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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

High-Velocity Rocks Final Report  

DOE Green Energy (OSTI)

The objective of our research was to develop and demonstrate seismic data-acquisition and data-processing technologies that allow geothermal prospects below high-velocity rock outcrops to be evaluated. To do this, we acquired a 3-component seismic test line across an area of exposed high-velocity rocks in Brewster County, Texas, where there is high heat flow and surface conditions mimic those found at numerous geothermal prospects. Seismic contractors have not succeeded in creating good-quality seismic data in this area for companies who have acquired data for oil and gas exploitation purposes. Our test profile traversed an area where high-velocity rocks and low-velocity sediment were exposed on the surface in alternating patterns that repeated along the test line. We verified that these surface conditions cause non-ending reverberations of Love waves, Rayleigh waves, and shallow critical refractions to travel across the earth surface between the boundaries of the fast-velocity and slow-velocity material exposed on the surface. These reverberating surface waves form the high level of noise in this area that does not allow reflections from deep interfaces to be seen and utilized. Our data-acquisition method of deploying a box array of closely spaced geophones allowed us to recognize and evaluate these surface-wave noise modes regardless of the azimuth direction to the surface anomaly that backscattered the waves and caused them to return to the test-line profile. With this knowledge of the surface-wave noise, we were able to process these test-line data to create P-P and SH-SH images that were superior to those produced by a skilled seismic data-processing contractor. Compared to the P-P data acquired along the test line, the SH-SH data provided a better detection of faults and could be used to trace these faults upward to the boundaries of exposed surface rocks. We expanded our comparison of the relative value of S-wave and P-wave seismic data for geothermal applications by inserting into this report a small part of the interpretation we have done with 3C3D data across Wister geothermal field in the Imperial Valley of California. This interpretation shows that P-SV data reveal faults (and by inference, also fractures) that cannot be easily, or confidently, seen with P-P data, and that the combination of P-P and P-SV data allows VP/VS velocity ratios to be estimated across a targeted reservoir interval to show where an interval has more sandstone (the preferred reservoir facies). The conclusion reached from this investigation is that S-wave seismic technology can be invaluable to geothermal operators. Thus we developed a strong interest in understanding the direct-S modes produced by vertical-force sources, particularly vertical vibrators, because if it can be demonstrated that direct-S modes produced by vertical-force sources can be used as effectively as the direct-S modes produced by horizontal-force sources, geothermal operators can acquire direct-S data across many more prospect areas than can be done with horizontal-force sources, which presently are limited to horizontal vibrators. We include some of our preliminary work in evaluating direct-S modes produced by vertical-force sources.

Hardage, Bob A; DeAngelo, Michael V; Ermolaeva, Elena; Hardage, Bob A; Remington, Randy; Sava, Diana; Wagner, Donald; Wei, Shuijion

2013-02-28T23:59:59.000Z

3

Perturbations in high-velocity gas flow  

DOE Green Energy (OSTI)

High velocity explosive products or other low-density gases are often used to accelerate metal plates to high velocities. Perturbations in otherwise uniform flow configurations are sometimes sufficient to cause interactions that can rapidly destroy the integrity of the plates. In this study perturbations were introduced in uniform gas flows of detonated HE products and strongly shocked polyethylene, CH{sub 2}. The primary diagnostics were smear-camera records obtained when these gases impinged on layers of plexiglas separated by small argon-filled gaps. These records show shock-arrival times at various levels and thus determine not only the size of the perturbation but also its strength. Perturbations in HE gases running into H{sub 2} and in CH{sub 2} into H{sub 2} have been studied. Two-dimensional hydrodynamic calculations are in excellent agreement with the experiments, and enable one to study details of the flow not possible from experimental results. 1 ref., 5 figs.

Harvey, W.B.; McQueen, R.G. (Los Alamos National Lab., NM (USA))

1989-01-01T23:59:59.000Z

4

Velocity  

Science Conference Proceedings (OSTI)

... Delta t ffl \\Delta t = 1ns. Pulse-Dri ven Wall Motion ( ff = ... varies, can increase (!), eventually decays tozero. Pulse-Dri ven Domain Wall Velocity ( ff = ...

2004-01-16T23:59:59.000Z

5

High Velocity Laser Accelerated Deposition (HVLAD)  

... thus producing a very broad range of advanced high-temperature and corrosion ... from stress corrosion cracking, corrosion fatigue, hydrogen ...

6

Superconducting spoke cavities for high-velocity applications  

SciTech Connect

To date, superconducting spoke cavities have been designed, developed, and tested for particle velocities up to {beta}{sub 0}~0.6, but there is a growing interest in possible applications of multispoke cavities for high-velocity applications. We have explored the design parameter space for low-frequency, high-velocity, double-spoke superconducting cavities in order to determine how each design parameter affects the electromagnetic properties, in particular the surface electromagnetic fields and the shunt impedance. We present detailed design for cavities operating at 325 and 352 MHz and optimized for {beta}{sub 0}~=0.82 and 1.

Hopper, Christopher S. [Old Dominion U.; Delayen, Jean R. [Old Dominion U., JLAB

2013-10-01T23:59:59.000Z

7

Lensing duct  

DOE Patents (OSTI)

A lensing duct to condense (intensify) light using a combination of front surface lensing and reflective waveguiding is described. The duct tapers down from a wide input side to a narrow output side, with the input side being lens-shaped and coated with an antireflective coating for more efficient transmission into the duct. The four side surfaces are uncoated, preventing light from escaping by total internal reflection as it travels along the duct (reflective waveguiding). The duct has various applications for intensifying light, such as in the coupling of diode array pump light to solid state lasing materials, and can be fabricated from inexpensive glass and plastic. 3 figures.

Beach, R.J.; Benett, W.J.

1994-04-26T23:59:59.000Z

8

The Case of Sharp Velocity Transitions in High Vertical Wind Shear When Measuring Doppler Velocities with Narrow Nyquist Intervals  

Science Conference Proceedings (OSTI)

An investigation was launched following unexpected observations of step-function transitions in Doppler velocities from scanning radars in regions of high vertical wind shear. It revealed that, if wind velocity transitions are sufficiently sharp ...

Frédéric Fabry; Clotilde Augros; Aldo Bellon

2013-03-01T23:59:59.000Z

9

On the capacity limits of hvac duct channel for high-speed internet access  

E-Print Network (OSTI)

Abstract—In this paper, we report theoretical and experimental channel-capacity estimates of heating, ventilation, and air conditioning (HVAC) ducts based on multicarrier transmission that uses-ary quadrature amplitude modulation and measured channel responses at the 2.4-GHz industrial, scientific, and medical band. It is shown theoretically that data rates in excess of 1 Gb/s are possible over distances up to 500 m in straight ducts in which reflections have been suppressed. Our experimental results also show that even in the case of more complex HVAC duct networks (i.e., HVAC duct networks that include bends, tees, etc.) data rates over 2 Gb/s are possible. Our estimations in this case are valid for distances of up to 22 m, which was the maximum distance of our experimental setup. These experimental results, measured with a large-scale testbed set

Ariton E. Xhafa; Ozan K. Tonguz; Ahmet G. Cepni; Student Member; Daniel D. Stancil; Pavel V. Nikitin; Dagfin Brodtkorb

2005-01-01T23:59:59.000Z

10

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.

11

Building Energy Software Tools Directory: DD4M Air Duct Design  

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

friction, constant velocity and or static regain procedures to design air ducts for air conditioning, heating, ventilation and materials handling. Allows 1000 duct sections...

12

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 temperature (2250oF) flue gas streams. The HTBDR was successfully tested in a steel soaking pit at B&W's Tubular Products Division in Koppel, Pennsylvania. The ceramic stage consisted of 50 bayonet style ceramic tube-in-tube assemblies supported by an insulated metallic tubesheet and sealed with a ceramic fiber product. The heat exchanger was designed to take maximum advantage of radiation heat transfer, minimize pressure drops on both the air and flue sides, and minimize thermal stresses and fouling. Modeling of the bayonet assemblies determined the outer-to-inner tube spacing to optimize the air-side pressure drop and heat transfer within the tubes. During the 1400 hour operation prior to plant closing, the ceramic stage performed well with no material related problems or air-to-flue leakage. Maximum preheat air produced was 1425°F with a flue gas temperature of 2250oF. Measured fuel savings of 17-24% were obtained over the previous recuperated (metallic heat exchanger) system. This projects a savings of 41% for an unrecuperated furnace. A simple payback analysis indicated acceptable payback for installation in unrecuperated furnaces but unacceptable payback for recuperated furnaces at today's low gas prices."

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

1988-09-01T23:59:59.000Z

13

Building Energy Software Tools Directory: Duct Calculator  

NLE Websites -- All DOE Office Websites (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

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

Velocity Mapping Capabilities of Present and Future Altimeter Missions: The Role of High-Frequency Signals  

Science Conference Proceedings (OSTI)

A detailed analysis of the velocity field mapping capabilities from existing and future multiple altimeter missions is carried out using the Los Alamos North Atlantic high-resolution model. The velocity mapping errors on the instantaneous fields ...

P. Y. Le Traon; G. Dibarboure

2002-12-01T23:59:59.000Z

16

CONTAM Overview - Ducts  

Science Conference Proceedings (OSTI)

... Ducts. As an alternative to the simple air-handling system, CONTAM allows you to model HVAC systems using detailed duct systems. ...

17

Force criterion prediction of damage for carbon/epoxy composite panels impacted by high velocity ice  

E-Print Network (OSTI)

H, Kedward, K. T. Modeling Hail Ice Impacts and PredictingInvestigation of High Velocity Ice Impacts on Woven Carbon/Analysis Correlation of Hail Ice Impacting Composite

Rhymer, Jennifer D.

2012-01-01T23:59:59.000Z

18

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

19

Irradiation dose and temperature dependence of fracture toughness in high dose HT9 steel from the fuel duct of FFTF  

SciTech Connect

Static fracture toughness tests have been performed for high dose HT9 steel using miniature disk compact tension (DCT) specimens to expand the knowledge base for fast reactor core materials. The HT9 steel DCT specimens were from the ACO-3 duct of the Fast Flux Test Facility (FFTF), which achieved high doses in the range of 3 148 dpa at 378 504oC. The static fracture resistance (J-R) tests have been performed in a servohydraulic testing machine in vacuum at selected temperatures including room temperature, 200 C, and each irradiation temperature. Brittle fracture with a low toughness less than 50 MPa m occurred in room temperature tests when irradiation temperature was below 400 C, while ductile fracture with stable crack growth was observed in all tests at higher irradiation temperatures. No fracture toughness less than 100 MPa m was measured when the irradiation temperature was above 430 C. It was shown that the influence of irradiation temperature was dominant in fracture toughness while the irradiation dose has only limited influence over the dose range 3 148 dpa. A post upper-shelf behavior was observed for the non-irradiated and high temperature (>430 C) irradiation cases, which indicates that the ductile-brittle transition temperatures (DBTTs) in those conditions are lower than room temperature. A comparison with the collection of existing data confirmed the dominance of irradiation temperature in the fracture toughness of HT9 steels.

Byun, Thak Sang [ORNL; Toloczko, M [Pacific Northwest National Laboratory (PNNL); Maloy, S [Los Alamos National Laboratory (LANL)

2012-01-01T23:59:59.000Z

20

Encapsulated and Buried Ducts  

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

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?

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

Hohlraum Designs for High Velocity Implosions on NIF  

Science Conference Proceedings (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

22

APPARATUS FOR PRODUCING HIGH VELOCITY SHOCK WAVES IN GASES  

DOE Patents (OSTI)

>A device for producing a high-energy ionized gas region comprises an evacuated tapered insulating vessel and a substantially hemispherical insulating cap hermetically affixed to the large end of the vessel, an annular electrode having a diameter equal to and supported in the interior wall of the vessel at the large end and having a conductive portion inside the vessel, a second electrode supported at the small end of the vessel, means connected to the vessel for introducing a selected gas therein, a source of high potential having two poles. means for connecting one pole of the high potential source to the annular electrode, and means for connecting the other pole of the potential source to the second electrode.

Scott, F.R.; Josephson, V.

1960-02-01T23:59:59.000Z

23

MAGNETIC METHOD FOR PRODUCING HIGH VELOCITY SHOCK WAVES IN GASES  

DOE Patents (OSTI)

A device is described for producing high-energy plasmas comprising a tapered shock tube of dielectric material and having a closed small end, an exceedingly low-inductance coll supported about and axially aligned with the small end of the tapered tube. an elongated multiturn coil supported upon the remninder of the exterior wall of the shock tube. a potential source and switch connected in series with the low-inductance coil, a potential source and switch connected in series with the elongated coil, means for hermetically sealing the large end of the tube, means for purging the tube of gases, and means for admitting a selected gas into the shock tube.

Josephson, V.

1960-01-26T23:59:59.000Z

24

Field-effect transistor having a superlattice channel and high carrier velocities at high applied fields  

DOE Patents (OSTI)

In a field-effect transistor comprising a semiconductor having therein a source, a drain, a channel and a gate in operational relationship, there is provided an improvement wherein said semiconductor is a superlattice comprising alternating quantum well and barrier layers, the quantum well layers comprising a first direct gap semiconductor material which in bulk form has a certain bandgap and a curve of electron velocity versus applied electric field which has a maximum electron velocity at a certain electric field, the barrier layers comprising a second semiconductor material having a bandgap wider than that of said first semiconductor material, wherein the layer thicknesses of said quantum well and barrier layers are sufficiently thin that the alternating layers constitute a superlattice having a curve of electron velocity versus applied electric field which has a maximum electron velocity at a certain electric field, and wherein the thicknesses of said quantum well layers are selected to provide a superlattice curve of electron velocity versus applied electric field whereby, at applied electric fields higher than that at which the maximum electron velocity occurs in said first material when in bulk form, the electron velocities are higher in said superlattice than they are in said first semiconductor material in bulk form.

Chaffin, R.J.; Dawson, L.R.; Fritz, I.J.; Osbourn, G.C.; Zipperian, T.E.

1984-04-19T23:59:59.000Z

25

High velocity impact of metal sphere on thin metallic plates: a comparative smooth particle hydrodynamics study  

Science Conference Proceedings (OSTI)

Four different shock-capturing schemes used in smooth particle hydrodynamics are compared as applied to moderately high-velocity impacts (at 3 km/s) and hypervelocity impacts (at ?6 km/s) of metallic projectiles on thin metal plates. The target ... Keywords: Riemann problem, artificial viscosity, hydrocode, hypervelocity impact

Vishal Mehra; Shashank Chaturvedi

2006-02-01T23:59:59.000Z

26

High Energy Tail of the Velocity Distribution of Driven Inelastic Gases  

E-Print Network (OSTI)

A model of homogeneously driven dissipative system, consisting of a collection of $N$ particles that are characterized by only their velocities, is considered. Adopting a discrete time dynamics, at each time step, a pair of velocities is randomly selected. They undergo inelastic collision with probability $p$. With probability $(1-p)$, energy of the system is changed by changing the velocities of both the particles independently according to $v\\rightarrow -r_w v +\\eta$, where $\\eta$ is a Gaussian noise drawn independently for each particle as well as at each time steps. For the case $r_w=\\pm 1$, although the energy of the system seems to saturate (indicating a steady state) after time steps of O(N), it grows linearly with time after time steps of $O(N^2)$, indicating the absence of a eventual steady state. For $ -1 injection limit, the velocity distribution is shown to be a Gaussian. For the general case, the high energy tail of the velocity distribution is shown to be again a Gaussian, with a different variance.

V. V. Prasad; Sanjib Sabhapandit; Abhishek Dhar

2013-07-12T23:59:59.000Z

27

Residential duct system leakage; Magnitude, impacts, and potential for reduction  

Science Conference Proceedings (OSTI)

This paper discusses the issues associated with leakage in residential air distribution systems, touching on the prevalence of duct leakage, the impacts of duct leakage, and on the techniques available for sealing duct systems. The issues examined in detail are: present techniques for measuring the leakage area of ducts existing data bases of duct leakage area measurements, the impacts of duct leakage on space-conditioning energy consumption and peak demand, and the ventilation impacts of duct leakage. The paper also includes a brief discussion of techniques for sealing duct systems in the field. The results derived from duct leakage are and driving pressure measurements indicate that in regions in which distribution systems pass through unconditioned spaces, air infiltration rates will typically double when the distribution fan is turned on, and that the average annual air infiltration rate is increased by 30% to 70% due to the existence of the distribution system. Estimates based upon a simplified analysis of leakage-induced energy losses also indicate the peak electricity demands due to duct leakage can be as high as 4 kW in Sacramento, California, and West Palm Beach, Florida, and that peak loads on the order of 1 to 2 kW are highly likely in these locations. Both peak loads and annual energy impacts are found to be strongly dependent on the location of the return duct, and attic return costing approximately 1500 kWh more energy than a crawlspace return in the two climates examined.

Modera, M.P. (Lawrence Berkeley Lab., Berkeley, CA (US))

1989-01-01T23:59:59.000Z

28

High-resolution seismic tomography of compressional wave velocity structure at Newberry Volcano, Oregon Cascade Range  

SciTech Connect

Compressional wave velocity structure is determined for the upper crust beneath Newberry Volcano, central Oregon, using a high-resolution active-source seismic-tomography method. Newberry Volcano is a bimodal shield volcano east of the axis of the Cascade Range. It is associated both with the Cascade Range and with northwest migrating silicic volcanism in southeast Oregon. High-frequency (approx.7 Hz) crustal phases, nominally Pg and a midcrustal reflected phase, travel upward through a target volume beneath Newberry Volcano to a dense array of 120 seismographs. This arrangement is limited by station spacing to 1- to 2-km resolution in the upper 5 to 6 km of the crust beneath the volcano's summit caldera. The experiment tests the hypothesis that Cascade Range volcanoes are underlain only by small magma chambers. A small low-velocity anomaly delineated abosut 3 km below the summit caldera supports this hypothesis for Newberry Volcano and is interpreted as a possible magma chamber of a few to a few tens of km/sup 3/ in volume. A ring-shaped high-velocity anomaly nearer the surface coincides with the inner mapped ring fractures of the caldera. It also coincides with a circular gravity high, and we interpret it as largely subsolidus silicic cone sheets. The presence of this anomaly and of silicic vents along the ring fractures suggests that the fractures are a likely eruption path between the small magma chamber and the surface.

Achauer, U.; Evans, J.R.; Stauber, D.A.

1988-09-10T23:59:59.000Z

29

Mapping Metal-Enriched High Velocity Clouds to Very Low HI Column Densities  

E-Print Network (OSTI)

Our galaxy is the nearest known quasar absorption line system, and it uniquely provides us with an opportunity to probe multiple lines of sight through the same galaxy. This is essential for our interpretations of the complex kinematic profiles seen in the MgII absorption due to lines of sight through intermediate redshift galaxies. The Milky Way halo has never been probed for high velocity clouds below the 21-cm detection threshold of N(HI)~10^18 cm-2. Through a survey of MgII absorption looking toward the brightest AGNs and quasars, it will be possible to reach down a few orders of magnitude in HI column density. The analogs to the high velocity components of the MgII absorption profiles due to intermediate redshift galaxies should be seen. We describe a program we are undertaking, and present some preliminary findings.

Chris Churchill; Jane Charlton; Joe Masiero

2001-08-13T23:59:59.000Z

30

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

DOE Patents (OSTI)

A method and apparatus for producing high-velocity material jets is provided. An electric current pulse generator is attached to an end of a coaxial two-conductor transmission line having an outer cylindrical conductor, an inner cylindrical conductor, and a solid plastic or ceramic insulator there between. A coaxial, thin-walled metal structure is conductively joined to the two conductors of the transmission line. An electrical current pulse applies magnetic pressure to and possibly explosively vaporizes metal structure, 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, together with the material that comprises any covering layers disposed on the structure. An electric current pulse generator of the explosively driven magnetic flux compression type or variety may be advantageously used in the practice of this invention. 3 figs.

Weingart, R.C.

1988-04-27T23:59:59.000Z

31

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

32

WHAM Observations of H-alpha from High-Velocity Clouds Are They Galactic or Extragalactic?  

E-Print Network (OSTI)

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the H-alpha line of high velocity clouds selected as the most likely candidates for being at larger than average distances. We have found H-alpha emission from 4 out of 5 of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group.

Tufte, S L; Madsen, G J; Haffner, L M; Reynolds, R J

2002-01-01T23:59:59.000Z

33

WHAM Observations of H-alpha from High-Velocity Clouds: Are They Galactic or Extragalactic?  

E-Print Network (OSTI)

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the H-alpha line of high velocity clouds selected as the most likely candidates for being at larger than average distances. We have found H-alpha emission from 4 out of 5 of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group.

S. L. Tufte; J. D. Wilson; G. J. Madsen; L. M. Haffner; R. J. Reynolds

2002-06-12T23:59:59.000Z

34

The collisions of high-velocity clouds with the galactic halo  

E-Print Network (OSTI)

Spiral galaxies are surrounded by a widely distributed hot coronal gas and seem to be fed by infalling clouds of neutral hydrogen gas with low metallicity and high velocities. We numerically study plasma waves produced by the collisions of these high-velocity clouds (HVCs) with the hot halo gas and with the gaseous disk. In particular, we tackle two problems numerically: 1) collisions of HVCs with the galactic halo gas and 2) the dispersion relations to obtain the phase and group velocities of plasma waves from the equations of plasma motion as well as further important physical characteristics such as magnetic tension force, gas pressure, etc. The obtained results allow us to understand the nature of MHD waves produced during the collisions in galactic media and lead to the suggestion that these waves can heat the ambient halo gas. These calculations are aiming at leading to a better understanding of dynamics and interaction of HVCs with the galactic halo and of the importance of MHD waves as a heating proce...

Jelinek, Petr; 10.1016/j.cpc.2011.01.023

2011-01-01T23:59:59.000Z

35

The Apache Point Observatory Galactic Evolution Experiment: First Detection of High Velocity Milky Way Bar Stars  

E-Print Network (OSTI)

Commissioning observations with the Apache Point Observatory Galactic Evolution Experiment (APOGEE), part of the Sloan Digital Sky Survey III, have produced radial velocities (RVs) for ~4700 K/M-giant stars in the Milky Way bulge. These high-resolution (R \\sim 22,500), high-S/N (>100 per resolution element), near-infrared (1.51-1.70 um; NIR) spectra provide accurate RVs (epsilon_v~0.2 km/s) for the sample of stars in 18 Galactic bulge fields spanning -1-32 deg. This represents the largest NIR high-resolution spectroscopic sample of giant stars ever assembled in this region of the Galaxy. A cold (sigma_v~30 km/s), high-velocity peak (V_GSR \\sim +200 km/s) is found to comprise a significant fraction (~10%) of stars in many of these fields. These high RVs have not been detected in previous MW surveys and are not expected for a simple, circularly rotating disk. Preliminary distance estimates rule out an origin from the background Sagittarius tidal stream or a new stream in the MW disk. Comparison to various Galac...

Nidever, David L; Majewski, Steven R; Bird, Jonathan; Robin, Annie C; Martinez-Valpuesta, Inma; Beaton, Rachael L; Schoenrich, Ralph; Schultheis, Mathias; Wilson, John C; Skrutskie, Michael F; O'Connell, Robert W; Shetrone, Matthew; Schiavon, Ricardo P; Johnson, Jennifer A; Weiner, Benjamin; Gerhard, Ortwin; Schneider, Donald P; Prieto, Carlos Allende; Sellgren, Kris; Bizyaev, Dmitry; Brewington, Howard; Brinkmann, Jon; Eisenstein, Daniel J; Frinchaboy, Peter M; Perez, Ana Elia Garcia; Holtzman, Jon; Hearty, Fred R; Malanushenko, Elena; Malanushenko, Viktor; Muna, Demitri; Oravetz, Daniel; Pan, Kaike; Simmons, Audrey; Snedden, Stephanie; Weaver, Benjamin A

2012-01-01T23:59:59.000Z

36

HIGH-RESOLUTION SEISMIC VELOCITY AND ATTENUATION MODELS OF THE CAUCASUS-CASPIAN REGION  

SciTech Connect

The southwest edge of Eurasia is a tectonically and structurally complex region that includes the Caspian and Black Sea basins, the Caucasus Mountains, and the high plateaus south of the Caucasus. Using data from 25 broadband stations located in the region, new estimates of crustal and upper mantle thickness, velocity structure, and attenuation are being developed. Receiver functions have been determined for all stations. Depth to Moho is estimated using slant stacking of the receiver functions, forward modeling, and inversion. Moho depths along the Caspian and in the Kura Depression are in general poorly constrained using only receiver functions due to thick sedimentary basin sediments. The best fitting models suggest a low velocity upper crust with Moho depths ranging from 30 to 40 km. Crustal thicknesses increase in the Greater Caucasus with Moho depths of 40 to 50 km. Pronounced variations with azimuth of source are observed indicating 3D structural complexity and upper crustal velocities are higher than in the Kura Depression to the south. In the Lesser Caucasus, south and west of the Kura Depression, the crust is thicker (40 to 50 km) and upper crustal velocities are higher. Work is underway to refine these models with the event based surface wave dispersion and ambient noise correlation measurements from continuous data. Regional phase (Lg and Pg) attenuation models as well as blockage maps for Pn and Sn are being developed. Two methods are used to estimate Q: the two-station method to estimate inter-station Q and the reversed, two-station, two event method. The results are then inverted to create Lg and Pg Q maps. Initial results suggest substantial variations in both Pg and Lg Q in the region. A zone of higher Pg Q extends west from the Caspian between the Lesser and Greater Caucasus and a narrow area of higher Lg Q is observed.

Mellors, R; Gok, R; Pasyanos, M; Skobeltsyn, G; Teoman, U; Godoladze, T; Sandvol, E

2008-07-01T23:59:59.000Z

37

EPRI Environmental Control Technology Center: FGD Wet Scrubber Performance At High Flue Gas Velocities  

Science Conference Proceedings (OSTI)

This report summarizes the impact of operating a wet flue gas desulfurization scrubber system at high flue gas velocities up to 20ft/sec (6.1 m/sec). It includes results for countercurrent spray, tray, and packing designs a variety of nozzle types. The report also describes the effect of adding dibasic acid and the impact of operation of state-of-the-art mist elimination systems. These results will be useful for planning compliance with SO2 emission regulations whether a new system is planned or addition...

1997-01-28T23:59:59.000Z

38

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

E-Print Network (OSTI)

The Environmental Protection Agency (EPA) has announced rules for continuous emissions monitoring (CEM) of stacks and ducts in nuclear facilities. EPA has recently approved use of Alternative Reference Methodologies (ARM) for air sampling in nuclear facilities which are based on the concept of single point representative sampling of flows in stacks and ducts. The ARM permits use of single point sampling of aerosol particles with a shrouded probe provided it can be demonstrated that both fluid momentum and contaminant concentration are well mixed. This work is mainly focused on developing an experimental model that will predict mixing of both mass and momentum in a highly turbulent flow. The experimental results for different duct configurations including 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 properties. These results would help the designers of sampling systems to select the proper locations for the collection of representative samples.

Langari, Abdolreza

1997-01-01T23:59:59.000Z

39

Particle deposition in ventilation ducts  

SciTech Connect

Exposure to airborne particles is detrimental to human health and indoor exposures dominate total exposures for most people. The accidental or intentional release of aerosolized chemical and biological agents within or near a building can lead to exposures of building occupants to hazardous agents and costly building remediation. Particle deposition in heating, ventilation and air-conditioning (HVAC) systems may significantly influence exposures to particles indoors, diminish HVAC performance and lead to secondary pollutant release within buildings. This dissertation advances the understanding of particle behavior in HVAC systems and the fates of indoor particles by means of experiments and modeling. Laboratory experiments were conducted to quantify particle deposition rates in horizontal ventilation ducts using real HVAC materials. Particle deposition experiments were conducted in steel and internally insulated ducts at air speeds typically found in ventilation ducts, 2-9 m/s. Behaviors of monodisperse particles with diameters in the size range 1-16 {micro}m were investigated. Deposition rates were measured in straight ducts with a fully developed turbulent flow profile, straight ducts with a developing turbulent flow profile, in duct bends and at S-connector pieces located at duct junctions. In straight ducts with fully developed turbulence, experiments showed deposition rates to be highest at duct floors, intermediate at duct walls, and lowest at duct ceilings. Deposition rates to a given surface increased with an increase in particle size or air speed. Deposition was much higher in internally insulated ducts than in uninsulated steel ducts. In most cases, deposition in straight ducts with developing turbulence, in duct bends and at S-connectors at duct junctions was higher than in straight ducts with fully developed turbulence. Measured deposition rates were generally higher than predicted by published models. A model incorporating empirical equations based on the experimental measurements was applied to evaluate particle losses in supply and return duct runs. Model results suggest that duct losses are negligible for particle sizes less than 1 {micro}m and complete for particle sizes greater than 50 {micro}m. Deposition to insulated ducts, horizontal duct floors and bends are predicted to control losses in duct systems. When combined with models for HVAC filtration and deposition to indoor surfaces to predict the ultimate fates of particles within buildings, these results suggest that ventilation ducts play only a small role in determining indoor particle concentrations, especially when HVAC filtration is present. However, the measured and modeled particle deposition rates are expected to be important for ventilation system contamination.

Sippola, Mark R.

2002-09-01T23:59:59.000Z

40

Galactic fountains and their connection with high and intermediate velocity clouds  

E-Print Network (OSTI)

The aim of this paper is to calculate the expansion law and chemical enrichment of a supershell powered by the energetic feedback of a typical Galactic OB association at various galactocentric radii. We study then the orbits of the fragments created when the supershell breaks out and we compare their kinetic and chemical properties with the available observations of high - and intermediate - velocity clouds. We use the Kompaneets (1960) approximation for the evolution of the superbubble driven by sequential supernova explosions and we compute the abundances of oxygen and iron residing in the thin cold supershell. We assume that supershells are fragmented by means of Rayleigh-Taylor instabilities and we follow the orbit of the clouds either ballistically or by means of a hybrid model considering viscous interaction between the clouds and the extra-planar gas.Given the self-similarity of the Kompaneets solutions, clouds are always formed ~ 448 pc above the plane. If the initial metallicity is solar, the pollution from dying stars of the OB association has a negligible effect on the chemical composition of the clouds. The maximum height reached by the clouds above the plane seldom exceeds 2 kpc and when averaging over different throwing angles, the landing coordinate differs from the throwing coordinate ~ 1 kpc at most. The range of heights and [O/Fe] ratios spun by our clouds suggest us that the high velocity clouds cannot have a Galactic origin, whereas intermediate velocity clouds have kinematic properties similar to our modeled clouds but overabundance observed for the [O/Fe] ratios which can be reproduced only with initial metallicities which are too low compared for those of the Galaxy disk.

E. Spitoni; S. Recchi; F. Matteucci

2008-03-20T23:59:59.000Z

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

High velocity continuous-flow reactor for the production of solar grade silicon. Second quarterly report  

DOE Green Energy (OSTI)

The objective is to determine the feasibility of a high volume-high velocity continuous reduction reactor as an economical means for producing solar grade polycrystalline silicon. Preheated streams of hydrogen and bromosilanes are used as feed to the reduction reactor. Nucleation and deposition sites are provided by the additional feed of preheated silicon particles to the reactor. The effort has been directed at studying the chemistry taking place in the reactor, determining the factors which influence its course, and making necessary reactor modifications as dictated by observed results. The initial reactor design has been extensively changed. Energy losses due to gas expansion in the nozzle/mixer section of the reactor dictated these design changes. A ''Tee'' configuration, in which the two preheated gas streams are merged at right angles without any expansion, has replaced the nozzle/mixer. Results of the hydrogen reduction of tetrabromosilane with and without the use of silicon deposition substrate particles are analyzed.

Woerner, L.

1978-03-01T23:59:59.000Z

42

Cornice Duct System  

Science Conference Proceedings (OSTI)

SYNERGETICS, INC., has designed, developed, and tested an air handling duct system that integrates the air duct with the cornice trim of interior spaces. The device has the advantage that the normal thermal losses from ducts into unconditioned attics and crawl spaces can be totally eliminated by bringing the ducts internal to the conditioned space. The following report details work conducted in the second budget period to develop the Cornice Duct System into a viable product for use in a variety of residential or small commercial building settings. A full-scale prototype has been fabricated and tested in a laboratory test building at the Daylighting Facility at North Carolina State University., Based on the results of that testing, the prototype design as been refined, fabricated, installed, and extensively tested in a residential laboratory house. The testing indicates that the device gives substantially superior performance to a standard air distribution system in terms of energy performance and thermal comfort. Patent Number US 6,511,373 B2 has been granted on the version of the device installed and tested in the laboratory house. (A copy of that patent is attached.) Refinements to the device have been carried through two additional design iterations, with a particular focus on reducing installation time and cost and refining the air control system. These new designs have been fabricated and tested and show substantial promise. Based on these design and testing iterations, a final design is proposed as part of this document. That final design is the basis for a continuation in part currently being filed with the U.5, Patent office.

Wayne Place; Chuck Ladd

2004-10-29T23:59:59.000Z

43

Tips: Air Ducts | Department of Energy  

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

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.

44

Duct Tape and Sealant Performance  

E-Print Network (OSTI)

were convinced that sealing air leaks in ducts was a costsealing approaches. Background UL has developed standards for closure systems for use with rigid air

Walker, Iain S.; Sherman, Max H.

2005-01-01T23:59:59.000Z

45

Increase Duct and Plenum Insulation  

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

changes to the commercial provisions of the 2012 IECC: Increase Duct and Plenum Insulation R Hart Pacific Northwest National Laboratory December 2012 Proposal Description This...

46

Modelling and Simulation of Tensile Fracture in High Velocity Compacted Metal Powder  

Science Conference Proceedings (OSTI)

In cold uniaxial powder compaction, powder is formed into a desired shape with rigid tools and a die. After pressing, but before sintering, the compacted powder is called green body. A critical property in the metal powder pressing process is the mechanical properties of the green body. Beyond a green body free from defects, desired properties are high strength and uniform density. High velocity compaction (HVC) using a hydraulic operated hammer is a production method to form powder utilizing a shock wave. Pre-alloyed water atomised iron powder has been HVC-formed into circular discs with high densities. The diametral compression test also called the Brazilian disc test is an established method to measure tensile strength in low strength material like e.g. rock, concrete, polymers and ceramics. During the test a thin disc is compressed across the diameter to failure. The compression induces a tensile stress perpendicular to the compressed diameter. In this study the test have been used to study crack initiation and the tensile fracture process of HVC-formed metal powder discs with a relative density of 99%. A fictitious crack model controlled by a stress versus crack-width relationship is utilized to model green body cracking. Tensile strength is used as a failure condition and limits the stress in the fracture interface. The softening rate of the model is obtained from the corresponding rate of the dissipated energy. The deformation of the powder material is modelled with an elastic-plastic Cap model. The characteristics of the tensile fracture development of the central crack in a diametrically loaded specimen is numerically studied with a three dimensional finite element simulation. Results from the finite element simulation of the diametral compression test shows that it is possible to simulate fracturing of HVC-formed powder. Results from the simulation agree reasonably with experiments.

Jonsen, P.; Haeggblad, H.-A. [Division of Solid Mechanics, Department of Applied Physics and Mechanical Engineering, Luleaa University of Technology, 971 87 Luleaa (Sweden)

2007-05-17T23:59:59.000Z

47

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

E-Print Network (OSTI)

Air duct systems in nuclear facilities must meet the requirements of ANSI N13.1-1999 and the Environmental Protection Agency (EPA) that the exhaust airflow be monitored with continuous sampling in case of an accidental release of airborne radionuclides. The continuous air sampling in a duct system is based on the concept of single point representative sampling at the sampling location where the velocity and contaminant profiles are nearly uniform. Sampling must be at a location where there is a uniform distribution via mixing in accordance with ANSI N13.1-1999. The purpose of this work is to identify the sampling locations where the velocity, momentum and contaminant concentrations fall below the 20% coefficient of variation (COV) requirements of ANSI N13.1-1999. Four sets of experiments were conducted on a generic 'T' mixing system. Measurements were made of the velocity, tracer gas concentration, ten micrometer particles and average flow swirl angle. The generic 'T' mixing system included three different combinations of sub duct sizes (6"x6", 9"x9" and 12"x12"), one main duct size (12"x12") and five air velocities (0, 100, 200, 300, and 400 fpm). An air blender was also introduced in some of the tests to promote mixing of the air streams from the main duct and sub duct. The experimental results suggested a turbulent mixing provided the accepted velocity COVs by 6 hydraulic diameters downstream. For similar velocity in the main duct and sub duct, an air blender provided the substantial 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 below 10%. With the air blender, most of the cases with the air blender had the lower COVs than without the blender. However, at an area ratio (sub duct area / main duct area) of 0.25 and above a velocity ratio (velocity in the sub duct / velocity in the main duct) of 3, the air blender proved to be less beneficial for mixing. These results can apply to other duct systems with similar geometries and, ultimately, be a basis for selecting a proper sampling location under the requirements of the single point representative sampling.

