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1

Turbulent combustion  

SciTech Connect (OSTI)

Turbulent combustion is the dominant process in heat and power generating systems. Its most significant aspect is to enhance the burning rate and volumetric power density. Turbulent mixing, however, also influences the chemical rates and has a direct effect on the formation of pollutants, flame ignition and extinction. Therefore, research and development of modern combustion systems for power generation, waste incineration and material synthesis must rely on a fundamental understanding of the physical effect of turbulence on combustion to develop theoretical models that can be used as design tools. The overall objective of this program is to investigate, primarily experimentally, the interaction and coupling between turbulence and combustion. These processes are complex and are characterized by scalar and velocity fluctuations with time and length scales spanning several orders of magnitude. They are also influenced by the so-called {open_quotes}field{close_quotes} effects associated with the characteristics of the flow and burner geometries. The authors` approach is to gain a fundamental understanding by investigating idealized laboratory flames. Laboratory flames are amenable to detailed interrogation by laser diagnostics and their flow geometries are chosen to simplify numerical modeling and simulations and to facilitate comparison between experiments and theory.

Talbot, L.; Cheng, R.K. [Lawrence Berkeley Laboratory, CA (United States)

1993-12-01T23:59:59.000Z

2

Petascale Simulations of Turbulent Nuclear Combustion | Argonne Leadership  

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

Flame Bubble in an Open Computational Domain for Constant Flame Speed, Gravitational Acceleration, and Changing Density Flame Bubble in an Open Computational Domain for Constant Flame Speed, Gravitational Acceleration, and Changing Density This image is from the simulation "Flame Bubble in an Open Computational Domain for Constant Flame Speed, Gravitational Acceleration, and Changing Density." Science: Ray Bair, Katherine Riley, Argonne National Laboratory; Anshu Dubey, Don Lamb, Dongwook Lee, University of Chicago; Robert Fisher, University of Massachusetts at Dartmouth and Dean Townsley, University of Alabama; Visualization: Jonathan Gallagher, University of Chicago; Randy Hudson, John Norris, and Michael E. Papka, Argonne National Laboratory/University of Chicago Petascale Simulations of Turbulent Nuclear Combustion PI Name: Don Lamb PI Email: lamb@oddjob.uchicago.edu

3

Preparing for Mira: experience with FLASH multiphysics simulations - Petascale Simulations of Turbulent Nuclear Combustion  

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

Code Code changes Optimization Performance Conclusion Preparing for Mira: experience with FLASH multiphysics simulations Petascale Simulations of Turbulent Nuclear Combustion Christopher Daley 1 2 1 The Flash Center for Computational Science at the University of Chicago 2 Argonne National Laboratory March 7, 2013 1 / 30 Outline Introduction Code changes Optimization Performance Conclusion 1 Introduction 2 Code changes Updating FLASH for BG/Q 3 Optimization Initialization Evolution 4 Performance Best FLASH configuration Scaling and hardware counter data 5 Conclusion 2 / 30 Outline Introduction Code changes Optimization Performance Conclusion Science objectives To improve our understanding of the explosion mechanism of Type Ia Supernova Simulate two key physical processes with the FLASH code: 1 Buoyancy-driven turbulent nuclear combustion Determines the amount of nuclear

4

Assessment of Combustion and Turbulence Models for the Simulation...  

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

Combustion and Turbulence Models for the Simulation of Combustion Processes in a DI Diesel Engine Assessment of Combustion and Turbulence Models for the Simulation of Combustion...

5

Reaction and diffusion in turbulent combustion  

SciTech Connect (OSTI)

The motivation for this project is the need to obtain a better quantitative understanding of the technologically-important phenomenon of turbulent combustion. In nearly all applications in which fuel is burned-for example, fossil-fuel power plants, furnaces, gas-turbines and internal-combustion engines-the combustion takes place in a turbulent flow. Designers continually demand more quantitative information about this phenomenon-in the form of turbulent combustion models-so that they can design equipment with increased efficiency and decreased environmental impact. For some time the PI has been developing a class of turbulent combustion models known as PDF methods. These methods have the important virtue that both convection and reaction can be treated without turbulence-modelling assumptions. However, a mixing model is required to account for the effects of molecular diffusion. Currently, the available mixing models are known to have some significant defects. The major motivation of the project is to seek a better understanding of molecular diffusion in turbulent reactive flows, and hence to develop a better mixing model.

Pope, S.B. [Mechanical and Aerospace Engineering, Ithaca, NY (United States)

1993-12-01T23:59:59.000Z

6

Four Lectures on Turbulent Combustion  

E-Print Network [OSTI]

, combustion in a Diesel engine or in furnaces essentially taakes place under non-premixed conditions. In the Diesel engine a liquid fuel spray is injected into hot compressed air, the fuel evaporates and mixes combustion are in general subdivided into two classes: premixed or non-premixed combustion. For example

Peters, Norbert

7

Turbulent Combustion in SDF Explosions  

SciTech Connect (OSTI)

A heterogeneous continuum model is proposed to describe the dispersion and combustion of an aluminum particle cloud in an explosion. It combines the gas-dynamic conservation laws for the gas phase with a continuum model for the dispersed phase, as formulated by Nigmatulin. Inter-phase mass, momentum and energy exchange are prescribed by phenomenological models. It incorporates a combustion model based on the mass conservation laws for fuel, air and products; source/sink terms are treated in the fast-chemistry limit appropriate for such gasdynamic fields, along with a model for mass transfer from the particle phase to the gas. The model takes into account both the afterburning of the detonation products of the C-4 booster with air, and the combustion of the Al particles with air. The model equations were integrated by high-order Godunov schemes for both the gas and particle phases. Numerical simulations of the explosion fields from 1.5-g Shock-Dispersed-Fuel (SDF) charge in a 6.6 liter calorimeter were used to validate the combustion model. Then the model was applied to 10-kg Al-SDF explosions in a an unconfined height-of-burst explosion. Computed pressure histories are compared with measured waveforms. Differences are caused by physical-chemical kinetic effects of particle combustion which induce ignition delays in the initial reactive blast wave and quenching of reactions at late times. Current simulations give initial insights into such modeling issues.

Kuhl, A L; Bell, J B; Beckner, V E

2009-11-12T23:59:59.000Z

8

Turbulence-Chemistry Interaction in Lean Premixed Hydrogen Combustion  

E-Print Network [OSTI]

Turbulence-Chemistry Interaction in Lean Premixed Hydrogen Combustion A. J. Aspden1,2 , M. S. Day2 between fuel consumption and heat release. Keywords: turbulent premixed combustion, low Mach number flow or hydrogen-rich mixtures obtained from gasi- fication of coal or biomass. These types of fuels provide clean

Bell, John B.

9

Assessment of Combustion and Turbulence Models for the Simulation of Combustion Processes in a DI Diesel Engine  

Broader source: Energy.gov [DOE]

Various applied combustion and turbulence models were investigated along with chemical kinetic mechanisms simulating a biodiesel-fueled engine

10

Simulation of lean premixed turbulent combustion  

E-Print Network [OSTI]

combustion systems that can burn fuels such as hydrogen or syngas.syngas, which is obtained from coal gasi?cation. E?ective utilization of these fuels requires combustion

2008-01-01T23:59:59.000Z

11

LES Simulations of Turbulent Combustion in a Type Ia Supernovae  

E-Print Network [OSTI]

to be thermonuclear explosions of white dwarfs. SNIa are important sources of energy and chemical elements deposited of the burning are all determined by the speed of thermonuclear burning [27]. The problem of turbulent combustion. The mechanism and the speed of thermonuclear burning in SNIa remain an unsolved theoretical problem. A recent

New York at Stoney Brook, State University of

12

A spray-suppression model for turbulent combustion  

SciTech Connect (OSTI)

A spray-suppression model that captures the effects of liquid suppressant on a turbulent combusting flow is developed and applied to a turbulent diffusion flame with water spray suppression. The spray submodel is based on a stochastic separated flow approach that accounts for the transport and evaporation of liquid droplets. Flame extinguishment is accounted for by using a perfectly stirred reactor (PSR) submodel of turbulent combustion. PSR pre-calculations of flame extinction times are determined using CHEMKIN and are compared to local turbulent time scales of the flow to determine if local flame extinguishment has occurred. The PSR flame extinguishment and spray submodels are incorporated into Sandia's flow fire simulation code, VULCAN, and cases are run for the water spray suppression studies of McCaffrey for turbulent hydrogen-air jet diffusion flames. Predictions of flame temperature decrease and suppression efficiency are compared to experimental data as a function of water mass loading using three assumed values of drop sizes. The results show that the suppression efficiency is highly dependent on the initial droplet size for a given mass loading. A predicted optimal suppression efficiency was observed for the smallest class of droplets while the larger drops show increasing suppression efficiency with increasing mass loading for the range of mass loadings considered. Qualitative agreement to the experiment of suppression efficiency is encouraging, however quantitative agreement is limited due to the uncertainties in the boundary conditions of the experimental data for the water spray.

DESJARDIN,PAUL E.; TIESZEN,SHELDON R.; GRITZO,LOUIS A.

2000-02-14T23:59:59.000Z

13

Assessment of combustion submodels for turbulent nonpremixed hydrocarbon flames  

Science Journals Connector (OSTI)

Data bases generated by direct numerical simulation (DNS) of nonpremixed combustion are used to evaluate stationary laminar flamelet and conditional moment closure (CMC) models of turbulent combustion. The chemical kinetics used for the simulation and modeling is a systematically reduced two-step mechanism for hydrocarbon combustion. Heat release effects on the chemistry are included but a constant density assumption is used. Three different Reynolds numbers and a range of Damköhler numbers are considered. Two different versions of stationary laminar flamelet models are considered. In one version, the instantaneous turbulent scalar dissipation rate at stoichiometry is used to match the laminar flamelets, whereas in another version the conditional average of scalar dissipation at stoichiometry is used. In the CMC calculations, turbulent mixing is modelled by a presumed beta function pdf with the mixture fraction variance being the only input quantity and this is obtained from the DNS. CMC predictions of major and minor species are excellent and are always within 6% despite the presence of some local extinction. Both versions of flamelet models predict the major species with much less accuracy than this. The minor species predictions, and hence the reaction rate predictions, are even less accurate.

N. Swaminathan; R.W. Bilger

1999-01-01T23:59:59.000Z

14

Gasdynamic Model of Turbulent Combustion in TNT Explosions  

SciTech Connect (OSTI)

A model is proposed to simulate turbulent combustion in confined TNT explosions. It is based on: (i) the multi-component gasdynamic conservation laws, (ii) a fast-chemistry model for TNT-air combustion, (iii) a thermodynamic model for frozen reactants and equilibrium products, (iv) a high-order Godunov scheme providing a non-diffusive solution of the governing equations, and (v) an ILES approach whereby adaptive mesh refinement is used to capture the energy bearing scales of the turbulence on the grid. Three-dimensional numerical simulations of explosion fields from 1.5-g PETN/TNT charges were performed. Explosions in six different chambers were studied: three calorimeters (volumes of 6.6-l, 21.2-l and 40.5-l with L/D = 1), and three tunnels (L/D = 3.8, 4.65 and 12.5 with volumes of 6.3-l) - to investigate the influence of chamber volume and geometry on the combustion process. Predicted pressures histories were quite similar to measured pressure histories for all cases studied. Experimentally, mass fraction of products, Y{sub p}{sup exp}, reached a peak value of 88% at an excess air ratio of twice stoichiometric, and then decayed with increasing air dilution; mass fractions Y{sub p}{sup calc} computed from the numerical simulations followed similar trends. Based on this agreement, we conclude that the dominant effect that controls the rate of TNT combustion with air is the turbulent mixing rate; the ILES approach along with the fast-chemistry model used here adequately captures this effect.

Kuhl, A L; Bell, J B; Beckner, V E

2010-01-08T23:59:59.000Z

15

SYMPOSIUM ON TURBULENCE AND COMBUSTION - SPECIAL SYMPOSIUM TO BRING TOGETHER TOP RESEARCHERS IN THE FIELDS OF FLUID TURBULENCE AND COMBUSTION TO PROMOTE ADVANCES IN TURBULENT, REACTING FLOWS  

SciTech Connect (OSTI)

A Symposium on Turbulence and Combustion was held at Cornell University on August 3-4, 2009. The overall goal of the Symposium was to promote future advances in the study of turbulence and combustion, through an unique forum intended to foster interactions between leading members of these two research communities. The Symposium program consisted of twelve invited lectures given by world-class experts in these fields, two poster sessions consisting of nearly 50 presentations, an open forum, and other informal activities designed to foster discussion. Topics covered in the lectures included turbulent dispersion, wall-bounded flows, mixing, finite-rate chemistry, and others, using experiment, modeling, and computations, and included perspectives from an international community of leading researchers from academia, national laboratories, and industry.

Caughey, David

2010-10-08T23:59:59.000Z

16

Accepted, Nuclear Fusion, 1999 Turbulent Transport and Turbulence in Radiative I-Mode Plasmas in  

E-Print Network [OSTI]

Accepted, Nuclear Fusion, 1999 Turbulent Transport and Turbulence in Radiative I-Mode Plasmas of Physics University of Alberta Edmonton, Alberta Canada, T6G 2J1 1/4/00 17:25 PM #12;Accepted, Nuclear Fusion, 1999 1 Abstract First measurements of turbulence levels and turbulence-induced transport

California at San Diego, University of

17

Simulation of coal combustion by AUSM turbulence-chemistry char combustion model and a full two-fluid model  

Science Journals Connector (OSTI)

An algebraic unified second-order moment (AUSM) turbulence-chemistry model of char combustion is introduced in this paper, to calculate the effect of particle temperature fluctuation on char combustion. The AUSM model is used to simulate gas-particle flows, in coal combustion in a pulverized coal combustor, together with a full two-fluid model for reacting gas-particle flows and coal combustion, including the sub-models as the k-?-kp two-phase turbulence model, the EBU-Arrhenius volatile and CO combustion model, and the six-flux radiation model. A new method for calculating particle mass flow rate is also used in this model to correct particle outflow rate and mass flow rate for inside sections, which can obey the principle of mass conservation for the particle phase and can also speed up the iterating convergence of the computation procedure effectively. The simulation results indicate that, the AUSM char combustion model is more preferable to the old char combustion model, since the later totally eliminate the influence of particle temperature fluctuation on char combustion rate.

Yu Zhang; Xiao-Lin Wei; Li-Xing Zhou; Hong-Zhi Sheng

2005-01-01T23:59:59.000Z

18

Visual Exploration of Turbulent Combustion and Laser-Wakefield Accelerator Simulations  

E-Print Network [OSTI]

hydrogen flames under different levels of turbulence ­ Lean combustion reduces emissions Important-dependent, difficult to characterize) · Scientific Goal: ­ Understanding the temporal evolution of burning cells Simulations 4 Feature Tracking in Combustion Simulations · Isotherm represents "flame surface" · Fuel

19

Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry  

SciTech Connect (OSTI)

The TSTC project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of our approach is direct numerical simulation (DNS) featuring highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a useful tool for development of sub-models needed in device-level simulations. The code named S3D, developed and shared with Chen and coworkers at Sandia National Laboratories, has been enhanced with new numerical algorithms and physical models to provide predictive capabilities for spray dynamics, combustion, and pollutant formation processes in turbulent combustion. Major accomplishments include improved characteristic boundary conditions, fundamental studies of auto-ignition in turbulent stratified reactant mixtures, flame-wall interaction, and turbulent flame extinction by water spray. The overarching scientific issue in our recent investigations is to characterize criticality phenomena (ignition/extinction) in turbulent combustion, thereby developing unified criteria to identify ignition and extinction conditions. The computational development under TSTC has enabled the recent large-scale 3D turbulent combustion simulations conducted at Sandia National Laboratories.

Hong G. Im; Arnaud Trouve; Christopher J. Rutland; Jacqueline H. Chen

2009-02-02T23:59:59.000Z

20

Influence of turbulence–chemical interaction on CFD pulverized coal MILD combustion modeling  

Science Journals Connector (OSTI)

MILD (Moderate and Intensive Low oxygen Dilution) combustion is a novel approach to reducing \\{NOx\\} emissions and improving combustion efficiency in fossil fuels power plants. It is characterized by elevated temperature and high dilution of reactants and strong recirculation inside the combustion chamber which produce a low temperature increase, thus reducing \\{NOx\\} formation. The main differences with conventional combustion concern the chemical reactions that take place in almost the entire volume of the combustion chamber and the uniformity of both temperature and the chemical species concentration. For this reason advanced turbulence-chemistry interaction models with detailed kinetic mechanisms are required to accurately simulate MILD by means of CFD calculations. The main aim of this work is to deepen the influence of turbulence-chemistry interaction on pulverized coal MILD combustion and to understand which models are more accurate and suitable to reproduce the process. In particular, two turbulence-chemistry interaction models are analyzed. On one hand, a conventional model based on infinitely fast chemistry Eddy Dissipation Model with a two-step global kinetic mechanism is considered. On the other hand, an advanced model based on finite rate chemistry Eddy Dissipation Concept is considered and used with both a global and detailed kinetic mechanisms. The results are finally compared with an experimental test-case. From the comparison, advanced turbulence-chemistry models used with complex kinetic mechanisms give, as expected, the best agreement with numerical results, despite the higher computational resources required.

M. Vascellari; G. Cau

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


21

Terascale High-Fidelity Simulations of Turbulent Combustion with Detailed Chemistry: Spray Simulations  

SciTech Connect (OSTI)

The Terascale High-Fidelity Simulations of Turbulent Combustion (TSTC) project is a multi-university collaborative effort to develop a high-fidelity turbulent reacting flow simulation capability utilizing terascale, massively parallel computer technology. The main paradigm of the approach is direct numerical simulation (DNS) featuring the highest temporal and spatial accuracy, allowing quantitative observations of the fine-scale physics found in turbulent reacting flows as well as providing a useful tool for development of sub-models needed in device-level simulations. Under this component of the TSTC program the simulation code named S3D, developed and shared with coworkers at Sandia National Laboratories, has been enhanced with new numerical algorithms and physical models to provide predictive capabilities for turbulent liquid fuel spray dynamics. Major accomplishments include improved fundamental understanding of mixing and auto-ignition in multi-phase turbulent reactant mixtures and turbulent fuel injection spray jets.

Rutland, Christopher J.

2009-04-26T23:59:59.000Z

22

A filter-independent model identification technique for turbulent combustion modeling  

E-Print Network [OSTI]

A filter-independent model identification technique for turbulent combustion modeling Amir Biglari, James C. Sutherland University of Utah, The Institute for Clean and Secure Energy, 155 South, 1452 East, Room 350, Salt Lake City, UT 84112, USA a r t i c l e i n f o Article history: Received 24 June 2011

23

Simulation of swirling coal combustion using a full two-fluid model and an AUSM turbulence-chemistry model?  

Science Journals Connector (OSTI)

A full two-fluid model of reacting gas-particle flows with an algebraic unified second-order moment turbulence-chemistry model for the turbulent reaction rate of NO formation are used to simulate swirling coal combustion. The sub-models are the k–?–kp two-phase turbulence model, the EBU–Arrhenius volatile and CO combustion model, the six-flux radiation model, coal devolatilization model and char combustion model. The prediction results are in good agreement with the experimental results taken from references.

L.X. Zhou; Y. Zhang; J. Zhang

2003-01-01T23:59:59.000Z

24

Evaluation of a reduced mechanism for turbulent premixed combustion  

E-Print Network [OSTI]

of chemical kinetics will be required to make gen- eral strides on the development of combustion sub-models for optimal design of future engines and fuels. The DNS of combusting flows in archetypical configurations with detailed chemistry and molecular... -Stirred Reactor (PSR) with the 49-reaction skeletal mechanism in Table 2 were used as input to CARM. This reduced mechanism is written as: đ1Ţ O2 ţH2Oţ 3CO ) 2Hţ 3CO2 đ2Ţ CO2 ţH2 ) H2Oţ CO đ3Ţ 2Hţ CO2 ) H2Oţ CO 2 2 2 2 7 H + O2 + N2 = HO2 + N2 2.535E+19 #2...

Nikolaou, Zacharias M.; Swaminathan, Nedunchezhian; Chen, Jyh-Yuan

2014-07-21T23:59:59.000Z

25

Numerical simulation of air/H2 combustion processes in a scramjet turbulent flow  

Science Journals Connector (OSTI)

The aim of this work is to develop a numerical approach, based on the Favre's averaged Navier-Stokes equations coupled with a turbulence model and with a complex finite rate Air/Hydrogen combustion kinetic model to simulate the unsteady axisymetric supersonic hydrogen-air mixing processes. The main application is dedicated to the scramjet hypersonic air-breathing propulsion engine. To achieve this goal the Spalart-Allmaras turbulence model (SA) with correction terms to model the compressibility effects and the complete finite rate chemistry model of Jachimowsky involving 13 species and 153 reactions have been implemented in a finite volume code.

Y. Burtschell; S. Seror; J.D. Parisse; D. Zeitoun

2008-01-01T23:59:59.000Z

26

Combustion Simulations [Heat Transfer and Fluid Mechanics] - Nuclear  

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

Combustion Simulations Combustion Simulations Capabilities Engineering Computation and Design Engineering and Structural Mechanics Systems/Component Design, Engineering and Drafting Heat Transfer and Fluid Mechanics Overview Thermal Hydraulic Optimization of Nuclear Systems Underhood Thermal Management Combustion Simulations Advanced Model and Methodology Development Multi-physics Reactor Performance and Safety Simulations Other Capabilities Work with Argonne Contact us For Employees Site Map Help Join us on Facebook Follow us on Twitter NE on Flickr Heat Transfer and Fluid Mechanics Bookmark and Share Combustion Simulations Density Distribution of Spray in Near-Injector Region Density Distribution of Spray in Near-Injector Region. Click on image to view larger image. Development of computer models based on Front-Tracking and

27

Uncertainty quantification of cinematic imaging for development of predictive simulations of turbulent combustion.  

SciTech Connect (OSTI)

Recent advances in high frame rate complementary metal-oxide-semiconductor (CMOS) cameras coupled with high repetition rate lasers have enabled laser-based imaging measurements of the temporal evolution of turbulent reacting flows. This measurement capability provides new opportunities for understanding the dynamics of turbulence-chemistry interactions, which is necessary for developing predictive simulations of turbulent combustion. However, quantitative imaging measurements using high frame rate CMOS cameras require careful characterization of the their noise, non-linear response, and variations in this response from pixel to pixel. We develop a noise model and calibration tools to mitigate these problems and to enable quantitative use of CMOS cameras. We have demonstrated proof of principle for image de-noising using both wavelet methods and Bayesian inference. The results offer new approaches for quantitative interpretation of imaging measurements from noisy data acquired with non-linear detectors. These approaches are potentially useful in many areas of scientific research that rely on quantitative imaging measurements.

Lawson, Matthew; Debusschere, Bert J.; Najm, Habib N.; Sargsyan, Khachik; Frank, Jonathan H.

2010-09-01T23:59:59.000Z

28

Terascale direct numerical simulations of turbulent combustion using S3D This article has been downloaded from IOPscience. Please scroll down to see the full text article.  

E-Print Network [OSTI]

-neutral biofuels, and burn in new combustion regimes that will attain high efficiency while minimizing emissions mechanisms in a lifted turbulent hydrogen/air jet flame in a hot air coflow, and the flame structure of a fuel-lean turbulent premixed jet flame. Computing at this scale requires close collaborations between

Kuzmanovic, Aleksandar

29

A Topological Framework for the Interactive Exploration of Large Scale Turbulent Combustion  

E-Print Network [OSTI]

qualitative and quantitative in- sights into the dynamics of the combustion process. 1 Introduction High

Knowles, David William

30

Paradigms in turbulent combustion research R.W. Bilgera,*, S.B. Popeb  

E-Print Network [OSTI]

at a fundamental level with the problems of combustion processes in engines (spark-igni- tion, diesel, gas then in combustion development. He cites the discovery of lead tetraethyl as an anti- knock additive after

31

Flow, Turbulence and Combustion 62: 295333, 1999. 1999 Kluwer Academic Publishers. Printed in the Netherlands.  

E-Print Network [OSTI]

in the Netherlands. 295 Application of PDF Modeling to Swirling and Nonswirling Turbulent Jets P.R. VAN SLOOTEN

32

Flow, Turbulence and Combustion 70: 153181, 2003. 2003 Kluwer Academic Publishers. Printed in the Netherlands.  

E-Print Network [OSTI]

in the Netherlands. 153 On Fokker­Planck Equations for Turbulent Reacting Flows. Part 2. Filter Density Function

Heinz, Stefan

33

Flow, Turbulence and Combustion 70: 115152, 2003. 2003 Kluwer Academic Publishers. Printed in the Netherlands.  

E-Print Network [OSTI]

in the Netherlands. 115 On Fokker-Planck Equations for Turbulent Reacting Flows. Part 1. Probability Density Function

Heinz, Stefan

34

Towards predicting dynamics in turbulent premixed combustion using PIV-PLIF measurements of flow-flame microstructure  

E-Print Network [OSTI]

Combustion dynamics are critical to the development of high-efficiency, low-emission and fuel-flexible combustion systems used for propulsion and power generation. Predicting the onset of dynamics remains a challenge because ...

Hong, Seung Hyuck

2014-01-01T23:59:59.000Z

35

Turbulence  

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

Turbulence Turbulence in Alcator C-Mod and Wendelstein 7-AS plasmas during controlled confinement transitions N.P.Basse, E.M.Edlund, C.L.Fiore, M.J.Greenwald, A.E.Hubbard, J.W.Hughes, J.H.Irby, G.J.Kramer 1 , L.Lin, Y.Lin, A.G.Lynn 2 , E.S.Marmar, D.R.Mikkelsen 1 , D.Mossessian, P.E.Phillips 2 , M.Porkolab, J.E.Rice, W.L.Rowan 2 , J.A.Snipes, J.L.Terry, S.M.Wolfe, S.J.Wukitch, K.Zhurovich, S.Zoletnik 3 and the C-Mod and W7-AS 4 Teams MIT Plasma Science and Fusion Center, Cambridge, USA 1 Princeton Plasma Physics Laboratory, Princeton, USA 2 University of Texas at Austin, Austin, USA 3 KFKI-RMKI, EURATOM Association, Budapest, Hungary 4 Max-Planck-Institut f¨ ur Plasmaphysik, EURATOM Association, Greifswald, Germany At certain values of the edge rotational transform, ι a = 1/q a , the confinement time of plasmas in the Wendelstein 7-AS (W7-AS) stellarator was found to

36

Twenty-Seventh Symposium (International) on Combustion/The Combustion Institute, 1998/pp. 10071014 THREE-SCALAR IMAGING IN TURBULENT NON-PREMIXED FLAMES  

E-Print Network [OSTI]

. Introduction Planar imaging of turbulent flames using laser di- agnostic techniques such as Lorenz­Mie [1], Ray and MARSHALL B. LONG Department of Mechanical Engineering and Center for Laser Diagnostics Yale University New. The present experimental setup requires only a single laser (532 nm) in a high-power intracavity configuration

Long, Marshall B.

37

An analytical investigation of primary zone combustion temperatures and NOx production for turbulent jet flames using low-BTU fuels  

E-Print Network [OSTI]

is the production of low-BTU gas from a coal gasification reactor for combustion before introduction to the topping cycle gas turbine (Minchener, 1990). Most low-BTU gases are heavily loaded with sulfur-containing compounds which appear to be a major problem... with direct combustion of coal and low-BTU gases (Caraway, 1995). Environmental standards require the removal of these compounds which can be expensive and hazardous when removed from coal in post-combustion processes. However, gasification of coal results...

Carney, Christopher Mark

2012-06-07T23:59:59.000Z

38

Pulse combustion  

Science Journals Connector (OSTI)

Pulse combustion has been gaining increased interest because of its potential for higher combustion efficiency greater combustion intensity and lower pollutant emissions. Unsteady combustion causes increased mass momentum and heat transfer. As a result reactants mix faster heat release is accelerated and heat transfer is enhanced in unsteady reacting flows. Many of these phenomena were discovered long ago by engineers looking for the cause of often detrimental combustion instabilities. Much more recently some of these enhanced transfer properties have been used to design efficient and compact pulse combustors. Although to date successful commercialization on a large scale has been limited to home heating units (e.g. the Lenox Pulse Furnace) highly efficient pulse spray dryers (Bepex Unison Dryer) pulse calciners and pulse waste incinerators have been designed. Pulsations have also been applied to carbon black fluidized bed gasifiers. Not all these designs will become economically viable. However the development of tunable pulse combustors that can be acoustically matched to the changing resonance frequency of these pulse processes have made many of them more promising. Recent findings that pulsation can enhance burning even in turbulent flows lend further encouragement to the developers of novel pulse combustion devices.

Jechiel I. Jagoda

2000-01-01T23:59:59.000Z

39

Emissions and Heat Transfer in Combustion Systems  

Science Journals Connector (OSTI)

A variety of combustion systems that employ turbulent diffusion combustion have been major sources of air pollutants such as NOx, particulates and hydrocarbons in spite of their high thermal efficiency compare...

Y. Daisho

1993-01-01T23:59:59.000Z

40

An evaluation of the assumed beta probability density function subgrid-scale model for large eddy simulation of nonpremixed, turbulent combustion with heat release  

SciTech Connect (OSTI)

The assumed beta distribution model for the subgrid-scale probability density function (PDF) of the mixture fraction in large eddy simulation of nonpremixed, turbulent combustion is tested, a priori, for a reacting jet having significant heat release (density ratio of 5). The assumed beta distribution is tested as a model for both the subgrid-scale PDF and the subgrid-scale Favre PDF of the mixture fraction. The beta model is successful in approximating both types of PDF but is slightly more accurate in approximating the normal (non-Favre) PDF. To estimate the subgrid-scale variance of mixture fraction, which is required by the beta model, both a scale similarity model and a dynamic model are used. Predictions using the dynamic model are found to be more accurate. The beta model is used to predict the filtered value of a function chosen to resemble the reaction rate. When no model is used, errors in the predicted value are of the same order as the actual value. The beta model is found to reduce this error by about a factor of two, providing a significant improvement. (c) 2000 American Institute of Physics.

Wall, Clifton [Center for Turbulence Research, Stanford University, Stanford, California 94305 (United States)] [Center for Turbulence Research, Stanford University, Stanford, California 94305 (United States); Boersma, Bendiks Jan [Center for Turbulence Research, Stanford University, Stanford, California 94305 (United States)] [Center for Turbulence Research, Stanford University, Stanford, California 94305 (United States); Moin, Parviz [Center for Turbulence Research, Stanford University, Stanford, California 94305 (United States)] [Center for Turbulence Research, Stanford University, Stanford, California 94305 (United States)

2000-10-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


41

Application of EPRI risk-based inservice inspection procedure to combustion engineering design of nuclear power plant  

SciTech Connect (OSTI)

The EPRI developed risk-based inservice inspection procedure is used to select the elements for inservice inspection on a section of the high pressure safety injection system of the Entergy Operations ANO2 nuclear plant. This plant is the pilot plant in a six utility-eleven plant EPRI tailored collaboration program to apply the general EPRI procedures to Combustion Engineering NSSS designs. The procedure results in a reduction of candidate inspection locations from 14, based on current ASME Section XI rules for B-J welds to 3, based on the risk-based selection criteria.

Lubin, B.T. [ABB Combustion Engineering, Windsor, CT (United States). Nuclear Operations; Fourgerousse, R. [Entergy Operations-ANO2, Russellville, AR (United States)

1996-12-01T23:59:59.000Z

42

Hydrogen-or-Fossil-Combustion Nuclear Combined-Cycle Systems for Base- and Peak-Load Electricity Production  

SciTech Connect (OSTI)

A combined-cycle power plant is described that uses (1) heat from a high-temperature nuclear reactor to meet base-load electrical demands and (2) heat from the same high-temperature reactor and burning natural gas, jet fuel, or hydrogen to meet peak-load electrical demands. For base-load electricity production, fresh air is compressed; then flows through a heat exchanger, where it is heated to between 700 and 900 C by heat provided by a high-temperature nuclear reactor via an intermediate heat-transport loop; and finally exits through a high-temperature gas turbine to produce electricity. The hot exhaust from the Brayton-cycle gas turbine is then fed to a heat recovery steam generator that provides steam to a steam turbine for added electrical power production. To meet peak electricity demand, the air is first compressed and then heated with the heat from a high-temperature reactor. Natural gas, jet fuel, or hydrogen is then injected into the hot air in a combustion chamber, combusts, and heats the air to 1300 C-the operating conditions for a standard natural-gas-fired combined-cycle plant. The hot gas then flows through a gas turbine and a heat recovery steam generator before being sent to the exhaust stack. The higher temperatures increase the plant efficiency and power output. If hydrogen is used, it can be produced at night using energy from the nuclear reactor and stored until needed. With hydrogen serving as the auxiliary fuel for peak power production, the electricity output to the electric grid can vary from zero (i.e., when hydrogen is being produced) to the maximum peak power while the nuclear reactor operates at constant load. Because nuclear heat raises air temperatures above the auto-ignition temperatures of the various fuels and powers the air compressor, the power output can be varied rapidly (compared with the capabilities of fossil-fired turbines) to meet spinning reserve requirements and stabilize the electric grid. This combined cycle uses the unique characteristics of high-temperature reactors (T>700 C) to produce electricity for premium electric markets whose demands can not be met by other types of nuclear reactors. It may also make the use of nuclear reactors economically feasible in smaller electrical grids, such as those found in many developing countries. The ability to rapidly vary power output can be used to stabilize electric grid performance-a particularly important need in small electrical grids.

Forsberg, Charles W [ORNL; Conklin, Jim [ORNL

2007-09-01T23:59:59.000Z

43

Simulation of Lean Premixed Turbulent Combustion J. Bell1, M. Day1, A. Almgren1, M. Lijewski1, C. Rendleman1, R.  

E-Print Network [OSTI]

. There is considerable technological interest in developing new fuel-flexible combustion systems that can burn fuels in alternative fuels such as hydrogen or syngas, which is obtained from coal gasification. Effective utilization of these fuels requires combustion devices that can operate cleanly and efficiently over a broad range of fuels

Bell, John B.

44

Combustion of Low-Calorific Waste Biomass Syngas  

Science Journals Connector (OSTI)

The industrial combustion chamber designed for burning low-calorific syngas from gasification of waste biomass is presented. ... chips and turkey feathers the non-premixed turbulent combustion in the chamber is s...

Kamil Kwiatkowski; Marek Dudy?ski; Konrad Bajer

2013-12-01T23:59:59.000Z

45

Department of Mechanical and Nuclear Engineering Spring 2013 Project Name Large Scale Biomass Combustion Verification and Analysis  

E-Print Network [OSTI]

Biomass Combustion Verification and Analysis Overview Team PSU PENNTAP 2 was tasked with determining was to produce a user-friendly analytical model of the Challenger 400 series biomass combustion system of experts in the field of biomass combustion and its analysis. These experts were Fred Fries of Dillon

Demirel, Melik C.

46

Efficient Parallel Implementation of a Hybrid Finite-Volume/Particle Method for the PDF Equations of Turbulent Reactive Flows  

E-Print Network [OSTI]

combustion engines, gas turbines, furnaces etc. The computational modelling of turbulent reacting flows pollutant emissions, reduce design costs and development times. However, turbulent combustion remains one strategies: multiple independent simulations, particle partitioning and mesh work partitioning are described

47

Studies in combustion dynamics  

SciTech Connect (OSTI)

The goal of this program is to develop a fundamental understanding and a quantitative predictive capability in combustion modeling. A large part of the understanding of the chemistry of combustion processes comes from {open_quotes}chemical kinetic modeling.{close_quotes} However, successful modeling is not an isolated activity. It necessarily involves the integration of methods and results from several diverse disciplines and activities including theoretical chemistry, elementary reaction kinetics, fluid mechanics and computational science. Recently the authors have developed and utilized new tools for parallel processing to implement the first numerical model of a turbulent diffusion flame including a {open_quotes}full{close_quotes} chemical mechanism.

Koszykowski, M.L. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

48

Jet plume injection and combustion system for internal combustion engines  

DOE Patents [OSTI]

An improved combustion system for an internal combustion engine is disclosed wherein a rich air/fuel mixture is furnished at high pressure to one or more jet plume generator cavities adjacent to a cylinder and then injected through one or more orifices from the cavities into the head space of the cylinder to form one or more turbulent jet plumes in the head space of the cylinder prior to ignition of the rich air/fuel mixture in the cavity of the jet plume generator. The portion of the rich air/fuel mixture remaining in the cavity of the generator is then ignited to provide a secondary jet, comprising incomplete combustion products which are injected into the cylinder to initiate combustion in the already formed turbulent jet plume. Formation of the turbulent jet plume in the head space of the cylinder prior to ignition has been found to yield a higher maximum combustion pressure in the cylinder, as well as shortening the time period to attain such a maximum pressure.

Oppenheim, Antoni K. (Kensington, CA); Maxson, James A. (Berkeley, CA); Hensinger, David M. (Albany, CA)

1993-01-01T23:59:59.000Z

49

Emission formation during wood log combustion in fireplaces â?? part I: volatile combustion stage  

Science Journals Connector (OSTI)

A CFD-based tool for the analysis of combustion and emissions in batch-fired wood log combustion is introduced. It consists of submodels for drying and pyrolysis of a wood log, for combustion of volatilised fuel and char, for radiative heat transfer, and for NO formation implemented in a commercial CFD-programme (Fluent) for turbulent flows. Comparing model predictions to experimental data in a test oven shows the applicability of the different submodels and combination of them.

M. Huttunen; J. Saastamoinen; P. Kilpinen; L. Kjaldman; H. Oravainen; S. Bostrom

2006-01-01T23:59:59.000Z

50

Advanced Combustion  

SciTech Connect (OSTI)

Topics covered in this presentation include: the continued importance of coal; related materials challenges; combining oxy-combustion & A-USC steam; and casting large superalloy turbine components.

Holcomb, Gordon R. [NETL

2013-03-05T23:59:59.000Z

51

The enhancement of the mixing and combustion processes in supersonic flow applied to scramjet engine  

SciTech Connect (OSTI)

The Reynolds averaged parabolized Navier-Stokes equations are employed for the numerical study of turbulent mixing and combustion of a supersonic hydrogen jet in a supersonic airflow. A one-equation differential turbulence model is utilized. The simplified flame sheet model is employed for the numerical simulation of the supersonic combustion. 24 refs.

Kopchenov, V.I.; Lomkov, K.E. (Tsentral'nyi NII Aviatsionnogo Motorostroeniia, Moscow (Russian Federation))

1992-07-01T23:59:59.000Z

52

Combustion Noise  

E-Print Network [OSTI]

stabilize or destabilize the modes of the system, depending on the configuration of the combustor and the form of the coupling [26, 30]. In contrast to combustion instability, in broad-band combustion noise the unsteadiness in the rate of combustion... from th s in a mod on tempera , entropic a de of indir t frequenci r, open que sical theory assical expe s [14] who it by a spa d a transie le gases. A e bubble si idered as a flame was ent was o ng and dif depended udy it wa ion, ? ?,p r t? : (a...

Dowling, Ann P.; Mahmoudi, Yasser

2014-01-01T23:59:59.000Z

53

Major research topics in combustion  

SciTech Connect (OSTI)

The Institute for Computer Applications in Science and Engineering (ICASE) and NASA Langley Research Center (LaRC) hosted a workshop on October 2--4, 1989 to discuss some combustion problems of technological interest to LaRC and to foster interaction with the academic community in these research areas. The topics chosen for this purpose were flame structure, flame holding/extinction, chemical kinetics, turbulence-kinetics interaction, transition to detonation, and reacting free shear layers. This document contains the papers and edited versions of general discussions on these topics. The lead paper set the stage for the meeting by discussing the status and issues of supersonic combustion relevant to the scramjet engine. Experts were then called upon to review the current knowledge in the aforementioned areas, to focus on how this knowledge can be extended and applied to high-speed combustion, and to suggest future directions of research in these areas.

