National Library of Energy BETA

Sample records for heat flow measurements

  1. Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland

    E-Print Network [OSTI]

    Graaf, Martin de

    Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland M. de Graaf #12;Heat transfer in katabatic flow Measurements on the Morteratsch glacier, Switzerland Martin de is used to calculate surface heat fluxes over glaciers. As determination of surface fluxes still

  2. Investigation of Groundwater Flow in Foothill and Mountain regions using Heat Flow measurements

    E-Print Network [OSTI]

    Fogg, Graham E.; Trask, James C

    2009-01-01

    Flow in Foothill and Mountain regions using Heat Flowenergy balance near mountain-front Finite element numericalcross-section for areal mountain-slope flow 10.2 2D cross-

  3. NEW MODEL AND MEASUREMENT PRINCIPLE OF FLOWING AND HEAT TRANSFER CHARACTERISTICS OF REGENERATOR

    SciTech Connect (OSTI)

    Chen, Y. Y.; Luo, E. C.; Dai, W.

    2008-03-16

    Regenerators play key role in oscillating-flow cryocoolers or thermoacoustic heat engine systems. However, their flowing and heat transfer mechanism is still not well understood. The complexities of the oscillating flow regenerator make traditional method of heat transfer research become difficult or helpless. In this paper, a model for porous media regenerator was given based on the linear thermoacoustic theory. Then the correlations for characteristic parameters were obtained by deducing universal expressions for thermoacoustic viscous function F{sub v} and thermal function F{sub T}. A simple acoustical method and experimental system to get F{sub v} and F{sub T} via measurements of isothermal regenerators were presented. Some measurements of packed stainless screen regenerators were performed, and preliminary experimental results for flow and convective coefficients were derived, which showing flowing friction factor is approximately within 132/Re to 173/Re.

  4. Convective heat flow probe

    DOE Patents [OSTI]

    Dunn, J.C.; Hardee, H.C.; Striker, R.P.

    1984-01-09

    A convective heat flow probe device is provided which measures heat flow and fluid flow magnitude in the formation surrounding a borehole. The probe comprises an elongate housing adapted to be lowered down into the borehole; a plurality of heaters extending along the probe for heating the formation surrounding the borehole; a plurality of temperature sensors arranged around the periphery of the probe for measuring the temperature of the surrounding formation after heating thereof by the heater elements. The temperature sensors and heater elements are mounted in a plurality of separate heater pads which are supported by the housing and which are adapted to be radially expanded into firm engagement with the walls of the borehole. The heat supplied by the heater elements and the temperatures measured by the temperature sensors are monitored and used in providing the desired measurements. The outer peripheral surfaces of the heater pads are configured as segments of a cylinder and form a full cylinder when taken together. A plurality of temperature sensors are located on each pad so as to extend along the length and across the width thereof, with a heating element being located in each pad beneath the temperature sensors. An expansion mechanism driven by a clamping motor provides expansion and retraction of the heater pads and expandable packet-type seals are provided along the probe above and below the heater pads.

  5. A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow...

    Open Energy Info (EERE)

    A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements And Heat-Flow Estimates From The Uk Geothermal Catalogue Jump to: navigation, search OpenEI Reference...

  6. Measurements of wall heat (mass) transfer for flow through blockages with round and square holes in a wide rectangular channel 

    E-Print Network [OSTI]

    Cervantes, Joel

    2002-01-01

    Naphthalene sublimation and pressure measurement experiments were conducted to study heat (mass) transfer enhancement by blockages with staggered round and square holes for turbulent air flows through the holes in the blockages in an 8:1 rectangular...

  7. Investigation of Groundwater Flow in Foothill and Mountain regions using Heat Flow measurements

    E-Print Network [OSTI]

    Fogg, Graham E.; Trask, James C

    2009-01-01

    1965) Rates of Vertical Groundwater Movement Estimated fromCrystalline Rocks. Groundwater, Vol. 2, pp. 6-12. Dettinger,horizontal and vertical groundwater flow components. Water

  8. Surface heat flow, crustal temperatures and mantle heat flow in the Proterozoic

    E-Print Network [OSTI]

    Rolandone, Frederique

    ) and an ancient island arc (Lynn Lake Belt) made of depleted juvenile rocks. Higher heat flow values foundSurface heat flow, crustal temperatures and mantle heat flow in the Proterozoic Trans-Hudson Orogen report on new measurements of heat flow and radiogenic heat production in 30 boreholes at 17 locations

  9. Radial flow heat exchanger

    DOE Patents [OSTI]

    Valenzuela, Javier (Hanover, NH)

    2001-01-01

    A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300). Certain heat exchangers in the assembly may be designed slightly differently than other heat exchangers to address changes in fluid properties during transport through the heat exchanger, so as to enhance overall thermal effectiveness of the assembly.

  10. Particle image velocimetry measurements for opposing flow in a vertical channel with a differential and asymmetric heating condition

    SciTech Connect (OSTI)

    Martinez-Suastegui, L. [Graduate Student, Facultad de Ingenieria, Universidad Nacional Autonoma de Mexico, C.U., Mexico 04510 D.F. (Mexico); Trevino, C. [Facultad de Ciencias, Universidad Nacional Autonoma de Mexico, C.U., Mexico 04510 D.F. (Mexico)

    2007-10-15

    Particle image velocimetry (PIV) measurements were carried out in an experimental investigation of laminar mixed convection in a vertical duct with a square cross-section. The main downward water-flow is driven by gravity while a portion of a lateral side is heated, and buoyancy forces produce non-stationary vortex structures close to the heated region. Various ranges of the Grashof number, Gr are studied in combination with the Reynolds number, Re varying from 300 to 700. The values of the generalized buoyancy parameter or Richardson number, Ri = Gr/Re{sup 2} parallel to the Grashof number are included in the results. The influence of these nondimensional parameters and how they affect the fluid flow structure and vortex sizes and locations are reported. The flow patterns are nonsymmetric, periodic, and exhibit increasing complexity and frequency for increasing buoyancy. For the averaged values of the resulting vortex dimensions, it was found that a better and more congruent representation occurs when employing the Grashof and Reynolds numbers as independent parameters. (author)

  11. Triaxial thermopile array geo-heat-flow sensor

    DOE Patents [OSTI]

    Carrigan, C.R.; Hardee, H.C.; Reynolds, G.D.; Steinfort, T.D.

    1990-01-01

    A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings. 6 figs.

  12. Triaxial thermopile array geo-heat-flow sensor

    DOE Patents [OSTI]

    Carrigan, Charles R. (Tracy, CA); Hardee, Harry C. (Albuquerque, NM); Reynolds, Gerald D. (Tijeras, NM); Steinfort, Terry D. (Tijeras, NM)

    1992-01-01

    A triaxial thermopile array geothermal heat flow sensor is designed to measure heat flow in three dimensions in a reconstituted or unperturbed subsurface regime. Heat flow can be measured in conductive or permeable convective media. The sensor may be encased in protective pvc tubing and includes a plurality of thermistors and an array of heat flow transducers arranged in a vertical string. The transducers produce voltage proportional to heat flux along the subsurface regime and permit direct measurement of heat flow in the subsurface regime. The presence of the thermistor array permits a comparison to be made between the heat flow estimates obtained from the transducers and heat flow calculated using temperature differences and Fourier's Law. The device is extremely sensitive with an accuracy of less than 0.1 Heat Flow Units (HFU) and may be used for long term readings.

  13. Lithospheric Heat Flow and Dynamics! obvious signals!

    E-Print Network [OSTI]

    Sandwell, David T.

    · $d( ) heat = flow scalar subsidence rate constant X #12;heat flow related to subsidence rate (qb ! quLithospheric Heat Flow and Dynamics! ! · obvious signals! - heat flow, depth, and geoid height?! - are transform faults thermal contraction cracks?! #12;global heat budget! 7.5 TW 44 TW 25-15 TW 3-13 TW

  14. MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER

    E-Print Network [OSTI]

    Lahey, Richard T.

    MODERN DEVELOPMENTS IN MULTIPHASE FLOW & HEAT TRANSFER "ENGINEERING APPLICATIONS OF FRACTAL and multiphase flow & heat transfer will be stressed. This paper will begin by reviewing some important concepts

  15. VOL. 167 -NO. 12 HEATS OF EXCHANGE MEASURED BY FLOW CALORIMETRY 777 kaolinitic soil clay that he derived from the tem-

    E-Print Network [OSTI]

    Ma, Lena

    #12;#12;#12;#12;VOL. 167 -NO. 12 HEATS OF EXCHANGE MEASURED BY FLOW CALORIMETRY 777 kaolinitic soil any reported values for K/Ca exchange. After look- ing at Udo's data more carefully,however, we be,-', not the 54.5 kJ mol,-' orig- inallyreported. If our calculation is correct,Udo's enthalpy for K/Ca exchange

  16. Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal...

    Open Energy Info (EERE)

    Heat Flow, Heat Transfer And Lithosphere Rheology In Geothermal Areas- Features And Examples Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article:...

  17. Colorado Heat Flow Data from IHFC

    SciTech Connect (OSTI)

    Zehner, Richard E.

    2012-02-01

    Citation Information: Originator: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Originator: The International Heat Flow Commission (IHFC) Publication Date: 2012 Title: Colorado IHFC Data Edition: First Publication Information: Publication Place: Earth Science & Observation Center, Cooperative Institute for Research in Environmental Science (CIRES), University of Colorado, Boulder Publisher: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Description: Abstract: This layer contains the heat flow sites and data of the State of Colorado compiled from the International Heat Flow Commission (IHFC) of the International Association of Seismology and Physics of the Earth's Interior (IASPEI) global heat flow database (www.heatflow.und.edu/index2.html). The data include different items: Item number, descriptive code, name of site, latitude and longitude, elevation, depth interval, number of temperature data, temperature gradient, number of conductivity measurement, average conductivity, number of heat generation measurements, average heat production, heat flow, number of individual sites, references, and date of publication. Spatial Domain: Extent: Top: 4522121.800672 m Left: 165356.134075 m Right: 621836.776246 m Bottom: 4097833.419676 m Contact Information: Contact Organization: Earth Science &Observation Center (ESOC), CIRES, University of Colorado at Boulder Contact Person: Khalid Hussein Address: CIRES, Ekeley Building Earth Science & Observation Center (ESOC) 216 UCB City: Boulder State: CO Postal Code: 80309-0216 Country: USA Contact Telephone: 303-492-6782 Spatial Reference Information: Coordinate System: Universal Transverse Mercator (UTM) WGS’1984 Zone 13N False Easting: 500000.00000000 False Northing: 0.00000000 Central Meridian: -105.00000000 Scale Factor: 0.99960000 Latitude Of Origin: 0.00000000 Linear Unit: Meter Datum: World Geodetic System 1984 (WGS ’1984) Prime Meridian: Greenwich Angular Unit: Degree Digital Form: Format Name: Shape file

  18. Sabdia's Radial Flow Air Bearing Heat Exchanger

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

    Sandia's Radial Flow ir Bearing Heat Exchanger 2014 Building Technologies Office Peer Review Sandia's TRL 5 Air Bearing Heat exchanger technology (a. k. a. The Sandia Cooler)...

  19. Pribnow, Kinoshita & Stein -1 -ODP Heat Flow Report Daniel Pribnow

    E-Print Network [OSTI]

    , Kinoshita & Stein - 4 - ODP Heat Flow Report Abstract. In this report the geothermal measurements made CD. 1. Introduction Geothermal measurements are important data needed to study the Earth's processes is essentially vertical and conductive, then heat flow can be calculated using Fourier's Law. In this case

  20. Heat Transfer Characteristics of a Generalized Divided Flow Heat Exchanger 

    E-Print Network [OSTI]

    Singh, K. P.

    1979-01-01

    CHARACTERISTICS OF A GENERALIZED DIVIDED FLrnJ HEAT EXCHANGER KRISHNA P. SINGH, CHIEF ENGINEER JOSEPH OAT CORPORATION 2500 Broadway, Camden, New Jersey 08104 ,l\\bstract The concept of a "Di vi ded-fl O~I" heat exchanger is general i zed by 1oca t i n...-Pass Split-Flow Shell Trans. of the ASME, Journal of Heat Transfer, pp 408-416, Aug. 1964. (4) Singh, K. P. and Holtz, ~I.J., "Generalization of the Split Flow Heat Exchanger - Geometry for Enhanced Heat Transfer", 18th National ASME/AICHE Heat Transfer...

  1. 4.A. HEAT FLOW 119 4.A. Heat flow

    E-Print Network [OSTI]

    Hunter, John K.

    denote the temperature, g : R the rate per unit volume at which heat sources create energy inside the body, and q : Rn the heat flux. That is, the rate per unit area at which heat energy diffuses across of energy implies that for any smooth open set the heat flux out of is equal to the rate at which heat

  2. Spring temperatures in the Sagehen Basin, Sierra Nevada, CA: implications for heat flow and groundwater circulation

    E-Print Network [OSTI]

    Manga, Michael

    to an underestimate of heat flow in the Sierras based purely on borehole measurements. Using temperature and discharge­40 mW m)2 of geothermal heat from the basin. This is comparable with other heat flow measurements of geothermal heat within the basin. Additionally, we use esti- mates of the mean residence time of water

  3. Thermal studies in a geothermal area: Report I. Thermal studies at Roosevelt Hot Springs, Utah; Report II. Heat flow above an arbitrarily dipping plane of heat sources; and Report III. A datum correction for heat flow measurements made on an arbitrary surface

    SciTech Connect (OSTI)

    Wilson, W.R.; Chapman, D.S.

    1980-10-01

    Separate abstracts were prepared for the three reports included in this volume on the interpretation of heat flow data in a geothermal area. (MHR)

  4. Structural power flow measurement

    SciTech Connect (OSTI)

    Falter, K.J.; Keltie, R.F.

    1988-12-01

    Previous investigations of structural power flow through beam-like structures resulted in some unexplained anomalies in the calculated data. In order to develop structural power flow measurement as a viable technique for machine tool design, the causes of these anomalies needed to be found. Once found, techniques for eliminating the errors could be developed. Error sources were found in the experimental apparatus itself as well as in the instrumentation. Although flexural waves are the carriers of power in the experimental apparatus, at some frequencies longitudinal waves were excited which were picked up by the accelerometers and altered power measurements. Errors were found in the phase and gain response of the sensors and amplifiers used for measurement. A transfer function correction technique was employed to compensate for these instrumentation errors.

  5. PIV flow measurements for heat transfer characterization in two-pass square channels with smooth and 90 ribbed walls

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    passages inside a turbine blade to convectively extract heat from the blade body. The coolant air Elsevier Science Ltd. All rights reserved. 1. Introduction Advanced gas turbine airfoils are subjected-pass square channel was reported using liquid crystal technique by Ekkad and Han [4]. Park and Lau [5] also

  6. Heat Flow Database Expansion for NGDS Data Development, Collection...

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

    Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU) Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance (SMU)...

  7. Electron Heat Transport Measured

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submitKansas Nuclear ProfileMultiferroicAward |Electron CorrelationHeat Transport

  8. The Impact of Refrigerant Charge, Air Flow and Expansion Devices on the Measured Performance of an Air-Source Heat Pump Part I

    SciTech Connect (OSTI)

    Shen, Bo [ORNL

    2011-01-01

    This paper describes extensive tests performed on a 3-ton R-22 split heat pump in heating mode. The tests contain 150 steady-state performance tests, 18 cyclic tests and 18 defrost tests. During the testing work, the refrigerant charge level was varied from 70 % to 130% relative to the nominal value; the outdoor temperature was altered by three levels at 17 F (-8.3 C), 35 F (1.7 C) and 47 F (8.3 C); indoor air flow rates ranged from 60% to 150% of the rated air flow rate; and the expansion device was switched from a fixed-orifice to a thermal expansion value. Detailed performance data from the extensive steady state cyclic and defrost testing performed were presented and compared.

  9. Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow

    E-Print Network [OSTI]

    Kostic, Milivoje M.

    Friction and Heat Transfer Characteristics of Silica and CNT Nanofluids in a Tube Flow MILIVOJE M@niu.edu * www.kostic.niu.edu Abstract: - An apparatus for exploring friction and heat transfer characteristics flow. Initial turbulent friction and heat transfer measurements for silica and carbon nanotube (CNT

  10. Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated by Joule effect

    E-Print Network [OSTI]

    Boyer, Edmond

    Infrared Thermography applied to measurement of Heat transfer coefficient of water in a pipe heated. It has been applied to measure heat transfer coefficients of water flowing in a round tube and in a multiport-flat tube. Models were developed to deduce heat transfer coefficient from wall temperature

  11. Heat Flow Database Expansion for NGDS Data Development, Collection...

    Open Energy Info (EERE)

    Heat Flow Database Expansion for NGDS Data Development, Collection and Maintenance Geothermal Project Jump to: navigation, search Last modified on July 22, 2011. Project Title Heat...

  12. Flow and heat transfer in vertical annuli

    SciTech Connect (OSTI)

    Ulke, A.; Goldberg, I.

    1993-11-01

    In shell-side boiling heat exchangers narrow crevices that are formed between the tubes and the tube support structure provide areas for local conditions which differ significantly from the bulk fluid conditions. A quasi-two-dimensional model which was developed to describe the local phenomena in a vertical, cylindrical crevice was described previously. The present work compares experimentally obtained flow and tube temperature distributions to those predicted by the model. The results confirm the characteristic ``W`` shape of the tube temperature profile centered at the line contact between a heated tube and tube support.

  13. Heat flow and microearthquake studies, Coso Geothermal Area,...

    Open Energy Info (EERE)

    Heat flow and microearthquake studies, Coso Geothermal Area, China Lake, California. Final report Jump to: navigation, search OpenEI Reference LibraryAdd to library Book: Heat flow...

  14. Heat flow studies, Coso Geothermal Area, China Lake, California...

    Open Energy Info (EERE)

    Heat flow studies, Coso Geothermal Area, China Lake, California. Technical report Jump to: navigation, search OpenEI Reference LibraryAdd to library Report: Heat flow studies, Coso...

  15. Hydrodynamics, heat transfer and flow boiling instabilities in microchannels 

    E-Print Network [OSTI]

    Barber, Jacqueline Claire

    2010-01-01

    Boiling in microchannels is a very efficient mode of heat transfer with high heat and mass transfer coefficients achieved. Less pumping power is required for two-phase flows than for single-phase liquid flows to achieve ...

  16. ARM - Measurement - Latent heat flux

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Comments?govInstrumentsnoaacrnBarrow, Alaska Outreach Home Roomparticle sizefractiongovMeasurementsLatent heat

  17. Buoyancy-driven heat transfer and flow between a wetted heat source and an isothermal cube

    SciTech Connect (OSTI)

    Close, D.J.; Peck, M.K.; White, R.F.; Mahoney, K.J. )

    1991-05-01

    This paper describes flow visualization and heat transfer experiments conducted with a heat source inside an isothermal cube filled with a saturated or near-saturated gas/vapor mixture. The mixture was formed by vaporizing liquid from the surface of the heat source, and allowing it to condense on the surfaces of the cube, which was initially filled with a noncondensing gas. Visualization studies showed that for air and ethanol below 35C, and for air and water, the flow patterns were similar with the hot plume rising from the source. For air and ethanol above 35C the flow pattern reversed with the hot plume flowing downward. For temperatures spanning 35C, which is the zero buoyancy temperature for the ethanol/water azeotrope and air, no distinct pattern was observed. Using water, liquid droplets fell like rain throughout the cube. Using ethanol, a fog of droplets moved with the fluid flow. Heat transfer experiments were made with water and air, and conductances between plate and cube of around 580 W{center dot}m{sup {minus}2}{center dot}K{sup {minus}1} measured. Agreement between the similarity theory developed for saturated gas/vapor mixtures, and correlations for single component fluids only, was very good. Together with qualitative support from the visualization experiments, the theory developed in a earlier paper deriving a similarity relationship between single fluids and gas/vapor mixtures has been validated.

  18. Hamiltonian Thermostats Fail to Promote Heat Flow

    E-Print Network [OSTI]

    Wm. G. Hoover; Carol G. Hoover

    2013-07-16

    Hamiltonian mechanics can be used to constrain temperature simultaneously with energy. We illustrate the interesting situations that develop when two different temperatures are imposed within a composite Hamiltonian system. The model systems we treat are "phi-4" chains, with quartic tethers and quadratic nearest-neighbor Hooke's-law interactions. This model is known to satisfy Fourier's law. Our prototypical problem sandwiches a Newtonian subsystem between hot and cold Hamiltonian reservoir regions. We have characterized four different Hamiltonian reservoir types. There is no tendency for any of these two-temperature Hamiltonian simulations to transfer heat from the hot to the cold degrees of freedom. Evidently steady heat flow simulations require energy sources and sinks, and are therefore incompatible with Hamiltonian mechanics.

  19. Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel

    E-Print Network [OSTI]

    Aussillous, Pascale

    Hydrodynamics and heat transfer during flow boiling instabilities in a single microchannel July 2008 Keywords: Boiling Microchannels Visualisation Flow boiling instabilities Heat transfer a b intensification heat removal. Flow boiling heat transfer in microchannel geometry and the associated flow

  20. Determining heat fluxes from temperature measurements made in massive walls

    SciTech Connect (OSTI)

    Balcomb, J.D.; Hedstrom, J.C.

    1980-01-01

    A technique is described for determining heat fluxes at the surfaces of masonry walls or floors using temperature data measured at two points within the wall, usually near the surfaces. The process consists of solving the heat diffusion equation in one dimension using finite difference techniques given two measured temperatures as input. The method is fast and accurate and also allows for an in-situ measurement of wall thermal diffusivity if a third temperature is measured. The method is documented in sufficient detail so that it can be readily used by the reader. Examples are given for heat flow through walls. Annual results for two cases are presented. The method has also been used to determine heat flow into floors.

  1. Heat transfer to air-water two-phase flow in slug/churn region

    SciTech Connect (OSTI)

    Wadekar, V.V. [AEA Technology, Harwell (United Kingdom). Heat Transfer and Fluid Flow Service; Tuzla, K.; Chen, J.C. [Lehigh Univ., Bethlehem, PA (United States). Dept. of Chemical Engineering

    1996-12-31

    Measured heat transfer data for air-water two-phase flow in the slug/churn flow region are reported. The measurements were obtained from a 1.3 m tall, 15.7 mm diameter vertical tube test-section. It is observed that the data exhibit different heat transfer characteristics to those predicted by the standard correlations for the convective component of flow boiling heat transfer. Comparison with the predictions of a slug flow model for evaporation shows a significant overprediction of the data. The reason for the overprediction is attributed to the sensible heating requirement of the gas phase. The slug flow model is therefore suitably modified for non-evaporating two-phase flow. This specially adapted model is found to give reasonably good predictions of the measured data.

  2. Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal Thermography

    E-Print Network [OSTI]

    Ghajar, Afshin J.

    62 TC02-007 Heat Transfer Measurements for a Horizontal Micro-Tube Using Liquid Crystal-tube and 1000m micro-tube. In the single-phase heat transfer experiments, the fully-developed flow heat transfer were also measured using thermocouples (TC). The results showed that the heat transfer coefficient

  3. Heat Exchanger Fouling- Prediction, Measurement and Mitigation 

    E-Print Network [OSTI]

    Peterson, G. R.

    1989-01-01

    of an industrial gas stream and to derive the fouling thermal resistance. The probe is a hollow metal cylinder capable of measuring the average heat flux along the length of the tube. The local heat flux is also measured by a heat flux meter embedded in the probe...

  4. Mixed convection heat transfer to and from a horizontal cylinder in cross-flow with heating from below.

    SciTech Connect (OSTI)

    Greif, Ralph (University of California, Berkeley, CA); Evans, Gregory Herbert; Kearney, Sean Patrick (Sandia National Laboratories, Albuquerque, NM); Laskowski, Gregory Michael

    2006-02-01

    Heat transfer to and from a circular cylinder in a cross-flow of water at low Reynolds number was studied both experimentally and numerically. The experiments were carried out in a high aspect ratio water channel. The test section inflow temperature and velocity, channel lower surface temperature and cylinder surface temperature were controlled to yield either laminar or turbulent flow for a desired Richardson number. When the lower surface was unheated, the temperatures of the lower surface and water upstream of the cylinder were maintained approximately equal and the flow was laminar. When the lower surface was heated, turbulence intensities as high as 20% were measured several cylinder diameters upstream of the cylinder due to turbulent thermal plumes produced by heating the lower surface. Variable property, two-dimensional simulations were undertaken using a variant of the u{sup 2}-f turbulence model with buoyancy production of turbulence accounted for by a simple gradient diffusion model. Predicted and measured heat flux distributions around the cylinder are compared for values of the Richardson number, Gr{sub d}/Re{sub d}{sup 2} from 0.3 to 9.3. For laminar flow, the predicted and measured heat flux results agreed to within the experimental uncertainty. When the lower surface was heated, and the flow was turbulent, there was qualitative agreement between predicted and measured heat flux distributions around the cylinder. However the predicted spatially averaged Nusselt number was from 37% to 53% larger than the measured spatially averaged Nusselt number. Additionally, spatially averaged Nusselt numbers are compared to correlations in the literature for mixed convection heat transfer to/from cylinders in cross-flow. The results presented here are larger than the correlation values. This is believed to be due to the effects of buoyancy-induced turbulence resulting from heating the lower surface and the proximity of the cylinder to that surface.

  5. Heat Flow Determinations and Implied Thermal Regime of the Coso...

    Open Energy Info (EERE)

    Heat Flow Determinations and Implied Thermal Regime of the Coso Geothermal Area California Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference Paper: Heat...

  6. Heat transfer and pressure drop in tape generated swirl flow

    E-Print Network [OSTI]

    Lopina, Robert F.

    1967-01-01

    The heat transfer and pressure drop characteristics of water in tape generated swirl flow were investigated. The test sections were electrically heated small diameter nickel tubes with tight fitting full length Inconel ...

  7. Numerical analysis of vapor flow in a micro heat pipe 

    E-Print Network [OSTI]

    Liu, Xiaoqin

    1996-01-01

    The vapor flow in a flat plate micro heat pipe with both uniform and linear heat flux boundary conditions has been numerically analyzed. For both types of boundary conditions, the Navier-Stokes equations with steady incompressible two...

  8. DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION

    E-Print Network [OSTI]

    Yee, G.

    2010-01-01

    DEVELOpiNG FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS9092 Developing Flow and Heat Transfer in Strongly CurvedForced Convection Heat Transfer in Curved Rectangular

  9. Heat flow determinations and implied thermal regime of the Coso...

    Open Energy Info (EERE)

    Heat flow determinations and implied thermal regime of the Coso geothermal area, California Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...

  10. Model of critical heat flux in subcooled flow boiling

    E-Print Network [OSTI]

    Fiori, Mario P.

    1968-01-01

    The physical phenomenon occurring before and at the critical heat flux (CHF) for subcooled flow boiling has been investigated. The first phase of this study established the basic nature of the flow structure at CHF. A ...

  11. Method of measuring heat influx of a cryogenic transfer system

    DOE Patents [OSTI]

    Niemann, Ralph C. (Downers Grove, IL); Zelipsky, Steven A. (Tinley Park, IL); Rezmer, Ronald R. (Lisle, IL); Smelser, Peter (Bruner, MO)

    1981-01-01

    A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

  12. Heat transfer to impacting drops and post critical heat flux dispersed flow

    E-Print Network [OSTI]

    Kendall, Gail E.

    1978-01-01

    Heat transfer to drops impacting on a hot surface is examined in context of dispersions of flowing, boiling fluids. The liquid contribution to heat transfer from a hot tube to a two-phase dispersion is formulated in terms ...

  13. Applications of the Strong Heat Transformation by Pulse Flow in the Shell and Tube Heat Exchanger 

    E-Print Network [OSTI]

    Chen, Y.; Zhao, J.

    2006-01-01

    This article deals with the heat exchange coefficient varied with pulse frequency in the pulsation tube with different flow forms. The findings show that heat can be exchanged coefficient with the pulse frequency, and it ...

  14. 16 Heat Transfer and Air Flow in a Domestic Refrigerator

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    445 16 Heat Transfer and Air Flow in a Domestic Refrigerator Onrawee Laguerre UMR Génie Industriel........................................................................447 16.2.2 Heat Transfer and Airflow Near a Vertical Plate..................................................448 16.2.3 Heat Transfer and Airflow in Empty Closed Cavity

  15. Experiments on transformation thermodynamics: Molding the flow of heat

    E-Print Network [OSTI]

    Schittny, Robert; Guenneau, Sebastien; Wegener, Martin

    2012-01-01

    It has recently been shown theoretically that the time-dependent heat conduction equation is form-invariant under curvilinear coordinate transformations. Thus, in analogy to transformation optics, fictitious transformed space can be mapped onto (meta-)materials with spatially inhomogeneous and anisotropic heat-conductivity tensors in the laboratory space. On this basis, we design, fabricate, and characterize a micro-structured thermal cloak that molds the flow of heat around an object in a metal plate. This allows for transient protection of the object from heating, while maintaining the same downstream heat flow as without object and cloak.

  16. Large deviations in stochastic heat-conduction processes provide a gradient-flow structure for heat conduction

    SciTech Connect (OSTI)

    Peletier, Mark A., E-mail: m.a.peletier@tue.nl [Department of Mathematics and Computer Science and Institute for Complex Molecular Systems, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven (Netherlands); Redig, Frank, E-mail: f.h.j.redig@tudelft.nl [Delft Institute of Applied Mathematics, Technische Universiteit Delft, Mekelweg 4, 2628 CD Delft (Netherlands); Vafayi, Kiamars, E-mail: k.vafayi@tue.nl [Department of Mathematics and Computer Science, Technische Universiteit Eindhoven, Postbus 513, 5600 MB Eindhoven (Netherlands)

    2014-09-01

    We consider three one-dimensional continuous-time Markov processes on a lattice, each of which models the conduction of heat: the family of Brownian Energy Processes with parameter m (BEP(m)), a Generalized Brownian Energy Process, and the Kipnis-Marchioro-Presutti (KMP) process. The hydrodynamic limit of each of these three processes is a parabolic equation, the linear heat equation in the case of the BEP(m) and the KMP, and a nonlinear heat equation for the Generalized Brownian Energy Process with parameter a (GBEP(a)). We prove the hydrodynamic limit rigorously for the BEP(m), and give a formal derivation for the GBEP(a). We then formally derive the pathwise large-deviation rate functional for the empirical measure of the three processes. These rate functionals imply gradient-flow structures for the limiting linear and nonlinear heat equations. We contrast these gradient-flow structures with those for processes describing the diffusion of mass, most importantly the class of Wasserstein gradient-flow systems. The linear and nonlinear heat-equation gradient-flow structures are each driven by entropy terms of the form -log ?; they involve dissipation or mobility terms of order ?² for the linear heat equation, and a nonlinear function of ? for the nonlinear heat equation.

  17. Heat pipe transient measurements incorporating visual methods 

    E-Print Network [OSTI]

    DeHart, Mark David

    1986-01-01

    !!CE December 1986 Major Subject: 1'uclear Eng nearing HEAT PIPE TRANSIENT MEASUREMENTS INCORPORATING VISUAL METHODS A Thesis by MARK DAVID DeHART Approved as to style and content by: Frederick R. Best (Chairman of Committee) Carl A. Erdman (Member... ) Dennis L. O'Neal (Member) K. L. Peddicord (Head of Department) December 1986 ABSTRACT Heat Pipe Transient Measurements Incorporating Visual Methods. (December 1986) Mark David DeHar t, B. S. , Texas A&M University Chairman of Advisory Committee...

  18. Geothermal Resource-Reservoir Investigations Based On Heat Flow...

    Open Energy Info (EERE)

    Geothermal Resource-Reservoir Investigations Based On Heat Flow And Thermal Gradient Data For The United States Jump to: navigation, search OpenEI Reference LibraryAdd to library...

  19. Temperatures, heat flow, and water chemistry from drill holes...

    Open Energy Info (EERE)

    Temperatures, heat flow, and water chemistry from drill holes in the Raft River geothermal system, Cassia County, Idaho Jump to: navigation, search OpenEI Reference LibraryAdd to...

  20. Development of Micro/Nano-Scale Sensors for Investigation of Heat Transfer in Multi-Phase Flows 

    E-Print Network [OSTI]

    Jeon, Sae Il

    2012-10-19

    The objective of this investigation was to develop micro/nano-scale temperature sensors for measuring surface temperature transients in multi-phase flows and heat transfer. Surface temperature fluctuations were measured on substrates exposed...

  1. Enhanced two phase flow in heat transfer systems

    DOE Patents [OSTI]

    Tegrotenhuis, Ward E; Humble, Paul H; Lavender, Curt A; Caldwell, Dustin D

    2013-12-03

    A family of structures and designs for use in devices such as heat exchangers so as to allow for enhanced performance in heat exchangers smaller and lighter weight than other existing devices. These structures provide flow paths for liquid and vapor and are generally open. In some embodiments of the invention, these structures can also provide secondary heat transfer as well. In an evaporate heat exchanger, the inclusion of these structures and devices enhance the heat transfer coefficient of the evaporation phase change process with comparable or lower pressure drop.

  2. Cross flow heat exchange of textile cellular metal core sandwich panels , T.J. Lu b,*, H.P. Hodson a

    E-Print Network [OSTI]

    Wadley, Haydn

    Cross flow heat exchange of textile cellular metal core sandwich panels J. Tian a , T.J. Lu b,*, H. Finally, the thermal performance of brazed woven tex- tiles is compared with other heat exchanger media flow resistance and heat transfer rate were measured. The flow friction factor is found to depend

  3. Heat flux carried by the Antarctic Circumpolar Current mean flow

    E-Print Network [OSTI]

    Rhode Island, University of

    Heat flux carried by the Antarctic Circumpolar Current mean flow Che Sun Geophysical Fluid Dynamics Graduate School of Oceanography, University of Rhode Island, Narragansett, Rhode Island, USA Received 18 of historical hydrographic data is applied to study the heat flux problem in the Antarctic Circumpolar Current

  4. Two-phase flow and pressure drop in flow passages of compact heat exchangers

    SciTech Connect (OSTI)

    Wambsganss, M.W.; Jendrzejczyk, J.A.; France, D.M.

    1992-01-01

    Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 {times} 1.59 mm (aspects ratio equal to 6), for applications to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1), and in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m{sup 2}s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation. 13 refs.

  5. Two-phase flow and pressure drop in flow passages of compact heat exchangers

    SciTech Connect (OSTI)

    Wambsganss, M.W.; Jendrzejczyk, J.A.; France, D.M.

    1992-02-01

    Two-phase flow experiments were performed with air/water mixtures in a small rectangular channel measuring 9.52 {times} 1.59 mm (aspects ratio equal to 6), for applications to compact heat exchangers. Pressure drop and flow pattern definition data were obtained over a large range of mass qualities (0.0002 to 1), and in the case of flow pattern data, a large range of mass fluxes (50 to 2,000 kg/m{sup 2}s). A flow pattern map, based on visual observations and photographs of the flow patterns, is presented and compared with a map developed for a rectangular channel of the same aspect ratio but with dimensions twice those of the test channel, and with a map developed for a circular tube with the same hydraulic diameter of 3 mm. Pressure drop data are presented as a function of both mass quality and Martinelli parameter and are compared with state-of-the-art correlations and a modified Chisholm correlation. 13 refs.

  6. Polymer Effects on Heat Transport in Laminar Boundary Layer Flow

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching; Vivien W. S. Chu

    2011-04-27

    We consider a laminar Blasius boundary-layer flow above a slightly heated horizontal plate and study the effect of polymer additives on the heat transport. We show that the action of the polymers can be understood as a space-dependent effective viscosity that first increases from the zero-shear value then decreases exponentially back to the zero-shear value as one moves away from the boundary. We find that with such an effective viscosity, both the horizontal and vertical velocities near the plate are decreased thus leading to an increase in the friction drag and a decrease in the heat transport in the flow.

  7. Convection Heat Transfer in Three-Dimensional Turbulent Separated/Reattached Flow

    SciTech Connect (OSTI)

    Bassem F. Armaly

    2007-10-31

    The measurements and the simulation of convective heat transfer in separated flow have been a challenge to researchers for many years. Measurements have been limited to two-dimensional flow and simulations failed to predict accurately turbulent heat transfer in the separated and reattached flow region (prediction are higher than measurements by more than 50%). A coordinated experimental and numerical effort has been initiated under this grant for examining the momentum and thermal transport in three-dimensional separated and reattached flow in an effort to provide new measurements that can be used for benchmarking and for improving the simulation capabilities of 3-D convection in separated/reattached flow regime. High-resolution and non-invasive measurements techniques are developed and employed in this study to quantify the magnitude and the behavior of the three velocity components and the resulting convective heat transfer. In addition, simulation capabilities are developed and employed for improving the simulation of 3-D convective separated/reattached flow. Such basic measurements and simulation capabilities are needed for improving the design and performance evaluation of complex (3-D) heat exchanging equipment. Three-dimensional (3-D) convective air flow adjacent to backward-facing step in rectangular channel is selected for the experimental component of this study. This geometry is simple but it exhibits all the complexities that appear in any other separated/reattached flow, thus making the results generated in this study applicable to any other separated and reattached flow. Boundary conditions, inflow, outflow, and wall thermal treatment in this geometry can be well measured and controlled. The geometry can be constructed with optical access for non-intrusive measurements of the flow and thermal fields. A three-component laser Doppler velocimeter (LDV) is employed to measure simultaneously the three-velocity components and their turbulent fluctuations. Infrared thermography is utilized to measure the wall temperature and that information is used to determine the local convective heat transfer coefficient. FLUENT – CFD code is used as the platform in the simulation effort and User Defined Functions are developed for incorporating advanced turbulence models into this simulation code. Predictions of 3-D turbulent convection in separated flow, using the developed simulation capabilities under this grant, compared well with measured results. Results from the above research can be found in the seventeen refereed journal articles, and thirteen refereed publications and presentations in conference proceedings that have been published by the PI during the this grant period. The research effort is still going on and several publications are being prepared for reporting recent results.

  8. Brine flow in heated geologic salt.

    SciTech Connect (OSTI)

    Kuhlman, Kristopher L.; Malama, Bwalya

    2013-03-01

    This report is a summary of the physical processes, primary governing equations, solution approaches, and historic testing related to brine migration in geologic salt. Although most information presented in this report is not new, we synthesize a large amount of material scattered across dozens of laboratory reports, journal papers, conference proceedings, and textbooks. We present a mathematical description of the governing brine flow mechanisms in geologic salt. We outline the general coupled thermal, multi-phase hydrologic, and mechanical processes. We derive these processes' governing equations, which can be used to predict brine flow. These equations are valid under a wide variety of conditions applicable to radioactive waste disposal in rooms and boreholes excavated into geologic salt.

  9. Enhanced flow boiling heat transfer in microchannels with structured surfaces at varied mass flow rates

    E-Print Network [OSTI]

    Bian, David (David Wei)

    2015-01-01

    This thesis investigates the role of mass flux on flow boiling heat transfer in microchannels with surface micropillar arrays. The motivation for this investigation was to determine the general trends of the optimal ...

  10. Supersonic combustion of a transverse injected H sub 2 jet in a radio frequency heated flow

    SciTech Connect (OSTI)

    Wantuck, P.J.; Tennant, R.A.; Watanabe, H.H.

    1991-01-01

    The combustion of a single hydrogen jet, normally injected into a radio frequency (RF) heated, oxidant-containing, supersonic flow, has been established to characterize the chemical and fluid dynamic phenomena associated with the reaction process and ultimately validate the predictive capability of computational computer dynamic (CFD) codes. The experimental system employed for this study is unique in that it uses an electrodeless, inductively coupled plasma tube to generate the high temperature oxidant-containing gas for subsequent nozzle expansion. Advantages of an RF heated flow system include reduced free-stream chemical contamination, continuous operation, and relative ease of integration into a typical flow laboratory environment. A description of the system utilized for this study is presented including preliminary results of the reactive flow characterization. In addition, the use of the laser-based diagnostic techniques, such as planar laser-induced fluorescence (PLIF), for measuring flow properties is also discussed. 8 refs., 7 figs.

  11. Friction-Induced Fluid Heating in Nanoscale Helium Flows

    SciTech Connect (OSTI)

    Li Zhigang [Department of Mechanical Engineering, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon (Hong Kong)

    2010-05-21

    We investigate the mechanism of friction-induced fluid heating in nanoconfinements. Molecular dynamics simulations are used to study the temperature variations of liquid helium in nanoscale Poiseuille flows. It is found that the fluid heating is dominated by different sources of friction as the external driving force is changed. For small external force, the fluid heating is mainly caused by the internal viscous friction in the fluid. When the external force is large and causes fluid slip at the surfaces of channel walls, the friction at the fluid-solid interface dominates over the internal friction in the fluid and is the major contribution to fluid heating. An asymmetric temperature gradient in the fluid is developed in the case of nonidentical walls and the general temperature gradient may change sign as the dominant heating factor changes from internal to interfacial friction with increasing external force.

  12. PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW

    E-Print Network [OSTI]

    Texas at Arlington, University of

    1 PYROLYSIS OF METHANE IN A SUPERSONIC, ARC-HEATED FLOW F.K. Lu,* C.M. Roseberry, J.M. Meyers and D arc pyrolysis of methane at supersonic conditions, representative of conditions in the reformer location of an aibreathing hypersonic vehicle. The rationale for arc pyrolysis is provided. Major

  13. INTERNAL FORCED iquid or gas flow through pipes or ducts is commonly used in heating and

    E-Print Network [OSTI]

    Ghajar, Afshin J.

    to flow by a fan or pump through a flow section that is sufficiently long to accomplish the desired heat Transitional Flow in Tubes* An important design problem in industrial heat exchangers arises when flow inside or ducts is commonly used in heating and cooling applications. The fluid in such applications is forced

  14. Heat transfer and pressure drop of supercritical carbon dioxide flowing in several printed circuit heat exchanger channel patterns

    SciTech Connect (OSTI)

    Carlson, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States); Kruizenga, A. [Sandia National Laboratory (United States); Anderson, M.; Corradini, M. [Univ. of Wisconsin - Madison, 839 Engineering Research Building, 1500 Engineering Drive, Madison, WI 53706 (United States)

    2012-07-01

    Closed-loop Brayton cycles using supercritical carbon dioxide (SCO{sub 2}) show potential for use in high-temperature power generation applications including High Temperature Gas Reactors (HTGR) and Sodium-Cooled Fast Reactors (SFR). Compared to Rankine cycles SCO{sub 2} Brayton cycles offer similar or improved efficiency and the potential for decreased capital costs due to a reduction in equipment size and complexity. Compact printed-circuit heat exchangers (PCHE) are being considered as part of several SCO{sub 2} Brayton designs to further reduce equipment size with increased energy density. Several designs plan to use a gas cooler operating near the pseudo-critical point of carbon dioxide to benefit from large variations in thermophysical properties, but further work is needed to validate correlations for heat transfer and pressure-drop characteristics of SCO{sub 2} flows in candidate PCHE channel designs for a variety of operating conditions. This paper presents work on experimental measurements of the heat transfer and pressure drop behavior of miniature channels using carbon dioxide at supercritical pressure. Results from several plate geometries tested in horizontal cooling-mode flow are presented, including a straight semi-circular channel, zigzag channel with a bend angle of 80 degrees, and a channel with a staggered array of extruded airfoil pillars modeled after a NACA 0020 airfoil with an 8.1 mm chord length facing into the flow. Heat transfer coefficients and bulk temperatures are calculated from measured local wall temperatures and local heat fluxes. The experimental results are compared to several methods for estimating the friction factor and Nusselt number of cooling-mode flows at supercritical pressures in millimeter-scale channels. (authors)

  15. Quantitative tomographic measurements of opaque multiphase flows

    SciTech Connect (OSTI)

    GEORGE,DARIN L.; TORCZYNSKI,JOHN R.; SHOLLENBERGER,KIM ANN; O'HERN,TIMOTHY J.; CECCIO,STEVEN L.

    2000-03-01

    An electrical-impedance tomography (EIT) system has been developed for quantitative measurements of radial phase distribution profiles in two-phase and three-phase vertical column flows. The EIT system is described along with the computer algorithm used for reconstructing phase volume fraction profiles. EIT measurements were validated by comparison with a gamma-densitometry tomography (GDT) system. The EIT system was used to accurately measure average solid volume fractions up to 0.05 in solid-liquid flows, and radial gas volume fraction profiles in gas-liquid flows with gas volume fractions up to 0.15. In both flows, average phase volume fractions and radial volume fraction profiles from GDT and EIT were in good agreement. A minor modification to the formula used to relate conductivity data to phase volume fractions was found to improve agreement between the methods. GDT and EIT were then applied together to simultaneously measure the solid, liquid, and gas radial distributions within several vertical three-phase flows. For average solid volume fractions up to 0.30, the gas distribution for each gas flow rate was approximately independent of the amount of solids in the column. Measurements made with this EIT system demonstrate that EIT may be used successfully for noninvasive, quantitative measurements of dispersed multiphase flows.

  16. Classical and Quantum Chaos and Control of Heat Flow

    E-Print Network [OSTI]

    Giulio Casati; Carlos Mejia-Monasterio

    2006-10-10

    We discuss the problem of heat conduction in classical and quantum low dimensional systems from a microscopic point of view. At the classical level we provide convincing numerical evidence for the validity of Fourier law of heat conduction in linear mixing systems, i.e. in systems without exponential instability. At the quantum level, where motion is characterized by the lack of exponential dynamical instability, we show that the validity of Fourier law is in direct relation with the onset of quantum chaos. We then study the phenomenon of thermal rectification and briefly discuss the different types of microscopic mechanisms that lead to the rectification of heat flow. The control of heat conduction by nonlinearity opens the possibility to propose new devices such as a thermal rectifier.

  17. Dependence of heat transport on the strength and shear rate of prescribed circulating flows

    E-Print Network [OSTI]

    Emily S. C. Ching; K. M. Pang

    2001-11-28

    We study numerically the dependence of heat transport on the maximum velocity and shear rate of physical circulating flows, which are prescribed to have the key characteristics of the large-scale mean flow observed in turbulent convection. When the side-boundary thermal layer is thinner than the viscous boundary layer, the Nusselt number (Nu), which measures the heat transport, scales with the normalized shear rate to an exponent 1/3. On the other hand, when the side-boundary thermal layer is thicker, the dependence of Nu on the Peclet number, which measures the maximum velocity, or the normalized shear rate when the viscous boundary layer thickness is fixed, is generally not a power law. Scaling behavior is obtained only in an asymptotic regime. The relevance of our results to the problem of heat transport in turbulent convection is also discussed.

