National Library of Energy BETA

Sample records for large combustors eia-463

  1. Large-eddy simulation of evaporating spray in a coaxial combustor

    E-Print Network [OSTI]

    Apte, Sourabh V.

    Large-eddy simulation of evaporating spray in a coaxial combustor Sourabh V. Apte a,*, Krishnan, Stanford, CA 94305, USA Abstract Large-eddy simulation of an evaporating isopropyl alcohol spray Mahesh b , Parviz Moin c a School of Mechanical, Industrial and Manufacturing Engineering, Oregon State

  2. Large-eddy Simulation of Realistic Gas Turbine Combustors , & Apte, S. V.

    E-Print Network [OSTI]

    Apte, Sourabh V.

    Large-eddy Simulation of Realistic Gas Turbine Combustors Moin, P. , & Apte, S. V. Center of reacting multiphase flows in practical gas-turbine combustion chambers involving complex physical phe specifically for gas-turbine applications. The non-dissipative, yet ro- bust numerical scheme for arbitrary

  3. Massively-Parallel Spectral Element Large Eddy Simulation of a Ring-Type Gas Turbine Combustor 

    E-Print Network [OSTI]

    Camp, Joshua Lane

    2012-07-16

    The average and fluctuating components in a model ring-type gas turbine combustor are characterized using a Large Eddy Simulation at a Reynolds number of 11,000, based on the bulk velocity and the mean channel height. A spatial filter is applied...

  4. Large-Eddy Simulation of Evaporating Spray in a Coaxial Combustor

    E-Print Network [OSTI]

    Mahesh, Krishnan

    Large-Eddy Simulation of Evaporating Spray in a Coaxial Combustor Sourabh V. Apte School of Mechanical, Industrial and Manufacturing Engineering, Oregon State University, Corvallis, OR 97331 Krishnan Mahesh Department of Aerospace Engineering and Mechanics, University of Minnesota, Minneapolis, MN 55455

  5. Flame Stability Analysis in an Ultra Compact Combustor Using Large-Eddy Simulation

    E-Print Network [OSTI]

    Raman, Venkat

    . Introduction The placement of inter-turbine burners (ITB) between the high and low pressure turbine stages as a conven- tional combustor path. In order to reduce the penalty due to increased weight of these burners-turbine burners using conventional combustion technology for aerospace applications would face similar size

  6. Large-eddy simulation of swirling particle-laden flows in a coaxial-jet combustor

    E-Print Network [OSTI]

    Apte, Sourabh V.

    combustion engines, liquid and solid propellant rocket motors, gas-turbine aircraft engines, International. In gas turbine combustors, for example, the liquid fuel jet undergoes primary and secondary atomization is performed. A mixture of air and lightly loaded, spherical, glass-particles with a prescribed size

  7. Scramjet combustor

    SciTech Connect (OSTI)

    Harshman, D.L.

    1991-12-17

    This patent describes a scramjet combustor having a longitudinal axis and two spaced-apart, generally opposing, and generally longitudinally extending walls, with at least one of the walls having an aft-facing step. The combustor also having a fuel injector disposed proximate the step at an acute positive angle with respect to the longitudinal axis, and wherein the improvement comprises means for varying the fuel injector angle during supersonic flight.

  8. Scramjet combustor

    SciTech Connect (OSTI)

    Harshman, D.L.

    1991-12-17

    This patent describes an improvement in a scramjet combustor having a longitudinal axis and two spaced-apart, generally opposing, and generally longitudinally extending walls, with each of the walls having an aft-facing step, the steps being a longitudinal distance apart, the combustor also having a fuel injector disposed proximate a the step at an acute positive angle with respect to the longitudinal axis. The improvement comprises: means for varying the longitudinal distance during supersonic flight; means for varying the fuel injector angle during supersonic flight; and means for varying the transverse distance between the walls during supersonic flight.

  9. Combustor and combustor screech mitigation methods

    SciTech Connect (OSTI)

    Kim, Kwanwoo; Johnson, Thomas Edward; Uhm, Jong Ho; Kraemer, Gilbert Otto

    2014-05-27

    The present application provides for a combustor for use with a gas turbine engine. The combustor may include a cap member and a number of fuel nozzles extending through the cap member. One or more of the fuel nozzles may be provided in a non-flush position with respect to the cap member.

  10. Fuel cell system combustor

    DOE Patents [OSTI]

    Pettit, William Henry (Rochester, NY)

    2001-01-01

    A fuel cell system including a fuel reformer heated by a catalytic combustor fired by anode and cathode effluents. The combustor includes a turbulator section at its input end for intimately mixing the anode and cathode effluents before they contact the combustors primary catalyst bed. The turbulator comprises at least one porous bed of mixing media that provides a tortuous path therethrough for creating turbulent flow and intimate mixing of the anode and cathode effluents therein.

  11. Gas turbine combustor transition

    DOE Patents [OSTI]

    Coslow, Billy Joe (Winter Park, FL); Whidden, Graydon Lane (Great Blue, CT)

    1999-01-01

    A method of converting a steam cooled transition to an air cooled transition in a gas turbine having a compressor in fluid communication with a combustor, a turbine section in fluid communication with the combustor, the transition disposed in a combustor shell and having a cooling circuit connecting a steam outlet and a steam inlet and wherein hot gas flows from the combustor through the transition and to the turbine section, includes forming an air outlet in the transition in fluid communication with the cooling circuit and providing for an air inlet in the transition in fluid communication with the cooling circuit.

  12. Gas turbine combustor transition

    DOE Patents [OSTI]

    Coslow, B.J.; Whidden, G.L.

    1999-05-25

    A method is described for converting a steam cooled transition to an air cooled transition in a gas turbine having a compressor in fluid communication with a combustor, a turbine section in fluid communication with the combustor, the transition disposed in a combustor shell and having a cooling circuit connecting a steam outlet and a steam inlet and wherein hot gas flows from the combustor through the transition and to the turbine section, includes forming an air outlet in the transition in fluid communication with the cooling circuit and providing for an air inlet in the transition in fluid communication with the cooling circuit. 7 figs.

  13. Combustor liner cooling system

    DOE Patents [OSTI]

    Lacy, Benjamin Paul; Berkman, Mert Enis

    2013-08-06

    A combustor liner is disclosed. The combustor liner includes an upstream portion, a downstream end portion extending from the upstream portion along a generally longitudinal axis, and a cover layer associated with an inner surface of the downstream end portion. The downstream end portion includes the inner surface and an outer surface, the inner surface defining a plurality of microchannels. The downstream end portion further defines a plurality of passages extending between the inner surface and the outer surface. The plurality of microchannels are fluidly connected to the plurality of passages, and are configured to flow a cooling medium therethrough, cooling the combustor liner.

  14. Circulating Fluid Bed Combustor 

    E-Print Network [OSTI]

    Fraley, L. D.; Do, L. N.; Hsiao, K. H.

    1982-01-01

    The circulating bed combustor represents an alternative concept of burning coal in fluid bed technology, which offers distinct advantages over both the current conventional fluidized bed combustion system and the pulverized coal boilers equipped...

  15. Low NO.sub.x combustor

    DOE Patents [OSTI]

    Taylor, Jack R. (Cincinnati, OH)

    1987-01-01

    A combustor having an annular first stage, a generally cylindrically-shaped second stage, and an annular conduit communicably connecting the first and second stages. The conduit has a relatively small annular height and a large number of quench holes in the walls thereof such that quench air injected into the conduit through the quench holes will mix rapidly with, or quench, the combustion gases flowing through the conduit. The rapid quenching reduces the amount of NO.sub.x produced in the combustor.

  16. Combustor burner vanelets

    DOE Patents [OSTI]

    Lacy, Benjamin (Greer, SC); Varatharajan, Balachandar (Loveland, OH); Kraemer, Gilbert Otto (Greer, SC); Yilmaz, Ertan (Albany, NY); Zuo, Baifang (Simpsonville, SC)

    2012-02-14

    The present application provides a burner for use with a combustor of a gas turbine engine. The burner may include a center hub, a shroud, a pair of fuel vanes extending from the center hub to the shroud, and a vanelet extending from the center hub and/or the shroud and positioned between the pair of fuel vanes.

  17. Gas turbine topping combustor

    DOE Patents [OSTI]

    Beer, J.; Dowdy, T.E.; Bachovchin, D.M.

    1997-06-10

    A combustor is described for burning a mixture of fuel and air in a rich combustion zone, in which the fuel bound nitrogen in converted to molecular nitrogen. The fuel rich combustion is followed by lean combustion. The products of combustion from the lean combustion are rapidly quenched so as to convert the fuel bound nitrogen to molecular nitrogen without forming NOx. The combustor has an air radial swirler that directs the air radially inward while swirling it in the circumferential direction and a radial fuel swirler that directs the fuel radially outward while swirling it in the same circumferential direction, thereby promoting vigorous mixing of the fuel and air. The air inlet has a variable flow area that is responsive to variations in the heating value of the fuel, which may be a coal-derived fuel gas. A diverging passage in the combustor in front of a bluff body causes the fuel/air mixture to recirculate with the rich combustion zone. 14 figs.

  18. Probabilistic aerothermal design of gas turbine combustors

    E-Print Network [OSTI]

    Bradshaw, Sean D. (Sean Darien), 1978-

    2006-01-01

    This thesis presents a probability-based framework for assessing the impact of manufacturing variability on combustor liner durability. Simplified models are used to link combustor liner life, liner temperature variability, ...

  19. Radial midframe baffle for can-annular combustor arrangement having tangentially oriented combustor cans

    DOE Patents [OSTI]

    Rodriguez, Jose L.

    2015-09-15

    A can-annular gas turbine engine combustion arrangement (10), including: a combustor can (12) comprising a combustor inlet (38) and a combustor outlet circumferentially and axially offset from the combustor inlet; an outer casing (24) defining a plenum (22) in which the combustor can is disposed; and baffles (70) configured to divide the plenum into radial sectors (72) and configured to inhibit circumferential motion of compressed air (16) within the plenum.

  20. Pulse combustor with controllable oscillations

    DOE Patents [OSTI]

    Richards, George A. (Morgantown, WV); Welter, Michael J. (Columbiana, OH); Morris, Gary J. (Morgantown, WV)

    1992-01-01

    A pulse combustor having thermally induced pulse combustion in a continuously flowing system is described. The pulse combustor is fitted with at lease one elongated ceramic body which significantly increases the heat transfer area in the combustion chamber of the combustor. The ceramic body or bodies possess sufficient mass and heat capacity to ignite the fuel-air charge once the ceramic body or bodies are heated by conventional spark plug initiated combustion so as to provide repetitive ignition and combustion of sequentially introduced fuel-air charges without the assistance of the spark plug and the rapid quenching of the flame after each ignition in a controlled manner so as to provide a selective control over the oscillation frequency and amplitude. Additional control over the heat transfer in the combustion chamber is provided by employing heat exchange mechanisms for selectively heating or cooling the elongated ceramic body or bodies and/or the walls of the combustion chamber.

  1. Pulse combustor with controllable oscillations

    SciTech Connect (OSTI)

    Richards, G.A.; Morris, G.J.; Welter, M.J.

    1991-12-31

    A pulse combustor having thermally induced pulse combustion in a continuously flowing system is described. The pulse combustor is fitted with at lease one elongated ceramic body which significantly increases the heat transfer area in the combustion chamber of the combustor. The ceramic body or bodies possess sufficient mass and heat capacity to ignite the fuel-air charge once the ceramic body or bodies are heated by conventional spark plug initiated combustion so as to provide repetitive ignition and combustion of sequentially introduced fuel-air charges without the assistance of the spark plug and the rapid quenching of the flame after each ignition in a controlled manner so as to provide a selective control over the oscillation frequency and amplitude. Additional control over the heat transfer in the combustion chamber is provided by employing heat exchange mechanisms for selectively heating or cooling the elongated ceramic body or bodies and/or the walls of the combustion chamber.

  2. Flame Dynamics and Structure Within Sub-Millimeter Combustors

    E-Print Network [OSTI]

    of micro-and mesoscale portable heat and power sources, and systems for a myriad of applications,1 of micro- and mesoscale heat sources through development of micro- combustors, engines, heaters) in confined spaces with a large surface-area-to-volume ratio.8,9 Relatively lower temperature devices

  3. CSP Tower Air Brayton Combustor

    Broader source: Energy.gov [DOE]

    This fact sheet describes a concentrating solar power tower air Brayton combustor project awarded under the DOE's 2012 SunShot CSP R&D award program. The team, led by the Southwest Research Institute, is working to develop an external combustor that allows for the mixing of CSP-heated air with natural gas in hybridized power plants. This project aims to increase the temperature capabilities of the CSP tower air receiver and gas turbine to 1,000ºC and achieve energy conversion efficiencies greater than 50%.

  4. Methanol tailgas combustor control method

    DOE Patents [OSTI]

    Hart-Predmore, David J. (Rochester, NY); Pettit, William H. (Rochester, NY)

    2002-01-01

    A method for controlling the power and temperature and fuel source of a combustor in a fuel cell apparatus to supply heat to a fuel processor where the combustor has dual fuel inlet streams including a first fuel stream, and a second fuel stream of anode effluent from the fuel cell and reformate from the fuel processor. In all operating modes, an enthalpy balance is determined by regulating the amount of the first and/or second fuel streams and the quantity of the first air flow stream to support fuel processor power requirements.

  5. Coal desulfurization in a rotary kiln combustor

    SciTech Connect (OSTI)

    Cobb, J.T. Jr.

    1992-09-11

    The purpose of this project was to demonstrate the combustion of coal and coal wastes in a rotary kiln reactor with limestone addition for sulfur control. The rationale for the project was the perception that rotary systems could bring several advantages to combustion of these fuels, and may thus offer an alternative to fluid-bed boilers. Towards this end, an existing wood pyrolysis kiln (the Humphrey Charcoal kiln) was to be suitably refurbished and retrofitted with a specially designed version of a patented air distributor provided by Universal Energy, Inc. (UEI). As the project progressed beyond the initial stages, a number of issues were raised regarding the feasibility and the possible advantages of burning coals in a rotary kiln combustor and, in particular, the suitability of the Humphrey Charcoal kiln as a combustor. Instead, an opportunity arose to conduct combustion tests in the PEDCO Rotary Cascading-Bed Boiler (RCBB) commercial demonstration unit at the North American Rayon CO. (NARCO) in Elizabethton, TN. The tests focused on anthracite culm and had two objectives: (a) determine the feasibility of burning anthracite culms in a rotary kiln boiler and (b) obtain input for any further work involving the Humphrey Charcoal kiln combustor. A number of tests were conducted at the PEDCO unit. The last one was conducted on anthracite culm procured directly from the feed bin of a commercial circulating fluid-bed boiler. The results were disappointing; it was difficult to maintain sustained combustion even when large quantities of supplemental fuel were used. Combustion efficiency was poor, around 60 percent. The results suggest that the rotary kiln boiler, as designed, is ill-suited with respect to low-grade, hard to burn solid fuels, such as anthracite culm. Indeed, data from combustion of bituminous coal in the PEDCO unit suggest that with respect to coal in general, the rotary kiln boiler appears inferior to the circulating fluid bed boiler.

  6. Low NO.sub.x multistage combustor

    DOE Patents [OSTI]

    Becker, Frederick E. (Reading, MA); Breault, Ronald W. (Newington, NH); Litka, Anthony F. (Hanover, MA); McClaine, Andrew W. (Lexington, MA); Shukla, Kailash (Boxborough, MA)

    2000-01-01

    A high efficiency, Vortex Inertial Staged Air (VIStA) combustor provides ultra-low NO.sub.X production of about 20 ppmvd or less with CO emissions of less than 50 ppmvd, both at 3% O.sub.2. Prompt NO.sub.X production is reduced by partially reforming the fuel in a first combustion stage to CO and H.sub.2. This is achieved in the first stage by operating with a fuel rich mixture, and by recirculating partially oxidized combustion products, with control over stoichiometry, recirculation rate and residence time. Thermal NO.sub.X production is reduced in the first stage by reducing the occurrence of high temperature combustion gas regions. This is achieved by providing the first stage burner with a thoroughly pre-mixed fuel/oxidant composition, and by recirculating part of the combustion products to further mix the gases and provide a more uniform temperature in the first stage. In a second stage combustor thermal NO.sub.X production is controlled by inducing a large flow of flue gas recirculation in the second stage combustion zone to minimize the ultimate temperature of the flame. One or both of the first and second stage burners can be cooled to further reduce the combustion temperature and to improve the recirculation efficiency. Both of these factors tend to reduce production of NO.sub.X.

  7. Optimization and neural modelling of pulse combustors for drying applications

    SciTech Connect (OSTI)

    Zbicinski, I.; Smucerowicz, I.; Strumillo, C.; Kasznia, J.; Stawczyk, J.; Murlikiewicz, K. [Technical Univ. of Lodz (Poland). Faculty of Process and Environmental Engineering

    1999-03-01

    Results of investigations of a valved pulse combustor to choose optimal geometry, which covered measurements of the flow rates of air and fuel, pressure oscillations, including pressure amplitude and frequency and flue gas composition are presented in the paper. Experimental studies comparing the operation of the pulse combustor coupled with a drying chamber and working separately are described. It was found that coupling of the pulse combustor with a drying chamber had no significant effect on the pulse combustion process. Smoother runs of pressure oscillations in the combustion chamber, lower noise level and slightly higher NO{sub x} emission were observed. The velocity flow field inside the drying chamber was measured by LDA technique. Results confirmed a complex character of pulsating flow in the chamber. A large experimental data set obtained from measurements enabled developing a neural model of pulse combustion process. Artificial neural networks were trained to predict amplitudes and frequencies of pressure oscillations, temperatures in the combustion chamber and emission of toxic substances. An excellent mapping performance of the developed neural models was obtained. Due to complex character of the pulse combustion process, the application of artificial neural networks seems to be the best way to predict inlet parameters of drying agent produced by the pulse combustor.

  8. Combustor with multistage internal vortices

    DOE Patents [OSTI]

    Shang, Jer Yu; Harrington, R.E.

    1987-05-01

    A fluidized bed combustor is provided with a multistage arrangement of vortex generators in the freeboard area. The vortex generators are provided by nozzle means which extend into the interior of the freeboard for forming vortices within the freeboard areas to enhance the combustion of particulate material entrained in product gases ascending into the freeboard from the fluidized bed. Each of the nozzles are radially inwardly spaced from the combustor walls defining the freeboard to provide for the formation of an essentially vortex-free, vertically extending annulus about the vortices whereby the particulate material centrifuged from the vortices against the inner walls of the combustor is returned through the annulus to the fluidized bed. By adjusting the vortex pattern within the freeboard, a significant portion of the full cross-sectional area of the freeboard except for the peripheral annulus can be contacted with the turbulent vortical flow for removing the particulate material from the gaseous products and also for enhancing the combustion thereof within the freeboard. 2 figs.

  9. Induction time effects in pulse combustors

    SciTech Connect (OSTI)

    Bell, J B; Marcus, D L; Pember, R B

    1999-04-09

    Combustion systems that take advantage of a periodic combustion process have many advantages over conventional systems. Their rate of heat transfer is greatly enhanced and their pollutant emissions are lower. They draw in their own supply of fuel and air and they are self-venting. They have few moving parts. The most common type of pulse combustor is based on a Helmholtz resonator - a burning cycle drives a resonant pressure wave, which in turn enhances the rate of combustion, resulting in a self-sustaining, large-scale oscillation. Although the basic physical mechanisms controlling such a process were explained by Rayleigh over a century ago, a full understanding of the operation of a pulse combustor still does not exist. The dominant processes in such a system--combustion, turbulent fluid dynamics, acoustics--are highly coupled and interact nonlinearly, which has reduced the design process to a costly and inefficient trial-and-error procedure. Several recent numerical and experimental studies, however, have been focused towards a better understanding of the basic underlying physics. Barr et al. [l] have elucidated the relative roles of the time scales governing the energy release, the turbulent mixing, and the acoustics. Keller et al. [5] have demonstrated the importance of the phase relation between the resonant pressure field in the tailpipe and the periodic energy release. Marcus et al. [6] have developed the capability for a fully three-dimensional simulation of the reacting flow in a pulse combustor. This paper is an application of that methodology to a detailed investigation of the frequency response of the model to changes in the chemical kinetics. The methodology consists of a fully conservative second-order Godunov algorithm for the inviscid, reacting gas dynamics equations coupled to an adaptive mesh refinement procedure[2]. The axisymmetric and three-dimensional simulations allow us to explore in detail the interaction between the transient fluid dynamics phenomena and the energy release associated with the combustion. For these simulations, we couple a second-order, unsplit Godunov algorithm for the inviscid, reacting gas dynamics equations to an adaptive Cartesian grid scheme[7]. In order to keep computational costs relatively low, we have developed a ''bootstrap'' procedure to initialize progressively higher-dimensional calculations. The quasi-one-dimensional code is run until transient phenomena have subsided and a desirable quasi-steady state has been achieved. The state data is then extrapolated to axisymmetric coordinates and these conditions used to initialize an axisymmetric calculation. The axisymmetric code is then run through several full combustion cycles and the data mapped to initialize a three-dimensional calculation.

  10. Slagging retrofit pulsed coal combustor: Final report

    SciTech Connect (OSTI)

    Not Available

    1987-01-01

    A concept for a novel form of slagging retrofit pulsed coal combustor was tested in the laboratory. The combustor is based on controlled use of a form of high pressure amplitude combustion instability. The approach adopted was to resolve, in single pulse experiments, the basic technical issues arising in the development of the combustor. In a cold flow device, the issues of coal spatial distribution were addressed and a combustor and solids disperser configuration was developed to give uniform coal distribution in the combustor. Single pulse ignition experiments were conducted to determine the pressure rise in combustor, pressure rise-decay times, and coal conversion a function of various operating variables. Coal injection, flame propagation, and blowdown times leading to potential combustor size reduction of three times over steady flow combustors were demonstrated. The results give high pressure exhaust leading to potentially improved downstream heat transfer and reduced boiler size. Finally, zero-, one-, and two-dimensional mathematical models were developed in support of the experiments and also to provide design capability. 11 refs., 43 figs.

  11. Combustor for fine particulate coal

    DOE Patents [OSTI]

    Carlson, L.W.

    1988-01-26

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

  12. Combustor for fine particulate coal

    DOE Patents [OSTI]

    Carlson, Larry W. (Oswego, IL)

    1988-01-01

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover.

  13. Combustor for fine particulate coal

    DOE Patents [OSTI]

    Carlson, L.W.

    1988-11-08

    A particulate coal combustor with two combustion chambers is provided. The first combustion chamber is toroidal; air and fuel are injected, mixed, circulated and partially combusted. The air to fuel ratio is controlled to avoid production of soot or nitrogen oxides. The mixture is then moved to a second combustion chamber by injection of additional air where combustion is completed and ash removed. Temperature in the second chamber is controlled by cooling and gas mixing. The clean stream of hot gas is then delivered to a prime mover. 4 figs.

  14. Wedge edge ceramic combustor tile

    DOE Patents [OSTI]

    Shaffer, J.E.; Holsapple, A.C.

    1997-06-10

    A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures. 7 figs.

  15. Wedge edge ceramic combustor tile

    DOE Patents [OSTI]

    Shaffer, James E. (Maitland, FL); Holsapple, Allan C. (Poway, CA)

    1997-01-01

    A multipiece combustor has a portion thereof being made of a plurality of ceramic segments. Each of the plurality of ceramic segments have an outer surface and an inner surface. Each of the plurality of ceramic segments have a generally cylindrical configuration and including a plurality of joints. The joints define joint portions, a first portion defining a surface being skewed to the outer surface and the inner surface. The joint portions have a second portion defining a surface being skewed to the outer surface and the inner surface. The joint portions further include a shoulder formed intermediate the first portion and the second portion. The joints provide a sealing interlocking joint between corresponding ones of the plurality of ceramic segments. Thus, the multipiece combustor having the plurality of ceramic segment with the plurality of joints reduces the physical size of the individual components and the degradation of the surface of the ceramic components in a tensile stress zone is generally eliminated reducing the possibility of catastrophic failures.

  16. Low NOx Advanced Vortex Combustor

    SciTech Connect (OSTI)

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

    2008-05-01

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

  17. Fuel cell system with combustor-heated reformer

    DOE Patents [OSTI]

    Pettit, William Henry (Rochester, NY)

    2000-01-01

    A fuel cell system including a fuel reformer heated by a catalytic combustor fired by anode effluent and/or fuel from a liquid fuel supply providing fuel for the fuel cell. The combustor includes a vaporizer section heated by the combustor exhaust gases for vaporizing the fuel before feeding it into the combustor. Cathode effluent is used as the principle oxidant for the combustor.

  18. Combustor oscillating pressure stabilization and method

    DOE Patents [OSTI]

    Gemmen, Randall S. (Morgantown, WV); Richards, George A. (Morgantown, WV); Yip, Mui-Tong Joseph (Morgantown, WV); Robey, Edward H. (Westover, WV); Cully, Scott R. (Morgantown, WV); Addis, Richard E. (Smithfield, PA)

    1998-01-01

    High dynamic pressure oscillations in hydrocarbon-fueled combustors typically occur when the transport time of the fuel to the flame front is at some fraction of the acoustic period. These oscillations are reduced to acceptably lower levels by restructuring or repositioning the flame front in the combustor to increase the transport time. A pilot flame front located upstream of the oscillating flame and pulsed at a selected frequency and duration effectively restructures and repositions the oscillating flame in the combustor to alter the oscillation-causing transport time.

  19. Chaos in an imperfectly premixed model combustor

    SciTech Connect (OSTI)

    Kabiraj, Lipika Saurabh, Aditya; Paschereit, Christian O.; Karimi, Nader; Sailor, Anna; Mastorakos, Epaminondas; Dowling, Ann P.

    2015-02-15

    This article reports nonlinear bifurcations observed in a laboratory scale, turbulent combustor operating under imperfectly premixed mode with global equivalence ratio as the control parameter. The results indicate that the dynamics of thermoacoustic instability correspond to quasi-periodic bifurcation to low-dimensional, deterministic chaos, a route that is common to a variety of dissipative nonlinear systems. The results support the recent identification of bifurcation scenarios in a laminar premixed flame combustor (Kabiraj et al., Chaos: Interdiscip. J. Nonlinear Sci. 22, 023129 (2012)) and extend the observation to a practically relevant combustor configuration.

  20. Combustor oscillating pressure stabilization and method

    DOE Patents [OSTI]

    Gemmen, R.S.; Richards, G.A.; Yip, M.T.J.; Robey, E.H.; Cully, S.R.; Addis, R.E.

    1998-08-11

    High dynamic pressure oscillations in hydrocarbon-fueled combustors typically occur when the transport time of the fuel to the flame front is at some fraction of the acoustic period. These oscillations are reduced to acceptably lower levels by restructuring or repositioning the flame front in the combustor to increase the transport time. A pilot flame front located upstream of the oscillating flame and pulsed at a selected frequency and duration effectively restructures and repositions the oscillating flame in the combustor to alter the oscillation-causing transport time. 7 figs.

  1. Scramjet including integrated inlet and combustor

    SciTech Connect (OSTI)

    Kutschenreuter, P.H. Jr.; Blanton, J.C.

    1992-02-04

    This patent describes a scramjet engine. It comprises: a first surface including an aft facing step; a cowl including: a leading edge and a trailing edge; an upper surface and a lower surface extending between the leading edge and the trailing edge; the cowl upper surface being spaced from and generally parallel to the first surface to define an integrated inlet-combustor therebetween having an inlet for receiving and channeling into the inlet-combustor supersonic inlet airflow; means for injecting fuel into the inlet-combustor at the step for mixing with the supersonic inlet airflow for generating supersonic combustion gases; and further including a spaced pari of sidewalls extending between the first surface to the cowl upper surface and wherein the integrated inlet-combustor is generally rectangular and defined by the sidewall pair, the first surface and the cowl upper surface.

  2. Combustor assembly in a gas turbine engine

    DOE Patents [OSTI]

    Wiebe, David J; Fox, Timothy A

    2013-02-19

    A combustor assembly in a gas turbine engine. The combustor assembly includes a combustor device coupled to a main engine casing, a first fuel injection system, a transition duct, and an intermediate duct. The combustor device includes a flow sleeve for receiving pressurized air and a liner disposed radially inwardly from the flow sleeve. The first fuel injection system provides fuel that is ignited with the pressurized air creating first working gases. The intermediate duct is disposed between the liner and the transition duct and defines a path for the first working gases to flow from the liner to the transition duct. An intermediate duct inlet portion is associated with a liner outlet and allows movement between the intermediate duct and the liner. An intermediate duct outlet portion is associated with a transition duct inlet section and allows movement between the intermediate duct and the transition duct.

  3. Combustor technology for broadened-properties fuels

    SciTech Connect (OSTI)

    Dodds, W.J.

    1984-01-01

    In order to increase the availability and reduce the cost of future fuels for aircraft gas turbine engines, it may be necessary to broaden fuel specifications. Anticipated changes in fuel properties, and the effects of these changes on combustion system performance, operating characteristics, durability, and emissions are briefly reviewed, and results to date of a program being conducted to develop and demonstrate combustor technology required to utilize broadened-properties fuels in current and next-generation engines are described. Combustion system design considerations and tradeoffs for burning broadened-properties fuels are discussed, and test experience with several applicable combustor design modifications to the G.E. CF6-80A combustion system is reviewed. Modifications have been demonstrated to improve liner cooling and reduce smoke in the conventional annular combustor, thereby reducing effects of variations in fuel hydrogen content. Advanced staged and variable geometry combustor concepts for burning broadened-properties fuels have also been demonstrated.

  4. NOx reduction in gas turbine combustors 

    E-Print Network [OSTI]

    Sung, Nak Won

    1976-01-01

    NOx REDUCTION IN GAS TURBINE COMBUSTORS A Thesis by Nak Won Sung Submitted to the Graduate College of Texas A&M University in partial fullfillment of the requirement for the degree of MASTER OF SCIENCE August 1976 Major Subject: Mechanical... Engineering NOx REDUCTION IN GAS TURBINE COMBUSTORS A Thesis by Nak Won Sung Approved as to style and content by: (Chairman of Committe (Head of Department) (Member) August 1976 "40308 (Member) 1 1. 1 ABSTRACT NOx Reduction in Gas Turbine...

  5. Rolling contact mounting arrangement for a ceramic combustor

    DOE Patents [OSTI]

    Boyd, Gary L. (328 Sneath Way, Alpine, CA 91901); Shaffer, James E. (1780 Geronimo Tr., Maitland, FL 32751)

    1995-01-01

    A combustor assembly having a preestablished rate of thermal expansion is mounted within a gas turbine engine housing having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the combustor assembly. The combustor assembly is constructed of a inlet end portion, a outlet end portion and a plurality of combustor ring segments positioned between the end portions. A mounting assembly is positioned between the combustor assembly and the gas turbine engine housing to allow for the difference in the rate of thermal expansion while maintaining axially compressive force on the combustor assembly to maintain contact between the separate components.

  6. Rolling contact mounting arrangement for a ceramic combustor

    DOE Patents [OSTI]

    Boyd, G.L.; Shaffer, J.E.

    1995-10-17

    A combustor assembly having a preestablished rate of thermal expansion is mounted within a gas turbine engine housing having a preestablished rate of thermal expansion being greater than the preestablished rate of thermal expansion of the combustor assembly. The combustor assembly is constructed of a inlet end portion, a outlet end portion and a plurality of combustor ring segments positioned between the end portions. A mounting assembly is positioned between the combustor assembly and the gas turbine engine housing to allow for the difference in the rate of thermal expansion while maintaining axially compressive force on the combustor assembly to maintain contact between the separate components. 3 figs.

  7. Micro-combustor for gas turbine engine

    DOE Patents [OSTI]

    Martin, Scott M. (Oviedo, FL)

    2010-11-30

    An improved gas turbine combustor (20) including a basket (26) and a multiplicity of micro openings (29) arrayed across an inlet wall (27) for passage of a fuel/air mixture for ignition within the combustor. The openings preferably have a diameter on the order of the quenching diameter; i.e. the port diameter for which the flame is self-extinguishing, which is a function of the fuel mixture, temperature and pressure. The basket may have a curved rectangular shape that approximates the shape of the curved rectangular shape of the intake manifolds of the turbine.

  8. System and method for controlling a combustor assembly

    DOE Patents [OSTI]

    York, William David; Ziminsky, Willy Steve; Johnson, Thomas Edward; Stevenson, Christian Xavier

    2013-03-05

    A system and method for controlling a combustor assembly are disclosed. The system includes a combustor assembly. The combustor assembly includes a combustor and a fuel nozzle assembly. The combustor includes a casing. The fuel nozzle assembly is positioned at least partially within the casing and includes a fuel nozzle. The fuel nozzle assembly further defines a head end. The system further includes a viewing device configured for capturing an image of at least a portion of the head end, and a processor communicatively coupled to the viewing device, the processor configured to compare the image to a standard image for the head end.

  9. Combustor for a low-emissions gas turbine engine

    DOE Patents [OSTI]

    Glezer, Boris (Del Mar, CA); Greenwood, Stuart A. (San Diego, CA); Dutta, Partha (San Diego, CA); Moon, Hee-Koo (San Diego, CA)

    2000-01-01

    Many government entities regulated emission from gas turbine engines including CO. CO production is generally reduced when CO reacts with excess oxygen at elevated temperatures to form CO2. Many manufactures use film cooling of a combustor liner adjacent to a combustion zone to increase durability of the combustion liner. Film cooling quenches reactions of CO with excess oxygen to form CO2. Cooling the combustor liner on a cold side (backside) away from the combustion zone reduces quenching. Furthermore, placing a plurality of concavities on the cold side enhances the cooling of the combustor liner. Concavities result in very little pressure reduction such that air used to cool the combustor liner may also be used in the combustion zone. An expandable combustor housing maintains a predetermined distance between the combustor housing and combustor liner.

  10. Stably operating pulse combustor and method

    DOE Patents [OSTI]

    Zinn, Ben T. (Atlanta, GA); Reiner, David (Haifa, IL)

    1990-01-01

    A pulse combustor apparatus adapted to burn either a liquid fuel or a pulverized solid fuel within a preselected volume of the combustion chamber. The combustion process is substantially restricted to an optimum combustion zone in order to attain effective pulse combustion operation.

  11. Stably operating pulse combustor and method

    DOE Patents [OSTI]

    Zinn, B.T.; Reiner, D.

    1990-05-29

    A pulse combustor apparatus is described which is adapted to burn either a liquid fuel or a pulverized solid fuel within a preselected volume of the combustion chamber. The combustion process is substantially restricted to an optimum combustion zone in order to attain effective pulse combustion operation. 4 figs.

  12. Pulsed atmospheric fluidized bed combustor apparatus

    DOE Patents [OSTI]

    Mansour, Momtaz N. (Columbia, MD)

    1993-10-26

    A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g., organic and medical waste, drying materials, heating air, calcining and the like.

  13. Controlling cycle-by-cycle variation in a pulse combustor

    SciTech Connect (OSTI)

    Daw, C.S.; Thomas, J.F. [Oak Ridge National Lab., TN (United States); Rhode, M.A.; Rollins, R.W. [Ohio Univ., Athens, OH (United States); Markworth, A.J. [Battelle Memorial Inst., Columbus, OH (United States)

    1995-06-01

    We describe a method for controlling chaos-generated cyclic variations in a pulse combustor. The method is applied to a recently developed thermal pulse combustor model and utilizes a map-based, adaptive proportional feedback algorithm. With this technique we show that it is possible to greatly reduce cycle-by-cycle pulse variation. We further show that minimizing cyclic variation allows combustor operation at conditions well beyond the normal flameout limit.

  14. Catalytic Combustor for Fuel-Flexible Turbine

    SciTech Connect (OSTI)

    Laster, W. R.; Anoshkina, E.

    2008-01-31

    Under the sponsorship of the U. S. Department of Energy’s National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1- Implementation Plan, Phase 2- Validation Testing and Phase 3 – Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

  15. Catalytic Combustor for Fuel-Flexible Turbine

    SciTech Connect (OSTI)

    W. R. Laster; E. Anoshkina

    2008-01-31

    Under the sponsorship of the U. S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse has conducted a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1 - Implementation Plan, Phase 2 - Validation Testing and Phase 3 - Field Testing. Both Phase 1 and Phase 2 of the program have been completed. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCLTM) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to oxidize a portion of the fuel, increasing the temperature of fuel/air mixture prior to the main combustion zone. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the technology necessary for the application of the catalytic concept to IGCC fuels was developed through detailed design and subscale testing. Phase III (currently not funded) will consist of full-scale combustor basket testing on natural gas and syngas.

  16. Catalytic Combustor for Fuel-Flexible Turbine

    SciTech Connect (OSTI)

    W. R. Laster; E. Anoshkina; P. Szedlacsek

    2006-03-31

    Under the sponsorship of the U.S. Department of Energy's National Energy Technology Laboratory, Siemens Westinghouse is conducting a three-year program to develop an ultra low NOx, fuel flexible catalytic combustor for gas turbine application in IGCC. The program is defined in three phases: Phase 1-Implementation Plan, Phase 2-Validation Testing and Phase 3-Field Testing. The Phase 1 program has been completed. Phase II was initiated in October 2004. In IGCC power plants, the gas turbine must be capable of operating on syngas as a primary fuel and an available back-up fuel such as natural gas. In this program the Rich Catalytic Lean (RCL{trademark}) technology is being developed as an ultra low NOx combustor. In this concept, ultra low NOx is achieved by stabilizing a lean premix combustion process by using a catalytic reactor to react part of the fuel, increasing the fuel/air mixture temperature. In Phase 1, the feasibility of the catalytic concept for syngas application has been evaluated and the key technology issues identified. In Phase II the catalytic concept will be demonstrated through subscale testing. Phase III will consist of full-scale combustor basket testing on natural gas and syngas.

  17. Rapid-quench axially staged combustor

    DOE Patents [OSTI]

    Feitelberg, Alan S. (Niskayuna, NY); Schmidt, Mark Christopher (Niskayuna, NY); Goebel, Steven George (Clifton Park, NY)

    1999-01-01

    A combustor cooperating with a compressor in driving a gas turbine includes a cylindrical outer combustor casing. A combustion liner, having an upstream rich section, a quench section and a downstream lean section, is disposed within the outer combustor casing defining a combustion chamber having at least a core quench region and an outer quench region. A first plurality of quench holes are disposed within the liner at the quench section having a first diameter to provide cooling jet penetration to the core region of the quench section of the combustion chamber. A second plurality of quench holes are disposed within the liner at the quench section having a second diameter to provide cooling jet penetration to the outer region of the quench section of the combustion chamber. In an alternative embodiment, the combustion chamber quench section further includes at least one middle region and at least a third plurality of quench holes disposed within the liner at the quench section having a third diameter to provide cooling jet penetration to at least one middle region of the quench section of the combustion chamber.

  18. Controlled pilot oxidizer for a gas turbine combustor

    DOE Patents [OSTI]

    Laster, Walter R. (Oviedo, FL); Bandaru, Ramarao V. (Greer, SC)

    2010-07-13

    A combustor (22) for a gas turbine (10) includes a main burner oxidizer flow path (34) delivering a first portion (32) of an oxidizer flow (e.g., 16) to a main burner (28) of the combustor and a pilot oxidizer flow path (38) delivering a second portion (36) of the oxidizer flow to a pilot (30) of the combustor. The combustor also includes a flow controller (42) disposed in the pilot oxidizer flow path for controlling an amount of the second portion delivered to the pilot.

  19. Fuel-Flexible, Low-Emissions Catalytic Combustor for Opportunity...

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

    to develop a unique, fuel-flexible catalytic combustor capable of enabling ultra-low emission, lean premixed combustion of a wide range of gaseous opportunity fuels. Fact...

  20. Apparatus and method for cooling a combustor cap

    DOE Patents [OSTI]

    Zuo, Baifang; Washam, Roy Marshall; Wu, Chunyang

    2014-04-29

    A combustor includes an end cap having a perforated downstream plate and a combustion chamber downstream of the downstream plate. A plenum is in fluid communication with the downstream plate and supplies a cooling medium to the combustion chamber through the perforations in the downstream plate. A method for cooling a combustor includes flowing a cooling medium into a combustor end cap and impinging the cooling medium on a downstream plate in the combustor end cap. The method further includes flowing the cooling medium into a combustion chamber through perforations in the downstream plate.

  1. Fuel-Flexible, Low-Emissions Catalytic Combustor for Opportunity...

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

    Next Generation Manufacturing Processes project to develop a unique, fuel-flexible catalytic combustor capable of enabling ultra-low emission, lean premixed combustion of a wide...

  2. Serial cooling of a combustor for a gas turbine engine

    DOE Patents [OSTI]

    Abreu, Mario E. (Poway, CA); Kielczyk, Janusz J. (Escondido, CA)

    2001-01-01

    A combustor for a gas turbine engine uses compressed air to cool a combustor liner and uses at least a portion of the same compressed air for combustion air. A flow diverting mechanism regulates compressed air flow entering a combustion air plenum feeding combustion air to a plurality of fuel nozzles. The flow diverting mechanism adjusts combustion air according to engine loading.

  3. American Institute of Aeronautics and Astronautics Ultra Low Emissions Combustor

    E-Print Network [OSTI]

    Seitzman, Jerry M.

    1 American Institute of Aeronautics and Astronautics T Ultra Low Emissions Combustor with Non-premixed modes of combustion with ultra low NOx emissions. The combustor consists of a tube with open and closed low temperatures with ultra low NOx emission in the 1 ppm range and below. It is also shown

  4. Combustor nozzle for a fuel-flexible combustion system

    DOE Patents [OSTI]

    Haynes, Joel Meier (Niskayuna, NY); Mosbacher, David Matthew (Cohoes, NY); Janssen, Jonathan Sebastian (Troy, NY); Iyer, Venkatraman Ananthakrishnan (Mason, OH)

    2011-03-22

    A combustor nozzle is provided. The combustor nozzle includes a first fuel system configured to introduce a syngas fuel into a combustion chamber to enable lean premixed combustion within the combustion chamber and a second fuel system configured to introduce the syngas fuel, or a hydrocarbon fuel, or diluents, or combinations thereof into the combustion chamber to enable diffusion combustion within the combustion chamber.

  5. Pulse Combustor Design, A DOE Assessment

    SciTech Connect (OSTI)

    National Energy Technology Laboratory

    2003-07-31

    The goal of the U.S. Department of Energy's (DOE) Clean Coal Technology (CCT) program is to furnish the energy marketplace with a number of advanced, more efficient, and environmentally responsible coal utilization technologies through demonstration projects. These projects seek to establish the commercial feasibility of the most promising advanced coal technologies that have developed beyond the proof-of-concept stage. This document serves as a DOE post-project assessment (PPA) of a project selected in CCT Round IV, the Pulse Combustor Design Qualification Test, as described in a Report to Congress (U.S. Department of Energy 1992). Pulse combustion is a method intended to increase the heat-transfer rate in a fired heater. The desire to demonstrate the use of pulse combustion as a source of heat for the gasification of coal, thus avoiding the need for an oxygen plant, prompted ThermoChem, Inc. (TCI), to submit a proposal for this project. In October 1992, TCI entered into a cooperative agreement with DOE to conduct this project. In 1998, the project was restructured and scaled down, and in September 1998, a new cooperative agreement was signed. The site of the revised project was TCI's facilities in Baltimore, Maryland. The original purpose of this CCT project was to demonstrate a unit that would employ ten identical 253-resonance tube combustors in a coal gasification unit. The objective of the scaled-down project was to test a single 253-resonance-tube combustor in a fluidized sand bed, with gasification being studied in a process development unit (PDU). DOE provided 50 percent of the total project funding of $8.6 million. The design for the demonstration unit was completed in February 1999, and construction was completed in November 2000. Operations were conducted in March 2001.

  6. Combustor air flow control method for fuel cell apparatus

    DOE Patents [OSTI]

    Clingerman, Bruce J. (Palmyra, NY); Mowery, Kenneth D. (Noblesville, IN); Ripley, Eugene V. (Russiaville, IN)

    2001-01-01

    A method for controlling the heat output of a combustor in a fuel cell apparatus to a fuel processor where the combustor has dual air inlet streams including atmospheric air and fuel cell cathode effluent containing oxygen depleted air. In all operating modes, an enthalpy balance is provided by regulating the quantity of the air flow stream to the combustor to support fuel cell processor heat requirements. A control provides a quick fast forward change in an air valve orifice cross section in response to a calculated predetermined air flow, the molar constituents of the air stream to the combustor, the pressure drop across the air valve, and a look up table of the orifice cross sectional area and valve steps. A feedback loop fine tunes any error between the measured air flow to the combustor and the predetermined air flow.

  7. Radial inlet guide vanes for a combustor

    DOE Patents [OSTI]

    Zuo, Baifang; Simons, Derrick; York, William; Ziminsky, Willy S

    2013-02-12

    A combustor may include an interior flow path therethrough, a number of fuel nozzles in communication with the interior flow path, and an inlet guide vane system positioned about the interior flow path to create a swirled flow therein. The inlet guide vane system may include a number of windows positioned circumferentially around the fuel nozzles. The inlet guide vane system may also include a number of inlet guide vanes positioned circumferentially around the fuel nozzles and adjacent to the windows to create a swirled flow within the interior flow path.

  8. Combined fluidized bed retort and combustor

    DOE Patents [OSTI]

    Shang, Jer-Yu (Fairfax, VA); Notestein, John E. (Morgantown, WV); Mei, Joseph S. (Morgantown, WV); Zeng, Li-Wen (Morgantown, WV)

    1984-01-01

    The present invention is directed to a combined fluidized bed retorting and combustion system particularly useful for extracting energy values from oil shale. The oil-shale retort and combustor are disposed side-by-side and in registry with one another through passageways in a partition therebetween. The passageways in the partition are submerged below the top of the respective fluid beds to preclude admixing or the product gases from the two chambers. The solid oil shale or bed material is transported through the chambers by inclining or slanting the fluidizing medium distributor so that the solid bed material, when fluidized, moves in the direction of the downward slope of the distributor.

  9. Development of a coal burning pulsating combustor for industrial power

    SciTech Connect (OSTI)

    Zinn, B.T.; Wang, M.R.; Daniel, B.R.

