma-omega (σ ω )], * wind-speed ratio method (u R ) * All evaluated using data from west

359

Elastic constants and velocity surfaces of indurated anisotropic shales  

Science Journals Connector (OSTI)

The velocities of two Devonian-Mississippian shales have been measured to confining pressures of 200 MPa in a laboratory study of anisotropy and wave propagation. Both samples were found to be transversely iso...

Joel E. Johnston; Nikolas I. Christensen

1994-09-01T23:59:59.000Z

360

Detonation velocity deficit and curvature radius of flexible detonation fuses  

Science Journals Connector (OSTI)

The detonation velocity deficit in bending flexible detonating fuses is studied, based on the detonation wave’s corner effects and delay time ... model and a theoretical mathematical equation of the detonation ve...

Y. -Q. Wen; Ya. -K. Ye; N. Yan

2012-03-01T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Effect of Adhesive Tape on the Velocity Profile of Water  

Science Journals Connector (OSTI)

... fully developed turbulent flow in order to discover the effect on the velocity profile of roughening the channel bed by sticking sand grains of various known dimensions to it by means ...

ALAN E. COSSAR

1970-09-05T23:59:59.000Z

362

Velocity of sound in solid methane near melting temperatures  

E-Print Network [OSTI]

VELOCITY OF SOUND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May... 1968 Ma)or Sub)ect: Physics VELOCITY OF SOVND IN SOLID METHANE NEAR MELTING TEMPERATURES A Thesis By JOHN MARTIN WHITEHEAD Approved as to style and content by& (Chairman of Committee) (Head of Departsmnt) (Mem er (Member) May 1968...

Whitehead, John Martin

2012-06-07T23:59:59.000Z

363

Temperature and velocity effects in naphthenic acid corrosion  

SciTech Connect (OSTI)

The effects of temperature and velocity were studied with respect to alloy selection for corrosion resistant service. The amount of molybdenum in the austenitic stainless steel alloys is critical in conferring corrosion resistance on the alloy as the temperature of the environment increases. Velocity effects have been studied in a closed loop hot oil circuit where the stream impinges on the target specimen. Film breakdown is prevented by increasing the molybdenum content.

Craig, H.L. Jr. [Corrosion Prevention and Control, Richmond, VA (United States)

1996-08-01T23:59:59.000Z

364

Spatiotemporal Signal Analysis via the Phase Velocity Transform  

Science Journals Connector (OSTI)

The phase velocity transform (PVT) is an integral transform that divides a function of space and time into components that propagate at uniform phase velocities without distortion. This paper examines the PVT as a method to analyze spatiotemporal fluctuation data. The transform is extended to systems with discretely sampled data on a periodic domain, and applied to data from eight azimuthally distributed probes on the Sustained Spheromak Physics Experiment (SSPX). This reveals features not shown by Fourier analysis, particularly regarding nonsinusoidal mode structure.

Nathan Mattor

2000-06-26T23:59:59.000Z

365

Vertical velocity in oceanic convection off tropical Australia  

E-Print Network [OSTI]

. . . . . . . v Vl Vl I I 1 3 6 10 Description of the Data Data Processing . . Event Criteria 10 15 21 III RESULTS . . . 26 Cores. Environment 26 34 IV COMPARISON WITH OTHER STUDIES . . . . . 40 Cores... Variations with altitude of median and strongest 10'/o-level statistics of (a) average vertical velocity, (b) maximum vertical velocity, (c) mass flux per unit length normal to the flight track and (d) diameter 32 Figure Page Reconstructed temperature...

Lucas, Christopher

2012-06-07T23:59:59.000Z

366

Interrelationships between air velocity and globe thermometer response  

E-Print Network [OSTI]

INTERRELATIONSHIPS BE~ AIR VELOCITY ANIl GLOBE THERMOMETER RESPONSE A Thesis JANES ROBERT THORNTON Submitted to the Graduate College of Texas ARAN University in partial fulfillment of the requirement for the degree of NASTER OF SCIENCE... August 197$ Najor Subject: Industrial Hygiene INTERRELATIONSHIPS BETWEEZ AIR VELOCITY AND GLOBE THERMOMETER RESPONSE A Thesis JAMES ROBERT THORNTON Approved as to style and content by: h z. an o ommmt ee ad o partmen Me er August 1$7$ ABSTRACT...

Thornton, James Robert

1973-01-01T23:59:59.000Z

367

Laser-induced fluorescence velocity measurements of a diverging cusped-field thruster  

Science Journals Connector (OSTI)

Measurements are presented of the most probable time-averaged ion velocities within the acceleration channel and in the plume of a diverging cusped-field thruster operating on xenon. Xenon ion velocities for the thruster are derived from laser-induced fluorescence measurements of the 5d[4]7/2–6p[3]5/2 xenon ion excited state transition centred at ? = 834.72?nm. The thruster is operated in both a high-current mode, where the anode discharge current is shown to oscillate periodically, and a low-current mode where operation is relatively quiescent. In the low-current mode, ion emission is predominantly in the form of a conical jet, whereas in the high-current mode, the emission is still divergent but more diffuse throughout the cone angle. These time-average measurements provide insight into the structure of the acceleration region. However, discerning the mechanism for the diffuse ion emission in the strongly oscillating high-current mode will require ion velocity measurements capable of resolving the time-dependent behaviour of the discharge.

N A MacDonald; M A Cappelli; S R Gildea; M Martínez-Sánchez; W A Hargus Jr

2011-01-01T23:59:59.000Z

368

The use of a heliostat to direct solar illuminance through a duct .  

E-Print Network [OSTI]

??The focus of the document is the development and use of an algorithm that controls a heliostat, and the high level design of that heliostat.… (more)

Ferreira, Kevin Shaun

2012-01-01T23:59:59.000Z

369

Exceptional Ground Accelerations and Velocities Caused by Earthquakes  

SciTech Connect (OSTI)

This project aims to understand the characteristics of the free-field strong-motion records that have yielded the 100 largest peak accelerations and the 100 largest peak velocities recorded to date. The peak is defined as the maximum magnitude of the acceleration or velocity vector during the strong shaking. This compilation includes 35 records with peak acceleration greater than gravity, and 41 records with peak velocities greater than 100 cm/s. The results represent an estimated 150,000 instrument-years of strong-motion recordings. The mean horizontal acceleration or velocity, as used for the NGA ground motion models, is typically 0.76 times the magnitude of this vector peak. Accelerations in the top 100 come from earthquakes as small as magnitude 5, while velocities in the top 100 all come from earthquakes with magnitude 6 or larger. Records are dominated by crustal earthquakes with thrust, oblique-thrust, or strike-slip mechanisms. Normal faulting mechanisms in crustal earthquakes constitute under 5% of the records in the databases searched, and an even smaller percentage of the exceptional records. All NEHRP site categories have contributed exceptional records, in proportions similar to the extent that they are represented in the larger database.

Anderson, John

2008-01-17T23:59:59.000Z

370

Smart panels with SISO or MIMO velocity feedback control systems  

Science Journals Connector (OSTI)

This paper summarizes and contrasts the research work that has been carried out on two types of smart panels with ASAC control systems: first a SISO velocity feedback control system with a sensor that detects the volumetric component of the vibration of the panel and an actuator that exerts a uniform force over the surface of the panel and second a MIMO decentralized feedback control system using a grid of sensors that measure the point velocities of the panel and a grid of actuators that generates point excitations in the locations of the sensors. Both theoretical predictions and experimental results are presented for a reference problem of control of sound radiation by a rectangular panel clamped along the perimeter. The simulations carried out for the two systems have shown that the smart panel with the volume velocity sensor and uniform force actuator can in principle give better control performance than the smart panel with the sixteen decentralized control units. However the practical implementation of the smart panel with the volume velocity sensor and uniform force actuator is limited by stability problems which are instead a minor issue for the panel with 16 decentralized velocity feedback control units.

2003-01-01T23:59:59.000Z

371

VELOCITY ANISOTROPY AND SHAPE BIAS IN THE CAUSTIC TECHNIQUE  

SciTech Connect (OSTI)

We use the Millennium Simulation to quantify the statistical accuracy and precision of the escape-velocity technique for measuring cluster-sized halo masses at z {approx} 0.1. We show that in three dimensions one can measure nearly unbiased (<4%) halo masses (>1.5 Multiplication-Sign 10{sup 14} M{sub Sun} h {sup -1}) with 10%-15% scatter. Line-of-sight projection effects increase the scatter to {approx}25%, where we include the known velocity anisotropies. The classical ''caustic'' technique incorporates a calibration factor that is determined from N-body simulations. We derive and test a new implementation that eliminates the need for calibration and utilizes only the observables: the galaxy velocities with respect to the cluster mean v, the projected positions r{sub p} , an estimate of the Navarro-Frenk-White (NFW) density concentration, and an estimate of the velocity anisotropies {beta}. We find that differences between the potential and density NFW concentrations induce a 10% bias in the caustic masses. We also find that large (100%) systematic errors in the observed ensemble average velocity anisotropies and concentrations translate to small (5%-10%) biases in the inferred masses.

Gifford, Daniel; Miller, Christopher J. [Department of Astronomy, University of Michigan, 500 Church St., Ann Arbor, MI 48109 (United States)

2013-05-10T23:59:59.000Z

372

Why should we correct reported pulsation frequencies for stellar line-of-sight Doppler velocity shifts?  

E-Print Network [OSTI]

In the age of Kepler and Corot, extended observations have provided estimates of stellar pulsation frequencies that have achieved new levels of precision, regularly exceeding fractional levels of a few parts in $10^{4}$. These high levels of precision now in principle exceed the point where one can ignore the Doppler shift of pulsation frequencies caused by the motion of a star relative to the observer. We present a correction for these Doppler shifts and use previously published pulsation frequencies to demonstrate the significance of the effect. We suggest that reported pulsation frequencies should be routinely corrected for stellar line-of-sight velocity Doppler shifts, or if a line-of-sight velocity estimate is not available, the frame of reference in which the frequencies are reported should be clearly stated.

Davies, G R; Miglio, A; Campante, T L; Chaplin, W J; Elsworth, Y

2014-01-01T23:59:59.000Z

373

Impacts of Raindrop Fall Velocity and Axis Ratio Errors on Dual-Polarization Radar Rainfall Estimation  

Science Journals Connector (OSTI)

Motivated by the field observations of fall velocity and axis ratio deviations from predicted terminal velocity and equilibrium axis ratio values, the combined effects of raindrop fall velocity and axis ratio deviations on dual-polarization radar ...

Bin Pei; Firat Y. Testik; Mekonnen Gebremichael

2014-10-01T23:59:59.000Z

374

DOE Zero Energy Ready Home Case Study, StreetScape Development...  

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

foam, R-49 open-cell spray-foam sealed attic, an HRV, and a tankless water heater for hydro coil furnace with high-velocity, small-diameter ducts. DOEZERHStreetScapeDevelopme...

375

Experiment and analyses for 14 MeV neutron streaming through a dogleg duct  

Science Journals Connector (OSTI)

......however, the reliability of the simple...for fusion reactors, although...Facility through analyses of high-energy...focused on the reliability of the simple...design of fusion reactor shielding...methods and the analysis to study the......

M. Yamauchi; K. Ochiai; Y. Morimoto; M. Wada; S. Sato; T. Nishitani

2005-12-20T23:59:59.000Z

376

Analytic solutions for seismic travel time and ray path geometry through simple velocity models.  

SciTech Connect (OSTI)

The geometry of ray paths through realistic Earth models can be extremely complex due to the vertical and lateral heterogeneity of the velocity distribution within the models. Calculation of high fidelity ray paths and travel times through these models generally involves sophisticated algorithms that require significant assumptions and approximations. To test such algorithms it is desirable to have available analytic solutions for the geometry and travel time of rays through simpler velocity distributions against which the more complex algorithms can be compared. Also, in situations where computational performance requirements prohibit implementation of full 3D algorithms, it may be necessary to accept the accuracy limitations of analytic solutions in order to compute solutions that satisfy those requirements. Analytic solutions are described for the geometry and travel time of infinite frequency rays through radially symmetric 1D Earth models characterized by an inner sphere where the velocity distribution is given by the function V (r) = A-Br{sup 2}, optionally surrounded by some number of spherical shells of constant velocity. The mathematical basis of the calculations is described, sample calculations are presented, and results are compared to the Taup Toolkit of Crotwell et al. (1999). These solutions are useful for evaluating the fidelity of sophisticated 3D travel time calculators and in situations where performance requirements preclude the use of more computationally intensive calculators. It should be noted that most of the solutions presented are only quasi-analytic. Exact, closed form equations are derived but computation of solutions to specific problems generally require application of numerical integration or root finding techniques, which, while approximations, can be calculated to very high accuracy. Tolerances are set in the numerical algorithms such that computed travel time accuracies are better than 1 microsecond.