  18. Local heat transfer measurement and thermo-fluid characterization of a pulsating heat pipe

    E-Print Network [OSTI]

    Khandekar, Sameer

    and possibly future specific requirements from electronics cooling [6,7], heat recovery [8,9] and passiveLocal heat transfer measurement and thermo-fluid characterization of a pulsating heat pipe Mauro 2013 Accepted 29 July 2013 Available online Keywords: Pulsating Heat Pipes Local heat transfer Pressure

  19. A Site-Scale Model For Fluid And Heat Flow In The Unsaturated...

    Open Energy Info (EERE)

    multicomponent fluid and heat flow through porous and fractured rock. Fracture and matrix flow is treated using both dual-permeability and effective-continuum modeling...

  20. Heat transfer and flow of an impinged plate with an elliptic jet

    SciTech Connect (OSTI)

    Matsuda, Shoichi; Yaga, Minoru; Oyakawa, Kenyu

    1999-07-01

    The time and spatial temperature profiles on a jet impingement plate were measured using an infrared radiometer with a two-dimensional array of Indium-Antimony (In Sb) sensors for various nozzle exit-to-plate spaces for when the jet being issued from an elliptic nozzle impinges on the target plate. The isotherms of infrared images as well as heat transfer coefficients were obtained by measurement data. The heat transfer coefficients were also measured by using thermocouples. In order to compare the isotherms and heat transfer contours with flow patterns, the flows on the plate were visualized by the oil-film method, and the velocity and the turbulence intensity were measured by a hot wire anemometer. The phenomena of axes switching which are caused by the differences in self-induced velocity in non-circular vortices and have been the typical behaviors of free jets were observed on the impingement plate. The distribution of the isotherm and iso-heat transfer coefficients for the center portion were shorted in the major direction with an increase of the space between nozzle exit and impingement plate and elongated in the minor direction. The isotherms from the infrared image corresponded closely to the distribution of iso-heat transfer coefficients by using thermocouples. The shapes of flow patterns also corresponded to both the shape of the isotherms and the iso-heat transfer contours. In the twice length of nozzle diameter downstream from nozzle exit, the oil film pattern was elongated in the major axis direction for the center portion, which corresponded to both the lower temperature and higher heat transfer coefficient.

  1. Heat Flow From Four New Research Drill Holes In The Western Cascades...

    Open Energy Info (EERE)

    Heat Flow From Four New Research Drill Holes In The Western Cascades, Oregon, Usa Jump to: navigation, search OpenEI Reference LibraryAdd to library Journal Article: Heat Flow From...

  2. Measuring the Costs & Benefits of Nationwide Geothermal Heat Deployment

    SciTech Connect (OSTI)

    Battocletti, Elizabeth C.; Glassley, William E.

    2013-02-28

    Recovery Act: Measuring the Costs & Economic, Social, Environmental Benefits of Nationwide Geothermal Heat Deployment & the Potential Employment

  3. Heat transport by laminar boundary layer flow with polymers

    E-Print Network [OSTI]

    Roberto Benzi; Emily S. C. Ching.; Vivien W. S. Chu

    2011-04-23

    Motivated by recent experimental observations, we consider a steady-state Prandtl-Blasius boundary layer flow with polymers above a slightly heated horizontal plate and study how the heat transport might be affected by the polymers. We discuss how a set of equations can be derived for the problem and how these equations can be solved numerically by an iterative scheme. By carrying out such a scheme, we find that the effect of the polymers is equivalent to producing a space-dependent effective viscosity that first increases from the zero-shear value at the plate then decreases rapidly back to the zero-shear value far from the plate. We further show that such an effective viscosity leads to an enhancement in the drag, which in turn leads to a reduction in heat transport.

  4. Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Numeric Simulation of Heat Transfer and Electrokinetic Flow in an Electroosmosis-Based Continuous is dedicated to under- standing the fluid flow and heat transfer mechanisms occurring in continuous flow PCR are discussed in detail. The importance of each heat transfer mechanism for different situations is also

  5. FliHy experimental facilities for studying open channel turbulent flows and heat transfer

    E-Print Network [OSTI]

    Abdou, Mohamed

    FliHy experimental facilities for studying open channel turbulent flows and heat transfer B. Freeze) facility was constructed at UCLA to study open channel turbulent flow and heat transfer of low supercritical flow regimes (Fr /1), in which the surface waves are amplified and heat transfer is enhanced due

  6. Numerical Study of Convective Heat Transfer in Flat Tube Heat Exchangers Operating in Self-Sustained Oscillatory Flow Regimes 

    E-Print Network [OSTI]

    Fullerton, Tracy

    2012-02-14

    Laminar, two-dimensional, constant-property numerical simulations of flat tube heat exchanger devices operating in flow regimes in which self-sustained oscillations occur were performed. The unsteady flow regimes were ...

  7. Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Flow and heat transfer of a third grade fluid past an exponentially stretching sheet with partial-Newtonian boundary layer flow and heat transfer over an exponentially stretch- ing sheet with partial slip boundary. The heat transfer analysis has been carried out for two heating processes, namely (i) with prescribed sur

  8. Underground Flow Measurement and Particle Release Test | Department...

    Office of Environmental Management (EM)

    Underground Flow Measurement and Particle Release Test Underground Flow Measurement and Particle Release Test This document was used to determine facts and conditions during the...

  9. Full-field velocity measurements of single and two phase flows using digital pulsed laser velocimetry 

    E-Print Network [OSTI]

    Canaan, Robert Ernst

    1990-01-01

    to reliably measure and quantify both component velocities of two phase systems would directly contribute toward the goal of understanding such fundamental two phase flow characteristics as void fraction and its effects, flow and heat transfer regime...-field non-intrusive analysis of two phase flow regimes which are of great concern in the field of nuclear engineering. Modeling of two phase flow systems presents a particularly challenging problem in which there is much room for continuing improvement...

  10. Verifying a Simplified Fuel Oil Flow Field Measurement Protocol

    SciTech Connect (OSTI)

    Henderson, H.; Dentz, J.; Doty, C.

    2013-07-01

    The Better Buildings program is a U.S. Department of Energy program funding energy efficiency retrofits in buildings nationwide. The program is in need of an inexpensive method for measuring fuel oil consumption that can be used in evaluating the impact that retrofits have in existing properties with oil heat. This project developed and verified a fuel oil flow field measurement protocol that is cost effective and can be performed with little training for use by the Better Buildings program as well as other programs and researchers.

  11. Conductive and convective heat transfer in fluid flows between differentially heated and rotating cylinders

    E-Print Network [OSTI]

    Lopez, Jose M; Avila, Marc

    2015-01-01

    The flow of fluid confined between a heated rotating cylinder and a cooled stationary cylinder is a canonical experiment for the study of heat transfer in engineering. The theoretical treatment of this system is greatly simplified if the cylinders are assumed to be of infinite length or periodic in the axial direction, in which cases heat transfer occurs only through conduction as in a solid. We here investigate numerically heat transfer and the onset of turbulence in such flows by using both periodic and no-slip boundary conditions in the axial direction. We obtain a simple linear criterion that determines whether the infinite-cylinder assumption can be employed. The curvature of the cylinders enters this linear relationship through the slope and additive constant. For a given length-to-gap aspect ratio there is a critical Rayleigh number beyond which the laminar flow in the finite system is convective and so the behaviour is entirely different from the periodic case. The criterion does not depend on the Pra...

  12. Geothermal Well and Heat Flow Data for the United States (Southern Methodist University (SMU) Geothermal Laboratory)

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

    Blackwell, D.D. and others

    Southern Methodist University makes two databases and several detailed maps available. The Regional Heat Flow Database for the United States contains information on primarily regional or background wells that determine the heat flow for the United States; temperature gradients and conductivity are used to generate heat flow measurements. Information on geology of the location, porosity, thermal conductivity, water table depth, etc. are also included when known. There are usually three data files for each state or region. The first files were generated in 1989 for the data base creating the Decade of North America Geology (DNAG) Geothermal Map. The second set is from 1996 when the data base was officially updated for the Department of Energy. The third set is from 1999 when the Western U.S. High Temperature Geothermal data base was completed. As new data is received, the files continue to be updated. The second major resource is the Western Geothermal Areas Database, a database of over 5000 wells in primarily high temperature geothermal areas from the Rockies to the Pacific Ocean. The majority of the data are from company documents, well logs, and publications with drilling dates ranging from 1960 to 2000. Many of the wells were not previously accessible to the public. Users will need to register, but will then have free, open access to the databases. The contents of each database can be viewed and downloaded as Excel spreadsheets. See also the heat flow maps at http://www.smu.edu/geothermal/heatflow/heatflow.htm

  13. Investigation of transient, two-dimensional coupled heat and moisture flow in soils

    SciTech Connect (OSTI)

    Shen, L.S.W.

    1986-01-01

    A two-dimensional finite difference numerical model has been developed to study coupled heat and moisture flow in the soil surrounding an earth-sheltered construction. The model is based on a mechanistic approach formulated by Milly and developed from the work of Philip and deVries. Using soil temperatures and matric potentials as the dependent variables, the model is capable of simulating unsaturated/saturated flow conditions in heterogeneous soil domains. The model is a fully implicit, integrated finite difference approach based on the Patankar Spalding method. The numerical modeling of the governing heat and moisture equations was validated against a number of analytical and quasi-analytical solutions. An axisymmetric, two-dimensional experiment was then defined to which the numerical model could be compared. The experimental apparatus was composed of a cylinder filled with a dredged Mississippi River sand. A series of one and two dimensional heat and moisture flow experiments were run, using boundary conditions consistent with those that occur in the soil surrounding a building. Soil properties used in the model were either calculated from theoretical models or measured experimentally. Agreement between the model and experiments were good, with an error of 10-15% obtained for the two-dimensional coupled heat and moisture flow experiment.

  14. Infrared thermography of a pulsating heat pipe: Flow regimes and multiple steady states

    E-Print Network [OSTI]

    Khandekar, Sameer

    Infrared thermography of a pulsating heat pipe: Flow regimes and multiple steady states V t Understanding of the operational characteristics of a closed loop Pulsating Heat Pipe (PHP) with non- intrusive. Introduction A pulsating heat pipe/oscillating heat pipe is essentially a pas- sive two-phase heat transfer

  15. The International Heat Flow Commission | Open Energy Information

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EA EISTJ AutomationTexas/Wind Resources <forGermanInternational Heat Flow

  16. Couette flow regimes with heat transfer in rarefied gas

    SciTech Connect (OSTI)

    Abramov, A. A., E-mail: alabr54@mail.ru; Butkovskii, A. V., E-mail: albutkov@mail.ru [Zhukovski Central Aerohydrodynamics Institute (Russian Federation)

    2013-06-15

    Based on numerical solution of the Boltzmann equation by direct statistic simulation, the Couette flow with heat transfer is studied in a broad range of ratios of plate temperatures and Mach numbers of a moving plate. Flow regime classification by the form of the dependences of the energy flux and friction stress on the Knudsen number Kn is proposed. These dependences can be simultaneously monotonic and nonmonotonic and have maxima. Situations are possible in which the dependence of the energy flux transferred to a plate on Kn has a minimum, while the dependence of the friction stress is monotonic or even has a maximum. Also, regimes exist in which the dependence of the energy flux on Kn has a maximum, while the dependence of the friction stress is monotonic, and vice versa.

  17. Flow regimes and heat transfer in vertical narrow annuli

    SciTech Connect (OSTI)

    Ulke, A.; Goldberg, I.

    1993-11-01

    In shell side boiling heat exchangers narrow crevices that are formed between the tubes and the tube support structure provide areas for local thermal-hydraulic conditions which differ significantly from bulk fluid conditions. Understanding of the processes of boiling and dryout in flow restricted crevices can help in designing of tube support geometries to minimize the likelihood of tube support plate and tube corrosion observed in commercial power plant steam generators. This paper describes a one dimensional thermal-hydraulic model of a vertical crevice between a tube and a support plate with cylindrical holes. The annulus formed by the support plate hole and an eccentrically located tube has been represented by vertical strips. The formation, growth and collapse of a steam bubble in each strip has been determined. Based on the bubble history, and flow regimes characterized by ``isolated`` bubbles, ``coalesced`` bubbles and liquid deficient regions have been defined.

  18. Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

    E-Print Network [OSTI]

    Marchese, Francis

    Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow Flow

  19. Temperature distribution in a flowing fluid heated in a microwave resonant cavity

    SciTech Connect (OSTI)

    Thomas, J.R. Jr. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States); Nelson, E.M.; Kares, R.J.; Stringfield, R.M. [Los Alamos National Lab., NM (United States)

    1996-04-01

    This paper presents results of an analytical study of microwave heating of a fluid flowing through a tube situated along the axis of a cylindrical microwave applicator. The interaction of the microwave field pattern and the fluid velocity profiles is illustrated for both laminar and turbulent flow. Resulting temperature profiles are compared with those generated by conventional heating through a surface heat flux. It is found that microwave heating offers several advantages over conventional heating.

  20. Solids flow rate measurement in dense slurries

    SciTech Connect (OSTI)

    Porges, K.G.; Doss, E.D.

    1993-09-01

    Accurate and rapid flow rate measurement of solids in dense slurries remains an unsolved technical problem, with important industrial applications in chemical processing plants and long-distance solids conveyance. In a hostile two-phase medium, such a measurement calls for two independent parameter determinations, both by non-intrusive means. Typically, dense slurries tend to flow in laminar, non-Newtonian mode, eliminating most conventional means that usually rely on calibration (which becomes more difficult and costly for high pressure and temperature media). These issues are reviewed, and specific solutions are recommended in this report. Detailed calculations that lead to improved measuring device designs are presented for both bulk density and average velocity measurements. Cross-correlation, chosen here for the latter task, has long been too inaccurate for practical applications. The cause and the cure of this deficiency are discussed using theory-supported modeling. Fluid Mechanics are used to develop the velocity profiles of laminar non-Newtonian flow in a rectangular duct. This geometry uniquely allows the design of highly accurate `capacitive` devices and also lends itself to gamma transmission densitometry on an absolute basis. An absolute readout, though of less accuracy, is also available from a capacitive densitometer and a pair of capacitive sensors yields signals suitable for cross-correlation velocity measurement.

  1. Method of measuring heat influx of a cryogenic transfer system. [Patent application

    DOE Patents [OSTI]

    Niemann, R.C.; Zelipsky, S.A.; Rezmer, R.R.; Smelser, P.

    1980-10-29

    A method is provided for measuring the heat influx of a cryogenic transfer system. A gaseous phase of the cryogen used during normal operation of the system is passed through the system. The gaseous cryogen at the inlet to the system is tempered to duplicate the normal operating temperature of the system inlet. The temperature and mass flow rate of the gaseous cryogen is measured at the outlet of the system, and the heat capacity of the cryogen is determined. The heat influx of the system is then determined from known thermodynamic relationships.

  2. Unsteady laminar flow and convective heat transfer in a sharp 180 bend

    E-Print Network [OSTI]

    Chung, Yongmann M.

    Unsteady laminar flow and convective heat transfer in a sharp 180° bend Yongmann M. Chung a , Paul Unsteady laminar flow and heat transfer in a sharp 180° bend is studied numerically to investigate to be strong. Ó 2002 Elsevier Science Inc. All rights reserved. Keywords: Laminar; Unsteady; Heat transfer

  3. PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES

    E-Print Network [OSTI]

    Sen, Mihir

    PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES A Thesis Submitted April 1995 #12;PERFORMANCE OF A SINGLE-ROW HEAT EXCHANGER AT LOW IN-TUBE FLOW RATES by Xiangwei Zhao Abstract The steady and time-dependentbehavior of a single-row heat exchanger with water and air in the in

  4. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-Print Network [OSTI]

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S the dynamical effects from the heat transfer process. The fluid flow in an enclosed disk system with axial with heat transfer along the stator, which corresponds to the experiment of Djaoui et al. [2]. Our results

  5. Flow Boiling Heat Transfer Coefficient In Minichannels Correlation and Trends Satish G. Kandlikar

    E-Print Network [OSTI]

    Kandlikar, Satish

    Flow Boiling Heat Transfer Coefficient In Minichannels ­ Correlation and Trends Satish G. Kandlikar York 14623, USA The flow boiling heat transfer in small diameter passages is being applied in many boiling heat transfer coefficient with the correlations developed for conventional channels. It is found

  6. Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law

    E-Print Network [OSTI]

    Boyer, Edmond

    Global weak solutions to magnetic fluid flows with nonlinear Maxwell-Cattaneo heat transfer law F transfer in a magnetic fluid flow under the action of an applied magnetic field. Instead of the usual heat-Cattaneo law, heat transfer, magnetic field, magnetization AMS subject classifications: 76N10, 35Q35. 1

  7. Measurement of the ratio of specific heats Brian D. Storey

    E-Print Network [OSTI]

    Storey, Brian D.

    Measurement of the ratio of specific heats Brian D. Storey Franklin W. Olin College of Engineering Needham, MA 02492 (Dated: September 25, 2005) I. INTRODUCTION The ratio of specific heats determines how to the differing pressures, "springs" designed with gases of different specific heat ratios have different natural

  8. THERMAL DESIGN METHODOLOGY FOR LOW FLOW RATE SINGLE-PHASE AND TWO-PHASE MICRO-CHANNEL HEAT SINKS

    E-Print Network [OSTI]

    Qu, Weilin

    THERMAL DESIGN METHODOLOGY FOR LOW FLOW RATE SINGLE-PHASE AND TWO-PHASE MICRO-CHANNEL HEAT SINKS-phase micro- channel heat sinks under a fixed liquid coolant flow rate. The parameters relevant to heat sink-channel dimensions corresponding to the prescribed dissipative heat flux and liquid coolant flow rate. Heat sink

  9. Flow visualization study of inverted annular flow of post dryout heat transfer region. [PWR; BWR

    SciTech Connect (OSTI)

    Ishii, M.; De Jarlais, G.

    1985-01-01

    The inverted annular flow is important in the area of LWR accident analysis in terms of the maximum cladding temperature and effectiveness of the emergency core cooling. However, the inverted annular flow thermal-hydraulics is not well understood due to its special heat transfer condition of film boiling. The review of existing data indicates further research is needed in the areas of basic hydrodynamics related to liquid core disintegration mechanisms, slug and droplet formation, entrainment, and droplet size distributions. In view of this, the inverted flow is studied in detail experimentally. A new experimental apparatus has been constructed in which film boiling heat transfer can be established in a transparent test section. The test section consists of two coaxial quartz tubes. The annular gap between these two tubes is filled with a hot, clear fluid (syltherm 800) so as to maintain film boiling temperatures and heat transfer rates at the inner quartz tube wall. Data on liquid core stability, core break-up mechanism, and dispersed-core liquid slug and droplet sizes are obtained using F 113 as a test fluid. Both high speed movies and flash photographs (3 ..mu..sec) are used.

  10. An experimental investigation of critical heat flux in subcooled internal flow 

    E-Print Network [OSTI]

    Shatto, Donald Patrick

    1997-01-01

    An experimental investigation has been conducted to determine the critical heat flux for subcooled refrigerant-11 and refrigerant-113 flowing upward in a vertical cylindrical tube. Critical heat flux (CHF) values are determined for a range of tube...

  11. A Variable Refrigerant Flow Heat Pump Computer Model in EnergyPlus

    SciTech Connect (OSTI)

    Raustad, Richard A. [Florida Solar Energy Center

    2013-01-01

    This paper provides an overview of the variable refrigerant flow heat pump computer model included with the Department of Energy's EnergyPlusTM whole-building energy simulation software. The mathematical model for a variable refrigerant flow heat pump operating in cooling or heating mode, and a detailed model for the variable refrigerant flow direct-expansion (DX) cooling coil are described in detail.

  12. Time variability of AGN and heating of cooling flows

    E-Print Network [OSTI]

    Carlo Nipoti; James Binney

    2005-05-03

    There is increasing evidence that AGN mechanical feedback is important in the energetics of cooling flows in galaxies and galaxy clusters. We investigate the implications of the variability of AGN mechanical luminosity L_m on observations of cooling flows and radio galaxies in general. It is natural to assume that l=ln(L_m/L_x) is a Gaussian process. Then L_m will be log-normally distributed at fixed cooling luminosity L_x, and the variance in a measure of L_m will increase with the time-resolution of the measure. We test the consistency of these predictions with existing data. These tests hinge on the power spectrum of l(t). Monitoring of Seyfert galaxies combined with estimates of the duty cycle of quasars imply flicker noise spectra, similar to those of microquasars. We combine a sample of sources in cooling flows that have cavities with the assumption that the average mechanical luminosity of the AGN equals L_x. Given that the mechanical luminosities are characterized by flicker noise, we find that their spectral amplitudes lie between the estimated amplitudes of quasars and the measured values for the radio luminosities of microquasars. The model together with the observation that powerful radio galaxies lie within a narrow range in optical luminosity, predicts the luminosity function of radio galaxies, in agreement with observations. Forthcoming radio surveys will test the prediction that the luminosity function turns over at about the smallest luminosities so far probed. [Abridged

  13. American Institute of Aeronautics and Astronautics Aero-Optical Measurements in a Heated, Subsonic,

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    American Institute of Aeronautics and Astronautics 1 Aero-Optical Measurements in a Heated-averaging = elevation angle ~ = mean Favre-averaging I. Introduction HE aero-optic problem is concerned with the study, compressible boundary layers, shocks, and mixed density flows are potential sources for aero

  14. Relaxation calorimetry technique for measuring low temperature specific heat

    E-Print Network [OSTI]

    Andrei, Eva Y.

    Relaxation calorimetry technique for measuring low temperature specific heat R. W. Newsome, Jr the temperature dependence of the specific heat of a 10 thick 0.62 mg copolymer film of vinylidene fluoride. INTRODUCTION Design improvements over recent years enable some calorimeters to precisely measure the specific

  15. Measuring the Costs & Benefits of Nationwide Geothermal Heat

    E-Print Network [OSTI]

    Measuring the Costs & Benefits of Nationwide Geothermal Heat Pump (GHP) Deployment ­ A Progress to measure the costs and benefits of nationwide geothermal heat pump (GHP) deployment. · First market study to quantify the entire GHP chain ­ Manufacturing ­ Design ­ Installation · GHPsRUS is short for "geothermal

  16. Experimental and numerical study of mixed convection with flow reversal in coaxial double-duct heat exchangers

    SciTech Connect (OSTI)

    Mare, Thierry; Voicu, Ionut; Miriel, Jacques [Laboratoire de Genie Civil et de Genie Mecanique (LGCGM), INSA de Rennes, IUT Saint Malo, 35043 Rennes (France); Galanis, Nicolas [Faculte de genie, Universite de Sherbrooke, Sherbrooke, QC (Canada); Sow, Ousmane [Laboratoire d'Energie Appliquee, Ecole superieure Polytechnique, Dakar (Senegal)

    2008-04-15

    Velocity vectors in a vertical coaxial double-duct heat exchanger for parallel ascending flow of water under conditions of laminar mixed convection have been determined experimentally using the particle image velocimetry technique. The measured velocity distributions for large annular flow rates, resulting in an essentially isothermal environment for the stream in the inner tube, are in very good agreement with corresponding numerical predictions. For flow rates of the same order of magnitude in the inner tube and the annulus, and corresponding temperature differences of about 20 C, experimental observations show that flow reversal occurs simultaneously in both streams over large axial distances for both heating and cooling of the flow in the inner tube. (author)

  17. Heat extracted from the long term flow test in the Fenton Hill HDR reservoir

    SciTech Connect (OSTI)

    Kruger, Paul; Robinson, Bruce

    1994-01-20

    A long-term flow test was carried out in the Fenton Hill HDR Phase-2 reservoir for 14 months during 1992-1993 to examine the potential for supplying thermal energy at a sustained rate as a commercial demonstration of HDR technology. The test was accomplished in several segments with changes in mean flowrate due to pumping conditions. Re-test estimates of the extractable heat content above a minimum useful temperature were based on physical evidence of the size of the Fenton Hill reservoir. A numerical model was used to estimate the extent of heat extracted during the individual flow segments from the database of measured production data during the test. For a reservoir volume of 6.5x10{sup 6}m{sup 3}, the total heat content above a minimum temperature of 150{degree} C was 1.5x10{sup 15}J. For the total test period at the three sustained mean flowrates, the integrated heat extracted was 0.088x10{sup 15}J, with no discernable temperature decline of the produced fluid. The fraction of energy extracted above the abandonment temperature was 5.9%. On the basis of a constant thermal energy extraction rate, the lifetime of the reservoir (without reservoir growth) to the abandonment temperature would be 13.3 years, in good agreement with the pre-test estimate of 15.0 years for the given reservoir volume.

  18. Technical Subtopic 2.1: Modeling Variable Refrigerant Flow Heat Pump and Heat Recovery Equipment in EnergyPlus

    SciTech Connect (OSTI)

    Raustad, Richard; Nigusse, Bereket; Domitrovic, Ron

    2013-09-30

    The University of Central Florida/Florida Solar Energy Center, in cooperation with the Electric Power Research Institute and several variable-refrigerant-flow heat pump (VRF HP) manufacturers, provided a detailed computer model for a VRF HP system in the United States Department of Energy's (U.S. DOE) EnergyPlus? building energy simulation tool. Detailed laboratory testing and field demonstrations were performed to measure equipment performance and compare this performance to both the manufacturer's data and that predicted by the use of this new model through computer simulation. The project goal was to investigate the complex interactions of VRF HP systems from an HVAC system perspective, and explore the operational characteristics of this HVAC system type within a laboratory and real world building environment. Detailed laboratory testing of this advanced HVAC system provided invaluable performance information which does not currently exist in the form required for proper analysis and modeling. This information will also be useful for developing and/or supporting test standards for VRF HP systems. Field testing VRF HP systems also provided performance and operational information pertaining to installation, system configuration, and operational controls. Information collected from both laboratory and field tests were then used to create and validate the VRF HP system computer model which, in turn, provides architects, engineers, and building owners the confidence necessary to accurately and reliably perform building energy simulations. This new VRF HP model is available in the current public release version of DOE?s EnergyPlus software and can be used to investigate building energy use in both new and existing building stock. The general laboratory testing did not use the AHRI Standard 1230 test procedure and instead used an approach designed to measure the field installed full-load operating performance. This projects test methodology used the air enthalpy method where relevant air-side parameters were controlled while collecting output performance data at discreet points of steady-state operation. The primary metrics include system power consumption and zonal heating and cooling capacity. Using this test method, the measured total cooling capacity was somewhat lower than reported by the manufacturer. The measured power was found to be equal to or greater than the manufacturers indicated power. Heating capacity measurements produced similar results. The air-side performance metric was total cooling and heating energy since the computer model uses those same metrics as input to the model. Although the sensible and latent components of total cooling were measured, they are not described in this report. The test methodology set the thermostat set point temperature very low for cooling and very high for heating to measure full-load performance and was originally thought to provide the maximum available capacity. Manufacturers stated that this test method would not accurately measure performance of VRF systems which is now believed to be a true statement. Near the end of the project, an alternate test method was developed to better represent VRF system performance as if field installed. This method of test is preliminarily called the Load Based Method of Test where the load is fixed and the indoor conditions and unit operation are allowed to fluctuate. This test method was only briefly attempted in a laboratory setting but does show promise for future lab testing. Since variable-speed air-conditioners and heat pumps include an on-board control algorithm to modulate capacity, these systems are difficult to test. Manufacturers do have the ability to override internal components to accommodate certification procedures, however, it is unknown if the resulting operation is replicated in the field, or if so, how often. Other studies have shown that variable-speed air-conditioners and heat pumps do out perform their single-speed counterparts though these field studies leave as many questions as they do provide answers. The measure

  19. Method and apparatus for measuring flow velocity using matched filters

    DOE Patents [OSTI]

    Raptis, A.C.

    1983-09-06

    An apparatus and method for measuring the flow velocities of individual phase flow components of a multiphase flow utilizes matched filters. 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. 8 figs.

  20. Method and apparatus for measuring flow velocity using matched filters

    DOE Patents [OSTI]

    Raptis, Apostolos C. (Downers Grove, IL)

    1983-01-01

    An apparatus and method for measuring the flow velocities of individual phase flow components of a multiphase flow utilizes matched filters. 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.

  1. 2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 Molecular dynamics methods in

    E-Print Network [OSTI]

    Maruyama, Shigeo

    2.13 HEAT TRANSFER & FLUID FLOW IN MICROCHANNELS 2.13.7-1 2.13.7 Molecular dynamics methods in microscale heat transfer Shigeo Maruyama A. Introduction In normal heat transfer and fluid flow calculations of molecules. This situation is approached in microscale heat transfer and fluid flow. Molecular level

  2. 1.12.2014bo Akademi Univ -Thermal and Flow Engineering Piispankatu 8, 20500 Turku 1/24 8. Heat pumps, heat pipes,

    E-Print Network [OSTI]

    Zevenhoven, Ron

    pumps, heat pipes, cold thermal energy storage Ron Zevenhoven Åbo Akademi University Thermal and Flow and Flow Engineering Piispankatu 8, 20500 Turku 2/24 8.1 Heat pumps #12;1.12.2014 Åbo Akademi Univ - Thermal and Flow Engineering Piispankatu 8, 20500 Turku 3/24 Heat pumps /1 Using a refrigeration cycle

  3. Improved flow cytometer measurement of binding assays

    DOE Patents [OSTI]

    Saunders, G.C.

    1984-05-30

    The invention relates to a method of measuring binding assays carried out with different size particles wherein the binding assay sample is run through a flow cytometer without separating the sample from the marking agent. The amount of a binding reactant present in a sample is determined by providing particles with a coating of binder and also a known quantity of smaller particles with a coating of binder reactant. The binding reactant is the same as the binding reactant present in the sample. The smaller particles also contain a fluorescent chemical. The particles are combined with the sample and the binding reaction is allowed to occur for a set length of time followed by combining the smaller particles with the mixture of the particles and the sample produced and allowing the binding reactions to proceed to equilibrium. The fluorescence and light scatter of the combined mixture is then measured as the combined mixture passes through a flow cytometer equipped with a laser to bring about fluorescence, and the number and strength of fluorescent events are compared. A similar method is also provided for determining the amount of antigen present in the sample by providing spheres with an antibody coating and some smaller spheres with an antigen coating. (LEW)

  4. TEMPERATURE CONTROLLABILITY IN CROSS-FLOW HEAT EXCHANGERS AND LONG DUCTS

    E-Print Network [OSTI]

    Sen, Mihir

    TEMPERATURE CONTROLLABILITY IN CROSS-FLOW HEAT EXCHANGERS AND LONG DUCTS A Dissertation Submitted-FLOW HEAT EXCHANGERS AND LONG DUCTS Abstract by Sorour Abdulhadi Alotaibi The performance of thermal control and long ducts, are investigated, and the following issues are addressed. (a) The first is controllability

  5. Temperature-Gated Thermal Rectifier for Active Heat Flow Control Kedar Hippalgaonkar,,

    E-Print Network [OSTI]

    Wu, Junqiao

    Temperature-Gated Thermal Rectifier for Active Heat Flow Control Jia Zhu,, Kedar Hippalgaonkar to develop advanced all-thermal solid-state devices that actively control heat flow without consuming other of solid-state active-thermal devices with a large rectification in the Rectifier state. This temperature

  6. IINDIX IYITM DIVIIIOM ANN AIIOit, MICH. NO. 28-July-66 Heat Flow EYperiment

    E-Print Network [OSTI]

    Rathbun, Julie A.

    to forward Arthur D. Little manpower loading (for heat flow experiment} to MSC". .2 Prepared 0£: f' ~ W. E BY ARTHUR D. LITTLE Classifications Principal Staff Engineer Principal Staff Associate Engineer Executive. ?oCOil Approved by9d.~~/ J7 Jack E. Dye PAOli #12;28-July-66 Heat Flow Experiment NO. A I.DIX IYITIMI

  7. Flow-Induced Deformation of a Flexible Thin Structure as Manifestation of Heat Transfer Enhancement

    E-Print Network [OSTI]

    Soti, Atul Kumar; Sheridan, John

    2015-01-01

    Flow-induced deformation of thin structures coupled with convective heat transfer has potential applications in energy harvesting and is important for understanding functioning of several biological systems. We numerically demonstrate large-scale flow-induced deformation as an effective passive heat transfer enhancement technique. An in-house, strongly-coupled fluid-structure interaction (FSI) solver is employed in which flow and structure solvers are based on sharp-interface immersed boundary and finite element method, respectively. In the present work, we validate convective heat transfer module of the in-house FSI solver against several benchmark examples of conduction and convective heat transfer including moving structure boundaries. The thermal augmentation is investigated as well as quantified for the flow-induced deformation of an elastic thin plate attached to lee side of a rigid cylinder in a heated channel laminar flow. We show that the wake vortices past the plate sweep higher sources of vorticity...

  8. Impingement cooling and heat transfer measurement using transient liquid crystal technique 

    E-Print Network [OSTI]

    Huang, Yizhe

    1996-01-01

    A heat transfer study on jet impingement cooling is presented. The study focuses on the effect of impingement jet flow rate, jet angle, and flow exit direction on various target surface heat transfer distributions. A two-channel test section...

  9. Energy Efficient Process Heating: Managing Air Flow Kevin Carpenter and Kelly Kissock

    E-Print Network [OSTI]

    Kissock, Kelly

    Energy Efficient Process Heating: Managing Air Flow Kevin Carpenter and Kelly Kissock Department important aspect to consider when attempting to improve the energy efficiency of most process heating. Infiltration air enters the system through openings in the system shell. For energy- efficient process heating

  10. Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow

    E-Print Network [OSTI]

    Boyer, Edmond

    Numerical modeling of heat transfer and fluid flow in rotor-stator cavities with throughflow S in a rotor-stator cavity subjected to a superimposed throughflow with heat transfer. Nu- merical predictions field from the heat transfer process. The turbulent flux is approximated by a gradient hypothesis

  11. Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a,

    E-Print Network [OSTI]

    Kandlikar, Satish

    Heat transfer and friction characteristics of air flow in microtubes Chien-Yuh Yang a, , Chia September 2011 Keywords: Microtube Heat transfer Liquid Crystal Thermography a b s t r a c t Several researches dealing with the single-phase forced convection heat transfer inside microchannels have been

  12. 3 omega method for specific heat and thermal conductivity measurements

    E-Print Network [OSTI]

    L. Lu; W. Yi; D. L. Zhang

    2002-02-06

    We present a 3 omega method for simultaneously measuring the specific heat and thermal conductivity of a rod- or filament-like specimen using a way similar to a four-probe resistance measurement. The specimen in this method needs to be electrically conductive and with a temperature-dependent resistance, for acting both as a heater to create a temperature fluctuation and as a sensor to measure its thermal response. With this method we have successfully measured the specific heat and thermal conductivity of platinum wire specimens at cryogenic temperatures, and measured those thermal quantities of tiny carbon nanotube bundles some of which are only 10^-9 g in mass.

  13. A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion in the

    E-Print Network [OSTI]

    of interlobular arteries in kidney cortex (1/cm2) n(r) number of blood vessels in a shell of tissue at radius r P) r radial distance from the center of the thermistor (cm) S kidney cortex cross sectional area (cm2A Small Artery Heat Transfer Model for Self-Heated Thermistor Measurements of Perfusion

  14. Ultrasonic fluid flow measurement method and apparatus

    DOE Patents [OSTI]

    Kronberg, J.W.

    1993-10-12

    An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible. 3 figures.

  15. Ultrasonic fluid flow measurement method and apparatus

    DOE Patents [OSTI]

    Kronberg, James W. (108 Independent Blvd., Aiken, SC 29801)

    1993-01-01

    An apparatus for measuring the flow of a fluid in a pipe using ultrasonic waves. The apparatus comprises an ultrasonic generator, a lens for focusing the sound energy produced by the generator, and means for directing the focused energy into the side of the pipe through an opening and in a direction close to parallel to the long axis of the pipe. A cone carries the sound energy to the lens from the generator. Depending on the choice of materials, there may be a quarter-wave, acoustic impedance matching section between the generator and the cone to reduce the reflections of energy at the cone boundary. The lens material has an acoustic impedance similar to that of the cone material but a different sonic velocity so that the lens can converge the sound waves in the fluid. A transition section between the lens and the fluid helps to couple the energy to the fluid and assures it is directed as close to parallel to the fluid flow direction as possible.

  16. Advanced Turbulence Measurements and Signal Processing for Hydropower Flow Characterization

    E-Print Network [OSTI]

    and developed a data post-processing method to reduce the cost of flow and turbulence measurements at MHKAdvanced Turbulence Measurements and Signal Processing for Hydropower Flow Characterization and flow characterization within full scale conventional hydropower systems, at marine and hydrokinetic

  17. Heat transport and weakening of atmospheric stability induced by mesoscale flows

    E-Print Network [OSTI]

    Pielke, Roger A.

    Heat transport and weakening of atmospheric stability induced by mesoscale flows G. A. Dalu boundary layer (CBL) is transported upward into the midtroposphere by mesoscale flows, and how the air, and diffusion, associated with the mesoscale flow, is more clearly shown when the forcing is periodic in time

  18. Heat generation rate measurement in a Li-ion cell at large C-rates through temperature and heat flux measurements

    E-Print Network [OSTI]

    Texas at Arlington, University of

    Heat generation rate measurement in a Li-ion cell at large C-rates through temperature and heat Keywords: Lithium-ion batteries Heat generation rate measurement Heat flux sensor Thermal conduction Battery safety a b s t r a c t Understanding the rate of heat generation in a Li-ion cell is critical

  19. Air flow in a high aspect ratio heat sink

    E-Print Network [OSTI]

    Allison, Jonathan Michael

    2010-01-01

    The increasing heat output of modern electronics requires concomitant advances in heat sinking technology: reductions in thermal resistance and required pumping power are necessary. This research covers the development of ...

  20. Heat Loss Measurement Using Infrared Imaging 

    E-Print Network [OSTI]

    Seeber, S. A.

    1983-01-01

    Infrared thermography has proven to be an important tool in numerous plant maintenance and energy conservation applications. Quantitative measurement, using infrared imaging instruments, is a powerful new dimension of infrared thermography...

  1. An analytical oscillating-flow thermal analysis of the heat exchangers and regenerator in Stirling machines

    SciTech Connect (OSTI)

    Monte, F. de; Galli, G.; Marcotullio, F.

    1996-12-31

    A closed form-expression for the effectiveness of the heat exchangers and regenerator of a Stirling cycle machine is given. This result may be used in a simple way in order to evaluate their effect on the machine performance. The proposed method, indeed, allows the actual cycle gas temperatures in the heater and cooler to be obtained readily, once the geometry of the heater, cooler and regenerator is known and some quantities characterizing the engine dynamics (strokes, frequency and phase angle of the moving elements) and its heat-exchange processes (inlet temperatures of the heating and cooling fluids, and their volumetric flow rates) are measured. Thus, an immediate indication about the effectiveness of the heat exchangers and regenerator as well as about the machine thermal efficiency may be obtained. The availability of a closed-form expression for the heater, regenerator and cooler effectiveness is useful especially for those engines, like the free-piston Stirling engines, whose design requires the application of analytically based optimization criteria.

  2. Controlling and measuring quantum transport of heat in trapped-ion crystals

    E-Print Network [OSTI]

    A. Bermudez; M. Bruderer; M. B. Plenio

    2013-07-23

    Measuring heat flow through nanoscale systems poses formidable practical difficulties as there is no `ampere meter' for heat. We propose to overcome this problem by realizing heat transport through a chain of trapped ions. Laser cooling the chain edges to different temperatures induces a current of local vibrations (vibrons). We show how to efficiently control and measure this current, including fluctuations, by coupling vibrons to internal ion states. This demonstrates that ion crystals provide a suitable platform for studying quantum transport, e.g., through thermal analogues of quantum wires and quantum dots. Notably, ion crystals may give access to measurements of the elusive large fluctuations of bosonic currents and the onset of Fourier's law. These results are supported by numerical simulations for a realistic implementation with specific ions and system parameters.

  3. Fusion Engineering and Design 81 (2006) 549553 Numerical analysis of MHD flow and heat transfer in a

    E-Print Network [OSTI]

    Abdou, Mohamed

    2006-01-01

    Fusion Engineering and Design 81 (2006) 549­553 Numerical analysis of MHD flow and heat transfer January 2006 Abstract MHD flow and heat transfer have been analyzed for a front poloidal channel blanket; Magnetohydrodynamics; Heat transfer 1. Introduction Using flow channel inserts (FCIs) made

  4. Bypass valve and coolant flow controls for optimum temperatures in waste heat recovery systems

    DOE Patents [OSTI]

    Meisner, Gregory P

    2013-10-08

    Implementing an optimized waste heat recovery system includes calculating a temperature and a rate of change in temperature of a heat exchanger of a waste heat recovery system, and predicting a temperature and a rate of change in temperature of a material flowing through a channel of the waste heat recovery system. Upon determining the rate of change in the temperature of the material is predicted to be higher than the rate of change in the temperature of the heat exchanger, the optimized waste heat recovery system calculates a valve position and timing for the channel that is configurable for achieving a rate of material flow that is determined to produce and maintain a defined threshold temperature of the heat exchanger, and actuates the valve according to the calculated valve position and calculated timing.

  5. Journal ofEnhanced Heat Transfer, 18 (3): 177-190 (2011) THERMALLY-INDUCED OSCILLATORY FLOW AND

    E-Print Network [OSTI]

    Zhang, Yuwen

    2011-01-01

    AND HEAT TRANSFER IN AN OSCILLATING HEAT PIPE Wei Shao & Yuwen Zhang* Department ofMechanical and Aerospace - a building block ofan Oscillating Heat Pipe (OHP) - is modeled by analyzing evaporation and condensation flow and by empirical correlationsfor a turbulent liquid flow. KEY WORDS: oscillating heat pipe

  6. System for measuring multiphase flow using multiple pressure differentials

    DOE Patents [OSTI]

    Fincke, James R. (Idaho Falls, ID)

    2003-01-01

    An improved method and system for measuring a multi-phase flow in a pressure flow meter. An extended throat venturi is used and pressure of the multi-phase flow is measured at three or more positions in the venturi, which define two or more pressure differentials in the flow conduit. The differential pressures are then used to calculate the mass flow of the gas phase, the total mass flow, and the liquid phase. The system for determining the mass flow of the high void fraction fluid flow and the gas flow includes taking into account a pressure drop experienced by the gas phase due to work performed by the gas phase in accelerating the liquid phase.

  7. Community-Scale Environmental Measures and Urban Heat Island

    E-Print Network [OSTI]

    interactions vary with climate. For example, while generating power, a photovoltaic system can also increaseCommunity-Scale Environmental Measures and Urban Heat Island Impacts Buildings End-Use Energy, are not well quantified. Community-scale environmental measures include solar collection technologies

  8. INVARIANT RADON MEASURES FOR HOROCYCLE FLOWS ON ABELIAN COVERS

    E-Print Network [OSTI]

    Sarig, Omri

    INVARIANT RADON MEASURES FOR HOROCYCLE FLOWS ON ABELIAN COVERS OMRI SARIG Dedicated to the memory of M. Babillot Abstract. We classify the ergodic invariant Radon measures for horocycle flows on Zd those supported on periodic orbits. There are however invariant Radon measures. Burger [Bu] classified

  9. Measurement of thermodynamics using gradient flow

    E-Print Network [OSTI]

    Masakiyo Kitazawa; Masayuki Asakawa; Tetsuo Hatsuda; Takumi Iritani; Etsuko Itou; Hiroshi Suzuki

    2014-12-15

    We analyze bulk thermodynamics and correlation functions of the energy-momentum tensor in pure Yang-Mills gauge theory using the energy-momentum tensor defined by the gradient flow and small flow time expansion. Our results on thermodynamic observables are consistent with those obtained by the conventional integral method. The analysis of the correlation function of total energy supports the energy conservation. It is also addressed that these analyses with gradient flow require less statistics compared with the previous methods. All these results suggest that the energy-momentum tensor can be successfully defined and observed on the lattice with moderate numerical costs with the gradient flow.

  10. Heat Flow in VC-2A and VC-2B, and Constraints on the Thermal...

    Open Energy Info (EERE)

    Heat Flow in VC-2A and VC-2B, and Constraints on the Thermal Regime of the Valles Caldera, New Mexico Jump to: navigation, search OpenEI Reference LibraryAdd to library Conference...

  11. The Effects of Frost Growth on Finned Tube Heat Exchangers under Laminar Flow 

    E-Print Network [OSTI]

    Kondepudi, Sekhar

    1988-01-01

    A study on the effects of frost growth on the performance of finned tube heat exchangers under laminar flow has been conducted. The study was both experimental and analytical. The experimental part of the investigation ...

  12. Visualization of flow boiling in an annular heat exchanger under reduced gravity conditions 

    E-Print Network [OSTI]

    Westheimer, David Thomas

    2000-01-01

    poorly with an Earth based flow regime map; (ii) predicting that the maximum two-phase heat transfer coefficient would occur near the location the boiling fluid reached a saturated state, which also corresponded with the location of maximum nucleate...

  13. Film boiling of saturated liquid flowing upward through a heated tube : high vapor quality range

    E-Print Network [OSTI]

    Laverty, W. F.

    1964-01-01

    Film boiling of saturated liquid flowing upward through a uniformly heated tube has been studied for the case in which pure saturated liquid enters the tube and nearly saturated vapor is discharged. Since a previous study ...

  14. NIST Measurement Services: Natural Gas Flow Calibration Service (NGFCS)

    E-Print Network [OSTI]

    NIST Measurement Services: Natural Gas Flow Calibration Service (NGFCS) NIST Special Publication of Standards and Technology #12;i Table of Contents for the Natural Gas Flowmeter Calibration Service (NGFCS;1 Abstract This document describes NIST's high pressure natural gas flow calibration service (NGFCS). Flow

  15. Spatially resolved heat release rate measurements in turbulent premixed flames

    SciTech Connect (OSTI)

    Ayoola, B.O.; Kaminski, C.F.; Balachandran, R.; Mastorakos, E.; Frank, J.H.

    2006-01-01

    Heat release rate is a fundamental property of great importance for the theoretical and experimental elucidation of unsteady flame behaviors such as combustion noise, combustion instabilities, and pulsed combustion. Investigations of such thermoacoustic interactions require a reliable indicator of heat release rate capable of resolving spatial structures in turbulent flames. Traditionally, heat release rate has been estimated via OH or CH radical chemiluminescence; however, chemiluminescence suffers from being a line-of-sight technique with limited capability for resolving small-scale structures. In this paper, we report spatially resolved two-dimensional measurements of a quantity closely related to heat release rate. The diagnostic technique uses simultaneous OH and CH{sub 2}O planar laser-induced fluorescence (PLIF), and the pixel-by-pixel product of the OH and CH{sub 2}O PLIF signals has previously been shown to correlate well with local heat release rates. Results from this diagnostic technique, which we refer to as heat release rate imaging (HR imaging), are compared with traditional OH chemiluminescence measurements in several flames. Studies were performed in lean premixed ethylene flames stabilized between opposed jets and with a bluff body. Correlations between bulk strain rates and local heat release rates were obtained and the effects of curvature on heat release rate were investigated. The results show that the heat release rate tends to increase with increasing negative curvature for the flames investigated for which Lewis numbers are greater than unity. This correlation becomes more pronounced as the flame gets closer to global extinction.