Hussaini, M.Y.; Kumar, A.; Voigt, R.G. (eds.)

1992-01-01T23:59:59.000Z

54

Combustion Engine  

Broader source: Energy.gov [DOE]

Pictured here is an animation showing the basic mechanics of how an internal combustion engine works. With support from the Energy Department, General Motors researchers developed a new technology ...

55

A Numerical Method for DNS/LES of Turbulent Reacting Flows Jeff Doom, Yucheng Hou & Krishnan Mahesh  

E-Print Network [OSTI]

of the solution. Turbulent combustion can occur at very low Mach numbers (e.g. gas-turbine combustors at low thicknesses. Turbulence introduces its own range of length and time-scales. Furthermore the nonlinear nature

Mahesh, Krishnan

56

COMBUSTION RESEARCH - FY-1979  

E-Print Network [OSTI]

deposition due to the heat of combustion. The problem wedimensionless heat of combustion, QpYoxoolhw t transferredfraction of specie i heat of combustion per gram of fuel

,

2012-01-01T23:59:59.000Z

57

Sandia National Laboratories: The CRF's Turbulent Combustion...  

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

safety envelope * International Fire Code. IFC * International Organization for Standardization * ISO * laser-based diagnostics * laser-based imaging capabilities * LFL * lower...

58

Advanced Combustion  

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

Systems Systems Advanced Combustion Background Conventional coal-fired power plants utilize steam turbines to generate electricity, which operate at efficiencies of 35-37 percent. Operation at higher temperatures and pressures can lead to higher efficiencies, resulting in reduced fuel consumption and lower greenhouse gas emissions. Higher efficiency also reduces CO2 production for the same amount of energy produced, thereby facilitating a reduction in greenhouse gas emissions. When combined, oxy-combustion comes with an efficiency hit, so it will actually increase the amount of CO2 to be captured. But without so much N2 in the flue gas, it will be easier and perhaps more efficient to capture, utilize and sequester. NETL's Advanced Combustion Project and members of the NETL-Regional University

59

Center for Turbulence Research Annual Research Briefs 2012  

E-Print Network [OSTI]

and coal fueled combustors. The advantage offered by biomass fuel is that its carbon content has been extracted from the Earth's atmosphere and surface envi- ronment. The combustion of these materials/particle interaction, and turbulence/chemistry interaction. Although turbulence and chemistry interactions are expected

Wang, Wei

60

Combustion & Health  

E-Print Network [OSTI]

FFCOMBUSTION & HEALTH Winifred J. Hamilton, PhD, SM Clear Air Through Energy Efficiency (CATEE) Galveston, TX October 9?11, 2012 FFCOMBUSTION & HEALTH FFCOMBUSTION: THE THREAT ? Biggest threat to world ecosystems (and to human health...) ? Combustion of fossil fuels for ? Electricity ? Industrial processes ? Vehicle propulsion ? Cooking and heat ? Other ? Munitions ? Fireworks ? Light ? Cigarettes, hookahs? FFCOMBUSTION & HEALTH FFCOMBUSTION: THE THREAT ? SCALE (think health...

Hamilton, W.

2012-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


61

Numerical modelling of MILD combustion for coal  

Science Journals Connector (OSTI)

Emissions of nitrogen oxides from coal combustion are a major environmental problem because they have been shown to contribute to the formation of acid rain and photochemical smog. Moderate and Intensive Low oxygen Dilution (MILD) combustion is a promising technology for decreasing pollutant emissions and improving combustion efficiency. A combination of air preheating and fuel dilution with combustion products of low oxygen concentration are the main features of this technique. In the MILD combustion mode, preheated air and fuel are gradually mixed with large amounts of recirculated exhaust gas. The objective of the present work is to investigate the capability of present fuel NO mechanisms for pulverised coal combustion to predict the observed nitrogen oxide levels in MILD combustion mode. For this purpose, knowledge of the fate of coal nitrogen during the combustion process is vital. The interaction between turbulence and chemistry is modelled by an advanced Eddy Dissipation Concept (EDC). The NOx model is used to predict NO profiles that are compared to measurements obtained from semi-industrial scale experiments.

Ju Pyo Kim; U. Schnell; G. Scheffknecht; A.C. Benim

2007-01-01T23:59:59.000Z

62

Stretch Efficiency for Combustion Engines: Exploiting New Combustion...  

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

Stretch Efficiency for Combustion Engines: Exploiting New Combustion Regimes Stretch Efficiency for Combustion Engines: Exploiting New Combustion Regimes 2012 DOE Hydrogen and Fuel...

63

Light Duty Combustion Research: Advanced Light-Duty Combustion...  

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

Light Duty Combustion Research: Advanced Light-Duty Combustion Experiments Light Duty Combustion Research: Advanced Light-Duty Combustion Experiments 2009 DOE Hydrogen Program and...

64

Turbulence-chemistry interactions in reacting flows  

SciTech Connect (OSTI)

Interactions between turbulence and chemistry in nonpremixed flames are investigated through multiscalar measurements. Simultaneous point measurements of major species, NO, OH, temperature, and mixture fraction are obtained by combining spontaneous Raman scattering, Rayleigh scattering, and laser-induced fluorescence (LIF). NO and OH fluorescence signals are converted to quantitative concentrations by applying shot-to-shot corrections for local variations of the Boltzmann fraction and collisional quenching rate. These measurements of instantaneous thermochemical states in turbulent flames provide insights into the fundamental nature of turbulence-chemistry interactions. The measurements also constitute a unique data base for evaluation and refinement of turbulent combustion models. Experimental work during the past year has focused on three areas: (1) investigation of the effects of differential molecular diffusion in turbulent combustion: (2) experiments on the effects of Halon CF{sub 3}Br, a fire retardant, on the structure of turbulent flames of CH{sub 4} and CO/H{sub 2}/N{sub 2}; and (3) experiments on NO formation in turbulent hydrogen jet flames.

Barlow, R.S.; Carter, C.D. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

65

Plasma turbulence  

SciTech Connect (OSTI)

The origin of plasma turbulence from currents and spatial gradients in plasmas is described and shown to lead to the dominant transport mechanism in many plasma regimes. A wide variety of turbulent transport mechanism exists in plasmas. In this survey the authors summarize some of the universally observed plasma transport rates.

Horton, W. [Univ. of Texas, Austin, TX (United States). Inst. for Fusion Studies; Hu, G. [Globalstar LP, San Jose, CA (United States)

1998-07-01T23:59:59.000Z

66

Combustion Control  

E-Print Network [OSTI]

using a liquid fuel. The air and fuel valve designs are vastly different, with different flow characteristics. These factors make the initial adjustment of the system difficult, and proper maintenance of ratio accuracy unlikely. Linked valves... casing of the fuel control regulator with the combustion air piping. The upstream pressure on the burner air orifice is applied to the main diaphragm of the pressure balanced regulator. Assuming sufficient gas pressure at the regulator inlet...

Riccardi, R. C.

1984-01-01T23:59:59.000Z

67

Compressible Turbulence and Interactions with Shock Waves and Material  

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

Compressible Turbulence Compressible Turbulence and Interactions with Shock Waves and Material Interfaces Compressible Turbulence and Interactions with Shock Waves and Material Interfaces Lele.jpg Alternate Title: High-fidelity simulations of supersonic turbulent mixing and combustion Key Challenges: Direct numerical simulation (DNS) of isotropic turbulence interacting with a normal shock wave and turbulent multi-material mixing in the Richtmyer-Meshkov instability (RMI) Why it Matters: Shock/turbulence interaction is a fundamental phenomenon in fluid mechanics that occurs in a wide range of interesting problems in various disciplines, including supernova explosions, inertial confinement fusion, hypersonic flight and propulsion, and shock wave lithotripsy. Accomplishments: A novel solution-adaptive algorithm that applies different

68

Combustion chemistry  

SciTech Connect (OSTI)

This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

1993-12-01T23:59:59.000Z

69

Direct numerical simulation of turbulent reacting flows  

SciTech Connect (OSTI)

The development of turbulent combustion models that reflect some of the most important characteristics of turbulent reacting flows requires knowledge about the behavior of key quantities in well defined combustion regimes. In turbulent flames, the coupling between the turbulence and the chemistry is so strong in certain regimes that is is very difficult to isolate the role played by one individual phenomenon. Direct numerical simulation (DNS) is an extremely useful tool to study in detail the turbulence-chemistry interactions in certain well defined regimes. Globally, non-premixed flames are controlled by two limiting cases: the fast chemistry limit, where the turbulent fluctuations. In between these two limits, finite-rate chemical effects are important and the turbulence interacts strongly with the chemical processes. This regime is important because industrial burners operate in regimes in which, locally the flame undergoes extinction, or is at least in some nonequilibrium condition. Furthermore, these nonequilibrium conditions strongly influence the production of pollutants. To quantify the finite-rate chemistry effect, direct numerical simulations are performed to study the interaction between an initially laminar non-premixed flame and a three-dimensional field of homogeneous isotropic decaying turbulence. Emphasis is placed on the dynamics of extinction and on transient effects on the fine scale mixing process. Differential molecular diffusion among species is also examined with this approach, both for nonreacting and reacting situations. To address the problem of large-scale mixing and to examine the effects of mean shear, efforts are underway to perform large eddy simulations of round three-dimensional jets.

Chen, J.H. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

70

In Situ NMR Spectroscopy of Combustion  

Science Journals Connector (OSTI)

In situ nuclear magnetic resonance spectroscopy (NMR) of high-temperature reactions is of potential value for the investigation of catalytic combustion and other high-temperature applications of catalysts such as partial oxidation of hydrocarbons and steam reforming. ... Two-dimensional (2D) studies of gas exchange within different heat zones of the combustion process provide valuable insights into the gas-phase dynamics. ... This may be the case at the high combustion temperatures, but neither experimental nor theoretical xenon chemical shift data is available in current literature for temperatures above 1000 K. ...

Satyanarayana Anala; Galina E. Pavlovskaya; Prakash Pichumani; Todd J. Dieken; Michael D. Olsen; Thomas Meersmann

2003-10-07T23:59:59.000Z

71

Stretch Efficiency for Combustion Engines: Exploiting New Combustion...  

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

D.C. ace15daw.pdf More Documents & Publications Stretch Efficiency for Combustion Engines: Exploiting New Combustion Regimes Stretch Efficiency for Combustion Engines:...

72

Advanced Combustion | Argonne National Laboratory  

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

Combustion Advanced Combustion Combustion engines drive a large percentage of our nation's transportation vehicles and power generation and manufacturing facilities. Today's...

73

Flamelet model for pulverized coal combustion  

Science Journals Connector (OSTI)

Abstract A new flamelet model applicable to the simulation of pulverized coal combustion has been developed. First, a modeling approach that considers the coupling with both devolatilization and char combustion was adopted. We changed the fuel composition of the flamelet equation relative to the states of devolatilization and char combustion. In order to determine the fuel composition coming through the char combustion, all the gasified char was assumed to be converted into CO by the oxidation reaction. The validity of the developed flamelet model was examined in a simple two-dimensional pulverized coal jet field ignited by burnt co-flows. The accuracy of the model was evaluated by comparing its instantaneous distributions of temperature, CO2 mass fraction, and OH mass fraction with those of a detailed chemistry model. Good agreement was obtained in terms of the overall features of turbulent structures and combustion state, although the flamelet model showed slightly quicker ignition due to the transitional state in the ignition process being insufficiently reproducible.

Junya Watanabe; Kenji Yamamoto

2014-01-01T23:59:59.000Z

74

Enhanced air/fuel mixing for automotive Stirling engine turbulator-type combustors  

SciTech Connect (OSTI)

This patent describes a combustor for use in a Stirling engine and the like. It comprises: a combustor chamber; a fuel inlet couple to the chamber to inject fuel therein; a turbulator means disposed in the chambers downstream of the fuel inlet means for injecting combustion air into the chamber, the turbulator means being so positioned to cause a mixing of the combustion air and fuel injected in the chamber; diverter means for dividing the combustion air and creating a primary mixing zone downstream fa the primary mixing zone; and wherein the primary mixing zone comprises a fuel rich zone where combustion initiates and the secondary mixing zone has sufficient combustion air to complete combustion of the fuel.

Riecke, G.T.; Stotts, R.E.

1992-02-25T23:59:59.000Z

75

CALTECH ASCI TECHNICAL REPORT 163 Mixing of a conserved scalar in a turbulent shear layer  

E-Print Network [OSTI]

with and without heat release at a reaction sheet. For high heat release, typical of hydrocarbon combustion combustion, is studied by direct numerical simulation (DNS) in strongly turbulent planar shear layers both, the mixing is found to be substantially different than without heat release. The probability density function

76

Chemical Looping Combustion  

Science Journals Connector (OSTI)

Chemical looping combustion (CLC) and looping cycles in general represent an important new ... technologies, which can be deployed for direct combustion as well as be used in gasification...2...stream suitable fo...

Edward John (Ben) Anthony

2012-01-01T23:59:59.000Z

77

Chemistry of Combustion Processes  

Science Journals Connector (OSTI)

The quantitative description and understanding of combustion processes needs extreme computational efforts and has at ... treatment can give a lot of insight into combustion processes, as demonstrated in the foll...

J. Warnatz

2000-01-01T23:59:59.000Z

78

Overview of Biomass Combustion  

Science Journals Connector (OSTI)

The main combustion systems for biomass fuels are presented and the respective requirements ... etc.) in industrial boilers or for co-combustion in power plants. For fuels with high ... moving grate firings are u...

T. Nussbaumer; J. E. Hustad

1997-01-01T23:59:59.000Z

79

Direct numerical simulation of turbulent mixing  

Science Journals Connector (OSTI)

...in-[5]. The low-cost approach to turbulence...growing with n. The graphs corresponding to these...rates-both chemical and nuclear. The same is true for...Figure-17 shows the graph of the TMZ boundary dependence...of providing safety in nuclear power production facilities...

2013-01-01T23:59:59.000Z

80

3-D turbulent particle dispersion submodel development. Quarterly progress report No. 1, 5 April--5 July 1991  

SciTech Connect (OSTI)

The lack of a mathematical description of the interactions of fluid turbulence with other physics-chemical processes is a major obstacle in modeling many industrial program. Turbulent two-phase flow is a phenomenon that is of significant practical importance to coal combustion as well as other disciplines. The interactions of fluid turbulence with the particulate phase has yet to be accurately and efficiently modeled for these industrial applications. On 15 May 1991 work was initiated to cover four major tasks toward the development of a computational submodel for turbulent particle dispersion that would be applicable to coal combustion simulations. Those four tasks are: 1. A critical evaluation of the 2-D Lagrangian particle dispersion submodel, 2. Development of a 3-D submodel for turbulent particle dispersion, 3. Evaluation of the 3-D submodel for turbulent particle dispersion, 4.Exploration of extensions of the Lagrangian dispersion theory to other applications including chemistry-turbulence interactions.

Smith, P.J.

1991-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


81

On Challenges for Hypersonic Turbulent Simulations  

SciTech Connect (OSTI)

This short note discusses some of the challenges for design of suitable spatial numerical schemes for hypersonic turbulent flows, including combustion, and thermal and chemical nonequilibrium flows. Often, hypersonic turbulent flows in re-entry space vehicles and space physics involve mixed steady strong shocks and turbulence with unsteady shocklets. Material mixing in combustion poses additional computational challenges. Proper control of numerical dissipation in numerical methods beyond the standard shock-capturing dissipation at discontinuities is an essential element for accurate and stable simulations of the subject physics. On one hand, the physics of strong steady shocks and unsteady turbulence/shocklet interactions under the nonequilibrium environment is not well understood. On the other hand, standard and newly developed high order accurate (fourth-order or higher) schemes were developed for homogeneous hyperbolic conservation laws and mixed hyperbolic and parabolic partial differential equations (PDEs) (without source terms). The majority of finite rate chemistry and thermal nonequilibrium simulations employ methods for homogeneous time-dependent PDEs with a pointwise evaluation of the source terms. The pointwise evaluation of the source term might not be the best choice for stability, accuracy and minimization of spurious numerics for the overall scheme.

Yee, H C; Sjogreen, B

2009-01-14T23:59:59.000Z

82

Center for Turbulence Research Annual Research Briefs 2012  

E-Print Network [OSTI]

a model for uncertainty quantification (UQ) of high-speed turbulent combustion in a scramjet engine/boundary layer interaction, a phenomenon important to scramjet combustors. In addition to aleatory uncertainties from simulation of a full scramjet engine to an investigation of crackling supersonic jets to solar

Wang, Wei

83

Low NOx combustion  

SciTech Connect (OSTI)

Combustion of hydrocarbon liquids and solids is achieved with less formation of NOx by feeding a small amount of oxygen into the fuel stream.

Kobayashi; Hisashi (Putnam Valley, NY), Bool, III; Lawrence E. (Aurora, NY)

2007-06-05T23:59:59.000Z

84

Low NOx combustion  

SciTech Connect (OSTI)

Combustion of hydrocarbon liquids and solids is achieved with less formation of NOx by feeding a small amount of oxygen into the fuel stream.

Kobayashi, Hisashi (Putnam Valley, NY); Bool, III, Lawrence E. (Aurora, NY)

2008-10-21T23:59:59.000Z

85

Introduction to Biomass Combustion  

Science Journals Connector (OSTI)

Biomass was the major fuel in the world ... hundreds when coal then became dominant. The combustion of solid biofuels as a primary energy...

Jenny M. Jones; Amanda R. Lea-Langton…

2014-01-01T23:59:59.000Z

86

The Combustion of Solid Biomass  

Science Journals Connector (OSTI)

The combustion of solid biomass is covered in this chapter. This covers the general mechanism of combustion, moisture evaporation, devolatilisation, the combustion of the volatiles gases and tars and finally char...

Jenny M. Jones; Amanda R. Lea-Langton…

2014-01-01T23:59:59.000Z

87

Coal Combustion Science  

SciTech Connect (OSTI)

The objective of this activity is to support the Office of Fossil Energy in executing research on coal combustion science. This activity consists of basic research on coal combustion that supports both the Pittsburgh Energy Technology Center Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency Coal Combustion Science Project. Specific tasks for this activity include: (1) coal devolatilization - the objective of this risk is to characterize the physical and chemical processes that constitute the early devolatilization phase of coal combustion as a function of coal type, heating rate, particle size and temperature, and gas phase temperature and oxidizer concentration; (2) coal char combustion -the objective of this task is to characterize the physical and chemical processes involved during coal char combustion as a function of coal type, particle size and temperature, and gas phase temperature and oxygen concentration; (3) fate of mineral matter during coal combustion - the objective of this task is to establish a quantitative understanding of the mechanisms and rates of transformation, fragmentation, and deposition of mineral matter in coal combustion environments as a function of coal type, particle size and temperature, the initial forms and distribution of mineral species in the unreacted coal, and the local gas temperature and composition.

Hardesty, D.R. (ed.); Fletcher, T.H.; Hurt, R.H.; Baxter, L.L. (Sandia National Labs., Livermore, CA (United States))

1991-08-01T23:59:59.000Z

88

Fifteenth combustion research conference  

SciTech Connect (OSTI)

The BES research efforts cover chemical reaction theory, experimental dynamics and spectroscopy, thermodynamics of combustion intermediates, chemical kinetics, reaction mechanisms, combustion diagnostics, and fluid dynamics and chemically reacting flows. 98 papers and abstracts are included. Separate abstracts were prepared for the papers.

NONE

1993-06-01T23:59:59.000Z

89

SIAM Conference on Numerical Combustion Sedona, AZ May 9-12, 2004  

SciTech Connect (OSTI)

The Society for Industrial and Applied Mathematics hosted the Tenth International Conference on Numerical Combustion held May 9-12, 2004 in Sedona, Arizona. This distinguished conference series began in 1985 in Sophia Antipolis, France and was followed by conferences in San Francisco, California (1987), Juan les Pins, France (1989), St. Petersburg Beach, Florida (1991), Garmisch, Germany (1993), New Orleans, Louisiana (1996), York, England (1998), Amelia Island, Florida (2000), and Sorrento, Italy (2002). SIAM is widely recognized as the originator and the U.S. anchor of this important meeting whose topics concerns the applied mathematics and computation associated with combustion and reactive flow. In particular, the International Numerical Combustion Symposiums have become one of the international major venues for research on direct simulation and modeling turbulent reacting flow. It is also one of the major international venues for theoretical work in reacting flows. This meeting drew approximately 200 participants from 30 countries whose research included the topics in turbulence, kinetics, detonation, flames, pollution, microgravity, micro-combustion, ignition, applications of parallel processing, tera-scale computation of combustion applications, material synthesis, droplets and sprays, heterogeneous combustion, energetic materials (propellants and explosives), engine and furnace combustion, fires, numerical methods and, software engineering for combustion applications.

None

2004-09-23T23:59:59.000Z

90

Stability Regimes of Turbulent Nitrogen-Diluted Hydrogen Jet Flames  

SciTech Connect (OSTI)

One option for combustion in zero-emission Integrated Gasification Combined Cycle (IGCC) power plants is non-premixed combustion of nitrogen-diluted hydrogen in air. An important aspect to non-premixed combustion is flame stability or anchoring, though only a few fundamental stability studies of these flames have taken place to date. The following paper presents the results of experiments investigating the effects of nitrogen diluent fraction, jet diameter, and exit velocity on the static stability limits of a turbulent hydrogen jet flame issuing from a thin-lipped tube into a quiescent atmosphere. Four different stability limits are observed: detachment from the burner lip, reattachment to the burner lip, transition from a laminar lifted flame base to blowout or to a turbulent lifted flame, and transition from a turbulent lifted flame to blowout. The applicability of existing theories and correlations to the stability results is discussed. These results are an important step in assessing the viability of a non-premixed combustion approach using hydrogen diluted with nitrogen as a fuel.

Weiland, N.T.; Strakey, P.A.

2007-03-01T23:59:59.000Z

91

Turbulent flame speed for syngas at gas turbine relevant conditions  

Science Journals Connector (OSTI)

Modifications of conventional natural-gas-fired burners for operation with syngas fuels using lean premixed combustion is challenging due to the different physicochemical properties of the two fuels. A key differentiating parameter is the turbulent flame velocity, ST, commonly expressed as its ratio to the laminar flame speed, SL. This paper reports an experimental investigation of premixed syngas combustion at gas turbine like conditions, with emphasis on the determination of ST/SL derived as global fuel consumption per unit time. Experiments at pressures up to 2.0 MPa, inlet temperatures and velocities up to 773 K and 150 m/s, respectively, and turbulence intensity to laminar flame speed ratios, u?/SL, exceeding 100 are presented for the first time. Comparisons between different syngas mixtures and methane clearly show much higher ST/SL for the former fuel. It is shown that ST/SL is strongly dependent on preferential diffusive-thermal (PDT) effects, co-acting with hydrodynamic effects, even for very high u?/SL. ST/SL increases with rising hydrogen content in the fuel mixture and with increasing pressure. A correlation for ST/SL valid for all investigated fuel mixtures, including methane, is proposed in terms of turbulence properties (turbulence intensity and integral length scale), combustion properties (laminar flame speed and laminar flame thickness) and operating conditions (pressure and inlet temperature). The correlation captures effects of preferential diffusive-thermal and hydrodynamic instabilities.

S. Daniele; P. Jansohn; J. Mantzaras; K. Boulouchos

2011-01-01T23:59:59.000Z

92

Turbulent flow in graphene  

E-Print Network [OSTI]

We demonstrate the possibility of a turbulent flow of electrons in graphene in the hydrodynamic region, by calculating the corresponding turbulent probability density function. This is used to calculate the contribution of the turbulent flow to the conductivity within a quantum Boltzmann approach. The dependence of the conductivity on the system parameters arising from the turbulent flow is very different from that due to scattering.

Kumar S. Gupta; Siddhartha Sen

2009-11-03T23:59:59.000Z

93

Oxy-coal Combustion Studies  

SciTech Connect (OSTI)

The objective of this project is to move toward the development of a predictive capability with quantified uncertainty bounds for pilot-scale, single-burner, oxy-coal operation. This validation research brings together multi-scale experimental measurements and computer simulations. The combination of simulation development and validation experiments is designed to lead to predictive tools for the performance of existing air fired pulverized coal boilers that have been retrofitted to various oxy-firing configurations. In addition, this report also describes novel research results related to oxy-combustion in circulating fluidized beds. For pulverized coal combustion configurations, particular attention is focused on the effect of oxy-firing on ignition and coal-flame stability, and on the subsequent partitioning mechanisms of the ash aerosol. To these ends, the project has focused on the following: â?˘ The development of reliable Large Eddy Simulations (LES) of oxy-coal flames using the Direct Quadrature Method of Moments (DQMOM) (Subtask 3.1). The simulations were validated for both non-reacting particle-laden jets and oxy-coal flames. â?˘ The modifications of an existing oxy-coal combustor to allow operation with high levels of input oxygen to enable in-situ laser diagnostic measurements as well as the development of strategies for directed oxygen injection (Subtask 3.2). Flame stability was quantified for various burner configurations. One configuration that was explored was to inject all the oxygen as a pure gas within an annular oxygen lance, with burner aerodynamics controlling the subsequent mixing. â?˘ The development of Particle Image Velocimetry (PIV) for identification of velocity fields in turbulent oxy-coal flames in order to provide high-fidelity data for the validation of oxy-coal simulation models (Subtask 3.3). Initial efforts utilized a laboratory diffusion flame, first using gas-fuel and later a pulverized-coal flame to ensure the methodology was properly implemented and that all necessary data and image-processing techniques were fully developed. Success at this stage of development led to application of the diagnostics in a large-scale oxy-fuel combustor (OFC). â?˘ The impact of oxy-coal-fired vs. air-fired environments on SO{sub x} (SO{sub 2}, SO{sub 3}) emissions during coal combustion in a pilot-scale circulating fluidized-bed (CFB) (Subtask 3.4). Profiles of species concentration and temperature were obtained for both conditions, and profiles of temperature over a wide range of O{sub 2} concentration were studied for oxy-firing conditions. The effect of limestone addition on SO{sub 2} and SO{sub 3} emissions were also examined for both air- and oxy- firing conditions. â?˘ The investigation of O{sub 2}/CO{sub 2} and O{sub 2}/N{sub 2} environments on SO{sub 2 emissions during coal combustion in a bench-scale single-particle fluidized-bed reactor (Subtask 3.5). Moreover, the sulfation mechanisms of limestone in O{sub 2}/CO{sub 2} and O{sub 2}/N{sub 2} environments were studied, and a generalized gassolid and diffusion-reaction single-particle model was developed to study the effect of major operating variables. â?˘ The investigation of the effect of oxy-coal combustion on ash formation, particle size distributions (PSD), and size-segregated elemental composition in a drop-tube furnace and the 100 kW OFC (Subtask 3.6). In particular, the effect of coal type and flue gas recycle (FGR, OFC only) was investigated.

J. Wendt; E. Eddings; J. Lighty; T. Ring; P. Smith; J. Thornock; Y. Jia, W. Morris; J. Pedel; D. Rezeai; L. Wang; J. Zhang; K. Kelly

2012-01-01T23:59:59.000Z

94

Coal combustion products (CCPs  

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

combustion products (CCPs) combustion products (CCPs) are solid materials produced when coal is burned to generate electricity. Since coal provides the largest segment of U.S. electricity generation (45 percent in 2010), finding a sustainable solution for CCPs is an important environmental challenge. When properly managed, CCPs offer society environmental and economic benefits without harm to public health and safety. Research supported by the U.S. Department of Energy's (DOE) Office of Fossil Energy (FE) has made an important contribution in this regard. Fossil Energy Research Benefits Coal Combustion Products Fossil Energy Research Benefits

95

Thermal ignition combustion system  

SciTech Connect (OSTI)

A thermal ignition combustion system adapted for use with an internal combustion engine is described comprising: (a) means for providing ignition chamber walls defining an ignition chamber, the chamber walls being made of a material having a thermal conductivity greater than 20 W/m/sup 0/C. and a specific heat greater than 480J/kg/sup 0/C., the ignition chamber being in constant communication with the main combustion chamber; (b) means for maintaining the temperature of the chamber walls above a threshold temperature capable of causing ignition of a fuel; and (c) means for conducting fuel to the ignition chamber.

Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

1988-04-19T23:59:59.000Z

96

Sandia Combustion Research: Technical review  

SciTech Connect (OSTI)

This report contains reports from research programs conducted at the Sandia Combustion Research Facility. Research is presented under the following topics: laser based diagnostics; combustion chemistry; reacting flow; combustion in engines and commercial burners; coal combustion; and industrial processing. Individual projects were processed separately for entry onto the DOE databases.

NONE

1995-07-01T23:59:59.000Z

97

Packed Bed Combustion: An Overview  

E-Print Network [OSTI]

;Packed Bed Combustion - University of Ottawa - CICS 2005 fuel fuel feed air products air fuel Retort) products Underfeed Combustion fuel feed air #12;Packed Bed Combustion - University of Ottawa - CICS 2005 required #12;Packed Bed Combustion - University of Ottawa - CICS 2005 Overfeed Bed fuel motion products air

Hallett, William L.H.

98

COMBUSTION RESEARCH - FY-1979  

E-Print Network [OSTI]

Island - Unit 2 Accident," Nuclear Safety Analysis Centre,of accident risks in U.S. commercial nuclear power plants,"

,

2012-01-01T23:59:59.000Z

99

Engine Combustion & Efficiency - FEERC  

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

Engine Combustion & Efficiency Engine Combustion & Efficiency ORNL currently and historically supports the U.S. DOE on multi-cylinder and vehicle applications of diesel combustion, lean burn gasoline combustion, and low temperature combustion processes, and performs principal research on efficiency enabling technologies including emission controls, thermal energy recovery, and bio-renewable fuels. Research areas span from fundamental concepts to engine/vehicle integration and demonstration with a particular emphasis on the following areas: Thermodynamics for identifying and characterizing efficiency opportunities for engine-systems as well as the development of non-conventional combustion concepts for reducing fundamental combustion losses. Nonlinear sciences for improving the physical understanding and

100

Definition: Combustion | Open Energy Information  

Open Energy Info (EERE)

Combustion Combustion Jump to: navigation, search Dictionary.png Combustion The process of burning; chemical oxidation accompanied by the generation of light and heat.[1][2] View on Wikipedia Wikipedia Definition "Burning" redirects here. For combustion without external ignition, see spontaneous combustion. For the vehicle engine, see internal combustion engine. For other uses, see Burning (disambiguation) and Combustion (disambiguation). Error creating thumbnail: Unable to create destination directory This article's introduction section may not adequately summarize its contents. To comply with Wikipedia's lead section guidelines, please consider modifying the lead to provide an accessible overview of the article's key points in such a way that it can stand on its own as a

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


101

Spontaneous Human Combustion  

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

Spontaneous Human Combustion Spontaneous Human Combustion Name: S. Phillips. Age: N/A Location: N/A Country: N/A Date: N/A Question: One of our 8th grade students has tried to find information in our library about spontaneous human combustion, but to no avail. Could you tell us where we might locate a simple reference, or provide some in information about this subject for him. Replies: Sorry, but this is definitely "fringe science"...try asking in bookstores. I seem to recall one of those "believe it or not" type of TV shows did an episode on spontaneous human combustion a few years ago in which they reported on some British scientists who investigated this purported phenomenon. Remember that people (back in the Dark Ages, and before) used to believe in "spontaneous generation" of certain plants and animals because they were not aware of the reproduction methods used by those plants and animals.

102

Advanced diesel combustion  

Science Journals Connector (OSTI)

Future emission norms will further reduce the vehicle emissions of diesel engines. To meet the goal of achieving these stringent limits while maintaining attractive attributes of marketability, the combustion ...

Dirk Adolph; Hartwig Busch; Stefan Pischinger; Andreas Kolbeck…

2008-01-01T23:59:59.000Z

103

Advanced Combustion Technologies  

Broader source: Energy.gov [DOE]

The workhorse of America's electric power sector is the coal-fired power plant. Today, coal combustion plants account for more than half of the Nation's electric power generation. Largely because...

104

Catalytic Combustion Processes  

Science Journals Connector (OSTI)

This work presents experimental data on the effect of catalytic additives on the combustion characteristics of ammonium nitrate and perchlorate and the explosives of different classes. Burning rates are determ...

A. P. Glaskova

1991-01-01T23:59:59.000Z

105

Advanced Combustion Technology to Enable High Efficiency Clean...  

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

Combustion Technology to Enable High Efficiency Clean Combustion Advanced Combustion Technology to Enable High Efficiency Clean Combustion Summary of advanced combustion research...

106

Coal combustion system  

DOE Patents [OSTI]

In a coal combustion system suitable for a gas turbine engine, pulverized coal is transported to a rich zone combustor and burned at an equivalence ratio exceeding 1 at a temperature above the slagging temperature of the coal so that combustible hot gas and molten slag issue from the rich zone combustor. A coolant screen of water stretches across a throat of a quench stage and cools the combustible gas and molten slag to below the slagging temperature of the coal so that the slag freezes and shatters into small pellets. The pelletized slag is separated from the combustible gas in a first inertia separator. Residual ash is separated from the combustible gas in a second inertia separator. The combustible gas is mixed with secondary air in a lean zone combustor and burned at an equivalence ratio of less than 1 to produce hot gas motive at temperature above the coal slagging temperature. The motive fluid is cooled in a dilution stage to an acceptable turbine inlet temperature before being transported to the turbine.

Wilkes, Colin (Lebanon, IN); Mongia, Hukam C. (Carmel, IN); Tramm, Peter C. (Indianapolis, IN)

1988-01-01T23:59:59.000Z

107

Sandia Combustion Research Program  

SciTech Connect (OSTI)

During the late 1970s, in response to a national energy crisis, Sandia proposed to the US Department of Energy (DOE) a new, ambitious program in combustion research. Shortly thereafter, the Combustion Research Facility (CRF) was established at Sandia's Livermore location. Designated a ''user facility,'' the charter of the CRF was to develop and maintain special-purpose resources to support a nationwide initiative-involving US inventories, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions several research projects which have been simulated by working groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship program, supported through the Office of Energy Research, has been instrumental in the success of some of these joint efforts. The remainder of this report presents results of calendar year 1988, separated thematically into eleven categories. Referred journal articles appearing in print during 1988 and selected other publications are included at the end of Section 11. Our traditional'' research activities--combustion chemistry, reacting flows, diagnostics, engine and coal combustion--have been supplemented by a new effort aimed at understanding combustion-related issues in the management of toxic and hazardous materials.

Johnston, S.C.; Palmer, R.E.; Montana, C.A. (eds.)

1988-01-01T23:59:59.000Z

108

Turbulent structures and budgets behind permeable ribs  

SciTech Connect (OSTI)

Different rib geometries are traditionally used to improve heat transfer and enhance mixing in different industrial applications, i.e. heat exchangers, cooling passages of gas turbine blades and fuel elements of nuclear reactors, etc. Permeable ribs have been proposed in literature for passive control of the reattaching flow past surface mounted ribs leading to superior performance. The flow past different surface mounted permeable rib geometries, i.e. solid, slit, split-slit and inclined split-slit ribs have been investigated in this study. Both two components and stereo particle image velocimetry (PIV) have been used in streamwise and cross stream planes to study the underlying flow structures. The detailed turbulent statistics, i.e. mean and rms velocity, higher order moments, quadrant decomposition of turbulent shear stress producing motions, skewness and components of the turbulent kinetic energy budgets have been compared for different rib geometries. Coherent structures are identified based on the invariant of velocity gradient tensor invariant and wavelet transform. The skewness results demonstrate the intermittency of quadrant motions. The reattachment length of the inclined split-slit rib is lowest among all rib geometries. The average Reynolds stresses and the production of turbulent kinetic energy are highest for the inclined split-slit rib. The pressure transport calculated as residual of the turbulent kinetic energy budget equation is highest for the inclined split-slit rib. This is attributed to the smaller reattachment length leading to greater adverse pressure gradient for the inclined split-slit rib. The quadrant motions, turbulent fluxes, skewness and kinetic energy budgets at post reattachment region compares well with that of flat plate turbulent boundary layer from hot wire measurements in literature. Overall, this study demonstrates the effectiveness of PIV technique for the detailed turbulent structures characterization of complex flows. (author)

Panigrahi, P.K. [Department of Mechanical Engineering, IIT Kanpur, UP 208016 (India); Schroeder, A.; Kompenhans, J. [Institute of Aerodynamics and Flow Technology, German Aerospace Center (DLR), Goettingen (Germany)

2008-02-15T23:59:59.000Z

109

Combustion Model for Engine Concept Development | Department...  

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

Combustion Model for Engine Concept Development Presentation shows how 1-cylinder testing, 3D combustion CFD and 1D gas exchange with an advanced combustion model are used...

110

Revised users manual, Pulverized Coal Gasification or Combustion: 2-dimensional (87-PCGC-2): Final report, Volume 2. [87-PCGC-2  

SciTech Connect (OSTI)

A two-dimensional, steady-state model for describing a variety of reactive and non-reactive flows, including pulverized coal combustion and gasification, is presented. Recent code revisions and additions are described. The model, referred to as 87-PCGC-2, is applicable to cylindrical axi-symmetric systems. Turbulence is accounted for in both the fluid mechanics equations and the combustion scheme. Radiation from gases, walls, and particles is taken into account using either a flux method or discrete ordinates method. The particle phase is modeled in a Lagrangian framework, such that mean paths of particle groups are followed. Several multi-step coal devolatilization schemes are included along with a heterogeneous reaction scheme that allows for both diffusion and chemical reaction. Major gas-phase reactions are modeled assuming local instantaneous equilibrium, and thus the reaction rates are limited by the turbulent rate mixing. A NO/sub x/ finite rate chemistry submodel is included which integrates chemical kinetics and the statistics of the turbulence. The gas phase is described by elliptic partial differential equations that are solved by an iterative line-by-line technique. Under-relaxation is used to achieve numerical stability. The generalized nature of the model allows for calculation of isothermal fluid mechanicsgaseous combustion, droplet combustion, particulate combustion and various mixtures of the above, including combustion of coal-water and coal-oil slurries. Both combustion and gasification environments are permissible. User information and theory are presented, along with sample problems. 106 refs.

Smith, P.J.; Smoot, L.D.; Brewster, B.S.

1987-12-01T23:59:59.000Z

111

Lattice Boltzmann equation simulations of turbulence, mixing, and combustion  

E-Print Network [OSTI]

with the continuum fluid behaviors through hydrodynamic variables such as density (rho), velocity (vector), pressure (p), temperature (T), etc. The continuum variables result from the collective average over a large number of individual trajectories... are represented by certain observable quantities such as density (rho), velocity (vector), pressure (p), temperature (T), and so on. These macroscopic quantities are manifestations of the molecular motions averaged in space or time. In fact, the primary task...

Yu, Huidan

2006-04-12T23:59:59.000Z

112

Turbulence radiation interaction modeling in hydrocarbon pool fire simulations  

SciTech Connect (OSTI)

The importance of turbulent fluctuations in temperature and species concentration in thermal radiation transport modeling for combustion applications is well accepted by the radiation transport and combustion communities. A number of experimental and theoretical studies over the last twenty years have shown that fluctuations in the temperature and species concentrations may increase the effective emittance of a turbulent flame by as much as 50% to 300% over the value that would be expected from the mean temperatures and concentrations. With the possibility of such a large effect on the principal mode of heat transfer from a fire, it is extremely important for fire modeling efforts that turbulence radiation interaction be well characterized and possible modeling approaches understood. Toward this end, this report seeks to accomplish three goals. First, the principal turbulence radiation interaction closure terms are defined. Second, an order of magnitude analysis is performed to understand the relative importance of the various closure terms. Finally, the state of the art in turbulence radiation interaction closure modeling is reviewed. Hydrocarbon pool fire applications are of particular interest in this report and this is the perspective from which this review proceeds. Experimental and theoretical analysis suggests that, for this type of heavily sooting flame, the turbulent radiation interaction effect is dominated by the nonlinear dependence of the Planck function on the temperature. Additional effects due to the correlation between turbulent fluctuations in the absorptivity and temperature may be small relative to the Planck function effect for heavily sooting flames. This observation is drawn from a number of experimental and theoretical discussions. Nevertheless, additional analysis and data is needed to validate this observation for heavily sooting buoyancy dominated plumes.