Ballard, Sanford

2007-12-01T23:59:59.000Z

377

MACCS2/Deposition Velocity Workshop | Department of Energy  

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

You are here You are here Home » MACCS2/Deposition Velocity Workshop MACCS2/Deposition Velocity Workshop The Department of Energy's Chief of Nuclear Safety hosted a MACCS2/Deposition Velocity Workshop on June 5-6, 2012, in Germantown, Maryland. Approximately 70 participants attended. The purpose of the workshop was to: Discuss MACCS2 and atmospheric dispersion models as applied to DOE consequence analysis. Discuss implementation of HSS Safety Bulletin 2011-2, Accident Analysis Parameter Update, at field sites. Develop a consistent Department-wide approach for responding to the HSS Safety Bulletin. Identify areas for improved DOE guidance for ensuring defensible consequence analyses. June Workshop Agenda- Final.docx Atmospheric Dispersion Modeling in Safety Analyses; GENII

378

Temporal Velocity Variations beneath the Coso Geothermal Field Observed  

Open Energy Info (EERE)

Velocity Variations beneath the Coso Geothermal Field Observed Velocity Variations beneath the Coso Geothermal Field Observed using Seismic Double Difference Tomography of Compressional and Shear Wave Arrival Times Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Conference Proceedings: Temporal Velocity Variations beneath the Coso Geothermal Field Observed using Seismic Double Difference Tomography of Compressional and Shear Wave Arrival Times Details Activities (1) Areas (1) Regions (0) Abstract: Microseismic imaging can be an important tool for characterizing geothermal reservoirs. Since microseismic sources occur more or less continuously both due to the operations of a geothermal field and the naturally occurring background seismicity, passive seismic monitoring is well suited to quantify the temporal variations in the vicinity of a

379

Phase-Resolved Measurements of Ion Velocity in a Radio-Frequency Sheath Brett Jacobs,1,* Walter Gekelman,1  

E-Print Network [OSTI]

-induced fluorescence in a commercial plasma process- ing tool. Discharge parameters were such that the 2.2 MHz rf upon the ratio of the ion transit time through the sheath to the rf period (ion=rf) [11]. In the high-frequencyPhase-Resolved Measurements of Ion Velocity in a Radio-Frequency Sheath Brett Jacobs,1,* Walter

California at Los Angles, University of

380

Backpulse and filter feed velocity effects on Norton filter performance  

SciTech Connect (OSTI)

A series of tests have been conducted using the 2.2 ft{sup 2} Norton filter to solve the fouling problems observed with the ETF Norton system. The objective of these tests was to determine filter efficiency as a function of backpulse strength and feed velocity. Based on experimental results, it is recommend that the filters should be operated at the following conditions: (1) Backpulse Transmembrane Pressure/FeedTransmembrane Pressure (BP/FP) > 1.5, preferably 2 or 3. (2) Feed crossflow velocity = 6--8 f/s. It is expected that operation at these conditions should improve performance by 30--60%.

Siler, J.L.

1990-05-08T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Extreme Value Analysis of Tidal Stream Velocity Perturbations  

SciTech Connect (OSTI)

This paper presents a statistical extreme value analysis of maximum velocity perturbations from the mean flow speed in a tidal stream. This study was performed using tidal velocity data measured using both an Acoustic Doppler Velocimeter (ADV) and an Acoustic Doppler Current Profiler (ADCP) at the same location which allows for direct comparison of predictions. The extreme value analysis implements of a Peak-Over-Threshold method to explore the effect of perturbation length and time scale on the magnitude of a 50-year perturbation.

Harding, Samuel; Thomson, Jim; Polagye, Brian; Richmond, Marshall C.; Durgesh, Vibhav; Bryden, Ian

2011-04-26T23:59:59.000Z

382

Fermi velocity renormalization and dynamical gap generation in graphene  

E-Print Network [OSTI]

We study the renormalization of the Fermi velocity by the long-range Coulomb interactions between the charge carriers in the Dirac-cone approximation for the effective low-energy description of the electronic excitations in graphene at half filling. Solving the coupled system of Dyson-Schwinger equations for the dressing functions in the corresponding fermion propagator with various approximations for the particle-hole polarization we observe that Fermi velocity renormalization effects generally lead to a considerable increase of the critical coupling for dynamical gap generation and charge-density wave formation at the semimetal-insulator transition.

C. Popovici; C. S. Fischer; L. von Smekal

2015-01-12T23:59:59.000Z

383

Dynamic optical properties in graphene: Length versus velocity gauge  

SciTech Connect (OSTI)

The dynamic optical properties of graphene are theoretically investigated in both length gauge and velocity gauge in the presence of ultrafast optical radiation field. The two gauges present different results of dynamic photo-induced carriers and optical conductance due to distinct dependencies on electric field and non-resonant optical absorption, while the two gauges give identical results in the steady state time. It shows that the choice of gauge affects evidently the dynamic optical properties of graphene. The velocity gauge represents an outcome of a real physical experiment.

Dong, H. M.; Han, K., E-mail: han6409@263.net [Department of Physics, China University of Mining and Technology, Xuzhou 221116 (China); Xu, W. [Key Laboratory of Materials Physics, Institute of Solid State Physics, Chinese Academy of Sciences, Hefei 230031 (China); Department of Physics, Yunnan University, Kunming 650091 (China)

2014-02-14T23:59:59.000Z

384

Design and Experimental Validation of a Ducted Counter-rotating Axial-flow Fans System  

E-Print Network [OSTI]

,8 ) than the front rotor (FR) diameter to re- duce interaction between the FR tip vortex and the RR blade that the efficiency is strongly increased compared to a conventional rotor or to a rotor-stator stage. The effects a very flexible use, with a large patch of high efficient operating points in the parameter space

Boyer, Edmond

385

Incorporating Velocity Shear into the Magneto-Boussinesq Approximation  

E-Print Network [OSTI]

Motivated by consideration of the solar tachocline, we derive, via an asymptotic procedure, a new set of equations incorporating velocity shear and magnetic buoyancy into the Boussinesq approximation. We demonstrate, by increasing the magnetic field scale height, how these equations are linked to the magneto-Boussinesq equations of Spiegel and Weiss (1982).

Bowker, Jordan A; Kersalé, Evy

2014-01-01T23:59:59.000Z

386

THE VELOCITY DEPENDENCE OF AERODYNAMIC DRAG: A PRIMER FOR MATHEMATICIANS  

E-Print Network [OSTI]

THE VELOCITY DEPENDENCE OF AERODYNAMIC DRAG: A PRIMER FOR MATHEMATICIANS LYLE N. LONG and HOWARD­entry of the space shuttle into the earth's atmosphere. Dimensional analysis is an important tool in aerodynamics­T E X 1 #12; For detailed information on the aerodynamics and fluid mechanics pertinent to this paper

387

Estimation of boundary layer transition noise from velocity measurements  

Science Journals Connector (OSTI)

Velocity measurements of artificially generatedflow structures in the transition region of an incompressible boundary layer with zero pressure gradient are described. These measurements made in a laminar flow water channel allow calculation of the velocity normal to the wall in a turbulent spot. This velocity specifies the linearized boundary condition for the acoustic equation at the wall. The approach relates the radiated noise to fluctuations in the normal velocity at the plate through fluctuations in the displacement thickness. Although this approach has been previously proposed [H. W. Liepmann unpublished (1954) J. Laufer J. E. Ffowcs?Williams and S. Childress AGARDograph 90 39–42 (1964) G. C. Lauchle J. Acoust. Soc. Am. 69 665–671 (1981) G. C. Lauchle ASME NCA 5 31–38 (1989)] it has never been applied. The results of these experiments will be compared to concurrent experiments run in an anechoic wind tunnel. Ultimately this work will be extended to naturally occurring structures in the transition region. [Work supported by ONR under Grant ?N00014?90?J?1365.

Michael H. Krane; Wayne R. Pauley

1991-01-01T23:59:59.000Z

388

Brady 1D seismic velocity model ambient noise prelim  

SciTech Connect (OSTI)

Preliminary 1D seismic velocity model derived from ambient noise correlation. 28 Green's functions filtered between 4-10 Hz for Vp, Vs, and Qs were calculated. 1D model estimated for each path. The final model is a median of the individual models. Resolution is best for the top 1 km. Poorly constrained with increasing depth.

Robert J. Mellors

2013-10-25T23:59:59.000Z

389

An experimental study of heat transfer in reciprocating square duct fitted with ribs skewed to the flow  

SciTech Connect (OSTI)

The fuel economy plays the most important requirement for a marine propulsion plant as it has the decisive influence on the operating cost of a ship. In general the improvements of the propulsive and engine efficiencies could reduce the fuel consumption. Therefore, for a marine main diesel engine, the substantial increase of stroke/bore ratio, so that the engine speed can be significantly reduced in order to increase the propulsive efficiency, is observed as a common trend of development in the industry of marine engineering. Along with the efforts in reducing the speed of a propulsive engine, the continuous increases of maximum cycle pressure and temperature of the engine in order to increase the engine efficiency has proceeded in the last decade. As a result, one of the main assemblies of a combustion chamber, the piston, experiences a more difficult working environment. To compensate for the increasing thermal and mechanical loads experienced by a piston, the designs of the piston crown and its cooling system have to be modified. However, due to the reciprocating nature of the piston, the coolant flow circulating within these cooling passages is subjected to an additional time-varied periodical body force induced by reciprocation. Therefore the influences of reciprocating force on the flow field and its cooling performance cannot be ignored if the optimum design of such a cooling system is to be achieved. This study investigated the cooling performance of skewed ribs in the reciprocating duct.

Chang, S.W.; Su, L.M. [National Kaosiung Inst. of Marine Technology (Taiwan, Province of China). Dept. of Marine Engineering; Yang, T.L.; Hwang, C.C. [National Cheng Kung Univ., Tainan (Taiwan, Province of China). Dept. of Naval Architecture and Marine Engineering

1999-02-01T23:59:59.000Z

390

Antiproliferation and apoptosis induced by tamoxifen in human bile duct carcinoma QBC939 cells via upregulated p53 expression  

SciTech Connect (OSTI)

Tamoxifen (TAM) is a nonsteroidal antiestrogen that has been used in the treatment of breast cancer for over 30 years. Recently, it was shown that TAM also has efficacy on gastrointestinal neoplasms such as hepatocarcinoma and pancreatic carcinoma, and that the chemopreventive activities of TAM might be due to its abilities to inhibit cell growth and induce apoptosis. In the present study, we investigated the effects of tamoxifen on growth and apoptosis in the human bile duct carcinoma (BDC) cell line QBC939 using MTT assay, inverted microscopy, fluorescence microscopy, transmission electron microscopy, classic DNA fragmentation agarose gel electrophoresis assay, PI single- and FITC/PI double-staining flow cytometry, and Western blotting. Our data revealed that TAM could significantly inhibit growth and induce apoptosis in QBC939 cells. Increased expression of p53 was observed in TAM-treated cells, indicating that p53 might play an important role in TAM-induced apoptosis in QBC939 cells. These results provide significant insight into the anticarcinogenic action of TAM on BDC.

Han, Peng; Kang, Jin-He; Li, Hua-Liang [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China)] [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Hu, Su-Xian [First Hospital Attached to Fujian Medical University, Xiamen 361004 (China)] [First Hospital Attached to Fujian Medical University, Xiamen 361004 (China); Lian, Hui-Hui; Qiu, Ping-Ping; Zhang, Jian [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China)] [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Li, Wen-Gang, E-mail: lwg11861@163.com [First Hospital Attached to Fujian Medical University, Xiamen 361004 (China)] [First Hospital Attached to Fujian Medical University, Xiamen 361004 (China); Chen, Qing-Xi, E-mail: chenqx@xmu.edu.cn [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China) [Key Laboratory of Ministry of Education for Cell Biology and Tumor Cell Engineering, School of Life Sciences, Xiamen University, Xiamen 361005 (China); Key Laboratory for Chemical Biology of Fujian Province, Xiamen University, Xiamen 361005 (China)

2009-07-24T23:59:59.000Z

391

Surgical, pathological and clinical correlation of Tc-99m DISIDA hepatobiliary imaging in 138 adult males, in the diagnosis of functional cystic duct obstruction VS acute or chronic cholecystitis  

SciTech Connect (OSTI)

Despite the wide acceptance of the hepatobiliary scintigraphy as a popular diagnostic imaging modality for gallbladder and hepatobiliary disease, correlation between radionuclide diagnoses and the final clinical and/or pathologic findings have not been thoroughly evaluated. The lack of correlative studies frequently generates difficulties in making appropriate diagnostic interpretation of the objective findings. A retrospective clinical pathological and surgical correlative study was undertaken by the authors in 138 male veteran patients, who underwent computer assisted minute by minute Tc-99m DISIDA cholescintigraphy. A very high percentage (75%) revealed abnormalities; non-visualization of gallbladder (GB) with normal choledochus system (46%), choledochal obstruction with no GB visualization (13%), choledochal obstruction with normal GB visualization (6%), severe hepatocellular disease with non-diagnostic GB (4%), and delayed GB visualization (longer than 60 minutes) (3%). Non-visualization of GB but normal choledochus demonstrated diverse pathologic etiologies, acute and chronic cholecystitis (64%), S/P cholecystectomy (8%), functional obstruction secondary to sepsis or pancreatitis (6%), and various other pathologies including porcelain GB and cholangitis (22%). The most important cause of choledochal obstruction was mass lesions or local infiltration with metastases (33%) rather than acute cholecystitis (27%). Although the sensitivity (98%) and specificity (92%) for cystic duct obstruction were very high, the specificity decreases significantly for cholecystitis.

Yoo, J.H.K.; Beal, W.H.; Ware, R.W.; Straw, J.D.; Chaudhuri, T.K.