  16. Finite element analysis of conjugate heat transfer in axisymmetric pipe flows 

    E-Print Network [OSTI]

    Fithen, Robert Miller

    1987-01-01

    FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Submitted to the Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree of MA STER... OF S CI EN CE August 1987 Major Subject: Mechanical Engineering FINITE ELEMENT ANALYSIS OF CONJUGATE HEAT TRANSFER IN AXISYMMETRIC PIPE FLOWS A Thesis by ROBERT MILLER FITHEN Approved ss to style and content by: N. K. Anand (Chairman of Committee...

  17. Simplified motional heating rate measurements of trapped ions

    E-Print Network [OSTI]

    R. J. Epstein; S. Seidelin; D. Leibfried; J. H. Wesenberg; J. J. Bollinger; J. M. Amini; R. B. Blakestad; J. Britton; J. P. Home; W. M. Itano; J. D. Jost; E. Knill; C. Langer; R. Ozeri; N. Shiga; D. J. Wineland

    2007-07-10

    We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence detection during Doppler recooling. We applied these methods to determine heating rates in a microfrabricated surface-electrode trap made of gold on fused quartz, which traps ions 40 microns above its surface. Heating rates obtained from the two techniques were found to be in reasonable agreement. In addition, the trap gives rise to a heating rate of 300 plus or minus 30 per second for a motional frequency of 5.25 MHz, substantially below the trend observed in other traps.

  18. Simplified motional heating rate measurements of trapped ions

    E-Print Network [OSTI]

    Epstein, R J; Leibfried, D; Wesenberg, J H; Bollinger, J J; Amini, J M; Blakestad, R B; Britton, J; Home, J P; Itano, W M; Jost, J D; Knill, E; Langer, C; Ozeri, R; Shiga, N; Wineland, D J

    2007-01-01

    We have measured motional heating rates of trapped atomic ions, a factor that can influence multi-ion quantum logic gate fidelities. Two simplified techniques were developed for this purpose: one relies on Raman sideband detection implemented with a single laser source, while the second is even simpler and is based on time-resolved fluorescence detection during Doppler recooling. We applied these methods to determine heating rates in a microfrabricated surface-electrode trap made of gold on fused quartz, which traps ions 40 microns above its surface. Heating rates obtained from the two techniques were found to be in reasonable agreement. In addition, the trap gives rise to a heating rate of 300 plus or minus 30 per second for a motional frequency of 5.25 MHz, substantially below the trend observed in other traps.

  19. Transient Thermal, Hydraulic, and Mechanical Analysis of a Counter Flow Offset Strip Fin Intermediate Heat Exchanger using an Effective Porous Media Approach

    E-Print Network [OSTI]

    Urquiza, Eugenio

    2009-01-01

    for Compact Plate-Type Heat Exchangers. ” American Institutethese conditions, plate-type heat exchangers with small flowHeatric plate-type compact heat exchanger showing multiple

  20. Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers

    E-Print Network [OSTI]

    Thole, Karen A.

    Measurements and Predictions of the Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Transfer at the Tube-Fin Junction for Louvered Fin Heat Exchangers Abstract The dominant thermal resistance used to increase heat transfer by initiating new boundary layer growth and increasing surface area

  1. ARC-HEATED GAS FLOW EXPERIMENTS FOR HYPERSONIC PROPULSION

    E-Print Network [OSTI]

    Texas at Arlington, University of

    the Supersonic Wind Tunnel. I have enjoyed working with Rod Duke, who has been an important asset to my research to be injected into the engine combustors. To investigate this approach, the UTA Arc-Heated #12;vi Wind Tunnel

  2. Control of reactor coolant flow path during reactor decay heat removal

    DOE Patents [OSTI]

    Hunsbedt, Anstein N. (Los Gatos, CA)

    1988-01-01

    An improved reactor vessel auxiliary cooling system for a sodium cooled nuclear reactor is disclosed. The sodium cooled nuclear reactor is of the type having a reactor vessel liner separating the reactor hot pool on the upstream side of an intermediate heat exchanger and the reactor cold pool on the downstream side of the intermediate heat exchanger. The improvement includes a flow path across the reactor vessel liner flow gap which dissipates core heat across the reactor vessel and containment vessel responsive to a casualty including the loss of normal heat removal paths and associated shutdown of the main coolant liquid sodium pumps. In normal operation, the reactor vessel cold pool is inlet to the suction side of coolant liquid sodium pumps, these pumps being of the electromagnetic variety. The pumps discharge through the core into the reactor hot pool and then through an intermediate heat exchanger where the heat generated in the reactor core is discharged. Upon outlet from the heat exchanger, the sodium is returned to the reactor cold pool. The improvement includes placing a jet pump across the reactor vessel liner flow gap, pumping a small flow of liquid sodium from the lower pressure cold pool into the hot pool. The jet pump has a small high pressure driving stream diverted from the high pressure side of the reactor pumps. During normal operation, the jet pumps supplement the normal reactor pressure differential from the lower pressure cold pool to the hot pool. Upon the occurrence of a casualty involving loss of coolant pump pressure, and immediate cooling circuit is established by the back flow of sodium through the jet pumps from the reactor vessel hot pool to the reactor vessel cold pool. The cooling circuit includes flow into the reactor vessel liner flow gap immediate the reactor vessel wall and containment vessel where optimum and immediate discharge of residual reactor heat occurs.

  3. 378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s

    E-Print Network [OSTI]

    Bahrami, Majid

    378 Solutions Manual x Fluid Mechanics, Fifth Edition where heat flow, J/s A surface area, m Q 2 'T Ans. L V VV U PU § ·' : 3 3 3 3 ¨ ¸ © ¹ 5.18 Under laminar conditions, the volume flow Q through temperature difference, K The dimensionless form of h, called the Stanton number, is a combination of h, fluid

  4. Simplified model and lattice Boltzmann algorithm for microscale electro-osmotic flows and heat transfer

    E-Print Network [OSTI]

    Zhao, Tianshou

    Simplified model and lattice Boltzmann algorithm for microscale electro-osmotic flows and heat The extremely small length scale of the electric double layer (EDL) of electro-osmotic flows (EOF and temperature as the velocity-slip and temperature-jump boundary conditions, form a simple model for the electro-osmotic

  5. A Facility for Accurate Heat Load and Mass Leak Measurements on Superfluid Helium Valves

    E-Print Network [OSTI]

    Bézaguet, Alain-Arthur; Ferlin, G; Losserand-Madoux, R; Perin, A; Vandoni, Giovanna; Van Weelderen, R

    1999-01-01

    The superconducting magnets of the Large Hadron Collider (LHC) will be protected by safety relief valves operating at 1.9 K in superfluid helium (HeII). A test facility was developed to precisely determine the heat load and the mass leakage of cryogenic valves with HeII at their inlet. The temperature of the valve inlet can be varied from 1.8 K to 2 K for pressures up to 3.5 bar. The valve outlet pipe temperature can be regulated between 5 K and 20 K. The heat flow is measured with high precision using a Kapitza-resistance heatmeter and is also crosschecked by a vaporization measurement. After calibration, a precision of 10 mW for heat flows up to 1.1 W has been achieved. The helium leak can be measured up to 15 mg/s with an accuracy of 0.2 mg/s. We present a detailed description of the test facility and the measurements showing its performances.

  6. Heat flows and energetic behavior of a telecommunication radio base station

    E-Print Network [OSTI]

    Petraglia, Antonio; Vetromile, Carmela; D'Onofrio, Antonio; Lubritto, Carmine

    2015-01-01

    This paper shows a study on energetic consumption of BTSs (Base Transceiver Stations) for mobile communication, related to conditioning functions. An energetic "thermal model" of a telecommunication station is proposed and studied. The results have been validated with a BTS in central Italy, showing good agreement. Findings show a substantial high internal-external temperature difference in the containing shelter, particularly during daytime and warm months, due to sources of heat (equipment, external temperature and sun radiation) and to the difficulty in spread the warmth out. The necessity to keep the operating temperatures within a given range for the correct functioning of the electronic equipment requires the use of conditioning setups, and this significantly increases the energetic demand of the whole system. The analysis of thermal flows across the shelter can help to gather further data on its temperature behavior and to devise practical measures to lower the power demand, while keeping the operating...

  7. Convective Heat Transfer Augmentation by Flexible fins in Laminar Channel Pulsating flow

    E-Print Network [OSTI]

    Joshi, Rakshitha U; Bhardwaj, Rajneesh

    2015-01-01

    Fluid-structure interaction (FSI) of thin flexible fins coupled with convective heat transfer has applications in energy harvesting and in understanding functioning of several biological systems. We numerically investigate FSI of the thin flexible fins involving large-scale flow-induced deformation as a potential heat transfer enhancement technique. An in-house, strongly-coupled fluid-structure interaction (FSI) solver is employed in which flow and structure solvers are based on sharp-interface immersed boundary and finite element method, respectively. We consider twin flexible fins in a heated channel with laminar pulsating cross flow. The vortex ring past the fin sweep higher sources of vorticity generated on the channel walls out into the downstream - promoting the mixing of the fluid. The moving fin assists in convective mixing, augmenting convection in bulk and at the walls; and thereby reducing thermal boundary layer thickness and improving heat transfer at the channel walls. The thermal augmentation is...

  8. Time-resolved fluorescence decay measurements for flowing particles

    DOE Patents [OSTI]

    Deka, C.; Steinkamp, J.A.

    1999-06-01

    Time-resolved fluorescence decay measurements are disclosed for flowing particles. An apparatus and method for the measurement and analysis of fluorescence for individual cells and particles in flow are described, wherein the rapid measurement capabilities of flow cytometry and the robust measurement and analysis procedures of time-domain fluorescence lifetime spectroscopy are combined. A pulse-modulated CW laser is employed for excitation of the particles. The characteristics and the repetition rate of the excitation pulses can be readily adjusted to accommodate for fluorescence decays having a wide range of lifetimes. 12 figs.

  9. Mapping Geothermal Heat Flow and Existing Plants | Department...

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

    new clean, renewable geothermal plants in the near future. EGS works by injecting cold water deep into the Earth's crust. This water flows through fissures and cracks in the...

  10. Effect of rolling motion on critical heat flux for subcooled flow boiling in vertical tube

    SciTech Connect (OSTI)

    Hwang, J. S.; Park, I. U.; Park, M. Y.; Park, G. C.

    2012-07-01

    This paper presents defining characteristics of the critical heat flux (CHF) for the boiling of R-134a in vertical tube operation under rolling motion in marine reactor. It is important to predict CHF of marine reactor having the rolling motion in order to increase the safety of the reactor. Marine Reactor Moving Simulator (MARMS) tests are conducted to measure the critical heat flux using R-134a flowing upward in a uniformly heated vertical tube under rolling motion. MARMS was rotated by motor and mechanical power transmission gear. The CHF tests were performed in a 9.5 mm I.D. test section with heated length of 1 m. Mass fluxes range from 285 to 1300 kg m{sup -2}s{sup -1}, inlet subcooling from 3 to 38 deg. C and outlet pressures from 13 to 24 bar. Amplitudes of rolling range from 15 to 40 degrees and periods from 6 to 12 sec. To convert the test conditions of CHF test using R-134a in water, Katto's fluid-to-fluid modeling was used in present investigation. A CHF correlation is presented which accounts for the effects of pressure, mass flux, inlet subcooling and rolling angle over all conditions tested. Unlike existing transient CHF experiments, CHF ratio of certain mass flux and pressure are different in rolling motion. For the mass fluxes below 500 kg m{sup -2}s{sup -1} at 13, 16 (region of relative low mass flux), CHF ratio was decreased but was increased above that mass flux (region of relative high mass flux). Moreover, CHF tend to enhance in entire mass flux at 24 bar. (authors)

  11. A Simple Heat-Flow Quality Function And Appraisal Of Heat-Flow Measurements

    Open Energy Info (EERE)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on QA:QA J-E-1 SECTION JEnvironmental Jump to:EAand Dalton JumpProgram |Recent Exploration Well DrillingandRoadmapAnd

  12. Heat flow and subsurface temperature distributions in central and western New York. Final report

    SciTech Connect (OSTI)

    Hodge, D.S.; Fromm, K.

    1984-01-01

    Initiation of a geothermal energy program in western and central New York requires knowledge of subsurface temperatures for targeting areas of potential resources. The temperature distribution in possible geothermal reservoirs, calculated from heat flow measurements and modeling techniques, shows that a large area of New York can be considered for exploitation of geothermal resources. Though the temperatures at currently accessible depths show the availability of only a low-temperature (less than 100/sup 0/C), direct-use resource, this can be considered as an alternative for the future energy needs of New York State. From analysis of bottom-hole-temperature data and direct heat flow measurements, estimates of temperatures in the Cambrian Sandstones provide the basis of the economic evaluation of the reservoir. This reservoir contains the extractable fluids needed for targeting a potential geothermal well site in the low-temperature geothermal target zone. In the northern section of the Appalachian basin, reservoir temperatures in the Cambrian are below 50/sup 0/C but may be over 80/sup 0/C in the deeper parts of the basin in southern New York State. Using a minimum of 50/sup 0/C as a useful reservoir temperature, temperatures in excess of this value are encountered in the Theresa Formation at depths in excess of 1300 meters. Considering a maximum depth for economical drilling to be 2500 meters with present technology, the 2500 meters to the Theresa (sea level datum) forms the lower limit of the geothermal resource. Temperatures in the range of 70/sup 0/C to 80/sup 0/C are predicted for the southern portion of New York State.

  13. Eccentricity fluctuations and its possible effect on elliptic flow measurements

    E-Print Network [OSTI]

    Mike Miller; Raimond Snellings

    2003-12-11

    The elliptic flow measured at RHIC has been interpreted as a signature for strong partonic interactions early in the collision and as an indication of a well developed quark-gluon plasma phase. The measured values of elliptic flow, using methods based on multi-particle correlations, are affected by fluctuations in the magnitude of the elliptic flow. In this Letter, using a Monte Carlo Glauber calculation, we estimate what the possible effect of spatial eccentricity fluctuations is on the determination of elliptic flow.

  14. A numerical study on the effects of 2d structured sinusoidal elements on fluid flow and heat transfer at microscale

    E-Print Network [OSTI]

    Kandlikar, Satish

    , the effect of structured roughness elements on incompress- ible laminar fluid flow is analyzedA numerical study on the effects of 2d structured sinusoidal elements on fluid flow and heat flow Structured roughness elements Laminar flow a b s t r a c t Better understanding of laminar flow

  15. The Hardy inequality and the heat flow in curved wedges

    E-Print Network [OSTI]

    David Krejcirik

    2015-07-13

    We show that the polynomial decay rate of the heat semigroup of the Dirichlet Laplacian in curved planar wedges equals the sum of the usual dimensional decay rate and a multiple of the reciprocal value of the opening angle. To prove the result, we develop the method of self-similar variables for the associated heat equation and study the asymptotic behaviour of the transformed non-autonomous parabolic problem for large times. We also establish an improved Hardy inequality for the Dirichlet Laplacian in non-trivially curved wedges and state a conjecture about an improved decay rate in this case.

  16. A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows Seyed Ali Ale Etrati Khosroshahi

    E-Print Network [OSTI]

    Victoria, University of

    A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows by Seyed Ali Ale A Detailed Analysis of Guard-Heated Wall Shear Stress Sensors for Turbulent Flows by Seyed Ali Ale Etrati-dimensional analysis of the performance of multi-element guard-heated hot-film wall shear stress microsensors

  17. Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid

    E-Print Network [OSTI]

    Attard, Phil

    Statistical mechanical theory for steady-state systems. III. Heat flow in a Lennard-Jones fluid March 2005; accepted 4 May 2005; published online 28 June 2005 A statistical mechanical theory for heat distribution for heat flow down an imposed thermal gradient is tested with simulations of a Lennard-Jones fluid

  18. Emissivity corrected infrared method for imaging anomalous structural heat flows

    DOE Patents [OSTI]

    Del Grande, Nancy K. (San Leandro, CA); Durbin, Philip F. (Livermore, CA); Dolan, Kenneth W. (Livermore, CA); Perkins, Dwight E. (Livermore, CA)

    1995-01-01

    A method for detecting flaws in structures using dual band infrared radiation. Heat is applied to the structure being evaluated. The structure is scanned for two different wavelengths and data obtained in the form of images. Images are used to remove clutter to form a corrected image. The existence and nature of a flaw is determined by investigating a variety of features.

  19. A Cross-Flow Ceramic Heat Recuperator for Industrial Heat Recovery 

    E-Print Network [OSTI]

    Gonzalez, J. M.; Cleveland, J. J.; Kohnken, K. H.; Rebello, W. J.

    1980-01-01

    With increasing fuel costs, the efficient use of fuel is very important to the U.S. process heat industries. Increase in fuel usage efficiency can be obtained by transferring the waste exhaust heat to the cold combustion air. The metallic...

  20. Changes in Hepatic Blood Flow During Transcatheter Arterial Infusion with Heated Saline in Hepatic VX2 Tumor

    SciTech Connect (OSTI)

    Cao Wei; Li Jing; Wu Zhiqun; Zhou Changxi; Liu Xi; Wan Yi; Duan Yunyou

    2013-06-15

    Purpose. This study evaluates the influence of transcatheter arterial infusion with heated saline on hepatic arterial and portal venous blood flows to tumor and normal hepatic tissues in a rabbit VX2 tumor model. Methods. All animal experiments were approved by the institutional animal care and use committee. Twenty rabbits with VX2 liver tumors were divided into the following two groups: (a) the treated group (n = 10), which received a 60 mL transarterial injection of 60 Degree-Sign C saline via the hepatic artery; (b) the control group (n = 10), which received a 60 mL injection of 37 Degree-Sign C saline via the hepatic artery. Using ultrasonography, the blood flows in both the portal vein and hepatic artery were measured, and the changes in the hemodynamic indices were recorded before and immediately after the injection. The changes in the tumor and normal liver tissues of the two groups were histopathologically examined by hematoxylin and eosin staining after the injection. Results. After the transcatheter arterial heated infusion, there was a decrease in the hepatic arterial blood flow to the tumor tissue, a significant decrease in the hepatic artery mean velocity (P < 0.05), and a significant increase in the resistance index (P < 0.05). On hematoxylin and eosin staining, there were no obvious signs of tissue destruction in the normal liver tissue or the tumor tissue after heated perfusion, and coagulated blood plasma was observed in the cavities of intratumoral blood vessels in the treated group. Conclusions. The changes in tumor blood flow in the rabbit VX2 tumor model were presumably caused by microthrombi in the tumor vessels, and the portal vein likely mediated the heat loss in normal liver tissue during the transarterial heated infusion.

  1. Work measurement in an optomechanical quantum heat engine

    E-Print Network [OSTI]

    Ying Dong; Keye Zhang; Francesco Bariani; Pierre Meystre

    2015-04-11

    We analyze theoretically the measurement of the mean output work and its fluctuations in a recently proposed optomechanical quantum heat engine [K. Zhang {\\it et al.} Phys. Rev. Lett. {\\bf112}, 150602 (2014)]. After showing that this work can be evaluated by a continuous measurements of the intracavity photon number we discuss both dispersive and absorptive measurement schemes and analyze their back-action effects on the efficiency of the engine. Both measurements are found to reduce the efficiency of the engine, but their back-action is both qualitatively and quantitatively different. For dispersive measurements the efficiency decreases as a result of the mixing of photonic and phononic excitations, while for absorptive measurements, its reduction results from photon losses due to the interaction with the quantum probe.

  2. Heat flow and seismicity patterns in the vicinity of the eastern Snake River Plain, Idaho

    SciTech Connect (OSTI)

    Blackwell, D.D. Kelley, S.A.; Steele, J.L. (Southern Methodist Univ., Dallas, TX (United States). Dept. of Geological Sciences)

    1993-04-01

    New heat flow data and thermal modeling are used to calculate crustal temperatures in and adjacent to the eastern Snake River Plain (SRP). The estimated crustal temperature are then used to investigate the relationship between crustal strength and the observed parabolic pattern of seismicity around the SRP. Heat flow below the SRP aquifer in deep wells on the Idaho National Engineering Laboratory (INEL) site near the northern margin of the SRP is 107 [plus minus] 15 mWm[sup [minus]2]. Heat flow values from deep wells on both the northern and southern margins of the eastern SRP average 100 [plus minus] 15 mWm[sup [minus]2]. 2-D finite-difference thermal models were developed to fit seismic and heat flow data in the vicinity of the SRP. The models have a shallow silicic magma chamber that is as wide as the SRP. The silicic chamber is underlain by mafic heat sources in the middle to lower crust and in the upper mantle. The heat flow data are best fit by models with deep heat sources that are wider than the SRP. These results are consistent with the presence of young basaltic centers that have been observed outside the SRP. The temperature from the authors thermal models were used to calculate strength envelopes for the crust in the SRP/Basin and Range region. The weakest part of the crust is along the edge of the Basin and Range, where it is heated by the SRP; thus the boundary to the two provinces may be a zone of weak coupling. Their modeling indicates that it is difficult to explain the earthquake pattern in the vicinity of the SRP as a thermomechanical effect related to the passage of the Yellowstone hot spot.

  3. EFFECT OF HORIZONTALLY INHOMOGENEOUS HEATING ON FLOW AND MAGNETIC FIELD IN THE CHROMOSPHERE OF THE SUN

    SciTech Connect (OSTI)

    Song, P.; Vasyli?nas, V. M.

    2014-12-01

    The solar chromosphere is heated by damped Alfvén waves propagating upward from the photosphere at a rate that depends on magnetic field strength, producing enhanced heating at low altitudes in the extended weak-field regions (where the additional heating accounts for the radiative losses) between the boundaries of the chromospheric network as well as enhanced heating per particle at higher altitudes in strong magnetic field regions of the network. The resulting inhomogeneous radiation and temperature distribution produces bulk flows, which in turn affect the configuration of the magnetic field. The basic flow pattern is circulation on the spatial scale of a supergranule, with upward flow in the strong-field region; this is a mirror image in the upper chromosphere of photospheric/subphotospheric convection widely associated with the formation of the strong network field. There are significant differences between the neutral and the ionized components of the weakly ionized medium: neutral flow streamlines can form closed cells, whereas plasma is largely constrained to flow along the magnetic field. Stresses associated with this differential flow may explain why the canopy/funnel structures of the network magnetic field have a greater horizontal extent and are relatively more homogeneous at high altitudes than is expected from simple current-free models.

  4. In-Situ Thermal Conductivity Testing Using a Portable Heat Flow Meter 

    E-Print Network [OSTI]

    Harr, K. S.; Hutto, F. B., Jr.

    1979-01-01

    A method has been developed for measuring heat losses from insulated systems in the field. While the measurements are not as precise as those made under laboratory conditions, they are more indicative of actual in service conditions. Extensive field...

  5. Emissivity corrected infrared method for imaging anomalous structural heat flows

    DOE Patents [OSTI]

    Del Grande, N.K.; Durbin, P.F.; Dolan, K.W.; Perkins, D.E.

    1995-08-22

    A method for detecting flaws in structures using dual band infrared radiation is disclosed. Heat is applied to the structure being evaluated. The structure is scanned for two different wavelengths and data obtained in the form of images. Images are used to remove clutter to form a corrected image. The existence and nature of a flaw is determined by investigating a variety of features. 1 fig.

  6. Geothermal Heat Flow and Existing Geothermal Plants | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE: Alternative Fuelsof Energy Services »Information ResourcesHeatGenericExploration

  7. Counter flow cooling drier with integrated heat recovery

    DOE Patents [OSTI]

    Shivvers, Steve D. (Prole, IA)

    2009-08-18

    A drier apparatus for removing water or other liquids from various materials includes a mixer, drying chamber, separator and regenerator and a method for use of the apparatus. The material to be dried is mixed with a heated media to form a mixture which then passes through the chamber. While passing through the chamber, a comparatively cool fluid is passed counter current through the mixture so that the mixture becomes cooler and drier and the fluid becomes hotter and more saturated with moisture. The mixture is then separated into drier material and media. The media is transferred to the regenerator and heated therein by the hot fluid from the chamber and supplemental heat is supplied to bring the media to a preselected temperature for mixing with the incoming material to be dried. In a closed loop embodiment of the apparatus, the fluid is also recycled from the regenerator to the chamber and a chiller is utilized to reduce the temperature of the fluid to a preselected temperature and dew point temperature.

  8. Master's Thesis Measured Performance of Flows and Applications over Commercial

    E-Print Network [OSTI]

    Moon, Sue B.

    Performance of Flows and Applications over Commercial WiBro Network. UDP/TCP . School of ElectricalMaster's Thesis UDP/TCP Measured Performance of Flows and Applications over Commercial WiBro Network ( Woo, Shinae) , School of Electrical Engineering and Computer Science Division of Computer

  9. An experimental study of endwall heat transfer enhancement for flow past staggered non-conducting pin fin arrays 

    E-Print Network [OSTI]

    Achanta, Vamsee Satish

    2004-09-30

    In this work, we study the enhanced endwall heat transfer for flow past non conducting pin fin arrays. The aim is to resolve the controversy over the heat transfer that is taking place from the endwall and the pin ...

  10. A Measure of Flow Vorticity with Helical Beams of Light

    E-Print Network [OSTI]

    Rosales-Guzmán, Aniceto Belmonte Carmelo

    2015-01-01

    Vorticity describes the spinning motion of a fluid, i.e., the tendency to rotate, at every point in a flow. The interest in performing accurate and localized measurements of vorticity reflects the fact that many of the quantities that characterize the dynamics of fluids are intimately bound together in the vorticity field, being an efficient descriptor of the velocity statistics in many flow regimes. It describes the coherent structures and vortex interactions that are at the leading edge of laminar, transitional, and turbulent flows in nature. The measurement of vorticity is of paramount importance in many research fields as diverse as biology microfluidics, complex motions in the oceanic and atmospheric boundary layers, and wake turbulence on fluid aerodynamics. However, the precise measurement of flow vorticity is difficult. Here we put forward an optical sensing technique to obtain a direct measurement of vorticity in fluids using Laguerre-Gauss (LG) beams, optical beams which show an azimuthal phase vari...

  11. Overall and average local heat transfer from a horizontal cylinder in a gas-fluidized bed with an opposing oscillatory flow

    SciTech Connect (OSTI)

    Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics; Beasley, D.E. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering

    1996-12-31

    The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines fundamental aspects of heat transfer in this hybrid combustor by measuring the effect of an opposing oscillatory flow on the overall and time-averaged local heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor. Data were acquired for a monodisperse distribution of particles with a mean diameter of 345 {micro}m and total fluidization ratios ranging from 1.1 through 2.7. Overall and time-averaged local heat flux measurements from the surface of a submerged horizontal cylinder show that heat transfer characteristics are significantly altered by an opposing oscillatory flow. Increases in overall heat transfer on the order of 12% were identified for operating conditions with low primary and secondary flow rates and low pulse frequencies. These enhancements were identified to be a consequence of significant localized enhancements. The fundamental trends and magnitude of the particle Nusselt number are effectively characterized by a modified form of the Strouhal number.

  12. An analysis of periodic heat flow through a plane slab 

    E-Print Network [OSTI]

    Gibson, Daniel Morgan

    1958-01-01

    = heat ener;;y ter perature temperature at end o" time interval w8 nor~el distance from the surface in contact t. ~ith the fluid mhose te", . perature va~ies time prefix, a finite increment densit~J of the slab Sbs '* the fluid. v... INT. HiICH GLIC"' Zigure 2 The al. ;, ebra'c e-lressions for calculating7 the amount of ener'-y er terin;. = an7 interior slice through eaca of its l&oundaries during a finite time interval nQ and. the con- sequent change in energy content...

  13. Compare Energy Use in Variable Refrigerant Flow Heat Pumps Field Demonstration and Computer Model

    SciTech Connect (OSTI)

    Sharma, Chandan; Raustad, Richard

    2013-06-01

    Variable Refrigerant Flow (VRF) heat pumps are often regarded as energy efficient air-conditioning systems which offer electricity savings as well as reduction in peak electric demand while providing improved individual zone setpoint control. One of the key advantages of VRF systems is minimal duct losses which provide significant reduction in energy use and duct space. However, there is limited data available to show their actual performance in the field. Since VRF systems are increasingly gaining market share in the US, it is highly desirable to have more actual field performance data of these systems. An effort was made in this direction to monitor VRF system performance over an extended period of time in a US national lab test facility. Due to increasing demand by the energy modeling community, an empirical model to simulate VRF systems was implemented in the building simulation program EnergyPlus. This paper presents the comparison of energy consumption as measured in the national lab and as predicted by the program. For increased accuracy in the comparison, a customized weather file was created by using measured outdoor temperature and relative humidity at the test facility. Other inputs to the model included building construction, VRF system model based on lab measured performance, occupancy of the building, lighting/plug loads, and thermostat set-points etc. Infiltration model inputs were adjusted in the beginning to tune the computer model and then subsequent field measurements were compared to the simulation results. Differences between the computer model results and actual field measurements are discussed. The computer generated VRF performance closely resembled the field measurements.

  14. IEA Heat Pump Conference 2011, 16 -19 May 2011, Tokyo, Japan ON SIDE REFRIGERANT MEASUREMENT OF HEAT PUMP

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    - 1 - 10th IEA Heat Pump Conference 2011, 16 - 19 May 2011, Tokyo, Japan ON SIDE REFRIGERANT MEASUREMENT OF HEAT PUMP SEASONAL PERFORMANCES C. T. Tran, PhD student, Centre for Energy and Processes, MINES, Research Engineer, ENERBAT, Electricity of France R&D, Moret/Loing, France Abstract Heat pump systems have

  15. DOE Fundamentals Handbook: Thermodynamics, Heat Transfer, and Fluid Flow, Volume 2

    SciTech Connect (OSTI)

    Not Available

    1992-06-01

    The Thermodynamics, Heat Transfer, and Fluid Flow Fundamentals Handbook was developed to assist nuclear facility operating contractors provide operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of the thermal sciences. The handbook includes information on thermodynamics and the properties of fluids; the three modes of heat transfer -- conduction, convection, and radiation; and fluid flow, and the energy relationships in fluid systems. This information will provide personnel with a foundation for understanding the basic operation of various types of DOE nuclear facility fluid systems.

  16. TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems

    SciTech Connect (OSTI)

    Moridis, G.J.; Pruess (editor), K.

    1992-11-01

    The TOUGH code [Pruess, 1987] for two-phase flow of water, air, and heat in penneable media has been exercised on a suite of test problems originally selected and simulated by C. D. Updegraff [1989]. These include five 'verification' problems for which analytical or numerical solutions are available, and three 'validation' problems that model laboratory fluid and heat flow experiments. All problems could be run without any code modifications (*). Good and efficient numerical performance, as well as accurate results were obtained throughout. Additional code verification and validation problems from the literature are briefly summarized, and suggestions are given for proper applications of TOUGH and related codes.

  17. Electrically heated particulate filter with zoned exhaust flow control

    DOE Patents [OSTI]

    Gonze, Eugene V [Pinckney, MI

    2012-06-26

    A system includes a particulate matter (PM) filter that includes X zones. An electrical heater includes Y heater segments that are associated with respective ones of the X zones. The electrical heater is arranged upstream from and proximate with the PM filter. A valve assembly includes Z sections that are associated with respective ones of the X zones. A control module adjusts flow through each of the Z sections during regeneration of the PM filter via control of the valve assembly. X, Y and Z are integers.

  18. Device and method for measuring the coefficient of performance of a heat pump

    DOE Patents [OSTI]

    Brantley, V.R.; Miller, D.R.

    1982-05-18

    A method and instrument is provided which allows quick and accurate measurement of the coefficient of performance of an installed electrically powered heat pump including auxiliary resistane heaters. Temperature-sensitive resistors are placed in the return and supply air ducts to measure the temperature increase of the air across the refrigerant and resistive-heating elements of the system. The voltages across the resistors which are directly proportional to the respective duct tempertures are applied to the inputs of a differential amplifier so that its output voltage is proportional to the temperature difference across the unit. A voltage-to-frequency converter connected to the output of the differential amplifier converts the voltage signal to a proportional-frequency signal. A digital watt meter is used to measure the power to the unit and produces a signal having a frequency proportional to the input power. A digital logic circuit ratios the temperature difference signal and the electric power input signal in a unique manner to produce a single number which is the coefficient of performance of the unit over the test interval. The digital logic and an in-situ calibration procedure enables the instrument to make these measurements in such a way that the ratio of heat flow/power input is obtained without computations. No specialized knowledge of thermodynamics or electrons is required to operate the instrument.

  19. Device and method for measuring the coefficient of performance of a heat pump

    DOE Patents [OSTI]

    Brantley, Vanston R. (Knoxville, TN); Miller, Donald R. (Kingston, TN)

    1984-01-01

    A method and instrument is provided which allows quick and accurate measurement of the coefficient of performance of an installed electrically powered heat pump including auxiliary resistance heaters. Temperature sensitive resistors are placed in the return and supply air ducts to measure the temperature increase of the air across the refrigerant and resistive heating elements of the system. The voltages across the resistors which are directly proportional to the respective duct temperatures are applied to the inputs of a differential amplifier so that its output voltage is proportional to the temperature difference across the unit. A voltage-to-frequency converter connected to the output of the differential amplifier converts the voltage signal to a proportional frequency signal. A digital watt meter is used to measure the power to the unit and produces a signal having a frequency proportional to the input power. A digital logic circuit ratios the temperature difference signal and the electric power input signal in a unique manner to produce a single number which is the coefficient of performance of the unit over the test interval. The digital logic and an in-situ calibration procedure enables the instrument to make these measurements in such a way that the ratio of heat flow/power input is obtained without computations. No specialized knowledge of thermodynamics or electronics is required to operate the instrument.

  20. New flow boiling heat transfer model for hydrocarbons evaporating inside horizontal tubes

    SciTech Connect (OSTI)

    Chen, G. F.; Gong, M. Q.; Wu, J. F.; Zou, X.; Wang, S.

    2014-01-29

    Hydrocarbons have high thermodynamic performances, belong to the group of natural refrigerants, and they are the main components in mixture Joule-Thomson low temperature refrigerators (MJTR). New evaluations of nucleate boiling contribution and nucleate boiling suppression factor in flow boiling heat transfer have been proposed for hydrocarbons. A forced convection heat transfer enhancement factor correlation incorporating liquid velocity has also been proposed. In addition, the comparisons of the new model and other classic models were made to evaluate its accuracy in heat transfer prediction.

  1. Numerical study of oscillatory flow and heat transfer in a loaded thermoacoustic stack

    SciTech Connect (OSTI)

    Worlikar, A.S.; Knio, O.M.

    1999-01-01

    A thermoacoustic refrigerator may be idealized as consisting of a straight resonance tube housing a stack of parallel plates and heat exchangers, and an acoustic source. Among the advantages of thermoacoustic refrigerators are the simplicity of their design and the fact that they naturally avoid the need for harmful refrigerants such as chlorofluorocarbons (CFCs). The operation of these devices is based on exploiting the well-known thermoacoustic effect to induce a temperature difference across the stack and to transport heat from one end of the plate to the other. Heat exchangers are then used to transfer energy from the thermoacoustic refrigerator to hot and cold reservoirs. A two-dimensional, low-Mach-number computational model is used to analyze the unsteady flow and temperature fields in the neighborhood of an idealized stack/heat exchanger configuration. The model relies on a vorticity-based formulation of the mass, momentum, and energy equations in the low-Mach-number, short-stack limit. The stack and heat exchangers are assumed to consist of flat plates of equal thickness. The heat exchanger plates are assumed isothermal and in perfect thermal contact with the stack plates. The simulations are used to study the effect of heat exchanger size and operating conditions on the heat transfer and stack performance. Computed results show that optimum stack performance is achieved when the length of the heat exchanger is nearly equal to the peak-to-peak particle displacement. Numerical estimates of the mean enthalpy flux within the channel are in good agreement with the predictions of linear theory. However, the results reveal that a portion of the heat exchangers is ineffective due to reverse heat transfer. Details of the energy flux density around the heat exchangers are visualized, and implications regarding heat exchanger design and model extension are discussed.

  2. Validation of an in-flight flow visualization scheme to quantitatively measure vortical flow phenomena 

    E-Print Network [OSTI]

    Dorsett, Kenneth Merle

    1993-01-01

    A flow visualization measurement scheme was validated in flight. Strake vortex trajectories and axial core velocities were determined using pulsed smoke and high speed video. A gothic strake, operated at an angle of attack of 220 and a Reynolds...

  3. A TECHNOLOGY ASSESSMENT AND FEASIBILITY EVALUATION OF NATURAL GAS ENERGY FLOW MEASUREMENT ALTERNATIVES

    SciTech Connect (OSTI)

    Kendricks A. Behring II; Eric Kelner; Ali Minachi; Cecil R. Sparks; Thomas B. Morrow; Steven J. Svedeman

    1999-01-01

    Deregulation and open access in the natural gas pipeline industry has changed the gas business environment towards greater reliance on local energy flow rate measurement. What was once a large, stable, and well-defined source of natural gas is now a composite from many small suppliers with greatly varying gas compositions. Unfortunately, the traditional approach to energy flow measurement [using a gas chromatograph (GC) for composition assay in conjunction with a flow meter] is only cost effective for large capacity supplies (typically greater than 1 to 30 million scfd). A less costly approach will encourage more widespread use of energy measurement technology. In turn, the US will benefit from tighter gas inventory control, more efficient pipeline and industrial plant operations, and ultimately lower costs to the consumer. An assessment of the state and direction of technology for natural gas energy flow rate measurement is presented. The alternative technologies were ranked according to their potential to dramatically reduce capital and operating and maintenance (O and M) costs, while improving reliability and accuracy. The top-ranked technologies take an unconventional inference approach to the energy measurement problem. Because of that approach, they will not satisfy the fundamental need for composition assay, but have great potential to reduce industry reliance on the GC. Technological feasibility of the inference approach was demonstrated through the successful development of data correlations that relate energy measurement properties (molecular weight, mass-based heating value, standard density, molar ideal gross heating value, standard volumetric heating value, density, and volume-based heating value) to three inferential properties: standard sound speed, carbon dioxide concentration, and nitrogen concentration (temperature and pressure are also required for the last two). The key advantage of this approach is that inexpensive on-line sensors may be used to measure the inferential variables, which can then be applied (through the data correlations) to convert existing flow meters (ultrasonic, orifice, turbine, rotary, Coriolis, diaphragm, etc.) for on-line energy measurement. The practical issues for field development were evaluated using two transducers extracted from a $100 ultrasonic domestic gas meter, and a $400 infrared sensor.

  4. Enhanced Oil Recovery: Aqueous Flow Tracer Measurement

    SciTech Connect (OSTI)

    Joseph Rovani; John Schabron

    2009-02-01

    A low detection limit analytical method was developed to measure a suite of benzoic acid and fluorinated benzoic acid compounds intended for use as tracers for enhanced oil recovery operations. Although the new high performance liquid chromatography separation successfully measured the tracers in an aqueous matrix at low part per billion levels, the low detection limits could not be achieved in oil field water due to interference problems with the hydrocarbon-saturated water using the system's UV detector. Commercial instrument vendors were contacted in an effort to determine if mass spectrometry could be used as an alternate detection technique. The results of their work demonstrate that low part per billion analysis of the tracer compounds in oil field water could be achieved using ultra performance liquid chromatography mass spectrometry.

  5. Flow Measurement with Tangential Paddlewheel Flow Meters: Analysis of Experimental Results and in-situ Diagnostics 

    E-Print Network [OSTI]

    Watt, J. B.; Haberl, J. S.

    1994-01-01

    or generate a totalized signal that can be recorded by data acquisition system. The accuracy of totalized flow and energy measurements is directly effected by the quality of thermal and flow measurement devices. In a closed-loop system a thermal energy meter... possible solution is to use a frequency to voltage converter between the magnetic paddlewheel flow meter and thermal energy meter to transform the sine wave to a square wave much like the signal generated by the non-magnetic-type meter (Doeblin 1990...

  6. CASCADE CONTROL EXPERIMENTS OF RISER SLUG FLOW USING TOPSIDE MEASUREMENTS

    E-Print Network [OSTI]

    Skogestad, Sigurd

    the flow using only topside measurements, as subsea measurements can be unavailable offshore. The results production facilities (Havre et al., 2000) and (Godhavn et al., 2005a). #12;The above applications use subsea been build to test different control strategies. Use of a simple PI-controller with a subsea pressure

  7. A Model of Plasma Heating by Large-Scale Flow

    E-Print Network [OSTI]

    Pongkitiwanichakul, P; Boldyrev, S; Mason, J; Perez, J C

    2015-01-01

    In this work we study the process of energy dissipation triggered by a slow large scale motion of a magnetized conducting fluid. Our consideration is motivated by the problem of heating the solar corona, which is believed to be governed by fast reconnection events set off by the slow motion of magnetic field lines anchored in the photospheric plasma. To elucidate the physics governing the disruption of the imposed laminar motion and the energy transfer to small scales, we propose a simplified model where the large-scale motion of magnetic field lines is prescribed not at the footpoints but rather imposed volumetrically. As a result, the problem can be treated numerically with an efficient, highly-accurate spectral method, allowing us to use a resolution and statistical ensemble exceeding those of the previous work. We find that, even though the large-scale deformations are slow, they eventually lead to reconnection events that drive a turbulent state at smaller scales. The small-scale turbulence displays many...

  8. In situ changes in the moisture content of heated, welded tuff based on thermal neutron measurements

    SciTech Connect (OSTI)

    Ramirez, A.L.; Carlson, R.C.; Buscheck, T.A.

    1991-07-01

    Thermal neutron logs were collected to monitor changes in moisture content within a welded tuff rock mass heated from a borehole containing an electrical heater which remained energized for 195 days. Thermal neutron measurements were made in sampling boreholes before, during and after heating. The results generally corroborated our conceptual understanding of hydrothermal flow as well as most of the numerical modeling conducting for this study. Conceptual models have been developed in conjunction with the numerical model calculations to explain differences in the drying and re-wetting behavior above and below the heater. Numerical modeling indicated that the re-wetting of the dried-out zone was dominated by the binary diffusion of water vapor through fractures. Saturation gradients in the rock matrix resulted in relative humidity gradients which drove water vapor (primarily along fractures) back to the dried-out zone where it condensed along the fracture walls and was imbibed by the matrix. 4 refs., 28 figs.

  9. November 28, 2006 Seismologists get handle on heat flow deep in earth

    E-Print Network [OSTI]

    Garnero, Ed

    November 28, 2006 Seismologists get handle on heat flow deep in earth Earth's interior placid inner Earth as a dynamic environment filled with exotic materials and substances roiling under that has an impact on what happens on our planet's surface. The latest evidence of this dynamic inner Earth

  10. Heat flow into spheres for a class of energies Norbert Hungerbuhler

    E-Print Network [OSTI]

    Hungerbühler, Norbert

    Heat flow into spheres for a class of energies Norbert Hungerb¨uhler Department of Mathematics Riemannian manifolds without boundaries. Then, for a map u : M N, we consider a class of energies which includes the popular Dirichlet energy and the more general p-energy. Geometric or physical questions

  11. Cyclic Concentration Measurements for Characterizing Pulsating Flow

    SciTech Connect (OSTI)

    Bamberger, Judith A.

    2013-07-07

    Slurry mixed in vessels via pulse jet mixers has a periodic, rather than steady, concentration profile. Measurements of local concentration taken at the center of the tank at a range of elevations within the mixed region were analyzed to obtain a greater understanding of how the periodic pulse jet mixing cycle affects the local concentration. Data were obtained at the critical suspension velocity, when all solids are suspended at the end of the pulse. The data at a range of solids loadings are analyzed to observe the effect of solids concentration during the suspension and settling portions of the mixing cycle.

  12. Fiber-optic interferometric sensor for gas flow measurements

    SciTech Connect (OSTI)

    Kaminski, W.R. ); Griffin, J.W.; Bates, J.M. )

    1991-12-01

    This paper presents the results of an investigation to determine the feasibility of a novel approach to measuring gas flow in a pipe. An optical fiber is stretched across a pipe and serves as a sensor which is based upon the well-established principle of vortex shedding of a cylinder in cross-flow. The resulting time varying optical signal produces a frequency component proportional to the average velocity in the pipe which is in turn proportional to volumetric flow. A Mach-Zehnder interferometer is used to enhance the accuracy of the vortex shedding frequency signal. The analytical and experimental effort discussed herein shows that the concept is feasible and holds promise for a sensitive and accurate flow measuring technique.

  13. Flow boiling and two-phase flow instabilities in silicon microchannel heat sinks for microsystems cooling 

    E-Print Network [OSTI]

    Bogojevi?, Dario

    2010-01-01

    Flow boiling in microchannels, while very promising as a cooling technology in electronics thermal management, is still a subject being explored that requires further investigation. Before applying this technology for ...

  14. System and method measuring fluid flow in a conduit

    DOE Patents [OSTI]

    Ortiz, Marcos German (Idaho Falls, ID); Kidd, Terrel G. (Blackfoot, ID)

    1999-01-01

    A system for measuring fluid mass flow in a conduit in which there exists a pressure differential in the fluid between at least two spaced-apart locations in the conduit. The system includes a first pressure transducer disposed in the side of the conduit at a first location for measuring pressure of fluid at that location, a second or more pressure transducers disposed in the side of the conduit at a second location, for making multiple measurements of pressure of fluid in the conduit at that location, and a computer for computing the average pressure of the multiple measurements at the second location and for computing flow rate of fluid in the conduit from the pressure measurement by the first pressure transducer and from the average pressure calculation of the multiple measurements.

  15. A WIND TUNNEL INVESTIGATION OF THE INFLUENCE OF SOLAR-INDUCED WALL-HEATING ON THE FLOW REGIME

    E-Print Network [OSTI]

    Savory, Eric

    -section canyon model in a wind tunnel. For reference purposes, the neutral case (no wall heating), has also been viscosity of air (m2 s-1 ) 1. Introduction The wind flow field within urban areas has been studiedA WIND TUNNEL INVESTIGATION OF THE INFLUENCE OF SOLAR-INDUCED WALL-HEATING ON THE FLOW REGIME

  16. Turbulent heat transfer in a channel flow at transitional Reynolds numbers

    E-Print Network [OSTI]

    Tsukahara, Takahiro

    2014-01-01

    Direct numerical simulation of a turbulent channel flow with heat transfer was performed at very low Reynolds numbers. Two different thermal boundary conditions were studied, and temperature was considered as a passive scalar. The computations were carried out with huge computational boxes (up to 327.7 x 2 x 128 in the streamwise, wall-normal, and spanwise directions, respectively). The emphases of this paper are to investigate the large-scale structure (puff) in the intermittent-turbulent flow including the scalar fields and to provide the values of the transitional and critical Reynolds numbers, below which the turbulent flow becomes intermittent and laminar, respectively. The statistics, such as the skin friction and the Stanton number, were also examined: they suggest that the puff should be effective in sustaining turbulence and in heat transfer enhancement.