    1983-11-01

    The research conducted under this program investigated the performance characteristics of a previously developed coal burning pulsating combustor whose design is based upon the Rijke tube principles. The combustor consists of a vertical tube opened at both ends with a fuel burning bed located in the middle of its lower half. Coal is supplied to the bed by a rotating auger-type feed system located 1 ft above the bed. Following ignition, the interaction between the combustion process and the combustor flow results in the excitation of high amplitude (up to 165 dB) fundamental, longitudinal acoustic mode oscillations with frequencies in the range 75 to 90 Hz in the combustor. Maximum amplitudes occurred near stoichiometric air/fuel ratio operation, suggesting that systems utilizing the developed combustor should possess high thermal efficiencies, as they could operate with relatively litle excess air. Both bituminous and subbituminous coals with sizes in the range 1/4'' to 1/2'' were burned in the developed pulsating combustor. The CO, CO/sub 2/, NO/sub x/, SO/sub 2/, O/sub 2/ and particulates concentrations in the exhaust flow were measured to evaluate the combustor performance. In tests with bituminous coal, combustion efficiencies higher than 95% for coal feed rates in the range 42 to 60 lb/ft/sup 2/hr were achieved with only 13% excess air while NO/sub x/ and SO/sub 2/ concentrations were comparable to those obtained with other steady state combustors. A higher performance was attained in initial tests with subbituminous coal. Finally, pulsating operation was possible under fuel rich conditions suggesting that the developed pulsating combustor could be possibly used as a gasifier.

  10. Systems and methods for detection of blowout precursors in combustors

    DOE Patents [OSTI]

    Lieuwen, Tim C.; Nair, Suraj

    2006-08-15

    The present invention comprises systems and methods for detecting flame blowout precursors in combustors. The blowout precursor detection system comprises a combustor, a pressure measuring device, and blowout precursor detection unit. A combustion controller may also be used to control combustor parameters. The methods of the present invention comprise receiving pressure data measured by an acoustic pressure measuring device, performing one or a combination of spectral analysis, statistical analysis, and wavelet analysis on received pressure data, and determining the existence of a blowout precursor based on such analyses. The spectral analysis, statistical analysis, and wavelet analysis further comprise their respective sub-methods to determine the existence of blowout precursors.

  11. Achieving improved cycle efficiency via pressure gain combustors

    SciTech Connect (OSTI)

    Gemmen, R.S.; Janus, M.C.; Richards, G.A.; Norton, T.S. [USDOE Morgantown Energy Technology Center, WV (United States); Rogers, W.A. [EG& G Technical Services of West Virginia, Morgantown, WV (United States)

    1995-04-01

    As part of the Department of Energy`s Advanced Gas Turbine Systems Program, an investigation is being performed to evaluate ``pressure gain`` combustion systems for gas turbine applications. This paper presents experimental pressure gain and pollutant emission data from such combustion systems. Numerical predictions for certain combustor geometries are also presented. It is reported that for suitable aerovalved pulse combustor geometries studied experimentally, an overall combustor pressure gain of nearly 1 percent can be achieved. It is also shown that for one combustion system operating under typical gas turbine conditions, NO{sub x} and CO emmissions, are about 30 ppmv and 8 ppmv, respectively.

  12. A valveless pulse combustor with wide operation range and low noise level

    SciTech Connect (OSTI)

    Ohiwa, N.; Yamaguchi, S. (Dept. of Mechanical Engineering, Nagoya Institute of Technology, Gokiso-cho, Showa-ku, Nagoya (JP))

    1989-09-01

    The possibility of a valveless pulse combustor with wide range and low noise level was experimentally examined by introducing two practical approaches simultaneously: one is the rich mixture supply outside the flammability limit, instead of the ordinary fuel supply without any primary air; the other is forced secondary air ventilation. An overall evaluation of pulsation limits was also made in terms of the volumetric efficiency of the pulse combustor. Fuel used was a commercial grade gaseous propane. The results show that, under a constant total of equivalence ratios of 0.9, a large turn-down ratio of 9.4-11.5 and a high combustion intensity of 55-67MW/m/sup 3/ could be obtained by setting the rich mixture equivalence ratio equal to 3.0. Also, the proposed valveless pulse combustor could operate more silently than the flapper-valued one by 3-8dB(A), being indicative of noise radiation due to valve flapping.

  13. DOE/EIA-0304 Survey of Large Combustors:

    Annual Energy Outlook [U.S. Energy Information Administration (EIA)]

    was prepared in the Office of Energy Markets and End Use under the directorship of Wray Smith (252-8544). Overall direct report supervision was provided by Kenneth A. Vagts...

  14. Large Eddy Simulations of Combustor Liner Flows | Argonne Leadership...

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

    barrels of oil per day, or about 6 percent of the world's total oil usage. Aviation gas turbine engines are also significant producers of CO2 and other harmful greenhouse gas...

  15. DOE/EIA-0304 Survey of Large Combustors:

    Gasoline and Diesel Fuel Update (EIA)

    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 of Natural GasAdjustments (Billion Cubic Feet)DecadeYear Jan Feb Mar Apr May Jun Jul AugAdditions1 0 0 0 0 0 2013304 Survey of

  16. Large Eddy Simulations of Combustor Liner Flows | Argonne Leadership

    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 Outreach Home Room NewsInformationJesse Bergkamp Graduate studentScienceLaboratory program LabsDesign

  17. Method for operating a combustor in a fuel cell system

    DOE Patents [OSTI]

    Chalfant, Robert W. (West Henrietta, NY); Clingerman, Bruce J. (Palmyra, NY)

    2002-01-01

    A method of operating a combustor to heat a fuel processor in a fuel cell system, in which the fuel processor generates a hydrogen-rich stream a portion of which is consumed in a fuel cell stack and a portion of which is discharged from the fuel cell stack and supplied to the combustor, and wherein first and second streams are supplied to the combustor, the first stream being a hydrocarbon fuel stream and the second stream consisting of said hydrogen-rich stream, the method comprising the steps of monitoring the temperature of the fuel processor; regulating the quantity of the first stream to the combustor according to the temperature of the fuel processor; and comparing said quantity of said first stream to a predetermined value or range of predetermined values.

  18. Characterization of supersonic mixing in a nonreacting Mach 2 combustor

    SciTech Connect (OSTI)

    Hollo, S.D.; Mcdaniel, J.C.; Hartfield, R.J., JR. )

    1992-01-01

    Planar measurements of the injection mole fraction distribution and the velocity field within a nonreacting model SCRAMJET combustor have been made using laser-induced iodine fluorescence. The combustor geometry investigated in this work is staged transverse injection of air into a Mach 2 freestream. A complete three-dimensional survey of the injectant mole fraction distribution has been generated and a single planar velocity measurement has been completed. The measurements reveal the dramatic effect of streamwise vortices on the mixing of the injectant in the near field of the injectors, as well as the rapid mixing generated by staging two field injectors. Analysis of the downstream decay of the maximum injectant mole fraction in this and other nonreacting combustor geometries indicates that the relative rate of injectant mixing well downstream of the injectors is independent of combustor geometry, combustor Mach number, and injectant molecular weight. Mixing within this region of the combustor is dominated by turbulent diffusion within the injectant plume. The transition of the dominant mixing mechanism, from vortex-driven mixing in the near field to turbulent diffusion in the far field, was found to occur in the region between 10 and 20 jet diameters downstream of the injectors. 22 refs.

  19. 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.

  20. Flow conditioner for fuel injector for combustor and method for low-NO.sub.x combustor

    DOE Patents [OSTI]

    Dutta, Partha; Smith, Kenneth O.; Ritz, Frank J.

    2013-09-10

    An injector for a gas turbine combustor including a catalyst coated surface forming a passage for feed gas flow and a channel for oxidant gas flow establishing an axial gas flow through a flow conditioner disposed at least partially within an inner wall of the injector. The flow conditioner includes a length with an interior passage opening into upstream and downstream ends for passage of the axial gas flow. An interior diameter of the interior passage smoothly reduces and then increases from upstream to downstream ends.

  1. Experimental studies on methane-fuel laboratory scale ram combustor

    SciTech Connect (OSTI)

    Kinoshita, Y.; Kitajima, J.; Seki, Y.; Tatara, A.

    1995-07-01

    The laboratory scale ram combustor test program has been investigating fundamental combustion characteristics of a ram combustor, which operates from Mach 2.5 to 5 for the super/hypersonic transport propulsion system. In the previous study, combustion efficiency had been found poor, less than 70 percent, due to a low inlet air temperature and a high velocity at Mach 3 condition. To improve the low combustion efficiency, a fuel zoning combustion concept was investigated by using a subscale combustor model first. Combustion efficiency more than 90 percent was achieved and the concept was found very effective. Then a laboratory scale ram combustor was fabricated and combustion tests were carried out mainly at the simulated condition of Mach 5. A vitiation technique wa used to simulate a high temperature of 1,263 K. The test results indicate that ignition, flame stability, and combustion efficiency were not significant, but the NO{sub x} emissions are a critical problem for the ram combustor at Mach 5 condition.

  2. Development of a pulse coal combustor for industrial applications

    SciTech Connect (OSTI)

    Not Available

    1990-10-31

    This report presents the results of the first phase of a program for the development of a retrofit pulse coal combustor for industrial applications. This phase was comprised of laboratory-scale (approximately 2 MMBtu/hr) combustor design optimization testing and the preparation of an integrated prototype combustor system design at approximately 3.5 to 5.0 MMBtu/hr scale for further development in Phase IA. The program objective was to develop an advanced pulse coal combustor system at the required scale that has high carbon utilization, high ash rejection, low flue gas emissions and low sensitivity to variations in fuels specifications. An optimized tandem advanced refractory chamber unit was designed and fabricate during October and November 1987. The unit logged approximately 100 hours of operation burning pulverized coals, micronized coals, coal-water slurries made of pulverized coal, and micronized coal. Sulfur capturing sorbents lime/limestone were injected into the combustor system to evaluate sulfur capturing efficiency. Staged air injections were also investigated. 42 figs., 16 tabs.

  3. Anomaly detection in thermal pulse combustors using symbolic time series analysis

    E-Print Network [OSTI]

    Ray, Asok

    pulse combustor. Results are presented to exemplify early detection of combustion instability due339 Anomaly detection in thermal pulse combustors using symbolic time series analysis S Gupta1 for anomaly detection in thermal pulse combustors. The anomaly detection method has been tested on the time

  4. LES-based Eulerian PDF approach for the simulation of scramjet combustors

    E-Print Network [OSTI]

    Raman, Venkat

    . The computational tool is used to simulate a cavity-stabilized Mach 2.2 supersonic combustor. The LESLES-based Eulerian PDF approach for the simulation of scramjet combustors Heeseok Koo , Pratik to oscillatory motions of the shock-system inside the combustor. Detailed analyses of the LES data are used

  5. Lean Blow-Out Prediction in Gas Turbine Combustors Using Symbolic Time Series Analysis

    E-Print Network [OSTI]

    Ray, Asok

    Lean Blow-Out Prediction in Gas Turbine Combustors Using Symbolic Time Series Analysis Achintya of lean blowout in gas turbine combustors based on symbolic analysis of time series data from optical. For the purpose of detecting lean blowout in gas turbine combustors, the state probability vector obtained

  6. Pulse combustor modeling demonstration of the importance of characteristic times

    SciTech Connect (OSTI)

    Barr, P.K.; Keller, J.O.; Bramlette, T.T.; Dec, J.E. (Combustion Research Facility, Sandia National Lab., Livermore, CA (US)); Westbrook, C.K. (Lawrence Livermore National Lab., Univ. of California, Livermore, CA (US))

    1990-12-01

    A numerical model has been developed to study the sensitivity of a pulse combustor's performance to changes in the relative timing between several of the dominant physical processes. The model is used to demonstrate the importance of the characteristic times associated with acoustics, fluid mixing, and chemical kinetics, which have been identified from both theoretical and experimental evidence. The combination of submodels for acoustics, injection, and combustion produces a pulse combustor model that is dynamic in that it fully couples the injection and mixing processes to the acoustic waves. Comparisons of simulations with experimental results show good agreement, verifying the model over a wide range of operating conditions. Because the model provides more control of the dominant processes than can be obtained in experiments, the parametric study establishes the cause-effect relations between the characteristic times and the resulting combustor performance.

  7. Gas turbine engine combustor can with trapped vortex cavity

    DOE Patents [OSTI]

    Burrus, David Louis; Joshi, Narendra Digamber; Haynes, Joel Meier; Feitelberg, Alan S.

    2005-10-04

    A gas turbine engine combustor can downstream of a pre-mixer has a pre-mixer flowpath therein and circumferentially spaced apart swirling vanes disposed across the pre-mixer flowpath. A primary fuel injector is positioned for injecting fuel into the pre-mixer flowpath. A combustion chamber surrounded by an annular combustor liner disposed in supply flow communication with the pre-mixer. An annular trapped dual vortex cavity located at an upstream end of the combustor liner is defined between an annular aft wall, an annular forward wall, and a circular radially outer wall formed therebetween. A cavity opening at a radially inner end of the cavity is spaced apart from the radially outer wall. Air injection first holes are disposed through the forward wall and air injection second holes are disposed through the aft wall. Fuel injection holes are disposed through at least one of the forward and aft walls.

  8. Combustor with two stage primary fuel assembly

    DOE Patents [OSTI]

    Sharifi, Mehran (Winter Springs, FL); Zolyomi, Wendel (Oviedo, FL); Whidden, Graydon Lane (Orlando, FL)

    2000-01-01

    A combustor for a gas turbine having first and second passages for pre-mixing primary fuel and air supplied to a primary combustion zone. The flow of fuel to the first and second pre-mixing passages is separately regulated using a single annular fuel distribution ring having first and second row of fuel discharge ports. The interior portion of the fuel distribution ring is divided by a baffle into first and second fuel distribution manifolds and is located upstream of the inlets to the two pre-mixing passages. The annular fuel distribution ring is supplied with fuel by an annular fuel supply manifold, the interior portion of which is divided by a baffle into first and second fuel supply manifolds. A first flow of fuel is regulated by a first control valve and directed to the first fuel supply manifold, from which the fuel is distributed to first fuel supply tubes that direct it to the first fuel distribution manifold. From the first fuel distribution manifold, the first flow of fuel is distributed to the first row of fuel discharge ports, which direct it into the first pre-mixing passage. A second flow of fuel is regulated by a second control valve and directed to the second fuel supply manifold, from which the fuel is distributed to second fuel supply tubes that direct it to the second fuel distribution manifold. From the second fuel distribution manifold, the second flow of fuel is distributed to the second row of fuel discharge ports, which direct it into the second pre-mixing passage.

  9. Modeling sulfur dioxide capture in a pulverized coal combustor

    SciTech Connect (OSTI)

    Nair, R.B.; Yavuzkurt, S. [Pennsylvania State Univ., University Park, PA (United States)

    1997-04-01

    The formation and capture of sulfur dioxide in a pulverized coal combustor is investigated. A two-dimensional, steady, axisymmetric code, PCGC-2 (Pulverized Coal Gasification and Combustion-two Dimensional), originally developed at Brigham Young University, has been used to simulate combustion of the pulverized coal. This paper represents part of a project to investigate simultaneously enhancing sulfur capture and particulate agglomeration in combustor effluents. Results from the code have been compared to experimental data obtained from MTCI`s (Manufacturing Technology and Conversion International) test pulse combustor, which generates sound pressure levels of {approximately}180 dB. The overall goal behind the pulse combustor program at MTCI is to develop combustors for stationary gas turbines that use relatively inexpensive coal-based fuels. This study attempts to model the capture of sulfur dioxide when injected into a pulse combustor firing micronized coal. While this work does not presume to model the complex gas flow-field generated by the pulsating flow, the effects of the acoustic field are expressed by increased heat and mass transfer to the particles (coal/sorbent) in question. A comprehensive calcination-sintering-sulfation model for single particles was used to model the capture of sulfur dioxide by limestone sorbent. Processes controlling sulfation are external heat and mass transfer, pore diffusion, diffusion through the product layer of CaSO{sub 4}, sintering, and calcination. The model was incorporated into the PCGC-2 program. Comparisons of exit concentrations of SO{sub 2} showed a fairly good agreement (within {approximately}10 percent) with the experimental results from MTCI.

  10. Waste incineration through pulsating combustion. Part I. Combustor characterization

    SciTech Connect (OSTI)

    Bai, Tiejun; Yeboah, Y.D.; Wang, Zhicheng [Clark Atlanta Univ., GA (United States)] [and others

    1996-12-31

    This paper describes work performed under the 1st phase of an on-going effort to develop pulsating combustion waste incineration technology. The primary objective of the effort is to study the effect of pulsating combustion upon the incineration of wastes, especially medical wastes, and to develop a laboratory scale experimental pulsating combustion medical waste incinerator. In this paper, the characteristics of the developed combustor are discussed. Specifically, emission measurement under various operating conditions of the combustor is discussed. The numerical analysis of the fluid flow is also presented.

  11. Method for operating a combustor in a fuel cell system

    DOE Patents [OSTI]

    Clingerman, Bruce J. (Palmyra, NY); Mowery, Kenneth D. (Noblesville, IN)

    2002-01-01

    In one aspect, the invention provides a method of operating a combustor to heat a fuel processor to a desired temperature in a fuel cell system, wherein the fuel processor generates hydrogen (H.sub.2) from a hydrocarbon for reaction within a fuel cell to generate electricity. More particularly, the invention provides a method and select system design features which cooperate to provide a start up mode of operation and a smooth transition from start-up of the combustor and fuel processor to a running mode.

  12. Turbine combustor with fuel nozzles having inner and outer fuel circuits

    DOE Patents [OSTI]

    Uhm, Jong Ho; Johnson, Thomas Edward; Kim, Kwanwoo

    2013-12-24

    A combustor cap assembly for a turbine engine includes a combustor cap and a plurality of fuel nozzles mounted on the combustor cap. One or more of the fuel nozzles would include two separate fuel circuits which are individually controllable. The combustor cap assembly would be controlled so that individual fuel circuits of the fuel nozzles are operated or deliberately shut off to provide for physical separation between the flow of fuel delivered by adjacent fuel nozzles and/or so that adjacent fuel nozzles operate at different pressure differentials. Operating a combustor cap assembly in this fashion helps to reduce or eliminate the generation of undesirable and potentially harmful noise.

  13. Coal desulfurization in a rotary kiln combustor. Final report, March 15, 1990--July 31, 1991

    SciTech Connect (OSTI)

    Cobb, J.T. Jr.

    1992-09-11

    The purpose of this project was to demonstrate the combustion of coal and coal wastes in a rotary kiln reactor with limestone addition for sulfur control. The rationale for the project was the perception that rotary systems could bring several advantages to combustion of these fuels, and may thus offer an alternative to fluid-bed boilers. Towards this end, an existing wood pyrolysis kiln (the Humphrey Charcoal kiln) was to be suitably refurbished and retrofitted with a specially designed version of a patented air distributor provided by Universal Energy, Inc. (UEI). As the project progressed beyond the initial stages, a number of issues were raised regarding the feasibility and the possible advantages of burning coals in a rotary kiln combustor and, in particular, the suitability of the Humphrey Charcoal kiln as a combustor. Instead, an opportunity arose to conduct combustion tests in the PEDCO Rotary Cascading-Bed Boiler (RCBB) commercial demonstration unit at the North American Rayon CO. (NARCO) in Elizabethton, TN. The tests focused on anthracite culm and had two objectives: (a) determine the feasibility of burning anthracite culms in a rotary kiln boiler and (b) obtain input for any further work involving the Humphrey Charcoal kiln combustor. A number of tests were conducted at the PEDCO unit. The last one was conducted on anthracite culm procured directly from the feed bin of a commercial circulating fluid-bed boiler. The results were disappointing; it was difficult to maintain sustained combustion even when large quantities of supplemental fuel were used. Combustion efficiency was poor, around 60 percent. The results suggest that the rotary kiln boiler, as designed, is ill-suited with respect to low-grade, hard to burn solid fuels, such as anthracite culm. Indeed, data from combustion of bituminous coal in the PEDCO unit suggest that with respect to coal in general, the rotary kiln boiler appears inferior to the circulating fluid bed boiler.

  14. Fluidized bed combustor and coal gun-tube assembly therefor

    DOE Patents [OSTI]

    Hosek, William S. (Mt. Tabor, NJ); Garruto, Edward J. (Wayne, NJ)

    1984-01-01

    A coal supply gun assembly for a fluidized bed combustor which includes heat exchange elements extending above the bed's distributor plate assembly and in which the gun's nozzles are disposed relative to the heat exchange elements to only discharge granular coal material between adjacent heat exchange elements and in a path which is substantially equidistant from adjacent heat exchange elements.

  15. Coanda injection system for axially staged low emission combustors

    DOE Patents [OSTI]

    Evulet, Andrei Tristan (Clifton Park, NY); Varatharajan, Balachandar (Cincinnati, OH); Kraemer, Gilbert Otto (Greer, SC); ElKady, Ahmed Mostafa (Niskayuna, NY); Lacy, Benjamin Paul (Greer, SC)

    2012-05-15

    The low emission combustor includes a combustor housing defining a combustion chamber having a plurality of combustion zones. A liner sleeve is disposed in the combustion housing with a gap formed between the liner sleeve and the combustor housing. A secondary nozzle is disposed along a centerline of the combustion chamber and configured to inject a first fluid comprising air, at least one diluent, fuel, or combinations thereof to a downstream side of a first combustion zone among the plurality of combustion zones. A plurality of primary fuel nozzles is disposed proximate to an upstream side of the combustion chamber and located around the secondary nozzle and configured to inject a second fluid comprising air and fuel to an upstream side of the first combustion zone. The combustor also includes a plurality of tertiary coanda nozzles. Each tertiary coanda nozzle is coupled to a respective dilution hole. The tertiary coanda nozzles are configured to inject a third fluid comprising air, at least one other diluent, fuel, or combinations thereof to one or more remaining combustion zones among the plurality of combustion zones.

  16. Catalytic combustor for integrated gasification combined cycle power plant

    DOE Patents [OSTI]

    Bachovchin, Dennis M. (Mauldin, SC); Lippert, Thomas E. (Murrysville, PA)

    2008-12-16

    A gasification power plant 10 includes a compressor 32 producing a compressed air flow 36, an air separation unit 22 producing a nitrogen flow 44, a gasifier 14 producing a primary fuel flow 28 and a secondary fuel source 60 providing a secondary fuel flow 62 The plant also includes a catalytic combustor 12 combining the nitrogen flow and a combustor portion 38 of the compressed air flow to form a diluted air flow 39 and combining at least one of the primary fuel flow and secondary fuel flow and a mixer portion 78 of the diluted air flow to produce a combustible mixture 80. A catalytic element 64 of the combustor 12 separately receives the combustible mixture and a backside cooling portion 84 of the diluted air flow and allows the mixture and the heated flow to produce a hot combustion gas 46 provided to a turbine 48. When fueled with the secondary fuel flow, nitrogen is not combined with the combustor portion.

  17. Flame-vortex interaction driven combustion dynamics in a backward-facing step combustor

    SciTech Connect (OSTI)

    Altay, H. Murat; Speth, Raymond L.; Hudgins, Duane E.; Ghoniem, Ahmed F.

    2009-05-15

    The combustion dynamics of propane-hydrogen mixtures are investigated in an atmospheric pressure, lean, premixed backward-facing step combustor. We systematically vary the equivalence ratio, inlet temperature and fuel composition to determine the stability map of the combustor. Simultaneous pressure, velocity, heat release rate and equivalence ratio measurements and high-speed video from the experiments are used to identify and characterize several distinct operating modes. When fuel is injected far upstream from the step, the equivalence ratio entering the flame is temporally and spatially uniform, and the combustion dynamics are governed only by flame-vortex interactions. Four distinct dynamic regimes are observed depending on the operating parameters. At high but lean equivalence ratios, the flame is unstable and oscillates strongly as it is wrapped around the large unsteady wake vortex. At intermediate equivalence ratios, weakly oscillating quasi-stable flames are observed. Near the lean blowout limit, long stable flames extending from the corner of the step are formed. At atmospheric inlet temperature, the unstable mode resonates at the 1/4 wavemode of the combustor. As the inlet temperature is increased, the 5/4 wavemode of the combustor is excited at high but lean equivalence ratios, forming the high-frequency unstable flames. Higher hydrogen concentration in the fuel and higher inlet temperatures reduce the equivalence ratios at which the transitions between regimes are observed. We plot combustion dynamics maps or the response curves, that is the overall sound pressure level as a function of the equivalence ratio, for different operating conditions. We demonstrate that numerical results of strained premixed flames can be used to collapse the response curves describing the transitions among the dynamic modes onto a function of the heat release rate parameter alone, rather than a function dependent on the equivalence ratio, inlet temperature and fuel composition separately. We formulate a theory for predicting the critical values of the heat release parameter at which quasi-stable to unstable and unstable to high-frequency unstable modes take place. (author)

  18. An investigation of the gas-fired pulsating combustor

    SciTech Connect (OSTI)

    Ku, S.H.

    1988-01-01

    The work reported here was mainly experimental although a methodology was developed for determining the combustion efficiency from the analysis of the exhaust gases, and also, simple, linear and non-linear models were developed to predict the pulsation frequency and the level of the boost pressure in the pulse combustor. The performance measurements indicated that the pulse frequency and the performance of the gas fired, valved pulse combustor depends upon the volume of the combustion chamber and the size of the tailpipe. Combustion efficiencies are extremely high and CO and NO{sub x} emissions are very low for fuel lean conditions. Visualization showed the fuel jet entering the mixing chamber followed by a wide air jet. Highly turbulent combustion then takes place in small pockets moving in two counter rotating vortices. The early heat release under very fuel lean conditions results in much of the combustion energy being released out of phase with pressure pulsations causing damping and, therefore, leading to the existence of a fuel lean limit. On the other hand, the delay in heat release near stoichiometric conditions caused by the belated entry of the air jet seems to prevent sufficient heat to be released during the remainder of the cycle, in phase with the pressure oscillations to provide enough driving to overcome the inherent losses in the pulse combustor. A fuel rich limit of operation of the pulse combustor is, therefore, reached as the equivalence ratio approaches one. LDV measurements confirmed the existence of an axial vortex and the pair of counter rotating vortices during the combustion part of the cycle. Very high turbulence intensity levels were observed throughout the combustor at all instances during the cycle.

  19. Heat release timing in a nonpremixed Helmholtz pulse combustor

    SciTech Connect (OSTI)

    Tang, Y.M. (Tam Kang Univ., Taipei (Taiwan, Province of China)); Waldherr, G.; Jagoda, J.I.; Zinn, B.T. (Georgia Inst. of Technology, Atlanta, GA (United States). Lab. for Pulse Combustion Processing)

    1995-01-01

    This paper discusses the mechanism by which heat release fluctuations drive pressure pulsations in Helmholtz pulse combustors with nonpremixed fuel and air injection, similar to those used in commercialized pulse furnaces. Flow and flame spread in the mixing chamber were mapped using high-speed shadowgraphy, extensive laser Doppler velocimetry, and radical imaging. Flow visualization and velocity measurements showed that a fuel jet followed by an air jet enter the pulse combustor as soon as the combustor pressure drops below the reactants' supply pressures. If most of the heat were released at that time, the heat release and pressure fluctuations would be out of phase, which according to Rayleigh's criterion, would prevent pulse combustion operation. In practice, pulse combustion operation is attained through the interaction of several processes. First, the fuel jet is ignited as soon as it enters the mixing chamber, generating pockets of burning gas. This reacting flow is entrained and convected by the air jet, which follows the fuel jet into the combustor, first downstream and then upstream in the mixing chamber. Simultaneously, fuel and air continue to enter the combustor, but are not immediately ignited, either because of excessive flame stretch caused by the fast moving fuel and air jets or because the air stream has displaced any hot gases that could act as ignition sources. Once the reacting gas pockets return to the upstream half of the mixing chamber, they ignite the combustible mixture that has collected there. This causes a rapid increase in heat release rate, which leads the pressure oscillation by around 30[degree]. This investigation showed that the interaction between complex flow and combustion process within the mixing chamber causes the time delay needed to produce heat release oscillations that are nearly in phase with the pressure oscillations, thus assuring pulse combustion operation.

  20. Large

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  1. OH-Planar Fluorescence Measurements of Pressurized, Hydrogen Premixed Flames in the SimVal Combustor

    SciTech Connect (OSTI)

    Strakey, P.A.; Woodruff, S.D.; Williams, T.C.; Schefer, R.W.

    2008-07-01

    Planar laser-induced fluorescence measurements of the hydroxyl radical in lean, premixed natural gas flames augmented with hydrogen are presented. The experiments were conducted in the Simulation Validation combustor at the National Energy Technology Laboratory at operating pressures from 1 to 8 atmospheres. The data, which were collected in a combustor with well-controlled boundary conditions, are intended to be used for validating computational fluid dynamics models under conditions directly relevant to land-based gas turbine engines. The images, which show significant effects of hydrogen on local flame quenching, are discussed in terms of a turbulent premixed combustion regime and nondimensional parameters such as Karlovitz number. Pressure was found to thin the OH region, but only had a secondary effect on overall flame shape compared with the effects of hydrogen addition, which was found to decrease local quenching and shorten the turbulent flame brush. A method to process the individual images based on local gradients of fluorescence intensity is proposed, and results are presented. Finally, the results of several large eddy simulations are presented and compared with the experimental data in an effort to understand the issues related to model validation, especially for simulations that do not include OH as an intermediate species.

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

    DOE Patents [OSTI]

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

    2009-10-20

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

  3. Investigation of the characteristics of liquid fuel burning, Rijke type, pulsating combustors, Annual report

    SciTech Connect (OSTI)

    Zinn, B.T.; Daniel, B.R.; Katz, U.; Xu, T.S.; Su, A.

    1986-11-01

    This report describes the results obtained during the first year of a DOE sponsored research program entitled ''Investigation of the Characteristics of Liquid Fuel Burning, Rijke Type, Pulse Combustors''. This research has been concerned with the development of an efficient, nonpolluting, pulse combustor which burns liquid fuels. The design of the developed combustor is based upon principles of the acoustic Rijke tube which had been previously used, by the principal investigators of this study, to guide the development of a highly efficient, coal burning pulse combustor. The present study was initiated with the objective of determining whether the high performance achieved with the coal burning pulse combustor can be duplicated with the liquid fuel burning, Rijke type, pulse combustors. This document also describes the development of the experimental set-up and its subsequent modifications which resulted in improved performance. These studies revealed that pulse combustion operation can be maintained by more than one mechanism.

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

    DOE Patents [OSTI]

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

    2012-11-20

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

  5. Modeling scramjet combustor flowfields with a grid adaptation scheme

    SciTech Connect (OSTI)

    Ramakrishnan, R.; Singh, D.J. )

    1994-05-01

    The accurate description of flow features associated with the normal injection of fuel into supersonic primary flows is essential in the design of efficient engines for hypervelocity aerospace vehicles. The flow features in such injections are complex with multiple interactions between shocks and between shocks and boundary layers. Numerical studies of perpendicular sonic N2 injection and mixing in a Mach 3.8 scramjet combustor environment are discussed. A dynamic grid adaptation procedure based on the equilibration of spring-mass systems is employed to enhance the description of the complicated flow features. Numerical results are compared with experimental measurements and indicate that the adaptation procedure enhances the capability of the modeling procedure to describe the flow features associated with scramjet combustor components. 14 refs.

  6. Pulse Combustor CRADA PC91-001 Final Report

    SciTech Connect (OSTI)

    none

    1992-08-31

    As outlined in the Cooperative Research and Development Agreement (CRADA) between BO Technical Developments, Ltd. (BO Tech) and the Pittsburgh Energy Technology Center (PETC) Coal Combustion Division, a BO Tech designed pulse-blade combustor was studied at PETC. Phase 1 involved limited tests of a single-blade pulsed-combustor module to evaluate the suitability of a gas-designed unit for firing coal for use in residential, commercial, or industrial sectors. During the course of the project, three different pulsed blade burners were designed and fabricated by BO Tech and subsequently delivered to PETC for evaluation. These units were designed to allow modification of the furnace dimensions, which would give PETC a means to take simple steps to improve coal firing performance is required. No major furnace design changes were to be included as part of the phase 1 activities.

  7. System and method for reducing combustion dynamics in a combustor

    DOE Patents [OSTI]

    Uhm, Jong Ho; Johnson, Thomas Edward; Zuo, Baifang; York, William David

    2013-08-20

    A system for reducing combustion dynamics in a combustor includes an end cap having an upstream surface axially separated from a downstream surface, and tube bundles extend through the end cap. A diluent supply in fluid communication with the end cap provides diluent flow to the end cap. Diluent distributors circumferentially arranged inside at least one tube bundle extend downstream from the downstream surface and provide fluid communication for the diluent flow through the end cap. A method for reducing combustion dynamics in a combustor includes flowing fuel through tube bundles that extend axially through an end cap, flowing a diluent through diluent distributors into a combustion chamber, wherein the diluent distributors are circumferentially arranged inside at least one tube bundle and each diluent distributor extends downstream from the end cap, and forming a diluent barrier in the combustion chamber between at least one pair of adjacent tube bundles.

  8. Self-regulating fuel staging port for turbine combustor

    DOE Patents [OSTI]

    Van Nieuwenhuizen, William F.; Fox, Timothy A.; Williams, Steven

    2014-07-08

    A port (60) for axially staging fuel and air into a combustion gas flow path 28 of a turbine combustor (10A). A port enclosure (63) forms an air path through a combustor wall (30). Fuel injectors (64) in the enclosure provide convergent fuel streams (72) that oppose each other, thus converting velocity pressure to static pressure. This forms a flow stagnation zone (74) that acts as a valve on airflow (40, 41) through the port, in which the air outflow (41) is inversely proportion to the fuel flow (25). The fuel flow rate is controlled (65) in proportion to engine load. At high loads, more fuel and less air flow through the port, making more air available to the premixing assemblies (36).

  9. Pulsed atmospheric fluidized bed combustor apparatus and process

    DOE Patents [OSTI]

    Mansour, Momtaz N. (Columbia, MD)

    1992-01-01

    A pulsed atmospheric fluidized bed reactor system is disclosed and claimed along with a process for utilization of same for the combustion of, e.g. high sulfur content coal. The system affords a economical, ecologically acceptable alternative to oil and gas fired combustors. The apparatus may also be employed for endothermic reaction, combustion of waste products, e.g. organic and medical waste, drying, calcining and the like.

  10. Sectoral combustor for burning low-BTU fuel gas

    DOE Patents [OSTI]

    Vogt, Robert L. (Schenectady, NY)

    1980-01-01

    A high-temperature combustor for burning low-BTU coal gas in a gas turbine is disclosed. The combustor includes several separately removable combustion chambers each having an annular sectoral cross section and a double-walled construction permitting separation of stresses due to pressure forces and stresses due to thermal effects. Arrangements are described for air-cooling each combustion chamber using countercurrent convective cooling flow between an outer shell wall and an inner liner wall and using film cooling flow through liner panel grooves and along the inner liner wall surface, and for admitting all coolant flow to the gas path within the inner liner wall. Also described are systems for supplying coal gas, combustion air, and dilution air to the combustion zone, and a liquid fuel nozzle for use during low-load operation. The disclosed combustor is fully air-cooled, requires no transition section to interface with a turbine nozzle, and is operable at firing temperatures of up to 3000.degree. F. or within approximately 300.degree. F. of the adiabatic stoichiometric limit of the coal gas used as fuel.

  11. High temperature degradation by erosion-corrosion in bubbling fluidized bed combustors

    E-Print Network [OSTI]

    Hou, Peggy Y.; MacAdam, S.; Niu, Y.; Stringer, J.

    2003-01-01

    a Laboratory Simulated Bubbling Fluidized Bed", Wear. 235,Tube Wastage in Bubbling Fluidized Bed, a Laboratory StudyWheeldon, "Wastage in bubbling fluidized-bed combustors: an

  12. Method and apparatus for controlling combustor temperature during transient load changes

    DOE Patents [OSTI]

    Clingerman, Bruce J. (Palmyra, NY); Chalfant, Robert W. (West Henrietta, NY)

    2002-01-01

    A method and apparatus for controlling the temperature of a combustor in a fuel cell apparatus includes a fast acting air bypass valve connected in parallel with an air inlet to the combustor. A predetermined excess quantity of air is supplied from an air source to a series connected fuel cell and combustor. The predetermined excess quantity of air is provided in a sufficient amount to control the temperature of the combustor during start-up of the fuel processor when the load on the fuel cell is zero and to accommodate any temperature transients during operation of the fuel cell.

  13. Maintenance of chaos in a computational model of a thermal pulse combustor

    SciTech Connect (OSTI)

    In, V.; Spano, M.L. [Naval Surface Warfare Center, Carderock Laboratory, West Bethesda, Maryland 20817 (United States)] [Naval Surface Warfare Center, Carderock Laboratory, West Bethesda, Maryland 20817 (United States); Neff, J.D.; Ditto, W.L. [Georgia Institute of Technology, Atlanta, Georgia 30332 (United States)] [Georgia Institute of Technology, Atlanta, Georgia 30332 (United States); Daw, C.S. [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States)] [Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831 (United States); Edwards, K.D.; Nguyen, K. [University of Tennessee, Knoxville, Tennessee 37996 (United States)] [University of Tennessee, Knoxville, Tennessee 37996 (United States)

    1997-12-01

    The dynamics of a thermal pulse combustor model are examined. It is found that, as a parameter related to the fuel flow rate is varied, the combustor will undergo a transition from periodic pulsing to chaotic pulsing to a chaotic transient leading to flameout. Results from the numerical model are compared to those obtained from a laboratory-scale thermal pulse combustor. Finally the technique of maintenance (or anticontrol) of chaos is successfully applied to the model, with the result that the operation of the combustor can be continued well into the flameout regime. {copyright} {ital 1997 American Institute of Physics.}

  14. 100 Hour test of the pressurized woodchip-fired gravel bed combustor

    SciTech Connect (OSTI)

    Ragland, K.W.; Aerts, D.J.

    1994-08-01

    Combustion of wood chips in a packed bed combustor for a gas turbine cogeneration system is described. A discussion on flue gas emissions and mass balances is included.

  15. Investigation of the characteristics of liquid fuel burning, Rijke type, pulse combustors; Progress report, July 1, 1988--September 30, 1988

    SciTech Connect (OSTI)

    Zinn, B.T.; Daniel, B.R.; Shani, S.; Bai, T.; Zhang, Z.

    1988-10-01

    This research program consists of three tasks. The objectives of Task A are to determine the performance characteristics of an uninsulated and an insulated, Rijke type, pulse combustors when burning different liquid fuels under different operating conditions. Task B is concerned with the elucidation of the mechanisms responsible for driving the pulsations in the developed combustors and Task C is concerned with the determination dependence of the performance of the combustor upon the amplitude of pulsations. The performance characteristics of this pulse combustor design were investigated extensively earlier under this program and the results are described in previous progress reports. In order to determine the effect of thermal conditions inside the combustor, a second insulated combustor was developed having the same design as the uninsulated combustor. The performance of this combustor was investigated this quarter. 21 figs.

  16. Second generation PFBC systems research and development: Phase 2, Topping combustor testing at UTSI

    SciTech Connect (OSTI)

    Johanson, N.R.; Foote, J.P.

    1992-12-01

    This report describes a second generation pressurized fluidized bed combustion (PFBC) power plant. The topping combustor testing is briefly described. The topping combustor burns low BTU gas produced from substoichiometric combustion of coal in a pressurized carbonizer. Char produced is burned in a PFBC.

  17. Development of a low NO/sub x/ lean premixed annular combustor

    SciTech Connect (OSTI)

    Roberts, P.B.; Kubasco, A.J.; Sekas, N.J.

    1982-01-01

    An atmospheric test program was conducted to define a low NOx annular combustor concept suitable for a supersonic, high-altitude aircraft application. The lean premixed combustor, known as the Vortex Air Blast (VAB) concept, was tested as a 22.0 cm diameter model in the early development phases to arrive at basic design and performance criteria. 9 refs.

  18. Second generation PFBC systems research and development: Phase 2, Topping combustor testing at UTSI

    SciTech Connect (OSTI)

    Johanson, N.R.; Foote, J.P.

    1992-01-01

    This report describes a second generation pressurized fluidized bed combustion (PFBC) power plant. The topping combustor testing is briefly described. The topping combustor burns low BTU gas produced from substoichiometric combustion of coal in a pressurized carbonizer. Char produced is burned in a PFBC.

  19. Comparison of direct and indirect combustion noise mechanisms in a model combustor

    E-Print Network [OSTI]

    Nicoud, Franck

    the combustor 1 quantity downstream from the combustor and upstream from the nozzle 2 quantity downstream from by the unsteady heat release from the turbulent flame propagate either upstream or downstream through/s wS dimensionless entropy wave w+ dimensionless acoustic wave propagating downstream w- dimensionless

  20. Investigation of the characteristics of a coal burning Rijke type pulsating combustor

    SciTech Connect (OSTI)

    Carvalho, J.A. Jr.

    1983-01-01

    The evaluation of the performance characteristics of a coal burning Rijke type pulsating combustor was studied. The combustor consists of an open ended vertical tube with a coal burning bed located in the middle of its lower half. The liberation of heat by the combustion process at this location results in spontaneous excitation of the fundamental, longitudinal, acoustic mode of the tube and the acoustic oscillations lead to significant intensification of the combustion process. An 108 inch long 5.5 inch internal diameter combustor was constructed and instrumented for this investigation. The measurements performed during a series of experiments conducted at various air/fuel ratios and coal feed rates include: dB level of pulsations at the mid section of the combustor, frequency of oscillations, temperature at different locations inside the combustor, mass emission rates of generated particulates, and CO, CO/sub 2/, NO/sub x/, and SP/sub 2/ concentrations in the exhaust products of the combustor. The study demonstrated that the developed pulsating combustor can burn coal stably and continuously under a variety of air/fuel ratios and that maximum amplitudes of acoustic pressure occur when operation is conducted near stoichiometric conditions. It was also verified that the presence of pulsations resulted in a very efficient and intense combustion process. The measured CO and CO/sub 2/ concentrations were used to determine the combustion efficiencies of the combustor which were higher than 95%.

  1. Piloted rich-catalytic lean-burn hybrid combustor

    DOE Patents [OSTI]

    Newburry, Donald Maurice (Orlando, FL)

    2002-01-01

    A catalytic combustor assembly which includes, an air source, a fuel delivery means, a catalytic reactor assembly, a mixing chamber, and a means for igniting a fuel/air mixture. The catalytic reactor assembly is in fluid communication with the air source and fuel delivery means and has a fuel/air plenum which is coated with a catalytic material. The fuel/air plenum has cooling air conduits passing therethrough which have an upstream end. The upstream end of the cooling conduits is in fluid communication with the air source but not the fuel delivery means.

  2. Combustion Dynamics in Multi-Nozzle Combustors Operating on High-Hydrogen Fuels

    SciTech Connect (OSTI)

    Santavicca, Dom; Lieuwen, Tim

    2013-09-30

    Actual gas turbine combustors for power generation applications employ multi-nozzle combustor configurations. Researchers at Penn State and Georgia Tech have extended previous work on the flame response in single-nozzle combustors to the more realistic case of multi-nozzle combustors. Research at Georgia Tech has shown that asymmetry of both the flow field and the acoustic forcing can have a significant effect on flame response and that such behavior is important in multi-flame configurations. As a result, the structure of the flame and its response to forcing is three-dimensional. Research at Penn State has led to the development of a three-dimensional chemiluminescence flame imaging technique that can be used to characterize the unforced (steady) and forced (unsteady) flame structure of multi-nozzle combustors. Important aspects of the flame response in multi-nozzle combustors which are being studied include flame-flame and flame-wall interactions. Research at Penn State using the recently developed three-dimensional flame imaging technique has shown that spatial variations in local flame confinement must be accounted for to accurately predict global flame response in a multi-nozzle can combustor.

  3. Investigation of the combustion of liquid fuels in Rijke type pulse combustors

    SciTech Connect (OSTI)

    Zinn, B.T.; Daniel, B.R.; Bai, T.

    1990-01-01

    The synopsis summarizes the accomplishments of DOE Contract NO. AS04-85AL31881, which investigated the combustion of different liquid fuels in Rijke type pulse combustors. Interest in the development of a Rijke pulse combustor capable of burning liquid fuels was stimulated by earlier studies by the investigators of this program which had demonstrated that various coals can be burned efficiently and with low pollutant emissions in Rijke type pulse combustors. This research program consisted of three tasks. Task A was concerned with the development of a Rijke pulse combustor design capable of burning different liquid fuels, and determination of the performances of uninsulated and insulated versions of the developed Rijke pulse combustor when burning different liquid fuels under different operating conditions. Task B was concerned with the elucidation of the mechanisms responsible for driving the pulsations in the developed combustors, and Task C was concerned with the determination of the dependence of the combustor performance upon the amplitude of pulsations. The results of these studies are briefly discussed in the remainder of this document. 2 figs.

  4. Slagging retrofit pulsed coal combustor. Quarterly progress report, October-December 1985

    SciTech Connect (OSTI)

    Not Available

    1986-02-01

    Design and fabrication of an experimental facility for cold flow studies in a pulsed combustor have been completed. The major units in the facility include a transparent combustor cold flow device, a solids injection system, an air injection system, and an expansion tank. Figure 1 is a schematic of the experimental set up. The experimental approach at this stage is aimed at resolving the basic technical issues and not at building an apparatus which is a functional pulsed combustor. The plexiglass combustor device contains elements to disperse injected solids (spherical target), swirl the inlet air (a plate with angled orifices), and control the flow rate (variable exhaust orifices). The solids and air injection systems are presently set up to permit single pulse inputs to the combustor. The main feature of these systems are fast acting ball valves that allow precisely controlled amounts of solids and air to pass through them to the combustor model. The speed of valve actuation, and hence the quantities of substances passed, is adjustable. In the cold flow experiments, the expansion tank serves as a chamber where the solids can be collected. This tank will also serve as a cooling tank during the ignition experiments. Diagnostics to be used on the combustor include high speed photography, fast acting sampling units, optical probes, pressure transducers and temperature probes.

  5. 100 Hour test of the pressurized woodchip-fired gravel bed combustor

    SciTech Connect (OSTI)

    Ragland, K.W.; Aerts, D.J.