Kim, Taehong

2003-01-01T23:59:59.000Z

48

Are Gamma Ray Bursts due to Rotation Powered High Velocity Pulsars in the Halo ?  

E-Print Network (OSTI)

The BATSE experiment has now observed more than 1100 gamma-ray bursts. The observed angular distribution is isotropic, while the brightness distribution of bursts shows a reduced number of faint events. These observations favor a cosmological burst origin. Alternatively, very extended Galactic Halo (EGH) models have been considered. In the latter scenario, the currently favored source of gamma-ray bursts involves high velocity pulsars ejected from the Galactic disk. To be compatible with the observed isotropy, most models invoke a sampling distance of 300 kpc, a turn-on delay of 30 Myrs, and a source life time of about 1 Gyr. We consider the global energy requirements of such models and show that the largest known resource. rotational kinetic energy, is insufficient by orders of magnitude to provide the observed burst rate. More exotic energy sources or differently tuned pulsar models may be able to get around the global energy constraint but at the cost of becoming contrived. Thus, while extended halo models are not ruled out, our arguments place a severe obstacle for such models and we encourage proponents of EGH models to clearly address the issue of global energetics.

Dieter Hartmann; Ramesh Narayan

1995-11-25T23:59:59.000Z

49

Probing Primordial and Pre-Galactic Lithium with High Velocity Clouds  

E-Print Network (OSTI)

The pre-Galactic abundance of lithium offers a unique window into non-thermal cosmological processes. The primordial Li abundance is guaranteed to be present and probes big bang nucleosynthesis (BBN), while an additional Li component is likely to have been produced by cosmic rays accelerated in large scale structure formation. Pre-Galactic Li currently can only be observed in low metallicity Galactic halo stars, but abundance measurements are plagued with systematic uncertainties due to modeling of stellar atmospheres and convection. We propose a new site for measuring pre-Galactic Li: low-metallicity, high-velocity clouds (HVCs) which are likely to be extragalactic gas accreted onto the Milky Way, and which already have been found to have deuterium abundances consistent with primordial. A Li observation in such an HVC would provide the first extragalactic Li measurement, and could shed new light on the apparent discrepancy between BBN predictions and halo star Li abundance determinations. Furthermore, HVC Li could at the same time test for the presence of non-primordial Li due to cosmic rays. The observability of elemental and isotopic Li abundances is discussed, and candidate sites identified.

Tijana Prodanovic; Brian D. Fields

2004-12-09T23:59:59.000Z

50

Measurement of a Magnetic Field in a Leading Arm High Velocity Cloud  

E-Print Network (OSTI)

Using a recent catalogue of extragalactic Faraday rotation derived from the NRAO VLA Sky Survey we have found an agreement between Faraday rotation structure and the HI emission structure of a High Velocity Cloud (HVC) associated with the Leading Arm of the Magellanic System. We suggest that this morphological agreement is indicative of Faraday rotation through the HVC. Under this assumption we have used 48 rotation measures through the HVC, together with estimates of the electron column density from H-\\alpha\\ measurements and QSO absorption lines to estimate a strength for the line-of-sight component of the coherent magnetic field in the HVC of > 6 {\\rm \\mu G}$. A coherent magnetic field of this strength is more than sufficient to dynamically stabilize the cloud against ram pressure stripping by the Milky Way halo and may also provide thermal insulation for the cold cloud. We estimate an upper limit to the ratio of random to coherent magnetic field of $B_{r}/B_{||} < 0.8$, which suggests that the random ...

McClure-Griffiths, N M; Gaensler, B M; McConnell, D; Schnitzeler, D H F M

2010-01-01T23:59:59.000Z

51

Stopping duct quacks: Longevity of residential duct sealants  

Science Conference Proceedings (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 shown that these seals tend to fail over time periods ranging from days to years. We have used several test methods over the last few years to evaluate the longevity of duct sealants when subjected to temperatures and pressures representative of those found in the field. Traditional cloth duct tapes have been found to significantly under-perform other sealants and have been banned from receiving duct tightness credits in California's energy code (California Energy Commission 1998). Our accelerated testing apparatus has been redesigned since its first usage for improved performance. The methodology is currently under consideration by the American Society for Testing and Materials (ASTM) as a potential new test method. This report will summarize the set of measurements to date, review the status of the test apparatus and test method, and summarize the applications of these results to codes and standards.

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

2000-08-01T23:59:59.000Z

52

Duct thermal performance models for large commercial buildings  

SciTech Connect

Despite the potential for significant energy savings by reducing duct leakage or other thermal losses from duct systems in large commercial buildings, California Title 24 has no provisions to credit energy-efficient duct systems in these buildings. A substantial reason is the lack of readily available simulation tools to demonstrate the energy-saving benefits associated with efficient duct systems in large commercial buildings. The overall goal of the Efficient Distribution Systems (EDS) project within the PIER High Performance Commercial Building Systems Program is to bridge the gaps in current duct thermal performance modeling capabilities, and to expand our understanding of duct thermal performance in California large commercial buildings. As steps toward this goal, our strategy in the EDS project involves two parts: (1) developing a whole-building energy simulation approach for analyzing duct thermal performance in large commercial buildings, and (2) using the tool to identify the energy impacts of duct leakage in California large commercial buildings, in support of future recommendations to address duct performance in the Title 24 Energy Efficiency Standards for Nonresidential Buildings. The specific technical objectives for the EDS project were to: (1) Identify a near-term whole-building energy simulation approach that can be used in the impacts analysis task of this project (see Objective 3), with little or no modification. A secondary objective is to recommend how to proceed with long-term development of an improved compliance tool for Title 24 that addresses duct thermal performance. (2) Develop an Alternative Calculation Method (ACM) change proposal to include a new metric for thermal distribution system efficiency in the reporting requirements for the 2005 Title 24 Standards. The metric will facilitate future comparisons of different system types using a common ''yardstick''. (3) Using the selected near-term simulation approach, assess the impacts of duct system improvements in California large commercial buildings, over a range of building vintages and climates. This assessment will provide a solid foundation for future efforts that address the energy efficiency of large commercial duct systems in Title 24. This report describes our work to address Objective 1, which includes a review of past modeling efforts related to duct thermal performance, and recommends near- and long-term modeling approaches for analyzing duct thermal performance in large commercial buildings.

Wray, Craig P.

2003-10-01T23:59:59.000Z

53

Duct Testing | Building Energy Codes Program  

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

Duct Testing This video offers tips and instruction for duct testing, and is a portion of the Duct Leakage Testing presentation given at Energy Codes 2009. Estimated Length: 12...

54

On HVAC duct acoustical end reflection  

Science Conference Proceedings (OSTI)

Duct end reflection (ER) is the apparent loss of sound power resulting from an abrupt change in a cross?sectional area of the duct. In most references

2000-01-01T23:59:59.000Z

55

Aerogel Impregnated Polyurethane Piping and Duct Insulation ...  

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

Polyurethane Piping and Duct Insulation Aerogel Impregnated Polyurethane Piping and Duct Insulation Emerging Technologies Project for the 2013 Building Technologies Office's...

56

Doping-Dependent Nodal Fermi Velocity in Bi-2212 Revealed by High-Resolution ARPES  

Science Conference Proceedings (OSTI)

The improved resolution of laser-based angle-resolved photoemission spectroscopy (ARPES) allows reliable access to fine structures in the spectrum. We present a systematic, doping-dependent study of a recently discovered low-energy kink in the nodal dispersion of Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8+{delta}} (Bi-2212), which demonstrates the ubiquity and robustness of this kink in underdoped Bi-2212. The renormalization of the nodal velocity due to this kink becomes stronger with underdoping, revealing that the nodal Fermi velocity is non-universal, in contrast to assumed phenomenology. This is used together with laser-ARPES measurements of the gap velocity, v{sub 2}, to resolve discrepancies with thermal conductivity measurements.

Vishik, I. M.

2011-08-19T23:59:59.000Z

57

Probing High-Velocity Transient-Field Strength Using Heavy-ions Traversing Fe and Gd  

SciTech Connect

The transient field strength for {sup 76}Ge ions, passing through iron and gadolinium layers at velocities approxZv{sub 0}, has been measured. Although a sizeable value has been obtained for Gd, a vanishing strength has been observed in Fe.

Fiori, E.; Georgiev, G.; Cabaret, S.; Lozeva, R. [CSNSM, CNRS/IN2P3, Universite Paris-Sud 11, UMR8609, F-91405 ORSAY-Campus (France); Stuchbery, A. E. [Department of Nuclear Physics, Australian National University, Canberra (Australia); Jungclaus, A.; Modamio, V.; Walker, J. [Instituto de Estructura de la Materia, CSIC, Madrid (Spain); Balabanski, D. L. [INRNE-BAS, Sofia (Bulgaria); Blazhev, A. [IKP, Cologne (Germany); Clement, E.; Grevy, S.; Stodel, C.; Thomas, J. C. [GANIL, Caen (France); Danchev, M. [University of Sofia (Bulgaria); Daugas, J. M. [CEA, DAM, DIF, 91297 Arpajon cedex (France); Hass, M.; Kumar, V. [The Weizmann Institute, Rehovot (Israel); Leske, J.; Pietralla, N. [TU Darmstadt, Darmstadt (Germany)

2009-08-26T23:59:59.000Z

58

On the X-ray low- and high-velocity outflows in AGNs  

E-Print Network (OSTI)

An exploration of the relationship between bolometric luminosity and outflow velocity, for two classes of X-ray outflows in a large sample of active galactic nuclei has been performed. We find that line radiation pressure could be one physical mechanism that might accelerate the gas we observe in warm absorber, v~100-1000 km/s, and on comparable but less stringent grounds the ultra-fast outflows (UFOs), v~0.03-0.3c. If comparable with the escape velocity of the system; the first is naturally located at distances of the dusty torus, ~ 1 pc, and the second at sub-parsec scales, ~ 0.01 pc, in accordance with large set of observational evidence existing in the literature. The presentation of this relationship might give us key clues for our understanding of the different physical mechanisms acting in the center of galaxies, the feedback process and its impact on the evolution of the host galaxy.

Ramirez, J M

2011-01-01T23:59:59.000Z

59

accepted to The Astrophysical Journal Letters WHAM Observations of H? from High Velocity Clouds: Are They Galactic or Extragalactic?  

E-Print Network (OSTI)

It has been suggested that high velocity clouds may be distributed throughout the Local Group and are therefore not in general associated with the Milky Way galaxy. With the aim of testing this hypothesis, we have made observations in the H? line of high velocity clouds selected as the most likely candidates for being at larger than average distances. We have found H? emission from 4 out of 5 of the observed clouds, suggesting that the clouds under study are being illuminated by a Lyman continuum flux greater than that of the metagalactic ionizing radiation. Therefore, it appears likely that these clouds are in the Galactic halo and not distributed throughout the Local Group.

S. L. Tufte; J. D. Wilson; G. J. Madsen; L. M. Haffner; R. J. Reynolds

2002-01-01T23:59:59.000Z

60

Flow duct for nuclear reactors  

DOE Patents (OSTI)

Improved liquid sodium flow ducts for nuclear reactors are described wherein the improvement comprises varying the wall thickness of each of the walls of a polygonal tubular duct structure so that each of the walls is of reduced cross-section along the longitudinal center line and of a greater cross-section along wall junctions with the other walls to form the polygonal tubular configuration.

Straalsund, Jerry L. (Richland, WA)

1978-01-01T23:59:59.000Z

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

WHAM Observations of H-alpha Emission from High Velocity Clouds in the M, A, and C Complexes  

E-Print Network (OSTI)

The first observations of the recently completed Wisconsin H-Alpha Mapper (WHAM) facility include a study of emission lines from high velocity clouds in the M, A, and C complexes, with most of the observations on the M I cloud. We present results including clear detections of H-alpha emission from all three complexes with intensities ranging from 0.06 R to 0.20 R. In every observed direction where there is significant high velocity H I gas seen in the 21 cm line we have found associated ionized hydrogen emitting the H-alpha line. The velocities of the H-alpha and 21 cm emission are well correlated in every case except one, but the intensities are not correlated. There is some evidence that the ionized gas producing the H-alpha emission envelopes the 21 cm emitting neutral gas but the H-alpha "halo", if present, is not large. If the H-alpha emission arises from the photoionization of the H I clouds, then the implied Lyman continuum flux F_{LC} at the location of the clouds ranges from 1.3 to 4.2 x 10^5 photons cm^{-2} s^{-1}. If, on the other hand, the ionization is due to a shock arising from the collision of the high-velocity gas with an ambient medium in the halo, then the density of the pre-shocked gas can be constrained. We have also detected the [S II] 6716 angstrom line from the M I cloud and have evidence that the [S II] to H-alpha ratio varies with location on the cloud.

S. L. Tufte; R. J. Reynolds; L. M. Haffner

1998-07-15T23:59:59.000Z

62

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.

63

WHAM Observations of H$\\alpha$ Emission from High Velocity Clouds in the M, A, and C Complexes  

E-Print Network (OSTI)

The first observations of the recently completed Wisconsin H-Alpha Mapper (WHAM) facility include a study of emission lines from high velocity clouds in the M, A, and C complexes, with most of the observations on the M I cloud. We present results including clear detections of H-alpha emission from all three complexes with intensities ranging from 0.06 R to 0.20 R. In every observed direction where there is significant high velocity H I gas seen in the 21 cm line we have found associated ionized hydrogen emitting the H-alpha line. The velocities of the H-alpha and 21 cm emission are well correlated in every case except one, but the intensities are not correlated. There is some evidence that the ionized gas producing the H-alpha emission envelopes the 21 cm emitting neutral gas but the H-alpha "halo", if present, is not large. If the H-alpha emission arises from the photoionization of the H I clouds, then the implied Lyman continuum flux F_{LC} at the location of the clouds ranges from 1.3 to 4.2 x 10^5 photons...

Tufte, S L; Haffner, L M

1998-01-01T23:59:59.000Z

64

THE APACHE POINT OBSERVATORY GALACTIC EVOLUTION EXPERIMENT: FIRST DETECTION OF HIGH-VELOCITY MILKY WAY BAR STARS  

Science Conference Proceedings (OSTI)

Commissioning observations with the Apache Point Observatory Galactic Evolution Experiment (APOGEE), part of the Sloan Digital Sky Survey III, have produced radial velocities (RVs) for {approx}4700 K/M-giant stars in the Milky Way (MW) bulge. These high-resolution (R {approx} 22, 500), high-S/N (>100 per resolution element), near-infrared (NIR; 1.51-1.70 {mu}m) spectra provide accurate RVs ({epsilon}{sub V} {approx} 0.2 km s{sup -1}) for the sample of stars in 18 Galactic bulge fields spanning -1 Degree-Sign -32 Degree-Sign . This represents the largest NIR high-resolution spectroscopic sample of giant stars ever assembled in this region of the Galaxy. A cold ({sigma}{sub V} {approx} 30 km s{sup -1}), high-velocity peak (V{sub GSR} Almost-Equal-To +200 km s{sup -1}) is found to comprise a significant fraction ({approx}10%) of stars in many of these fields. These high RVs have not been detected in previous MW surveys and are not expected for a simple, circularly rotating disk. Preliminary distance estimates rule out an origin from the background Sagittarius tidal stream or a new stream in the MW disk. Comparison to various Galactic models suggests that these high RVs are best explained by stars in orbits of the Galactic bar potential, although some observational features remain unexplained.

Nidever, David L.; Zasowski, Gail; Majewski, Steven R.; Beaton, Rachael L.; Wilson, John C.; Skrutskie, Michael F.; O'Connell, Robert W. [Department of Astronomy, University of Virginia, Charlottesville, VA 22904-4325 (United States); Bird, Jonathan; Schoenrich, Ralph; Johnson, Jennifer A.; Sellgren, Kris [Department of Astronomy and the Center for Cosmology and Astro-Particle Physics, The Ohio State University, Columbus, OH 43210 (United States); Robin, Annie C.; Schultheis, Mathias [Institut Utinam, CNRS UMR 6213, OSU THETA, Universite de Franche-Comte, 41bis avenue de l'Observatoire, F-25000 Besancon (France); Martinez-Valpuesta, Inma; Gerhard, Ortwin [Max-Planck-Institut fuer Extraterrestrische Physik, Giessenbachstrasse, D-85748 Garching (Germany); Shetrone, Matthew [McDonald Observatory, University of Texas at Austin, Fort Davis, TX 79734 (United States); Schiavon, Ricardo P. [Gemini Observatory, 670 North A'Ohoku Place, Hilo, HI 96720 (United States); Weiner, Benjamin [Steward Observatory, 933 North Cherry Street, University of Arizona, Tucson, AZ 85721 (United States); Schneider, Donald P. [Department of Astronomy and Astrophysics, The Pennsylvania State University, University Park, PA 16802 (United States); Allende Prieto, Carlos, E-mail: dln5q@virginia.edu [Instituto de Astrofisica de Canarias, E-38205 La Laguna, Tenerife (Spain); and others

2012-08-20T23:59:59.000Z

65

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

Science Conference Proceedings (OSTI)

The objective of our research was to develop and demonstrate seismic data-acquisition and data-processing technologies that allow geothermal prospects below high-velocity rock outcrops to be evaluated. To do this, we acquired a 3-component seismic test line across an area of exposed high-velocity rocks in Brewster County, Texas, where there is high heat flow and surface conditions mimic those found at numerous geothermal prospects. Seismic contractors have not succeeded in creating good-quality seismic data in this area for companies who have acquired data for oil and gas exploitation purposes. Our test profile traversed an area where high-velocity rocks and low-velocity sediment were exposed on the surface in alternating patterns that repeated along the test line. We verified that these surface conditions cause non-ending reverberations of Love waves, Rayleigh waves, and shallow critical refractions to travel across the earth surface between the boundaries of the fast-velocity and slow-velocity material exposed on the surface. These reverberating surface waves form the high level of noise in this area that does not allow reflections from deep interfaces to be seen and utilized. Our data-acquisition method of deploying a box array of closely spaced geophones allowed us to recognize and evaluate these surface-wave noise modes regardless of the azimuth direction to the surface anomaly that backscattered the waves and caused them to return to the test-line profile. With this knowledge of the surface-wave noise, we were able to process these test-line data to create P-P and SH-SH images that were superior to those produced by a skilled seismic data-processing contractor. Compared to the P-P data acquired along the test line, the SH-SH data provided a better detection of faults and could be used to trace these faults upward to the boundaries of exposed surface rocks. We expanded our comparison of the relative value of S-wave and P-wave seismic data for geothermal applications by inserting into this report a small part of the interpretation we have done with 3C3D data across Wister geothermal field in the Imperial Valley of California. This interpretation shows that P-SV data reveal faults (and by inference, also fractures) that cannot be easily, or confidently, seen with P-P data, and that the combination of P-P and P-SV data allows VP/VS velocity ratios to be estimated across a targeted reservoir interval to show where an interval has more sandstone (the preferred reservoir facies). The conclusion reached from this investigation is that S-wave seismic technology can be invaluable to geothermal operators. Thus we developed a strong interest in understanding the direct-S modes produced by vertical-force sources, particularly vertical vibrators, because if it can be demonstrated that direct-S modes produced by vertical-force sources can be used as effectively as the direct-S modes produced by horizontal-force sources, geothermal operators can acquire direct-S data across many more prospect areas than can be done with horizontal-force sources, which presently are limited to horizontal vibrators. We include some of our preliminary work in evaluating direct-S modes produced by vertical-force sources.

Hardage, Bob A; DeAngelo, Michael V; Ermolaeva, Elena; Hardage, Bob A; Remington, Randy; Sava, Diana; Wagner, Donald; Wei, Shuijion

2013-02-28T23:59:59.000Z

66

THE 21 cm 'OUTER ARM' AND THE OUTER-GALAXY HIGH-VELOCITY CLOUDS: CONNECTED BY KINEMATICS, METALLICITY, AND DISTANCE  

Science Conference Proceedings (OSTI)

Using high-resolution ultraviolet spectra obtained with the Hubble Space Telescope Space Telescope Imaging Spectrograph and the Far Ultraviolet Spectroscopic Explorer, we study the metallicity, kinematics, and distance of the gaseous 'outer arm' (OA) and the high-velocity clouds (HVCs) in the outer Galaxy. We detect the OA in a variety of absorption lines toward two QSOs, H1821+643 and HS0624+6907. We search for OA absorption toward eight Galactic stars and detect it in one case, which constrains the OA Galactocentric radius to 9 kpc absorption toward two stars; Complex G is therefore in the same region at R{sub G} = 8-10 kpc. HVC Complex C is known to be at a similar Galactocentric radius. Toward H1821+643, the low-ionization absorption lines are composed of multiple narrow components, indicating the presence of several cold clouds and rapid cooling and fragmentation. Some of the highly ionized gas is also surprisingly cool. Accounting for ionization corrections, we find that the OA metallicity is Z = 0.2-0.5 Z{sub Sun }, but nitrogen is underabundant and some species are possibly mildly depleted by dust. The similarity of the OA metallicity, Galactocentric location, and kinematics to those of the adjacent outer-Galaxy HVCs, including high velocities that are not consistent with Galactic rotation, suggests that the OA and outer-Galaxy HVCs could have a common origin.

Tripp, Todd M.; Song Limin, E-mail: tripp@astro.umass.edu [Department of Astronomy, University of Massachusetts, Amherst, MA 01003 (United States)

2012-02-20T23:59:59.000Z

67

Duct/Air sealing | Open Energy Information  

Open Energy Info (EERE)

Community Login | Sign Up Search Page Edit History Facebook icon Twitter icon DuctAir sealing Jump to: navigation, search TODO: Add description List of DuctAir sealing...

68

Program on Technology Innovation: Liquid Precursor High-Velocity Oxy-Fuel Spray Process for Making Fine Structured and Highly Bonded Alloy Coatings  

Science Conference Proceedings (OSTI)

High velocity oxygen-fuel (HVOF) thermal spray processes are used in applications requiring the highest density and adhesion strength, which is not achievable in most other thermal spray processes. Like other thermal spray processes, however, a normal HVOF process is not able to apply fine powders less than 10m via a conventional powder feeder like other thermal spray processes. The advantages of using smaller nano-sized particles in a HVOF process include uniform coating, uniform microstructure, higher ...

2007-03-28T23:59:59.000Z

69

Evaluation of Fish-Injury Mechanisms During Exposure to a High-Velocity Jet  

DOE Green Energy (OSTI)

As part of the research supported by U.S. Department of Energy (DOE) Advanced Hydropower Turbine System (AHTS) Program, the Pacific Northwest National Laboratory (PNNL) conducted a study where age-0 and age-1 chinook salmon, as well as several other types of fish, were released into a submerged water jet to quantify injuries caused by shear stresses and turbulence (Neitzel et al. 2000). The fish releases were videotaped. These videotape records were digitized and analyzed using new methods to identify the injury mechanisms and the stresses involved. Visible external injuries sustained by fish in this study generally occurred during the initial contact with the jet and not during the tumbling that occurred after the fish fully entered the turbulent flow. The inertial stresses of tumbling, however, may cause temporary or even permanent vestibular and neurological injuries. Such injuries can result in disorientation and loss of equilibrium, which are life threatening in the ''natural'' environment. Operculum injuries predominated at moderate water jet speeds (12 and 15 m {center_dot} s{sup -1}). At the highest speed, eye, operculum, isthmus, and gill injuries were equally common, and disorientation was most common. Bruising and descaling were relatively rare, especially for age-0 fish. Age-0 fish were less susceptible than the larger age-1 fish to all visible injury types, especially at lower speeds. This is presumably because age-0 fish have less mass and inertia, and therefore sustain smaller forces on exposed organs during acceleration. Alternatively, age-0 fish were substantially more susceptible to behavioral impairments such as disorientation. This may also relate to the smaller mass of the age-0 fish. The less massive age-0 fish sustain larger accelerations and jerks, which may be important sources of the internal injuries to the vestibular and neurological systems. All the dynamic parameters computed from the bulk motion of the fish (velocity, jerk, and force) were positively correlated with injury level, based on the results of this study. Multinomial response model results further suggested that force is most predictive of injury.

Guensch, Greg R.; Mueller, Robert P.; McKinstry, Craig A.; Dauble, Dennis D.

2003-01-24T23:59:59.000Z

70

CALIFORNIA ENERGY Residential Duct Placement  

E-Print Network (OSTI)

Science Corporation, Bruce Wilcox of Berkeley Solar Group, Jamie Lyons of Energetics, Inc., Marshall Hunt improve the quality of life in California by bringing environmentally safe, affordable, and reliable shingles, energy credits, measurement issues, duct access, and equipment sizing issues. Commercial issues

71

High Resolution Measurements of Turbulence, Velocity and Stress Using a Pulse-to-Pulse Coherent Sonar  

Science Conference Proceedings (OSTI)

Considered are the capabilities of a recently developed pulse-to-pulse coherent sonar called the High Resolution Current Profiler (HRCP). Special emphasis is placed on methods whereby reliable and accurate vertical profiles of turbulence ...

Atle Lohrmann; Bruce Hackett; Lars Petter Røed

1990-02-01T23:59:59.000Z

72

Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor fueling  

DOE Green Energy (OSTI)

Three separate papers are included which report research progress during this period: (1) A new railgun configuration with perforated sidewalls, (2) development of a fuseless small-bore railgun for injection of high-speed hydrogen pellets into magnetically confined plasmas, and (3) controls and diagnostics on a fuseless railgun for solid hydrogen pellet injection.

Kim, K.; Zhang, J.

1992-01-01T23:59:59.000Z

73

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

Science Conference Proceedings (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

74

The effect of load thickness on Rayleigh-Taylor mitigation in high velocity, annular z pinch implosion  

SciTech Connect

Numerical calculations have been performed to investigate the role that load thickness may play in the performance of fast annular z pinch implosions. In particular, the effects of load thickness on the mitigation of the magnetically-driven Rayleigh-Taylor (RT) instability and energy coupling between the load and generator are addressed. using parameters representative of the Z accelerator [R.B.Spielman et al., Phys.Plasmas, 5, 2105 (1998)] at Sandia National Laboratories, two dimensional magnetohydrodynamic (MHD) simulations show that increased shell thickness results in lower amplitude, slightly longer wavelength RT modes. In addition, there appears to be an optimum in load velocity which is directly associated with the thickness of the sheath and subsequent RT growth. Thin, annular loads, which should couple efficiently to the accelerator, show a large reduction in implosion velocity due to extreme RT development and increased load inductance. As a consequence, thicker loads on the order of 5 mm, couple almost as efficiently to the generator since the RT growth is reduced. This suggests that z-pinch loads can be tailored for different applications, depending on the need for uniformity or high powers.

DOUGLAS,MELISSA R.; DEENEY,CHRISTOPHER; RODERICK,NORMAN F.

2000-05-16T23:59:59.000Z

75

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

DOE Green Energy (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

76

Design of Flexible-Duct Junction Boxes  

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

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

77

Influence of the inlet velocity profiles on the prediction of velocity distribution inside an electrostatic precipitator  

SciTech Connect

The influence of the velocity profile at the inlet boundary on the simulation of air velocity distribution inside an electrostatic precipitator is presented in this study. Measurements and simulations were performed in a duct and an electrostatic precipitator (ESP). A four-hole cobra probe was used for the measurement of velocity distribution. The flow simulation was performed by using the computational fluid dynamics (CFD) code FLUENT. Numerical calculations for the air flow were carried out by solving the Reynolds-averaged Navier-Stokes equations coupled with the realizable k-{epsilon} turbulence model equations. Simulations were performed with two different velocity profiles at the inlet boundary - one with a uniform (ideal) velocity profile and the other with a non-uniform (real) velocity profile to demonstrate the effect of velocity inlet boundary condition on the flow simulation results inside an ESP. The real velocity profile was obtained from the velocity measured at different points of the inlet boundary whereas the ideal velocity profile was obtained by calculating the mean value of the measured data. Simulation with the real velocity profile at the inlet boundary was found to predict better the velocity distribution inside the ESP suggesting that an experimentally measured velocity profile could be used as velocity inlet boundary condition for an accurate numerical simulation of the ESP. (author)

Haque, Shah M.E.; Deev, A.V.; Subaschandar, N. [Process Engineering and Light Metals (PELM) Centre, Faculty of Sciences, Engineering and Health, Central Queensland University, Gladstone, Queensland 4680 (Australia); Rasul, M.G.; Khan, M.M.K. [College of Engineering and Built Environment, Faculty of Sciences, Engineering and Health, Central Queensland University, Rockhampton, Queensland 4702 (Australia)

2009-01-15T23:59:59.000Z

78

High velocity impact fracture  

E-Print Network (OSTI)

An in-depth understanding of dynamic ductile fracture is one of the most important steps to improve the survivability of critical structures such as the lost Twin Towers. In the present thesis, the macroscopic fracture ...

Teng, Xiaoqing

2005-01-01T23:59:59.000Z

79

The Far Ultraviolet Spectroscopic Explorer: Mission Overview and Prospects for Studies of the Interstellar Medium and High Velocity Clouds  

E-Print Network (OSTI)

The Far Ultraviolet Spectroscopic Explorer (FUSE) is a NASA astronomy mission that will explore the 905-1187 A wavelength region at high spectral resolution. Funded by NASA's Explorer Program, this Origins mission is scheduled for a 1999 launch and at least three years of operations. The development of FUSE is being led by the Johns Hopkins University, with major contributions to the program from the University of Colorado, the University of California-Berkeley, the space agencies of Canada and France, and corporate partners. FUSE will have approximately 10,000 times the sensitivity of its pioneering predecessor, Copernicus, which operated in the 1970s. Much of the FUSE Science Team observing time will be dedicated to studying the interstellar medium of the Milky Way and Magellanic Clouds. Observations of high velocity clouds play an important role in the FUSE program. In this paper, I outline some of the FUSE Science Team plans for observing HVCs. Simple absorption line models are also provided for investigators seeking to identify atomic and molecular species in this wavelength region.

Kenneth R. Sembach

1998-11-19T23:59:59.000Z

80

A compact single-camera system for high-speed, simultaneous 3-D velocity and temperature measurements.  

SciTech Connect

The University of Michigan and Sandia National Laboratories collaborated on the initial development of a compact single-camera approach for simultaneously measuring 3-D gasphase velocity and temperature fields at high frame rates. A compact diagnostic tool is desired to enable investigations of flows with limited optical access, such as near-wall flows in an internal combustion engine. These in-cylinder flows play a crucial role in improving engine performance. Thermographic phosphors were proposed as flow and temperature tracers to extend the capabilities of a novel, compact 3D velocimetry diagnostic to include high-speed thermometry. Ratiometric measurements were performed using two spectral bands of laser-induced phosphorescence emission from BaMg2Al10O17:Eu (BAM) phosphors in a heated air flow to determine the optimal optical configuration for accurate temperature measurements. The originally planned multi-year research project ended prematurely after the first year due to the Sandia-sponsored student leaving the research group at the University of Michigan.

Lu, Louise [University of Michigan, Ann Arbor, MI; Sick, Volker [University of Michigan, Ann Arbor, MI; Frank, Jonathan H.

2013-09-01T23:59:59.000Z

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.


81

Residential Duct Sealing Cost-Benefit Analysis  

Science Conference Proceedings (OSTI)

Residential air duct leakage can account for as much as 15 percent of a utility bill. Research has shown that houses with supply leakage fractions of 10 percent or greater are viable candidates for air duct sealing or retrofit. This report details the development of a regional program designed to measure and improve residential heating system distribution efficiency via air duct sealing and retrofits. The program consolidates the efforts of several utilities and coordinates a region-wide assessment of th...

2000-06-05T23:59:59.000Z

82

Home test kit for duct leakage  

SciTech Connect

An inexpensive device whose purpose is to test for duct leakage in the home is described. This device is intended for use by homeowners and others untrained in the art of duct testing. While not as accurate as testing done by professionals, it should be able to give the homeowners enough information to justify a decision whether or not to call on professional assistance for further testing and possible remediation of their duct systems. The device has been reduced to practice.

Andrews, J.W.

1997-04-01T23:59:59.000Z

83

Evaluation of PEGIT duct connection system  

E-Print Network (OSTI)

flex duct-to-sheet metal). Air sealing is separate from thisconcentrate on the air sealing. The connections designed byeffect of production tolerance on air sealing and assembly

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

2003-01-01T23:59:59.000Z

84

Compression effects on pressure loss in flexible HVAC ducts  

E-Print Network (OSTI)

to Determine Flow Resistance of HVAC Air Ducts and Fittings.Pressure Loss in Flexible HVAC Ducts Bass Abushakra, Ph.D.to Determine Flow Resistance of HVAC Air Ducts and Fittings.

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

2002-01-01T23:59:59.000Z

85

Observations of Strong Surface Radar Ducts over the Persian Gulf  

Science Conference Proceedings (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

86

Measure Guideline: Sealing and Insulating of Ducts in Existing Homes  

SciTech Connect

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

87

Reducing Uncertainty for the DeltaQ Duct Leakage Test  

E-Print Network (OSTI)

the DeltaQ duct Leakage Test”. ASHRAE Transactions (inof a new Duct Leakage Test: DeltaQ. LBNL 47308. Walker, I,Uncertainties in the DeltaQ test for Duct Leakage.

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

2004-01-01T23:59:59.000Z

88

Experimental evaluation of gas filled plenum (GFP) insulation for ducts  

E-Print Network (OSTI)

Gas Filled Plenum (GFP) Insulation for Ducts LBNL 52084 Iaina flexible duct. Most duct insulation has an R-value of 4.2,used. With glass fiber insulation being about R4 per inch (

Walker, Iain S.; Guillot, Cyril

2003-01-01T23:59:59.000Z

89

Double-duct liquid metal magnetohydrodynamic engine  

DOE Patents (OSTI)

An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has-four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

Haaland, Carsten M. (Oak Ridge, TN)

1995-01-01T23:59:59.000Z

90

Double-duct liquid metal magnetohydrodynamic engine  

DOE Patents (OSTI)

An internal combustion, liquid metal (LM) magnetohydrodynamic (MHD) engine and an alternating current (AC) magnetohydrodynamic generator, are used in combination to provide useful AC electric energy output. The engine design has four pistons and a double duct configuration, with each duct containing sodium potassium liquid metal confined between free pistons located at either end of the duct. The liquid metal is forced to flow back and forth in the duct by the movement of the pistons, which are alternatively driven by an internal combustion process. In the MHD generator, the two LM-MHD ducts pass in close proximity through a Hartmann duct with output transformer. AC power is produced by operating the engine with the liquid metal in the two generator ducts always flowing in counter directions. The amount of liquid metal maintained in the ducts may be varied. This provides a variable stroke length for the pistons. The engine/generator provides variable AC power at variable frequencies that correspond to the power demands of the vehicular propulsion. Also the engine should maintain nearly constant efficiency throughout the range of power usage. Automobiles and trucks could be powered by the invention, with no transmission or power converter devices being required.

Haaland, Carsten M. (Oak Ridge, TN)

1997-01-01T23:59:59.000Z

91

Aerosol-Based Duct Sealing Technology  

NLE Websites -- All DOE Office Websites (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

92

Success Stories: Duct Sealing - Lawrence Berkeley National Laboratory  

Leaking ducts can be sealed in an average house in about a day. Start-Ups - Carrier Aeroseal, LLC. Aerosol-Based Duct Sealing Technology. Berkeley Lab has ...

93

Duct systems in large commercial buildings: physical characterization...  

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

Duct systems in large commercial buildings: physical characterization, air leakage and heat conduction gains Title Duct systems in large commercial buildings: physical...

94

X-ray polarization spectroscopy to study anisotropic velocity distribution of hot electrons produced by an ultra-high-intensity laser  

SciTech Connect

The anisotropy of the hot-electron velocity distribution in ultra-high-intensity laser produced plasma was studied with x-ray polarization spectroscopy using multilayer planar targets including x-ray emission tracer in the middle layer. This measurement serves as a diagnostic for hot-electron transport from the laser-plasma interaction region to the overdense region where drastic changes in the isotropy of the electron velocity distribution are observed. These polarization degrees are consistent with analysis of a three-dimensional polarization spectroscopy model coupled with particle-in-cell simulations. Electron velocity distribution in the underdense region is affected by the electric field of the laser and that in the overdense region becomes wider with increase in the tracer depth. A full-angular spread in the overdense region of 22.4 deg.{sub -2.4}{sup +5.4} was obtained from the measured polarization degree.