  17. Critical heat-flux experiments under low-flow conditions in a vertical annulus. [PWR; BWR; LMFBR

    SciTech Connect (OSTI)

    Mishima, K.; Ishii, M.

    1982-03-01

    An experimental study was performed on critical heat flux (CHF) at low flow conditions for low pressure steam-water upward flow in an annulus. The test section was transparent, therefore, visual observations of dryout as well as various instrumentations were made. The data indicated that a premature CHF occurred due to flow regime transition from churn-turbulent to annular flow. It is shown that the critical heat flux observed in the experiment is essentially similar to a flooding-limited burnout and the critical heat flux can be well reproduced by a nondimensional correlation derived from the previously obtained criterion for flow regime transition. The observed CHF values are much smaller than the standard high quality CHF criteria at low flow, corresponding to the annular flow film dryout. This result is very significant, because the coolability of a heater surface at low flow rates can be drastically reduced by the occurrence of this mode of CHF.

  18. Convective heat transfer on leeward building walls in an urban environment: Measurements in an outdoor scale model

    E-Print Network [OSTI]

    Nottrott, A.; Onomura, S.; Inagaki, A.; Kanda, M.; Kleissl, J.

    2011-01-01

    Vortex structure and heat transfer in turbulent flow over asurface, Proc. 5 th Int. Heat Transfer Conf. 3 (1974) 129-a vertical plate, J. Heat Transfer 109(1) [13] K. Patel,

  19. Flow cytometric measurement of total DNA and incorporated halodeoxyuridine

    DOE Patents [OSTI]

    Dolbeare, Frank A. (Livermore, CA); Gray, Joe W. (Livermore, CA)

    1986-01-01

    A method for the simultaneous flow cytometric measurement of the total DNA content and the level of DNA synthesis in normal and malignant cells is disclosed. The sensitivity of the method allows a study of cell cycle traverse rates for large scale cell populations as well as single cell measurements. A DNA stain such as propidium iodide is used as the probe for the measurement of total DNA content and a monoclonal antibody reactive with a DNA precursor such as bromodeoxyuridine (BrdU) is used as a probe for the measurement of BrdU uptake by the cells as a measure of DNA synthesis.

  20. Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non intrusive method

    E-Print Network [OSTI]

    Boiling heat transfer in a vertical microchannel: Local estimation during flow boiling with a non the results of experimental and numerical studies concerning boiling heat transfer inside vertical in minichannels for several gravity levels (µg, 1g, 2g). To fully understand the high heat transfer potential

  1. Optimal operation of a concurrent-flow corn dryer with a drying heat pump using superheated steam

    SciTech Connect (OSTI)

    Moraitis, C.S. [Systelligence Consultants and Research Associates, Volos (Greece); Akritidis, C.B. [Dept. of Hydraulics and Agricultural Engineering, Thessaloniki (Greece)

    1998-07-01

    A numerical model of a concurrent-flow dryer of corn using superheated steam as drying medium is solved applying a shooting technique, so as to satisfy boundary conditions imposed by the optimal design of a drying heat pump. The drying heat pump is based on the theory of minimum energy cycles. The solution of the model proves the applicability of the heat pump to a concurrent-flow dryer, achieving a Specific Energy Consumption as low as 1080 kJ/kg.

  2. Silver Sinter Heat Exchangers Construction of a sinter press and a BET-system to measure

    E-Print Network [OSTI]

    Zumbühl, Dominik

    Silver Sinter Heat Exchangers Construction of a sinter press and a BET-system to measure specific, efficient heat exchangers are of special importance. As the thermal boundary resistance, called Kapitza­resistance, is inversely proportional to the interface area, heat exchangers with large surface areas are used for the heat

  3. Modelling for post-dryout heat transfer and droplet sizes at low pressure and low flow conditions

    SciTech Connect (OSTI)

    Jeong, H.Y.; No, H.C. [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering] [Korea Advanced Inst. of Science and Technology, Taejon (Korea, Republic of). Dept. of Nuclear Engineering

    1996-10-01

    A correlation describing the initial droplet size just after the CHF position at low mass flux is suggested through regression analysis. The history-dependent post-dryout model of Varone and Rohsenow replaced by the Webb-Chen model for wall-vapor heat transfer is used as a reference model in the analysis. In the post-dryout region at low pressure and low flow, it is found that the suggested one-dimensional mechanistic model is valid only in the churn-turbulent flow regime (j*{sub g} = 0.5 {approximately} 4.5). It is also suggested that the droplet size generated from the churn-turbulent surface is dependent not only on the pressure but also on the vapor velocity. It turns out that the present model can predict the measured cladding and vapor temperatures within 20% and 15%, respectively.

  4. Differential heating: A versatile method for thermal conductivity measurements in high-energy-density matter

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

    Ping, Y.; Fernandez-Panella, A.; Sio, H.; Correa, A.; Shepherd, R.; Landen, O.; London, R. A.; Sterne, P. A.; Whitley, H. D.; Fratanduono, D.; et al

    2015-09-04

    We propose a method for thermal conductivity measurements of high energy density matter based on differential heating. A temperature gradient is created either by surface heating of one material or at an interface between two materials by different energy deposition. The subsequent heat conduction across the temperature gradient is observed by various time-resolved probing techniques. Conceptual designs of such measurements using laser heating, proton heating, and x-ray heating are presented. As a result, the sensitivity of the measurements to thermal conductivity is confirmed by simulations.

  5. Direct numerical simulations of fluid flow, heat transfer and phase changes

    SciTech Connect (OSTI)

    Juric, D.; Tryggvason, G.; Han, J.

    1997-04-01

    Direct numerical simulations of fluid flow, heat transfer, and phase changes are presented. The simulations are made possible by a recently developed finite difference/front tracking method based on the one-field formulation of the governing equations where a single set of conservation equations is written for all the phases involved. The conservation equations are solved on a fixed rectangular grid, but the phase boundaries are kept sharp by tracking them explicitly by a moving grid of lower dimension. The method is discussed and applications to boiling heat transfer and the solidification of drops colliding with a wall are shown.

  6. Measured Performance of a Low Temperature Air Source Heat Pump

    SciTech Connect (OSTI)

    R.K. Johnson

    2013-09-01

    A 4-ton Low Temperature Heat Pump (LTHP) manufactured by Hallowell International was installed in a residence near New Haven, Connecticut and monitored over two winters of operation. After attending to some significant service issues, the heat pump operated as designed. This report should be considered a review of the dual compressor “boosted heat pump” technology. The Low Temperature Heat Pump system operates with four increasing levels of capacity (heat output) as the outdoor temperature drops.

  7. Heat release and flame structure measurements of self-excited acoustically-driven premixed methane flames

    SciTech Connect (OSTI)

    Kopp-Vaughan, Kristin M.; Tuttle, Steven G.; Renfro, Michael W.; King, Galen B.

    2009-10-15

    An open-open organ pipe burner (Rijke tube) with a bluff-body ring was used to create a self-excited, acoustically-driven, premixed methane-air conical flame, with equivalence ratios ranging from 0.85 to 1.05. The feed tube velocities corresponded to Re = 1780-4450. Coupled oscillations in pressure, velocity, and heat release from the flame are naturally encouraged at resonant frequencies in the Rijke tube combustor. This coupling creates sustainable self-excited oscillations in flame front area and shape. The period of the oscillations occur at the resonant frequency of the combustion chamber when the flame is placed {proportional_to}1/4 of the distance from the bottom of the tube. In this investigation, the shape of these acoustically-driven flames is measured by employing both OH planar laser-induced fluorescence (PLIF) and chemiluminescence imaging and the images are correlated to simultaneously measured pressure in the combustor. Past research on acoustically perturbed flames has focused on qualitative flame area and heat release relationships under imposed velocity perturbations at imposed frequencies. This study reports quantitative empirical fits with respect to pressure or phase angle in a self-generated pressure oscillation. The OH-PLIF images were single temporal shots and the chemiluminescence images were phase averaged on chip, such that 15 exposures were used to create one image. Thus, both measurements were time resolved during the flame oscillation. Phase-resolved area and heat release variations throughout the pressure oscillation were computed. A relation between flame area and the phase angle before the pressure maximum was derived for all flames in order to quantitatively show that the Rayleigh criterion was satisfied in the combustor. Qualitative trends in oscillating flame area were found with respect to feed tube flow rates. A logarithmic relation was found between the RMS pressure and both the normalized average area and heat release rate for all flames. (author)

  8. Unsteady two-phase flow instrumentation and measurement

    SciTech Connect (OSTI)

    Bernier, R.J.N.

    1982-01-01

    The performance of a transverse field electromagnetic flowmeter in a steady two-phase flow was investigated analytically for a disperse and an annular flow regime. In both cases the flowmeter output voltage was found to be proportional to the mean velocity of the liquid phase. Experiments in a steady air-water mixture showed good agreement with the analysis. An impedance void fraction meter was designed and built to conduct measurements of unsteady void fractions. Short electrodes excited by voltages of opposite polarity were used in combination with a highly sensitive signal processor. The steady state calibration indicated that the meter was somewhat sensitive to the void fraction distribution for the bubbly flow regime. However, the transition to a churn turbulent regime greatly affected the meter steady state response. The dynamic capability of the void fraction meter was estimated by comparison of the statistical properties of the voltage fluctuations in a nominally steady bubbly flow with those of a shot-noise process. Also some properties of the disperse phase could be inferred from the statistical analysis. Two void fraction meters were used to measure the propagation speed of kinematic shocks in an air-water bubbly mixture for various void fractions and water flow rates. Measurements of the propagation speed of shocks of decreasing strength provided a good verification of the kinematic wave theory. The shock thicknesses could also be determined leading to the conclusion that an important diffusion mechanism was responsible for arresting the steepening of the wave. Cross-correlations of the fluctuating voltage of two void fraction meters in a steady bubbly flow were determined. The speed measured by this technique was identified as the infinitesimal wave speed of the void fraction and not the velocity of the dispersed phase as postulated by some authors. The cross spectral density revealed that the waves present in these disturbances were non-dispersive.

  9. UNIVERSITY OF CALIFORNIA, Ion Flow Measurements and Plasma Current Analysis

    E-Print Network [OSTI]

    Heidbrink, William W.

    UNIVERSITY OF CALIFORNIA, IRVINE Ion Flow Measurements and Plasma Current Analysis in the Irvine OF THE DISSERTATION xvii 1 Introduction 1 2 Field Reversed Configurations 4 2.1 FRC Fundamentals . . . . . . . . . . . . . . . . . . . . . . . . . . 7 2.1.3 FRC Instabilities . . . . . . . . . . . . . . . . . . . . . . . . . 10 2.1.4 FRC Formation

  10. Fundamental Mass Flow Measurement of Solid Department of Agricultural Engineering

    E-Print Network [OSTI]

    Engineering University of Illinois Urbana-Champaign, Illinois, USA A generic mass flow measurement device formation and direct counting of individual particles is impossible. If a method could be available correspondence to Tony Grift, Department of Agricultural Engineering, University of Illinois, Urbana

  11. Streaming potential measurements 2. Relationship between electrical and hydraulic flow

    E-Print Network [OSTI]

    Avouac, Jean-Philippe

    that variations of electric potential observed in a variety of geophysical contexts (geothermal fields, volcanoes gradient, is measured by recording the voltage across a sample through which an electrolyte is flowing to the pressure gradient and a quantity called the potential, which characterizes the structure of the EDL

  12. New tube bundle heat transfer correlations and flow regime maps for a Once Through Steam Generator 

    E-Print Network [OSTI]

    Blanchat, Thomas Kevin

    1988-01-01

    ' . Another study on annular film ? flow boiling in a vertical channel with ofFset strip fins (geom- etry similar to tube bundles) also concludes that the transition occurs at a, value of void fraction below that for tubes . The accuracy of predicted heat... film ? flow boiling in a, vertical channel with offset strip fins (geometry similar to tube bundles) also concludes that the transition occurs at a, value of void fraction below that 1' or tubes . In ter1ns of the parameter j* defined by g Wallis...

  13. Method and apparatus for measuring coupled flow, transport, and reaction processes under liquid unsaturated flow conditions

    DOE Patents [OSTI]

    McGrail, Bernard P. (Pasco, WA); Martin, Paul F. (Richland, WA); Lindenmeier, Clark W. (Richland, WA)

    1999-01-01

    The present invention is a method and apparatus for measuring coupled flow, transport and reaction processes under liquid unsaturated flow conditions. The method and apparatus of the present invention permit distinguishing individual precipitation events and their effect on dissolution behavior isolated to the specific event. The present invention is especially useful for dynamically measuring hydraulic parameters when a chemical reaction occurs between a particulate material and either liquid or gas (e.g. air) or both, causing precipitation that changes the pore structure of the test material.

  14. Thermochimica Acta 447 (2006) 5256 Metabolic heat and CO2 evolution rates measured by calorimetry during

    E-Print Network [OSTI]

    Lieth, J. Heinrich

    2006-01-01

    Thermochimica Acta 447 (2006) 52­56 Metabolic heat and CO2 evolution rates measured by calorimetry the embryogenic/organogenic development of the explanted cotyledons. Calorespirometric (metabolic heat rate, Rq measure metabolic parameters of respiring plant tissues, such as the rate of metabolic heat pro- duction

  15. Time-resolved heat transfer in the oscillating turbulent flow of a pulse-combustor tail pipe

    SciTech Connect (OSTI)

    Dec, J.E.

    1988-01-01

    The need for efficient combustion systems has led to active research in pulse combustion. One advantage of pulse combustor heating systems is a high rate of heat transfer in the tail pipe. These high heat transfer rates result from large velocity oscillations, which occur in the tailpipe as a result of the acoustic resonance of the pulse combustor. Past research on the effects of flow oscillations on heat transfer rates is inconclusive; however, some oscillating turbulent flows have been shown to have Nusselt numbers, which are much higher than those to steady turbulent flow at the same mean Reynolds number. An experimental study of the heat transfer rates and convective transport processes in a pulse combustor tail pipe was conducted. A test combustor was used, in which the oscillation frequencies could be varied from 54 to 101 Hz, with peak-to-peak velocity oscillations from zero (steady flow) to 10 times the mean velocity, and mean Reynolds numbers from 3100 to 4750. Nusselt numbers in the tail pipe are enhanced by the oscillations up to a factor of 2.5 times the expected value for steady turbulent flow. The Nusselt number enhancement increases with both oscillation frequency and velocity oscillation amplitude. Increases in the mean Reynolds number decreased the enhancement. Possible causes for the heat-transfer enhancement in oscillating flows are discussed. The data indicate that the heat transfer enhancement results from a combination of increased turbulence intensity and transverse flows generated during the streamwise velocity reversals.

  16. Flow Measurement and Instrumentation 9 (1998) 159169 Measurement of angular velocities using electrical impedance

    E-Print Network [OSTI]

    1998-01-01

    Flow Measurement and Instrumentation 9 (1998) 159­169 Measurement of angular velocities using, the predominant component of velocity is angular in nature. In this paper a novel technique based on electrical impedance tomography (EIT) is introduced for measuring and mapping these angular velocities. The technique

  17. Measuring the heat exchange of a quantum process

    E-Print Network [OSTI]

    John Goold; Ulrich Poschinger; Kavan Modi

    2014-08-19

    Very recently, interferometric methods have been proposed to measure the full statistics of work performed on a driven quantum system [Dorner et al. Phys. Rev. Lett. 110 230601 (2013)] and [Mazzola et al. Phys. Rev. Lett. 110 230602 (2013)]. The advantage of such schemes is that they replace the necessity to make projective measurements by performing phase estimation on an appropriately coupled ancilla qubit. These proposals are one possible route to the tangible experimental exploration of quantum thermodynamics, a subject which is the centre of much current attention due to the current control of mesoscopic quantum systems. In this Letter we demonstrate that a modification of the phase estimation protocols can be used in order to measure the heat distribution of a quantum process. In addition we demonstrate how our scheme may be implemented using ion trap technology. Our scheme should pave the way for the first experimental explorations of the Landauer principle and hence the intricate energy to information conversion in mesoscopic quantum systems.

  18. Sealable stagnation flow geometries for the uniform deposition of materials and heat

    DOE Patents [OSTI]

    McCarty, Kevin F. (Livermore, CA); Kee, Robert J. (Livermore, CA); Lutz, Andrew E. (Alamo, CA); Meeks, Ellen (Livermore, CA)

    2001-01-01

    The present invention employs a constrained stagnation flow geometry apparatus to achieve the uniform deposition of materials or heat. The present invention maximizes uniform fluxes of reactant gases to flat surfaces while minimizing the use of reagents and finite dimension edge effects. This results, among other things, in large area continuous films that are uniform in thickness, composition and structure which is important in chemical vapor deposition processes such as would be used for the fabrication of semiconductors.

  19. Micro- and Nanoscale Measurement Methods for Phase Change Heat Transfer on Planar and Structured Surfaces

    E-Print Network [OSTI]

    Buongiorno, Jacopo

    In this opinion piece, we discuss recent advances in experimental methods for characterizing phase change heat transfer. We begin with a survey of techniques for high-resolution measurements of temperature and heat flux ...

  20. Color Key 1/25/2012 4.1.1 PTCS and Heat Pump Measures

    E-Print Network [OSTI]

    Color Key 1/25/2012 4.1.1 PTCS and Heat Pump Measures Staff Summary of Ecotope Recommendation: Staff Response and Recommended Action: 4.1.3 Ductless Heat Pumps Staff Summary of Ecotope Recommendation

  1. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    SciTech Connect (OSTI)

    Hong, Tainzhen; Liu, Xaiobing

    2009-11-01

    With the current movement toward net zero energy buildings, many technologies are promoted with emphasis on their superior energy efficiency. The variable refrigerant flow (VRF) and ground source heat pump (GSHP) systems are probably the most competitive technologies among these. However, there are few studies reporting the energy efficiency of VRF systems compared with GSHP systems. In this article, a preliminary comparison of energy efficiency between the air-source VRF and GSHP systems is presented. The computer simulation results show that GSHP system is more energy efficient than the air-source VRF system for conditioning a small office building in two selected US climates. In general, GSHP system is more energy efficient than the air-source VRV system, especially when the building has significant heating loads. For buildings with less heating loads, the GSHP system could still perform better than the air-source VRF system in terms of energy efficiency, but the resulting energy savings may be marginal.

  2. Shock-Wave Heating Model for Chondrule Formation: Hydrodynamic Simulation of Molten Droplets exposed to Gas Flows

    E-Print Network [OSTI]

    Hitoshi Miura; Taishi Nakamoto

    2006-11-09

    Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. One of the most plausible scenarios is that the chondrule precursor dust particles are heated and melt in the high-velocity gas flow (shock-wave heating model). We developed the non-linear, time-dependent, and three-dimensional hydrodynamic simulation code for analyzing the dynamics of molten droplets exposed to the gas flow. We confirmed that our simulation results showed a good agreement in a linear regime with the linear solution analytically derived by Sekiya et al. (2003). We found that the non-linear terms in the hydrodynamical equations neglected by Sekiya et al. (2003) can cause the cavitation by producing negative pressure in the droplets. We discussed that the fragmentation through the cavitation is a new mechanism to determine the upper limit of chondrule sizes. We also succeeded to reproduce the fragmentation of droplets when the gas ram pressure is stronger than the effect of the surface tension. Finally, we compared the deformation of droplets in the shock-wave heating with the measured data of chondrules and suggested the importance of other effects to deform droplets, for example, the rotation of droplets. We believe that our new code is a very powerful tool to investigate the hydrodynamics of molten droplets in the framework of the shock-wave heating model and has many potentials to be applied to various problems.

  3. Active region emission measure distributions and implications for nanoflare heating

    SciTech Connect (OSTI)

    Cargill, P. J., E-mail: p.cargill@imperial.ac.uk [Space and Atmospheric Physics, The Blackett Laboratory, Imperial College, London SW7 2BW, UKAND (United Kingdom); School of Mathematics and Statistics, University of St Andrews, St Andrews, Scotland KY16 9SS (United Kingdom)

    2014-03-20

    The temperature dependence of the emission measure (EM) in the core of active regions coronal loops is an important diagnostic of heating processes. Observations indicate that EM(T) ? T{sup a} below approximately 4 MK, with 2 < a < 5. Zero-dimensional hydrodynamic simulations of nanoflare trains are used to demonstrate the dependence of a on the time between individual nanoflares (T{sub N} ) and the distribution of nanoflare energies. If T{sub N} is greater than a few thousand seconds, a < 3. For smaller values, trains of equally spaced nanoflares cannot account for the observed range of a if the distribution of nanoflare energies is either constant, randomly distributed, or a power law. Power law distributions where there is a delay between consecutive nanoflares proportional to the energy of the second nanoflare do lead to the observed range of a. However, T{sub N} must then be of the order of hundreds to no more than a few thousand seconds. If a nanoflare leads to the relaxation of a stressed coronal field to a near-potential state, the time taken to build up the required magnetic energy is thus too long to account for the EM measurements. Instead, it is suggested that a nanoflare involves the relaxation from one stressed coronal state to another, dissipating only a small fraction of the available magnetic energy. A consequence is that nanoflare energies may be smaller than previously envisioned.

  4. Experimental investigation on impingement heat transfer of gas-solid suspension flow

    SciTech Connect (OSTI)

    Yokomine, Takenhiko; Shimizu, Akihiko

    1999-07-01

    This paper aims to demonstrate experimentally the heat transfer performance of dense gas-solid suspension impinging jet for diverter cooling of the fusion power reactor. Prior to the experimental study, a tentative goal of 20 kW/m{sup 2}K was set as the heat transfer coefficient based on the expected temperature level of both coolant and diverter plate materials. Figure A-1 summarizes the results of experiments, where H/D is non-dimensional space between nozzle exit and impingement plate. The ranges of examined nozzle Reynolds number Re{sub N} and thermal loading ratio {Gamma}{sub th} were 5.5 x 10{sup 4} {<=} Re{sub N} {<=} 2.4 x 10{sup 5} and 0 {<=} {Gamma}{sub th} {<=} 8.55, respectively. When the glassy-carbon (G-C) particles with 26{micro}m in diameter were used, the maximum heat transfer coefficient could not reach the target value because the solid flow rate was restricted by the crucial erosion damage of test plate and a strong vibration observed in the test line. On the other hand, in the case that the fine graphite particles (10{micro}m in diameter) were used, the maximum heat transfer coefficient of 20 kW/m{sup 2}K was obtained at relatively dilute condition of solid loading ratio, which is considered to be due to the additive production of turbulence by particles' wake. Furthermore, the following consideration can be obtained. (1) Changing the particle from hard glassy carbon to soft and fine graphite is effective not only for anti-erosion but also for heat transfer enhancement by increasing heat capacity. (2) Turbulence augmentation by particles is also important for heat transfer enhancement in addition to the increased heat capacity. However, increasing the solid loading is likely to lead to the saturation of heat transfer enhancement effect, on the contrary, to the attenuation of turbulence. (3) If soft and fine particle, like graphite of 10{micro}m diameter employed in present study, is used as suspended particle in coolant for anti-erosion, the cooling by the gas-solid suspension impinging jet will be able to correspond to the thermal heat flux on the diverter plate when the nozzle Reynolds number is 1.5 x 10{sup 5} and thermal loading ratio is only 3. Provided that fine particles is used, however, some additional difficulties may be occurred, such as handling of powder and thermophoresis adhesion on the heat transfer surface.

  5. Flow cytometric measurement of total DNA and incorporated halodeoxyuridine

    DOE Patents [OSTI]

    Dolbeare, F.A.; Gray, J.W.

    1983-10-18

    A method for the simultaneous flow cylometric measurement of total cellular DNA content and of the uptake of DNA precursors as a measure of DNA synthesis during various phases of the cell cycle in normal and malignant cells in vitro and in vivo is described. The method comprises reacting cells with labelled halodeoxyuridine (HdU), partially denaturing cellular DNA, adding to the reaction medium monoclonal antibodies (mabs) reactive with HdU, reacting the bound mabs with a second labelled antibody, incubating the mixture with a DNA stain, and measuring simultaneously the intensity of the DNA stain as a measure of the total cellular DNA and the HdU incorporated as a measure of DNA synthesis. (ACR)

  6. Flow cytometric measurement of total DNA and incorporated halodeoxyuridine

    DOE Patents [OSTI]

    Dolbeare, Frank A. (Livermore, CA); Gray, Joe W. (Livermore, CA)

    1988-01-01

    A method for the simultaneous flow cytometric measurement of the total DNA content and the level of DNA synthesis in normal and malignant cells is disclosed. The sensitivity of the method allows a study of cell cycle traverse rates for large scale cell populations as well as single cell measurements. A DNA stain such as propidium iodide or Hoechst 33258 is used as the probe for the measurement of total DNA content and a monoclonal antibody reactive with a DNA precursor such as halodeoxy-uridine (HdU), more specifically bromodeoxyuridine (BrdU) is used as a probe for the measurement of HdU or BrdU uptake by the cells as a measure of DNA synthesis.

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

    E-Print Network [OSTI]

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

    2006-01-01

    and Heat Flow Near Yucca Mountain, Nevada: Some Tectonic andLarge Block Test at Yucca Mountain, Nevada, Water Resourcesthe Drift Scale Test at Yucca Mountain, Nevada, Journal of

  8. A Method for Measuring Elliptic Flow Fluctuations in PHOBOS

    E-Print Network [OSTI]

    B. Alver; for the PHOBOS Collaboration

    2007-03-08

    We introduce an analysis method to measure elliptic flow (v_2) fluctuations using the PHOBOS detector for Au+Au collisions at sqrt(s) = 200 GeV. In this method, v_2 is determined event-by-event by a maximum likelihood fit. The non-statistical fluctuations are determined by unfolding the contribution of statistical fluctuations and detector effects using Monte Carlo simulations(MC). Application of this method to measure dynamical fluctuations embedded in special MC are presented. It is shown that the input fluctuations are reconstructed successfully for >= 0.03.

  9. Numerical study on coupled fluid flow and heat transfer process in parabolic trough solar collector tube

    SciTech Connect (OSTI)

    Tao, Y.B.; He, Y.L.

    2010-10-15

    A unified two-dimensional numerical model was developed for the coupled heat transfer process in parabolic solar collector tube, which includes nature convection, forced convection, heat conduction and fluid-solid conjugate problem. The effects of Rayleigh number (Ra), tube diameter ratio and thermal conductivity of the tube wall on the heat transfer and fluid flow performance were numerically analyzed. The distributions of flow field, temperature field, local Nu and local temperature gradient were examined. The results show that when Ra is larger than 10{sup 5}, the effects of nature convection must be taken into account. With the increase of tube diameter ratio, the Nusselt number in inner tube (Nu{sub 1}) increases and the Nusselt number in annuli space (Nu{sub 2}) decreases. With the increase of tube wall thermal conductivity, Nu{sub 1} decreases and Nu{sub 2} increases. When thermal conductivity is larger than 200 W/(m K), it would have little effects on Nu and average temperatures. Due to the effect of the nature convection, along the circumferential direction (from top to down), the temperature in the cross-section decreases and the temperature gradient on inner tube surface increases at first. Then, the temperature and temperature gradients would present a converse variation at {theta} near {pi}. The local Nu on inner tube outer surface increases along circumferential direction until it reaches a maximum value then it decreases again. (author)

  10. Decoupled cantilever arms for highly versatile and sensitive temperature and heat flux measurements

    E-Print Network [OSTI]

    Burg, Brian R.

    Microfabricated cantilever beams have been used in microelectromechanical systems for a variety of sensor and actuator applications. Bimorph cantilevers accurately measure temperature change and heat flux with resolutions ...

  11. Low-temperature specific heat measurement of a ferroelectric copolymer film of vinylidene fluoride and trifluoroethylene

    E-Print Network [OSTI]

    Andrei, Eva Y.

    Low-temperature specific heat measurement of a ferroelectric copolymer film of vinylidene fluoride; published 13 February 2004 The specific heat of a highly crystallized ferroelectric copolymer film to the pyroelectric coefficient in this temperature range. The specific heat data also show a rapid transition from

  12. Estimation of Rate of Heat Release by Means of Oxygen Consumption Measurements

    E-Print Network [OSTI]

    Womeldorf, Carole

    Estimation of Rate of Heat Release by Means of Oxygen Consumption Measurements Intuitively, the rate of heat release from an unwanted fire is a major indication of the threat of the fire to life and property. This is indeed true, and a reliable mea- surement of a fire's heat release rate was a goal

  13. A COMPARISON OF LABORATORY AND FIELD-TEST MEASUREMENTS OF HEAT PUMP WATER HEATERS

    E-Print Network [OSTI]

    Oak Ridge National Laboratory

    #12;A COMPARISON OF LABORATORY AND FIELD-TEST MEASUREMENTS OF HEAT PUMP WATER HEATERS William P a heat pump water heater (HPWH). After developing the HPWH, a field-test plan was implemented whereby 20 estimates were that a heat pump water heater (HPWH) could save from 50 to 70% of the energy used

  14. Heat Transfer in Smooth and Ribbed Rectangular Two-Pass Channels with a Developing Flow Entrance at High Rotation Numbers 

    E-Print Network [OSTI]

    Huh, Michael

    2010-01-16

    regionally averaged heat transfer coefficient i designates a given region in the channel (1?i?12) I current k thermal conductivity of the coolant L length of the heated portion of the test section m mass flow rate Nu regionally averaged... 16 1:4 Smooth streamwise Nu ratio distributions at different Reynolds numbers................................................................................................... 45 17 1:4 Smooth streamwise Nu ratio distributions...

  15. Two Phase Flow Measurements by Nuclear Magnetic Resonance (NMR)

    SciTech Connect (OSTI)

    Altobelli, Stephen A; Fukushima, Eiichi

    2006-08-14

    In concentrated suspensions, there is a tendency for the solid phase to migrate from regions of high shear rate to regions of low shear (Leighton & Acrivos, 1987). In the early years that our effort was funded by the DOE Division of Basic Energy Science, quantitative measurement of this process in neutrally buoyant suspensions was a major focus (Abbott, et al., 1991; Altobelli, et al., 1991). Much of this work was used to improve multi-phase numerical models at Sandia National Laboratories. Later, our collaborators at Sandia and the University of New Mexico incorporated body forces into their numerical models of suspension flow (Rao, Mondy, Sun, et al., 2002). We developed experiments that allow us to study flows driven by buoyancy, to characterize these flows in well-known and useful engineering terms (Altobelli and Mondy, 2002) and to begin to explore the less well-understood area of flows with multiple solid phases (Beyea, Altobelli, et al., 2003). We also studied flows that combine the effects of shear and buoyancy, and flows of suspensions made from non-Newtonian liquids (Rao, Mondy, Baer, et al, 2002). We were able to demonstrate the usefulness of proton NMR imaging of liquid phase concentration and velocity and produced quantitative data not obtainable by other methods. Fluids flowing through porous solids are important in geophysics and in chemical processing. NMR techniques have been widely used to study liquid flow in porous media. We pioneered the extension of these studies to gas flows (Koptyug, et al, 2000, 2000, 2001, 2002). This extension allows us to investigate a wider range of Peclet numbers, and to gather data on problems of interest in catalysis. We devised two kinds of NMR experiments for three-phase systems. Both experiments employ two NMR visible phases and one phase that gives no NMR signal. The earlier method depends on the two visible phases differing in a NMR relaxation property. The second method (Beyea, Altobelli, et al., 2003) uses two different nuclei, protons and 19F. It also uses two different types of NMR image formation, a conventional spin-echo and a single-point method. The single-point method is notable for being useful for imaging materials which are much more rigid than can usually be studied by NMR imaging. We use it to image “low density” polyethylene (LDPE) plastic in this application. We have reduced the imaging time for this three-phase imaging method to less than 10 s per pair of profiles by using new hardware. Directly measuring the solid LDPE signal was a novel feature for multi-phase flow studies. We also used thermally polarized gas NMR (as opposed to hyper-polarized gas) which produces low signal to noise ratios because gas densities are on the order of 1000 times smaller than liquid densities. However since we used multi-atom molecules that have short T1's and operated at elevated pressures we could overcome some of the losses. Thermally polarized gases have advantages over hyperpolarized gases in the ease of preparation, and in maintaining a well-defined polarization. In these studies (Codd and Altobelli, 2003), we used stimulated echo sequences to successfully obtain propagators of gas in bead packs out to observation times of 300 ms. Zarraga, et al. (2000) used laser-sheet profilometry to investigate normal stress differences in concentrated suspensions. Recently we developed an NMR imaging analog for comparison with numerical work that is being performed by Rekha Rao at Sandia National Laboratories (Rao, Mondy, Sun, et al, 2002). A neutrally buoyant suspension of 100 mm PMMA spheres in a Newtonian liquid was sheared in a vertical Couette apparatus inside the magnet. The outer cylinder rotates and the inner cylinder is fixed. At these low rotation rates, the free-surface of the Newtonian liquid shows no measurable deformation, but the suspension clearly shows its non-Newtonian character.

  16. Transient PVT measurements and model predictions for vessel heat transfer. Part II.

    SciTech Connect (OSTI)

    Felver, Todd G.; Paradiso, Nicholas Joseph; Winters, William S., Jr.; Evans, Gregory Herbert; Rice, Steven F.

    2010-07-01

    Part I of this report focused on the acquisition and presentation of transient PVT data sets that can be used to validate gas transfer models. Here in Part II we focus primarily on describing models and validating these models using the data sets. Our models are intended to describe the high speed transport of compressible gases in arbitrary arrangements of vessels, tubing, valving and flow branches. Our models fall into three categories: (1) network flow models in which flow paths are modeled as one-dimensional flow and vessels are modeled as single control volumes, (2) CFD (Computational Fluid Dynamics) models in which flow in and between vessels is modeled in three dimensions and (3) coupled network/CFD models in which vessels are modeled using CFD and flows between vessels are modeled using a network flow code. In our work we utilized NETFLOW as our network flow code and FUEGO for our CFD code. Since network flow models lack three-dimensional resolution, correlations for heat transfer and tube frictional pressure drop are required to resolve important physics not being captured by the model. Here we describe how vessel heat transfer correlations were improved using the data and present direct model-data comparisons for all tests documented in Part I. Our results show that our network flow models have been substantially improved. The CFD modeling presented here describes the complex nature of vessel heat transfer and for the first time demonstrates that flow and heat transfer in vessels can be modeled directly without the need for correlations.

  17. A numerical study of heat island flows in an open domain: Stationary solutions

    E-Print Network [OSTI]

    Dubois, Thierry

    2007-01-01

    We present two dimensional numerical simulations of a natural convection problem in an unbounded domain. A thermal stratification is applied in the vertical direction and the flow circulation is induced by a heat island located on the ground. For this problem, thermal perturbations are convected in the horizontal direction far from the heated element so that very elongated computational domains have to be used in order to compute accurate numerical solutions. To avoid this difficulty thermal sponge layers are added at the vertical boundaries. With this approach, stationary solutions at $Ra\\le 10^5$ are investigated. Boussinesq equations are discretized with a second-order finite volume scheme on a staggered grid combined with a second-order projection method for the time integration.

  18. Heat-flux measurements for the rotor of a full-stage turbine: Part I - Time-averaged results

    SciTech Connect (OSTI)

    Dunn, M.G.

    1986-07-01

    This paper describes time-average heat-flux distributions obtained for the blade of a Garrett TFE 731-2 hp full stage rotating turbine. Blade measurements were obtained both with and without injection. The injected gas was supplied from a separate reservoir and was directed into the turbine gas path via nozzle guide vane (NGV) pressure surface slots located at approximately 63 percent of the wetted distance. Blade heat-flux measurements were performed fro two different injection gas temperatures, T/sub c/T/sub o/ = 0.53 and T/sub c/T/sub o/ - 0.82. A shock tube is used as a short-duration source of heated air to which the turbine is subjected and thin-film gages are used to obtain the heat-flux measurements. Results are presented along the blade in the flow direction at 10, 50, and 90 percent span for both the pressure and suction surfaces. A sufficient number of measurements were obtained to also present spanwise distributions. At approximately the 50 percent span location, two contoured inserts containing closely spaced gages were installed in the blade so that the leading-edge region distribution could be resolved in detail. The blade results are compared with predictions obtained using a flat-plate technique and with predictions obtained using a version of STAN 5.

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

    E-Print Network [OSTI]

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

    2006-01-01

    , Shenzhen, China Renewable Energy Resources and a Greener Future Vol.VIII-8-4 Urban Sewage Delivery Heat Transfer System (1): Flow Resistance and Energy Analysis1 Chenghu Zhang Ronghua Wu Guitao Li Xin Li Lei Huang Dexing Sun Doctor Master...) By the numeric calculation and the simplification, the power function form, can be obtained, which is used in the engineering easily. It is 0.30 0.0235 w d? = (2) The result of (2) is slight bigger than that of (1), but the errors are within 3...

  20. Reduced heat flow in light water (H2O) due to heavy water (D2O)

    E-Print Network [OSTI]

    William R. Gorman; James D. Brownridge

    2008-09-04

    The flow of heat, from top to bottom, in a column of light water can be decreased by over 1000% with the addition of heavy water. A column of light water cools from 25 C to 0 C in 11 hours, however, with the addition of heavy water it takes more than 100 hours. There is a concentration dependence where the cooling time increases as the concentration of added (D2O) increases, with a near maximum being reached with as little as 2% of (D2O) added. This phenomenon will not occur if the water is mixed after the heavy water is added.

  1. The flow and heat transfer in a viscous fluid over an unsteady stretching surface

    E-Print Network [OSTI]

    Ene, Remus-Daniel; Marinca, Bogdan

    2015-01-01

    In this paper we have studied the flow and heat transfer in a viscous fluid by a horizontal sheet. The stretching rate and temperature of the sheet vary with time. The governing equations for momentum and thermal energy are reduced to ordinary differential equations by means of similarity transformation. These equations are solved approximately by means of the Optimal Homotopy Asymptotic Method (OHAM) which provides us with a convenient way to control the convergence of approximation solutions and adjust convergence rigorous when necessary. Some examples are given and the results obtained reveal that the proposed method is effective and easy to use.

  2. Flow cytomeric measurement of DNA and incorporated nucleoside analogs

    DOE Patents [OSTI]

    Dolbeare, Frank A. (Livermore, CA); Gray, Joe W. (Livermore, CA)

    1989-01-01

    A method is provided for simultaneously measuring total cellular DNA and incorporated nucleoside analog. The method entails altering the cellular DNA of cells grown in the presence of a nucleoside analog so that single stranded and double stranded portions are present. Separate stains are used against the two portions. An immunochemical stain is used against the single stranded portion to provide a measure of incorporated nucleoside analog, and a double strand DNA-specific stain is used against the double stranded portion to simultaneously provide a measure of total cellular DNA. The method permits rapid flow cytometric analysis of cell populations, rapid identification of cycling and noncycling subpopulations, and determination of the efficacy of S phase cytotoxic anticancer agents.

  3. Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter

    DOE Patents [OSTI]

    Ortiz, M.G.; Boucher, T.J.

    1997-06-24

    A system is described for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit. 2 figs.

  4. Device and method for measuring multi-phase fluid flow in a conduit using an elbow flow meter

    DOE Patents [OSTI]

    Ortiz, Marcos G. (Idaho Falls, ID); Boucher, Timothy J. (Helena, MT)

    1997-01-01

    A system for measuring fluid flow in a conduit. The system utilizes pressure transducers disposed generally in line upstream and downstream of the flow of fluid in a bend in the conduit. Data from the pressure transducers is transmitted to a microprocessor or computer. The pressure differential measured by the pressure transducers is then used to calculate the fluid flow rate in the conduit. Control signals may then be generated by the microprocessor or computer to control flow, total fluid dispersed, (in, for example, an irrigation system), area of dispersal or other desired effect based on the fluid flow in the conduit.

  5. Measurement of Heat Flux at Metal-Mold Interface during Casting Solidification

    SciTech Connect (OSTI)

    Sabau, Adrian S [ORNL

    2006-01-01

    All previous studies on interfacial heat transfer coefficient have been based on indirect methods for estimating the heat flux that employed either inverse heat transfer analysis procedures or instrumentation arrangements to measure temperatures and displacements near the metal-mold interface. In this paper, the heat transfer at the metal-mold interfaces is investigated using a sensor for the direct measurement of heat flux. The heat flux sensor (HFS) was rated for 700oC and had a time response of less than 10 ms. Casting experiments were conducted using graphite molds for aluminum alloy A356. Several casting experiments were performed using a graphite coating and a boron nitride coating. The measurement errors were estimated. The temperature of the mold surface was provided by the HFS while the temperature of the casting surface was measured using a thermocouple. Results for the heat transfer coefficients were obtained based on measured heat flux and temperatures. Four stages were clearly identified for the variation in time of the heat flux. Values of the heat transfer coefficient were in good agreement with data from previous studies.

  6. Measuring Edinburgh’s Surface Urban Heat Island 

    E-Print Network [OSTI]

    Mackinnon, Kerr A H

    2013-10-27

    This project investigated Edinburgh’s surface urban heat island (SUHI) in relation to land cover and land use. Thermal channels of Landsat TM, Landsat ETM+ and ASTER imagery captured between 1999 and 2011 provide land surface temperatures (LST...

  7. Direct measurements of heat output by marine microbial and phage communities

    E-Print Network [OSTI]

    Salamon, Peter

    for monitoring microbial activities via their energy usage. Calorimeters have been used to measure the heat and energy. Phage are also important mediators of microbial diversity. Most phage are strain1 Direct measurements of heat output by marine microbial and phage communities E. Djamali1, 2 , P

  8. Continued development of a semianalytical solution for two-phase fluid and heat flow in a porous medium

    SciTech Connect (OSTI)

    Doughty, C.; Pruess, K. [Lawrence Berkeley Lab., CA (United States)

    1991-06-01

    Over the past few years the authors have developed a semianalytical solution for transient two-phase water, air, and heat flow in a porous medium surrounding a constant-strength linear heat source, using a similarity variable {eta} = r/{radical}t. Although the similarity transformation approach requires a simplified geometry, all the complex physical mechanisms involved in coupled two-phase fluid and heat flow can be taken into account in a rigorous way, so that the solution may be applied to a variety of problems of current interest. The work was motivated by adverse to predict the thermohydrological response to the proposed geologic repository for heat-generating high-level nuclear wastes at Yucca Mountain, Nevada, in a partially saturated, highly fractured volcanic formation. The paper describes thermal and hydrologic conditions near the heat source; new features of the model; vapor pressure lowering; and the effective-continuum representation of a fractured/porous medium.

  9. Procedures for measuring the properties of heat-pipe wick materials

    SciTech Connect (OSTI)

    Adkins, D.R.; Dykhuizen, R.C.

    1993-07-01

    Accurate measurements of wick properties must be available to design high-performance beat pipes and to properly interpret results from heat pipe tests. In a program that is aimed at developing heat-pipe receivers for solar-Stirling electric systems, we have recently explored procedures to measure the effective pore radius and permeability of wick materials in their final ``as fabricated`` condition. Measurement techniques are compared in this paper and problems that are frequently encountered in measuring wick properties are discussed.

  10. Description of heat flux measurement methods used in hydrocarbon and propellant fuel fires at Sandia.

    SciTech Connect (OSTI)

    Nakos, James Thomas

    2010-12-01

    The purpose of this report is to describe the methods commonly used to measure heat flux in fire applications at Sandia National Laboratories in both hydrocarbon (JP-8 jet fuel, diesel fuel, etc.) and propellant fires. Because these environments are very severe, many commercially available heat flux gauges do not survive the test, so alternative methods had to be developed. Specially built sensors include 'calorimeters' that use a temperature measurement to infer heat flux by use of a model (heat balance on the sensing surface) or by using an inverse heat conduction method. These specialty-built sensors are made rugged so they will survive the environment, so are not optimally designed for ease of use or accuracy. Other methods include radiometers, co-axial thermocouples, directional flame thermometers (DFTs), Sandia 'heat flux gauges', transpiration radiometers, and transverse Seebeck coefficient heat flux gauges. Typical applications are described and pros and cons of each method are listed.

  11. Measurements of sideward flow around the balance energy

    E-Print Network [OSTI]

    INDRA collaboration; D. Cussol; T. Lefort; J. Péter

    2001-11-13

    Sideward flow values have been determined with the INDRA multidetector for Ar+Ni, Ni+Ni and Xe+Sn systems studied at GANIL in the 30 to 100 A.MeV incident energy range. The balance energies found for Ar+Ni and Ni+Ni systems are in agreement with previous experimental results and theoretical calculations. Negative sideward flow values have been measured. The possible origins of such negative values are discussed. They could result from a more important contribution of evaporated particles with respect to the contribution of promptly emitted particles at mid-rapidity. But effects induced by the methods used to reconstruct the reaction plane cannot be totally excluded. Complete tests of these methods are presented and the origins of the ``auto-correlation'' effect have been traced back. For heavy fragments, the observed negative flow values seem to be mainly due to the reaction plane reconstruction methods. For light charged particles, these negative values could result from the dynamics of the collisions and from the reaction plane reconstruction methods as well. These effects have to be taken into account when comparisons with theoretical calculations are done.

  12. Device for accurately measuring mass flow of gases

    DOE Patents [OSTI]

    Hylton, J.O.; Remenyik, C.J.

    1994-08-09

    A device for measuring mass flow of gases which utilizes a substantially buoyant pressure vessel suspended within a fluid/liquid in an enclosure is disclosed. The pressure vessel is connected to a weighing device for continuously determining weight change of the vessel as a function of the amount of gas within the pressure vessel. In the preferred embodiment, this pressure vessel is formed from inner and outer right circular cylindrical hulls, with a volume between the hulls being vented to the atmosphere external the enclosure. The fluid/liquid, normally in the form of water typically with an added detergent, is contained within an enclosure with the fluid/liquid being at a level such that the pressure vessel is suspended beneath this level but above a bottom of the enclosure. The buoyant pressure vessel can be interconnected with selected valves to an auxiliary pressure vessel so that initial flow can be established to or from the auxiliary pressure vessel prior to flow to or from the buoyant pressure vessel. 5 figs.