    1992-08-01

    In this project a downdraft, packed bed combustor for a gas turbine cogeneration system using woodchips is being developed. The combustor is designed to promote intense combustion in a thin reaction zone and to control particulate growth by using high excess air. The combustor contains a magnesia and alumina gravel bed on top of which woodchips are fed. The following test objectives were established for the 100 hr test: (a) demonstrate preliminary durability of the combustor; (b) demonstrate steady operation of the system; (c) investigate combustor pressure drop; (d) investigate bed ash cake buildup; (e) expose metal alloy coupons for corrosion examination; (f) obtain closure within 10% on mass and energy balances; and (g) obtain emissions data. The plan for the 100 hr test was to operate the combustor at the following conditions: day 1, 4 atm (absolute) pressure and 700--800 C outlet temperature; day 2, 4 atm pressure and 800--900 C outlet temperature; day 3, 5 atm pressure and 800--900 C outlet temperature; days 4 and 5, repeat day 3. The inlet air was not preheated. The paper gives test results and discusses fuel characterization, combustor performance, mass and energy balance, emissions, composition of ash and deposits, and metal coupons representing turbine blade material.

  6. NONEQUILIBRIUM SULFUR CAPTURE & RETENTION IN AN AIR COOLED SLAGGING COAL COMBUSTOR

    SciTech Connect (OSTI)

    Bert Zauderer

    2003-04-21

    Calcium oxide injected in a slagging combustor reacts with the sulfur from coal combustion to form sulfur-bearing particles. The reacted particles impact and melt in the liquid slag layer on the combustor wall by the centrifugal force of the swirling combustion gases. Due to the low solubility of sulfur in slag, it must be rapidly drained from the combustor to limit sulfur gas re-evolution. Prior analyses and laboratory scale data indicated that for Coal Tech's 20 MMBtu/hour, air-cooled, slagging coal combustor slag mass flow rates in excess of 400 lb/hr should limit sulfur re-evolution. The objective of this 42-month project was to validate this sulfur-in-slag model in a group of combustor tests. A total of 36 days of testing on the combustor were completed during the period of performance of this project. This was more that double the 16 test days that were required in the original work statement. The extra tests were made possible by cost saving innovations that were made in the operation of the combustor test facility and in additional investment of Coal Tech resources in the test effort. The original project plan called for two groups of tests. The first group of tests involved the injection of calcium sulfate particles in the form of gypsum or plaster of Paris with the coal into the 20 MMBtu/hour-combustor. The second group of tests consisted of the entire two-step process, in which lime or limestone is co-injected with coal and reacts with the sulfur gas released during combustion to form calcium sulfate particles that impact and dissolve in the slag layer. Since this sulfur capture process has been validated in numerous prior tests in this combustor, the primary effort in the present project was on achieving the high slag flow rates needed to retain the sulfur in the slag.

  7. Quantitative characterization of a nonreacting, supersonic combustor flowfield using unified, laser-induced iodine fluorescence

    SciTech Connect (OSTI)

    Fletcher, D.G.; McDaniel, J.C.

    1989-01-01

    A calibrated, nonintrusive optical technique, laser-induced iodine fluorescence (LIIF) was used to quantify the steady, compressible flowfield of a nonreacting, supersonic combustor. The combustor was configured with single and staged, transverse-air injection into a supersonic-air freestream behind a rearward-facing step. Pressure, temperature, two-velocity components, and injectant mole fraction were measured with high spatial resolution in the three-dimensional flowfields. These experimental results provide a benchmark set of data for validation of computational fluid dynamic (CFD) codes being developed to model supersonic combustor flowfields. 8 refs.

  8. Near-zero emissions combustor system for syngas and biofuels

    SciTech Connect (OSTI)

    Yongho, Kim [Los Alamos National Laboratory; Rosocha, Louis [Los Alamos National Laboratory

    2010-01-01

    A multi-institutional plasma combustion team was awarded a research project from the DOE/NNSA GIPP (Global Initiative for Prolifereation Prevention) office. The Institute of High Current Electronics (Tomsk, Russia); Leonardo Technologies, Inc. (an American-based industrial partner), in conjunction with the Los Alamos National Laboratory are participating in the project to develop novel plasma assisted combustion technologies. The purpose of this project is to develop prototypes of marketable systems for more stable and cleaner combustion of syngas/biofuels and to demonstrate that this technology can be used for a variety of combustion applications - with a major focus on contemporary gas turbines. In this paper, an overview of the project, along with descriptions of the plasma-based combustors and associated power supplies will be presented. Worldwide, it is recognized that a variety of combustion fuels will be required to meet the needs for supplying gas-turbine engines (electricity generation, propulsion), internal combustion engines (propulsion, transportation), and burners (heat and electricity generation) in the 21st Century. Biofuels and biofuel blends have already been applied to these needs, but experience difficulties in modifications to combustion processes and combustor design and the need for flame stabilization techniques to address current and future environmental and energy-efficiency challenges. In addition, municipal solid waste (MSW) has shown promise as a feedstock for heat and/or electricity-generating plants. However, current combustion techniques that use such fuels have problems with achieving environmentally-acceptable air/exhaust emissions and can also benefit from increased combustion efficiency. This project involves a novel technology (a form of plasma-assisted combustion) that can address the above issues. Plasma-assisted combustion (PAC) is a growing field that is receiving worldwide attention at present. The project is focused on research necessary to develop a novel, high-efficiency, low-emissions (near-zero, or as low as reasonably achievable), advanced combustion technology for electricity and heat production from biofuels and fuels derived from MSW. For any type of combustion technology, including the advanced technology of this project, two problems of special interest must be addressed: developing and optimizing the combustion chambers and the systems for igniting and sustaining the fuel-burning process. For MSW in particular, there are new challenges over gaseous or liquid fuels because solid fuels must be ground into fine particulates ({approx} 10 {micro}m diameter), fed into the advanced combustor, and combusted under plasma-assisted conditions that are quite different than gaseous or liquid fuels. The principal idea of the combustion chamber design is to use so-called reverse vortex gas flow, which allows efficient cooling of the chamber wall and flame stabilization in the central area of the combustor (Tornado chamber). Considerable progress has been made in design ing an advanced, reverse vortex flow combustion chamber for biofuels, although it was not tested on biofuels and a system that could be fully commercialized has never been completed.

  9. Development of a pressure gain combustor for improved cycle efficiency

    SciTech Connect (OSTI)

    Gemmen, R.S.; Richards, G.A.; Janus, M.C.

    1994-09-01

    This paper presents results from an experimental research program attempting to improve the thermodynamic efficiencies of gas-turbine combustors. An elementary thermodynamic analysis shows that the thermodynamic cycle efficiencies of gas turbines can be significantly improved by using unsteady combustion that achieves quasi-constant-volume combustion. The ability to produce the so-called pressure gain via this process has already been demonstrated by others for pressures less than 3 atmospheres. This paper presents experimental results for pressures up to 11 atmospheres, compares certain process parameters to a numerical simulation, and briefly examines the problem of scale-up. Results of pollutant measurements over the 2--11 atmospheric range of operation are also included.

  10. Suppression of thermoacoustic instabilities in a swirl combustor through microjet air injection

    E-Print Network [OSTI]

    LaBry, Zachary Alexander

    2010-01-01

    Thermoacoustic or combustion instability, a positive feedback loop coupling heat release rate and acoustic oscillations in a combustor, is one of the greatest challenges currently facing the development of new gas turbine ...

  11. A physics-based emissions model for aircraft gas turbine combustors

    E-Print Network [OSTI]

    Allaire, Douglas L

    2006-01-01

    In this thesis, a physics-based model of an aircraft gas turbine combustor is developed for predicting NO. and CO emissions. The objective of the model is to predict the emissions of current and potential future gas turbine ...

  12. Deterministic quantities characterizing noise driven Hopf bifurcations in gas turbine combustors

    E-Print Network [OSTI]

    Daraio, Chiara

    Deterministic quantities characterizing noise driven Hopf bifurcations in gas turbine combustors Nicolas Noiray, Bruno Schuermans Alstom Power, Baden, Switzerland Abstract Lean premix gas turbine observed in gas turbines is used to validate the proposed identification methods. In a second step

  13. Exposure of Ceramics and Ceramic Matrix Composites in Simulated and Actual Combustor Environments

    SciTech Connect (OSTI)

    Brentnall, W.D.; Ferber, M.K.; Keiser, j.R.; Miriyala, N.; More, K.L.; Price, J.R.; Tortorelli, P.F.; Walker, L.R.

    1999-06-07

    A high-temperature, high-pressure, tube furnace has been used to evaluate the long term stability of different monolithic ceramic and ceramic matrix composite materials in a simulated combustor environment. All of the tests have been run at 150 psia, 1204 degrees C, and 15% steam in incremental 500 h runs. The major advantage of this system is the high sample throughput; >20 samples can be exposed in each tube at the same time under similar exposure conditions. Microstructural evaluations of the samples were conducted after each 500 h exposure to characterize the extent of surface damage, to calculate surface recession rates, and to determine degradation mechanisms for the different materials. The validity of this exposure rig for simulating real combustor environments was established by comparing materials exposed in the test rig and combustor liner materials exposed for similar times in an actual gas turbine combustor under commercial operating conditions.

  14. American Institute of Aeronautics and Astronautics Numerical Simulation of a Gas Turbine Combustor Using

    E-Print Network [OSTI]

    Roy, Subrata

    1 American Institute of Aeronautics and Astronautics Numerical Simulation of a Gas Turbine of combustion by using nanosecond pulsed plasma actuators for a gas turbine combustor. Moreau [2] and Corke et

  15. Numerical Simulation of Enhanced Mixing in Scramjet Combustor Using Ramp, Tabs and Suction Collar

    E-Print Network [OSTI]

    Hwang, Seung-Jae

    2011-06-09

    injection) and normal fuel injection (wall injection) schemes. Incorporated in the scramjet combustors are delta tabs and suction collars of two types as means of mixing enhancement. The main mechanism of the tabs and suction collars for mixing enhancement...

  16. Performance of an industrial type combustor burning simulated fuels of medium BTU content 

    E-Print Network [OSTI]

    Goehring, Howard Lee

    1983-01-01

    I I ~ THEORETICAL CON SIDERAT IQN S Page v1 A. COMBUSTION CHAMBER OPERATING PRINCIPLES, . 4 B. PERFORMANCE REQUIREMENTS C. AFFECT QF CHANGING ENGINE CONDITIONS ON COMBUSTOR PERFORMANCE D. HOW LOW BTU FUELS AFFECT COMBUSTOR PERFO RMAN C E... CHAPTER III . EXPERIMENTATION A. INTRODUCTION 15 20 28 B. CONDITIONS TO BE TESTED C. EXPERIMENTAL SET-UP D. EXPERIMENTAL PROCEDURE CHAPTER IV . SUMMARY A. RESULTS AND CONCLUSIONS B. RECOMMENDAT ION S RE FEREN CE S 75 TABLE OF CONTENTS...

  17. Second generation PFBC system research and development: Phase 2, Topping combustor development

    SciTech Connect (OSTI)

    Domeracki, W.; Pillsbury, P.W.; Dowdy, T.E.; Foote, J.

    1992-12-01

    The use of a Circulating Pressurized Fluidized Bed Combustor (CPFBC) as the primary combustion system for a combustion turbine requires transporting compressor air to the CPFBC and vitiated air/flue gas back to the turbine. In addition, the topping combustion system must be located in the returning vitiated airflow path. The conventional fuel system and turbine center section require major change for the applications. The selected arrangement, which utilizes two topping combustor assemblies, one on each side of the unit, is shown in Figure 1. Half of the vitiated air from the CPFBC enters an intemal plenum chamber in which topping combustors are mounted. Fuel gas enters the assembly via the fuel nozzles at the head end of the combustor. Combustion occurs, and the products of combustion are ducted into the main shell for distribution to the first-stage turbine vanes. Compressor discharge air leaves the main shell, flowing around the annular duct into the adjacent combustion shells. The air flows around the vitiated air plenums and leaves each combustion assembly via nozzles and is ducted to the CPFBC and carbonizer. Because the air entering the combustor is at 1600{degrees}F rather than the 700{degrees}F usual for gas turbines, the conventional type of combustor is not suitable. Both emissions and wall cooling problems preclude the use of the conventional design. Therefore, a combustor that will meet the requirements of utilizing the higher temperature air for both wall cooling and combustion is required. In selecting a combustor design that will withstand the conditions expected in the topping application, the effective utilization of the 1600{degrees}F air mentioned above could satisfy the wall cooling challenge by maintaining a cooling air layer of substantial thickness.

  18. Thermal and Economic Analyses of Energy Saving by Enclosing Gas Turbine Combustor Section 

    E-Print Network [OSTI]

    Li, X.; Wang, T.; Day, B.

    2006-01-01

    of Energy Saving by Enclosing Gas Turbine Combustor Section Xianchang Li, Ting Wang Benjamin Day ? Research Engineer Professor Engineer Energy Conversion and Conservation Center Venice Natural Gas... a high-temperature area (500~560°F) at the combustor section of the GE Frame 5 gas turbine of Dynegy Gas Processing Plant at Venice, Louisiana. To improve the thermal efficiency and reduce energy cost, thermal and economic analyses are conducted...

  19. Investigation and demonstration of a rich combustor cold-start device for alcohol-fueled engines

    SciTech Connect (OSTI)

    Hodgson, J.W.; Irick, D.K. [Univ. of Tennessee, Knoxville, TN (United States)] [Univ. of Tennessee, Knoxville, TN (United States)

    1998-04-01

    The authors have completed a study in which they investigated the use of a rich combustor to aid in cold starting spark-ignition engines fueled with either neat ethanol or neat methanol. The rich combustor burns the alcohol fuel outside the engine under fuel-rich conditions to produce a combustible product stream that is fed to the engine for cold starting. The rich combustor approach significantly extends the cold starting capability of alcohol-fueled engines. A design tool was developed that simulates the operation of the combustor and couples it to an engine/vehicle model. This tool allows the user to determine the fuel requirements of the rich combustor as the vehicle executes a given driving mission. The design tool was used to design and fabricate a rich combustor for use on a 2.8 L automotive engine. The system was tested using a unique cold room that allows the engine to be coupled to an electric dynamometer. The engine was fitted with an aftermarket engine control system that permitted the fuel flow to the rich combustor to be programmed as a function of engine speed and intake manifold pressure. Testing indicated that reliable cold starts were achieved on both neat methanol and neat ethanol at temperatures as low as {minus}20 C. Although starts were experienced at temperatures as low as {minus}30 C, these were erratic. They believe that an important factor at the very low temperatures is the balance between the high mechanical friction of the engine and the low energy density of the combustible mixture fed to the engine from the rich combustor.

  20. A feasibility study of oil shale fired pulse combustors with applications to oil shale retorting

    SciTech Connect (OSTI)

    Morris, G.J.; Johnson, E.K.; Zhang, G.Q.; Roach, R.A.

    1992-07-01

    The results of the experimental investigation performed to determine the feasibility of using pulverized Colorado oil shale to fuel a bench scale pulse combustor reveal that oil shale cannot sustain pulsations when used alone as fuel. Trace amounts of propane mixed with the oil shale enabled the pulsations, however. Up to 80% of the organic material in the oil shale was consumed when it was mixed with propane in the combustor. Beyond the feasibility objectives, the operating conditions of the combustor fuel with propane and mixtures of oil shale and propane were characterized with respect to pulsation amplitude and frequency and the internal combustor wall temperature over fuel lean and fuel rich stoichiometries. Maximum pressure excursions of 12.5 kPa were experienced in the combustor. Pulsation frequencies ranged from 50 to nearly 80 Hz. Cycle resolved laser Doppler anemometry velocities were measured at the tail pipe exit plane. Injecting inert mineral matter (limestone) into the pulse combustor while using propane fuel had only a slight effect on the pulsation frequency for the feed rates tested.

  1. Industrial Gas Turbine Engine Catalytic Pilot Combustor-Prototype Testing

    SciTech Connect (OSTI)

    Shahrokh Etemad; Benjamin Baird; Sandeep Alavandi; William Pfefferle

    2009-09-30

    PCI has developed and demonstrated its Rich Catalytic Lean-burn (RCL®) technology for industrial and utility gas turbines to meet DOEâ??s goals of low single digit emissions. The technology offers stable combustion with extended turndown allowing ultra-low emissions without the cost of exhaust after-treatment and further increasing overall efficiency (avoidance of after-treatment losses). The objective of the work was to develop and demonstrate emission benefits of the catalytic technology to meet strict emissions regulations. Two different applications of the RCL® concept were demonstrated: RCL® catalytic pilot and Full RCL®. The RCL® catalytic pilot was designed to replace the existing pilot (a typical source of high NOx production) in the existing Dry Low NOx (DLN) injector, providing benefit of catalytic combustion while minimizing engine modification. This report discusses the development and single injector and engine testing of a set of T70 injectors equipped with RCL® pilots for natural gas applications. The overall (catalytic pilot plus main injector) program NOx target of less than 5 ppm (corrected to 15% oxygen) was achieved in the T70 engine for the complete set of conditions with engine CO emissions less than 10 ppm. Combustor acoustics were low (at or below 0.1 psi RMS) during testing. The RCL® catalytic pilot supported engine startup and shutdown process without major modification of existing engine controls. During high pressure testing, the catalytic pilot showed no incidence of flashback or autoignition while operating over a wide range of flame temperatures. In applications where lower NOx production is required (i.e. less than 3 ppm), in parallel, a Full RCL® combustor was developed that replaces the existing DLN injector providing potential for maximum emissions reduction. This concept was tested at industrial gas turbine conditions in a Solar Turbines, Incorporated high-pressure (17 atm.) combustion rig and in a modified Solar Turbines, Incorporated Saturn engine rig. High pressure single-injector rig and modified engine rig tests demonstrated NOx less than 2 ppm and CO less than 10 ppm over a wide flame temperature operating regime with low combustion noise (<0.15% peak-to-peak). Minimum NOx for the optimized engine retrofit Full RCL® designs was less than 1 ppm with CO emissions less than 10 ppm. Durability testing of the substrate and catalyst material was successfully demonstrated at pressure and temperature showing long term stable performance of the catalytic reactor element. Stable performance of the reactor element was achieved when subjected to durability tests (>5000 hours) at simulated engine conditions (P=15 atm, Tin=400C/750F.). Cyclic tests simulating engine trips was also demonstrated for catalyst reliability. In addition to catalyst tests, substrate oxidation testing was also performed for downselected substrate candidates for over 25,000 hours. At the end of the program, an RCL® catalytic pilot system has been developed and demonstrated to produce NOx emissions of less than 3 ppm (corrected to 15% O2) for 100% and 50% load operation in a production engine operating on natural gas. In addition, a Full RCL® combustor has been designed and demonstrated less than 2 ppm NOx (with potential to achieve 1 ppm) in single injector and modified engine testing. The catalyst/substrate combination has been shown to be stable up to 5500 hrs in simulated engine conditions.

  2. Development of a retrofit coal combustor for industrial applications, (Phase 1-A)

    SciTech Connect (OSTI)

    Not Available

    1988-10-01

    During this past quarter, two tandem-fired pulse combustors were designed to fire at a nominal rate of 3.5 to 5.5 MMBtu/hr under continuation of Phase I work on DOE project DE-AC22-87PC79654. In prior work, MTCI demonstrated the operation of a 1--2 MMBtu/h coal-fired tandem pulse combustor that is intended for small industrial applications. These component tests emphasized verification of key design issues such as combustor coupling, slag rejection, and staged air addition. The current work, which represents an extension of the Phase I effort, focuses on integrated testing of the tandem pulse combustor with a fire-tube boiler, and the addition of a slag quench vessel. A tandem-fired pulse combustion unit designed to fire at a nominal rate of 3.5-5 MMBtu/hr was designed and fabricated. The configuration includes two combustion chambers cast in a single monolith, tailpipes cast separately with annular air preheating capability, and a cyclonic decoupler. Design analysis and evaluations were performed to optimize the system with respect to minimizing heat losses, size, and cost. Heat losses from the combustor and decoupler walls are predicted to be approximately 3 percent. The final designs for the ancillary items (slag quench, tertiary air addition, scrubber and sampling system) were completed and fabrication and installation initiated. A Cleaver-Brooks 150 hp-4 pass boiler was delivered and installed and modifications for interfacing with the retrofit pulse combustor unit completed. A below-ground slag collection pit was excavated to permit direct in-line coupling of the combustor to the boiler and to reduce head-room requirements. The pit is 30 inches deep and lined with waterproof and fireproof siding.

  3. Investigations of swirl flames in a gas turbine model combustor

    SciTech Connect (OSTI)

    Meier, W.; Duan, X.R.; Weigand, P.

    2006-01-01

    The thermochemical states of three swirling CH{sub 4}/air diffusion flames, stabilized in a gas turbine model combustor, were investigated using laser Raman scattering. The flames were operated at different thermal powers and air/fuel ratios and exhibited different flame behavior with respect to flame instabilities. They had previously been characterized with respect to their flame structures, velocity fields, and mean values of temperature, major species concentrations, and mixture fraction. The single-pulse multispecies measurements presented in this article revealed very rapid mixing of fuel and air, accompanied by strong effects of turbulence-chemistry interactions in the form of local flame extinction and ignition delay. Flame stabilization is accomplished mainly by hot and relatively fuel-rich combustion products, which are transported back to the flame root within an inner recirculation zone. The flames are not attached to the fuel nozzle, and are stabilized approximately 10 mm above the fuel nozzle, where fuel and air are partially premixed before ignition. The mixing and reaction progress in this area are discussed in detail. The flames are short (<50 mm), especially that exhibiting thermoacoustic oscillations, and reach a thermochemical state close to adiabatic equilibrium at the flame tip. The main goals of this article are to outline results that yield deeper insight into the combustion of gas turbine flames and to establish an experimental database for the validation of numerical models.

  4. Fuel burner and combustor assembly for a gas turbine engine

    DOE Patents [OSTI]

    Leto, Anthony (Franklin Lakes, NJ)

    1983-01-01

    A fuel burner and combustor assembly for a gas turbine engine has a housing within the casing of the gas turbine engine which housing defines a combustion chamber and at least one fuel burner secured to one end of the housing and extending into the combustion chamber. The other end of the fuel burner is arranged to slidably engage a fuel inlet connector extending radially inwardly from the engine casing so that fuel is supplied, from a source thereof, to the fuel burner. The fuel inlet connector and fuel burner coact to anchor the housing against axial movement relative to the engine casing while allowing relative radial movement between the engine casing and the fuel burner and, at the same time, providing fuel flow to the fuel burner. For dual fuel capability, a fuel injector is provided in said fuel burner with a flexible fuel supply pipe so that the fuel injector and fuel burner form a unitary structure which moves with the fuel burner.

  5. Development of an industrial l-star pulsed gas combustor. Final report, April 1986-December 1989

    SciTech Connect (OSTI)

    Kotidis, P.A.

    1990-08-01

    A pulsed gas combustor has been developed based on the L-Star pulsed combustion principle. This concept is quite different from that of the more conventional acoustic pulsed combustor. In the L-Star system, there is no resonator, and the combustor volume and exhaust orifice area are chosen such that the time for pressure decay is greater than or equal to the time for combustion, in order to achieve high combustion pressures. A bench scale unit was constructed and tested. Maximum average peak pressure and combustion efficiency were realized for stoichiometric fuel/air ratio at 11.7 Hz, combustor volume of 0.2 cu ft, and air flow (steady) of 200 CFM. The combustor at these conditions produced 10 to the 6th power BTU/hr. Two backflow prevention configurations were tested: fluidic-aerodynamic valve and flapper valve. Peak pressures of 25 and 39 psig, respectively, were achieved. CO and combustibles emissions were high for both schemes (1000-3000 ppm); however, NOx emissions were as low as 10 ppm.

  6. Pulse combustor NO/sub x/ as affected by fuel-bound nitrogen

    SciTech Connect (OSTI)

    Putnam, A.A.; Merryman, L.

    1985-10-01

    A short series of tests were run using nitrogen-doped liquid fuel in a gasoline fired pulse combustor and a similar capacity steady-state combustor. Four different fuel mixtures were used, white gasoline, and white gasoline doped with 0.2, 0.4 and 0.6 weight percent nitrogen in the form of pyridine. The pulse combustor used was a Golden Eagle Model 2610 Dyna-Fog insecticide fog generator. For comparison purposes, a Coleman range-top type burner, modified to include a chimney vent, was used. The Coleman data indicate a decreasing efficiency of conversion of fuel nitrogen to NO/sub x/ as the amount of fuel nitrogen increases. While the pulse combustor NO/sub x/ lies in the same region, there is very little deviation from a constant conversion rate of about 42 percent of the fuel-bound nitrogen. A pulse combustor system might have some advantages for studying the conversion of fuel-bound nitrogen to NO and NO/sub 2/. 4 references, 1 figure.

  7. Mass transfer in oscillating flows: Efficient drying via pulse combustors. Final report, January 1988-September 1991

    SciTech Connect (OSTI)

    Arpaci, V.S.; Gemmen, R.

    1992-04-01

    Pulse combustors are known to have high rates of heat and mass transfer in the tailpipe because of velocity oscillations created by the acoustic resonance of the combustor. The results so far reported in the literature are inconclusive. A study of the mass transfer rates in a pulse combustor tailpipe has been conducted. The significant parameters including mean flow rate, frequency and amplitude of pulsation were varied nearly independently and their effects on the mass transfer were investigated. The mass transfer in the tailpipe is found to be enhanced by the oscillations up to a factor of 2 over steady turbulent flow. A correlation for mass transfer in pulsating turbulent flow is developed using a novel approach based on the appropriate microscales of turbulence and guided by the physical insight gained from experiments. The final form of the correlation will be available upon the completion of a doctoral thesis which is being written.

  8. Combustion dynamics of a low-swirl combustor

    SciTech Connect (OSTI)

    Kang, D.M.; Culick, F.E.C.; Ratner, A.

    2007-11-15

    The methodology for the measurement of dynamic combustor behavior has never been clearly established, due to the complexities associated with unsteady premixed flames and the difficulties in their measurement. The global and local distribution of Rayleigh index and the flame response functions are the main parameters normally employed to quantify and describe combustion dynamics. The Rayleigh index quantifies the thermoacoustic coupling, while the flame response function is a measure of the response of the system to outside disturbances. The primary objective of this work is to investigate the combustion dynamics of a commonly used low-swirl burner and to develop tools and methods for examining the dynamics of a combustion system. To this end, the effect of acoustic forcing at various frequencies on flame heat release behavior has been investigated. The current work uses OH-PLIF imaging of the flame region to produce phase-resolved measurements of flame behavior at each frequency. The response of the flame to the imposed acoustic field over the range of 22-400 Hz is then calculated from the processed images. This provides a starting point for an extension/extrapolation to practical acoustic ranges ({proportional_to}5000 Hz). It was found that the thermoacoustic coupling was mainly evident in the shear mixing zone, producing a toroidal Rayleigh index distribution pattern. The phase shift of the flame fluctuation from the imposed acoustic wave seems to be very closely coupled to the vortices generated at the flame boundary due to shear mixing (Kelvin-Helmholtz instability), thus inducing the alternating toroidal structures. The peak value of the flame response function coincides with the peak absolute value of the Rayleigh index. (author)

  9. Fuel Flexible, Low Emission Catalytic Combustor for Opportunity Fuel Applications

    SciTech Connect (OSTI)

    Eteman, Shahrokh

    2013-06-30

    Limited fuel resources, increasing energy demand and stringent emission regulations are drivers to evaluate process off-gases or process waste streams as fuels for power generation. Often these process waste streams have low energy content and/or highly reactive components. Operability of low energy content fuels in gas turbines leads to issues such as unstable and incomplete combustion. On the other hand, fuels containing higher-order hydrocarbons lead to flashback and auto-ignition issues. Due to above reasons, these fuels cannot be used directly without modifications or efficiency penalties in gas turbine engines. To enable the use of these wide variety of fuels in gas turbine engines a rich catalytic lean burn (RCL®) combustion system was developed and tested in a subscale high pressure (10 atm.) rig. The RCL® injector provided stability and extended turndown to low Btu fuels due to catalytic pre-reaction. Previous work has shown promise with fuels such as blast furnace gas (BFG) with LHV of 85 Btu/ft3 successfully combusted. This program extends on this work by further modifying the combustor to achieve greater catalytic stability enhancement. Fuels containing low energy content such as weak natural gas with a Lower Heating Value (LHV) of 6.5 MJ/m3 (180 Btu/ft3 to natural gas fuels containing higher hydrocarbon (e.g ethane) with LHV of 37.6 MJ/m3 (1010 Btu/ft3) were demonstrated with improved combustion stability; an extended turndown (defined as the difference between catalytic and non-catalytic lean blow out) of greater than 250oF was achieved with CO and NOx emissions lower than 5 ppm corrected to 15% O2. In addition, for highly reactive fuels the catalytic region preferentially pre-reacted the higher order hydrocarbons with no events of flashback or auto-ignition allowing a stable and safe operation with low NOx and CO emissions.

  10. EFFECT OF COMBUSTOR INLET GEOMETRY ON ACOUSTIC SIGNATURE AND FLOW FIELD BEHAVIOUR OF THE LOW SWIRL INJECTOR

    SciTech Connect (OSTI)

    Therkelsen, Peter L.; Littlejohn, David; Cheng, Robert K.; Portillo, J. Enrique; Martin, Scott M.

    2009-11-30

    Low Swirl Injector (LSI) technology is a lean premixed combustion method that is being developed for fuel-flexible gas turbines. The objective of this study is to characterize the fuel effects and influences of combustor geometry on the LSI's overall acoustic signatures and flowfields. The experiments consist of 24 flames at atmospheric condition with bulk flows ranging between 10 and 18 m/s. The flames burn CH{sub 4} (at {phi} = 0.6 & 0.7) and a blend of 90% H{sub 2} - 10% CH{sub 4} by volume (at {phi} = 0.35 & 0.4). Two combustor configurations are used, consisting of a cylindrical chamber with and without a divergent quarl at the dump plane. The data consist of pressure spectral distributions at five positions within the system and 2D flowfield information measured by Particle Imaging Velocimetry (PIV). The results show that acoustic oscillations increase with U{sub 0} and {phi}. However, the levels in the 90% H{sub 2} flames are significantly higher than in the CH{sub 4} flames. For both fuels, the use of the quarl reduces the fluctuating pressures in the combustion chamber by up to a factor of 7. The PIV results suggest this to be a consequence of the quarl restricting the formation of large vortices in the outer shear layer. A Generalized Instability Model (GIM) was applied to analyze the acoustic response of baseline flames for each of the two fuels. The measured frequencies and the stability trends for these two cases are predicted and the triggered acoustic mode shapes identified.

  11. Time-resolved gas temperatures in the oscillating turbulent flow of a pulse combustor tail pipe

    SciTech Connect (OSTI)

    Dec, J.E. (Michigan Univ., Ann Arbor, MI (USA)); Keller, J.O. (Sandia National Labs., Livermore, CA (USA). Combustion Research Faclity)

    1990-06-01

    This paper reports the cyclic behavior of the gas temperature in the oscillating turbulent flow in a pulse combustor tail pipe studied using two-line atomic fluorescence. In this flow, the oscillations result from an acoustic resonance, and have amplitudes of up to 5 times the mean velocity. Oscillation frequencies were varied from 67 to 101 Hz. Spatially resolved temperature measurements were made to within 400 {mu}m of the wall, providing cycle-resolved profiles of the temperature and the random temperature fluctuations. The combustor-cycle phase relationships among the gas temperature, random-temperature-fluctuation intensity, velocity, and combustion chamber pressure, are compared.

  12. The effect of fuel injection angle and pressure on combustor performance 

    E-Print Network [OSTI]

    Brown, Michael Lee

    1976-01-01

    TIIE EFFECT OF FUEL INJECTION ANGLE AND PRESSURE ON COMBUSTOR PERI ORMANCE A Thos is by Mi?hael Lee Brown Submitted to the Graduate College of Texas AI1M University in partial fulfillment of the requirement for the degree of MASTER... OF SCIFNCE December 1976 Major Subject: Mechanical Engineering THE EFFECT OF FUEL INJECTION ANGLE AND PRESSURE ON COMBUSTOR PERFORMANCE A Thesis by Michael Lee Brown Approved as to style and content by: C airman o ommrttee / Hea o epartment Mm er...

  13. Apparatus and filtering systems relating to combustors in combustion turbine engines

    DOE Patents [OSTI]

    Johnson, Thomas Edward (Greer, SC); Zuo, Baifang (Simpsonville, SC); Stevenson, Christian Xavier (Inman, SC)

    2012-07-24

    A combustor for a combustion turbine engine, the combustor that includes: a chamber defined by an outer wall and forming a channel between windows defined through the outer wall toward a forward end of the chamber and at least one fuel injector positioned toward an aft end of the chamber; a screen; and a standoff comprising a raised area on an outer surface of the outer wall near the periphery of the windows; wherein the screen extends over the windows and is supported by the standoff in a raised position in relation to the outer surface of the outer wall and the windows.

  14. CONTINUED DEVELOPMENT OF THE ROTARY COMBUSTOR FOR REFIRING PULVERIZED COAL BOILERS

    SciTech Connect (OSTI)

    Murray F. Abbott; Jamal B. Mereb; Simon P. Hanson; Michael J. Virr

    2000-11-01

    The Rotary Combustor is a novel concept for burning coal with low SO{sub 2} and NO{sub x} emissions. It burns crushed coal in a fluid bed where the bed is maintained in a rotating drum by centripetal force. Since this force may be varied, the combustor may be very compact, and thus be a direct replacement for a p.c. burner on existing boilers. The primary objective of this project is to demonstrate that a typical industrial boiler can be refired with the modified prototype Rotary Combustor to burn Ohio high-sulfur coal with low emissions of SO{sub 2} and NO{sub x}. The primary problem that must be resolved to demonstrate sustained operations with coal is temperature control in the rotating fluid bed. The prototype Rotary Combustor was assembled and installed on the T-850P CNB boiler at the CONSOL Energy site in South Park, Pennsylvania. Several design improvements were investigated and implemented during the assembly to improve the prototype Rotary Combustor operations compared to prior tests at Detroit Stoker in Monroe, Michigan. An Operating Manual and Safety Review were completed. The shakedown test phase was initiated. Two major problems were initially encountered: binding of the rotating drum at operating temperatures, and reduced fluid-bed pressure drop after short periods of operation. Plating the brush seal rotary land ring with a chrome carbide plasma spray and lubricating the seal prior to each test sufficiently resolved these problems to permit a limited number of operations tests. Unlike previous tests at Detroit Stoker, sustained operation of the prototype Rotary Combustor was accomplished burning a high-Btu fuel, metallurgical coke. The prototype Rotary Combustor was operated with coke in gasifier mode on two occasions. Fluid-bed temperature spiking was minimized with manual control of the feeds (coke, air and steam), and no clinker formation problems were encountered in either test. Emission levels of NO{sub x} were measured at about 270 ppmv which were higher those targeted for the device which were 100 ppmv. This was assumed to be because of the aforementioned temperature spiking. The primary operating problem remains control of the fluid-bed temperature. Although improvements were made, steam flow control was manual, and very coarse. To accomplish this will require finer control of the steam flow to the rotary drum air plenum, and development of an algorithm for automatic control using the Moore APACS{trademark}. This is the recommended succeeding step in the development of the Rotary Combustor for industrial or utility use.

  15. Investigations of swirl flames in a gas turbine model combustor

    SciTech Connect (OSTI)

    Weigand, P.; Meier, W.; Duan, X.R.; Stricker, W.; Aigner, M.

    2006-01-01

    A gas turbine model combustor for swirling CH{sub 4}/air diffusion flames at atmospheric pressure with good optical access for detailed laser measurements is discussed. Three flames with thermal powers between 7.6 and 34.9 kW and overall equivalence ratios between 0.55 and 0.75 were investigated. These behave differently with respect to combustion instabilities: Flame A burned stably, flame B exhibited pronounced thermoacoustic oscillations, and flame C, operated near the lean extinction limit, was subject to sudden liftoff with partial extinction and reanchoring. One aim of the studies was a detailed experimental characterization of flame behavior to better understand the underlying physical and chemical processes leading to instabilities. The second goal of the work was the establishment of a comprehensive database that can be used for validation and improvement of numerical combustion models. The flow field was measured by laser Doppler velocimetry, the flame structures were visualized by planar laser-induced fluorescence (PLIF) of OH and CH radicals, and the major species concentrations, temperature, and mixture fraction were determined by laser Raman scattering. The flow fields of the three flames were quite similar, with high velocities in the region of the injected gases, a pronounced inner recirculation zone, and an outer recirculation zone with low velocities. The flames were not attached to the fuel nozzle and thus were partially premixed before ignition. The near field of the flames was characterized by fast mixing and considerable finite-rate chemistry effects. CH PLIF images revealed that the reaction zones were thin (=<0.5 mm) and strongly corrugated and that the flame zones were short (h=<50 mm). Despite the similar flow fields of the three flames, the oscillating flame B was flatter and opened more widely than the others. In the current article, the flow field, structures, and mean and rms values of the temperature, mixture fraction, and species concentrations are discussed. Turbulence intensities, mixing, heat release, and reaction progress are addressed. In a second article, the turbulence-chemistry interactions in the three flames are treated.

  16. Large Eddy Simulation Analysis of Flow Field Inside a High-g Combustor

    E-Print Network [OSTI]

    Raman, Venkat

    Base, Ohio 45433 Inter-turbine burners are useful devices for increasing engine power. To enable inter. Introduction Inter-turbine burners (ITBs) are emerging as a useful concept for increasing aircraft engine power

  17. Assessment of combustion noise in a premixed swirled combustor via Large-Eddy Simulation

    E-Print Network [OSTI]

    Nicoud, Franck

    in the study of aerodynamical generated noise of numerous practical cases that range from air jets, high [1,2]. On the contrary, thermoacoustics is less understood than aeroacoustics. This is caused with thermoacoustics since the transport equation of each species must be considered in order to solve the problem

  18. Large-eddy simulation of swirling particle-laden flows in a coaxial-jet combustor

    E-Print Network [OSTI]

    Mahesh, Krishnan

    , the resulting droplets evaporate/condense and collide/coalesce, fuel and oxidizer then mix yielding spray. Mahesh b , P. Moin c , J.C. Oefelein d a Department of Mechanical Engineering, Stanford University, Bldg

  19. A tool to study azimuthal standing and spinning modes in annular combustors

    E-Print Network [OSTI]

    Nicoud, Franck

    combustion insta- bilities which can occur in annular combustors is proposed in this work. A thermoacoustic or rotating azimuthal eigenmodes depending on parameters n and . 1 INTRODUCTION Although thermo-acoustic thermoacoustic model tool to compute azimuthal thermoacoustic instabilities, which can oc- cur in annular

  20. Thermoacoustic limit cycles in a premixed laboratory combustor with open and choked exits

    SciTech Connect (OSTI)

    Hield, Peter A.; Brear, Michael J.; Jin, Seong Ho

    2009-09-15

    This paper presents an experimental and theoretical investigation of the response of a turbulent premixed flame during thermoacoustic limit cycle in a simple, laboratory combustor. The flame dynamics are examined using high-speed pressure transducers and CH* chemiluminescence. The so-called 'interaction index' and time delay between the acoustic velocity fluctuations at the flame holder and the flame's overall heat release fluctuations are then determined. A wide range of operating conditions, traversing the combustor's flammability limits in Mach number and equivalence ratio, are studied for four different combustor exits, including one where the exit is choked. In all cases the time delay correlates very well with the amplitude of the velocity fluctuations. There is also some correlation between the interaction index and these velocity fluctuations, but this is less clear. These results suggest a novel, nonlinear flame model, derived entirely empirically. An existing low-order thermoacoustic model is then extended to include convection and dispersion of entropy fluctuations downstream of the flame, enabling the effect of the choked nozzle to be examined. The novel nonlinear flame model is integrated into the low-order thermoacoustic model, and used to investigate the experimentally observed thermoacoustic limit cycles. The model correctly simulates the observed switch to a low-frequency, entropically driven instability observed when the combustor exit is choked. (author)

  1. Micro Catalytic Combustor with Pd/Nano-porous Alumina for High-Temperature Application

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    . A heat exchanger with a temperature efficiency of 0.78 is assumed for heat recirculation. Thus as high as 850 o C and extremely high heat generation density of 2-5x108 W/m3 has been achieved been made for radial-flow-type combustors using Fluent 6 (Fluent Inc.). Figure 1 shows a radial-flow-type

  2. ==================== !"#$%&'()*+,-+./,0)12 Development of Micro Ejector for Butane Catalytic Combustor

    E-Print Network [OSTI]

    Kasagi, Nobuhide

    . 3 Effect of total pressure on the primary flow rate. (c)(b)(a) 42 µm 60 µm Rough Heat Exchanger pressure of ejector is set as 11.6 Pa. Yong FAN, Yuji SUZUKI and Nobuhide KASAGI Department of Mechanical Combustor, Convergent-divergent Nozzle, Ejector, Back pressure. Fig. 1 Configuration of micro heat

  3. Lire la premire partie de la thse LES of combustor-turbine

    E-Print Network [OSTI]

    Mailhes, Corinne

    Lire la première partie de la thèse #12;Part II LES of combustor-turbine interactions 89 #12;#12;Chapter 5 Indirect combustion noise generation in a high-pressure turbine Contents 5.1 Motivation case: 2D entropy spot propagation in a periodic channel . . 95 5.4 Turbine stage simulation set

  4. Investigation of heat transfer and combustion in the advanced fluidized bed combustor (FBC)

    SciTech Connect (OSTI)

    Dr. Seong W. Lee

    1998-10-01

    The objective of this project is to predict the heat transfer and combustion performance in newly-designed fluidized bed combustor (FBC) and to provide the design guide lines and innovative concept for small-scale boiler and furnace. The major accomplishments are summarized.

  5. Reduction of NO sub x and SO sub 2 emissions from coal burning pulse combustors

    SciTech Connect (OSTI)

    Powell, E.A.; Zinn, B.T.; Miller, N.; Chen, F.

    1990-12-01

    In this investigation, a Rijke pulse combustor was constructed, in which unpulverized coal was burned on a rotating bed where the presence of acoustic velocity oscillations resulted in bed fluidization and intensification of the combustion process. The objectives of this investigation were to determine (1) if the nitrogen oxides emissions of the experimental Rijke pulse combustor could be reduced by air staging the combustion process and (2) if the sulfur dioxide emissions of this pulse combustor could be reduced by the addition of sorbent materials such as limestone to the coal bed or to the gas stream above the bed. Air staging experiments were conducted for total dimensionless air fuel ratios ranging from 1.0 to 1.4 and primary dimensionless air/fuel ratios ranging from 0.6 to 0.9. Injection heights ranged from 20 cm to 52 cm above the coal bed. Air staging was effective in reducing the nitrogen oxides emissions of coal burning Rijke type pulse combustors under the proper conditions. Another series of experiments was conducted using sorbent addition to reduce sulfur dioxide emissions. In some of these experiments, pulverized dolomitic limestone was introduced along with the coal through the coal delivery tube just above the bed, while in the remainder of the experiments, the sorbent was dispersed in an air stream and injected at 15 cm or 23 cm above the coal bed. 9 refs., 49 figs., 9 tabs.

  6. The interaction of liquid reacting droplets with the pulsating flow in a Rijke-tube combustor

    SciTech Connect (OSTI)

    Carvalho, J.A.; Gotac, P.R. [Inst. Nacional de Pesquisas Espaciais, Cachoeira Paulista, Sao Paulo (Brazil). Lab. Associado de Combustao e Propulsao] [Inst. Nacional de Pesquisas Espaciais, Cachoeira Paulista, Sao Paulo (Brazil). Lab. Associado de Combustao e Propulsao; McQuay, M.Q. [Brigham Young Univ., Provo, UT (United States). Mechanical Engineering Dept.] [Brigham Young Univ., Provo, UT (United States). Mechanical Engineering Dept.

    1997-01-01

    This paper presents the results of a theoretical investigation on the characteristics of a reacting liquid droplet in the self-generated oscillatory flow of a Rijke-pulse combustor. The droplet motion equation, accounting for droplet evaporation due to combustion, was solved using a fourth-order, Runge-Kutta method. The model was applied to a Rijke-type, alcohol-fired combustor for which experimental data exist to be used as entrance parameters. The main conclusions derived from this study are (1) for a range of droplet initial velocity, pulsating flames of liquid fuels are shorter than the corresponding steady flames because of a reduction in lifetime of droplets with the same initial diameter in the pulsating flow, (2) for a range of droplet initial diameter, time-resolved heat generation rates from pulsating sprays exhibit a preferred frequency equal to twice the frequency of the pulsating flow, and (3) droplet initial diameter, droplet initial velocity, and location of the spray in the tube influence the excitation and maintenance of acoustic oscillations in a Rijke-type combustor based on evaluation of the Rayleigh integral over time and volume in the combustor. The theoretical results presented and discussed herein are supported by experimental observations.

  7. Effects of Combustor Rig Exposure on a Porous-Matrix Oxide Composite

    E-Print Network [OSTI]

    Zok, Frank

    Effects of Combustor Rig Exposure on a Porous-Matrix Oxide Composite Michael A. Mattoni, James Y composite. The material consists of a porous mullite­alumina matrix and Nextel 720 fibers in an eight for aircraft engines have spurred the development of continuous fiber ceramic composites (CFCCs). Ma- terials

  8. Fuel injection staged sectoral combustor for burning low-BTU fuel gas

    DOE Patents [OSTI]

    Vogt, Robert L. (Schenectady, NY)

    1981-01-01

    A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone; this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe; swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone; this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

  9. Fuel injection staged sectoral combustor for burning low-BTU fuel gas

    DOE Patents [OSTI]

    Vogt, Robert L. (Schenectady, NY)

    1985-02-12

    A high-temperature combustor for burning low-BTU coal gas in a gas turbine is described. The combustor comprises a plurality of individual combustor chambers. Each combustor chamber has a main burning zone and a pilot burning zone. A pipe for the low-BTU coal gas is connected to the upstream end of the pilot burning zone: this pipe surrounds a liquid fuel source and is in turn surrounded by an air supply pipe: swirling means are provided between the liquid fuel source and the coal gas pipe and between the gas pipe and the air pipe. Additional preheated air is provided by counter-current coolant air in passages formed by a double wall arrangement of the walls of the main burning zone communicating with passages of a double wall arrangement of the pilot burning zone: this preheated air is turned at the upstream end of the pilot burning zone through swirlers to mix with the original gas and air input (and the liquid fuel input when used) to provide more efficient combustion. One or more fuel injection stages (second stages) are provided for direct input of coal gas into the main burning zone. The countercurrent air coolant passages are connected to swirlers surrounding the input from each second stage to provide additional oxidant.