1985-05-01T23:59:59.000Z

392

Effect of the q-nonextensive electron velocity distribution on a magnetized plasma sheath  

SciTech Connect (OSTI)

In this work, a sheath model has been developed to investigate the effect of the q-nonextensive electron velocity distribution on the different characteristics of a magnetized plasma. By using Segdeev potential method, a modified Bohm criterion for a magnetized plasma with the nonextensive electron velocity distribution is derived. The sheath model is then used to analyze numerically the sheath structure under different q, the parameter quantifying the nonextensivity degree of the system. The results show that as the q-parameter decreases, the floating potential becomes more negative. The sheath length increases at the lower values of the q-parameter due to the increase in the electron population at the high-energy tail of the distribution function. As q-parameter decreases, the effective temperature of the electrons increases which results in a more extended plasma sheath. The ion velocity and density profiles for the different nonextensivity degrees of the system reflect the gyro-motion of the ions in the presence of the magnetic field. Furthermore, the results coincide with those given by the Maxwellian electron distribution function, when q tends to 1.

Safa, N. Navab, E-mail: n-navabsafa@sbu.ac.ir; Ghomi, H.; Niknam, A. R. [Laser and Plasma Research Institute, Shahid Beheshti University, Tehran 1983963113 (Iran, Islamic Republic of)

2014-08-15T23:59:59.000Z

393

SDSS 0956+5128: A BROAD-LINE QUASAR WITH EXTREME VELOCITY OFFSETS  

SciTech Connect (OSTI)

We report on the discovery of a Type 1 quasar, SDSS 0956+5128, with a surprising combination of extreme velocity offsets. SDSS 0956+5128 is a broad-lined quasar exhibiting emission lines at three substantially different redshifts: a systemic redshift of z {approx} 0.714 based on narrow emission lines, a broad Mg II emission line centered 1200 km s{sup -1} bluer than the systemic velocity, at z {approx} 0.707, and broad H{alpha} and H{beta} emission lines centered at z {approx} 0.690. The Balmer line peaks are 4100 km s{sup -1} bluer than the systemic redshift. There are no previously known objects with such an extreme difference between broad Mg II and broad Balmer emission. The two most promising explanations are either an extreme disk emitter or a high-velocity black hole recoil. However, neither explanation appears able to explain all of the observed features of SDSS 0956+5128, so the object may provide a challenge to our general understanding of quasar physics.

Steinhardt, Charles L.; Schramm, Malte; Silverman, John D. [Kavli IPMU, University of Tokyo, Kashiwanoha 5-1-5, Kashiwa-shi, Chiba (Japan); Alexandroff, Rachael; Pattarakijwanich, Petchara; Strauss, Michael A. [Department of Astrophysical Sciences, Princeton University, Ivy Lane, Princeton, NJ 08544 (United States); Capak, Peter [California Institute of Technology, MC 249-17, 1200 East California Boulevard, Pasadena, CA 91125 (United States); Civano, Francesca; Elvis, Martin [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Masters, Dan; Mobasher, Bahram [Department of Physics and Astronomy, University of California, Riverside, CA 92508 (United States)

2012-11-01T23:59:59.000Z

394

Super Star Cluster Velocity Dispersions and Virial Masses in the M82 Nuclear Starburst  

E-Print Network [OSTI]

We use high-resolution near-infrared spectroscopy from Keck Observatory to measure the stellar velocity dispersions of 19 super star clusters (SSCs) in the nuclear starburst of M82. The clusters have ages on the order of 10 Myr, which is many times longer than the crossing times implied by their velocity dispersions and radii. We therefore apply the Virial Theorem to derive the kinematic mass for 15 of the SSCs. The SSCs have masses of 2 x 10^5 to 4 x 10^6 solar masses, with a total population mass of 1.4 x 10^7 solar masses. Comparison of the loci of the young M82 SSCs and old Milky Way globular clusters in a plot of radius versus velocity dispersion suggests that the SSCs are a population of potential globular clusters. We present the mass function for the SSCs, and find a power law fit with an index of gamma = -1.91 +/- 0.06. This result is nearly identical to the mass function of young SSCs in the Antennae galaxies.

Nate McCrady; James R. Graham

2007-04-04T23:59:59.000Z

395

PROBING THE HALO FROM THE SOLAR VICINITY TO THE OUTER GALAXY: CONNECTING STARS IN LOCAL VELOCITY STRUCTURES TO LARGE-SCALE CLOUDS  

SciTech Connect (OSTI)

This paper presents the first potential connections made between two local features in velocity space found in a survey of M giant stars and stellar spatial inhomogeneities on global scales. Comparison to cosmological, chemodynamical stellar halo models confirms that the M giant population is particularly sensitive to rare, recent and massive accretion events. These events can give rise to locally observed velocity sequences-each made from a small fraction of debris from a massive progenitor, passing at high velocity through the survey volume, near the pericenter of the eccentric orbit of the system. The majority of the debris is found in much larger structures, whose morphologies are more cloud-like than stream-like and which lie at the orbital apocenters. Adopting this interpretation, the full-space motions represented by the observed M giant velocity features are derived under the assumption that the members within each sequence share a common space velocity. Orbit integrations are then used to trace the past and future trajectories of these stars across the sky revealing plausible associations with large, previously discovered, cloud-like structures. The connections made between nearby velocity structures and these distant clouds represent preliminary steps toward developing coherent maps of such giant debris systems. These maps promise to provide new insights into the origin of debris clouds, new probes of Galactic history and structure, and new constraints on the high-velocity tails of the local dark matter distribution that are essential for interpreting direct dark matter particle detection experiments.

Johnston, Kathryn V.; Sheffield, Allyson A. [Department of Astronomy, Columbia University, New York, NY 10027 (United States); Majewski, Steven R. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-0818 (United States); Sharma, Sanjib [Sydney Institute for Astronomy, School of Physics, University of Sydney, NSW 2006 (Australia); Rocha-Pinto, Helio J., E-mail: kvj@astro.columbia.edu [Observatorio do Valongo, Universidade Federal do Rio de Janeiro (Brazil)

2012-11-20T23:59:59.000Z

396

Low Velocity Sphere Impact of a Soda Lime Silicate Glass  

SciTech Connect (OSTI)

This report summarizes TARDEC-sponsored work at Oak Ridge National Laboratory (ORNL) during the FY11 involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Starphire soda lime silicate glass. The intent was to better understand low velocity impact response in the Starphire for sphere densities that bracketed that of rock. Five sphere materials were used: borosilicate glass, soda-lime silicate glass, steel, silicon nitride, and alumina. A gas gun was fabricated to produce controlled velocity delivery of the spheres against Starphire tile targets. Minimum impact velocities to initiate fracture in the Starphire were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the any of the five sphere-Starphire-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Frictional effects contribute to fracture initiation. (2) Spheres with a lower elastic modulus require less force to initiate fracture in the Starphire than spheres with a higher elastic modulus. (3) Contact-induced fracture did not initiate in the Starphire SLS for impact kinetic energies < 150 mJ. Fracture sometimes initiated or kinetic energies between {approx} 150-1100 mJ; however, it tended to occur when lower elastic modulus spheres were impacting it. Contact-induced fracture would always occur for impact energies > 1100 mJ. (4) The force necessary to initiate contact-induced fracture is higher under dynamic or impact conditions than it is under quasi-static indentation conditions. (5) Among the five used sphere materials, silicon nitride was the closest match to 'rock' in terms of both density and (probably) elastic modulus.

Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL; Morrissey, Timothy G [ORNL; Vuono, Daniel J [ORNL

2011-10-01T23:59:59.000Z

397

Report of IAU Commission 30 on Radial Velocities (2006-2009)  

E-Print Network [OSTI]

Brief summaries are given on the following subjects: Radial velocities and exoplanets (Toward Earth-mass planets; Retired A stars and their planets; Current status and prospects); Toward higher radial velocity precision; Radial velocities and asteroseismology; Radial velocities in Galactic and extragalactic clusters; Radial velocities for field giants; Galactic structure -- Large surveys (The Geneva-Copenhagen Survey; Sloan Digital Sky Survey; RAVE); Working groups (WG on radial velocity standards; WG on stellar radial velocity bibliography; WG on the catalogue of orbital elements of spectroscopic binaries [SB9]).

G. Torres; E. V. Glushkova; J. A. Johnson; H. Levato; B. Nordström; D. Pourbaix; G. Torres; S. Udry

2008-10-24T23:59:59.000Z

398

Study of Air Ingress Across the Duct During the Accident Conditions  

SciTech Connect (OSTI)

The goal of this project is to study the fundamental physical phenoena associated with air ingress in very high temperature reactors (VHTRs). Air ingress may occur due to a nupture of primary piping and a subsequent breach in the primary pressure boundary in helium-cooled and graphite-moderated VHTRs. Significant air ingress is a concern because it introduces potential to expose the fuel, graphite support rods, and core to a risk of severe graphite oxidation. Two of the most probable air ingress scenarios involve rupture of a control rod or fuel access standpipe, and rupture in the main coolant pipe on the lower part of the reactor pressure vessel. Therefor, establishing a fundamental understanding of air ingress phenomena is critical in order to rationally evaluate safety of existing VHTRs and develop new designs that mimimize these risks. But despite this importance, progress toward development these predictive capabilities has been slowed by the complex nature of the underlaying phenomena. The combination of interdiffusion among multiple species, molecular diffusion, natural convection, and complex geometries, as well as the multiple chemical reactions involved, impose significant roadblocks to both modeling and experiment design. The project team will employ a coordinated experimental and computational effort that will help gain a deeper understanding of multiphased air ingress phenomena. THis project will enhance advanced modeling and simulation methods, enabling calculation of nuclear power plant transients and accident scenarios with a high degree of confidence. The following are the project tasks: Perform particle image velocimetry measurement of multiphase air ingresses Perform computational fluid dynamics analysis of air ingress phenomena

Hassan, Yassin

2013-05-06T23:59:59.000Z

399

Low velocity ion stopping in binary ionic mixtures  

SciTech Connect (OSTI)

Attention is focused on the low ion velocity stopping mechanisms in multicomponent and dense target plasmas built of quasiclassical electron fluids neutralizing binary ionic mixtures, such as, deuterium-tritium of current fusion interest, proton-heliumlike iron in the solar interior or proton-helium ions considered in planetology, as well as other mixtures of fiducial concern in the heavy ion beam production of warm dense matter at Bragg peak conditions. The target plasma is taken in a multicomponent dielectric formulation a la Fried-Conte. The occurrence of projectile ion velocities (so-called critical) for which target electron slowing down equals that of given target ion components is also considered. The corresponding multiquadrature computations, albeit rather heavy, can be monitored analytical through a very compact code operating a PC cluster. Slowing down results are systematically scanned with respect to target temperature and electron density, as well as ion composition.

Tashev, Bekbolat; Baimbetov, Fazylkhan [Department of Physics, Kazakh National University, Tole Bi 96, Almaty 480012 (Kazakhstan); Deutsch, Claude [LPGP (UMR-CNRS 8578), Universite Paris XI, 91405 Orsay (France); Fromy, Patrice [Direction de l'Informatique, Universite Paris XI, 91405 Orsay (France)

2008-10-15T23:59:59.000Z

400

Velocity of sound in relativistic heavy-ion collisions  

Science Journals Connector (OSTI)

We have studied the rapidity distribution of secondary hadrons produced in nucleus-nucleus collisions at ultrarelativistic energies within the ambit of the Landau’s hydrodynamical model. A reasonable description of the data can also be obtained by using the Bjorken’s hydrodynamical model if the boost invariance is restricted to a finite rapidity range. The sensitivity of the hadronic spectra on the equation of state vis-à-vis the velocity of sound has been discussed. The correlation between the velocity of sound and the freeze-out temperature has been indicated. The effects of the nonzero widths of various mesonic and baryonic degrees of freedom up to the mass value ?2.5GeV are seen to be small.

Bedangadas Mohanty and Jan-e Alam

2003-12-11T23:59:59.000Z

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401

Measuring In-Situ Mdf Velocity Of Detonation  

DOE Patents [OSTI]

A system for determining the velocity of detonation of a mild detonation fuse mounted on the surface of a device includes placing the device in a predetermined position with respect to an apparatus that carries a couple of sensors that sense the passage of a detonation wave at first and second spaced locations along the fuse. The sensors operate a timer and the time and distance between the locations is used to determine the velocity of detonation. The sensors are preferably electrical contacts that are held spaced from but close to the fuse such that expansion of the fuse caused by detonation causes the fuse to touch the contact, causing an electrical signal to actuate the timer.

Horine, Frank M. (Albuquerque, NM); James, Jr., Forrest B. (Albuquerque, NM)

2005-10-25T23:59:59.000Z

402

On fuel-optimal velocity control of a motor vehicle  

Science Journals Connector (OSTI)

This paper presents the motor vehicle velocity control that, under certain well-defined conditions, ensures a minimum fuel consumption. To this purpose, a vehicle with a stepped mechanical transmission is considered, assuming that the gear is unchanged during the movement. The optimal control problem is formulated for different cases and solved by applying Pontryagin's maximum principle. Whenever there is a singular solution, it is shown to correspond to the uniform motion law. The optimal velocity controls include the following phases that may be combined in different ways: deceleration without engine shut-off (null engine power), strong decelerative braking, constant speed movement and full-throttle acceleration. Examples are presented by using the experimental data on engine fuel consumption. The stress falls on the significant reductions in fuel consumption that can be achieved compared to uniform motion.