  13. Device for accurately measuring mass flow of gases

    DOE Patents [OSTI]

    Hylton, James O. (Clinton, TN); Remenyik, Carl J. (Knoxville, TN)

    1994-01-01

    A device for measuring mass flow of gases which utilizes a substantially buoyant pressure vessel suspended within a fluid/liquid in an enclosure. The pressure vessel is connected to a weighing device for continuously determining weight change of the vessel as a function of the amount of gas within the pressure vessel. In the preferred embodiment, this pressure vessel is formed from inner and outer right circular cylindrical hulls, with a volume between the hulls being vented to the atmosphere external the enclosure. The fluid/liquid, normally in the form of water typically with an added detergent, is contained within an enclosure with the fluid/liquid being at a level such that the pressure vessel is suspended beneath this level but above a bottom of the enclosure. The buoyant pressure vessel can be interconnected with selected valves to an auxiliary pressure vessel so that initial flow can be established to or from the auxiliary pressure vessel prior to flow to or from the buoyant pressure vessel.

  14. Modeling of Residential Buildings and Heating Systems 

    E-Print Network [OSTI]

    Masy, G.; Lebrun, J.

    2004-01-01

    of the central heating plant, with measurements of water temperatures and flow rates is used to adjust the parameters of the boiler model....

  15. Phonons and defects in semiconductors and nanostructures: Phonon trapping, phonon scattering, and heat flow at heterojunctions

    SciTech Connect (OSTI)

    Estreicher, S. K., E-mail: Stefan.Estreicher@ttu.edu; Gibbons, T. M.; Kang, By.; Bebek, M. B. [Physics Department, Texas Tech University, Lubbock, Texas 79409-1051 (United States)

    2014-01-07

    Defects in semiconductors introduce vibrational modes that are distinct from bulk modes because they are spatially localized in the vicinity of the defect. Light impurities produce high-frequency modes often visible by Fourier-transform infrared absorption or Raman spectroscopy. Their vibrational lifetimes vary by orders of magnitude and sometimes exhibit unexpectedly large isotope effects. Heavy impurities introduce low-frequency modes sometimes visible as phonon replicas in photoluminescence bands. But other defects such as surfaces or interfaces exhibit spatially localized modes (SLMs) as well. All of them can trap phonons, which ultimately decay into lower-frequency bulk phonons. When heat flows through a material containing defects, phonon trapping at localized modes followed by their decay into bulk phonons is usually described in terms of phonon scattering: defects are assumed to be static scattering centers and the properties of the defect-related SLMs modes are ignored. These dynamic properties of defects are important. In this paper, we quantify the concepts of vibrational localization and phonon trapping, distinguish between normal and anomalous decay of localized excitations, discuss the meaning of phonon scattering in real space at the atomic level, and illustrate the importance of phonon trapping in the case of heat flow at Si/Ge and Si/C interfaces.

  16. STOCHASTIC HEATING, DIFFERENTIAL FLOW, AND THE ALPHA-TO-PROTON TEMPERATURE RATIO IN THE SOLAR WIND

    SciTech Connect (OSTI)

    Chandran, B. D. G.; Verscharen, D.; Isenberg, P. A.; Bourouaine, S.; Quataert, E.; Kasper, J. C. E-mail: s.bourouaine@unh.edu E-mail: daniel.verscharen@unh.edu E-mail: jkasper@cfa.harvard.edu

    2013-10-10

    We extend previous theories of stochastic ion heating to account for the motion of ions along the magnetic field B . We derive an analytic expression for the temperature ratio T{sub i}/T{sub p} in the solar wind assuming that stochastic heating is the dominant ion heating mechanism, where T{sub i} is the perpendicular temperature of species i and T{sub p} is the perpendicular proton temperature. This expression describes how T{sub i}/T{sub p} depends upon U{sub i} and ?{sub ?p}, where U{sub i} is the average velocity along B of species i in the proton frame and ?{sub ?p} is the ratio of the parallel proton pressure to the magnetic pressure, which we take to be ?< 1. We compare our model with previously published measurements of alpha particles and protons from the Wind spacecraft. We find that stochastic heating offers a promising explanation for the dependence of T{sub ?}/T{sub p} on U{sub ?} and ?{sub ?p} when the fractional cross helicity and Alfvén ratio at the proton-gyroradius scale have values that are broadly consistent with solar-wind measurements. We also predict how the temperatures of other ion species depend on their drift speeds.

  17. Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01

    SciTech Connect (OSTI)

    Trehu, Anne; Kannberg, Peter

    2011-06-30

    The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m2). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that ~50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a "toe-thrust" ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those ~70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the KG basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m2. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basin is at the low end of glob

  18. Heat Flow and Gas Hydrates on the Continental Margin of India: Building on Results from NGHP Expedition 01

    SciTech Connect (OSTI)

    Anne Trehu; Peter Kannberg

    2011-06-30

    The Indian National Gas Hydrate Program (NGHP) Expedition 01 presented the unique opportunity to constrain regional heat flow derived from seismic observations by using drilling data in three regions on the continental margin of India. The seismic bottom simulating reflection (BSR) is a well-documented feature in hydrate bearing sediments, and can serve as a proxy for apparent heat flow if data are available to estimate acoustic velocity and density in water and sediments, thermal conductivity, and seafloor temperature. Direct observations of temperature at depth and physical properties of the sediment obtained from drilling can be used to calibrate the seismic observations, decreasing the uncertainty of the seismically-derived estimates. Anomalies in apparent heat flow can result from a variety of sources, including sedimentation, erosion, topographic refraction and fluid flow. We constructed apparent heat flow maps for portions of the Krishna-Godavari (K-G) basin, the Mahanadi basin, and the Andaman basin and modeled anomalies using 1-D conductive thermal models. Apparent heat flow values in the Krishna-Godavari (K-G) basin and Mahanadi basin are generally 0.035 to 0.055 watts per square meter (W/m{sup 2}). The borehole data show an increase in apparent heat flow as water depth increases from 900 to 1500 m. In the SW part of the seismic grid, 1D modeling of the effect of sedimentation on heat flow shows that {approx}50% of the observed increase in apparent heat flow with increasing water depth can be attributed to trapping of sediments behind a 'toe-thrust' ridge that is forming along the seaward edge of a thick, rapidly accumulating deltaic sediment pile. The remainder of the anomaly can be explained either by a decrease in thermal conductivity of the sediments filling the slope basin or by lateral advection of heat through fluid flow along stratigraphic horizons within the basin and through flexural faults in the crest of the anticline. Such flow probably plays a role in bringing methane into the ridge formed by the toe-thrust. Because of the small anomaly due to this process and the uncertainty in thermal conductivity, we did not model this process explicitly. In the NE part of the K-G basin seismic grid, a number of local heat flow lows and highs are observed, which can be attributed to topographic refraction and to local fluid flow along faults, respectively. No regional anomaly can be resolved. Because of lack of continuity between the K-G basin sites within the seismic grid and those {approx}70 km to the NE in water depths of 1200 to 1500 m, we do not speculate on the reason for higher heat flow at these depths. The Mahanadi basin results, while limited in geographic extent, are similar to those for the K-G basin. The Andaman basin exhibits much lower apparent heat flow values, ranging from 0.015 to 0.025 W/m{sup 2}. Heat flow here also appears to increase with increasing water depth. The very low heat flow here is among the lowest heat flow observed anywhere and gives rise to a very thick hydrate stability zone in the sediments. Through 1D models of sedimentation (with extremely high sedimentation rates as a proxy for tectonic thickening), we concluded that the very low heat flow can probably be attributed to the combined effects of high sedimentation rate, low thermal conductivity, tectonic thickening of sediments and the cooling effect of a subducting plate in a subduction zone forearc. Like for the K-G basin, much of the local variability can be attributed to topography. The regional increase in heat flow with water depth remains unexplained because the seismic grid available to us did not extend far enough to define the local tectonic setting of the slope basin controlling this observational pattern. The results are compared to results from other margins, both active and passive. While an increase in apparent heat flow with increasing water depth is widely observed, it is likely a result of different processes in different places. The very low heat flow due to sedimentation and tectonics in the Andaman basi

  19. Time-evolving measures and macroscopic modeling of pedestrian flow

    E-Print Network [OSTI]

    Benedetto Piccoli; Andrea Tosin

    2010-04-27

    This paper deals with the early results of a new model of pedestrian flow, conceived within a measure-theoretical framework. The modeling approach consists in a discrete-time Eulerian macroscopic representation of the system via a family of measures which, pushed forward by some motion mappings, provide an estimate of the space occupancy by pedestrians at successive time steps. From the modeling point of view, this setting is particularly suitable to treat nonlocal interactions among pedestrians, obstacles, and wall boundary conditions. In addition, analysis and numerical approximation of the resulting mathematical structures, which is the main target of this work, follow more easily and straightforwardly than in case of standard hyperbolic conservation laws, also used in the specialized literature by some Authors to address analogous problems.

  20. Ice flow sensitivity to geothermal heat flux of Pine Island Glacier, Antarctica

    E-Print Network [OSTI]

    Larour, E; Morlighem, M; Seroussi, H; Schiermeier, J; Rignot, E; Rignot, E

    2012-01-01

    to geothermal heat flux of Pine Island Glacier, Antarcticato geothermal heat flux of Pine Island Glacier, Antarctica,Pine Island Glacier, West Antarctica: (a) geothermal heat

  1. A Temperature-Profile Method for Estimating Flow Processes in Geologic Heat Pipes

    E-Print Network [OSTI]

    Birkholzer, Jens T.

    2004-01-01

    change and capillarity—the heat pipe effect, Int. J. Heatgeothermal reservoirs as heat pipes in fractured porousfor the radial-symmetric heat pipe system (without gravity)

  2. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    Performance of ground source heat pump system in a near-zerosimulation tool for ground- source heat pump system designflow systems and ground source heat pump systems Abstract

  3. Influence of lubricant oil on heat transfer performance of refrigerant flow boiling inside small diameter tubes. Part I: Experimental study

    SciTech Connect (OSTI)

    Wei, Wenjian; Ding, Guoliang; Hu, Haitao; Wang, Kaijian

    2007-10-15

    Two-phase flow pattern and heat transfer characteristics of refrigerant-oil mixture flow boiling inside small tubes with inside diameters of 6.34 mm and 2.50 mm are investigated experimentally. The test condition of nominal oil concentration is from 0% to 5%, mass flux from 200 to 400 kg m{sup -2} s{sup -1}, heat flux from 3.2 to 14 kW m{sup -2}, evaporation temperature of 5 C, inlet quality from 0.1 to 0.8, and quality change from 0.1 to 0.2. Wavy, wavy-annular, annular and mist-annular flow pattern in 6.34 mm tube are observed, while only slug-annular and annular flow pattern are observed in 2.50 mm tube. Oil presence can make annular flow to form early and to retard to diminish in quality direction at nominal oil concentration {>=}3%. Augmentation effect of oil on heat transfer coefficient becomes weakened or even diminishes for small diameter tube while detrimental effect of oil on small tube performance becomes more significant than large tube. For both test tubes, variation of heat transfer coefficient and enhanced factor with oil concentration is irregular. Two-phase heat transfer multiplier with refrigerant-oil mixture properties increases consistently and monotonically with local oil concentration at different vapor quality. (author)

  4. Measurement of void fraction at different flow regimes in vertical upward two-phase flow of cryogenic fluid

    SciTech Connect (OSTI)

    Pattanayak, S.Ch.; Das, R.K. [Indian Institute of Technology, Kharagpur (India)

    1995-12-01

    Local void fraction in a vertical cryogenic two-phase flow has been measured with the help of a small capacitance sensor. The time varying capacitance signal of the sensor is used to modulate the pulse width of a multivibrator. The probability distribution function (PDF) of the pulse width data is analysed for identifying the flow regimes, while average pulse width is correlated with the average void fraction. The calibrations of the void fraction sensor are found to be sensitive to the flow regimes. In slug and churn flow regimes the calibrations are also found to be sensitive to fluid flow rates. But no such dependence is observed in bubble and annular flow regimes. The sensitivity towards flow rates could be correlated with the position of PDF peaks of the concerned flow regimes.

  5. Quantitative method for measuring heat flux emitted from a cryogenic object

    DOE Patents [OSTI]

    Duncan, R.V.

    1993-03-16

    The present invention is a quantitative method for measuring the total heat flux, and of deriving the total power dissipation, of a heat-fluxing object which includes the steps of placing an electrical noise-emitting heat-fluxing object in a liquid helium bath and measuring the superfluid transition temperature of the bath. The temperature of the liquid helium bath is thereafter reduced until some measurable parameter, such as the electrical noise, exhibited by the heat-fluxing object or a temperature-dependent resistive thin film in intimate contact with the heat-fluxing object, becomes greatly reduced. The temperature of the liquid helum bath is measured at this point. The difference between the superfluid transition temperature of the liquid helium bath surrounding the heat-fluxing object, and the temperature of the liquid helium bath when the electrical noise emitted by the heat-fluxing object becomes greatly reduced, is determined. The total heat flux from the heat-fluxing object is determined as a function of this difference between these temperatures. In certain applications, the technique can be used to optimize thermal design parameters of cryogenic electronics, for example, Josephson junction and infrared sensing devices.

  6. Using and Measuring the Combined Heat and Power Advantage 

    E-Print Network [OSTI]

    John, T.

    2011-01-01

    compared to other power generation systems. Fuel Charged to Power (FCP) is the fuel, net of credit for thermal output, required to produce a kilowatt-hour of electricity. This provides a metric that is used for comparison to the heat rate of other types...

  7. Estimation of the local heat-transfer coefficient in the laminar flow regime in coiled tubes by the Tikhonov regularisation method

    E-Print Network [OSTI]

    Bazán, Fermín S. V.

    Estimation of the local heat-transfer coefficient in the laminar flow regime in coiled tubes February 2014 Keywords: Heat-transfer enhancement Coiled tubes Local convective heat-flux estimation. Although many authors have investigated the forced convective heat transfer in coiled tubes, most of them

  8. Acute Increase in Hepatic Arterial Flow During TIPS Identified by Intravascular Flow Measurements

    SciTech Connect (OSTI)

    Radeleff, Boris, E-mail: Boris_Radeleff@med.uni-heidelberg.de; Sommer, Christof-Matthias; Heye, Tobias; Lopez-Benitez, Ruben [University of Heidelberg Medical Center, Department of Diagnostic Radiology (Germany); Sauer, Peter [University of Heidelberg Medical Center, Department of Internal Medicine IV, Gastroenterology, Hepatology, Infectious Diseases, and Intoxications (Germany); Schmidt, Jan [University of Heidelberg Medical Center, General, Visceral, and Accident Surgery (Germany); Kauczor, Haus-Ulrich; Richter, Goetz Martin [University of Heidelberg Medical Center, Department of Diagnostic Radiology (Germany)

    2009-01-15

    The purpose of this study was to investigate alterations of hepatic arterial flow during transjugular intrahepatic portosystemic stent shunt (TIPS) applying intravascular Doppler sonography. This prospective monocenter study included 25 patients with liver cirrhosis (alcohol induced [n = 19], chronic hepatitis associated [n = 3], primary biliary cirrhosis associated [n = 1], and cryptogenic [n = 2]) successfully treated with TIPS. All patients underwent intravascular hepatic arterial flow measurements during TIPS using an endoluminal flow sensor. The average arterial peak velocity (APV) and the maximum arterial peak velocity (MPV) were registered. Twenty-two patients (88%) showed increased APV, one patient (4%) showed unaffected APV, and two patients (8%) showed decreased APV after TIPS. The average portosystemic pressure gradient decreased significantly, from 22.0 {+-} 5.1 mmHg before TIPS to 11.0 {+-} 4.1 mmHg after TIPS (-50.0%; p < 0.0001). The average APV increased significantly, from 41.9 {+-} 17.8 cm/s before TIPS to 60.7 {+-} 19.0 cm/s after TIPS (+44.9%; p < 0.0001). The average MPV increased significantly, from 90.8 {+-} 31.7 cm/s before TIPS to 112.6 {+-} 34.9 cm/s after TIPS (+24.0%; p = 0.0002). These changes in perfusion set in within seconds after TIPS tract formation in all the patients with increased APV. We conclude that TIPS-induced portosystemic decompression leads to a significant increase in hepatic arterial flow. The changes occurred within seconds, suggesting a reflex-like mechanism.

  9. Local wall heat flux/temperature meter for convective flow and method of utilizing same

    DOE Patents [OSTI]

    Boyd, Ronald D.; Ekhlassi, Ali; Cofie, Penrose

    2004-11-30

    According to one embodiment of the invention, a method includes providing a conduit having a fluid flowing therethrough, disposing a plurality of temperature measurement devices inside a wall of the conduit, positioning at least some of the temperature measurement devices proximate an inside surface of the wall of the conduit, positioning at least some of the temperature measurement devices at different radial positions at the same circumferential location within the wall, measuring a plurality of temperatures of the wall with respective ones of the temperature measurement devices to obtain a three-dimensional temperature topology of the wall, determining the temperature dependent thermal conductivity of the conduit, and determining a multi-dimensional thermal characteristic of the inside surface of the wall of the conduit based on extrapolation of the three-dimensional temperature topology and the temperature dependent thermal conductivities.

  10. Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K

    E-Print Network [OSTI]

    Yang, S.W.; Oxford U.

    2004-01-01

    is to put part of the heat exchange surface inside thewall as well as added heat exchange surface. This study

  11. Co-flow anode/cathode supply heat exchanger for a solid-oxide fuel cell assembly

    DOE Patents [OSTI]

    Haltiner, Jr., Karl J.; Kelly, Sean M.

    2005-11-22

    In a solid-oxide fuel cell assembly, a co-flow heat exchanger is provided in the flow paths of the reformate gas and the cathode air ahead of the fuel cell stack, the reformate gas being on one side of the exchanger and the cathode air being on the other. The reformate gas is at a substantially higher temperature than is desired in the stack, and the cathode gas is substantially cooler than desired. In the co-flow heat exchanger, the temperatures of the reformate and cathode streams converge to nearly the same temperature at the outlet of the exchanger. Preferably, the heat exchanger is formed within an integrated component manifold (ICM) for a solid-oxide fuel cell assembly.

  12. Heating of solid earthen material, measuring moisture and resistivity

    DOE Patents [OSTI]

    Heath, W.O.; Richardson, R.L.; Goheen, S.C.

    1994-07-19

    The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants. Six electrodes are inserted into a region of earthen material to be treated in a substantially equilateral hexagonal arrangement. Six phases of voltages are applied to corresponding electrodes. The voltages are adjusted within a first range of voltages to create multiple current paths between pairs of the electrodes. The current paths are evenly distributed throughout the region defined by the electrodes and therefore uniformly heat the region. The region of earthen material is heated to a temperature sufficient to substantially remove volatile and semi-volatile contaminants by promoting microbial action. This temperature is less than a melting temperature of the earthen material. 13 figs.

  13. Optimal homotopy perturbation method for nonlinear differential equations governing MHD Jeffery-Hamel flow with heat transfer problem

    E-Print Network [OSTI]

    Marinca, Vasile

    2015-01-01

    In this paper, Optimal Homotopy Perturbation Method (OHPM) is employed to determine an analytic approximate solutions for nonlinear MHD Jeffery-Hamel flow and heat transfer problem. The Navier-Stokes equations, taking into account Maxwell's electromagnetism and heat transfer lead to two nonlinear ordinary differential equations. The obtained results by means of OHPM show a very good agreement in comparison with the numerical results and with Homotopy Perturbation Method (HPM).

  14. The effects of orientation angle, subcooling, heat flux, mass flux, and pressure on bubble growth and detachment in subcooled flow boiling

    E-Print Network [OSTI]

    Sugrue, Rosemary M

    2012-01-01

    The effects of orientation angle, subcooling, heat flux, mass flux, and pressure on bubble growth and detachment in subcooled flow boiling were studied using a high-speed video camera in conjunction with a two-phase flow ...

  15. Microscopic PIV Measurements for Electro-osmotic Flows in PDMS Microchannels

    E-Print Network [OSTI]

    Kihm, IconKenneth David

    Microscopic PIV Measurements for Electro-osmotic Flows in PDMS Microchannels Kim, M. J. *1 and Kihm of experimental measurements of electro-osmotically driven flows in elementary microchannel configurations, which various micro-configurations show feasibilities of the electro-osmotic flows to use for micro

  16. Laboratory studies of subaqueous debris flows by measurements of pore-fluid pressure and total stress

    E-Print Network [OSTI]

    Laboratory studies of subaqueous debris flows by measurements of pore-fluid pressure and total flows is reported where total stress as well as pore pressure transducers were mounted in the bed; hydroplaning; laboratory experiment; pore pressure measurements 1. Introduction Debris flow is an important

  17. Experimental Study on the Subcooled Boiling Flow via Optical Measurement Techniques 

    E-Print Network [OSTI]

    Yoo, Jun Soo

    2015-04-16

    ............................................................................................... 183 xiii Figure V-12. Effects of inlet subcooling (?Tsub,in) on probability density function (PDF) for bubble size and its development in the upward flow direction .. 187 Figure V-13. Effects of liquid mass flux (G) on probability density... function (PDF) for bubble size and its development in the upward flow direction ............. 188 Figure V-14. Effects of wall heat flux (qw) on probability density function (PDF) for bubble size and its development in the upward flow direction...

  18. Fusion Engineering and Design 42 (1998) 289297 Nuclear heating measurements for SS-316, copper, graphite,

    E-Print Network [OSTI]

    Abdou, Mohamed

    1998-01-01

    Fusion Engineering and Design 42 (1998) 289­297 Nuclear heating measurements for SS-316, copper for the reduction of design margins are stringently addressed in the design criteria. The uncertainty of the data base relevant to nuclear heating is considered as one of the most crucial problems in the designs

  19. Quantitative measurement by artificial vision of small bubbles in flowing mercury

    SciTech Connect (OSTI)

    Paquit, Vincent C [ORNL; Wendel, Mark W [ORNL; Felde, David K [ORNL; Riemer, Bernie [ORNL

    2011-01-01

    At the Spallation Neutron Source (SNS), an accelerator-based neutron source located at the Oak Ridge National Laboratory (Tennessee, USA), the production of neutrons is obtained by accelerating protons against a mercury target. This self-cooling target, however, suffers rapid heat deposition by the beam pulse leading to large pressure changes and thus to cavitations that may be damaging to the container. In order to locally compensate for pressure increases, a small-bubble population is added to the mercury flow using gas bubblers. The geometry of the bubblers being unknown, we are testing several bubblers configurations and are using machine vision techniques to characterize their efficiency by quantitative measurement of the created bubble population. In this paper we thoroughly detail the experimental setup and the image processing techniques used to quantitatively assess the bubble population. To support this approach we are comparing our preliminary results for different bubblers and operating modes, and discuss potential improvements.

  20. Measurement of Heat Flux and Heat Transfer Coefficient Due to Spray Application for the Die Casting Process

    SciTech Connect (OSTI)

    Sabau, Adrian S

    2007-01-01

    Lubricant spray application experiments were conducted for the die casting process. The heat flux was measured in situ using a differential thermopile sensor for three application techniques. First, the lubricant was applied under a constant flowrate while the nozzle was held in the same position. Second, the lubricant was applied in a pulsed, static manner, in which the nozzle was held over the same surface while it was turned on and off several times. Third, the lubricant was applied in a sweeping manner, in which the nozzle was moved along the die surface while it was held open. The experiments were conducted at several die temperatures and at sweep speeds of 20, 23, and 68 cm/s. The heat flux data, which were obtained with a sensor that was located in the centre of the test plate, were presented and discussed. The sensor can be used to evaluate lubricants, monitor the consistency of die lubrication process, and obtain useful process data, such as surface temperature, heat flux, and heat transfer coefficients. The heat removed from the die surface during lubricant application is necessary for (a) designing the cooling channels in the die, i.e. their size and placement, and (b) performing accurate numerical simulations of the die casting process.

  1. A parametric study of shock jump chemistry, electron temperature, and radiative heat transfer models in hypersonic flows 

    E-Print Network [OSTI]

    Greendyke, Robert Brian

    1988-01-01

    will examine the radiance model and various step models in order to determine their appropriateness to the flight regime of the AOTV. The final area to be investigated will be the effect of nonequilibrium corrections on the radiative heat transfer models... of T and e T will be valid as long as there is a reasonable amount vNs of nitrogen molecules in the flow. Radiative Heat Transfer Models For this study, four radiative heat transfer models were examined. One of these models is an optically thin radiance...

  2. Enhanced Algorithm for Traceability Measurements in UF6 Flow Pipe

    SciTech Connect (OSTI)

    Copinger, Thomas E; March-Leuba, Jose A; Upadhyaya, Belle R

    2007-01-01

    The Blend Down Monitoring System (BDMS) is used to continually assess the mixing and downblending of highly enriched uranium (HEU) with low-enriched uranium (LEU). This is accomplished by measuring the enrichment and the fissile mass flow rate of the UF{sub 6} gas located in each process pipe of the system by inducing the fission of the {sup 235}U contained in the gas. Measurements are taken along this process route to trace the HEU content all the way to the product stream, ensuring that HEU was down blended. A problem associated with the current traceability measuring algorithm is that it does not account for the time-varying background that is introduced to the system by the movement of the shutter located at the HEU leg of the process. The current way of dealing with that problem is to discard the data for periods when the HEU shutter is open (50% of overall data) because it correlates with the same timeframe in which the direct contribution to background from the HEU shutter was seen. The advanced algorithm presented in this paper allows for continuous measurement of traceability (100%) by accurately accounting for the varying background during the shutter-movement cycle. This algorithm utilizes advanced processing techniques that identify and discriminate the different sources of background radiation, instead of grouping them into one background group for the whole measurement cycle. By using this additional information, the traceability measurement statistics can achieve a greater number of values, thus improving the overall usefulness of these measurements in the BDMS. The effectiveness of the new algorithm was determined by modeling it in a simulation and ensuring that it retained its integrity through a large number of runs, including various shutter-failure conditions. Each run was performed with varying amounts of background radiation from each individual source and with varying traceability counts. The simulations documented in this paper prove that the algorithm can stand up to various transients introduced into the system, such as failure of shutter movement.

  3. UNSAT-H Version 2. 0: Unsaturated soil water and heat flow model

    SciTech Connect (OSTI)

    Fayer, M.J.; Jones, T.L.

    1990-04-01

    This report documents UNSAT-H Version 2.0, a model for calculating water and heat flow in unsaturated media. The documentation includes the bases for the conceptual model and its numerical implementation, benchmark test cases, example simulations involving layered soils and plant transpiration, and the code listing. Waste management practices at the Hanford Site have included disposal of low-level wastes by near-surface burial. Predicting the future long-term performance of any such burial site in terms of migration of contaminants requires a model capable of simulating water flow in the unsaturated soils above the buried waste. The model currently used to meet this need is UNSAT-H. This model was developed at Pacific Northwest Laboratory to assess water dynamics of near-surface, waste-disposal sites at the Hanford Site. The code is primarily used to predict deep drainage as a function of such environmental conditions as climate, soil type, and vegetation. UNSAT-H is also used to simulate the effects of various practices to enhance isolation of wastes. 66 refs., 29 figs., 7 tabs.

  4. Investigation of Groundwater Flow in Foothill and Mountain regions using Heat Flow measurements

    E-Print Network [OSTI]

    Fogg, Graham E.; Trask, James C

    2009-01-01

    or shortly after drilling for each well. We performed one orGondola well dropped substantially as drilling progressed toft amsl. However, drilling of the peak well may have short-

  5. Investigation of Groundwater Flow in Foothill and Mountain regions using Heat Flow measurements

    E-Print Network [OSTI]

    Fogg, Graham E.; Trask, James C

    2009-01-01

    ambient conductive geothermal gradient = dT/dz = constant (state conductive geothermal gradient dT/dz due to ambientthan the conductive geothermal gradient 0.0073 C/ft in

  6. Investigation of Groundwater Flow in Foothill and Mountain regions using Heat Flow measurements

    E-Print Network [OSTI]

    Fogg, Graham E.; Trask, James C

    2009-01-01

    depth. Heavenly Gondola well: Hydraulic tests together withReferences Tables Hydraulic parameters for wells completedthe cost of standard hydraulic methods of well/aquifer yield

  7. Fuel Ion Ratio Measurements in NBI Heated Deuterium Tritium Fusion Plasmas at JET using Neutron Emission Spectrometry

    E-Print Network [OSTI]

    Fuel Ion Ratio Measurements in NBI Heated Deuterium Tritium Fusion Plasmas at JET using Neutron Emission Spectrometry

  8. Heating of solid earthen material, measuring moisture and resistivity

    DOE Patents [OSTI]

    Heath, W.O.; Gauglitz, P.A.; Pillay, G.; Bergsman, T.M.; Eschbach, E.A.; Goheen, S.C.; Richardson, R.L.; Roberts, J.S.; Schalla, R.

    1996-08-13

    The present invention includes a method of treating solid earthen material having volatile, semi-volatile, and non-volatile contaminants that utilizes electrical energy. A plurality of electrodes are inserted into a region of earthen material to be treated in a selected geometric pattern. Varying phase and voltages configurations are applied to corresponding electrodes to achieve heating, physical phase changes, and the placement of substances within the treatment region. Additionally, treatment mediums can be added to either treat the contamination within the soil or to restrict their mobility. 29 figs.

  9. Influence of lubricant oil on heat transfer performance of refrigerant flow boiling inside small diameter tubes. Part II: Correlations

    SciTech Connect (OSTI)

    Wei, Wenjian; Ding, Guoliang; Hu, Haitao; Wang, Kaijian

    2007-10-15

    The predictive ability of the available state-of-the-art heat transfer correlations of refrigerant-oil mixture is evaluated with the present experiment data of small tubes with inside diameter of 6.34 mm and 2.50 mm. Most of these correlations can be used to predict the heat transfer coefficient of 6.34 mm tube, but none of them can predict heat transfer coefficient of 2.50 mm tube satisfactorily. A new correlation of two-phase heat transfer multiplier with local properties of refrigerant-oil mixture is developed. This correlation approaches the actual physical mechanism of flow boiling heat transfer of refrigerant-oil mixture and can reflect the actual co-existing conditions of refrigerant and lubricant oil. More than 90% of the experiment data of both test tubes have less than {+-}20% deviation from the prediction values of the new correlations. (author)

  10. Flow visualization and leakage measurements of worn labyrinth seals 

    E-Print Network [OSTI]

    Allen, Brian Frank

    1997-01-01

    A large-scale flow visualization test facility is used to conduct an experimental investigation into the leakage resistance and flow characteristics of worn labyrinth seals. Wear in labyrinth seals is a consequence of ...

  11. AN AUTOMATED CONTROLLED-FLOW AIR INFILTRATION MEASUREMENT SYSTEM

    E-Print Network [OSTI]

    Condon, P.E.

    2010-01-01

    Infiltration," Princeton University, Center for Environmental Studies,infiltration controlled flow technique has been used by Honma in his studies

  12. MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE

    E-Print Network [OSTI]

    Khandekar, Sameer

    MEASUREMENT OF HEAT TRANSFER DURING DROP-WISE CONDENSATION OF WATER ON POLYETHYLENE Gagan Deep distribution of temperature during drop-wise condensation over a polyethylene substrate was measured using on the substrate was simultaneously visualized. Static contact angles of water on polyethylene are measured

  13. Measurement of non-flow correlations and elliptic flow fluctuations in Au+Au collisions at RHIC

    E-Print Network [OSTI]

    Alver, Burak Han

    2010-01-01

    Measurements of collective flow and two-particle correlations have proven to be effective tools for understanding the properties of the system produced in ultrarelativistic nucleus-nucleus collisions at the Relativistic ...

  14. EXPERIMENTS OF RISER SLUG FLOW USING TOPSIDE MEASUREMENTS: PART I

    E-Print Network [OSTI]

    Skogestad, Sigurd

    flow in pipelines is of great concern in the offshore oil and gas industry, and a lot of time due to varying flow rates and pressure in the system. This usually happens in the end of the life cycle of a well, when flow rates are lower than the system was designed for. The rate and pressure

  15. TOUGH Simulations of the Updegraff's Set of Fluid and Heat Flow Problems

    E-Print Network [OSTI]

    Moridis, G.J.

    2010-01-01

    A schematic of the heat pipe problem (from Updegraff [1989])19. A schematic of the heat pipe problem (from Updegraff[Problem No.5. START Heat pipe problem - Udell and Fitch (

  16. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    tool for geothermal water loop heat pump systems, 9thInternational IEA Heat Pump Conference, Zürich, Switzerland,of ground source heat pump system in a near-zero energy

  17. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    tool for geothermal water loop heat pump systems, 9thInternational IEA Heat Pump Conference, Zürich, Switzerland,Performance of ground source heat pump system in a near-zero

  18. Laboratory Evaluation of Air Flow Measurement Methods for Residential...

    Office of Scientific and Technical Information (OSTI)

    used in commissioning California heating and air conditioning systems in Title 24 (Building and Appliance Efficiency Standards), thereby improving system performance and...

  19. Electron heat flow in the solar corona: Implications of non-Maxwellian velocity distributions, the solar gravitational

    E-Print Network [OSTI]

    Scudder, Jack

    Electron heat flow in the solar corona: Implications of non-Maxwellian velocity distributions, the solar gravitational field, and Coulomb collisions John C. Dorelli Space and Atmospheric Science Group, Los Alamos National Laboratory, Los Alamos, New Mexico, USA Jack D. Scudder Department of Physics

  20. Pressure drop, heat transfer, critical heat flux, and flow stability of two-phase flow boiling of water and ethylene glycol/water mixtures - final report for project "Efficent cooling in engines with nucleate boiling."

    SciTech Connect (OSTI)

    Yu, W.; France, D. M.; Routbort, J. L.

    2011-01-19

    Because of its order-of-magnitude higher heat transfer rates, there is interest in using controllable two-phase nucleate boiling instead of conventional single-phase forced convection in vehicular cooling systems to remove ever increasing heat loads and to eliminate potential hot spots in engines. However, the fundamental understanding of flow boiling mechanisms of a 50/50 ethylene glycol/water mixture under engineering application conditions is still limited. In addition, it is impractical to precisely maintain the volume concentration ratio of the ethylene glycol/water mixture coolant at 50/50. Therefore, any investigation into engine coolant characteristics should include a range of volume concentration ratios around the nominal 50/50 mark. In this study, the forced convective boiling heat transfer of distilled water and ethylene glycol/water mixtures with volume concentration ratios of 40/60, 50/50, and 60/40 in a 2.98-mm-inner-diameter circular tube has been investigated in both the horizontal flow and the vertical flow. The two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux of the test fluids were determined experimentally over a range of the mass flux, the vapor mass quality, and the inlet subcooling through a new boiling data reduction procedure that allowed the analytical calculation of the fluid boiling temperatures along the experimental test section by applying the ideal mixture assumption and the equilibrium assumption along with Raoult's law. Based on the experimental data, predictive methods for the two-phase pressure drop, the forced convective boiling heat transfer coefficient, and the critical heat flux under engine application conditions were developed. The results summarized in this final project report provide the necessary information for designing and implementing nucleate-boiling vehicular cooling systems.

  1. Oscillatory motion based measurement method and sensor for measuring wall shear stress due to fluid flow

    DOE Patents [OSTI]

    Armstrong, William D. (Laramie, WY); Naughton, Jonathan (Laramie, WY); Lindberg, William R. (Laramie, WY)

    2008-09-02

    A shear stress sensor for measuring fluid wall shear stress on a test surface is provided. The wall shear stress sensor is comprised of an active sensing surface and a sensor body. An elastic mechanism mounted between the active sensing surface and the sensor body allows movement between the active sensing surface and the sensor body. A driving mechanism forces the shear stress sensor to oscillate. A measuring mechanism measures displacement of the active sensing surface relative to the sensor body. The sensor may be operated under periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor measurably changes the amplitude or phase of the motion of the active sensing surface, or changes the force and power required from a control system in order to maintain constant motion. The device may be operated under non-periodic excitation where changes in the nature of the fluid properties or the fluid flow over the sensor change the transient motion of the active sensor surface or change the force and power required from a control system to maintain a specified transient motion of the active sensor surface.

  2. Subcooled flow boiling heat transfer and critical heat flux in water-based nanofluids at low pressure

    E-Print Network [OSTI]

    Kim, Sung Joong, Ph. D. Massachusetts Institute of Technology

    2009-01-01

    A nanofluid is a colloidal suspension of nano-scale particles in water, or other base fluids. Previous pool boiling studies have shown that nanofluids can improve the critical heat flux (CHF) by as much as 200%. In this ...

  3. Measurement of Ion Motional Heating Rates over a Range of Trap Frequencies and Temperatures

    E-Print Network [OSTI]

    C. D. Bruzewicz; J. M. Sage; J. Chiaverini

    2014-12-16

    We present measurements of the motional heating rate of a trapped ion at different trap frequencies and temperatures between $\\sim$0.6 and 1.5 MHz and $\\sim$4 and 295 K. Additionally, we examine the possible effect of adsorbed surface contaminants with boiling points below $\\sim$105$^{\\circ}$C by measuring the ion heating rate before and after locally baking our ion trap chip under ultrahigh vacuum conditions. We compare the heating rates presented here to those calculated from available electric-field noise models. We can tightly constrain a subset of these models based on their expected frequency and temperature scaling interdependence. Discrepancies between the measured results and predicted values point to the need for refinement of theoretical noise models in order to more fully understand the mechanisms behind motional trapped-ion heating.

  4. Geothermal Resource/Reservoir Investigations Based on Heat Flow and Thermal Gradient Data for the United States

    SciTech Connect (OSTI)

    D. D. Blackwell; K. W. Wisian; M. C. Richards; J. L. Steele

    2000-04-01

    Several activities related to geothermal resources in the western United States are described in this report. A database of geothermal site-specific thermal gradient and heat flow results from individual exploration wells in the western US has been assembled. Extensive temperature gradient and heat flow exploration data from the active exploration of the 1970's and 1980's were collected, compiled, and synthesized, emphasizing previously unavailable company data. Examples of the use and applications of the database are described. The database and results are available on the world wide web. In this report numerical models are used to establish basic qualitative relationships between structure, heat input, and permeability distribution, and the resulting geothermal system. A series of steady state, two-dimensional numerical models evaluate the effect of permeability and structural variations on an idealized, generic Basin and Range geothermal system and the results are described.

  5. Liquid Salts as Media for Process Heat Transfer from VHTR's: Forced Convective Channel Flow Thermal Hydraulics, Materials, and Coating

    SciTech Connect (OSTI)

    Sridharan, Kumar; Anderson, Mark; Allen, Todd; Corradini, Michael

    2012-01-30

    The goal of this NERI project was to perform research on high temperature fluoride and chloride molten salts towards the long-term goal of using these salts for transferring process heat from high temperature nuclear reactor to operation of hydrogen production and chemical plants. Specifically, the research focuses on corrosion of materials in molten salts, which continues to be one of the most significant challenges in molten salts systems. Based on the earlier work performed at ORNL on salt properties for heat transfer applications, a eutectic fluoride salt FLiNaK (46.5% LiF-11.5%NaF-42.0%KF, mol.%) and a eutectic chloride salt (32%MgCl2-68%KCl, mole %) were selected for this study. Several high temperature candidate Fe-Ni-Cr and Ni-Cr alloys: Hastelloy-N, Hastelloy-X, Haynes-230, Inconel-617, and Incoloy-800H, were exposed to molten FLiNaK with the goal of understanding corrosion mechanisms and ranking these alloys for their suitability for molten fluoride salt heat exchanger and thermal storage applications. The tests were performed at 850��������C for 500 h in sealed graphite crucibles under an argon cover gas. Corrosion was noted to occur predominantly from dealloying of Cr from the alloys, an effect that was particularly pronounced at the grain boundaries Alloy weight-loss due to molten fluoride salt exposure correlated with the initial Cr-content of the alloys, and was consistent with the Cr-content measured in the salts after corrosion tests. The alloys���¢�������� weight-loss was also found to correlate to the concentration of carbon present for the nominally 20% Cr containing alloys, due to the formation of chromium carbide phases at the grain boundaries. Experiments involving molten salt exposures of Incoloy-800H in Incoloy-800H crucibles under an argon cover gas showed a significantly lower corrosion for this alloy than when tested in a graphite crucible. Graphite significantly accelerated alloy corrosion due to the reduction of Cr from solution by graphite and formation on Cr-carbide on the graphite surface. Ni-electroplating dramatically reduced corrosion of alloys, although some diffusion of Fe and Cr were observed occur through the Ni plating. A pyrolytic carbon and SiC (PyC/SiC) CVD coating was also investigated and found to be effective in mitigating corrosion. The KCl-MgCl2 molten salt was less corrosive than FLiNaK fluoride salts for corrosion tests performed at 850oC. Cr dissolution in the molten chloride salt was still observed and consequently Ni-201 and Hastelloy N exhibited the least depth of attack. Grain-boundary engineering (GBE) of Incoloy 800H improved the corrosion resistance (as measured by weight loss and maximum depth of attack) by nearly 50% as compared to the as-received Incoloy 800H sample. Because Cr dissolution is an important mechanism of corrosion, molten salt electrochemistry experiments were initiated. These experiments were performed using anodic stripping voltammetry (ASV). Using this technique, the reduction potential of Cr was determined against a Pt quasi-reference electrode as well as against a Ni(II)-Ni reference electrode in molten FLiNaK at 650 oC. The integrated current increased linearly with Cr-content in the salt, providing for a direct assessment of the Cr concentration in a given salt of unknown Cr concentration. To study heat transfer mechanisms in these molten salts over the forced and mixed convection regimes, a forced convective loop was constructed to measure heat transfer coefficients, friction factors and corrosion rates in different diameter tubes in a vertical up flow configuration in the laminar flow regime. Equipment and instrumentation for the forced convective loop was designed, constructed, and tested. These include a high temperature centrifugal pump, mass flow meter, and differential pressure sensing capabilities to an uncertainty of < 2 Pa. The heat transfer coefficient for the KCl-MgCl2 salt was measured in t

  6. Nonlinear convection stagnation point heat transfer and MHD fluid flow in porous medium towards a permeable shrinking sheet

    E-Print Network [OSTI]

    Kumar, Rakesh

    2015-01-01

    This investigation deals with the analysis of stagnation point heat transfer and corresponding flow features of hydromagnetic viscous incompressible fluid over a vertical shrinking sheet. The considered sheet is assumed to be permeable and subject to addition of stagnation point to control the generated vorticity in the boundary layer. The sheet is placed on the right side of the fluid saturated porous medium which is having permeability of specified form. Nonlinear convection waves in the flow field are realized due to the envisaged nonlinear relation between density and temperature. The equations governing the nonlinear convection boundary layer flow are modeled and simplified using similarity transformations. The economized equations are solved for numerical solutions by employing the implicit finite difference scheme also known as Keller-box method. The influence of the associated parameters of the problem on velocity and temperature distributions, skin friction and rate of heat transfer are presented thr...

  7. Measuring important parameters for air-sea heat exchange Christoph S. Garbeab, Uwe Schimpfab and Bernd Jhneab

    E-Print Network [OSTI]

    Garbe, Christoph S.

    Measuring important parameters for air-sea heat exchange Christoph S. Garbeab, Uwe Schimpfab Exchange, Heat flux, Digital Image Processing, Surface Renewal 1. INTRODUCTION Thermographic techniques-water heat exchange. A driving force in air sea interactions is the net sea surface heat flux. It is a vital

  8. Standard Test Method for Measuring Heat Flux Using Flush-Mounted Insert Temperature-Gradient Gages

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method describes the measurement of the net heat flux normal to a surface using gages inserted flush with the surface. The geometry is the same as heat-flux gages covered by Test Method E 511, but the measurement principle is different. The gages covered by this standard all use a measurement of the temperature gradient normal to the surface to determine the heat that is exchanged to or from the surface. Although in a majority of cases the net heat flux is to the surface, the gages operate by the same principles for heat transfer in either direction. 1.2 This general test method is quite broad in its field of application, size and construction. Two different gage types that are commercially available are described in detail in later sections as examples. A summary of common heat-flux gages is given by Diller (1). Applications include both radiation and convection heat transfer. The gages used for aerospace applications are generally small (0.155 to 1.27 cm diameter), have a fast time response ...

  9. Film Cooling, Heat Transfer and Aerodynamic Measurements in a Three Stage Research Gas Turbine 

    E-Print Network [OSTI]

    Suryanarayanan, Arun

    2010-07-14

    turbine rotational speeds namely, 2400rpm, 2550rpm and 3000rpm. Interstage aerodynamic measurements with miniature five hole probes are also acquired at these speeds. The aerodynamic data characterizes the flow along the first stage rotor exit, second...

  10. EXPERIMENTAL MEASUREMENT OF RADIATION HEAT TRANSFER FROM COMPLEX

    E-Print Network [OSTI]

    17, United States Code. ProQuest Information and Learning Company 300 North Zeeb Road P.O. Box 1346 Ann Arbor, MI 48106-1346 by ProQuest Information and Learning Company. #12;ii EXPERIMENTAL MEASUREMENT. I would also like to thank my entire family, who are always willing to give advice and time whenever

  11. Uncertainty analysis of steady state incident heat flux measurements in hydrocarbon fuel fires.

    SciTech Connect (OSTI)

    Nakos, James Thomas

    2005-12-01

    The objective of this report is to develop uncertainty estimates for three heat flux measurement techniques used for the measurement of incident heat flux in a combined radiative and convective environment. This is related to the measurement of heat flux to objects placed inside hydrocarbon fuel (diesel, JP-8 jet fuel) fires, which is very difficult to make accurately (e.g., less than 10%). Three methods will be discussed: a Schmidt-Boelter heat flux gage; a calorimeter and inverse heat conduction method; and a thin plate and energy balance method. Steady state uncertainties were estimated for two types of fires (i.e., calm wind and high winds) at three times (early in the fire, late in the fire, and at an intermediate time). Results showed a large uncertainty for all three methods. Typical uncertainties for a Schmidt-Boelter gage ranged from {+-}23% for high wind fires to {+-}39% for low wind fires. For the calorimeter/inverse method the uncertainties were {+-}25% to {+-}40%. The thin plate/energy balance method the uncertainties ranged from {+-}21% to {+-}42%. The 23-39% uncertainties for the Schmidt-Boelter gage are much larger than the quoted uncertainty for a radiative only environment (i.e ., {+-}3%). This large difference is due to the convective contribution and because the gage sensitivities to radiative and convective environments are not equal. All these values are larger than desired, which suggests the need for improvements in heat flux measurements in fires.