  10. Design, installation and operation of the Wainwright regional waste-to-energy authority combustor

    SciTech Connect (OSTI)

    Cieslak, J.P. [Basic Envirotech Inc., Glen Ellyn, IL (United States); Ryan, M.T. [Trotter and Morton Environmental Services, Calgary, Alberta (Canada); Brinckman, G.A. [W.L. Gore and Associates, Inc., Elkton, MD (United States)

    1996-09-01

    A state-of-the-art municipal Waste-to-Energy (WTE) combustor began operation in the town of Wainwright, Alberta, Canada in 1995. The combustor design utilizes a radiant waterwall, multichamber, multi-stage combustor design, followed by a convective boiler section, a flue gas economizer and an air to air heat exchanger. The air pollution control system consists of an all dry lime injection system followed by a fabric filter collector. The system has the capability for delivering activated carbon, if needed, for the control of various pollutants. The pulse-jet fabric filter collector utilizes GORE-TEX{reg_sign} membrane/TEFLON{reg_sign} B fiberglass filter bags for highly efficient capture of the Particulate Matter (PM), which includes lime reaction and absorbent products, unreacted lime, and fly ash which is rich in trace metals and other fine particulates. Compliance testing revealed that the system is providing low outlet emission levels and would meet the proposed US EPA New Source Performance Specifications for Municipal Waste Combustor`s in the US for all categories. This includes acid gases, trace heavy metals, including Pb, Cd, Hg, and PCDD/PCDF as measured by toxic equivalency factors. PM levels were measured at 9.8 mg/Rm{sup 3}. Lead, cadmium and mercury emission levels were measured at 0.37 {micro}g/Rm{sup 3}, < 0.001 {micro}g/Rm{sup 3}, and 0.24 {micro}g/Rm{sup 3} respectively. PCDD/PCDF emissions were measured to be 0.044 {micro}g/Rm{sup 3} (TEQ). Finally, HCl and SO{sub 2} emissions were measured to be 11 mg/Rm{sup 3} and 13 mg/Rm{sup 3} respectively.

  11. A Study of Strain Rate Effects for Turbulent Premixed Flames with Application to LES of a Gas Turbine Combustor Model

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

    Kemenov, Konstantin A.; Calhoon, William H.

    2015-03-24

    Large-scale strain rate field, a resolved quantity which is easily computable in large-eddy simulations (LES), could have profound effects on the premixed flame properties by altering the turbulent flame speed and inducing local extinction. The role of the resolved strain rate has been investigated in a posterior LES study of GE lean premixed dry low NOx emissions LM6000 gas turbine combustor model. A novel approach which is based on the coupling of the lineareddy model with a one-dimensional counter-flow solver has been applied to obtain the parameterizations of the resolved premixed flame properties in terms of the reactive progress variable,more »the local strain rate measure, and local Reynolds and Karlovitz numbers. The strain rate effects have been analyzed by comparing LES statistics for several models of the turbulent flame speed, i.e, with and without accounting for the local strain rate effects, with available experimental data. The sensitivity of the simulation results to the inflow velocity conditions as well as the grid resolution have been also studied. Overall, the results suggest the necessity to represent the strain rate effects accurately in order to improve LES modeling of the turbulent flame speed.« less

  12. A Study of Strain Rate Effects for Turbulent Premixed Flames with Application to LES of a Gas Turbine Combustor Model

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

    Kemenov, Konstantin A.; Calhoon, William H.

    2015-03-24

    Large-scale strain rate field, a resolved quantity which is easily computable in large-eddy simulations (LES), could have profound effects on the premixed flame properties by altering the turbulent flame speed and inducing local extinction. The role of the resolved strain rate has been investigated in a posterior LES study of GE lean premixed dry low NOx emissions LM6000 gas turbine combustor model. A novel approach which is based on the coupling of the lineareddy model with a one-dimensional counter-flow solver has been applied to obtain the parameterizations of the resolved premixed flame properties in terms of the reactive progress variable, the local strain rate measure, and local Reynolds and Karlovitz numbers. The strain rate effects have been analyzed by comparing LES statistics for several models of the turbulent flame speed, i.e, with and without accounting for the local strain rate effects, with available experimental data. The sensitivity of the simulation results to the inflow velocity conditions as well as the grid resolution have been also studied. Overall, the results suggest the necessity to represent the strain rate effects accurately in order to improve LES modeling of the turbulent flame speed.

  13. Thermal performance of a scramjet combustor operating at Mach 5.6 flight conditions. Final report, May 1996--May 1997

    SciTech Connect (OSTI)

    Stouffer, S.D.; Neumann, R.D.; Emmer, D.S.

    1997-10-01

    This report describes the experimental data and the procedures used in acquiring and reducing the thermal loads data during tests of a hydrocarbon-fueled scramjet combustor at United Technologies Research Center (UTRC). This research effort is part of the UTRC effort to develop dual-mode scramjet combustor technology to support the development of Mach S missile technology. The objective of the thermal loads testing was to map the thermal and mechanical loads, including heat transfer, dynamic and static pressures, and skin friction in a scramjet combustor during direct-connect scramjet tests. The tests were conducted at the UTRC Ramject/Scramjet direct-connect combustor test facility in East Hartford, CT.

  14. Field testing of a pulse combustor in a cement plant. Final report, April 1, 1993-November 30, 1995

    SciTech Connect (OSTI)

    Plavnik, Z.Z.; Daniel, B.R.; Zinn, B.T.; Shekhter, M.Y.; Geskin, O.

    1996-07-01

    This document describes work performed under GRI Contract No. 5091-236-2251 during the period April 1, 1993, to November 30, 1995. This project was entitled `Field Testing of a Pulse Combustor in a Cement Plant.` The main objective of this program was to determine the effect of pulsations excited by a tunable pulse combustor upon the performance of a cement calciner located in a Holnam Cement plant in La Porte, Colorado. A 12.5 MMbtu/hr tunable pulse combustor was retrofitted to a cement calciner and number of tests were conducted under similar operating conditions with the pulse combustor on and off and the calciner`s performance in these tests was compared. Comparisons of the calciner`s performance with the PCRS on and off showed that the pulsations increased the calcination rate by 2.2 - 3.7 percent.

  15. The development of a cyclonic combustor for high particulate, low caloric value gas produced by a fluidized bed 

    E-Print Network [OSTI]

    Cardenas, Manuel Moises

    1985-01-01

    THE DEVELOPMENT OF A CYCLONIC COMBUSTOR FOR HIGH PARTICULATE, LOW CALORIC VALUE GAS PRODUCED BY A FLUIDIZED BED A Thesis by MANUEL MOISES CARDENAS JR. Submitted to the Graduate College of Texas ALM University in partial fulfillment... of the requirements for the degree of MASTER OF SCIENCE December 1985 Major Subject: Mechanical Engineering THE DEVELOPMENT OF A CYCLONIC COMBUSTOR FOR HIGH PARTICULATE, LOW CALORIC VALUE GAS PRODUCED BY A FLUIDIZED BED A Thesis MANUEL MOISES CARDENAS JR...

  16. A feasibility study of oil shale fired pulse combustors with applications to oil shale retorting. Final report

    SciTech Connect (OSTI)

    Morris, G.J.; Johnson, E.K.; Zhang, G.Q.; Roach, R.A.

    1992-07-01

    The results of the experimental investigation performed to determine the feasibility of using pulverized Colorado oil shale to fuel a bench scale pulse combustor reveal that oil shale cannot sustain pulsations when used alone as fuel. Trace amounts of propane mixed with the oil shale enabled the pulsations, however. Up to 80% of the organic material in the oil shale was consumed when it was mixed with propane in the combustor. Beyond the feasibility objectives, the operating conditions of the combustor fuel with propane and mixtures of oil shale and propane were characterized with respect to pulsation amplitude and frequency and the internal combustor wall temperature over fuel lean and fuel rich stoichiometries. Maximum pressure excursions of 12.5 kPa were experienced in the combustor. Pulsation frequencies ranged from 50 to nearly 80 Hz. Cycle resolved laser Doppler anemometry velocities were measured at the tail pipe exit plane. Injecting inert mineral matter (limestone) into the pulse combustor while using propane fuel had only a slight effect on the pulsation frequency for the feed rates tested.

  17. Method and apparatus for the control of fluid dynamic mixing in pulse combustors

    DOE Patents [OSTI]

    Bramlette, T.T.; Keller, J.O.

    1992-06-02

    In a method and apparatus for controlling total ignition delay time in a pulse combustor, and thus controlling the mixing characteristics of the combustion reactants and the combustion products in the combustor, the total ignition delay time is controlled by adjusting the inlet geometry of the inlet to the combustion chamber. The inlet geometry may be fixed or variable for controlling the mixing characteristics. A feedback loop may be employed to sense actual combustion characteristics, and, in response to the sensed combustion characteristics, the inlet geometry may be varied to obtain the total ignition delay time necessary to achieve the desired combustion characteristics. Various embodiments relate to the varying of the mass flow rate of reactants while holding the radius/velocity ratio constant. 10 figs.

  18. Method and apparatus for the control of fluid dynamic mixing in pulse combustors

    DOE Patents [OSTI]

    Bramlette, T. Tazwell (San Ramon, CA); Keller, Jay O. (Oakland, CA)

    1992-06-02

    In a method and apparatus for controlling total ignition delay time in a pulse combustor, and thus controlling the mixing characteristics of the combustion reactants and the combustion products in the combustor, the total ignition delay time is controlled by adjusting the inlet geometry of the inlet to the combustion chamber. The inlet geometry may be fixed or variable for controlling the mixing characteristics. A feedback loop may be employed to sense actual combustion characteristics, and, in response to the sensed combustion characteristics, the inlet geometry may be varied to obtain the total ignition delay time necessary to achieve the desired combustion characteristics. Various embodiments relate to the varying of the mass flow rate of reactants while holding the radius/velocity ratio constant.

  19. An evaluation of a pre-charging pulse-jet filter for small combustor particulate control

    SciTech Connect (OSTI)

    Quimby, J.M.

    1990-11-01

    The objective of this test program is the performance and economic evaluation of a pre-charged-pulse jet filter as the principal particulate control device for a commercial or industrial scale coal fired combustor. Performance factors that will be considered are the effects of particle charge, air/cloth ratio, fabric types, percent humidity and inlet particulate loading on fine particle collection efficiency, and pressure drop. Economic factors that will be considered are capital costs, energy and other operating costs, and maintenance costs. The program will result in a recommendation regarding the relative suitability of the pre charged pulse-jet filter for small combustor particulate control, as compared to other control devices. Fine particle control capability, ease of operation, and overall economics will be taken into consideration in making comparisons.

  20. An evaluation of a pre-charging pulse-jet filter for small combustor particulate control

    SciTech Connect (OSTI)

    Helfritch, D.J.; Quimby, J.M.

    1991-04-01

    The objective of this test program was the performance and economic evaluation of a pre-charged pulse-jet filter as the principal particulate control device for a commercial- or industrial-scale coal-fired combustor. Performance factors that were considered were the effects of particle charge, air/cloth ratio, pulse frequency, pulse pressure, fabric types, humidity, and inlet particulate loading on fine particle collection efficiency and pressure drop. Economic factors that were considered included capital costs, energy requirements, and operating and maintenance costs. The program resulted in a recommendation regarding the relative suitability of the pre-charged pulse-jet filter for small combustor particulate control, as compared to a pulse-jet filter without pre-charging. Fine particle control capability, ease of operation, and overall economics were taken into consideration in making comparisons. 23 refs., 16 figs., 10 tabs.

  1. Numerical Simulation of Combustion and Rotor-Stator Interaction in a Turbine Combustor

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

    Isvoranu, Dragos D.; Cizmas, Paul G. A.

    2003-01-01

    This article presents the development of a numerical algorithm for the computation of flow and combustion in a turbine combustor. The flow and combustion are modeled by the Reynolds-averaged Navier-Stokes equations coupled with the species-conservation equations. The chemistry model used herein is a two-step, global, finite-rate combustion model for methane and combustion gases. The governing equations are written in the strong conservation form and solved using a fully implicit, finite-difference approximation. The gas dynamics and chemistry equations are fully decoupled. A correction technique has been developed to enforce the conservation of mass fractions. The numerical algorithm developed herein has beenmore »used to investigate the flow and combustion in a one-stage turbine combustor.« less

  2. Ultra low injection angle fuel holes in a combustor fuel nozzle

    DOE Patents [OSTI]

    York, William David

    2012-10-23

    A fuel nozzle for a combustor includes a mixing passage through which fluid is directed toward a combustion area and a plurality of swirler vanes disposed in the mixing passage. Each swirler vane of the plurality of swirler vanes includes at least one fuel hole through which fuel enters the mixing passage in an injection direction substantially parallel to an outer surface of the plurality of swirler vanes thereby decreasing a flameholding tendency of the fuel nozzle. A method of operating a fuel nozzle for a combustor includes flowing a fluid through a mixing passage past a plurality of swirler vanes and injecting a fuel into the mixing passage in an injection direction substantially parallel to an outer surface of the plurality of swirler vanes.

  3. Fuel-Flexible, Low-Emissions Catalytic Combustor for Opportunity Fuels

    SciTech Connect (OSTI)

    2009-11-01

    Precision Combustion, Inc. will develop a unique, fuel-flexible Rich Catalytic Lean-Burn (RCL®) injector with catalytic combustor capable of enabling ultralow-emission, lean premixed combustion of a wide range of gaseous opportunity fuels. This will broaden the range of opportunity fuels that can be utilized to include low- and ultralow-Btu gases, such as digester and blast furnace gases, and fuels containing reactive species, such as refinery, wellhead, and industrial byproduct gases.

  4. Report covering examination of parts from downhole steam generators. [Combustor head and sleeve parts

    SciTech Connect (OSTI)

    Pettit, F. S.; Meier, G. H.

    1983-08-01

    Combustor head and sleeve parts were examined by using optical and scanning electron metallography after use in oxygen/diesel and air/diesel downhole steam generators. The degradation of the different alloy components is described in terms of reactions with oxygen, sulfur and carbon in the presence of cyclic stresses, all generated by the combustion process. Recommendations are presented for component materials (alloys and coatings) to extend component lives in the downhole steam generators. 9 references, 22 figures, 3 tables.

  5. Development of a retrofit coal combustor for industrial applications, (Phase 2)

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    The objective of Phase I of the program for the development of a retrofit pulse coal combustor for industrial applications was to design, fabricate, test and evaluate advanced chamber designs at the laboratory-scale utilizing several fuels (Task 1). The activities were structured to provide design criteria for scaling up to the pilot-scale level for the demonstration of a pulse combustor fired with coal-water mixtures for industrial boiler and process heater retrofit applications. The design data and information acquired during Task I of the initial phase was to develop scale-up design criteria for scaling the laboratory-scale design to pilot-scale including interface requirements for the field demonstration. The scale-up pilot unit design was to be sufficiently developed to allow fabrication of the unit for testing in the existing test facility upon DOE exercising its option for the follow-on activities of this program. These follow-on activities (Phase II) included the fabrication, test, and engineering evaluation of the pilot-scale combustor as well as technical and laboratory test support activities for reducing the technical risks and costs of development at the pilot-scale. Based on the information, test, data and technical support activities, a retrofit combustor system was to be designed for field demonstration. An additional effort - Phase IA - was added to the contract by modification A005. This modification added a Phase IA in place of the original Task 2 of Phase I activity. This interim phase consisted of three technical tasks described in previous quarterly reports. Phase II was initiated in April 1989.

  6. Development of a retrofit coal combustor for industrial applications, (Phase 2)

    SciTech Connect (OSTI)

    Not Available

    1989-07-01

    The objective of Phase I of the program for the development of a retrofit pulse coal combustor for industrial applications was to design, fabricate, test and evaluate advanced chamber designs at the laboratory-scale utilizing several fuels (Task 1). The activities were structured to provide design criteria for scaling up to the pilot-scale level for the demonstration of a pulse combustor fired with coal-water mixtures for industrial boiler and process heater retrofit applications. The design data and information acquired during Task 1 of the initial phase was to develop scale-up design criteria for scaling the laboratory-scale design to pilot-scale including interface requirements for the field demonstration. The scale-up pilot unit design was to be sufficiently developed to allow fabrication of the unit for testing in the existing test facility upon DOE exercising its option for the follow-on activities of this program. These follow-on activities (Phase II) included the fabrication, test, and engineering evaluation of the pilot-scale combustor as well as technical and laboratory test support activities for reducing the technical risks and costs of development at the pilot-scale. Based on the information, test, data and technical support activities, a retrofit combustor system was to be designed for field demonstration. An additional effort was added to the contract by modification A005. This modification added a Phase IA in place of the original Task 2 of Phase I activity. This interim phase consisted of three technical tasks described in previous quarterly reports. Phase II was initiated in April 1989.

  7. The effect of acoustics on an ethanol spray flame in a propane-fired pulse combustor

    SciTech Connect (OSTI)

    Dubey, R.K.; Black, D.L.; McQuay, M.Q. [Brigham Young Univ., Provo, UT (United States). Mechanical Engineering Dept.] [Brigham Young Univ., Provo, UT (United States). Mechanical Engineering Dept.; Carvalho, J.A. Jr. [Inst. Nacional de Pesquisas Espaciais, Cachoeira Paulista, Sao Paulo (Brazil). Lab. Associado de Comubustao e Propulsao] [Inst. Nacional de Pesquisas Espaciais, Cachoeira Paulista, Sao Paulo (Brazil). Lab. Associado de Comubustao e Propulsao

    1997-07-01

    The influence of an acoustic field on the combustion characteristics of a hydrogen-stabilized ethanol spray flame has been experimentally investigated using a phase-Doppler particle analyzer in a propane-fired, Rijke-tube, pulse combustor. The controlled sinusoidal acoustic field in the combustor had a sound pressure level of 155 dB and a frequency of 80 Hz. Experiments were performed to study the effect of oscillations on Sauter-mean and arithmetic-mean diameters, droplet velocity, and droplet number density for the present operating conditions of the Rijke-tube combustor. Similar measurements were also performed on a water spray in the propane-fired reactor to study the effect of the acoustic field on the atomization process for the nozzle type used. Spectral analysis of the droplet axial velocity component for the oscillating conditions revealed a dominant frequency equal to the frequency of the sinusoidal acoustic wave in the combustor. The Sauter-mean diameter of the ethanol spray decreased by 15%, on average, in the presence of the acoustic field because of enhanced evaporation, while the droplet arrival rate at the probe volume increased due to changes in the flame structure. Analysis of the measured size distributions indicated that under an oscillating flow there was a larger population of droplets in the diameter range of 3--20 {micro}m. Experiments conducted with the water spray indicated that the oscillations did affect droplet size distributions in the ethanol spray due to enhanced evaporation caused by the relocation of the flame front inside and around the spray cone.

  8. Nonlinear heat-release/acoustic model for thermoacoustic instability in lean premixed combustors

    SciTech Connect (OSTI)

    Peracchio, A.A.; Proscia, W.M.

    1999-07-01

    Lean premixed combustors, such as those used in industrial gas turbines to achieve low emissions, are often susceptible to thermoacoustic combustion instabilities, which manifest themselves as pressure and heat release oscillations in the combustor. These oscillations can result in increased noise and decreased durability due to vibration and flame motion. A physically based nonlinear parametric model has been developed that captures this instability. It describes the coupling of combustor acoustics with the rate of heat release. The model represents this coupling by accounting for the effect of acoustic pressure fluctuations on the varying fuel/air ratio being delivered to the flame, causing a fluctuating heat release due to both fuel air ratio variations and flame front oscillations. If the phasing of the fluctuating heat release and pressure are proper, an instability results that grows into a limit cycle. The nonlinear nature of the model predicts the onset of the instability and additionally captures the resulting limit cycle. Tests of a lean premixed nozzle at engine scale and engine operating conditions in the UTRC single nozzle rig, conducted under DARPA contract, exhibited instabilities. Parameters from the model were adjusted so that analytical results were consistent with relevant experimental data from this test. The parametric model captures the limit cycle behavior over a range of mean fuel air ratios, showing the instability amplitude (pressure and heat release) to increase and limit cycle frequency to decrease as mean fuel air ratio is reduced.

  9. Investigation of the mechanism in Rijke pulse combustors with tangential air and fuel injection. Final report

    SciTech Connect (OSTI)

    Zinn, B.T.; Jagoda, J.I.; Daniel, B.R.; Bai, T.

    1993-03-01

    To study the mechanisms that control the operation of this combustor, an experimental setup is developed with access for detailed optical measurements. Propane is employed as fuel because the absence of liquid drops and combustion generated particulates in the combustion region significantly simplifies the optical diagnostics. The experimental techniques utilized include acoustic pressure measurements, space and time resolved radiation measurements, steady temperature measurements, exhaust flow chemical analysis, high speed video and intensified images of the reacting flow field by a computer based CCD camera imaging system. Flow visualization by the imaging system and the results from radiation intensity distribution measurements suggest that the periodic combustion processes caused by periodic vortex shedding and impingement provide the energy required to sustain the pressure oscillations. High radiation intensity occurs during a relatively short period of time and is in phase with the pressure oscillations, indicating that Rayleigh`s criterion is satisfied. Periodic variations of the air and fuel flow rates and, consequently, the air/fuel ratio of the reacting mixture inside the combustor appear to be another mechanism that contributes to the occurrence of periodic combustion and heat release processes. The presence of this mechanism has been uncovered by acoustic pressure measurements that revealed the presence of traveling pressure waves inside the air and fuel feed lines. These traveling waves produce periodic fuel and air feed rates which, in turn, result in periodic combustion and heat release processes within the combustor.

  10. Development of a coal fired pulse combustor for residential space heating. Phase I, Final report

    SciTech Connect (OSTI)

    NONE

    1988-04-01

    This report presents the results of the first phase of a program for the development of a coal-fired residential combustion system. This phase consisted of the design, fabrication, testing, and evaluation of an advanced pulse combustor sized for residential space heating requirements. The objective was to develop an advanced pulse coal combustor at the {approximately} 100,000 Btu/hr scale that can be integrated into a packaged space heating system for small residential applications. The strategy for the development effort included the scale down of the feasibility unit from 1-2 MMBtu/hr to 100,000 Btu/hr to establish a baseline for isolating the effect of scale-down and new chamber configurations separately. Initial focus at the residential scale was concentrated on methods of fuel injection and atomization in a bare metal unit. This was followed by incorporating changes to the advanced chamber designs and testing of refractory-lined units. Multi-fuel capability for firing oil or gas as a secondary fuel was also established. Upon completion of the configuration and component testing, an optimum configuration would be selected for integrated testing of the pulse combustor unit. The strategy also defined the use of Dry Ultrafine Coal (DUC) for Phases 1 and 2 of the development program with CWM firing to be a product improvement activity for a later phase of the program.

  11. NO{sub x} and CO emissions from an aerovalve pulse combustor

    SciTech Connect (OSTI)

    Norton, T.S.; Richards, G.A.; Casleton, K.H.; Jenkins, L.C.

    1993-12-31

    The Morgantown Energy Technology Center (METC) has an ongoing research program to investigate the benefits of pulse combustion in advanced energy systems. The overall goals are to study and improve the pressure-gain performance of pulse combustors, to investigate the effects of pressure on operating characteristics, and ultimately to determine the feasibility of using pulse combustors in gas turbine applications [Gemmen et al., 1992, 1993]. An additional goal is to ensure that the combustor designs under consideration produce low levels of NO{sub x} and CO pollutant emissions. The gas sampling and analysis system is currently under development. Preliminary data on NO{sub x} and CO emissions concentrations have been obtained and appear encouraging. After further leak checking, system debugging, and calibrating are completed, new experimental data should be available to be reported at the conference. In addition, a modeling effort is being initiated to aid in the interpretation of the experimental results. Some details of the experimental and modeling approaches are given below.

  12. Response of a pulse combustor to changes in total ignition delay time

    SciTech Connect (OSTI)

    Keller, J.O.; Westbrook, C.K.; Bramlette, T.T.; Dec, J.E.

    1987-03-31

    The response of a valved pulse combustor to changes in the relative timing between the resonant pressure wave and the energy release rate is examined. Experiments were performed in which measurements of combustion chamber pressure, operating frequency, and spatially-integrated, time-resolved ensemble-averaged chemiluminescence were made. The total time interval required for energy release is divided into a fluid dynamic species mixing time, a second fluid dynamic mixing time between cold reactants and hot reaction products, and a homogeneous chemical kinetic ignition delay time. Each of these time scales is varied independently, as well as the characteristic resonance time of the pulse combustor. It is shown that each time scale can be varied separately to optimize the operation of the pulse combustor. All of these system responses are interpreted in terms of Rayleigh's Criterion. In addition, theoretical models for the fluid dynamic mixing process and the chemical kinetic ignition delay are used to determine actual values for the time scales for some of these subprocesses.

  13. Development of a retrofit coal combustor for industrial applications, (Phase 1-A). Technical progress report, July--September 1988

    SciTech Connect (OSTI)

    Not Available

    1988-10-01

    During this past quarter, two tandem-fired pulse combustors were designed to fire at a nominal rate of 3.5 to 5.5 MMBtu/hr under continuation of Phase I work on DOE project DE-AC22-87PC79654. In prior work, MTCI demonstrated the operation of a 1--2 MMBtu/h coal-fired tandem pulse combustor that is intended for small industrial applications. These component tests emphasized verification of key design issues such as combustor coupling, slag rejection, and staged air addition. The current work, which represents an extension of the Phase I effort, focuses on integrated testing of the tandem pulse combustor with a fire-tube boiler, and the addition of a slag quench vessel. A tandem-fired pulse combustion unit designed to fire at a nominal rate of 3.5-5 MMBtu/hr was designed and fabricated. The configuration includes two combustion chambers cast in a single monolith, tailpipes cast separately with annular air preheating capability, and a cyclonic decoupler. Design analysis and evaluations were performed to optimize the system with respect to minimizing heat losses, size, and cost. Heat losses from the combustor and decoupler walls are predicted to be approximately 3 percent. The final designs for the ancillary items (slag quench, tertiary air addition, scrubber and sampling system) were completed and fabrication and installation initiated. A Cleaver-Brooks 150 hp-4 pass boiler was delivered and installed and modifications for interfacing with the retrofit pulse combustor unit completed. A below-ground slag collection pit was excavated to permit direct in-line coupling of the combustor to the boiler and to reduce head-room requirements. The pit is 30 inches deep and lined with waterproof and fireproof siding.

  14. Investigation of the mechanism in RIJKE pulse combustors with tangential air and fuel injection. Progress report, August 1, 1992--January 31, 1993

    SciTech Connect (OSTI)

    Zinn, B.T.; Jagoda, J.I.; Daniel, B.R.; Bai, T.

    1993-02-01

    This report summarizes the accomplishments of DOE Contract No. DE-AS04-85AL31881. This three year investigation started in August 1989 and its objective was to elucidate the mechanisms that control the driving of pulsations in the liquid fuel burning, Rijke type, pulse combustor developed under a preceding DOE contracts. It was demonstrated in that contract that the developed Rijke type pulse combustor can burn a variety of light and heavy liquid fuel oils with high combustion efficiencies while using low excess air, which produces high thermal efficiencies. Since the elucidation of the driving mechanism in the Rijke pulse combustor required the use of optical diagnostics (e.g., radiation measurements), it was decided to perform these investigations in a Rijke pulse combustor that burned propane instead of a liquid fuel in order to avoid difficulties that are often encountered due to the presence of liquid droplets in the combustion region. Consequently, an effort was made to develop a Rijke pulse combustor that is similar to the one developed in the preceding program and demonstrated similar performance characteristics. Such a pulse combustor was developed in the early phases of this program. The developed experimental setup was provided with capabilities for measuring steady combustor temperature distributions, the characteristics of the excited pressure oscillations, the exhaust flow composition, the characteristics of the flow field and the reaction rates. This pulse combustor consists of a cylindrical tube that is attached to a decoupling chamber at each end. Fuel and air are supplied via a tangential air/fuel injection system that is located at a distance of L/4 from the combustor entrance, where L is the combustor length. Part of the combustor tube, where combustion occurs, is water cooled. This section is also equipped with flat quartz windows to permit optical diagnostics.

  15. Large Eddy Simulation based Studies of Reacting and Non-reacting Transverse Jets in Supersonic Crossflow

    E-Print Network [OSTI]

    Raman, Venkat

    Large Eddy Simulation based Studies of Reacting and Non-reacting Transverse Jets in Supersonic.S. Air Force Research Laboratory, WrightPatterson Air Force Base, Ohio, 45433, USA Jet in supersonic and oxidizer .2­5 Here, the fuel jet issues from an injector typically mounted on the combustor walls either

  16. LARGE EDDY SIMULATION/EULERIAN PROBABILITY DENSITY FUNCTION APPROACH FOR SIMULATING HYDROGEN-ENRICHED GAS TURBINE

    E-Print Network [OSTI]

    Raman, Venkat

    LARGE EDDY SIMULATION/EULERIAN PROBABILITY DENSITY FUNCTION APPROACH FOR SIMULATING HYDROGEN 78712 Email: v.raman@mail.utexas.edu Scott Martin Siemens Energy Corp. Orlando, Florida Email:scott.m.martin@siemens.com ABSTRACT To describe partially-premixed combustion inside hydrogen- rich combustors, a novel quadrature

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

    SciTech Connect (OSTI)

    Ahsan Choudhuri

    2011-03-31

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

  18. Design and fabrication of a meso-scale stirling engine and combustor.

    SciTech Connect (OSTI)

    Echekki, Tarek (Sandia National Laboratories, Livermore, CA); Haroldsen, Brent L. (Sandia National Laboratories, Livermore, CA); Krafcik, Karen L. (Sandia National Laboratories, Livermore, CA); Morales, Alfredo Martin; Mills, Bernice E.; Liu, Shiling; Lee, Jeremiah C. (Sandia National Laboratories, Livermore, CA); Karpetis, Adionos N. (Sandia National Laboratories, Livermore, CA); Chen, Jacqueline H. (Sandia National Laboratories, Livermore, CA); Ceremuga, Joseph T. (Sandia National Laboratories, Livermore, CA); Raber, Thomas N.; Hekmuuaty, Michelle A.

    2005-05-01

    Power sources capable of supplying tens of watts are needed for a wide variety of applications including portable electronics, sensors, micro aerial vehicles, and mini-robotics systems. The utility of these devices is often limited by the energy and power density capabilities of batteries. A small combustion engine using liquid hydrocarbon fuel could potentially increase both power and energy density by an order of magnitude or more. This report describes initial development work on a meso-scale external combustion engine based on the Stirling cycle. Although other engine designs perform better at macro-scales, we believe the Stirling engine cycle is better suited to small-scale applications. The ideal Stirling cycle requires efficient heat transfer. Consequently, unlike other thermodynamic cycles, the high heat transfer rates that are inherent with miniature devices are an advantage for the Stirling cycle. Furthermore, since the Stirling engine uses external combustion, the combustor and engine can be scaled and optimized semi-independently. Continuous combustion minimizes issues with flame initiation and propagation. It also allows consideration of a variety of techniques to promote combustion that would be difficult in a miniature internal combustion engine. The project included design and fabrication of both the engine and the combustor. Two engine designs were developed. The first used a cylindrical piston design fabricated with conventional machining processes. The second design, based on the Wankel rotor geometry, was fabricated by through-mold electroforming of nickel in SU8 and LIGA micromolds. These technologies provided the requisite precision and tight tolerances needed for efficient micro-engine operation. Electroformed nickel is ideal for micro-engine applications because of its high strength and ductility. A rotary geometry was chosen because its planar geometry was more compatible with the fabrication process. SU8 lithography provided rapid prototypes to verify the design. A final high precision engine was created via LIGA. The micro-combustor was based on an excess enthalpy concept. Development of a micro-combustor included both modeling and experiments. We developed a suite of simulation tools both in support of the design of the prototype combustors, and to investigate more fundamental aspects of combustion at small scales. Issues of heat management and integration with the micro-scale Stirling engine were pursued using CFD simulations. We found that by choice of the operating conditions and channel dimensions energy conversion occurs by catalysis-dominated or catalysis-then-homogeneous phase combustion. The purpose of the experimental effort in micro-combustion was to study the feasibility and explore the design parameters of excess enthalpy combustors. The efforts were guided by the necessity for a practical device that could be implemented in a miniature power generator, or as a stand-alone device used for heat generation. Several devices were fabricated and successfully tested using methane as the fuel.

  19. An evaluation of a pre-charging pulse-jet filter for small combustor particulate control

    SciTech Connect (OSTI)

    Quimby, J.M.

    1991-03-01

    The objective of this test program is the performance and economic evaluation of a pre charged-pulse jet filter as the principal particulate control device for a commercial or industrial scale coal fired combustor. Performance factors that will be considered are the effects of particle charge, air/cloth ratio, fabric types, percent humidity and inlet particulate loading on fine particle collection efficiency, and pressure drop. Economic factors that will be considered are capital costs, energy and other operating costs, and maintenance costs.

  20. In-bed tube bank for a fluidized-bed combustor

    DOE Patents [OSTI]

    Hemenway, Jr., Lloyd F. (Morgantown, WV)

    1990-01-01

    An in-bed tube bank (10) for a fluidized bed combustor. The tube bank (10) of the present invention comprises one or more fluid communicating boiler tubes (30) which define a plurality of selectively spaced boiler tube sections (32). The tube sections (32) are substantially parallel to one another and aligned in a common plane. The tube bank (10) further comprises support members (34) for joining adjacent tube sections (32), the support members (34) engaging and extending along a selected length of the tube sections (32) and spanning the preselected space therebetween.

  1. Measurement of flowfield in a simulated solid-propellant ducted rocket combustor using laser Doppler velocimetry

    SciTech Connect (OSTI)

    Hsieh, W.H.; Yang, V.; Chuang, C.L.; Yang, A.S.; Cherng, D.L.

    1989-01-01

    A two-component LDV system was used to obtain detailed flow velocity and turbulence measurements in order to study the flow characteristics in a simulated solid-propellant ducted rocket combustor. The vortical structures near the dome region, the size of the recirculation zone, and the location of the reattachment point are all shown to be strongly affected by the jet momentum of both ram air and fuel streams. It is found that the turbulence intensity is anisotropic throughout the front portion of the simulated conbustor, and that the measured Reynolds stress conmponent distribution is well correlated with the local mean velocity vector distribution. 25 refs.

  2. Turbine combustor configured for high-frequency dynamics mitigation and related method

    DOE Patents [OSTI]

    Uhm, Jong Ho; Zuo, Baifang; York, William David; Srinivasan, Shivakumar

    2014-11-04

    A turbomachine combustor includes a combustion chamber; a plurality of micro-mixer nozzles mounted to an end cover of the combustion chamber, each including a fuel supply pipe affixed to a nozzle body located within the combustion chamber, wherein fuel from the supply pipe mixes with air in the nozzle body prior to discharge into the combustion chamber; and wherein at least some of the nozzle bodies of the plurality of micro-mixer nozzles have axial length dimensions that differ from axial length dimensions of other of the nozzle bodies.

  3. Melt Infiltrated Ceramic Matrix Composites for Shrouds and Combustor Liners of Advanced Industrial Gas Turbines

    SciTech Connect (OSTI)

    Gregory Corman; Krishan Luthra; Jill Jonkowski; Joseph Mavec; Paul Bakke; Debbie Haught; Merrill Smith

    2011-01-07

    This report covers work performed under the Advanced Materials for Advanced Industrial Gas Turbines (AMAIGT) program by GE Global Research and its collaborators from 2000 through 2010. A first stage shroud for a 7FA-class gas turbine engine utilizing HiPerComp{reg_sign}* ceramic matrix composite (CMC) material was developed. The design, fabrication, rig testing and engine testing of this shroud system are described. Through two field engine tests, the latter of which is still in progress at a Jacksonville Electric Authority generating station, the robustness of the CMC material and the shroud system in general were demonstrated, with shrouds having accumulated nearly 7,000 hours of field engine testing at the conclusion of the program. During the latter test the engine performance benefits from utilizing CMC shrouds were verified. Similar development of a CMC combustor liner design for a 7FA-class engine is also described. The feasibility of using the HiPerComp{reg_sign} CMC material for combustor liner applications was demonstrated in a Solar Turbines Ceramic Stationary Gas Turbine (CSGT) engine test where the liner performed without incident for 12,822 hours. The deposition processes for applying environmental barrier coatings to the CMC components were also developed, and the performance of the coatings in the rig and engine tests is described.

  4. Method for control of NOx emission from combustors using fuel dilution

    DOE Patents [OSTI]

    Schefer, Robert W. (Alamo, CA); Keller, Jay O (Oakland, CA)

    2007-01-16

    A method of controlling NOx emission from combustors. The method involves the controlled addition of a diluent such as nitrogen or water vapor, to a base fuel to reduce the flame temperature, thereby reducing NOx production. At the same time, a gas capable of enhancing flame stability and improving low temperature combustion characteristics, such as hydrogen, is added to the fuel mixture. The base fuel can be natural gas for use in industrial and power generation gas turbines and other burners. However, the method described herein is equally applicable to other common fuels such as coal gas, biomass-derived fuels and other common hydrocarbon fuels. The unique combustion characteristics associated with the use of hydrogen, particularly faster flame speed, higher reaction rates, and increased resistance to fluid-mechanical strain, alter the burner combustion characteristics sufficiently to allow operation at the desired lower temperature conditions resulting from diluent addition, without the onset of unstable combustion that can arise at lower combustor operating temperatures.

  5. Measurement and Capture of Fine and Ultrafine Particles from a Pilot-Scale Pulverized Coal Combustor with an

    E-Print Network [OSTI]

    Li, Ying

    Measurement and Capture of Fine and Ultrafine Particles from a Pilot-Scale Pulverized Coal out in a pilot-scale pulverized coal combustor at the Energy and Environmental Re- search Center (EERC) burning a Powder River Basin (PRB) subbituminous coal. A scanning mobility particle sizer (SMPS

  6. Multidimensional Numerical Simulation of a Pulse Combustor \\Lambda Daniel L. Marcus, Richard B. Pember, John B. Bell, Vincent E. Beckner,

    E-Print Network [OSTI]

    Bell, John B.

    Multidimensional Numerical Simulation of a Pulse Combustor \\Lambda Daniel L. Marcus, Richard B Abstract We have developed a new three­dimensional modeling capability to study the behavior of pulse­dimensional, reacting fluid dynamics in the combustion chamber and in­ corporates lower­dimensional approximations

  7. Numerical Modeling of Non-adiabatic Heat-Recirculating Combustors C. H. Kuo and P. D. Ronney

    E-Print Network [OSTI]

    @usc.edu Colloquium topic area: 12. New Technology Concepts Keywords: Micro-combustion, Heat-recirculating combustors) for propane-air mixtures. These limits showed reasonable quantitative agreement with experiments. Comparison based on existing macro-scale designs such as internal combustion engines may be impractical

  8. Method of and apparatus for preheating pressurized fluidized bed combustor and clean-up subsystem of a gas turbine power plant

    DOE Patents [OSTI]

    Cole, Rossa W. (E. Rutherford, NJ); Zoll, August H. (Cedar Grove, NJ)

    1982-01-01

    In a gas turbine power plant having a pressurized fluidized bed combustor, gas turbine-air compressor subsystem and a gas clean-up subsystem interconnected for fluid flow therethrough, a pipe communicating the outlet of the compressor of the gas turbine-air compressor subsystem with the interior of the pressurized fluidized bed combustor and the gas clean-up subsystem to provide for flow of compressed air, heated by the heat of compression, therethrough. The pressurized fluidized bed combustor and gas clean-up subsystem are vented to atmosphere so that the heated compressed air flows therethrough and loses heat to the interior of those components before passing to the atmosphere.

  9. Dispersion of seed vapor and gas ionization in an MHD second stage combustor and channel

    SciTech Connect (OSTI)

    Chang, S.L.; Lottes, S.A.; Bouillard, J.X.

    1992-01-01

    An approach is introduced for the simulation of a magnetohydrodynamic system consisting of a second stage combustor, a convergent nozzle, and a channel. The simulation uses an Argonne integral combustion flow computer code and another Argonne channel computer code to predict flow, thermal and electric properties in the seed particle laden reacting flow in the system. The combustion code is a general hydrodynamics computer code for two-phase, two-dimensional, turbulent, and reacting flows, based on mass, momentum, and energy conservation laws for gaseous and condensed phases. The channel code is a multigrid three-dimensional computer code for compressible flow subject to magnetic and electric interactions. Results of this study suggests that (1) the processes of seed particle evaporation, seed vapor dispersion, and gas ionization in the reacting flow are critical to the evaluation of the downstream channel performance and (2) particle size, loading, and inlet profile have strong effects on wall deposition and plasma temperature development.

  10. Dispersion of seed vapor and gas ionization in an MHD second stage combustor and channel

    SciTech Connect (OSTI)

    Chang, S.L.; Lottes, S.A.; Bouillard, J.X.

    1992-07-01

    An approach is introduced for the simulation of a magnetohydrodynamic system consisting of a second stage combustor, a convergent nozzle, and a channel. The simulation uses an Argonne integral combustion flow computer code and another Argonne channel computer code to predict flow, thermal and electric properties in the seed particle laden reacting flow in the system. The combustion code is a general hydrodynamics computer code for two-phase, two-dimensional, turbulent, and reacting flows, based on mass, momentum, and energy conservation laws for gaseous and condensed phases. The channel code is a multigrid three-dimensional computer code for compressible flow subject to magnetic and electric interactions. Results of this study suggests that (1) the processes of seed particle evaporation, seed vapor dispersion, and gas ionization in the reacting flow are critical to the evaluation of the downstream channel performance and (2) particle size, loading, and inlet profile have strong effects on wall deposition and plasma temperature development.

  11. Regeneratively cooled coal combustor/gasifier with integral dry ash removal

    DOE Patents [OSTI]

    Beaufrere, A.H.

    1982-04-30

    A coal combustor/gasifier is disclosed which produces a low or medium combustion gas fired furnances or boilers. Two concentric shells define a combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

  12. Process for generating electricity in a pressurized fluidized-bed combustor system

    DOE Patents [OSTI]

    Kasper, Stanley (Pittsburgh, PA)

    1991-01-01

    A process and apparatus for generating electricity using a gas turbine as part of a pressurized fluidized-bed combustor system wherein coal is fed as a fuel in a slurry in which other constituents, including a sulfur sorbent such as limestone, are added. The coal is combusted with air in a pressurized combustion chamber wherein most of the residual sulfur in the coal is captured by the sulfur sorbent. After particulates are removed from the flue gas, the gas expands in a turbine, thereby generating electric power. The spent flue gas is cooled by heat exchange with system combustion air and/or system liquid streams, and the condensate is returned to the feed slurry.

  13. Nonequilibrium sulfur capture and retention in an air cooled slagging coal combustor. Third quarterly technical progress report, April 1--June 30, 1996

    SciTech Connect (OSTI)

    Zauderer, B.

    1996-09-01

    The primary project objective is to determine the degree of sulfur retention in slag in a full scale cyclone coal combustor. This non-equilibrium process is a key step in the capture and retention of sulfur released during coal combustion by the interaction with calcium based sorbent particles. By encapsulating the sulfur bearing calcium particles in slag, the need for landfilling of this waste is eliminated. This objective will be implemented through a series of up to 20 one day tests carried out in a 20 MMBtu/hr air cooled, slagging combustor-boiler installation located in Philadelphia, PA. The project will consist of two tasks. Task 1 consists of the experiments conducted in the 20 MMBtu/hr combustor, and task 2 will consist of analysis of this data. All the operating procedures for this effort have been developed in the 7 years of operation of this combustor.

  14. NO{sub x} and CO emissions from a pulse combustor operating in a lean premixed mode

    SciTech Connect (OSTI)

    Keller, J.O.; Bramlette, T.T.; Barr, P.K.; Alvarez, J.

    1993-04-01

    Emission levels below 5.0 ppM NO{sub x}, with corresponding levels of 75 ppM CO (corrected to 3% O{sub 2}), were achieved in a pulse combustor operating in a lean premixed mode. Both NO{sub x} and CO concentrations were invariant with the total mass flow rate, but NO{sub x} and CO concentrations did vary with the rate of microscopic mixing.

  15. Development of a retrofit coal combustor for industrial applications, (Phase 2). Technical progress report, October--December 1989

    SciTech Connect (OSTI)

    Not Available

    1990-01-01

    The objective of Phase I of the program for the development of a retrofit pulse coal combustor for industrial applications was to design, fabricate, test and evaluate advanced chamber designs at the laboratory-scale utilizing several fuels (Task 1). The activities were structured to provide design criteria for scaling up to the pilot-scale level for the demonstration of a pulse combustor fired with coal-water mixtures for industrial boiler and process heater retrofit applications. The design data and information acquired during Task I of the initial phase was to develop scale-up design criteria for scaling the laboratory-scale design to pilot-scale including interface requirements for the field demonstration. The scale-up pilot unit design was to be sufficiently developed to allow fabrication of the unit for testing in the existing test facility upon DOE exercising its option for the follow-on activities of this program. These follow-on activities (Phase II) included the fabrication, test, and engineering evaluation of the pilot-scale combustor as well as technical and laboratory test support activities for reducing the technical risks and costs of development at the pilot-scale. Based on the information, test, data and technical support activities, a retrofit combustor system was to be designed for field demonstration. An additional effort - Phase IA - was added to the contract by modification A005. This modification added a Phase IA in place of the original Task 2 of Phase I activity. This interim phase consisted of three technical tasks described in previous quarterly reports. Phase II was initiated in April 1989.