BURNS,SHAWN P.

1999-12-01T23:59:59.000Z

113

Combustible structural composites and methods of forming combustible structural composites  

DOE Patents [OSTI]

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Daniels, Michael A.; Heaps, Ronald J.; Steffler, Eric D.; Swank, W. David

2013-04-02T23:59:59.000Z

114

Combustible structural composites and methods of forming combustible structural composites  

DOE Patents [OSTI]

Combustible structural composites and methods of forming same are disclosed. In an embodiment, a combustible structural composite includes combustible material comprising a fuel metal and a metal oxide. The fuel metal is present in the combustible material at a weight ratio from 1:9 to 1:1 of the fuel metal to the metal oxide. The fuel metal and the metal oxide are capable of exothermically reacting upon application of energy at or above a threshold value to support self-sustaining combustion of the combustible material within the combustible structural composite. Structural-reinforcing fibers are present in the composite at a weight ratio from 1:20 to 10:1 of the structural-reinforcing fibers to the combustible material. Other embodiments and aspects are disclosed.

Daniels, Michael A. (Idaho Falls, ID); Heaps, Ronald J. (Idaho Falls, ID); Steffler, Eric D (Idaho Falls, ID); Swank, William D. (Idaho Falls, ID)

2011-08-30T23:59:59.000Z

115

Tidal Flow Turbulence Measurements  

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

max quire specification of a turbulence intensity, and it is a metric in the wind energy industry. For acoustic Dop surements, a noise-corrected expression of...

116

Combustion Safety Overview  

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

March 1-2, 2012 March 1-2, 2012 Building America Stakeholders Meeting Austin, Texas Combustion Safety in the Codes Larry Brand Gas Technology Institute Acknowledgement to Paul Cabot - American Gas Association 2 | Building America Program www.buildingamerica.gov Combustion Safety in the Codes Widely adopted fuel gas codes: * National Fuel Gas Code - ANSI Z223.1/NFPA 54, published by AGA and NFPA (NFGC) * International Fuel Gas Code - published by the International Code Council (IFGC) * Uniform Plumbing Code published by IAPMO (UPC) Safety codes become requirements when adopted by the Authority Having Jurisdiction (governments or fire safety authorities) 3 | Building America Program www.buildingamerica.gov Combustion Safety in the Codes Formal Relationships Between these codes: - The IFGC extracts many safety

117

A MODEL FOR POROUS-MEDIUM COMBUSTION  

Science Journals Connector (OSTI)

......these applied in coal combustion appears in...understanding of the chemistry of combustion...GLASSMAN, Combustion (Academic Press...ESSENHIGH, In Chemistry of Coal Utilization...POROUS-MEDIUM COMBUSTION 177 8. D. A......

J. NORBURY; A. M. STUART

1989-02-01T23:59:59.000Z

118

Noise in non?premixed turbulent syngas flames  

Science Journals Connector (OSTI)

A turbulent syngas flame may generate acoustic noise of high acoustic intensity in a combustion chamber. This may lead to the failure of construction components in a gas turbine engine in periods of the order of 1–100 hours. The research as described in the literature has almost exclusively been performed on the generation of noise in premixed methane or propane flames. Syngas fuel is a mixture of hydrogen and carbon monoxide and the burners used are of the non?premixed type. In this research the effect of turbulence and syngas composition on noise generation is investigated. A laboratory is set up to test syngas flames of a thermal power of 50 kW in a cylindrical air?cooled combustion chamber. Experiments are performed at several fuel compositions and burner inlet conditions. The flame sound intensity is measured in the combustion chamber equipped with acoustic dampers. The paper discusses the measured sound spectra. A model is derived for the generation of sound in a turbulent non?premixed flame. In this model it is shown that the sound generation is related to the dependence of density on mixture fraction in a flame with fast chemistry. A fluctuation in mixture fraction will lead to sound generation.

Sikke A. Klein; Jim B. W. Kok

1998-01-01T23:59:59.000Z

119

Vehicle Technologies Office: Combustion Engine Research  

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

Combustion Engine Combustion Engine Research to someone by E-mail Share Vehicle Technologies Office: Combustion Engine Research on Facebook Tweet about Vehicle Technologies Office: Combustion Engine Research on Twitter Bookmark Vehicle Technologies Office: Combustion Engine Research on Google Bookmark Vehicle Technologies Office: Combustion Engine Research on Delicious Rank Vehicle Technologies Office: Combustion Engine Research on Digg Find More places to share Vehicle Technologies Office: Combustion Engine Research on AddThis.com... Just the Basics Hybrid & Vehicle Systems Energy Storage Advanced Power Electronics & Electrical Machines Advanced Combustion Engines Combustion Engines Emission Control Waste Heat Recovery Fuels & Lubricants Materials Technologies Combustion Engine Research

120

Vehicle Technologies Office: Advanced Combustion Engines  

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

Advanced Combustion Advanced Combustion Engines to someone by E-mail Share Vehicle Technologies Office: Advanced Combustion Engines on Facebook Tweet about Vehicle Technologies Office: Advanced Combustion Engines on Twitter Bookmark Vehicle Technologies Office: Advanced Combustion Engines on Google Bookmark Vehicle Technologies Office: Advanced Combustion Engines on Delicious Rank Vehicle Technologies Office: Advanced Combustion Engines on Digg Find More places to share Vehicle Technologies Office: Advanced Combustion Engines on AddThis.com... Just the Basics Hybrid & Vehicle Systems Energy Storage Advanced Power Electronics & Electrical Machines Advanced Combustion Engines Combustion Engines Emission Control Waste Heat Recovery Fuels & Lubricants Materials Technologies Advanced Combustion Engines

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


121

Detailed numerical simulation of syngas combustion under partially premixed combustion engine conditions  

Science Journals Connector (OSTI)

Two-dimensional detailed numerical simulation is performed to study syngas/air combustion under partially premixed combustion (PPC) engine conditions. Detailed chemical kinetics and transport properties are employed in the study. The fuel, a mixture of CO and H2 with a 1:1 molar ratio, is introduced to the domain at two different instances of time, corresponding to the multiple injection strategy of fuel used in PPC engines. It is found that the ratio of the fuel mass between the second injection and the first injection affects the combustion and emission process greatly; there is a tradeoff between NO emission and CO emission when varying the fuel mass ratio. The ignition zone structures under various fuel mass ratios are examined. A premixed burn region and a diffusion burn region are identified. The premixed burn region ignites first, followed by the ignition of mixtures at the diffusion burn region, and finally a thin diffusion flame is formed to burn out the remaining fuel. NO is produced mainly in the premixed burn region, and later from the diffusion burn region in mixtures close to stoichiometry, whereas unburned CO emission is mainly from the diffusion burn region. An optimization of the fuel mass in the two regions can offer a better tradeoff between NO emission and CO emission. The effects of initial temperature and turbulence on the premixed burn and diffusion burn regions are investigated.

F. Zhang; R. Yu; X.S. Bai

2012-01-01T23:59:59.000Z

122

Thermal ignition combustion system  

DOE Patents [OSTI]

The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m C and a specific heat greater than 480 J/kg C with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber. 8 figs.

Kamo, R.; Kakwani, R.M.; Valdmanis, E.; Woods, M.E.

1988-04-19T23:59:59.000Z

123

Thermal ignition combustion system  

SciTech Connect (OSTI)

The thermal ignition combustion system comprises means for providing walls defining an ignition chamber, the walls being made of a material having a thermal conductivity greater than 20 W/m.degree. C. and a specific heat greater than 480 J/kg.degree. C. with the ignition chamber being in constant communication with the main combustion chamber, means for maintaining the temperature of the walls above a threshold temperature capable of causing ignition of a fuel, and means for conducting fuel to the ignition chamber.

Kamo, Roy (Columbus, IN); Kakwani, Ramesh M. (Columbus, IN); Valdmanis, Edgars (Columbus, IN); Woods, Melvins E. (Columbus, IN)

1988-01-01T23:59:59.000Z

124

Nanoparticle Emissions from Internal Combustion Engines | Department...  

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

Nanoparticle Emissions from Internal Combustion Engines Nanoparticle Emissions from Internal Combustion Engines 2004 Diesel Engine Emissions Reduction (DEER) Conference...

125

Improving alternative fuel utilization: detailed kinetic combustion...  

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

alternative fuel utilization: detailed kinetic combustion modeling & experimental testing Improving alternative fuel utilization: detailed kinetic combustion modeling &...

126

Mechanism of Hydrocarbon Formation in Combustion Processes  

Science Journals Connector (OSTI)

Emissions from transportation systems that derive their energy directly from combustion processes include products of incomplete combustion, oxides of...

R. A. Matula

1973-01-01T23:59:59.000Z

127

Reversed flow fluidized-bed combustion apparatus  

DOE Patents [OSTI]

The present invention is directed to a fluidized-bed combustion apparatus provided with a U-shaped combustion zone. A cyclone is disposed in the combustion zone for recycling solid particulate material. The combustion zone configuration and the recycling feature provide relatively long residence times and low freeboard heights to maximize combustion of combustible material, reduce nitrogen oxides, and enhance sulfur oxide reduction.

Shang, Jer-Yu (Fairfax, VA); Mei, Joseph S. (Morgantown, WV); Wilson, John S. (Morgantown, WV)

1984-01-01T23:59:59.000Z

128

Turbulent Nonpremixed Flames (TNF): Experimental Data Archives and Computational Submodels  

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

In the 1990s an international collaboration formed around a series of workshops that became known collectively as the International Workshop on Measurement and Computation of Turbulent Non-Premixed Flames (TNF). An online library, hosted by Sandia National Laboratory (California) was established that provides data sets and submodels or "mechanisms" for the study of turbulence-chemistry interactions in turbulent nonpremixed and partially premixed combustion. Data are organized by flame types: simple jet flames, piloted jet flames, bluff body flames, and swirl flames. These data sets provide a means for collaborative comparisons of both measured and simulated/modeled research results and also assist scientists in determining priorities for further research. More than 20 data sets or databases are available from this website, along with various downloadable files of chemical mechanisms. The website also provides an extensive bibliography and the proceedings of the workshops themselves from 1996 through 2012. Information continues to be added to this collection.

129

Aviation Combustion Toxicology: An Overview  

Science Journals Connector (OSTI)

......in a radiant heat furnace. Rats...the produced combustion products in...in both the combustion tube and radiant heat systems proved...literature data for CO2, low...acrolein, and heat expo- sures...primary toxic combustion gases and are...structures. The hydrocarbon constituents......

Arvind K. Chaturvedi

2010-01-01T23:59:59.000Z

130

Multidimensional modeling of diesel ignition and combustion using a multistep kinetics model  

SciTech Connect (OSTI)

Ignition and combustion mechanisms in diesel engines were studied using the KIVA code, with modifications to the combustion, heat transfer, crevice flow, and spray models. A laminar-and-turbulent characteristic-time combustion model that has been used successfully for spark-ignited engine studies was extended to allow predictions of ignition and combustion in diesel engines. A more accurate prediction of ignition delay was achieved by using a multistep chemical kinetics model. The Shell knock model was implemented for this purpose and was found to be capable of predicting successfully the autoignition of homogeneous mixtures in a rapid compression machine and diesel spray ignition under engine conditions. The physical significance of the model parameters is discussed and the sensitivity of results to the model constants is assessed. The ignition kinetics model was also applied to simulate the ignition process in a Cummins diesel engine. The post-ignition combustion was simulated using both a single-step Arrhenius kinetics model and also the characteristic-time model to account for the energy release during the mixing-controlled combustion phase. The present model differs from that used in earlier multidimensional computations of diesel ignition in that it also includes state-of-the-art turbulence and spray atomization models. In addition, in this study the model predictions are compared to engine data. It is found that good levels of agreement with the experimental data are obtained using the multistep chemical kinetics model for diesel ignition modeling. However, further study is needed of the effects of turbulent mixing on post-ignition combustion.

Kong, S.C.; Reitz, R.D. (Univ. of Wisconsin, Madison, WI (United States). Dept. of Mechanical Engineering)

1993-10-01T23:59:59.000Z

131

Long time mass fraction statistics in stationary compressible isotropic turbulence at supercritical pressure  

E-Print Network [OSTI]

turbulent binary nitrogen­hydrocarbon mixtures under supercritical pressure conditions. The governing equation, and generalized heat and mass diffusion derived from nonequilibrium thermodynamics. A highly of Physics. S1070-6631 00 00608-5 I. INTRODUCTION A variety of modern air­fuel mixing and combustion devices

Miller, Richard S.

132

Measurements and analysis of turbulent consumption speeds of H2/CO mixtures Prabhakar Venkateswaran a,  

E-Print Network [OSTI]

Available online 9 February 2011 Keywords: Syngas Hydrogen Global consumption speeds Turbulent flame speed since they are the primary constitu- ents of syngas fuels. Data are reported at mean flow velocities than SL,0. Ă? 2011 The Combustion Institute. Published by Elsevier Inc. All rights reserved. 1

Lieuwen, Timothy C.

133

LES SOFTWARE FOR THE DESIGN OF LOW EMISSION COMBUSTION SYSTEMS FOR VISION 21 PLANTS  

SciTech Connect (OSTI)

Vision 21 combustion systems will require innovative low emission designs and low development costs if Vision 21 goals are to be realized. In this three-year project, an advanced computational software tool will be developed for the design of low emission combustion systems required for Vision 21 clean energy plants. The combustion Large Eddy Simulation (LES) software will be able to accurately simulate the highly transient nature of gaseous-fueled turbulent combustion so that innovative concepts can be assessed and developed with fewer high-cost experimental tests. During the first year, the project included the development and implementation of improved chemistry (reduced GRI mechanism), subgrid turbulence (localized dynamic), and subgrid combustion-turbulence interaction (Linear Eddy) models into the CFDACE+ code. University expertise (Georgia Tech and UC Berkeley) was utilized to help develop and implement these advanced submodels into the unstructured, parallel CFD flow solver, CFD-ACE+. Efficient numerical algorithms that rely on in situ look-up tables or artificial neural networks were implemented for chemistry calculations. In the second year, the combustion LES software was evaluated and validated using experimental data from lab-scale and industrial test configurations. This code testing (i.e., alpha testing) was performed by CFD Research Corporation's engineers. During the third year, six industrial and academic partners used the combustion LES code and exercised it on problems of their choice (i.e., beta testing). Final feedback and optimizations were then be implemented in the final release version of the combustion LES software that will be licensed to the general public. An additional one-year task was added for the fourth year of this program entitled, ''LES Simulations of SIMVAL Results''. For this task, CFDRC performed LES calculations of selected SIMVAL cases, and compared predictions with measurements. In addition to comparisons with NO{sub x} and CO exit measurements, comparisons were made to measured pressure oscillations. Possible gaps in the data sets were identified, as well as potential areas of improvement for combustion and turbulence models. Work in this seventeenth quarter (October-December 2004) consisted of writing the draft final report for review by DOE. The report was delivered to DOE in January, 2005.

Clifford E. Smith

2005-04-01T23:59:59.000Z

134

Combustion powered linear actuator  

DOE Patents [OSTI]

The present invention provides robotic vehicles having wheeled and hopping mobilities that are capable of traversing (e.g. by hopping over) obstacles that are large in size relative to the robot and, are capable of operation in unpredictable terrain over long range. The present invention further provides combustion powered linear actuators, which can include latching mechanisms to facilitate pressurized fueling of the actuators, as can be used to provide wheeled vehicles with a hopping mobility.

Fischer, Gary J. (Albuquerque, NM)

2007-09-04T23:59:59.000Z

135

US DRIVE Advanced Combustion and Emission Control Technical Team Roadmap  

Broader source: Energy.gov [DOE]

The ACEC focuses on advanced engine and aftertreatment technology for three major combustion strategies: (1) Low-Temperature Combustion, (2) Dilute Gasoline combustion, and (3) Clean Diesel Combustion.

136

US DRIVE Advanced Combustion and Emission Control Technical Team...  

Energy Savers [EERE]

for three major combustion strategies: (1) Low-Temperature Combustion, (2) Dilute Gasoline combustion, and (3) Clean Diesel Combustion. acecroadmapjune2013.pdf More Documents...

137

NETL: Combustion Technologies  

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

Abbreviations & Acronyms Abbreviations & Acronyms Reference Shelf Solicitations & Awards Abbreviations & Acronyms The Combustion Technologies Product uses a number of abbreviations and acronyms. This web page gives you a definition of frequently used terms, as follows: 1½-Generation PFBC -- A PFBC plant where the hot (about 1400ºF) PFBC exhaust gases are used as a vitiated air supply for a natural gas combustor supplying high-temperature gas (above 2000ºF) to a combustion turbine expander (synonym for "PFB-NGT"). 1st-Generation PFBC -- Commercial PFBC technology where an unfired low-temperature (below 1650ºF) ruggedized turbine expander expands PFBC exhaust gases (synonym for "PFB-EGT"). 2nd-Generation PFBC (see synonyms: "APFBC," "PFB-CGT") -- Advanced PFBC where a carbonizer (mild gasifier) provides hot (about 1400ºF) coal-derived synthetic fuel gas to a special topping combustor. The carbonizer char is burned in the PFBC, and the PFBC exhaust is used as a hot (about 1400ºF) vitiated air supply for the topping combustor. The syngas and vitiated air are burned in a topping combustor to provide high-temperature gas (above 1700ºF) to a combustion turbine expander.

138

NETL: Combustion Technologies  

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

Nebraska Public Power District's Sheldon Station with APFBC Technology Nebraska Public Power District's Sheldon Station with APFBC Technology FBC Repower APFBC AES Greenidge APFBC Dan River FBC, APFBC Four Corners CHIPPS H.F. Lee Products Summary Sheldon Summary APFBC Sheldon GFBCC Sheldon APFBC L.V. Sutton Contents: APFBC Repowering Project Summary Key Features Site Layout Performance Environmental Characteristics Cost Other Combustion Systems Repowering Study Links: A related study is underway that would repower Sheldon Unit 1 and Unit 2 with gasification fluidized-bed combined cycle technology (GFBCC). CLICK HERE to find out more about repowering the Sheldon station with GFBCC instead. APFBC Repowering Project Summary Click on picture to enlarge Advanced circulating pressurized fluidized-bed combustion combined cycle systems (APFBC) are systems with jetting-bed pressurized fluidized-bed (PFB) carbonizer/gasifier and circulating PFBC combustor. The PFB carbonizer and PFBC both operate at elevated pressures (10 to 30 times atmospheric pressure) to provide syngas for operating a gas turbine topping combustor giving high cycle energy efficiency. The remaining char from the PFB carbonizer is burned in the pressurized PFBC. The combustion gas from the PFB also feeds thermal energy to the gas turbine topping combustor. This provides combined cycle plant efficiency on coal by providing the opportunity to generate electricity using both high efficiency gas turbines and steam.

139

Advanced combustion technologies for gas turbine power plants  

SciTech Connect (OSTI)

Objectives are to develop actuators for enhancing the mixing between gas streams, increase combustion stability, and develop hgih-temperature materials for actuators and sensors in combustors. Turbulent kinetic energy maps of an excited jet with co-flow in a cavity with a partially closed exhaust end are given with and without a longitudinal or a transverse acoustic field. Dielectric constants and piezoelectric coefficients were determined for Sr{sub 2}(Nb{sub x}Ta{sub 1-x}){sub 2}O{sub 7} ceramics.

Vandsburger, U. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Mechanical Engineering; Roe, L.A. [Arkansas Univ., Fayetteville, AR (United States). Dept. of Mechanical Engineering; Desu, S.B. [Virginia Polytechnic Inst. and State Univ., Blacksburg, VA (United States). Dept. of Materials Science and Engineering

1995-12-31T23:59:59.000Z

140

Three-dimensional turbulent particle dispersion submodel development. Final report, 15 April 1991--15 April 1993  

SciTech Connect (OSTI)

Many practical combustion processes which use solid particles, liquid droplets, or slurries as fuels introduce these fuels into turbulent environments. Examples include spray combustion, pulverized coal and coal slurry combustion, fluidized beds, sorbent injection, and hazardous waste incineration. The interactions of the condensed phases with turbulent environments in such applications have not been well described. Such a description is complicated by the difficulty of describing turbulence in general, even in the absence of particles or droplets. But the complications in describing the dispersion and reaction of the condensed phases in turbulent environments do not stem entirely, or even primarily, from the uncertainties in the description of the turbulence. Even when the turbulence characteristics are known, computational methods for coupling the dynamics of the particulate phase with the continuous phase have not been well established. Several new theoretical descriptions of the turbulent dispersion of particles and droplets have been proposed over the past few years. It has been the purpose of this project to explore the potential of these theories for coupling with the other aspects of three-dimensional, reacting, turbulent, particle-laden systems, to provide computational simulations that could be useful for addressing industrial problems. Two different approaches were explored in this project. The major thrust of this project was on identifying a suitable dispersion submodel for dilute dispersed flows, implementing it in a comprehensive three-dimensional CFD code framework for combustion simulation and evaluating its performance rigorously. In another effort the potential of a dispersion submodel for densely loaded systems was analyzed. This report discusses the main issues that were resolved as part of this project.

Smith, P.J.

1993-12-31T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


141

Stretch Efficiency for Combustion Engines: Exploiting New Combustion...  

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

boost. * H 2 enrichment extends lean limit, improves C p C v ratio, lowers cylinder heat loss, assists cold start, lowers combustion irreversibility. IC Engine Work Reformer...

142

Observations of Edge Turbulence  

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

Edge Turbulence Edge Turbulence near the X-point of Alcator C-Mod APS-2007 (1) J.L. Terry, S.J. Zweben*, B. LaBombard, I. Cziegler, O. Grulke + , D.P. Stotler* MIT - Plasma Science and Fusion Center *Princeton Plasma Physics Laboratory + MPI for Plasma Physics, EURATOM Assoc., Greifswald, Germany American Physical Society - Div. of Plasma Physics Orlando, FL Nov. 12 - Nov. 16, 2007 APS-2007 (2) Background and Motivation for "Xpt-region" View Strong edge turbulence has been observed in nearly all magnetic confinement devices. Desire predictive capability Most previous measurements made near outboard midplane where the turbulence has the following main features: - generation is ballooning-like (absent at inboard midplane, etc.) - filaments/blobs moves radially outward with some poloidal motion

143

ARM - Measurement - Atmospheric turbulence  

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

turbulence turbulence ARM Data Discovery Browse Data Comments? We would love to hear from you! Send us a note below or call us at 1-888-ARM-DATA. Send Measurement : Atmospheric turbulence High frequency velocity fluctuations that lead to turbulent transport of momentum, heat, mositure, and passive scalars, and often expressed in terms of variances and covariances. Categories Atmospheric State, Surface Properties Instruments The above measurement is considered scientifically relevant for the following instruments. Refer to the datastream (netcdf) file headers of each instrument for a list of all available measurements, including those recorded for diagnostic or quality assurance purposes. ARM Instruments CO2FLX : Carbon Dioxide Flux Measurement Systems ECOR : Eddy Correlation Flux Measurement System

144

Information Content of Turbulence  

E-Print Network [OSTI]

We treat a turbulent velocity field as a message in the same way as a book or a picture. All messages can be described by their entropy per symbol $h$, defined as in Shannon's theory of communication. In a turbulent flow, as the Reynolds number $Re$ increases, more correlated degrees of freedom are excited and participate in the turbulent cascade. Experiments in a turbulent soap film suggest that the spatial entropy density $h$ is a decreasing function of $Re$, namely $h \\propto -\\log Re$ + const. In the logistic map, also analyzed here, increasing the control parameter $r$ increases $h$. A modified logistic map with additional coupling to past iterations suggests the significance of correlations.

Rory Cerbus; Walter Goldburg

2013-07-03T23:59:59.000Z

145

Progress in sub-grid scale modeling of shock-turbulence interaction  

SciTech Connect (OSTI)

The authors report on progress in the development of sub grid scale (SGS) closure relationships for the unresolved motion scales in compressible large eddy simulations (LES). At present they are refining the SGS model and overall LES procedure to include: a linearized viscoelastic model for finite thickness shock distortions and shocked turbulence field response; multiple scale asymptotic considerations to improve predictions of average near-wall surface behavior; and a spectral statistical model simulating the effects of high wave number stochastic feed-back from the unresolved SGS nonlinear motion influences on the explicitly resolved grid scale motions. Predicted amplification levels, modal energy partition, shock translational to turbulence kinetic energy transfer, and viscoelastic spatio-temporal response of turbulence to shock interaction are examined in comparison with available experimental evidence. Supplemental hypersonic compressible turbulence experimental information is developed from sub nanosecond interval pulsed shadowgraph evidence of laser impulse generated hypervelocity shocks interacting with intense, previously developed and carefully characterized initial turbulence. Accurate description of the influence of shock-turbulence interactions is vital for predicting their influence on: Supersonic/hypersonic flow field analysis, aerodynamic design, and aerostructural materials selection. Practical applications also include interior supersonic combustion analysis and combustion chamber design. It is also the essential foundation for accurately predicting the development and evolution of flow-field generated thermal and electromagnetic radiation important to hypersonic flight vehicle survivability, detection and communication.

Buckingham, A.C. [Lawrence Livermore National Lab., CA (United States). Center for Advanced Fluid Dynamics Applications; Grun, J. [Naval Research Lab., Washington, DC (United States). Plasma Physics Div.

1994-12-01T23:59:59.000Z

146

Sandia National Laboratories: Diesel Combustion  

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

Diesel Combustion Caterpillar, Sandia CRADA Opens Door to Multiple Research Projects On April 17, 2013, in Capabilities, Computational Modeling & Simulation, CRF, Materials...

147

Improve Your Boiler's Combustion Efficiency  

SciTech Connect (OSTI)

This revised ITP tip sheet on boiler combustion efficiency provides how-to advice for improving industrial steam systems using low-cost, proven practices and technologies.

Not Available

2006-01-01T23:59:59.000Z

148

Municipal Waste Combustion (New Mexico)  

Broader source: Energy.gov [DOE]

This rule establishes requirements for emissions from, and design and operation of, municipal waste combustion units. "Municipal waste" means all materials and substances discarded from residential...

149

ALS Evidence Confirms Combustion Theory  

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

are produced, generally, when insufficient oxygen or other factors result in incomplete combustion of organic matter (e.g., in engines and incinerators, when biomass burns in...

150

Numerical Modeling of HCCI Combustion  

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

Numerical Modeling of HCCI Combustion Salvador M. Aceves, Daniel L. Flowers, J. Ray Smith, Joel Martinez-Frias, Francisco Espinosa-Loza, Tim Ross, Bruce Buchholz, Nick...

151

Power-Law Wrinkling Turbulence-Flame Interaction Model for Astrophysical Flames  

E-Print Network [OSTI]

We extend a model for turbulence-flame interactions (TFI) to consider astrophysical flames with a particular focus on combustion in type Ia supernovae. The inertial range of the turbulent cascade is nearly always under-resolved in simulations of astrophysical flows, requiring the use of a model in order to quantify the effects of subgrid-scale wrinkling of the flame surface. We provide implementation details to extend a well-tested TFI model to low-Prandtl number flames for use in the compressible hydrodynamics code FLASH. A local, instantaneous measure of the turbulent velocity is calibrated for FLASH and verification tests are performed. Particular care is taken to consider the relation between the subgrid rms turbulent velocity and the turbulent flame speed, especially for high-intensity turbulence where the turbulent flame speed is not expected to scale with the turbulent velocity. Finally, we explore the impact of different TFI models in full-star, three-dimensional simulations of type Ia supernovae.

Jackson, Aaron P; Calder, Alan C

2014-01-01T23:59:59.000Z

152

Combustion Byproducts Recycling Consortium  

SciTech Connect (OSTI)

Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, 'clean coal' combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered 'allowable' under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and private-sector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

2008-08-31T23:59:59.000Z

153

Combustion Byproducts Recycling Consortium  

SciTech Connect (OSTI)

Each year, over 100 million tons of solid byproducts are produced by coal-burning electric utilities in the United States. Annual production of flue gas desulfurization (FGD) byproducts continues to increase as the result of more stringent sulfur emission restrictions. In addition, stricter limits on NOx emissions mandated by the 1990 Clean Air Act have resulted in utility burner/boiler modifications that frequently yield higher carbon concentrations in fly ash, which restricts the use of the ash as a cement replacement. Controlling ammonia in ash is also of concern. If newer, “clean coal” combustion and gasification technologies are adopted, their byproducts may also present a management challenge. The objective of the Combustion Byproducts Recycling Consortium (CBRC) is to develop and demonstrate technologies to address issues related to the recycling of byproducts associated with coal combustion processes. A goal of CBRC is that these technologies, by the year 2010, will lead to an overall ash utilization rate from the current 34% to 50% by such measures as increasing the current rate of FGD byproduct use and increasing in the number of uses considered “allowable” under state regulations. Another issue of interest to the CBRC would be to examine the environmental impact of both byproduct utilization and disposal. No byproduct utilization technology is likely to be adopted by industry unless it is more cost-effective than landfilling. Therefore, it is extremely important that the utility industry provide guidance to the R&D program. Government agencies and privatesector organizations that may be able to utilize these materials in the conduct of their missions should also provide input. The CBRC will serve as an effective vehicle for acquiring and maintaining guidance from these diverse organizations so that the proper balance in the R&D program is achieved.

Ziemkiewicz, Paul; Vandivort, Tamara; Pflughoeft-Hassett, Debra; Chugh, Y Paul; Hower, James

2008-08-31T23:59:59.000Z

154

Space shuttle based microgravity smoldering combustion experiments  

E-Print Network [OSTI]

zone, and smolder heat of combustion (energy per unit massand Q is the smolder heat of combustion. The mass fluxes ofdata. The smolder heat of combustion is not well determined

Walther, David C; Fernandez-Pello, Carlos; Urban, David L

1999-01-01T23:59:59.000Z

155

Combustion Catalysts in Industry- An Update  

E-Print Network [OSTI]

applications of combustion catalysts for coal are presented. Combustion efficiency and calculations are discussed, followed by an explanation of the theories of combustion catalysis and a review of three case histories....

Merrell, G. A.; Knight, R. S.

156

Self-tuning regulators for combustion oscillations  

Science Journals Connector (OSTI)

...interaction of acoustic waves and combustion processes. An abundant literature...numerical simulations of the combustion processes and coupled fluid dynamics...nonlinear analysis of controlled combustion processes. In Proc. 1999 IEEE Int...

2003-01-01T23:59:59.000Z

157

Source terms for plutonium aerosolization from nuclear weapon accidents  

SciTech Connect (OSTI)

The source term literature was reviewed to estimate aerosolized and respirable release fractions for accidents involving plutonium in high-explosive (HE) detonation and in fuel fires. For HE detonation, all estimates are based on the total amount of Pu. For fuel fires, all estimates are based on the amount of Pu oxidized. I based my estimates for HE detonation primarily upon the results from the Roller Coaster experiment. For hydrocarbon fuel fire oxidation of plutonium, I based lower bound values on laboratory experiments which represent accident scenarios with very little turbulence and updraft of a fire. Expected values for aerosolization were obtained from the Vixen A field tests, which represent a realistic case for modest turbulence and updraft, and for respirable fractions from some laboratory experiments involving large samples of Pu. Upper bound estimates for credible accidents are based on experiments involving combustion of molten plutonium droplets. In May of 1991 the DOE Pilot Safety Study Program established a group of experts to estimate the fractions of plutonium which would be aerosolized and respirable for certain nuclear weapon accident scenarios.

Stephens, D.R.

1995-07-01T23:59:59.000Z

158

Turbulence Structure and Wall Signature in Hypersonic Turbulent Boundary Layer  

E-Print Network [OSTI]

Turbulence Structure and Wall Signature in Hypersonic Turbulent Boundary Layer Yin-Chiu Kan , Clara and hypersonic turbulent boundary layer datasets from direct numerical simulation (DNS). Contour plots and Marusic5 and Mathis, Hutchins and Marusic16 ). In contrast to supersonic and hypersonic flow regimes

MartĂ­n, Pino

159

Combustion-thermoelectric tube  

SciTech Connect (OSTI)

In direct combustion-thermoelectric energy conversion, direct fuel injection and reciprocation of the air flowing in a solid matrix are combined with the solid conduction to allow for obtaining super-adiabatic temperatures at the hot junctions. While the solid conductivity is necessary, the relatively large thermal conductivity of the available high-temperature thermoelectric materials (e.g., Si-Ge alloys) results in a large conduction loss from the hot junctions and deteriorates the performance. Here a combustion-thermoelectric tube is introduced and analyzed. Radially averaged temperatures are used for the fluid and solid phases. A combination of external cooling of the cold junctions, and direct injection of the fuel, has been used to increase the energy conversion efficiency for low thermal conductivity, high-melting temperature thermoelectric materials. The parametric study (geometry, flow, stoichiometry, materials) shows that with the current high figure of merit, high temperature Si{sub 0.7}Ge{sub 0.3} properties, a conversion efficiency of about 11% is achievable. With lower thermal conductivities for these high-temperature materials, efficiencies about 25% appear possible. This places this energy conversion in line with the other high efficiency, direct electric power generation methods.

Park, C.W.; Kaviany, M.

1999-07-01T23:59:59.000Z

160

Ultrarich Filtration Combustion of Ethane  

Science Journals Connector (OSTI)

Ultrarich filtration combustion of ethane is studied in a porous medium composed of alumina spheres with the aim to achieve optimized conversion to hydrogen and syngas. ... Dhamrat, R. S.; Ellzey, J. L.Numerical and experimental study of the conversion of methane to hydrogen in a porous media reactor Combust. ...

Mario Toledo; Khriscia Utria; Alexei V. Saveliev

2014-01-28T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


161

A Generalized Pyrolysis Model for Combustible Solids  

E-Print Network [OSTI]

model. ?H c is the heat of combustion, and the ratio ?H c /?may have widely varying heats of combustion (CO vs. gaseous

Lautenberger, Chris

2007-01-01T23:59:59.000Z

162

Optimization of Advanced Diesel Engine Combustion Strategies...  

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

Optimization of Advanced Diesel Engine Combustion Strategies Optimization of Advanced Diesel Engine Combustion Strategies 2010 DOE Vehicle Technologies and Hydrogen Programs Annual...

163

Advanced Combustion Concepts - Enabling Systems and Solutions...  

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

engine * Integration of proposed air path and HCCI combustion control strategies into ECU software * Prototype level 2 updates and proof of combustion concept for vehicle readiness...

164

Advanced Combustion Concepts - Enabling Systems and Solutions...  

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

engine installed and vehicle available for application, emission and fuel economy optimization with advanced combustion modes. 4 Advanced combustion control strategy, capable of...

165

Premix charge, compression ignition combustion system optimization...  

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

Premix charge, compression ignition combustion system optimization Premix charge, compression ignition combustion system optimization Presentation given at DEER 2006, August 20-24,...

166

Vehicle Technologies Office: Advanced Combustion Engines | Department...  

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

Batteries Fuel Efficiency & Emissions Combustion Engines Fuel Effects on Combustion Idle Reduction Emissions Waste Heat Recovery Lightweighting Parasitic Loss Reduction Lubricants...

167

Sandia Hydrogen Combustion Research | Department of Energy  

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

Sandia Hydrogen Combustion Research Sandia Hydrogen Combustion Research Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008 on February 25, 2008...

168

Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling...  

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

Spray, Combustion, & Emission Modeling using KH-ACT Primary Breakup Model & Detailed Chemistry Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling using KH-ACT Primary...

169

turbulence | OpenEI  

Open Energy Info (EERE)

turbulence turbulence Dataset Summary Description This raw data reflects readings from instruments mounted on or near a 82 meter meteorological tower located at the National Wind Technology Center (NWTC), approximately 5 miles south of Boulder, CO (specifically: 39.9107 N, 105.2348 W, datum WGS84). Source NREL Date Released Unknown Date Updated Unknown Keywords DOE irradiance NREL NWTC temperature turbulence wind wind direction wind speed Data text/plain icon Raw data (txt, 82 KiB) application/vnd.openxmlformats-officedocument.spreadsheetml.sheet icon Raw data field descriptions (xlsx, 52.5 KiB) Quality Metrics Level of Review Some Review Comment Data have not been reviewed for accuracy or completeness; disclaimer available (http://www.nrel.gov/disclaimer.html). Temporal and Spatial Coverage

170

Nuclear Thermal Rockets: The Physics of the Fission Reactor  

E-Print Network [OSTI]

Nuclear Thermal Rockets: The Physics of the Fission Reactor Shane D. Ross Control and Dynamical combustion are those powered by nuclear fission. Comparison of Chemical and Nuclear Rockets. Most existent.g., hydrogen and oxygen). In a nuclear rocket, or more precisely, a nuclear thermal rocket, the propellant

Ross, Shane

171

Combustion of viscous hydrocarbons  

SciTech Connect (OSTI)

A method is described for utilizing viscous hydrocarbons as combustible pre-atomized fuels, comprising: (A) forming a hydrocarbon-in-water emulsion using an effective amount of a surfactant package comprising at least one water-soluble surfactant, the hydrocarbon-in-water emulsion (1) comprising a hydrocarbon characterized by API gravity of about 20/sup 0/ API or less, viscosity of about 1000 centipoise or greater at 212/sup 0/F., a paraffin content of about 50% by weight or less and, an aromatic content of about 15% by weight or greater, and (2) having a hydrocarbon water ratio from about 60:40 to about 90:10 by volume; and (B) burning the resultant hydrocarbon-in-water emulsion.

Hayes, M.E.; Hrebenar, K.R.; Murphy, P.L.; Futch, L.E. Jr.; Deal, J.F. III; Bolden, P.L. Jr.

1987-08-04T23:59:59.000Z

172

Combustion of viscous hydrocarbons  

SciTech Connect (OSTI)

A method is described for utilizing viscous hydrocarbons as combustible fuels comprising: (A) forming a hydrocarbosol using a surfactant package in a proportion of about 1:100 to about 1:20,000 by weight based on hydrocarbon, (1) the surfactant package comprising (a) at least one water-soluble surfactant, an effective amount of which surfactant promotes emulsification of a hydrocarbon with API gravity of about 20/sup 0//sup o/ API or less; and (b) at least one water-soluble bioemulsifier, being a microboally-derived substance which predominantly resides at hydrocarbon/water interfaces to substantially surround hydrocarbon droplets in hydrocarbon-in-water emulsions; (2) the hydrocarbosol (a) comprising a hydrocarbon characterized by an API gravity of about 20/sup 0//sup o/ API or less; (b) having a hydrocarbon:water ratio of about 70:30 by volume; and (B) burning the resultant hydrocarbosol.