A.P. Stoicescu

1995-01-01T23:59:59.000Z

403

Velocity renormalization in graphene from lattice Monte Carlo  

E-Print Network [OSTI]

We compute the Fermi velocity of the Dirac quasiparticles in clean graphene at the charge neutrality point for strong Coulomb coupling alpha_g. We perform a Lattice Monte Carlo calculation within the low-energy Dirac theory, which includes an instantaneous, long-range Coulomb interaction. We find a renormalized Fermi velocity v_FR > v_F, where v_F = c/300. Our results are consistent with a momentum-independent v_FR which increases approximately linearly with alpha_g, although a logarithmic running with momentum cannot be excluded at present. At the predicted critical coupling alpha_gc for the semimetal-insulator transition due to excitonic pair formation, we find v_FR/v_F = 3.3, which we discuss in light of experimental findings for v_FR/v_F at the charge neutrality point in ultra-clean suspended graphene.

Joaquín E. Drut; Timo A. Lähde

2014-03-26T23:59:59.000Z

404

The peculiar velocity field in a quintessence model  

E-Print Network [OSTI]

We investigate the evolution of matter density perturbations and some properties of the peculiar velocity field for a special class of exponential potentials in a scalar field model for quintessence, for which a general exact solution is known. The data from the 2-degree Field Galaxy Redshift Survey (2dFGRS) suggest a value of the today pressureless matter density Omega_M0 = 0.18 +- 0.05.

Claudio Rubano; Mauro Sereno

2002-03-13T23:59:59.000Z

405

Extracting Fish and Water Velocity from Doppler Profiler Data  

E-Print Network [OSTI]

Extracting Fish and Water Velocity from Doppler Profiler Data �º Ð 1 ¸ � � �¹ � Ý�¹� � 2 1 to measure fish swimming speeds. This is possible when fish form schools that are large enough so that the multiple Doppler sonar beams are sampling the fish speeds at the same time. In situations where fish

deYoung, Brad

406

Experimental investigation of velocity biasing in laser Doppler anemometry  

E-Print Network [OSTI]

Tech University; Chair of Advisory Commettee: Dr. Gerald L. Morrison The effects of several velocity bias reduction schemes were invest- igated using a 3-D laser Doppler anemometer and counter type (burst) signal processors. Amongst these schemes... was the McLaughlin Tiederman 3-D weighting factor, time between data weighting factor, equal time interval sampling and analogue instrumentation measurements. The ana- logue instrumentation measurements were obtained from the analogue frequency outputs...

Wiedner, Brian Gregory

1988-01-01T23:59:59.000Z

407

Boltzmann Solver with Adaptive Mesh in Velocity Space  

SciTech Connect (OSTI)

We describe the implementation of direct Boltzmann solver with Adaptive Mesh in Velocity Space (AMVS) using quad/octree data structure. The benefits of the AMVS technique are demonstrated for the charged particle transport in weakly ionized plasmas where the collision integral is linear. We also describe the implementation of AMVS for the nonlinear Boltzmann collision integral. Test computations demonstrate both advantages and deficiencies of the current method for calculations of narrow-kernel distributions.

Kolobov, Vladimir I.; Arslanbekov, Robert R. [CFD Research Corporation, 215 Wynn Dr, Huntsville, AL, 35803 (United States); Frolova, Anna A. [Dorodnicyn Computing Centre of the Russian Academy of Sciences, Vavilova Str., 40, Moscow, 119333 (Russian Federation)

2011-05-20T23:59:59.000Z

408

Studies of the velocity fields near a submerged rectangular object  

E-Print Network [OSTI]

of the time periodic waves past a submerged rectangular object. For sotne wave conditions, large energy dissipation occurred at the submerged object due to vortex generation. The amount of energy dissipation was examined by comparing incident wave energy... object. A two component laser-Doppler anemometer (LDA) was used to obtain detailed measurements of the instantaneous velocity field and flow visualization was conducted to study the vortex structure around the submerged object. The measured wave...

Kim, Young-Ki

2012-06-07T23:59:59.000Z

409

Time, Distance, Velocity, Redshift: a personal guided tour  

E-Print Network [OSTI]

An attempt to answer the question 'Can we observe galaxies that recede faster than light ?' led to a re-examination of the notions of time, distance, velocity and redshift as they occur in newtonian physics, special relativity, general relativity and cosmology. A number of misconceptions were uncovered. It was found that, once freed of special relativity preconceptions, the above question is easily and unequivocally answered

T. Kiang

2003-08-01T23:59:59.000Z

410

Distant Metastasis Risk Stratification for Patients Undergoing Curative Resection Followed by Adjuvant Chemoradiation for Extrahepatic Bile Duct Cancer  

SciTech Connect (OSTI)

Purpose: To analyze the prognostic factors predicting distant metastasis in patients undergoing adjuvant chemoradiation for extrahepatic bile duct (EHBD) cancer. Methods and Materials: Between January 1995 and August 2006, 166 patients with EHBD cancer underwent resection with curative intent, followed by adjuvant chemoradiation. There were 120 males and 46 females, and median age was 61 years (range, 34-86). Postoperative radiotherapy was delivered to tumor bed and regional lymph nodes (median dose, 40 Gy; range, 34-56 Gy). A total of 157 patients also received fluoropyrimidine chemotherapy as a radiosensitizer, and fluoropyrimidine-based maintenance chemotherapy was administered to 127 patients. Median follow-up duration was 29 months. Results: The treatment failed for 97 patients, and the major pattern of failure was distant metastasis (76 patients, 78.4%). The 5-year distant metastasis-free survival rate was 49.4%. The most common site of distant failure was the liver (n = 36). On multivariate analysis, hilar tumor, tumor size {>=}2 cm, involved lymph node, and poorly differentiated tumor were associated with inferior distant metastasis-free survival (p = 0.0348, 0.0754, 0.0009, and 0.0078, respectively), whereas T stage was not (p = 0.8081). When patients were divided into four groups based on these risk factors, the 5-year distant metastasis-free survival rates for patients with 0, 1, 2, and 3 risk factors were 86.4%, 59.9%, 32.5%, and 0%, respectively (p < 0.0001). Conclusion: Despite maintenance chemotherapy, distant metastasis was the major pattern of failure in patients undergoing adjuvant chemoradiation for EHBD cancer after resection with curative intent. Intensified chemotherapy is warranted to improve the treatment outcome, especially in those with multiple risk factors.

Kim, Kyubo [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of)] [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Chie, Eui Kyu, E-mail: ekchie93@snu.ac.kr [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jang, Jin-Young; Kim, Sun Whe [Department of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of)] [Department of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of); Han, Sae-Won; Oh, Do-Youn; Im, Seock-Ah; Kim, Tae-You; Bang, Yung-Jue [Department of Internal Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of)] [Department of Internal Medicine, Seoul National University College of Medicine, Seoul (Korea, Republic of); Ha, Sung W. [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of) [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Institute of Radiation Medicine, Medical Research Center, Seoul National University (Korea, Republic of)

2012-09-01T23:59:59.000Z

411

Is Duodenal Invasion a Relevant Prognosticator in Patients Undergoing Adjuvant Chemoradiotherapy for Distal Common Bile Duct Cancer?  

SciTech Connect (OSTI)

Purpose: To analyze the outcome of adjuvant chemoradiotherapy for patients with distal common bile duct (CBD) cancer who underwent curative surgery, and to identify the prognostic factors for these patients. Methods and Materials: Between January 1991 and December 2002, 38 patients with adenocarcinoma of the distal CBD underwent curative resection followed by adjuvant chemoradiotherapy. There were 27 men and 11 women, and the median age was 60 years (range, 34-73). Adjuvant radiotherapy was delivered to the tumor bed and regional lymph nodes up to 40 Gy at 2 Gy/fraction with a 2-week planned rest. Intravenous 5-fluorouracil (500mg/m{sup 2}/day) was given on day 1 to day 3 of each split course. The median follow-up period was 39 months. Results: The 5-year overall survival rate of all patients was 49.1%. On univariate analysis, only histologic differentiation (p = 0.0005) was associated with overall survival. Tumor size ({<=}2cm vs. >2cm) had a marginally significant impact on the treatment outcome (p = 0.0624). However, there was no difference in overall survival rates between T3 and T4 tumors (p = 0.6189), for which the main determinants were pancreatic and duodenal invasion, respectively. On multivariate analysis, histologic differentiation (p = 0.0092) and tumor size (p = 0.0046) were independent risk factors for overall survival. Conclusions: Long-term survival can be expected in patients with distal CBD cancer undergoing curative surgery and adjuvant chemoradiotherapy. Histologic differentiation and tumor size were significant prognostic factors predicting overall survival, whereas duodenal invasion was not. This finding suggests the need for further refinement in tumor staging.

Kim, Kyubo [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Chie, Eui Kyu, E-mail: ekchie93@snu.ac.k [Department of Radiation Oncology, Seoul National University College of Medicine, Seoul (Korea, Republic of); Jang, Jin-Young; Kim, Sun Whe [Department of Surgery, Seoul National University College of Medicine, Seoul (Korea, Republic of)

2010-07-15T23:59:59.000Z

412

Airflow Simulations around OA Intake Louver with Electronic Velocity Sensors  

SciTech Connect (OSTI)

It is important to control outdoor airflow rates into HVAC systems in terms of energy conservation and healthy indoor environment. Technologies are being developed to measure outdoor air (OA) flow rates through OA intake louvers on a real time basis. The purpose of this paper is to investigate the airflow characteristics through an OA intake louver numerically in order to provide suggestions for sensor installations. Airflow patterns are simulated with and without electronic air velocity sensors within cylindrical probes installed between louver blades or at the downstream face of the louver. Numerical results show quite good agreements with experimental data, and provide insights regarding measurement system design. The simulations indicate that velocity profiles are more spatially uniform at the louver outlet relative to between louver blades, that pressure drops imposed by the sensor bars are smaller with sensor bars at the louver outlet, and that placement of the sensor bars between louver blades substantially increases air velocities inside the louver. These findings suggest there is an advantage to placing the sensor bars at the louver outlet face.

Han, Hwataik; Sullivan, Douglas P.; Fisk, William J.

2009-04-01T23:59:59.000Z

413

The Velocity of Sound in an Absorptive Gas  

Science Journals Connector (OSTI)

The theory of velocity propagation in a gas as conditioned by internal energy exchanges is considered in detail for the simplest case in which the "lags" may be different—namely, the model with three sets of states. This "second order" theory is required for the interpretation of experimental results where the wave period is of the order of the lag for some states. Assuming the first vibration state of CO2 to have the largest lag in accordance with Kneser's interpretation of his recent experiments, the necessary approximations are given explicitly and the results are directly applicable to CO2. The apparent lag as measured in sound velocity experiments is not the simple stationary state mean "collision life" nor the mean life of the energy quantum except under special conditions and then for only one of the states. The velocity increment in the "resonance" region is given more accurately in terms of transition probabilities and is not described completely by the specific heats as might be expected from the "first order" theory. Contrary to the indications of the simple theory with an empirical constant the external energy is always merely the translation term. The status of the assumed lag assignment in CO2 is discussed in the light of the results and underlying theory of this paper.

D. G. Bourgin

1932-12-01T23:59:59.000Z

414

On velocities beyond the speed of light c  

E-Print Network [OSTI]

From a mathematical point of view velocities can be larger than c. It has been shown that Lorentz transformations are easily extended in Minkowski space to address velocities beyond the speed of light. Energy and momentum conservation fixes the relation between masses and velocities larger than c, leading to the possible observation of negative mass squared particles from a standard reference frame. Current data on neutrinos' mass square yeld negative values, making neutrinos as possible candidates for having speed larger than c. In this paper, an original analysis of the SN1987A supernova data is proposed. It is shown that all the data measured in '87 by all the experiments are consistent with the quantistic description of neutrinos as combination of superluminal mass eigenstates. The well known enigma on the arrival times of the neutrino bursts detected at LSD, several hours earlier than at IMB, K2 and Baksan, is explained naturally. It is concluded that experimental evidence for superluminal neutrinos was recorded since the SN1987A explosion, and that data are quantitatively consistent with the introduction of tachyons in Einstein's equation.