Inubushi, Y. [Institute of Laser Engineering, Osaka University, Suita, Osaka (Japan); Graduate School of Engineering, Osaka University, Suita, Osaka (Japan); Okano, Y.; Nishimura, H.; Cai, H.; Nagatomo, H.; Kai, T.; Fujioka, S.; Nakamura, T.; Johzaki, T.; Mima, K. [Institute of Laser Engineering, Osaka University, Suita, Osaka (Japan); Kawamura, T. [Tokyo Institute of Technology, Yokohama, Kanagawa (Japan); Batani, D.; Morace, A.; Redaelli, R. [Dipartmento di Fisica 'G. Occhialini', University of Milano-Bicocca, Milan (Italy); Fourment, C.; Santos, J. J.; Malka, G. [CELIA, Universite de Bordeaux/CNRS/CEA, Talence (France); Boscheron, A.; Bonville, O.; Grenier, J. [CEA/CESTA, Le Barp (France)

2010-03-15T23:59:59.000Z

95

Imaging Molecular Gas in the Luminous Merger NGC 3256 : Detection of High-Velocity Gas and Twin Gas Peaks in the Double Nucleus  

E-Print Network (OSTI)

Molecular gas in the merging starburst galaxy NGC 3256 has been imaged with the Submillimeter Array at a resolution of 1'' x 2'' (170 x 340 pc at 35 Mpc). This is the first interferometric imaging of molecular gas in the most luminous galaxy within z=0.01. There is a large disk of molecular gas (r > 3 kpc) in the center of the merger with a strong gas concentration toward the double nucleus. The gas disk having a mass of ~3*10^9 Msun in the central 3 kpc rotates around a point between the two nuclei that are 850 pc apart on the sky. The molecular gas is warm and turbulent and shows spatial variation of the intensity ratio between CO isotopomers. High-velocity molecular gas is discovered at the galactic center. Its velocity in our line of sight is up to 420 km/s offset from the systemic velocity of the galaxy; the terminal velocity is twice as large as that due to the rotation of the main gas disk. The high-velocity gas is most likely due to a molecular outflow from the gas disk, entrained by the starburst-driven superwind in the galaxy. The molecular outflow is estimated to have a rate of ~10 Msun/yr and to play a significant role in the dispersal or depletion of molecular gas from the galactic center. A compact gas concentration and steep velocity gradient are also found around each of the twin nuclei. They are suggestive of a small gas disk rotating around each nucleus. If these are indeed mini-disks, their dynamical masses are ~10^9 Msun within a radius of 170 pc.

Kazushi Sakamoto; Paul T. P. Ho; Alison B. Peck

2006-03-03T23:59:59.000Z

96

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 evaporator airflow, and return air leakage from hot attic spaces. There were five sets of tests used for this research: two of them for the charging tests, two for the reduced evaporator airflow, and one for the return air leakage tests. For the charging tests, the indoor room conditions were 80'F (27.8'C) dry-bulb and 50% relative humidity. The outdoor conditions ranged from 95'F (350C) all the way up to 120'F (48.9'C). Charge levels ranged from 30% undercharged to 40% overcharged for the short-tube orifice unit. For the thermal expansion valve (TXV) unit, charge levels ranged from-36% charging to +27% charging. Performance was quantified with the following variables: total capacity, energy efficiency ratio (EER), and power. The performance of the orifice unit was more sensitive to charge than it was for the TXV unit. For the TXV unit on the -27% to +27% charging range, the capacity and EER changed little with charge. A TXV unit and a short-tube orifice unit were also tested for reduced evaporator airflow. As evaporator airflow decreased, the capacity and EER both decreased as expected. However, the drop was not as significant as with the charging tests. For the extreme case of 50% reduced evaporator airflow, neither unit's capacity or EER dropped more than 25%. Return air leakage from hot attic spaces was simulated by assuming adiabatic mixing of the indoor air at normal conditions with the attic air at high temperatures. Effective capacity and EER both decreased with increased return air leakage. However, power consumption was relatively constant for all variables except outdoor temperature, which meant that for the same power consumption, the unit delivered much lower performance when there was return air leakage. The increase in sensible heat ratio (SHR) with increasing leakage showed perhaps the most detrimental effect of return air leakage on performance, which was the inability of the unit to absorb moisture from the environment.

Rodriguez, Angel Gerardo

1995-01-01T23:59:59.000Z

97

Effect of Refrigerant Charge, Duct Leakage, and Evaporator Air Flow on the High Temperature 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 evaporator airflow, and return air leakage from hot attic spaces. There were five sets of tests used for this research: two of them for the charging tests, two for the reduced evaporator airflow, and one for the return air leakage tests. For the charging tests, the indoor room conditions were 80°F (27.8°C) dry-bulb and 50% relative humidity. The outdoor conditions ranged from 95°F (35°C) all the way up to 120°F (48.9°C). Charge levels ranged from 30% undercharged to 40% overcharged for the short-tube orifice unit. For the thermal expansion valve (TXV) unit, charge levels ranged from -36% charging to +27% charging. Performance was quantified with the following variables: total capacity, energy efficiency ratio (EER), and power. The performance of the orifice unit was more sensitive to charge than it was for the TXV unit. For the TXV unit on the -27% to +27% charging range, the capacity and EER changed little with charge. A TXV unit and a short-tube orifice unit were also tested for reduced evaporator airflow. As evaporator airflow decreased, the capacity and EER both decreased as expected. However, the drop was not as significant as with the charging tests. For the extreme case of 50% reduced evaporator airflow, neither unit's capacity or EER dropped more than 25%. Return air leakage from hot attic spaces was simulated by assuming adiabatic mixing of the indoor air at normal conditions with the attic air at high temperatures. Effective capacity and EER both decreased with increased return air leakage. However, power consumption was relatively constant for all variables except outdoor temperature, which meant that for the same power consumption, the unit delivered much lower performance when there was return air leakage. The increase in sensible heat ratio (SHR) with increasing leakage showed perhaps the most detrimental effect of return air leakage on performance, which was the inability of the unit to absorb moisture from the environment.

Rodriguez, Angel Gerardo

2007-11-29T23:59:59.000Z

98

AEDG Implementation Recommendations: Ducts | Building Energy...  

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

Ducts The Advanced Energy Design Guide (AEDG) for Small Office Buildings, 30% series, seeks to achieve 30% savings over ASHRAE Standard 90.1-1999. This guide focuses on...

99

Aerogel Impregnated Polyurethane Piping and Duct Insulation  

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

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...

100

INTERIOR DUCT SYSTEM DESIGN, CONSTRUCTION, AND PERFORMANCE  

DOE Green Energy (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

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

Aerogel Impregnated Polyurethane Piping and Duct Insulation  

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

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.

102

Detection of high-velocity material from the wind-wind collision zone of Eta Carinae across the 2009.0 periastron passage  

E-Print Network (OSTI)

We report near-IR spectroscopic observations of the Eta Carinae massive binary system during 2008-2009 using VLT/CRIRES. We detect a strong, broad absorption wing in He I 10833 extending up to -1900 km/s across the 2009.0 spectroscopic event. Archival HST/STIS ultraviolet and optical data shows a similar high-velocity absorption (up to -2100 km/s) in the UV resonance lines of Si IV 1394, 1403 across the 2003.5 event. UV lines from low-ionization species, such as Si II 1527, 1533 and C II 1334, 1335, show absorption up to -1200 km/s, indicating that the absorption with v from -1200 to -2100 km/s originates in a region markedly faster and more ionized than the nominal wind of the primary star. Observations obtained at the OPD/LNA during the last 4 spectroscopic cycles (1989-2009) also display high-velocity absorption in He I 10833 during periastron. Based on the OPD/LNA dataset, we determine that material with v 1.049. Therefore, we constrain the duration of the high-velocity absorption to be 95 to 206 days (o...

Groh, Jose H; Damineli, Augusto; Gull, Theodore R; Madura, Thomas I; Hillier, D J; Teodoro, Mairan; Driebe, Thomas; Weigelt, Gerd; Hartman, Henrik; Kerber, Florian; Okazaki, Atsuo T; Owocki, Stan P; Millour, Florentin; Murakawa, Koji; Kraus, Stefan; Hofmann, Karl-Heinz; Schertl, Dieter

2010-01-01T23:59:59.000Z

103

Experimental research of temperature and velocity fields in high-temperature flow of liquid heavy metal coolant  

Science Conference Proceedings (OSTI)

Presented are the results of experimental research of temperature and velocity fields for lead and lead-bismuth coolant flows in channels having circular and annular cross sections under varying oxygen content in the coolant and varying characteristics of insulating coatings. Tests are performed under the following operating conditions: (1) lead-bismuth eutectic-temperature T = 400-520 Degree-Sign C, thermodynamic oxygen activity a = 10{sup -5}-10{sup 0}, average flow velocity of the coolant w = 0.12-1.84 m/s, value of magnetic induction B = 0-0.85 T, Reynolds number Re = (0.24-3.5) Multiplication-Sign 10{sup 5}, Hartmann number Ha = 0-500, and Peclet number Pe = 320-4600; (2) lead coolant-T = 400-550 Degree-Sign C, a = 10{sup -5}-10{sup 0}, w = 0.1-1.5 m/s, Re = (2.36-2.99) Multiplication-Sign 10{sup 5}, and Pe = 500-7000.

Besnosov, A. V., E-mail: ats@nntu.nnov.ru; Savinov, S. Yu., E-mail: Savinov.S@mail.ru; Novozhilova, O. O.; Antonenkov, M. A. [Nizhni Novgorod State Technical University (Russian Federation)

2011-12-15T23:59:59.000Z

104

STELLAR VELOCITY DISPERSION MEASUREMENTS IN HIGH-LUMINOSITY QUASAR HOSTS AND IMPLICATIONS FOR THE AGN BLACK HOLE MASS SCALE  

SciTech Connect

We present new stellar velocity dispersion measurements for four luminous quasars with the Near-Infrared Integral Field Spectrometer instrument and the ALTAIR laser guide star adaptive optics system on the Gemini North 8 m telescope. Stellar velocity dispersion measurements and measurements of the supermassive black hole (BH) masses in luminous quasars are necessary to investigate the coevolution of BHs and galaxies, trace the details of accretion, and probe the nature of feedback. We find that higher-luminosity quasars with higher-mass BHs are not offset with respect to the M{sub BH}-{sigma}{sub *} relation exhibited by lower-luminosity active galactic nuclei (AGNs) with lower-mass BHs, nor do we see correlations with galaxy morphology. As part of this analysis, we have recalculated the virial products for the entire sample of reverberation-mapped AGNs and used these data to redetermine the mean virial factor (f) that places the reverberation data on the quiescent M{sub BH}-{sigma}{sub *} relation. With our updated measurements and new additions to the AGN sample, we obtain (f) = 4.31 {+-} 1.05, which is slightly lower than, but consistent with, most previous determinations.

Grier, C. J.; Martini, P.; Peterson, B. M.; Pogge, R. W.; Zu, Y. [Department of Astronomy, Ohio State University, 140 W 18th Avenue, Columbus, OH 43210 (United States); Watson, L. C. [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Bentz, M. C. [Department of Physics and Astronomy, Georgia State University, Atlanta, GA 30303 (United States); Dasyra, K. M. [Observatoire de Paris, LERMA (CNRS:UMR8112), 61 Avenue de l'Observatoire, F-75014, Paris (France); Dietrich, M. [Department of Physics and Astronomy, Ohio University, Athens, OH 45601 (United States); Ferrarese, L. [Herzberg Institute of Astrophysics, National Research Council of Canada, 5071 West Saanich Road, Victoria BV V9E 2E7 (Canada)

2013-08-20T23:59:59.000Z

105

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

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 1MHz 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 nuclear-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

2008-02-27T23:59:59.000Z

106

Aerodynamic Experiments on a Ducted Fan in Hover and Edgewise Flight.  

E-Print Network (OSTI)

??Ducted fans and ducted rotors have been integrated into a wide range of aerospace vehicles, including manned and unmanned systems. Ducted fans offer many potential… (more)

Myers, Leighton

2009-01-01T23:59:59.000Z

107

The CRIRES Search for Planets Around the Lowest-Mass Stars. I. High-Precision Near-Infrared Radial Velocities with an Ammonia Gas Cell  

E-Print Network (OSTI)

Radial velocities measured from near-infrared spectra are a potentially powerful tool to search for planets around cool stars and sub-stellar objects. However, no technique currently exists that yields near-infrared radial velocity precision comparable to that which is routinely obtained in the visible. We describe a method for measuring high-precision relative radial velocities of cool stars from K-band spectra. The method makes use of a glass cell filled with ammonia gas to calibrate the spectrograph response similar to the iodine cell technique that has been used so successfully in the visible. Stellar spectra are obtained through the ammonia cell and modeled as the product of a Doppler-shifted template spectrum of the object and a spectrum of the cell, convolved with a variable instrumental profile model. A complicating factor is that a significant number of telluric absorption lines are present in the spectral regions containing useful stellar and ammonia lines. The telluric lines are modeled simultaneou...

Bean, Jacob L; Hartman, Henrik; Nilsson, Hampus; Wiedemann, Guenter; Reiners, Ansgar; Dreizler, Stefan; Henry, Todd J

2009-01-01T23:59:59.000Z

108

Measuring OutdoorAir Intake Rates Using Electronic Velocity Sensors at Louvers and Downstream of Airflow Straighteners  

SciTech Connect

Practical and accurate technologies are needed for continuously measuring and controlling outdoor air (OA) intake rates in commercial building heating, ventilating, and air conditioning (HVAC) systems. This project evaluated two new measurement approaches. Laboratory experiments determined that OA flow rates were measurable with errors generally less than 10percent using electronic air velocity probes installed between OA intake louver blades or at the outlet face of louvers. High accuracy was maintained with OA flow rates as low as 15percent of the maximum for the louvers. Thus, with this measurement approach HVAC systems do not need separate OA intakes for minimum OA supply. System calibration parameters are required for each unique combination of louver type and velocity sensor location but calibrations are not necessary for each system installation. The research also determined that the accuracy of measuring OA flow rates with velocity probes located in the duct downstream of the intake louver was not improved by installing honeycomb airflow straighteners upstream of the probes. Errors varied with type of upstream louver, were as high as 100percent, and were often greater than 25percent. In conclusion, use of electronic air velocity probes between the blades of OA intake louvers or at the outlet face of louvers is a highly promising means of accurately measuring rates of OA flow into HVAC systems. The use of electronic velocity probes downstream of airflow straighteners is less promising, at least with the relatively small OA HVAC inlet systems employed in this research.

Fisk, William; Sullivan, Douglas; Cohen, Sebastian; Han, Hwataik

2008-10-01T23:59:59.000Z

109

IMPROVEMENTS IN OR RELATING TO VALVED DUCTING  

SciTech Connect

A coaxial valved ducting is designed for fluid flow to and from a heat exchanger. The ducting comprises an inner pipe for flow of hot fluid, an outer pipe providing an annular passage for the countercurrent flow of cool fluid, a butterfly valve in the inner pipe, peripherally spaced longitudinal ribs joining the two pipes in the region of the valve, an extension of the outer pipe, and a butterfly or poppet valve associated with the extension. the inner pipe communicates with the heat exchanger by means of an extension through the outer pipe wall. (D.L.C.)

Blackburn, G.; Long, E.

1962-05-30T23:59:59.000Z

110

Velocity and Temperature Structure Functions in the Upper Troposphere and Lower Stratosphere from High-Resolution Aircraft Measurements  

Science Conference Proceedings (OSTI)

High-resolution measurements obtained from NOAA “best” atmospheric turbulence (BAT) probes mounted on an EGRETT high-altitude research aircraft were used to characterize turbulence in the upper troposphere and lower stratosphere at scales from 2 ...

Donald E. Wroblewski; Owen R. Coté; Jorg M. Hacker; Ronald J. Dobosy

2010-04-01T23:59:59.000Z

111

Minimizing Energy Losses in Ducts | Department of Energy  

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

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.

112

On the Evaporation Duct for Inhomogeneous Conditions in Coastal Regions  

Science Conference Proceedings (OSTI)

Evaporation ducts are ubiquitous phenomena over the oceans, and they are responsible for much of the over-the-horizon propagation occurring with millimeter and microwave radars. The height of the evaporation duct depends on meteorological ...

G. L. Geernaert

2007-04-01T23:59:59.000Z

113

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

114

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.

115

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

116

Reducing Uncertainty for the DeltaQ Duct Leakage Test  

SciTech Connect

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

117

Research Results from A Few Alternate Methods of Interior Duct Systems in Factory Built Housing Located In the Hot Humid Climate  

E-Print Network (OSTI)

The U.S. Department of Energy’s (DOE) Building America1 Industrialized Housing Partnership (BAIHP) has collaborated with two of its industry partners to work on a portion of the project that relates to the construction and evaluation of prototype interior duct systems. In 2006, work began on a duct system design that would locate the entire length of duct work within the air and thermal barriers of the envelope. One of these designs incorporated a high-side supply register that connects to the conventional floor duct. The other design utilized a single soffit located within the conditioned space at the marriage line. The Florida Solar Energy Center’s (FSEC) Manufactured Housing Lab (MHLab) was retrofitted with an interior soffit duct. The duct system was added on so that either the attic duct system or the new interior duct system would be able to supply air to the conditioned space using the same mechanical equipment. The initial results of this work show approximately a 10% to 20% heating/cooling savings when compared to conventional attic duct work construction techniques and nearly 7% savings when compared to a conventional in-floor system.

Moyer, N.; Stroer, D.; Hoak, D.; McIlvaine, J.; Chandra, S.

2008-12-01T23:59:59.000Z

118

NEW GUN CAPABILITY WITH INTERCHANGABLE BARRELS TO INVESTIGATE LOW VELOCITY IMPACT REGIMES AT THE LAWRENCE LIVERMORE NATIONAL LABORATORY HIGH EXPLOSIVES APPLICATIONS FACILITY  

SciTech Connect

A new gas gun capability is being activated at Lawrence Livermore National Laboratories located in the High Explosives Applications Facility (HEAF). The single stage light gas (dry air, nitrogen, or helium) gun has interchangeable barrels ranging from 25.4 mm to 76.2 mm in diameter with 1.8 meters in length and is being fabricated by Physics Applications, Inc. Because it is being used for safety studies involving explosives, the gun is planned for operation inside a large enclosed firing tank, with typical velocities planned in the range of 10-300 m/s. Three applications planned for this gun include: low velocity impact of detonator or detonator/booster assemblies with various projectile shapes, the Steven Impact test that involves impact initiation of a cased explosive target, and the Taylor impact test using a cylindrical explosive sample impacted onto a rigid anvil for fracture studies of energetic materials. A highlight of the gun features, outline on work in progress for implementing this capability, and discussion of the planned areas of research will be included.

Vandersall, K S; Behn, A; Gresshoff, M; Jr., L F; Chiao, P I

2009-09-16T23:59:59.000Z

119

A New Diagnostic for Duct Leakage: DeltaQ  

NLE Websites -- All DOE Office Websites (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

120

Dimensional changes in FFTF (Fast Flux Test Facility) austenitic cladding and ducts  

SciTech Connect

As the standard cladding and duct material for the Fast Flux Test Facility driver fuel, 20% cold-worked 316 stainless steel has provided good service up to a fast fluence of 16 {times} 10{sup 22} n/cm{sup 2} in extreme cases. The titanium-stabilized variant of 316 SS, called D9, has extended the useful life of the austenitic alloys by increasing the incubation fluence necessary for the onset of volumetric swelling. Duct flat-to-flat, length and bow, pin bundle distortion, fuel pin diameter and length, as well as cladding volumetric swelling have been examined for high fluence components representing both alloys. These data emphasize the importance of the swelling process, the superiority of D9, and the interrelation between deformations in the duct, bundle, and individual pins. 8 refs., 10 figs.

Makenas, B.J.; Chastain, S.A.; Gneiting, B.C.

1990-11-01T23:59:59.000Z

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

BONA FIDE, STRONG-VARIABLE GALACTIC LUMINOUS BLUE VARIABLE STARS ARE FAST ROTATORS: DETECTION OF A HIGH ROTATIONAL VELOCITY IN HR CARINAE  

Science Conference Proceedings (OSTI)

We report optical observations of the luminous blue variable (LBV) HR Carinae which show that the star has reached a visual minimum phase in 2009. More importantly, we detected absorptions due to Si IV lambdalambda4088-4116. To match their observed line profiles from 2009 May, a high rotational velocity of v{sub rot} approx = 150 +- 20 km s{sup -1} is needed (assuming an inclination angle of 30 deg.), implying that HR Car rotates at approx =0.88 +- 0.2 of its critical velocity for breakup (v{sub crit}). Our results suggest that fast rotation is typical in all strong-variable, bona fide galactic LBVs, which present S-Dor-type variability. Strong-variable LBVs are located in a well-defined region of the HR diagram during visual minimum (the 'LBV minimum instability strip'). We suggest this region corresponds to where v{sub crit} is reached. To the left of this strip, a forbidden zone with v{sub rot}/v{sub crit}>1 is present, explaining why no LBVs are detected in this zone. Since dormant/ex LBVs like P Cygni and HD 168625 have low v{sub rot}, we propose that LBVs can be separated into two groups: fast-rotating, strong-variable stars showing S-Dor cycles (such as AG Car and HR Car) and slow-rotating stars with much less variability (such as P Cygni and HD 168625). We speculate that supernova (SN) progenitors which had S-Dor cycles before exploding (such as in SN 2001ig, SN 2003bg, and SN 2005gj) could have been fast rotators. We suggest that the potential difficulty of fast-rotating Galactic LBVs to lose angular momentum is additional evidence that such stars could explode during the LBV phase.

Groh, J. H. [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Damineli, A.; Moises, A. P.; Teodoro, M. [Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, Universidade de Sao Paulo, Rua do Matao 1226, Cidade Universitaria, 05508-090, Sao Paulo, SP (Brazil); Hillier, D. J. [Department of Physics and Astronomy, University of Pittsburgh, 3941 O'Hara Street, Pittsburgh, PA 15260 (United States); Barba, R. [Departamento de fisica, Universidad de La Serena, Benavente 980, La Serena (Chile); Fernandez-Lajus, E.; Gamen, R. C.; Solivella, G., E-mail: jgroh@mpifr-bonn.mpg.d [Facultad de Ciencias Astronomicas y Geofisicas, Universidad Nacional de La Plata, and Instituto de Astrofisica de La Plata (CCT La Plata-CONICET), Paseo del Bosque S/N, B1900FWA, La Plata (Argentina)

2009-11-01T23:59:59.000Z

122

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles  

NLE Websites -- All DOE Office Websites (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

123

Effect of radiant barriers and attic ventilation on residential attics and attic duct systems: New tools for measuring and modeling  

Science Conference Proceedings (OSTI)

A simple duct system was installed in an attic test module for a large scale climate simulator at a US national laboratory. The goal of the tests and subsequent modeling was to develop an accurate method of assessing duct system performance in the laboratory, enabling limiting conditions to be imposed at will and results to be applied to residential attics with attic duct systems. Steady-state tests were done at a severe summer and a mild winter condition. In all tests the roof surface was heated above ambient air temperatures by infrared lights. The attic test module first included then did not include the duct system. Attic ventilation from eave vents to a ridge vent was varied from none to values achievable by a high level of power ventilation. A radiant barrier was attached to the underside of the roof deck, both with and without the duct system in place. Tests were also done without the radiant barrier, both with and without the duct system. When installed, the insulated ducts ran along the floor of the attic, just above the attic insulation and along the edge of the attic near the eaves and one gable. These tests in a climate simulator achieved careful control and reproducibility of conditions. This elucidated dependencies that would otherwise be hidden by variations in uncontrolled variables. Based on the comparisons with the results of the tests at the mild winter condition and the severe summer condition, model predictions for attic air and insulation temperatures should be accurate within {+-} 10 F ({+-} 6 C). This is judged adequate for design purposes and could be better when exploring the effect of changes in attic and duct parameters at fixed climatic conditions.

Petrie, T.W.; Childs, P.W.; Christian, J.E.; Wilkes, K.E.

1998-07-01T23:59:59.000Z

124

Thermal performance of residential duct systems in basements  

Science Conference Proceedings (OSTI)

There are many unanswered questions about the typical effects of duct system operation on the infiltration rates and energy usage of single- family residences with HVAC systems in their basements. In this paper, results from preliminary field studies and computer simulations are used to examine the potential for improvements in efficiency of air distribution systems in such houses. The field studies comprise thermal and flow measurements on four houses in Maryland. The houses were found to have significant envelope leakage, duct leakage, and duct conduction losses. Simulations of a basement house, the characteristics of which were chosen from the measured houses, were performed to assess the energy savings potential for basement house. The simulations estimate that a nine percent reduction in space conditioning energy use is obtained by sealing eighty percent of the duct leaks and insulating ducts to an R-value of 0.88 {degree}C{center_dot}m{sup 2}/W (5{degree}F{center_dot}ft{sup 2}{center_dot}h/BTU) where they are exposed in the basement. To determine the maximum possible reduction m energy use, simulations were run with all ducts insulated to 17.6 {degree}C{center_dot}m{sup 2}/W (100 {degree}F{center_dot}ft{sup 2}{center_dot}h/BTU) and with no duct leakage. A reduction of energy use by 14% is obtained by using perfect ducts instead of nominal ducts.

Treidler, B.; Modera, M.

1994-02-01T23:59:59.000Z

125

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

SciTech Connect

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

126

Aerosol Duct Sealing : Technologies : From the Lab to the Marketplace...  

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

the California building code changes and increasing availability of the aerosol sealing technology, more homeowners and facilities managers will seal their duct systems and save...

127

Building Energy Software Tools Directory: Varitrane Duct Designer  

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

Testing NA Expertise Required Basic knowledge of duct systems, methodologies, and terms. Users Approximately 1000 users worldwide. Audience Mechanical engineers and system...

128

Building Energy Software Tools Directory: Varitrane Duct Designer  

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

this task and improves calculation precision, allowing you to optimize your designs from fan to diffuser and be more productive The program consists of three applications: Duct...

129

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 for dual-fan, dual-duct air-handling units. The economizer has significant heating energy penalties for single-fan, dual-duct air-handling units. The penalties are higher than the cooling energy savings when the cold airflow is less than the hot airflow. Detailed engineering analyses are required to evaluate the feasibility of the economizer for single-fan, dual-duct systems.

Joo, I.; Liu, M.

2002-01-01T23:59:59.000Z

130

Duct injection technology prototype development: Evaluation of engineering data  

SciTech Connect

The objective of the Duct Injection Technology Prototype Development Project is to develop a sound design basis for applying duct injection technology as a post-combustion SO{sub 2}emissions control method to existing coal-fired power plants. The necessary engineering design and scale-up criteria will be developed for the commercialization of duct injection technology for the control of SO{sub 2} emissions from coal-fired boilers in the utility industry. The primary focus of the analyses summarized in this Topical Report is the review of the known technical and economic information associated with duct injection technology. (VC)

Not Available

1990-07-01T23:59:59.000Z

131

Leaf seal for transition duct in turbine system  

DOE Patents (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 leaf 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

2013-06-11T23:59:59.000Z

132

Duct Systems in Large Commercial Buildings: Physical  

NLE Websites -- All DOE Office Websites (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

133

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)

A Generic Tee Plenum System (GTPS) based on three different duct systems (Configuration-I, II and III) used in nuclear facilities has been developed which creates suitable conditions for single point representative sampling. This single point sampling is an acceptable standard methodology for sampling emissions from stacks and ducts of the nuclear industry (ANSI/HPS N13.1-1999 and US EPA 2000). These air duct systems in nuclear facilities must meet the requirements of ANSI/HPS N13.1-1999 that the exhaust airflow be monitored with continuous sampling in case of an accidental release of airborne radionuclides. Results show that the GTPS system performance is well within the requirements of ANSI/HPS N13.1-1999 - the COVs for velocity, tracer gas concentration and 10 [u]m AD aerosol particle are less than the mixing criteria 20% of ANSI/HPS N13.1-1999. The objective of this work is to provide data on the mixing effectiveness of various duct configurations found in nuclear facilities. These data can be applied in new facilities as well as in upgrades to existing U.S. DOE nuclear facilities. The data should also provide a basis for testing the efficacy of mixing models that may be generated in the future. Experiments were conducted to characterize the degree of mixing at downstream locations as affected by several types of flow disturbances, including a plenum consisting with duct intakes, a rectangular elbow with turning vanes, 90? elbows, tees, commercial static mixing device and GTPS in circular and non-circular ducts. The mixing performance of a plenum duct configuration (Configuration-I) with two-intake sources was studied to develop recommendations for suitable sampling locations less than 4 duct diameters downstream of a plenum. Several mixing element options were considered both upstream and downstream of a security grille. A stack model system with straight circular ducts downstream of rectangular elbow with turning vanes (Configuration-II) were characterized for velocity, tracer gas and particle concentration profiles COVs. The application of a mixing system was designed for achieving maximum conditions in round-elbow and tee element system interfaced to a stack (Configuration-III). Several options were 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 and numerical results.

Han, Tae Won

2003-01-01T23:59:59.000Z

134

Unitaxial constant velocity microactuator  

SciTech Connect

A uniaxial drive system or microactuator capable of operating in an ultra-high vacuum environment. 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-manometer 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.

McIntyre, Timothy J. (Knoxville, TN)

1994-01-01T23:59:59.000Z

135

Compression effects on pressure loss in flexible HVAC ducts  

SciTech Connect

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

136

Comparison Between Predicted Duct Effectiveness from Proposed ASHRAE  

E-Print Network (OSTI)

LBNL-50008 Comparison Between Predicted Duct Effectiveness from Proposed ASHRAE Standard 152P of California. #12;1 LBNL-50008 Comparison Between Predicted Duct Effectiveness from Proposed ASHRAE Standard. McWilliams Iain S. Walker, Ph.D. ASHRAE Student Member ASHRAE Member ABSTRACT The proposed ASHRAE

137

Guidelines for the Fluid Dynamic Design of Power Plant Ducts  

Science Conference Proceedings (OSTI)

The design of air and flue gas duct systems for electric power plants is an important but often neglected part of the complete design. By following the procedures outline in this report the duct engineer can develop a cost-effective design that minimizes pressure drop losses and the related operating costs.

1998-04-27T23:59:59.000Z

138

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

139

Fiber Optic Velocity Interferometry  

SciTech Connect

This paper explores the use of a new velocity measurement technique that has several advantages over existing techniques. It uses an optical fiber to carry coherent light to and from a moving target. A Fabry-Perot interferometer, formed by a gradient index lens and the moving target, produces fringes with a frequency proportional to the target velocity. This technique can measure velocities up to 10 km/s, is accurate, portable, and completely noninvasive.

Neyer, Barry T.

1988-04-01T23:59:59.000Z

140

Development of a new duct leakage test: DeltaQ  

SciTech Connect

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

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

Energy impacts of attic duct retrofits in Sacramento houses  

Science Conference Proceedings (OSTI)

Inefficiencies in air distribution systems have been identified as a major source of energy loss in US sunbelt homes. Research indicates that approximately 30--40% of the thermal energy delivered to the ducts passing through unconditioned spaces is lost through air leakage and conduction through the duct walls. Field experiments over the past several years have well documented the expected levels of air leakage and the extent to which that leakage can be reduced by retrofit. Energy savings have been documented to a more limited extent, based upon a few field studies and simulation model results. Simulations have also indicated energy loss through ducts during the off cycle caused by thermosiphon-induced flows, however this effect had not been confirmed experimentally. A field study has been initiated to separately measure the impacts of combined duct leak sealing and insulation retrofits, and to optimize a retrofit protocol for utility DSM programs. This paper describes preliminary results from 6 winter and 5 summer season houses. These retrofits cut overall duct leakage area approximately 64%, which translated to a reduction in envelope ELA of approximately 14%. Wrapping ducts and plenums with R-6 insulation translated to a reduction in average flow-weighted conduction losses of 33%. These experiments also confirmed the appropriateness of using duct ELA and operating pressures to estimate leakage flows for the population, but indicated significant variations between these estimates and measured flows on a house by house basis. In addition, these experiments provided a confirmation of the predicted thermosiphon flows, both under winter and summer conditions. Finally, average material costs were approximately 20% of the total retrofit costs, and estimates of labor required for retrofits based upon these experiments were: 0.04 person-hrs/cm{sup 2} of duct sealed and 0.21 person-hrs/m{sup 2} of duct insulated.

Jump, D.; Modera, M. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.

1994-08-01T23:59:59.000Z

142

Duct Leakage Impacts on VAV System Performance in Large Commercial  

NLE Websites -- All DOE Office Websites (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.

143

Development of a New Duct leakage Test: Delta Q  

NLE Websites -- All DOE Office Websites (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

144

Analysis of Aerosol-Based Duct Improvement Business in PEPCO's Service Territory  

Science Conference Proceedings (OSTI)

Studies in the last ten years have indicated potentially large energy savings with residential duct sealing. However, market penetration of duct sealing services has been very limited. This project analyzed the viability of selling duct sealing as part of a duct improvement service in PEPCO's Washington, D.C., service territory.

2000-03-14T23:59:59.000Z

145

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

146

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

147

Vertical Velocity Focus Group  

NLE Websites -- All DOE Office Websites (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

148

ARM - Measurement - Vertical velocity  

NLE Websites -- All DOE Office Websites (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

149

Cirrus Crystal Terminal Velocities  

Science Conference Proceedings (OSTI)

Cirrus crystal terminal velocities are of primary importance in determining the rate of transport of condensate from upper- to middle-tropospheric levels and profoundly influence the earth’s radiation balance through their effect on the rate of ...

Andrew J. Heymsfield; Jean Iaquinta

2000-04-01T23:59:59.000Z

150

New and Underutilized Technology: Duct Sealants | Department of Energy  

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

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

151

Investigation of Surface Duct Conditions over Istanbul, Turkey  

Science Conference Proceedings (OSTI)

A comprehensive examination of 2 yr of radiosonde data to determine the surface duct conditions over Istanbul (4°N, 29°E), Turkey, was made. The refractivity of the atmosphere is a function of air temperature and water vapor pressure. Any ...

?Sibel Mentes; Zerefsan Kaymaz

2007-03-01T23:59:59.000Z

152

Mesoscale Modeling of Boundary Layer Refractivity and Atmospheric Ducting  

Science Conference Proceedings (OSTI)

In this study four mesoscale forecasting systems were used to investigate the four-dimensional structure of atmospheric refractivity and ducting layers that occur within evolving synoptic conditions over the eastern seaboard of the United States. ...

Tracy Haack; Changgui Wang; Sally Garrett; Anna Glazer; Jocelyn Mailhot; Robert Marshall

2010-12-01T23:59:59.000Z

153

Longevity of Duct Tape in Residential Air Distribution Systems...  

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

Longevity of Duct Tape in Residential Air Distribution Systems: 1-D, 2-D, and 3-D Joints Speaker(s): Bass Abushakra Date: July 30, 2002 - 12:00pm Location: Bldg. 90 Seminar Host...

154

BETTER DUCT SYSTEMS FOR HOME HEATING AND COOLING.  

SciTech Connect

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

155

Measure Guideline: Buried and/or Encapsulated Ducts  

SciTech Connect

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

156

Single channel double-duct liquid metal electrical generator using a magnetohydrodynamic device  

SciTech Connect

A single channel double-duct liquid metal electrical generator using a magnetohydrodynamic (MHD) device. The single channel device provides useful output AC electric energy. The generator includes a two-cylinder linear-piston engine which drives liquid metal in a single channel looped around one side of the MHD device to form a double-duct contra-flowing liquid metal MHD generator. A flow conduit network and drive mechanism are provided for moving liquid metal with an oscillating flow through a static magnetic field to produce useful AC electric energy at practical voltages and currents. Variable stroke is obtained by controlling the quantity of liquid metal in the channel. High efficiency is obtained over a wide range of frequency and power output. 5 figs.

Haaland, C.M.; Deeds, W.E.

1999-07-13T23:59:59.000Z

157

Diagnosing Mesoscale Vertical Motion from Horizontal Velocity and Density Data  

Science Conference Proceedings (OSTI)

The mesoscale vertical velocity is obtained by solving a generalized omega equation (? equation) using density and horizontal velocity data from three consecutive quasi-synoptic high-resolution surveys in the Alboran Sea. The Atlantic Jet (AJ) ...

Enric Pallàs Sanz; Álvaro Viúdez

2005-10-01T23:59:59.000Z

158

Scaleup tests and supporting research for the development of duct injection technology  

Science Conference Proceedings (OSTI)

DOE's Duct Injection Test Facility at Ohio Power Company's Muskingum River Plant was modified to enable performance of a comprehensive test program concerning duct injection of sorbents for SO[sub 2] control. Injection of slaked lime slurries and injection of dry calcium hydroxide powder with humidification were carried out under a variety of process conditions. Slaked lime slurry injection as found to be superior in both operational reliability and S0[sub 2] removal capability compared with dry hydrated lime injection with humidification. Calcium utilization of 50% was achieved with 50% S0[sub 2] removal at the ESP outlet with recycle of unreacted sorbent collected in the precipitatorhoppers. Electrostatic precipitator collection performance was found to be highly variable with sorbent injection, especially with close approach to saturation temperatures and high inlet mass loadings. Small-scale tests with a fabric filter in parallel with the precipitator indicated 5 to 10% more S0[sub 2] removal could be obtained across the fabric filter than the ESP for all test conditions. Over 95% S0[sub 2] removal was achieved with the fabric filter using a two stage cooling process in which the filter was cooled below the operating temperature ofthe duct spray dryer.

Felix, L.G.; Gooch, J.P.; Merritt, R.L. (Southern Research Inst., Birmingham, AL (United States)); Klett, M.G.; Demian, A.G.; Hunt, J.E. (Gilbert/Commonwealth, Inc., Reading, PA (United States))

1992-10-30T23:59:59.000Z

159

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant  

NLE Websites -- All DOE Office Websites (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.