Hayes, M.E.; Hrebenar, K.R.; Murphy, P.L.; Futch, L.E. Jr.; Deal, J.F. III

1986-10-21T23:59:59.000Z

173

NETL: Combustion Technologies  

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

Gas Turbines for APFBC Gas Turbines for APFBC FBC Repower Simple Description Detailed Description APFBC Specs GTs for APFBC Suited for Repowering Existing Power Plants with Advanced Pressurized Fluidized-Bed Combined Cycles APFBC combined cycles have high energy efficiency levels because they use modern, high-temperature, high-efficiency gas turbines as the core of a combined power cycle. This web page discusses a current U.S. Department of Energy project that is evaluating combustion turbines suited for repowering existing steam plants. The natural-gas-fueled version of the Siemens Westinghouse Power Corporation W501F. Modified versions of this gas turbine core are suited for operating in APFBC power plants. Contents: Introduction APFBC Repowering Considerations

174

Feature-Based Statistical Analysis of Combustion Simulation Data  

SciTech Connect (OSTI)

We present a new framework for feature-based statistical analysis of large-scale scientific data and demonstrate its effectiveness by analyzing features from Direct Numerical Simulations (DNS) of turbulent combustion. Turbulent flows are ubiquitous and account for transport and mixing processes in combustion, astrophysics, fusion, and climate modeling among other disciplines. They are also characterized by coherent structure or organized motion, i.e. nonlocal entities whose geometrical features can directly impact molecular mixing and reactive processes. While traditional multi-point statistics provide correlative information, they lack nonlocal structural information, and hence, fail to provide mechanistic causality information between organized fluid motion and mixing and reactive processes. Hence, it is of great interest to capture and track flow features and their statistics together with their correlation with relevant scalar quantities, e.g. temperature or species concentrations. In our approach we encode the set of all possible flow features by pre-computing merge trees augmented with attributes, such as statistical moments of various scalar fields, e.g. temperature, as well as length-scales computed via spectral analysis. The computation is performed in an efficient streaming manner in a pre-processing step and results in a collection of meta-data that is orders of magnitude smaller than the original simulation data. This meta-data is sufficient to support a fully flexible and interactive analysis of the features, allowing for arbitrary thresholds, providing per-feature statistics, and creating various global diagnostics such as Cumulative Density Functions (CDFs), histograms, or time-series. We combine the analysis with a rendering of the features in a linked-view browser that enables scientists to interactively explore, visualize, and analyze the equivalent of one terabyte of simulation data. We highlight the utility of this new framework for combustion science; however, it is applicable to many other science domains.

Bennett, J; Krishnamoorthy, V; Liu, S; Grout, R; Hawkes, E; Chen, J; Pascucci, V; Bremer, P T

2011-11-18T23:59:59.000Z

175

Numerical simulations of industrial-scale combustion chamber - LES versus RANS  

Science Journals Connector (OSTI)

In this work we focus on the simulation of the process of biomass syngas combustion in the industrial combustion chamber directly linked with gasification chamber, where this gas is continuously producing from the biomass. Conflicting demands from the engineers to have rapid results and hints how to ensure the best conditions for combustion of this particular fuel and to lower the emission of pollutants, with simultaneously deep view inside the process and its stability motivates us to use both the RANS and LES techniques of turbulence modelling, compare it and take their advantages. We designed and performed series of 3D numerical simulations of both cold flow and combustion in complex geometry of industrial burner. It seems to us that the proper approach for modelling of biomass syngas combustion is steady flamelets model. Simulations performed with RANS closure are used as the initialisation of LES models, but their main goal is to predict the long-time oscillation of pressure and temperature observed in the working combustion chamber. On the other hand the main goal of the simulations with LES closure is to predict the proper level of short-time behaviour of the flame and local phenomena.

Kamil Kwiatkowski; Daniel Jasi?ski; Konrad Bajer

2011-01-01T23:59:59.000Z

176

Characterization of Relativistic MHD Turbulence  

E-Print Network [OSTI]

The objective of this work is to understand if and how the characteristics of relativistic MHD turbulence may differ from those of nonrelativistic MHD turbulence. We accomplish this by studying the invariants in the relativistic case and comparing them to what we know of nonrelativistic turbulence. Although much work has been done to understand the dynamics of nonrelativistic systems (mostly for ideal incompressible fluids), there is minimal literature explicitly describing the dynamics of relativistic MHD turbulence. Many authors simply assume that relativistic turbulence has the same invariants and obeys the same inverse energy cascade as non-relativistic systems.

Garrison, David

2015-01-01T23:59:59.000Z

177

Comparative study of micromixing models in transported scalar PDF simulations of turbulent nonpremixed bluff body flames  

SciTech Connect (OSTI)

Numerical simulation results are presented for turbulent jet diffusion flames with various levels of turbulence-chemistry interaction, stabilized behind a bluff body (Sydney Flames HM1-3). Interaction between turbulence and combustion is modeled with the transported joint-scalar PDF approach. The mass density function transport equation is solved in a Lagrangian manner. A second-moment-closure turbulence model is applied to obtain accurate mean flow and turbulent mixing fields. The behavior of two micromixing models is discussed: the Euclidean minimum spanning tree model and the modified Curl coalescence dispersion model. The impact of the micromixing model choice on the results in physical space is small, although some influence becomes visible as the amount of local extinction increases. Scatter plots and profiles of conditional means and variances of thermochemical quantities, conditioned on the mixture fraction, are discussed both within and downstream of the recirculation region. A distinction is made between local extinction and incomplete combustion, based on the CO species mass fraction. The differences in qualitative behavior between the micromixing models are explained and quantitative comparison to experimental data is made. (author)

Merci, Bart [Department of Flow, Heat and Combustion Mechanics, Ghent University-UGent, Ghent (Belgium); Roekaerts, Dirk [Department of Multi-Scale Physics, Delft University of Technology, Delft (Netherlands); Naud, Bertrand [CIEMAT, Madrid (Spain); Pope, Stephen B. [Mechanical and Aerospace Engineering, Cornell University, Ithaca, NY (United States)

2006-07-15T23:59:59.000Z

178

A commotion over turbulence  

Science Journals Connector (OSTI)

... calculations) of dimensionless parameters of the reactor setup9. This has led to the IFS/PPPL model, named after the main institutions involved in its development. The basis for this ... other components besides the turbulence-induced diffusivity. Dorland and Kotschen-reuther have combined the IFS/PPPL diffusivity model with an assumed prescription for the density evolution and the boundary temperatures, ...

Benjamin A. Carreras

1997-01-23T23:59:59.000Z

179

Cellular burning in lean premixed turbulent hydrogen-air flames: Coupling experimental and computational analysis at the laboratory scale  

Science Journals Connector (OSTI)

One strategy for reducing US dependence on petroleum is to develop new combustion technologies for burning the fuel-lean mixtures of hydrogen or hydrogen-rich syngas fuels obtained from the gasification of coal and biomass. Fuel-flexible combustion systems based on lean premixed combustion have the potential for dramatically reducing pollutant emissions in transportation systems, heat and stationary power generation. However, lean premixed flames are highly susceptible to fluid-dynamical combustion instabilities making robust and reliable systems difficult to design. Low swirl burners are emerging as an important technology for meeting design requirements in terms of both reliability and emissions for next generation combustion devices. In this paper, we present simulations of a lean, premixed hydrogen flame stabilized on a laboratory-scale low swirl burner. The simulations use detailed chemistry and transport without incorporating explicit models for turbulence or turbulence/chemistry interaction. Here we discuss the overall structure of the flame and compare with experimental data. We also use the simulation data to elucidate the characteristics of the turbulent flame interaction and how this impacts the analysis of experimental measurements.

M S Day; J B Bell; R K Cheng; S Tachibana; V E Beckner; M J Lijewski

2009-01-01T23:59:59.000Z

180

Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion  

Broader source: Energy.gov [DOE]

Applied low temperature combustion to the Navistar 6.4L V8 engine with 0.2g NOx/bhp-hr operation attained at the rated 16.5 BMEP

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
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181

Modeling of Combustion Processes in Internal Combustion Engines  

Science Journals Connector (OSTI)

Improving internal combustion engines (ICE) and increasing the quality of operation are linked with the necessity of maximally increasing the degree of compression. For ICE with spark ignition (otto cycle), th...

V. A. Vinokurov; V. A. Kaminskii; V. A. Frost…

2000-11-01T23:59:59.000Z

182

Some recent advances in droplet combustion  

Science Journals Connector (OSTI)

This paper reviews the theoretical and experimental advances in droplet combustion since the 1982 Second International Colloquium on Drops and Bubbles. Specific topics discussed include multicomponent droplet combustion and microexplosion convection droplet combustion the combustion of slurries propellants and hazardous wastes soot formation in droplet burning and several miscellaneous subjects. Areas of further research are suggested.

C. K. Law

1990-01-01T23:59:59.000Z

183

"Optimization of efficiency of internal combustion engines via using  

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

Optimization of efficiency of internal combustion engines via using Optimization of efficiency of internal combustion engines via using spinning gas and non-spectroscopic method of determining gas constituents through rotation ..--.. Inventors Nathaniel Fisch, Vasily Geyko An important use of the disclosed approach is the improvement efficiency of thermal cycles and as result efficiency of engines. Different cycles and different ways of compression of spinning gas may be used to maximize possible efficiency gain. In conventional internal combustion engines, gas spinning is either not used at all or used only with the purpose of increasing turbulence and better mixing. In the disclosed method, gas rotation is used for energy storage, hence it allows an improvement in thermal cycle efficiency. To achieve significant effect related to

184

Combustion system development of a two-stroke, spark-assisted DI diesel engine  

SciTech Connect (OSTI)

A loop-scavenged, two-stroke, spark-assisted DI diesel engine was developed by modifying an outboard marine gasoline engine to operate on diesel fuel with high fuel efficiency similar to a diesel engine, yet retain the two-stroke engine advantages of low cost, light weight, and high power-to-weight ratio. Engine modification was concentrated in the area of the combustion system, including transfer port design to generate air swirl in the cylinder, and combustion chamber design to generate air squish and turbulence. Bore and stroke (84 x 72 mm) remained the same as those of the base engine. The experimental engine used the production engine's piston, crankshaft, connecting rod, bearings, and cylinder block. The transfer port design was optimized using a flow test bench for best swirl and air flow pattern with a simple flow visualization technique. The best combustion chamber geometry, compression ratio, and fuel injection spray pattern were determined through engine experiments.

Ariga, S.; Matsushita, Y.

1988-01-01T23:59:59.000Z

185

LES of swirl-stabilised pulverised coal combustion in IFRF furnace No. 1  

Science Journals Connector (OSTI)

Abstract Swirl-stabilised turbulent flow and pulverised coal combustion in the semi-industrial (2.5 MW) IFRF furnace No. 1 are for the first time simulated by means of large eddy simulation and compared to results from the experimental campaign and RANS predictions by Weber et al. (1992). The large eddy simulation uses the Euler–Lagrange framework for two-phase flows and relatively simple sub-models for the particle heat-up, devolatilisation, char combustion and radiation governing the pulverised coal combustion process are employed. The simulations yield improved predictions of the velocity statistics in the quarl region and result in a favourable agreement of the mean species profiles along the burner centreline compared with the measurements, while some temperature underprediction can be observed. Furthermore, the transient Euler–Lagrange approach allows for a cross-comparison of the velocity and scalar statistics between the two phases and the comparison of the mean axial velocity and temperature shows the two phases to be near thermal and kinetic equilibrium along the burner axis. Individual particle time histories, which are crucial for the coal combustion sub-processes and overall flame stabilisation, are analysed. It is found that there is a lack of oxygen in the inner quarl region leading to a decreased volatile burning rate, which could however, be related to the simplified EBU turbulence–chemistry interaction model.

G. Olenik; O.T. Stein; A. Kronenburg

2014-01-01T23:59:59.000Z

186

First-Principles Simulations of High-Speed Combustion and Detonation |  

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

Picture shows a numerically generated pseudo-schlieren image of the onset of a detonation in a turbulent boundary layer. Picture shows a numerically generated pseudo-schlieren image of the onset of a detonation in a turbulent boundary layer. Weak ignition behind a reflected Mach=1.5 shock in a stoichiometric hydrogen-oxygen mixture at 0.1 atm initial pressure. Picture shows a numerically generated pseudo-schlieren image of the onset of a detonation in a turbulent boundary layer. Alexei Khokhlov, University of Chicago, Charles Bacon, Argonne National Laboratory, Joanna Austin and Andrew Knisely, University of Illinois at Urbanna-Champaign. First-Principles Simulations of High-Speed Combustion and Detonation PI Name: Alexei Khokhlov PI Email: ajk@oddjob.uchicago.edu Institution: University of Chicago Allocation Program: INCITE Allocation Hours at ALCF: 150 Million Year: 2014

187

A new BML-based RANS modelling for the description of gas turbine typical combustion processes  

Science Journals Connector (OSTI)

The work is concentrated on the formulation and validation of integral models within RANS framework for the numerical prediction of the premixed and partially premixed flames occurring in gas turbine combustors. The premixed combustion modelling is based on the BML approach coupled to the mixing transport providing variable equivalence ratio. Chemistry is described by means of ILDM model solving transport equations for reaction progress variables conditioned on the flame front. Multivariate presumed PDF model is used for the turbulence-chemistry interaction treatment. Turbulence is modelled using the second moment closure (SMC) and the standard ?-? model as well. The influence of non-gradient turbulent transport is investigated comparing the gradient diffusion closure and the solution of the scalar flux transport equations. Different model combinations are assessed simulating several premixed and partially premixed flame configurations and comparing results to the experimental data. The proposed model provides good predictions particularly in combination with SMC.

A. Maltsev; A. Sadiki; J. Janicka

2004-01-01T23:59:59.000Z

188

Euler-Euler simulation of wood chip combustion on a grate - effect of fuel moisture content and full scale application  

Science Journals Connector (OSTI)

Nowadays, it is common practice to perform CFD calculations for optimisation purposes of technical biomass combustion applications. A numerical model for wood chip combustion on grate firing arrangements has been developed. The model is based on an Euler-Euler approach, enabling a detailed multiphase description of the combustion chamber in terms of flow, turbulence and heat transfer. The model explicitly accounts for interactions between bed and freeboard region and comprises a global description of the whole incineration process associated with wood combustion. For validation purposes, the effect of fuel moisture content in a 240 kWth test facility has been observed experimentally and the results are opposed to the model predictions. Additionally, measurements within a 58 MWth full scale grate firing system have been conducted and the scalability of the numerical model towards industrial applications is investigated.

D. Kurz; U. Schnell; G. Scheffknecht

2013-01-01T23:59:59.000Z

189

Dilute Oxygen Combustion Phase I Final Report  

SciTech Connect (OSTI)

A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300°F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (<35 ppm). Detailed in-furnace species measurements revealed the importance of the interior furnace circulation patterns, as influenced by fuel and oxidant injection schemes, on pollutant emissions. The combustion stability traits of several DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.

Ryan, H.M.; Riley, M.F.; Kobayashi, H.

1997-10-31T23:59:59.000Z

190

Dilute Oxygen Combustion Phase 2 Final Report  

SciTech Connect (OSTI)

A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NOx) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NOx through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NOx production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature (~1366 K) oxidant (7-27% O2 vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d+ scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d+ scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW (~0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NOx emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NOx emissions below 5-10-3 g/MJ (10 ppm-air equivalent at 3% O2 dry) were obtained for furnace temperatures below 1533 K (2300?F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (<35 ppm). Detailed in-furnace species measurements revealed the importance of the interior furnace circulation patterns, as influenced by fuel and oxidant injection schemes, on pollutant emissions. The combustion stability traits of several DOC burner arrangements were ascertained through furnace pressure measurements, wit6h increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of lower utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, required additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.

Ryan, H.M.; Riley, M.F.; Kobayashi, H.

2005-09-30T23:59:59.000Z

191

Dilute oxygen combustion. Phase I report  

SciTech Connect (OSTI)

A novel burner, in which fuel (natural gas) and oxidant (oxygen or air) are separately injected into a furnace, shows promise for achieving very low nitrogen oxide(s) (NO{sub x}) emissions for commercial furnace applications. The dilute oxygen combustion (DOC) burner achieves very low NO{sub x} through in-furnace dilution of the oxidant stream prior to combustion, resulting in low flame temperatures, thus inhibiting thermal NO{sub x} production. The results of a fundamental and applied research effort on the development of the DOC burner are presented. In addition, the results of a market survey detailing the potential commercial impact of the DOC system are disclosed. The fundamental aspects of the burner development project involved examining the flame characteristics of a natural gas turbulent jet in a high-temperature ({approximately}1366 K) oxidant (7-27% O{sub 2} vol. wet). Specifically, the mass entrainment rate, the flame lift-off height, the velocity field and major species field of the jet were evaluated as a function of surrounding-gas temperature and composition. The measured entrainment rate of the fuel jet decreased with increasing oxygen content in the surrounding high-temperature oxidant, and was well represented by the d{sup +} scaling correlation found in the literature. The measured flame lift-off height decreased with increasing oxygen content and increasing temperature of the surrounding gas. An increase in surrounding-gas oxygen content and/or temperature inhibited the velocity decay within the jet periphery as a function of axial distance as compared to isothermal turbulent jets. However, the velocity measurements were only broadly represented by the d{sup +} scaling correlation. Several DOC burner configurations were tested in a laboratory-scale furnace at a nominal firing rate of 185 kW ({approximately}0.63 MMBtu/h). The flue gas composition was recorded as a function of furnace nitrogen content, furnace temperature, burner geometric arrangement, firing rate, and fuel injection velocity. NO{sub x} emissions increased with increasing furnace nitrogen content and furnace temperature, but remained relatively insensitive to variations in fuel injection velocity and firing rate. NO{sub x} emissions below 5{times}10{sup -3} g/MJ (10 ppm-air equivalent at 3% O{sub 2} dry) were obtained for furnace temperatures below 1533 K (2300{degree}F) and furnace nitrogen levels between 1 and 40%. CO emissions were typically low (<35 ppm). Detailed in- furnace species measurements revealed the importance of the interior furnace circulation patterns, as influenced by fuel and oxidant injection schemes, on pollutant emissions. The combustion stability traits of several DOC burner arrangements were ascertained through furnace pressure measurements, with increased stability occurring as furnace temperature increased and as the separation distance between fuel and oxidant inputs decreased. Based on current market conditions, oxy-fuel conversion of batch steel reheat furnaces with a DOC burner is justified on the basis of utility costs alone. However, conversion of continuous steel reheat furnaces, which are responsible for most steel production, requires additional economic incentives, such as further fuel savings, increased furnace productivity, or emission credits.

NONE

1997-10-01T23:59:59.000Z

192

Staged Combustion of Pulverized Coal  

Science Journals Connector (OSTI)

The emissions of nitrogen oxides are much higher with the combustion of fossil fuels containing organic bound nitrogen compounds than with clean fuels like natural gas and light distillate oil. During combusti...

H. Kremer; R. Mechenbier; W. Schulz

1987-01-01T23:59:59.000Z

193

Light Duty Efficient Clean Combustion  

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

fuel efficiency over the FTP city drive cycle by 10.5% over today's state-of-the-art diesel engine. Develop & design an advanced combustion system that synergistically meets...

194

20 - Chemical looping combustion (CLC)  

Science Journals Connector (OSTI)

Abstract: Chemical-looping combustion (CLC) is a new combustion technology with inherent separation of the greenhouse gas CO2. The technology involves the use of a metal oxide as an oxygen carrier which transfers oxygen from combustion air to the fuel, and hence a direct contact between air and fuel is avoided. Two inter-connected fluidized beds, i.e. fuel reactor and air reactor, are used in the process. The outlet gas from the fuel reactor consists ideally of CO2 and H2O, and the latter is easily removed by condensation. This chapter presents the basic principles, gives an overview of oxygen-carrier materials and operational experiences, discusses the application to gaseous, liquid and solid fuels, and the use for combustion as well as for hydrogen production.

A. Lyngfelt

2013-01-01T23:59:59.000Z

195

Chemical Kinetics of Combustion Processes  

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

of Combustion Processes Hai Wang B. Yang, J. Camacho, S. Lieb, S. Memarzadeh, S.-K. Gao and S. Koumlis University of Southern California 2010 CEFRC Conference Benzene + O( 3 P) ...

196

Plum Combustion | Open Energy Information  

Open Energy Info (EERE)

Plum Combustion Plum Combustion Jump to: navigation, search Name Plum Combustion Place Atlanta, Georgia Product Combustion technology, which reduces NOx-emissions. Coordinates 33.748315°, -84.391109° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":33.748315,"lon":-84.391109,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

197

Combustion method for simultaneous control of nitrogen oxides and products of incomplete combustion  

SciTech Connect (OSTI)

A method is described for combusting material with controlled generation of both nitrogen oxides and products of incomplete combustion comprising: (A) combusting material in a first combustion zone to produce gaseous exhaust containing products of incomplete combustion and products of complete combustion; (B) passing the gaseous exhaust from the first combustion zone into a second combustion zone having a width and an axial direction; (C) injecting through a lance with an orientation substantially parallel to said axial direction at least one stream of oxidant, without fuel, having a diameter less than 1/100 of the width of the second combustion zone and having an oxygen concentration of at least 30% into the second combustion zone at a high velocity of at least 300 feet per second; (D) aspirating products of incomplete combustion into the high velocity oxidant; (E) combusting products of incomplete combustion aspirated into the high velocity oxidant with high velocity oxidant within the second combustion zone to carry out a stable combustion by the mixing of the aspirated products of incomplete combustion with the high velocity oxidant; and (F) spreading out the combustion reaction by aspiration of products of complete combustion into the oxidant, said products of complete combustion also serving as a heat sink, to inhibit NO[sub x] formation.

Ho, Min-Da.

1993-05-25T23:59:59.000Z

198

Chemical Looping Combustion Kinetics  

SciTech Connect (OSTI)

One of the most promising methods of capturing CO{sub 2} emitted by coal-fired power plants for subsequent sequestration is chemical looping combustion (CLC). A powdered metal oxide such as NiO transfers oxygen directly to a fuel in a fuel reactor at high temperatures with no air present. Heat, water, and CO{sub 2} are released, and after H{sub 2}O condensation the CO{sub 2} (undiluted by N{sub 2}) is ready for sequestration, whereas the nickel metal is ready for reoxidation in the air reactor. In principle, these processes can be repeated endlessly with the original nickel metal/nickel oxide participating in a loop that admits fuel and rejects ash, heat, and water. Our project accumulated kinetic rate data at high temperatures and elevated pressures for the metal oxide reduction step and for the metal reoxidation step. These data will be used in computational modeling of CLC on the laboratory scale and presumably later on the plant scale. The oxygen carrier on which the research at Utah is focused is CuO/Cu{sub 2}O rather than nickel oxide because the copper system lends itself to use with solid fuels in an alternative to CLC called 'chemical looping with oxygen uncoupling' (CLOU).

Edward Eyring; Gabor Konya

2009-03-31T23:59:59.000Z

199

E-Print Network 3.0 - autoridad reguladora nuclear Sample Search...  

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

13 Comisin de Energa Cmara de Diputados Summary: , especialmente en el uso de energas renovables, la energa nuclear y combustibles sintticos como el Hidrgeno... diversas...

200

Particulate emissions from combustion of biomass in conventional combustion (air) and oxy-combustion conditions.  

E-Print Network [OSTI]

??Oxy-fuel combustion is a viable technology for new and existing coal-fired power plants, as it facilitates carbon capture and thereby, can reduce carbon dioxide emissions.… (more)

Ruscio, Amanda

2013-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


201

Modeling Turbulent Flow  

National Nuclear Security Administration (NNSA)

Turbulent Turbulent Flow with Implicit LES L.G. Margolin 1 Proceedings of the Joint Russian-American Five Laboratory Conference on Computational Mathematics/Physics 19-23 June, 2005 Vienna, Austria 1 Applied Physics Division, Los Alamos National Laboratory, Los Alamos, NM 87545, len@lanl.gov 1 Abstract Implicit large eddy simulation (ILES) is a methodology for modeling high Reynolds' num- ber flows that combines computational efficiency and ease of implementation with predictive calculations and flexible application. Although ILES has been used for more than fifteen years, it is only recently that significant effort has gone into providing a physical rationale that speaks to its capabilities and its limitations. In this talk, we will present new theoret- ical results aimed toward building a justification and discuss some remaining gaps in our understanding and our practical

202

Advanced High Efficiency Clean Diesel Combustion with Low Cost...  

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

Efficiency Clean Diesel Combustion with Low Cost for Hybrid Engines Advanced High Efficiency Clean Diesel Combustion with Low Cost for Hybrid Engines Clean, in-cylinder combustion...

203

Low-Temperature Automotive Diesel Combustion | Department of...  

Office of Environmental Management (EM)

in Low Temperature Automotive Diesel Combustion Systems Mixture Formation in a Light-Duty Diesel Engine Light Duty Combustion Research: Advanced Light-Duty Combustion Experiments...

204

Oxy-Combustion CO2 Control | netl.doe.gov  

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

Advanced Combustion Oxy-Combustion Chemical Looping Combustion Program Plan Project Portfolio Project Information POSTED January 27, 2015 - Funding Opportunity Announcement DE-FOA-...

205

PARAMETRIC STUDY OF SUBMICRON PARTICULATES FROM PULVERIZED COAL COMBUSTION  

E-Print Network [OSTI]

D. , Trace Element Chemistry of Coal during Combustion andthe Emissions from Coal-Fired Plants. Prog. Energy Combust.Combustion of Pulverized Coal, Lawrence Berkeley Laboratory

Pennucci, J.

2014-01-01T23:59:59.000Z

206

Fuel Effects on Mixing-Controlled Combustion Strategies for High...  

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

Fuel Effects on Mixing-Controlled Combustion Strategies for High-Efficiency Clean-Combustion Engines Fuel Effects on Mixing-Controlled Combustion Strategies for High-Efficiency...

207

Transition to turbulence in ferrofluids  

E-Print Network [OSTI]

It is known that in classical fluids turbulence typically occurs at high Reynolds numbers. But can turbulence occur at low Reynolds numbers? Here we investigate the transition to turbulence in the classic Taylor-Couette system in which the rotating fluids are manufactured ferrofluids with magnetized nanoparticles embedded in liquid carriers. We find that, in the presence of a magnetic field turbulence can occur at Reynolds numbers that are at least one order of magnitude smaller than those in conventional fluids. This is established by extensive computational ferrohydrodynamics through a detailed bifurcation analysis and characterization of behaviors of physical quantities such as the energy, the wave number, and the angular momentum through the bifurcations. A striking finding is that, as the magnetic field is increased, the onset of turbulence can be determined accurately and reliably. Our results imply that experimental investigation of turbulence can be greatly facilitated by using ferrofluids, opening up...

Altmeyer, Sebastian; Lai, Ying-Cheng

2015-01-01T23:59:59.000Z

208

The Effects of Ethanol/Gasoline Blends on Advanced Combustion Strategies in Internal Combustion Engines.  

E-Print Network [OSTI]

??This dissertation presents the effects of blending ethanol with gasoline on advanced combustion strategies in internal combustion engines. The unique chemical, physical and thermal properties… (more)

Fatouraie, Mohammad

2014-01-01T23:59:59.000Z

209

Quantum ghost imaging through turbulence  

SciTech Connect (OSTI)

We investigate the effect of turbulence on quantum ghost imaging. We use entangled photons and demonstrate that for a specific experimental configuration the effect of turbulence can be greatly diminished. By decoupling the entangled photon source from the ghost-imaging central image plane, we are able to dramatically increase the ghost-image quality. When imaging a test pattern through turbulence, this method increases the imaged pattern visibility from V=0.15{+-}0.04 to 0.42{+-}0.04.

Dixon, P. Ben; Howland, Gregory A.; Howell, John C. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Chan, Kam Wai Clifford [Rochester Optical Manufacturing Company, Rochester, New York 14606 (United States); O'Sullivan-Hale, Colin; Rodenburg, Brandon [Institute of Optics, University of Rochester, Rochester, New York 14627 (United States); Hardy, Nicholas D.; Shapiro, Jeffrey H. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States); Simon, D. S.; Sergienko, A. V. [Department of Electrical and Computer Engineering, Boston University, Boston, Massachusetts 02215 (United States); Boyd, R. W. [Department of Physics and Astronomy, University of Rochester, Rochester, New York 14627 (United States); Institute of Optics, University of Rochester, Rochester, New York 14627 (United States)

2011-05-15T23:59:59.000Z

210

Combustion Byproducts Recycling Consortium  

SciTech Connect (OSTI)

The Combustion Byproducts Recycling Consortium (CBRC) program was developed as a focused program to remove and/or minimize the barriers for effective management of over 123 million tons of coal combustion byproducts (CCBs) annually generated in the USA. At the time of launching the CBRC in 1998, about 25% of CCBs were beneficially utilized while the remaining was disposed in on-site or off-site landfills. During the ten (10) year tenure of CBRC (1998-2008), after a critical review, 52 projects were funded nationwide. By region, the East, Midwest, and West had 21, 18, and 13 projects funded, respectively. Almost all projects were cooperative projects involving industry, government, and academia. The CBRC projects, to a large extent, successfully addressed the problems of large-scale utilization of CCBs. A few projects, such as the two Eastern Region projects that addressed the use of fly ash in foundry applications, might be thought of as a somewhat smaller application in comparison to construction and agricultural uses, but as a novel niche use, they set the stage to draw interest that fly ash substitution for Portland cement might not attract. With consideration of the large increase in flue gas desulfurization (FGD) gypsum in response to EPA regulations, agricultural uses of FGD gypsum hold promise for large-scale uses of a product currently directed to the (currently stagnant) home construction market. Outstanding achievements of the program are: (1) The CBRC successfully enhanced professional expertise in the area of CCBs throughout the nation. The enhanced capacity continues to provide technology and information transfer expertise to industry and regulatory agencies. (2) Several technologies were developed that can be used immediately. These include: (a) Use of CCBs for road base and sub-base applications; (b) full-depth, in situ stabilization of gravel roads or highway/pavement construction recycled materials; and (c) fired bricks containing up to 30%-40% F-fly ash. Some developed technologies have similar potential in the longer term. (3) Laboratory studies have been completed that indicate that much higher amounts of fly ash could be added in cement-concrete applications under some circumstances. This could significantly increase use of fly ash in cement-concrete applications. (4) A study of the long-term environmental effects of structural fills in a surface mine in Indiana was completed. This study has provided much sought after data for permitting large-volume management options in both beneficial as well as non-beneficial use settings. (5) The impact of CBRC on CCBs utilization trends is difficult to quantify. However it is fair to say that the CBRC program had a significant positive impact on increased utilization of CCBs in every region of the USA. Today, the overall utilization of CCBs is over 43%. (6) CBRC-developed knowledge base led to a large number of other projects completed with support from other sources of funding. (7) CBRC research has also had a large impact on CCBs management across the globe. Information transfer activities and visitors from leading coal producing countries such as South Africa, Australia, England, India, China, Poland, Czech Republic and Japan are truly noteworthy. (8) Overall, the CBRC has been a truly successful, cooperative research program. It has brought together researchers, industry, government, and regulators to deal with a major problem facing the USA and other coal producing countries in the world.

Paul Ziemkiewicz; Tamara Vandivort; Debra Pflughoeft-Hassett; Y. Paul Chugh; James Hower

2008-08-31T23:59:59.000Z

211

Filtering Turbulent Sparsely Observed Geophysical Flows  

Science Journals Connector (OSTI)

Filtering sparsely turbulent signals from nature is a central problem of contemporary data assimilation. Here, sparsely observed turbulent signals from nature are generated by solutions of two-layer quasigeostrophic models with turbulent cascades ...

John Harlim; Andrew J. Majda

2010-04-01T23:59:59.000Z

212

HCCI Combustion: Analysis and Experiments  

SciTech Connect (OSTI)

Homogeneous charge compression ignition (HCCI) is a new combustion technology that may develop as an alternative to diesel engines with high efficiency and low NOx and particulate matter emissions. This paper describes the HCCI research activities being currently pursued at Lawrence Livermore National Laboratory and at the University of California Berkeley. Current activities include analysis as well as experimental work. On analysis, we have developed two powerful tools: a single zone model and a multi-zone model. The single zone model has proven very successful in predicting start of combustion and providing reasonable estimates for peak cylinder pressure, indicated efficiency and NOX emissions. This model is being applied to develop detailed engine performance maps and control strategies, and to analyze the problem of engine startability. The multi-zone model is capable of very accurate predictions of the combustion process, including HC and CO emissions. The multi-zone model h as applicability to the optimization of combustion chamber geometry and operating conditions to achieve controlled combustion at high efficiency and low emissions. On experimental work, we have done a thorough evaluation of operating conditions in a 4-cylinder Volkswagen TDI engine. The engine has been operated over a wide range of conditions by adjusting the intake temperature and the fuel flow rate. Satisfactory operation has been obtained over a wide range of operating conditions. Cylinder-to-cylinder variations play an important role in limiting maximum power, and should be controlled to achieve satisfactory performance.

Salvador M. Aceves; Daniel L. Flowers; Joel Martinez-Frias; J. Ray Smith; Robert Dibble; Michael Au; James Girard

2001-05-14T23:59:59.000Z

213

Finite-rate chemistry and transient effects in direct numerical simulations of turbulent nonpremixed flames  

SciTech Connect (OSTI)

Three-dimensional direct numerical simulations (DNS) of turbulent nonpremixed flames including finite-rate chemistry and heat release effects were performed. Two chemical reaction models were considered: (1) a single-step global reaction model in which the heat release and activation energy parameters are typical combustion applications, and (2) a two-step reaction model to stimulate radical production and consumption and to compare against the single-step model. The model problem consists of the interaction between an initially unstained laminar diffusion flame and a three-dimensional field of homogeneous turbulence. Conditions ranging from fast chemistry to the pure mixing limit were studied by varying a global Damkoehler number. Results suggest that turbulence-induced mixing acting along the stoichiometric line leads to a strong modification of the inner structure of the turbulent flame compared with a laminar strained flame, resulting in intermediate species concentrations well above the laminar prediction. This result is consistent the experimental observations. Comparison of the response of the turbulent flame structure due to changes in the scalar dissipation rate with a steady strained laminar flame reveals that unsteady strain rates experienced by the turbulent flame may be responsible for h3e observed high concentrations of reaction intermediates.

Mahalingam, S. [Univ. of Colorado, Boulder, CO (United States). Center for Combustion Research] [Univ. of Colorado, Boulder, CO (United States). Center for Combustion Research; Chen, J.H. [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility] [Sandia National Labs., Livermore, CA (United States). Combustion Research Facility; Vervisch, L. [CORIA, Rouen (France). Laboratoire de Mechanique des Fluides Numeriques] [CORIA, Rouen (France). Laboratoire de Mechanique des Fluides Numeriques

1995-08-01T23:59:59.000Z

214

On the validation of magnetic resonance velocimetry in single-phase turbulent pipe flows  

SciTech Connect (OSTI)

A nuclear magnetic resonance imaging technique is used to measure velocity distributions in turbulent pipe flows up to Re = 24580. While turbulent intensity is usually determined from signal attenuation, we deduce turbulent intensity from velocity distribution with no need to suppose a Gaussian distribution for velocity fluctuations. Skewness and flatness measurements are also presented in this paper. Comparison with DNS show good agreement and we show that NMR data is sufficiently accurate to provide turbulent viscosity profile. The low field system used in this study allow the suppression of susceptibility artifacts and thus open its use for studying two-phase flows. We postulate that the method used here could be applied to two-phase flows and would thus provide valuable information on turbulent viscosity models. (authors)

Jullien, P.; Lemonnier, H. [CEA Grenoble, DTN LITA SE2T, F-38054 Grenoble 9, (France)

2012-03-15T23:59:59.000Z

215

Global simulations of magnetorotational turbulence – II. Turbulent energetics  

Science Journals Connector (OSTI)

......Importantly, as we are using an ideal MHD simulation, this shows that...construct a simplified energy flow diagram, which is shown in Fig...the heart of self-sustaining MHD turbulence in accretion discs. Figure 14. Energy flow diagram for turbulence in a global disc......

E. R. Parkin

2014-01-01T23:59:59.000Z

216

Supercomputers Capture Turbulence in the Solar Wind  

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

Capture Turbulence in the Solar Wind Supercomputers Capture Turbulence in the Solar Wind Berkeley Lab visualizations could help scientists forecast destructive space weather...

217

Natural Ores as Oxygen Carriers in Chemical Looping Combustion  

Science Journals Connector (OSTI)

Natural Ores as Oxygen Carriers in Chemical Looping Combustion ... Chemical looping combustion (CLC) is a combustion technology that utilizes oxygen from oxygen carriers (OC), such as metal oxides, instead of air to combust fuels. ...

Hanjing Tian; Ranjani Siriwardane; Thomas Simonyi; James Poston

2013-01-02T23:59:59.000Z

218

Modelling turbulence effects in wildland fire propagation by the randomized level-set method  

E-Print Network [OSTI]

Turbulence is of paramount importance in wildland fire propagation since it randomly transports the hot air mass that can pre-heat and then ignite the area ahead the fire. This contributes to give a random character to the firefront position together with other phenomena as for example fire spotting, vegetation distribution (patchiness), gaseous combustion fluctuation, small-scale terrain elevation changes. Here only turbulence is considered. The level-set method is used to numerically describe the evolution of the fireline contour that is assumed to have a random motion because of turbulence. The progression of the combustion process is then described by a level-set contour distributed according to a weight function given by the probability density function of the air particles in turbulent motion. From the comparison between the ordinary and the randomized level-set methods, it emerges that the proposed modelling approach turns out to be suitable to simulate a moving firefront fed by the ground fuel and dri...

Pagnini, Gianni

2014-01-01T23:59:59.000Z

219

Combustion heater for oil shale  

DOE Patents [OSTI]

A combustion heater for oil shale heats particles of spent oil shale containing unburned char by burning the char. A delayed fall is produced by flowing the shale particles down through a stack of downwardly sloped overlapping baffles alternately extending from opposite sides of a vertical column. The delayed fall and flow reversal occurring in passing from each baffle to the next increase the residence time and increase the contact of the oil shale particles with combustion supporting gas flowed across the column to heat the shale to about 650 to 700/sup 0/C for use as a process heat source.

Mallon, R.; Walton, O.; Lewis, A.E.; Braun, R.

1983-09-21T23:59:59.000Z

220

Combustion heater for oil shale  

DOE Patents [OSTI]

A combustion heater for oil shale heats particles of spent oil shale containing unburned char by burning the char. A delayed fall is produced by flowing the shale particles down through a stack of downwardly sloped overlapping baffles alternately extending from opposite sides of a vertical column. The delayed fall and flow reversal occurring in passing from each baffle to the next increase the residence time and increase the contact of the oil shale particles with combustion supporting gas flowed across the column to heat the shale to about 650.degree.-700.degree. C. for use as a process heat source.

Mallon, Richard G. (Livermore, CA); Walton, Otis R. (Livermore, CA); Lewis, Arthur E. (Los Altos, CA); Braun, Robert L. (Livermore, CA)

1985-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


221

Chemical kinetics and combustion modeling  

SciTech Connect (OSTI)

The goal of this program is to gain qualitative insight into how pollutants are formed in combustion systems and to develop quantitative mathematical models to predict their formation rates. The approach is an integrated one, combining low-pressure flame experiments, chemical kinetics modeling, theory, and kinetics experiments to gain as clear a picture as possible of the process in question. These efforts are focused on problems involved with the nitrogen chemistry of combustion systems and on the formation of soot and PAH in flames.

Miller, J.A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

222

Combustion synthesis method and products  

DOE Patents [OSTI]

Disclosed is a method of producing dense refractory products, comprising: (a) obtaining a quantity of exoergic material in powder form capable of sustaining a combustion synthesis reaction; (b) removing absorbed water vapor therefrom; (c) cold-pressing said material into a formed body; (d) plasma spraying said formed body with a molten exoergic material to form a coat thereon; and (e) igniting said exoergic coated formed body under an inert gas atmosphere and pressure to produce self-sustained combustion synthesis. Also disclosed are products produced by the method.

Holt, J.B.; Kelly, M.

1993-03-30T23:59:59.000Z

223

Combustion synthesis method and products  

DOE Patents [OSTI]

Disclosed is a method of producing dense refractory products, comprising: (a) obtaining a quantity of exoergic material in powder form capable of sustaining a combustion synthesis reaction; (b) removing absorbed water vapor therefrom; (c) cold-pressing said material into a formed body; (d) plasma spraying said formed body with a molten exoergic material to form a coat thereon; and (e) igniting said exoergic coated formed body under an inert gas atmosphere and pressure to produce self-sustained combustion synthesis. Also disclosed are products produced by the method.