S. Giani

1997-12-04T23:59:59.000Z

415

Microstructure and Property Evolution in Advanced Cladding and Duct Materials Under Long-Term and Elevated Temperature Irradiation: Modeling and Experimental Investigation  

SciTech Connect (OSTI)

The in-service degradation of reactor core materials is related to underlying changes in the irradiated microstructure. During reactor operation, structural components and cladding experience displacement of atoms by collisions with neutrons at temperatures at which the radiation-induced defects are mobile, leading to microstructure evolution under irradiation that can degrade material properties. At the doses and temperatures relevant to fast reactor operation, the microstructure evolves by dislocation loop formation and growth, microchemistry changes due to radiation-induced segregation, radiation-induced precipitation, destabilization of the existing precipitate structure, and in some cases, void formation and growth. These processes do not occur independently; rather, their evolution is highly interlinked. Radiationinduced segregation of Cr and existing chromium carbide coverage in irradiated alloy T91 track each other closely. The radiation-induced precipitation of Ni-Si precipitates and RIS of Ni and Si in alloys T91 and HCM12A are likely related. Neither the evolution of these processes nor their coupling is understood under the conditions required for materials performance in fast reactors (temperature range 300-600°C and doses beyond 200 dpa). Further, predictive modeling is not yet possible as models for microstructure evolution must be developed along with experiments to characterize these key processes and provide tools for extrapolation. To extend the range of operation of nuclear fuel cladding and structural materials in advanced nuclear energy and transmutation systems to that required for the fast reactor, the irradiation-induced evolution of the microstructure, microchemistry, and the associated mechanical properties at relevant temperatures and doses must be understood. Predictive modeling relies on an understanding of the physical processes and also on the development of microstructure and microchemical models to describe their evolution under irradiation. This project will focus on modeling microstructural and microchemical evolution of irradiated alloys by performing detailed modeling of such microstructure evolution processes coupled with well-designed in situ experiments that can provide validation and benchmarking to the computer codes. The broad scientific and technical objectives of this proposal are to evaluate the microstructure and microchemical evolution in advanced ferritic/martensitic and oxide dispersion strengthened (ODS) alloys for cladding and duct reactor materials under long-term and elevated temperature irradiation, leading to improved ability to model structural materials performance and lifetime. Specifically, we propose four research thrusts, namely Thrust 1: Identify the formation mechanism and evolution for dislocation loops with Burgers vector of a<100> and determine whether the defect microstructure (predominately dislocation loop/dislocation density) saturates at high dose. Thrust 2: Identify whether a threshold irradiation temperature or dose exists for the nucleation of growing voids that mark the beginning of irradiation-induced swelling, and begin to probe the limits of thermal stability of the tempered Martensitic structure under irradiation. Thrust 3: Evaluate the stability of nanometer sized Y- Ti-O based oxide dispersion strengthened (ODS) particles at high fluence/temperature. Thrust 4: Evaluate the extent to which precipitates form and/or dissolve as a function of irradiation temperature and dose, and how these changes are driven by radiation induced segregation and microchemical evolutions and determined by the initial microstructure.

Wirth, Brian; Morgan, Dane; Kaoumi, Djamel; Motta, Arthur

2013-12-01T23:59:59.000Z

416

Effect of H2/CO ratio and N2/CO2 dilution rate on laminar burning velocity of syngas investigated by direct measurement and simulation  

Science Journals Connector (OSTI)

Abstract Laminar burning velocities of syngas/air premixed flames, varying with H2/CO ratio (from 5/95 to 75/25) and N2 or CO2 dilution rate (from 0% to 60%), were accurately measured using a Teflon coated Heat Flux burner and OH-PLIF based Bunsen flame method. Experiments were carried out at atmospheric pressure and room temperature, with fuel/air equivalence ratios ranging from fuel-lean to fuel-rich. Coupled with experimental data, three chemical kinetic mechanisms, namely GRI-Mech 3.0, USC Mech II and Davis H2–CO mechanism, were validated. The Davis H2–CO and USC Mech II mechanisms appear to provide a better prediction for the laminar burning velocity. The laminar burning velocity variations with H2 and dilution gas contents were systematically investigated. For given dilution gas fraction, the laminar burning velocity reduction rate was enhanced as H2/CO ratio increasing. Effects of the syngas components and equivalence ratio variation on the concentrations of radical H and OH were also studied. It appears that there is a strong linear correlation between the laminar burning velocity and the maximum concentration of the H radical in the reaction zone for syngas. This characteristic is exclusively different from that in methane air premixed flame. These findings indicated that the high thermal diffusivity of the H radical played an important role in the laminar burning velocity enhancement and affected the laminar burning velocity reduction rate under dilution condition.

Z.H. Wang; W.B. Weng; Y. He; Z.S. Li; K.F. Cen

2014-01-01T23:59:59.000Z

417

TURBULENCE-INDUCED RELATIVE VELOCITY OF DUST PARTICLES. I. IDENTICAL PARTICLES  

SciTech Connect (OSTI)

We study the relative velocity of inertial particles suspended in turbulent flows and discuss implications for dust particle collisions in protoplanetary disks. We simulate a weakly compressible turbulent flow, evolving 14 particle species with friction timescale, ?{sub p}, covering the entire range of scales in the flow. The particle Stokes numbers, St, measuring the ratio of ?{sub p} to the Kolmogorov timescale, are in the range 0.1 ?< St ?< 800. Using simulation results, we show that the model by Pan and Padoan gives satisfactory predictions for the rms relative velocity between identical particles. The probability distribution function (PDF) of the relative velocity is found to be highly non-Gaussian. The PDF tails are well described by a 4/3 stretched exponential function for particles with ?{sub p} ? 1-2 T{sub L}, where T{sub L} is the Lagrangian correlation timescale, consistent with a prediction based on PP10. The PDF approaches Gaussian only for very large particles with ?{sub p} ?> 54 T{sub L}. We split particle pairs at given distances into two types with low and high relative speeds, referred to as continuous and caustic types, respectively, and compute their contributions to the collision kernel. Although amplified by the effect of clustering, the continuous contribution vanishes in the limit of infinitesimal particle distance, where the caustic contribution dominates. The caustic kernel per unit cross section rises rapidly as St increases toward ? 1, reaches a maximum at ?{sub p} ? 2 T{sub L}, and decreases as ?{sub p}{sup -1/2} for ?{sub p} >> T{sub L}.

Pan, Liubin [Harvard-Smithsonian Center for Astrophysics, 60 Garden St., Cambridge, MA 02138 (United States); Padoan, Paolo, E-mail: lpan@cfa.harvard.edu, E-mail: ppadoan@icc.ub.edu [ICREA and ICC, University of Barcelona, Marti i Franquès 1, E-08028 Barcelona (Spain)

2013-10-10T23:59:59.000Z

418

Engineering development of coal-fired high performance power systems, Phase II and Phase III. Quarter progress report, April 1, 1996--June 30, 1996  

SciTech Connect (OSTI)

Work is presented on the development of a coal-fired high performance power generation system by the year 2000. This report describes the design of the air heater, duct heater, system controls, slag viscosity, and design of a quench zone.

NONE

1996-11-01T23:59:59.000Z

419

Measurements of Spatially Resolved Velocity Variations in Shock Compressed Heterogeneous Materials Using a Line-Imaging Velocity Interferometer  

SciTech Connect (OSTI)

Relatively straightforward changes in the optical design of a conventional optically recording velocity interferometer system (ORVIS) can be used to produce a line-imaging velocity interferometer wherein both temporal and spatial resolution can be adjusted over a wide range. As a result line-imaging ORVIS can be tailored to a variety of specific applications involving dynamic deformation of heterogeneous materials as required by the characteristic length scale of these materials (ranging from a few {micro}m for ferroelectric ceramics to a few mm for concrete). A line-imaging ORVIS has been successfully interfaced to the target chamber of a compressed gas gun driver and fielded on numerous tests in combination with simultaneous measurements using a dual delay-leg, ''push-pull'' VISAR system. These tests include shock loading of glass-reinforced polyester composites, foam reverberation experiments (measurements at the free surface of a thin aluminum plate impacted by foam), and measurements of dispersive velocity in a shock-loaded explosive simulant (sugar). Comparison of detailed spatially-resolved material response to the spatially averaged VISAR measurements will be discussed.

ASAY,JAMES R.; CHHABILDAS,LALIT C.; KNUDSON,MARCUS D.; TROTT,WAYNE M.

1999-09-01T23:59:59.000Z

420

Spectroscopic measurement of ion temperature and ion velocity distributions in the flux-coil generated FRC  

SciTech Connect (OSTI)

One aim of the flux-coil generated field reversed configuration at Tri Alpha Energy (TAE) is to establish the plasma where the ion rotational energy is greater than the ion thermal energy. To verify this, an optical diagnostic was developed to simultaneously measure the Doppler velocity-shift and line-broadening using a 0.75 m, 1800 groves/mm, spectrometer. The output spectrum is magnified and imaged onto a 16-channel photomultiplier tube (PMT) array. The individual PMT outputs are coupled to high-gain, high-frequency, transimpedance amplifiers, providing fast-time response. The Doppler spectroscopy measurements, along with a survey spectrometer and photodiode-light detector, form a suite of diagnostics that provide insights into the time evolution of the plasma-ion distribution and current when accelerated by an azimuthal-electric field.

Gupta, D.; Gota, H.; Hayashi, R.; Kiyashko, V.; Morehouse, M.; Primavera, S. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Bolte, N. [Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Marsili, P. [Department of Physics, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Roche, T. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Wessel, F. [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Tri Alpha Energy, Inc., Rancho Santa Margarita, California 92688 (United States)

2010-10-15T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Photons from Heavy-Ion Collisions at Fermi Velocity  

E-Print Network [OSTI]

'I ~ (+l Ii & & .~ I + I I 'f Il I I PHYSICAL REVIEW C VOLUME 35, NUMBER 5 MAY 1987 Photons from heavy-ion collisions at Fermi velocity Che Ming Ko Center for Theoretical Physics, Physics Department and Cyclotron Institute, Texas Ad... from the first col- lision model are slightly diff'erent from theirs as we treat the distortion of the Fermi spheres more realistically. The angular distribution for 30-MeV photon emission is shown in Fig. 2. The solid curve is the calculated...

Ko, Che Ming; Alchelin, J.

1987-01-01T23:59:59.000Z

422

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

SciTech Connect (OSTI)

In this study, hydraulic and seismic tomographic measurements were used to derive a site-specific relationship between the geophysical parameter p-wave velocity and the hydraulic parameters, diffusivity and specific storage. Our field study includes diffusivity tomograms derived from hydraulic travel time tomography, specific storage tomograms, derived from hydraulic attenuation tomography, and p-wave velocity tomograms, derived from seismic tomography. The tomographic inversion was performed in all three cases with the SIRT (Simultaneous Iterative Reconstruction Technique) algorithm, using a ray tracing technique with curved trajectories. The experimental set-up was designed such that the p-wave velocity tomogram overlaps the hydraulic tomograms by half. The experiments were performed at a wellcharacterized sand and gravel aquifer, located in the Leine River valley near Göttingen, Germany. Access to the shallow subsurface was provided by direct-push technology. The high spatial resolution of hydraulic and seismic tomography was exploited to derive representative site-specific relationships between the hydraulic and geophysical parameters, based on the area where geophysical and hydraulic tests were performed. The transformation of the p-wave velocities into hydraulic properties was undertaken using a k-means cluster analysis. Results demonstrate that the combination of hydraulic and geophysical tomographic data is a promising approach to improve hydrogeophysical site characterization.

Brauchler, R.; Doetsch, J.; Dietrich, P.; Sauter, M.

2012-01-10T23:59:59.000Z

423

The radial velocity profile of the filament galaxies in the vicinity of the Virgo cluster as a test of gravity  

E-Print Network [OSTI]

The radial velocities of the galaxies in the vicinity of a massive cluster shows deviation from the pure Hubble flow due to their gravitational interaction with the cluster. According to a recent study of Falco et al. with a high-resolution N-body simulation based on General Relativity (GR), the radial velocity profile of the galaxies located at distances larger than three times the virial radius of a neighbour cluster has a universal shape and could be reconstructed from direct observables provided that the galaxies are distributed along one dimensional filament. Analyzing the narrow filamentary structure identified by Kim et al. in the vicinity of the Virgo cluster from the NASA-Sloan-Atlas catalog, we reconstruct the radial velocity profile of the Virgo filament galaxies and compare it with the universal formula derived by Falco et al. It is found that unless the virial mass of the Virgo cluster exceeds $10^{15}\\,h^{-1}M_{\\odot}$ the universal formula fails to describe the reconstructed radial velocity pro...

Lee, Jounghun; Rey, Soo-Chang

2015-01-01T23:59:59.000Z

424

Light bullets and supercontinuum spectrum during femtosecond pulse filamentation under conditions of anomalous group-velocity dispersion in fused silicalicati  

SciTech Connect (OSTI)

We report the results of theoretical and experimental research on spectrum transformation and spatiotemporal distribution of the femtosecond laser radiation intensity during filamentation in fused silica. The formation of light bullets with a high power density is first observed in a femtosecond laser pulse in the anomalous group velocity dispersion regime at a wavelength of 1800 nm. The minimum duration of the light bullet is about two oscillation cycles of the light field. (extreme light fields and their applications)

Chekalin, Sergei V; Kompanets, V O; Smetanina, E O; Kandidov, V P

2013-04-30T23:59:59.000Z

425

Low-velocity cosmic strings in accelerating universe  

E-Print Network [OSTI]

We study the model of the homogeneous and isotropic universe with non-zero cosmological constant filled with a perfect gas of low-velocity cosmic strings (LambdaCS model). It is shown that pressure-free matter can obtain the properties of a gas of low-velocity cosmic strings, if matter is affected by inertial force as described by Sciama's inertial force law. We take notice of the fact that this law, which corresponds to one of the realizations of Mach's principle, follows from quantum geometrodynamical approach. The exact solutions of the Einstein equations for the LambdaCS model are found. It is demonstrated that this model is equivalent to the open de Sitter model. In the limit of zero cosmological constant the corresponding universe evolves as a Milne universe, but in contrast to it, such a universe contains matter with nonzero energy density. The Whitrow-Randall equation is re-derived. We draw a comparison of the standard LambdaCDM and LambdaCS models. It turns out that after the scale transformation of ...