160

The velocity campaign for ignition on NIF  

SciTech Connect

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

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

Perspectives on Deposition Velocity  

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

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

162

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

163

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

164

Ducts in the Attic? What Were They Thinking? Preprint  

SciTech Connect

As energy-efficiency efforts focus increasingly on existing homes, we scratch our heads about construction decisions made 30, 40, 50-years ago and ask: 'What were they thinking?' A logical follow-on question is: 'What will folks think in 2050 about the homes we're building today?' This question can lead to a lively discussion, but the current practice that we find most alarming is placing ducts in the attic. In this paper, we explore through literature and analysis the impact duct location has on cooling load, peak demand, and energy cost in hot climates. For a typical new home in these climates, we estimate that locating ducts in attics rather than inside conditioned space increases the cooling load 0.5 to 1 ton, increases cooling costs 15% and increases demand by 0.75 kW. The aggregate demand to service duct loss in homes built in Houston, Las Vegas, and Phoenix during the period 2000 through 2009 is estimated to be 700 MW. We present options for building homes with ducts in conditioned space and demonstrate that these options compare favorably with other common approaches to achieving electricity peak demand and consumption savings in homes.

Roberts, D.; Winkler, J.

2010-08-01T23:59:59.000Z

165

Chromospheric Doppler Velocity Oscillations in a Sunspot  

E-Print Network (OSTI)

We analyse the chromospheric Doppler velocity oscillations in a sunspot using the high resolution spectral observations obtained from the Fast Imaging Solar Spectrograph(FISS) of the New Solar Telescope at the Big Bear Solar Observatory. The Doppler velocity maps are constructed from the bisectors of the spectral observations. The time series analysis of Doppler velocity maps show enhanced power in the sunspot umbra at higher frequencies and in the penumbra at lower frequencies. We find that the peak power frequency decreases gradually from the umbra to outward.

Maurya, R A

2013-01-01T23:59:59.000Z

166

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

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

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.

167

Our Dog Discovered Our Ducts Have Cats | Department of Energy  

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

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

168

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

SciTech Connect

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

169

Advanced Strategy Guideline: Air Distribution Basics and Duct Design  

SciTech Connect

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

170

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

NLE Websites -- All DOE Office Websites (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

171

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

Science Conference Proceedings (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

172

Comparative Testing of the Combined Radiant Barrier and Duct Models in the ESL's Code-Compliant Simulation Model  

E-Print Network (OSTI)

This report presents a study of the application of the radiant barrier / duct models to the DOE-2.1e simulation program based on the previous methods (eQuest version 3.55 and EnergyGauge version 2.42) and the comparison of the results of the ESL’s model and the EnergyGauge program by the Florida Solar Energy Center (FSEC). Sensitivity analyses were performed by varying duct insulation level, supply duct area, return duct area, supply duct leakage, return duct leakage, and ceiling insulation levels. The results of sensitivity analyses show acceptable agreement versus the EnergyGauge program for duct insulation level, supply duct area, return duct area, supply duct leakage, and ceiling insulation level. Significant differences in the return duct leakage calculations were observed. These comparisons show the ESL model is more sensitive to return duct leakage than the EnergyGauge model Comparison of the results of the duct model for two cases (with radiant barrier and without radiant barrier) show acceptable agreements for the parameters of duct insulation, supply duct surface area, return duct surface area, supply duct leakage and ceiling insulation. The results of savings (with and without radiant barriers) indicate that the ESL model shows slightly more savings for all parameters. In terms of the sensitivity of the results, the ESL model also shows more sensitivity for all parameters except supply duct leakage.

Kim, S.; Haberl, J. S.

2007-07-10T23:59:59.000Z

173

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.

174

Cooling air recycling for gas turbine transition duct end frame and related method  

SciTech Connect

A method of cooling a transition duct end frame in a gas turbine includes the steps of a) directing cooling air into the end frame from a region external of the transition duct and the impingement cooling sleeve; and b) redirecting the cooling air from the end frame into the annulus between the transition duct and the impingement cooling sleeve.

Cromer, Robert Harold (Johnstown, NY); Bechtel, William Theodore (Scotia, NY); Sutcu, Maz (Niskayuna, NY)

2002-01-01T23:59:59.000Z

175

Annular linear induction pump with an externally supported duct  

DOE Patents (OSTI)

Several embodiments of an annular linear induction pump for pumping liquid metals are disclosed having the features of generally one pass flow of the liquid metal through the pump and an increased efficiency resulting from the use of thin duct walls to enclose the stator. The stator components of this pump are removable for repair and replacement.

Craig, Edwin R. (San Jose, CA); Semken, Robert S. (Idaho Falls, ID)

1979-01-01T23:59:59.000Z

176

Development of an ASHRAE 152-2004 Duct Model for the Single-Family Residential House  

E-Print Network (OSTI)

This paper presents the results of the development of the duct model based on ASHRAE standard 152-2004 (ASHRAE, 2004) using the DOE-2.1e building energy simulation program. To accomplish this, FUNCTION commands for DOE-2 were used to develop the duct model and provide the improved predictions of the duct heat loss or gain from the unconditioned space as well as supply or return duct leakage. After applying the duct model to the DOE-2 base-case simulation model, simulation results were compared with the measurement from the case-study house for verification.

Kim, S.; Haberl, J.

2008-12-01T23:59:59.000Z

177

Application of railgun principle to high-velocity hydrogen pellet injection for magnetic fusion reactor fueling. Progress report, August 16, 1991--September 30, 1992  

DOE Green Energy (OSTI)

Three separate papers are included which report research progress during this period: (1) A new railgun configuration with perforated sidewalls, (2) development of a fuseless small-bore railgun for injection of high-speed hydrogen pellets into magnetically confined plasmas, and (3) controls and diagnostics on a fuseless railgun for solid hydrogen pellet injection.

Kim, K.; Zhang, J.

1992-12-01T23:59:59.000Z

178

Impact of Hight Velocity Cold Spray Particles  

SciTech Connect

This paper presents experimental data and an computational model of the cold spray solid particle impact process. Copper particles impacting onto a polished stainless steel substrate are examined. The high velocity impact causes significant plastic deformation of both the particle and the sub- strate, but no melting is observed. The plastic deformation exposes clean surfaces that, under the high impact pressures, result in significant bond strengths between the particle and substrate. Experimental measurements of the splat and crater sizes compare well with the numerical calculations. It is shown that the crater depth is significant and increases with impact velocity. However, the splat diameter is much less sensitive to the impact velocity. It is also shown that the geometric lengths of the splat and crater scale linearly with the diameter of the impacting particle. It is hoped that the results presented will allow better understanding of the bonding process during cold spray.

Dykhuizen, R.C.; Gilmore, D.L.; Jiang, X.; Neiser, R.A.; Sampath, S.; Smith, M.F.

1998-12-01T23:59:59.000Z

179

VELOCITY INDICATOR FOR EXTRUSION PRESS  

DOE Patents (OSTI)

An indicator is presented for measuring the lowspeed velocity of an object in one direction where the object returns in the opposite direction at a high speed. The indicator comprises a drum having its axis of rotation transverse to the linear movement of the object and a tape wound upon the drum with its free end extending therefrom and adapted to be connected to the object. A constant torque is applied to the drum in a direction to wind the tape on the drum. The speed of the tape in the unwinding direction is indicated on a tachometer which is coupled through a shaft and clutch means to the drum only when the tape is unwinding.

Digney, F.J. Jr.; Bevilacqua, F.

1959-04-01T23:59:59.000Z

180

A steady state thermal duct model derived by fin-theory approach and applied on an unglazed solar collector  

SciTech Connect

This paper presents the thermal modelling of an unglazed solar collector (USC) flat panel, with the aim of producing a detailed yet swift thermal steady-state model. The model is analytical, one-dimensional (1D) and derived by a fin-theory approach. It represents the thermal performance of an arbitrary duct with applied boundary conditions equal to those of a flat panel collector. The derived model is meant to be used for efficient optimisation and design of USC flat panels (or similar applications), as well as detailed thermal analysis of temperature fields and heat transfer distributions/variations at steady-state conditions; without requiring a large amount of computational power and time. Detailed surface temperatures are necessary features for durability studies of the surface coating, hence the effect of coating degradation on USC and system performance. The model accuracy and proficiency has been benchmarked against a detailed three-dimensional Finite Difference Model (3D FDM) and two simpler 1D analytical models. Results from the benchmarking test show that the fin-theory model has excellent capabilities of calculating energy performances and fluid temperature profiles, as well as detailed material temperature fields and heat transfer distributions/variations (at steady-state conditions), while still being suitable for component analysis in junction to system simulations as the model is analytical. The accuracy of the model is high in comparison to the 3D FDM (the prime benchmark), as long as the fin-theory assumption prevails (no 'or negligible' temperature gradient in the fin perpendicularly to the fin length). Comparison with the other models also shows that when the USC duct material has a high thermal conductivity, the cross-sectional material temperature adopts an isothermal state (for the assessed USC duct geometry), which makes the 1D isothermal model valid. When the USC duct material has a low thermal conductivity, the heat transfer course of events adopts a 1D heat flow that reassembles the conditions of the 1D simple model (for the assessed USC duct geometry); 1D heat flow through the top and bottom fins/sheets as the duct wall reassembles a state of adiabatic condition. (author)

Stojanovic, B.; Hallberg, D.; Akander, J. [Building Materials Technology, KTH Research School, Centre for Built Environment, University of Gaevle, SE-801 76 Gaevle (Sweden)

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.


181

Fragmentation of multiply charged hydrocarbon molecules C{sub n}H{sup q+} (n{<=} 4, q{<=} 9) produced in high-velocity collisions: Branching ratios and kinetic energy release of the H{sup +} fragment  

Science Conference Proceedings (OSTI)

Fragmentation branching ratios for channels involving H{sup +} emission and associated kinetic energy release of the H{sup +} fragment [KER(H{sup +})] have been measured for multicharged C{sub n}H{sup q+} molecules produced in high velocity (3.6 a.u.) collisions between C{sub n}H{sup +} projectiles and helium atoms. For CH{sup q+} (q{=} 5), inner-shell ionization contributed in a prominent way to the ion production. In these two cases it was shown that measured KER(H{sup +}) were in good agreement with PCCM predictions when those were corrected for Auger relaxation with the same Auger lifetime value as in CH{sup 3+}.

Beroff, K.; Pino, T.; Carpentier, Y. [Institut des Sciences Moleculaires d'Orsay (ISMO), UMR CNRS 8214, Universite Paris Sud 11, bat.210, F-91405 Orsay Cedex (France); Van-Oanh, N. T. [Laboratoire de Chimie Physique (LCP), UMR CNRS 8000, Universite Paris Sud 11, Bat.349, F-91405 Orsay Cedex (France); Chabot, M.; Tuna, T.; Martinet, G. [Institut de Physique Nucleaire d'Orsay (IPNO), IN2P3- CNRS, Universite Paris Sud 11, F-91406 Orsay Cedex (France); Le Padellec, A. [Institut de Recherche en Astrophysique et Planetologie (IRAP), UMR CNRS 5187, Universite de Toulouse, 9 avenue du Colonel Roche, F-31028 Toulouse Cedex 9 (France); Lavergne, L. [Laboratoire de Physique Nucleaire et de Hautes Energies (LPNHE) UPMC, UPD, CNRS-IN2P3, 4 Place Jussieu, F-75005 Paris (France)

2011-09-15T23:59:59.000Z

182

Residential Duct Design: A Practical Handbook  

Science Conference Proceedings (OSTI)

Well-designed and properly installed air distribution ductwork is essential for optimum performance of residential space-conditioning systems. This handbook is both a practical study guide and a ready reference work that can help students, designers, and installers of ductwork deliver a high level of comfort with trouble-free, low-cost maintenance.

1991-08-01T23:59:59.000Z

183

Flow control optimization in a jet engine serpentine inlet duct  

E-Print Network (OSTI)

Computational investigations were carried out on an advanced serpentine jet engine inlet duct to understand the development and propagation of secondary flow structures. Computational analysis which went in tandem with experimental investigation was required to aid secondary flow control required for enhanced pressure recovery and decreased distortion at the engine face. In the wake of earlier attempts with modular fluidic actuators used for this study, efforts were directed towards optimizing the actuator configurations. Backed by both computational and experimental resources, many variations in the interaction of fluidic actuators with the mainstream flow were attempted in the hope of best controlling secondary flow formation. Over the length of the studies, better understanding of the flow physics governing flow control for 3D curved ducts was developed. Blowing tangentially, to the wall at the bends of the S-duct, proved extremely effective in enforcing active flow control. At practical jet momentum coefficients, significant improvements characterized by an improved pressure recove ry of 37% and a decrease in distortion close to 90% were seen.

Kumar, Abhinav

2007-08-01T23:59:59.000Z

184

Is there Lower Limit to Velocity or Velocity Change?  

E-Print Network (OSTI)

Here we explore the possibility of a lower limit to velocity or velocity change which is 20 orders of magnitude smaller than the speed of light and explore the various observable signatures including those in cosmic rays and gamma ray bursts.

B. N. Sreenath; Kenath Arun; C. Sivaram

2012-09-17T23:59:59.000Z

185

Scaleup tests and supporting research for the development of duct injection technology. Final report, Task 4.5  

Science Conference Proceedings (OSTI)

DOE`s Duct Injection Test Facility at Ohio Power Company`s Muskingum River Plant was modified to enable performance of a comprehensive test program concerning duct injection of sorbents for SO{sub 2} control. Injection of slaked lime slurries and injection of dry calcium hydroxide powder with humidification were carried out under a variety of process conditions. Slaked lime slurry injection as found to be superior in both operational reliability and S0{sub 2} removal capability compared with dry hydrated lime injection with humidification. Calcium utilization of 50% was achieved with 50% S0{sub 2} removal at the ESP outlet with recycle of unreacted sorbent collected in the precipitatorhoppers. Electrostatic precipitator collection performance was found to be highly variable with sorbent injection, especially with close approach to saturation temperatures and high inlet mass loadings. Small-scale tests with a fabric filter in parallel with the precipitator indicated 5 to 10% more S0{sub 2} removal could be obtained across the fabric filter than the ESP for all test conditions. Over 95% S0{sub 2} removal was achieved with the fabric filter using a two stage cooling process in which the filter was cooled below the operating temperature ofthe duct spray dryer.

Felix, L.G.; Gooch, J.P.; Merritt, R.L. [Southern Research Inst., Birmingham, AL (United States); Klett, M.G.; Demian, A.G.; Hunt, J.E. [Gilbert/Commonwealth, Inc., Reading, PA (United States)

1992-10-30T23:59:59.000Z

186

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

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

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

187

Building America Top Innovations 2013 Profile … Buried and Encapsulated Ducts  

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

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

188

Building America Top Innovations 2013 Profile … Buried and Encapsulated Ducts  

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

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

189

Performance Analysis of Dual-Fan, Dual-Duct Constant Volume Air-Handling Units  

E-Print Network (OSTI)

Dual-fan, dual-duct air-handling units introduce outside air directly into the cooling duct and use two variable speed devices to independently maintain the static pressure of the hot and the cold air ducts. Analytical models have been developed to compare fan power and thermal energy consumption of dualfan, dual-duct constant volume air-handling units with single-fan, dual-duct constant volume airhandling units. This study shows that the dual-fan, dual-duct system uses less fan power and less thermal energy during winter, and uses more thermal energy during summer. Thermal energy performance can be significantly improved if the thermal energy penalty can be decreased or eliminated.

Joo, I. S.; Liu, M.

2001-01-01T23:59:59.000Z

190

Thermionic nuclear reactor with internal heat distribution and multiple duct cooling  

DOE Patents (OSTI)

A Thermionic Nuclear Reactor is described having multiple ribbon-like coolant ducts passing through the core, intertwined among the thermionic fuel elements to provide independent cooling paths. Heat pipes are disposed in the core between and adjacent to the thermionic fuel elements and the ribbon ducting, for the purpose of more uniformly distributing the heat of fission among the thermionic fuel elements and the ducts.

Fisher, C.R.; Perry, L.W. Jr.

1975-11-01T23:59:59.000Z

191

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

E-Print Network (OSTI)

A variety of methods of sealing supply-air registers wereand sealing practices when leakage at connections to duct-mounted equipment is not considered. The measured air-

Fisk, W.J.

2011-01-01T23:59:59.000Z

192

Field Measurements of Efficiency and Duct Effectiveness in Residential Forced Air Distributions Systems  

E-Print Network (OSTI)

sealing and insulating the duct system. ABSTRACT Forced airair conditioning, gas furnaces, electric furnaces and heat pumps. The retrofits consisted of sealing

Jump, D.A.

2011-01-01T23:59:59.000Z

193

DUCTED FAN INLET/EXIT AND ROTOR TIP FLOWIMPROVEMENTS FOR VERTICAL LIFT SYSTEMS.  

E-Print Network (OSTI)

??Ducted fan based vertical lift systems are excellent candidates to be in the group of the next generation vertical lift vehicles, with many potential applications… (more)

Akturk, Ali

2010-01-01T23:59:59.000Z

194

FLIGHT CONTROL DESIGN OF TANDEM DUCTED FAN AIRCRAFT USING REDUNDANT CONTROL EFFECTORS.  

E-Print Network (OSTI)

??Controllability and stability of ducted fan air vehicles is a challenging problem due to their complex nonlinear aerodynamics and dynamic behavior. At the same time,… (more)

Ozdemir, Gurbuz

2010-01-01T23:59:59.000Z

195

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

196

ARM - Measurement - Hydrometeor fall velocity  

NLE Websites -- All DOE Office Websites (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

197

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

Science Conference Proceedings (OSTI)

This study was performed in order to find suitable efficiency and leakage specifications for Energy Star duct systems and provide recommendations on duct insulation specifications. This analysis looks at a typical house, with a selection of duct locations, climates, duct insulation (R-value), and duct leakage. A set of calculations were performed with reduced capacity and airflow to look at the effect of variable capacity systems. This was done to address concerns regarding the increased efficiency of multi-capacity equipment due to good part load performance and how these efficiency gains may be offset by increased duct losses. The duct system efficiencies were calculated using the procedures in proposed ASHRAE Standard 152P ''Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems'' (ASHRAE 1999). This proposed ASHRAE Standard can be used to calculate duct efficiency for both design and seasonal weather conditions. In this report, the seasonal efficiencies are used for most of the analysis because they are the most appropriate for estimating energy consumption in buildings. The effects at peak conditions are examined for changing duct insulation in order to provide preliminary estimates of the potential responses to time of use pricing. The study was performed in two parts. The first part focused on duct leakage and the second part on duct insulation. The HVAC systems in the two parts share many attributes, however, they differ in detail and so are treated separately here. All the calculation results are summarized in tables in the Appendix, and specific results are given in the text.

Walker, Iain

2001-09-01T23:59:59.000Z

198

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

E-Print Network (OSTI)

The lecture hall of the Richardson Petroleum Building at Texas A&M University is a large lecture hall, with a total floor area of approximately 2500 ft^2. The lecture hall was served by a constant air volume (CAV) air handling unit (AHU) which had no reheat coil. This resulted in high room humidity levels although the room temperature was satisfied for part load conditions, especially when there was very little sensible load from the room. This paper presents Continuous Commissioning efforts (CC), which turned this inefficient, humid lecture hall into a comfortable learning environment. This case study also explores other possibilities to solve the humidity control problem with single-duct, single-zone constant air volume systems.

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

2000-01-01T23:59:59.000Z

199

A VAD-Based Dealiasing Method for Radar Velocity Data Quality Control  

Science Conference Proceedings (OSTI)

This paper describes a new velocity–azimuth display (VAD)-based dealiasing method developed for automated radar radial velocity data quality control to satisfy the high-quality standard and efficiency required by operational radar data ...

Qin Xu; Kang Nai; Li Wei; Pengfei Zhang; Shun Liu; David Parrish

2011-01-01T23:59:59.000Z

200

Experimental and theoretical investigations on the dynamic response of EBR- II ducts under pressure pulse loading  

SciTech Connect

In order to assess the potential damage to hexagonal subassembly ducts (cans) that may result from rapid gas release from a failed element the EBR-II project has conducted experiments and analyses. Additional experimental and analytical investigations are now being conducted to assure fail-safety of the ducts. Fail-safety is defined as the ability of a duct to withstand pressure pulses from failed elements during all reactor conditions without damage to adjacent ducts or any other problems in fuel handling. The results of 93 EBR-II duct tests conducted primarily by Koenig have been reported previously. The results of empirical correlations of some of these tests to determine the influence of several variables on the pressure pulse experienced by a duct and on the duct deformation are presented. The variables include the type of gas contained in the simulated element (tube), the element and duct materials, the presence or absence of flow restrictors in the element, and the way gas was released. 8 references. (auth)

Chopra, P.S.; Srinivas, S.

1975-01-01T23:59:59.000Z

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

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.

202

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.

203

Evaluating and Avoiding Heat Recovery Steam Generator Tube Damage Caused by Duct Burners  

Science Conference Proceedings (OSTI)

In heat recovery steam generators (HRSGs), supplemental firing in duct burners introduces the potential for serious HRSG tube failure and damage. Duct burners that are specified, designed, and operated properly can produce a number of significant benefits. This report will assist operators in accruing these benefits.

2007-03-20T23:59:59.000Z

204

Simulation of water hammer phenomenon in a pumping discharge duct protected by air  

Science Conference Proceedings (OSTI)

Air chamber and free air dispersed throughout the water are two efficient means of protection of a discharge duct from water hammer damages. The paper presents the results regarding the extreme pressures in the discharge duct of a pumping installation, ... Keywords: air chamber, dissolution, free air, pumping installation, water hammer

Anca Constantin; Claudiu Stefan Nitescu

2010-07-01T23:59:59.000Z

205

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%) following the draw through methodology in ASHRAE Standard 120 -1999 – Methods of Testing to Determine Flow Resistance of Air Ducts and Fittings. With the pressure drop data gathered, equations were developed to approximate the pressure loss at a given air flow rate for a given duct size. The data gathered showed general agreement with previous studies showing an increase in compression ratio leads to an increase in static pressure loss through the duct. It was determined that pressure losses for compression ratios greater than 4% were over four times greater than maximum stretched flexible duct of corresponding duct size. The increased static pressure losses can lead to decreased performance in HVAC systems. The findings of this study add to the existing ASHRAE and industry data for flexible duct with varying compression ratios.

Cantrill, David Lee

2013-08-01T23:59:59.000Z

206

ASHRAE Transactions: Research 105 Current duct design methods for variable air volume  

E-Print Network (OSTI)

ASHRAE Transactions: Research 105 ABSTRACT Current duct design methods for variable air volume (VAV for different design conditions are sought using a duct fitting database program as described in ASHRAE (1993 Jeffrey D. Spitler, Ph.D., P.E. Ronald D. Delahoussaye, Ph.D. Member ASHRAE Taecheol Kim is a Ph

207

Design Analysis Report for 244-AR Interim Stabilization Exhaust Ventilation Ducting  

SciTech Connect

This report documents the design analysis performed for the exhaust ducting associated with the 244-AR Interim Stabilization Project. The exhaust ducting connects portable exhausters PORO5 and PORO6 to the existing east dog house of the 291-AR filter vault and the vessel ventilation system. This analysis examines loads on the ductwork and ductwork supports.

RUTHERFORD, J.

2002-11-21T23:59:59.000Z

208

Vorticity from Line-of-Sight Lidar Velocity Scans  

Science Conference Proceedings (OSTI)

A method is presented to compute the spanwise vorticity in polar coordinates from 2D vertical cross sections of high-resolution line-of-sight Doppler wind lidar observations. The method uses the continuity equation to derive the velocity ...

Martin Weissmann; Andreas Dörnbrack; James D. Doyle

2009-12-01T23:59:59.000Z

209

Building America Top Innovations Hall of Fame Profile – Integration of HVAC System Design with Simplified Duct Distribution  

Energy.gov (U.S. Department of Energy (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.

210

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

NLE Websites -- All DOE Office Websites (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.

211

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

E-Print Network (OSTI)

This paper discusses improved control strategies for dual-duct single-fan variable air volume (VAV) systems. Common control strategy for supply air volume modulation is evaluated, and an improved air volume control strategy that maintains separate 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 pressures and overall system energy consumption. To compensate the negative impact of non-ideal cold and hot deck temperature set points, the authors propose using real-time duct static pressure readings as feedback signals to fine-tune the deck temperature set points. These new control schemes can reduce simultaneous cooling and heating while reducing fan power consumption.

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

2003-01-01T23:59:59.000Z

212

Sealing Ducts in Large Commercial Buildings with Aerosolized Sealant Particles  

E-Print Network (OSTI)

of Diffusers Nominal Pre-Sealing Air Flow [L/s (cfm)] Tablepressurized with clean air during the sealing process. ) Theduring sealing. The objective is to maintain an air velocity

2001-01-01T23:59:59.000Z

213

The Velocity-Selecting Cerenkov Counter  

E-Print Network (OSTI)

BAFFLE VELOCITY - SELECTING CERENKOV COUNTER (C 2) FiJI. 1velocity-selectinp: Cerenkov counter. ueaL-31;S CYLINDRICA~

Chamberlain, Owen; Weigand, Clyde

1956-01-01T23:59:59.000Z

214

Experimental Techniques for Measuring Temperature and Velocity...  

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

Measuring Temperature and Velocity Fields to Improve the Use and Validation of Building Heat Transfer Models Title Experimental Techniques for Measuring Temperature and Velocity...

215

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

216

Acetic Acid Sclerotherapy for Treatment of a Bile Leak from an Isolated Bile Duct After Laparoscopic Cholecystectomy  

Science Conference Proceedings (OSTI)

Bile leak after laparoscopic cholecystectomy is not uncommon, and it mainly occurs from the cystic duct stump and can be easily treated by endoscopic techniques. However, treatment for leakage from an isolated bile duct can be troublesome. We report a successful case of acetic acid sclerotherapy for bile leak from an isolated bile duct after laparoscopic cholecystectomy.

Choi, Gibok, E-mail: choigibok@yahoo.co.kr; Eun, Choong Ki, E-mail: ilovegod@chollian.net [Inje University, Department of Radiology, Haeundae Paik Hospital, College of Medicine (Korea, Republic of); Choi, HyunWook, E-mail: gdkid92@daum.net [Maryknoll Medical Center, Department of Radiology (Korea, Republic of)

2011-02-15T23:59:59.000Z

217

DOE Challenge Home Technical Training - Ducts in Conditioned Space  

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

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

218

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

SciTech Connect

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

219

Device for temporarily closing duct-formers in well completion apparatus  

SciTech Connect

A duct-forming device is disclosed for use in a well completion apparatus of the kind, wherein a bore hole casing is positioned in a bore hole and duct-forming devices of alkali- and acid resistant metal-such as steel-are secured at spaced levels to the casing in alignment with holes machined in the casing wall. In accordance with the invention, a closure device is arranged within the duct-forming device which permits flow of predetermined amounts of liquid, such as acid, from the interior of the casing through the duct-forming device and into the producing formation, while gradually being moved by the liquid into a position in which such fluid flow is prevented. After the fluid flow has been stopped by the closure device and when the formation pressure exceeds the pressure within the duct-forming device and the casing, fluid from the formation then forces the closure device toward and into the casing space to permit thereafter free flow of formation fluid into the duct-forming device and the casing or of pressurized treatment liquid from the casing into the formation. The inventive arrangement permits inter alia the establishment of a sufficient and substantially uniform feeding rate of treatment liquid, such as acid, from the casing into the producing formation through all the duct-formers in preparation for subsequent acidification or other treatments, such as sand fracking.

Zandmer, H.M.; Zandmer, S.M.

1981-08-25T23:59:59.000Z

220

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

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

Forcing and Velocity Correlations in a Vibrated Granular Monolayer  

E-Print Network (OSTI)

The role of forcing on the dynamics of a vertically shaken granular monolayer is investigated. Using a flat plate, surprising negative velocity correlations are measured. A mechanism for this anti-correlation is proposed with support from both experimental results and molecular dynamics simulations. Using a rough plate, velocity correlations are positive, and the velocity distribution evolves from a gaussian at very low densities to a broader distribution at high densities. These results are interpreted as a balance between stochastic forcing, interparticle collisions, and friction with the plate.

Alexis Prevost; David A. Egolf; Jeffrey S. Urbach

2002-03-14T23:59:59.000Z

222

Particle Velocity and Deposition Efficiency in the Cold Spray Process  

SciTech Connect

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

223

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

E-Print Network (OSTI)

Air Leakage, and Heat Conduction Gains William 1. Fisk,0.75 to 0.90; thus, heat conduction decreased the coolingby air leakage or heat conduction, because these ducts are

Fisk, W.J.

2011-01-01T23:59:59.000Z

224

Experimental Verification of Thermo-Mechanical Models for XLPE Cable in Pipes and Ducts  

Science Conference Proceedings (OSTI)

In 2002 EPRI began investigations of the thermo-mechanical (T-M) behavior of transmission-class cable systems with extruded insulation in duct-manhole and pipe systems and began work on a design guide. The project consisted primarily of two efforts: experimental measurement of cable parameters and development of a mathematical simulation of the thermal and mechanical behavior of transmission-class cable with extruded cross-linked polyethylene (XLPE) insulation when installed in ducts and pipes. ...

2012-12-20T23:59:59.000Z

225

Duct injection technology prototype development: Scale-up methodology and engineering design criteria  

Science Conference Proceedings (OSTI)

The objective of the Duct Injection Technology Prototype Development project is to develop a sound design basis for applying duct injection technology as a post-combustion SO{sub 2} emissions control method to existing, pre-NSPS, coal-fired power plants. This report is divided into five major topics: (1) design criteria; (2) engineering drawings; (3) equipment sizing and design; (4) plant and equipment arrangement considerations; and (5) equipment bid specification guidelines.

Not Available

1991-04-01T23:59:59.000Z

226

A Residential Duct Leakage Case Study on 'Good Cents' Homes  

E-Print Network (OSTI)

The “Good Cents” program has been adopted by many cities across the United States and has encouraged builders to employ aggressive energy conservation building techniques in residential applications. The program is well established and has been recognized for the added value it brings to homeowners. The primary energy using system in a residence is the heating and cooling system and in the hot and humid Southeast Texas climate, cooling is the predominant mode of operation for the HVAC system. This makes the system particularly susceptible to degraded performance if there are leaks in the air distribution system. Nine Good Cents homes in the College Station, Texas area were chosen for a study to determine the extent of HVAC air distribution leakage in the HVAC system. It was found that all the homes had significant measured leakage for the return-air side of the system. Houses with vertical sheet-rock lined plenums had significantly higher rates of return air leakage than homes with ducted returns.

Bryant, J. A.; Perez, R.

2001-01-01T23:59:59.000Z

227

Field measurement of the interactions between heat pumps and attic duct systems in residential buildings  

SciTech Connect

Research efforts to improve residential heat-pump performance have tended to focus on laboratory and theoretical studies of the machine itself, with some limited field research having been focused on in-situ performance and installation issues. One issue that has received surprisingly little attention is the interaction between the heat pump and the duct system to which it is connected. This paper presents the results of a field study that addresses this interaction. Field performance measurements before and after sealing and insulating the duct systems were made on three heat pumps. From the pre-retrofit data it was found that reductions in heat-pump capacity due to low outdoor temperatures and/or coil frosting are accompanied by lower duct-system energy delivery efficiencies. The conduction loss reductions, and thus the delivery temperature improvements, due to adding duct insulation were found to vary widely depending on the length of the particular duct section, the thermal mass of that duct section, and the cycling characteristics of the heat-pump. In addition, it was found that the use of strip-heat back-up decreased after the retrofits, and that heat-pump cycling increased dramatically after the retrofits, which respectively increase and decrease savings due to the retrofits. Finally, normalized energy use for the three systems which were operated consistently pre- and post-retrofit showed an average reduction of 19% after retrofit, which corresponds to a chance in overall distribution-system efficiency of 24%.

Modera, M.P.; Jump, D.A. [Lawrence Berkeley Lab., CA (United States). Energy and Environment Div.

1994-11-01T23:59:59.000Z

228

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 +

229

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 +

230

Universal Velocity-Field Characteristics for a Nanowire Arbitrary Degeneracy  

Science Conference Proceedings (OSTI)

The effects of electric field on the carrier motion and drift velocity in nanowire (NW) are presented in this paper. When the electric field is applied in NW, the electron is expected to move in anti-parallel direction to the electric field. This is so-called randomness motion is transformed into streamlined motion in extremely high electric field. The normalized Fermi energy and relative electron population as a function of electric field are examined for various degeneracies. It was found that the electric field has lesser influence on the relative electron population with the increased degeneracy. The drift velocity in NW is shown to increase with electric field until it reaches the saturation velocity. Two approximations have been made to simplify the theoretical equation. It is also shown in this paper that when the quantum emission is taken into account, the drift and saturation velocity degrades.

Chek, Desmond C. Y.; Hashim, Abdul Manaf [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Tan, Michael Loong Peng [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Electrical Engineering Division, Engineering Department, University of Cambridge, 9 J.J. Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Arora, Vijay K. [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Division of Engineering and Physics, Wilkes University, Wilkes-Barre, PA 18766 (United States)

2011-05-25T23:59:59.000Z

231

Duct Leakage Modeling in EnergyPlus and Analysis of Energy Savings from  

NLE Websites -- All DOE Office Websites (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.

232

DOE Workshop - Deposition Velocity Status  

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

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)

233

Velocity Probability Density Functions for Oceanic Floats  

Science Conference Proceedings (OSTI)

Probability density functions (PDFs) of daily velocities from subsurface floats deployed in the North Atlantic and equatorial Atlantic Oceans are examined. In general, the PDFs are approximately Gaussian for small velocities, but with significant ...

Annalisa Bracco; J. H. LaCasce; Antonello Provenzale

2000-03-01T23:59:59.000Z

234

Equatorial Velocity Profiles. Part II: Zonal Component  

Science Conference Proceedings (OSTI)

Vertical profiles of horizontal velocity made along 53°E in the western Indian Ocean, during and after he onset of the southwest monsoon in 1976, show features in zonal velocity of relatively small vertical scale. Persistence of the features over ...

Kathleen O'Neill; James R. Luyten

1984-12-01T23:59:59.000Z

235

Determining Vertical Water Velocities from Seaglider  

Science Conference Proceedings (OSTI)

Vertical velocities in the world’s oceans are typically small, less than 1 cm s?1, posing a significant challenge for observational techniques. Seaglider, an autonomous profiling instrument, can be used to estimate vertical water velocity in the ...

Eleanor Frajka-Williams; Charles C. Eriksen; Peter B. Rhines; Ramsey R. Harcourt

2011-12-01T23:59:59.000Z

236

Velocity Probability Density Functions from Altimetry  

Science Conference Proceedings (OSTI)

Probability density functions (pdfs) are employed to evaluate the distribution of velocities in the global ocean. This study computes pdfs of ocean surface velocity using altimetric data from the TOPEX/Poseidon satellite. Results show that the ...

Sarah T. Gille; Stefan G. Llewellyn Smith

2000-01-01T23:59:59.000Z

237

Determining Velocities and Mixing Coefficients from Tracers  

Science Conference Proceedings (OSTI)

The effort to determine oceanic velocities from tracer distributions relies on a knowledge of the effects of mixing. However, the macroscopic diffusion coefficient, K, is generally not known and must be calculated along with the velocity. The ...

Jae Hak Lee; George Veronis

1989-04-01T23:59:59.000Z

238

An Acoustic Doppler and Electromagnetic Velocity Profiler  

Science Conference Proceedings (OSTI)

A freely failing current meter called the Absolute Velocity Profiler (AVP) is described. This profiler is an expansion of a previously developed instrument, the Electro-Magnetic Velocity Profiler (EMVP), with the additional capability of acoustic ...

Thomas B. Sanford; Robert G. Driver; John H. Dunlap

1985-06-01T23:59:59.000Z

239

Equatorial Velocity Profiles. Part I: Meridional Component  

Science Conference Proceedings (OSTI)

A time series or vertical profiles of horizontal velocity was collected in the western equatorial Indian Ocean during late spring of 1976. The meridional velocity component is examined here, the zonal component in Part II of this paper. The ...

Kathleen O'Neill

1984-12-01T23:59:59.000Z

240

Waterspout Velocity Measurements by Airborne Doppler Lidar  

Science Conference Proceedings (OSTI)

A Doppler lidar measures the line-of-sight velocity of cloud droplets in a waterspout much as a meteorological Doppler radar measures the velocity of larger hydrometeors. We discuss details of the application of an airborne Doppler lidar to ...