  12. YOUNG MEASURES AND ORDER-DISORDER TRANSITION IN STATIONARY FLOW OF LIQUID CRYSTALS

    E-Print Network [OSTI]

    YOUNG MEASURES AND ORDER-DISORDER TRANSITION IN STATIONARY FLOW OF LIQUID CRYSTALS By M. Carme AND ORDER-DISORDER TRANSITION IN STATIONARY FLOW OF LIQUID CRYSTALS M. CARME CALDERER AND ALEXANDER of the governing equations. It is experimentally well known that liquid crystal flows with large Ericksen number

  13. Dynamic measurement of heat loss coefficients through Trombe wall glazing systems

    SciTech Connect (OSTI)

    Balcomb, J.D.

    1981-01-01

    A Trombe wall presents a unique opportunity to measure the heat-loss coefficient through the glazing system because the wall itself can be used as a heat meter. Since the instantaneous heat flux through the outer wall surface can be determined, the heat loss coefficient at night can be calculated by dividing by the wall surface-to-ambient temperature difference. This technique has been used to determine heat-loss coefficients for Los Alamos test rooms during the winter of 1980-1981. Glazing systems studied include single and double glazing both with and without night insulation used in conjunction with a flat black paint, and both single and double glazing used in conjunction with a selective surface.

  14. An experimental study of convective heat transfer with microencapsulated phase change material suspension: Laminar flow in a circular tube under constant heat flux

    SciTech Connect (OSTI)

    Chen, Binjiao; Wang, Xin; Zeng, Ruolang; Zhang, Yinping; Di, Hongfa [Department of Building Science, Tsinghua University, Beijing 100084 (China); Wang, Xichun; Niu, Jianlei [Department of Building Service Engineering, The Hong Kong Polytechnic University, Hong Kong (China); Li, Yi [Institute of Textiles and Clothing, The Hong Kong Polytechnic University, Hong Kong (China)

    2008-09-15

    By contrast with the conventional heat transfer fluid (water), the microencapsulated phase change material (MPCM) suspension, with a small temperature difference between storing and releasing heat, is of much larger apparent specific heat and much higher thermal energy storage capacity. It has been suggested to serve as a dual-functional medium for thermal energy transport and/or storage. The heat transfer characteristics of a kind of MPCM suspension, formed by microencapsulating industrial-grade 1-bromohexadecane (C{sub 16}H{sub 33}Br) as phase change material, were experimentally studied for laminar flow in a circular tube under constant heat flux. A new expression of Ste is put forward in the paper, according to the physical definition of Stefan number. The results in the experiments show: (a) the dimensionless internal wall temperature of the MPCM suspension is lower than pure water, and the decrease can be up to 30% of that of water; (b) the heat transfer enhancement ratio can be 1.42 times of that of water at x{sup +} = 4.2 x 10{sup -2} for 15.8 wt% MPCM suspension, which is not as much as in some references; and (c) the pump consumption of the MPCM suspension system decrease greatly for the larger heat transfer rate compared with water, due to phase change, the decrease can be up to 67.5% of that of water at q = 750 W (15.8 wt%). The kind of MPCM suspension has good application feasibility in practice. (author)

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

    SciTech Connect (OSTI)

    Sippola, Mark R.; Nazaroff, William W.

    2003-08-01

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

  16. DEVELOPING FLOW AND HEAT TRANSFER IN STRONGLY CURVED DUCTS OF RECTANGULAR CROSS-SECTION

    E-Print Network [OSTI]

    Yee, G.

    2010-01-01

    123. HUMPHREY, J.A.C. , "Flow in Ducts with Curvature andViscous Flow in Curved Ducts of Rectangular Cross-Sections,"Laminar Flow in a Square Duct of Strong Curvature,1I J.

  17. Electron Heat Transport Measured in a Stochastic Magnetic Field T. M. Biewer,* C. B. Forest,

    E-Print Network [OSTI]

    Biewer, Theodore

    Electron Heat Transport Measured in a Stochastic Magnetic Field T. M. Biewer,* C. B. Forest, J. K where magnetic islands overlap and field lines are stochastic. The measurements show that (1 are small, the magnetic field lines break into chains of magnetic islands at mode-rational sur- faces where

  18. Heat transfer in ice hockey halls: measurements, energy analysis and analytical ice pad temperature profile

    E-Print Network [OSTI]

    Ferrantelli, Andrea

    2015-01-01

    We consider heat transfer processes in an ice hockey hall, during operating conditions, with a bottom-up approach based upon on-site measurements. Detailed temperature data of both the ice pad and the air above the ice rink are used for a heat balance calculation in the steady-state regime, which quantifies the impact of each single heat source. We solve the heat equation in the ice slab in transient regime, and obtain a general analytical formula for the temperature profile. This solution is then applied to the resurfacing process by using our measurements as (time-dependent) boundary conditions (b.c.), and compared to an analogous numerical computation with good agreement. Our analytical formula is given with implicit initial condition and b.c., therefore it can be used not only in ice halls, but in a large variety of engineering applications.

  19. Heat transfer in ice hockey halls: measurements, energy analysis and analytical ice pad temperature profile

    E-Print Network [OSTI]

    Andrea Ferrantelli; Klaus Viljanen

    2015-06-30

    We consider heat transfer processes in an ice hockey hall, during operating conditions, with a bottom-up approach based upon on-site measurements. Detailed temperature data of both the ice pad and the air above the ice rink are used for a heat balance calculation in the steady-state regime, which quantifies the impact of each single heat source. We solve the heat equation in the ice slab in transient regime, and obtain a general analytical formula for the temperature profile. This solution is then applied to the resurfacing process by using our measurements as (time-dependent) boundary conditions (b.c.), and compared to an analogous numerical computation with good agreement. Our analytical formula is given with implicit initial condition and b.c., therefore it can be used not only in ice halls, but in a large variety of engineering applications.

  20. DNS of heat transfer in a transitional channel flow accompanied by a turbulent puff-like structure

    E-Print Network [OSTI]

    Tsukahara, Takahiro

    2014-01-01

    Direct numerical simulations of turbulent heat transfer in fully-developed channel flows have been performed in a range of friction Reynolds number between 60 and 180, based on the friction velocity and the channel half width $\\delta$, with emphasis on a puff-like structure, large-scale spatial intermittency. For the Reynolds numbers lower than 80 with a large computational domain of 51.2 x 2 x 22.5, the turbulent puff was observed and its significant influences on the momentum and heat transports were found. The spatial structure of the equilibrium puff, or the localized turbulence, was examined with taking account of two different thermal boundary conditions: the uniform heat-flux heating and the constant temperature difference between the walls. It was revealed that there existed a localized strong turbulent region in the form of an oblique band, along which a spanwise secondary flow was induced. In consequence, at the present lowest Reynolds number as low as 60, the flow remained turbulent and the larger ...

  1. A Comprehensive Statistically-Based Method to Interpret Real-Time Flowing Measurements

    SciTech Connect (OSTI)

    Pinan Dawkrajai; Keita Yoshioka; Analis A. Romero; Ding Zhu; A.D. Hill; Larry W. Lake

    2005-10-01

    This project is motivated by the increasing use of distributed temperature sensors for real-time monitoring of complex wells (horizontal, multilateral and multi-branching wells) to infer the profiles of oil, gas, and water entry. Measured information can be used to interpret flow profiles along the wellbore including junction and build section. In this second project year, we have completed a forward model to predict temperature and pressure profiles in complex wells. As a comprehensive temperature model, we have developed an analytical reservoir flow model which takes into account Joule-Thomson effects in the near well vicinity and multiphase non-isothermal producing wellbore model, and couples those models accounting mass and heat transfer between them. For further inferences such as water coning or gas evaporation, we will need a numerical non-isothermal reservoir simulator, and unlike existing (thermal recovery, geothermal) simulators, it should capture subtle temperature change occurring in a normal production. We will show the results from the analytical coupled model (analytical reservoir solution coupled with numerical multi-segment well model) to infer the anomalous temperature or pressure profiles under various conditions, and the preliminary results from the numerical coupled reservoir model which solves full matrix including wellbore grids. We applied Ramey's model to the build section and used an enthalpy balance to infer the temperature profile at the junction. The multilateral wellbore temperature model was applied to a wide range of cases varying fluid thermal properties, absolute values of temperature and pressure, geothermal gradients, flow rates from each lateral, and the trajectories of each build section.

  2. Standard Test Method for Measuring Heat Flux Using Surface-Mounted One-Dimensional Flat Gages

    E-Print Network [OSTI]

    American Society for Testing and Materials. Philadelphia

    2009-01-01

    1.1 This test method describes the measurement of the net heat flux normal to a surface using flat gages mounted onto the surface. Conduction heat flux is not the focus of this standard. Conduction applications related to insulation materials are covered by Test Method C 518 and Practices C 1041 and C 1046. The sensors covered by this test method all use a measurement of the temperature difference between two parallel planes normal to the surface to determine the heat that is exchanged to or from the surface in keeping with Fourier’s Law. The gages operate by the same principles for heat transfer in either direction. 1.2 This test method is quite broad in its field of application, size and construction. Different sensor types are described in detail in later sections as examples of the general method for measuring heat flux from the temperature gradient normal to a surface (1). Applications include both radiation and convection heat transfer. The gages have broad application from aerospace to biomedical en...

  3. Multi-Scale Experiments in Turbulent Subcooled Boiling Flow Through a Square Channel with a Single Heated Wall 

    E-Print Network [OSTI]

    Estrada Perez, Carlos Eduardo

    2014-12-12

    flow through a square channel. The explored visualization techniques were: 1) Particle tracking velocimetry (PTV), which provides velocity measurements of the liquid phase, 2) High-speed shadowgraphy (HSS) which is used to study the dispersed phase...

  4. Why Insertion Turbine Meters are Replacing Orifice Plates for Steam Flow Measurement 

    E-Print Network [OSTI]

    Rusnak, J. J.

    1983-01-01

    when it was the best choice available. No area typifies this situation more than the problem of measuring steam flows. While the orifice has a number of draw back for steam flow measurement, it is superior to the only alternative available (until...

  5. Measuring 3D Plant Growth Using Optical Flow J.L. Barron A. Liptay

    E-Print Network [OSTI]

    Barron, John

    1 Measuring 3D Plant Growth Using Optical Flow J.L. Barron A. Liptay Dept. of Computer Science is presented for measuring 3D plant growth using the optical flow computed on an image sequence of a growing made by projecting the plant's orthogonal image onto a mirror oriented at 45 ffi with respect

  6. YOUNG MEASURES AND ORDER-DISORDER TRANSITION IN STATIONARY FLOW OF LIQUID CRYSTALS

    E-Print Network [OSTI]

    Panchenko, Alexander

    YOUNG MEASURES AND ORDER-DISORDER TRANSITION IN STATIONARY FLOW OF LIQUID CRYSTALS M. CARME measures generated by sequences of weak solutions of the governing equations. It is experimentally well [-1, 1] with R2 Ã? (-1, 1), representing the domain of the flow. The governing system is highly

  7. Full-Scale Boiler Measurements Demonstrating Striated Flows during Biomass Co-Firing

    E-Print Network [OSTI]

    ACERC-2008 Full-Scale Boiler Measurements Demonstrating Striated Flows during Biomass Co based measurements methods #12;Objective Minor impact of biomass cofiring with coal on boiler operation) · Experimentally demonstrate the existence of stratified flows in boilers Indication: SO2, ash composition, straw

  8. Laboratory Evaluation of Air Flow Measurement Methods for Residential...

    Office of Scientific and Technical Information (OSTI)

    research team at Lawrence Berkeley National Laboratory addressed the issue that typical tools used by contractors in the field to test air flows may not be accurate enough to...

  9. Extensional viscosity measurements of polyethylene using a melt flow indexer 

    E-Print Network [OSTI]

    Moffatt, Scott Gordon

    1999-01-01

    . . . . . . . . 142 APPENDIX C: CONSTANT STRESS RHEOMETER TESTING PROCEDURE. . . . . . APPENDIX D: MELT FLOW INDEXER DATA . . . . . 147 APPENDIX E: CAPILLARY RHEOMETER DATA. . . . . . 184 APPENDIX F: OSCILLATORY RHEOMETER DATA . . . . . . . . 213 APPENDIX G...) [Padmanabhan and Macosko (1997)] . . . . . 14 5 Bagley Correction Factor for the Capillary Rheometer. 23 6 Flow Index Determination. . . . . . . 28 7 Definitions of Lengths Used in the Darby Method. 8 Carreau-Yasuda Fit of Complex Viscosity Data for Resin E...

  10. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, L.D.

    1987-02-11

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation. 5 figs.

  11. Rotary magnetic heat pump

    DOE Patents [OSTI]

    Kirol, Lance D. (Shelly, ID)

    1988-01-01

    A rotary magnetic heat pump constructed without flow seals or segmented rotor accomplishes recuperation and regeneration by using split flow paths. Heat exchange fluid pumped through heat exchangers and returned to the heat pump splits into two flow components: one flowing counter to the rotor rotation and one flowing with the rotation.

  12. Analytical and Numerical Study of Joule Heating Effects on Electrokinetically Pumped Continuous Flow PCR Chips

    E-Print Network [OSTI]

    Le Roy, Robert J.

    Analytical and Numerical Study of Joule Heating Effects on Electrokinetically Pumped Continuous, and the potential for integration.1-3 Joule heating is inevitable when electrokinetic pumping is used Form: December 8, 2007 Joule heating is an inevitable phenomenon for microfluidic chips involving

  13. Influences of peripherally-cut twisted tape insert on heat transfer and thermal performance characteristics in laminar and turbulent tube flows

    SciTech Connect (OSTI)

    Eiamsa-ard, Smith [Department of Mechanical Engineering, Faculty of Engineering, Mahanakorn University of Technology, Bangkok 10530 (Thailand); Seemawute, Panida [Department of Civil Engineering, Faculty of Engineering, Mahanakorn University of Technology, Bangkok 10530 (Thailand); Wongcharee, Khwanchit [Department of Chemical Engineering, Faculty of Engineering, Mahanakorn University of Technology, Bangkok 10530 (Thailand)

    2010-09-15

    Effects of peripherally-cut twisted tape insert on heat transfer, friction loss and thermal performance factor characteristics in a round tube were investigated. Nine different peripherally-cut twisted tapes with constant twist ratio (y/W = 3.0) and different three tape depth ratios (DR = d/W = 0.11, 0.22 and 0.33), each with three different tape width ratios (WR = w/W = 0.11, 0.22 and 0.33) were tested. Besides, one typical twisted tape was also tested for comparison. The measurement of heat transfer rate was conducted under uniform heat flux condition while that of friction factor was performed under isothermal condition. Tests were performed with Reynolds number in a range from 1000 to 20,000, using water as a working fluid. The experimental results revealed that both heat transfer rate and friction factor in the tube equipped with the peripherally-cut twisted tapes were significantly higher than those in the tube fitted with the typical twisted tape and plain tube, especially in the laminar flow regime. The higher turbulence intensity of fluid in the vicinity of the tube wall generated by the peripherally-cut twisted tape compared to that induced by the typical twisted tape is referred as the main reason for achieved results. The obtained results also demonstrated that as the depth ratio increased and width ratio decreased, the heat transfer enhancement increased. Over the range investigated, the peripherally-cut twisted tape enhanced heat transfer rates in term of Nusselt numbers up to 2.6 times (turbulent regime) and 12.8 times (laminar regime) of that in the plain tube. These corresponded to the maximum performance factors of 1.29 (turbulent regime) and 4.88 (laminar regime). (author)

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

    SciTech Connect (OSTI)

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

    1990-05-01

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

  15. Gravitational collapse of a spherical star with heat flow as a possible energy mechanism of gamma-ray bursts

    E-Print Network [OSTI]

    Zhe Chang; Cheng-Bo Guan; Chao-Guang Huang; Xin Li

    2008-03-26

    We investigate the gravitational collapse of a spherically symmetric, inhomogeneous star, which is described by a perfect fluid with heat flow and satisfies the equation of state $p=\\rho/3$ at its center. In the process of the gravitational collapsing, the energy of the whole star is emitted into space. And the remaining spacetime is a Minkowski one without a remnant at the end of the process. For a star with a solar mass and solar radius, the total energy emitted is at the order of $10^{54}$ {\\rm erg}, and the time-scale of the process is about $8s$. These are in the typical values for a gamma-ray burst. Thus, we suggest the gravitational collapse of a spherical star with heat flow as a possible energy mechanism of gamma-ray bursts.

  16. Apparatus for passive removal of subsurface contaminants and mass flow measurement

    DOE Patents [OSTI]

    Jackson, Dennis G. (Augusta, GA); Rossabi, Joseph (Aiken, SC); Riha, Brian D. (Augusta, GA)

    2003-07-15

    A system for improving the Baroball valve and a method for retrofitting an existing Baroball valve. This invention improves upon the Baroball valve by reshaping the interior chamber of the valve to form a flow meter measuring chamber. The Baroball valve sealing mechanism acts as a rotameter bob for determining mass flow rate through the Baroball valve. A method for retrofitting a Baroball valve includes providing static pressure ports and connecting a measuring device, to these ports, for measuring the pressure differential between the Baroball chamber and the well. A standard curve of nominal device measurements allows the mass flow rate to be determined through the retrofitted Baroball valve.

  17. Apparatus for passive removal of subsurface contaminants and volume flow measurement

    DOE Patents [OSTI]

    Jackson, Dennis G. (Augusta, GA); Rossabi, Joseph (Aiken, SC); Riha, Brian D. (Augusta, GA)

    2002-01-01

    A system for improving the Baroball valve and a method for retrofitting an existing Baroball valve. This invention improves upon the Baroball valve by reshaping the interior chamber of the valve to form a flow meter measuring chamber. The Baroball valve sealing mechanism acts as a rotameter bob for determining volume flow rate through the Baroball valve. A method for retrofitting a Baroball valve includes providing static pressure ports and connecting a measuring device, to these ports, for measuring the pressure differential between the Baroball chamber and the well. A standard curve of nominal device measurements allows the volume flow rate to be determined through the retrofitted Baroball valve.

  18. Innovative Coal Solids-Flow Monitoring and Measurement Using Phase-Doppler and Mie Scattering Techniques

    SciTech Connect (OSTI)

    Stephen Seong Lee

    2010-01-19

    Fuel flow to individual burners is complicated and difficult to determine on coal fired boilers, since coal solids were transported in a gas suspension that is governed by the complex physics of two-phase flow. The objectives of the project were the measurements of suspended coal solids-flows in the simulated test conditions. Various extractive methods were performed manually and can give only a snapshot result of fuel distribution. In order to measure particle diameter & velocity, laser based phase-Doppler particle analyzer (PDPA) and particle image velocimetry (PIV) were carefully applied. Statistical methods were used to analyze particle characteristics to see which factors have significant effect. The transparent duct model was carefully designed and fabricated for the laser-based-instrumentation of solids-flow monitoring (LISM). The experiments were conducted with two different kinds of particles with four different particle diameters. The particle types were organic particles and saw dust particles with the diameter range of 75-150 micron, 150-250 micron, 250-355 micron and 355-425 micron. The densities of the particles were measured to see how the densities affected the test results. Also the experiment was conducted with humid particles and fog particles. To generate humid particles, the humidifier was used. A pipe was connected to the humidifier to lead the particle flow to the intersection of the laser beam. The test results of the particle diameter indicated that, the mean diameter of humid particles was between 6.1703 microns and 6.6947 microns when the humid particle flow was low. When the humid particle flow was high, the mean diameter was between 6.6728 microns and 7.1872 microns. The test results of the particle mean velocity indicated that the mean velocity was between 1.3394 m/sec and 1.4556 m/sec at low humid particle flow. When the humid particle flow was high, the mean velocity was between 1.5694 m/sec and 1.7856 m/sec. The Air Flow Module, TQ AF 17 and shell ondina oil were used to generate fog particles. After the oil was heated inside the fog generator, the blower was used to generate the fog. The fog flew along the pipe to the intersection of the laser beam. The mean diameter of the fog particles was 5.765 microns. Compared with the humid particle diameter, we observed that the mean diameter of the fog particles was smaller than the humid particles. The test results of particle mean velocity was about 3.76 m/sec. Compared with the mean velocity of the humid particles, we can observed the mean velocity of fog particles were greater than humid particles. The experiments were conducted with four different kinds of particles with five different particle diameters. The particle types were organic particles, coal particles, potato particles and wheat particles with the diameter range of 63-75 micron, less than 150 micron, 150-250 micron, 250-355 micron and 355-425 micron. To control the flow rate, the control gate of the particle dispensing hopper was adjusted to 1/16 open rate, 1/8 open rate and 1/4 open rate. The captured image range was 0 cm to 5 cm from the control gate, 5 cm to 10 cm from the control gate and 10 cm to 15 cm from the control gate. Some of these experiments were conducted under both open environment conditions and closed environment conditions. Thus these experiments had a total of five parameters which were type of particles, diameter of particles, flow rate, observation range, and environment conditions. The coal particles (diameter between 63 and 75 microns) tested under the closed environment condition had three factors that were considered as the affecting factors. They were open rate, observation range, and environment conditions. In this experiment, the interaction of open rate and observation range had a significant effect on the lower limit. On the upper limit, the open rate and environment conditions had a significant effect. In addition, the interaction of open rate and environment conditions had a significant effect. The coal particles tested (diameter between 63 and 75

  19. Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain

    E-Print Network [OSTI]

    Levinson, Ronnen

    2010-01-01

    the coe?cients of heat transfer by convection, radiation andconduction heat transfer coe?cient radiation heat transfer

  20. MEASURE-EENT OF WATER CONTENT I N POROUS MEDIA UNDER GEOTHERMAL FLUID FLOW CONDITIONS

    E-Print Network [OSTI]

    Stanford University

    MEASURE-EENT OF WATER CONTENT I N POROUS MEDIA UNDER GEOTHERMAL FLUID FLOW CONDITIONS for t h e i n - s i t u measurement of water content i n porous media, expressed as a volume f r a c t i o n of t h e pore space; ( 2 ) t o measure water content i n t h e two-phase geothermal f l u i d flow

  1. Development Of An Experiment For Measuring Flow Phenomena Occurring In A Lower Plenum For VHTR CFD Assessment

    SciTech Connect (OSTI)

    D. M. McEligot; K.G. Condie; G. E. Mc Creery; H. M. Mc Ilroy

    2005-09-01

    The objective of the present report is to document the design of our first experiment to measure generic flow phenomena expected to occur in the lower plenum of a typical prismatic VHTR (Very High Temperature Reactor) concept. In the process, fabrication sketches are provided for the use of CFD (computational fluid dynamics) analysts wishing to employ the data for assessment of their proposed codes. The general approach of the project is to develop new benchmark experiments for assessment in parallel with CFD and coupled CFD/systems code calculations for the same geometry. One aspect of the complex flow in a prismatic VHTR is being addressed: flow and thermal mixing in the lower plenum ("hot streaking" issue). Current prismatic VHTR concepts were examined to identify their proposed flow conditions and geometries over the range from normal operation to decay heat removal in a pressurized cooldown. Approximate analyses were applied to determine key non-dimensional parameters and their magnitudes over this operating range. The flow in the lower plenum can locally be considered to be a situation of multiple jets into a confined crossflow -- with obstructions. Flow is expected to be turbulent with momentum-dominated turbulent jets entering; buoyancy influences are estimated to be negligible in normal full power operation. Experiments are needed for the combined features of the lower plenum flows. Missing from the typical jet experiments available are interactions with nearby circular posts and with vertical posts in the vicinity of vertical walls - with near stagnant surroundings at one extreme and significant crossflow at the other.

  2. Flow visualization and leakage measurements of labyrinth seals 

    E-Print Network [OSTI]

    Johnson, James Wayne

    1996-01-01

    , seals are tested over a range of Reynolds numbers, step heights, and axial offset positions (where applicable) for a fixed annular clearance. A permanent flow visualization record for each experiment is kept and analyzed in both real-time and slow motion...

  3. CONNECTING STAR FORMATION QUENCHING WITH GALAXY STRUCTURE AND SUPERMASSIVE BLACK HOLES THROUGH GRAVITATIONAL HEATING OF COOLING FLOWS

    SciTech Connect (OSTI)

    Guo, Fulai

    2014-12-20

    Recent observations suggested that star formation quenching in galaxies is related to galaxy structure. Here we propose a new mechanism to explain the physical origin of this correlation. We assume that while quenching is maintained in quiescent galaxies by a feedback mechanism, cooling flows in the hot halo gas can still develop intermittently. We study cooling flows in a large suite of around 90 hydrodynamic simulations of an isolated galaxy group, and find that the flow development depends significantly on the gravitational potential well in the central galaxy. If the galaxy's gravity is not strong enough, cooling flows result in a central cooling catastrophe, supplying cold gas and feeding star formation to galactic bulges. When the bulge grows prominent enough, compressional heating starts to offset radiative cooling and maintains cooling flows in a long-term hot mode without producing a cooling catastrophe. Our model thus describes a self-limited growth channel for galaxy bulges and naturally explains the connection between quenching and bulge prominence. In particular, we explicitly demonstrate that M{sub ?}/R{sub eff}{sup 1.5} is a good structural predictor of quenching. We further find that the gravity from the central supermassive black hole also affects the bimodal fate of cooling flows, and we predict a more general quenching predictor to be M{sub bh}{sup 1.6}M{sub ?}/R{sub eff}{sup 1.5}, which may be tested in future observational studies.

  4. Measurement and computation of heat transfer in high-pressure compressor drum geometries with axial throughflow

    SciTech Connect (OSTI)

    Long, C.A.; Morse, A.P.; Tucker, P.G.

    1997-01-01

    This paper makes comparisons between CFD computations and experimental measurements of heat transfer for the axial throughflow of cooling air in a high-pressure compressor spool rig and a plane cavity rig. The heat transfer measurements are produced using fluxmeters and by the conduction solution method from surface temperature measurements. Numerical predictions are made by solving the Navier-Stokes equations in a full three-dimensional, time-dependent form using the finite-volume method. Convergence is accelerated using a multigrid algorithm and turbulence modeled using a simple mixing length formulation. Notwithstanding systematic differences between the measurements and the computations, the level of agreement can be regarded as promising in view of the acknowledged uncertainties in the experimental data, the limitations of the turbulence model and, perhaps more importantly, the modest grid densities used for the computations.

  5. Measure Guideline. Heat Pump Water Heaters in New and Existing Homes

    SciTech Connect (OSTI)

    Shapiro, Carl; Puttagunta, Srikanth; Owens, Douglas

    2012-02-01

    This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs

  6. Local Measurement of Non-Classical Ion Heating During Magnetic Reconnection

    E-Print Network [OSTI]

    particles. Solar observations suggest that hard X-rays from solar flares are produced by reconnection [3" of reconnected field lines, and global ion heating was at- tributed to thermalization of the sheared Alfv measurements 2 #12;remains an open question due to the plasma potential being unknown [11] and the inherent

  7. Local Measurement of NonClassical Ion Heating During Magnetic Reconnection

    E-Print Network [OSTI]

    particles. Solar observations suggest that hard X­rays from solar flares are produced by reconnection [3#ect'' of reconnected field lines, and global ion heating was at­ tributed to thermalization of the sheared Alfv measurements 2 #12; remains an open question due to the plasma potential being unknown [11] and the inherent

  8. Ice flow sensitivity to geothermal heat flux of Pine Island Glacier, Antarctica

    E-Print Network [OSTI]

    Larour, E; Morlighem, M; Seroussi, H; Schiermeier, J; Rignot, E; Rignot, E

    2012-01-01

    as heat available from geothermal energy. The consequence isbasal friction and geothermal energy are all on the sameis influenced by geothermal energy in the slow moving areas

  9. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    type air-source VRF system and a GSHP system that uses single-stage scroll compressors and vertical ground loop heat exchanger (

  10. Comparison of energy efficiency between variable refrigerant flow systems and ground source heat pump systems

    E-Print Network [OSTI]

    Hong, Tainzhen

    2010-01-01

    dual compressor available on the market Compared with the selected building, a more energy efficient building will have lower space cooling and heating

  11. Method and apparatus for measuring the mass flow rate of a fluid

    DOE Patents [OSTI]

    Evans, Robert P. (Idaho Falls, ID); Wilkins, S. Curtis (Idaho Falls, ID); Goodrich, Lorenzo D. (Shelley, ID); Blotter, Jonathan D. (Pocatello, ID)

    2002-01-01

    A non invasive method and apparatus is provided to measure the mass flow rate of a multi-phase fluid. An accelerometer is attached to a pipe carrying a multi-phase fluid. Flow related measurements in pipes are sensitive to random velocity fluctuations whose magnitude is proportional to the mean mass flow rate. An analysis of the signal produced by the accelerometer shows a relationship between the mass flow of a fluid and the noise component of the signal of an accelerometer. The noise signal, as defined by the standard deviation of the accelerometer signal allows the method and apparatus of the present invention to non-intrusively measure the mass flow rate of a multi-phase fluid.

  12. Indriect Measurement Of Nitrogen In A Mult-Component Natural Gas By Heating The Gas

    DOE Patents [OSTI]

    Morrow, Thomas B. (San Antonio, TX); Behring, II, Kendricks A. (Torrance, CA)

    2004-06-22

    Methods of indirectly measuring the nitrogen concentration in a natural gas by heating the gas. In two embodiments, the heating energy is correlated to the speed of sound in the gas, the diluent concentrations in the gas, and constant values, resulting in a model equation. Regression analysis is used to calculate the constant values, which can then be substituted into the model equation. If the diluent concentrations other than nitrogen (typically carbon dioxide) are known, the model equation can be solved for the nitrogen concentration.

  13. Vanadium redox-flow batteries Installation at Ris for characterisation measurements

    E-Print Network [OSTI]

    Vanadium redox-flow batteries ­ Installation at Risø for characterisation measurements Henrik-flow batteries hold a great promise for storing electric energy on a large scale. They have many attractive of the project is to characterise a vanadium battery as a system component. The vanadium battery

  14. Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions-sur-Loing, France. Working on fluid mechanics aspects of nuclear valves since 2004. Zachary Leutwyler zleutwyler and numerical investigation of flow- induced forces and torque acting on linear and quarter turn valves. hal

  15. DEPLOYING CONTENDER: EARLY LESSONS IN DATA, MEASUREMENT, AND TESTING OF MULTIPLE CALL FLOW DECISIONS

    E-Print Network [OSTI]

    Suendermann, David

    DEPLOYING CONTENDER: EARLY LESSONS IN DATA, MEASUREMENT, AND TESTING OF MULTIPLE CALL FLOW on lessons we learned from live deployments in production systems. Altogether, seven Contenders were in the application's call flow and the performance difference of the competing alternatives, potentially large

  16. MEASUREMENT OF THE SHOCK-HEATED MELT CURVE OF LEAD USING PYROMETRY AND REFLECTOMETRY

    SciTech Connect (OSTI)

    D. Partouche-Sebban and J. L. Pelissier, Commissariat a` l'Energie Atomique,; F. G. Abeyta, Los Alamos National Laboratory; W. W. Anderson, Los Alamos National Laboratory; M. E. Byers, Los Alamos National Laboratory; D. Dennis-Koller, Los Alamos National Laboratory; J. S. Esparza, Los Alamos National Laboratory; S. D. Borror, Bechtel Nevada; C. A. Kruschwitz, Bechtel Nevada

    2004-01-01

    Data on the high-pressure melting temperatures of metals is of great interest in several fields of physics including geophysics. Measuring melt curves is difficult but can be performed in static experiments (with laser-heated diamond-anvil cells for instance) or dynamically (i.e., using shock experiments). However, at the present time, both experimental and theoretical results for the melt curve of lead are at too much variance to be considered definitive. As a result, we decided to perform a series of shock experiments designed to provide a measurement of the melt curve of lead up to about 50 GPa in pressure. At the same time, we developed and fielded a new reflectivity diagnostic, using it to make measurements on tin. The results show that the melt curve of lead is somewhat higher than the one previously obtained with static compression and heating techniques.

  17. Measurement of laser heating in spin exchange optical pumping by NMR diffusion sensitization gradients

    SciTech Connect (OSTI)

    Parnell, Steven R.; Deppe, Martin H.; Ajraoui, Salma; Parra-Robles, Juan; Wild, Jim M.; Boag, Stephen

    2010-05-15

    This paper details pulsed gradient NMR measurements of the {sup 3}He diffusion coefficient in sealed cells during spin exchange optical pumping. The potential of ultra low field magnetic resonance imgaing (MRI) and NMR for noninvasive measurement of cell pressure is demonstrated. Diffusion sensitization gradients allow measurement of the {sup 3}He diffusion coefficient from which the pressure and/or temperature of the gas can be determined during optical pumping. The pressure measurements were compared with neutron time of flight transmission measurements. Good agreement was observed between the temperature/pressure measurements and predictions based on Chapman-Enskog theory. The technique had sufficient sensitivity to observe the diffusion coefficient increasing with temperature in a sealed cell. With this method, evidence for laser heating of the {sup 3}He during optical pumping was found. The results show that NMR diffusion measurements allow noninvasive measurement of the cell temperature and/or pressure in an optical pumping setup. The method can be expanded using MRI to probe the spatial distribution of the diffusion coefficient. These techniques can be applied to the further investigation of polarization limiting effects such as laser heating.

  18. Statistical Relationships of the Tropical Rainfall Measurement Mission (TRMM) Precipitation and Large-scale Flow 

    E-Print Network [OSTI]

    Borg, Kyle

    2010-07-14

    The relationship between precipitation and large-flow is important to understand and characterize in the climate system. We examine statistical relationships between the Tropical Rainfall Measurement Mission (TRMM) 3B42 ...

  19. Continuous Flow Diffusion Chamber Measurements of IN Concentration

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit the followingConcentrating Department of Energy'sContango in150.1A,Flow

  20. A FULL SCALE ROOM FOR THE EXPERIMENTAL STUDY OF INTERIOR BUILDING CONVECTIVE HEAT TRANSFER

    E-Print Network [OSTI]

    heated panel system mounted on the inside of the cells. ASHRAE Standard 51 was employed for volumetric air flow measurement. A water source heat pump provided chilled water to a fan-coil unit which in turn on volumetric air flow measurement and an overall room heat balance. Analysis was directed at results from

  1. Heat Transfer Engineering, 28(6):525540, 2007 Copyright C Taylor and Francis Group, LLC

    E-Print Network [OSTI]

    Ghajar, Afshin J.

    Heat Transfer Engineering, 28(6):525­540, 2007 Copyright C Taylor and Francis Group, LLC ISSN: 0145-7632 print / 1521-0537 online DOI: 10.1080/01457630701193906 Heat Transfer Measurements, Flow Pattern Maps, Stillwater, Oklahoma, USA Local heat transfer coefficients and flow parameters were measured for air

  2. Momentum and heat fluxes in a turbulent air flow over a wet, smooth boundary 

    E-Print Network [OSTI]

    Rice, Warren

    1958-01-01

    groundwater-land surface model, ParFlow.CLM, to develop a spatial distributed ecohydrological model at the stand scale (~1000 m^(2)). The modified ParFlow.CLM was used to conduct a 8-year simulation with half hourly time step at a AmeriFlux oak savanna site...

  3. Acoustic measurement of the Deepwater Horizon Macondo well flow rate

    E-Print Network [OSTI]

    Camilli, Richard

    On May 31, 2010, a direct acoustic measurement method was used to quantify fluid leakage rate from the Deepwater Horizon Macondo well prior to removal of its broken riser. This method utilized an acoustic imaging sonar and ...

  4. Alumina Nanoparticle Pre-coated Tubing Ehancing Subcooled Flow Boiling Cricital Heat Flux

    E-Print Network [OSTI]

    Truong, Bao H.

    Nanofluids are engineered colloidal dispersions of nano-sized particle in common base fluids. Previous pool boiling studies have shown that nanofluids can improve critical heat flux (CHF) up to 200% for pool boiling and ...

  5. Heat transfer characteristics of circular impinging jet arrays in an annular section with cross flow effects 

    E-Print Network [OSTI]

    Mhetras, Shantanu Prakash

    2002-01-01

    Jet impingement has been shown to be an effective method for enhancing convective heat transfer. There are a variety of applications of impinging jets in industry, including tempering and shaping of glass, annealing of metal and plastic sheets...

  6. Measurement and calculation of nozzle guide vane end wall heat transfer

    SciTech Connect (OSTI)

    Harvey, N.W.; Rose, M.G.; Coupland, J. [Rolls-Royce plc, Derby (United Kingdom); Jones, T.V. [Univ. of Oxford, Derby (United Kingdom). Dept. of Engineering Science

    1999-04-01

    A three-dimensional steady viscous finite volume pressure correction method for the solution of the Reynolds-averaged Navier-Stokes equations has been used to calculate the heat transfer rates on the end walls of a modern High Pressure Turbine first-stage stator. Surface heat transfer rates have been calculated at three conditions and compared with measurements made on a model of the vane tested in annular cascade in the Isentropic Light Piston Facility at DERA, Pyestock. The NGV Mach numbers, Reynolds numbers, and geometry are fully representative of engine conditions. Design condition data have previously been presented by Harvey and Jones (1990). Off-design data are presented here for the first time. In the areas of highest heat transfer, the calculated heat transfer rates are shown to be within 20% of the measured values at all three conditions. Particular emphasis is placed on the use of wall functions in the calculations with which relatively coarse grids (of around 140,000 nodes) can be used to keep computational run times sufficiently low for engine design purposes.

  7. 1992 Columbia River Salmon Flow Measures Options Analysis/EIS.

    SciTech Connect (OSTI)

    Not Available

    1992-01-01

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

  8. Device and method for measuring fluid flow in a conduit having a gradual bend

    DOE Patents [OSTI]

    Ortiz, M.G.; Boucher, T.J.

    1998-11-10

    A system is described for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.

  9. Device and method for measuring fluid flow in a conduit having a gradual bend

    DOE Patents [OSTI]

    Ortiz, Marcos German (Idaho Falls, ID); Boucher, Timothy J (Helena, MT)

    1998-01-01

    A system for measuring fluid flow in a conduit having a gradual bend or arc, and a straight section. The system includes pressure transducers, one or more disposed in the conduit on the outside of the arc, and one disposed in the conduit in a straight section thereof. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.

  10. Comparative Analysis of Natural Convection Flows Simulated by both the Conservation and Incompressible Forms of the Navier-Stokes Equations in a Differentially-Heated Square Cavity

    SciTech Connect (OSTI)

    Richard C. Martineau; Ray A. Berry; Aurélia Esteve; Kurt D. Hamman; Dana A. Knoll; Ryosuke Park; William Taitano

    2009-01-01

    This report illustrates a comparative study to analyze the physical differences between numerical simulations obtained with both the conservation and incompressible forms of the Navier-Stokes equations for natural convection flows in simple geometries. The purpose of this study is to quantify how the incompressible flow assumption (which is based upon constant density advection, divergence-free flow, and the Boussinesq gravitational body force approximation) differs from the conservation form (which only assumes that the fluid is a continuum) when solving flows driven by gravity acting upon density variations resulting from local temperature gradients. Driving this study is the common use of the incompressible flow assumption in fluid flow simulations for nuclear power applications in natural convection flows subjected to a high heat flux (large temperature differences). A series of simulations were conducted on two-dimensional, differentially-heated rectangular geometries and modeled with both hydrodynamic formulations. From these simulations, the selected characterization parameters of maximum Nusselt number, average Nusselt number, and normalized pressure reduction were calculated. Comparisons of these parameters were made with available benchmark solutions for air with the ideal gas assumption at both low and high heat fluxes. Additionally, we generated body force, velocity, and divergence of velocity distributions to provide a basis for further analysis. The simulations and analysis were then extended to include helium at the Very High Temperature gas-cooled Reactor (VHTR) normal operating conditions. Our results show that the consequences of incorporating the incompressible flow assumption in high heat flux situations may lead to unrepresentative results. The results question the use of the incompressible flow assumption for simulating fluid flow in an operating nuclear reactor, where large temperature variations are present. The results show that the use of the incompressible flow assumption with the Boussinesq gravitational body force approximation should be restricted to flows where the density change of a fluid particle along a pathline is negligible.

  11. Thorough approach to measurement uncertainty analysis applied to immersed heat exchanger testing

    SciTech Connect (OSTI)

    Farrington, R.B.; Wells, C.V.

    1986-04-01

    This paper discusses the value of an uncertainty analysis, discusses how to determine measurement uncertainty, and then details the sources of error in instrument calibration, data acquisition, and data reduction for a particular experiment. Methods are discussed to determine both the systematic (or bias) error in an experiment as well as to determine the random (or precision) error in the experiment. The detailed analysis is applied to two sets of conditions in measuring the effectiveness of an immersed coil heat exchanger. It shows the value of such analysis as well as an approach to reduce overall measurement uncertainty and to improve the experiment. This paper outlines how to perform an uncertainty analysis and then provides a detailed example of how to apply the methods discussed in the paper. The authors hope this paper will encourage researchers and others to become more concerned with their measurement processes and to report measurement uncertainty with all of their test results.

  12. Large-Eddy Simulation of Flow and Pollutant Transport in Urban Street Canyons with Ground Heating

    E-Print Network [OSTI]

    Li, Xian-Xiang

    Our study employed large-eddy simulation (LES) based on a one-equation subgrid-scale model to investigate the flow field and pollutant dispersion characteristics inside urban street canyons. Unstable thermal stratification ...

  13. Modeling Free Convection Flow of Liquid Hydrogen within a Cylindrical Heat Exchanger Cooled to 14 K

    E-Print Network [OSTI]

    Yang, S.W.; Oxford U.

    2004-01-01

    M. A. , “Comments on Liquid Hydrogen Absorbers for MICE,”Gas at 14 to 18 K and Liquid Hydrogen at 20 K circulated byFREE CONVECTION FLOW OF LIQUID HYDROGEN WITHIN A CYLINDRICAL

  14. Measure Guideline: Heat Pump Water Heaters in New and Existing Homes

    SciTech Connect (OSTI)

    Shapiro, C.; Puttagunta, S.; Owens, D.

    2012-02-01

    This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. This document is intended to explore the issues surrounding heat pump water heaters (HPWHs) to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Heat pump water heaters (HPWHs) promise to significantly reduce energy consumption for domestic hot water (DHW) over standard electric resistance water heaters (ERWHs). While ERWHs perform with energy factors (EFs) around 0.9, new HPWHs boast EFs upwards of 2.0. High energy factors in HPWHs are achieved by combining a vapor compression system, which extracts heat from the surrounding air at high efficiencies, with electric resistance element(s), which are better suited to meet large hot water demands. Swapping ERWHs with HPWHs could result in roughly 50% reduction in water heating energy consumption for 35.6% of all U.S. households. This Building America Measure Guideline is intended for builders, contractors, homeowners, and policy-makers. While HPWHs promise to significantly reduce energy use for DHW, proper installation, selection, and maintenance of HPWHs is required to ensure high operating efficiency and reliability. This document is intended to explore the issues surrounding HPWHs to ensure that homeowners and contractors have the tools needed to appropriately and efficiently install HPWHs. Section 1 of this guideline provides a brief description of HPWHs and their operation. Section 2 highlights the cost and energy savings of HPWHs as well as the variables that affect HPWH performance, reliability, and efficiency. Section 3 gives guidelines for proper installation and maintenance of HPWHs, selection criteria for locating HPWHs, and highlights of important differences between ERWH and HPWH installations. Throughout this document, CARB has included results from the evaluation of 14 heat pump water heaters (including three recently released HPWH products) installed in existing homes in the northeast region of the United States.

  15. PLASMA FLOWS AT VOYAGER 2 AWAY FROM THE MEASURED SUPRATHERMAL PRESSURES

    SciTech Connect (OSTI)

    McComas, D. J.; Schwadron, N. A.

    2014-11-01

    Plasma flows measured by Voyager 2 show a clear rotation away from radially outward with increasing penetration into the inner heliosheath while the overall flow speed remains roughly constant. However, the direction of rotation is far more into the transverse, and less into the polar direction, than predicted. No current model reproduces the key observational results of (1) the direction of flow rotation or (2) constancy of the flow speed. Here we show that the direction is consistent with flow away from the region of maximum pressure in the inner heliosheath, ?20° south of the upwind direction, as measured by the Interstellar Boundary Explorer (IBEX). Further, we show that the dominance of the suprathermal ion pressure in the inner heliosheath measured by IBEX can explain both the observed flow rotation and constancy of the flow speed. These results indicate the critical importance of suprathermal ions in the physics of the inner heliosheath and have significant implications for understanding this key region of the heliosphere's interstellar interaction and astrophysical plasmas more broadly.

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

    E-Print Network [OSTI]

    Ferrantelli, Andrea; Viljanen, Martti

    2013-01-01

    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.

  17. Measured heating system efficiency retrofits in eight manufactured (HUD-code) homes

    SciTech Connect (OSTI)

    Siegel, J.; Davis, B.; Francisco, P.; Palmiter, L.

    1998-07-01

    This report presents the results of field measurements of heating efficiency performed on eight all-electric manufactured homes sited in the Pacific Northwest with forced-air distribution systems. These homes, like more than four million existing manufactured homes in the US, were constructed to thermal specifications that were mandated by the US Department of Housing and Urban Development in 1976. The test protocol compares real-time measurements of furnace energy usage with energy usage during periods when zonal heaters heat the homes to the same internal temperature. By alternating between the furnace and zonal heaters on 2 hour cycles, a short-term coheat test is performed. Additional measurements, including blower door and duct tightness tests, are conducted to measure and characterize the home's tightness and duct leakage so that coheat test results might be linked to other measures of building performance. The testing was done at each home before and after an extensive duct sealing retrofit was performed. The average pre-retrofit system efficiency for these homes was 69%. After the retrofit, the average system efficiency increased to 83%. The average simple payback period for the retrofits ranges from 1 to 5 years in Western Oregon and 1 to 3 years in colder Eastern Oregon.

  18. Shock-Wave Heating Model for Chondrule Formation: Hydrodynamic Simulation of Molten Droplets exposed to Gas Flows

    E-Print Network [OSTI]

    Miura, H; Miura, Hitoshi; Nakamoto, Taishi

    2006-01-01

    Millimeter-sized, spherical silicate grains abundant in chondritic meteorites, which are called as chondrules, are considered to be a strong evidence of the melting event of the dust particles in the protoplanetary disk. One of the most plausible scenarios is that the chondrule precursor dust particles are heated and melt in the high-velocity gas flow (shock-wave heating model). We developed the non-linear, time-dependent, and three-dimensional hydrodynamic simulation code for analyzing the dynamics of molten droplets exposed to the gas flow. We confirmed that our simulation results showed a good agreement in a linear regime with the linear solution analytically derived by Sekiya et al. (2003). We found that the non-linear terms in the hydrodynamical equations neglected by Sekiya et al. (2003) can cause the cavitation by producing negative pressure in the droplets. We discussed that the fragmentation through the cavitation is a new mechanism to determine the upper limit of chondrule sizes. We also succeeded t...