Holt, J. Birch (San Jose, CA); Kelly, Michael (West Alexandria, OH)

1993-01-01T23:59:59.000Z

224

Engine Combustion Network Experimental Data  

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

Maintained by the Engine Combustion Department of Sandia National Laboratories, data currently available on the website includes reacting and non-reacting sprays in a constant-volume chamber at conditions typical of diesel combustion. The data are useful for model development and validation because of the well-defined boundary conditions and the wide range of conditions employed. A search utility displays data based on experimental conditions such as ambient temperature, ambient density, injection pressure, nozzle size, fuel, etc. Experiment-related visualizations are also available. The search utility for experimental data is located at http://public.ca.sandia.gov/ecn/cvdata/frameset.html (Specialized Interface)

225

Transonic Combustion Inc | Open Energy Information  

Open Energy Info (EERE)

Transonic Combustion Inc Transonic Combustion Inc Jump to: navigation, search Name Transonic Combustion, Inc. Place Camarillo, California Zip CA 93012 Sector Efficiency, Renewable Energy Product Transonic Combustion, Inc. is a US based research & development company focused on developing ultra-high efficiency automotive engines that run on gasoline and bio-renewable flex fuels. References Transonic Combustion, Inc.[1] LinkedIn Connections CrunchBase Profile No CrunchBase profile. Create one now! This article is a stub. You can help OpenEI by expanding it. Transonic Combustion, Inc. is a company located in Camarillo, California . References ↑ "Transonic Combustion, Inc." Retrieved from "http://en.openei.org/w/index.php?title=Transonic_Combustion_Inc&oldid=352376

226

Biomass Combustion: Carbon Capture and Storage  

Science Journals Connector (OSTI)

This chapter deals with the capture and storage of carbon dioxide produced by the combustion of biomass. Since biomass combustion is potentially carbon neutral, this technique could provide a method of reducing t...

Jenny M. Jones; Amanda R. Lea-Langton…

2014-01-01T23:59:59.000Z

227

Coal Characterization in Relation to Coal Combustion  

Science Journals Connector (OSTI)

Most coals are used worldwide for combustion today. Generally all kinds of coals are applicable for combustion. The major methods of burning are fixed bed firing, fluidized bed firing and suspension firing. Th...

Harald Jüntgen

1987-01-01T23:59:59.000Z

228

Practical Use of Coal Combustion Research  

Science Journals Connector (OSTI)

Laboratory measurements of coal rapid pyrolysis char yield and char reactivity, together with a simple model of pulverized coal combustion, have been used to predict coal combustion efficiency in utility boile...

P. T. Roberts; C. Morley

1987-01-01T23:59:59.000Z

229

Combustion of Solid Biomass: Classification of Fuels  

Science Journals Connector (OSTI)

The combustion of solid biomass and the classification of these fuels are considered. Firstly the different methods of combustion appliances and plants are outlined from a ... view. The forms and types of solid biomass

Jenny M. Jones; Amanda R. Lea-Langton…

2014-01-01T23:59:59.000Z

230

Volatile Organic Compounds — Emissions from Biomass Combustion  

Science Journals Connector (OSTI)

The emissions of Volatile Organic Compounds (VOC) from biomass combustion have been investigated. VOC contribute both to ... 0.5–10 MW. A variety of biomass fuel types and combustion equipment was covered. The su...

Lennart Gustavsson; Mats-Lennart Karlsson

1993-01-01T23:59:59.000Z

231

Fuel Modification t Facilitate Future Combustion Regimes? | Department...  

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

Modification t Facilitate Future Combustion Regimes? Fuel Modification t Facilitate Future Combustion Regimes? 2005 Diesel Engine Emissions Reduction (DEER) Conference...

232

Turbulent Magnetic Reconnection Near a  

E-Print Network [OSTI]

Turbulent Magnetic Reconnection Near a 3D Magnetic Null C. S. Ng Space Science Center Institute for the Study of Earth, Oceans, and Space University of New Hampshire, Durham, NH 03824 #12;Turbulent Magnetic Reconnection Near a 3D Magnetic Null C. S. Ng, chung-sang.ng@unh.edu, Space Science Center, Institute

Ng, Chung-Sang

233

Advances in compressible turbulent mixing  

SciTech Connect (OSTI)

This volume includes some recent additions to original material prepared for the Princeton International Workshop on the Physics of Compressible Turbulent Mixing, held in 1988. Workshop participants were asked to emphasize the physics of the compressible mixing process rather than measurement techniques or computational methods. Actual experimental results and their meaning were given precedence over discussions of new diagnostic developments. Theoretical interpretations and understanding were stressed rather than the exposition of new analytical model developments or advances in numerical procedures. By design, compressibility influences on turbulent mixing were discussed--almost exclusively--from the perspective of supersonic flow field studies. The papers are arranged in three topical categories: Foundations, Vortical Domination, and Strongly Coupled Compressibility. The Foundations category is a collection of seminal studies that connect current study in compressible turbulent mixing with compressible, high-speed turbulent flow research that almost vanished about two decades ago. A number of contributions are included on flow instability initiation, evolution, and transition between the states of unstable flow onset through those descriptive of fully developed turbulence. The Vortical Domination category includes theoretical and experimental studies of coherent structures, vortex pairing, vortex-dynamics-influenced pressure focusing. In the Strongly Coupled Compressibility category the organizers included the high-speed turbulent flow investigations in which the interaction of shock waves could be considered an important source for production of new turbulence or for the enhancement of pre-existing turbulence. Individual papers are processed separately.

Dannevik, W.P.; Buckingham, A.C.; Leith, C.E. [eds.

1992-01-01T23:59:59.000Z

234

Flame front structure of turbulent premixed flames of syngas oxyfuel mixtures  

Science Journals Connector (OSTI)

Abstract In order to investigate oxyfuel combustion characteristics of typical composition of coal gasification syngas connected to CCS systems. Instantaneous flame front structure of turbulent premixed flames of CO/H2/O2/CO2 mixtures which represent syngas oxyfuel combustion was quantitatively studied comparing with CH4/air and syngas/air flames by using a nozzle-type Bunsen burner. Hot-wire anemometer and OH-PLIF were used to measure the turbulent flow and detect the instantaneous flame front structure, respectively. Image processing and statistical analyzing were performed using the Matlab Software. Flame surface density, mean progress variable, local curvature radius, mean flame volume, and flame thickness, were obtained. Results show that turbulent premixed flames of syngas possess wrinkled flame front structure which is a general feature of turbulent premixed flames. Flame surface density for the CO/H2/O2/CO2 flame is much larger than that of CO/H2/O2/air and CH4/air flames. This is mainly caused by the smaller flame intrinsic instability scale, which would lead to smaller scales and less flame passivity response to turbulence presented by Markstain length, which reduce the local flame stretch against turbulence vortex. Peak value of Possibility Density Function (PDF) distribution of local curvature radius, R, for CO/H2/O2/CO2 flames is larger than those of CO/H2/O2/air and CH4/air flames at both positive and negative side and the corresponding R of absolute peak PDF is the smallest. This demonstrates that the most frequent scale is the smallest for CO/H2/O2/CO2 flames. Mean flame volume of CO/H2/O2/CO2 flame is smaller than that of CH4/air flame even smaller than that of CO/H2/O2/air flame. This would be due to the lower flame height and smaller flame wrinkles.

Meng Zhang; Jinhua Wang; Jin Wu; Zhilong Wei; Zuohua Huang; Hideaki Kobayashi

2014-01-01T23:59:59.000Z

235

Modeling of HCCI and PCCI Combustion Processes  

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

combustion timing control - Startup - Fuel air ratio measurement and control - Low Power Density - Hydrocarbon and CO emissions Approach: Fundamental and...

236

Oxy-combustion Boiler Material Development  

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

Oxy-combustion Boiler Material Oxy-combustion Boiler Material Development Background In an oxy-combustion system, combustion air (79 percent nitrogen, 21 percent oxygen) is replaced by oxygen and recycled flue gas (carbon dioxide [CO 2 ] and water), eliminating nitrogen in the flue gas stream. When applied to an existing boiler, the flue gas recirculation rate is adjusted to enable the boiler to maintain its original air-fired heat absorption performance, eliminating the need to derate the boiler

237

LES SOFTWARE FOR THE DESIGN OF LOW EMISSION COMBUSTION SYSTEMS FOR VISION 21 PLANTS  

SciTech Connect (OSTI)

In this project, an advanced computational software tool will be developed for the design of low emission combustion systems required for Vision 21 clean energy plants. This computational tool will utilize Large Eddy Simulation (LES) methods to predict the highly transient nature of turbulent combustion. The time-accurate software will capture large scale transient motion, while the small scale motion will be modeled using advanced subgrid turbulence and chemistry closures. This three-year project is composed of: Year 1--model development/implementation, Year 2--software alpha validation, and Year 3--technology transfer of software to industry including beta testing. In this first year of the project, subgrid models for turbulence and combustion are being developed through university research (Suresh Menon-Georgia Tech and J.-Y. Chen- UC Berkeley) and implemented into a leading combustion CFD code, CFD-ACE+. The commercially available CFDACE+ software utilizes unstructured , parallel architecture and 2nd-order spatial and temporal numerics. To date, the localized dynamic turbulence model and reduced chemistry models (up to 19 species) for natural gas, propane, hydrogen, syngas, and methanol have been incorporated. The Linear Eddy Model (LEM) for subgrid combustion-turbulence interaction has been developed and implementation into CFD-ACE+ has started. Ways of reducing run-time for complex stiff reactions is being studied, including the use of in situ tabulation and neural nets. Initial validation cases have been performed. CFDRC has also completed the integration of a 64 PC cluster to get highly scalable computing power needed to perform the LES calculations ({approx} 2 million cells) in several days. During the second year, further testing and validation of the LES software will be performed. Researchers at DOE-NETL are working with CFDRC to provide well-characterized high-pressure test data for model validation purposes. To insure practical, usable software is developed, a consortium of gas turbine and industrial burner manufacturers has been established to guide and direct the software development/validation effort. The consortium members include Siemens- Westinghouse, GE Power Systems, Pratt & Whitney, Rolls-Royce, Honeywell, Solar, Coen, McDermott, Vapor Power, Woodward FST, Parker Hannifin, John Zink, RamGen Power, Virginia Tech, DOE-NETL, Air Force Research Laboratory, DOE-ANL, and NASA GRC. Annual consortium meetings are being held in Huntsville, with the 2nd meeting scheduled for January 31-February 1, 2002. 2 Benefits of the program will include the ability to assess complex combustion challenges such as combustion instability, lean blowout, flashback, emissions and the effect of fuel type on performance. The software will greatly reduce development costs and the time cycle of combustor development. And perhaps the greatest benefit will be that the software will stimulate new, creative ideas to solve the combustion challenges of the Vision 21 plant.

Cannon, Steven M.; Adumitroaie, Virgil; McDaniel, Keith S.; Smith, Clifford E.

2001-11-06T23:59:59.000Z

238

Polymer combustion: effects of flame emissivity  

Science Journals Connector (OSTI)

...gas phase. Polymer combustion chemistry is modelled...investigating polymer combustion it has proven advantageous...properties and treat the heat flux from the ignition...luminous flames from hydrocarbon fuels, it is common...A (1999) Polymer combustion: effects of flame emissivity...

1999-01-01T23:59:59.000Z

239

Fundamental Study of Single Biomass Particle Combustion  

E-Print Network [OSTI]

Fundamental Study of Single Biomass Particle Combustion Maryam Momeni #12;Fundamental Study of Single Biomass Particle Combustion Maryam Momeni Dissertation submitted to the Faculty of Engineering Fundamental Study of Single Biomass Particle Combustion This thesis is a comprehensive study of single biomass

Berning, Torsten

240

Effects of primary breakup modeling on spray and combustion characteristics of compression ignition engines  

SciTech Connect (OSTI)

Injector flow dynamics and primary breakup processes are known to play a pivotal role in determining combustion and emissions in diesel engines. In the present study, we examine the effects of primary breakup modeling on the spray and combustion characteristics under diesel engine conditions. The commonly used KH model, which considers the aerodynamically induced breakup based on the Kelvin-Helmholtz instability, is modified to include the effects of cavitation and turbulence generated inside the injector. The KH model and the new (KH-ACT) model are extensively evaluated by performing 3-D time-dependent simulations with detailed chemistry under diesel engine conditions. Results indicate that the inclusion of cavitation and turbulence enhances primary breakup, leading to smaller droplet sizes, decrease in liquid penetration, and increase in the radial dispersion of spray. Predictions are compared with measurements for non-evaporating and evaporating sprays, as well as with flame measurements. While both the models are able to reproduce the experimentally observed global spray and combustion characteristics, predictions using the KH-ACT model exhibit closer agreement with measurements in terms of liquid penetration, cone angle, spray axial velocity, and liquid mass distribution for non-evaporating sprays. Similarly, the KH-ACT model leads to better agreement with respect to the liquid length and vapor penetration distance for evaporating sprays, and with respect to the flame lift-off location for combusting sprays. The improved agreement is attributed to the ability of the new model to account for the effects of turbulence and cavitation generated inside the injector, which enhance the primary breakup. Results further indicate that the combustion under diesel engine conditions is characterized by a double-flame structure with a rich premixed reaction zone near the flame stabilization region and a non-premixed reaction zone further downstream. This flame structure is consistent with the Dec's model for diesel engine combustion (Dec, 1997), and well captured by a newly developed flame index based on the scalar product of CO and O{sub 2} mass fraction gradients. (author)

Som, S.; Aggarwal, S.K. [Department of Mechanical and Industrial Engineering, University of Illinois at Chicago, Chicago, IL 60607 (United States)

2010-06-15T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


241

Method of combustion for dual fuel engine  

DOE Patents [OSTI]

Apparatus and a method of introducing a primary fuel, which may be a coal water slurry, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure. 19 figures.

Hsu, B.D.; Confer, G.L.; Zujing Shen; Hapeman, M.J.; Flynn, P.L.

1993-12-21T23:59:59.000Z

242

Method of combustion for dual fuel engine  

DOE Patents [OSTI]

Apparatus and a method of introducing a primary fuel, which may be a coal water slutty, and a high combustion auxiliary fuel, which may be a conventional diesel oil, into an internal combustion diesel engine comprises detecting the load conditions of the engine, determining the amount of time prior to the top dead center position of the piston to inject the main fuel into the combustion chamber, and determining the relationship of the timing of the injection of the auxiliary fuel into the combustion chamber to achieve a predetermined specific fuel consumption, a predetermined combustion efficiency, and a predetermined peak cylinder firing pressure.

Hsu, Bertrand D. (Erie, PA); Confer, Gregory L. (Erie, PA); Shen, Zujing (Erie, PA); Hapeman, Martin J. (Edinboro, PA); Flynn, Paul L. (Fairview, PA)

1993-12-21T23:59:59.000Z

243

Modeling of Laser-Induced Metal Combustion  

SciTech Connect (OSTI)

Experiments involving the interaction of a high-power laser beam with metal targets demonstrate that combustion plays an important role. This process depends on reactions within an oxide layer, together with oxygenation and removal of this layer by the wind. We present an analytical model of laser-induced combustion. The model predicts the threshold for initiation of combustion, the growth of the combustion layer with time, and the threshold for self-supported combustion. Solutions are compared with detailed numerical modeling as benchmarked by laboratory experiments.

Boley, C D; Rubenchik, A M

2008-02-20T23:59:59.000Z

244

Memory effects in turbulent transport  

E-Print Network [OSTI]

In the mean-field theory of magnetic fields, turbulent transport, i.e. the turbulent electromotive force, is described by a combination of the alpha effect and turbulent magnetic diffusion, which are usually assumed to be proportional respectively to the mean field and its spatial derivatives. For a passive scalar there is just turbulent diffusion, where the mean flux of concentration depends on the gradient of the mean concentration. However, these proportionalities are approximations that are valid only if the mean field or the mean concentration vary slowly in time. Examples are presented where turbulent transport possesses memory, i.e. where it depends crucially on the past history of the mean field. Such effects are captured by replacing turbulent transport coefficients with time integral kernels, resulting in transport coefficients that depend effectively on the frequency or the growth rate of the mean field itself. In this paper we perform numerical experiments to find the characteristic timescale (or memory length) of this effect as well as simple analytical models of the integral kernels in the case of passive scalar concentrations and kinematic dynamos. The integral kernels can then be used to find self-consistent growth or decay rates of the mean fields. In mean-field dynamos the growth rates and cycle periods based on steady state values of alpha effect and turbulent diffusivity can be quite different from the actual values.

Alexander Hubbard; Axel Brandenburg

2008-11-17T23:59:59.000Z

245

Compound cooling flow turbulator for turbine component  

DOE Patents [OSTI]

Multi-scale turbulation features, including first turbulators (46, 48) on a cooling surface (44), and smaller turbulators (52, 54, 58, 62) on the first turbulators. The first turbulators may be formed between larger turbulators (50). The first turbulators may be alternating ridges (46) and valleys (48). The smaller turbulators may be concave surface features such as dimples (62) and grooves (54), and/or convex surface features such as bumps (58) and smaller ridges (52). An embodiment with convex turbulators (52, 58) in the valleys (48) and concave turbulators (54, 62) on the ridges (46) increases the cooling surface area, reduces boundary layer separation, avoids coolant shadowing and stagnation, and reduces component mass.

Lee, Ching-Pang; Jiang, Nan; Marra, John J; Rudolph, Ronald J

2014-11-25T23:59:59.000Z

246

Measurement and simulation of swirling coal combustion  

Science Journals Connector (OSTI)

Particle image velocimetry (PIV), thermocouples and flue gas analyzer are used to study swirling coal combustion and NO formation under different secondary-air ratios. Eulerian–Lagrangian large-eddy simulation (LES) using the Smagorinsky–Lilly sub-grid scale stress model, presumed-PDF fast chemistry and eddy-break-up (EBU) gas combustion models, particle devolatilization and particle combustion models, are simultaneously used to simulate swirling coal combustion. Statistical LES results are validated by measurement results. Instantaneous LES results show that the coherent structures for swirling coal combustion are stronger than those for swirling gas combustion. Particles are shown to concentrate along the periphery of the coherent structures. Combustion flame is located in the high vorticity and high particle concentration zones. Measurement shows that secondary-air ratios have little effect on final NO formation at the exit of the combustor.

Liyuan Hu; Lixing Zhou; Yonghao Luo; Caisong Xu

2013-01-01T23:59:59.000Z

247

Information theoretical characterization of turbulence  

Science Journals Connector (OSTI)

A method of describing turbulence in terms of dynamical connectivity in the wave-number space is proposed. The connectivity is quantified by the information theoretical quantities, i.e., mutual information and cross information flow rate. This method is applied to the analysis of two simple examples of turbulence in one spatial dimension. Although the examples have quite different physical origins, the information structures of the wave-number space turn out to be quite similar: The wave-number space consists of several regions generating information in different ways, and how information flows between these regions reflects the dynamical structure of turbulence.

K. Ikeda and K. Matsumoto

1989-05-08T23:59:59.000Z

248

Turbulence-Flame Interactions in Type Ia Supernovae  

E-Print Network [OSTI]

The large range of time and length scales involved in type Ia supernovae (SN Ia) requires the use of flame models. As a prelude to exploring various options for flame models, we consider, in this paper, high-resolution three-dimensional simulations of the small-scale dynamics of nuclear flames in the supernova environment in which the details of the flame structure are fully resolved. The range of densities examined, 1 to $8 \\times 10^7$ g cm$^{-3}$, spans the transition from the laminar flamelet regime to the distributed burning regime where small scale turbulence disrupts the flame. The use of a low Mach number algorithm facilitates the accurate resolution of the thermal structure of the flame and the inviscid turbulent kinetic energy cascade, while implicitly incorporating kinetic energy dissipation at the grid-scale cutoff. For an assumed background of isotropic Kolmogorov turbulence with an energy characteristic of SN Ia, we find a transition density between 1 and $3 \\times 10^7$ g cm$^{-3}$ where the nature of the burning changes qualitatively. By $1 \\times 10^7$ g cm$^{-3}$, energy diffusion by conduction and radiation is exceeded, on the flame scale, by turbulent advection. As a result, the effective Lewis Number approaches unity. That is, the flame resembles a laminar flame, but is turbulently broadened with an effective diffusion coefficient, $D_T \\sim u' l$, where $u'$ is the turbulent intensity and $l$ is the integral scale. For the larger integral scales characteristic of a real supernova, the flame structure is predicted to become complex and unsteady. Implications for a possible transition to detonation are discussed.

A. J. Aspden; J. B. Bell; M. S. Day; S. E. Woosley; M. Zingale

2008-11-17T23:59:59.000Z

249

Observations of turbulent fluxes and turbulence dynamics in the ocean surface boundary layer  

E-Print Network [OSTI]

This study presents observations of turbulence dynamics made during the low winds portion of the Coupled Boundary Layers and Air-Sea Transfer experiment (CBLAST-Low). Observations were made of turbulent fluxes, turbulent ...

Gerbi, Gregory Peter

2008-01-01T23:59:59.000Z

250

Level set simulations of turbulent thermonuclear deflagration in degenerate carbon and oxygen  

E-Print Network [OSTI]

We study the dynamics of thermonuclear flames propagating in fuel stirred by stochastic forcing. The fuel consists of carbon and oxygen in a state which is encountered in white dwarfs close to the Chandrasekhar limit. The level set method is applied to represent the flame fronts numerically. The computational domain for the numerical simulations is cubic, and periodic boundary conditions are imposed. The goal is the development of a suitable flame speed model for the small-scale dynamics of turbulent deflagration in thermonuclear supernovae. Because the burning process in a supernova explosion is transient and spatially inhomogeneous, the localised determination of subgrid scale closure parameters is essential. We formulate a semi-localised model based on the dynamical equation for the subgrid scale turbulence energy $k_{\\mathrm{sgs}}$. The turbulent flame speed $s_{\\mathrm{t}}$ is of the order $\\sqrt{2k_{\\mathrm{sgs}}}$. In particular, the subgrid scale model features a dynamic procedure for the calculation of the turbulent energy transfer from resolved toward subgrid scales, which has been successfully applied to combustion problems in engineering. The options of either including or suppressing inverse energy transfer in the turbulence production term are compared. In combination with the piece-wise parabolic method for the hydrodynamics, our results favour the latter option. Moreover, different choices for the constant of proportionality in the asymptotic flame speed relation, $s_{\\mathrm{t}}\\propto\\sqrt{2k_{\\mathrm{sgs}}}$, are investigated.

W. Schmidt; W. Hillebrandt; J. C. Niemeyer

2005-08-02T23:59:59.000Z

251

Combustion synthesis continuous flow reactor  

DOE Patents [OSTI]

The present invention is a reactor for combustion synthesis of inorganic powders. The reactor includes a reaction vessel having a length and a first end and a second end. The reaction vessel further has a solution inlet and a carrier gas inlet. The reactor further has a heater for heating both the solution and the carrier gas. In a preferred embodiment, the reaction vessel is heated and the solution is in contact with the heated reaction vessel. It is further preferred that the reaction vessel be cylindrical and that the carrier gas is introduced tangentially into the reaction vessel so that the solution flows helically along the interior wall of the reaction vessel. As the solution evaporates and combustion produces inorganic material powder, the carrier gas entrains the powder and carries it out of the reactor.

Maupin, Gary D. (Richland, WA); Chick, Lawrence A. (West Richland, WA); Kurosky, Randal P. (Maple Valley, WA)

1998-01-01T23:59:59.000Z

252

Computational experience with a three-dimensional rotary engine combustion model  

SciTech Connect (OSTI)

A new computer code was developed to analyze the chemically reactive flow and spray combustion processes occurring inside a stratified-charge rotary engine. Mathematical and numerical details of the new code were recently described by the present authors. The results are presented of limited, initial computational trials as a first step in a long-term assessment/validation process. The engine configuration studied was chosen to approximate existing rotary engine flow visualization and hot firing test rigs. Typical results include: (1) pressure and temperature histories, (2) torque generated by the nonuniform pressure distribution within the chamber, (3) energy release rates, and (4) various flow-related phenomena. These are discussed and compared with other predictions reported in the literature. The adequacy or need for improvement in the spray/combustion models and the need for incorporating an appropriate turbulence model are also discussed.

Raju, M.S.; Willis, E.A.

1990-04-01T23:59:59.000Z

253

Comparative Investigation of Blade Lean Effect in Hydrogen?Fueled Combustion Turbine  

Science Journals Connector (OSTI)

Recently environmental problems have been actively researched all over the world. To overcome air pollution and fossil fuel exhaustion we have been investigating a hydrogen?fueled propulsion system. In the system hydrogen is injected from the turbine blade and/or vane surface. The system can realize higher power lighter weight and lower emission than conventional systems. However there exist many problems for the realization. One of them is the extremely high temperature region appearing on the wall. In the present study we clarify the effect of blade lean on the generation of high temperature region. The combusting turbulent flowfield around a normal a compound lean and a reverse compound lean blades are simulated using RANS and 5?step reduced combustion model. Comparing the numerical results it is confirmed that compound lean is promising to suppress the high temperature region.

R. Nakamura; M. Suzuki; M. Yamamoto

2011-01-01T23:59:59.000Z

254

Homogeneous catalysts in hypersonic combustion  

SciTech Connect (OSTI)

Density and residence time both become unfavorably small for efficient combustion of hydrogen fuel in ramjet propulsion in air at high altitude and hypersonic speed. Raising the density and increasing the transit time of the air through the engine necessitates stronger contraction of the air flow area. This enhances the kinetic and thermodynamic tendency of H/sub 2/O to form completely, accompanied only by N/sub 2/ and any excess H/sub 2/(or O/sub 2/). The by-products to be avoided are the energetically expensive fragment species H and/or O atoms and OH radicals, and residual (2H/sub 2/ plus O/sub 2/). However, excessive area contraction raises air temperature and consequent combustion-product temperature by adiabatic compression. This counteracts and ultimately overwhelms the thermodynamic benefit by which higher density favors the triatomic product, H/sub 2/O, over its monatomic and diatomic alternatives. For static pressures in the neighborhood of 1 atm, static temperature must be kept or brought below ca. 2400 K for acceptable stability of H/sub 2/O. Another measure, whose requisite chemistry we address here, is to extract propulsive work from the combustion products early in the expansion. The objective is to lower the static temperature of the combustion stream enough for H/sub 2/O to become adequately stable before the exhaust flow is massively expanded and its composition ''frozen.'' We proceed to address this mechanism and its kinetics, and then examine prospects for enhancing its rate by homogeneous catalysts. 9 refs.

Harradine, D.M.; Lyman, J.L.; Oldenborg, R.C.; Pack, R.T.; Schott, G.L.

1989-01-01T23:59:59.000Z

255

LES SOFTWARE FOR THE DESIGN OF LOW EMISSION COMBUSTION SYSTEMS FOR VISION 21 PLANTS  

SciTech Connect (OSTI)

Further development of a combustion Large Eddy Simulation (LES) code for the design of advanced gaseous combustion systems is described in this fifth quarterly report. CFD Research Corporation (CFDRC) is developing the LES module within the parallel, unstructured solver included in the commercial CFD-ACE+ software. In this quarter, in-situ adaptive tabulation (ISAT) for efficient chemical rate storage and retrieval was further tested in the LES code. The use of multiple trees and periodic tree dumping was investigated. Implementation of the Linear Eddy Model (LEM) for subgrid chemistry was finished for serial applications. Validation of the model on a backstep reacting case was performed. Initial calculations of the SimVal experiment were performed for various barrel lengths, equivalence ratio, combustor shapes, and turbulence models. The effects of these variables on combustion instability was studied. Georgia Tech continues the effort to parameterize the LEM over composition space so that a neural net can be used efficiently in the combustion LES code. Next quarter, the 2nd consortium meeting will be held at CFDRC. LES software development and testing will continue. Alpha testing of the code will be performed on cases of interest to the industrial consortium. Optimization of subgrid models will be pursued, particularly with the ISAT approach. Also next quarter, the demonstration of the neural net approach, for chemical kinetics speed-up in CFD-ACE+, should be accomplished.

Steve Cannon; Baifang Zuo; Virgil Adumitroaie; Keith McDaniel; Cliff Smith

2002-01-01T23:59:59.000Z

256

On numerical simulation of flow, heat transfer and combustion processes in tangentially-fired furnace  

SciTech Connect (OSTI)

In this work, an Eulerian/Lagrangian approach has been employed to investigate numerically flow characteristics, heat transfer and combustion processes inside corner-fired power plant boiler furnace. To avoid pseudo-diffusion that is significant in modeling tangentially-fired furnaces, some attempts have been made at improving the finite-difference scheme. Comparisons have been made between standard {kappa}-{epsilon} model and RNG {kappa}-{epsilon} model. Some new developments on turbulent diffusion of particles are taken into account in an attempt to improve computational accuracy. Finally, temperature deviation is studied numerically so as to gain deeper insight into tangentially fired furnace.

Sun, P.; Fan, J.; Cen, K.

1999-07-01T23:59:59.000Z

257

Nuclear Energy  

Science Journals Connector (OSTI)

Nuclear Energy ... A brief summary of the history and key concepts of nuclear energy. ... Nuclear / Radiochemistry ...

Charles D. Mickey

1980-01-01T23:59:59.000Z

258

Nuclear batteries  

Science Journals Connector (OSTI)

Nuclear batteries ... Describes the structure, operation, and application of nuclear batteries. ... Nuclear / Radiochemistry ...

Alfred B. Garrett

1956-01-01T23:59:59.000Z

259

Characteristics of biomass in flameless combustion: A review  

Science Journals Connector (OSTI)

Abstract The demands of energy and pollutant emissions reduction have motivated the combustion researchers to work on combustion improvement. Flameless combustion or high temperature air combustion has many features such as flame stability, low pollutant emission and uniform profiles of temperature compared to the other modes of combustion. Combustion of solid fuels likes biomass and wastes in flameless combustion conditions has not been investigated as comprehensive as combustion of gaseous fuels. The aim of using biomass in combustion is to reduce the pollutant emissions and to decrease the rate of fossil fuel consumption. In this review, combustion characteristics of biomass in flameless combustion are explained. The paper summarizes the research on the mass loss, ignition time, and \\{NOx\\} emissions during biomass flameless combustion. These summaries show that biomass under flameless combustion gives low pollutant emissions, low mass loss and it decreases the ignition time.

A.A.A. Abuelnuor; M.A. Wahid; Seyed Ehsan Hosseini; A. Saat; Khalid M. Saqr; Hani H. Sait; M. Osman

2014-01-01T23:59:59.000Z

260

Waste gas combustion in a Hanford radioactive waste tank  

SciTech Connect (OSTI)

It has been observed that a high-level radioactive waste tank generates quantities of hydrogen, ammonia, nitrous oxide, and nitrogen that are potentially well within flammability limits. These gases are produced from chemical and nuclear decay reactions in a slurry of radioactive waste materials. Significant amounts of combustible and reactant gases accumulate in the waste over a 110- to 120-d period. The slurry becomes Taylor unstable owing to the buoyancy of the gases trapped in a matrix of sodium nitrate and nitrite salts. As the contents of the tank roll over, the generated waste gases rupture through the waste material surface, allowing the gases to be transported and mixed with air in the cover-gas space in the dome of the tank. An ignition source is postulated in the dome space where the waste gases combust in the presence of air resulting in pressure and temperature loadings on the double-walled waste tank. This analysis is conducted with hydrogen mixing studies HMS, a three-dimensional, time-dependent fluid dynamics code coupled with finite-rate chemical kinetics. The waste tank has a ventilation system designed to maintain a slight negative gage pressure during normal operation. We modeled the ventilation system with the transient reactor analysis code (TRAC), and we coupled these two best-estimate accident analysis computer codes to model the ventilation system response to pressures and temperatures generated by the hydrogen and ammonia combustion.

Travis, J.R.; Fujita, R.K.; Spore, J.W.

1994-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


261

Multi-zone modelling of partially premixed low-temperature combustion in pilot-ignited natural-gas engines  

SciTech Connect (OSTI)

Detailed results from a multi-zone phenomenological simulation of partially premixed advanced-injection low-pilot-ignited natural-gas low-temperature combustion are presented with a focus on early injection timings (the beginning of (pilot) injection (BOI)) and very small diesel quantities (2-3 per cent of total fuel energy). Combining several aspects of diesel and spark ignition engine combustion models, the closed-cycle simulation accounted for diesel autoignition, diesel spray combustion, and natural-gas combustion by premixed turbulent flame propagation. The cylinder contents were divided into an unburned zone, several pilot fuel zones (or 'packets') that modelled diesel evaporation and ignition, a flame zone for natural-gas combustion, and a burned zone. The simulation predicted the onset of ignition, cylinder pressures, and heat release rate profiles satisfactorily over a wide range of BOIs (20-60���° before top dead centre (before TDC)) but especially well at early BOIs. Strong coupling was observed between pilot spray combustion in the packets and premixed turbulent combustion in the flame zone and, therefore, the number of ignition centres (packets) profoundly affected flame combustion. The highest local peak temperatures (greater than 2000 K) were observed in the packets, while the flame zone was much cooler (about 1650 K), indicating that pilot diesel spray combustion is probably the dominant source of engine-out emissions of nitrogen oxide (NO x). Further, the 60���° before TDC BOI yielded the lowest average peak packet temperatures (about 1720 K) compared with the 20���° before TDC BOI (about 2480 K) and 40���° before TDC BOI (about 2700 K). These trends support experimental NO x trends, which showed the lowest NO x emissions for the 60���°, 20���°, and 40���° before TDC BOIs in that order. Parametric studies showed that increasing the intake charge temperature, pilot quantity, and natural-gas equivalence ratio all led to higher peak heat release rates and hotter packets but the pilot quantity and intake temperature affected the potential for NO x formation to a greater extent.

Krishnan, S. R.; Srinivasan, K. K.

2010-06-29T23:59:59.000Z

262

Sandia Combustion Research Program: Annual report, 1986  

SciTech Connect (OSTI)

This report presents research results of the past year, divided thematically into some ten categories. Publications and presentations arising from this work are included in the appendix. Our highlighted accomplishment of the year is the announcement of the discovery and demonstration of the RAPRENOx process. This new mechanism for the elimination of nitrogen oxides from essentially all kinds of combustion exhausts shows promise for commercialization, and may eventually make a significant contribution to our nation's ability to control smog and acid rain. The sections of this volume describe the facility's laser and computer system, laser diagnostics of flames, combustion chemistry, reacting flows, liquid and solid propellant combustion, mathematical models of combustion, high-temperature material interfaces, studies of engine/furnace combustion, coal combustion, and the means of encouraging technology transfer. 182 refs., 170 figs., 12 tabs.

Not Available

1986-01-01T23:59:59.000Z

263

NETL: IEP – Post-Combustion CO2 Emissions Control - Oxy-Combustion Boiler  

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

Oxy-Combustion Boiler Material Development Oxy-Combustion Boiler Material Development Project No.: DE-NT0005262 CLICK ON IMAGE TO ENLARGE Foster Wheeler Oxy-combustion CFD Graphic The objectives of this Foster Wheeler Corporation-managed program are to assess the corrosion characteristics of oxy-combustion relative to air-fired combustion; identify the corrosion mechanisms involved; and determine the effects of oxy-combustion on conventional boiler tube materials, conventional protective coatings, and alternative materials and coatings when operating with high to low sulfur coals. The program involves the prediction of oxy-combustion gas compositions by computational fluid dynamic calculations, exposure of coupons of boiler materials and coverings coated with coal ash deposit to simulated oxy-combustion gases in electric

264

A fundamental study of biomass oxy-fuel combustion and co-combustion.  

E-Print Network [OSTI]

??While oxy-fuel combustion research is developing and large scale projects are proceeding, little information is available on oxy-biomass combustion and cocombustion with coal. To address… (more)

Farrow, Timipere Salome

2013-01-01T23:59:59.000Z

265

Estimating heat of combustion for waste materials  

SciTech Connect (OSTI)

Describes a method of estimating the heat of combustion of hydrocarbon waste (containing S,N,Q,C1) in various physical forms (vapor, liquid, solid, or mixtures) when the composition of the waste stream is known or can be estimated. Presents an equation for predicting the heat of combustion of hydrocarbons containing some sulfur. Shows how the method is convenient for estimating the heat of combustion of a waste profile as shown in a sample calculation.

Chang, Y.C.

1982-11-01T23:59:59.000Z

266

Nuclear Forensics  

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

nuclear forensics Nuclear Forensics AMS is a Powerful Tool for Nuclear Forensics Nuclear forensics, which can be applied to both interdicted materials and debris from a nuclear...

267

Supersonic combustion studies using a multivariate quadrature based method for combustion modeling  

E-Print Network [OSTI]

of predictive models for supersonic combustion is a critical step in design and development of scramjet engines

Raman, Venkat

268

Researchers create successful predictions of combustion reaction...  

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

chemical reactions that take place during the combustion process, said Sandia's Ahren Jasper, the study's lead author. As they determine and understand the speeds and outcomes of...

269

combustion index | netl.doe.gov  

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

in electricity cost. Advanced Combustion Research Overview Experience with steam boilers has provided information on existing boiler alloys, but limited data is available at...

270

Optimization of Advanced Diesel Engine Combustion Strategies  

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

B, extending combustion duration Location B with dummy plug installed Location A with optics installed fiber to FTIR common rail injector common rail fuel spray Location B with...

271

Chemical Kinetic Models for Advanced Engine Combustion  

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

barriers to increased engine efficiency and decreased emissions by allowing optimization of fuels with advanced engine combustion 6 LLNL-PRES-652979 2014 DOE Merit Review...

272

Oxygen-Enriched Combustion | Department of Energy  

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

tip sheet discusses how an increase in oxygen in combustion air can reduce the energy loss in the exhaust gases and increase process heating system efficiency. PROCESS HEATING...

273

Vehicle Technologies Office: Advanced Combustion Strategies ...  

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

element of LTC - is achieved by controlling the timing of the autoignition and rate of heat release. This process works to eliminate excessive combustion rates that can cause...

274

Advanced Combustion Concepts - Enabling Systems and Solutions...  

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

Fuel efficiency as key market driver Stringent emission requirements System cost of advanced combustion Targets 30% fuel efficiency improvement SULEV emissions...

275

Laser in situ monitoring of combustion processes  

Science Journals Connector (OSTI)

Several examples of laser in situ monitoring of combustion processes are presented. Using a frequency modulated 13CO2 waveguide laser, in situ concentrations of...

Arnold, A; Becker, H; Hemberger, R; Hentschel, W; Ketterle, W; Kollner, M; Meienburg, W; Monkhouse, P; Neckel, H; Schafer, M; Schindler, K P; Sick, V; Suntz, R; Wolfrum, J

1990-01-01T23:59:59.000Z

276

Supersonic Jet Sampling for Combustion Diagnostics  

Science Journals Connector (OSTI)

The purpose of this note is to describe a novel application of supersonic molecular beam spectrometry to the study of combustion processes in piston engines. In this technique,...

Whitten, W B

1986-01-01T23:59:59.000Z

277

Advanced Control Methodology for Biomass Combustion.  

E-Print Network [OSTI]

??This thesis presents a feasibility study for a low cost sensor-based combustion control system using a predictive chemical kinetic model that captures efficiencies and pollution… (more)

Bjornsson, Stefan

2014-01-01T23:59:59.000Z

278

Partially Premixed Combustion | Department of Energy  

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

that enables PPC to reach the market deer11andersson.pdf More Documents & Publications Combustion Model for Engine Concept Development Path to High Efficiency Gasoline Engine...

279

Research Teams - Combustion Energy Frontier Research Center  

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

Research Teams Research Teams Associates Greg Smith, Senior Research Chemist, SRI International Jeffrey A. Sutton, Assistant Professor, Ohio State Univeristy Combustion Energy...

280

Chemistry and Transport - Combustion Energy Frontier Research...  