R. L. Schwiesow; R. E. Cupp; P. C. Sinclair; R. F. Abbey Jr.

1981-04-01T23:59:59.000Z

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

On the Fundamental Unsteady Fluid Dynamics of Shock-Induced Flows through Ducts  

E-Print Network (OSTI)

Unsteady shock wave propagation through ducts has many applications, ranging from blast wave shelter design to advanced high-speed propulsion systems. The research objective of this study was improved fundamental understanding of the transient flow structures during unsteady shock wave propagation through rectangular ducts with varying cross-sectional area. This research focused on the fluid dynamics of the unsteady shock-induced flow fields, with an emphasis placed on understanding and characterizing the mechanisms behind flow compression (wave structures), flow induction (via shock waves), and enhanced mixing (via shock-induced viscous shear layers). A theoretical and numerical (CFD) parametric study was performed, in which the effects of these parameters on the unsteady flow fields were examined: incident shock strength, area ratio, and viscous mode (inviscid, laminar, and turbulent). Two geometries were considered: the backward-facing step (BFS) geometry, which provided a benchmark and conceptual framework, and the splitter plate (SP) geometry, which was a canonical representation of the engine flow path. The theoretical analysis was inviscid, quasi-1D and quasi-steady; and the computational analysis was fully 2D, time-accurate, and viscous. The theory provided the wave patterns and primary wave strengths for the BFS geometry, and the simulations verified the wave patterns and quantified the effects of geometry and viscosity. It was shown that the theoretical wave patterns on the BFS geometry can be used to systematically analyze the transient, 2D, viscous flows on the SP geometry. This work also highlighted the importance and the role of oscillating shock and expansion waves in the development of these unsteady flows. The potential for both upstream and downstream flow induction was addressed. Positive upstream flow induction was not found in this study due to the persistent formation of an upstream-moving shock wave. Enhanced mixing was addressed by examining the evolution of the unsteady shear layer, its instability, and their effects on the flow field. The instability always appeared after the reflected shock interaction, and was exacerbated in the laminar cases and damped out in the turbulent cases. This research provided new understanding of the long-term evolution of these confined flows. Lastly, the turbulent work is one of the few turbulent studies on these flows.

Mendoza, Nicole Renee

2013-05-01T23:59:59.000Z

242

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

NLE Websites -- All DOE Office Websites (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.

243

Advanced in-duct sorbent injection for SO{sub 2} control. Final technical report  

Science Conference Proceedings (OSTI)

The objective of this research project was to develop a second generation duct sorbent injection technology as a cost-effective compliance option for the 1990 Clean Air Act Amendments. Research and development work was focused on the Advanced Coolside process, which showed the potential for exceeding the original performance targets of 90% SO{sub 2} removal and 60% sorbent utilization. Process development was conducted in a 1000 acfm pilot plant. The pilot plant testing showed that the Advanced Coolside process can achieve 90% SO{sub 2} removal at sorbent utilizations up to 75%. The testing also showed that the process has the potential to achieve very high removal efficiency (90 to >99%). By conducting conceptual process design and economic evaluations periodically during the project, development work was focused on process design improvements which substantially lowered process capital and operating costs, A final process economic study projects capital costs less than one half of those for limestone forced oxidation wet FGD. Projected total SO{sub 2} control cost is about 25% lower than wet FGD for a 260 MWe plant burning a 2.5% sulfur coal. A waste management study showed the acceptability of landfill disposal; it also identified a potential avenue for by-product utilization which should be further investigated. Based on the pilot plant performance and on the above economic projections, future work to scale up the Advanced Coolside process is recommended.

Stouffer, M.R.; Withium, J.A.; Rosenhoover, W.A.; Maskew, J.T.

1994-12-01T23:59:59.000Z

244

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

E-Print Network (OSTI)

Testing for duct leakage was done in 155 homes. Tracer gas tests found that infiltration rates were three times greater when the air handler was operating than when it was off. Infiltration averaged 0.85 air changes per hour (ach) with the air handler (AH) operating continuously and 0.29 ach with the AH off. Return leaks were found to average 10.3% of AH total flow. House airtightness, in 90 of these homes, determined by blower door testing, averaged 12.58 air changes per hour at 50 Pascals (ACHSO). When the duct registers were sealed, ACHSO decreased to 11.04, indicating that 12.2% of the house leaks were in the duct system. Duct leaks have a dramatic impact upon peak electrical demand. Based on theoretical analysis, a fifteen percent 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 capacity.

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

1990-01-01T23:59:59.000Z

245

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

NLE Websites -- All DOE Office Websites (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

246

Velocity of sound in the relic photon sea  

E-Print Network (OSTI)

We determine the velocity of sound in the blackbody gas of photons and in the gas of relic photons. Derivation is based on the thermodynamic theory of the photon gas and the Einstein relation between energy and mass. The spectral form for the n-dimensional blackbody is derived. The 1D, 2D and 3D blackbody radiation is specified. It is mentioned the possibility of creation of the Mach cone in case that the high energy cosmical particles moves with the speed greater than the velocity of sound in cosmical relic photon sea. Key words: Sound, elasticity, thermodynamics, blackbody, relic photons, Mach's cone.

Pardy, Miroslav

2013-01-01T23:59:59.000Z

247

Velocity of sound in the relic photon sea  

E-Print Network (OSTI)

We determine the velocity of sound in the blackbody gas of photons and in the gas of relic photons. Derivation is based on the thermodynamic theory of the photon gas and the Einstein relation between energy and mass. The spectral form for the n-dimensional blackbody is derived. The 1D, 2D and 3D blackbody radiation is specified. It is mentioned the possibility of creation of the Mach cone in case that the high energy cosmical particles moves with the speed greater than the velocity of sound in cosmical relic photon sea. Key words: Sound, elasticity, thermodynamics, blackbody, relic photons, Mach's cone.

Miroslav Pardy

2013-02-18T23:59:59.000Z

248

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

Science Conference Proceedings (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

249

Scaleup tests and supporting research for the development of duct injection technology  

SciTech Connect

Gilbert Commonwealth, Southern Research Institute and the American Electric Power Service Corporation have embarked on a program to convert DOE's Duct Injection Test Facility located at the Muskingum River Power Plant of Ohio Power Company to test alternate duct injection technologies. The technologies to be tested include slurry sorbent injection of hydrated lime using dual fluid nozzles, or a rotary atomizer and pneumatic injection of hydrated lime, with flue gas humidification before or after sorbent injection. The literature review and analysis contained in this report is a part of the preparatory effort for the test program.

Gooch, J.P.; Dismukes, E.B.; Dahlin, R.S.; Faulkner, M.G. (Southern Research Inst., Birmingham, AL (United States)); Klett, M.G.; Buchanan, T.L.; Hunt, J.E. (Gilbert/Commonwealth, Inc., Reading, PA (United States))

1989-05-01T23:59:59.000Z

250

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

251

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.

252

INSTALLATION CERTIFICATE CF-6R-MECH-29-HERS Supply Duct Compliance Credits -Location; Surface Area; R-value (Page 1 of 2)  

E-Print Network (OSTI)

requirements and the building must meet Quality Insulation Installation requirements. Yes No The duct. Yes No Ducts are located within the conditioned volume of building. Yes to this compliance credit performance insulation. In order to claim these credits a detailed duct system design is required

253

Anomalous recovery of damped radial modes in a circular?sector duct with locally heated flow  

Science Conference Proceedings (OSTI)

It is often desirable to predict acoustic propagation in a circular duct carrying a locally heated flow. Common examples include jet engines and certain industrial and commercial burners whose combustion?related noise can be an environmental problem if allowed to penetrate into the surroundings. In these cases axial gradients in the steady flow variables

J. R. Maham; S.?Y. Yeh

1984-01-01T23:59:59.000Z

254

Active flow control in an advanced serpentine jet engine inlet duct  

E-Print Network (OSTI)

An experimental investigation was performed to understand the development and suppression of the secondary flow structures within a compact, serpentine jet engine inlet duct. By employing a variety of flow diagnostic techniques, the formation of a pair of counter-rotating vortices was revealed. A modular fluidic actuator system that would apply several different methods of flow control was then designed and manufactured to improve duct performance. At the two bends of the inlet, conformal flow control devices were installed to deliver varying degrees of boundary layer suction, suction and steady fluid injection, and suction and oscillatory injection. Testing showed that suction alone could delay flow separation and improve the pressure recovery of the duct by as much as 70%. However, this technique was not able to rid the duct completely of the nonuniformities that exist at the engine face plane. Suction with steady blowing, however, increased pressure recovery by 37% and reduced distortion by 41% at the engine face. Suction with pulsed injection had the least degree of success in suppressing the secondary flow structures, with improvements in pressure recovery of only 16.5% and a detrimental impact on distortion. The potential for gains in the aerodynamic efficiency of serpentine inlets by active flow control was demonstrated in this study.

Kirk, Aaron Michael

2006-12-01T23:59:59.000Z

255

A model for stratified gas-liquid turbulent flow in ducts of arbitrary cross-section  

E-Print Network (OSTI)

93 A model for stratified gas-liquid turbulent flow in ducts of arbitrary cross-section J. M the pressure gradient and the liquid fraction in two-phase gas- liquid fully developed stratified flow.60 Nomenclature. - TWO-PHASE VARIABLES. Definition densities statistical average (gas, liquid) mass average phase

Paris-Sud XI, Université de

256

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

E-Print Network (OSTI)

96 ASHRAE Transactions: Research ABSTRACT Current duct design methods for variable air volume (VAV in the 1997 ASHRAE Handbook--Fundamentals (ASHRAE 1997): equal friction, static regain, and the T Systems Taecheol Kim Jeffrey D. Spitler, Ph.D., P.E. Ronald D. Delahoussaye, Ph.D. Member ASHRAE Taecheol

257

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

258

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

259

Estimation of Critical Flow Velocity for Collapse of Gas Test Loop Booster Fuel Assembly  

Science Conference Proceedings (OSTI)

This paper presents calculations performed to determine the critical flow velocity for plate collapse due to static instability for the Gas Test Loop booster fuel assembly. Long, slender plates arranged in a parallel configuration can experience static divergence and collapse at sufficiently high coolant flow rates. Such collapse was exhibited by the Oak Ridge High Flux Reactor in the 1940s and the Engineering Test Reactor at the Idaho National Laboratory in the 1950s. Theoretical formulas outlined by Miller, based upon wide-beam theory and Bernoulli’s equation, were used for the analysis. Calculations based upon Miller’s theory show that the actual coolant flow velocity is only 6% of the predicted critical flow velocity. Since there is a considerable margin between the theoretically predicted plate collapse velocity and the design velocity, the phenomena of plate collapse due to static instability is unlikely.

Guillen; Mark J. Russell

2006-07-01T23:59:59.000Z

260

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 much higher than the space dew point and the dehumidification capability of the system is diminished. Buildings served by this type of air handler often experience exceptionally high humidity levels under humid weather conditions. Many potential solutions and improvements exist. However, these solutions require system modifications or upgrades and therefore are less attractive to some facility owners. A Critical Humidity Control Program (CHCP) was developed to change the normal control sequence of the air-handling units during high humidity periods to help improve the moisture removal capability of the system. The program was not designed to solve the problem completely, but the overall humidity levels can be lowered and controlled within a reasonably low range (58% - 65%) for a significant part of the high humidity seasons. This approach is relatively easy to implement and does not require any hardware changes. This paper also summarizes various potential solutions to improve humidity control for SDSZ units. The advantages and disadvantages for each solution are compared.

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

2006-01-01T23:59:59.000Z

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

Velocity and Attenuation Structure of the Geysers Geothermal Field, California  

DOE Green Energy (OSTI)

The Geysers geothermal field is located in northern California and is one of the world's largest producers of electricity from geothermal energy. The resource consists of primarily dry steam which is produced from a low, porosity fractured graywacke. Over the last several years steam pressure at the Geysers has been dropping. Concern over decline of the resource has prompted research to understand its fundamental nature. A key issue is the distribution of fluid in the matrix of the reservoir rock. In this paper we interpret seismic compressional-wave velocity and attenuation data at the Geysers in terms of the geologic structure and fluid saturation in the reservoir. Our data consist of approximately 300 earthquakes that are of magnitude 1.2 and are distributed in depth between sea level and 2.5 km. Using compressional-wave arrival times, we invert for earthquake location, origin time, and velocity along a three-dimensional grid. Using the initial pulse width of the compressional-wave, we invert for the initial pulse width associated with the source, and the one-dimensional Q structure. We find that the velocity structure correlates with known mapped geologic units, including a velocity high that is correlated with a felsite body at depth that is known from drilling. The dry steam reservoir, which is also known from drilling, is mostly correlated with low velocity. The Q increases with depth to the top of the dry steam reservoir and decreases with depth within the reservoir. The decrease of Q with depth probably indicates that the saturation of the matrix of the reservoir rock increases with depth.

Zucca, J. J.; Hutchings, L. J.; Kasameyer, P. W.

1993-01-01T23:59:59.000Z

262

Wave Ducting in a Stratified Shear Flow over a Two-Dimensional Mountain. Part I: General Linear Criteria  

Science Conference Proceedings (OSTI)

A linear theory for wave ducting is developed by solving a three-layer, steady-state nonrotating flow over a two-dimensional mountain analytically. The reflection coefficient (Ref), transmission coefficient, and the strongest horizontal wind ...

Ting-An Wang; Yuh-Lang Lin

1999-02-01T23:59:59.000Z

263

CHARACTERIZATION OF LEAK PATHWAYS IN THE BELOW GRADE DUCTS OF THE BROOKHAVEN GRAPHITE RESEARCH REACTOR USING PERFLUOROCARBON TRACERS.  

SciTech Connect

The focus of this program was the characterization of the soils beneath the main air ducts connecting the exhaust plenums with the Fan House. The air plenums experienced water intrusion during BGRR operations and after shutdown. The water intrusions were attributed to rainwater leaks into degraded parts of the system and to internal cooling water system leaks. As part of the overall characterization efforts, a state-of-the-art gaseous perfluorocarbon tracer technology was utilized to characterize leak pathways from the ducts. This in turn suggests what soil regions under or adjacent to the ductwork should be emphasized in the characterization process. Knowledge of where gaseous tracers leak from the ducts yields a conservative picture of where water transport, out of or into, the ducts might have occurred.

HEISER,J.; SULLIVAN,T.; KALB,P.; MILIAN,L.; WILKE,R.; NEWSON,C.; LILIMPAKIS,M.

2001-04-01T23:59:59.000Z

264

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

DOE Patents (OSTI)

A clog-resistant injector spray nozzle allows relatively unobtrusive insertion through a small access aperture into existing ductwork in occupied buildings for atomized particulate sealing of a ductwork. The spray nozzle comprises an easily cleaned and easily replaced straight liquid tube whose liquid contents are principally propelled by a heated propellant gas, such as heated air. Heat transfer is minimized from the heated propellant gas to the liquid tube until they both exit the injector, thereby greatly reducing the likelihood of nozzle clogging. A method of duct sealing using particles driven by heated propellant gas is described, whereby duct-sealing operations become both faster, and commercially practicable in inhabited commercial and residential buildings.

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

2007-01-02T23:59:59.000Z

265

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

SciTech Connect

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

266

Percutaneous Transhepatic Removal of Bile Duct Stones: Results of 261 Patients  

SciTech Connect

Purpose: To determine the effectiveness of percutaneous transhepatic removal of bile duct stones when the procedure of endoscopic therapy fails for reasons of anatomical anomalies or is rejected by the patient. Methods: Between April 2001 and May 2010, 261 patients (138 male patients and 123 female patients; age range, 14-92 years; mean age, 64.6 years) with bile duct stones (common bile duct [CBD] stones = 248 patients and hepatolithiasis = 13 patients) were included in the study. Percutaneous transhepatic cholangiography was performed, and stones were identified. Percutaneous transhepatic balloon dilation of the papilla of Vater was performed. Then stones were pushed out into the duodenum with a Fogarty balloon catheter. If the stone diameter was larger than 15 mm, then basket lithotripsy was performed before balloon dilation. Results: Overall success rate was 95.7%. The procedure was successful in 97.5% of patients with CBD stones and in 61.5% of patients with hepatolithiasis. A total of 18 major complications (6.8%), including cholangitis (n = 7), subcapsular biloma (n = 4), subcapsular hematoma (n = 1), subcapsular abscess (n = 1), bile peritonitis (n = 1), duodenal perforation (n = 1), CBD perforation (n = 1), gastroduodenal artery pseudoaneurysm (n = 1), and right hepatic artery transection (n = 1), were observed after the procedure. There was no mortality. Conclusion: Our experience suggests that percutaneous transhepatic stone expulsion into the duodenum through the papilla is an effective and safe approach in the nonoperative management of the bile duct stones. It is a feasible alternative to surgery when endoscopic extraction fails or is rejected by the patient.

Ozcan, Nevzat, E-mail: nevzatcan@yahoo.com; Kahriman, Guven, E-mail: guvenkahriman@hotmail.com; Mavili, Ertugrul, E-mail: ertmavili@yahoo.com [Erciyes University, Department of Radiology, Medical Faculty (Turkey)

2012-08-15T23:59:59.000Z

267

What Should Be Considered When Simulating Doppler Velocities Measured by Ground-Based Weather Radars?  

Science Conference Proceedings (OSTI)

A sophisticated and flexible simulator of Doppler velocities measured by ground-based weather radars is appended to a high-resolution nonhydrostatic atmospheric model. Sensitivity experiments are conducted by using different configurations for ...

Olivier Caumont; Véronique Ducrocq

2008-08-01T23:59:59.000Z

268

Ensemble Kalman Filter Assimilation of Simulated HIWRAP Doppler Velocity Data in a Hurricane  

Science Conference Proceedings (OSTI)

This study utilizes ensemble Kalman filter (EnKF) observing system simulation experiments (OSSEs) to analyze the potential impact of assimilating radial velocity observations of hurricanes from the High-altitude Imaging Wind and Rain Airborne ...

Jason A. Sippel; Scott A. Braun; Fuqing Zhang; Yonghui Weng

2013-08-01T23:59:59.000Z

269

Potential Vorticity and Vertical Velocity at the Iceland-Færœs Front  

Science Conference Proceedings (OSTI)

Using data from high-resolution surveys of the Iceland- Færœs Front, the authors have calculated synoptic maps of the geostrophic velocity, vorticity, and potential vorticity on isopycnal surfaces. The data have also been used to diagnose the ...

J. T. Allen; D. A. Smeed

1996-12-01T23:59:59.000Z

270

Duct injection technology prototype development: Scale-up methodology and engineering design criteria. Topical report No. 4  

Science Conference Proceedings (OSTI)

The objective of the Duct Injection Technology Prototype Development project is to develop a sound design basis for applying duct injection technology as a post-combustion SO{sub 2} emissions control method to existing, pre-NSPS, coal-fired power plants. This report is divided into five major topics: (1) design criteria; (2) engineering drawings; (3) equipment sizing and design; (4) plant and equipment arrangement considerations; and (5) equipment bid specification guidelines.

Not Available

1991-04-01T23:59:59.000Z

271

Laboratory Characterization of Advanced SO2 Control By-Products: Dry Sodium and Calcium In-Duct Injection Wastes  

Science Conference Proceedings (OSTI)

Extensive laboratory investigation indicates that the physical and chemical characterization and engineering properties of dry sodium and calcium in-duct injection wastes differ, as do the refuse and by-product management options associated with them. Utilities can use this report on the chemical, physical, engineering, and leachate properties of dry sodium and calcium in-duct injection wastes to better plan for and manage future waste disposal and/or use.

1990-01-08T23:59:59.000Z

272

Estimating Spatial Velocity Statistics with Coherent Doppler Lidar  

Science Conference Proceedings (OSTI)

The spatial statistics of a simulated turbulent velocity field are estimated using radial velocity estimates from simulated coherent Doppler lidar data. The structure functions from the radial velocity estimates are processed to estimate the ...

Rod Frehlich; Larry Cornman

2002-03-01T23:59:59.000Z

273

The impact of glazing selection on residential duct design and comfort  

SciTech Connect

The vast majority of residential HVAC contractors design and install duct systems using rules of thumb and design guidelines based on obsolete assumptions about house thermal characteristics. Perhaps the most widely accepted rule of thumb is that conditioned air should be delivered at the building perimeter to control the load and achieve acceptable comfort at the windows. The basis for this rule dates back to testing performed in uninsulated houses and laboratory facilities with single-glazed windows. Through computer modeling, field testing, and laboratory testing, initial guidelines have been developed to allow the builder or HVAC contractor to forsake perimeter duct distribution when certain levels of energy efficiency are met, which typically involves better performing windows than are typically selected. The concept of minimized duct design (MDD) affords the opportunity to mitigate many of the problems associated with ductwork, including energy waste, poor indoor air quality, and compromised combustion appliance safety, while encouraging the use of higher performance glazing. Analysis shows that in many cases the cost savings in the ductwork will offset the added cost of the window upgrade.

Hawthorne, W.A.; Reilly, S.

2000-07-01T23:59:59.000Z

274

Ducted kinetic Alfven waves in plasma with steep density gradients  

SciTech Connect

Given their high plasma density (n {approx} 10{sup 13} cm{sup -3}), it is theoretically possible to excite Alfven waves in a conventional, moderate length (L {approx} 2 m) helicon plasma source. However, helicon plasmas are decidedly inhomogeneous, having a steep radial density gradient, and typically have a significant background neutral pressure. The inhomogeneity introduces regions of kinetic and inertial Alfven wave propagation. Ion-neutral and electron-neutral collisions alter the Alfven wave dispersion characteristics. Here, we present the measurements of propagating kinetic Alfven waves in helium helicon plasma. The measured wave dispersion is well fit with a kinetic model that includes the effects of ion-neutral damping and that assumes the high density plasma core defines the radial extent of the wave propagation region. The measured wave amplitude versus plasma radius is consistent with the pile up of wave magnetic energy at the boundary between the kinetic and inertial regime regions.

Houshmandyar, Saeid [Solar Observatory Department, Prairie View A and M University, Prairie View, Texas 77446 (United States); Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States); Scime, Earl E. [Department of Physics, West Virginia University, Morgantown, West Virginia 26506-6315 (United States)

2011-11-15T23:59:59.000Z

275

ARM - Evaluation Product - Convective Vertical Velocity  

NLE Websites -- All DOE Office Websites (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

276

Visibility graph analysis of solar wind velocity  

E-Print Network (OSTI)

We analyze in situ measurements of solar wind velocity obtained by Advanced Composition Explorer (ACE) spacecraft and Helios spacecraft during the years 1998-2012 and 1975-1983 respectively. The data belong to mainly solar cycle 23 (1996-2008) and solar cycle 21 (1976-1986) respectively. We use Directed Horizontal Visibility graph (DHVg) algorithm and estimate a graph functional, namely, the degree distance (D) as the Kullback-Leibler divergence (KLD) argument to understand time irreversibility of solar wind time series. We estimate this degree distance irreversibility parameter for these time series at different phases of solar activity cycle. Irreversibility parameter is first established for known dynamical data and then applied for solar wind velocity time series. It is observed that irreversibility in solar wind velocity fluctuations show similar behaviour at 0.3 AU (Helios data) and 1 AU (ACE data). Moreover it changes over the different phases of solar activity cycle.

Suyal, Vinita; Singh, Harinder P

2013-01-01T23:59:59.000Z

277

Visually Impaired Transcript for Net-Zero Energy House Video  

Science Conference Proceedings (OSTI)

... piping in ceiling, a thermostat, an air duct with the words “high velocity” on it, solar panels on roof, computer connections, geothermal energy pipes ...

2012-09-21T23:59:59.000Z

278

Experimental study of layer mixing, relative ionic escape velocity, and electron temperature gradients in spherical multilayered targets by XUV spectroscopy  

SciTech Connect

This past year we have undertaken experiments at the University of Rochester's Laboratory for Laser Energetics investigating layer mixing and expansion velocities of spherical targets uniformly irradiated by high intensity laser light. We performed high resolution spectroscopic measurements of spherical plasmas, produced using the Omega laser, and have observed enhanced broadening of XUV emission lines due to the expansion velocities.

Griem, H.R.

1990-07-01T23:59:59.000Z

279

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

SciTech Connect

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

280

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

Science Conference Proceedings (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

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.
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281

Vehicle Velocity Estimation Based on RSS Measurements  

Science Conference Proceedings (OSTI)

This paper presents a technique which is based on pattern recognition techniques, in order to estimate Mobile Terminal (MT) velocity. The proposed technique applies on received signal strength (RSS) measurements and more precisely on information extracted ... Keywords: HIDden Markov Model, WCDMA, clustering, location based services, pattern recognition, propagation modeling, traffic information

Theodore S. Stamoulakatos; Antonis S. Markopoulos; Miltiadis E. Anagnostou; Michalis E. Theologou

2007-03-01T23:59:59.000Z

282

Aggregate Terminal Velocity/Temperature Relations  

Science Conference Proceedings (OSTI)

Terminal velocities of snow aggregates in storms along the Front Range in eastern Colorado are examined with a ground-based two-dimensional video disdrometer. Power-law relationships for particles having equivalent volume diameters of 0.5–20 mm ...

Edward A. Brandes; Kyoko Ikeda; Gregory Thompson; Michael Schönhuber

2008-10-01T23:59:59.000Z

283

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

DOE Green Energy (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.

2011-12-01T23:59:59.000Z

284

Modeling of Weld Penetration in High Velocity GTAW  

Science Conference Proceedings (OSTI)

... Boosted Suction (DDBS) System Doubles Pot Suction, Reduces Roof Emission ... Phase Change Materials in Thermal Energy Storage for Concentrating Solar ...

285

New Developments in High Velocity Air-fuel Spraying  

Science Conference Proceedings (OSTI)

This is possible because of the low temperature of air-fuel combustion. The heating of the spray ... Conditioning of Composite Lubricant Powder for Cold Spray.

286

Effects of CO/sub 2/ flooding on wave velocities in rocks with hydrocarbons  

SciTech Connect

Compressional and shear-wave velocities were measured in the laboratory in seven sandstones (porosities ranging from 6 to 29%) and one unconsolidated sand (37% porosity) saturated with n-hexadecane (C/sub 16/H/sub 34/) both before and after CO/sub 2/ flooding. CO/sub 2/ flooding decreased compressional-wave velocities significantly, while shear-wave velocities were less affected. The magnitude of these effects was found to depend on confining and pore pressures, temperature, and porosities of the rocks. The experimental results and theoretical analysis show that the decreases in compressional-wave velocities caused by CO/sub 2/ flooding may be seismically resolvable in situ. Therefore, seismic--especially high-frequency, high-resolution seismic--methods may be useful in mapping and locating CO/sub 2/ zones, tracking movements of CO/sub 2/ fronts, and monitoring flooding processes in reservoirs undergoing CO/sub 2/ flooding.

Wang, Z. (Core Labs., Calgary (CA)); Nur, A.M. (Stanford Univ., Geophysics Dept., CA (US))

1989-11-01T23:59:59.000Z

287

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.

288

On the theory of turbulent flame velocity  

E-Print Network (OSTI)

The renormalization ideas of self-similar dynamics of a strongly turbulent flame front are applied to the case of a flame with realistically large thermal expansion of the burning matter. In that case a flame front is corrugated both by external turbulence and the intrinsic flame instability. The analytical formulas for the velocity of flame propagation are obtained. It is demonstrated that the flame instability is of principal importance when the integral turbulent length scale is much larger than the cut off wavelength of the instability. The developed theory is used to analyse recent experiments on turbulent flames propagating in tubes. It is demonstrated that most of the flame velocity increase measured experimentally is provided by the large scale effects like the flame instability, and not by the small-scale external turbulence.

Vitaly Bychkov; Vyacheslav Akkerman; Arkady Petchenko

2012-10-19T23:59:59.000Z

289

A fast iterative model for discrete velocity calculations on triangular grids  

SciTech Connect

A fast synthetic type iterative model is proposed to speed up the slow convergence of discrete velocity algorithms for solving linear kinetic equations on triangular lattices. The efficiency of the scheme is verified both theoretically by a discrete Fourier stability analysis and computationally by solving a rarefied gas flow problem. The stability analysis of the discrete kinetic equations yields the spectral radius of the typical and the proposed iterative algorithms and reveal the drastically improved performance of the latter one for any grid resolution. This is the first time that stability analysis of the full discrete kinetic equations related to rarefied gas theory is formulated, providing the detailed dependency of the iteration scheme on the discretization parameters in the phase space. The corresponding characteristics of the model deduced by solving numerically the rarefied gas flow through a duct with triangular cross section are in complete agreement with the theoretical findings. The proposed approach may open a way for fast computation of rarefied gas flows on complex geometries in the whole range of gas rarefaction including the hydrodynamic regime.

Szalmas, Lajos [Department of Mechanical Engineering, University of Thessaly, Pedion Areos, Volos 38334 (Greece); Valougeorgis, Dimitris [Department of Mechanical Engineering, University of Thessaly, Pedion Areos, Volos 38334 (Greece)], E-mail: diva@mie.uth.gr

2010-06-01T23:59:59.000Z

290

A new rf structure for intermediate-velocity particles  

Science Conference Proceedings (OSTI)

This paper describes an rf structure with high shunt impedance and good field stability for particle velocities o.1 {le} {beta} {le} 0.5. Traditionally, the drift-tube linac (DTL) has been the structure of choice for this velocity range. The new structure, called a coupled-cavity drift-tube linac (CCDTL), combines features of the Alvarez DTL and the {pi}-mode coupled-cavity linac (CCL). Each accelerating cavity is a two-cell, 0-mode DTL. The center-to-center distance between gaps is {gamma}{lambda}. Adjacent accelerating cavities have oppositely directed electric fields, alternating in phase by 180{degrees}. The chain of cavities operates in a {pi}/2 structure mode so the coupling cavities are nominally unexcited. We will discuss 2-D and 3-D electromagnetic code calculations, and some initial measurements on a low-power model of a CCDTL. We will compare shunt impedance calculations for DTL, CCL, and CCDTL structures. The CCDTL has potential application for a wide range of ion linacs. For example, high-intensity proton linacs could use the CCDTL instead of a DTL up to an energy of about 200 MeV. Another example is a stand-alone, low-duty, low-current, very high gradient, proton, cancer therapy machine. The advantage for this application would be a saving in the cost of the machine because the linac would be short.

Billen, J.H.; Krawczyk, F.L.; Wood, R.L.; Young, L.M.

1994-09-01T23:59:59.000Z

291

Application of an ASHRAE 152-2004 Duct Model for Simulating Code-Compliant 2000/2001 IECC Residences  

E-Print Network (OSTI)

This paper presents the results of the application of the duct model based on ASHRAE 152-2004 - Method of Test for Determining the Design and Seasonal Efficiencies of Residential Thermal Distribution Systems (ASHRAE 2004) to the code compliant 2001 International Energy Conservation Code (IECC)1 (ICC 1999, 2001) using DOE-2.1e building energy simulation program2. Code compliant DOE-2 simulation model was developed based on IECC and the duct model (Kim and Haberl 20083) was applied to the IECC-code compliant model. Then, the efficiency analyses of the IECC-compliant simulation model were performed on: 1) duct properties, and 2) the different locations of HVAC system and ductwork including the attic space and conditioned space based on the different climate zones.

Haberl, J.S.; Kim, S.

2010-01-01T23:59:59.000Z

292

Scaleup tests and supporting research for the development of duct injection technology  

Science Conference Proceedings (OSTI)

This Topical Report No. 2 is an interim report on the Duct Injection Test Facility being operated for the Department of Energy at Beverly, Ohio. Either dry calcium hydroxide or an aqueous slurry of calcium hydroxide (prepared by slaking quicklime) is injected into a slipstream of flue gas to achieve partial removal of SO{sub 2} from a coal-burning power station. Water injected with the slurry or injected separately from the dry sorbents cools the flue gas and increases the water vapor content of the gas. The addition of water, either in the slurry or in a separate spray, makes the extent of reaction between the sorbent and the SO{sub 2} more complete; the presumption is that water is effective in the liquid state, when it is able to wet the sorbent particles physically, and not especially effective in the vapor state. An electrostatic precipitator collects the combination of suspended solids (fly ash from the boiler and sorbent from the duct injection process). All of the operations are being carried out on the scale of approximately 50,000 acfm of flue gas.

Felix, L.G.; Dismukes, E.B.; Gooch, J.P. (Southern Research Inst., Birmingham, AL (United States)); Klett, M.G.; Demian, A.G. (Gilbert/Commonwealth, Inc., Reading, PA (United States))

1992-04-20T23:59:59.000Z

293

Heat transfer and pressure drop in hexagonal ducts with surface dimples  

SciTech Connect

Measurements of detailed Nusselt number (Nu) distributions and pressure drop coefficients (f) for four hexagonal ducts with smooth and dimpled walls are performed to comparatively examine the thermal performances of three sets of dimpled walls with concave-concave, convex-convex and concave-convex configurations at Reynolds numbers (Re) in the range of 900-30,000. A set of selected experimental data illustrates the influences of dimple configuration and Re on the detailed Nu distributions, the area-averaged Nu over developed flow region (Nu-bar) and the pressure drop coefficients. Relative enhancements of Nu and f from the smooth-walled references (Nu{sub {infinity}} and f{sub {infinity}}) along with the thermal performance factor ({eta}) defined as (Nu-bar/Nu{sub {infinity}})/(f/f{sub {infinity}}){sup 1/3} are examined. Nu-bar and f correlations are individually obtained for each tested hexagonal duct using Re as the controlling parameter. (author)

Chang, S.W. [Thermal Fluids Laboratory, National Kaohsiung Marine University, No. 142, Haijhuan Road, Nanzih District, Kaohsiung City 81143 (China); Chiang, K.F. [Thermal Dissipation Department, AVC International Company (China); Chou, T.C. [Department of Marine Engineering, National Kaohsiung Marine University (China)

2010-11-15T23:59:59.000Z

294

Bench-scale studies of in-duct mercury capture using cupric chloride-impregnated carbons  

Science Conference Proceedings (OSTI)

A brominated activated carbon (Darco Hg-LH) and cupric chloride-impregnated activated carbon (CuCl{sub 2}-ACs) sorbent have been tested in a bench-scale entrained-flow reactor system which was developed for simulating in-flight mercury capture in ducts upstream of particulate matter control devices. The bench-scale experimental system has been operated with the conditions of a residence time of 0.75 s and a gas temperature of 140{sup o}C to simulate typical conditions in the duct of coal-fired exhaust gas. In addition, sorbent deposition on walls which can occur in a laboratory-scale system more than in a full-scale system was significantly reduced so that additional mercury capture by the deposited sorbent was minimized. In the entrained-flow system, CuCl{sub 2}-ACs demonstrated similar performance in Hg adsorption and better performance in Hg{sup 0} oxidation than Darco Hg-LH. In addition, the carbon content of those sorbents was found to determine their Hg adsorption capability in the entrained-flow system. The bench-scale entrained-flow system was able to demonstrate the important Hg adsorption and oxidation characteristics of the tested sorbents. 18 refs., 9 figs., 1 tab.

Sang-Sup Lee; Joo-Youp Lee; Tim C. Keener [University of Cincinnati, Cincinnati, OH (United States). Department of Civil and Environmental Engineering

2009-04-15T23:59:59.000Z

295

Drift velocity of electrons in quantum wells of selectively doped In{sub 0.5}Ga{sub 0.5}As/Al{sub x}In{sub 1-x}As and In{sub 0.2}Ga{sub 0.8}As/Al{sub x}Ga{sub 1-x}As heterostructures in high electric fields  

Science Conference Proceedings (OSTI)

The field dependence of drift velocity of electrons in quantum wells of selectively doped In{sub 0.5}Ga{sub 0.5}As/Al{sub x}In{sub 1-x}As and In{sub 0.2}Ga{sub 0.8}As/Al{sub x}Ga{sub 1-x}As heterostructures is calculated by the Monte Carlo method. The influence of varying the molar fraction of Al in the composition of the Al{sub x}Ga{sub 1-x}As and Al{sub x}In{sub 1-x}As barriers of the quantum well on the mobility and drift velocity of electrons in high electric fields is studied. It is shown that the electron mobility rises as the fraction x of Al in the barrier composition is decreased. The maximum mobility in the In{sub 0.5}Ga{sub 0.5}As/In{sub 0.8}Al{sub 0.2}As quantum wells exceeds the mobility in a bulk material by a factor of 3. An increase in fraction x of Al in the barrier leads to an increase in the threshold field E{sub th} of intervalley transfer (the Gunn effect). The threshold field is E{sub th} = 16 kV/cm in the In{sub 0.5}Ga{sub 0.5}As/Al{sub 0.5}In{sub 0.5}As heterostructures and E{sub th} = 10 kV/cm in the In{sub 0.2}Ga{sub 0.8}As/Al{sub 0.3}Ga{sub 0.7}As heterostructures. In the heterostructures with the lowest electron mobility, E{sub th} = 2-3 kV/cm, which is lower than E{sub th} = 4 kV/cm in bulk InGaAs.

Pozela, J., E-mail: pozela@pfi.lt; Pozela, K.; Raguotis, R.; Juciene, V. [Center for Physical Sciences and Technology, Semiconductor Physics Institute (Lithuania)

2011-06-15T23:59:59.000Z

296

Scaleup tests and supporting research for the development of duct injection technology. Topical report No. 1, Literature review  

Science Conference Proceedings (OSTI)

Gilbert Commonwealth, Southern Research Institute and the American Electric Power Service Corporation have embarked on a program to convert DOE`s Duct Injection Test Facility located at the Muskingum River Power Plant of Ohio Power Company to test alternate duct injection technologies. The technologies to be tested include slurry sorbent injection of hydrated lime using dual fluid nozzles, or a rotary atomizer and pneumatic injection of hydrated lime, with flue gas humidification before or after sorbent injection. The literature review and analysis contained in this report is a part of the preparatory effort for the test program.