,

2011-01-01T23:59:59.000Z

426

Measurements of parallel electron velocity distributions using whistler wave absorption  

SciTech Connect (OSTI)

We describe a diagnostic to measure the parallel electron velocity distribution in a magnetized plasma that is overdense ({omega}{sub pe} > {omega}{sub ce}). This technique utilizes resonant absorption of whistler waves by electrons with velocities parallel to a background magnetic field. The whistler waves were launched and received by a pair of dipole antennas immersed in a cylindrical discharge plasma at two positions along an axial background magnetic field. The whistler wave frequency was swept from somewhat below and up to the electron cyclotron frequency {omega}{sub ce}. As the frequency was swept, the wave was resonantly absorbed by the part of the electron phase space density which was Doppler shifted into resonance according to the relation {omega}-k{sub ||v||} = {omega}{sub ce}. The measured absorption is directly related to the reduced parallel electron distribution function integrated along the wave trajectory. The background theory and initial results from this diagnostic are presented here. Though this diagnostic is best suited to detect tail populations of the parallel electron distribution function, these first results show that this diagnostic is also rather successful in measuring the bulk plasma density and temperature both during the plasma discharge and into the afterglow.

Thuecks, D. J.; Skiff, F.; Kletzing, C. A. [Department of Physics and Astronomy, University of Iowa, 203 Van Allen Hall, Iowa City, Iowa 52242 (United States)

2012-08-15T23:59:59.000Z

427

Cosmic density and velocity fields in Lagrangian perturbation theory  

E-Print Network [OSTI]

A first- and second-order relation between cosmic density and peculiar-velocity fields is presented. The calculation is purely Lagrangian and it is derived using the second-order solutions of the Lagrange-Newton system obtained by Buchert & Ehlers. The procedure is applied to two particular solutions given generic initial conditions. In this approach, the continuity equation yields a relation between the over-density and peculiar-velocity fields that automatically satisfies Euler's equation because the orbits are derived from the Lagrange-Newton system. This scheme generalizes some results obtained by Nusser et al. (1991) in the context of the Zel'dovich approximation. As opposed to several other reconstruction schemes, in this approach it is not necessary to truncate the expansion of the Jacobian given by the continuity equation in order to calculate a first- or second-order expression for the density field. In these previous schemes, the density contrast given by (a) the continuity equation and (b) Euler's equation are mutually incompatible. This inconsistency arises as a consequence of an improper handling of Lagrangian and Eulerian coordinates in the analysis. Here, we take into account the fact that an exact calculation of the density is feasible in the Lagrangian picture and therefore an accurate and consistent description is obtained.

Mikel Susperregi; Thomas Buchert

1997-08-04T23:59:59.000Z

428

Diagnosis of ion velocity distribution from pin to plate geometry in atmospheric argon dielectric barrier discharge  

SciTech Connect (OSTI)

A new method, fast Fourier transform, is presented to calculate ion velocity distribution by analyzing electromagnetic radiation signal from plasma. This method is based on a dipole model that does not require the assumption of thermodynamic equilibrium. To understand the discharge evolution, the ion velocity distribution is calculated in different oscillation cycles. Results show that the ion velocity distribution deviates from Maxwell distribution over time. The ion velocity and relative ion number fluctuate regularly with time.

Qi, Bing; Pan, Lizhu; Huang, Jianjun; Liu, Ying [Applied Low Temperature Plasma Laboratory, Shenzhen Key Laboratory of Sensors Technology, School of Physics, Shenzhen University, Shenzhen 518060 (China)] [Applied Low Temperature Plasma Laboratory, Shenzhen Key Laboratory of Sensors Technology, School of Physics, Shenzhen University, Shenzhen 518060 (China)

2013-07-15T23:59:59.000Z

429

Anticavitation protection of pressure outlets through regulation of velocities in wall layer of the flow  

Science Journals Connector (OSTI)

1. The tests showed that an installation forming a continuous low-velocity flow along a wall comprising a solid ...

P. R. Khlopenkov; G. A. Chepaikin

1976-08-01T23:59:59.000Z

430

Analysis and forecasting of wind velocity in chetumal, quintana roo, using the single exponential smoothing method  

Science Journals Connector (OSTI)

In this paper the analysis and forecasting of wind velocities in Chetumal, Quintana Roo, Mexico is presented. Measurements were made by the Instituto de Investigaciones Eléctricas (IIE) during two years, from 2004 to 2005. This location exemplifies the wind energy generation potential in the Caribbean coast of Mexico that could be employed in the hotel industry in the next decade. The wind speed and wind direction were measured at 10 m above ground level. Sensors with high accuracy and a low starting threshold were used. The wind velocity was recorded using a data acquisition system supplied by a 10 W photovoltaic panel. The wind speed values were measured with a frequency of 1 Hz and the average wind speed was recorded considering regular intervals of 10 min. First a statistical analysis of the time series was made in the first part of the paper through conventional and robust measures. Also the forecasting of the last day of measurements was made utilizing the single exponential smoothing method (SES). The results showed a very good accuracy of the data with this technique for an ? value of 0.9. Finally the SES method was compared with the artificial neural network (ANN) method showing the former better results.

E. Cadenas; O.A. Jaramillo; W. Rivera

2010-01-01T23:59:59.000Z

431

Characterization of Vertical Velocity and Drop Size Distribution Parameters in Widespread Precipitation at ARM Facilities  

SciTech Connect (OSTI)

Extended, high-resolution measurements of vertical air motion and median volume drop diameter D0 in widespread precipitation from three diverse Atmospheric Radiation Measurement Program (ARM) locations [Lamont, Oklahoma, Southern Great Plains site (SGP); Niamey, Niger; and Black Forest, Germany] are presented. The analysis indicates a weak (0-10 cm{sup -1}) downward air motion beneath the melting layer for all three regions, a magnitude that is to within the typical uncertainty of the retrieval methods. On average, the hourly estimated standard deviation of the vertical air motion is 0.25 m s{sup -1} with no pronounced vertical structure. Profiles of D0 vary according to region and rainfall rate. The standard deviation of 1-min-averaged D0 profiles for isolated rainfall rate intervals is 0.3-0.4 mm. Additional insights into the form of the raindrop size distribution are provided using available dual-frequency Doppler velocity observations at SGP. The analysis suggests that gamma functions better explain paired velocity observations and radar retrievals for the Oklahoma dataset. This study will be useful in assessing uncertainties introduced in the measurement of precipitation parameters from ground-based and spaceborne remote sensors that are due to small-scale variability.

Giangrande S. E.; Luke, E. P.; Kollias, P.

2012-02-01T23:59:59.000Z

432

Effects of neutral interactions on velocity-shear-driven plasma waves  

SciTech Connect (OSTI)

In a laboratory experiment, we demonstrate the substantial effects that collisions between charged and neutral particles have on low-frequency (?{sub i}????????{sub e}) shear-driven electrostatic lower hybrid waves in a plasma. We establish a strong (up to 2.5?kV/m) highly localized electric field with a length scale shorter than the ion gyroradius, so that the ions in the plasma, unlike the electrons, do not develop the full E?×?B drift velocity. The resulting shear in the particle velocities initiates the electron-ion hybrid (EIH) instability, and we observe the formation of strong waves in the vicinity of the shear with variations in plasma densities of 10% or greater. Our experimental configuration allows us to vary the neutral background density by more than a factor of two while holding the charged particle density effectively constant. Not surprisingly, increasing the neutral density decreases the growth rate/saturation amplitude of the waves and increases the threshold electric field necessary for wave formation, but the presence of neutrals affects the dominant wave frequency as well. We show that a 50% increase in the neutral density decreases the wave frequency by 20% while also suppressing the electric field dependence of the frequency that is observed when fewer neutrals are present. The majority of these effects, as well as the values of the frequencies we observe, closely match the predictions of previously developed linear EIH instability theory, for which we present the results of a numerical solution.

Enloe, C. L. [Physics Department, US Air Force Academy, Colorado Springs, Colorado 80840 (United States); Tejero, E. M.; Amatucci, W. E.; Crabtree, C.; Ganguli, G. [Plasma Physics Division, Naval Research Laboratory, Washington, DC 20375 (United States); Sotnikov, V. [Sensors Directorate, Air Force Research Laboratory, Dayton, Ohio 45433 (United States)

2014-06-15T23:59:59.000Z

433

GENERALIZED 2D EULER-BOUSSINESQ EQUATIONS WITH A SINGULAR VELOCITY  

E-Print Network [OSTI]

GENERALIZED 2D EULER-BOUSSINESQ EQUATIONS WITH A SINGULAR VELOCITY DURGA KC, DIPENDRA REGMI a system of equations generalizing the two-dimensional incompressible Boussinesq equa- tions. The velocity- value problem of this generalized Boussinesq equations when the velocity is "double logarithmically

Wu, Jiahong

434

Evidence for correlation of electrical resistivity and seismic velocity in heterogeneous near-surface materials  

E-Print Network [OSTI]

-surface materials. For both trends, the resistivity (r) and p-wave velocity (Vp) are related in the form Log10 r = m resistivity and seismic velocity in heterogeneous near-surface materials, Geophys. Res. Lett., 30(7), 1373Evidence for correlation of electrical resistivity and seismic velocity in heterogeneous near

Meju, Max

435

Nested Velocity Feedback Control -1 Presented at CS 2007 Dr Richard Mitchell 2007  

E-Print Network [OSTI]

Nested Velocity Feedback Control - 1 Presented at CS 2007 © Dr Richard Mitchell 2007 Nested tolerant to changes in the plant under control #12;Nested Velocity Feedback Control - 2 Presented at CS path #12;Nested Velocity Feedback Control - 3 Presented at CS 2007 © Dr Richard Mitchell 2007 Cherry

Mitchell, Richard

436

Modeling and Control of High-Velocity Oxygen-Fuel (HVOF) Thermal Spray: A Tutorial Review  

E-Print Network [OSTI]

vs. Fuzzy Logic: Simple Tools to Predict and Control Complexfuzzy logic (Ref 73, 74). For the HVOF thermal spray process, a feedback control

Li, Mingheng; Christofides, Panagiotis D.

2009-01-01T23:59:59.000Z

437

Broad absorption line quasars with redshifted troughs: high-velocity infall or rotationally dominated outflows?  

Science Journals Connector (OSTI)

......Section-5.5). 18 J1034 has an unresolved, red object 4.62arcsec away which was not...K., Kilic M., Anderson S. F., Gates E. AJ (2008) 136:76. Hall P. B...J. ApJ (2012) 746:2. Knigge C. , Woods J. A., Drew J. E. MNRAS (1995) 273......

P. B. Hall; W. N. Brandt; P. Petitjean; I. Pâris; N. Filiz Ak; Yue Shen; R. R. Gibson; É. Aubourg; S. F. Anderson; D. P. Schneider; D. Bizyaev; J. Brinkmann; E. Malanushenko; V. Malanushenko; A. D. Myers; D. J. Oravetz; N. P. Ross; A. Shelden; A. E. Simmons; A. Streblyanska; B. A. Weaver; D. G. York

2013-01-01T23:59:59.000Z

438

High-resolution velocity field imaging around a borehole: Excavation Damaged Zone characterization  

E-Print Network [OSTI]

in the laboratory offers a large number of boreholes. These boreholes form linear excavations with a perfectly round to deploy significant resources with a large number of sensors and boreholes (Balland et al, 2009). Instead induced around a borehole drilled for survey purposes. This would involve the installation of several

Boyer, Edmond

439

EROSIVE WEAR OF DUCTILE METALS BY A PARTICLE-LADEN HIGH-VELOCITY LIQUID-JET  

E-Print Network [OSTI]

angle Concentration of coal ( 0 /o) XBL 8012-2452 20% by wtscale) Equivalent Diameter (11m) Coal Al 2 o 3 SiC Metals (for Fossil Energy, Office of Coal Research, Materials and

Li, Simon Ka-Keung

2014-01-01T23:59:59.000Z

440

Burning Velocities in Catalytically Assisted Self-Propagating High-Temperature Combustion Synthesis Systems  

E-Print Network [OSTI]

the compact yielding a solid product, typically a metal carbide or boride, for example, Me s C s 3 MeC s (1) where Me is a transition metal species such as titanium or tantalum, and C is carbon (graphite, carbon) is included in the system. The transport agent aids in the transport of the metal or carbon (or boron

Wooldridge, Margaret S.