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

Chemistry and Transport Chemistry and Transport The overall goal of the flame chemistry working group is to obtain fundamental combustion and emission properties of low and high...

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


281

Integrated Nozzle Flow, Spray, Combustion, & Emission Modeling...  

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

Combustion, and Emission Modeling Using KH-ACT Primary Breakup Model & Detailed Chemistry Sibendu Som, Douglas E. Longman Engine and Emissions Group (Energy Systems Division)...

282

Chemistry: Mechanism and Experiment - Combustion Energy Frontier...  

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

Chemistry: Mechanism and Experiment Chemistry: Mechanism and Experiment The Mechanism and Experiment DWG uses an array of advanced experimental apparatus to probe the combustion...

283

Progress of the Engine Combustion Network  

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

liquid volume fraction * Droplet size and velocity * Maximum liquid penetration * Vapor penetration rate * Velocity and turbulence within spray * Mixture fraction (non-reacting)...

284

Assessment of TurbulenceChemistry Interaction in Hypersonic Turbulent Boundary Layers  

E-Print Network [OSTI]

Assessment of Turbulence­Chemistry Interaction in Hypersonic Turbulent Boundary Layers L. Duan of the turbulence­chemistry interaction are performed in hypersonic turbulent boundary layers using direct numerical simulation flowfields under typical hypersonic conditions representative of blunt-body and slender- body

MartĂ­n, Pino

285

Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers  

E-Print Network [OSTI]

Effect of Finite-rate Chemical Reactions on Turbulence in Hypersonic Turbulent Boundary Layers Lian on future air-breathing hypersonic cruise vehicles will be turbulent and chemically reacting. To aid the design of such vehicles, a greater understanding of turbulent hypersonic flows is needed. Although

MartĂ­n, Pino

286

Theoretical studies of combustion dynamics  

SciTech Connect (OSTI)

The basic objectives of this research program are to develop and apply theoretical techniques to fundamental dynamical processes of importance in gas-phase combustion. There are two major areas currently supported by this grant. One is reactive scattering of diatom-diatom systems, and the other is the dynamics of complex formation and decay based on L{sup 2} methods. In all of these studies, the authors focus on systems that are of interest experimentally, and for which potential energy surfaces based, at least in part, on ab initio calculations are available.

Bowman, J.M. [Emory Univ., Atlanta, GA (United States)

1993-12-01T23:59:59.000Z

287

Circulating fluidised-bed combustion  

SciTech Connect (OSTI)

Steam generators with circulating fluidized-bed combustion systems (CFBC) are characterized by a high degree of environmental comparability and a wide acceptance for FBC boiler plants involving a wide fuel spectrum which ranges from dried brown coal to high-ash coal and low-volatile bituminous coal as well as wood waste and bark. These plants incorporate a variety of CFBC systems. The choice in favor of different system options was not motivated by the inherent fuel properties but has evolved from the progressive advancement in power station FBC technology. The article elucidates several FBC system variants.

Rettemeier, W.; von der Kammer, G. (Steinmueller (L.u.C.) GmbH, Gummersbach (Germany, F.R.))

1990-01-01T23:59:59.000Z

288

Flame kernel characterization of laser ignition of natural gas–air mixture in a constant volume combustion chamber  

Science Journals Connector (OSTI)

In this paper, laser-induced ignition was investigated for compressed natural gas–air mixtures. Experiments were performed in a constant volume combustion chamber, which simulate end of the compression stroke conditions of a SI engine. This chamber simulates the engine combustion chamber conditions except turbulence of air–fuel mixture. It has four optical windows at diametrically opposite locations, which are used for laser ignition and optical diagnostics simultaneously. All experiments were conducted at 10 bar chamber pressure and 373 K chamber temperature. Initial stage of combustion phenomena was visualized by employing Shadowgraphy technique using a high speed CMOS camera. Flame kernel development of the combustible fuel–air mixture was investigated under different relative air–fuel ratios (?=1.2?1.7) and the images were interrogated for temporal propagation of flame front. Pressure-time history inside the combustion chamber was recorded and analyzed. This data is useful in characterizing the laser ignition of natural gas–air mixture and can be used in developing an appropriate laser ignition system for commercial use in SI engines.

Dhananjay Kumar Srivastava; Kewal Dharamshi; Avinash Kumar Agarwal

2011-01-01T23:59:59.000Z

289

Selected problems in turbulence theory and modeling  

E-Print Network [OSTI]

Three different topics of turbulence research that cover modeling, theory and model computation categories are selected and studied in depth. In the first topic, "velocity gradient dynamics in turbulence" (modeling), the Lagrangian linear diffusion...

Jeong, Eun-Hwan

2004-09-30T23:59:59.000Z

290

Usage of turbulence for superresolved imaging  

Science Journals Connector (OSTI)

We have used the turbulent flow of hot air to improve the diffraction limits of resolution in an imaging system. A time-multiplexing approach was applied and used the turbulent flow...

Zalevsky, Zeev; Rozental, Shay; Meller, Moshe

2007-01-01T23:59:59.000Z

291

Flight–crash events in turbulence  

Science Journals Connector (OSTI)

...Institute of Science, Rehovot 76100...Mechanical and Aerospace Engineering, Cornell...14). The recent advances in our ability...turbulent flow . Science 311 ( 5762 ): 835...turbulence: recent results...Cooperation in Science and Technology...

Haitao Xu; Alain Pumir; Gregory Falkovich; Eberhard Bodenschatz; Michael Shats; Hua Xia; Nicolas Francois; Guido Boffetta

2014-01-01T23:59:59.000Z

292

Effects of Atmospheric Turbulence on Ballistic Testing  

Science Journals Connector (OSTI)

The effects of atmospheric turbulence on munition target scatter are determined from numerical simulations of ballistic trajectories through many realizations of realistic simulated turbulent wind fields. A technique is evaluated for correcting ...

Rod Frehlich; Robert Sharman; Charles Clough; Michael Padovani; Kelly Fling; Ward Boughers; W. Scott Walton

2008-05-01T23:59:59.000Z

293

Holographic Vortex Liquids and Superfluid Turbulence  

Science Journals Connector (OSTI)

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

Paul M. Chesler; Hong Liu; Allan Adams

2013-07-26T23:59:59.000Z

294

Chemical looping combustion of coal in interconnected fluidized beds  

Science Journals Connector (OSTI)

Chemical looping combustion is the indirect combustion by use of oxygen carrier. It can...2...capture in power generating processes. In this paper, chemical looping combustion of coal in interconnected fluidized ...

LaiHong Shen; Min Zheng; Jun Xiao; Hui Zhang…

2007-04-01T23:59:59.000Z

295

Fuel reforming for scramjet thermal management and combustion optimization  

E-Print Network [OSTI]

Fuel reforming for scramjet thermal management and combustion optimization E. DANIAU* , M. BOUCHEZ in a Scramjet combustion chamber. Another critical point is that mixing and combustion should be sufficiently

Paris-Sud XI, Université de

296

Flame-wall interaction simulation in a turbulent channel flow  

SciTech Connect (OSTI)

The interaction between turbulent premixed flames and channel walls is studied. Combustion is represented by a simple irreversible reaction with a large activation temperature. A low heat release assumption is used, but feedback to the flowfield can be allowed through viscosity changes. The effect of wall distance on local and global flame structure is investigated. Quenching distances and maximum wall heat fluxed computed in laminar cases are compared to DNS results. It is found that quenching distances decrease and maximum heat fluxes increase relative to laminar flame values, scaling with the turbulent strain rate. It is shown that these effects are due to large coherent structures which push flame elements towards the wall. The effect of wall strain in flame-wall interaction is studied in a stagnation line flow; this is used to explain the DNS results. The effects of the flame on the flow through viscosity changes is studied. It is also shown that remarkable flame events are produced by flame interaction with a horseshoe vortex: burned gases are pushed towards the wall at high speed and induce quenching and high wall heat flux while fresh gases are expelled from the wall region and form finger-like structures. Effects of the wall on flame surface density are investigated.

Bruneaux, G.; Akselvoll, K.; Poinsot, T.; Ferziger, J.H.

1996-10-01T23:59:59.000Z

297

Stimulated Neutrino Transformation Through Turbulence  

E-Print Network [OSTI]

We derive an analytical solution for the flavor evolution of a neutrino through a turbulent density profile which is found to accurately predict the amplitude and transition wavelength of numerical solutions on a case-by-case basis. The evolution is seen to strongly depend upon those Fourier modes in the turbulence which are approximately the same as the splitting between neutrino eigenvalues. Transitions are strongly enhanced by those Fourier modes in the turbulence which are approximately the same as the splitting between neutrino eigenvalues. We also find a suppression of transitions due to the long wavelength modes when the ratio of their amplitude and the wavenumber is of order, or greater than, the first root of the Bessel function $J_0$.

Kelly M. Patton; James P. Kneller; Gail C. McLaughlin

2014-04-15T23:59:59.000Z

298

turbulent heat International Journal of Numerical  

E-Print Network [OSTI]

Enhanced turbulent heat transfer 47 International Journal of Numerical Methods for Heat & Fluid, Hsinchu,Taiwan Keywords Heat transfer, Fluids, Flow, Turbulence, Numerical methods Abstract This study evaluates low Reynolds number models of turbulence for numerical computations on the heat transfer and fluid

Lin, Wen-Wei

299

TURBULENCE IN SUPERSONIC AND HYPERSONIC BOUNDARY LAYERS  

E-Print Network [OSTI]

TURBULENCE IN SUPERSONIC AND HYPERSONIC BOUNDARY LAYERS Alexander J. Smits and M. Pino Martin in supersonic and hypersonic flow where the effects of compressibility have a direct influence on the turbulence. Experimental and DNS results are presented and compared. Key words: Turbulence, supersonic, hypersonic, shocks

MartĂ­n, Pino

300

Protostellar Outflow Evolution in Turbulent Environments  

SciTech Connect (OSTI)

The link between turbulence in star formatting environments and protostellar jets remains controversial. To explore issues of turbulence and fossil cavities driven by young stellar outflows we present a series of numerical simulations tracking the evolution of transient protostellar jets driven into a turbulent medium. Our simulations show both the effect of turbulence on outflow structures and, conversely, the effect of outflows on the ambient turbulence. We demonstrate how turbulence will lead to strong modifications in jet morphology. More importantly, we demonstrate that individual transient outflows have the capacity to re-energize decaying turbulence. Our simulations support a scenario in which the directed energy/momentum associated with cavities is randomized as the cavities are disrupted by dynamical instabilities seeded by the ambient turbulence. Consideration of the energy power spectra of the simulations reveals that the disruption of the cavities powers an energy cascade consistent with Burgers-type turbulence and produces a driving scale-length associated with the cavity propagation length. We conclude that fossil cavities interacting either with a turbulent medium or with other cavities have the capacity to sustain or create turbulent flows in star forming environments. In the last section we contrast our work and its conclusions with previous studies which claim that jets can not be the source of turbulence.

Cunningham, A; Frank, A; Carroll, J; Blackman, E; Quillen, A

2008-04-11T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


301

Internal combustion engine intake valve  

SciTech Connect (OSTI)

In a inlet valve for use in an internal combustion engine in which the valve has a stem and a head, the head having, when seated, a first side positioned within a combustion chamber of an engine block and a second, opposite, side attached to the stem, the second side including that piston of the head forming the seat with the engine block when the valve is in a seated position, and first side including that portion of the head from the seat toward the chamber when the valve is in the seated position, and the engine including means for moving the valve from the closed position to an open position to allow a fuel mixture to enter the chamber, the improvement in the valve comprising: an extension ridge from the first side, positioned in alignment with the periphery of the valve head, the ridge forming with the seat a single, continuous, smooth outer surface along the periphery thereof for reducing the coefficient of drag of the fuel entering the chamber around the valve head when the valve is in the open position.

Mosler, W.B.

1988-10-25T23:59:59.000Z

302

Method and system for controlled combustion engines  

DOE Patents [OSTI]

A system for controlling combustion in internal combustion engines of both the Diesel or Otto type, which relies on establishing fluid dynamic conditions and structures wherein fuel and air are entrained, mixed and caused to be ignited in the interior of a multiplicity of eddies, and where these structures are caused to sequentially fill the headspace of the cylinders.

Oppenheim, A. K. (Berkeley, CA)

1990-01-01T23:59:59.000Z

303

The Cool Flame Combustion of Ethanol  

Science Journals Connector (OSTI)

...research-article The Cool Flame Combustion of Ethanol J. Brown C. F. H. Tipper The kinetics...products of the cool flame combustion of ethanol between about 280 and 330 C have been...much less for a 1 : 2 than for a 1 : 1 ethanol/oxygen mixture at constant T and varied...

1969-01-01T23:59:59.000Z

304

Redeeming features of in situ combustion  

SciTech Connect (OSTI)

In situ combustion remains the most tantalizing enhanced oil recovery method. It has been tested extensively - in over 150 field tests - in both heavy and light oil reservoirs. What we have learned from this experience is that in situ combustion works under most conditions, but the nature of the problems is such that it is seldom profitable. Also, looking at many previous in situ combustion tests, steam injection, and even waterflooding, would have been a better choice. Yet in situ combustion has unique features not found in any other EOR method. These must be weighed against its shortcomings to evaluate a potential application. This paper discusses the redeeming features of in situ combustion, in particular the reservoir conditions under which in situ combustion may be superior to other EOR methods are outlined. All variations of in situ combustion - forward, reverse, wet, dry - as well as combinations with other EOR methods are considered. The conclusions is that in situ combustion still has a place, and its future application would depend on research on certain crucial aspects of the process.

Farouq Ali, S.M. [Univ. of Alberta, Edmonton (Canada)

1995-02-01T23:59:59.000Z

305

NETL- High-Pressure Combustion Research Facility  

SciTech Connect (OSTI)

NETL's High-Pressure Combustion Facility is a unique resource within the National Laboratories system. It provides the test capabilities needed to evaluate new combustion concepts for high-pressure, high-temperature hydrogen and natural gas turbines. These concepts will be critical for the next generation of ultra clean, ultra efficient power systems.

None

2013-07-08T23:59:59.000Z

306

Generating Resources Combined Cycle Combustion Turbine  

E-Print Network [OSTI]

turbine (s) Heat recovery steam generator (s) - HRSG with or without duct firing Natural gas supply11/17/2014 1 Generating Resources Combined Cycle Combustion Turbine Utility Scale Solar PV Steven doing recently around two key supply-side resource technologies 1. Combined Cycle Combustion Turbine

307

Coal slurry combustion and technology. Volume 2  

SciTech Connect (OSTI)

Volume II contains papers presented at the following sessions of the Coal Slurry Combustion and Technology Symposium: (1) bench-scale testing; (2) pilot testing; (3) combustion; and (4) rheology and characterization. Thirty-three papers have been processed for inclusion in the Energy Data Base. (ATT)

Not Available

1983-01-01T23:59:59.000Z

308

NETL- High-Pressure Combustion Research Facility  

ScienceCinema (OSTI)

NETL's High-Pressure Combustion Facility is a unique resource within the National Laboratories system. It provides the test capabilities needed to evaluate new combustion concepts for high-pressure, high-temperature hydrogen and natural gas turbines. These concepts will be critical for the next generation of ultra clean, ultra efficient power systems.

None

2014-06-26T23:59:59.000Z

309

Pulse Combustion Characteristics of Various Gaseous Fuels  

Science Journals Connector (OSTI)

Pulse combustion performance of fuels with low and high heating values is also compared. ... Selected gaseous fuels such as low molecular weight hydrocarbons, high molecular weight hydrocarbons, biofuels, and mixed fuels are tested for pulse combustion, and their operational properties are presented and compared. ... Heat transfer data for several exptl. ...

Wu Zhonghua; Arun S. Mujumdar

2008-02-06T23:59:59.000Z

310

Combustion Modeling for Diesel Engine Control Design  

E-Print Network [OSTI]

Combustion Modeling for Diesel Engine Control Design Von der Fakult¨at f¨ur Maschinenwesen der Combustion Modeling for Diesel Engine Control Design WICHTIG: D 82 überprüfen !!! #12;Bibliographic research stays at General Motors R&D in Warren, MI, USA, possible. Furthermore, I would like thank Tom

Peters, Norbert

311

Boiler Combustion Control and Monitoring System  

Broader source: Energy.gov [DOE]

Efficiency of existing boilers can be improved in three ways; replacement with new boilers, replacement of the burner, or installation of a combustion control system. While installation of a new boiler or replacement of the burner can lead to the greatest efficiency gains, the higher costs associated with these measures typically leads to longer payback periods than combustion control systems.

312

Collaborative Combustion Research with BES | Department of Energy  

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

Combustion Research with BES Collaborative Combustion Research with BES 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer...

313

Overview of Sonex Combustion Systems (SCS) for DI Engines | Department...  

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

Sonex Combustion Systems (SCS) for DI Engines Overview of Sonex Combustion Systems (SCS) for DI Engines The SCS system has undergone computational and experimental verification and...

314

Sandia National Laboratories: Low--Temperature Combustion Enables...  

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

ECFacilitiesCRFLow--Temperature Combustion Enables Cleaner, More Efficient Engines Low--Temperature Combustion Enables Cleaner, More Efficient Engines Assessing the Economic...

315

Evaluation of High Efficiency Clean Combustion (HECC) Strategies...  

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

Combustion (HECC) Strategies for Meeting Future Emissions Regulations in Light-Duty Engines Evaluation of High Efficiency Clean Combustion (HECC) Strategies for Meeting Future...

316

2008 DOE Annual Merit Review Advanced Combustion Engines and...  

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

Advanced Combustion Engines and Fuels R&DTechnology Integration Plenary Session Overview 2008 DOE Annual Merit Review Advanced Combustion Engines and Fuels R&DTechnology...

317

High-Efficiency Clean Combustion Design for Compression Ignition...  

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

High-Efficiency Clean Combustion Design for Compression Ignition Engines High-Efficiency Clean Combustion Design for Compression Ignition Engines Presentation given at DEER 2006,...

318

Complete Fuel Combustion for Diesel Engines Resulting in Greatly...  

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

Complete Fuel Combustion for Diesel Engines Resulting in Greatly Reduced Emissions and Improved Fuel Efficiency Complete Fuel Combustion for Diesel Engines Resulting in Greatly...

319

Syngas Enhanced High Efficiency Low Temperature Combustion for...  

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

Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines Syngas Enhanced High Efficiency Low Temperature Combustion for Clean Diesel Engines A significant...

320

Non-Petroleum-Based Fuel Effects on Advanced Combustion | Department...  

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

Non-Petroleum-Based Fuel Effects on Advanced Combustion Non-Petroleum-Based Fuel Effects on Advanced Combustion 2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit...

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


321

Catalyst for Improving the Combustion Efficiency of Petroleum...  

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

for Improving the Combustion Efficiency of Petroleum Fuels in Diesel Engines Catalyst for Improving the Combustion Efficiency of Petroleum Fuels in Diesel Engines 2005 Diesel...

322

World's Largest Post-Combustion Carbon Capture Project Begins...  

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

World's Largest Post-Combustion Carbon Capture Project Begins Construction World's Largest Post-Combustion Carbon Capture Project Begins Construction July 15, 2014 - 9:55am Addthis...

323

The Role of Advanced Combustion in Improving Thermal Efficiency  

Broader source: Energy.gov [DOE]

Combustion plays an important role in enabling high thermal efficiencies. Technologies that deliver short combustion duration and low soot emissions are needed.

324

Low-Temperature Diesel Combustion Cross-Cut Research | Department...  

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

Low-Temperature Diesel Combustion A Conceptual Model for Partially PremixedLow-Temperature Diesel Combustion Based onIn-Cylinder Laser Diagnostics and Chemical Kinetics Modeling...

325

Enabling High Efficiency Clean Combustion with Micro-Variable...  

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

of variable orifice fuel injector are described that will extend the operation maps of early PCCI combustion and enable dual-mode combustion over full operating maps....

326

Low-Temperature Diesel Combustion Cross-Cut Research | Department...  

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

Low-Temperature Diesel Combustion Cross-Cut Research Low-Temperature Diesel Combustion Cross-Cut Research 2010 DOE Vehicle Technologies and Hydrogen Programs Annual Merit Review...

327

Development of Fuel-Flexible Combustion Systems Utilizing Opportunity...  

Office of Environmental Management (EM)

Fuel-Flexible Combustion Systems Utilizing Opportunity Fuels in Gas Turbines - Fact Sheet, May 2014 Development of Fuel-Flexible Combustion Systems Utilizing Opportunity Fuels in...

328

Oscillatory Flame Response in Acoustically Coupled Fuel Droplet Combustion  

E-Print Network [OSTI]

and volumetric heats of combustion in biofuels render themVaporization [kJ/kg] Heat of Combustion [kJ/kg] †Estimated

Sevilla Esparza, Cristhian Israel

2013-01-01T23:59:59.000Z

329

2014 Annual Merit Review Results Report - Advanced Combustion...  

Energy Savers [EERE]

Advanced Combustion Engine Technologies 2014 Annual Merit Review Results Report - Advanced Combustion Engine Technologies Merit review of DOE Vehicle Technologies research...

330

Advanced Combustion Technology to Enable High Efficiency Clean...  

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

Combustion System + Air Handling Air Handling + Sensors + Calibration Low P, High Flow Rate EGR + VVA - Simulated Robustness Advanced Combustion Concepts - Simulated 0.0...

331

2.61 Internal Combustion Engines, Spring 2004  

E-Print Network [OSTI]

Fundamentals of how the design and operation of internal combustion engines affect their performance, operation, fuel requirements, and environmental impact. Study of fluid flow, thermodynamics, combustion, heat transfer ...

Heywood, John B.

332

Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines  

Broader source: Energy.gov [DOE]

Document:  ace012_flowers_2013_o.pdfTechnology Area: Advanced Combustion; Combustion and Emissions ControlPresenter: Dan FlowersPresenting Organization: Lawrence Livermore National Laboratory (LLNL...

333

Haraldrud Municipal Solid Waste Combustion Plant in Oslo.  

E-Print Network [OSTI]

??This thesis has studied Haraldrud MSW combustion process. Haraldrud is a realcombustion plant burning waste for citizens of Oslo. A thoroughly description ofthe combustion process… (more)

Gudim, Simen Johan

2011-01-01T23:59:59.000Z

334

Combustion Turbine CHP System for Food Processing Industry -...  

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

Combustion Turbine CHP System for Food Processing Industry - Presentation by Frito-Lay North America, June 2011 Combustion Turbine CHP System for Food Processing Industry -...

335

Oxygen-Enriched Combustion for Military Diesel Engine Generators...  

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

Combustion for Military Diesel Engine Generators Oxygen-Enriched Combustion for Military Diesel Engine Generators Substantial increases in brake power and considerably lower peak...

336

Modeling Combustion Control for High Power Diesel Mode Switching...  

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

Combustion Control for High Power Diesel Mode Switching Modeling Combustion Control for High Power Diesel Mode Switching Poster presentation given at the 16th Directions in...

337

High Efficiency Clean Combustion for Heavy-Duty Engine  

Broader source: Energy.gov [DOE]

Explore advancements in engine combustion systems using high-efficiency clean combustion (HECC) techniques to minimize engine-out emissions while optimizing fuel economy.

338

Low Temperature Combustion and Diesel Emission Reduction Research...  

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

Low Temperature Combustion and Diesel Emission Reduction Research Low Temperature Combustion and Diesel Emission Reduction Research Presentation given at DEER 2006, August 20-24,...

339

Dilute Clean Diesel Combustion Achieves Low Emissions and High...  

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

Dilute Clean Diesel Combustion Achieves Low Emissions and High Efficiency While Avoiding Control Problems of HCCI Dilute Clean Diesel Combustion Achieves Low Emissions and High...

340

Unregulated Emissions from High-Efficiency Clean Combustion Modes...  

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

Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Unregulated Emissions from High-Efficiency Clean Combustion Modes - ORNL-FEERC Poster presentation at...

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


341

Low-Temperature Automotive Diesel Combustion | Department of...  

Energy Savers [EERE]

Diesel Combustion Low-Temperature Automotive Diesel Combustion 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

342

State Grid Biomass Fuel and Combustion Technology Laboratory...  

Open Energy Info (EERE)

Combustion Technology Laboratory Jump to: navigation, search Name: State Grid Biomass Fuel and Combustion Technology Laboratory Place: Beijing Municipality, China Sector: Biomass...

343

Fuel Effects on Ignition and Their Impact on Advanced Combustion...  

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

Ignition and Their Impact on Advanced Combustion Engines Fuel Effects on Ignition and Their Impact on Advanced Combustion Engines Presentation given at DEER 2006, August 20-24,...

344

Combustion Exhaust Gas Heat to Power Using Thermoelectric Engines...  

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

Combustion Exhaust Gas Heat to Power Using Thermoelectric Engines Combustion Exhaust Gas Heat to Power Using Thermoelectric Engines Discusses a novel TEG which utilizes a...

345

Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel...  

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

Assisted Diesel Combustion in a Common Rail Turbodiesel Engine P-3 Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel Engine P-3 Gregory Lilik, Jos Martn...

346

Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel...  

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

Assisted Diesel Combustion in a Common Rail Turbodiesel Engine Hydrogen Assisted Diesel Combustion in a Common Rail Turbodiesel Engine This study measured the effects of hydrogen...

347

Heavy-Duty Low Temperature Combustion Development Activities...  

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

soot emissions - Cylinder pressure and rise rate limits - Low load combustion stabilityignition Robust combustion control - Cylinder-to-cylinder variability - Ambient...

348

2011 2nd Annual CEFRC Conference - Combustion Energy Frontier...  

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

chemistry and diagnostics (HansenYang) Chemical kinetics and transport of combustion processes (Wang) H2O number density measurements in an RCM and plasma combustion using...

349

Modeling of High Efficiency Clean Combustion Engines | Department...  

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

merit08flowers.pdf More Documents & Publications Modeling of HCCI and PCCI Combustion Processes Numerical Modeling of HCCI Combustion Improving alternative fuel utilization:...

350

Modeling of HCCI and PCCI Combustion Processes | Department of...  

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

HCCI and PCCI Combustion Processes Modeling of HCCI and PCCI Combustion Processes 2005 Diesel Engine Emissions Reduction (DEER) Conference Presentations and Posters...

351

Factors Affecting HCCI Combustion Phasing for Fuels with Single...  

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

Affecting HCCI Combustion Phasing for Fuels with Single- and Dual-Stage Chemistry Factors Affecting HCCI Combustion Phasing for Fuels with Single- and Dual-Stage Chemistry 2004...

352

CFD Combustion Modeling with Conditional Moment Closure using Tabulated Chemistry  

Broader source: Energy.gov [DOE]

A method is presented that allows for efficient conditional moment closure combustion simulations through the use of a progress variable based parameterization of the combustion chemistry.

353

CFD Combustion Modeling with Conditional Moment Closure using...  

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

Combustion Modeling with Conditional Moment Closure using Tabulated Chemistry CFD Combustion Modeling with Conditional Moment Closure using Tabulated Chemistry A method is...

354

Accurate Predictions of Fuel Effects on Combustion and Emissions...  

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

on Combustion and Emissions in Engines Using CFD Simulations With Detailed Fuel Chemistry Accurate Predictions of Fuel Effects on Combustion and Emissions in Engines Using...

355

Numerical Modeling of PCCI Combustion | Department of Energy  

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

Modeling of HCCI and PCCI Combustion Processes Numerical Modeling of HCCI Combustion Bridging the Gap between Fundamental Physics and Chemistry and Applied Models for HCCI Engines...

356

Fuel Effects on Advanced Combustion Engines | Department of Energy  

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

More Documents & Publications Fuel Effects on Advanced Combustion: Heavy-Duty Optical-Engine Research Greenpower Trap Mufflerl System Low-Temperature Diesel Combustion...

357

High Efficiency Clean Combustion Engine Designs for Gasoline...  

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

High Efficiency Clean Combustion Engine Designs for Gasoline and Diesel Engines High Efficiency Clean Combustion Engine Designs for Gasoline and Diesel Engines 2009 DOE Hydrogen...

358

Light-Duty Diesel Combustion | Department of Energy  

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

Light-Duty Diesel Combustion Light-Duty Diesel Combustion 2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting...

359

Light Duty Efficient Clean Combustion | Department of Energy  

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

Light Duty Efficient Clean Combustion Light Duty Efficient Clean Combustion 2009 DOE Hydrogen Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation...

360

Advanced Diesel Combustion with Low Hydrocarbon and Carbon Monoxide...  

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

Combustion with Low Hydrocarbon and Carbon Monoxide Emissions Advanced Diesel Combustion with Low Hydrocarbon and Carbon Monoxide Emissions Poster presented at the 16th Directions...

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


361

Dry low NOx combustion system with pre-mixed direct-injection secondary fuel nozzle  

DOE Patents [OSTI]

A combustion system includes a first combustion chamber and a second combustion chamber. The second combustion chamber is positioned downstream of the first combustion chamber. The combustion system also includes a pre-mixed, direct-injection secondary fuel nozzle. The pre-mixed, direct-injection secondary fuel nozzle extends through the first combustion chamber into the second combustion chamber.

Zuo, Baifang; Johnson, Thomas; Ziminsky, Willy; Khan, Abdul

2013-12-17T23:59:59.000Z

362
363

Investigation of the nonlinear response of turbulent premixed flames to imposed inlet velocity oscillations  

SciTech Connect (OSTI)

Acoustically forced lean premixed turbulent bluff-body stabilized flames are investigated using turbulent combustion CFD. The calculations simulate aspects of the experimental investigation by Balachandran et al. [R. Balachandran, B. Ayoola, C. Kaminski, A. Dowling, E. Mastorakos, Combust. Flame 143 (2005) 37-55] and focus on the amplitude dependence of the flame response. For the frequencies of interest in this investigation an unsteady Reynolds-averaged Navier-Stokes (URANS) approach is appropriate. The combustion is represented using a modified laminar flamelet approach with an algebraic representation of the flame surface density. The predictions are compared with flame surface density (FSD) and OH* chemiluminescence measurements. In the experiments the response of the flame has been quantified by means of a number of single-frequency, amplitude-dependent transfer functions. The predicted flame shape and position are in good agreement with the experiment. The dynamic response of the flame to inlet velocity forcing is also well captured by the calculations. At moderate frequencies nonlinear behavior of the transfer functions is observed as the forcing amplitude is increased. In the experiments this nonlinearity was attributed in part to the rollup of the reacting shear layer into vortices and in part to the collision of the inner and outer flame sheets. This transition to nonlinearity is also observed in the transfer functions obtained from the predictions. Furthermore, the vortex shedding and flame-sheet collapse may be seen in snapshots of the predicted flow field taken throughout the forcing cycle. The URANS methodology successfully predicts the behavior of the forced premixed turbulent flames and captures the effects of saturation in the transfer function of the response of the heat release to velocity fluctuations. (author)

Armitage, C.A.; Mastorakos, E.; Cant, R.S. [Department of Engineering, Trumpington Street, University of Cambridge, Cambridge, CB2 1PZ (United Kingdom); Balachandran, R. [Department of Mechanical Engineering, University College London, Torrington Place, London, WC1E 7JE (United Kingdom)

2006-08-15T23:59:59.000Z

364

Rayleigh/Raman/LIF measurements in a turbulent lean premixed combustor  

SciTech Connect (OSTI)

Much of the industrial electrical generation capability being added worldwide is gas-turbine engine based and is fueled by natural gas. These gas-turbine engines use lean premixed (LP) combustion to meet the strict NO{sub x} emission standards, while maintaining acceptable levels of CO. In conventional, diffusion flame gas turbine combustors, large amount of NO{sub x} forms in the hot stoichiometric zones via the Zeldovich (thermal) mechanism. Hence, lean premixed combustors are rapidly becoming the norm, since they are specifically designed to avoid these hot stoichiometric zones and the associated thermal NO{sub x}. However, considerable research and development are still required to reduce the NO{sub x} levels (25-40 ppmvd adjusted to 15% O{sub 2} with the current technology), to the projected goal of under 10 ppmvd by the turn of the century. Achieving this objective would require extensive experiments in LP natural gas (or CH{sub 4}) flames for understanding the combustion phenomena underlying the formation of the exhaust pollutants. Although LP combustion is an effective way to control NO{sub x}, the downside is that it increases the CO emissions. The formation and destruction of the pollutants (NO{sub x} and CO) are strongly affected by the fluid mechanics, the finite-rate chemistry, and their (turbulence-chemistry) interactions. Hence, a thorough understanding of these interactions is vital for controlling and reducing the pollutant emissions. The present research is contributing to this goal by providing a detailed nonintrusive laser based data set with good spatial and temporal resolutions of the pollutants (NO and CO) along with the major species, temperature, and OH. The measurements reported in this work, along with the existing velocity data on a turbulent LP combustor burning CH{sub 4}, would provide insight into the turbulence-chemistry interactions and their effect on pollutant formation.

Nandula, S.P.; Pitz, R.W. [Vanderbilt Univ., Nashville, TN (United States). Dept. of Mechanical Engineering; Barlow, R.S.; Fiechtner, G.J. [Sandia National Labs., Albuquerque, NM (United States)

1995-12-31T23:59:59.000Z

365

LES SOFTWARE FOR THE DESIGN OF LOW EMISSION COMBUSTION SYSTEMS FOR VISION 21 PLANTS  

SciTech Connect (OSTI)

Further development of a combustion Large Eddy Simulation (LES) code for the design of advanced gaseous combustion systems is described in this fourth quarterly report. CFD Research Corporation (CFDRC) is developing the LES module within the parallel, unstructured solver included in the commercial CFD-ACE+ software. In this quarter, in-situ adaptive tabulation (ISAT) for efficient chemical rate storage and retrieval was further tested in the LES code. A more efficient PK binary tree data structure is being developed and implemented to replace the original BSP-tree structure. Implementation of the Linear Eddy Model (LEM) for subgrid chemistry has also started. In addition, Georgia Tech has shown that a chemical neural net (1-step chemistry) trained at certain turbulent conditions can be used at different turbulent conditions without expensive chemical kinetic integrations. Initial evaluations of the code accuracy have also been carried out. The evaluations cases included the unstable DOE-NETL combustor and a lid-driven cavity. Next quarter, the ISAT algorithm for efficient chemistry will be tested for the unstable DOE-NETL combustor. Initial flame calculations, with the LEM subgrid chemistry model are planned. Also, demonstration of the neural net approach, for chemical kinetics speed-up, should be demonstrated for more advanced chemistry (8-species and 19-species mechanisms).

Steve Cannon; Virgil Adumitroaie; Keith McDaniel; Cliff Smith

2001-10-01T23:59:59.000Z

366

Argonne TTRDC - Engines - Combustion Visualization - emissions,  

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

Combustion Visualization Combustion Visualization Exploring Combustion Using Advanced Imaging Techniques In the photo, the GM diesel test cell is shown with vehicle exhaust aftertreatment hardware (diesel particulate filtration and diesel oxidation catalyst) along with other advanced technology-such as a variable geometry turbocharger, cooled exhaust gas recirculation and a common-rail fuel injection system. Fig. 1. The GM diesel test cell is shown with vehicle exhaust aftertreatment hardware (diesel particulate filtration and diesel oxidation catalyst) along with other advanced technology-such as a variable geometry turbocharger, cooled exhaust gas recirculation and a common-rail fuel injection system. Two-dimensional image of hydrogen combustion OH chemiluminescence. Fig. 2. Two-dimensional image of hydrogen combustion OH chemiluminescence.

367

Fine Particle Emissions from Combustion Systems  

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

Fine Particle Emissions from Combustion Systems Fine Particle Emissions from Combustion Systems Speaker(s): Allen Robinson Date: November 11, 2005 - 12:00pm Location: 90-3122 Combustion systems such as motor vehicles and power plants are major sources of fine particulate matter. This talk describes some of the changes in fine particle emissions that occur as exhaust from combustion systems mix with background air. This mixing cools and dilutes the exhaust which influences gas-particle partitioning of semi-volatile species, the aerosol size distribution, and the fine particle mass. Dilution sampling is used to characterize fine particle emissions from combustion systems because it simulates the rapid cooling and dilution that occur as exhaust mixes with the atmosphere. Results from dilution sampler

368

Advanced Combustion Technologies | Department of Energy  

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

Science & Innovation » Clean Coal » Advanced Combustion Science & Innovation » Clean Coal » Advanced Combustion Technologies Advanced Combustion Technologies Joe Yip, a researcher at FE's National Energy Technology Laboratory, uses laser-based Rayleigh light scattering to measure flame density and speed over a flat flame burner. Oxyfuel combustion, using oxygen in place of air with diluents such as steam or carbon dioxide, can reduce pollutant emissions in advanced power cycles using gas turbines. Photo courtesy of NETL Multimedia. Joe Yip, a researcher at FE's National Energy Technology Laboratory, uses laser-based Rayleigh light scattering to measure flame density and speed over a flat flame burner. Oxyfuel combustion, using oxygen in place of air with diluents such as steam or carbon dioxide, can reduce pollutant

369

Scaling and efficiency of PRISM in adaptive simulations of turbulent premixed flames  

SciTech Connect (OSTI)

The dominant computational cost in modeling turbulent combustion phenomena numerically with high fidelity chemical mechanisms is the time required to solve the ordinary differential equations associated with chemical kinetics. One approach to reducing that computational cost is to develop an inexpensive surrogate model that accurately represents evolution of chemical kinetics. One such approach, PRISM, develops a polynomial representation of the chemistry evolution in a local region of chemical composition space. This representation is then stored for later use. As the computation proceeds, the chemistry evolution for other points within the same region are computed by evaluating these polynomials instead of calling an ordinary differential equation solver. If initial data for advancing the chemistry is encountered that is not in any region for which a polynomial is defined, the methodology dynamically samples that region and constructs a new representation for that region. The utility of this approach is determined by the size of the regions over which the representation provides a good approximation to the kinetics and the number of these regions that are necessary to model the subset of composition space that is active during a simulation. In this paper, we assess the PRISM methodology in the context of a turbulent premixed flame in two dimensions. We consider a range of turbulent intensities ranging from weak turbulence that has little effect on the flame to strong turbulence that tears pockets of burning fluid from the main flame. For each case, we explore a range of sizes for the local regions and determine the scaling behavior as a function of region size and turbulent intensity.

Tonse, Shaheen R.; Bell, J.B.; Brown, N.J.; Day, M.S.; Frenklach, M.; Grcar, J.F.; Propp, R.M.

1999-12-01T23:59:59.000Z

370

Perpendicular ion acceleration in whistler turbulence  

SciTech Connect (OSTI)

Whistler turbulence is an important contributor to solar wind turbulence dissipation. This turbulence contains obliquely propagating whistler waves at electron scales, and these waves have electrostatic components perpendicular to the mean magnetic field. In this paper, a full kinetic, two-dimensional particle-in-cell simulation shows that whistler turbulence can accelerate ions in the direction perpendicular to the mean magnetic field. When the ions pass through wave-particle resonances region in the phase space during their cyclotron motion, the ions are effectively accelerated in the perpendicular direction. The simulation results suggest that whistler turbulence contributes to the perpendicular heating of ions observed in the solar wind.

Saito, S. [Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8601 (Japan)] [Graduate School of Science, Nagoya University, Furocho, Chikusa, Nagoya 464-8601 (Japan); Nariyuki, Y. [Faculty of Human Development, University of Toyama, 3190, Toyama 930-8555 (Japan)] [Faculty of Human Development, University of Toyama, 3190, Toyama 930-8555 (Japan)

2014-04-15T23:59:59.000Z

371

Wave turbulence in quantum fluids  

Science Journals Connector (OSTI)

...range, as shown by the inset bifurcation diagram. Fig. 2. Second sound turbulence...metastable state. (Inset) Bifurcation diagram showing regions of stability (unshaded) and...159 . 9 Ryutova M Tarbell T ( 2003 ) MHD shocks and the origin of the solar transition...