  16. Development of a retrofit coal combustor for industrial applications, (Phase 2). Technical progress report, April--June 1989

    SciTech Connect (OSTI)

    Not Available

    1989-07-01

    The objective of Phase I of the program for the development of a retrofit pulse coal combustor for industrial applications was to design, fabricate, test and evaluate advanced chamber designs at the laboratory-scale utilizing several fuels (Task 1). The activities were structured to provide design criteria for scaling up to the pilot-scale level for the demonstration of a pulse combustor fired with coal-water mixtures for industrial boiler and process heater retrofit applications. The design data and information acquired during Task 1 of the initial phase was to develop scale-up design criteria for scaling the laboratory-scale design to pilot-scale including interface requirements for the field demonstration. The scale-up pilot unit design was to be sufficiently developed to allow fabrication of the unit for testing in the existing test facility upon DOE exercising its option for the follow-on activities of this program. These follow-on activities (Phase II) included the fabrication, test, and engineering evaluation of the pilot-scale combustor as well as technical and laboratory test support activities for reducing the technical risks and costs of development at the pilot-scale. Based on the information, test, data and technical support activities, a retrofit combustor system was to be designed for field demonstration. An additional effort was added to the contract by modification A005. This modification added a Phase IA in place of the original Task 2 of Phase I activity. This interim phase consisted of three technical tasks described in previous quarterly reports. Phase II was initiated in April 1989.

  17. NO[sub x] and CO emissions from a pulse combustor operating in a lean premixed mode

    SciTech Connect (OSTI)

    Keller, J.O.; Bramlette, T.T.; Barr, P.K.; Alvarez, J.R. (Sandia National Labs., Livermore, CA (United States). Combustion Research Facility)

    1994-12-01

    Control over the combustion fluid dynamics was used to minimize the emission of NO[sub x] and CO. The combustion kinetics were controlled by operating the combustor premixed and were varied by modifying the equivalence ratio over the lean stability envelope. A wide dynamic range in fluid dynamic mixing characteristics was also investigated by modifying the degree of macroscopic mixing and microscopic mixing. The residence time at high temperature was controlled by modifying the frequency of the periodic reacting flow in a pulse combustor. It was found that controlling the flame temperature, chemical kinetics, and residence time at high temperature was best accomplished by controlling the equivalence ratio and the degree of macroscopic mixing rather than controlling the microscopic mixing over the dynamic range obtainable by the techniques used in this study. Emission levels below 5.0 ppm NO[sub x], with corresponding levels of 5.0 ppm CO (corrected to 3% O[sub 2]), were achieved in a pulse combustor operating in a lean premixed mode, without the use of any post combustion cleanup technologies. Both NO[sub 2] and CO emissions were invariant to changes in the power input.

  18. Spatially distributed flame transfer functions for predicting combustion dynamics in lean premixed gas turbine combustors

    SciTech Connect (OSTI)

    Kim, K.T.; Lee, J.G.; Quay, B.D.; Santavicca, D.A.

    2010-09-15

    The present paper describes a methodology to improve the accuracy of prediction of the eigenfrequencies and growth rates of self-induced instabilities and demonstrates its application to a laboratory-scale, swirl-stabilized, lean-premixed, gas turbine combustor. The influence of the spatial heat release distribution is accounted for using local flame transfer function (FTF) measurements. The two-microphone technique and CH{sup *} chemiluminescence intensity measurements are used to determine the input (inlet velocity perturbation) and the output functions (heat release oscillation), respectively, for the local flame transfer functions. The experimentally determined local flame transfer functions are superposed using the flame transfer function superposition principle, and the result is incorporated into an analytic thermoacoustic model, in order to predict the linear stability characteristics of a given system. Results show that when the flame length is not acoustically compact the model prediction calculated using the local flame transfer functions is better than the prediction made using the global flame transfer function. In the case of a flame in the compact flame regime, accurate predictions of eigenfrequencies and growth rates can be obtained using the global flame transfer function. It was also found that the general response characteristics of the local FTF (gain and phase) are qualitatively the same as those of the global FTF. (author)

  19. The impact of equivalence ratio oscillations on combustion dynamics in a backward-facing step combustor

    SciTech Connect (OSTI)

    Murat Altay, H.; Speth, Raymond L.; Hudgins, Duane E.; Ghoniem, Ahmed F.

    2009-11-15

    The combustion dynamics of propane-air flames are investigated in an atmospheric pressure, atmospheric inlet temperature, lean, premixed backward-facing step combustor. We modify the location of the fuel injector to examine the impact of equivalence ratio oscillations arriving at the flame on the combustion dynamics. Simultaneous pressure, velocity, heat-release rate and equivalence ratio measurements and high-speed video from the experiments are used to identify and characterize several distinct operating modes. When the fuel is injected far upstream from the step, the equivalence ratio arriving at the flame is steady and the combustion dynamics are controlled only by flame-vortex interactions. In this case, different dynamic regimes are observed depending on the operating parameters. When the fuel is injected close to the step, the equivalence ratio arriving at the flame exhibits oscillations. In the presence of equivalence ratio oscillations, the measured sound pressure level is significant across the entire range of lean mean equivalence ratios even if the equivalence ratio oscillations arriving at the flame are out-of-phase with the pressure oscillations. The combustion dynamics are governed primarily by the flame-vortex interactions, while the equivalence ratio oscillations have secondary effects. The equivalence ratio oscillations could generate variations in the combustion dynamics in each cycle under some operating conditions, destabilize the flame at the entire range of the lean equivalence ratios, and increase the value of the mean equivalence ratio at the lean blowout limit. (author)

  20. Apparatus and filtering systems relating to combustors in combustion turbine engines

    DOE Patents [OSTI]

    Johnson, Thomas Edward (Greer, SC); Zuo, Baifang (Simpsonville, SC); Stevenson, Christian Xavier (Inman, SC)

    2012-03-27

    A combustor for a combustion turbine engine that includes: a chamber defined by an outer wall and forming a channel between windows defined through the outer wall toward a forward end of the chamber and at least one fuel injector positioned toward an aft end of the chamber; and a multilayer screen filter comprising at least two layers of screen over at least a portion of the windows and at least one layer of screen over the remaining portion of the windows. The windows include a forward end and a forward portion, and an aft end and an aft portion. The multilayer screen filter is positioned over the windows such that, in operation, a supply of compressed air entering the chamber through the windows passes through at least one layer of screen. The multilayer screen filter is configured such that the aft portion of the windows include at least two layers of screen, and the forward portion of the windows includes one less layer of screen than the aft portion of the windows.

  1. Regeneratively cooled coal combustor/gasifier with integral dry ash removal

    DOE Patents [OSTI]

    Beaufrere, Albert H. (Huntington, NY)

    1983-10-04

    A coal combustor/gasifier is disclosed which produces a low or medium combustion gas for further combustion in modified oil or gas fired furnaces or boilers. Two concentric shells define a combustion volume within the inner shell and a plenum between them through which combustion air flows to provide regenerative cooling of the inner shell for dry ash operation. A fuel flow and a combustion air flow having opposed swirls are mixed and burned in a mixing-combustion portion of the combustion volume and the ash laden combustion products flow with a residual swirl into an ash separation region. The ash is cooled below the fusion temperature and is moved to the wall by centrifugal force where it is entrained in the cool wall boundary layer. The boundary layer is stabilized against ash re-entrainment as it is moved to an ash removal annulus by a flow of air from the plenum through slots in the inner shell, and by suction on an ash removal skimmer slot.

  2. Plasma assisted NO{sub x} reduction in existing coal combustors. Final report

    SciTech Connect (OSTI)

    Yao, S.C.; Russell, T.

    1991-12-31

    The feasibility of NO{sub x} reduction using plasma injection has been investigated. Both numerical and experimental methods were used in the development of this new NO{sub x}reduction technique. The numerical analysis was used to investigate various flow mechanisms in order to provide fundamental support in the development of this new NO{sub x} control technique. The calculations using this approach can give the information of the particle trajectories and distributions which are important for the design of the in-flame plasma injection configuration. The group model also established the necessary ground for further complete modeling of the whole process including the chemical kinetics. Numerical calculations were also performed for a turbulent gas flow field with variable properties. The results provided fundamental understanding of mixing effects encountered in the experiments at Pittsburgh Energy and Technology Center. A small scale experiment facility was designed and constructed at the heterogeneous combustion laboratory at Carnegie Mellon University. A series of tests were conducted in this setup to investigate the potential of the ammonia plasma injection for NO{sub x} reduction and parametric effects of this process. The experimental results are very promising. About 86% NO{sub x} reduction was achieved using ammonia radicals produced by argon plasma within the present test range. The total percentage of NO{sub x} reduction increases when ammonia flowrate, argon flow rate and initial NO concentration increase and when plasma power and the amount of excess air in the combustor decrease. A combined transport and reaction model was postulated for understanding the mechanism of NO{sub x} reduction using the plasma injection.

  3. Combustion characteristics of pulverized coal and air/gas premixed flame in a double swirl combustor

    SciTech Connect (OSTI)

    Kamal, M.M.

    2009-07-01

    An experimental work was performed to investigate the co-firing of pulverized coal and premixed gas/air streams in a double swirl combustor. The results showed that the NOx emissions are affected by the relative rates of thermal NOx formation and destruction via the pyrolysis of the fuel-N species in high temperature fuel-rich zones. Various burner designs were tested in order to vary the temperature history and the residence time across both coal and gas flames inside the furnace. It was found that by injecting the coal with a gas/air mixture as a combined central jet surrounded by a swirled air stream, a double flame envelope develops with high temperature fuel-rich conditions in between the two reaction zones such that the pyrolysis reactions to N{sub 2} are accelerated. A further reduction in the minimum NOx emissions, as well as in the minimum CO concentrations, was reported for the case where the coal particles are fed with the gas/air mixture in the region between the two swirled air streams. On the other hand, allocating the gas/air mixture around the swirled air-coal combustion zone provides an earlier contact with air and retards the NOx reduction mechanism in such a way that the elevated temperatures around the coal particles allow higher overall NOx emissions. The downstream impingement of opposing air jets was found more efficient than the impinging of particle non-laden premixed flames for effective NOx reduction. In both cases, there is an upstream flow from the stagnation region to the coal primary combustion region, but with the case of air impingement, the hot fuel-rich zone develops earlier. The optimum configuration was found by impinging all jets of air and coal-gas/air mixtures that pronounced minimum NOx and CO concentrations of 310 and 480ppm, respectively.

  4. Assessment of pulverized-coal-fired combustor performance. Seventh quarterly technical progress report, April 1-June 30, 1982

    SciTech Connect (OSTI)

    Richter, W.; Clark, W.; Payne, R.

    1982-08-01

    There are substantial economic incentives to explore the possibility of converting boilers and other industrial processes from natural gas or oil to pulverized-fuel firing; however, such a change can have a considerable impact on the thermal performance of the system, due mainly to: fuel specific adiabatic flame temperatures; different flow and combustion patterns in the furnace; differences in the type and concentration of radiative species, especially particles, in the combustion products; and ash deposition on heat transfer surfaces. This program is concerned with the provision of a technology base to expedite the conversion of industrial processes from oil and gas to coal and other pulverized fuels. It addresses primarily the impact of fuel type on the thermal performance of a combustor. The program incorporates two experimental tasks and is constructed around an analytical task (Task 1) which will identify and upgrade a family of computer programs required to undertake thermal performance analysis studies. These analytical tools will thus be used to predict the effects of parameters such as fuel type and furnace variables on combustor performance, and to identify those properties which have a major impact on thermal performance. The second task uses a combustion reactor to screen the key variable identified in Task 1 and to provide data on the properties of coal particulate matter which affect heat transfer performance. Verification of the engineering analytical approach will be provided by measurements made in a pilot-scale furnace in the third task.

  5. Economic evaluation of a novel fuel-saver hybrid combining a solar receiver with a combustor for a solar power tower

    E-Print Network [OSTI]

    Balasuriya, Sanjeeva

    achieves the same combus- tion efficiency as the boiler for twice the capital cost of a solar receiverEconomic evaluation of a novel fuel-saver hybrid combining a solar receiver with a combustor for a solar power tower G.J. Nathan a, , D.L. Battye b , P.J. Ashman b a Centre for Energy Technology, Schools

  6. Modelling of Particle Pyrolysis in a Packed Bed Combustor A.R.C. Tuck and W.L.H. Hallett ,1 2*

    E-Print Network [OSTI]

    Hallett, William L.H.

    Modelling of Particle Pyrolysis in a Packed Bed Combustor A.R.C. Tuck and W.L.H. Hallett ,1 2 are accounted for [2]. However, initial efforts to include pyrolysis were quite crude: a simple one-step global presented here is therefore to upgrade the current treatment of pyrolysis in the bed by developing a more

  7. Final Environmental Impact Statement for the JEA Circulating Fluidized Bed Combustor Project

    SciTech Connect (OSTI)

    N /A

    2000-06-30

    This EIS assesses environmental issues associated with constructing and demonstrating a project that would be cost-shared by DOE and JEA (formerly the Jacksonville Electric Authority) under the Clean Coal Technology Program. The project would demonstrate circulating fluidized bed (CFB) combustion technology at JEA's existing Northside Generating Station in Jacksonville, Florida, about 9 miles northeast of the downtown area of Jacksonville. The new CFB combustor would use coal and petroleum coke to generate nearly 300 MW of electricity by repowering the existing Unit 2 steam turbine, a 297.5-MW unit that has been out of service since 1983. The proposed project is expected to demonstrate emission levels of sulfur dioxide (SO{sub 2}), oxides of nitrogen (NO{sub x}), and particulate matter that would be lower than Clean Air Act limits while at the same time producing power more efficiently and at less cost than conventional coal utilization technologies. At their own risk, JEA has begun initial construction activities without DOE funding. Construction would take approximately two years and, consistent with the original JEA schedule, would be completed in December 2001. Demonstration of the proposed project would be conducted during a 2-year period from March 2002 until March 2004. In addition, JEA plans to repower the currently operating Unit 1 steam turbine about 6 to 12 months after the Unit 2 repowering without cost-shared funding from DOE. Although the proposed project consists of only the Unit 2 repowering, this EIS analyzes the Unit 1 repowering as a related action. The EIS also considers three reasonably foreseeable scenarios that could result from the no-action alternative in which DOE would not provide cost-shared funding for the proposed project. The proposed action, in which DOE would provide cost-shared finding for the proposed project, is DOE's preferred alternative. The EIS evaluates the principal environmental issues, including air quality, traffic, noise, and ecological resources, that could result from construction and operation of the proposed project. Key findings include that maximum modeled increases in ground-level concentrations of SO{sub 2} nitrogen dioxide (NO{sub 2}), and particulate matter (for the proposed project alone or in conjunction with the related action) would always be less than 10% of their corresponding standards for increases in pollutants. For potential cumulative air quality impacts, results of modeling regional sources and the proposed project indicate that the maximum 24-hour average SO{sub 2} concentration would closely approach (i.e., 97%) but not exceed the corresponding Florida standard. After the Unit 1 repowering, results indicate that the maximum 24-hour average SO{sub 2} concentration would be 91% of the Florida standard. Concentrations for other averaging periods and pollutants would be lower percentages of their standards. Regarding toxic air pollutants from the proposed project, the maximum annual cancer risk to a member of the public would be approximately 1 in 1 million; given the conservative assumptions in the estimate, the risk would probably be less. With regard to threatened and endangered species, impacts to manatees, gopher tortoises, and other species would be negligible or non-existent. Construction-induced traffic would result in noticeable congestion. In the unlikely event that all coal were transported by rail, up to 3 additional trains per week would exacerbate impacts associated with noise, vibration, and blocked roads at on-grade rail crossings. Additional train traffic could be minimized by relying more heavily on barges and ships for coal transport, which is likely to be a more economic fuel delivery mode. During construction of the proposed project, noise levels would increase from the current operational levels. Except possibly during steam blowouts and possibly during operation of equipment used to construct a nearby segment of a conveyor, construction noise should not appreciably affect the background noise of nearby residences or exceed local nois

  8. Ash and pulverized coal deposition in combustors and gasifiers. Quarterly technical progress report, April 1, 1996--June 30, 1996

    SciTech Connect (OSTI)

    Ahmadi, G.

    1996-10-01

    The general goal of this project is to provide a fundamental understanding of deposition processes of flyash and pulverized coal particles in coal combustors and coal gasifiers. In the period of April 1 to June 30, 1996, further research progress was made. The computational model for simulating particle motions in turbulent flows was applied to the dispersion and deposition analysis. The study of particle transport and deposition in a circular duct was completed and the major findings are summarized. A detailed model for particle resuspension process in a gas flow is developed. The new model accounts for the surface adhesion, surface roughness, as well as the structure of near wall turbulent flows. The model also accounts for all the relevant hydrodynamic forces and torques exerted on the particle attached to a surface. Progress was also made in the experimental study of glass fiber transport and deposition in the aerosol wind tunnel.

  9. Interagency nitric oxide measurement investigation: AEDC results for phase III (comparison of optical and probe measurements of nitric oxide concentration in combustors). Final report, October 1979-January 1980

    SciTech Connect (OSTI)

    Few, J.D.; Lowry, H.S. III; McGregor, W.K.

    1981-01-01

    The purpose of Phase III of this program was to measure NO concentration on three successively more complicated combustion systems using both optical and probe techniques. The results of all measurements, both probe and optical, were compared and analyzed. Generally, the NO concentrations determined by the optical method were no larger than 30 percent above the values obtained with probes for a methane/air flat-frame burner, a propane/air swirl combustor, and a liquid-fueled simulated jet engine combustor. Close examination of the data revealed that probe results were influenced by some chemical reaction. The probes were designed for subsonic, atmospheric pressure flows, and arguments are presented to show that the agreement found in these experiments need not be expected in near sonic or supersonic flow using the same probe designs.

  10. Combined planar imaging of schlieren photography with OH-LIPF and spontaneous OH-emission in a 2-D valveless pulse combustor

    SciTech Connect (OSTI)

    Ishino, Yojiro; Hasegawa, Tatsuya; Yamaguchi, Shigeki; Ohiwa, Norio

    1999-07-01

    Using a novel optical system, simultaneous imaging of schlieren photography and laser induced predissociation fluorescence of OH radicals (OH-LIPF) have been carried out to examine combustion processes and flame structure in a two-dimensional valveless pulse combustor. Simultaneous imaging of schlieren photographs and spontaneous OH-emission have also been made, in order to obtain information on the behavior of the flame front during a cycle of pulsation. The pulse combustor used in this experiment consists of a combustion chamber of a volume of 125 cm{sup 3} and a tailpipe of a length of 976 mm, which is followed by an automobile muffler. The fuel used is commercial grade gaseous propane.

  11. Coal-Based Oxy-Fuel System Evaluation and Combustor Development; Oxy-Fuel Turbomachinery Development for Energy Intensive Industrial Applications

    SciTech Connect (OSTI)

    Hollis, Rebecca

    2013-03-31

    Clean Energy Systems, Inc. (CES) partnered with the U.S. Department of Energy’s National Energy Technology Laboratory in 2005 to study and develop a competing technology for use in future fossil-fueled power generation facilities that could operate with near zero emissions. CES’s background in oxy-fuel (O-F) rocket technology lead to the award of Cooperative Agreement DE-FC26-05NT42645, “Coal-Based Oxy-Fuel System Evaluation and Combustor Development,” where CES was to first evaluate the potential of these O-F power cycles, then develop the detailed design of a commercial-scale O-F combustor for use in these clean burning fossil-fueled plants. Throughout the studies, CES found that in order to operate at competitive cycle efficiencies a high-temperature intermediate pressure turbine was required. This led to an extension of the Agreement for, “Oxy-Fuel Turbomachinery Development for Energy Intensive Industrial Applications” where CES was to also develop an intermediate-pressure O-F turbine (OFT) that could be deployed in O-F industrial plants that capture and sequester >99% of produced CO2, at competitive cycle efficiencies using diverse fuels. The following report details CES’ activities from October 2005 through March 2013, to evaluate O-F power cycles, develop and validate detailed designs of O-F combustors (main and reheat), and to design, manufacture, and test a commercial-scale OFT, under the three-phase Cooperative Agreement.

  12. On-line instrumentation for the real-time monitoring of polynuclear aromatic hydrocarbons in the effluents from a fluidized bed combustor - a feasibility study

    SciTech Connect (OSTI)

    D'Silva, A.P.; Iles, M.; Rice, G.; Fassel, V.A.

    1984-04-01

    When polynuclear aromatic hydrocargons in the vapor phase are diluted preferably in a rare gas and undergo supersonic jet expansion, rotationally cooled molecules with absorption bandwidths of the order of 0.01 nm (FWHM) are obtained. Selective excitation with a tunable dye laser into such narrow absorption bands leads to the observation of highly specific luminescence spectra. Such an approach has been utilized for the on-line, real-time monitoring of polynuclear aromatic hydrocarbons in the effluents from a fluidized bed combustor.

  13. Effect of fuel properties on the bottom ash generation rate by a laboratory fluidized bed combustor

    SciTech Connect (OSTI)

    Rozelle, P.L.; Pisupati, S.V.; Scaroni, A.W.

    2007-06-15

    The range of fuels that can be accommodated by an FBC boiler system is affected by the ability of the fuel, sorbent, and ash-handling equipment to move the required solids through the boiler. Of specific interest is the bottom ash handling equipment, which must have sufficient capacity to remove ash from the system in order to maintain a constant bed inventory level, and must have sufficient capability to cool the ash well below the bed temperature. Quantification of a fuel's bottom ash removal requirements can be useful for plant design. The effect of fuel properties on the rate of bottom ash production in a laboratory FBC test system was examined. The work used coal products ranging in ash content from 20 to 40+ wt. %. The system's classification of solids by particle size into flyash and bottom ash was characterized using a partition curve. Fuel fractions in the size range characteristic of bottom ash were further analyzed for distributions of ash content with respect to specific gravity, using float sink tests. The fuel fractions were then ashed in a fixed bed. In each case, the highest ash content fraction produced ash with the coarsest size consist (characteristic of bottom ash). The lower ash content fractions were found to produce ash in the size range characteristic of flyash, suggesting that the high ash content fractions were largely responsible for the production of bottom ash. The contributions of the specific gravity fractions to the composite ash in the fuels were quantified. The fuels were fired in the laboratory test system. Fuels with higher amounts of high specific gravity particles, in the size ranges characteristic of bottom ash, were found to produce more bottom ash, indicating the potential utility of float sink methods in the prediction of bottom ash removal requirements.

  14. Annular vortex combustor

    DOE Patents [OSTI]

    Nieh, Sen (Burtonsville, MD); Fu, Tim T. (Camarillo, CA)

    1992-01-01

    An apparatus for burning coal water fuel, dry ultrafine coal, pulverized l and other liquid and gaseous fuels including a vertically extending outer wall and an inner, vertically extending cylinder located concentrically within the outer wall, the annnular space between the outer wall and the inner cylinder defining a combustion chamber and the all space within the inner cylinder defining an exhaust chamber. Fuel and atomizing air are injected tangentially near the bottom of the combustion chamber and secondary air is introduced at selected points along the length of the combustion chamber. Combustion occurs along the spiral flow path in the combustion chamber and the combined effects of centrifugal, gravitational and aerodynamic forces cause particles of masses or sizes greater than the threshold to be trapped in a stratified manner until completely burned out. Remaining ash particles are then small enough to be entrained by the flue gas and exit the system via the exhaust chamber in the opposite direction.

  15. Development of a Large Pulse Detonation Engine Demonstrator

    E-Print Network [OSTI]

    Texas at Arlington, University of

    combustor was designed to run on most common fuels, including kerosene, propane and hydrogen, with air deflagration-to-detonation transition. Dynamic pressure transducers and ion detectors were used for combustion

  16. Aerodynamic force measurement on a large-scale model in a short duration test facility

    SciTech Connect (OSTI)

    Tanno, H.; Kodera, M.; Komuro, T.; Sato, K.; Takahasi, M.; Itoh, K.

    2005-03-01

    A force measurement technique has been developed for large-scale aerodynamic models with a short test time. The technique is based on direct acceleration measurements, with miniature accelerometers mounted on a test model suspended by wires. Measuring acceleration at two different locations, the technique can eliminate oscillations from natural vibration of the model. The technique was used for drag force measurements on a 3 m long supersonic combustor model in the HIEST free-piston driven shock tunnel. A time resolution of 350 {mu}s is guaranteed during measurements, whose resolution is enough for ms order test time in HIEST. To evaluate measurement reliability and accuracy, measured values were compared with results from a three-dimensional Navier-Stokes numerical simulation. The difference between measured values and numerical simulation values was less than 5%. We conclude that this measurement technique is sufficiently reliable for measuring aerodynamic force within test durations of 1 ms.

  17. The demonstration of an advanced cyclone coal combustor, with internal sulfur, nitrogen, and ash control for the conversion of a 23 MMBtu/hour oil fired boiler to pulverized coal

    SciTech Connect (OSTI)

    Zauderer, B.; Fleming, E.S.

    1991-08-30

    The project objective was to demonstrate a technology which can be used to retrofit oil/gas designed boilers, and conventional pulverized coal fired boilers to direct coal firing, by using a patented sir cooled coal combustor that is attached in place of oil/gas/coal burners. A significant part of the test effort was devoted to resolving operational issues related to uniform coal feeding, efficient combustion under very fuel rich conditions, maintenance of continuous slag flow and removal from the combustor, development of proper air cooling operating procedures, and determining component materials durability. The second major focus of the test effort was on environmental control, especially control of SO{sub 2} emissions. By using staged combustion, the NO{sub x} emissions were reduced by around 3/4 to 184 ppmv, with further reductions to 160 ppmv in the stack particulate scrubber. By injection of calcium based sorbents into the combustor, stack SO{sub 2} emissions were reduced by a maximum of of 58%. (VC)

  18. Large displacement spherical joint

    DOE Patents [OSTI]

    Bieg, Lothar F. (Albuquerque, NM); Benavides, Gilbert L. (Albuquerque, NM)

    2002-01-01

    A new class of spherical joints has a very large accessible full cone angle, a property which is beneficial for a wide range of applications. Despite the large cone angles, these joints move freely without singularities.

  19. Running Large Scale Jobs

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

    try on their large scale applications on Hopper for better performance. Try different compilers and compiler options The available compilers on Hopper are PGI, Cray, Intel, GNU,...

  20. Large eddy simulations of premixed turbulent flame dynamics : combustion modeling, validation and analysis

    E-Print Network [OSTI]

    Kewlani, Gaurav

    2014-01-01

    High efficiency, low emissions and stable operation over a wide range of conditions are some of the key requirements of modem-day combustors. To achieve these objectives, lean premixed flames are generally preferred as ...

  1. he behavior of fluid flows influences, and often determines, the performance of a large

    E-Print Network [OSTI]

    Koochesfahani, Manoochehr M.

    (IC) engines and combustors, aerodynamics of flow around objects moving in air and water, liquid into long-lifetime tracers when excited by photons of an appropriate wavelength. Typically a pulsed laser from a pulsed ex

  2. Large Customers (DR Sellers)

    SciTech Connect (OSTI)

    Kiliccot, Sila

    2011-10-25

    State of the large customers for demand response integration of solar and wind into electric grid; openADR; CAISO; DR as a pseudo generation; commercial and industrial DR strategies; California regulations

  3. Pattern Alteration: Large Abdomen 

    E-Print Network [OSTI]

    2006-08-04

    A large abdomen causes the hemline on a skirt to hike in front and pulls the side seam forward. This publication gives instructions on altering patterns for a basic skirt and pants....

  4. Results of combustion and emissions testing when co-firing blends of binder-enhanced densified refuse-derived fuel (b-dRDF) pellets and coal in a 440 MW{sub e} cyclone fired combustor. Volume 3: Appendices

    SciTech Connect (OSTI)

    Ohlsson, O.

    1994-07-01

    This report contains the data resulting from the co-firing of b-dRDF pellets and coal in a 440-MW{sub e} cyclone-fired combustor. These tests were conducted under a Collaborative Research and Development Agreement (CRADA). The CRADA partners included the U.S. Department of Energy (DOE), National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), Otter Tail Power Company, Green Isle Environmental, Inc., XL Recycling Corporation, and Marblehead Lime Company. The report is made up of three volumes. This volume contains other supporting information, along with quality assurance documentation and safety and test plans. With this multi-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.

  5. Composting Large Animal Carcasses 

    E-Print Network [OSTI]

    Auvermann, Brent W.; Mukhtar, Saqib; Heflin, Kevin

    2006-10-31

    and Kevin Heflin* Livestock producers and large-animal veterinar- ians face a growing problem in rural Texas?what to do with dead animals. Rendering services are getting more expensive and harder to come by, and just leav- ing carcasses to predators... set up a polyethylene tank to hold water and rig it with a float valve so that it stays ?topped off? and ready. If one of your stock tanks stays wet year-round, you can simply lay a suction line with a foot valve into the middle of the pond...

  6. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Large Magnetization at Carbon Surfaces Print Wednesday, 31 August 2011 00:00 From organic matter to pencil lead, carbon is a versatile...

  7. Large scale tracking algorithms.

    SciTech Connect (OSTI)

    Hansen, Ross L.; Love, Joshua Alan; Melgaard, David Kennett; Karelitz, David B.; Pitts, Todd Alan; Zollweg, Joshua David; Anderson, Dylan Z.; Nandy, Prabal; Whitlow, Gary L.; Bender, Daniel A.; Byrne, Raymond Harry

    2015-01-01

    Low signal-to-noise data processing algorithms for improved detection, tracking, discrimination and situational threat assessment are a key research challenge. As sensor technologies progress, the number of pixels will increase signi cantly. This will result in increased resolution, which could improve object discrimination, but unfortunately, will also result in a significant increase in the number of potential targets to track. Many tracking techniques, like multi-hypothesis trackers, suffer from a combinatorial explosion as the number of potential targets increase. As the resolution increases, the phenomenology applied towards detection algorithms also changes. For low resolution sensors, "blob" tracking is the norm. For higher resolution data, additional information may be employed in the detection and classfication steps. The most challenging scenarios are those where the targets cannot be fully resolved, yet must be tracked and distinguished for neighboring closely spaced objects. Tracking vehicles in an urban environment is an example of such a challenging scenario. This report evaluates several potential tracking algorithms for large-scale tracking in an urban environment.

  8. Large forging manufacturing process

    DOE Patents [OSTI]

    Thamboo, Samuel V. (Latham, NY); Yang, Ling (Niskayuna, NY)

    2002-01-01

    A process for forging large components of Alloy 718 material so that the components do not exhibit abnormal grain growth includes the steps of: a) providing a billet with an average grain size between ASTM 0 and ASTM 3; b) heating the billet to a temperature of between 1750.degree. F. and 1800.degree. F.; c) upsetting the billet to obtain a component part with a minimum strain of 0.125 in at least selected areas of the part; d) reheating the component part to a temperature between 1750.degree. F. and 1800.degree. F.; e) upsetting the component part to a final configuration such that said selected areas receive no strains between 0.01 and 0.125; f) solution treating the component part at a temperature of between 1725.degree. F. and 1750.degree. F.; and g) aging the component part over predetermined times at different temperatures. A modified process achieves abnormal grain growth in selected areas of a component where desirable.

  9. Large Scale Energy Storage: From Nanomaterials to Large Systems

    E-Print Network [OSTI]

    Fisher, Frank

    Large Scale Energy Storage: From Nanomaterials to Large Systems Wednesday October 26, 2011, Babbio energy storage devices. Specifically, this talk discusses 1) the challenges for grid scale of emergent technologies with ultralow costs on new energy storage materials and mechanisms. Dr. Jun Liu

  10. QUENCHES IN LARGE SUPERCONDUCTING MAGNETS

    E-Print Network [OSTI]

    Eberhard, P.H.

    2010-01-01

    QUENCHES IN LARGE SUPERCONDUCTING MAGNETS. P. H. Eberhard,Study of an Unprotected Superconducting Coil Going Normal,"Method for Testing Superconducting Magnets," LBL Physics

  11. American Institute of Aeronautics and Astronautics Evolution of Large-Scale Structures Generated by a Strut

    E-Print Network [OSTI]

    Texas at Arlington, University of

    located at the base of the ramp. The investigation was conducted in the supersonic wind tunnel flights require low total pressure losses of the flow through the engine and short combustor lengths/air mixing process. Streamwise vortices in supersonic flow have been studied due to their enhanced mixing

  12. Large-Eddy Simulation of a Supersonic Inlet-Isolator Heeseok Koo

    E-Print Network [OSTI]

    Raman, Venkat

    in a dual-mode scramjet engine that provides stable compressed flow to the combustor. However the combustion chamber, where fast mixing with fuel is necessary to ensure stable combustion and engine operation. Dual- mode scramjets provide a practical solution to hypersonic flight by operating at both low

  13. Large Magnetization at Carbon Surfaces

    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 likeUniverseIMPACTThousand CubicResourcelogo and mastheadLakeLanguage of aLargeLargeLarge

  14. Large-scale pool fires 

    E-Print Network [OSTI]

    Steinhaus, Thomas; Welch, Stephen; Carvel, Ricky O; Torero, Jose L

    2007-03-29

    A review of research into the burning behaviour of large pool fires and fuel spill fires is presented. The features which distinguish such fires from smaller pool fires are mainly associated with the fire dynamics at low ...

  15. Large Magnetization at Carbon Surfaces

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

    Large Magnetization at Carbon Surfaces Print From organic matter to pencil lead, carbon is a versatile element. Now, another use has been found: magnets. One would not expect pure...

  16. Large Area Vacuum Deposited Coatings

    SciTech Connect (OSTI)

    Martin, Peter M.

    2003-04-30

    It's easy to make the myriad of types of large area and decorative coatings for granted. We probably don't even think about most of them; the low-e and heat mirror coatings on our windows and car windows, the mirrors in displays, antireflection coatings on windows and displays, protective coatings on aircraft windows, heater coatings on windshields and aircraft windows, solar reflectors, thin film solar cells, telescope mirrors, Hubble mirrors, transparent conductive coatings, and the list goes on. All these products require large deposition systems and chambers. Also, don't forget that large batches of small substrates or parts are coated in large chambers. In order to be cost effective hundreds of ophthalmic lenses, automobile reflectors, display screens, lamp reflectors, cell phone windows, laser reflectors, DWDM filters, are coated in batches.

  17. Universal anomalous dimensions at large spin and large twist

    E-Print Network [OSTI]

    Apratim Kaviraj; Kallol Sen; Aninda Sinha

    2015-06-09

    In this paper we consider anomalous dimensions of double trace operators at large spin ($\\ell$) and large twist ($\\tau$) in CFTs in arbitrary dimensions ($d\\geq 3$). Using analytic conformal bootstrap methods, we show that the anomalous dimensions are universal in the limit $\\ell\\gg \\tau\\gg 1$. In the course of the derivation, we extract an approximate closed form expression for the conformal blocks arising in the four point function of identical scalars in any dimension. We compare our results with two different calculations in holography and find perfect agreement.

  18. Large aperture optical switching devices

    SciTech Connect (OSTI)

    Goldhar, J.; Henesian, M.A.

    1983-12-12

    We have developed a new approach to constructing large aperture optical switches for next generation inertial confinement fusion lasers. A transparent plasma electrode formed in low pressure ionized gas acts as a conductive coating to allow the uniform charging of the optical faces of an electro-optic material. In this manner large electric fields can be applied longitudinally to large aperture, high aspect ratio Pockels cells. We propose a four-electrode geometry to create the necessary high conductivity plasma sheets, and have demonstrated fast (less than 10 nsec) switching in a 5x5 cm aperture KD*P Pockels cell with such a design. Detaid modelling of Pockels cell performance with plasma electrodes has been carried out for 15 and 30 cm aperture designs.

  19. Inflating with large effective fields

    SciTech Connect (OSTI)

    Burgess, C.P. [PH-TH Division, CERN, CH-1211, Genève 23 (Switzerland); Cicoli, M. [Dipartimento di Fisica e Astronomia, Università di Bologna, Via Irnerio 46, 40126 Bologna (Italy); Quevedo, F. [Abdus Salam ICTP, Strada Costiera 11, Trieste 34014 (Italy); Williams, M., E-mail: cburgess@perimeterinstitute.ca, E-mail: mcicoli@ictp.it, E-mail: f.quevedo@damtp.cam.ac.uk, E-mail: mwilliams@perimeterinsititute.ca [Department of Physics and Astronomy, McMaster University, 1280 Main Street West, Hamilton ON (Canada)

    2014-11-01

    We re-examine large scalar fields within effective field theory, in particular focussing on the issues raised by their use in inflationary models (as suggested by BICEP2 to obtain primordial tensor modes). We argue that when the large-field and low-energy regimes coincide the scalar dynamics is most effectively described in terms of an asymptotic large-field expansion whose form can be dictated by approximate symmetries, which also help control the size of quantum corrections. We discuss several possible symmetries that can achieve this, including pseudo-Goldstone inflatons characterized by a coset G/H (based on abelian and non-abelian, compact and non-compact symmetries), as well as symmetries that are intrinsically higher dimensional. Besides the usual trigonometric potentials of Natural Inflation we also find in this way simple large-field power laws (like V ? ?{sup 2}) and exponential potentials, V(?) = ?{sub k}V{sub x}e{sup ?k?/M}. Both of these can describe the data well and give slow-roll inflation for large fields without the need for a precise balancing of terms in the potential. The exponential potentials achieve large r through the limit |?| || ? and so predict r ? (8/3)(1-n{sub s}); consequently n{sub s} ? 0.96 gives r ? 0.11 but not much larger (and so could be ruled out as measurements on r and n{sub s} improve). We examine the naturalness issues for these models and give simple examples where symmetries protect these forms, using both pseudo-Goldstone inflatons (with non-abelian non-compact shift symmetries following familiar techniques from chiral perturbation theory) and extra-dimensional models.

  20. Large Magnetization at Carbon Surfaces

    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 Outreach Home Room NewsInformationJesse Bergkamp Graduate studentScienceLaboratory program LabsDesignLargeLarge

  1. Large Magnetization at Carbon Surfaces

    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 likeUniverseIMPACTThousand CubicResourcelogo and mastheadLakeLanguage of a flyLargeLarge

  2. Large Magnetization at Carbon Surfaces

    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 likeUniverseIMPACTThousand CubicResourcelogo and mastheadLakeLanguage of aLargeLarge

  3. INTERNATIONAL COMMISSION ON LARGE DAMS

    E-Print Network [OSTI]

    Bowles, David S.

    Q76-R INTERNATIONAL COMMISSION ON LARGE DAMS 20TH CONGRESS BEIJING, CHINA THE STATUS OF METHODS FOR ESTIMATION OF THE PROBABILITY OF FAILURE OF DAMS FOR USE IN QUANTITATIVE RISK ASSESSMENT (* ) Robin FELL. INTRODUCTION The use of Quantitative Risk Assessment (QRA) techniques to assist in dam safety management

  4. CALIFORNIA ENERGY Large HVAC Building

    E-Print Network [OSTI]

    CALIFORNIA ENERGY COMMISSION Large HVAC Building Survey Information Database of Buildings over 100 Energy Systems: Productivity and Building Science Program. This program was funded by the California of Portland Energy Conservation, Inc. Project Management: Cathy Higgins, Program Director for New Buildings

  5. Chunking of Large Multidimensional Arrays

    SciTech Connect (OSTI)

    Rotem, Doron; Otoo, Ekow J.; Seshadri, Sridhar

    2007-02-28

    Data intensive scientific computations as well on-lineanalytical processing applications as are done on very large datasetsthat are modeled as k-dimensional arrays. The storage organization ofsuch arrays on disks is done by partitioning the large global array intofixed size hyper-rectangular sub-arrays called chunks or tiles that formthe units of data transfer between disk and memory. Typical queriesinvolve the retrieval of sub-arrays in a manner that accesses all chunksthat overlap the query results. An important metric of the storageefficiency is the expected number of chunks retrieved over all suchqueries. The question that immediately arises is "what shapes of arraychunks give the minimum expected number of chunks over a query workload?"In this paper we develop two probabilistic mathematical models of theproblem and provide exact solutions using steepest descent and geometricprogramming methods. Experimental results, using synthetic workloads onreal life data sets, show that our chunking is much more efficient thanthe existing approximate solutions.

  6. Large Eddy Simulations of extinction

    E-Print Network [OSTI]

    Ayache, S.; Garmory, A.; Tyliszczak, A.; Mastorakos, E.

    2012-08-29

    -Martinez, A. Kronenburg. Flame stabilization mechanism in lifted flames. Flow, Tur- bulence and Combustion, 87:377–406, 2011. 8. M. Mortensen, R.W. Bilger. Derivation of the conditional moment closure equations for spray combustion. Combustion and Flame, 156... .B. Devaud, R.W. Bilger. Modeling evaporation effects in conditional moment closure for spray autoignition. Combustion Theory and Modelling, 15:725–752, 2011. 13. N. Branley and W. P. Jones. Large Eddy Simulation of a Turbulent Non-premixed Flame. Combus...

  7. Large Component Removal/Disposal

    SciTech Connect (OSTI)

    Wheeler, D. M.

    2002-02-27

    This paper describes the removal and disposal of the large components from Maine Yankee Atomic Power Plant. The large components discussed include the three steam generators, pressurizer, and reactor pressure vessel. Two separate Exemption Requests, which included radiological characterizations, shielding evaluations, structural evaluations and transportation plans, were prepared and issued to the DOT for approval to ship these components; the first was for the three steam generators and one pressurizer, the second was for the reactor pressure vessel. Both Exemption Requests were submitted to the DOT in November 1999. The DOT approved the Exemption Requests in May and July of 2000, respectively. The steam generators and pressurizer have been removed from Maine Yankee and shipped to the processing facility. They were removed from Maine Yankee's Containment Building, loaded onto specially designed skid assemblies, transported onto two separate barges, tied down to the barges, th en shipped 2750 miles to Memphis, Tennessee for processing. The Reactor Pressure Vessel Removal Project is currently under way and scheduled to be completed by Fall of 2002. The planning, preparation and removal of these large components has required extensive efforts in planning and implementation on the part of all parties involved.

  8. CSP Tower Air Brayton Combustor (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2012-09-01

    Southwest Research Institute is one of the 2012 SunShot CSP R&D awardees for their advanced power cycles. This fact sheet explains the motivation, description, and impact of the project.

  9. Predictive models of circulating fluidized bed combustors

    SciTech Connect (OSTI)

    Gidaspow, D.

    1992-07-01

    Steady flows influenced by walls cannot be described by inviscid models. Flows in circulating fluidized beds have significant wall effects. Particles in the form of clusters or layers can be seen to run down the walls. Hence modeling of circulating fluidized beds (CFB) without a viscosity is not possible. However, in interpreting Equations (8-1) and (8-2) it must be kept in mind that CFB or most other two phase flows are never in a true steady state. Then the viscosity in Equations (8-1) and (8-2) may not be the true fluid viscosity to be discussed next, but an Eddy type viscosity caused by two phase flow oscillations usually referred to as turbulence. In view of the transient nature of two-phase flow, the drag and the boundary layer thickness may not be proportional to the square root of the intrinsic viscosity but depend upon it to a much smaller extent. As another example, liquid-solid flow and settling of colloidal particles in a lamella electrosettler the settling process is only moderately affected by viscosity. Inviscid flow with settling is a good first approximation to this electric field driven process. The physical meaning of the particulate phase viscosity is described in detail in the chapter on kinetic theory. Here the conventional derivation resented in single phase fluid mechanics is generalized to multiphase flow.

  10. Ash & Pulverized Coal Deposition in Combustors & Gasifiers

    SciTech Connect (OSTI)

    Goodarz Ahmadi

    1998-12-02

    Further progress in achieving the objectives of the project was made in the period of January I to March 31, 1998. The direct numerical simulation of particle removal process in turbulent gas flows was completed. Variations of particle trajectories are studied. It is shown that the near wall vortices profoundly affect the particle removal process in turbulent boundary layer flows. Experimental data for transport and deposition of fibrous particles in the aerosol wind tunnel was obtained. The measured deposition velocity for irregular fibrous particles is compared with the empirical correlation and the available data for glass fibers and discussed. Additional progress on the sublayer model for evaluating the particle deposition and resuspension in turbulent flows was made.

  11. Ash & Pulverized Coal Deposition in Combustors & Gasifiers

    SciTech Connect (OSTI)

    Goodarz Ahmadi

    1998-12-02

    Further progress in achieving the objectives of the project was made in the period of October I to December 31, 1997. The direct numerical simulation of particle removal process in turbulent gas flows was continued. Variations of vorticity contours which are averaged over a short time duration are studied. It is shown that the near wall vortices profoundly affect the particle removal process in turbulent boundary layer flows. The sublayer model for evaluating the particle deposition in turbulent flows was extended to include the effect of particle rebound. A new more advance flow model for the near wall vortices is also used in these analysis. Sample particle trajectories are obtained and discussed. Experimental data for transport and deposition of fibrous particles in the aerosol wind tunnel was obtained. The measured deposition velocity is compared with the empirical correlation and the available data and discussed. Particle resuspension process in turbulent flows are studied. The model is compared with the experimental data. It is shown that when the effects of the near wall flow structure, as well as the surface roughness are included the model agrees with the available experimental data.

  12. Ash & Pulverized Coal Deposition in Combustors & Gasifiers

    SciTech Connect (OSTI)

    Goodarz Ahmadi

    1998-12-02

    Further progress in achieving the objectives of the project was made in the period of October 1 to December 31, 1996. In particular, the sublayer model for evaluating the particle deposition in turbulent flows was extended to include the effect of particle rebound. A new more advance flow model for the near wall vortices is also used in these analysis. The computational model for simulating particle transport in turbulent flows was used to analyze the dispersion and deposition of particles in a recirculating flow region. The predictions of the particle resuspension model is compared with the experimental data. It is shown that when the effects of the near wall flow structure, as we as the surface roughness are included the model agrees with the available experimental data. Considerable progress was also made in the direct numerical simulation of particle removal process in turbulent gas flows. Experimental data for transport and deposition of glass fiber in the aerosol wind tunnel was also obtained.