  19. Can the frequency-dependent specific heat be measured by thermal effusion methods?

    E-Print Network [OSTI]

    Tage Christensen; Niels Boye Olsen; Jeppe C. Dyre

    2007-10-26

    It has recently been shown that plane-plate heat effusion methods devised for wide-frequency specific-heat spectroscopy do not give the isobaric specific heat, but rather the so-called longitudinal specific heat. Here it is shown that heat effusion in a spherical symmetric geometry also involves the longitudinal specific heat.

  20. Experimental investigation on heat transfer for two-phase flow under natural convection

    SciTech Connect (OSTI)

    Amizic, Milan; Guyez, Estelle; Seiler, Jean-Marie

    2012-07-01

    In the frame of severe accident research for the second and the third generation of nuclear power plants, some aspects of the concrete cavity ablation during the molten corium - concrete interaction are still remaining issues. The determination of heat transfer along the interfacial region between the molten corium pool and the ablating basemat concrete is crucial for the assessment of concrete ablation progression and eventually the basemat melt-through. For the purpose of experimental investigation of thermal-hydraulics inside a liquid pool agitated by gas bubbles, the CLARA project has been launched jointly by CEA, EDF, IRSN, GDF-Suez and SARNET. The CLARA experiments are performed using simulant materials and they reveal the influence of superficial gas velocity, liquid viscosity and pool geometry on the heat transfer coefficient between the internally heated liquid pool and vertical and horizontal pool walls maintained at uniform temperature. The first test campaign has been conducted with the smallest pool configuration (50 cm x 25 cm x 25 cm). The tests have been performed with liquids covering a wide range of dynamic viscosity from approximately 1 mPa s to 10000 mPa s. This paper presents some preliminary conclusions deduced from the experiments which involve a liquid pool with the gas injection only from the bottom plate. A comparison with existing models for the assessment of heat transfer has also been carried out. (authors)

  1. Application of a two-fluid model to simulate the heating of two-phase flows.

    E-Print Network [OSTI]

    Saleh, Khaled

    using an analytical solution. Eventually, a test case of the heating of a mixture of steam and water is presented, which is representative of a steam generator device. 1 Introduction Most of the industrial either as a coolant fluid or to ensure the production of mechanical work through the turbines which

  2. Simulation of three-dimensional laminar flow and heat transfer in an array of parallel microchannels 

    E-Print Network [OSTI]

    Mlcak, Justin Dale

    2009-05-15

    ranges from 50 to 400. A constant heat flux of 90 W/cm2 is applied to the northern face of the computational domain, which simulates thermal energy generation from an integrated circuit. A simplified model is validated against analytical fully developed...

  3. Study of Laminar Flow Forced Convection Heat Transfer Behavior of a Phase Change Material Fluid 

    E-Print Network [OSTI]

    Ravi, Gurunarayana

    2010-01-14

    takes into account the melting point and latent heat of fusion of the PCM as shown in Eq. (14) and (15). () ( ) ( ) b sl m p m f 1 2 Cp Cp c Cp 1 c Cp for T T== +? (19) () ( m emf 1 21 cL Cp 1 c Cp for T < T < T (T...

  4. Heat transfer enhancement for turbulent flow through blockages with elongated holes in a rectangular channel 

    E-Print Network [OSTI]

    Lee, Yonghee

    2007-09-17

    In this thesis, turbulent forced convective heat transfer downstream of blockages with elongated holes in a rectangular channel was studied. The rectangular channel has a width-to-height ratio of 12:1. The blockages have the same cross section...

  5. Lattice Boltzmann methods for multiphase flow and phase-change heat transfer

    E-Print Network [OSTI]

    Li, Qing; Kang, Q J; He, Y L; Chen, Q; Liu, Q

    2015-01-01

    Over the past few decades, tremendous progress has been made in the development of particle-based discrete simulation methods versus the conventional continuum-based methods. In particular, the lattice Boltzmann (LB) method has evolved from a theoretical novelty to a ubiquitous, versatile and powerful computational methodology for both fundamental research and engineering applications. It is a kinetic-based mesoscopic approach that bridges the microscales and macroscales, which offers distinctive advantages in simulation fidelity and computational efficiency. Applications of the LB method have been found in a wide range of disciplines including physics, chemistry, materials, biomedicine and various branches of engineering. The present work provides a comprehensive review of the LB method for thermofluids and energy applications, focusing on multiphase flows, thermal flows and thermal multiphase flows with phase change. The review first covers the theoretical framework of the LB method, revealing the existing ...

  6. Measurements of instantaneous heat flux to metal and ceramic surfaces in a diesel engine

    SciTech Connect (OSTI)

    Huang, J.C.; Borman, G.L.

    1987-02-01

    The effects of surface materials and extent of insulation on the heat transfer to the head of an open-chamber diesel were studied. A large instrumentation plug designed to incorporate plates of various materials on the gas-side surface was utilized with a special research head. Instantaneous rates of heat transfer to the plate gas-side surface were measured. Measurement results obtained with a zirconia plate and an insulated metal plate are compared to data for an inunsulated metal plate. The insulation of the metal plate increased its gas-side surface temperature over the uninsulated case by about the same amount achieved with a 6.35-mm-thick zirconia plate. The magnitude of the surface temperature swing for zirconia is not as high as expected from conduction theory, but is substantially higher than that for the uninsulated metal. Significant reductions of steady-state heat fluxes were achieved with both the zirconia and the insulated metal compared to the uninsulated metal.

  7. UNSAT-H Version 3.0: Unsaturated Soil Water and Heat Flow Model Theory, User Manual, and Examples

    SciTech Connect (OSTI)

    MJ Fayer

    2000-06-12

    The UNSAT-H model was developed at Pacific Northwest National Laboratory (PNNL) to assess the water dynamics of arid sites and, in particular, estimate recharge fluxes for scenarios pertinent to waste disposal facilities. During the last 4 years, the UNSAT-H model received support from the Immobilized Waste Program (IWP) of the Hanford Site's River Protection Project. This program is designing and assessing the performance of on-site disposal facilities to receive radioactive wastes that are currently stored in single- and double-shell tanks at the Hanford Site (LMHC 1999). The IWP is interested in estimates of recharge rates for current conditions and long-term scenarios involving the vadose zone disposal of tank wastes. Simulation modeling with UNSAT-H is one of the methods being used to provide those estimates (e.g., Rockhold et al. 1995; Fayer et al. 1999). To achieve the above goals for assessing water dynamics and estimating recharge rates, the UNSAT-H model addresses soil water infiltration, redistribution, evaporation, plant transpiration, deep drainage, and soil heat flow as one-dimensional processes. The UNSAT-H model simulates liquid water flow using Richards' equation (Richards 1931), water vapor diffusion using Fick's law, and sensible heat flow using the Fourier equation. This report documents UNSAT-H .Version 3.0. The report includes the bases for the conceptual model and its numerical implementation, benchmark test cases, example simulations involving layered soils and plants, and the code manual. Version 3.0 is an, enhanced-capability update of UNSAT-H Version 2.0 (Fayer and Jones 1990). New features include hysteresis, an iterative solution of head and temperature, an energy balance check, the modified Picard solution technique, additional hydraulic functions, multiple-year simulation capability, and general enhancements.

  8. Measuring solar reflectance - Part I: Defining a metric that accurately predicts solar heat gain

    SciTech Connect (OSTI)

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul [Heat Island Group, Environmental Energy Technologies Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720 (United States)

    2010-09-15

    Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective ''cool colored'' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland US latitudes, this metric R{sub E891BN} can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {<=} 5:12 [23 ]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool roof net energy savings by as much as 23%. We define clear sky air mass one global horizontal (''AM1GH'') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer. (author)

  9. Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain

    SciTech Connect (OSTI)

    Levinson, Ronnen; Akbari, Hashem; Berdahl, Paul

    2010-05-14

    Solar reflectance can vary with the spectral and angular distributions of incident sunlight, which in turn depend on surface orientation, solar position and atmospheric conditions. A widely used solar reflectance metric based on the ASTM Standard E891 beam-normal solar spectral irradiance underestimates the solar heat gain of a spectrally selective 'cool colored' surface because this irradiance contains a greater fraction of near-infrared light than typically found in ordinary (unconcentrated) global sunlight. At mainland U.S. latitudes, this metric RE891BN can underestimate the annual peak solar heat gain of a typical roof or pavement (slope {le} 5:12 [23{sup o}]) by as much as 89 W m{sup -2}, and underestimate its peak surface temperature by up to 5 K. Using R{sub E891BN} to characterize roofs in a building energy simulation can exaggerate the economic value N of annual cool-roof net energy savings by as much as 23%. We define clear-sky air mass one global horizontal ('AM1GH') solar reflectance R{sub g,0}, a simple and easily measured property that more accurately predicts solar heat gain. R{sub g,0} predicts the annual peak solar heat gain of a roof or pavement to within 2 W m{sup -2}, and overestimates N by no more than 3%. R{sub g,0} is well suited to rating the solar reflectances of roofs, pavements and walls. We show in Part II that R{sub g,0} can be easily and accurately measured with a pyranometer, a solar spectrophotometer or version 6 of the Solar Spectrum Reflectometer.

  10. FLIHY EXPERIMENTAL FACILITIES FOR STUDYING OPEN CHANNEL TURBULENT FLOWS AND HEAT TRANSFER

    E-Print Network [OSTI]

    California at Los Angeles, University of

    . The pump station is composed of two centrifugal pumps connected in parallel, capable of pumping 75 L/s of water at maximum speed. The pumps are individually controlled with variable speed inverters to allow feeds the fluid to the pumps. 3. Built-in diagnostics tools include the flow meter, thermocouples

  11. Effect of wall conduction on heat transfer for turbulent flow in a circular tube 

    E-Print Network [OSTI]

    Lin, Yie-Kuang

    1980-01-01

    ) then ~ y+) 1+ g-7 x? ~? CmR. ~&r I'g g x I, & " pig. p()c)} f so as tm Lr=b rnn ? y Z. C R?(v)e~P( ? P X ) ~ M o (14) 2 where P =1, b. = (i+1) w. m m, ' i i+1 + + F (x )= (1 ? exp(-P x ) }/P 0 Ill Itl + . +i + F, (x )= (x -iF, (x )}/P...") &)(. ? Gz & ( 0 0 (K, ( L ) Zi( ~ )+ Z, (" L ) K, ( L')j/ J (i+2-, 7. X )C. S Z X dX (23) Heat Exchan e Between the Fluid and the Solid Wall (i) Constant Heat Flux The following relations are applicable at the fluid-solid interface (24) Using Eq...

  12. Experimental Measurement of the Flow Field of Heavy Trucks

    SciTech Connect (OSTI)

    Fred Browand; Charles Radovich

    2005-05-31

    Flat flaps that enclose the trailer base on the sides and top are known to reduce truck drag and reduce fuel consumption. Such flapped-truck geometries have been studied in laboratory wind tunnels and in field tests. A recent review of wind tunnel data for a variety of truck geometries and flow Reynolds numbers show roughly similar values of peak drag reduction, but differ in the determination of the optimum flap angle. Optimum angles lie in the range 12 degrees-20 degrees, and may be sensitive to Reynolds number and truck geometry. The present field test is undertaken to provide additional estimates of the magnitude of the savings to be expected on a typical truck for five flap angles 10, 13, 16, 19, and 22 degrees. The flaps are constructed from a fiberglass-epoxy-matrix material and are one-quarter of the base width in length (about 61 cm, or 2 feet). They are attached along the rear door hinge lines on either side of the trailer, so that no gap appears at the joint between the flap and the side of the trailer The flap angle is adjusted by means of two aluminum supports. The present test is performed on the NASA Crows Landing Flight Facility at the northern end of the San Joaquin valley in California. The main runway is approximately 2400 meters in length, and is aligned approximately in a north-south direction The test procedure is to make a series of runs starting at either end of the runway. All runs are initiated under computer control to accelerate the truck to a target speed of 60 mph (96 6 km/hr), to proceed at the target speed for a fixed distance, and to decelerate at the far end of the runway. During a run, the broadcast fuel rate, the engine rpm, forward speed, elapsed time--as well as several other parameters (10 in all)--are digitized at a rate of 100 digitizations per second. Various flapped-conditions are interspersed with the ''no flaps'' control, and are sequenced in a different order on different days. Approximately 310 runs are accumulated over the 5-day test period, May 17-21, 2004. The runway slopes rather uniformly upward from north-to-south. Over the distance of 2424 meters between our two ''start'' markers at either end of the runway, the net change in elevation is a little over ten meters. Test results clearly show the greater fuel consumption required to lift the truck against gravity in the southbound direction For this reason, it is important that the tests be averaged over a round trip circuit--that is, a run in both directions over the identical portion of the roadway. Northbound-southbound averages require an overlap segment of the runway (near the middle of the runway) where the truck--starting from either end--has achieved its target speed. For the target truck speed of 60 mph, this overlap region is approximately 700 meters in length. Typically a run and the return run are accomplished within a time interval of 6 minutes. Analysis of the data show fuel consumption savings at all flap angle settings tested, when compared to the ''no flaps'' condition. The most beneficial flap angle appears to be 13 degrees, for which the fuel consumption is 0.3778 {+-} 0.0025 liters/km compared to the ''no flaps'' control of 0.3941 {+-} 0.0034 liters/km. The error bounds expressed above mark the 99% confidence interval in the mean values given. That is, additional estimates of the mean fuel consumption would be expected to lie within the bounds given, approximately 99% of the time. The fuel consumption saving is--to reasonable accuracy--about 1.63 liters/100 kilometers. These savings represent the increment associated only with the change in drag due to the presence or absence of flaps. The result will hold for any truck of similar size and shape and engine performance regardless of the loading of the truck or the rolling resistance. The economy achieved by use of base flaps can be compared to the economy resulting from driving two trucks in a tandem configuration. In December 2003, such fuel consumption tests were performed at the same Crows Landing testsite. In the tests, two identical trucks are ope

  13. Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb:YAG

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Direct and absolute temperature mapping and heat transfer measurements in diode-end-pumped Yb and heat sink grease respectively). The dynamics of thermal effects is also presented. PACS 42.55.Xi (Diode-pumped in a diode-end-pumped Yb:YAG crystal, using a calibrated infrared camera, with a 60-µm spatial resolution

  14. Measured Space Conditioning and Water Heating Performance of a Ground-Source Integrated Heat Pump in a Residential Application

    SciTech Connect (OSTI)

    Munk, Jeffrey D [ORNL] [ORNL; Ally, Moonis Raza [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL; Gehl, Anthony C [ORNL] [ORNL

    2014-01-01

    In an effort to reduce residential building energy consumption, a ground-source integrated heat pump was developed to meet a home s entire space conditioning and water heating needs, while providing 50% energy savings relative to a baseline suite of minimum efficiency equipment. A prototype 7.0 kW system was installed in a 344 m2 research house with simulated occupancy in Oak Ridge, TN. The equipment was monitored from June 2012 through January 2013.

  15. A study of the Oklahoma City urban heat island using ground measurements and remote sensing

    SciTech Connect (OSTI)

    Brown, M. J. (Michael J.); Ivey, A. (Austin); McPherson, T. N. (Timothy N.); Boswell, D. (David); Pardyjak, E. R. (Eric R.)

    2004-01-01

    Measurements of temperature and position were collected during the night from an instrumented van on routes through Oklahoma City and the rural outskirts. The measurements were taken as part of the Joint URBAN 2003 Tracer Field Experiment conducted in Oklahoma City from June 29, 2003 to July 30, 2003 (Allwine et al., 2004). The instrumented van was driven over four primary routes that included legs from the downtown core to four different 'rural' areas. Each route went through residential areas and most often went by a line of permanently fixed temperature probes (Allwine et al., 2004) for cross-checking purposes. Each route took from 20 to 40 minutes to complete. Based on seven nights of data, initial analyses indicate that there was a temperature difference of 0.5-6.5 C between the urban core and nearby 'rural' areas. Analyses also suggest that there were significant fine scale temperature differences over distances of tens of meters within the city and in the nearby rural areas. The temperature measurements that were collected are intended to supplement the meteorological measurements taken during the Joint URBAN 2003 Field Experiment, to assess the importance of the urban heat island phenomenon in Oklahoma City, and to test new urban canopy parameterizations that have been developed for regional scale meteorological codes (e.g., Chin et al., 2000; Holt and Shi, 2004). In addition to the ground measurements, skin temperature measurements were also analyzed from remotely sensed images taken from the Earth Observing System's Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER). A surface kinetic temperature thermal infrared image captured by the ASTER of the Oklahoma City area on July 21, 2001 was analyzed within ESRI's ArcGIS 8.3 to correlate variations in temperature with land use type. Analysis of this imagery suggests distinct variations in temperature across different land use categories. Through the use of remotely sensed imagery we hope to better understand the development of the urban heat island analysis.

  16. Measurements of continuous mix evolution in a high energy density shear flow

    SciTech Connect (OSTI)

    Loomis, E. Doss, F.; Flippo, K.; Fincke, J.

    2014-04-15

    We report on the novel integration of streaked radiography into a counter-flowing High Energy Density (HED) shear environment that continually measures a growing mix layer of Al separating two low-density CH foams. Measurements of the mix width allow us to validate compressible turbulence models and with streaked imaging, make this possible with a minimal number of experiments on large laser facilities. In this paper, we describe how the HED counter-flowing shear layer is created and diagnosed with streaked radiography. We then compare the streaked data to previous two-dimensional, single frame radiography and radiation hydrodynamic simulations of the experiment with inline compressible turbulent mix models.

  17. Rotor bore and turbine rotor wheel/spacer heat exchange flow circuit

    DOE Patents [OSTI]

    Caruso, Philip M. (Selkirk, NY); Eldrid, Sacheverel Quentin (Saratoga Springs, NY); Ladhani, Azad A. (Niskayuna, NY); DeMania, Alan Richard (Niskayuna, NY); Palmer, Gene David (Clifton Park, NY); Wilson, Ian David (Clifton Park, NY); Rathbun, Lisa Shirley (Scotia, NY); Akin, Robert Craig (Schenectady, NY)

    2002-01-01

    In a turbine having closed-circuit steam-cooling passages about the rim of the rotor during steady-state operation, compressor discharge air is supplied to the rotor bore for passage radially outwardly into the wheel space cavities between the wheels and spacers. Communicating slots and channels in the spacers and wheels at circumferentially spaced positions enable egress of the compressor discharge air into the hot gas flow path. At turbine startup, cooling air flows through the closed-circuit steam passages to cool the outer rim of the rotor while compressor discharge air pre-warms the wheels and spacers. At steady-state, cooling steam is supplied in the closed-circuit steam-cooling passages and compressor discharge air is supplied through the bore and into the wheel space cavities to cool the rotor.

  18. Numerical simulation of flow and heat transfer of internal cooling passage in gas turbine blade 

    E-Print Network [OSTI]

    Su, Guoguang

    2007-04-25

    for efficient energy utilization; one of the most powerful means of achieving higher efficiency in industrial gas turbine engines is to raise the turbine inlet temperature (TIT). Sophisticated cooling techniques must be employed to cool the components... for momentum, energy, and turbulence quantities are solved in curvilinear, body-fitted coordinates using the finite-analytic method. 2.1 The Governing Equation and Chimera Method For unsteady incompressible flow, the continuty equation and momentum...

  19. Heating rate and electrode charging measurements in a scalable, microfabricated, surface-electrode ion trap

    E-Print Network [OSTI]

    D. T. C. Allcock; T. P. Harty; H. A. Janacek; N. M. Linke; C. J. Ballance; A. M. Steane; D. M. Lucas; R. L. Jarecki Jr.; S. D. Habermehl; M. G. Blain; D. Stick; D. L. Moehring

    2011-05-24

    We characterise the performance of a surface-electrode ion "chip" trap fabricated using established semiconductor integrated circuit and micro-electro-mechanical-system (MEMS) microfabrication processes which are in principle scalable to much larger ion trap arrays, as proposed for implementing ion trap quantum information processing. We measure rf ion micromotion parallel and perpendicular to the plane of the trap electrodes, and find that on-package capacitors reduce this to heating rate for a single trapped ion. The performance of this trap is found to be comparable with others of the same size scale.

  20. Macro-to-microchannel transition in two-phase flow: Part 1 - Two-phase flow patterns and film thickness measurements

    SciTech Connect (OSTI)

    Ong, C.L.; Thome, J.R. [Ecole Polytechnique Federale de Lausanne, EPFL-STI-IGM-LTCM, Station 9, CH-1015 Lausanne (Switzerland)

    2011-01-15

    The classification of macroscale, mesoscale and microscale channels with respect to two-phase processes is still an open question. The main objective of this study focuses on investigating the macro-to-microscale transition during flow boiling in small scale channels of three different sizes with three different refrigerants over a range of saturation conditions to investigate the effects of channel confinement on two-phase flow patterns and liquid film stratification in a single circular horizontal channel (Part 2 covers the flow boiling heat transfer and critical heat flux). This paper presents the experimental two-phase flow pattern transition data together with a top/bottom liquid film thickness comparison for refrigerants R134a, R236fa and R245fa during flow boiling in small channels of 1.03, 2.20 and 3.04 mm diameter. Based on this work, an improved flow pattern map has been proposed by determining the flow patterns transitions existing under different conditions including the transition to macroscale slug/plug flow at a confinement number of Co {approx} 0.3-0.4. From the top/bottom liquid film thickness comparison results, it was observed that the gravity forces are fully suppressed and overcome by the surface tension and shear forces when the confinement number approaches 1, Co {approx} 1. Thus, as a new approximate rule, the lower threshold of macroscale flow is Co = 0.3-0.4 while the upper threshold of symmetric microscale flow is Co {approx} 1 with a transition (or mesoscale) region in-between. (author)

  1. Meridional flow in the solar convection zone. I. Measurements from gong data

    SciTech Connect (OSTI)

    Kholikov, S. [National Solar Observatories, Tucson, AZ 85719 (United States); Serebryanskiy, A. [Ulugh Beg Astronomical Institute, Uzbek Academy of Science, Tashkent 100052 (Uzbekistan); Jackiewicz, J., E-mail: kholikov@noao.edu [Department of Astronomy, New Mexico State University, Las Cruces, NM 88003 (United States)

    2014-04-01

    Large-scale plasma flows in the Sun's convection zone likely play a major role in solar dynamics on decadal timescales. In particular, quantifying meridional motions is a critical ingredient for understanding the solar cycle and the transport of magnetic flux. Because the signal of such features can be quite small in deep solar layers and be buried in systematics or noise, the true meridional velocity profile has remained elusive. We perform time-distance helioseismology measurements on several years worth of Global Oscillation Network Group Doppler data. A spherical harmonic decomposition technique is applied to a subset of acoustic modes to measure travel-time differences to try to obtain signatures of meridional flows throughout the solar convection zone. Center-to-limb systematics are taken into account in an intuitive yet ad hoc manner. Travel-time differences near the surface that are consistent with a poleward flow in each hemisphere and are similar to previous work are measured. Additionally, measurements in deep layers near the base of the convection zone suggest a possible equatorward flow, as well as partial evidence of a sign change in the travel-time differences at mid-convection zone depths. This analysis on an independent data set using different measurement techniques strengthens recent conclusions that the convection zone may have multiple 'cells' of meridional flow. The results may challenge the common understanding of one large conveyor belt operating in the solar convection zone. Further work with helioseismic inversions and a careful study of systematic effects are needed before firm conclusions of these large-scale flow structures can be made.

  2. Heat Transfer and Pressure Drop Measurement for Square Channels with V-shape Ribs at High Reynolds Numbers 

    E-Print Network [OSTI]

    Alkhamis, Nawaf Yahya

    2010-10-12

    for the degree of MASTER OF SCIENCE August 2009 Major Subject: Mechanical Engineering HEAT TRANSFER AND PRESSURE DROP MEASUREMENT FOR SQUARE CHANNELS WITH V-SHAPE RIBS AT HIGH REYNOLDS NUMBERS A Thesis by NAWAF YAHYA ALKHAMIS... of Department, Dennis O?Neal August 2009 Major Subject: Mechanical Engineering iii ABSTRACT Heat Transfer and Pressure Drop Measurement for Square Channels with V-shape Ribs at High Reynolds Numbers. (August 2009) Nawaf Yahya Alkhamis, B.Sc King...

  3. Measurement of Flow Phenomena in a Lower Plenum Model of a Prismatic Gas-Cooled Reactor

    SciTech Connect (OSTI)

    Hugh M. McIlroy, Jr.; Donald M. McEligot; Robert J. Pink

    2008-05-01

    Mean-velocity-field and turbulence data are presented that measure turbulent flow phenomena in an approximately 1:7 scale model of a region of the lower plenum of a typical prismatic gas-cooled reactor (GCR) similar to a General Atomics Gas-Turbine-Modular Helium Reactor (GTMHR) design. The data were obtained in the Matched-Index-of-Refraction (MIR) facility at Idaho National Laboratory (INL) and are offered for assessing computational fluid dynamics (CFD) software. This experiment has been selected as the first Standard Problem endorsed by the Generation IV International Forum. This paper reviews the experimental apparatus and procedures, presents a sample of the data set, and reviews the INL Standard Problem. Results concentrate on the region of the lower plenum near its far reflector wall (away from the outlet duct). The flow in the lower plenum consists of multiple jets injected into a confined cross flow - with obstructions. The model consists of a row of full circular posts along its centerline with half-posts on the two parallel walls to approximate flow scaled to that expected from the staggered parallel rows of posts in the reactor design. The model is fabricated from clear, fused quartz to match the refractive-index of the mineral oil working fluid so that optical techniques may be employed for the measurements. The benefit of the MIR technique is that it permits optical measurements to determine flow characteristics in complex passages in and around objects to be obtained without locating intrusive transducers that will disturb the flow field and without distortion of the optical paths. An advantage of the INL system is its large size, leading to improved spatial and temporal resolution compared to similar facilities at smaller scales. A three-dimensional (3-D) Particle Image Velocimetry (PIV) system was used to collect the data. Inlet jet Reynolds numbers (based on the jet diameter and the time-mean average flow rate) are approximately 4,300 and 12,400. Uncertainty analysis and a discussion of the standard problem are included. The measurements reveal undeveloped, non-uniform, turbulent flow in the inlet jets and complicated flow patterns in the model lower plenum. Data include three-dimensional vector plots, data displays along the coordinate planes (slices) and presentations that describe the component flows at specific regions in the model. Information on inlet conditions are also presented.

  4. Measurement of gas species, temperatures, coal burnout, and wall heat fluxes in a 200 MWe lignite-fired boiler with different overfire air damper openings

    SciTech Connect (OSTI)

    Jianping Jing; Zhengqi Li; Guangkui Liu; Zhichao Chen; Chunlong Liu

    2009-07-15

    Measurements were performed on a 200 MWe, wall-fired, lignite utility boiler. For different overfire air (OFA) damper openings, the gas temperature, gas species concentration, coal burnout, release rates of components (C, H, and N), furnace temperature, and heat flux and boiler efficiency were measured. Cold air experiments for a single burner were conducted in the laboratory. The double-swirl flow pulverized-coal burner has two ring recirculation zones starting in the secondary air region in the burner. As the secondary air flow increases, the axial velocity of air flow increases, the maxima of radial velocity, tangential velocity and turbulence intensity all increase, and the swirl intensity of air flow and the size of recirculation zones increase slightly. In the central region of the burner, as the OFA damper opening widens, the gas temperature and CO concentration increase, while the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and coal particles ignite earlier. In the secondary air region of the burner, the O{sub 2} concentration, NOx concentration, coal burnout, and release rates of components (C, H, and N) decrease, and the gas temperature and CO concentration vary slightly. In the sidewall region, the gas temperature, O{sub 2} concentration, and NOx concentration decrease, while the CO concentration increases and the gas temperature varies slightly. The furnace temperature and heat flux in the main burning region decrease appreciably, but increase slightly in the burnout region. The NOx emission decreases from 1203.6 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 0% to 511.7 mg/m{sup 3} (6% O{sub 2}) for a damper opening of 80% and the boiler efficiency decreases from 92.59 to 91.9%. 15 refs., 17 figs., 3 tabs.

  5. Industrial Waste Heat Recovery Using Heat Pipes 

    E-Print Network [OSTI]

    Ruch, M. A.

    1981-01-01

    For almost a decade now, heat pipes with secondary finned surfaces have been utilized in counter flow heat exchangers to recover sensible energy from industrial exhaust gases. Over 3,000 such heat exchangers are now in service, recovering...

  6. Comparison of electrical capacitance tomography and gamma densitometer measurement in viscous oil-gas flows

    SciTech Connect (OSTI)

    Archibong Eso, A.; Zhao, Yabin; Yeung, Hoi

    2014-04-11

    Multiphase flow is a common occurrence in industries such as nuclear, process, oil and gas, food and chemical. A prior knowledge of its features and characteristics is essential in the design, control and management of such processes due to its complex nature. Electrical Capacitance Tomography (ECT) and Gamma Densitometer (Gamma) are two promising approaches for multiphase visualization and characterization in process industries. In two phase oil and gas flow, ECT and Gamma are used in multiphase flow monitoring techniques due to their inherent simplicity, robustness, and an ability to withstand wide range of operational temperatures and pressures. High viscous oil (viscosity > 100 cP) is of interest because of its huge reserves, technological advances in its production and unlike conventional oil (oil viscosity < 100 cP) and gas flows where ECT and Gamma have been previously used, high viscous oil and gas flows comes with certain associated concerns which include; increased entrainment of gas bubbles dispersed in oil, shorter and more frequent slugs as well as oil film coatings on the walls of flowing conduits. This study aims to determine the suitability of both devices in the visualization and characterization of high-viscous oil and gas flow. Static tests are performed with both devices and liquid holdup measurements are obtained. Dynamic experiments were also conducted in a 1 and 3 inch facility at Cranfield University with a range of nominal viscosities (1000, 3000 and 7500 cP). Plug, slug and wavy annular flow patterns were identified by means of Probability Mass Function and time series analysis of the data acquired from Gamma and ECT devices with high speed camera used to validate the results. Measured Liquid holdups for both devices were also compared.

  7. Measuring solar reflectance Part I: Defining a metric that accurately predicts solar heat gain

    E-Print Network [OSTI]

    Levinson, Ronnen

    2010-01-01

    z = 60 ? ) based on prediction of annual peak solar heatgain, prediction of annual mean solar heat gain, andFirst criterion: prediction of annual peak solar heat gain.

  8. Measurement of the three-dimensional tip region flow field in an axial compressor

    SciTech Connect (OSTI)

    Stauter, R.C. )

    1993-07-01

    A two-color, five-beam LDV system has been configured to make simultaneous three-component velocity measurements of the flow field in a two-stage axial compressor model. The system has been used to make time-resolved measurements both between compressor blade rows and within the rotating blade passages in an axial compressor. The data show the nature and behavior of the complex, three-dimensional flow phenomena present in the tip region of a compressor as the convect downstream. In particular, the nature of the tip leakage vortex is apparent, being manifested by high blockage as well as the expected vortical motion. The data indicate that the radial flows associated with the tip leakage vortex begin to decrease while within the rotor passage, and that they temporarily increase aft of the passage.

  9. Measurements of excess heat from a Pons-Fleischmann type electrolytic cell using palladium sheet

    SciTech Connect (OSTI)

    Storms, E.K.

    1992-09-01

    Two pieces of palladium sheet were loaded with deuterium in a Pons-Fleischmann type electrolytic cell and measurements were made of heat production. One sheet produced a steady increase in excess power that reached 7.5 watts (20% of input power) before the study was interrupted. A second similar sheet from a different batch of palladium did not produce any measurable excess power. There was a difference between the loading behavior, the maximum stoichiometry, and the presence of excess volume in the deuteride made from these materials. The first sheet contained 0.8% excess volume after deloading from D/Pd=0.82 to D/Pd=0.73, and the second sheet contained 13.5 % excess volume while at D/Pd=0.75. The high excess volume in the latter case is an indication of internal cracks.

  10. Measurements of excess heat from a Pons-Fleischmann type electrolytic cell using palladium sheet

    SciTech Connect (OSTI)

    Storms, E.K.

    1992-01-01

    Two pieces of palladium sheet were loaded with deuterium in a Pons-Fleischmann type electrolytic cell and measurements were made of heat production. One sheet produced a steady increase in excess power that reached 7.5 watts (20% of input power) before the study was interrupted. A second similar sheet from a different batch of palladium did not produce any measurable excess power. There was a difference between the loading behavior, the maximum stoichiometry, and the presence of excess volume in the deuteride made from these materials. The first sheet contained 0.8% excess volume after deloading from D/Pd=0.82 to D/Pd=0.73, and the second sheet contained 13.5 % excess volume while at D/Pd=0.75. The high excess volume in the latter case is an indication of internal cracks.

  11. Wake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa)

    E-Print Network [OSTI]

    Liepmann, Dorian

    counterpart is made by a drag correction factor, K FD 6 0aUt , 3 where FD is the drag force on the sphere which balances the force due to gravity, ( s f)*( 4 3 ga3 ). The drag correc- tion factor is, in generalWake measurements for flow around a sphere in a viscoelastic fluid Drazen Fabrisa) Department

  12. THEMIS observations of a hot flow anomaly: Solar wind, magnetosheath, and ground-based measurements

    E-Print Network [OSTI]

    Mende, Stephen B.

    solar wind, and it has been suggested that they have a significant impact on the mag- netosphere [eTHEMIS observations of a hot flow anomaly: Solar wind, magnetosheath, and ground-based measurements and the subsequent downstream response. THEMIS-A, in the solar wind, observed classic HFA signatures. Isotropic

  13. advertisement | your ad herePrint This Article Back to Robots measure flow of Sacramento

    E-Print Network [OSTI]

    advertisement | your ad herePrint This Article Back to Article Robots measure flow of Sacramento River David Perlman Wednesday, May 9, 2012 A fleet of 100 robots floated down the Sacramento River, demonstrating their ability to navigate the water route from their launch site at Walnut Grove (Sacramento

  14. Aero-Optical and Flow Measurements Over a Flat-Windowed Turret

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    Aero-Optical and Flow Measurements Over a Flat-Windowed Turret Stanislav Gordeyev University the aircraft, referred to as the aero-optic problem [1], and the intervening, orders- propagation effects on the beam; however, both the spatial and temporal bandwidths of the aero-optic problem

  15. Measurements of ship-induced flow and its effect on bank erosion 

    E-Print Network [OSTI]

    Yu, Hongbin

    1997-01-01

    for prediction of drawdown and return velocity. The ship induced waves model is verified with field measurements. The method of energy computation for ship induced flow is developed in order to determine its relative contribution to bank erosion. In this study...

  16. Aerodynamic pressure and flow-visualization measurement from a rotating wind turbine blade

    SciTech Connect (OSTI)

    Butterfield, C.P.

    1988-11-01

    Aerodynamic, load, flow-visualization, and inflow measurements have been made on a 10-m, three-bladed, downwind, horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor was used to record nighttime and daytime video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted at every 10% of the blade's span. Pressure measurements were made at 80% of the blade's span. Pressure taps were located at 32 chordwise positions, revealing pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. One objective of this comprehensive research program was to study the effects of blade rotation on aerodynamic behavior below, near, and beyond stall. To this end, flow patterns are presented here that reveal the dynamic and steady behavior of flow conditions on the blade. Pressure distributions are compared to flow patterns and two-dimensional wind tunnel data. Separation boundary locations are shown that change as a function of spanwise location, pitch angle, and wind speed. 6 refs., 23 figs., 1 tab.

  17. Interplay between Dephasing and Geometry and Directed Heat Flow in Exciton Transfer Complexes

    E-Print Network [OSTI]

    Dubi, Yonatan

    2015-01-01

    The striking efficiency of energy transfer in natural photosynthetic systems and the recent evidence of long-lived quantum coherence in biological light harvesting complexes has triggered much excitement, due to the evocative possibility that these systems - essential to practically all life on earth -- use quantum mechanical effects to achieve optimal functionality. A large body of theoretical work has addressed the role of local environments in determining the transport properties of excitons in photosynthetic networks and the survival of quantum coherence in a classical environment. Nonetheless, understanding the connection between quantum coherence, exciton network geometry and energy transfer efficiency remains a challenge. Here we address this connection from the perspective of heat transfer within the exciton network. Using a non-equilibrium open quantum system approach and focusing on the Fenna-Matthews-Olson complex, we demonstrate that finite local dephasing can be beneficial to the overall power ou...

  18. Heat Transfer Characteristics of Sulfur and Sulfur Diluted with Hydrogen Sulfide Flowing Through Circular Tubes 

    E-Print Network [OSTI]

    Stone, Porter Walwyn

    1960-01-01

    is the tube length. Letting q = q, to obtain a relationship for equivalent heat transfer, gives h d L 6t s w w w h d L ht W s s s Substituting into the equation above, 0. 8 d 0. 2 w w w =H s w d L 0. 8d 0. 2 s s s v w s This may be simpbified... isolated. The derivation of the "geometry relationship" follows that outlined in the previous section. h ? 1 30087 d ~P c ql/3 k x 0 023 v 0. 8 d -0. 2 pr -2/3 ( ~) -0. 2 (Io w'ww wow wpw 0 3354 ( P ) 1/3 k 2/3 Pr 0/3 ( P) 0. 2 1/3d -1/3 s s s s w...

  19. Experimental studies on heat transfer and friction factor characteristics of Al{sub 2}O{sub 3}/water nanofluid in a circular pipe under laminar flow with wire coil inserts

    SciTech Connect (OSTI)

    Chandrasekar, M.; Suresh, S. [Department of Mechanical Engineering, National Institute of Technology, Tiruchirappalli 620015 (India); Chandra Bose, A. [Nanomaterials Laboratory, Department of Physics, National Institute of Technology, Tiruchirappalli 620015 (India)

    2010-02-15

    In this paper, fully developed laminar flow convective heat transfer and friction factor characteristics of Al{sub 2}O{sub 3}/water nanofluid flowing through a uniformly heated horizontal tube with and without wire coil inserts is presented. For this purpose, Al{sub 2}O{sub 3} nanoparticles of 43 nm size were synthesized, characterized and dispersed in distilled water to form stable suspension containing 0.1% volume concentration of nanoparticles. The Nusselt number in the fully developed region were measured and found to increase by 12.24% at Re = 2275 for plain tube with nanofluid compared to distilled water. Two wire coil inserts made of stainless steel with pitch ratios 2 and 3 were used which increased the Nusselt numbers by 15.91% and 21.53% respectively at Re = 2275 with nanofluid compared to distilled water. The better heat transfer performance of nanofluid with wire coil insert is attributed to the effects of dispersion or back-mixing which flattens the temperature distribution and make the temperature gradient between the fluid and wall steeper. The measured pressure loss with the use of nanofluids is almost equal to that of the distilled water. The empirical correlations developed for Nusselt number and friction factor in terms of Reynolds/Peclet number, pitch ratio and volume concentration fits with the experimental data within {+-}15%. (author)

  20. Petrophysical analysis of regional-scale thermal properties for improved simulations of geothermal installations and basin-scale heat and fluid flow

    E-Print Network [OSTI]

    Hartmann, Andreas; Clauser, Christoph

    2008-01-01

    Development of geothermal energy and basin-scale simulations of fluid and heat flow both suffer from uncertain physical rock properties at depth. Therefore, building better prognostic models are required. We analysed hydraulic and thermal properties of the major rock types in the Molasse Basin in Southern Germany. On about 400 samples thermal conductivity, density, porosity, and sonic velocity were measured. Here, we propose a three-step procedure with increasing complexity for analysis of the data set: First, univariate descriptive statistics provides a general understanding of the data structure, possibly still with large uncertainty. Examples show that the remaining uncertainty can be as high as 0.8 W/(m K) or as low as 0.1 W/(m K). This depends on the possibility to subdivide the geologic units into data sets that are also petrophysically similar. Then, based on all measurements, cross-plot and quick-look methods are used to gain more insight into petrophysical relationships and to refine the analysis. Be...

  1. User's Guide of TOUGH2-EGS. A Coupled Geomechanical and Reactive Geochemical Simulator for Fluid and Heat Flow in Enhanced Geothermal Systems Version 1.0

    SciTech Connect (OSTI)

    Fakcharoenphol, Perapon; Xiong, Yi; Hu, Litang; Winterfeld, Philip H.; Xu, Tianfu; Wu, Yu-Shu

    2013-05-01

    TOUGH2-EGS is a numerical simulation program coupling geomechanics and chemical reactions for fluid and heat flows in porous media and fractured reservoirs of enhanced geothermal systems. The simulator includes the fully-coupled geomechanical (THM) module, the fully-coupled geochemical (THC) module, and the sequentially coupled reactive geochemistry (THMC) module. The fully-coupled flow-geomechanics model is developed from the linear elastic theory for the thermo-poro-elastic system and is formulated with the mean normal stress as well as pore pressure and temperature. The chemical reaction is sequentially coupled after solution of flow equations, which provides the flow velocity and phase saturation for the solute transport calculation at each time step. In addition, reservoir rock properties, such as porosity and permeability, are subjected to change due to rock deformation and chemical reactions. The relationships between rock properties and geomechanical and chemical effects from poro-elasticity theories and empirical correlations are incorporated into the simulator. This report provides the user with detailed information on both mathematical models and instructions for using TOUGH2-EGS for THM, THC or THMC simulations. The mathematical models include the fluid and heat flow equations, geomechanical equation, reactive geochemistry equations, and discretization methods. Although TOUGH2-EGS has the capability for simulating fluid and heat flows coupled with both geomechanical and chemical effects, it is up to the users to select the specific coupling process, such as THM, THC, or THMC in a simulation. There are several example problems illustrating the applications of this program. These example problems are described in details and their input data are presented. The results demonstrate that this program can be used for field-scale geothermal reservoir simulation with fluid and heat flow, geomechanical effect, and chemical reaction in porous and fractured media.

  2. Measurement Of The Fluid Flow Load On A Globe Valve Stem Under Various Cavitation Conditions

    E-Print Network [OSTI]

    Ferrari, Jerome

    2009-01-01

    The evaluation of fluid forces on the stem is important for wear prediction of valve and actuator guidance parts. While estimating the axial load is straight forward, estimating and/or measuring the side load is more difficult, especially for globe valves. Therefore, measurements are carried out on an ad hoc, scale 1, model of a 2" globe valve. The body is replicated in Plexiglas to enable flow visualization and the original stem is heavily instrumented to allow force measurements in every direction. The flow loop facility used for this experiment is designed to allow fine-tuning of the cavitation intensity. The experiment is run for a set of cavitation conditions, flow rates and disc positions. The results show that the transverse force (perpendicular to the stem) can reach the order of the axial force; thus it should not be ignored. We also observed that it depends very weakly on the cavitation levels. Videos made with a high-speed camera allow an interesting understanding of the fluid flow and the cavitati...

  3. Mass flow rate measurements in gas-liquid flows by means of a venturi or orifice plate coupled to a void fraction sensor

    SciTech Connect (OSTI)

    Oliveira, Jorge Luiz Goes; Passos, Julio Cesar [Departamento de Engenharia Mecanica-LEPTEN/Boiling-UFSC, Campus Universitario, Trindade, 88.040-900 Florianopolis-SC (Brazil); Verschaeren, Ruud; Geld, Cees van der [Eindhoven University of Technology, Faculty of Mechanical Engineering, W-hoog 2.135, P.O. Box 513, 5600 MB, Eindhoven (Netherlands)

    2009-01-15

    Two-phase flow measurements were carried out using a resistive void fraction meter coupled to a venturi or orifice plate. The measurement system used to estimate the liquid and gas mass flow rates was evaluated using an air-water experimental facility. Experiments included upward vertical and horizontal flow, annular, bubbly, churn and slug patterns, void fraction ranging from 2% to 85%, water flow rate up to 4000 kg/h, air flow rate up to 50 kg/h, and quality up to almost 10%. The fractional root mean square (RMS) deviation of the two-phase mass flow rate in upward vertical flow through a venturi plate is 6.8% using the correlation of Chisholm (D. Chisholm, Pressure gradients during the flow of incompressible two-phase mixtures through pipes, venturis and orifice plates, British Chemical Engineering 12 (9) (1967) 454-457). For the orifice plate, the RMS deviation of the vertical flow is 5.5% using the correlation of Zhang et al. (H.J. Zhang, W.T. Yue, Z.Y. Huang, Investigation of oil-air two-phase mass flow rate measurement using venturi and void fraction sensor, Journal of Zhejiang University Science 6A (6) (2005) 601-606). The results show that the flow direction has no significant influence on the meters in relation to the pressure drop in the experimental operation range. Quality and slip ratio analyses were also performed. The results show a mean slip ratio lower than 1.1, when bubbly and slug flow patterns are encountered for mean void fractions lower than 70%. (author)

  4. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    such as the urban heat island and increase in urban energyloads and the urban heat island-the effects of albedo,modeling of urban heat islands. Final report prepared by

  5. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    loads and the urban heat island-the effects of albedo,modeling of urban heat islands. Final report prepared byeffects such as the urban heat island and increase in urban

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

    E-Print Network [OSTI]

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

    2006-01-01

    two-phase zone, is the heat-pipe (i.e. , a zone of constant4a), when there is a heat pipe just above the emplacementduring ventilation, the heat-pipe signature is absent in

  7. Large eddy simulation of atmospheric boundary layer flow in urban terrain : implications for transport of pollution and heat

    E-Print Network [OSTI]

    Sun, Long

    2011-01-01

    loads and the urban heat island-the effects of albedo,modeling of urban heat islands. Final report prepared byespecially the urban heat island (UHI) and urban air

  8. Mitigation Measures Following a Loss-of-Residual-Heat-Removal Event During Shutdown

    SciTech Connect (OSTI)

    Seul, Kwang Won; Bang, Young Seok; Kim, Hho Jung

    2000-10-15

    The transient following a loss-of-residual-heat-removal event during shutdown was analyzed to determine the containment closure time (CCT) to prevent uncontrolled release of fission products and the gravity-injection path and rate (GIPR) for effective core cooling using the RELAP5/MOD3.2 code. The plant conditions of Yonggwang Units 3 and 4, a pressurized water reactor (PWR) of 2815-MW(thermal) power in Korea, were reviewed, and possible event sequences were identified. From the CCT analysis for the five cases of typical plant configurations, it was estimated for the earliest CCT to be 40 min after the event in a case with a large cold-leg opening and emptied steam generators (SGs). However, the case with water-filled SGs significantly delayed the CCT through the heat removal to the secondary side. From the GIPR analysis for the six possible gravity-injection paths from the refueling water storage tank (RWST), the case with the injection point and opening on the other leg side was estimated to be the most suitable path to avoid core boiling. In addition, from the sensitivity study, it was evaluated for the plant to be capable of providing the core cooling for the long-term transient if nominal RWST water is available. As a result, these analysis methods and results will provide useful information in understanding the plant behavior and preparing the mitigation measures after the event, especially for Combustion Engineering-type PWR plants. However, to directly apply the analysis results to the emergency procedure for such an event, additional case studies are needed for a wide range of operating conditions such as reactor coolant inventory, RWST water temperature, and core decay heat rate.