German V. Kolmakov; Peter Vaughan Elsmere McClintock; Sergey V. Nazarenko

2014-01-01T23:59:59.000Z

372

Axial cylinder internal combustion engine  

SciTech Connect (OSTI)

This patent describes improvement in a barrel type internal combustion engine including an engine block having axial-positioned cylinders with reciprocating pistons arranged in a circular pattern: a drive shaft concentrically positioned within the cylinder block having an offset portion extending outside the cylinder block; a wobble spider rotatably journaled to the offset portion; connecting rods for each cylinder connecting each piston to the wobble spider. The improvement comprising: a first sleeve bearing means supporting the drive shaft in the engine block in a cantilevered manner for radial loads; a second sleeve bearing means rotatably supporting the wobble spider on the offset portion of the drive shaft for radial loads; a first roller bearing means positioned between the offset portion of the drive shaft and the wobble spider carrying thrust loadings only; a second roller bearing means carrying thrust loads only reacting to the first roller bearing located on the opposite end of the driveshaft between the shaft and the engine block.

Gonzalez, C.

1992-03-10T23:59:59.000Z

373

Advances in pulverized coal combustion  

SciTech Connect (OSTI)

A combustion system has been developed to operate cost effectively in the difficult regulatory and economic climate of the 1980's. The system is designed to reduce auxiliary fuel oil comsumption by at least 30% while meeting all relevant emissions limits. This is achieved with the fewest components consistent with practical reliable design criteria. The Controlled Flow Split/Flame low NO/sub x/ burner, MBF pulverizer and Two-Stage ignition system are integrated into a mutually supporting system which is applicable to both new steam generators and, on a retrofit basis, to existing units. In the future, a pulverized coal ignition system will be available to eliminate fuel oil use within the boiler.

Vatsky, J.

1981-01-01T23:59:59.000Z

374

Turbulent phenomena in protein folding  

Science Journals Connector (OSTI)

Protein folding and hydrodynamic turbulence are two long-standing challenges, in molecular biophysics and fluid dynamics, respectively. The theories of these phenomena have been developed independently and used different formalisms. Here we show that the protein folding flows can be surprisingly similar to turbulent fluid flows. Studying a benchmark model protein (an SH3 domain), we have found that the flows for the slow folding trajectories of the protein, in which a partly formed N- and C-terminal ? sheet hinders the RT loop from attaching to the protein core, have many properties of turbulent flows of a fluid. The flows are analyzed in a three-dimensional (3D) space of collective variables, which are the numbers of native contacts between the terminal ? strands, between the RT loop and the protein core, and the rest of the native contacts. We have found that the flows have fractal nature and are filled with 3D eddies; the latter contain strange attractors, at which the tracer flow paths behave as saddle trajectories. Two regions of the space increment have been observed, in which the flux variations are self-similar with the scaling exponent h=1/3, in surprising agreement with the Kolmogorov inertial range theory of turbulence. In one region, the cascade of protein rearrangements is directed from larger to smaller scales (net folding), and in the other, it is oppositely directed (net unfolding). Folding flows for the fast trajectories are essentially “laminar” and do not have the property of self-similarity. Based on the results of our study, we infer, and support this inference by simulations, that the origin of the similarity between the protein folding and turbulent motion of a fluid is in a cascade mechanism of structural transformations in the systems that underlies these phenomena.

Igor V. Kalgin and Sergei F. Chekmarev

2011-01-31T23:59:59.000Z

375

On the modelling of coal combustion in a 550 MWel coal-fired utility boiler  

Science Journals Connector (OSTI)

The furnace of a pulverised coal-fired utility boiler with an electrical output of 550 MW, the dimensions of 19m x 15m x 48m and 32 swirl burners located on four elevations is considered. Coal combustion is described by a four-step reaction scheme. The model covers two heterogeneous reactions for pyrolysis and char combustion and three gas-phase reactions for the oxidation of volatile matter. A standard k; ?-model is used for the description of turbulence. The interaction between turbulence and chemistry is modelled using the Eddy Dissipation Concept (EDC). Radiation is computed by means of the Discrete Ordinates method. The discretisation is based on a non-staggered finite-volume approach. The coupling of velocities and pressure is achieved by the SIMPLEC-method, and the UPWIND or MLU discretisation schemes are used for the computation of the convective fluxes. All gas phase transport equations are formulated in the Eulerian way in general curvilinear co-ordinates allowing an accurate treatment of boundaries and a very good distribution of the grid lines. The coal particle phase is either treated with a Eulerian description assuming no slip between the gas and particle phase, or with a Lagrangian description. The Lagrangian approach to the particle phase is fully coupled with the gas phase using the Particle-Source-in-Cell method and taking the turbulence effects of the gas phase on particle dispersion into account. The differences in the predictions using the Eulerian and Eulerian/Lagrangian approaches are elaborated by comparing the computational results with in-furnace measurements of carbon monoxide, carbon dioxide and oxygen concentrations.

Hermann Knaus; Uwe Schnell; Klaus R. G. Hein

2001-01-01T23:59:59.000Z

376

Vehicle Technologies Office: Advanced Combustion Engines  

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

Combustion Engines Combustion Engines Improving the efficiency of internal combustion engines is one of the most promising and cost-effective near- to mid-term approaches to increasing highway vehicles' fuel economy. The Vehicle Technologies Office's research and development activities address critical barriers to commercializing higher efficiency, very low emissions advanced internal combustion engines for passenger and commercial vehicles. This technology has great potential to reduce U.S. petroleum consumption, resulting in greater economic, environmental, and energy security. Already offering outstanding drivability and reliability to over 230 million passenger vehicles, internal combustion engines have the potential to become substantially more efficient. Initial results from laboratory engine tests indicate that passenger vehicle fuel economy can be improved by more than up to 50 percent, and some vehicle simulation models estimate potential improvements of up to 75 percent. Advanced combustion engines can utilize renewable fuels, and when combined with hybrid electric powertrains could have even further reductions in fuel consumption. As the EIA reference case forecasts that by 2035, more than 99 percent of light- and heavy-duty vehicles sold will still have internal combustion engines, the potential fuel savings is tremendous.

377

Low NOx combustion system for heavy oil  

SciTech Connect (OSTI)

As a result of the increasing demand for white oil as one of countermeasures for pollution control and as a fuel for motor vehicle, coupled with the increasing import of heavy crude oil, heavy oils such as asphalt and distillation residue have become surplus in Japan. It is difficult by the conventional low NOx technology to control the NOx emission from the industrial small and medium capacity boilers, which use heavy oil as their fuels. The authors have been developing and improving NOx control technologies for boilers such as low NOx burners, two-stage combustion methods and so on. They have developed a new combustion system for heavy oil, which generates less NOx and soot than conventional systems, by applying the knowledge, obtained in the course of their development of Coal Partial Combustor (CPC). The conventional low NOx combustion method for oil firing boilers has been developed based on decreasing the flame temperature and delaying the combustion reaction. In the system, however, the heavy oil shall be combusted in the intense reducing atmosphere at the high flame temperature between 1,500 C and 1,600 C, and then the combustions gas shall be cooled and oxidized by two-stage combustion air. With this system, NOx emission can be suppressed below 100ppm (converted as O{sub 2}=4%).

Kurata, Chikatoshi; Sasaki, Hideki

1999-07-01T23:59:59.000Z

378

Simulation of turbulent explosion of hydrogen-air mixtures  

E-Print Network [OSTI]

L = s0L ? ?L for small values of ? and the Markstein length scale L can be positive or negative [10]. The stretch rate is defined as the rate of change of flame area per unit area, A, ie., ? = (dA/dt)/A and it is given as ? = (2/rf)(drf/dt), for a spher... ]. Also, fundamental understanding of hydrogen combustion is important from safety view points, for example generation and accumulation of hydrogen in nuclear reactors [7] and rupturing of a pressurised hydrogen storage tank can lead to explosions. A...

Ahmed, I.; Swaminathan, N.

2014-04-27T23:59:59.000Z

379

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

Science Journals Connector (OSTI)

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

Artur Pozarlik; Jim B. Kok

2008-01-01T23:59:59.000Z

380

Magnetic field effects on the thermonuclear combustion front of Chandrasekhar mass white dwarfs  

E-Print Network [OSTI]

The explosion of a type Ia supernova starts in a white dwarf as a laminar deflagration at the center of the star and soon several hydrodynamic instabilities, in particular, the Rayleigh-Taylor instability, begin to act. A cellular stationary combustion and a turbulent combustion regime are rapidly achieved by the flame and maintained up to the end of the so-called flamelet regime when the transition to detonation is believed to occur. The burning velocity at these regimes is well described by the fractal model of combustion. Using a semi-analytic approach, we describe the effect of magnetic fields on the fractalization of the front considering a white dwarf with a nearly dipolar magnetic field. We find an intrinsic asymmetry on the velocity field that may be maintained up to the free expansion phase of the remnant. Considering the strongest values inferred for a white dwarf's magnetic fields with strengths up to $10^{8}-10^{9}$ G at the surface and assuming that the field near the centre is roughly 10 times greater, asymmetries in the velocity field higher than $10-20 %$ are produced between the magnetic polar and the equatorial axis of the remnant which may be related to the asymmetries found from recent spectropolarimetric observations of very young SN Ia remnants. Dependence of the asymmetry with white dwarf composition is also analyzed.

Cristian R. Ghezzi; Elisabete M. de Gouveia Dal Pino; Jorge E. Horvath

2000-12-06T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


381

Gas turbine alternative fuels combustion characteristics  

SciTech Connect (OSTI)

An experimental investigation was conducted to obtain combustion performance and exhaust pollutant concentrations for specific synthetic hydrocarbon fuels. Baseline comparison fuels used were gasoline and diesel fuel number two. Testing was done over a range of fuel to air mass ratios, total mass flow rates, and input combustion air temperatures in a flame-tube-type gas turbine combustor. Test results were obtained in terms of released heat and combustion gas emission values. The results were comparable to those obtained with the base fuels with variations being obtained with changing operating conditions. The release of carbon particles during the tests was minimal. 22 refs., 12 figs., 2 tabs.

Rollbuhler, R.J.

1989-02-01T23:59:59.000Z

382

Combustion in cracks of PBX 9501  

SciTech Connect (OSTI)

Recent experiments involving the combustion of PBX 9501 explosive under confined conditions reveal the importance of crack and flaws in reaction violence. Experiments on room temperature confined disks of pristine and thermally damaged PBX 9501 reveal that crack ignition depends on hot gases entering existing or pressure induced cracks rather than on energy release at the crack tip. PBX 9501 slot combustion experiments show that the reaction propagation rate in the slot does not depend on the external pressure. We have observed 1500 d s in long slots of highly-confined PBX 9501. We present experiments that examine the combustion of mechanically and thermally damaged samples of PBX 9501.

Berghout, H. L. (Henry L.); Son, S. F. (Steven F.); Bolme, C. A. (Cynthia A.); Hill, L. G. (Larry G.); Asay, B. W. (Blaine W.); Dickson, P. M. (Peter M.); Henson, B. F. (Bryan F.); Smilowitz, L. B. (Laura B.)

2002-01-01T23:59:59.000Z

383

Diesel knock noise from combustion phenomenon to perceived signals  

E-Print Network [OSTI]

Diesel knock noise from combustion phenomenon to perceived signals O. Sauvagea , A. Lauracb , M for reducing Diesel knock are modifications of engine parameters used for controlling combustion processes-acoustic properties, throught its noticeable combustion noise (also called "Diesel knock"). Combustion noise generated

Paris-Sud XI, Université de

384

Thermodynamic Analysis of Alternative Approaches to Chemical Looping Combustion  

Science Journals Connector (OSTI)

Thermodynamic Analysis of Alternative Approaches to Chemical Looping Combustion ... Because H2 and syngas have similar combustion irreversibilities, when reforming is done optimally (with TR close to 650 K), iso-octane can be combusted with the same efficiency as that of preheated, isothermal H2 combustion. ... A loop of chem. ...

V. Kalyana Chakravarthy; C. Stuart Daw; Josh A. Pihl

2011-01-19T23:59:59.000Z

385

US National Technical Meeting of the Combustion Institute  

E-Print Network [OSTI]

potential to enhance combustion performance in gas turbines and scramjet engines. Extensive efforts have

Ju, Yiguang

386

Robust Feedback Control of Combustion Instability with Modeling Uncertainty  

E-Print Network [OSTI]

to mod- ulate combustion processes in propulsion sys- tems has recently received extensive attention [1

Ray, Asok

387

Planar Richtmyer-Meshkov instabilities and transition to turbulence  

SciTech Connect (OSTI)

Extensive recent work has demonstrated that predictive under-resolved simulations of the velocity fields in turbulent flows are possible without resorting to explicit subgrid models. When using a class of physics-capturing high-resolution finite-volume numerical algorithms. This strategy is denoted implicit large eddy simulation (ILES, MILES). The performance of ILES in the substantially more difficult problem of under-resolved material mixing driven by under-resolved velocity fields and initial conditions (ICs) is a focus of the present work. Progress is presented in analyzing the effects of IC combined spectral content and thickness parametrizations. In the large eddy simulation (LES). the large energy containing structures are resolved, the smaller, presumably more isotropic, structures are filtered out, and effects of subgrid scales (SGS) are modeled. ILES effectively addresses the seemingly insurmountable issues posed to LES by under-resolution. by relying on the use of SGS modeling and filtering provided implicitly by a class of physics capturing numerics; extensive verification and validation in areas of engineering. geophysics. and astrophysics has been reported. In many areas of interest such as. inertial confinement fusion. understanding the collapse of the outer cores of supernovas. and supersonic combustion engines, vorticity is introduced at material interfaces by the impulsive loading of shock waves. and turbulence is generated via Richtmyer-Meshkov instabilities (RMI). Given that ILES is based on locally-adaptive, non-oscillatory. finite-volume methods it is naturally suited to emulate shock physics. The unique combination of shock and turbulence emulation capabilities supports direct use of ILES as an effective simulation anzatz for RMI. Here, we further test this approach using a particular strategy based on a nominally-inviscid, Schmidt number {approx} 1, simulation model that uses the LANL RAGE code to investigate planar RMI. Issues of initial material interface characterization and modeling difficulties, and effects of IC resolved spectral content on transitional and late-time turbulent mixing were examined in our previous work. The focus here is to carry out a systematic analysis of effects of combined IC spectral content and thickness.

Grinstein, Fernando F [Los Alamos National Laboratory; Gowardhan, Akshay [Los Alamos National Laboratory; Ristorcelli, Ray [Los Alamos National Laboratory

2011-01-21T23:59:59.000Z

388

Nonlinear Gyrokinetic Simulations of Ion-Temperature-Gradient Turbulence for the Optimized Wendelstein 7-X Stellarator  

SciTech Connect (OSTI)

Ion-temperature-gradient turbulence constitutes a possibly dominant transport mechanism for optimized stellarators, in view of the effective suppression of neoclassical losses characterizing these devices. Nonlinear gyrokinetic simulation results for the Wendelstein 7-X stellarator [G. Grieger et al., in Proceedings of the IAEA Conference on Plasma Physics and Controlled Nuclear Fusion Research, 1990 (IAEA, Vienna, 1991) Vol. 3, p. 525]--assuming an adiabatic electron response--are presented. Several fundamental features are discussed, including the role of zonal flows for turbulence saturation, the resulting flux-gradient relationship, and the coexistence of ion-temperature-gradient modes with trapped ion modes in the saturated state.

Xanthopoulos, P. [Max-Planck-Institut fuer Plasmaphysik, Teilinstitut Greifswald, Wendelsteinstrasse 1, D-17491 Greifswald (Germany); Merz, F.; Goerler, T.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, Boltzmannstrasse 2, D-85748 Garching (Germany)

2007-07-20T23:59:59.000Z

389

Turbulent equipartitions in two dimensional drift convection  

SciTech Connect (OSTI)

Unlike the thermodynamic equipartition of energy in conservative systems, turbulent equipartitions (TEP) describe strongly non-equilibrium systems such as turbulent plasmas. In turbulent systems, energy is no longer a good invariant, but one can utilize the conservation of other quantities, such as adiabatic invariants, frozen-in magnetic flux, entropy, or combination thereof, in order to derive new, turbulent quasi-equilibria. These TEP equilibria assume various forms, but in general they sustain spatially inhomogeneous distributions of the usual thermodynamic quantities such as density or temperature. This mechanism explains the effects of particle and energy pinch in tokamaks. The analysis of the relaxed states caused by turbulent mixing is based on the existence of Lagrangian invariants (quantities constant along fluid-particle or other orbits). A turbulent equipartition corresponds to the spatially uniform distribution of relevant Lagrangian invariants. The existence of such turbulent equilibria is demonstrated in the simple model of two dimensional electrostatically turbulent plasma in an inhomogeneous magnetic field. The turbulence is prescribed, and the turbulent transport is assumed to be much stronger than the classical collisional transport. The simplicity of the model makes it possible to derive the equations describing the relaxation to the TEP state in several limits.

Isichenko, M.B.; Yankov, V.V. [Univ. of California, Santa Barbara, CA (United States). Inst. for Theoretical Physics

1995-07-25T23:59:59.000Z

390

Biomass Combustion Systems Inc | Open Energy Information  

Open Energy Info (EERE)

Combustion Systems Inc Combustion Systems Inc Jump to: navigation, search Name Biomass Combustion Systems Inc Address 67 Millbrook St Place Worcester, Massachusetts Zip 01606 Sector Biomass Product Combustion systems for wood fuel Website http://www.biomasscombustion.c Coordinates 42.290195°, -71.799627° Loading map... {"minzoom":false,"mappingservice":"googlemaps3","type":"ROADMAP","zoom":14,"types":["ROADMAP","SATELLITE","HYBRID","TERRAIN"],"geoservice":"google","maxzoom":false,"width":"600px","height":"350px","centre":false,"title":"","label":"","icon":"","visitedicon":"","lines":[],"polygons":[],"circles":[],"rectangles":[],"copycoords":false,"static":false,"wmsoverlay":"","layers":[],"controls":["pan","zoom","type","scale","streetview"],"zoomstyle":"DEFAULT","typestyle":"DEFAULT","autoinfowindows":false,"kml":[],"gkml":[],"fusiontables":[],"resizable":false,"tilt":0,"kmlrezoom":false,"poi":true,"imageoverlays":[],"markercluster":false,"searchmarkers":"","locations":[{"text":"","title":"","link":null,"lat":42.290195,"lon":-71.799627,"alt":0,"address":"","icon":"","group":"","inlineLabel":"","visitedicon":""}]}

391

Chemical Looping for Combustion and Hydrogen Production  

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

ChemiCal looping for Combustion and ChemiCal looping for Combustion and hydrogen produCtion Objective The objective of this project is to determine the benefits of chemical looping technology used with coal to reduce CO 2 emissions. Background Chemical looping is a new method to convert coal or gasified coal to energy. In chemical looping, there is no direct contact between air and fuel. The chemical looping process utilizes oxygen from metal oxide oxygen carrier for fuel combustion, or for making hydrogen by "reducing" water. In combustion applications, the products of chemical looping are CO 2 and H 2 O. Thus, once the steam is condensed, a relatively pure stream of CO 2 is produced ready for sequestration. The production of a sequestration ready CO 2 stream does not require any additional separation units

392

Coal fuel slurry for internal combustion engines  

Science Journals Connector (OSTI)

A technoeconomic study of the production of coal-water fuel slurry for internal combustion engines and thermal power plants was performed. Based on the accumulated experimental data, it was found that, in the ...

N. I. Red’kina; G. S. Khodakov; E. G. Gorlov

2013-09-01T23:59:59.000Z

393

The Role of Volatiles in Coal Combustion  

Science Journals Connector (OSTI)

Our knowledge of the role of volatiles in coal combustion ranges at this time from the self-evident to the ambiguous. The clearest point on which all agree is that pyrolysis will occur during the total coal co...

Robert H. Essenhigh; Eric M. Suuberg

1987-01-01T23:59:59.000Z

394

Oil shale retorting and combustion system  

DOE Patents [OSTI]

The present invention is directed to the extraction of energy values from l shale containing considerable concentrations of calcium carbonate in an efficient manner. The volatiles are separated from the oil shale in a retorting zone of a fluidized bed where the temperature and the concentration of oxygen are maintained at sufficiently low levels so that the volatiles are extracted from the oil shale with minimal combustion of the volatiles and with minimal calcination of the calcium carbonate. These gaseous volatiles and the calcium carbonate flow from the retorting zone into a freeboard combustion zone where the volatiles are burned in the presence of excess air. In this zone the calcination of the calcium carbonate occurs but at the expense of less BTU's than would be required by the calcination reaction in the event both the retorting and combustion steps took place simultaneously. The heat values in the products of combustion are satisfactorily recovered in a suitable heat exchange system.

Pitrolo, Augustine A. (Fairmont, WV); Mei, Joseph S. (Morgantown, WV); Shang, Jerry Y. (Fairfax, VA)

1983-01-01T23:59:59.000Z

395

Coal Combustion By-Products (Maryland)  

Broader source: Energy.gov [DOE]

The Department of the Environment is responsible for regulating fugitive air emissions from the transportation of coal combustion by-products and the permissible beneficial uses of these by...

396

Control of NOx by combustion process modifications  

E-Print Network [OSTI]

A theoretical and experimental study was carried out to determine lower bounds of NOx emission from staged combustion of a 0.7%N #6 fuel oil. Thermodynamic and chemical kinetic calculations have shown minimum NOx emissions ...

Ber?, J. M.

1981-01-01T23:59:59.000Z

397

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the fourth quarter January-March 2001 in the following task areas: Task 1 - Oxygen Enhanced Combustion, Task 2 - Oxygen Transport Membranes and Task 4 - Program Management. This report will also recap the results of the past year. The program is proceeding in accordance with the objectives for the first year. OTM material characterization was completed. 100% of commercial target flux was demonstrated with OTM disks. The design and assembly of Praxair's single tube high-pressure test facility was completed. The production of oxygen with a purity of better than 99.5% was demonstrated. Coal combustion testing was conducted at the University of Arizona. Modest oxygen enhancement resulted in NOx emissions reduction. The injector for oxygen enhanced coal based reburning was conducted at Praxair. Combustion modeling with Keystone boiler was completed. Pilot-scale combustion test furnace simulations continued this quarter.

David R. Thompson; Lawrence E. Bool; Jack C. Chen

2001-04-01T23:59:59.000Z

398

Virtual Design of Stirling Engine Combustion Chamber  

Science Journals Connector (OSTI)

The paper deals with the designing of a combustion chamber of the Stirling engine using the CFD approach. Virtual prototypes enabled ... . The presented results help to increase the Stirling engine efficiency tog...

Z. Kaplan; P. Novotný; V. Píšt?k

2010-01-01T23:59:59.000Z

399

Vortex driven flame dynamics and combustion instability  

E-Print Network [OSTI]

Combustion instability in premixed combustors mostly arises due to the coupling between heat release rate dynamics and system acoustics. It is crucial to understand the instability mechanisms to design reliable, high ...

Altay, Hurrem Murat

2005-01-01T23:59:59.000Z

400

State of Industrial Fluidized Bed Combustion  

E-Print Network [OSTI]

A new combustion technique has been developed in the last decade that permits the burning of low quality coal, lignite and other fuels, while maintaining stack emissions within State and Federal limits. Low quality fuels can be burned directly...

Mesko, J. E.

1982-01-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


401

Research on late-robust combustion  

E-Print Network [OSTI]

To better understand the role that turbulence plays in causing cycle-by-cycle variations, an experimental study was carried out in which charge motion or laminar flame speed was varied. Two sets of tests were done. The ...

Wildman, Craig B. E. (Craig Bradley Edward), 1987-

2005-01-01T23:59:59.000Z

402

Coal Combustion Products Extension Program  

SciTech Connect (OSTI)

This final project report presents the activities and accomplishments of the ''Coal Combustion Products Extension Program'' conducted at The Ohio State University from August 1, 2000 to June 30, 2005 to advance the beneficial uses of coal combustion products (CCPs) in highway and construction, mine reclamation, agricultural, and manufacturing sectors. The objective of this technology transfer/research program at The Ohio State University was to promote the increased use of Ohio CCPs (fly ash, FGD material, bottom ash, and boiler slag) in applications that are technically sound, environmentally benign, and commercially competitive. The project objective was accomplished by housing the CCP Extension Program within The Ohio State University College of Engineering with support from the university Extension Service and The Ohio State University Research Foundation. Dr. Tarunjit S. Butalia, an internationally reputed CCP expert and registered professional engineer, was the program coordinator. The program coordinator acted as liaison among CCP stakeholders in the state, produced information sheets, provided expertise in the field to those who desired it, sponsored and co-sponsored seminars, meetings, and speaking at these events, and generally worked to promote knowledge about the productive and proper application of CCPs as useful raw materials. The major accomplishments of the program were: (1) Increase in FGD material utilization rate from 8% in 1997 to more than 20% in 2005, and an increase in overall CCP utilization rate of 21% in 1997 to just under 30% in 2005 for the State of Ohio. (2) Recognition as a ''voice of trust'' among Ohio and national CCP stakeholders (particularly regulatory agencies). (3) Establishment of a national and international reputation, especially for the use of FGD materials and fly ash in construction applications. It is recommended that to increase Ohio's CCP utilization rate from 30% in 2005 to 40% by 2010, the CCP Extension Program be expanded at OSU, with support from state and federal agencies, utilities, trade groups, and the university, to focus on the following four specific areas of promise: (a) Expanding use in proven areas (such as use of fly ash in concrete); (b) Removing or reducing regulatory and perceptual barriers to use (by working in collaboration with regulatory agencies); (c) Developing new or under-used large-volume market applications (such as structural fills); and (d) Placing greater emphasis on FGD byproducts utilization.

Tarunjit S. Butalia; William E. Wolfe

2006-01-11T23:59:59.000Z

403

Fundamental Studies in Syngas Premixed Combustion Dynamics  

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

Studies Studies in Syngas Premixed Combustion Dynamics Ahmed F. Ghoniem, Anuradha M. Annaswamy, Raymond L. Speth, H. Murat Altay Massachusetts Institute of Technology SCIES Project 05-01-SR121 Project Awarded (08/01/2005, 36 Month Duration) Needs & Objectives Gas Turbine Needs Flexibility to operate with variable syngas compositions Ensure stable operation over a wide range of conditions Reduce emissions of CO and NO x Project Objectives Study experimentally lean premixed syngas combustion

404

Oxy-combustion: Oxygen Transport Membrane Development  

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

combustion: Oxygen Transport combustion: Oxygen Transport Membrane Development Background The mission of the U.S. Department of Energy's (DOE) Existing Plants, Emissions & Capture (EPEC) Research & Development (R&D) Program is to develop innovative environmental control technologies to enable full use of the nation's vast coal reserves, while at the same time allowing the current fleet of coal-fired power plants to comply with existing and emerging environmental regulations. The EPEC R&D

405

Building America Expert Meeting: Combustion Safety  

SciTech Connect (OSTI)

This is a meeting overview of 'The Best Approach to Combustion Safety in a Direct Vent World', held June 28, 2012, in San Antonio, Texas. The objective of this Expert Meeting was to identify gaps and barriers that need to be addressed by future research, and to develop data-driven technical recommendations for code updates so that a common approach for combustion safety can be adopted by all members of the building energy efficiency and code communities.

Brand, L.

2013-03-01T23:59:59.000Z

406

Reflective ghost imaging through turbulence  

SciTech Connect (OSTI)

Recent work has indicated that ghost imaging may have applications in standoff sensing. However, most theoretical work has addressed transmission-based ghost imaging. To be a viable remote-sensing system, the ghost imager needs to image rough-surfaced targets in reflection through long, turbulent optical paths. We develop, within a Gaussian-state framework, expressions for the spatial resolution, image contrast, and signal-to-noise ratio of such a system. We consider rough-surfaced targets that create fully developed speckle in their returns and Kolmogorov-spectrum turbulence that is uniformly distributed along all propagation paths. We address both classical and nonclassical optical sources, as well as a computational ghost imager.

Hardy, Nicholas D.; Shapiro, Jeffrey H. [Research Laboratory of Electronics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 (United States)

2011-12-15T23:59:59.000Z

407

Transport enhancement and suppression in turbulent magnetic reconnection: A self-consistent turbulence model  

SciTech Connect (OSTI)

Through the enhancement of transport, turbulence is expected to contribute to the fast reconnection. However, the effects of turbulence are not so straightforward. In addition to the enhancement of transport, turbulence under some environment shows effects that suppress the transport. In the presence of turbulent cross helicity, such dynamic balance between the transport enhancement and suppression occurs. As this result of dynamic balance, the region of effective enhanced magnetic diffusivity is confined to a narrow region, leading to the fast reconnection. In order to confirm this idea, a self-consistent turbulence model for the magnetic reconnection is proposed. With the aid of numerical simulations where turbulence effects are incorporated in a consistent manner through the turbulence model, the dynamic balance in the turbulence magnetic reconnection is confirmed.

Yokoi, N. [Institute of Industrial Science, University of Tokyo, Tokyo (Japan)] [Institute of Industrial Science, University of Tokyo, Tokyo (Japan); Higashimori, K.; Hoshino, M. [Department of Earth and Planetary Science, University of Tokyo, Tokyo (Japan)] [Department of Earth and Planetary Science, University of Tokyo, Tokyo (Japan)

2013-12-15T23:59:59.000Z

408

Rapid Deployment of Rich Catalytic Combustion  

SciTech Connect (OSTI)

The overall objective of this research under the Turbines Program is the deployment of fuel flexible rich catalytic combustion technology into high-pressure ratio industrial gas turbines. The resulting combustion systems will provide fuel flexibility for gas turbines to burn coal derived synthesis gas or natural gas and achieve NO{sub x} emissions of 2 ppmvd or less (at 15 percent O{sub 2}), cost effectively. This advance will signify a major step towards environmentally friendly electric power generation and coal-based energy independence for the United States. Under Phase 1 of the Program, Pratt & Whitney (P&W) performed a system integration study of rich catalytic combustion in a small high-pressure ratio industrial gas turbine with a silo combustion system that is easily scalable to a larger multi-chamber gas turbine system. An implementation plan for this technology also was studied. The principal achievement of the Phase 1 effort was the sizing of the catalytic module in a manner which allowed a single reactor (rather than multiple reactors) to be used by the combustion system, a conclusion regarding the amount of air that should be allocated to the reaction zone to achieve low emissions, definition of a combustion staging strategy to achieve low emissions, and mechanical integration of a Ceramic Matrix Composite (CMC) combustor liner with the catalytic module.

Richard S. Tuthill

2004-06-10T23:59:59.000Z

409

Effect of Oxyfuel Combustion on Superheater Corrosion  

SciTech Connect (OSTI)

Combustion of coal in an oxygen environment (as opposed to air) will facilitate the sequestering of carbon dioxide by minimizing the amount of nitrogen in the exit gas stream. The presence of higher levels of certain gases associated with oxyfuel combustion (eg, CO2, SO2, and H2O) may impact the corrosion of waterwalls, superheaters, headers, reheaters, and other boiler components. Research is being conducted on bare and ash-embedded boiler tube materials in simulated oxyfuel- combustion and air-combustion environments at a superheater temperature of 675°C. Alloys were exposed at temperature to two different gaseous environments. Preliminary results show: (1) an increase in corrosion rate of bare K02707, K11547, K21590, K91560, K92460, S30409, S34700, and N06617 exposed to the oxyfuel combustion environment when compared to the air combustion environment; (2) an increase in corrosion rate of alloys K21590, K92460, S34700, and N06617, when embedded in ash in comparison to bare exposure; and (3) no effect of gaseous environment on alloy corrosion rate when embedded in ash.

Covino, B.S., Jr.; Matthes, S.A.; Bullard, S.J.

2008-03-16T23:59:59.000Z

410

Quantifying Turbulence for Tidal Power Applications  

SciTech Connect (OSTI)

Using newly collected data from a tidal power site in Puget Sound, WA, metrics for turbulence quantification are assessed and discussed. The quality of raw ping Acoustic Doppler Current Profiler (ADCP) data for turbulence studies is evaluated against Acoustic Doppler Velocimeter (ADV) data at a point. Removal of Doppler noise from the raw ping data is shown to be a crucial step in turbulence quantification. Excluding periods of slack tide, the turbulent intensity estimates at a height of 4.6 m above the seabed are 8% and 11% from the ADCP and ADV, respectively. Estimates of the turbulent dissipation rate are more variable, from 10e-3 to 10e-1 W/m^3. An example analysis of coherent Turbulent Kinetic Energy (TKE) is presented.

Thomson, Jim; Richmond, Marshall C.; Polagye, Brian; Durgesh, Vibhav

2010-08-01T23:59:59.000Z

411

Odor Landscapes in Turbulent Environments  

Science Journals Connector (OSTI)

The olfactory system of male moths is exquisitely sensitive to pheromones emitted by females and transported in the environment by atmospheric turbulence. Moths respond to minute amounts of pheromones, and their behavior is sensitive to the fine-scale structure of turbulent plumes where pheromone concentration is detectible. The signal of pheromone whiffs is qualitatively known to be intermittent, yet quantitative characterization of its statistical properties is lacking. This challenging fluid dynamics problem is also relevant for entomology, neurobiology, and the technological design of olfactory stimulators aimed at reproducing physiological odor signals in well-controlled laboratory conditions. Here, we develop a Lagrangian approach to the transport of pheromones by turbulent flows and exploit it to predict the statistics of odor detection during olfactory searches. The theory yields explicit probability distributions for the intensity and the duration of pheromone detections, as well as their spacing in time. Predictions are favorably tested by using numerical simulations, laboratory experiments, and field data for the atmospheric surface layer. The resulting signal of odor detections lends itself to implementation with state-of-the-art technologies and quantifies the amount and the type of information that male moths can exploit during olfactory searches.

Antonio Celani; Emmanuel Villermaux; Massimo Vergassola

2014-10-28T23:59:59.000Z

412

Nuclear Fusion Simulation Code Optimization on GPU Clusters  

Science Journals Connector (OSTI)

GT5D is a nuclear fusion simulation program which aims to analyze the turbulence phenomena in tokamak plasma. In this research, we optimize it for GPU clusters with multiple GPUs on a node. Based on the profile result of GT5D on a CPU node, we decide ... Keywords: GPU, CUDA, Nuclear Fusion

Norihisa Fujita, Hideo Nuga, Taisuke Boku, Yasuhiro Idomura

2013-12-01T23:59:59.000Z

413

Flow, Turbulence and Combustion 71: 105118, 2003. 2004 Kluwer Academic Publishers. Printed in the Netherlands.  

E-Print Network [OSTI]

]; and theoretically by Wu and Chwang [37], Sparenberg and Wiersma [22], and Streitlien and Triantafyllou [24, 25

414

Simulation of magnetohydrodynamics turbulence with application to plasma-assisted supersonic combustion.  

E-Print Network [OSTI]

??The main objective of this thesis is to develop a comprehensive model with the capability of modeling both a high Reynolds number and high magnetic… (more)

Miki, Kenji

2009-01-01T23:59:59.000Z

415

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

E-Print Network [OSTI]

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 ...

Kewlani, Gaurav

2014-01-01T23:59:59.000Z

416

PSR-based microstructural modeling for turbulent combustion processes and pollutant formation in double swirler combustors  

Science Journals Connector (OSTI)

The present study numerically investigates the fuel-air mixing characteristics, flame structure, and pollutant emission inside a double-swirler combustor. A PSR (Perfectly Stirred Reactor) based microstructura...

Seong-Ku Kim; Sung-Mo Kang; Yong-Mo Kim; Jeong-Lak Sohn

2001-01-01T23:59:59.000Z

417

Turbulent resuspension of small nondeformable particles  

SciTech Connect (OSTI)

An energy-balance resuspension model is modified and applied to the resuspension of a monolayer of nondeformable spherical particles. The particle-surface adhesive force is calculated from a microscopic model based on the Lennard-Jones intermolecular potential. Pairwise additivity of intermolecular interactions is assumed and elastic flattening of the particles is neglected. From the resulting particle-surface interaction potential the natural frequency of vibration of a particle on a surface and the depth of the potential well are calculated. The particle resuspension rate is calculated using the results of a previously developed energy-balance model, where the influence of fluid flow on the bound particle motion is recognized. The effect of surface roughness is included by introducing an effective particle radius that results in log-normally distributed adhesive forces. The predictions of the model are compared with experimental results for the resuspension of Al{sub 2}O{sub 3} particles from stainless steel surfaces. Particle resuspension due to turbulent fluid flow is important in the interaction of the atmosphere with various surfaces and in numerous industrial processes. For example, in the nuclear industry, fission-product aerosols released during a postulated severe accident in a Light Water Reactor may deposit and resuspend repeatedly in the vessel circuit and containment.

Lazaridis, M.; Drossinos, Y. [European Commission, Ispra (Italy). Joint Research Centre] [European Commission, Ispra (Italy). Joint Research Centre; Georgopoulos, P.G. [Rutgers-the State Univ., Piscataway, NJ (United States). Environmental and Occupational Health Sciences Inst.] [Rutgers-the State Univ., Piscataway, NJ (United States). Environmental and Occupational Health Sciences Inst.; [Univ. of Medicine and Dentistry of New Jersey, Piscataway, NJ (United States)

1998-08-01T23:59:59.000Z

418

Combustion kinetics and reaction pathways  

SciTech Connect (OSTI)

This project is focused on the fundamental chemistry of combustion. The overall objectives are to determine rate constants for elementary reactions and to elucidate the pathways of multichannel reactions. A multitechnique approach that features three independent experiments provides unique capabilities in performing reliable kinetic measurements over an exceptionally wide range in temperature, 300 to 2500 K. Recent kinetic work has focused on experimental studies and theoretical calculations of the methane dissociation system (CH{sub 4} + Ar {yields} CH{sub 3} + H + Ar and H + CH{sub 4} {yields} CH{sub 3} + H{sub 2}). Additionally, a discharge flow-photoionization mass spectrometer (DF-PIMS) experiment is used to determine branching fractions for multichannel reactions and to measure ionization thresholds of free radicals. Thus, these photoionization experiments generate data that are relevant to both reaction pathways studies (reaction dynamics) and fundamental thermochemical research. Two distinct advantages of performing PIMS with high intensity, tunable vacuum ultraviolet light at the National Synchrotron Light Source are high detection sensitivity and exceptional selectivity in monitoring radical species.

Klemm, R.B.; Sutherland, J.W. [Brookhaven National Laboratory, Upton, NY (United States)

1993-12-01T23:59:59.000Z

419

Two techniques for forecasting clear air turbulence  

E-Print Network [OSTI]

for the height of the 200- and )00-mb pressure surfaces associated with nonturbulent and turbulent cases . . . . . . o. . . . . o o ~ o ~ . ~ . 17 4. Empirical frequency distributions for the temperature of the 200- and 300-mb pressure surfaces associated... with nonturbulent and turbulent areas. . . . . . ~ . . . . . ~ . ~ ~ Empirical frequency distributions of the zonal wind component on the 200- and 300-mb press- ure surfaces associated with nonturbulent and turbulent areas . . . . . . . . . . . . ~ ~ 20...