  13. Ash & Pulverized Coal Deposition in Combustors & Gasifiers

    SciTech Connect (OSTI)

    Goodarz Ahmadi

    1998-12-02

    Further progress in achieving the objectives of the project was made in the period of July 1 to September 30, 1997. The direct numerical simulation of particle removal process in turbulent gas flows was continued. Variations of vorticity contours which are averaged over a short time duration are studied. It is shown that the near wall vortices profoundly affect the particle removal process in turbulent boundary layer flows. The sublayer model for evaluating the particle deposition in turbulent flows was extended to include the effect of particle rebound. A new more advance flow model for the near wall vortices is also used in these analysis. Sample particle trajectories are obtained and discussed. Experimental data for transport and deposition of fibrous particles in the aerosol wind tunnel was obtained. The measured deposition velocity is compared with the empirical correlation and the available data and discussed. Particle resuspension process in turbulent flows are studied. The model is compared with the experimental data. It is shown that when the effects of the near wall flow structure, as well as the surface roughness are included the model agrees with the available experimental data.

  14. Results of combustion and emissions testing when co-firing blends of binder-enhanced densified refuse-derived fuel (b-dRDF) pellets and coal in a 440 MW{sub e} cyclone fired combustor. Volume 2: Field data and laboratory analysis

    SciTech Connect (OSTI)

    Ohlsson, O.

    1994-07-01

    This report contains the data resulting from the co-firing of b-dRDF pellets and coal in a 440-MW{sub e} cyclone-fired combustor. These tests were conducted under a Collaborative Research and Development Agreement (CRADA). The CRADA partners included the U.S. Department of Energy (DOE), National Renewable Energy Laboratory (NREL), Argonne National Laboratory (ANL), Otter Tail Power Company, Green Isle Environmental, Inc., XL Recycling Corporation, and Marblehead Lime Company. The report is made up of three volumes. This volume contains the field data and laboratory analysis of each individual run. With this multi-volume approach, readers can find information at the desired level of detail, depending on individual interest or need.

  15. Elliptic Flow at Large Viscosity

    E-Print Network [OSTI]

    Volker Koch

    2009-09-18

    In this contribution we present an alternative scenario for the large elliptic flow observed in relativistic heavy ion collisions. Motivated by recent results from Lattice QCD on flavor off-diagonal susceptibilities we argue that the matter right above $T_{c}$ can be described by single-particle dynamics in a repulsive single-particle potential, which in turn gives rise to elliptic flow. These ideas can be tested experimentally by measuring elliptic flow of heavy quarks, preferably via the measurement of $J/\\Psi$ elliptic flow.

  16. Planetary Migration to Large Radii

    E-Print Network [OSTI]

    R. G. Martin; S. H. Lubow; J. E. Pringle; M C. Wyatt

    2007-04-25

    There is evidence for the existence of massive planets at orbital radii of several hundred AU from their parent stars where the timescale for planet formation by core accretion is longer than the disc lifetime. These planets could have formed close to their star and then migrated outwards. We consider how the transfer of angular momentum by viscous disc interactions from a massive inner planet could cause significant outward migration of a smaller outer planet. We find that it is in principle possible for planets to migrate to large radii. We note, however, a number of effects which may render the process somewhat problematic.

  17. Extra-Large Memory Nodes

    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 Outreach Home Room NewsInformation Current HABFES OctoberEvan Racah Evan-5 BeamlineGE, Ford,Extra-Large Memory

  18. Large Magnetization at Carbon Surfaces

    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 Outreach Home Room NewsInformationJesse Bergkamp Graduate studentScienceLaboratory program LabsDesignLarge

  19. Large Magnetization at Carbon Surfaces

    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 likeUniverseIMPACTThousand CubicResourcelogo and mastheadLakeLanguage of a flyLarge

  20. Large Magnetization at Carbon Surfaces

    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 likeUniverseIMPACTThousand CubicResourcelogo and mastheadLakeLanguage of aLarge

  1. Large aperture diffractive space telescope

    DOE Patents [OSTI]

    Hyde, Roderick A. (Livermore, CA)

    2001-01-01

    A large (10's of meters) aperture space telescope including two separate spacecraft--an optical primary objective lens functioning as a magnifying glass and an optical secondary functioning as an eyepiece. The spacecraft are spaced up to several kilometers apart with the eyepiece directly behind the magnifying glass "aiming" at an intended target with their relative orientation determining the optical axis of the telescope and hence the targets being observed. The objective lens includes a very large-aperture, very-thin-membrane, diffractive lens, e.g., a Fresnel lens, which intercepts incoming light over its full aperture and focuses it towards the eyepiece. The eyepiece has a much smaller, meter-scale aperture and is designed to move along the focal surface of the objective lens, gathering up the incoming light and converting it to high quality images. The positions of the two space craft are controlled both to maintain a good optical focus and to point at desired targets which may be either earth bound or celestial.

  2. Adaptive Optics for Large Telescopes

    SciTech Connect (OSTI)

    Olivier, S

    2008-06-27

    The use of adaptive optics was originally conceived by astronomers seeking to correct the blurring of images made with large telescopes due to the effects of atmospheric turbulence. The basic idea is to use a device, a wave front corrector, to adjust the phase of light passing through an optical system, based on some measurement of the spatial variation of the phase transverse to the light propagation direction, using a wave front sensor. Although the original concept was intended for application to astronomical imaging, the technique can be more generally applied. For instance, adaptive optics systems have been used for several decades to correct for aberrations in high-power laser systems. At Lawrence Livermore National Laboratory (LLNL), the world's largest laser system, the National Ignition Facility, uses adaptive optics to correct for aberrations in each of the 192 beams, all of which must be precisely focused on a millimeter scale target in order to perform nuclear physics experiments.

  3. Large-Scale Information Systems

    SciTech Connect (OSTI)

    D. M. Nicol; H. R. Ammerlahn; M. E. Goldsby; M. M. Johnson; D. E. Rhodes; A. S. Yoshimura

    2000-12-01

    Large enterprises are ever more dependent on their Large-Scale Information Systems (LSLS), computer systems that are distinguished architecturally by distributed components--data sources, networks, computing engines, simulations, human-in-the-loop control and remote access stations. These systems provide such capabilities as workflow, data fusion and distributed database access. The Nuclear Weapons Complex (NWC) contains many examples of LSIS components, a fact that motivates this research. However, most LSIS in use grew up from collections of separate subsystems that were not designed to be components of an integrated system. For this reason, they are often difficult to analyze and control. The problem is made more difficult by the size of a typical system, its diversity of information sources, and the institutional complexities associated with its geographic distribution across the enterprise. Moreover, there is no integrated approach for analyzing or managing such systems. Indeed, integrated development of LSIS is an active area of academic research. This work developed such an approach by simulating the various components of the LSIS and allowing the simulated components to interact with real LSIS subsystems. This research demonstrated two benefits. First, applying it to a particular LSIS provided a thorough understanding of the interfaces between the system's components. Second, it demonstrated how more rapid and detailed answers could be obtained to questions significant to the enterprise by interacting with the relevant LSIS subsystems through simulated components designed with those questions in mind. In a final, added phase of the project, investigations were made on extending this research to wireless communication networks in support of telemetry applications.

  4. Large optics inspection, tilting, and washing stand

    DOE Patents [OSTI]

    Ayers, Marion Jay (Brentwood, CA); Ayers, Shannon Lee (Brentwood, CA)

    2010-08-24

    A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

  5. Large optics inspection, tilting, and washing stand

    DOE Patents [OSTI]

    Ayers, Marion Jay; Ayers, Shannon Lee

    2012-10-09

    A large optics stand provides a risk free means of safely tilting large optics with ease and a method of safely tilting large optics with ease. The optics are supported in the horizontal position by pads. In the vertical plane the optics are supported by saddles that evenly distribute the optics weight over a large area.

  6. Sustainability of Large Photovoltaic Deployment: Environmental Research

    E-Print Network [OSTI]

    Homes, Christopher C.

    Sustainability of Large Photovoltaic Deployment: Environmental Research Sustainability of Large Photovoltaic Deployment: Environmental ResearchEnvironmental ResearchEnvironmental Research Vasilis Fthenakis and Te from Cadmium Telluride Photovoltaic Manufacturing Scrap, Progress in Photovoltaics: Research

  7. Supply chain responsiveness for a large retailer

    E-Print Network [OSTI]

    Anand, Sunil (Sunil Harbhushankumar)

    2011-01-01

    A large U.S. based retailer underwent a large, complex multi-year supply chain network transformation. This transformation resulted in significant savings in logistics costs. Additionally, the regional distribution center ...

  8. Conundrum of the Large Scale Streaming

    E-Print Network [OSTI]

    T. M. Malm

    1999-09-12

    The etiology of the large scale peculiar velocity (large scale streaming motion) of clusters would increasingly seem more tenuous, within the context of the gravitational instability hypothesis. Are there any alternative testable models possibly accounting for such large scale streaming of clusters?

  9. Alternative large Nc baryons and holography

    E-Print Network [OSTI]

    Carlos Hoyos-Badajoz; Andreas Karch

    2009-06-24

    In gauge theories in the limit of a large number Nc of colors, baryons are usually described as heavy solitonic objects with mass of order Nc. We discuss an alternative large Nc description both directly in the field theory as well as using holography. In this alternative large Nc limit at least some of the baryons behave like mesons, that is they stay light even at large Nc and their interactions vanish in that limit. For Nc=3 these alternative large Nc baryons are equivalent to the standard baryons. In the holographic description it is manifest that the Regge slopes of mesons and alternative baryons are degenerate.

  10. High Performance Electronic Structure Engineering: Large Scale...

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

    High Performance Electronic Structure Engineering: Large Scale GW Calculations Event Sponsor: Argonne Leadership Computing Facility Seminar Start Date: Aug 7 2015 - 10:00am...

  11. A Database Index to Large Biological Sequences

    E-Print Network [OSTI]

    Hunt, E.

    Hunt,E. Atkinson,M.P. Irving,R.W. Proceedings of the 27th Conference on Very Large Databases pp 139-148 Morgan Kaufmann

  12. MASS STORAGE SYSTEMS AND LARGE RESEARCH LIBRARIES

    E-Print Network [OSTI]

    Baker, James A.

    2013-01-01

    Symposium on Mass Storage Systems, Denver, CO, April15-17, 1980 MASS STORAGE SYSTEMS AND LARGE RESEARCHSymposium on Mass Storage Systems, Denver, Colorado, April

  13. Generating Precise Dependencies for Large Software

    E-Print Network [OSTI]

    Cortes, Corinna

    Generating Precise Dependencies for Large Software Pei Wang, Jinqiu Yang, Lin Tan University-term software development, especially for large software with millions of lines of code. This paper designs/C++ software projects. The tool extracts both symbol- level and module-level dependencies of a software system

  14. Microfluidic Large-Scale Integration: The Evolution

    E-Print Network [OSTI]

    Quake, Stephen R.

    Microfluidic Large-Scale Integration: The Evolution of Design Rules for Biological Automation, polydimethylsiloxane Abstract Microfluidic large-scale integration (mLSI) refers to the develop- ment of microfluidic, are discussed. Several microfluidic components used as building blocks to create effective, complex, and highly

  15. Prospective Climate Change Impact on Large Rivers

    E-Print Network [OSTI]

    Julien, Pierre Y.

    1 Prospective Climate Change Impact on Large Rivers in the US and South Korea Pierre Y. Julien Dept. of Civil and Environ. Eng. Colorado State University Seoul, South Korea August 11, 2009 Climate Change and Large Rivers 1. Climatic changes have been on-going for some time; 2. Climate changes usually predict

  16. Large power grid analysis using domain decomposition

    E-Print Network [OSTI]

    Mohanram, Kartik

    Large power grid analysis using domain decomposition Quming Zhou, Kai Sun, Kartik Mohanram, Danny C referred to as the power grid. The power grid for a modern integrated circuit may consist of several grid is traditionally described as a large-scale linear system. Simulation of power grids usually

  17. Factors Influencing Succession: Lessons from Large, Infrequent

    E-Print Network [OSTI]

    Turner, Monica G.

    intense disturbances of large and small extent. Key words: disturbance frequency; disturbance intensityFactors Influencing Succession: Lessons from Large, Infrequent Natural Disturbances Monica G ABSTRACT Disturbance events vary in intensity, size, and fre- quency, but few opportunities exist to study

  18. Management of Large-Scale International

    E-Print Network [OSTI]

    Management of Large- Scale International Science Projects Dr. Benjamin J. Cross, P.E. Savannah of Government Commerce) #12;Extending Project Management to New, Complex Challenges · Emergence of large-scale-of-the-art R&D and technologies ­ Exceedingly high energies, temperatures, radiological conditions, special

  19. Program Management for Large Scale Engineering Programs

    E-Print Network [OSTI]

    Oehmen, Josef

    The goal of this whitepaper is to summarize the LAI research that applies to program management. The context of most of the research discussed in this whitepaper are large-scale engineering programs, particularly in the ...

  20. SCALABLE REACHABILITY INDEXING FOR VERY LARGE GRAPHS

    E-Print Network [OSTI]

    Zaki, Mohammed Javeed

    . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 34 iii #12;3. GRAIL: Scalable Reachability Index for Large Graphs . . . . . . . . . . . . . 36 3 . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 37 3.3 GRAIL Approach . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 39 3.3.1 Index GRAIL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 51 4.1 Topological Level Filter

  1. Large-Scale Wind Training Program

    SciTech Connect (OSTI)

    Porter, Richard L. [Hudson Valley Community College

    2013-07-01

    Project objective is to develop a credit-bearing wind technician program and a non-credit safety training program, train faculty, and purchase/install large wind training equipment.

  2. Robust comparative statics in large static games

    E-Print Network [OSTI]

    Acemoglu, Daron

    We provide general comparative static results for large finite and infinite-dimensional aggregative games. In aggregative games, each player's payoff depends on her own actions and an aggregate of the actions of all the ...

  3. DLFM library tools for large scale dynamic applications.

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

    DLFM library tools for large scale dynamic applications DLFM library tools for large scale dynamic applications Large scale Python and other dynamic applications may spend huge...

  4. Permutation Orbifolds in the large N Limit

    E-Print Network [OSTI]

    Belin, Alexandre; Maloney, Alexander

    2015-01-01

    The space of permutation orbifolds is a simple landscape of two dimensional CFTs, generalizing the well-known symmetric orbifolds. We consider constraints which a permutation orbifold with large central charge must obey in order to be holographically dual to a weakly coupled (but possibly stringy) theory of gravity in AdS. We then construct explicit examples of permutation orbifolds which obey these constraints. In our constructions the spectrum remains finite at large N, but differs qualitatively from that of symmetric orbifolds. We also discuss under what conditions the correlation functions factorize at large N and thus reduce to those of a generalized free field in AdS. We show that this happens not just for symmetric orbifolds, but also for permutation groups which act "democratically" in a sense which we define.

  5. Large volume flow-through scintillating detector

    DOE Patents [OSTI]

    Gritzo, Russ E. (Los Alamos, NM); Fowler, Malcolm M. (Los Alamos, NM)

    1995-01-01

    A large volume flow through radiation detector for use in large air flow situations such as incinerator stacks or building air systems comprises a plurality of flat plates made of a scintillating material arranged parallel to the air flow. Each scintillating plate has a light guide attached which transfers light generated inside the scintillating plate to an associated photomultiplier tube. The output of the photomultiplier tubes are connected to electronics which can record any radiation and provide an alarm if appropriate for the application.

  6. A Fast Shutdown Technique for Large Tokamaks

    E-Print Network [OSTI]

    complicated by the prospect that large numbers of runaway electrons could be generated, in e#11;ect converting current rampdown. We use a realistic 2D plasma simulation to demonstrate that this method is e#11;ective modeling with the Tokamak Simulation Code us- ing a newly developed pellet mass deposition model shows

  7. Transmission consequences of coinfection: cytokines writ large?

    E-Print Network [OSTI]

    Transmission consequences of coinfection: cytokines writ large? Andrea L. Graham1 , Isabella M between- host transmission. Cytokines, immune signalling mol- ecules with a fundamental role-host transmission represents a major challenge in parasite ecology and applied biomedicine [1­5]. Co- infection (see

  8. Modeling needs for very large systems.

    SciTech Connect (OSTI)

    Stein, Joshua S.

    2010-10-01

    Most system performance models assume a point measurement for irradiance and that, except for the impact of shading from nearby obstacles, incident irradiance is uniform across the array. Module temperature is also assumed to be uniform across the array. For small arrays and hourly-averaged simulations, this may be a reasonable assumption. Stein is conducting research to characterize variability in large systems and to develop models that can better accommodate large system factors. In large, multi-MW arrays, passing clouds may block sunlight from a portion of the array but never affect another portion. Figure 22 shows that two irradiance measurements at opposite ends of a multi-MW PV plant appear to have similar irradiance (left), but in fact the irradiance is not always the same (right). Module temperature may also vary across the array, with modules on the edges being cooler because they have greater wind exposure. Large arrays will also have long wire runs and will be subject to associated losses. Soiling patterns may also vary, with modules closer to the source of soiling, such as an agricultural field, receiving more dust load. One of the primary concerns associated with this effort is how to work with integrators to gain access to better and more comprehensive data for model development and validation.

  9. Electronic Aromaticity Index for Large Rings

    E-Print Network [OSTI]

    Matito, Eduard

    2015-01-01

    We introduce a new electronic aromaticity index, AV1245, consisting in the average of the 4-center MCI values along the ring that keep a positional relationship of 1,2,4,5. AV1245 measures the extent of transferability of the delocalized electrons between bonds 1-2 and 4-5, which is expected to be large in conjugated circuits and, therefore, in aromatic molecules. A new algorithm for the calculation of MCI for large rings is also introduced and used to produce the data for the calibration of the new aromaticity index. AV1245 does not rely on reference values, does not suffer from large numerical precision errors, and it does not present any limitation on the nature of atoms, the molecular geometry or the level of calculation. It is a size-extensive measure with a small computational cost that grows linearly with the number of ring members. Therefore, it is specially suitable to study the aromaticity of large molecular rings as those occurring in belt-shaped M\\"obius structures or porphyrins.

  10. Engineering Large scale separation and purification processes

    E-Print Network [OSTI]

    glassy polymers, polymer-selective nanoparticle hybrids and carbon molecular sieve (CMS) materials cover a heavy burden on available energy resources and lead to large increases in carbon dioxide emissions under a "business as usual" scenario. Advanced membrane and sorbent approaches that minimize energy intensive phase

  11. Large families of mutually singular Radon measures

    E-Print Network [OSTI]

    Plebanek, Grzegorz

    Large families of mutually singular Radon measures David H. Fremlin & Grzegorz Plebanek \\Lambda mutually singular Radon probability measures. 1. Introduction. We present here a partial answer with a family (¯ s ) s2S of mu­ tually singular Radon measures on X such that #(S) ? #(X)? In section 2 we

  12. Analysis of large soil samples for actinides

    DOE Patents [OSTI]

    Maxwell, III; Sherrod L. (Aiken, SC)

    2009-03-24

    A method of analyzing relatively large soil samples for actinides by employing a separation process that includes cerium fluoride precipitation for removing the soil matrix and precipitates plutonium, americium, and curium with cerium and hydrofluoric acid followed by separating these actinides using chromatography cartridges.

  13. Large-scale gyrokinetic particle simulation of

    E-Print Network [OSTI]

    Oliker, Leonid

    areas of research including plasma astrophysics and fusion energy science. Fusion is the power source that are still needed to make fusion energy a practical realization. Research in plasma science requiresLarge-scale gyrokinetic particle simulation of microturbulence in magnetically confined fusion

  14. learn invent impact Design of Large Scale

    E-Print Network [OSTI]

    McCalley, James D.

    learn invent impact Design of Large Scale Permanent Magnet Synchronous Generators for Wind Turbines.iastate.edu Permanent Magnet Synchronous Generators (PMSGs) Source: http://www.digikey.com/en-US/articles/techzone/2012of% 20PM_Generator_RPI_Qu_v8.pdf Permanent Magnet Synchronous Generators Rotor PMDD Generator Full

  15. Adaptive Training for Large Vocabulary Continuous

    E-Print Network [OSTI]

    Hain, Thomas

    Adaptive Training for Large Vocabulary Continuous Speech Recognition Kai Yu Hughes Hall College for the degree of Doctor of Philosophy #12;ii Summary In recent years, there has been a trend towards training is to train hidden Markov models (HMMs) on the whole data set as if all data comes from a single acoustic

  16. Aerodynamic beam generator for large particles

    DOE Patents [OSTI]

    Brockmann, John E. (Albuquerque, NM); Torczynski, John R. (Albuquerque, NM); Dykhuizen, Ronald C. (Albuquerque, NM); Neiser, Richard A. (Albuquerque, NM); Smith, Mark F. (Albuquerque, NM)

    2002-01-01

    A new type of aerodynamic particle beam generator is disclosed. This generator produces a tightly focused beam of large material particles at velocities ranging from a few feet per second to supersonic speeds, depending on the exact configuration and operating conditions. Such generators are of particular interest for use in additive fabrication techniques.

  17. How large is 'large N{sub c}' for nuclear matter?

    SciTech Connect (OSTI)

    Torrieri, G. Mishustin, I.

    2012-06-15

    We argue that a so far neglected dimensionless scale, the number of neighbors in a closely packed system, is relevant for the convergence of the large-N{sub c} expansion at high chemical potential. It is only when the number of colors is large w.r.t. this new scale ({approx} O(10)) that a convergent large-N{sub c} limit is reached. This provides an explanation as to why the large-N{sub c} expansion, qualitatively successful in vacuum QCD, fails to describe high baryo-chemical potential systems, such as nuclear matter. It also means that phenomenological claims about high-density matter based on large-N{sub c} extrapolations should be treated with caution. This work is based on [1].

  18. Entanglement Entropy at Large Central Charge

    E-Print Network [OSTI]

    Thomas Hartman

    2013-03-27

    Two-dimensional conformal field theories with a large central charge and a small number of low-dimension operators are studied using the conformal block expansion. A universal formula is derived for the Renyi entropies of N disjoint intervals in the ground state, valid to all orders in a series expansion. This is possible because the full perturbative answer in this regime comes from the exchange of the stress tensor and other descendants of the vacuum state. Therefore, the Renyi entropy is related to the Virasoro vacuum block at large central charge. The entanglement entropy, computed from the Renyi entropy by an analytic continuation, decouples into a sum of single-interval entanglements. This field theory result agrees with the Ryu-Takayanagi formula for the holographic entanglement entropy of a 2d CFT, applied to any number of intervals, and thus can be interpreted as a microscopic calculation of the area of minimal surfaces in 3d gravity.

  19. GLAST Large Area Telescope Multiwavelength Planning

    E-Print Network [OSTI]

    O. Reimer; P. F. Michelson; R. A. Cameron; S. W. Digel; D. J. Thompson; K. S. Wood

    2006-11-21

    Gamma-ray astrophysics depends in many ways on multiwavelength studies. The Gamma-ray Large Area Space Telescope (GLAST) Large Area Telescope (LAT) Collaboration has started multiwavelength planning well before the scheduled 2007 launch of the observatory. Some of the high-priority multiwavelength needs include: (1) availability of contemporaneous radio and X-ray timing of pulsars; (2) expansion of blazar catalogs, including redshift measurements; (3) improved observations of molecular clouds, especially at high galactic latitudes; (4) simultaneous broad-band blazar monitoring; (5) characterization of gamma-ray transients, including gamma ray bursts; (6) radio, optical, X-ray and TeV counterpart searches for reliable and effective sources identification and characterization. Several of these activities are needed to be in place before launch.

  20. The International Large Detector: Letter of Intent

    E-Print Network [OSTI]

    Abe, Toshinori; Abramowicz, Halina; Adamus, Marek; Adeva, Bernardo; Afanaciev, Konstantin; Aguilar-Saavedra, Juan Antonio; Alabau Pons, Carmen; Albrecht, Hartwig; Andricek, Ladislav; Anduze, Marc; Aplin, Steve J.; Arai, Yasuo; Asano, Masaki; Attie, David; Attree, Derek J.; Burger, Jochen; Bailey, David; Balbuena, Juan Pablo; Ball, Markus; Ballin, James; Barbi, Mauricio; Barlow, Roger; Bartels, Christoph; Bartsch, Valeria; Bassignana, Daniela; Bates, Richard; Baudot, Jerome; Bechtle, Philip; Beck, Jeannine; Beckmann, Moritz; Bedjidian, Marc; Behnke, Ties; Belkadhi, Khaled; Bellerive, Alain; Bentvelsen, Stan; Bergauer, Thomas; Berggren, C.Mikael U.; Bergholz, Matthias; Bernreuther, Werner; Besancon, Marc; Besson, Auguste; Bhattacharya, Sudeb; Bhuyan, Bipul; Biebel, Otmar; Bilki, Burak; Blair, Grahame; Blumlein, Johannes; Bo, Li; Boisvert, Veronique; Bondar, A.; Bonvicini, Giovanni; Boos, Eduard; Boudry, Vincent; Bouquet, Bernard; Bouvier, Joel; Bozovic-Jelisavcic, Ivanka; Brient, Jean-Claude; Brock, Ian; Brogna, Andrea; Buchholz, Peter; Buesser, Karsten; Bulgheroni, Antonio; Butler, John; Buttar, Craig; Buzulutskov, A.F.; Caccia, Massimo; Caiazza, Stefano; Calcaterra, Alessandro; Caldwell, Allen; Callier, Stephane L.C.; Calvo Alamillo, Enrique; Campbell, Michael; Campbell, Alan J.; Cappellini, Chiara; Carloganu, Cristina; Castro, Nuno; Castro Carballo, Maria Elena; Chadeeva, Marina; Chakraborty, Dhiman; Chang, Paoti; Charpy, Alexandre; Chen, Xun; Chen, Shaomin; Chen, Hongfang; Cheon, Byunggu; Choi, Suyong; Choudhary, B.C.; Christen, Sandra; Ciborowski, Jacek; Ciobanu, Catalin; Claus, Gilles; Clerc, Catherine; Coca, Cornelia; Colas, Paul; Colijn, Auke; Colledani, Claude; Combaret, Christophe; Cornat, Remi; Cornebise, Patrick; Corriveau, Francois; Cvach, Jaroslav; Czakon, Michal; D'Ascenzo, Nicola; Da Silva, Wilfrid; Dadoun, Olivier; Dam, Mogens; Damerell, Chris; Danilov, Mikhail; Daniluk, Witold; Daubard, Guillaume; David, Dorte; David, Jacques; De Boer, Wim; De Groot, Nicolo; De Jong, Sijbrand; De Jong, Paul; De La Taille, Christophe; De Masi, Rita; De Roeck, Albert; Decotigny, David; Dehmelt, Klaus; Delagnes, Eric; Deng, Zhi; Desch, Klaus; Dieguez, Angel; Diener, Ralf; Dima, Mihai-Octavian; Dissertori, Gunther; Dixit, Madhu S.; Dolezal, Zdenek; Dolgoshein, Boris A.; Dollan, Ralph; Dorokhov, Andrei; Doublet, Philippe; Doyle, Tony; Doziere, Guy; Dragicevic, Marko; Drasal, Zbynek; Drugakov, Vladimir; Duarte Campderros, Jordi; Dulucq, Frederic; Dumitru, Laurentiu Alexandru; Dzahini, Daniel; Eberl, Helmut; Eckerlin, Guenter; Ehrenfeld, Wolfgang; Eigen, Gerald; Eklund, Lars; Elsen, Eckhard; Elsener, Konrad; Emeliantchik, Igor; Engels, Jan; Evrard, Christophe; Fabbri, Riccardo; Faber, Gerard; Faucci Giannelli, Michele; Faus-Golfe, Angeles; Feege, Nils; Feng, Cunfeng; Ferencei, Jozef; Fernandez Garcia, Marcos; Filthaut, Frank; Fleck, Ivor; Fleischer, Manfred; Fleta, Celeste; Fleury, Julien L.; Fontaine, Jean-Charles; Foster, Brian; Fourches, Nicolas; Fouz, Mary-Cruz; Frank, Sebastian; Frey, Ariane; Frotin, Mickael; Fujii, Hirofumi; Fujii, Keisuke; Fujimoto, Junpei; Fujita, Yowichi; Fusayasu, Takahiro; Fuster, Juan; Gaddi, Andrea; Gaede, Frank; Galkin, Alexei; Galkin, Valery; Gallas, Abraham; Gallin-Martel, Laurent; Gamba, Diego; Gao, Yuanning; Garrido Beltran, Lluis; Garutti, Erika; Gastaldi, Franck; Gaur, Bakul; Gay, Pascal; Gellrich, Andreas; Genat, Jean-Francois; Gentile, Simonetta; Gerwig, Hubert; Gibbons, Lawrence; Ginina, Elena; Giraud, Julien; Giraudo, Giuseppe; Gladilin, Leonid; Goldstein, Joel; Gonzalez Sanchez, Francisco Javier; Gournaris, Filimon; Greenshaw, Tim; Greenwood, Z.D.; Grefe, Christian; Gregor, Ingrid-Maria; Grenier, Gerald Jean; Gris, Philippe; Grondin, Denis; Grunewald, Martin; Grzelak, Grzegorz; Gurtu, Atul; Haas, Tobias; Haensel, Stephan; Hajdu, Csaba; Hallermann, Lea; Han, Liang; Hansen, Peter H.; Hara, Takanori; Harder, Kristian; Hartin, Anthony; Haruyama, Tomiyoshi; Harz, Martin; Hasegawa, Yoji; Hauschild, Michael; He, Qing; Hedberg, Vincent; Hedin, David; Heinze, Isa; Helebrant, Christian; Henschel, Hans; Hensel, Carsten; Hertenberger, Ralf; Herve, Alain; Higuchi, Takeo; Himmi, Abdelkader; Hironori, Kazurayama; Hlucha, Hana; Hommels, Bart; Horii, Yasuyuki; Horvath, Dezso; Hostachy, Jean-Yves; Hou, Wei-Shu; Hu-Guo, Christine; Huang, Xingtao; Huppert, Jean Francois; Ide, Yasuhiro; Idzik, Marek; Iglesias Escudero, Carmen; Ignatenko, Alexandr; Igonkina, Olga; Ikeda, Hirokazu; Ikematsu, Katsumasa; Ikemoto, Yukiko; Ikuno, Toshinori; Imbault, Didier; Imhof, Andreas; Imhoff, Marc; Ingbir, Ronen; Inoue, Eiji

    2010-01-01

    The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle ow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which st...

  1. A Charged Membrane Paradigm at Large D

    E-Print Network [OSTI]

    Bhattacharyya, Sayantani; Minwalla, Shiraz; Thakur, Somyadip

    2015-01-01

    We study the effective dynamics of black hole horizons in Einstein-Maxwell theory in a large number of spacetime dimensions $D$. We demonstrate that horizon dynamics may be recast as a well posed initial value problem for the motion of a codimension one non gravitational membrane moving in flat space. The dynamical degrees of freedom of this membrane are its shape, charge density and a divergence free velocity field. We determine the equations that govern membrane dynamics at leading order in the large $D$ expansion. Our derivation of the membrane equations assumes that the solution preserves an SO$(D-p-2)$ isometry with $p$ held fixed as $D$ is taken to infinity. However we are able to cast our final membrane equations into a completely geometric form that makes no reference to this symmetry algebra.

  2. Single and large grain activities at Fermilab

    SciTech Connect (OSTI)

    Antoine, Claire; /Fermilab

    2006-01-01

    This paper describes the ongoing activities at Fermilab for large grains and monocrystalline niobium. In addition to acquisition of local fabrication expertise, we plan to develop an R&D program dedicated to evidence the possible influence of crystal orientation on physical and chemical properties of niobium, such as mechanical properties, magnetic properties or surface contamination. Some considerations are also given about the morphology at grain boundaries and its role on the behavior of superconducting cavities.

  3. Large-Angle Anomalies in the CMB

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

    Copi, Craig J.; Huterer, Dragan; Schwarz, Dominik J.; Starkman, Glenn D.

    2010-01-01

    We review the recently found large-scale anomalies in the maps of temperature anisotropies in the cosmic microwave background. These include alignments of the largest modes of CMB anisotropy with each other and with geometry and direction of motion of the solar ssystem, and the unusually low power at these largest scales. We discuss these findings in relation to expectation from standard inflationary cosmology, their statistical significance, the tools to study them, and the various attempts to explain them.

  4. Large Scale Weather Control Using Nuclear Reactors

    E-Print Network [OSTI]

    Moninder Singh Modgil

    2002-10-02

    It is pointed out that controlled release of thermal energy from fission type nuclear reactors can be used to alter weather patterns over significantly large geographical regions. (1) Nuclear heat creates a low pressure region, which can be used to draw moist air from oceans, onto deserts. (2) Creation of low pressure zones over oceans using Nuclear heat can lead to Controlled Cyclone Creation (CCC).(3) Nuclear heat can also be used to melt glaciers and control water flow in rivers.

  5. Large Scale Weather Control Using Nuclear Reactors

    E-Print Network [OSTI]

    Singh-Modgil, M

    2002-01-01

    It is pointed out that controlled release of thermal energy from fission type nuclear reactors can be used to alter weather patterns over significantly large geographical regions. (1) Nuclear heat creates a low pressure region, which can be used to draw moist air from oceans, onto deserts. (2) Creation of low pressure zones over oceans using Nuclear heat can lead to Controlled Cyclone Creation (CCC).(3) Nuclear heat can also be used to melt glaciers and control water flow in rivers.

  6. Can fermions save large N dimensional reduction?

    E-Print Network [OSTI]

    Paulo F. Bedaque; Michael I. Buchoff; Aleksey Cherman; Roxanne P. Springer

    2009-08-21

    This paper explores whether Eguchi-Kawai reduction for gauge theories with adjoint fermions is valid. The Eguchi-Kawai reduction relates gauge theories in different numbers of dimensions in the large $N$ limit provided that certain conditions are met. In principle, this relation opens up the possibility of learning about the dynamics of 4D gauge theories through techniques only available in lower dimensions. Dimensional reduction can be understood as a special case of large $N$ equivalence between theories related by an orbifold projection. In this work, we focus on the simplest case of dimensional reduction, relating a 4D gauge theory to a 3D gauge theory via an orbifold projection. A necessary condition for the large N equivalence between the 4D and 3D theories to hold is that certain discrete symmetries in the two theories must not be broken spontaneously. In pure 4D Yang-Mills theory, these symmetries break spontaneously as the size of one of the spacetime dimensions shrinks. An analysis of the effect of adjoint fermions on the relevant symmetries of the 4D theory shows that the fermions help stabilize the symmetries. We consider the same problem from the point of view of the lower dimensional 3D theory and find that, surprisingly, adjoint fermions are not generally enough to stabilize the necessary symmetries of the 3D theory. In fact, a rich phase diagram arises, with a complicated pattern of symmetry breaking. We discuss the possible causes and consequences of this finding.

  7. Sensitivity analysis for Eulerian PDF methods Pratik Donde

    E-Print Network [OSTI]

    Raman, Venkat

    is then used for studying an experimental supersonic combustor. Large eddy simulation (LES) has emerged signifiantly influence flame stabilization in turbulent combustors. A systematic approach is required inside supersonic engines or scramjets. In LES, the large scale features of the flow are resolved

  8. Large Bore Powder Gun Qualification (U)

    SciTech Connect (OSTI)

    Rabern, Donald A.; Valdiviez, Robert

    2012-04-02

    A Large Bore Powder Gun (LBPG) is being designed to enable experimentalists to characterize material behavior outside the capabilities of the NNSS JASPER and LANL TA-55 PF-4 guns. The combination of these three guns will create a capability to conduct impact experiments over a wide range of pressures and shock profiles. The Large Bore Powder Gun will be fielded at the Nevada National Security Site (NNSS) U1a Complex. The Complex is nearly 1000 ft below ground with dedicated drifts for testing, instrumentation, and post-shot entombment. To ensure the reliability, safety, and performance of the LBPG, a qualification plan has been established and documented here. Requirements for the LBPG have been established and documented in WE-14-TR-0065 U A, Large Bore Powder Gun Customer Requirements. The document includes the requirements for the physics experiments, the gun and confinement systems, and operations at NNSS. A detailed description of the requirements is established in that document and is referred to and quoted throughout this document. Two Gun and Confinement Systems will be fielded. The Prototype Gun will be used primarily to characterize the gun and confinement performance and be the primary platform for qualification actions. This gun will also be used to investigate and qualify target and diagnostic modifications through the life of the program (U1a.104 Drift). An identical gun, the Physics Gun, will be fielded for confirmatory and Pu experiments (U1a.102D Drift). Both guns will be qualified for operation. The Gun and Confinement System design will be qualified through analysis, inspection, and testing using the Prototype Gun for the majority of process. The Physics Gun will be qualified through inspection and a limited number of qualification tests to ensure performance and behavior equivalent to the Prototype gun. Figure 1.1 shows the partial configuration of U1a and the locations of the Prototype and Physics Gun/Confinement Systems.

  9. Director's colloquium March 18 large hadron collider

    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 theCovalentLaboratory | National Nuclear SecurityDirector's colloquium large

  10. Method for large and rapid terahertz imaging

    DOE Patents [OSTI]

    Williams, Gwyn P.; Neil, George R.

    2013-01-29

    A method of large-scale active THz imaging using a combination of a compact high power THz source (>1 watt), an optional optical system, and a camera for the detection of reflected or transmitted THz radiation, without the need for the burdensome power source or detector cooling systems required by similar prior art such devices. With such a system, one is able to image, for example, a whole person in seconds or less, whereas at present, using low power sources and scanning techniques, it takes several minutes or even hours to image even a 1 cm.times.1 cm area of skin.

  11. The geometry of coexistence in large ecosystems

    E-Print Network [OSTI]

    Grilli, Jacopo; Suweis, Samir; Barabás, György; Banavar, Jayanth R; Allesina, Stefano; Maritan, Amos

    2015-01-01

    The role of interactions in shaping the interplay between the stability of an ecosystem and its biodiversity is still not well understood. We introduce a geometrical approach, that lends itself to both analytic and numerical analyses, for studying the domain of interaction parameters that results in stable coexistence. We find the remarkable result that just a few attributes of the interactions are responsible for stable coexistence in large random ecosystems. We analyze more than 100 empirical networks and find that their architecture generally has a limited effect on in sustaining biodiversity.

  12. Large-Scale PV Integration Study

    SciTech Connect (OSTI)

    Lu, Shuai; Etingov, Pavel V.; Diao, Ruisheng; Ma, Jian; Samaan, Nader A.; Makarov, Yuri V.; Guo, Xinxin; Hafen, Ryan P.; Jin, Chunlian; Kirkham, Harold; Shlatz, Eugene; Frantzis, Lisa; McClive, Timothy; Karlson, Gregory; Acharya, Dhruv; Ellis, Abraham; Stein, Joshua; Hansen, Clifford; Chadliev, Vladimir; Smart, Michael; Salgo, Richard; Sorensen, Rahn; Allen, Barbara; Idelchik, Boris

    2011-07-29

    This research effort evaluates the impact of large-scale photovoltaic (PV) and distributed generation (DG) output on NV Energy’s electric grid system in southern Nevada. It analyzes the ability of NV Energy’s generation to accommodate increasing amounts of utility-scale PV and DG, and the resulting cost of integrating variable renewable resources. The study was jointly funded by the United States Department of Energy and NV Energy, and conducted by a project team comprised of industry experts and research scientists from Navigant Consulting Inc., Sandia National Laboratories, Pacific Northwest National Laboratory and NV Energy.

  13. Heavy baryons in the large Nc limit

    E-Print Network [OSTI]

    Albertus, C; Fernando, I P; Goity, J L

    2015-01-01

    It is shown that in the large Nc limit heavy baryon masses can be estimated quantitatively in a 1/Nc expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio between the square root of the string tension and the heavy quark mass tension independent of Nc. Using a potential adjusted to agree with the one obtained in lattice QCD, a variational analysis of the ground state spin averaged baryon mass is performed using Gaussian Hartree wave functions. Relativistic corrections through the quark kinetic energy are included. The results provide good estimates for the first sub-leading in 1/Nc corrections.

  14. Heavy baryons in the large Nc limit

    E-Print Network [OSTI]

    C. Albertus; E. Ruiz Arriola; I. P. Fernando; J. L. Goity

    2015-07-16

    It is shown that in the large Nc limit heavy baryon masses can be estimated quantitatively in a 1/Nc expansion using the Hartree approximation. The results are compared with available lattice calculations for different values of the ratio between the square root of the string tension and the heavy quark mass tension independent of Nc. Using a potential adjusted to agree with the one obtained in lattice QCD, a variational analysis of the ground state spin averaged baryon mass is performed using Gaussian Hartree wave functions. Relativistic corrections through the quark kinetic energy are included. The results provide good estimates for the first sub-leading in 1/Nc corrections.

  15. LHC - Large Hadon Collider Exhibition LEPFest 2000

    E-Print Network [OSTI]

    2000-01-01

    The Large Hadron Collider (LHC) will accelerate two proton beams to an energy corresponding to about 7,000 times their mass (7000 GeV). The collision of the two beams reproduces the conditions in the Universe when it was about 10 -1 2 sec old. Many innovative techniques - such as cooling with superfluid helium, the extensive use of high temperature superconducting cables, the two-in-one design for super-conducting dipole magnets, and new ultra-high vacuum technologies - had to be developed to make its construc-tion possible.

  16. Melting Instantons, Domain Walls, and Large N

    E-Print Network [OSTI]

    H. B. Thacker

    2008-10-22

    Monte Carlo studies of $CP^{N-1}$ sigma models have shown that the structure of topological charge in these models undergoes a sharp transition at $N=N_c\\approx 4$. For $NN_c$ it is dominated by extended, thin, 1-dimensionally coherent membranes of topological charge, which can be interpreted as domain walls between discrete quasi-stable vacua. These vacua differ by a unit of background electric flux. The transition can be identified as the delocalization of topological charge, or "instanton melting," a phenomenon first suggested by Witten to resolve the conflict between instantons and large $N$ behavior. Implications for $QCD$ are discussed.

  17. Autonomie Large Scale Deployment | 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:FinancingPetroleum Based Fuels Research atDepartmentAuditsDepartment of(TEG)of Energy1Large

  18. Conte Large Flume | 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 SECTIONRobertsdale, Alabama (Utility Company)| Open(Evans, Et Al.,InformationMinorConte Large Flume

  19. Penn Large Water Tunnel | 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 J APPENDIXsourceII JumpQuarterly Smart GridNorth Carolina:ParamountEnergy GroupPeetzPenescalLarge

  20. Sector Profiles of Significant Large CHP Markets, March 2004...

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

    Sector Profiles of Significant Large CHP Markets, March 2004 Sector Profiles of Significant Large CHP Markets, March 2004 In this 2004 report, three sectors were identified as...

  1. Building America Webinar: Opportunities in Large Data Collection...

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

    in Large Data Collection and Analysis-Presentation 1 Building America Webinar: Opportunities in Large Data Collection and Analysis-Presentation 1 This presentation is titled...

  2. The Effective Field Theory of Cosmological Large Scale Structures...

    Office of Scientific and Technical Information (OSTI)

    The Effective Field Theory of Cosmological Large Scale Structures Citation Details In-Document Search Title: The Effective Field Theory of Cosmological Large Scale Structures...

  3. The Effective Field Theory of Cosmological Large Scale Structures...

    Office of Scientific and Technical Information (OSTI)

    The Effective Field Theory of Cosmological Large Scale Structures Citation Details In-Document Search Title: The Effective Field Theory of Cosmological Large Scale Structures ...

  4. DOE Receives Responses on the Implementation of Large-Capacity...

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

    of Large-Capacity Clothes Washer Waivers DOE Issues Enforcement Guidance on Large-Capacity Clothes Washer Waivers and the Waiver Process Electrolux Gibson Air Conditioner...

  5. Vehicle Technologies Office Merit Review 2015: Large Eddy Simulation...

    Office of Environmental Management (EM)

    Large Eddy Simulation (LES) Applied to Advanced Engine Combustion Research Vehicle Technologies Office Merit Review 2015: Large Eddy Simulation (LES) Applied to Advanced Engine...

  6. Large kinetic asymmetry in the metal-insulator transition nucleated...

    Office of Scientific and Technical Information (OSTI)

    Journal Article: Large kinetic asymmetry in the metal-insulator transition nucleated at localized and extended defects Citation Details In-Document Search Title: Large kinetic...

  7. Study finds radioactivity around Los Alamos largely due to natural...

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

    Radioactivity largely due to natural sources Study finds radioactivity around Los Alamos largely due to natural sources The study was subsequently peer reviewed externally by...

  8. ACCOLADES: A Scalable Workflow Framework for Large-Scale Simulation...

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

    ACCOLADES: A Scalable Workflow Framework for Large-Scale Simulation and Analyses of Automotive Engines Title ACCOLADES: A Scalable Workflow Framework for Large-Scale Simulation and...

  9. Large Scale Computing and Storage Requirements for Advanced Scientific...

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

    Large Scale Computing and Storage Requirements for Advanced Scientific Computing Research: Target 2014 ASCRFrontcover.png Large Scale Computing and Storage Requirements for...

  10. Overcoming the Barrier to Achieving Large-Scale Production -...

    Office of Environmental Management (EM)

    Overcoming the Barrier to Achieving Large-Scale Production - A Case Study Overcoming the Barrier to Achieving Large-Scale Production - A Case Study This presentation summarizes the...

  11. Large Higgs energy region in Higgs associated top pair production...

    Office of Scientific and Technical Information (OSTI)

    Large Higgs energy region in Higgs associated top pair production at the Linear Collider Citation Details In-Document Search Title: Large Higgs energy region in Higgs associated...

  12. Assessing Galaxy Limiting Magnitudes in Large Optical Surveys...

    Office of Scientific and Technical Information (OSTI)

    Assessing Galaxy Limiting Magnitudes in Large Optical Surveys Citation Details In-Document Search Title: Assessing Galaxy Limiting Magnitudes in Large Optical Surveys Authors:...

  13. Large-dimension, high-ZT Thermoelectric Nanocomposites for High...

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

    Large-dimension, high-ZT Thermoelectric Nanocomposites for High-Power High-efficiency Waste Heat Recovery for Electricity Generation Large-dimension, high-ZT Thermoelectric...