Note: This page contains sample records for the topic "duct high velocity" 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

Modeling of Sediment Bed Behavior for Critical Velocity in Horizontal Piping  

SciTech Connect (OSTI)

This paper compares results from a predictive tool for modeling transport of a multiphase mixture (solids in a liquid) in a pipeline, (up to and including plugging) with experiments performed to support the Hanford site’s Waste Treatment and Immobilization Plant (WTP). The treatment of high-level waste at the DOE Office of River Protection’s WTP will involve the transfer of high solid content suspensions through pipelines. Pipeline plugging was identified as a significant potential issue by a panel of external experts. In response to their concerns an experimental effort was initiated at PNNL to determine the critical velocities for a variety of operating conditions. A computational method has been developed to predict the dynamic behavior of a sediment bed in response to the surrounding suspension flow. The flow field is modeled using a lattice kinetics method, similar to the lattice Boltzmann method, which scales very well on highly parallel computers. Turbulent quantities are calculated using a k-epsilon RANS model. This work is part of a larger effort to develop a process simulation capability for a wide range of applications. Solids are represented using two different continuum fields. The suspended solids are treated as passive scalars in the flow field, including terms for hindered settling and Brownian diffusion. Normal stresses created by the irreversible collisions of particles during shearing are added to the pressure tensor. The sediment bed interface is represented using a continuum phase field with a diffuse interface. The bed may change with time due to settling, erosion and deposition through convection. The erosion rates are calculated using the local shear stress obtained from the turbulence model. The method is compared with data from the PNNL pipeline experiments conducted at PNNL (Poloski et al. 2008). The experimental flow loop consists of 3-inch schedule 40 piping with instrumentation for determining flow rate and pressure gradient. The simulant test particles ranged in density from 2.5 to 8 g/cc while the nominal particle size ranged from 10 to 100 ?m. At the beginning of each test, the slurry flow velocity was nominally set to 8 ft/sec. The flow was incrementally ramped down, and a steady-state pressure gradient was obtained at each flow condition. A rise in pressure gradient as the flow rate drops indicates that the pipe cross-sectional area is beginning to fill with sediment. This point is referred to as the “critical velocity”. Visualization information is provided using Electrical Resistance Tomography (ERT). The paper will show favorable comparison of results with data.

Rector, David R.; Stewart, Mark L.; Poloski, Adam P.

2009-10-01T23:59:59.000Z

442

Corrosion behavior of zirconia-coated Hastelloy X in a high-temperature helium environment  

SciTech Connect (OSTI)

The corrosion behavior of Hastelloy X coated with (NiCrAl)/(ZrO/sub 2/-CaC/sub 2/) was examined, after serving as the liner tube of helium engineering demonstration loop (HENDEL) hot gas duct. The Hastelloy X with the ceramic coating system was exposed to high-temperature helium gas for --6000 h. The compositions of oxide films formed on Hastelloy X were entirely different between the noncoated and ceramic-coated tubes.

Kondo, Y.; Fukaya, K.

1989-01-01T23:59:59.000Z

443

Lifetime of nuclear velocity dispersion drops in barred galaxies  

E-Print Network [OSTI]

We have made hydro/N-body simulations with and without star formation to shed some light on the conditions under which a central kinematically cold stellar component (characterized by a velocity dispersion drop or \\sigma-drop) could be created in a hot medium (e.g. a bulge) and survive enough time to be observed. We found that the timescale for a \\sigma-drop formation could be short (less than 500 Myr) whereas its lifetime could be long (more than 1 Gyr) provided that the central region is continuously or regularly fed by fresh gas which leads to a continuous star formation activity. Star formation in the central region, even at a low rate as 1M_{sol} yr^{-1}, is mandatory to sustain a permanent \\sigma-drop by replacing heated particles by new low-\\sigma ones. We moreover show that as soon as star formation is switched off, the \\sigma-drop begins to disappear.

Herve Wozniak; Nicolas Champavert

2006-03-29T23:59:59.000Z

444

Active galactic nuclei-driven outflows without immediate quenching in simulations of high-redshift disc galaxies  

Science Journals Connector (OSTI)

......outflows with velocities km1 and mass outflow rates...Outflowing winds escape perpendicular...summary, high-mass outflow rates...drives high-velocity winds. Since BH...face-on maps of maximum outflow velocity with 1kpc...of stellar mass of the galaxy......

J. M. Gabor; Frédéric Bournaud

2014-01-01T23:59:59.000Z

445

Building America Top Innovations Hall of Fame Profile … Affordable High Performance in Production Homes: Artistic Homes, Albuquerque, NM  

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

help from Building America, Artistic help from Building America, Artistic Homes built affordable, high-performance homes in New Mexico and Colorado with HERS scores of 0 to 60. Many builders remain resistant to adopting high-performance innovations based on misconceptions about high cost and design challenges. Thus, Building America projects such as Artistic Homes have had an extraordinary impact, demonstrating the mainstream builder's business case for adopting proven innovations such as efficient thermal enclosures and ducts inside the conditioned space, even in entry-level homes. The U.S. Department of Energy's Building America program has helped develop best practices for creating efficient thermal enclosures and locating HVAC ducts inside the conditioned space. These measures cost-effectively reduce heating and

446

Continued Evaluation of the Pulse-Echo Ultrasonic Instrument for Critical Velocity Determination during Hanford Tank Waste Transfer Operations  

SciTech Connect (OSTI)

Laboratory (PNNL) conducted an extensive evaluation of the ability of three ultrasonic instruments to detect critical velocity for a broad range of simulated Hanford nuclear waste streams containing particles with mean particle sizes of >50 microns. Evaluations were perform using the pipe loop at the Process Development Laboratory – East (PDL-E) at PNNL that was designed and built to evaluate the pipeline plugging issue during slurry transfer operations at the Hanford Waste Treatment Plant. In 2011 the ability of the ultrasonic PulseEcho system to detect critical velocity continued to be evaluated using the PDL-E flow loop and new simulants containing high-density particles with a mean particle size of < 15 microns. The PDL-E flow loop was modified for the 2011 testing to include a new test section that contained 5-MHz and 10-MHz ultrasonic transducers non-invasively mounted to schedule 40 pipe. The test section also contained reference instrumentation to facilitate direct comparison of the real-time PulseEcho transducer responses with experimentally observed critical velocities. This paper presents the results from the 2011 PulseEcho evaluation using a variety of simulated Hanford nuclear waste streams that were selected to encompass the expected high-level waste feed properties.

Denslow, Kayte M.; Bontha, Jagannadha R.; Adkins, Harold E.; Jenks, Jeromy WJ; Burns, Carolyn A.; Schonewill, Philip P.; Hopkins, Derek F.; Thien, Michael G.; Wooley, Theodore A.

2012-04-01T23:59:59.000Z

447

Distributions of velocity and turbulence in a parallel flow along an asymmetric rod bundle  

SciTech Connect (OSTI)

An experimental investigation was performed to obtain detailed information on the velocity and turbulence distributions in a parallel turbulent flow through an asymmetric rod bundle. The rod bundle consisted of four parallel rods arranged asymmetrically in a rectangular channel. The pitch-to-diameter (P/D) ratio of the rods was P/D = 1.072. Experimental results were obtained in two wall subchannels with wall-to-diameter (W/D) ratios of W/D = 1.096 and 1.048, respectively. The experimental results showed high anisotropy of the momentum transport, particularly in the gaps of the rod bundle. Comparisons between the measured wall shear stresses and data computed by the VELASCO code show considerable differences, particularly for the wall subchannel with W/D = 1.048.

Rehme, K.

1982-10-01T23:59:59.000Z

448

Performance testing of lead free primers: blast waves, velocity variations, and environmental testing  

E-Print Network [OSTI]

Results are presented for lead free primers based on diazodinitrophenol (DDNP)compared with tests on lead styphnate based primers. First, barrel friction measurements in 5.56 mm NATO are presented. Second, shot to shot variations in blast waves are presented as determined by detonating primers in a 7.62x51mm rifle chamber with a firing pin, but without any powder or bullet loaded and measuring the blast wave at the muzzle with a high speed pressure transducer. Third, variations in primer blast waves, muzzle velocities, and ignition delay are presented after environmental conditioning (150 days) for two lead based and two DDNP based primers under cold and dry (-25 deg C,0% relative humidity), ambient (20 deg C, 50% relative humidity), and hot & humid (50 deg C, 100% relative humidity) conditions in 5.56 mm NATO. Taken together, these results indicate that DDNP based primers are not sufficiently reliable for service use.

Courtney, Elya; Summer, Peter David; Courtney, Michael

2014-01-01T23:59:59.000Z

449

Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles  

DOE Patents [OSTI]

An apparatus for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously.

Benjamin, R.F.

1983-10-18T23:59:59.000Z

450

Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles  

DOE Patents [OSTI]

An apparatus for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously.

Benjamin, Robert F. (315 Rover Blvd., Los Alamos, NM 87544)

1987-01-01T23:59:59.000Z

451

Optical pin apparatus for measuring the arrival time and velocity of shock waves and particles  

DOE Patents [OSTI]

An apparatus is disclosed for the detection of the arrival and for the determination of the velocity of disturbances such as shock-wave fronts and/or projectiles. Optical pins using fluid-filled microballoons as the light source and an optical fiber as a link to a photodetector have been used to investigate shock-waves and projectiles. A microballoon filled with a noble gas is affixed to one end of a fiber-optic cable, and the other end of the cable is attached to a high-speed streak camera. As the shock-front or projectile compresses the microballoon, the gas inside is heated and compressed producing a bright flash of light. The flash of light is transmitted via the optic cable to the streak camera where it is recorded. One image-converter streak camera is capable of recording information from more than 100 microballoon-cable combinations simultaneously. 3 figs.

Benjamin, R.F.

1987-03-10T23:59:59.000Z

452

Particle in cell simulations of Buneman instability of a current-driven plasma with q-nonextensive electron velocity distribution  

SciTech Connect (OSTI)

The nonlinear evolution of low frequency Buneman instability in an unmagnetized current-driven plasma with q-nonextensive electron velocity distribution is investigated using particle in cell simulation. Simulation results show that the generation of electron phase space holes and the counter-streaming current induced in the plasma strongly depend on the q-parameter. It is found that by increasing the nonextensive parameter, the distribution of electron density becomes highly peaked. This density steepening or grating-like pattern occurs at the saturation time. In addition, a generalized dispersion relation is obtained using the kinetic theory. Analysis of the dispersion relation and the temporal evolution of the electric field energy density reveal that the growth rate of instability increases by increasing the q-parameter. Finally, the results of Maxwellian and q-nonextensive velocity distributions have been compared and discussed.

Niknam, A. R., E-mail: a-niknam@sbu.ac.ir; Roozbahani, H.; Komaizi, D. [Laser and Plasma Research Institute, Shahid Beheshti University, G.C., Tehran (Iran, Islamic Republic of); Hashemzadeh, M. [Faculty of Physics, Shahrood University, Shahrood (Iran, Islamic Republic of)

2014-09-15T23:59:59.000Z

453

Velocity Anisotropy of shales and sandstones from core sample and well log on the Norwegian Continental shelf.  

E-Print Network [OSTI]

??Abstract Velocity anisotropy referse the directional inequality of velocity on the subsurface. Often sedimentary rocks are anisotropic and occurse at all scales from core plugs… (more)

Meseret, Malaku

2008-01-01T23:59:59.000Z

454

Resuspension studies in cylindrical microcosms: Effects of stirring velocity on the dynamics of redox sensitive elements in a coastal sediment  

Science Journals Connector (OSTI)

Effects of resuspension on the release of dissolved, redox sensitive ... At current velocities below the threshold velocity for resuspension (37 cm s-1), Mn release...

Mario Hose Calado Laima; Henning Matthiesen; Lars Chresten Lund-Hansen…

1998-12-01T23:59:59.000Z

455

Sensible and Latent Cooling Load Control Using Centrally-Ducted, Variable-Capacity Space Conditioning Systems in Low Sensible Load Environments  

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

Sensible and Latent Cooling Load Control Using Centrally-Ducted, Variable-Capacity Space Conditioning Systems in Low Sensible Load Environments James Cummings BA-PIRC; Florida Solar Energy Center Presented at BA Summer Meeting, July 26, 2012 The gist of my message * Fixed capacity AC systems generally provide good RH control in typical residences. * In low-load homes, they may be less effective in achieving good RH control. * On the other hand, variable capacity AC systems have several characteristics which can provide improved RH control in homes. - Both Nordyne and Carrier have variable capacity units, varying from about 40% to 100% of nominal full capacity. - What is variable capacity? -- condenser fan, compressor speed, and AHU fan speed. The gist, continued

456

Radiation Hydrodynamics Test Problems with Linear Velocity Profiles  

SciTech Connect (OSTI)

As an extension of the works of Coggeshall and Ramsey, a class of analytic solutions to the radiation hydrodynamics equations is derived for code verification purposes. These solutions are valid under assumptions including diffusive radiation transport, a polytropic gas equation of state, constant conductivity, separable flow velocity proportional to the curvilinear radial coordinate, and divergence-free heat flux. In accordance with these assumptions, the derived solution class is mathematically invariant with respect to the presence of radiative heat conduction, and thus represents a solution to the compressible flow (Euler) equations with or without conduction terms included. With this solution class, a quantitative code verification study (using spatial convergence rates) is performed for the cell-centered, finite volume, Eulerian compressible flow code xRAGE developed at Los Alamos National Laboratory. Simulation results show near second order spatial convergence in all physical variables when using the hydrodynamics solver only, consistent with that solver's underlying order of accuracy. However, contrary to the mathematical properties of the solution class, when heat conduction algorithms are enabled the calculation does not converge to the analytic solution.