Gooch, J.P.; Dismukes, E.B.; Dahlin, R.S.; Faulkner, M.G. [Southern Research Inst., Birmingham, AL (United States); Klett, M.G.; Buchanan, T.L.; Hunt, J.E. [Gilbert/Commonwealth, Inc., Reading, PA (United States)

1989-05-01T23:59:59.000Z

297

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

SciTech Connect

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: 10percent upstream and 10percent downstream leakage increases supply fan power 30percent on average compared to a tight duct system (2.5percent upstream and 2.5percent 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 30percent). 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.

Wray, Craig; Sherman, Max

2010-03-01T23:59:59.000Z

298

Unexplored Aspect of Velocity of light  

E-Print Network (OSTI)

In the post-Maxwellian era, sensing that the tide of discoveries in electromagnetim indicated a decline of the mechanical view, Einstein replaced Newton's three absolutes -- space, time and mass, with a single one, the velocity of light. The magnitude of the velocity of light was first determined and proven to be finite independently by Ole Romer and Bradley in the eighteenth century. In the nineteenth century, Fizeau carried out the first successful measurement of the speed of light using an earthbound apparatus. Thereafter, many earthbound experiments were conducted for its determination till 1983, when its magnitude was frozen at a fixed value after it was determined up to an accuracy level of a fraction of a meter per second. Einstein considered the speed of light derived from terrestrial experiments, to be the limiting speed of all natural phenomena. Einstein stated in connection with his general relativity theory that light rays could curve only when the velocity of propagation of light varies with position. Experiments have been conducted to prove the phenomenon of light deflection to higher and higher accuracy levels, but none so far to determine the speed of light at locations closer to the sun. To verify some essential aspects of general relativity, NASA had commendably planned many costly experiments. Hence, NASA can now be expected to expeditiously plan and execute the low cost experiment proposed here, so as to conclusively verify the effect of the solar gravitational field on the speed of light, as regards the important predictions of Einstein's theory of gravitation and of its remodeled form -- the Remodeled Relativity Theory, which retained and incorporated only experimentally proven concepts and principles.

Abhijit Biswas; Krishnan RS Mani

2008-05-13T23:59:59.000Z

299

Laser Doppler Velocimeter particle velocity measurement system  

DOE Green Energy (OSTI)

This report gives a detailed description of the operation of the Laser Doppler Velocimeter (LDV) system maintained by DIAL at MSU. LDV is used for the measurement of flow velocities and turbulence levels in various fluid flow settings. Ills report details the operation and maintenance of the LDV system and provides a first-time user with pertinent information regarding the system`s setup for a particular application. Particular attention has been given to the use of the Doppler signal analyzer (DSA) and the burst spectrum analyzer (BSA) signal processors and data analysis.

Wilson, W.W.; Srikantaiah, D.V.; Philip, T.; George, A.

1993-10-01T23:59:59.000Z

300

Radar Wind Profiler Radial Velocity: A Comparison with Doppler Lidar  

Science Conference Proceedings (OSTI)

The accuracy of the radial wind velocity measured with a radar wind profiler will depend on turbulent variability and instrumental noise. Radial velocity estimates of a boundary layer wind profiler are compared with those estimated by a Doppler ...

Stephen A. Cohn; R. Kent Goodrich

2002-12-01T23:59:59.000Z

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.


301

The Accuracy of Vertical Air Velocities from Doppler Radar Data  

Science Conference Proceedings (OSTI)

Eight methods of calculating vertical air velocity in a column are compared. Each method requires some or all of the following data: horizontal divergence, vertical precipitation velocity, hydrometeor terminal fall speed, and vertical air ...

Thomas Matejka; Diana L. Bartels

1998-01-01T23:59:59.000Z

302

Terminal Velocity Adjustments for Plate-like Crystals and Graupel  

Science Conference Proceedings (OSTI)

Velocity adjustments are evaluated for altitude changes using Reynolds number-Davies number correlations of the form Re = aXb which have been obtained from empirical fall velocities of ice particles. In general, the altitude adjustment was found ...

Kenneth V. Beard; Andrew J. Heymsfield

1988-11-01T23:59:59.000Z

303

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

304

HALO VELOCITY GROUPS IN THE PISCES OVERDENSITY  

Science Conference Proceedings (OSTI)

We report spectroscopic observations of five faint (V {approx} 20) RR Lyrae stars associated with the Pisces overdensity conducted with the Gemini South Telescope. At a heliocentric and galactocentric distance of {approx}80 kpc, this is the most distant substructure in the Galactic halo known to date. We combined our observations with literature data and confirmed that the substructure is composed of two different kinematic groups. The main group contains eight stars and has (V{sub gsr}) = 50 km s{sup -1}, while the second group contains four stars at a velocity of (V{sub gsr}) = -52 km s{sup -1}, where V{sub gsr} is the radial velocity in the galactocentric standard of rest. The metallicity distribution of RR Lyrae stars in the Pisces overdensity is centered on [Fe/H] = -1.5 dex and has a width of 0.3 dex. The new data allowed us to establish that both groups are spatially extended making it very unlikely that they are bound systems, and are more likely to be debris of a tidally disrupted galaxy or galaxies. Due to small sky coverage, it is still unclear whether these groups have the same or different progenitors.

Sesar, Branimir; Ivezic, Zeljko [Department of Astronomy, University of Washington, P.O. Box 351580, Seattle, WA 98195-1580 (United States); Vivas, A. Katherina [Centro de Investigaciones de Astronomia (CIDA), Apartado Postal 264, Merida 5101-A (Venezuela, Bolivarian Republic of); Duffau, Sonia, E-mail: bsesar@u.washington.ed, E-mail: zi@u.washington.ed, E-mail: akvivas@cida.v, E-mail: sonia.duffau@gmail.co [Astronomisches Rechen-Institut, Zentrum fuer Astronomie der Universitaet Heidelberg, Moenchhofstrasse 12-14, D-69120 Heidelberg (Germany)

2010-07-01T23:59:59.000Z

305

Temporal Entropy Generation in the Viscous Layers of Laterally-converging Duct Flows  

SciTech Connect

Since insight into entropy generation is a key to increasing efficiency and thereby reducing fuel consumption and/or waste and -- for wall-bounded flows -- most entropy is generated in the viscous layer, we examine the transient behavior of its dominant contributor there for a non-canonical flow. New measurements in oil flow are presented for the effects of favorable streamwise mean pressure gradients on temporal entropy generation rates and, in the process, on key Reynolds-stress-producing events such as sweep front passage and on the deceleration/outflow phase of the overall bursting process. Two extremes have been considered: (1) a high pressure gradient, nearing "laminarization," and (2), for comparison, a low pressure gradient corresponding to many earlier experiments. In both cases, the peak temporal entropy generation rate occurs shortly after passage of the ejection/sweep interface. Whether sweep and ejection rates appear to decrease or increase with the pressure gradient depends on the feature examined and the manner of sampling. When compared using wall coordinates for velocities, distances and time, the trends and magnitudes of the transient behaviors are mostly the same. The main effects of the higher pressure gradient are (1) changes in the time lag between detections -- representing modification of the shape of the sweep front and the sweep angle with the wall, (2) modification of the magnitude of an instantaneous Reynolds shear stress with wall distance and (3) enlarging the sweeps and ejections. Results new for both low and high pressure gradients are the temporal behaviors of the dominant contribution to entropy generation; it is found to be much more sensitive to distance from the wall than to streamwise pressure gradient.

Donald M. McEligot; Robert S. Brodkey; Helmut Eckelmann

2008-12-01T23:59:59.000Z

306

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

Science Conference Proceedings (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

307

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

308

Three-dimensional p-velocity structure of the summit caldera of Newberry Volcano, Oregon  

DOE Green Energy (OSTI)

A three-dimensional high-resolution seismic study of the summit caldera of Newberry Volcano, Oregon, was conducted by the US Geological Survey using an adaptation of the method applied by Mercessian et al. (1984). Preliminary interpretation of the traveltime residuals reveals a ring of high P-velocity material coinciding with the inner ring fault system of the caldera in the upper 2 km. A zone of lower P velocities extends deeper than 2 km in the center of the caldera. 9 refs., 5 figs.

Stauber, D.A.; Iyer, N.M.; Mooney, W.D.; Dawson, P.B.

1985-01-01T23:59:59.000Z

309

Laminar burning velocities and flame instabilities of butanol isomers-air mixtures  

SciTech Connect

Laminar burning velocities and flame instabilities of the butanol-air premixed flames and its isomers are investigated using the spherically expanding flame with central ignition at initial temperature of 428 K and initial pressures of 0.10 MPa, 0.25 MPa, 0.50 MPa and 0.75 MPa. Laminar burning velocities and sensitivity factor of n-butanol-air mixtures are computed using a newly developed kinetic mechanism. Unstretched laminar burning velocity, adiabatic temperature, Lewis number, Markstein length, critical flame radius and Peclet number are obtained over a wide range of equivalence ratios. Effect of molecular structure on laminar burning velocity of the isomers of butanol is analyzed from the aspect of C-H bond dissociation energy. Study indicates that although adiabatic flame temperatures of the isomers of butanol are the same, laminar burning velocities give an obvious difference among the isomers of butanol. This indicates that molecular structure has a large influence on laminar burning velocities of the isomers of butanol. Branching (-CH3) will decrease laminar burning velocity. Hydroxyl functional group (-OH) attaching to the terminal carbon atoms gives higher laminar burning velocity compared to that attaching to the inner carbon atoms. Calculated dissociation bond energies show that terminal C-H bonds have larger bond energies than that of inner C-H bonds. n-Butanol, no branching and with hydroxyl functional group (-OH) attaching to the terminal carbon atom, gives the largest laminar burning velocity. tert-Butanol, with highly branching and hydroxyl functional group (-OH) attaching to the inner carbon atom, gives the lowest laminar burning velocity. Laminar burning velocities of iso-butanol and sec-butanol are between those of n-butanol and tert-butanol. The instant of transition to cellularity is experimentally determined for the isomers of butanol and subsequently interpreted on the basis of hydrodynamic and diffusion-thermal instabilities. Little effect on flame instability is observed for the isomers of butanol. Critical flame radii are the same for the isomers of butanol. Peclet number decreases with the increase in equivalence ratio. (author)

Gu, Xiaolei; Huang, Zuohua; Wu, Si; Li, Qianqian [State Key Laboratory of Multiphase Flow in Power Engineering, Xi'an Jiaotong University, Xi'an 710049 (China)

2010-12-15T23:59:59.000Z

310

Force-velocity relations for multiple-molecular-motor transport  

E-Print Network (OSTI)

A transition rate model of cargo transport by $N$ molecular motors is proposed. Under the assumption of steady state, the force-velocity curve of multi-motor system can be derived from the force-velocity curve of single motor. Our work shows, in the case of low load, the velocity of multi-motor system can decrease or increase with increasing motor number, which is dependent on the single motor force-velocity curve. And most commonly, the velocity decreases. This gives a possible explanation to some recent

Ziqing Wang; Ming Li

2009-06-26T23:59:59.000Z

311

Turbulent Velocity-Variance Profiles in the Stable Boundary Layer Generated by a Nocturnal Low-Level Jet  

Science Conference Proceedings (OSTI)

Profiles of mean winds and turbulence were measured by the High Resolution Doppler lidar in the strong-wind stable boundary layer (SBL) with continuous turbulence. The turbulence quantity measured was the variance of the streamwise wind velocity ...

Robert M. Banta; Yelena L. Pichugina; W. Alan Brewer

2006-11-01T23:59:59.000Z

312

Development of a Laboratory Verified Single-Duct VAV System Model with Fan Powered Terminal Units Optimized Using Computational Fluid Dynamics  

E-Print Network (OSTI)

Single Duct Variable Air Volume (SDVAV) systems use series and parallel Fan Powered Terminal Units to control the air flow in conditioned spaces. This research developed a laboratory verified model of SDVAV systems that used series and parallel fan terminal units where the fan speeds were controlled by either Silicon Controlled Rectifiers (SCR) or Electronically Commutated Motors (ECM) motors. As part of the research, the model was used to compare the performance of the systems and to predict the harmonics generated by ECM systems. All research objectives were achieved. The CFD model, which was verified with laboratory measurements, showed the potential to identify opportunities for improvement in the design of the FPTU and accurately predicted the static pressure drop as air passed through the unit over the full operating range of the FPTU. Computational fluid dynamics (CFD) models of typical a FPTU were developed and used to investigate opportunities for optimizing the design of FPTUs. The CFD model identified key parameters required to conduct numerical simulations of FPTU and some of the internal components used to manufacture the units. One key internal component was a porous baffle used to enhance mixing when primary air and induced air entered the mixing chamber. The CFD analysis showed that a pressure-drop based on face velocity model could be used to accurately predict the performance of the FPTU. The SDVAV simulation results showed that parallel FPTUs used less energy overall than series systems that used SCR motors as long as primary air leakage was not considered. Simulation results also showed that series ECM FPTUs used about the same amount of energy, within 3 percent, of parallel FPTU even when leakage was not considered. A leakage rate of 10 percent was enough to reduce the performance of the parallel FPTU to the level of the series SCR system and the series ECM FPTUs outperformed the parallel FPTUs at all weather locations used in the study.

Davis, Michael A.

2010-08-01T23:59:59.000Z

313

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

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

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

314

A Hypothetical Burning-Velocity Formula for Very Lean Hydrogen-Air Mixtures  

E-Print Network (OSTI)

K. Fig. 2 Comparisons of burning-velocity predictions withcurve), when an experimental burning velocity (points) of 53and calculated laminar burning velocities of lean hydrogen-

Grcar, Joseph F

2008-01-01T23:59:59.000Z

315

Laser-Doppler velocimeter for measuring droplet velocities in two-phase liquid-dominated nozzle flows  

DOE Green Energy (OSTI)

A new laser-Doppler velocimeter (LDV) arrangement for measuring droplet velocities in high velocity, liquid-dominated two-phase nozzle flows was developed. The transmitting optics arrangement for this LDV system is identical to that of a dual beam heterodyne LDV, i.e., the light beam from a single frequency argon laser is divided into two parallel identical beams, which are focused to an intersection volume in the flow. The light backscattered from droplets traveling through this volume is collected for analysis using a scanning confocal Fabry-Perot interferometer (FPI). Because of the dual beam arrangement an unscattered or reference beam is not necessary, and the optical alignment ease and stability are greatly improved over similar LDV-FPI systems. Results of droplet velocity measurements in high velocity, high droplet concentration nozzle jet flows are presented.

Alger, T.W.; Crowe, C.T.; Giedt, W.H.

1978-01-01T23:59:59.000Z

316

Initial Examination of Low Velocity Sphere Impact of Glass Ceramics  

SciTech Connect

This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) sphere impact testing of two materials from the lithium aluminosilicate family reinforced with different amounts of ceramic particulate, i.e., glass-ceramic materials, SCHOTT Resistan{trademark}-G1 and SCHOTT Resistan{trademark}-L. Both materials are provided by SCHOTT Glass (Duryea, PA). This work is a follow-up to similar sphere impact studies completed by the authors on PPG's Starphire{reg_sign} soda-lime silicate glass and SCHOTT BOROFLOAT{reg_sign} borosilicate glass. A gas gun or a sphere-drop test setup was used to produce controlled velocity delivery of silicon nitride (Si{sub 3}N{sub 4}) spheres against the glass ceramic tile targets. Minimum impact velocities to initiate fracture in the glass-ceramics were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between sphere and target material. Quasistatic spherical indentation was also performed on both glass ceramics and their contact damage responses were compared to those of soda-lime silicate and borosilicate glasses. Lastly, variability of contact damage response was assessed by performing spherical indentation testing across the area of an entire glass ceramic tile. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Resistan{trademark}-L glass ceramic required the highest velocity of sphere impact for damage to initiate. Starphire{reg_sign} soda-lime silicate glass was second best, then Resistan{trademark}-G1 glass ceramic, and then BOROFLOAT{reg_sign} borosilicate glass. (2) Glass-ceramic Resistan{trademark}-L also required the largest force to initiate ring crack from quasi-static indentation. That ranking was followed, in descending order, by Starphire{reg_sign} soda-lime silicate glass, Resistan{trademark}-G1 glass ceramic, and BOROFLOAT{reg_sign} borosilicate glass. (3) Spheres with a lower elastic modulus require less force to initiate fracture in Resistan{trademark}-G1 from quasi-static spherical indentation. This indicates that friction is affecting ring crack initiation in Resistan{trademark}-G1. Friction also affected ring crack initiation in Starphire{reg_sign} soda-lime silicate and BOROFLOAT{reg_sign} borosilicate glasses. Among these three materials, friction was the most pronounced (largest slope in the RCIF-elastic modulus graph) in the Starphire{reg_sign} and least pronounced in the BOROFLOAT{reg_sign}. The reason for this is not understood, but differences in deformation behavior under high contact stresses could be a cause or contributor to this. (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than it is under quasi-static conditions in Resistan{trademark}-L and Resistan{trademark}-G1 glass ceramics. This is a trend observed too in Starphire{reg_sign} and BOROFLOAT{reg_sign}. (5) There is a subtle indication there was intra-tile differences in spherical indentation-induced ring crack initiation forces. This is not a material property nor is it exclusive to glass-ceramic Resistan{trademark}-G1 glass ceramic, rather, it is a statistical mechanical response to an accumulated history of processing and handling of that specific tile.

Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Ferber, Mattison K [ORNL

2012-06-01T23:59:59.000Z

317

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

318

Standardization of the cumulative absolute velocity  

SciTech Connect

EPRI NP-5930, A Criterion for Determining Exceedance of the Operating Basis Earthquake,'' was published in July 1988. As defined in that report, the Operating Basis Earthquake (OBE) is exceeded when both a response spectrum parameter and a second damage parameter, referred to as the Cumulative Absolute Velocity (CAV), are exceeded. In the review process of the above report, it was noted that the calculation of CAV could be confounded by time history records of long duration containing low (nondamaging) acceleration. Therefore, it is necessary to standardize the method of calculating CAV to account for record length. This standardized methodology allows consistent comparisons between future CAV calculations and the adjusted CAV threshold value based upon applying the standardized methodology to the data set presented in EPRI NP-5930. The recommended method to standardize the CAV calculation is to window its calculation on a second-by-second basis for a given time history. If the absolute acceleration exceeds 0.025g at any time during each one second interval, the earthquake records used in EPRI NP-5930 have been reanalyzed and the adjusted threshold of damage for CAV was found to be 0.16g-set.

O'Hara, T.F.; Jacobson, J.P. (Yankee Atomic Electric Co., Bolton, MA (United States))

1991-12-01T23:59:59.000Z

319

Out-of-plane ultrasonic velocity measurement  

DOE Patents (OSTI)

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated.

Hall, Maclin S. (Marietta, GA); Brodeur, Pierre H. (Smyrna, GA); Jackson, Theodore G. (Atlanta, GA)

1998-01-01T23:59:59.000Z

320

Out-of-plane ultrasonic velocity measurement  

DOE Patents (OSTI)

A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated. 20 figs.

Hall, M.S.; Brodeur, P.H.; Jackson, T.G.

1998-07-14T23:59:59.000Z

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.


321

Initial Examination of Low Velocity Sphere Impact of Glass Ceramics  

Science Conference Proceedings (OSTI)

This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (energy of impact and the elastic property mismatch between sphere and target material. Quasistatic spherical indentation was also performed on both glass ceramics and their contact damage responses were compared to those of soda-lime silicate and borosilicate glasses. Lastly, variability of contact damage response was assessed by performing spherical indentation testing across the area of an entire glass ceramic tile. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) Resistan{trademark}-L glass ceramic required the highest velocity of sphere impact for damage to initiate. Starphire{reg_sign} soda-lime silicate glass was second best, then Resistan{trademark}-G1 glass ceramic, and then BOROFLOAT{reg_sign} borosilicate glass. (2) Glass-ceramic Resistan{trademark}-L also required the largest force to initiate ring crack from quasi-static indentation. That ranking was followed, in descending order, by Starphire{reg_sign} soda-lime silicate glass, Resistan{trademark}-G1 glass ceramic, and BOROFLOAT{reg_sign} borosilicate glass. (3) Spheres with a lower elastic modulus require less force to initiate fracture in Resistan{trademark}-G1 from quasi-static spherical indentation. This indicates that friction is affecting ring crack initiation in Resistan{trademark}-G1. Friction also affected ring crack initiation in Starphire{reg_sign} soda-lime silicate and BOROFLOAT{reg_sign} borosilicate glasses. Among these three materials, friction was the most pronounced (largest slope in the RCIF-elastic modulus graph) in the Starphire{reg_sign} and least pronounced in the BOROFLOAT{reg_sign}. The reason for this is not understood, but differences in deformation behavior under high contact stresses could be a cause or contributor to this. (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than it is under quasi-static conditions in Resistan{trademark}-L and Resistan{trademark}-G1 glass ceramics. This is a trend observed too in Starphire{reg_sign} and BOROFLOAT{reg_sign}. (5) There is a subtle indication there was intra-tile differences in spherical indentation-induced ring crack initiation forces. This is not a material property nor is it exclusive to glass-ceramic Resistan{trademark}-G1 glass ceramic, rather, it is a statistical mechanical response to an accumulated history of processing and handling of that specific tile.

Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Ferber, Mattison K [ORNL

2012-06-01T23:59:59.000Z

322

Comparison between predicted duct effectiveness from proposed ASHRAE Standard 152P and measured field data for residential forced air cooling systems  

E-Print Network (OSTI)

for Forced Air Systems in Proposed ASHRAE Standard 152P.ASHRAE Transactions, 104(1B), 1360-1375. Walker I, ShermanDuct Effectiveness from Proposed ASHRAE Standard 152P and

Siegel, Jeffrey A.; McWilliams, Jennifer A.; Walker, Iain S.

2002-01-01T23:59:59.000Z

323

Simultaneous Measurements of Drop Size and Velocity in ...  

Science Conference Proceedings (OSTI)

... of entrained air velocity. An example is presented in Prahl and Wendt (1988) and Wendt and Prahl (1986) where the authors ...

324

Modified definition of group velocity and electromagnetic energy conservation equation  

E-Print Network (OSTI)

The classical definition of group velocity has two flaws: (a) the group velocity can be greater than the phase velocity in a non-dispersive medium; (b) the definition is not consistent with the principle of relativity. To remove the flaws, a modified definition is proposed. A criterion is set up to identify the justification of group velocity definition. A "superluminal power flow" is constructed to show that the electromagnetic energy conservation equation cannot uniquely define the power flow if the principle of Fermat is not taken into account.

Changbiao Wang

2013-06-13T23:59:59.000Z

325

New Insights Into Deep Convective Core Vertical Velocities Using...  

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

Insights Into Deep Convective Core Vertical Velocities Using ARM UHF Wind Profilers For original submission and image(s), see ARM Research Highlights http:www.arm.govscience...

326

Temporal Velocity Variations beneath the Coso Geothermal Field...  

Open Energy Info (EERE)

events and determine the compressional and shear wave velocity as well as their ratio. In a first step, we apply traveltime tomography based on the observed microearthquake...

327

P wave velocity variations in the Coso region, California, derived...  

Open Energy Info (EERE)

P wave velocity variations in the Coso region, California, derived from local earthquake travel times Jump to: navigation, search GEOTHERMAL ENERGYGeothermal Home Journal...

328

Tracking granules at the Sun's surface and reconstructing velocity fields. II. Error analysis  

E-Print Network (OSTI)

The determination of horizontal velocity fields at the solar surface is crucial to understanding the dynamics and magnetism of the convection zone of the sun. These measurements can be done by tracking granules. Tracking granules from ground-based observations, however, suffers from the Earth's atmospheric turbulence, which induces image distortion. The focus of this paper is to evaluate the influence of this noise on the maps of velocity fields. We use the coherent structure tracking algorithm developed recently and apply it to two independent series of images that contain the same solar signal. We first show that a k-\\omega filtering of the times series of images is highly recommended as a pre-processing to decrease the noise, while, in contrast, using destretching should be avoided. We also demonstrate that the lifetime of granules has a strong influence on the error bars of velocities and that a threshold on the lifetime should be imposed to minimize errors. Finally, although solar flow patterns are easily recognizable and image quality is very good, it turns out that a time sampling of two images every 21 s is not frequent enough, since image distortion still pollutes velocity fields at a 30% level on the 2500 km scale, i.e. the scale on which granules start to behave like passive scalars. The coherent structure tracking algorithm is a useful tool for noise control on the measurement of surface horizontal solar velocity fields when at least two independent series are available.

R. Tkaczuk; M. Rieutord; N. Meunier; T. Roudier

2007-07-13T23:59:59.000Z

329

Effect of temperature on wave velocities in sands and sandstones with heavy hydrocarbons  

SciTech Connect

A laboratory investigation was made of the effects of temperature on wave velocities in well cemented Massillon and Boise sandstones and unconsolidated Ottawa sand saturated with heavy hydrocarbons, as well as the dependence of compressional velocities in the hydrocarbons themselves as a function of temperature. The hydrocarbons selected as pore saturants were a commercial paraffin wax, 1-Eicosene, natural heavy crude, and natural tar. The experimental results show that the compressional wave velocities in the hydrocarbons decrease markedly with increasing temperature. In contrast wave velocities in the Massillon and Boise sandstones and unconsolidated Ottawa sand saturated with air or water decrease only little with increasing temperatures. The main reason for the large decreases in rocks with hydrocarbons is the melting of solid hydrocarbons, and high pore pressure. Thermal expansion of the saturants, and possibly thermal cracking of the heavy fractions and vaporization of the light fractions of the hydrocarbons may also contribute. The large decreases of the compressional and shear wave velocities in the hydrocarbon-saturated rocks and sands with temperature, suggest that seismic measurements such as used in seismology or borehole tomography may be very useful in detecting steam fronts in heavy hydrocarbon reservoirs undergoing steam flooding.

Wang, Z.; Nur, A.M.

1986-01-01T23:59:59.000Z

330

Velocity measurements in the near field of a diesel fuel injector by ultrafast imagery  

E-Print Network (OSTI)

This paper examines the velocity profile of fuel issuing from a high-pressure single-orifice diesel injector. Velocities of liquid structures were determined from time-resolved ultrafast shadow images, formed by an amplified two-pulse laser source coupled to a double-frame camera. A statistical analysis of the data over many injection events was undertaken to map velocities related to spray formation near the nozzle outlet as a function of time after start of injection. These results reveal a strong asymmetry in the liquid profile of the test injector, with distinct fast and slow regions on opposite sides of the orifice. Differences of ~100 m/s can be observed between the 'fast' and 'slow' sides of the jet, resulting in different atomization conditions across the spray. On average, droplets are dispersed at a greater distance from the nozzle on the 'fast' side of the flow, and distinct macrostructure can be observed under the asymmetric velocity conditions. The changes in structural velocity and atomization b...

Sedarsky, David

2013-01-01T23:59:59.000Z

331

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

332

Two-dimensional Imaging Velocity Interferometry: Technique and Data Analysis  

Science Conference Proceedings (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

333

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

NLE Websites -- All DOE Office Websites (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

334

Normalized Span Method for Thermo-Mechanical Design of Duct-Manhole and Pipe-Manhole Cable Systems  

Science Conference Proceedings (OSTI)

The EPRI Normalized Span (NSPAN) method provides design tools for the mechanical design of transmission-class XLPE insulated power cables installed in pipe or duct manhole systems. It is based on the method and experimentally measured XLPE cable parameters recorded in EPRI report 1001849, Mechanical Effects on Extruded Dielectric Cables and Joints Installed in Underground Transmission Systems in North America (publically available at no charge). The NSPAN method is implemented in an EPRI software program...

2010-12-23T23:59:59.000Z

335

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

SciTech Connect

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

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

1984-06-01T23:59:59.000Z

336

Impact properties of irradiated HT9 from the fuel duct of FFTF  

SciTech Connect

This paper reports Charpy impact test data for the ACO-3 duct material (HT9) from the Fast Flux Test Facility (FFTF) and its archive material. Irradiation doses for the specimens were in the range of 3– 148 dpa and irradiation temperatures in the range of 378–504 *C. The impact tests were performed for the small V-notched Charpy specimens with dimensions of 3 * 4 * 27 mm at an impact speed of 3.2 m/s in a 25 J capacity machine. Irradiation lowered the upper-shelf energy (USE) and increased the transition temperatures significantly. The shift of ductile–brittle transition temperatures (DDBTT) was greater after relatively low temperature irradiation. The USE values were in the range of 5.5–6.7 J before irradiation and decreased to the range of 2–5 J after irradiation. Lower USEs were measured for lower irradiation temperatures and specimens with T-L orientation. The dose dependences of transition temperature and USE were not significant because of the radiation effect on impact behavior nearly saturated at the lowest dose of about 3 dpa. A comparison showed that the lateral expansion of specimens showed a linear correlation with absorbed impact energy, but with large scatter in the results. Size effect was also discussed to clarify the differences in the impact property data from subsize and standard specimens as well as to provide a basis for comparison of data from different specimens. The USE and DDBTT data from different studies were compared.

Byun, Thak Sang; Lewis, W. Daniel; Toloczko, Mychailo B.; Maloy, Stuart A.

2012-02-01T23:59:59.000Z

337

Impact Properties of Irradiated HT9 from the Fuel Duct of FFTF  

SciTech Connect

This paper reports Charpy impact test data for the ACO-3 duct material (HT9) from the Fast Flux Test Facility (FFTF) and its archive material. Irradiation doses for the specimens were in the range of 3 148 dpa and irradiation temperatures in the range of 378 504 oC. The impact tests were performed for the small V-notched Charpy specimens with dimensions of 3 4 27 mm at an impact speed of 3.2 m/s in a 25J capacity machine. Irradiation lowered the upper-shelf energy (USE) and increased the transition temperatures significantly. The shift of transition temperatures was greater after relatively low temperature irradiation. The USE values were in the range of 5.5 6.7 J before irradiation and decreased to the range of 2 5 J after irradiation. Lower USEs were measured for lower irradiation temperatures and specimens with T-L orientation. For the irradiated specimens, the dose dependences of transition temperature and USE were not significant because of the radiation effect on impact behavior nearly saturated at the lowest dose of about 3 dpa. A comparison showed that the lateral expansion of specimens showed a linear correlation with absorbed impact energy, but with large scatter in the results. The size effect was also discussed to clarify the differences in the impact data of subsize and standard specimens.

Byun, Thak Sang [ORNL; Maloy, S [Los Alamos National Laboratory (LANL); Toloczko, M [Pacific Northwest National Laboratory (PNNL); Lewis, William Daniel [ORNL

2012-01-01T23:59:59.000Z

338

Measurements of Laminar Flame Velocity for Components of Natural Gas  

E-Print Network (OSTI)

Measurements of Laminar Flame Velocity for Components of Natural Gas Patricia Dirrenberger1 flame velocity of components of natural gas, methane, ethane, propane, and nbutane as well as of binary and tertiary mixtures of these compounds proposed as surrogates for natural gas. These measurements have been

339

Correlation of turbulent burning velocities of ethanol-air, measured in a fan-stirred bomb up to 1.2 MPa  

SciTech Connect

The turbulent burning velocity is defined by the mass rate of burning and this also requires that the associated flame surface area should be defined. Previous measurements of the radial distribution of the mean reaction progress variable in turbulent explosion flames provide a basis for definitions of such surface areas for turbulent burning velocities. These inter-relationships. in general, are different from those for burner flames. Burning velocities are presented for a spherical flame surface, at which the mass of unburned gas inside it is equal to the mass of burned gas outside it. These can readily be transformed to burning velocities based on other surfaces. The measurements of the turbulent burning velocities presented are the mean from five different explosions, all under the same conditions. These cover a wide range of equivalence ratios, pressures and rms turbulent velocities for ethanol-air mixtures. Two techniques are employed, one based on measurements of high speed schlieren images, the other on pressure transducer measurements. There is good agreement between turbulent burning velocities measured by the two techniques. All the measurement are generalised in plots of burning velocity normalised by the effective unburned gas rms velocity as a function of the Karlovitz stretch factor for different strain rate Markstein numbers. For a given value of this stretch factor a decrease in Markstein number increases the normalised burning velocity. Comparisons are made with the findings of other workers. (author)

Bradley, D.; Lawes, M.; Mansour, M.S. [School of Mechanical Engineering, University of Leeds (United Kingdom)

2011-01-15T23:59:59.000Z

340

Multiple mapping conditioning of velocity in turbulent jet flames  

Science Conference Proceedings (OSTI)

Multiple mapping conditioning (MMC) has emerged as a new approach to model turbulent reacting flows. This study revises the standard MMC closure for velocity in turbulent jet flows from linearity in the reference space to linearity in the composition space. This modeling amendment ensures that the standard velocity model in conditional moment closure studies can now be used for MMC computation as well. A simplified model for the velocity-dependence of MMC drift coefficients is derived without loss of generality and is implemented for the revised velocity closure. Modeling results have been corroborated against the Direct Numerical Simulation database of a spatially evolving, planar turbulent jet flame. The revised model shows marked improvement over standard MMC closure in predicting velocity statistics close to the nozzle. (author)

Vaishnavi, P. [Mechanical Engineering Department, Imperial College, London SW7 2AZ (United Kingdom); Kronenburg, A. [Institut fuer Technische Verbrennung, Universitaet Stuttgart, 70174 Stuttgart (Germany)

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.


341

Local Equation of State and Velocity Distributions of a Driven Granular Gas  

E-Print Network (OSTI)

We present event-driven simulations of a granular gas of inelastic hard disks with incomplete normal restitution in two dimensions between vibrating walls (without gravity). We measure hydrodynamic quantities such as the stress tensor, density and temperature profiles, as well as velocity distributions. Relating the local pressure to the local temperature and local density, we construct a local constitutive equation. For strong inelasticities the local constitutive relation depends on global system parameters, like the volume fraction and the aspect ratio. For moderate inelasticities the constitutive relation is approximately independent of the system parameters and can hence be regarded as a local equation of state, even though the system is highly inhomogeneous with heterogeneous temperature and density profiles arising as a consequence of the energy injection. Concerning the local velocity distributions we find that they do not scale with the square root of the local granular temperature. Moreover the high-velocity tails are different for the distribution of the x- and the y-component of the velocity, and even depend on the position in the sample, the global volume fraction, and the coefficient of restitution.

Olaf Herbst; Peter Müller; Matthias Otto; Annette Zippelius

2004-02-04T23:59:59.000Z

342

SIMULATIONS OF EARLY BARYONIC STRUCTURE FORMATION WITH STREAM VELOCITY. II. THE GAS FRACTION  

SciTech Connect

Understanding the gas content of high-redshift halos is crucial for studying the formation of the first generation of galaxies and reionization. Recently, Tseliakhovich and Hirata showed that the relative 'stream' velocity between the dark matter and baryons at the time of recombination-formally a second-order effect, but an unusually large one-can influence the later structure formation history of the universe. We quantify the effect of the stream velocity on the so-called characteristic mass-the minimum mass of a dark matter halo capable of retaining most of its baryons throughout its formation epoch-using three different high-resolution sets of cosmological simulations (with separate transfer functions for baryons and dark matter) that vary in box size, particle number, and the value of the relative velocity between the dark matter and baryons. In order to understand this effect theoretically, we generalize the linear theory filtering mass to properly account for the difference between the dark matter and baryonic density fluctuation evolution induced by the stream velocity. We show that the new filtering mass provides an accurate estimate for the characteristic mass, while other theoretical ansatzes for the characteristic mass are substantially less precise.

Naoz, Smadar [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)] [Institute for Theory and Computation, Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States); Yoshida, Naoki [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan)] [Department of Physics, University of Tokyo, Tokyo 113-0033 (Japan); Gnedin, Nickolay Y., E-mail: snaoz@cfa.harvard.edu [Particle Astrophysics Center, Fermi National Accelerator Laboratory, Batavia, IL 60510 (United States)

2013-01-20T23:59:59.000Z

343

Vertical Velocities in Continental Boundary Layer Stratocumulus...  

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

- Persist of long time-scales * Impact on radiation budget - High SW albedo compared to land or ocean Klein and Hartmann 1993 But Why Continental Clouds? * They do exist -...

344

An Adaptive Dealiasing Method Based on Variational Analysis for Radar Radial Velocities Scanned with Small Nyquist Velocities  

Science Conference Proceedings (OSTI)

Previous velocity–azimuth display (VAD)-based methods of dealiasing folded radial velocities have relied heavily on the VAD uniform-wind assumption and, thus, can fail when the uniform-wind assumption becomes poor around azimuthal circles in a ...