  14. Large vortex state in ferromagnetic disks

    E-Print Network [OSTI]

    Metlov, Konstantin L

    2013-01-01

    Magnetic vortices in soft ferromagnetic nano-disks have been extensively studied for at least several decades both for their fundamental (as a "live" macroscopic realization of a field theory model of an elementary particle) as well as applied value for high-speed high-density power-independent information storage. Here it is shown that there is another vortex state in nano-scale ferromagnetic disks of several exchange lengths in size. The energy of this large vortex state is computed numerically (within the framework of Magnetism@home distributed computing project) and its stability is studied analytically, which allows to plot it on magnetic phase diagram. It is the ground state of cylinders of certain sizes and is metastable in a wider set of geometries. Large vortices exist on par with classical ones, while being separated by an energy barrier, controllable by tuning the geometry and material of ferromagnetic disk. This state can be an excellent candidate for magnetic information storage not only because ...

  15. The International Large Detector: Letter of Intent

    E-Print Network [OSTI]

    The ILD Concept Group

    2010-06-17

    The International Large Detector (ILD) is a concept for a detector at the International Linear Collider, ILC. The ILC will collide electrons and positrons at energies of initially 500 GeV, upgradeable to 1 TeV. The ILC has an ambitious physics program, which will extend and complement that of the Large Hadron Collider (LHC). A hallmark of physics at the ILC is precision. The clean initial state and the comparatively benign environment of a lepton collider are ideally suited to high precision measurements. To take full advantage of the physics potential of ILC places great demands on the detector performance. The design of ILD is driven by these requirements. Excellent calorimetry and tracking are combined to obtain the best possible overall event reconstruction, including the capability to reconstruct individual particles within jets for particle ow calorimetry. This requires excellent spatial resolution for all detector systems. A highly granular calorimeter system is combined with a central tracker which stresses redundancy and efficiency. In addition, efficient reconstruction of secondary vertices and excellent momentum resolution for charged particles are essential for an ILC detector. The interaction region of the ILC is designed to host two detectors, which can be moved into the beam position with a push-pull scheme. The mechanical design of ILD and the overall integration of subdetectors takes these operational conditions into account.

  16. Recent advances in upgrading large pumps

    SciTech Connect (OSTI)

    Nolt, J.R. Jr.; Russell, G.J. [American Hydro Corp., York, PA (United States)

    1995-12-31

    The benefits of upgrading hydraulic turbines and pump/turbines via the installation of custom designed replacement runners has been well documented in recent years. The increased operating efficiency and capacity, and improved cavitation and operating characteristics of modern replacement runners bears strong testimony to the specialized design an manufacturing techniques developed by turbine manufacturers who specialize in the upgrade business. The integration of computerized design and manufacturing technologies has resulted in the production of turbine and pump/turbine runners with a quality level not approachable with traditional techniques. This same technology can have dramatic results when applied to the upgrade of large pumps. The energy utilized to operate large irrigation, storage and cooling water pumps represents a major cost to the owners of the pumps. The operation of a 25,000 horsepower pump through one irrigation season represents an energy cost of approximately $4,000,000 per year. An increase in efficiency of 2% could result in an energy cost savings of over $100,000 per year. Pump impellers are subject to cavitation and erosion damage which reduces pump efficiency and capacity and may require costly maintenance and repairs. When designed and manufactured using modern computerized methods, an upgraded impeller can operate cavitation free at higher capacities and efficiencies than the original design. The costs of pump operation and maintenance can be substantially reduced by the replacement of the impellers with impellers of modern, custom design.

  17. Massachusetts Large Blade Test Facility Final Report

    SciTech Connect (OSTI)

    Rahul Yarala; Rob Priore

    2011-09-02

    Project Objective: The Massachusetts Clean Energy Center (CEC) will design, construct, and ultimately have responsibility for the operation of the Large Wind Turbine Blade Test Facility, which is an advanced blade testing facility capable of testing wind turbine blades up to at least 90 meters in length on three test stands. Background: Wind turbine blade testing is required to meet international design standards, and is a critical factor in maintaining high levels of reliability and mitigating the technical and financial risk of deploying massproduced wind turbine models. Testing is also needed to identify specific blade design issues that may contribute to reduced wind turbine reliability and performance. Testing is also required to optimize aerodynamics, structural performance, encourage new technologies and materials development making wind even more competitive. The objective of this project is to accelerate the design and construction of a large wind blade testing facility capable of testing blades with minimum queue times at a reasonable cost. This testing facility will encourage and provide the opportunity for the U.S wind industry to conduct more rigorous testing of blades to improve wind turbine reliability.

  18. Validation/Uncertainty Quantification for Large Eddy Simulations of the heat flux in the Tangentially Fired Oxy-Coal Alstom Boiler Simulation Facility

    SciTech Connect (OSTI)

    Smith, P.J.; Eddings, E.G.; Ring, T.; Thornock, J.; Draper, T.; Isaac, B.; Rezeai, D.; Toth, P.; Wu, Y.; Kelly, K.

    2014-08-01

    The objective of this task is to produce predictive capability with quantified uncertainty bounds for the heat flux in commercial-scale, tangentially fired, oxy-coal boilers. Validation data came from the Alstom Boiler Simulation Facility (BSF) for tangentially fired, oxy-coal operation. This task brings together experimental data collected under Alstom’s DOE project for measuring oxy-firing performance parameters in the BSF with this University of Utah project for large eddy simulation (LES) and validation/uncertainty quantification (V/UQ). The Utah work includes V/UQ with measurements in the single-burner facility where advanced strategies for O2 injection can be more easily controlled and data more easily obtained. Highlights of the work include: • Simulations of Alstom’s 15 megawatt (MW) BSF, exploring the uncertainty in thermal boundary conditions. A V/UQ analysis showed consistency between experimental results and simulation results, identifying uncertainty bounds on the quantities of interest for this system (Subtask 9.1) • A simulation study of the University of Utah’s oxy-fuel combustor (OFC) focused on heat flux (Subtask 9.2). A V/UQ analysis was used to show consistency between experimental and simulation results. • Measurement of heat flux and temperature with new optical diagnostic techniques and comparison with conventional measurements (Subtask 9.3). Various optical diagnostics systems were created to provide experimental data to the simulation team. The final configuration utilized a mid-wave infrared (MWIR) camera to measure heat flux and temperature, which was synchronized with a high-speed, visible camera to utilize two-color pyrometry to measure temperature and soot concentration. • Collection of heat flux and temperature measurements in the University of Utah’s OFC for use is subtasks 9.2 and 9.3 (Subtask 9.4). Several replicates were carried to better assess the experimental error. Experiments were specifically designed for the generation of high-fidelity data from a turbulent oxy-coal flame for the validation of oxy-coal simulation models. Experiments were also conducted on the OFC to determine heat flux profiles using advanced strategies for O2 injection. This is important when considering retrofit of advanced O2 injection in retrofit configurations.

  19. Pair Creation at Large Inherent Angles

    SciTech Connect (OSTI)

    Chen, P.; Tauchi, T.; Schroeder, D.V.; /SLAC

    2007-04-25

    In the next-generation linear colliders, the low-energy e{sup +}e{sup -} pairs created during the collision of high-energy e{sup +}e{sup -} beams would cause potential deleterious background problems to the detectors. At low collider energies, the pairs are made essentially by the incoherent process, where the pair is created by the interaction of beamstrahlung photons on the individual particles in the oncoming beam. This problem was first identified by Zolotarev, et al[1]. At energies where the beamstrahlung parameter {Upsilon} lies approximately in the range 0.6 {approx}< {Upsilon} {approx}< 100, pair creation from the beamstrahlung photons is dominated by a coherent process, first noted by Chen[2]. The seriousness of this pair creation problem lies in the transverse momenta that the pair particles carry when leaving the interaction point (IP) with large angles. One source of transverse momentum is from the kick by the field of the oncoming beam which results in an outcoming angle {theta} {proportional_to} 1/{radical}x, where x is the fractional energy of the particle relative to the initial beam particle energy[2,3]. As was shown in Ref. 131, there in fact exists an energy threshold for the coherent pairs, where x{sub th} {approx}> 1/2{Upsilon}. Thus within a tolerable exiting angle, there exists an upper limit for {Upsilon} where all coherent pairs would leave the detector through the exhaust port[4]. A somewhat different analysis has been done by Schroeder[5]. In the next generation of linear colliders, as it occurs, the coherent pairs can be exponentially suppressed[2] by properly choosing the {Upsilon}({approx}< 0.6). When this is achieved, the incoherent pairs becomes dominant. Since the central issue is the transverse momentum for particles with large angles, we notice that there is another source for it. Namely, when the pair particles are created at low energies, the intrinsic angles of these pairs when produced may already be large. This issue was first studied in Ref. [1]. In this paper we reinvestigate the problem, following essentially the same equivalent photon approach, but with changes in specific details including the virtual photon spectrum. In addition, various assumptions are made more explicit. The formulas derived are then applied to the collider parameters designed by Palmer[6].

  20. Multilevel comparison of large urban systems

    E-Print Network [OSTI]

    Pumain, Denise; Cottineau, Clémentine; Vacchiani-Marcuzzo, Céline; Ignazzi, Antonio; Bretagnolle, Anne; Delisle, François; Cura, Robin; Lizzi, Liliane; Baffi, Solène

    2015-01-01

    For the first time the systems of cities in seven countries or regions among the largest in the world (China, India, Brazil, Europe, the Former Soviet Union (FSU), the United States and South Africa) are made comparable through the building of spatio-temporal standardised statistical databases. We first explain the concept of a generic evolutionary urban unit ("city") and its necessary adaptations to the information provided by each national statistical system. Second, the hierarchical structure and the urban growth process are compared at macro-scale for the seven countries with reference to Zipf's and Gibrat's model: in agreement with an evolutionary theory of urban systems, large similarities shape the hierarchical structure and growth processes in BRICS countries as well as in Europe and United States, despite their positions at different stages in the urban transition that explain some structural peculiarities. Third, the individual trajectories of some 10,000 cities are mapped at micro-scale following a...

  1. Strongly Coupled Striped Superconductor with Large Modulation

    E-Print Network [OSTI]

    Jimmy A. Hutasoit; Suman Ganguli; George Siopsis; Jason Therrien

    2012-02-27

    We analytically calculate properties of a strongly coupled striped superconductor, with the charge density wave sourced by a modulated chemical potential, in the large modulation wavenumber Q limit. In the absence of a homogeneous term in the chemical potential, we show that the critical temperature scales as a negative power of Q for scaling dimensions \\Delta 3/2, there is no phase transition above a certain critical value of Q. The condensate is found to scale as a positive power of Q such that the gap is proportional to Q. We discuss how these results change if a homogeneous term is added to the chemical potential. We compare our analytic results with numerical calculations whenever the latter are available and find good agreement.

  2. Sympathetic cooling in a large ion crystal

    E-Print Network [OSTI]

    Guin-Dar Lin; L. -M. Duan

    2015-11-08

    We analyze the dynamics and steady state of a linear ion array when some of the ions are continuously laser cooled. We calculate the ions' local temperature measured by its position fluctuation under various trapping and cooling configurations, taking into account background heating due to the noisy environment. For a large system, we demonstrate that by arranging the cooling ions evenly in the array, one can suppress the overall heating considerably. We also investigate the effect of different cooling rates and find that the optimal cooling efficiency is achieved by an intermediate cooling rate. We discuss the relaxation time for the ions to approach the steady state, and show that with periodic arrangement of the cooling ions, the cooling efficiency does not scale down with the system size.

  3. Meteorological aspects of siting large wind turbines

    SciTech Connect (OSTI)

    Hiester, T.R.; Pennell, W.T.

    1981-01-01

    This report, which focuses on the meteorological aspects of siting large wind turbines (turbines with a rated output exceeding 100 kW), has four main goals. The first is to outline the elements of a siting strategy that will identify the most favorable wind energy sites in a region and that will provide sufficient wind data to make responsible economic evaluations of the site wind resource possible. The second is to critique and summarize siting techniques that were studied in the Department of Energy (DOE) Wind Energy Program. The third goal is to educate utility technical personnel, engineering consultants, and meteorological consultants (who may have not yet undertaken wind energy consulting) on meteorological phenomena relevant to wind turbine siting in order to enhance dialogues between these groups. The fourth goal is to minimize the chances of failure of early siting programs due to insufficient understanding of wind behavior.

  4. Active Optics in Modern, Large Optical Telescopes

    E-Print Network [OSTI]

    Lothar Noethe

    2001-11-07

    Active optics is defined as the control of the shape and the alignment of the components of an optical system at low temporal frequencies. For modern large telescopes with flexible monolithic or segmented primary mirrors and also flexible structures this technique is indispensable to reach a performance which is either diffraction limited for an operation in space or limited by the atmosphere for an operation on the ground. This article first describes the theory of active optics, both of the wavefront analysis and the correction mechanisms, then the design of three representative active optics systems, two in telescopes of the four and eight meter class with meniscus mirrors and one in a telescope with a segmented primary mirror, and, finally, presents practical experience with these active optics systems.

  5. Instability of large solitary water waves

    E-Print Network [OSTI]

    Zhiwu Lin

    2008-03-03

    We consider the linearized instability of 2D irrotational solitary water waves. The maxima of energy and the travel speed of solitary waves are not obtained at the highest wave, which has a 120 degree angle at the crest. Under the assumption of non-existence of secondary bifurcation which is confirmed numerically, we prove linear instability of solitary waves which are higher than the wave of maximal energy and lower than the wave of maximal travel speed. It is also shown that there exist unstable solitary waves approaching the highest wave. The unstable waves are of large amplitude and therefore this type of instability can not be captured by the approximate models derived under small amplitude assumptions. For the proof, we introduce a family of nonlocal dispersion operators to relate the linear instability problem with the elliptic nature of solitary waves. A continuity argument with a moving kernel formula is used to study these dispersion operators to yield the instability criterion.

  6. Batteries for Large Scale Energy Storage

    SciTech Connect (OSTI)

    Soloveichik, Grigorii L.

    2011-07-15

    In recent years, with the deployment of renewable energy sources, advances in electrified transportation, and development in smart grids, the markets for large-scale stationary energy storage have grown rapidly. Electrochemical energy storage methods are strong candidate solutions due to their high energy density, flexibility, and scalability. This review provides an overview of mature and emerging technologies for secondary and redox flow batteries. New developments in the chemistry of secondary and flow batteries as well as regenerative fuel cells are also considered. Advantages and disadvantages of current and prospective electrochemical energy storage options are discussed. The most promising technologies in the short term are high-temperature sodium batteries with ?”-alumina electrolyte, lithium-ion batteries, and flow batteries. Regenerative fuel cells and lithium metal batteries with high energy density require further research to become practical.

  7. Weird Weather: Large Abrupt Widespread Climate Changes

    SciTech Connect (OSTI)

    Alley, Richard B. (Penn State) [Penn State

    2001-01-24

    Ice-core records and other paleoclimatic indicators show that large (up to 10 degrees C), abrupt (in about 10 years), widespread (hemispheric to global) climate changes have been common for much of the last 100,000 years and beyond, but rare during the most recent few millennia. Changes in the coupled ocean-atmosphere system with a center of activity in the north Atlantic probably have been important, but several hypotheses remain possible including solar influence and a stochastically resonant interaction with changing freshwater fluxes. Our current understanding does not allow us to exclude the possibility that human or natural processes could 'flip the switch' of another abrupt change in the future.

  8. Storage and retrieval of large digital images

    DOE Patents [OSTI]

    Bradley, J.N.

    1998-01-20

    Image compression and viewing are implemented with (1) a method for performing DWT-based compression on a large digital image with a computer system possessing a two-level system of memory and (2) a method for selectively viewing areas of the image from its compressed representation at multiple resolutions and, if desired, in a client-server environment. The compression of a large digital image I(x,y) is accomplished by first defining a plurality of discrete tile image data subsets T{sub ij}(x,y) that, upon superposition, form the complete set of image data I(x,y). A seamless wavelet-based compression process is effected on I(x,y) that is comprised of successively inputting the tiles T{sub ij}(x,y) in a selected sequence to a DWT routine, and storing the resulting DWT coefficients in a first primary memory. These coefficients are periodically compressed and transferred to a secondary memory to maintain sufficient memory in the primary memory for data processing. The sequence of DWT operations on the tiles T{sub ij}(x,y) effectively calculates a seamless DWT of I(x,y). Data retrieval consists of specifying a resolution and a region of I(x,y) for display. The subset of stored DWT coefficients corresponding to each requested scene is determined and then decompressed for input to an inverse DWT, the output of which forms the image display. The repeated process whereby image views are specified may take the form an interaction with a computer pointing device on an image display from a previous retrieval. 6 figs.

  9. Storage and retrieval of large digital images

    DOE Patents [OSTI]

    Bradley, Jonathan N. (Los Alamos, NM)

    1998-01-01

    Image compression and viewing are implemented with (1) a method for performing DWT-based compression on a large digital image with a computer system possessing a two-level system of memory and (2) a method for selectively viewing areas of the image from its compressed representation at multiple resolutions and, if desired, in a client-server environment. The compression of a large digital image I(x,y) is accomplished by first defining a plurality of discrete tile image data subsets T.sub.ij (x,y) that, upon superposition, form the complete set of image data I(x,y). A seamless wavelet-based compression process is effected on I(x,y) that is comprised of successively inputting the tiles T.sub.ij (x,y) in a selected sequence to a DWT routine, and storing the resulting DWT coefficients in a first primary memory. These coefficients are periodically compressed and transferred to a secondary memory to maintain sufficient memory in the primary memory for data processing. The sequence of DWT operations on the tiles T.sub.ij (x,y) effectively calculates a seamless DWT of I(x,y). Data retrieval consists of specifying a resolution and a region of I(x,y) for display. The subset of stored DWT coefficients corresponding to each requested scene is determined and then decompressed for input to an inverse DWT, the output of which forms the image display. The repeated process whereby image views are specified may take the form an interaction with a computer pointing device on an image display from a previous retrieval.

  10. LIGHT CURVES OF 32 LARGE TRANSNEPTUNIAN OBJECTS

    SciTech Connect (OSTI)

    Benecchi, Susan D.; Sheppard, Scott S.

    2013-05-15

    We present observations of 32 primarily bright, newly discovered Transneptunian objects (TNOs) observable from the Southern Hemisphere during 39 nights of observation with the Irenee du Pont 2.5 m telescope at Las Campanas Observatory. Our dataset includes objects in all dynamical classes, but is weighted toward scattered objects. We find 15 objects for which we can fit periods and amplitudes to the data, and place light curve amplitude upper limits on the other 17 objects. Combining our sample with the larger light curve sample in the literature, we find a 3{sigma} correlation between light curve amplitude and absolute magnitude with fainter objects having larger light curve amplitudes. We looked for correlations between light curve and individual orbital properties, but did not find any statistically significant results. However, if we consider light curve properties with respect to object dynamical classification, we find statistically different distributions between the classical-scattered and classical-resonant populations at the 95.60% and 94.64% level, respectively, with the classical objects having larger amplitude light curves. The significance is 97.05% if the scattered and resonant populations are combined. The properties of binary light curves are largely consistent with the greater TNO population except in the case of tidally locked systems. All the Haumea family objects measured so far have light curve amplitudes and rotation periods {<=}10 hr, suggesting that they are not significantly different from the larger TNO population. We expect multiple factors are influencing object rotations: object size dominates light curve properties except in the case of tidal, or proportionally large collisional interactions with other TNOs, the influence of the latter being different for each TNO sub-population. We also present phase curves and colors for some of our objects.

  11. CHEMICAL EVOLUTION OF THE LARGE MAGELLANIC CLOUD

    SciTech Connect (OSTI)

    Bekki, Kenji [ICRAR, M468, University of Western Australia, 35 Stirling Highway, Crawley Western Australia 6009 (Australia); Tsujimoto, Takuji [National Astronomical Observatory of Japan, Mitaka-shi, Tokyo 181-8588 (Japan)

    2012-12-20

    We adopt a new chemical evolution model for the Large Magellanic Cloud (LMC) and thereby investigate its past star formation and chemical enrichment histories. The delay time distribution of Type Ia supernovae recently revealed by Type Ia supernova surveys is incorporated self-consistently into the new model. The principle results are summarized as follows. The present gas mass fraction and stellar metallicity as well as the higher [Ba/Fe] in metal-poor stars at [Fe/H] < -1.5 can be more self-consistently explained by models with steeper initial mass functions. The observed higher [Mg/Fe] ({>=}0.3) at [Fe/H] {approx} -0.6 and higher [Ba/Fe] (>0.5) at [Fe/H] {approx} -0.3 could be due to significantly enhanced star formation about 2 Gyr ago. The observed overall [Ca/Fe]-[Fe/H] relation and remarkably low [Ca/Fe] (< - 0.2) at [Fe/H] > -0.6 are consistent with models with short-delay supernova Ia and with the more efficient loss of Ca possibly caused by an explosion mechanism of Type II supernovae. Although the metallicity distribution functions do not show double peaks in the models with a starburst about 2 Gyr ago, they show characteristic double peaks in the models with double starbursts {approx}200 Myr and {approx}2 Gyr ago. The observed apparent dip of [Fe/H] around {approx}1.5 Gyr ago in the age-metallicity relation can be reproduced by models in which a large amount ({approx}10{sup 9} M{sub Sun }) of metal-poor ([Fe/H] < -1) gas can be accreted onto the LMC.

  12. Soft Failures in Large Datacenters Sriram Sankar and Sudhanva Gurumurthi

    E-Print Network [OSTI]

    Gurumurthi, Sudhanva

    Soft Failures in Large Datacenters Sriram Sankar and Sudhanva Gurumurthi Abstract-- A major problem in managing large-scale datacenters is diagnosing and fixing machine failures. Most large datacenter an important issue at large datacenters with minimum human intervention. Soft failures in the datacenter do

  13. Large-Spin and Large-Winding Expansions of Giant Magnons and Single Spikes

    E-Print Network [OSTI]

    Emmanuel Floratos; Georgios Linardopoulos

    2015-11-11

    We generalize the method of our recent paper on the large-spin expansions of Gubser-Klebanov-Polyakov (GKP) strings to the large-spin and large-winding expansions of finite-size giant magnons and finite-size single spikes. By expressing the energies of long open strings in RxS2 in terms of Lambert's W-function, we compute the leading, subleading and next-to-subleading series of classical exponential corrections to the dispersion relations of Hofman-Maldacena giant magnons and infinite-winding single spikes. We also compute the corresponding expansions in the doubled regions of giant magnons and single spikes that are respectively obtained when their angular and linear velocities become smaller or greater than unity.

  14. 1 National Roadmap Committee for Large-Scale Research Facilities the netherlands' roadmap for large-scale research facilities

    E-Print Network [OSTI]

    Horn, David

    #12;1 National Roadmap Committee for Large-Scale Research Facilities the netherlands' roadmap for large-scale research facilities #12;2 National Roadmap Committee for Large-Scale Research Facilities1 by Roselinde Supheert) #12;3 National Roadmap Committee for Large-Scale Research Facilities The Netherlands

  15. A Large Area Detector proposed for the Large Observatory for X-ray Timing (LOFT)

    E-Print Network [OSTI]

    Zane, S; Kennedy, T; Feroci, M; Herder, J -W Den; Ahangarianabhari, M; Argan, A; Azzarello, P; Baldazzi, G; Barret, D; Bertuccio, G; Bodini, P; Bozzo, E; Cadoux, F; Cais, P; Campana, R; Coker, J; Cros, A; Del Monte, E; De Rosa, A; Di Cosimo, S; Donnarumma, I; Evangelista, Y; Favre, Y; Feldman, C; Fraser, G; Fuschino, F; Grassi, M; Hailey, M R; Hudec, R; Labanti, C; Macera, D; Malcovati, P; Marisaldi, M; Martindale, A; Mineo, T; Muleri, F; Nowak, M; Orlandini, M; Pacciani, L; Perinati, E; Petracek, V; Pohl, M; Rachevski, A; Smith, P; Santangelo, A; Seyler, J -Y; Schmid, C; Soffitta, P; Suchy, S; Tenzer, C; Uttley, P; Vacchi, A; Zampa, G; Zampa, N; Wilms, J; Winter, B

    2012-01-01

    The Large Observatory for X-ray Timing (LOFT) is one of the four candidate ESA M3 missions considered for launch in the 2022 time-frame. It is specifically designed to perform fast X-ray timing and probe the status of the matter near black holes and neutron stars. The LOFT scientific payload is composed of a Large Area Detector (LAD) and a Wide Field Monitor (WFM). The LAD is a 10 m2-class pointed instrument with 20 times the collecting area of the best past timing missions (such as RXTE) over the 2-30 keV range, which holds the capability to revolutionize studies of X-ray variability down to the millisecond time scales. Its ground-breaking characteristic is a low mass per unit surface, enabling an effective area of ~10 m^2 (@10 keV) at a reasonable weight. The development of such large but light experiment, with low mass and power per unit area, is now made possible by the recent advancements in the field of large-area silicon detectors - able to time tag an X-ray photon with an accuracy <10 {\\mu}s and an...

  16. Numerical methods for the solution of large and very large, sparse Lyapunov equations

    SciTech Connect (OSTI)

    Hodel, A.S.

    1989-01-01

    In this dissertation the author considers the numerical solution of large (100 {le} n {le} 1000) and very large (n {ge} 1000), sparse Lyapunov equations AX-+ XA' + Q = 0. The author first presents a parallel version of the Hammarling algorithm for the solution of Lyapunov equations where the coefficient matrix A is large and dense. The author then presents a novel parallel algorithm for the solution of Lyapunov equations where A is large and banded. A detailed analysis of the computational requirements in tandem with the results of numerical experiments with these algorithms on an Alliant FX-8 multiprocessor is provided. In the second half of this dissertation, the author considers the numerical solution of Lyapunov equations where the coefficient matrix A is very large and sparse. Under these conditions, the solution X of the Lyapunov equation is typically full rank and dense. The associated excessive storage requirements compel us to compute low rank approximations of the solution X of the Lyapunov equation. The author presents in detail two methods for the low rank approximate solution of the Lyapunov equation. The first method, Trace Maximization, computes an orthogonal matrix V {element of}{Re}{sup n{times}k} that maximizes the trace of the solution {Sigma}{sub V} of the associated reduced order Lyapunov equation (V'AV){Sigma}{sub V} + {Sigma}{sub V}(V'A'V) + V'QV = 0. While Trace Maximization is an effective method for low rank approximation of explicitly specified Hermitian matrices, the author shows that Trace Maximization is not an effective strategy for low rank approximation of positive semidefinite Hermitian matrices X that are implicitly specified as the solution of a Lyapunov equation. Our second algorithm for low rank approximate solution of Lyapunov equations, Approximate Power Iteration, attempts to directly compute an orthogonal basis of the dominant eigenspace of the solution X.

  17. Multiphoton ionization of large water clusters

    SciTech Connect (OSTI)

    Apicella, B.; Li, X.; Passaro, M.; Spinelli, N.; Wang, X.

    2014-05-28

    Water clusters are multimers of water molecules held together by hydrogen bonds. In the present work, multiphoton ionization in the UV range coupled with time of flight mass spectrometry has been applied to water clusters with up to 160 molecules in order to obtain information on the electronic states of clusters of different sizes up to dimensions that can approximate the bulk phase. The dependence of ion intensities of water clusters and their metastable fragments produced by laser ionization at 355 nm on laser power density indicates a (3+1)-photon resonance-enhanced multiphoton ionization process. It also explains the large increase of ionization efficiency at 355 nm compared to that at 266 nm. Indeed, it was found, by applying both nanosecond and picosecond laser ionization with the two different UV wavelengths, that no water cluster sequences after n = 9 could be observed at 266 nm, whereas water clusters up to m/z 2000 Th in reflectron mode and m/z 3000 Th in linear mode were detected at 355 nm. The agreement between our findings on clusters of water, especially true in the range with n > 10, and reported data for liquid water supports the hypothesis that clusters above a critical dimension can approximate the liquid phase. It should thus be possible to study clusters just above 10 water molecules, for getting information on the bulk phase structure.

  18. Theoretical Tools for Large Scale Structure

    E-Print Network [OSTI]

    J. R. Bond; L. Kofman; D. Pogosyan; J. Wadsley

    1998-10-06

    We review the main theoretical aspects of the structure formation paradigm which impinge upon wide angle surveys: the early universe generation of gravitational metric fluctuations from quantum noise in scalar inflaton fields; the well understood and computed linear regime of CMB anisotropy and large scale structure (LSS) generation; the weakly nonlinear regime, where higher order perturbation theory works well, and where the cosmic web picture operates, describing an interconnected LSS of clusters bridged by filaments, with membranes as the intrafilament webbing. Current CMB+LSS data favour the simplest inflation-based $\\Lambda$CDM models, with a primordial spectral index within about 5% of scale invariant and $\\Omega_\\Lambda \\approx 2/3$, similar to that inferred from SNIa observations, and with open CDM models strongly disfavoured. The attack on the nonlinear regime with a variety of N-body and gas codes is described, as are the excursion set and peak-patch semianalytic approaches to object collapse. The ingredients are mixed together in an illustrative gasdynamical simulation of dense supercluster formation.

  19. A large hadron electron collider at CERN

    SciTech Connect (OSTI)

    Abelleira Fernandez, J. L.

    2015-04-06

    This document provides a brief overview of the recently published report on the design of the Large Hadron Electron Collider (LHeC), which comprises its physics programme, accelerator physics, technology and main detector concepts. The LHeC exploits and develops challenging, though principally existing, accelerator and detector technologies. This summary is complemented by brief illustrations of some of the highlights of the physics programme, which relies on a vastly extended kinematic range, luminosity and unprecedented precision in deep inelastic scattering. Illustrations are provided regarding high precision QCD, new physics (Higgs, SUSY) and eletron-ion physics. The LHeC is designed to run synchronously with the LHC in the twenties and to achieve an integrated luminosity of O(100)fb–1. It will become the cleanest high resolution microscope of mankind and will substantially extend as well as complement the investigation of the physics of the TeV energy scale, which has been enabled by the LHC.

  20. Effective upliftings in Large volume compactifications

    E-Print Network [OSTI]

    Gallego, Diego

    2015-01-01

    After reviewing several mechanisms proposed to get a dS/Minkowski vacuum in moduli stabilization scenarios of type-IIB superstring orientifold compactifications we propose a criterium for characterizing those that may effectively lead to a positive small cosmological constant. We suggest that the variation in the expectation value of a good uplifting term, due to the shift in the minimum of the potential after uplifting, is much smaller than the original cosmological constant. This is studied with some detail in Large volume scenarios where the dependency on the volume direction is rather generic and easy to spot. Here we find that an uplifting term in the potential, with generic form $V_{up}\\sim 1/{\\cal V}^\\gamma$, should be restricted to the one satisfying $\\gamma\\ll 12$. Such a bound might explain why in models previously studied no uplifting has been achieved, and gives motivations to study a novel proposal of dilaton dependent uplifting mechanism for which no numerical studies has been performed before. ...

  1. Effective upliftings in Large volume compactifications

    E-Print Network [OSTI]

    Diego Gallego

    2015-08-05

    After reviewing several mechanisms proposed to get a dS/Minkowski vacuum in moduli stabilization scenarios of type-IIB superstring orientifold compactifications we propose a criterium for characterizing those that may effectively lead to a positive small cosmological constant. We suggest that the variation in the expectation value of a good uplifting term, due to the shift in the minimum of the potential after uplifting, is much smaller than the original cosmological constant. This is studied with some detail in Large volume scenarios where the dependency on the volume direction is rather generic and easy to spot. Here we find that an uplifting term in the potential, with generic form $V_{up}\\sim 1/{\\cal V}^\\gamma$, should be restricted to the one satisfying $\\gamma^2\\ll 12$. Such a bound might explain why in models previously studied no uplifting has been achieved, and gives motivations to study a novel proposal of dilaton dependent uplifting mechanism for which no numerical studies has been performed before. We find that in this case it is actually possible to get a dS vacuum, but still leave open the question of a more precise discrimination feature the good uplifting mechanisms should satisfy.

  2. Large magnetocapacitance in electronic ferroelectric manganite systems

    SciTech Connect (OSTI)

    Chowdhury, Ujjal; Goswami, Sudipta; Bhattacharya, Dipten; Midya, Arindam; Mandal, P.; Das, Pintu; Mukovskii, Ya. M.

    2013-11-21

    We have observed a sizable positive magnetocapacitance (?5%–90%) in perovskite Pr{sub 0.55}Ca{sub 0.45}MnO{sub 3} and bilayer Pr(Sr{sub 0.1}Ca{sub 0.9}){sub 2}Mn{sub 2}O{sub 7} system under 5?T magnetic field across 20–100?K below the magnetic transition point T{sub N}. The magnetodielectric effect, on the other hand, exhibits a crossover: (a) from positive to negative for the perovskite system and (b) from negative to positive for the bilayer system over the same temperature range. The bilayer Pr(Sr{sub 0.1}Ca{sub 0.9}){sub 2}Mn{sub 2}O{sub 7} system exhibits a sizable anisotropy as well. We have also noticed the influence of magnetic field on the dielectric relaxation characteristics of these systems. These systems belong to a class of improper ferroelectrics and are expected to exhibit charge/orbital order driven ferroelectric polarization below the transition point T{sub CO}. Large magnetocapacitance in these systems shows a typical multiferroic behavior even though the ferroelectric polarization is small in comparison to that of other ferroelectrics.

  3. Fermi Large Area Telescope Third Source Catalog

    E-Print Network [OSTI]

    ,

    2015-01-01

    We present the third Fermi Large Area Telescope source catalog (3FGL) of sources in the 100~MeV--300~GeV range. Based on the first four years of science data from the Fermi Gamma-ray Space Telescope mission, it is the deepest yet in this energy range. Relative to the 2FGL catalog, the 3FGL catalog incorporates twice as much data as well as a number of analysis improvements, including improved calibrations at the event reconstruction level, an updated model for Galactic diffuse gamma-ray emission, a refined procedure for source detection, and improved methods for associating LAT sources with potential counterparts at other wavelengths. The 3FGL catalog includes 3033 sources above 4 sigma significance, with source location regions, spectral properties, and monthly light curves for each. Of these, 78 are flagged as potentially being due to imperfections in the model for Galactic diffuse emission. Twenty-five sources are modeled explicitly as spatially extended, and overall 232 sources are considered as identifie...

  4. Mirror World at the Large Hadron Collider

    E-Print Network [OSTI]

    Riccardo Barbieri; Thomas Gregoire; Lawrence J. Hall

    2005-09-22

    A mirror world can modify in a striking way the LHC signals of the Higgs sector. An exact or approximate Z_2 symmetry between the mirror world and our world allows large mixing between the Higgs bosons of these worlds, leading to production rates and branching ratios for these states that are markedly different from the standard model and are characteristic of a mirror world. The constraints on these Higgs boson masses from precision electroweak data differ from the standard model bound, so that the new physics that cancels the quadratic divergence induced by the top quark may appear at a larger scale, possibly beyond the reach of the LHC. However, the scale of new physics needed to cancel the quadratic divergence induced by the Higgs boson is not significantly changed. With small breakings of the Z_2 parity, the lightest mirror quarks (and possibly charged mirror leptons) could be the dark matter in the universe, forming galactic halos that are stable to cooling. A possible signal from the relic radiation density of the mirror world is also discussed.

  5. Airbrushed Nickel Nanoparticles for Large-Area

    SciTech Connect (OSTI)

    Sarac, Mehmet; ANDERSON, BRYAN; Pearce, Ryan; Railsback, Justin; Oni, Adedapo; White, Ryan M.; Hensley, Dale K; Lebeau, James M; Melechko, Anatoli; Tracy, Joseph B

    2013-01-01

    Vertically aligned carbon nanofibers (VACNFs) were grown by plasma-enhanced chemical vapor deposition (PECVD) using Ni nanoparticle (NP) catalysts that were deposited by airbrushing onto Si, Al, Cu, and Ti substrates. Airbrushing is a simple method for depositing catalyst NPs over large areas that is compatible with roll-to-roll processing. The distribution and morphology of VACNFs are affected by the airbrushing parameters and the composition of the metal foil. Highly concentrated Ni NPs in heptane give more uniform distributions than pentane and hexanes, resulting in more uniform coverage of VACNFs. For VACNF growth on metal foils, Si micropowder was added as a precursor for Si-enriched coatings formed in situ on the VACNFs that impart mechanical rigidity. Interactions between the catalyst NPs and the metal substrates impart control over the VACNF morphology. Growth of carbon nanostructures on Cu is particularly noteworthy because the miscibility of Ni with Cu poses challenges for VACNF growth, and carbon nanostructures anchored to Cu substrates are desired as anode materials for Li-ion batteries and for thermal interface materials.

  6. Chemical evolution of the Large Magellanic Cloud

    E-Print Network [OSTI]

    Bekki, Kenji

    2012-01-01

    We adopt a new chemical evolution model for the Large Magellanic Cloud (LMC) and thereby investigate its past star formation and chemical enrichment histories. The delay time distribution of type Ia supernovae recently revealed by type Ia supernova surveys is incorporated self-consistently into the new model. The principle results are summarized as follows. The present gas mass fraction and stellar metallicity as well as the higher [Ba/Fe] in metal-poor stars at [Fe/H] 0.3) at [Fe/H] ~ -0.6 and higher [Ba/Fe] (>0.5) at [Fe/H] ~ -0.3 can be due to significantly enhanced star formation about 2 Gyr ago. The observed overall [Ca/Fe]-[Fe/H] relation and remarkably low [Ca/Fe] (-0.6 are consistent with models with short-delay supernova Ia and with the more efficient loss of Ca possibly caused by an explosion mechanism of type II supernovae. Although the metallicity distribution functions do not show double peaks in the models with a starburst about 2 Gyr ago, they show characteristic double peaks in the models with...

  7. Large area atmospheric-pressure plasma jet

    DOE Patents [OSTI]

    Selwyn, Gary S. (Los Alamos, NM); Henins, Ivars (Los Alamos, NM); Babayan, Steve E. (Huntington Beach, CA); Hicks, Robert F. (Los Angeles, CA)

    2001-01-01

    Large area atmospheric-pressure plasma jet. A plasma discharge that can be operated at atmospheric pressure and near room temperature using 13.56 MHz rf power is described. Unlike plasma torches, the discharge produces a gas-phase effluent no hotter than 250.degree. C. at an applied power of about 300 W, and shows distinct non-thermal characteristics. In the simplest design, two planar, parallel electrodes are employed to generate a plasma in the volume therebetween. A "jet" of long-lived metastable and reactive species that are capable of rapidly cleaning or etching metals and other materials is generated which extends up to 8 in. beyond the open end of the electrodes. Films and coatings may also be removed by these species. Arcing is prevented in the apparatus by using gas mixtures containing He, which limits ionization, by using high flow velocities, and by properly spacing the rf-powered electrode. Because of the atmospheric pressure operation, there is a negligible density of ions surviving for a sufficiently long distance beyond the active plasma discharge to bombard a workpiece, unlike the situation for low-pressure plasma sources and conventional plasma processing methods.

  8. Superconducting materials for large scale applications

    SciTech Connect (OSTI)

    Scanlan, Ronald M.; Malozemoff, Alexis P.; Larbalestier, David C.

    2004-05-06

    Significant improvements in the properties ofsuperconducting materials have occurred recently. These improvements arebeing incorporated into the latest generation of wires, cables, and tapesthat are being used in a broad range of prototype devices. These devicesinclude new, high field accelerator and NMR magnets, magnets for fusionpower experiments, motors, generators, and power transmission lines.These prototype magnets are joining a wide array of existing applicationsthat utilize the unique capabilities of superconducting magnets:accelerators such as the Large Hadron Collider, fusion experiments suchas ITER, 930 MHz NMR, and 4 Tesla MRI. In addition, promising newmaterials such as MgB2 have been discovered and are being studied inorder to assess their potential for new applications. In this paper, wewill review the key developments that are leading to these newapplications for superconducting materials. In some cases, the key factoris improved understanding or development of materials with significantlyimproved properties. An example of the former is the development of Nb3Snfor use in high field magnets for accelerators. In other cases, thedevelopment is being driven by the application. The aggressive effort todevelop HTS tapes is being driven primarily by the need for materialsthat can operate at temperatures of 50 K and higher. The implications ofthese two drivers for further developments will be discussed. Finally, wewill discuss the areas where further improvements are needed in order fornew applications to be realized.

  9. Spectral Hardening of Large Solar Flares

    E-Print Network [OSTI]

    Paolo C. Grigis; Arnold O. Benz

    2008-05-01

    RHESSI observations are used to quantitatively study the hard X-ray evolution in 5 large solar flares selected for spectral hardening in the course of the event. The X-ray bremsstrahlung emission from non-thermal electrons is characterized by two spectroscopically distinct phases: impulsive and gradual. The impulsive phase usually consists of several emission spikes following a soft-hard-soft spectral pattern, whereas the gradual stage manifests itself as spectral hardening while the flux slowly decreases. Both the soft-hard-soft (impulsive) phase and the hardening (gradual) phase are well described by piecewise linear dependence of the photon spectral index on the logarithm of the hard X-ray flux. The different linear parts of this relation correspond to different rise and decay phases of emission spikes. The temporal evolution of the spectra is compared with the configuration and motion of the hard X-ray sources in RHESSI images. These observations reveal that the two stages of electron acceleration causing these two different behaviors are closely related in space and time. The transition between the impulsive and gradual phase is found to be smooth and progressive rather than abrupt. This suggests that they arise because of a slow change in a common accelerator rather than being caused by two independent and distinct acceleration processes. We propose that the hardening during the decay phase is caused by continuing particle acceleration with longer trapping in the accelerator before escape.

  10. ACTIVE INSTABILITY CONTROL EFFECTIVENESS IN A LIQUID FUELED COMBUSTOR

    E-Print Network [OSTI]

    Lieuwen, Timothy C.

    in aircraft and land based gas turbines (Cohen and Banaszuk, 2003; Paschereit et al., 1998). Active control Laboratory or the DOE. Ã Address correspondence to tim.lieuwen@aerospace.gatech.edu Combust. Sci. and Tech effectiveness. Keywords: combustion control, combustion instability INTRODUCTION This note describes

  11. Effect of multiperforated plates on the acoustic modes in combustors

    E-Print Network [OSTI]

    Mendez, Simon

    related to the wave equation in the frequency domain, and is able to provide the acoustic modes effect on acoustics [5], [1], which is enhanced by the presence of a mean bias flow [6]. Acoustic waves in the presence of an acoustic wave and is well adapted to be inserted in the Helmholtz solver. It was validated

  12. EIS-0289: JEA Circulating Fluidized Bed Combustor Project

    Broader source: Energy.gov [DOE]

    This EIS assesses environmental issues associated with constructing and demonstrating a project that would be cost-shared by DOE and JEA (formerly the Jacksonville Electric Authority) under the...

  13. Combustion of Cattle Manure in a Fluidized Bed Combustor 

    E-Print Network [OSTI]

    Annamalai, K.; Colaluca, M. A.; Ibrahim, M. Y.; Sweeten, J. M.

    1988-01-01

    from -ZO to +ZO percent while keeping bed temperature constant at 650 0 e (lZ00?F) and u/u mf - 1.5. The concentrations of eo z , eo, eH 4 , e H , and e H Z 4 3 6 diminished with the increase in percentage of excess air (Figure 4). Even though... there is increased production of eo due to oxidation of Z eo, eH 4 , etc., the air dilution effect had a tendency to reduce eo Z concentration. The eo and hydrocarbons appear to have decreased with more excess air. Similar results were observed and Madan [la...

  14. Project Profile: CSP Tower Air Brayton Combustor | Department...

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

    This project addresses key technical hurdles for an optimized CSP central tower hybrid gas turbine system to increase energy conversion efficiency to greater than 50%, greatly...

  15. CSP Tower Air Brayton Combustor- FY12 Q4

    Broader source: Energy.gov [DOE]

    This document summarizes the progress of this SWRI project, funded by SunShot, for the fourth quarter of fiscal year 2012.

  16. Development of a liquid-fueled micro-combustor

    E-Print Network [OSTI]

    Peck, Jhongwoo, 1976-

    2008-01-01

    Advances in Micro-Electro-Mechanical Systems (MEMS) have made possible the development of shirtbutton-sized gas turbine engines for use as portable power sources. As part of an effort to develop a microscale gas turbine ...

  17. Combustion and direct energy conversion in a micro-combustor 

    E-Print Network [OSTI]

    Lei, Yafeng

    2006-10-30

    . Since batteries have low specific energy (~200 kJ/kg) and liquid hydrocarbon fuels have a very high specific energy (~50000 kJ/kg), a miniaturized power-generating device, even with a relatively inefficient conversion of hydrocarbon fuels to power, would...

  18. Coaxial fuel and air premixer for a gas turbine combustor

    DOE Patents [OSTI]

    York, William D; Ziminsky, Willy S; Lacy, Benjamin P

    2013-05-21

    An air/fuel premixer comprising a peripheral wall defining a mixing chamber, a nozzle disposed at least partially within the peripheral wall comprising an outer annular wall spaced from the peripheral wall so as to define an outer air passage between the peripheral wall and the outer annular wall, an inner annular wall disposed at least partially within and spaced from the outer annular wall, so as to define an inner air passage, and at least one fuel gas annulus between the outer annular wall and the inner annular wall, the at least one fuel gas annulus defining at least one fuel gas passage, at least one air inlet for introducing air through the inner air passage and the outer air passage to the mixing chamber, and at least one fuel inlet for injecting fuel through the fuel gas passage to the mixing chamber to form an air/fuel mixture.

  19. Large Break LOCA Accident Management Strategies for Accidents With Large Containment Leaks

    SciTech Connect (OSTI)

    Sdouz, Gert [ARC Seibersdorf Research GmbH, Viktor Kaplan-Strasse 2, 2700 Wr. Neustadt (Austria)

    2006-07-01

    The goal of this work is the investigation of the influence of different accident management strategies on the thermal-hydraulics in the containment during a Large Break Loss of Coolant Accident with a large containment leak from the beginning of the accident. The increasing relevance of terrorism suggests a closer look at this kind of severe accidents. Normally the course of severe accidents and their associated phenomena are investigated with the assumption of an intact containment from the beginning of the accident. This intact containment has the ability to retain a large part of the radioactive inventory. In these cases there is only a release via a very small leakage due to the un-tightness of the containment up to cavity bottom melt through. This paper represents the last part of a comprehensive study on the influence of accident management strategies on the source term of VVER-1000 reactors. Basically two different accident sequences were investigated: the 'Station Blackout'- sequence and the 'Large Break LOCA'. In a first step the source term calculations were performed assuming an intact containment from the beginning of the accident and no accident management action. In a further step the influence of different accident management strategies was studied. The last part of the project was a repetition of the calculations with the assumption of a damaged containment from the beginning of the accident. This paper concentrates on the last step in the case of a Large Break LOCA. To be able to compare the results with calculations performed years ago the calculations were performed using the Source Term Code Package (STCP), hydrogen explosions are not considered. In this study four different scenarios have been investigated. The main parameter was the switch on time of the spray systems. One of the results is the influence of different accident management strategies on the source term. In the comparison with the sequence with intact containment it was demonstrated that the accident management measures have quite lower consequences. In addition it was shown that in the case of a 'Large Break LOCA'-sequence the intact containment retains the nuclides up to a factor of 20 000. This is much more than in the case of a 'Station Blackout'-sequence. Within the frame of the study 17 source terms have been generated to evaluate in detail accident management strategies for VVER-1000 reactors. (authors)0.