Hendon, Raymond C. [Los Alamos National Laboratory; Ramsey, Scott D. [Los Alamos National Laboratory

2012-08-22T23:59:59.000Z

457

Teleseismic evidence for a low-velocity body under the Coso geothermal area  

Open Energy Info (EERE)

Teleseismic evidence for a low-velocity body under the Coso geothermal area Teleseismic evidence for a low-velocity body under the Coso geothermal area Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal Article: Teleseismic evidence for a low-velocity body under the Coso geothermal area Details Activities (1) Areas (1) Regions (0) Abstract: Teleseismic P wave arrivals were recorded by a dense array of seismograph stations located in the Coso geothermal area, California. The resulting pattern of relative residuals an area showing approximately 0.2-s excess travel time that migrates with changing source azimuth, suggesting that the area is the 'delay shadow' produced by a deep, low-velocity body. Inversion of the relative residual data for three-dimensional velocity structure determines the lateral variations in velocity to a depth of 22.5

458

Propagation Distance Required to Reach Steady-State Detonation Velocity in Finite-Sized Charges  

E-Print Network [OSTI]

The decay of a detonation wave from its initial CJ velocity to its final, steady state velocity upon encountering a finite thickness or diameter charge is investigated numerically and theoretically. The numerical simulations use an ideal gas equation of state and pressure dependent reaction rate in order to ensure a stable wave structure. The confinement is also treated as an ideal gas with variable impedance. The velocity decay along the centerline is extracted from the simulations and compared to predictions base on a front evolution equation that uses the steady state detonation velocity-front curvature relation ($D_n-\\kappa$). This model fails to capture the finite signaling speed of the leading rarefaction resulting from the interaction with the yielding confinement. This signaling speed is verified to be the maximum signal velocity occurring in the ideal ZND wave structure of the initial CJ velocity. A simple heuristic model based on the rarefaction generated by a one-dimensional interaction between the...

Li, Jianling; Higgins, Andrew J

2014-01-01T23:59:59.000Z

459

A numerical study of geometry dependent errors in velocity, temperature, and density measurements from single grid planar retarding potential analyzers  

SciTech Connect (OSTI)

Planar retarding potential analyzers (RPAs) have been utilized numerous times on high profile missions such as the Communications/Navigation Outage Forecast System and the Defense Meteorological Satellite Program to measure plasma composition, temperature, density, and the velocity component perpendicular to the plane of the instrument aperture. These instruments use biased grids to approximate ideal biased planes. These grids introduce perturbations in the electric potential distribution inside the instrument and when unaccounted for cause errors in the measured plasma parameters. Traditionally, the grids utilized in RPAs have been made of fine wires woven into a mesh. Previous studies on the errors caused by grids in RPAs have approximated woven grids with a truly flat grid. Using a commercial ion optics software package, errors in inferred parameters caused by both woven and flat grids are examined. A flat grid geometry shows the smallest temperature and density errors, while the double thick flat grid displays minimal errors for velocities over the temperature and velocity range used. Wire thickness along the dominant flow direction is found to be a critical design parameter in regard to errors in all three inferred plasma parameters. The results shown for each case provide valuable design guidelines for future RPA development.

Davidson, R. L.; Earle, G. D.; Heelis, R. A. [William B. Hanson Center for Space Sciences, University of Texas at Dallas, 800 W. Campbell Road, WT15, Richardson, Texas 75080 (United States); Klenzing, J. H. [Space Weather Laboratory/Code 674, Goddard Space Flight Center, Greenbelt, Maryland 20771 (United States)

2010-08-15T23:59:59.000Z

460

Laser initiated reactions in N{sub 2}O clusters studied by time-sliced ion velocity imaging technique  

SciTech Connect (OSTI)

Laser initiated reactions in N{sub 2}O clusters were studied by a time-sliced velocity imaging technique. The N{sub 2}O clusters, (N{sub 2}O){sub n}, generated by supersonic expansion were irradiated by an ultraviolet laser around 204 nm to convert reactant pairs, O({sup 1}D{sub 2})-(N{sub 2}O){sub n?1}. The NO molecules formed from these reactant pairs were ionized by the same laser pulse and their velocity distribution was determined by the time-sliced velocity imaging technique. At low nozzle pressure, lower than 1.5 atm, the speed distribution in the frame moving with the clusters consists of two components. These components were ascribed to the products appeared in the backward and forward directions in the center-of-mass frame, respectively. The former consists of the vibrational ground state and the latter consists of highly vibrational excited states. At higher nozzle pressure, a single broad speed distribution became dominant for the product NO. The pressure and laser power dependences suggested that this component is attributed to the product formed in the clusters larger than dimer, (N{sub 2}O){sub n} (n ? 3)

Honma, Kenji [Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297 (Japan)] [Graduate School of Material Science, University of Hyogo, 3-2-1 Kohto, Kamigori, Hyogo 678-1297 (Japan)

2013-07-28T23:59:59.000Z

Note: This page contains sample records for the topic "duct high velocity" 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

Evaluation of mixing in three duct configurations and development of a Generic Tee Plenum System (GTPS) for application to single point aerosol sampling  

E-Print Network [OSTI]

considered when using different types of elbows upstream of the stack. Numerical studies for velocity profile in the GTPS were conducted with a commercial computational fluid dynamics (CFD) software, FLUENT. Good agreement was found between the experimental...

Han, Tae Won

2012-06-07T23:59:59.000Z

462

Estimation of Velocity Distribution and Suspended Sediment Discharge in Open Channels Using Entropy  

E-Print Network [OSTI]

up a coordinate system?????..??????.. 30 4.1.2 Velocity isovels?????..??????...?????.. 31 4.1.3 Cumulative distribution function?????...?????.. 32 4.1.4 Verification of cumulative distribution function?????. 38 4.2 1D velocity distribution... a and G values??????... 56 Figure 5.2 Dimensionless velocity distribution for various m values (data from Ponte Felcino River, Italy)????????????????... 59 Figure 5.3 The relationship between G and um/umax??????????... 60 Figure 5.4 Distribution...

Cui, Huijuan

2011-08-08T23:59:59.000Z

463

Experimental techniques for measuring temperature and velocity fields to improve the use and validation of building heat transfer models  

SciTech Connect (OSTI)

When modeling thermal performance of building components and envelopes, researchers have traditionally relied on average surface heat-transfer coefficients that often do not accurately represent surface heat-transfer phenomena at any specific point on the component being evaluated. The authors have developed new experimental techniques that measure localized surface heat-flow phenomena resulting from convection. The data gathered using these new experimental procedures can be used to calculate local film coefficients and validate complex models of room and building envelope heat flows. These new techniques use a computer-controlled traversing system to measure both temperatures and air velocities in the boundary layer near the surface of a building component, in conjunction with current methods that rely on infrared (IR) thermography to measure surface temperatures. Measured data gathered using these new experimental procedures are presented here for two specimens: (1) a Calibrated Transfer Standard (CTS) that approximates a constant-heat-flux, flat plate; and (2) a dual-glazed, low-emittance (low-e), wood-frame window. The specimens were tested under steady-state heat flow conditions in laboratory thermal chambers. Air temperature and mean velocity data are presented with high spatial resolution (0.25- to 25-mm density). Local surface heat-transfer film coefficients are derived from the experimental data by means of a method that calculates heat flux using a linear equation for air temperature in the inner region of the boundary layer. Local values for convection surface heat-transfer rate vary from 1 to 4.5 W/m{sup 2} {center_dot} K. Data for air velocity show that convection in the warm-side thermal chamber is mixed forced/natural, but local velocity maximums occur from 4 to 8 mm from the window glazing.

Griffith, Brent; Turler, Daniel; Goudey, Howdy; Arasteh, Dariush

1998-04-01T23:59:59.000Z

464

CALIBRATING STELLAR VELOCITY DISPERSIONS BASED ON SPATIALLY RESOLVED H-BAND SPECTRA FOR IMPROVING THE M{sub BH}-{sigma}{sub *} RELATION  

SciTech Connect (OSTI)

To calibrate stellar velocity dispersion measurements from optical and near-IR stellar lines, and to improve the black hole mass (M{sub BH})-stellar velocity dispersion ({sigma}{sub *}) relation, we measure {sigma}{sub *} based on high-quality H-band spectra for a sample of 31 nearby galaxies, for which dynamical M{sub BH} is available in the literature. By comparing velocity dispersions measured from stellar lines in the H-band with those measured from optical stellar lines, we find no significant difference, suggesting that optical and near-IR stellar lines represent the same kinematics and that dust effect is negligible for early-type galaxies. Based on the spatially resolved rotation and velocity dispersion measurements along the major axis of each galaxy, we find that a rotating stellar disk is present for 80% of galaxies in the sample. For galaxies with a rotation component, {sigma}{sub *} measured from a single aperture spectrum can vary by up to {approx}20%, depending on the size of the adopted extraction aperture. To correct for the rotational broadening, we derive luminosity-weighted {sigma}{sub *} within the effective radius of each galaxy, providing uniformly measured velocity dispersions to improve the M{sub BH}-{sigma}{sub *} relation.

Kang, Wol-Rang; Woo, Jong-Hak; Park, Daeseong [Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 151-742 (Korea, Republic of)] [Astronomy Program, Department of Physics and Astronomy, Seoul National University, 1 Gwanak-ro Gwanak-gu, Seoul, 151-742 (Korea, Republic of); Schulze, Andreas [Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing (China)] [Kavli Institute for Astronomy and Astrophysics, Peking University, 100871 Beijing (China); Riechers, Dominik A. [Astronomy Department, Cornell University, 220 Space Science Building, Ithaca, NY 14853 (United States)] [Astronomy Department, Cornell University, 220 Space Science Building, Ithaca, NY 14853 (United States); Kim, Sang Chul [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of)] [Korea Astronomy and Space Science Institute, Daejeon 305-348 (Korea, Republic of); Smolcic, Vernesa, E-mail: woo@astro.snu.ac.kr [Physics Department, University of Zagreb, Bijenicka cesta 32, 10002 Zagreb (Croatia)] [Physics Department, University of Zagreb, Bijenicka cesta 32, 10002 Zagreb (Croatia)

2013-04-10T23:59:59.000Z

465

Model of bubble velocity vector measurement in upward and downward bubbly two-phase flows using a four-sensor optical probe  

Science Journals Connector (OSTI)

Abstract The knowledge of bubble behaviors is of considerable significance for a proper understanding and modeling of two-phase flows. To obtain the information on the bubble motion, a novel model was developed, by which the bubble velocity vector can be directly calculated from six time intervals measured with a four-sensor probe. The measurements of local bubble velocity vector and void fraction were performed in both upward and downward bubbly flows by using a four-sensor optical probe. The area-averaged void fraction and bubble velocity obtained from the probe agree well with those measured by other cross-calibration methods, and the measurement errors are within 15% under various flow conditions. Experimental results of the bubble velocity vector reveal that the bubble lateral migration may be suppressed in upward flows, but be strengthened in downward flows as the liquid flow rate increases. Also, with an increase in gas flow rate, the bubble velocity distribution varies into the power–law profile in upward flows, but into an off-center peak profile in downward flows. In addition, the void fraction shows a core peak distribution at low void fraction for downward flows, but a wall peak distribution for upward flows. However, when the void fraction is relatively high, it displays an off-center peak distribution for downward flows but a core peak distribution for upward flows.

Daogui Tian; Changqi Yan; Licheng Sun

2015-01-01T23:59:59.000Z

466

AN ASSESSMENT OF THE ACCURACY OF MAGENTIC RESONANCE PHASE VELOCITY MAPPING IN TURBULENT FLOW THROUGH ORIFICES.  

E-Print Network [OSTI]

?? Magnetic resonance phase velocity mapping (MRPVM) is an established clinical technique to measure blood flow. The acquired information can be used to diagnose a… (more)

Pidaparthi, Sahitya

2011-01-01T23:59:59.000Z

467

Test Loop Demonstration and Evaluation of Slurry Transfer Line Critical Velocity Measurement Instruments  

SciTech Connect (OSTI)

This report presents the results of the evaluation of three ultrasonic sensors for detecting critical velocity during slurry transfer between the Hanford tank farms and the WTP.

Bontha, Jagannadha R.; Jenks, Jeromy WJ; Morgen, Gerald P.; Peters, Timothy J.; Wilcox, Wayne A.; Adkins, Harold E.; Burns, Carolyn A.; Greenwood, Margaret S.; MacFarlan, Paul J.; Denslow, Kayte M.; Schonewill, Philip P.; Blanchard, Jeremy; Baer, Ellen BK

2010-07-31T23:59:59.000Z

468

Particle Velocity Distributions and Ionization Processes in a Gas-Puff Z Pinch  

Science Journals Connector (OSTI)

We have measured the time-dependent radial velocity distributions of singly to five times ionized ions in an imploding plasma shell by observing the spectral shapes and intensities of emission lines in various directions. An ionization wave propagating much faster than the local radial ion velocities is observed. The ionization front velocity is found to be consistent with estimates of electron heat conduction into the plasma-neutral layer. The ionization and velocity histories of the particles are experimentally determined. The mechanisms of momentum transfer to the particles are also determined and compared with existing models.

M. E. Foord; Y. Maron; G. Davara; L. Gregorian; A. Fisher

1994-06-13T23:59:59.000Z

469

Hot Carrier Velocities in Doped and in Ultra-pure Germanium Crystals at Millikelvin Temperatures  

Science Journals Connector (OSTI)

We present new experimental data for the electron and hole velocity laws in Ge at 20 mK as a function of the field between...

J. Domange; E. Olivieri; A. Broniatowski

2012-06-01T23:59:59.000Z

470

E-Print Network 3.0 - air stream velocities Sample Search Results  

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

and Environment GIS Lab Collection: Engineering 11 1 Copyright 1997 by ASME 1997 ASME Fluids Engineering Division Summer Meeting Summary: or structure velocity u Streamwise...