Qin Xu; Kang Nai

2012-12-01T23:59:59.000Z

345

Investigation of a combustion driven oscillation in a refinery flare. Part B: Visualisation of a periodic flow instability in a bifurcating duct following a contraction  

SciTech Connect

A flow visualisation study was performed to investigate a periodic flow instability in a bifurcating duct within the tip of the flares at the Shell refinery in Clyde, NSW, to verify the trigger of a combustion-driven oscillation proposed in Part A of this study, and to identify its features. The model study assessed only the flow instability, uncoupled from the acoustic resonance and the combustion that are also present in the actual flare. Three strong, coupled flow oscillations were found to be present in three regions of the fuel line in the flare tip model. A periodic flow separation was found to occur within the contraction at the inlet to the tip, a coupled, periodic flow oscillation was found in the two transverse ''cross-over ducts'' from the central pipe to the outer annulus and an oscillating flow recirculation was present in the ''end-cap'' region of the central pipe. The dimensionless frequency of these oscillations in the model was found to match that measured in the full-scale plant for high fuel flow rates. This, and the strength of these flow oscillations, gives confidence that they are integral to the full-scale combustion-driven oscillation and most likely the primary trigger. The evidence indicates that the periodic flow instability is initiated by the separation and roll-up of the annular boundary layer at the start of the contraction in the fuel section of the flare tip. The separation generates an annular vortex which interacts with the blind-ended pipe downstream, leading to a pressure wave which propagates back upstream, initiating the next separation event and repeating the cycle. The study also investigated flow control devices with a view to finding a practical approach to mitigate the oscillations. The shape of these devices was constrained to allow installation without removing the tip of the flare. This aspect of the study highlighted the strength and nature of the coupled oscillation, since it proved to be very difficult to mitigate the oscillation in this way. An effective configuration is presented, comprising of three individual components, all three of which were found to be necessary to eliminate the oscillation completely. (author)

Riese, M.; Kelso, R.M.; Nathan, G.J. [School of Mechanical Engineering, The University of Adelaide, SA 5005 (Australia); Mullinger, P.J. [School of Chemical Engineering, The University of Adelaide, SA 5005 (Australia)

2007-08-15T23:59:59.000Z

346

Performance and Impact from Duct Repair and Ventilation Modifications of Two Newly Constructed Manufactured Houses Located in a Hot and Humid Climate  

E-Print Network (OSTI)

Two nearly identical houses situated next to each other in Bossier City, Louisiana were studied in an effort to better understand moisture and cooling energy related problems in manufactured houses with low thermostat set-points during the cooling season. By design, the major difference between houses was the type of air conditioning units. House A had a standard split air conditioner and House B had a twospeed split air conditioner. In an effort to make the buildings more similar, the building airtightness was adjusted until it was the same in each house, and duct leaks were sealed so that the ducts were tight and there was equal tightness in both houses. A ventilation system was also added at the same time of duct repair. Duct repair and the ventilation modifications resulted in significant impacts on the cooling energy, temperature, relative humidity, and building pressures. Cooling energy decreased 37% in House A and 18% in House B, while the floor space dewpoint increased significantly. It is estimated that 35 % savings was due solely to duct repair in House A and 17% in House B. The primary cause of House A savings being twice House B is attributed to House A operating at nearly twice the capacity most of the time and had more duct leakage repaired. This resulted in higher system pressures and therefore greater duct leakage than in House B. Before building modifications, House A used 15.4 kWh per day (32%) more than House B and 3.4 kWh per day (11%) more after modifications. A method of characterizing interstitial spaces using dewpoint measurement is presented and shows that the belly space became 2.6 times more like outdoor conditions after repairs in House A and 2.0 times more in House B.

Withers, C.; Moyer, N.; Chasar, D.; Chandra, S.

2002-01-01T23:59:59.000Z

347

Estimating fracture parameters from p-wave velocity profiles about a geothermal well  

DOE Green Energy (OSTI)

The feasibility of locating fracture zones and estimating their crack parameters was examined using an areal well shoot method centered on Utah State Geothermal Well 9-1, Beaver County, Utah. High-resolution travel time measurements were made between a borehole sensor and an array of shot stations distributed radially and azimuthally about the well. Directional velocity behavior in the vicinity of the well was investigated by comparing velocity logs derived from the travel time data. Three fracture zones were identified form the velocity data, corroborating fracture indicators seen in other geophysical logs conducted in Well 9-1. Crack densities and average crack aspect ratios for these fracture zones were estimated using a self-consistent velocity theory (O'Connell and Budiansy 1974). Probable trends of these fracture zones were established from a combination of the data from the more distant shot stations and the results of a gravity survey. The results of this study indicate that the areal well shoot is a potentially powerful tool for the reconnaisance of fracture-controlled fluid and gas reservoirs. Improvements in methodology and hardware could transform it into an operationally viable survey method.

Jenkinson, J.T.; Henyey, T.L.; Sammis, C.G.; Leary, P.C.; McRaney, J.K.

1981-12-01T23:59:59.000Z

348

The Rossiter-McLaughlin effect and analytic radial velocity curves for transiting extrasolar planetary systems  

E-Print Network (OSTI)

A transiting extrasolar planet sequentially blocks off the light coming from the different parts of the disk of the host star in a time dependent manner. Due to the spin of the star, this produces an asymmetric distortion in the line profiles of the stellar spectrum, leading to an apparent anomaly of the radial velocity curves, known as the Rossiter - McLaughlin effect. Here, we derive approximate but accurate analytic formulae for the anomaly of radial velocity curves taking account of the stellar limb darkening. The formulae are particularly useful in extracting information of the projected angle between the planetary orbit axis and the stellar spin axis, \\lambda, and the projected stellar spin velocity, V sin I_s. We create mock samples for the radial curves for the transiting extrasolar system HD209458, and demonstrate that constraints on the spin parameters (V sin I_s, \\lambda) may be significantly improved by combining our analytic template formulae and the precision velocity curves from high-resolution spectroscopic observations with 8-10 m class telescopes. Thus future observational exploration of transiting systems using the Rossiter - McLaughlin effect is one of the most important probes to better understanding of the origin of extrasolar planetary systems, especially the origin of their angular momentum.

Yasuhiro Ohta; Atsushi Taruya; Yasushi Suto

2004-10-21T23:59:59.000Z

349

Sensitivity studies of heat transfer: forced convection across a cylindrical pipe and duct flow  

E-Print Network (OSTI)

We consider two common heat transfer processes and perform a through sensitivity study of the variables involved. We derive and discuss analytical formulas for the heat transfer coefficient in function of film velocity, air temperature and pipe diameter. The according plots relate to a qualitative analysis of the multi-variable function $h$, according to functional optimization. For each process, we provide with graphs and tables of the parameters of interest, such as the Reynolds number. This method of study and the specific values can constitute a useful reference for didactic purposes.

Ferrantelli, Andrea; Viljanen, Martti

2013-01-01T23:59:59.000Z

350

Composite Vertical Structure of Vertical Velocity in Nonprecipitating Cumulus Clouds  

Science Conference Proceedings (OSTI)

Vertical transects of Doppler vertical velocity data, obtained from an airborne profiling millimeter-wave cloud radar, are composited for a large number of cumulus clouds (Cu) at various stages of their life cycle, to examine typical circulations ...

Yonggang Wang; Bart Geerts

2013-05-01T23:59:59.000Z

351

Efficient Dealiasing of Doppler Velocities Using Local Environment Constraints  

Science Conference Proceedings (OSTI)

A Doppler velocity dealiasing algorithm is described that processes one radial at a time by comparing that radial with a previous radial. This technique has worked reliably on numerous Doppler radar datasets for clear air, thunderstorm, and ...

Michael D. Eilts; Steven D. Smith

1990-02-01T23:59:59.000Z

352

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

353

Y-12 Site Experience with Deposition Velocity Issues  

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

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

354

Vertical Velocity Structures in an Axisymmetric, Nonhydrostatic Tropical Cyclone Model  

Science Conference Proceedings (OSTI)

A statistical analysis of several experiments with different microphysical parameterizations in an axisymmetric, nonhydrostatic tropical cyclone model illustrates the impact of icc-phase microphysics on model vertical velocity structure. The ...

Stephen J. Lord; Jacqueline M. Lord

1988-05-01T23:59:59.000Z

355

Detiding Three-Dimensional Velocity Survey Data in Coastal Waters  

Science Conference Proceedings (OSTI)

A three-dimensional data interpolation technique is proposed that efficiently removes tidal currents from spatial velocity surveys. The least squares method extends prior two-dimensional detiding methods to three spatial dimensions using ...

Andreas Münchow

2000-05-01T23:59:59.000Z

356

The Finescale Response of Lowered ADCP Velocity Profiles  

Science Conference Proceedings (OSTI)

Lowered acoustic Doppler current profiler (LADCP) velocity profiles are compared with simultaneous higher-resolution expendable current profiler (XCP) profiles to determine the lowered ADCP's response at short wavelengths. Although lowered ADCP ...

Kurt Polzin; Eric Kunze; Jules Hummon; Eric Firing

2002-02-01T23:59:59.000Z

357

Mass Transport Velocity in Free Barotropic Poincaré Waves  

Science Conference Proceedings (OSTI)

The mass transport velocity induced by long surface waves in a shallow, rotating viscous ocean is studied theoretically by using a Lagrangian description of motion. The depth is constant, and the water is homogeneous. Such waves are referred to ...

Frode Høydalsvik; Jan Erik Weber

2003-09-01T23:59:59.000Z

358

TOPS: A Free-Fall Velocity and CTD Profiler  

Science Conference Proceedings (OSTI)

A free-fall instrument, TOPS, measures vertical profiles of horizontal ocean velocity, conductivity and temperature. Profiling capability extends throughout the full water column (6000 db pressure limitation). Larger vertical wavelength (water ...

S. P. Hayes; H. B. Milburn; E. F. Ford

1984-09-01T23:59:59.000Z

359

LOW VELOCITY SHPERE IMPACT OF SODA LIME SILICATE GLASS  

Science Conference Proceedings (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.

Morrissey, Timothy G [ORNL; Fox, Ethan E [ORNL; Wereszczak, Andrew A [ORNL; Vuono, Daniel J [ORNL

2012-01-01T23:59:59.000Z

360

Representation of Velocity Gradient Effects in a Gaussian Puff Model  

Science Conference Proceedings (OSTI)

The Gaussian puff model framework is extended to provide a description of velocity shear distortion effects. An efficient splitting-merging algorithm is presented so that a maximum puff size can be specified for a calculation. This localizes the ...

R. I. Sykes; D. S. Henn

1995-12-01T23:59:59.000Z

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.


361

Equatorial Atlantic Velocity and Temperature Observations: February–November 1981  

Science Conference Proceedings (OSTI)

Upper ocean velocity and temperature measurements were obtained in the central equatorial Atlantic using surface moored current meters from February to November 1981. Distinct seasonal variations were observed in the zonal momentum and ...

R. H. Weisberg

1985-05-01T23:59:59.000Z

362

Simulation of Three-Dimensional Turbulent Velocity Fields  

Science Conference Proceedings (OSTI)

New algorithms for the simulation of three-dimensional homogeneous turbulent velocity fields are compared with standard spectral domain algorithms. Results are presented for a von Kármán model of the covariance tensor. For typical atmospheric ...

Rod Frehlich; Larry Cornman; Robert Sharman

2001-02-01T23:59:59.000Z

363

A New Relationship between Mean Doppler Velocity and Differential Reflectivity  

Science Conference Proceedings (OSTI)

A new relationship has been established linking the vertical mean Doppler velocity of raindrop spectra and the accompanying differential reflectivities. It is based upon the specific radar combination of a vertically pointing Doppler and a ...

Matthias Steiner

1991-06-01T23:59:59.000Z

364

Dealiasing of Doppler Radar Velocities Using a Torus Mapping  

Science Conference Proceedings (OSTI)

A novel dealiasing algorithm for Doppler radar velocity data has been developed at the Swedish Meteorological and Hydrological Institute (SMHI). Unlike most other methods, it does not need independent wind information from other instruments (e.g.,...

Günther Haase; Tomas Landelius

2004-10-01T23:59:59.000Z

365

Eulerian and Lagrangian Velocity Distributions in the North Atlantic  

Science Conference Proceedings (OSTI)

Velocity probability density functions (PDFs) are calculated using data from subsurface current meters in the western North Atlantic Ocean. The PDFs are weakly, but significantly, non-Gaussian. They deviate from normality because of an excess of ...

J. H. LaCasce

2005-12-01T23:59:59.000Z

366

Benthic Boundary-Layer Velocity Profiles: Dependence on Averaging Period  

Science Conference Proceedings (OSTI)

The relationship between benthic boundary-layer velocity profiles and current meter averaging time is investigated using detailed (0.61 Hz) current measurements recorded within 1 m of the bottom on the inner continental shelf. The percentage of ...

Barry M. Lesht

1980-06-01T23:59:59.000Z

367

GPS velocity field for the Tien Shan and surrounding regions  

E-Print Network (OSTI)

Measurements at ?400 campaign-style GPS points and another 14 continuously recording stations in central Asia define variations in their velocities both along and across the Kyrgyz and neighboring parts of Tien Shan. They ...

Zubovich, Alexander V.

368

Profiler Measurements of Vertical Velocity Fluctuations in the Ocean  

Science Conference Proceedings (OSTI)

A method is described for measuring the vertical component of velocity fluctuations due to three-dimensional turbulence in the ocean from a freely falling microstructure profiler. The dynamic pressure measurement relies on a commercially ...

J. N. Moum

1990-04-01T23:59:59.000Z

369

Deep Velocity Measurements in the Western Equatorial Indian Ocean  

Science Conference Proceedings (OSTI)

Vertical profiles of horizontal current collected in April and June 1979 in the western Indian Ocean revealed the presence of short vertical scale (150–300 m) deep zonal jets, trapped to within 1° of the equator. Meridional velocity records ...

Rui M. Ponte; James Luyten

1990-01-01T23:59:59.000Z

370

Platform-Motion Correction of Velocity Measured by Doppler Lidar  

Science Conference Proceedings (OSTI)

The NOAA/Earth System Research Laboratory (ESRL) has two coherent Doppler lidar systems that have been deployed on board research vessels to obtain data during several experiments. The instruments measure the wind velocity relative to the motion ...

Reginald J. Hill; W. Alan Brewer; Sara C. Tucker

2008-08-01T23:59:59.000Z

371

Field-effect transistor having a superlattice channel and high carrier velocities at high applied fields  

DOE Patents (OSTI)

A field effect transistor comprises a semiconductor having a source, a drain, a channel and a gate in operational relationship. The semiconductor is a strained layer superlattice comprising alternating quantum well and barrier layers, the quantum well layers and barrier layers being selected from the group of layer pairs consisting of InGaAs/AlGaAs, InAs/InAlGaAs, and InAs/InAlAsP. The layer thicknesses of the quantum well and barrier layers are sufficiently thin that the alternating layers constitute a superlattice which has a superlattice conduction band energy level structure in k-vector space which includes a lowest energy .GAMMA.-valley and a next lowest energy L-valley, each k-vector corresponding to one of the orthogonal directions defined by the planes of said layers and the directions perpendicular thereto. The layer thicknesses of the quantum well layers are selected to provide a superlattice L.sub.2D -valley which has a shape which is substantially more two-dimensional than that of said bulk L-valley.

Chaffin, deceased, Roger J. (late of Albuquerque, NM); Dawson, Ralph (Albuquerque, NM); Fritz, Ian J. (Albuquerque, NM); Osbourn, Gordon C. (Albuquerque, NM); Zipperian, Thomas E. (Albuquerque, NM)

1989-01-01T23:59:59.000Z

372

Field-effect transistor having a superlattice channel and high carrier velocities at high applied fields  

DOE Patents (OSTI)

A field effect transistor comprises a semiconductor having a source, a drain, a channel and a gate in operational relationship. The semiconductor is a strained layer superlattice comprising alternating quantum well and barrier layers, the quantum well layers and barrier layers being selected from the group of layer pairs consisting of InGaAs/AlGaAs, InAs/InAlGaAs, and InAs/InAlAsP. The layer thicknesses of the quantum well and barrier layers are sufficiently thin that the alternating layers constitute a superlattice which has a superlattice conduction band energy level structure in k-vector space. The layer thicknesses of the quantum well layers are selected to provide a superlattice L/sub 2D/-valley which has a shape which is substantially more two-dimensional than that of said bulk L-valley. 2 figs.

Chaffin, R.J.; Dawson, L.R.; Fritz, I.J.; Osbourn, G.C.; Zipperian, T.E.

1987-06-08T23:59:59.000Z

373

Steam Generating Units (duct burners) 40 CFR Part 60 Subpart GG- Standards of Performance for Stationary Gas Turbines  

E-Print Network (OSTI)

For nitrogen oxides has been determined to be selective catalytic reduction. l As authorized by the Northwest Clean Air Agency Regulation Section 300, this order is issued subject to the following restrictions and conditions: 1) The gas turbines shall burn either pipeline natural gas, or number 2 distillate oil with a sulfur content not to exceed 0.05 weight percent. The HRSG duct burners shall burn only pipeline natural gas. 2) Pollutant concentrations for each gas turbinelheat recovery steam generator stack shall not exceed the following:

unknown authors

2007-01-01T23:59:59.000Z

374

NEUTRONIC REACTOR HAVING LOCALIZED AREAS OF HIGH THERMAL NEUTRON DENSITIES  

DOE Patents (OSTI)

A nuclear reactor for the irradiation of materials designed to provide a localized area of high thermal neutron flux density in which the materials to be irradiated are inserted is described. The active portion of the reactor is comprised of a cubicle graphite moderator of about 25 feet in length along each axis which has a plurality of cylindrical channels for accommodatirg elongated tubular-shaped fuel elements. The fuel elements have radial fins for spacing the fuel elements from the channel walls, thereby providing spaces through which a coolant may be passed, and also to serve as a heatconductirg means. Ducts for accommnodating the sample material to be irradiated extend through the moderator material perpendicular to and between parallel rows of fuel channels. The improvement is in the provision of additional fuel element channels spaced midway between 2 rows of the regular fuel channels in the localized area surrounding the duct where the high thermal neutron flux density is desired. The fuel elements normally disposed in the channels directly adjacent the duct are placed in the additional channels, and the channels directly adjacent the duct are plugged with moderator material. This design provides localized areas of high thermal neutron flux density without the necessity of providing additional fuel material.

Newson, H.W.

1958-06-01T23:59:59.000Z

375

VELOCITY EVOLUTION AND THE INTRINSIC COLOR OF TYPE Ia SUPERNOVAE  

SciTech Connect

To understand how best to use observations of Type Ia supernovae (SNe Ia) to obtain precise and accurate distances, we investigate the relations between spectra of SNe Ia and their intrinsic colors. Using a sample of 1630 optical spectra of 255 SNe, based primarily on data from the CfA Supernova Program, we examine how the velocity evolution and line strengths of Si II {lambda}6355 and Ca II H and K are related to the B - V color at peak brightness. We find that the maximum-light velocity of Si II {lambda}6355 and Ca II H and K and the maximum-light pseudo-equivalent width of Si II {lambda}6355 are correlated with intrinsic color, with intrinsic color having a linear relation with the Si II {lambda}6355 measurements. Ca II H and K does not have a linear relation with intrinsic color, but lower-velocity SNe tend to be intrinsically bluer. Combining the spectroscopic measurements does not improve intrinsic color inference. The intrinsic color scatter is larger for higher-velocity SNe Ia-even after removing a linear trend with velocity-indicating that lower-velocity SNe Ia are more 'standard crayons'. Employing information derived from SN Ia spectra has the potential to improve the measurements of extragalactic distances and the cosmological properties inferred from them.

Foley, Ryan J.; Sanders, Nathan E.; Kirshner, Robert P., E-mail: rfoley@cfa.harvard.edu [Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)

2011-12-01T23:59:59.000Z

376

Design of regulated velocity flow assurance device for petroleum industry  

E-Print Network (OSTI)

The petroleum industry faces problems in transportation of crude petroleum be- cause of the deposition of paraffins, hydrates and asphaltenes on the insides of the pipeline. These are conventionally removed using either chemical inhibitors or mechani- cal devices, called pigs, which travel through the pipeline and mechanically scrape away the deposits. These pigs are propelled by the pipeline product itself and hence travel at the same velocity as the product. Research has indicated that cleaning would be better if the pigs are traveling at a relatively constant velocity of around 70% of the product velocity. This research utilizes the concept of regulating the bypass flow velocity in order to maintain the pig velocity. The bypass flow is regulated by the control unit based on the feedback from the turbine flowmeter, which monitors the bypass flow. A motorized butterfly valve is used for actually controlling the bypass flow. In addition to cleaning, the proposed pig utilizes on-board electronics like accelerom- eter and pressure transducers to store the data gathered during the pig run. This data can then be analyzed and the condition of the pipeline predicted. Thus, this research addresses the problem of designing a pig to maintain a constant velocity in order to achieve better cleaning. It also helps gather elementary data that can be used to predict the internal conditions in the pipe.

Yardi, Chaitanya Narendra

2004-12-01T23:59:59.000Z

377

Mechanical joining with self piercing solid-rivets at elevated tool velocities  

Science Conference Proceedings (OSTI)

In the present paper the influence of a higher setting velocity in the joining process of self piercing solid-rivets is shown. In the conventional process tool velocities well below 1 m/s are common. The present research results show the potential of increasing them in the range of about 5 m/s. The results are especially relevant for joining high-strength steels. These steel sheets often cause problems in the process of riveting mixed materials, e. g. aluminium-steel compound. The high strength of the steel sometimes leads to undesirable material flow in the joining process or unwanted burr development. These effects, which are described in detail in the article, can be reduced significantly for the investigated cases by the use of higher tool velocities. Using a high speed camera and a load cell, a test setup based on a drop tower was realized. It was used to time the force signals and the motion profile of the high speed riveting process. The results of the force analysis show an oscillating force progression. Within a numerical research the principal effects influencing the results of the riveting process can be shown. It was found that the pulse-like force transmission between riveting machine and punch, results in various vibrations especially of long and thin tool parts. Hence the rivet penetrates the sheet metal with non-uniform velocities. As a result the early indentation of die into the lower sheet metal at the beginning of the process is reduced, so that the final process step provides a sufficient material flow into the circular rivet groove. A strain-rate dependent process model with elastic tool properties and consideration of inertia effects is presented.

Neugebauer, R.; Jesche, F.; Kraus, C.; Hensel, S. [Fraunhofer Institute for Machine Tools and Forming Technology IWU, Reichenhainer Strasse 88, 09126 Chemnitz (Germany)

2011-05-04T23:59:59.000Z

378

Scaleup tests and supporting research for the development of duct injection technology. Topical report No. 2, Task 3.1: Evaluation of system performance, Duct Injection Test Facility, Muskingum River Power Plant, Beverly, Ohio  

Science Conference Proceedings (OSTI)

This Topical Report No. 2 is an interim report on the Duct Injection Test Facility being operated for the Department of Energy at Beverly, Ohio. Either dry calcium hydroxide or an aqueous slurry of calcium hydroxide (prepared by slaking quicklime) is injected into a slipstream of flue gas to achieve partial removal of SO{sub 2} from a coal-burning power station. Water injected with the slurry or injected separately from the dry sorbents cools the flue gas and increases the water vapor content of the gas. The addition of water, either in the slurry or in a separate spray, makes the extent of reaction between the sorbent and the SO{sub 2} more complete; the presumption is that water is effective in the liquid state, when it is able to wet the sorbent particles physically, and not especially effective in the vapor state. An electrostatic precipitator collects the combination of suspended solids (fly ash from the boiler and sorbent from the duct injection process). All of the operations are being carried out on the scale of approximately 50,000 acfm of flue gas.

Felix, L.G.; Dismukes, E.B.; Gooch, J.P. [Southern Research Inst., Birmingham, AL (United States); Klett, M.G.; Demian, A.G. [Gilbert/Commonwealth, Inc., Reading, PA (United States)

1992-04-20T23:59:59.000Z

379

Precipitation Identification from Radar Wind Profiler Spectral Moment Data: Vertical Velocity Histograms, Velocity Variance, and Signal Power–Vertical Velocity Correlations  

Science Conference Proceedings (OSTI)

Correlations between range-corrected signal power Src and radial vertical velocity Vr, from the vertical beam of a UHF wind profiler can be used to distinguish between air- and precipitation-dominated echoes using an Src–Vr correlation diagram. ...

F. Martin Ralph; Paul J. Neiman; Dominique Ruffieux

1996-06-01T23:59:59.000Z

380

An Improved Gaussian Jet Model for Deriving Absolute Geostrophic Velocity from Satellite Altimetry  

Science Conference Proceedings (OSTI)

Key aspects of a Gaussian jet model for deriving absolute geostrophic velocity from TOPEX/Poseidon altimeter data are improved. Velocities are obtained by synthesizing Gaussian fits to cross-stream velocity anomaly profiles of the Kuroshio and ...

Seung-Bum Kim; M. A. Saunders

2002-12-01T23:59:59.000Z

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.


381

DEPOSITION VELOCITY ESTIMATION WITH THE GENII V2 SOFTWARE  

SciTech Connect

In 2010, the Department of Energy (DOE) Chief of Nuclear Safety and Office of Health, Safety and Security (HSS), with the support of industry experts in atmospheric sciences and accident dose consequences analysis, performed detailed analyses of the basis for the dry deposition velocity (DV) values used in the MACCS2 computer code. As a result of these analyses, DOE concluded that the historically used default DV values of 1 centimeter/second (cm/s) for unfiltered/unmitigated releases and 0.1 cm/s for filtered/mitigated releases may not be reasonably conservative for all DOE sites and accident scenarios. HSS recently issued Safety Bulletin 2011-02, Accident Analysis Parameter Update, recommending the use of the newly developed default DV, 0.1 cm/s for an unmitigated/unfiltered release. Alternatively site specific DV values can be developed using GENII version 2 (GENII v2) computer code. Key input parameters for calculating DV values include surface roughness, maximum wind speed for calm, particle size, particle density and meteorological data (wind speed and stability class). This paper will include reasonably conservative inputs, and a truncated parametric study. In lieu of the highly-conservative recommended DV value (0.1cm/s) for unmitigated/unfiltered release, GENII v2 has been used to justify estimated 95th percentile DV values. Also presented here are atmospheric dilution factors ({chi}/Q values) calculated with the MACCS2 code using the DV values form GENII v2, {chi}/Q values calculated directly with GENII v2, and a discussion of these results compare with one another. This paper will give an overview of the process of calculating DV with GENII v2 including a discussion of the sensitivity of input parameters.

Hutchins, H.

2012-04-23T23:59:59.000Z

382

Exceptional Ground Accelerations and Velocities Caused by Earthquakes  

Science Conference Proceedings (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

383

Three-dimensional P velocity structure of the crust below Newberry Volcano, Oregon  

SciTech Connect

Utilizing teleseismic P residuals, we have detected a column of high P velocity material extending from within 10 km of the surface below the summit of Newberry Volcano, Oregon to midcrustal depths near 25 km. We interpret this column to be the expression of a swarm of predominantly subsolidus gabbroic sills and dikes which were intruded as the volcano was built. The high P velocities observed below the volcano severely limit the size of magma chambers which could presently exist in the crust below Newberry Volcano. Those possible include a few percent of partial melt distributed through large volumes of a mafic intrusion zone in the midcrust; a few smaller, higher melt fraction zones in the midcrust with dimensions less than 6 km and whose aggregate volume is only a few percent of enclosing volumes of 200 km/sup 3/; small magma bodies with dimensions of a few kilometers located within the upper 10 km of the crust; or a mafic, crystal-rich magma of arbitrary dimensions located in the upper few km. The low P velocities detected in the upper 4 km beneath the center of the summit caldera may be partially caused by a magma chamber in the second of these catagories.

Stauber, D.A.; Green, S.M.; Iyer, H.M.

1988-09-10T23:59:59.000Z

384

Modelling Solar Oscillation Power Spectra: II. Parametric Model of Spectral Lines Observed in Doppler Velocity Measurements  

E-Print Network (OSTI)

We describe a global parametric model for the observed power spectra of solar oscillations of intermediate and low degree. A physically motivated parameterization is used as a substitute for a direct description of mode excitation and damping as these mechanisms remain poorly understood. The model is targeted at the accurate fitting of power spectra coming from Doppler velocity measurements and uses an adaptive response function that accounts for both the vertical and horizontal components of the velocity field on the solar surface and for possible instrumental and observational distortions. The model is continuous in frequency, can easily be adapted to intensity measurements and extends naturally to the analysis of high-frequency pseudo modes (interference peaks at frequencies above the atmospheric acoustic cutoff).

Vorontsov, Sergei V

2013-01-01T23:59:59.000Z

385

On mass and velocity distributions in members of star clusters An analytical approach  

E-Print Network (OSTI)

Dynamical evolution of stellar mass distribution in star clusters is analysed by considering simultaneously the effects of dynamical friction, stochastic heating and the gravitational potential due to mass distribution in the clusters. A simple expression is suggested for the dynamical friction which adequately describes it in both high and low velocity ranges and the effect of mass distribution in the cluster on the dynamics of a test mass can be described by an anharmonic potential. With the help of energy considerations we describe the dispersions in position and in velocity for stars of different masses showing how the slowing down and mass segregation of stars evolve in the cluster. Results are presented with the parameters for the star clusters of our Galaxy.

Chatterjee, S; Sagar, R; Kumar, Brijesh; Sagar, Ram

2002-01-01T23:59:59.000Z

386

On mass and velocity distributions in members of star clusters : An analytical approach  

E-Print Network (OSTI)

Dynamical evolution of stellar mass distribution in star clusters is analysed by considering simultaneously the effects of dynamical friction, stochastic heating and the gravitational potential due to mass distribution in the clusters. A simple expression is suggested for the dynamical friction which adequately describes it in both high and low velocity ranges and the effect of mass distribution in the cluster on the dynamics of a test mass can be described by an anharmonic potential. With the help of energy considerations we describe the dispersions in position and in velocity for stars of different masses showing how the slowing down and mass segregation of stars evolve in the cluster. Results are presented with the parameters for the star clusters of our Galaxy.

S. Chatterjee; Brijesh Kumar; Ram Sagar

2002-11-18T23:59:59.000Z

387

The Velocity of Money in a Life-Cycle Model  

E-Print Network (OSTI)

The determinants of the velocity of money have been examined based on life-cycle hypothesis. The velocity of money can be expressed by reciprocal of the average value of holding time which is defined as interval between participating exchanges for one unit of money. This expression indicates that the velocity is governed by behavior patterns of economic agents and open a way to constructing micro-foundation of it. It is found that time pattern of income and expense for a representative individual can be obtained from a simple version of life-cycle model, and average holding time of money resulted from the individual's optimal choice depends on the expected length of relevant planning periods.

Wang, Y; Wang, Yougui; Qiu, Hanqing

2005-01-01T23:59:59.000Z

388

MACCS2/Deposition Velocity Workshop | Department of Energy  

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

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

389

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

390

Determination of the transverse velocity of Q2237+0305  

E-Print Network (OSTI)

The largest systematic uncertainty present in the analysis of gravitationally microlensed quasar light curves is that of the galactic transverse velocity. We describe a method for determining the transverse velocity as well as its application to published monitoring data of Q2237+0305 (Irwin et al. 1989; Corrigan et al. 1991; Ostensen et al 1995). We find that while this data displays strong evidence for microlensing, it limits the transverse velocity to be < 500 km/sec (for microlens masses of 0.5 solar masses). In addition, by combining these results with a new method for modelling the microlensing contribution of stellar proper motions, we find that the masses of microlenses in Q2237+0305 are consistent with those of low mass stars.

J. S. B. Wyithe

1999-09-21T23:59:59.000Z

391

The Velocity Field of Quasar Broad Emission Line Gas  

E-Print Network (OSTI)

In this Letter, the broad emission line (BEL) profiles of superluminal quasars with apparent jet velocities, $\\beta_{a}>10$, (ultraluminal QSOs, or ULQSOs hereafter) are studied as a diagnostic of the velocity field of the BEL emitting gas in quasars. The ULQSOs are useful because they satisfy a very strict kinematical constraint, their parsec scale jets must be propagating within $12^{\\circ}$ of the line of sight. We know the orientation of these objects with great certainty. The large BEL FWHM, $\\sim 3,000 \\mathrm{km/s} - 6,000 \\mathrm{km/s}$, in ULQSOs tend to indicate that the BEL gas has a larger component of axial velocity (either random or in a wind) along the jet direction than previously thought.

Brian Punsly

2007-01-25T23:59:59.000Z

392

Planar velocity analysis of diesel spray shadow images  

E-Print Network (OSTI)

The focus of this work is to demonstrate how spatially resolved image information from diesel fuel injection events can be obtained using a forward-scatter imaging geometry, and used to calculate the velocities of liquid structures on the periphery of the spray. In order to obtain accurate velocities directly from individual diesel spray structures, those features need to be spatially resolved in the measurement. The distributed structures measured in a direct shadowgraphy arrangement cannot be reliably analyzed for this kind of velocity information. However, by utilizing an intense collimated light source and adding imaging optics which modify the signal collection, spatially resolved optical information can be retrieved from spray edge regions within a chosen object plane. This work discusses a set of measurements where a diesel spray is illuminated in rapid succession by two ultrafast laser pulses generated by a mode-locked Ti-Sapphire oscillator seeding a matched pair of regenerative amplifiers. Light fro...

Sedarsky, David

2012-01-01T23:59:59.000Z

393

Comparative Study of Ultimate Saturation Velocity in Zigzag and Chiral Carbon Nanotubes  

Science Conference Proceedings (OSTI)

Charge transfer mechanism in carbon nanotubes (CNTs) from the scattering-limited Ohmic transport to high-field-initiated ballistic transport is studied. It is shown that the electrons changes their motion from randomness (in equilibrium) to streamlined one (in non-equilibrium) when high electric field is applied. The intrinsic velocity is discussed in non-parabolic semiconducting limits considering the nondegenerate and degenerate situations. The results obtained are significant in extracting carrier transport properties from experimental data on CNTs and in understanding the fundamental processes controlling the charge transport in nanoscale devices.

Chek, Desmond C. Y.; Hashim, Abdul Manaf [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Tan, Michael Loong Peng [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Electrical Engineering Division, Engineering Department, University of Cambridge, 9 J.J. Thomson Avenue, Cambridge CB3 0FA (United Kingdom); Arora, Vijay K. [Faculty of Electrical Eng., Universiti Teknologi Malaysia, 81310 Skudai, Johor (Malaysia); Division of Engineering and Physics, Wilkes University, Wilkes-Barre, PA 18766 (United States)

2011-05-25T23:59:59.000Z

394

How Required Reserve Ratio Affects Distribution and Velocity of Money  

E-Print Network (OSTI)

In this paper the dependence of wealth distribution and the velocity of money on the required reserve ratio is examined based on a random transfer model of money and computer simulations. A fractional reserve banking system is introduced to the model where money creation can be achieved by bank loans and the monetary aggregate is determined by the monetary base and the required reserve ratio. It is shown that monetary wealth follows asymmetric Laplace distribution and latency time of money follows exponential distribution. The expression of monetary wealth distribution and that of the velocity of money in terms of the required reserve ratio are presented in a good agreement with simulation results.

Xi, N; Wang, Y; Xi, Ning; Ding, Ning; Wang, Yougui

2005-01-01T23:59:59.000Z

395

Edge Turbulence Velocity Changes with Lithium Coating on NSTX  

SciTech Connect

Lithium coating improves energy confinement and eliminates edge localized modes in NSTX, but the mechanism of this improvement is not yet well understood. We used the gas-puff-imaging (GPI) diagnostic on NSTX to measure the changes in edge turbulence which occurred during a scan with variable lithium wall coating, in order to help understand the reason for the confinement improvement with lithium. There was a small increase in the edge turbulence poloidal velocity and a decrease in the poloidal velocity fluctuation level with increased lithium. The possible effect of varying edge neutral density on turbulence damping was evaluated for these cases in NSTX. __________________________________________________

A. Cao, S.J. Zweben, D.P. Stotler, M. Bell, A. Diallo, S.M. Kaye and B. LeBlanc

2012-08-10T23:59:59.000Z

396

Source shape determination with directional fragment-fragment velocity correlations  

E-Print Network (OSTI)

Correlation functions, constructed from directional projections of the relative velocities of fragments, are used to determine the shape of the breakup volume in coordinate space. For central collisions of 129Xe + natSn at 50 MeV per nucleon incident energy, measured with the 4pi multi-detector INDRA at GSI, a prolate shape aligned along the beam direction with an axis ratio of 1:0.7 is deduced. The sensitivity of the method is discussed in comparison with conventional fragment-fragment velocity correlations.

A. Le Fevre; C. Schwarz; G. Auger; M. L. Begemann-Blaich; N. Bellaize; R. Bittiger; F. Bocage; B. Borderie; R. Bougault; B. Bouriquet; J. L. Charvet; A. Chbihi; R. Dayras; D. Durand; J. D. Frankland; E. Galichet; D. Gourio; D. Guinet; S. Hudan; P. Lautesse; F. Lavaud; R. Legrain; O. Lopez; J. Lukasik; U. Lynen; W. F. J. Mueller; L. Nalpas; H. Orth; E. Plagnol; E. Rosato; A. Saija; C. Sfienti; B. Tamain; W. Trautmann; A. Trzcinski; K. Turzo; E. Vient; M. Vigilante; C. Volant; B. Zwieglinski

2007-11-09T23:59:59.000Z

397

Clutter in the GMTI range-velocity map.  