  20. Sensitivity technologies for large scale simulation.

    SciTech Connect (OSTI)

    Collis, Samuel Scott; Bartlett, Roscoe Ainsworth; Smith, Thomas Michael; Heinkenschloss, Matthias; Wilcox, Lucas C.; Hill, Judith C.; Ghattas, Omar; Berggren, Martin Olof; Akcelik, Volkan; Ober, Curtis Curry; van Bloemen Waanders, Bart Gustaaf; Keiter, Eric Richard

    2005-01-01

    Sensitivity analysis is critically important to numerous analysis algorithms, including large scale optimization, uncertainty quantification,reduced order modeling, and error estimation. Our research focused on developing tools, algorithms and standard interfaces to facilitate the implementation of sensitivity type analysis into existing code and equally important, the work was focused on ways to increase the visibility of sensitivity analysis. We attempt to accomplish the first objective through the development of hybrid automatic differentiation tools, standard linear algebra interfaces for numerical algorithms, time domain decomposition algorithms and two level Newton methods. We attempt to accomplish the second goal by presenting the results of several case studies in which direct sensitivities and adjoint methods have been effectively applied, in addition to an investigation of h-p adaptivity using adjoint based a posteriori error estimation. A mathematical overview is provided of direct sensitivities and adjoint methods for both steady state and transient simulations. Two case studies are presented to demonstrate the utility of these methods. A direct sensitivity method is implemented to solve a source inversion problem for steady state internal flows subject to convection diffusion. Real time performance is achieved using novel decomposition into offline and online calculations. Adjoint methods are used to reconstruct initial conditions of a contamination event in an external flow. We demonstrate an adjoint based transient solution. In addition, we investigated time domain decomposition algorithms in an attempt to improve the efficiency of transient simulations. Because derivative calculations are at the root of sensitivity calculations, we have developed hybrid automatic differentiation methods and implemented this approach for shape optimization for gas dynamics using the Euler equations. The hybrid automatic differentiation method was applied to a first order approximation of the Euler equations and used as a preconditioner. In comparison to other methods, the AD preconditioner showed better convergence behavior. Our ultimate target is to perform shape optimization and hp adaptivity using adjoint formulations in the Premo compressible fluid flow simulator. A mathematical formulation for mixed-level simulation algorithms has been developed where different physics interact at potentially different spatial resolutions in a single domain. To minimize the implementation effort, explicit solution methods can be considered, however, implicit methods are preferred if computational efficiency is of high priority. We present the use of a partial elimination nonlinear solver technique to solve these mixed level problems and show how these formulation are closely coupled to intrusive optimization approaches and sensitivity analyses. Production codes are typically not designed for sensitivity analysis or large scale optimization. The implementation of our optimization libraries into multiple production simulation codes in which each code has their own linear algebra interface becomes an intractable problem. In an attempt to streamline this task, we have developed a standard interface between the numerical algorithm (such as optimization) and the underlying linear algebra. These interfaces (TSFCore and TSFCoreNonlin) have been adopted by the Trilinos framework and the goal is to promote the use of these interfaces especially with new developments. Finally, an adjoint based a posteriori error estimator has been developed for discontinuous Galerkin discretization of Poisson's equation. The goal is to investigate other ways to leverage the adjoint calculations and we show how the convergence of the forward problem can be improved by adapting the grid using adjoint-based error estimates. Error estimation is usually conducted with continuous adjoints but if discrete adjoints are available it may be possible to reuse the discrete version for error estimation. We investigate the advantages and disadvantages of continuous and discre

  1. Metal Cutting for Large Component Removal

    SciTech Connect (OSTI)

    Hulick, Robert M.

    2008-01-15

    Decommissioning of commercial nuclear power plants presents technological challenges. One major challenge is the removal of large components mainly consisting of the reactor vessel, steam generators and pressurizer. In order to remove and package these large components nozzles must be cut from the reactor vessel to precise tolerances. In some cases steam generators must be segmented for size and weight reduction. One innovative technology that has been used successfully at several commercial nuclear plant decommissioning is diamond wire sawing. Diamond wire sawing is performed by rotating a cable with diamond segments attached using a flywheel approximately 24 inches in diameter driven remotely by a hydraulic pump. Tension is provided using a gear rack drive which also takes up the slack in the wire. The wire is guided through the use of pulleys keeps the wire in a precise location. The diamond wire consists of 1/4 inch aircraft cable with diamond beads strung over the cable separated by springs and brass crimps. Standard wire contains 40 diamond beads per meter and can be made to any length. Cooling the wire and controlling the spread of contamination presents significant challenges. Under normal circumstances the wire is cooled and the cutting kerf cleaned by using water. In some cases of reactor nozzle cuts the use of water is prohibited because it cannot be controlled. This challenge was solved by using liquid Carbon Dioxide as the cooling agent. The liquid CO{sub 2} is passed through a special nozzle which atomizes the liquid into snowflakes which is introduced under pressure to the wire. The snowflakes attach to the wire keeping it cool and to the metal shavings. As the CO{sub 2} and metal shavings are released from the wire due to its fast rotation, the snowflakes evaporate leaving only the fine metal shavings as waste. Secondary waste produced is simply the small volume of fine metal shavings removed from the cut surface. Diamond wire sawing using CO{sub 2} cooling has been employed for cutting the reactor nozzles at San Onofre Unit 1 and at Connecticut Yankee. These carbon steel nozzles ranged up to 54 inch diameter with a 15 inch thick wall and an interior stainless cladding. Diamond wire sawing using traditional water cooling has been used to segment the reactor head at Rancho Seco and for cutting reactor nozzles and control rod drive tubes at Dairyland Power's Lacrosse BWR project. Advantages: - ALARA: All cutting is preformed remotely significantly reducing dose. Stringing of wires is accomplished using long handle tools. - Secondary waste is reduced to just the volume of material cut with the diamond wire. - The potential for airborne contamination is eliminated. Due to the flexibility of the wire, any access restrictions and interferences can be accommodated using pulleys and long handle tools. - The operation is quiet. Disadvantages: - With Liquid Carbon Dioxide cooling and cleaning, delivery of the material must be carefully planned. The longer the distance from the source to the cut area, the greater the chance for pressure drop and subsequent problems with line freezing. - Proper shrouding and ventilation are required for environmental reasons. In each case, the metal structures were cut at a precise location. Radiation dose was reduced significantly by operating the equipment from a remote location. The cuts were very smooth and completed on schedule. Each project must be analyzed individually and take into account many factors including access, radiological conditions, environmental conditions, schedule requirements, packaging requirements and size of cuts.

  2. W. F. Colban A. T. Lethander

    E-Print Network [OSTI]

    Thole, Karen A.

    in a gas turbine engine. The experiments were performed in a large-scale wind tunnel facility.1115/1.1561812 Introduction The flow and thermal fields at the combustor-turbine junction in a gas turbine engine are highly Combustor Turbine Interface Studies--Part 2: Flow and Thermal Field Measurements Most turbine inlet flows

  3. Fabrication and characterization of large arrays of mesoscopic gold rings on large-aspect-ratio cantilevers

    SciTech Connect (OSTI)

    Ngo, D. Q.; Petkovi?, I. Lollo, A.; Castellanos-Beltran, M. A.; Harris, J. G. E.

    2014-10-15

    We have fabricated large arrays of mesoscopic metal rings on ultrasensitive cantilevers. The arrays are defined by electron beam lithography and contain up to 10{sup 5} rings. The rings have a circumference of 1 ?m, and are made of ultrapure (6N) Au that is deposited onto a silicon-on-insulator wafer without an adhesion layer. Subsequent processing of the SOI wafer results in each array being supported at the end of a free-standing cantilever. To accommodate the large arrays while maintaining a low spring constant, the cantilevers are nearly 1 mm in both lateral dimensions and 100 nm thick. The extreme aspect ratio of the cantilevers, the large array size, and the absence of a sticking layer are intended to enable measurements of the rings' average persistent current in the presence of relatively small magnetic fields. We describe the motivation for these measurements, the fabrication of the devices, and the characterization of the cantilevers' mechanical properties. We also discuss the devices' expected performance in measurements of .

  4. Locations of Smart Grid Demonstration and Large-Scale Energy...

    Office of Environmental Management (EM)

    Locations of Smart Grid Demonstration and Large-Scale Energy Storage Projects Locations of Smart Grid Demonstration and Large-Scale Energy Storage Projects Map of the United States...

  5. Efficient Sensor Placement Optimization for Securing Large Water Distribution Networks

    E-Print Network [OSTI]

    Pratt, Vaughan

    Efficient Sensor Placement Optimization for Securing Large Water Distribution Networks Andreas Abstract: The problem of deploying sensors in a large water distribution network is considered, in order water--exhibits an important diminishing returns effect called submodularity. The submodularity

  6. Large deformation and electrochemistry of polyelectrolyte gels , Xuanhe Zhao b

    E-Print Network [OSTI]

    Suo, Zhigang

    Large deformation and electrochemistry of polyelectrolyte gels Wei Hong a , Xuanhe Zhao b , Zhigang. This paper develops a field theory to couple large deformation and electrochemistry. A specific material

  7. FEMP Helps Federal Facilities Develop Large-Scale Renewable Energy...

    Office of Environmental Management (EM)

    FEMP Helps Federal Facilities Develop Large-Scale Renewable Energy Projects FEMP Helps Federal Facilities Develop Large-Scale Renewable Energy Projects August 21, 2013 - 12:00am...

  8. Energy Department Loan Guarantee Would Support Large-Scale Rooftop...

    Energy Savers [EERE]

    Loan Guarantee Would Support Large-Scale Rooftop Solar Power for U.S. Military Housing Energy Department Loan Guarantee Would Support Large-Scale Rooftop Solar Power for U.S....

  9. Search for Large Extra Dimensions Based on Observations of Neutron...

    Office of Scientific and Technical Information (OSTI)

    ThesisDissertation: Search for Large Extra Dimensions Based on Observations of Neutron Stars with the Fermi-LAT Citation Details In-Document Search Title: Search for Large Extra...

  10. Exploring large coherent spin systems with solid state NMR

    E-Print Network [OSTI]

    Cho, HyungJoon, Ph. D. Massachusetts Institute of Technology

    2005-01-01

    Solid state Nuclear Magnetic Resonance (NMR) allows us to explore a large coherent spin system and provides an ideal test-bed for studying strongly interacting multiple-spin system in a large Hilbert space. In this thesis, ...

  11. Development of Large Format Lithium Ion Cells with Higher Energy...

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

    Large Format Lithium Ion Cells with Higher Energy Density Exceeding 500WhL Development of Large Format Lithium Ion Cells with Higher Energy Density Exceeding 500WhL 2012 DOE...

  12. Evaluating Benefits of Idling Restrictions in a Large Northern...

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

    Evaluating Benefits of Idling Restrictions in a Large Northern City While an anti-idling law in a large northern city has brought about the deployment of anti-idling technologies...

  13. A Look at Health Care Buildings - How large are they

    U.S. Energy Information Administration (EIA) Indexed Site

    Large? Return to: A Look at Health Care Buildings How large are they? How many employees are there? Where are they located? How old are they? Who owns and occupies them? Are they...

  14. ACCELERATORS: ENGINES FOR TRAVERSING A LARGE AND OFTEN DIFFICULT LANDSCAPE

    E-Print Network [OSTI]

    Sessler, Andrew M.

    2014-01-01

    California. ACCELERATORS: ENGINES FOR TRAVERSING A LARGE ANDthat go with them, are from: “Engines of Discovery: Particle

  15. Administrator's Record of Decision (ROD) on New Large Single...

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

    NEW LARGE SINGLE LOAD POLICY ISSUE REVIEW ADMINISTRATOR'S RECORD OF DECISION MARCH 2002 TABLE OF CONTENTS I. Introduction ......

  16. Lessons Learned: Planning and Operating Power Systems with Large

    E-Print Network [OSTI]

    flow) run-of-river hydro plant. While there are plans for large size photovoltaic (PV) installations

  17. Ris-R-Report Power fluctuations from large wind farms -

    E-Print Network [OSTI]

    Abstract (max. 2000 char.): Experience from power system operation with the first large offshore wind farm acquired at the two large offshore wind farms in Denmark are applied to validate the models. FinallyRisø-R-Report Power fluctuations from large wind farms - Final report Poul Sørensen, Pierre Pinson

  18. Detailed Execution Planning for Large Oil and Gas Construction Projects

    E-Print Network [OSTI]

    Calgary, University of

    Detailed Execution Planning for Large Oil and Gas Construction Projects Presented by James Lozon, University of Calgary There is currently 55.8 billion dollars worth of large oil and gas construction projects scheduled or underway in the province of Alberta. Recently, large capital oil and gas projects

  19. CONSULTATION RESPONSE Wellcome Trust response to RCUK Large Facilities Roadmap

    E-Print Network [OSTI]

    Rambaut, Andrew

    CONSULTATION RESPONSE Wellcome Trust response to RCUK Large Facilities Roadmap December 2007 Page 1 of 4 RCUK Large Facilities Roadmap Response by the Wellcome Trust December 2007 1. The Wellcome Trust is pleased to have the opportunity to feed into the process of prioritising the RCUK Large Facilities Roadmap

  20. Identification and Tracking of Parameters for a Large Synchronous Generator

    E-Print Network [OSTI]

    Identification and Tracking of Parameters for a Large Synchronous Generator Final Project Report and Tracking of Parameters for a Large Synchronous Generator Final Project Report G. T. Heydt, Project Leader for a Large Synchronous Generator 1. Introduction The power system state estimation problem ha

  1. 1Design limits and solutions for very large wind turbines Design limits and solutions for very large wind turbines

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    #12;#12;1Design limits and solutions for very large wind turbines UpWind Design limits and solutions for very large wind turbines A 20 MW turbine is feasible March 2011 Supported by: #12;March 20112 Photo:Nordex #12;3Design limits and solutions for very large wind turbines Contents 1. UpWind: Summary

  2. Nuclear EMP simulation for large-scale urban environments. FDTD for electrically large problems.

    SciTech Connect (OSTI)

    Smith, William S.; Bull, Jeffrey S.; Wilcox, Trevor; Bos, Randall J.; Shao, Xuan-Min; Goorley, John T.; Costigan, Keeley R.

    2012-08-13

    In case of a terrorist nuclear attack in a metropolitan area, EMP measurement could provide: (1) a prompt confirmation of the nature of the explosion (chemical or nuclear) for emergency response; and (2) and characterization parameters of the device (reaction history, yield) for technical forensics. However, urban environment could affect the fidelity of the prompt EMP measurement (as well as all other types of prompt measurement): (1) Nuclear EMP wavefront would no longer be coherent, due to incoherent production, attenuation, and propagation of gamma and electrons; and (2) EMP propagation from source region outward would undergo complicated transmission, reflection, and diffraction processes. EMP simulation for electrically-large urban environment: (1) Coupled MCNP/FDTD (Finite-difference time domain Maxwell solver) approach; and (2) FDTD tends to be limited to problems that are not 'too' large compared to the wavelengths of interest because of numerical dispersion and anisotropy. We use a higher-order low-dispersion, isotropic FDTD algorithm for EMP propagation.

  3. Jet Physics with A Large Ion Collider Experiment at the Large Hadron Collider

    E-Print Network [OSTI]

    Klein, Jochen

    In the presence of the strongly-interacting medium created in relativistic heavy-ion collisions, highly energetic partons from hard interactions lose energy through scattering and radiating. This effect, referred to as jet quenching, is observed as a suppression of particles with large momenta transverse to the beam axis (high-$p_\\perp$). To study the impact of the medium evolution on the energy loss modelling in the Monte Carlo event generator JEWEL, we compare results obtained for different scenarios of Au-Au collisions at $\\sqrt{s_\\mathrm{NN}} = 200~\\mathrm{GeV}$. For this purpose, JEWEL was extended to use the output of relativistic hydrodynamic calculations in the OSCAR2008H format. We find the modelling of common observables, e.g. the nuclear modification factor, to be rather insensitive to the details of the medium evolution, for which the analytically accessible Bjorken expansion can thus be considered adequate. The OSCAR interface now allows further studies also at LHC energies. Jets of large transve...

  4. Performance of large electron energy filter in large volume plasma device

    SciTech Connect (OSTI)

    Singh, S. K.; Srivastava, P. K.; Awasthi, L. M.; Mattoo, S. K.; Sanyasi, A. K.; Kaw, P. K. [Institute for Plasma Research, Gandhinagar 382 428, Gujarat (India)] [Institute for Plasma Research, Gandhinagar 382 428, Gujarat (India); Singh, R. [Institute for Plasma Research, Gandhinagar 382 428, Gujarat (India) [Institute for Plasma Research, Gandhinagar 382 428, Gujarat (India); WCI Center for Fusion Theory, National Fusion Research Institute Gwahangno 113, Yu-seong-gu, Daejeon, 305-333 (Korea, Republic of)

    2014-03-15

    This paper describes an in-house designed large Electron Energy Filter (EEF) utilized in the Large Volume Plasma Device (LVPD) [S. K. Mattoo, V. P. Anita, L. M. Awasthi, and G. Ravi, Rev. Sci. Instrum. 72, 3864 (2001)] to secure objectives of (a) removing the presence of remnant primary ionizing energetic electrons and the non-thermal electrons, (b) introducing a radial gradient in plasma electron temperature without greatly affecting the radial profile of plasma density, and (c) providing a control on the scale length of gradient in electron temperature. A set of 19 independent coils of EEF make a variable aspect ratio, rectangular solenoid producing a magnetic field (B{sub x}) of 100?G along its axis and transverse to the ambient axial field (B{sub z} ? 6.2?G) of LVPD, when all its coils are used. Outside the EEF, magnetic field reduces rapidly to 1?G at a distance of 20 cm from the center of the solenoid on either side of target and source plasma. The EEF divides LVPD plasma into three distinct regions of source, EEF and target plasma. We report that the target plasma (n{sub e} ? 2 × 10{sup 11}?cm{sup ?3} and T{sub e} ? 2?eV) has no detectable energetic electrons and the radial gradients in its electron temperature can be established with scale length between 50?and?600 cm by controlling EEF magnetic field. Our observations reveal that the role of the EEF magnetic field is manifested by the energy dependence of transverse electron transport and enhanced transport caused by the plasma turbulence in the EEF plasma.

  5. Thermodynamics of QCD at large quark chemical potential

    E-Print Network [OSTI]

    Andreas Gerhold; Andreas Ipp; Anton Rebhan

    2005-12-21

    We review the existing weak-coupling results on the thermodynamic potential of deconfined QCD at small and large quark chemical potential and compare with results from lattice gauge theory as well as the exactly solvable case of large-N_f QCD. We also discuss the new analytical results on non-Fermi-liquid effects in entropy and specific heat as well as in dispersion laws of quark quasiparticles at large quark chemical potential.

  6. Optimizing Cluster Heads for Energy Efficiency in Large-Scale...

    Office of Scientific and Technical Information (OSTI)

    Optimizing Cluster Heads for Energy Efficiency in Large-Scale Heterogeneous Wireless Sensor Networks Gu, Yi; Wu, Qishi; Rao, Nageswara S. V. Hindawi Publishing Corporation None...

  7. QER- Comment of Large Public Power Council 1

    Broader source: Energy.gov [DOE]

    Attached are the Comments of the Large Public Power Council on the QER. Please feel to contact me if you have any questions.

  8. Large Fleets Lead in Petroleum Reduction (Fact Sheet)

    SciTech Connect (OSTI)

    Proc, H.

    2011-03-01

    Fact sheet describes Clean Cities' National Petroleum Reduction Partnership, an initiative through which large private fleets can receive support from Clean Cities to reduce petroleum consumption.

  9. Energy Department Applauds Nation's First Large-Scale Industrial...

    Office of Environmental Management (EM)

    Large-Scale Industrial Carbon Capture, Storage Plant Begins Construction The 15,000 square-foot sustainably designed National Sequestration Education Center, located at Richland...

  10. Development of Large Area Gas Electron Multiplier Detector and...

    Office of Scientific and Technical Information (OSTI)

    Development of Large Area Gas Electron Multiplier Detector and Its Application to a Digital Hadron Calorimeter for Future Collider Experiments Citation Details In-Document Search...

  11. Visualization and analysis of large medical image collections using pipelines

    E-Print Network [OSTI]

    Sridharan, Ramesh

    2015-01-01

    Medical image analysis often requires developing elaborate algorithms that are implemented as computational pipelines. A growing number of large medical imaging studies necessitate development of robust and flexible ...

  12. Optimizing Cluster Heads for Energy Efficiency in Large-Scale...

    Office of Scientific and Technical Information (OSTI)

    clustering is generally considered as an efficient and scalable way to facilitate the management and operation of such large-scale networks and minimize the total energy...

  13. Author's personal copy Large deformation and electrochemistry of polyelectrolyte gels

    E-Print Network [OSTI]

    Hong, Wei

    Author's personal copy Large deformation and electrochemistry of polyelectrolyte gels Wei Hong and electrochemistry. A specific material model is described, including the effects of stretching the network, mixing

  14. Large-Eddy Simulation for Green Energy and Propulsion Systems...

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

    Large-Eddy Simulation for Green Energy and Propulsion Systems PI Name: Umesh Paliath PI Email: paliath@ge.com Institution: General Electric Allocation Program: INCITE Allocation...

  15. Towards large-cohort comparative studies to define the factors...

    Office of Scientific and Technical Information (OSTI)

    Towards large-cohort comparative studies to define the factors influencing the gut microbial community structure of ASD patients Citation Details In-Document Search Title:...

  16. Parallel Large-Neighborhood Search Techniques for LNG Inventory ...

    E-Print Network [OSTI]

    Apr 17, 2014 ... Parallel Large-Neighborhood Search Techniques for LNG Inventory Routing. Badrinarayanan Velamur Asokan(badri.velamur.asokan ***at*** ...

  17. ORNL demonstrates first large-scale graphene fabrication | ornl...

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

    ORNL demonstrates first large-scale graphene composite fabrication ORNL's ultrastrong graphene features layers of graphene and polymers and is an effective conductor of...

  18. A Model for Turbulent Combustion Simulation of Large Scale Hydrogen...

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

    A Model for Turbulent Combustion Simulation of Large Scale Hydrogen Explosions Event Sponsor: Argonne Leadership Computing Facility Seminar Start Date: Oct 6 2015 - 10:00am...

  19. Early science with the large millimeter telescope: exploring...

    Office of Scientific and Technical Information (OSTI)

    Early science with the large millimeter telescope: exploring the effect of AGN activity on the relationships between molecular gas, dust, and star formation Citation Details...

  20. Energy Department Applauds Nation's First Large-Scale Industrial...

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

    today's groundbreaking for construction of the nation's first large-scale industrial carbon capture and storage (ICCS) facility in Decatur, Illinois. Supported by the 2009...

  1. Finding Large Aperture Fractures in Geothermal Resource Areas...

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

    Seismic Survey DOE Geothermal Peer Review 2010 - Presentation. Project summary: Drilling into large aperture open fractures (LAFs) typically yield production wells with...

  2. Large Eddy Simulation (LES) Applied to Advanced Engine Combustion...

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

    Advanced Engine Combustion Research Large Eddy Simulation (LES) Applied to Advanced Engine Combustion Research 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies...

  3. Effects of Volcanism, Crustal Thickness, and Large Scale Faulting...

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

    Effects of Volcanism, Crustal Thickness, and Large Scale Faulting on the Development and Evolution of Geothermal Systems: Collaborative Project in Chile Effects of Volcanism,...

  4. Large Scale GSHP as Alternative Energy for American Farmers Geothermal...

    Open Energy Info (EERE)

    technologies, and remove the farming business risk associated with fluctuating fuel prices. PI Xu has many years experience in large scale GSHP for commercial and industrial...

  5. Optimization Online - A fictitious play approach to large-scale ...

    E-Print Network [OSTI]

    Theodore Lambert

    2004-08-01

    Aug 1, 2004 ... A fictitious play approach to large-scale optimization. Theodore Lambert (tlambert ***at*** tmcc.edu) Marina A. Epelman (mepelman ***at*** ...

  6. Advancing Cellulosic Ethanol for Large Scale Sustainable Transportation

    E-Print Network [OSTI]

    Wyman, C

    2007-01-01

    Advancing Cellulosic Ethanol for Large Scale SustainableHydrogen Batteries Nuclear By Lee Lynd, Dartmouth Ethanol •Ethanol, ethyl alcohol, fermentation ethanol, or just “

  7. Development of Integrated Die Casting Process for Large Thin...

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

    Applications Enabling Production of Lightweight Magnesium Parts for Near-Term Automotive Applications. Most large automobile parts, such as door panels, are made from...

  8. Panel 1, Towards Sustainable Energy Systems: The Role of Large...

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

    Towards sustainable energy systems - The role of large scale hydrogen storage in Germany May 14th, 2014 | Sacramento Political background for the transition to renewable...

  9. Large-Scale Manufacturing of Nanoparticle-Based Lubrication Additives

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

    component failure. Poor lubricant performance can cause significant energy and material losses. The already large global demand for lubricants is expected to continue growing in...

  10. Publisher's Note: "Chiral symmetry restoration at large chemical...

    Office of Scientific and Technical Information (OSTI)

    Publisher's Note: "Chiral symmetry restoration at large chemical potential 2 in strongly coupled SU(N) gauge theories" J. Math. Phys. 54, 122301 (2013) Citation Details...

  11. Towards a Large-Scale Recording System: Demonstration of Polymer...

    Office of Scientific and Technical Information (OSTI)

    Towards a Large-Scale Recording System: Demonstration of Polymer-Based Penetrating Array for Chronic Neural Recording Citation Details In-Document Search Title: Towards a...

  12. Assessing the Stability of Protein Complexes within Large Assemblies

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Assessing the Stability of Protein Complexes within Large Assemblies F. Cazals and T. Dreyfus reconstructions of the Nuclear Pore Complex. 1 Large assemblies and tandem affinity purification data: com- plexes or mixtures? Structural genomics projects, in particular those exploiting Tandem Affinity Purification (TAP

  13. UNSUPERVISED CONDITION CHANGE DETECTION IN LARGE DIESEL ENGINES

    E-Print Network [OSTI]

    UNSUPERVISED CONDITION CHANGE DETECTION IN LARGE DIESEL ENGINES Niels Henrik Pontoppidan and Jan detection in large diesel engines from acoustical emis- sion sensor signal and compared to more classical diesel engines and stationary power plants. The possibility of early detecting small defects prior

  14. Aalborg Universitet FACTS Devices for Large Wind Power Plants

    E-Print Network [OSTI]

    Berning, Torsten

    of wind power has become significant, grid performance and stability is affected [3]-[5]. ThereforeAalborg Universitet FACTS Devices for Large Wind Power Plants Adamczyk, Andrzej Grzegorz., Teodorescu, R., Rodriguez, P., & Mukerjee, R. N. (2010). FACTS Devices for Large Wind Power Plants

  15. CHALLENGES OF INTEGRATING LARGE AMOUNTS OF WIND Jonathan D. Rose

    E-Print Network [OSTI]

    CHALLENGES OF INTEGRATING LARGE AMOUNTS OF WIND POWER Jonathan D. Rose Univ. of Wisconsin ­ Madison and reducing torque shocks caused by wind gusts. However, they absorbed large amounts of reactive power and turbine improvements that make wind energy more grid-compatible to ensure further growth of this promising

  16. POWER SYSTEMS STABILITY WITH LARGE-SCALE WIND POWER PENETRATION

    E-Print Network [OSTI]

    Bak-Jensen, Birgitte

    of offshore wind farms, wind power fluctuations may introduce several challenges to reliable power system behaviour due to natural wind fluctuations. The rapid power fluctuations from the large scale wind farms Generation Control (AGC) system which includes large- scale wind farms for long-term stability simulation

  17. Ris-R-1518(EN) The necessary distance between large

    E-Print Network [OSTI]

    Risø-R-1518(EN) The necessary distance between large wind farms offshore - study Sten Frandsen. As it is often the need for offshore wind farms, the model handles a regular array-geometry with straight rows distance between large wind farms in the offshore environment. The main results are given in Section 1

  18. Materials Availability Expands the Opportunity for Large-Scale

    E-Print Network [OSTI]

    Kammen, Daniel M.

    , 2009. Accepted January 22, 2009. Solar photovoltaics have great promise for a low-carbon future­3). Solar photovoltaics (PV) are frequently cited as a promising but an economically unre- alistic largeMaterials Availability Expands the Opportunity for Large-Scale Photovoltaics Deployment C Y R U S W

  19. Language Requirements for Large-Scale Generic Libraries

    E-Print Network [OSTI]

    Lumsdaine, Andrew

    Language Requirements for Large-Scale Generic Libraries Jeremy Siek and Andrew Lumsdaine {jsiek-scale software libraries. The fundamental principle of generic pro- gramming is the realization of interfaces programming and large-scale libraries. In this paper, we present an overview of G and analyze

  20. Minimal Schemes for Large Neutrino Mixings with Inverted Hierarchy

    E-Print Network [OSTI]

    Duane A. Dicus; Hong-Jian He; John N. Ng

    2002-05-17

    Existing oscillation data point to nonzero neutrino masses with large mixings. We analyze the generic features of the neutrino Majorana mass matrix with inverted hierarchy and construct realistic {\\it minimal schemes} for the neutrino mass matrix that can explain the large (but not maximal) \

  1. Minimization of welding residual stress and distortion in large structures

    E-Print Network [OSTI]

    Michaleris, Panagiotis

    1 Minimization of welding residual stress and distortion in large structures P. Michaleris at Champaign Urbana, Urbana, IL Abstract Welding distortion in large structures is usually caused by buckling due to the residual stress. In cases where the design is fixed and minimum weld size requirements

  2. Large Blood Vessels 1.1 Introduction --The Cardiovascular System

    E-Print Network [OSTI]

    Luo, Xiaoyu

    Chapter 1 Large Blood Vessels 1.1 Introduction -- The Cardiovascular System The heart is a pump vessels, the capillaries, in which the main ex- change processes between the blood and tissues take place- sue, collagen, with a few muscle cells. 3 #12;4 CHAPTER 1. LARGE BLOOD VESSELS Figure 1.1: Structure

  3. STATISTICAL ANALYSIS AND STRUCTURE OPTIMIZATION OF LARGE PHOTOVOLTAIC MODULE

    E-Print Network [OSTI]

    Qiu, Qinru

    STATISTICAL ANALYSIS AND STRUCTURE OPTIMIZATION OF LARGE PHOTOVOLTAIC MODULE RATHEESH R on the output power of large Photovoltaic (PV) module by modeling each PV cell as a current source whose short. Photovoltaic (PV) is a simple and elegant method of harnessing the sun's energy. PV devices (solar cells

  4. Large area 3D helical photonic crystals A. K. Rauba)

    E-Print Network [OSTI]

    New Mexico, University of

    of helical structures (3D photonic crystals) using a simple, parallel, large-area lithography processLarge area 3D helical photonic crystals A. K. Rauba) and S. R. J. Brueckb) Center for High, enabling a high index contrast chiral meta- material. Optical transmission measurements of these helical

  5. Reducing Aviation's Environmental Impact Through Large Aircraft For Short Ranges

    E-Print Network [OSTI]

    Zingg, David W.

    aviation's impact on climate change. Examples include alternative fuels,4,5 blendedReducing Aviation's Environmental Impact Through Large Aircraft For Short Ranges Gaetan K.W Kenway,500 nm. We show that the impact of civil aviation on climate change can be reduced by using large

  6. GRAIL: Scalable Reachability Index for Large Graphs Hilmi Yildirim

    E-Print Network [OSTI]

    Zaki, Mohammed Javeed

    GRAIL: Scalable Reachability Index for Large Graphs Hilmi Yildirim Rensselaer Polytechnic large real-world graphs. We present a very simple, but scalable reachability index, called GRAIL on small graphs, GRAIL is the only index that can scale to millions of nodes and edges. GRAIL has linear

  7. Probabilistic Damage Detection Based on Large Area Electronics Sensing Sheets

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    Probabilistic Damage Detection Based on Large Area Electronics Sensing Sheets Yao Yao and Branko-stage damage detection and characterization requires continuous sensing over large areas of structure are not sensitive to damage. In this research, a probabilistic approach based on Monte Carlo (MC) simulations

  8. Information Delivery in Large Wireless Networks with Minimum Energy Expense

    E-Print Network [OSTI]

    Wang, Wenye

    Information Delivery in Large Wireless Networks with Minimum Energy Expense Yi Xu and Wenye Wang in large-scale multihop wireless networks because of the limited energy supplies from batteries. We and strategies that reduce energy consumption in wireless net- works to extend network lifetimes. Examples

  9. Climate impacts of a large-scale biofuels expansion*

    E-Print Network [OSTI]

    Climate impacts of a large-scale biofuels expansion* Willow Hallgren, C. Adam Schlosser, Erwan impacts of a large-scale biofuels expansion Willow Hallgren,1 C. Adam Schlosser,1 Erwan Monier,1 David March 2013. [1] A global biofuels program will potentially lead to intense pressures on land supply

  10. Large-Scale Eucalyptus Energy Farms and Power Cogeneration1

    E-Print Network [OSTI]

    Large-Scale Eucalyptus Energy Farms and Power Cogeneration1 Robert C. Noronla2 The initiation of a large-scale cogeneration project, especially one that combines construction of the power generation supplemental fuel source must be sought if the cogeneration facility will consume more fuel than

  11. Doctoral Position Aeroelastic Analysis of Large Wind Turbines

    E-Print Network [OSTI]

    Doctoral Position Aeroelastic Analysis of Large Wind Turbines In the research project "Aeroelastic Analysis Horizontal-axis wind turbine and numerical model. of Large Wind Turbines" funded by the Ger- man involving the in-house Finite-Element CFD code XNS to enable the simulation of wind turbines. The ability

  12. Detection and Classification of Ash Dieback on Large-Scale

    E-Print Network [OSTI]

    Detection and Classification of Ash Dieback on Large-Scale Color Aerial Photographs Ralph J of Agriculture 1966 #12;Croxton, Ralph J. 1966. Detection and classification of ash dieback on large- scale. Forest Serv. Res. Paper PSW-35) Aerial color photographs were taken at two scales over ash stands in New

  13. Hi-LION: Hierarchical Large-Scale Interconnection Optical Network

    E-Print Network [OSTI]

    Yoo, S. J. Ben

    Hi-LION: Hierarchical Large-Scale Interconnection Optical Network With AWGRs [Invited] Zheng Cao, Roberto Proietti, and S. J. B. Yoo Abstract--This paper proposes Hi-LION, a hierarchical large wavelength routing property of AWGRs together with electrical switching inside the processors, Hi-LION can

  14. Large Deformation of Nitinol Under Shear Dominant Loading

    E-Print Network [OSTI]

    Daly, Samantha

    Large Deformation of Nitinol Under Shear Dominant Loading S. Daly & D. Rittel & K. Bhattacharya & G in Nitinol under large shear- dominated deformation are presented. To achieve a shear- dominated deformation transformation that is seen in uniaxial testing. The shear-dominant deformation of Nitinol in the plastic regime

  15. Large Deformation of Nitinol Under Shear Dominant Loading

    E-Print Network [OSTI]

    Bhattacharya, Kaushik

    Large Deformation of Nitinol Under Shear Dominant Loading S. Daly & D. Rittel & K. Bhattacharya & G Abstract Full-field quantitative strain maps of phase transformation and plasticity in Nitinol under large that is seen in uniaxial testing. The shear-dominant deformation of Nitinol in the plastic regime exhibits low

  16. Engineering analyses of large precision cathode strip chambers for GEM

    SciTech Connect (OSTI)

    Horvath, J.A.; Belser, F.C.; Pratuch, S.M.; Wuest, C.R. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); Mitselmakher, G. [Superconducting Super Collider Lab., Dallas, TX (United States)] [Superconducting Super Collider Lab., Dallas, TX (United States); Gordeev, A. [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation)] [Institute of Theoretical and Experimental Physics, Moscow (Russian Federation); Johnson, C.V. [Lawrence Livermore National Lab., CA (United States)] [Lawrence Livermore National Lab., CA (United States); [Superconducting Super Collider Lab., Dallas, TX (United States); Polychronakos, V.A. [Brookhaven National Lab., Upton, NY (United States)] [Brookhaven National Lab., Upton, NY (United States); Golutvin, I.A. [Joint Institute for Nuclear Research, Dubna (Russian Federation)] [Joint Institute for Nuclear Research, Dubna (Russian Federation)

    1993-10-21

    Structural analyses of large precision cathode strip chambers performed up to the date of this publication are documented. Mechanical property data for typical chamber materials are included. This information, originally intended to be an appendix to the {open_quotes}CSC Structural Design Bible,{close_quotes} is presented as a guide for future designers of large chambers.

  17. Markov Chain Analysis for Large-Scale Grid Systems

    E-Print Network [OSTI]

    Markov Chain Analysis for Large-Scale Grid Systems Christopher Dabrowski Fern Hunt NISTIR 7566 #12;2 #12;3 NISTIR 7566 Markov Chain Analysis for Large-Scale Grid Systems Christopher Dabrowski Software and Systems Division Information Technology Laboratory National Institute of Standards and Technology

  18. Scaling relations for molecular gas in the Large Magellanic Cloud

    E-Print Network [OSTI]

    Hardcastle, Martin

    Scaling relations for molecular gas in the Large Magellanic Cloud By A r t o H e i kk i l ¨a e (virial mass versus CO luminosity, luminosity versus size, linewidth versus size) for molecular clouds in the 30 Dor and N 159 regions in the Large Magel­ lanic Cloud. The analysis is based on CO J = 1 ! 0

  19. Lessons from Large-Scale Renewable Energy Integration Studies: Preprint

    SciTech Connect (OSTI)

    Bird, L.; Milligan, M.

    2012-06-01

    In general, large-scale integration studies in Europe and the United States find that high penetrations of renewable generation are technically feasible with operational changes and increased access to transmission. This paper describes other key findings such as the need for fast markets, large balancing areas, system flexibility, and the use of advanced forecasting.

  20. Sustainability of Very Large Photovoltaic DeploymentSustainability of Very Large Photovoltaic Deployment email: vmf5@columbia.edu

    E-Print Network [OSTI]

    Ohta, Shigemi

    Criteria Low Cost Resource Availability Lowest Environmental Impact Affordability in a competitive world Te: Research Areas #12;7 Life Cycle Environmental ImpactsLife Cycle Environmental Impacts Raw Material1 Sustainability of Very Large Photovoltaic DeploymentSustainability of Very Large Photovoltaic

  1. Structural Analysis of LargeStructural Analysis of Large Caliber Hybrid Ceramic/SteelCaliber Hybrid Ceramic/Steel

    E-Print Network [OSTI]

    Grujicic, Mica

    Structural Analysis of LargeStructural Analysis of Large Caliber Hybrid Ceramic/SteelCaliber Hybrid Ceramic/Steel Gun BarrelsGun Barrels MS ThesisMS Thesis Jon DeLongJon DeLong Department of Mechanical ·Merger of ceramics into the conventional steel gun barrel design ·Use of a probabilistic structural

  2. Stabilization of Large Scale Structure by Adhesive Gravitational Clustering

    E-Print Network [OSTI]

    Thomas Buchert

    1999-08-13

    The interplay between gravitational and dispersive forces in a multi-streamed medium leads to an effect which is exposed in the present note as the genuine driving force of stabilization of large-scale structure. The conception of `adhesive gravitational clustering' is advanced to interlock the fairly well-understood epoch of formation of large-scale structure and the onset of virialization into objects that are dynamically in equilibrium with their large-scale structure environment. The classical `adhesion model' is opposed to a class of more general models traced from the physical origin of adhesion in kinetic theory.

  3. Manufacturing process to reduce large grain growth in zirconium alloys

    DOE Patents [OSTI]

    Rosecrans, P.M.

    1984-08-01

    It is an object of the present invention to provide a procedure for desensitizing zirconium-based alloys to large grain growth (LGG) during thermal treatment above the recrystallization temperature of the alloy. It is a further object of the present invention to provide a method for treating zirconium-based alloys which have been cold-worked in the range of 2 to 8% strain to reduce large grain growth. It is another object of the present invention to provide a method for fabricating a zirconium alloy clad nuclear fuel element wherein the zirconium clad is resistant to large grain growth.

  4. Orientation Estimation for Multiple Large Fractures by Scattering Energy

    E-Print Network [OSTI]

    Zhang, Yang

    2006-01-01

    We have done the numerical modeling of seismic response to multiple sets of vertical large fractures by using finite-difference method (FD), which can easily handle media with monoclinic anisotropy. We consider three types ...

  5. Evaluating the SDN control traffic in large ISP networks

    E-Print Network [OSTI]

    the benign "ecosystem" of a large datacenter, where the network design is simplified by the adoption networks could lead to rethink the WAN as a kind of distributed datacenter. Many solutions have been

  6. Duct Leakage Impacts on VAV System Performance in California Large

    E-Print Network [OSTI]

    LBNL-53605 Duct Leakage Impacts on VAV System Performance in California Large Commercial Buildings and for implementing the duct models in a form that could readily be used in this project; and Brian Smith (LBNL

  7. Finding Large Aperture Fractures in Geothermal Resource Areas...

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

    A Three-Component Long-Offset Surface Seismic Survey, PSInSAR, and Kinematic Analysis Finding Large Aperture Fractures in Geothermal Resource Areas Using A Three-Component...

  8. Bonsai: a philosophy for efficient exhaustion of large sparse spaces 

    E-Print Network [OSTI]

    Nguyen, Phuong-Anh Nguyet

    1995-01-01

    This thesis introduces the Bonsai technique which can efficiently improve the identification of large nonsolution spaces in the search space. The technique can make exponential improvements in the reduction of the search space using a linear method...

  9. GIS Framework for Large River Geomorphic Classification to Aid...

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

    GIS Framework for Large River Geomorphic Classification to Aid in the Evaluation of Flow-Ecology Relationships CR Vernon EV Arntzen MC Richmond RA McManamay 1 TP Hanrahan CL...

  10. How Three Retail Buyers Source Large-Scale Solar Electricity

    Broader source: Energy.gov [DOE]

    Large-scale, non-utility solar power purchase agreements (PPAs) are still a rarity despite the growing popularity of PPAs across the country. In this webinar, participants will learn more about how...

  11. LARGE-SCALE CORONAL PROPAGATING FRONTS IN SOLAR ERUPTIONS AS...

    Office of Scientific and Technical Information (OSTI)

    LARGE-SCALE CORONAL PROPAGATING FRONTS IN SOLAR ERUPTIONS AS OBSERVED BY THE ATMOSPHERIC IMAGING ASSEMBLY ON BOARD THE SOLAR DYNAMICS OBSERVATORY-AN ENSEMBLE STUDY Re-direct...

  12. Vacuum gaps with small tunnel currents at large electric field...

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

    Vacuum gaps with small tunnel currents at large electric field and its potential applications for energy storage, charge storage and power supplies. Friday, May 27, 2011 - 4:00pm...

  13. Non-traditional growth in large, established firms

    E-Print Network [OSTI]

    Sunderrajan, Suresh, 1970-

    2004-01-01

    Firms must continuously strive to grow through the creation of new sources of competitive advantage. The challenges to growth are more severe for large, established firms that derive a predominant amount of their present ...

  14. Surrogate modeling for large-scale black-box systems

    E-Print Network [OSTI]

    Liem, Rhea Patricia

    2007-01-01

    This research introduces a systematic method to reduce the complexity of large-scale blackbox systems for which the governing equations are unavailable. For such systems, surrogate models are critical for many applications, ...

  15. Fail Safe Design for Large Capacity Lithium-ion Batteries

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

    Fail Safe Design for Large Capacity Lithium-ion Batteries NREL Commercialization & Tech Transfer Webinar March 27, 2011 Gi-Heon Kim gi-heon.kim@nrel.gov John Ireland, Kyu-Jin Lee,...

  16. Building America Webinar: Opportunities in Large Data Collection and Analysis

    Broader source: Energy.gov [DOE]

    The webinar focused on specific Building America projects that are looking to gather and analyze large bodies of data on new and existing homes, and will feature opportunities for industry to collaborate with researchers to gather and analyze valuable data.

  17. Glendale Water and Power- Large Business Energy Efficiency Program

    Broader source: Energy.gov [DOE]

    Glendale Water and Power (GWP) offers a rebate to its medium and large business customers with electric bills of more than $3000 per month (electric usage of 250,000 kWh annually ~ $36,000 per year...

  18. Authoring Large and Complex Hypertext with Reusable Components 

    E-Print Network [OSTI]

    Park, Yung Ah

    2011-10-21

    from Petri net theory to select, categorize, and modify existing net fragments as building blocks for composing larger networks. Authors may switch modes between visual and textual authoring at will, thus combining the strengths of expressing large nets...

  19. An Integrated Air Handling Unit System for Large Commercial Buildings 

    E-Print Network [OSTI]

    Song, L.; Liu, M.

    2001-01-01

    This paper presents an integrated air handling unit system (OAHU) for large commercial buildings. The system introduces outside air into the interior section and circulates the return air to the exterior section. Detailed analytical models...

  20. Measuring Large Optical Transmission Matrices of Disordered Media

    E-Print Network [OSTI]

    Yu, Hyeonseung

    We report a measurement of the large optical transmission matrix (TM) of a complex turbid medium. The TM is acquired using polarization-sensitive, full-field interferometric microscopy equipped with a rotating galvanometer ...