  9. The effect of velocity boundary conditions on the heat transfer and flow topology in two-dimensional Rayleigh-B\\'enard convection

    E-Print Network [OSTI]

    van der Poel, Erwin P; Verzicco, Roberto; Lohse, Detlef

    2015-01-01

    The effect of various velocity boundary condition is studied in two-dimensional Rayleigh-B\\'enard convection. Combinations of no-slip, stress-free and periodic boundary conditions are used on both the sidewalls and the horizontal plates. For the studied Rayleigh numbers Ra between $10^8$ and $10^{11}$ the heat transport is lower for $\\Gamma = 0.33$ than for $\\Gamma = 1$ in case of no-slip sidewalls. This is surprisingly opposite for stress-free sidewalls, where the heat transport increases for lower aspect-ratio. In wider cells the aspect-ratio dependence is observed to disappear for $\\text{Ra} \\ge 10^{10}$. Two distinct flow types with very different dynamics can be seen, mostly dependent on the plate velocity boundary condition, namely roll-like flow and horizontal zonal flow, which have a substantial effect on the dynamics and heat transport in the system. The predominantly horizontal zonal flow suppresses heat flux and is observed for stress-free and asymmetric plates. Low aspect-ratio periodic sidewall s...

  10. Interannual Changes in Seasonal Ground Freezing and Near-surface Heat Flow Beneath Bottom-fast Ice in the Near-shore Zone, Mackenzie Delta, NWT, Canada

    E-Print Network [OSTI]

    Moorman, Brian

    Interannual Changes in Seasonal Ground Freezing and Near-surface Heat Flow Beneath Bottom-fast Ice Resources Canada, Dartmouth, Nova Scotia, Canada ABSTRACT Interannual changes in seasonal ground freezing. KEY WORDS: seasonal ground freezing; permafrost; bottom-fast ice; Mackenzie Delta INTRODUCTION Arctic

  11. 6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xi'an, China, 11-15 July 2009

    E-Print Network [OSTI]

    Khandekar, Sameer

    from a variety of sources including fossil fuels (coal, natural gas, LPG, gasoline, diesel, methane in the process. Use of natural gas or naphtha as a raw material is an industrial process. Typical reactions6th International Symposium on Multiphase Flow, Heat Mass Transfer and Energy Conversion Xi

  12. Experimental and numerical investigation of turbulent flow and heat (mass) transfer in a two-pass trapezoidal channel with turbulence promoters 

    E-Print Network [OSTI]

    Oh, Sung Hyuk

    2009-05-15

    , as results of the secondary flow induced by the (–) 60º ribs. The overall average heat (mass) transfer for the larger inlet cases was always higher than that for the smaller inlet cases in the ribbed trapezoidal channel. Considering the thermal performance...

  13. Proceedings of HT2009 2009 ASME Summer Heat Transfer Conference

    E-Print Network [OSTI]

    Hidrovo, Carlos H.

    , TX, USA Carlos H. Hidrovo The University of Texas at Austin Austin, TX, USA ABSTRACT Heat pipes in a heat pipe is done passively by means of a wicking structure that induces capillary-driven flow from measurements of baseline mesh wicks and nanowicks. Since the thermal performance of most heat pipes is usually

  14. Interim Columbia and Snake rivers flow improvement measures for salmon: Final Supplemental Environmental Impact Statement (SEIS)

    SciTech Connect (OSTI)

    Not Available

    1993-03-01

    Public comments are sought on this final SEIS, which supplements the 1992 Columbia River Salmon Flow Measures Options Analysis (OA)/Environmental Impact Statement (EIS). The Corps of Engineers, in cooperation with the Bonneville Power Administration and the Bureau of Reclamation proposes five alternatives to improve flows of water in the lower Columbia-Snake rivers in 1993 and future years to assist the migration of juvenile and adult anadromous fish past eight hydropower dams. These are: (1) Without Project (no action) Alternative, (2) the 1992 Operation, (3) the 1992 Operation with Libby/Hungry Horse Sensitivity, (4) a Modified 1992 Operation with Improvements to Salmon Flows from Dworshak, and (5) a Modified 1992 Operation with Upper Snake Sensitivity. Alternative 4, Modified 1992 Operations, has been identified as the preferred alternative.

  15. Primary pump power as a measure of fluid density during bubbly two-phase flow. [PWR

    SciTech Connect (OSTI)

    McCreery, G.E.; Linebarger, J.H.; Koske, J.E.

    1983-01-01

    A nuclear plant operator requires other information on reactor coolant system inventory besides just pressurizer liquid level, which often disappears or gives ambiguous indications during a loss-of-coolant accident. Erroneous instrument readings during the Three Mile Island and Ginna accidents are examples. Pump power or current is shown in this paper to provide an additional source of inventory information. When the reactor coolant pumps are operating, it allows the operator to make decisions about the advisability of continued pump- and safety-injection operation. The inventory information is provided by a simple method of calculating fluid density for bubbly two-phase flow by relating pump power or current to fluid density. The calculational method is derived and compared with data in this paper. Calculations using the method agree well with the measured experimental data with increasing void fraction, until the flow transitions from bubbly to partially stratified churn flow within the pump.

  16. Two-dimensional model of the air flow and temperature distribution in a cavity-type heat receiver of a solar stirling engine

    SciTech Connect (OSTI)

    Makhkamov, K.K.; Ingham, D.B.

    1999-11-01

    A theoretical study on the air flow and temperature in the heat receiver, affected by free convection, of a Stirling Engine for a Dish/Stirling Engine Power System is presented. The standard {kappa}-{epsilon} turbulence model for the fluid flow has been used and the boundary conditions employed were obtained using a second level mathematical model of the Stirling Engine working cycle. Physical models for the distribution of the solar insolation from the Concentrator on the bottom and side walls of the cavity-type heat receiver have been taken into account. The numerical results show that most of the heat losses in the receiver are due to re-radiation from the cavity and conduction through the walls of the cavity. It is in the region of the boundary of the input window of the heat receiver where there is a sensible reduction in the temperature in the shell of the heat exchangers and this is due to the free convection of the air. Further, the numerical results show that convective heat losses increase with decreasing tilt angle.

  17. Infrared Spectroscope for Electron Bunch-length Measurement: Heat Sensor Parameters Analysis

    SciTech Connect (OSTI)

    Domgmo-Momo, Gilles; /Towson U. /SLAC

    2012-09-05

    The Linac Coherent Light Source (LCLS) is used for many experiments. Taking advantage of the free electron laser (FEL) process, scientists of various fields perform experiments of all kind. Some for example study protein folding; other experiments are more interested in the way electrons interact with the molecules before they are destroyed. These experiments among many others have very little information about the electrons x-ray produced by the FEL, except that the FEL is using bunches less than 10 femtoseconds long. To be able to interpret the data collected from those experiments, more accurate information is needed about the electron's bunch-length. Existing bunch length measurement techniques are not suitable for the measurement of such small time scales. Hence the need to design a device that will provide more precise information about the electron bunch length. This paper investigates the use of a pyreoelectric heat sensor that has a sensitivity of about 1.34 micro amps per watt for the single cell detector. Such sensitivity, added to the fact that the detector is an array sensor, makes the detector studied the primary candidate to be integrated to an infrared spectrometer designed to better measure the LCLS electron bunch length.

  18. Measurement and Model Validation of Nanofluid Specific Heat Capacity with Differential Scanning Calorimetry

    E-Print Network [OSTI]

    O'Hanley, Harrison F.

    Nanofluids are being considered for heat transfer applications; therefore it is important to know their thermophysical properties accurately. In this paper we focused on nanofluid specific heat capacity. Currently, there ...

  19. Measurements of Heat Transfer Coefficients to Cylinders in Shallow Bubble Columns

    E-Print Network [OSTI]

    Tow, Emily W.

    High heat transfer coefficients and large interfacial areas make bubble columns ideal for dehumidification. However, the effect of geometry on the heat transfer coefficients outside cooling coils in shallow bubble columns, ...

  20. Convective flow measurements in a heated cavity using pulsed laser velocimetry with digital image processing 

    E-Print Network [OSTI]

    Chavez, Hector Luis

    1990-01-01

    . This is essentially the trapezoidal sheet shown in figure 4. The thickness of the beam remains on the order of 1-1. 5 13 x-v plane z-y plane First Lens Focal Point Second Lens Third Lens Fig. 4. Laser light passing through a trio of piano-convex cylindrical...2 U3 v1 v2 3 u4 u5 u7 u8 u6 u9 v4 v5 v7 v8 Figure 24. Pixel positions in relation to vector components. Expressing equation (15) spatially, where uij and vij are gray level values ranging from 0 to 255 at position i and j of each region...

  1. Wall pressure measurements of flooding in vertical countercurrent annular air–water flow

    SciTech Connect (OSTI)

    Choutapalli, I., Vierow, K.

    2010-01-01

    An experimental study of flooding in countercurrent air-water annular flow in a large diameter vertical tube using wall pressure measurements is described in this paper. Axial pressure profiles along the length of the test section were measured up to and after flooding using fast response pressure transducers for three representative liquid flow rates representing a wide range of liquid Reynolds numbers (ReL = 4?/?; ? is the liquid mass flow rate per unit perimeter; ? is the dynamic viscosity) from 3341 to 19,048. The results show that flooding in large diameter tubes cannot be initiated near the air outlet and is only initiated near the air inlet. Fourier analysis of the wall pressure measurements shows that up to the point of flooding, there is no dominant wave frequency but rather a band of frequencies encompassing both the low frequency and the broad band that are responsible for flooding. The data indicates that flooding in large diameter vertical tubes may be caused by the constructive superposition of a plurality of waves rather than the action of a single large-amplitude wave.

  2. Formulation and sequential numerical algorithms of coupled fluid/heat flow and geomechanics for multiple porosity materials

    E-Print Network [OSTI]

    Kim, J.

    2014-01-01

    Settari A. Modeling of geomechanics in naturally fracturedway coupled fluid flow and geomechanics in hydrate deposits.for coupled flow and geomechanics: Drained and undrained

  3. Measured Performance and Analysis of Ground Source Heat Pumps for Space Conditioning and for Water Heating in a Low-Energy Test House Operated under Simulated Occupancy Conditions

    SciTech Connect (OSTI)

    Ally, Moonis Raza [ORNL] [ORNL; Munk, Jeffrey D [ORNL] [ORNL; Baxter, Van D [ORNL] [ORNL; Gehl, Anthony C [ORNL] [ORNL

    2012-01-01

    In this paper we present measured performance and efficiency metrics of Ground Source Heat Pumps (GSHPs) for space conditioning and for water heating connected to a horizontal ground heat exchanger (GHX) loop. The units were installed in a 345m2 (3700ft2) high-efficiency test house built with structural insulated panels (SIPs), operated under simulated occupancy conditions, and located in Oak Ridge, Tennessee (USA) in US Climate Zone 4 . The paper describes distinctive features of the building envelope, ground loop, and equipment, and provides detailed monthly performance of the GSHP system. Space conditioning needs of the house were completely satisfied by a nominal 2-ton (7.0 kW) water-to-air GSHP (WA-GSHP) unit with almost no auxiliary heat usage. Recommendations for further improvement through engineering design changes are identified. The comprehensive set of data and analyses demonstrate the feasibility and practicality of GSHPs in residential applications and their potential to help achieve source energy and greenhouse gas emission reduction targets set under the IECC 2012 Standard.

  4. Measurements of excess heat from a Pons-Fleischmann-type electrolytic cell using palladium sheet

    SciTech Connect (OSTI)

    Storms, E. )

    1993-03-01

    Two pieces of palladium sheet similar to that used by Takahashi were loaded with deuterium in a Pons-Fleischmann-type electrolytic cell, and heat production was measured. One sheet produced a steady increase in excess power that reached 7.5 W (20% of input power) before the study was interrupted. A second similar sheet from a different batch of palladium did not produce any measurable excess power. There were differences in the loading behavior, the maximum stoichiometry, and the presence of excess volume in the deuteride made from these materials. The first sheet contained 0.8% excess volume after having been deloaded from its maximum deuterium/palladium (D/Pd) ratio of 0.82 to 0.73, and the second sheet contained 13.5% excess volume while at its maximum ratio of 0.75. The high excess volume in the latter case is an indication of internal escape paths that reduce the required high D/Pd ratio. 30 refs., 17 figs., 3 tabs.

  5. Measure Guideline. Combination Forced-Air Space and Tankless Domestic Hot Water Heating Systems

    SciTech Connect (OSTI)

    Rudd, Armin

    2012-08-01

    This document describes design and application guidance for combination space and tankless domestic hot water heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings conducted by Building Science Corporation. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multi-family residential buildings, both new and retrofitted.

  6. Measure Guideline: Combination Forced-Air Space and Tankless Domestic Hot Water Heating Systems

    SciTech Connect (OSTI)

    Rudd, A.

    2012-08-01

    This document describes design and application guidance for combination space and tankless domestic hot water heating systems (combination systems) used in residential buildings, based on field evaluation, testing, and industry meetings conducted by Building Science Corporation. As residential building enclosure improvements continue to drive heating loads down, using the same water heating equipment for both space heating and domestic water heating becomes attractive from an initial cost and space-saving perspective. This topic is applicable to single- and multi-family residential buildings, both new and retrofitted.

  7. Lift, drag and flow-field measurements around a small ornithopter

    SciTech Connect (OSTI)

    Balakumar, B J [Los Alamos National Laboratory; Chavez - Alarcon, Ramiro [NMSU; Shu, Fangjun [NMSU

    2011-01-12

    The aerodynamics of a flight-worthy, radio controlled ornithopter is investigated using a combination of Particle-Image Velocimetry (PIV), load cell measurements, and high-speed photography of smoke visualizations. The lift and thrust forces of the ornithopter are measured at various flow speeds, flapping frequencies and angles of attack to characterize the flight performance. These direct force measurements are then compared with forces estimated using control volume analysis on PIV data. High-speed photography of smoke streaks is used to visualize the evolution of leading edge vortices, and to qualitatively infer the effect of wing deformation on the net downwash. Vortical structures in the wake are compared to previous studies on root flapping, and direct measurements of flapping efficiency are used to argue that the current ornithopter operates sub-optimally in converting the input energy into propulsive work.

  8. User's guide of TOUGH2-EGS-MP: A Massively Parallel Simulator with Coupled Geomechanics for Fluid and Heat Flow in Enhanced Geothermal Systems VERSION 1.0

    SciTech Connect (OSTI)

    Xiong, Yi; Fakcharoenphol, Perapon; Wang, Shihao; Winterfeld, Philip H.; Zhang, Keni; Wu, Yu-Shu

    2013-12-01

    TOUGH2-EGS-MP is a parallel numerical simulation program coupling geomechanics with fluid and heat flow in fractured and porous media, and is applicable for simulation of enhanced geothermal systems (EGS). TOUGH2-EGS-MP is based on the TOUGH2-MP code, the massively parallel version of TOUGH2. In TOUGH2-EGS-MP, the fully-coupled flow-geomechanics model is developed from linear elastic theory for thermo-poro-elastic systems and is formulated in terms of mean normal stress as well as pore pressure and temperature. Reservoir rock properties such as porosity and permeability depend on rock deformation, and the relationships between these two, obtained from poro-elasticity theories and empirical correlations, are incorporated into the simulation. This report provides the user with detailed information on the TOUGH2-EGS-MP mathematical model and instructions for using it for Thermal-Hydrological-Mechanical (THM) simulations. The mathematical model includes the fluid and heat flow equations, geomechanical equation, and discretization of those equations. In addition, the parallel aspects of the code, such as domain partitioning and communication between processors, are also included. Although TOUGH2-EGS-MP has the capability for simulating fluid and heat flows coupled with geomechanical effects, it is up to the user to select the specific coupling process, such as THM or only TH, in a simulation. There are several example problems illustrating applications of this program. These example problems are described in detail and their input data are presented. Their results demonstrate that this program can be used for field-scale geothermal reservoir simulation in porous and fractured media with fluid and heat flow coupled with geomechanical effects.

  9. Integrated heat pump system

    SciTech Connect (OSTI)

    Reedy, W.R.

    1988-03-01

    An integrated heat pump and hot water system is described that includes: a heat pump having an indoor heat exchanger and an outdoor heat exchanger that are selectively connected to the suction line and the discharge line respectively of a compressor by a flow reversing means, and to each other by a liquid line having an expansion device mounted therein, whereby heating and cooling is provided to an indoor comfort zone by cycling the flow reversing means, a refrigerant to water heat exchanger having a hot water flow circuit in heat transfer relation with a first refrigerant condensing circuit and a second refrigerant evaporating circuit, a connection mounted in the liquid between the indoor heat exchanger and the expansion device, control means for regulating the flow of refrigerant through the refrigerant to water heat exchanger to selectively transfer heat into and out of the hot water flow circuit.

  10. Heat pump system

    DOE Patents [OSTI]

    Swenson, Paul F. (Cleveland, OH); Moore, Paul B. (Fedhaurn, FL)

    1982-01-01

    An air heating and cooling system for a building includes an expansion-type refrigeration circuit and a heat engine. The refrigeration circuit includes two heat exchangers, one of which is communicated with a source of indoor air from the building and the other of which is communicated with a source of air from outside the building. The heat engine includes a heat rejection circuit having a source of rejected heat and a primary heat exchanger connected to the source of rejected heat. The heat rejection circuit also includes an evaporator in heat exchange relation with the primary heat exchanger, a heat engine indoor heat exchanger, and a heat engine outdoor heat exchanger. The indoor heat exchangers are disposed in series air flow relationship, with the heat engine indoor heat exchanger being disposed downstream from the refrigeration circuit indoor heat exchanger. The outdoor heat exchangers are also disposed in series air flow relationship, with the heat engine outdoor heat exchanger disposed downstream from the refrigeration circuit outdoor heat exchanger. A common fluid is used in both of the indoor heat exchanges and in both of the outdoor heat exchangers. In a first embodiment, the heat engine is a Rankine cycle engine. In a second embodiment, the heat engine is a non-Rankine cycle engine.

  11. How to Measure Specific Heat Using Event-by-Event Average $p_T$ Fluctuations

    E-Print Network [OSTI]

    M. J. Tannenbaum; for the PHENIX Collaboration

    2005-12-01

    A simple way to visualize event-by-event average $p_T$ fluctuations is by assuming that each collision has a different temperature parameter (inverse $p_T$ slope) and that the ensemble of events has a temperature distribution about the mean, $$, with standard deviation $\\sigma_T$. PHENIX characterizes the non-random fluctuation of $M_{p_T}$, the event-by-event average $p_T$, by $F_{p_T}$, the fractional difference of the standard deviation of the data from that of a random sample obtained with mixed events. This can be related to the temperature fluctuation: \\[ F_{p_T}=\\sigma^{\\rm data}_{M_{p_T}}/\\sigma^{\\rm random}_{M_{p_T}}-1\\simeq( -1) \\sigma^2_{T}/^2 \\] Combining this with the Gavai, {\\it et al.},\\cite{Gavai05} and Korus, {\\it et al.},\\cite{Korus} definitions of the specific heat per particle, a simple relationship is obtained: \\[ c_v/T^3={\\mean{n}\\over \\mean{N_{tot}}} {1\\over F_{p_T}} \\] $F_{p_T}$ is measured with a fraction $\\mean{n}/\\mean{N_{tot}}$ of the total particles produced, a purely geometrical factor representing the fractional acceptance, $\\sim 1/33$ in PHENIX. Gavai, {\\it et al.} predict that $c_v/T^3=15$, which corresponds to $F_{p_T}\\sim 0.20$% in PHENIX, which may be accessible by measurements of $M_{p_T}$ in the range $0.2\\leq p_T\\leq 0.6$ GeV/c. In order to test the Gavai, {\\it et al.} prediction that $c_v/T^3$ is reduced in a QGP compared to the ideal gas value (15 compared to 21), precision measurements of $F_{p_T}$ in the range 0.20% for $0.2\\leq p_T\\leq 0.6$ GeV/c may be practical.

  12. Dealing with big circulation flow, small temperature difference based on verified dynamic model simulations of a hot water district heating system 

    E-Print Network [OSTI]

    Zhong, L.

    2014-01-01

    d design en enclosure ex exchanger f fuel h heater int internal n number of HES o outside r return s supply sp set point sols solar radiation from south side v verify w, w2i water, water in secondary system for each HES z zone ESL... temperatures, solar radiation and wind speed; the heat balance has been regulated based on the average water temperature in the secondary system by adjusting the water mass flow rate (u1) of each HES in the primary system; and the water mass flow rate...

  13. Modeling of Heat Transfer in Rooms in the Modelica Buildings Library

    E-Print Network [OSTI]

    Wetter, Michael

    2013-01-01

    U ) and flow variables (heat flow rate ? mass flow rate m,variables temperature T and heat flow rate Q flow. Then, thesuch as prescribed heat flow rate or temperature. Thus, in

  14. Application of reconstructive tomography to the measurement of density distribution in two-phase flow

    SciTech Connect (OSTI)

    Fincke, J.R.; Berggren, M.J.; Johnson, S.A.

    1980-01-01

    The technique of reconstructive tomography has been applied to the measurement of average density and density distribution in multiphase flows. The technique of reconstructive tomography provides a model independent method of obtaining flow field density information. The unique features of interest in application of a practical tomographic densitometer system are the limited number of data values and the correspondingly coarse reconstruction grid (0.5 by 0.5 cm). These features were studied both experimentally, through the use of prototype hardware on a 3-in. pipe, and analytically, through computer generation of simulated data. Prototypical data were taken on phantoms constructed of Plexiglas and laminated Plexiglas, wood, and polyurethane foam. Reconstructions obtained from prototype data were compared with reconstructions from the simulated data.

  15. EIS-0163-S: Supplemental EIS/1993 Interim Columbia and Snake Rivers Flow Improvement Measures for Salmon

    Broader source: Energy.gov [DOE]

    The U.S. Army Corps of Engineers – Walla Walla District has prepared this statement to assess alternatives to improve flows of water in the lower Columbia-Snake rivers in 1993 and future years to assist the migration of juvenile and adult anadromous fish past eight hydropower dams. The U.S. Department of Energy’s Bonneville Power Administration served as a cooperating agency in developing this supplement due to its key role in direct operation of the integrated and coordinated Columbia-Snake River System, and adopted this statement in March of 1993. This statement supplements the 1992 Columbia River Salmon Flow Measures Options Analysis Environmental Impact Statement, which evaluated ways to alter water management operations in 1992 on the lower Columbia and Snake rivers to enhance the survival of wild Snake River salmon.

  16. Measurement of the Damping Rate of n = 1 Toroidal Alfvén Eigenmodes as a Function of the Neutral Beam Heating Power and plasma ? on JET.

    E-Print Network [OSTI]

    Measurement of the Damping Rate of n = 1 Toroidal Alfvén Eigenmodes as a Function of the Neutral Beam Heating Power and plasma ? on JET.

  17. Finite Larmor Radii Effects in Fast Ion Measurements as Demonstrated Using Neutron Emission Spectrometry of JET Plasmas Heated with 3rd Harmonic ICRF

    E-Print Network [OSTI]

    Finite Larmor Radii Effects in Fast Ion Measurements as Demonstrated Using Neutron Emission Spectrometry of JET Plasmas Heated with 3rd Harmonic ICRF

  18. A Comprehensive Statistically-Based Method to Interpret Real-Time Flowing Measurements

    SciTech Connect (OSTI)

    Keita Yoshioka; Pinan Dawkrajai; Analis A. Romero; Ding Zhu; A. D. Hill; Larry W. Lake

    2007-01-15

    With the recent development of temperature measurement systems, continuous temperature profiles can be obtained with high precision. Small temperature changes can be detected by modern temperature measuring instruments such as fiber optic distributed temperature sensor (DTS) in intelligent completions and will potentially aid the diagnosis of downhole flow conditions. In vertical wells, since elevational geothermal changes make the wellbore temperature sensitive to the amount and the type of fluids produced, temperature logs can be used successfully to diagnose the downhole flow conditions. However, geothermal temperature changes along the wellbore being small for horizontal wells, interpretations of a temperature log become difficult. The primary temperature differences for each phase (oil, water, and gas) are caused by frictional effects. Therefore, in developing a thermal model for horizontal wellbore, subtle temperature changes must be accounted for. In this project, we have rigorously derived governing equations for a producing horizontal wellbore and developed a prediction model of the temperature and pressure by coupling the wellbore and reservoir equations. Also, we applied Ramey's model (1962) to the build section and used an energy balance to infer the temperature profile at the junction. The multilateral wellbore temperature model was applied to a wide range of cases at varying fluid thermal properties, absolute values of temperature and pressure, geothermal gradients, flow rates from each lateral, and the trajectories of each build section. With the prediction models developed, we present inversion studies of synthetic and field examples. These results are essential to identify water or gas entry, to guide flow control devices in intelligent completions, and to decide if reservoir stimulation is needed in particular horizontal sections. This study will complete and validate these inversion studies.

  19. Measurements of net radiation, ground heat flux and surface temperature in an urban canyon

    SciTech Connect (OSTI)

    Gouveia, F J; Leach, M J; Shinn, J H

    2003-11-06

    The Joint Urban 2003 (JU2003) field study was conducted in Oklahoma City in July 2003 to collect data to increase our knowledge of dispersion in urban areas. Air motions in and around urban areas are very complicated due to the influence of urban structures on both mechanical and thermal forcing. During JU2003, meteorological instruments were deployed at various locations throughout the urban area to characterize the processes that influence dispersion. Some of the instruments were deployed to characterize urban phenomena, such as boundary layer development. In addition, particular sites were chosen for more concentrated measurements to investigate physical processes in more detail. One such site was an urban street canyon on Park Avenue between Broadway and Robinson Avenues in downtown Oklahoma City. The urban canyon study was designed to examine the processes that control dispersion within, into and out of the urban canyon. Several towers were deployed in the Park Avenue block, with multiple levels on each tower for observing the wind using sonic anemometers. Infrared thermometers, net radiometers and ground heat flux plates were deployed on two of the towers midway in the canyon to study the thermodynamic effects and to estimate the surface energy balance. We present results from the surface energy balance observations.

  20. Virtual Measurement in Pipes, Part 1: Flowing Bottom Hole Pressure Under Multi-Phase Flow and Inclined Wellbore Conditions

    E-Print Network [OSTI]

    Mohaghegh, Shahab

    and the enhancement is clearly demonstrated. The developed VMP is applied to wellbore hydraulic problems. It addresses three-phase (oil, water, and gas) flow in wellbores. This tool applies to a variety of wells, including vertical wells and those with various degrees of inclination. Introduction Concurrent flow of oil and gas

  1. Heat engine regenerators: Research status and needs

    SciTech Connect (OSTI)

    Hutchinson, R.A.

    1987-08-01

    The rapidly oscillating, variable density flows of regenerative heat engines provide a class of poorly understood unsteady flow and heat transfer problems. These problems are not currently amenable to direct experimental resolution. Experiences in engine development and test programs and efforts to develop analysis tools point to the regenerator as a key area of insufficient understanding. Focusing on flow and heat transfer in regenerators, this report discusses similarity parameters for the flows and reviews the experimental data currently available for Stirling analysis. Then a number of experimental results are presented from recent fundamental fluid mechanical and thermal investigations that shed additional light on the functioning of heat engine regenerators. Suggestions are made for approaches for further measurement and analysis efforts.

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

    E-Print Network [OSTI]

    Jardim, Wilson de Figueiredo

    measurements. The use of flow analysis for the determination of dissolved carbon dioxide by membrane separation a hydrophobic membrane into a flow of deionized water, generating a gradient of conductivity proportional the processes related to the carbon cycle within the aquatic environment. The direction of CO2 gas exchange

  3. Introduction to Heat Exchangers

    E-Print Network [OSTI]

    Heller, Barbara

    . Since, the effectiveness can be written in terms of heat capacitance rate [W/K], C, and change in temperature [K], . The heat capacitance rate is defined in terms of mass flow rate [kg/s], , and specific heat: ! ! ! " # = ! ! "# ! ! ! - ! ! ! ! ! ! = ! !! ! ! ! ! = ! ! ! ! ! - ! ! ! ! ! "# ! ! ! - ! ! ! ! ! ! = ! ! ! ! ! - ! ! ! ! ! "# ! ! ! - ! ! ! ! ! Heat%Capacitance%Rate % ! = ! !! ! ! Heat%Capacitance%Rate%[W % ! = ! ! ! ! ! ! ! = ! ! !! ! ! ! max

  4. Field Measurement of Heating System in a Hotel Building in Harbin 

    E-Print Network [OSTI]

    Zhao, T.; Zhang, J.; Li, Y.

    2006-01-01

    Heating energy consumption in winter is an important component of the whole building energy consumption in the severe cold zone in north China. This paper presents a heating water system of a hotel building in Harbin, finishes the testing of its...

  5. A computational study of ultrasonic film thickness measurements in annular two-phase flows under microgravity conditions 

    E-Print Network [OSTI]

    Pautz, Shawn Daniel

    1995-01-01

    An ultrasonic system has previously been proposed to measure interfacial characteristics of annular two-phase flows in reduced acceleration environments. A computational model based on ray tracing is developed to predict ...

  6. Bayonet heat exchangers in heat-assisted Stirling heat pump

    SciTech Connect (OSTI)

    Yagyu, S.; Fukuyama, Y.; Morikawa, T.; Isshiki, N.; Satoh, I.; Corey, J.; Fellows, C.

    1998-07-01

    The Multi-Temperature Heat Supply System is a research project creating a city energy system with lower environmental load. This system consists of a gas-fueled internal combustion engine and a heat-assisted Stirling heat pump utilizing shaft power and thermal power in a combination of several cylinders. The heat pump is mainly driven by engine shaft power and is partially assisted by thermal power from engine exhaust heat source. Since this heat pump is operated by proportioning the two energy sources to match the characteristics of the driving engine, the system is expected to produce cooling and heating water at high COP. This paper describes heat exchanger development in the project to develop a heat-assisted Stirling heat pump. The heat pump employs the Bayonet type heat exchangers (BHX Type I) for supplying cold and hot water and (BHX Type II) for absorbing exhaust heat from the driving engine. The heat exchanger design concepts are presented and their heat transfer and flow loss characteristics in oscillating gas flow are investigated. The main concern in the BHX Type I is an improvement of gas side heat transfer and the spirally finned tubes were applied to gas side of the heat exchanger. For the BHX Type II, internal heat transfer characteristics are the main concern. Shell-and-tube type heat exchangers are widely used in Stirling machines. However, since brazing is applied to the many tubes for their manufacturing processes, it is very difficult to change flow passages to optimize heat transfer and loss characteristics once they have been made. The challenge was to enhance heat transfer on the gas side to make a highly efficient heat exchanger with fewer parts. It is shown that the Bayonet type heat exchanger can have good performance comparable to conventional heat exchangers.

  7. Local, instantaneous heat transfer in pulse-stabilized fluidization

    SciTech Connect (OSTI)

    Pence, D.V. [Univ. of Rhode Island, Kingston, RI (United States). Dept. of Mechanical Engineering and Applied Mechanics; Beasley, D.E. [Clemson Univ., SC (United States). Dept. of Mechanical Engineering

    1996-12-31

    The Pulsed Atmospheric Fluidized Bed Combustor (PAFBC), a hybrid combustor concept that couples a pulsed combustor with an atmospheric bubbling fluidized bed, has technical advantages in energy efficiency and emissions. The present study examines the effect of an opposing oscillatory flow on the local, instantaneous heat transfer in a laboratory scale bubbling gas-fluidized bed. This opposing secondary flow consisted of a steady mean component and an oscillating component thereby modeling the flow in the tailpipe of a pulsed combustor. Spectral and contact time analyses of local, instantaneous heat flux measurements from a heated, submerged horizontal cylinder clearly indicate that the bed hydrodynamics were significantly altered by the opposing secondary flow. These heat flux measurements were accomplished by employing an isothermal platinum film heat flux gage. For the present investigation, data were acquired for a monodisperse distribution of particles with a mean diameter of 345 {micro}m and total fluidization ratios ranging from 1.1 through 2.7. Heat transfer observed under conditions of secondary flows with a superimposed waveform exhibit characteristics of globally dominated, as opposed to locally dominated, hydrodynamics. For low primary and secondary flow rates and a forcing frequency of 5 Hz, a substantial enhancement in heat transfer was observed. Increases in the bubble phase and emulsion phase heat transfer coefficients were identified as the primary contributors to the observed increases in time-averaged local heat transfer coefficients.

  8. Microjet array single-phase and flow boiling heat transfer with R134a Eric A. Browne a

    E-Print Network [OSTI]

    Peles, Yoav

    :6 6 Nud 6 128. Boiling experiments were conducted with liquid subcoolings of 10, 20, and 30 °C at jet effective than forced air convection will be required. Single-phase flow and flow boiling in microchannels have been studied [4­10] with a variety of fluids and flow schemes and have been used to cool turbine

  9. Flowing versus Static Conditions for Measuring Multiple Exciton Generation in PbSe Quantum Dots

    SciTech Connect (OSTI)

    Midgett, Aaron G. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States); Hillhouse, Hugh W. [Univ. of Washington, Seattle, WA (United States); Hughes, Barbara K. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States); Nozik, Arthur J. [National Renewable Energy Lab. (NREL), Golden, CO (United States); Univ. of Colorado, Boulder, CO (United States); Beard, Matthew C. [Univ. of Colorado, Boulder, CO (United States)

    2010-09-22

    Recent reports question the validity of pulsed fs-laser experiments for measuring the photon-to-exciton quantum yields (QYs) that result from multiple exciton generation (MEG). The repetitive nature of these experiments opens up an alternative relaxation pathway that may produce artificially high results. We present transient-absorption (TA) data for 4.6 and 6.6 nm diameter PbSe quantum dots (QDs) at a variety of pump photon energies. The data are collected under laminar flow conditions with volumetric flow rates ranging from 0 to 150 mL/min (resulting in Reynolds numbers up to 460). The results are modeled with a spatially resolved population balance of generation, recombination, convective replacement, and accumulation of long-lived excited QDs. By comparing the simulations and experiments, the steady-state population of the long-lived QD-excited states and their kinetics are determined for different experimental conditions. We also improve upon reported photon-to-exciton QYs for PbSe QDs. We find differences in the observed TA dynamics between flowing and static conditions that depend upon photon fluence, pump photon energy, and quality of the QD surfaces. For excitation energies below 2 Eg, independent of QD size or photon fluence, we observe no flow rate dependence in the TA dynamics. At excitation energies of h? > 3 Eg, we observe differences between static and flowing conditions that are most pronounced for high photon fluences. At 3.7 Eg and for 4.6 nm PbSe QDs we find a QY of 1.2 ± 0.1 and at 4.5 Eg the QY is 1.55 ± 0.05. With 6.6 nm QDs excited at 4.7 Eg we observe no difference between static and flowing conditions and find a QY of 1.61 ± 0.05. We also find that by treating the surface of QDs, we can decrease the charging probability (Pg ? 5 × 10-5) by a factor of 3-4. The observed variations suggest that different QD samples vary regarding their susceptibility to the creation of long-lived states.

  10. Expanded microchannel heat exchanger: design, fabrication and preliminary experimental test

    E-Print Network [OSTI]

    Denkenberger, David C; Pearce, Joshua M; Zhai, John; 10.1177/0957650912442781

    2012-01-01

    This paper first reviews non-traditional heat exchanger geometry, laser welding, practical issues with microchannel heat exchangers, and high effectiveness heat exchangers. Existing microchannel heat exchangers have low material costs, but high manufacturing costs. This paper presents a new expanded microchannel heat exchanger design and accompanying continuous manufacturing technique for potential low-cost production. Polymer heat exchangers have the potential for high effectiveness. The paper discusses one possible joining method - a new type of laser welding named "forward conduction welding," used to fabricate the prototype. The expanded heat exchanger has the potential to have counter-flow, cross-flow, or parallel-flow configurations, be used for all types of fluids, and be made of polymers, metals, or polymer-ceramic precursors. The cost and ineffectiveness reduction may be an order of magnitude or more, saving a large fraction of primary energy. The measured effectiveness of the prototype with 28 micro...

  11. Foundation Heat Exchanger Final Report: Demonstration, Measured Performance, and Validated Model and Design Tool

    SciTech Connect (OSTI)

    Hughes, Patrick [ORNL; Im, Piljae [ORNL

    2012-01-01

    Geothermal heat pumps, sometimes called ground-source heat pumps (GSHPs), have been proven capable of significantly reducing energy use and peak demand in buildings. Conventional equipment for controlling the temperature and humidity of a building, or supplying hot water and fresh outdoor air, must exchange energy (or heat) with the building's outdoor environment. Equipment using the ground as a heat source and heat sink consumes less non-renewable energy (electricity and fossil fuels) because the earth is cooler than outdoor air in summer and warmer in winter. The most important barrier to rapid growth of the GSHP industry is high first cost of GSHP systems to consumers. The most common GSHP system utilizes a closed-loop ground heat exchanger. This type of GSHP system can be used almost anywhere. There is reason to believe that reducing the cost of closed-loop systems is the strategy that would achieve the greatest energy savings with GSHP technology. The cost premium of closed-loop GSHP systems over conventional space conditioning and water heating systems is primarily associated with drilling boreholes or excavating trenches, installing vertical or horizontal ground heat exchangers, and backfilling the excavations. This project investigates reducing the cost of horizontal closed-loop ground heat exchangers by installing them in the construction excavations, augmented when necessary with additional trenches. This approach applies only to new construction of residential and light commercial buildings or additions to such buildings. In the business-as-usual scenario, construction excavations are not used for the horizontal ground heat exchanger (HGHX); instead the HGHX is installed entirely in trenches dug specifically for that purpose. The potential cost savings comes from using the construction excavations for the installation of ground heat exchangers, thereby minimizing the need and expense of digging additional trenches. The term foundation heat exchanger (FHX) has been coined to refer exclusively to ground heat exchangers installed in the overcut around the basement walls. The primary technical challenge undertaken by this project was the development and validation of energy performance models and design tools for FHX. In terms of performance modeling and design, ground heat exchangers in other construction excavations (e.g., utility trenches) are no different from conventional HGHX, and models and design tools for HGHX already exist. This project successfully developed and validated energy performance models and design tools so that FHX or hybrid FHX/HGHX systems can be engineered with confidence, enabling this technology to be applied in residential and light commercial buildings. The validated energy performance model also addresses and solves another problem, the longstanding inadequacy in the way ground-building thermal interaction is represented in building energy models, whether or not there is a ground heat exchanger nearby. Two side-by-side, three-level, unoccupied research houses with walkout basements, identical 3,700 ft{sup 2} floor plans, and hybrid FHX/HGHX systems were constructed to provide validation data sets for the energy performance model and design tool. The envelopes of both houses are very energy efficient and airtight, and the HERS ratings of the homes are 44 and 45 respectively. Both houses are mechanically ventilated with energy recovery ventilators, with space conditioning provided by water-to-air heat pumps with 2 ton nominal capacities. Separate water-to-water heat pumps with 1.5 ton nominal capacities were used for water heating. In these unoccupied research houses, human impact on energy use (hot water draw, etc.) is simulated to match the national average. At House 1 the hybrid FHX/HGHX system was installed in 300 linear feet of excavation, and 60% of that was construction excavation (needed to construct the home). At House 2 the hybrid FHX/HGHX system was installed in 360 feet of excavation, 50% of which was construction excavation. There are six pipes in all excavations (three par

  12. Laser Doppler Velocimetry for Joint Measurements of Acoustic and Mean Flow Velocities : LMS-based Algorithm and CRB Calculation

    E-Print Network [OSTI]

    Simon, Laurent; Degroot, Anne; Lionet, Louis; 10.1109/TIM.2008.917670

    2009-01-01

    This paper presents a least mean square (LMS) algorithm for the joint estimation of acoustic and mean flow velocities from laser doppler velocimetry (LDV) measurements. The usual algorithms used for measuring with LDV purely acoustic velocity or mean flow velocity may not be used when the acoustic field is disturbed by a mean flow component. The LMS-based algorithm allows accurate estimations of both acoustic and mean flow velocities. The Cram\\'er-Rao bound (CRB) of the associated problem is determined. The variance of the estimators of both acoustic and mean flow velocities is also given. Simulation results of this algorithm are compared with the CRB and the comparison leads to validate this estimator.

  13. Heat Transfer Modeling and Use of Distributed Temperature Measurements to Predict Rate 

    E-Print Network [OSTI]

    Hashmi, Gibran Mushtaq

    2014-07-08

    in the literature. The steady-state model is used where the fluid flow is essentially steady and any change in rate is followed by a sufficiently long steady schedule. The transient model is used where the well is still flowing in the initial stages or fluctuations...

  14. Determination of the permeability of carbon aerogels by gas flow measurements

    SciTech Connect (OSTI)

    Kong, F.M.; Hulsey, S.S.; Alviso, C.T.; Pekala, R.W.

    1992-04-01

    Carbon aerogels are synthesized via the polycondensation of resorcinol and formaldehyde, followed by supercritical drying and pyrolysis at 1050{degree}C in nitrogen. Because of their interconnected porosity, ultrafine cell structure and high surface area, carbon aerogels have many potential applications, such as in supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, we calculated the permeability of carbon aerogels from equations based upon Darcy's law. Our measurements show that carbon aerogels have apparent permeabilities on the order of 10{sup {minus}12}to 10{sup {minus}10} cm{sup 2} for densities ranging from 0.44 to 0.05 g/cm{sup 3}. Like their mechanical properties, the permeability of carbon aerogels follows a power law relationship with density and average pore size. Such findings help us to estimate the average pore sizes of carbon aerogels once their densities are known. This paper reveals the relationships among permeability, pore size and density in carbon aerogels.

  15. Determination of the permeability of carbon aerogels by gas flow measurements

    SciTech Connect (OSTI)

    Kong, F.M.; Hulsey, S.S.; Alviso, C.T.; Pekala, R.W.

    1992-04-01

    Carbon aerogels are synthesized via the polycondensation of resorcinol and formaldehyde, followed by supercritical drying and pyrolysis at 1050{degree}C in nitrogen. Because of their interconnected porosity, ultrafine cell structure and high surface area, carbon aerogels have many potential applications, such as in supercapacitors, battery electrodes, catalyst supports, and gas filters. The performance of carbon aerogels in the latter two applications depends on the permeability or gas flow conductance in these materials. By measuring the pressure differential across a thin specimen and the nitrogen gas flow rate in the viscous regime, we calculated the permeability of carbon aerogels from equations based upon Darcy`s law. Our measurements show that carbon aerogels have apparent permeabilities on the order of 10{sup {minus}12}to 10{sup {minus}10} cm{sup 2} for densities ranging from 0.44 to 0.05 g/cm{sup 3}. Like their mechanical properties, the permeability of carbon aerogels follows a power law relationship with density and average pore size. Such findings help us to estimate the average pore sizes of carbon aerogels once their densities are known. This paper reveals the relationships among permeability, pore size and density in carbon aerogels.

  16. Experimental studies on heat transfer and friction factor characteristics of laminar flow through a circular tube fitted with regularly spaced helical screw-tape inserts

    SciTech Connect (OSTI)

    Sivashanmugam, P.; Suresh, S. [Department of Chemical Engineering, National Institute of Technology, Tiruchirappalli 620 015, Tamil Nadu (India)

    2007-02-15

    Experimental investigation of heat transfer and friction factor characteristics of circular tube fitted with full-length helical screw element of different twist ratio, and helical screw inserts with spacer length 100, 200, 300 and 400mm have been studied with uniform heat flux under laminar flow condition. The experimental data obtained are verified with those obtained from plain tube published data. The effect of spacer length on heat transfer augmentation and friction factor, and the effect of twist ratio on heat transfer augmentation and friction factor have been presented separately. The decrease in Nusselt number for the helical twist with spacer length is within 10% for each subsequent 100mm increase in spacer length. The decrease in friction factor is nearly two times lower than the full length helical twist at low Reynolds number, and four times lower than the full length helical twist at high Reynolds number for all twist ratio. The regularly spaced helical screw inserts can safely be used for heat transfer augmentation without much increase in pressure drop than full length helical screw inserts. (author)

  17. The heat recovery steam generator (HRSG) is a key component of Combined Cycle Power Plants (CCPP). The exhaust (flue gas) from the CCPP gas turbine flows through the HRSG -this gas typically contains a high

    E-Print Network [OSTI]

    The heat recovery steam generator (HRSG) is a key component of Combined Cycle Power Plants (CCPP). The exhaust (flue gas) from the CCPP gas turbine flows through the HRSG - this gas typically contains a high

  18. Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend

    DOE Patents [OSTI]

    Ortiz, M.G.

    1998-02-10

    A system is described for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow. 1 fig.

  19. Device and method for measuring multi-phase fluid flow in a conduit having an abrupt gradual bend

    DOE Patents [OSTI]

    Ortiz, Marcos German (Idaho Falls, ID)

    1998-01-01

    A system for measuring fluid flow in a conduit having an abrupt bend. The system includes pressure transducers, one disposed in the conduit at the inside of the bend and one or more disposed in the conduit at the outside of the bend but spaced a distance therefrom. The pressure transducers measure the pressure of fluid in the conduit at the locations of the pressure transducers and this information is used by a computational device to calculate fluid flow rate in the conduit. For multi-phase fluid, the density of the fluid is measured by another pair of pressure transducers, one of which is located in the conduit elevationally above the other. The computation device then uses the density measurement along with the fluid pressure measurements, to calculate fluid flow.

  20. Generation of a Parabolic Trough Collector Efficiency Curve from Separate Measurements of Outdoor Optical Efficiency and Indoor Receiver Heat Loss

    SciTech Connect (OSTI)

    Kutscher, C.; Burkholder, F.; Stynes, J. K.

    2012-02-01

    The thermal efficiency of a parabolic trough collector is a function of both the fraction of direct normal radiation absorbed by the receiver (the optical efficiency) and the heat lost to the environment when the receiver is at operating temperature. The thermal efficiency can be determined by testing the collector under actual operating conditions or by separately measuring these two components. This paper describes how outdoor measurement of the optical efficiency is combined with laboratory measurements of receiver heat loss to obtain the thermal efficiency curve. This paper describes this approach and also makes the case that there are advantages to plotting collector efficiency versus the difference between the operating temperature and the ambient temperature at which the receiver heat loss was measured divided by radiation to a fractional power (on the order of 1/3 but obtained via data regression) - as opposed to the difference between operating and ambient temperatures divided by the radiation. The results are shown to be robust over wide ranges of ambient temperature, sky temperature, and wind speed.