SciTech Connect

Ground Moving Target Indicator (GMTI) radar maps echo data to range and range-rate, which is a function of a moving target's velocity and its position within the antenna beam footprint. Even stationary clutter will exhibit an apparent motion spectrum and can interfere with moving vehicle detections. Consequently it is very important for a radar to understand how stationary clutter maps into radar measurements of range and velocity. This mapping depends on a wide variety of factors, including details of the radar motion, orientation, and the 3-D topography of the clutter.

Doerry, Armin Walter

2009-04-01T23:59:59.000Z

398

THE RADIAL VELOCITY EXPERIMENT (RAVE): THIRD DATA RELEASE  

Science Conference Proceedings (OSTI)

We present the third data release of the RAdial Velocity Experiment (RAVE) which is the first milestone of the RAVE project, releasing the full pilot survey. The catalog contains 83,072 radial velocity measurements for 77,461 stars in the southern celestial hemisphere, as well as stellar parameters for 39,833 stars. This paper describes the content of the new release, the new processing pipeline, as well as an updated calibration for the metallicity based upon the observation of additional standard stars. Spectra will be made available in a future release. The data release can be accessed via the RAVE Web site.

Siebert, A. [Observatoire Astronomique de Strasbourg, Universite de Strasbourg, CNRS, UMR 7550, 11 rue de l'universite, 67000 Strasbourg (France); Williams, M. E. K.; Siviero, A.; Boeche, C.; Steinmetz, M.; De Jong, R. S.; Enke, H.; Anguiano, B. [Leibniz-Institut fuer Astrophysik Potsdam (AIP), An der Sternwarte 16, D-14482 Potsdam (Germany); Reid, W.; Ritter, A. [Department of Physics and Astronomy, Faculty of Sciences, Macquarie University, NSW 2109, Sydney (Australia); Fulbright, J.; Wyse, R. F. G. [Department of Physics and Astronomy, Johns Hopkins University, 366 Bloomberg Center, 3400 N. Charles St., Baltimore, MD 21218 (United States); Munari, U. [INAF Osservatorio Astronomico di Padova, 36012 Asiago (Italy); Zwitter, T. [Faculty of Mathematics and Physics, University of Ljubljana, Jadranska 19, 1000 Ljubljana (Slovenia); Watson, F. G.; Burton, D.; Cass, C. J. P.; Fiegert, K.; Hartley, M.; Russel, K. S. [Australian Astronomical Observatory, P.O. Box 296, Epping, NSW 1710 (Australia)

2011-06-15T23:59:59.000Z

399

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

2013-08-28T23:59:59.000Z

400

In Proc. 1996 ACEEE Summer Study, August 1996, Asilomar, CA. Energy Effectiveness of Duct Sealing and Insulation in Two Multifamily Buildings  

E-Print Network (OSTI)

of Duct Sealing and Insulation in Two Multifamily Buildings Iain S. Walker, Mark P. Modera, Adrian Tuluca forced air distribution systems have a significant impact on the energy efficiency of buildings. Little work has been done to quantify these losses in apartment buildings. In this paper we will discuss field

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.


401

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

Science Conference Proceedings (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

402

Velocity Autocorrelation Functions and Diffusion of Dusty Plasma  

SciTech Connect

The velocity autocorrelation functions and square displacements were calculated on the basis of experimental data obtained on experimental setup with dc discharge. Computer simulation of the system of dust particles by the method of the Langevin dynamics was performed. The comparisons of experimental and theoretical results are given.

Ramazanov, T. S.; Dzhumagulova, K. N.; Daniyarov, T. T.; Dosbolayev, M. K.; Jumabekov, A. N. [IETP, al-Farabi Kazakh National University, 96a, Tole bi St., Almaty, 050012 (Kazakhstan)

2008-09-07T23:59:59.000Z

403

Velocity-Space Proton Diffusion in the Solar Wind Turbulence  

E-Print Network (OSTI)

We study a velocity-space quasilinear diffusion of the solar wind protons driven by oblique Alfven turbulence at proton kinetic scales. Turbulent fluctuations at these scales possess properties of kinetic Alfven waves (KAWs) that are efficient in Cherenkov resonant interactions. The proton diffusion proceeds via Cherenkov kicks and forms a quasilinear plateau - nonthermal proton tail in the velocity distribution function (VDF). The tails extend in velocity space along the mean magnetic field from 1 to (1.5-3) VA, depending on the spectral break position, turbulence amplitude at the spectral break, and spectral slope after the break. The most favorable conditions for the tail generation occur in the regions where the proton thermal and Alfven velocities are about the same, VTp/VA = 1. The estimated formation times are within 1-2 h for typical tails at 1 AU, which is much shorter than the solar wind expansion time. Our results suggest that the nonthermal proton tails, observed in-situ at all heliocentric distan...

Voitenko, Yuriy

2013-01-01T23:59:59.000Z

404

Seismic imaging for velocity and attenuation structure in geothermal fields  

DOE Green Energy (OSTI)

We have applied the attenuation inversion technique developed by Evans and Zucca (1988) to a seismic tomographic data set taken at Newberry Volcano by Achauer et al. (1988). Our preliminary results suggest that the interpretation of the velocity data by Achauer et al. that a magma chamber is present 3 km beneath the caldera is not confirmed by the attenuation data.

Zucca, J.J. (Lawrence Livermore National Lab., CA (USA)); Evans, J.R. (Geological Survey, Menlo Park, CA (USA))

1989-06-01T23:59:59.000Z

405

Effects of Velocity Shear in Advective Mixed-Layer Models  

Science Conference Proceedings (OSTI)

A general multidimensional model of the upper mixed layer of oceans and lakes is presented. The density profile is approximated as uniform over the depth of the layer. Such an assumption is not made for the distribution of the horizontal velocity ...

Will P. M. de Ruijter

1983-09-01T23:59:59.000Z

406

Measurement of turbulent wind velocities using a rotating boom apparatus  

DOE Green Energy (OSTI)

The present report covers both the development of a rotating-boom facility and the evaluation of the spectral energy of the turbulence measured relative to the rotating boom. The rotating boom is composed of a helicopter blade driven through a pulley speed reducer by a variable speed motor. The boom is mounted on a semiportable tower that can be raised to provide various ratios of hub height to rotor diameter. The boom can be mounted to rotate in either the vertical or horizontal plane. Probes that measure the three components of turbulence can be mounted at any location along the radius of the boom. Special hot-film sensors measured two components of the turbulence at a point directly in front of the rotating blade. By using the probe rotated 90/sup 0/ about its axis, the third turbulent velocity component was measured. Evaluation of the spectral energy distributions for the three components of velocity indicates a large concentration of energy at the rotational frequency. At frequencies slightly below the rotational frequency, the spectral energy is greatly reduced over that measured for the nonrotating case measurements. Peaks in the energy at frequencies that are multiples of the rotation frequency were also observed. We conclude that the rotating boom apparatus is suitable and ready to be used in experiments for developing and testing sensors for rotational measurement of wind velocity from wind turbine rotors. It also can be used to accurately measure turbulent wind for testing theories of rotationally sampled wind velocity.

Sandborn, V.A.; Connell, J.R.

1984-04-01T23:59:59.000Z

407

A fixed complexity velocity estimation method for mobile MIMO users  

Science Conference Proceedings (OSTI)

To estimate speed of a moving user transmitting data over a Single Input Single Output (SISO) Rayleigh fading channels, many Autocorrelation function (ACF) based schemes have been presented in literature [2-7]. Recently, it was shown that in a Multiple ... Keywords: autocorrelation function, complexity reduction, correlated MIMO channels, velocity estimation

Salman A. Khan

2010-01-01T23:59:59.000Z

408

The relativistic velocity addition law optimizes a forecast gambler's profit  

E-Print Network (OSTI)

We extend the projective covariant bookmaker's bets model to the forecasting gamblers case. The probability of correctness of forecasts shifts probabilities of branching. The formula for the shift of probabilities leads to the velocity addition rule of the special theory of relativity. In the absence of information about bookmaker's wagers the stochastic logarithmic rates completely determines the optimal stakes of forecast gambler.

Piotrowski, Edward W

2007-01-01T23:59:59.000Z

409

The Cartesian Diver: A Self-Profiling Lagrangian Velocity Recorder  

Science Conference Proceedings (OSTI)

The Cartesian diver is an autonomous velocity profiler capable of operating to 1 km depth in the ocean. It has a self-controlled buoyancy changer which is used to control the direction of profiling. The buoyancy changer has two states, full ...

T. F. Duda; C. S. Cox; T. K. Deaton

1988-02-01T23:59:59.000Z

410

Particle velocity measurements of the reaction zone in nitromethane  

DOE Green Energy (OSTI)

The detonation reaction-zone length in neat, deuterated, and chemically sensitized nitromethane (NM) has been measured by using several different laser-based velocity interferometry systems. The experiments involved measuring the particle velocity history at a NM/PMMA (polymethylmethacrylate) window interface during the time a detonation in the NM interacted with the interface. Initially, Fabry-Perot interferometry was used, but, because of low time resolution (>5 ns), several different configurations of VISAR interferometry were subsequently used. Early work was done with VISARs with a time resolution of about 3 ns. By making changes to the recording system, we were able to improve this to {approx}1 ns. Profiles measured at the NM/PMMA interface agree with the ZND theory, in that a spike ({approx}2.45 mm/{micro}s) is measured that is consistent with an extrapolated reactant NM Hugoniot matched to the PMMA window. The spike is rather sharp, followed by a rapid drop in particle velocity over a time of 5 to 10 ns; this is evidence of early fast reactions. Over about 50 ns, a much slower particle velocity decrease occurs to the assumed CJ condition - indicating a total reaction zone length of {approx}300 {micro}m. When the NM is chemically changed, such as replacing the hydrogen atoms with deuterium or chemically sensitizing with a base, some changes are observed in the early part of the reaction zone.

Sheffield, S. A. (Stephen A.); Engelke, R. P. (Raymond P.); Alcon, R. R. (Robert R.); Gustavsen, R. L. (Richard L.); Robbins, D. L. (David L.); Stahl, D. B. (David B.); Stacy, H. L. (Howard L.); Whitehead, M. (Michael)

2002-01-01T23:59:59.000Z

411

Velocity and Stress in the Deep-Ocean Boundary Layer  

Science Conference Proceedings (OSTI)

In order to predict the response of deep ocean sediments to the near-bottom currents, accurate estimates of the near-bottom velocity and the boundary shear stress are necessary. Because of the unsteady nature of deep ocean currents, dynamic ...

S. R. McLean; J. Yean

1987-09-01T23:59:59.000Z

412

Deep ADCP Velocity Measurements in the Gulf Stream  

Science Conference Proceedings (OSTI)

This paper presents observations of the velocity structure from two transects across a Gulf Stream meander near 37°N, 68°W. Data were collected with a vessel-mounted 75-kHz acoustic Doppler current profiler (ADCP) to a depth of about 700 m. The ...

A. V. Berezutskii; S. E. Maximov; V. E. Sklyarov; R. L. Gordon

1991-12-01T23:59:59.000Z

413

Generalization of Child-Langmuir Law for Non-Zero Injection Velocities in a Planar Diode  

E-Print Network (OSTI)

The Child-Langmuir law relates the voltage applied across a planar diode to the saturation value J_CL of current density that can be transmitted through it in case the injection velocity of electrons into the diode is zero. The Child-Langmuir current density J_CL is, at the same time, (i) the maximum current density that can be transmitted through a planar diode, (ii) the current density below which the flow is steady and unidirectional in the long time limit and (iii) the average transmitted current density for {\\em any} value of injected current density above J_CL. Existing generalizations of Child-Langmuir law to non-zero velocities of injection are based on the characteristics (i) and (ii) of J_CL. This paper generalizes the law to non-zero velocities of injection based on the characteristic (iii) by deriving an analytical expression for the saturation value of current density. The analytical expression for the saturation current density is found to be well supported by numerical computations. A reason behind preferring the saturation property of the Child-Langmuir current density as the basis for its generalization is the importance of that property in numerical simulations of high current diode devices.

R. R. Puri; Debabrata Biswas; Raghwendra Kumar

2004-11-19T23:59:59.000Z

414

Low Velocity Sphere Impact of a Soda Lime Silicate Glass  

SciTech Connect

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

415

Possibility of generating strong magnetic fields in conducting ...  

Science Conference Proceedings (OSTI)

ducting medium moving under the action of a high-velocity penetrating body is analyzed .... head part of the impactor are subjected to extremely large tensile strains [3]. ... Such "pumping" can be accompanied by physical phenomena (

416

Generation of Ultrahigh-Velocity Ionizing Shocks with Petawatt-Class Laser Pulses  

Science Conference Proceedings (OSTI)

Ultrahigh-velocity shock waves (approx10 000 km/s or 0.03c) are generated by focusing a 350-TW laser pulse into low-density helium gas. The collisionless ultrahigh-Mach-number electrostatic shock propagates from the plasma into the surrounding gas, ionizing gas as it becomes collisional. The shock undergoes a corrugation instability due to propagation of the ionizing shock within the gas (the Dyakov-Kontorovich instability). This system may be relevant to the study of very high-Mach-number ionizing shocks in astrophysical situations.

Nilson, P. M.; Mangles, S. P. D.; Willingale, L.; Kaluza, M. C.; Thomas, A. G. R.; Najmudin, Z.; Evans, R. G.; Dangor, A. E.; Krushelnick, K. [Department of Physics, Imperial College, London SW7 2AZ United Kingdom (United Kingdom); Tatarakis, M.; Lancaster, K. L. [Technological Educational Institute of Crete, Romanou, 3-GR73133 Chania (Greece); Clarke, R. J. [CLF, Rutherford Appleton Laboratory, Chilton, Didcot, Oxon., OX11 0QX United Kingdom (United Kingdom); Karsch, S. [Max-Planck Institut fuer Quantenoptik, Hans-Kopfermann-Strasse, D-85748, Garching (Germany); Schreiber, J. [Max-Planck Institut fuer Quantenoptik, Hans-Kopfermann-Strasse, D-85748, Garching (Germany); Ludwig-Maximilians-Universistaet Munchen, Am Coulombwall, D-85748, Garching (Germany)

2009-12-18T23:59:59.000Z

417

Low Velocity Sphere Impact of a Soda Lime Silicate Glass  

Science Conference Proceedings (OSTI)

This report summarizes TARDEC-sponsored work at Oak Ridge National Laboratory (ORNL) during the FY11 involving low velocity (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 (energies 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

418

Velocity and density spectra of the Small Magellanic Cloud  

E-Print Network (OSTI)

This paper reports results on the statistical analysis of HI turbulence in the Small Magellanic Cloud (SMC). We use 21 cm channel maps, obtained with the Australia Telescope Compact Array and the Parkes telescope, and analyze the spectrum of observed intensity fluctuations as a function of the velocity slice thickness. We confirm predictions by Lazarian & Pogosyan (2000) on the change of the power law index and establish the spectra of 3-D density and velocity. The obtained spectral indices, -3.3 and -3.4, are slightly more shallow than the predictions for the Kolmogorov spectrum. This contrasts to the predictions for the shock-type spectra that are steeper than the Kolmogorov one. The nature of the energy injection in the SMC is unclear as no distinct energy injection scales are observed up to the entire scale of the SMC.

S. Stanimirovi?; A. Lazarian

2001-02-11T23:59:59.000Z

419

The AMS-RICH velocity and charge reconstruction  

E-Print Network (OSTI)

The AMS detector, to be installed on the International Space Station, includes a Ring Imaging Cerenkov detector with two different radiators, silica aerogel (n=1.05) and sodium fluoride (n=1.334). This detector is designed to provide very precise measurements of velocity and electric charge in a wide range of cosmic nuclei energies and atomic numbers. The detector geometry, in particular the presence of a reflector for acceptance purposes, leads to complex Cerenkov patterns detected in a pixelized photomultiplier matrix. The results of different reconstruction methods applied to test beam data as well as to simulated samples are presented. To ensure nominal performances throughout the flight, several detector parameters have to be carefully monitored. The algorithms developed to fulfill these requirements are presented. The velocity and charge measurements provided by the RICH detector endow the AMS spectrometer with precise particle identification capabilities in a wide energy range. The expected performances on light isotope separation are discussed.

F. Barao; M. Aguilar-Benitez; L. Arruda; B. Baret; A. Barrau; G. Barreira; E. Belmont; J. Berdugo; J. Borges; M. Buenerd; D. Casadei; J. Casaus; E. Cortina; M. Costado; D. Crespo; C. Delgado; C. Diaz; L. Derome; P. Goncalves; R. Garcia-Lopez; C. de la Guia; A. Herrero; E. Lanciotti; G. Laurenti; A. Malinin; C. Mana; J. Marin; M. Mangin-Brinet; G. Martinez; A. Menchaca-Rocha; C. Palomares; R. Pereira; M. Pimenta; A. Putze; Y. Sallaz-Damaz; E. S. Seo; I. Sevilla; A. Torrento; M. Vargas-Trevino; O. Veziant

2007-09-13T23:59:59.000Z

420

Superluminal group velocity through near-maximal neutrino oscillations  

E-Print Network (OSTI)

Recently it was suggested that the observation of superluminal neutrinos by the OPERA collaboration may be due to group velocity effects resulting from close-to-maximal oscillation between neutrino mass eigenstates, in analogy to known effects in optics. We show that superluminal propagation does occur through this effect for a series of very narrow energy ranges, but this phenomenum cannot explain the OPERA measurement.

Tim R. Morris

2011-10-11T23:59:59.000Z

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

Shear wave velocities from noise correlation at local scale  

Science Conference Proceedings (OSTI)

Cross correlations of ambient seismic noise recordings have been studied to infer shear seismic velocities with depth. Experiments have been done in the crowded and noisy historical centre of Napoli over inter-station distances from 50 m to about 400 m, whereas active seismic spreadings are prohibitive, even for just one receiver. Group velocity dispersion curves have been extracted with FTAN method from the noise cross correlations and then the non linear inversion of them has resulted in Vs profiles with depth. The information of near by stratigraphies and the range of Vs variability for samples of Neapolitan soils and rocks confirms the validity of results obtained with our expeditious procedure. Moreover, the good comparison of noise H/V frequency of the first main peak with 1D and 2D spectral amplifications encourages to continue experiments of noise cross-correlation. If confirmed in other geological settings, the proposed approach could reveal a low cost methodology to obtain reliable and detailed Vs velocity profiles.

De Nisco, G.; Nunziata, C. [Dipartimento di Scienze della Terra, Univ. Napoli Federico II (Italy); Vaccari, F. [Dipartimento di Scienze della Terra, Univ. Trieste (Italy); Panza, G. F. [Dipartimento di Scienze della Terra, Univ. Trieste (Italy); The Abdus Salam International Center for Theoretical Physics, ESP-SAND Group, Trieste (Italy)

2008-07-08T23:59:59.000Z

422

Fermi velocity renormalization and the excitonic insulator in graphene  

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. This method is non-perturbative and takes full account of quantum fluctuations. We find a finite renormalized Fermi velocity v_FR > v_F, where v_F = c/300. We introduce the critical Fermi velocity renormalization v_c = v_FR(alpha_gc)/v_F, where alpha_gc is the critical coupling for the semimetal-insulator transition due to excitonic pair formation. We compare our results with empirical studies of interaction-induced spectral changes in graphene. We find v_c = 3.3, which should be contrasted with v_FR/v_F = 2 - 3 for ultra-clean suspended graphene and v_FR/v_F = 1.2 for graphene on a boron nitride substrate. Our results are consistent with the non-observation of insulating states in suspended graphene in the absence of an external magnetic field. We also discuss the dynamical critical exponent z.

Joaquín E. Drut; Timo A. Lähde

2013-04-05T23:59:59.000Z

423

Experimental Verification of Thermo-Mechanical Models for Cross-Linked Polyethylene Cable in Pipes and Ducts: Interim Report on First Cable Test  

Science Conference Proceedings (OSTI)

In 2002, the Electric Power Research Institute (EPRI) began investigations of the thermo-mechanical (T-M) behavior of transmission-class cable systems with extruded insulation in duct-manhole and pipe systems and began work on a design guide. The project consisted primarily of two efforts: experimental measurement of cable parameters and development of a mathematical simulation of the thermal and mechanical behavior of transmission-class cable with extruded cross-linked polyethylene (XLPE) ...

2013-12-23T23:59:59.000Z

424

Low Velocity Sphere Impact of a Borosilicate Glass  

SciTech Connect

This report summarizes US Army TARDEC sponsored work at Oak Ridge National Laboratory (ORNL) involving low velocity (< 30 m/s or < 65 mph) ball impact testing of Borofloat borosilicate glass, and is a follow-up to a similar study completed by the authors on Starphire soda-lime silicate glass last year. The response of the borosilicate glass to impact testing at different angles was also studied. The Borofloat glass was supplied by the US Army Research Laboratory and its tin-side was impacted or indented. The intent was to better understand low velocity impact response in the Borofloat. Seven sphere materials were used whose densities bracket that of rock: borosilicate glass, soda-lime silicate glass, silicon nitride, aluminum oxide, zirconium oxide, carbon steel, and a chrome steel. A gas gun or a ball-drop test setup was used to produce controlled velocity delivery of the spheres against the glass tile targets. Minimum impact velocities to initiate fracture in the Borofloat were measured and interpreted in context to the kinetic energy of impact and the elastic property mismatch between the seven sphere-Borofloat-target combinations. The primary observations from this low velocity (< 30 m/s or < 65 mph) testing were: (1) BS glass responded similarly to soda-lime silicate glass when spherically indented but quite differently under sphere impact conditions; (2) Frictional effects contributed to fracture initiation in BS glass when it spherically indented. This effect was also observed with soda-lime silicate glass; (3) The force necessary to initiate fracture in BS glass under spherical impact decreases with increasing elastic modulus of the sphere material. This trend is opposite to what was observed with soda-lime silicate glass. Friction cannot explain this trend and the authors do not have a legitimate explanation for it yet; (4) The force necessary to initiate contact-induced fracture is higher under dynamic conditions than under quasi-static conditions. That difference decreases with increasing elastic modulus mismatch between the sphere material and borosilicate This trend was opposite in soda-lime silicate glass; (5) Fracture in borosilicate glass occurs at lower velocities (i.e., easier) at 24{sup o} than at 0{sup o} (orthogonal) and 46{sup o} of impact for the same probability of failure. Though not analyzed yet, this suggests that a convolution of kinetic energy and friction is contributing to that trend; (6) There is a subtle indication there was intra-tile differences in spherical indentation RCIF. This likely is not a material property nor exclusive to borosilicate glass, rather, it is a statistical response of a combination of local, surface-located flaw and imposed tensile stress. Understanding of the surface flaw population and flaw positioning can likely enable prediction of spherical indentation RCIF; and (7) Contact-induced fracture did not initiate in the Borofloat BS for impact kinetic energies up to {approx} 20 mJ. For kinetic energies between {approx} 20-150 mJ, fracture sometimes initiated. Contact-induced fracture would always occur for impact energies > 150 mJ. The energy values, and their boundaries, were much lower for BS glass than they were for soda-lime silicate glass.

Morrissey, Timothy G [ORNL; Ferber, Mattison K [ORNL; Wereszczak, Andrew A [ORNL; Fox, Ethan E [ORNL

2012-05-01T23:59:59.000Z

425

Single-Duct Constant Air Volume System Supply Air Temperature Reset: Using Return Air Temperature or Outside Air Temperature?  

E-Print Network (OSTI)

The supply air temperature set point for a singleduct constant air volume air handling unit (AHU) system is often reset based on either return air temperature or outside air temperature in order to reduce simultaneous cooling and heating energy consumption. Both reset strategies make engineering sense as long as the reset schedules are reasonable. Quite often the decision to use one over the other is made with the assumption that they will all achieve some sorts of energy savings. However, the impact of these two strategies on AHU energy consumption could be very different. A comparison of these two commonly used supply air temperature reset strategies for a single-duct constant air volume system is presented in this paper. It is shown that from either the building energy consumption or building comfort point of view, the reset strategy based on outside air temperature is inherently better than that based on return air temperature. Significant amount of heating energy savings can be achieved by switching from return air temperature based reset to outside air temperature based reset. The reset strategy can also benefit variable air volume (VAV) AHUs. An improved supply air temperature set point reset control strategy is proposed by combining and staging the outside air and return air temperature based resets.

Wei, G.; Turner, W. D.; Claridge, D.; Liu, M.

2002-01-01T23:59:59.000Z

426

Two-Phase Frictional Pressure Drop Multipliers for SUVA R-134a Flowing in a Rectangular Duct  

SciTech Connect

The adiabatic two-phase frictional multipliers for SUVA, R-134a flowing in a rectangular duct (with D{sub H} = 4.8 mm) have been measured for 3 nominal system pressures (0.9 MPa, 1.38 MPa and 2.41 MPa) and 3 nominal mass fluxes (510, 1020 and 2040 kg/m{sup 2}/s). The data is compared with several classical correlations to assess their predictive capabilities. The Lockhart-Martinelli model gives reasonable results at the lowest pressure and mass flux, near the operating range of most refrigeration systems, but gives increasingly poor comparisons as the pressure and mass flux is increased. The Chisholm B-coefficient model is found to best predict the data over the entire range of test conditions; however, there is significant disagreement at the highest pressure tested (with the model over predicting the data upwards of 100% for some cases). The data shows an increased tendency toward homogeneous flow as the pressure and flow rate are increased, and in fact the homogeneous model best predicts the bulk of the data at the highest pressure tested.

P Vassallo; K Keller

2004-12-13T23:59:59.000Z

427

Derivation of site-specific relationships between hydraulic parameters and p-wave velocities based on hydraulic and seismic tomography  

SciTech Connect

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

428

The Michigan/MIKE Fiber System Survey of Stellar Radial Velocities in Dwarf Spheroidal Galaxies: Acquisition and Reduction of Data  

E-Print Network (OSTI)

We introduce a stellar velocity survey of dwarf spheroidal galaxies, undertaken using the Michigan/MIKE Fiber System (MMFS) at the Magellan/Clay 6.5 m telescope at Las Campanas Observatory. As of 2006 November we have used MMFS to collect 6415 high-resolution (R= 20000-25000) spectra from 5180 stars in four dwarf spheroidal galaxies: Carina, Fornax, Sculptor and Sextans. Spectra sample the range 5140-5180 Angstroms, which includes the prominent magnesium triplet absorption feature. We measure radial velocity (RV) to a median precision of 2.0 km/s for stars as faint as V ~ 20.5. From the spectra we also are able to measure the strength of iron and magnesium absorption features using spectral indices that correlate with effective temperature, surface gravity and chemical abundance. Measurement of line strength allows us to identify interloping foreground stars independently of velocity, and to examine the metallicity distribution among dSph members. Here we present detailed descriptions of MMFS, our target selection and spectroscopic observations, the data reduction procedure, and error analysis. We compare our RV results to previously published measurements for individual stars. In some cases we find evidence for a mild, velocity-dependent offset between the RVs we measure using the magnesium triplet and previously published RV measurements derived from the infrared calcium triplet. In companion papers we will present the complete data sets and kinematic analyses of these new observations.

Matthew G. Walker; Mario Mateo; Edward W. Olszewski; Rebecca Bernstein; Bodhisattva Sen; Michael Woodroofe

2007-03-12T23:59:59.000Z

429

VELOCITY SELECTOR METHOD FOR THE SEPARATION OF ISOTOPES  

DOE Patents (OSTI)

A velocity selector apparatus is described for separating and collecting an enriched fraction of the isotope of a particular element. The invention has the advantage over conventional mass spectrometers in that a magnetic field is not used, doing away with the attendant problems of magnetic field variation. The apparatus separates the isotopes by selectively accelerating the ionized constituents present in a beam of the polyisotopic substance that are of uniform kinetic energy, the acceleration being applied intermittently and at spaced points along the beam and in a direction normal to the direction of the propagation of the uniform energy beam whereby a transverse displacement of the isotopic constituents of different mass is obtained.

Britten, R.J.

1957-12-31T23:59:59.000Z

430

Velocity shear-induced effects on electrostatic ion perturbations  

Science Conference Proceedings (OSTI)

Linear evolution of electrostatic perturbations in an unmagnetized electron{endash}ion plasma shear flow is studied. New physical effects, arising due to the non-normality of linear dynamics are disclosed. A new class of {ital nonperiodic collective mode} with vortical motion of ions, characterized by intense energy exchange with the mean flow, is found. It is also shown that the velocity shear induces extraction of the mean flow energy by ion-sound waves and that during the shear-induced evolution the ion-sound waves turn eventually into ion plasma oscillations. {copyright} {ital 1997 American Institute of Physics.}

Rogava, A.D. [Department of Physics, Tbilisi State University, and Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia)] [Department of Physics, Tbilisi State University, and Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia); Chagelishvili, G.D. [Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia)] [Department of Theoretical Astrophysics, Abastumani Astrophysical Observatory, Tbilisi, Republic of (Georgia); [Department of Cosmogeophysics, Space Research Institute, Moscow (Russia); Berezhiani, V.I. [Department of Plasma Physics, Institute of Physics, Tbilisi, Republic of (Georgia)] [Department of Plasma Physics, Institute of Physics, Tbilisi, Republic of (Georgia)

1997-12-01T23:59:59.000Z

431

Determination of sputtered atom densities and velocities via simulation  

Science Conference Proceedings (OSTI)

Transport of sputtered atoms in a plasma sputtering unit is simulated using two known elastic collision models. The methods of studying the collision of two atoms are isotropic random scattering angle in the center of mass frame and the so-called center to center collision model in which the impact parameter is ignored and the two particles collide such as two material points. The obtained results for the density and velocity of sputtered atoms in both models are compared with some experimental reports. This investigation shows that the copper and argon atoms present pointlike behavior in the collision process.

Khorram, S.; Sobhanian, S. [Faculty of Physics, University of Tabriz, Tabriz, 51666 (Iran, Islamic Republic of); Research Institute for Applied Physics and Astronomy, University of Tabriz, Tabriz, 51666 (Iran, Islamic Republic of); Naghshara, H. [Faculty of Physics, University of Tabriz, Tabriz, 51666 (Iran, Islamic Republic of)

2011-04-01T23:59:59.000Z

432

Method and apparatus for measuring flow velocity using matched filters  

DOE Patents (OSTI)

An apparatus and method for measuring the flow velocities of individual phase flow components of a multiphase flow is disclosed. Signals arising from flow noise disturbance are extracted from the flow, at upstream and downstream locations. The signals are processed through pairs of matched filters which are matched to the flow disturbance frequency characteristics of the phase flow component to be measured. The processed signals are then cross-correlated to determine the transit delay time of the phase flow component between sensing positions.

Raptis, A.C.

1981-07-17T23:59:59.000Z

433

Velocity Profiles in a Cylindrical Liquid Jet by Reconstructed Velocimetry  

E-Print Network (OSTI)

in such a way that the jet boundaries appeared sharply focused. The Newtonian liquid used in all the experiments was a mixture of 74.7% glycerol (99.9% pure) with 25.3% tri- distilled water (weight percentage). Its measured properties were: density ? = 1250... dynamics theory (or numerical simulations) for un-wetted nozzles, but to explore the effects of nozzle wetting on the velocity profiles. It is well-known that nozzle face wetting slightly enlarges the jet diameter for some distance down- stream from...

Castrejon-Pita, J.R.; Hoath, S.D.; Hutchings, I.M.

2012-01-01T23:59:59.000Z

434

An Optical Array Instrument for Shape and Fall Velocity Measurements of Hydrometeors  

Science Conference Proceedings (OSTI)

A ground-based optical array instrument for the measurement of shapes, sizes, and fall velocities of freely falling hydrometeors is presented. The instrument, the Hydrometeor Velocity and Shape Detector (HVSD), is designed to accurately measure ...

E. Barthazy; S. Göke; R. Schefold; D. Högl

2004-09-01T23:59:59.000Z

435

Combining Inverted Echo Sounder and Horizontal Electric Field Recorder Measurements to Obtain Absolute Velocity Profiles  

Science Conference Proceedings (OSTI)

Profiles of absolute velocity are difficult to obtain in the ocean, especially over long periods of time at the same location. This paper presents a method of estimating full water column absolute horizontal velocity profiles as a function of ...

Christopher S. Meinen; Douglas S. Luther; D. Randolph Watts; Karen L. Tracey; Alan D. Chave; James Richman

2002-10-01T23:59:59.000Z

436

A Comparison of Vertical Velocity in Cirrus Obtained from Aircraft and Lidar Divergence Measurements during FIRE  

Science Conference Proceedings (OSTI)

Techniques are presented to obtain vertical velocity in cirrus clouds from in situ aircraft lateral wind measurements and from ground-based remote Doppler lidar measurements. In general, direct measurements of absolute vertical velocity w from ...

I. Gultepe; A. J. Heymsfield; D. H. Lenschow

1990-02-01T23:59:59.000Z

437

Dependence of Turbulent and Mesoscale Velocity Variances on Scale and Stability  

Science Conference Proceedings (OSTI)

The scale dependence of velocity variances is studied using data collected from a grassland site, a heather site, and four forested sites. The dependence of velocity variances on averaging time, used to define the fluctuation quantities, is ...

L. Mahrt; Erin Moore; Dean Vickers; N. O. Jensen

2001-03-01T23:59:59.000Z

438

Peak ground velocity evaluation by artificial neural network for west america region  

Science Conference Proceedings (OSTI)

With the Peak Ground Velocity 283 records in three dimensions, the velocity attenuation relationship with distance was discussed by neural network in this paper. The earthquake magnitude, epicenter distance, site intensity and site condition were considered ...

Ben-yu Liu; Liao-yuan Ye; Mei-ling Xiao; Sheng Miao

2006-10-01T23:59:59.000Z

439

Non-Gaussian Velocity Probability Density Functions: An Altimetric Perspective of the Mediterranean Sea  

Science Conference Proceedings (OSTI)

Velocity probability density functions (PDFs) are a key tool to study complex flows and are of great importance to model particle dispersion. The PDFs of geostrophic velocities derived from sea level anomalies maps for the Mediterranean Sea have ...

Jordi Isern-Fontanet; Emilio García-Ladona; Jordi Font; Antonio García-Olivares

2006-11-01T23:59:59.000Z

440

Effects of Radar Proximity on Single-Doppler Velocity Signatures of Axisymmetric Rotation and Divergence  

Science Conference Proceedings (OSTI)

Geometrical and mathematical relationships are developed to explain the variation with radar range of idealized single-Doppler velocity patterns of axisymmetric rotation and divergence regions. The velocity patterns become distorted as they ...

Vincent T. Wood; Rodger A. Brown

1992-12-01T23:59:59.000Z

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441

An Intercomparison Study Using Electromagnetic Three-Component Turbulent Velocity Probes  

Science Conference Proceedings (OSTI)

An intercomparison study was performed with four Russian-made, electromagnetic probes capable of measuring three components of oceanic turbulent velocities and two single-axis velocity sensors familiar to western scientists, namely, a hot-film ...

David Y. Lai; Vadim T. Paka; Donald P. Delisi; Anatoli V. Arjannikov; Sergei A. Khanaev

2000-07-01T23:59:59.000Z

442

A QUANTUM MECHANICAL APPROACH TO THE VELOCITY OF DISLOCATIONS IN ICE  

E-Print Network (OSTI)

~, A. ~ Higashi, A. , Physics of Ice, edited by N. Riehl, B.THE VELOCITY OF DISLOCATIONS IN ICE RECEIVED LAWRENCE A. R.the velocity of dislocations in ice ref. (3,4) with which we

Forouhi, A.R.

2011-01-01T23:59:59.000Z

443

Computation of the Streamfunction and Velocity Potential for Limited and Irregular Domains  

Science Conference Proceedings (OSTI)

An algorithm is proposed for the computation of streamfunction and velocity potential from given horizontal velocity vectors based on solving a minimization problem. To guarantee the uniqueness of the solution and computational reliability of the ...

Zhijin Li; Yi Chao; James C. McWilliams

2006-11-01T23:59:59.000Z

444

On the Structure of the Velocity Field over Progressive Mechanically-Generated Water Waves  

Science Conference Proceedings (OSTI)

The structure of the velocity field over a propagating wave of fixed frequency is examined. The vertical and horizontal velocities were measured in a transformed Eulerian wave-following frame of reference in a wind-wave research facility at ...

Yiannis Alex Papadimitrakis; En Yun Hsu; Robert L. Street

1984-12-01T23:59:59.000Z

445

Robust Estimations of Current Velocities with Four-Beam Broadband ADCPs  

Science Conference Proceedings (OSTI)

An extended explanation of the hypothesis and equations traditionally used to transform between four-beam ADCP radial beam velocities and current velocity components is presented. This explanation includes a dissertation about the meaning of the ...

M. Gilcoto; Emlyn Jones; Luis Fariña-Busto

2009-12-01T23:59:59.000Z

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