Arbeiter, Randolph George

2012-06-07T23:59:59.000Z

420

GASFLOW: A computational model to analyze accidents in nuclear containment and facility buildings  

SciTech Connect (OSTI)

GASFLOW is a finite-volume computer code that solves the time-dependent, compressible Navier-Stokes equations for multiple gas species. The fluid-dynamics algorithm is coupled to the chemical kinetics of combusting liquids or gases to simulate diffusion or propagating flames in complex geometries of nuclear containment or confinement and facilities` buildings. Fluid turbulence is calculated to enhance the transport and mixing of gases in rooms and volumes that may be connected by a ventilation system. The ventilation system may consist of extensive ductwork, filters, dampers or valves, and fans. Condensation and heat transfer to walls, floors, ceilings, and internal structures are calculated to model the appropriate energy sinks. Solid and liquid aerosol behavior is simulated to give the time and space inventory of radionuclides. The solution procedure of the governing equations is a modified Los Alamos ICE`d-ALE methodology. Complex facilities can be represented by separate computational domains (multiblocks) that communicate through overlapping boundary conditions. The ventilation system is superimposed throughout the multiblock mesh. Gas mixtures and aerosols are transported through the free three-dimensional volumes and the restricted one-dimensional ventilation components as the accident and fluid flow fields evolve. Combustion may occur if sufficient fuel and reactant or oxidizer are present and have an ignition source. Pressure and thermal loads on the building, structural components, and safety-related equipment can be determined for specific accident scenarios. GASFLOW calculations have been compared with large oil-pool fire tests in the 1986 HDR containment test T52.14, which is a 3000-kW fire experiment. The computed results are in good agreement with the observed data.

Travis, J.R. [Science Applications International Corp., Albuquerque, NM (United States); Nichols, B.D.; Wilson, T.L.; Lam, K.L.; Spore, J.W.; Niederauer, G.F. [Los Alamos National Lab., NM (United States)

1993-07-01T23:59:59.000Z

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


421

GASFLOW: A computational model to analyze accidents in nuclear containment and facility buildings  

SciTech Connect (OSTI)

GASFLOW is a finite-volume computer code that solves the time-dependent, compressible Navier-Stokes equations for multiple gas species. The fluid-dynamics algorithm is coupled to the chemical kinetics of combusting liquids or gases to simulate diffusion or propagating flames in complex geometries of nuclear containment or confinement and facilities' buildings. Fluid turbulence is calculated to enhance the transport and mixing of gases in rooms and volumes that may be connected by a ventilation system. The ventilation system may consist of extensive ductwork, filters, dampers or valves, and fans. Condensation and heat transfer to walls, floors, ceilings, and internal structures are calculated to model the appropriate energy sinks. Solid and liquid aerosol behavior is simulated to give the time and space inventory of radionuclides. The solution procedure of the governing equations is a modified Los Alamos ICE'd-ALE methodology. Complex facilities can be represented by separate computational domains (multiblocks) that communicate through overlapping boundary conditions. The ventilation system is superimposed throughout the multiblock mesh. Gas mixtures and aerosols are transported through the free three-dimensional volumes and the restricted one-dimensional ventilation components as the accident and fluid flow fields evolve. Combustion may occur if sufficient fuel and reactant or oxidizer are present and have an ignition source. Pressure and thermal loads on the building, structural components, and safety-related equipment can be determined for specific accident scenarios. GASFLOW calculations have been compared with large oil-pool fire tests in the 1986 HDR containment test T52.14, which is a 3000-kW fire experiment. The computed results are in good agreement with the observed data.

Travis, J.R. (Science Applications International Corp., Albuquerque, NM (United States)); Nichols, B.D.; Wilson, T.L.; Lam, K.L.; Spore, J.W.; Niederauer, G.F. (Los Alamos National Lab., NM (United States))

1993-01-01T23:59:59.000Z

422

Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent  

E-Print Network [OSTI]

Effect of Turbulence Fluctuations on Surface Heating Rate in Hypersonic Turbulent Boundary Layers) of reacting hypersonic turbulent boundary layers at conditions typical of reen- try vehicles. Surface heat in designing hypersonic vehicles is to predict aerothermo- dynamic heating. When the boundary layer

MartĂ­n, Pino

423

Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers  

E-Print Network [OSTI]

Study of turbulence-chemistry interaction in hypersonic turbulent boundary layers Lian Duan and M of the turbulence-chemistry interaction (TCI) are performed in hypersonic tur- bulent boundary layers using direct numerical simulation (DNS) flow fields under typical hypersonic conditions representative of blunt

MartĂ­n, Pino

424

Heat release effects on decaying homogeneous compressible turbulence  

E-Print Network [OSTI]

turbulence. A good understanding of high-enthalpy compressible turbulence is crucial for analyzing the flow around re-entry spacecrafts and hypersonic flight vehicles, and inside scramjet engines. One main factor affecting turbulence in these high...

Lee, Kurn Chul

2009-05-15T23:59:59.000Z

425

COHERENT STRUCTURES IN PLASMA TURBULENCE: PERSISTENCE, INTERMITTENCY...  

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

TURBULENCE: PERSISTENCE, INTERMITTENCY, AND CONNECTIONS WITH OBSERVATIONS by Kurt W. Smith A dissertation submitted in partial fulfillment of the requirements for the degree of...

426

Particle pinch and collisionality in gyrokinetic simulations of tokamak plasma turbulence  

SciTech Connect (OSTI)

The generic problem of how, in a turbulent plasma, the experimentally relevant conditions of a particle flux very close to the null are achieved, despite the presence of strong heat fluxes, is addressed. Nonlinear gyrokinetic simulations of plasma turbulence in tokamaks reveal a complex dependence of the particle flux as a function of the turbulent spatial scale and of the velocity space as collisionality is increased. At experimental values of collisionality, the particle flux is found close to the null, in agreement with the experiment, due to the balance between inward and outward contributions at small and large scales, respectively. These simulations provide full theoretical support to the prediction of a peaked density profile in a future nuclear fusion reactor.

Angioni, C. [IPP-EURATOM Association, Max-Planck-Institut fuer Plasmaphysik, D-85748 Garching (Germany); Candy, J.; Waltz, R. E. [General Atomics, San Diego, California 92121 (United States); Fable, E.; Maslov, M.; Weisen, H. [Centre de Recherches en Physique des Plasmas, Association Euratom-Confederation Suisse, EPFL, 1015 Lausanne (Switzerland); Peeters, A. G. [Department of Physics, Center for Fusion, Space and Astrophysics, University of Warwick, CV4 7AL Coventry (United Kingdom)

2009-06-15T23:59:59.000Z

427

Reducible Oxide Based Oxygen Carriers for Chemical Looping Combustion and Partial Oxidation of Methane.  

E-Print Network [OSTI]

??Chemical looping combustion (CLC) is a novel combustion technology that offers a highly efficient route towards clean combustion of fuel with inherent CO2 capture. In… (more)

Bhavsar, Saurabh

2014-01-01T23:59:59.000Z

428

An In-Cylinder Imaging Survey of Low-Temperature, High-Efficiency Combustion Strategies  

Broader source: Energy.gov [DOE]

High speed imaging of in-cylinder spray and combustion luminosity of low temperature combustion strategies are contrasted to conventional gasoline and diesel engine combustion

429

Advanced High Efficiency Clean Diesel Combustion with Low Cost for Hybrid Engines  

Broader source: Energy.gov [DOE]

Clean, in-cylinder combustion can be enabled by a micro-variable circular orifice, dual mode PCCI, dew film combustion, and a novel combustion chamber design

430

Emissions of trace gases and aerosols during the open combustion of biomass in the laboratory  

E-Print Network [OSTI]

emissions during biomass combustion: Controlling factors andfrom smoldering combustion of biomass measured by open-pathduring the open combustion of biomass in the laboratory

McMeeking, Gavin R.

2009-01-01T23:59:59.000Z

431

Fuel Effects on Advanced Combustion: Heavy-Duty Optical-Engine...  

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

More Documents & Publications Fuel Effects on Advanced Combustion: Heavy-Duty Optical-Engine Research Fuels and Combustion Strategies for High-Efficiency Clean-Combustion...

432

Combustion Synthesis of Silicon Carbide 389 Combustion Synthesis of Silicon Carbide  

E-Print Network [OSTI]

Combustion Synthesis of Silicon Carbide 389 X Combustion Synthesis of Silicon Carbide Alexander S velocity and 17 #12;Properties and Applications of Silicon Carbide390 reaction rate throughout the mixture by graphite during SHS of carbides. Local reaction initiation is typically accomplished by hot tungsten wire

Mukasyan, Alexander

433

Utilization of Combustion?Driven Oscillations  

Science Journals Connector (OSTI)

The possible applications of combustion?driven oscillations fall into two categories. The first category includes applications that are related to the combustion process itself such as those concerned with the possibility of alterlog space heat?release rate combustion efficiency heat transfer to surfaces and agglomeration of solid or liquid products of combustion. A consideration of available experimental and theoreticalinformation indicates that none of these applications are too promising when compared with alternative methods of performing the same functions. The second category includes applications that use pulsatory phenomena to do a particular iob. Examples are the application of valveless pulse jets to (a) the propulsion of drones (b) helicopter blade?tip propulsion (c) cutting of Arctic ice and (d) inducing pressure rises in through?flow combustion systems. For one reason or another most of these ideas have been dropped. However the use of the pulsating?combustion process to supply both the air at a high flow velocity to a combustor and the products of combustion at a high velocity to a heat exchanger thereby making possible a compact self?contained unit appears to have great promise. One such unit of residential boiler size is already available. Although this unit is valved as was the V?1 conversion to a valveless unit appears possible. The development of industrial?sized units appears equally feasible. Apparently the development of such units is contingent upon (a) adequate understanding of how to design effective aerodynamic valves and (b) the collaboration of an inventor experimentalist analyst and financier on a specific program.

Abbott A. Putnam

1963-01-01T23:59:59.000Z

434

NETL: IEP – Post-Combustion CO2 Emissions Control - Oxy-Combustion  

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

IEP - Oxy-Combustion CO2 Emissions Control IEP - Oxy-Combustion CO2 Emissions Control Oxy-Combustion Technology Development for Industrial-Scale Boiler Applications Project No.: DE-NT0005290 Alstom oxy-combustion test facility Alstom oxy-combustion test facility. Alstom will develop an oxyfuel firing system design specifically for retrofit to tangential-fired (T-fired) boilers and provide information to address the technical gaps for commercial boiler design. Several oxyfuel system design concepts, such as internal flue gas recirculation and various oxygen injection schemes, will be evaluated for cost-effectiveness in satisfying furnace design conditions in a T-fired boiler. The evaluation will use an array of tools, including Alstom's proprietary models and design codes, along with 3-D computational fluid dynamics modeling. A

435

Buoyancy-generated variable-density turbulence  

SciTech Connect (OSTI)

Because of the importance of turbulence mixing in many applications, a number of turbulence mixing models have been proposed for variable- density flows. These engineering models (one- point statistical models) typically include the transport of the turbulent kinetic energy and the turbulent energy dissipation rate (i.e., k - {epsilon} models). The model presented by Besnard, Harlow, Rauenzahn and Zemach (1992) (herein referred to as BHRZ) is a one-point model intended to describe variable-density turbulent flows. Transport equations for the Reynolds stress tensor, R{sub ij}, and the turbulent energy dissipation rate, the density-velocity correlation, a{sub i}, and the density-specific volume correlation, b are derived. This model employs- techniques and concepts from incompressible, constant- density turbulence modeling and incorporates ideas from two-phase flow models. Clark and Spitz (1994) present a two-point model for variable-density turbulence. Their derivation is based on transport equations that, are based 0481 on two-point- generalizations of R{sub ij}, a{sub ij}, and b. These equations are Fourier transformed with respect to the separation distance between the two points. Transport equations are derived for R{sub ij}, a{sub i}, b. As in the one-point model, this model contains many ad-hoc assumptions and unknown model coefficients that must be determined by comparison with experimental and numerical data. However, the two-point formalism requires fewer equilibrium assumptions then does a single-point model. Our primary concern in this paper lies in the nonlinear processes of turbulence and the influence of large density variations (not within the Boussinesq limit) on these processes. To. isolate the effects of variable-density on the turbulence we restrict our flow to be incompressible, statistically homogeneous buoyancy-generated. turbulence. To our knowledge there have not been any simulations reported for this problem.

Sandoval, D.L.; Clark, T.T.; Riley, J.J.

1996-07-01T23:59:59.000Z

436

Environmental Assessment for the Installation and Operation of Combustion Turbine Generators at Los Alamos National Laboratory, Los Alamos, New Mexico  

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

DOElEA- 430 DOElEA- 430 LA-UR-02-6482 Nationat Nudea- Security Administration Environmental Assessment for the Installation and Operation of Combustion Turbine Generators at Los Alamos National Laboratory, Los Alamos, New Mexico December II,2002 Department of Energy National Nuclear Security Administration Los Alamos Site Office Environmental Assessment for the Installation and Operation of Combustion Turbine Generators at LANL DOE LASO December 11, 2002 iii Contents ACRONYMS AND TERMS.......................................................................................................V EXECUTIVE SUMMARY ....................................................................................................... IX 1.0 PURPOSE AND NEED ........................................................................................................1

437

Federal Energy Management Program: FEMP Technology Brief: Boiler Combustion  

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

FEMP Technology FEMP Technology Brief: Boiler Combustion Control and Monitoring System to someone by E-mail Share Federal Energy Management Program: FEMP Technology Brief: Boiler Combustion Control and Monitoring System on Facebook Tweet about Federal Energy Management Program: FEMP Technology Brief: Boiler Combustion Control and Monitoring System on Twitter Bookmark Federal Energy Management Program: FEMP Technology Brief: Boiler Combustion Control and Monitoring System on Google Bookmark Federal Energy Management Program: FEMP Technology Brief: Boiler Combustion Control and Monitoring System on Delicious Rank Federal Energy Management Program: FEMP Technology Brief: Boiler Combustion Control and Monitoring System on Digg Find More places to share Federal Energy Management Program: FEMP

438

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the fourth quarter January-March 2002 in the following task areas: Task 1--Oxygen Enhanced Combustion, Task 2--Oxygen Transport Membranes, Task 3--Economic Evaluation and Task 4--Program Management. This report will also recap the results of the past year. The program is proceeding in accordance with the objectives for the second year. The first round of pilot scale testing with 3 bituminous coals was completed at the University of Utah. Full-scale testing equipment is in place and experiments are underway. Coal combustion lab-scale testing was completed at the University of Arizona. Modest oxygen enhancement resulted in NOx emissions reduction. Combustion modeling activities continued with pilot-scale combustion test furnace simulations. 75% of target oxygen flux was demonstrated with small PSO1 tube in Praxair's single tube high-pressure test facility. The production of oxygen with a purity of better than 99.999% was demonstrated. Economic evaluation has confirmed the advantage of oxygen-enhanced combustion. Two potential host sites have been identified.

David R. Thompson; Lawrence E. Bool; Jack C. Chen

2002-04-01T23:59:59.000Z

439

Descargue Datos de Ahorro de Combustible  

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

Descargue Datos de Ahorro de Combustible Descargue Datos de Ahorro de Combustible Los datos de ahorro de combustible son el resultado de las pruebas realizadas en el Laboratorio de Emisiones de Combustible y VehĂ­culos de la Agencia Nacional de ProtecciĂłn del Medio Ambiente en Ann Arbor, Michigan y por fabricantes de automĂłviles, con la supervisiĂłn de la EPA. Archivo Descargable de Ahorro de Combustible Archivo* de la GuĂ­a de Ahorremos Gasolina Archivo 2014 No Disponible Archivo 2013 de la GuĂ­a de Ahorremos Gasolina 2013 ĂŤcono de Adobe Acrobat Archivo 2012 de la GuĂ­a de Ahorremos Gasolina 2012 ĂŤcono de Adobe Acrobat Archivo 2011 de la GuĂ­a de Ahorremos Gasolina 2011 ĂŤcono de Adobe Acrobat Archivo 2010 de la GuĂ­a de Ahorremos Gasolina 2010 ĂŤcono de Adobe Acrobat Archivo 2009 de la GuĂ­a de Ahorremos Gasolina 2009 ĂŤcono de Adobe Acrobat

440

Nuclear Energy  

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

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441

Turbulent transport of energetic ions  

SciTech Connect (OSTI)

Approaching ITER operation, the issue of anomalous transport of fast particles becomes more and more important. This is partly because the ITER heating and current drive system relies heavily on neutral beam injection. Moreover burning plasmas are heated by fast fusion {alpha} particles.Fusion {alpha} particles are characterised by a fixed energy and an isotropic velocity distribution. Therefore they have gyroradii one magnitude larger than the thermal ions. The dependency of the particle diffusion of {alpha} test particles on the Kubo number K = VExB{tau}c/{lambda}c (VExB mean E x B velocity, {tau}c, {lambda}c correlation time and length of the turbulent potential) is presented. For different turbulent regimes, different dependency of the diffusion on the gyroradius is found. For large Kubo numbers, the transport is found to remain constant for gyroradii up to the correlation length of the potential, whereas it is drastically reduced in the small Kubo number regime.In the second part, a model for beam ions injected along the equilibrium magnetic field is described. The beam ions are treated gyrokinetically in a self-consistent way with the equilibrium distribution function taken as a shifted Maxwellian. The implications of such a model for the Vlasov equation, the field equations, and the calculation of moments and fluxes are discussed. Linear and nonlinear results, obtained with the gyrokinetic flux tube code GENE show the existence of a new instability driven by fast beam ions. The instability has a maximum growth rate at perpendicular wave numbers of ky{rho}s {approx} 0.15 and depends mainly on the beam velocity and the density gradient of the beam ions. This instability leads to a replacement of bulk ion particle transport by fast ion particle transport, connected to a strongly enhanced heat flux. In the presence of this instability, the turbulent particle and heat transport is dominated by fast ions.

Dannert, Tilman; Hauff, Thilo; Jenko, Frank; Guenter, Sibylle [Max-Planck-Institut fuer Plasmaphysik, Garching (Germany)

2006-11-30T23:59:59.000Z

442

CHARACTERIZING MAGNETIZED TURBULENCE IN M51  

SciTech Connect (OSTI)

We use previously published high-resolution synchrotron polarization data to perform an angular dispersion analysis with the aim of characterizing magnetized turbulence in M51. We first analyze three distinct regions (the center of the galaxy, and the northwest and southwest spiral arms) and can clearly discern the turbulent correlation length scale from the width of the magnetized turbulent correlation function for two regions and detect the imprint of anisotropy in the turbulence for all three. Furthermore, analyzing the galaxy as a whole allows us to determine a two-dimensional Gaussian model for the magnetized turbulence in M51. We measure the turbulent correlation scales parallel and perpendicular to the local mean magnetic field to be, respectively, {delta}{sub ||} = 98 {+-} 5 pc and {delta} = 54 {+-} 3 pc, while the turbulent-to-ordered magnetic field strength ratio is found to be B{sub t}/B{sub 0} = 1.01 {+-} 0.04. These results are consistent with those of Fletcher et al., who performed a Faraday rotation dispersion analysis of the same data, and our detection of anisotropy is consistent with current magnetized turbulence theories.

Houde, Martin [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada)] [Department of Physics and Astronomy, The University of Western Ontario, London, ON N6A 3K7 (Canada); Fletcher, Andrew [School of Mathematics and Statistics, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom)] [School of Mathematics and Statistics, Newcastle University, Newcastle-upon-Tyne NE1 7RU (United Kingdom); Beck, Rainer [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany)] [Max-Planck-Institut fuer Radioastronomie, Auf dem Huegel 69, D-53121 Bonn (Germany); Hildebrand, Roger H. [Department of Astronomy and Astrophysics and Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637 (United States)] [Department of Astronomy and Astrophysics and Enrico Fermi Institute, The University of Chicago, Chicago, IL 60637 (United States); Vaillancourt, John E. [Stratospheric Observatory for Infrared Astronomy, Universities Space Research Association, NASA Ames Research Center, Moffet Field, CA 94035 (United States)] [Stratospheric Observatory for Infrared Astronomy, Universities Space Research Association, NASA Ames Research Center, Moffet Field, CA 94035 (United States); Stil, Jeroen M. [Department of Physics and Astronomy, The University of Calgary, Calgary, AB T2N 1N4 (Canada)] [Department of Physics and Astronomy, The University of Calgary, Calgary, AB T2N 1N4 (Canada)

2013-03-20T23:59:59.000Z

443

Electric field statistics in MHD turbulence  

E-Print Network [OSTI]

Electric field statistics in MHD turbulence Bernard Knaepen, Nicolas Denewet & Daniele Carati, ULB #12;Electric field statistics in MHD turbulence Outline Electric field in MHD? Particle acceleration Statistics of the electric & magnetic fields #12;Outline Electric field in MHD? Particle acceleration

Low, Robert

444

Stochastic models for turbulent reacting flows  

SciTech Connect (OSTI)

The goal of this program is to develop and apply stochastic models of various processes occurring within turbulent reacting flows in order to identify the fundamental mechanisms governing these flows, to support experimental studies of these flows, and to further the development of comprehensive turbulent reacting flow models.

Kerstein, A. [Sandia National Laboratories, Livermore, CA (United States)

1993-12-01T23:59:59.000Z

445

On the dynamics of magnetorotational turbulent stresses  

Science Journals Connector (OSTI)

......C 5= 1 are adopted.The diagram is self-similar and therefore...corresponding to a state of steady MHD turbulence. A typical result...state of statistically steady MHD turbulence.The solution approached...stable. Figure 4 Stability diagram for rotating plane Couette flow......

G.I. Ogilvie

2003-04-11T23:59:59.000Z

446

AIAA-92-5101 Hypersonic Turbulent  

E-Print Network [OSTI]

AIAA-92-5101 Hypersonic Turbulent Expansion-Corner Flow with Impingement K. Chung & F. Lu;HYPERSONIC TURBULENT EXPANSION-CORNER FLOW WITH SHOCK IMPINGEMENT ICung-Ming Chung* and Frank IC. Lut of considcrablc research.' Recently, renewed in- tcrcst in supersonic and hypersonic flight vehicles has

Texas at Arlington, University of

447

Shape of isoshear contours in turbulent friction  

Science Journals Connector (OSTI)

We analyze line measurements of turbulent shear stress in a turbulent boundary layer in terms of isoshear contours. The statistics of the relative location of contour center lines points to a relation with coherent structures. The shape of these contours exhibits a remarkable scaling behavior that is reminiscent of that found in spatiotemporal chaos.

Willem van de Water and Eric van de Wetering

1992-06-15T23:59:59.000Z

448

Parametric Instabilities in Turbulent, Inhomogeneous Plasma  

Science Journals Connector (OSTI)

It is known that parametric instabilities involving two coupled modes, with oppositely directed group velocities, saturate convectively if the medium is inhomogeneous. This work considers the modification of that result when weak long-wave turbulence is present, in addition to the background inhomogeneity. We find that the convective saturation disappears when the turbulence exceeds a certain level, absolute growth occurring instead.

Dwight R. Nicholson and Allan N. Kaufman

1974-11-11T23:59:59.000Z

449

Electromagnetic weak turbulence theory revisited  

SciTech Connect (OSTI)

The statistical mechanical reformulation of weak turbulence theory for unmagnetized plasmas including fully electromagnetic effects was carried out by Yoon [Phys. Plasmas 13, 022302 (2006)]. However, the wave kinetic equation for the transverse wave ignores the nonlinear three-wave interaction that involves two transverse waves and a Langmuir wave, the incoherent analogue of the so-called Raman scattering process, which may account for the third and higher-harmonic plasma emissions. The present paper extends the previous formalism by including such a term.

Yoon, P. H. [IPST, University of Maryland, College Park, Maryland 20742 (United States); Ziebell, L. F. [Instituto de Fisica, UFRGS, Porto Alegre, RS (Brazil); Gaelzer, R.; Pavan, J. [Instituto de Fisica e Matematica, UFPel, Pelotas, RS (Brazil)

2012-10-15T23:59:59.000Z

450

On observing acoustic backscattering from salinity turbulence  

Science Journals Connector (OSTI)

It has been hypothesized that at sufficiently high levels of oceanic salinity turbulence it should be possible to observe acoustic backscattering. However there have been limited in situmeasurements to confirm this hypothesis. Using an autonomous underwater vehicle equipped with upward and downward looking 1.2 MHz acoustic Doppler current profilers and with turbulence and fine scale sensors measurements were performed in a region of intense turbulence and a strong salinity gradient. The approach taken was to correlate variations in the backscattered acoustic intensity I with a theoretical acoustic backscattering cross section per volume for salinity turbulence ? s to obtain an estimated scattering cross section per volume ? e . Results indicated that of order 50% of the observed region was characterized by salinity turbulence induced backscattering.

Louis Goodman; Marcos M. Sastre-Córdova

2011-01-01T23:59:59.000Z

451

OXYGEN ENHANCED COMBUSTION FOR NOx CONTROL  

SciTech Connect (OSTI)

This quarterly technical progress report will summarize work accomplished for the Program through the second quarter July--September 2000 in the following task areas: Task 1-Oxygen Enhanced Combustion, Task 2-Oxygen Transport Membranes and Task 4-Program Management. The program is proceeding in accordance with the objectives for the first year. OTM tube characterization is well underway, the design and assembly of the high pressure permeation test facility is complete and the facility will be in full operation during the next quarter. Combustion testing has been initiated at both the University of Arizona and Praxair. Testing at the University of Arizona has experienced some delays; steps have been take to get the test work back on schedule. Completion of the first phase of the testing is expected in next quarter. Combustion modeling has been started at both REI and Praxair, preliminary results are expected in the next quarter.

Lawrence E. Bool; Jack C. Chen; David R. Thompson

2000-10-01T23:59:59.000Z

452

Understanding the thermodynamic inefficiencies in combustion processes  

Science Journals Connector (OSTI)

Abstract The thermodynamic inefficiencies associated with any energy conversion process are expressed by the exergy destruction and the exergy losses associated with the process. Combustion processes exhibit very high thermodynamic inefficiencies caused by chemical reaction, heat transfer, friction, and mixing. In this paper, we discuss how to estimate the thermodynamic inefficiencies resulting from each one of these sources. The thermodynamic evaluation can be conducted with the aid of either a conventional exergetic analysis or an advanced one. The latter allows estimation of the potential for improvement of the process being considered and demonstrates the interactions among the components of the system in which combustion takes place. The paper discusses how advanced exergy-based evaluations can be used to reduce the thermodynamic inefficiencies, costs, and environmental impacts associated with energy conversion systems including combustion processes.

George Tsatsaronis; Tatiana Morosuk; Daniela Koch; Max Sorgenfrei

2013-01-01T23:59:59.000Z

453

Premixed Combustion of Hydrogen Augmented Natural Gas  

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

Premixed Combustion of Hydrogen Premixed Combustion of Hydrogen Augmented Natural Gas * Lean premixed combustion * Effective for emission reduction with natural gas * High hydrogen flame speed requires care in premixer design for SGH fuels * UC Irvine study quantifies effectiveness of hydrogen augmentation strategy * Lean stability limit improves linearly with hydrogen augmentation * Emissions reduction can be achieved * Two OEM's and the California Energy Commission have used the results to help guide them on adapting to hydrogen fuel UC Irvine Scott Samuelsen / Vince McDonell Project 98-01-SR062 1200 1300 1400 1500 1600 1700 1800 1900 0 10 20 30 40 50 60 Hydrogen Volume in Main Fuel (%) Adiabatic Flame Temperature (K) P0(3/4) High Stability High Stability Low emission Low emission operational zone operational zone

454

Study of the potential valorization of metal contaminated Salix via phytoextraction by combustion  

E-Print Network [OSTI]

, different energy-recovery- techniques (incineration, combustion, gasification, pyrolysis, anaerobic

Paris-Sud XI, Université de

455

http://www.genie.uottawa.ca/~hallett/hallett.htm Combustion Research  

E-Print Network [OSTI]

Engineering Main themes: - solid fuel combustion/packed beds - liquid droplet combustion - biofuels (biomass, Mechanical Engineering #12;Liquid Droplet Combustion W. Hallett, Mechanical Engineering Recent Work - biomasshttp://www.genie.uottawa.ca/~hallett/hallett.htm Combustion Research W. Hallett, Mechanical

Hallett, William L.H.

456

Hydrothermal combustion of biofuels in supercritical water  

SciTech Connect (OSTI)

Supercritical water oxidation (SCWO) has long been recognized as a safe, clean and energy efficient method for destroying a wide range of organic materials and hazardous wastes. As SCWO systems operate at elevated pressure, all effluent streams are fully contained allowing efficient recovery of thermal energy using compact heat exchangers. Water vapor produced by the combustion efficiency, especially for fuels with increasing moisture content such as biomass. This paper compares the performance of a simple Rankine vapor power cycle which derives it`s heat input from (1) a hydrothermal combustion system, and (2) a conventionally-fired steam boiler. The study is based on a hypothetical cellulose-based organic fuel with a higher heating value of 7,000 BT/1bm (dry). For a constant organic feedrate of 100 tons/day (bone dry) mixed in 20:80 fuel/water ratio with water, the calculated net electric power output from the 31.93%. Whereas, for an organic feedrate of 100 tons/day (bone dry) with zero of 5,382 kW, at an overall thermal efficiency of 31.48%. The hydrothermal combustion power cycle is unaffected by free moisture in the fuel, and thereby uniquely well-suited for use in biomass power generation applications. The hydrothermal combustion process is exceptionally clean burning, and allows full control over carbon dioxide and SOx emissions. NOx levels are inherently ultra-low due to lower combustion temperatures. Hydrothermal combustion technology is ready for pilot-scale engineering development and demonstration.

McGuinness, T.G. [Summit Research Corporation, Sante Fe, NM (United States); Marentis, R. [Summit Research Corporation, Allentown, PA (United States)

1994-12-31T23:59:59.000Z

457

Nuclear Debate  

Science Journals Connector (OSTI)

Nuclear Debate ... This month, the Senate will consider the nominations of two women to serve on the Nuclear Regulatory Commission. ... Svinicki is a nuclear engineer with experience in the Department of Energy’s nuclear energy programs. ...

JEFF JOHNSON

2012-06-11T23:59:59.000Z

458

Argonne TTRDC - Engines - Home - combustion, compression ignition,  

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

* Combustion Visualization * Combustion Visualization * Compression-Ignition * Emissions Control * Fuel Injection and Sprays * Idling * Multi-Dimensional Modeling * Particulate Matter * Spark Ignition Green Racing GREET Hybrid Electric Vehicles Hydrogen & Fuel Cells Materials Modeling, Simulation & Software Plug-In Hybrid Electric Vehicles PSAT Smart Grid Student Competitions Technology Analysis Transportation Research and Analysis Computing Center Working With Argonne Contact TTRDC Engines Omnivorous engine tested by Thomas Wallner Thomas Wallner tests the omnivorous engine, a type of spark-ignition engine. Argonne's engine research is contributing to advances in technology that will impact the use of conventional and alternative fuels and the design of advanced technology vehicles. Compression Ignition

459

Building America Expert Meeting: Combustion Safety  

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

Meeting: Combustion Safety Meeting: Combustion Safety L. Brand Partnership for Advanced Residential Retrofit March 2013 NOTICE This report was prepared as an account of work sponsored by an agency of the United States government. Neither the United States government nor any agency thereof, nor any of their employees, subcontractors, or affiliated partners makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial product, process, or service by trade name, trademark, manufacturer, or otherwise does not necessarily constitute or imply

460

Building America Expert Meeting: Combustion Safety  

Broader source: Energy.gov [DOE]

This expert meeting, The Best Approach to Combustion Safety in a Direct Vent World, was conducted by the Partnership for Advanced Residential Retrofit team on June 28, 2012, in San Antonio, TX. The objective of this Expert Meeting was to identify gaps and barriers that need to be addressed by future research, and to develop data-driven technical recommendations for code updates so that a common approach for combustion safety can be adopted by all members of the building energy efficiency and code communities.

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


461

Kinetic data base for combustion modeling  

SciTech Connect (OSTI)

The aim of this work is to develop a set of evaluated rate constants for use in the simulation of hydrocarbon combustion. The approach has been to begin with the small molecules and then introduce larger species with the various structural elements that can be found in all hydrocarbon fuels and decomposition products. Currently, the data base contains most of the species present in combustion systems with up to four carbon atoms. Thus, practically all the structural grouping found in aliphatic compounds have now been captured. The direction of future work is the addition of aromatic compounds to the data base.

Tsang, W.; Herron, J.T. [National Institute of Standards and Technology, Gaithersburg, MD (United States)

1993-12-01T23:59:59.000Z

462

Resonance ionization detection of combustion radicals  

SciTech Connect (OSTI)

Fundamental research on the combustion of halogenated organic compounds with emphasis on reaction pathways leading to the formation of chlorinated aromatic compounds and the development of continuous emission monitoring methods will assist in DOE efforts in the management and disposal of hazardous chemical wastes. Selective laser ionization techniques are used in this laboratory for the measurement of concentration profiles of radical intermediates in the combustion of chlorinated hydrocarbon flames. A new ultrasensitive detection technique, made possible with the advent of tunable VUV laser sources, enables the selective near-threshold photoionization of all radical intermediates in premixed hydrocarbon and chlorinated hydrocarbon flames.

Cool, T.A. [Cornell Univ., Ithaca, NY (United States)

1993-12-01T23:59:59.000Z

463

Past experiences with automotive external combustion engines  

SciTech Connect (OSTI)

GMR (General Motors Research Laboratories, now GM R and D Center) has a history of improving the internal combustion engine, especially as it relates to automotive use. During the quarter century from 1950--75, considerable effort was devoted to evaluating alternative powerplants based on thermodynamic cycles different from those on which the established spark-ignition and diesel engines are founded. Two of these, the steam engine and the Stirling engine, incorporated external combustion. Research on those two alternatives is reviewed. Both were judged to fall short of current needs for commercial success as prime movers for conventional automotive vehicles.

Amann, C.A.

1999-07-01T23:59:59.000Z

464

Evaluating the fluidized bed combustion options  

SciTech Connect (OSTI)

The proceedings from a conference on fluidized bed combustion are now available. The book discusses the immediate availability of atmospheric fluidized bed combustion technology as a practical, environmentally sound option for burning all grades of coal, wood, wood wastes, and biomass. The economics and technical fundamentals of atmospheric FBC are explained for the benefit of owners and managers of industrial boilers, boiler operators, architects/engineers, boiler manufacturers, and fuel suppliers. More than 15 FBC experts have contributed their expertise and experiences to the book.

Sheahan, R.T. (ed.)

1984-01-01T23:59:59.000Z

465

1 - Combustion processes of textile fibres  

Science Journals Connector (OSTI)

Abstract: This chapter reviews the current knowledge of the processes involved in the combustion behaviour of textiles and approaches to their flame retardant protection. Synthetic fibre-forming polymers, both thermoplastic and high temperature resistant, as well as naturally occurring fibre types are discussed. The combustion process is described with reference to the thermal stability, degradation and oxidative degradation of various individual polymer types. The significance of textile structure is considered with respect to the textile flammability. The mechanisms of the different flame retardant systems applied to various textiles are discussed as well as the more recent application of nano-composites. Finally, a prediction of potential future developments is presented.

D. Price; A.R. Horrocks

2013-01-01T23:59:59.000Z

466

Non-Petroleum Based Fuel Effects on Advanced Combustion (Agreement...  

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

Non-Petroleum Based Fuel Effects on Advanced Combustion (Agreement 13425) Non-Petroleum Based Fuel Effects on Advanced Combustion (Agreement 13425) Presentation from the U.S. DOE...

467

Conditions of realization of superwet in-situ combustion  

SciTech Connect (OSTI)

In in-situ combustion adding water to the air considerably improves the characteristics of the process: the combustible fuel concentration is reduced, the steam plateau ahead of the combustion front increases, less oxidizer is required to displace the oil, and the thermal wave has a higher propagation velocity. In wet combustion the temperature in the combustion zone reaches approx. 500/sup 0/C. In superwet combustion it depends on the reservoir pressure and may be 200-300/sup 0/C. It is not known in advance whether the heat of combustion will suffice to sustain the thermal wave, and if it does suffice, what will be the maximum values of the water-air ratio for the process. This paper attempts to construct a mathematical model of the superwet combustion process.

Bokserman, A.A.; Stepanov, V.P.

1985-07-01T23:59:59.000Z

468

A new type of self-organization in combustion  

Science Journals Connector (OSTI)

... a solid-phase gasless combustion3 which proceeds with the formation of a melt or a flameless gas3'4. ... gas3'4. Flameless combustion has recently been described for several tetrazole compounds5.

A. I. Lesnikovich; V. V. Sviridov; G. V. Printsev; O. A. Ivashkevich; P. N. Gaponik

1986-10-23T23:59:59.000Z

469

Large-Eddy Simulation of Swirling Pulverized-Coal Combustion  

Science Journals Connector (OSTI)

A Eulerian-Lagrangian large-eddy simulation (LES) with a Smagorinsky-Lilly sub-grid scale stress model, presumed-PDF fast chemistry and EBU gas combustion models, particle devolatilization and particle combustion

L. Y. Hu; L. X. Zhou; Y. H. Luo; C. S. Xu

2013-01-01T23:59:59.000Z

470

Carbonation of Fly Ash in Oxy-fuel CFB Combustion  

Science Journals Connector (OSTI)

Oxy-fuel combustion of fossil fuel is one of the most promising methods to produce a stream of concentrated CO2 ready for sequestration. Oxy-fuel FBC (fluidized bed combustion) can use limestone as a sorbent for

Chunbo Wang; Lufei Jia; Yewen Tan…

2007-01-01T23:59:59.000Z

471

A Comparison of Combustion and Emissions of Diesel Fuels and...  

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

A Comparison of Combustion and Emissions of Diesel Fuels and Oxygenated Fuels in a Modern DI Diesel Engine A Comparison of Combustion and Emissions of Diesel Fuels and Oxygenated...

472

Advanced Combustion Systems Project Information | netl.doe.gov  

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

FC26-07NT43088 Recovery Act: Oxy-combustion: Oxygen Transport Membrane Development Praxair, Inc. Completed Projects FE0009686 High Efficiency Molten-Bed Oxy-Coal Combustion...

473

COMBUSTION RESEARCH PROGRAM. CHAPTER FROM ENERGY & ENVIRONMENT ANNUAL REPORT 1977  

E-Print Network [OSTI]

The pulverized coal has significant ash content, about 6%.of Ash and Trace Metals from Pulverized Coal Combustion P.of Ash and Trace Metals from Pulverized Coal Combustion P.

Authors, Various

2011-01-01T23:59:59.000Z

474

MILD combustion for hydrogen and syngas at elevated pressures  

Science Journals Connector (OSTI)

As gas recirculation constitutes a fundamental condition for the realization of MILD combustion, it is necessary to determine gas recirculation ratio before designing MILD combustor. MILD combustion model with ga...

Mingming Huang; Zhedian Zhang; Weiwei Shao; Yan Xiong…

2014-02-01T23:59:59.000Z

475

The role played by self-inhibition in combustion processes  

Science Journals Connector (OSTI)

The absence of correlations between the heat of combustion of substances and substance combustion characteristics is shown to be caused by the special features of competition between reaction chain branching a...

V. V. Azatyan; I. A. Bolod’yan; Yu. N. Shebeko…

2006-04-01T23:59:59.000Z

476

Thermogravimetric analysis of co-combustion of biomass and biochar  

Science Journals Connector (OSTI)

The co-combustion of biomass and biochar was investigated by thermogravimetric analysis....R M...) for different blends were used to evaluate co-combustion features. As the biomass content increas...

Qiguo Yi; Fangjie Qi; Gong Cheng…

2013-06-01T23:59:59.000Z

477

The Inorganic Chemistry of Biomass Combustion: Problems and Solutions  

Science Journals Connector (OSTI)

High temperature molten products of the combustion of biomass present special problems related to fouling and ... performed calculations of the total inorganic chemistry of biomass combustion using a free energy ...

M. Blander

1997-01-01T23:59:59.000Z

478

Light-Duty Advanced Diesel Combustion Research | Department of...  

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

Light-Duty Advanced Diesel Combustion Research Light-Duty Advanced Diesel Combustion Research Presentation from the U.S. DOE Office of Vehicle Technologies "Mega" Merit Review 2008...

479

Novel New Oxygen Carriers for Chemical Looping Combustion of Solid Fuels  

Science Journals Connector (OSTI)

Novel New Oxygen Carriers for Chemical Looping Combustion of Solid Fuels ... A loop of chem. ... Energy Combust. ...

Yueying Fan; Ranjani Siriwardane

2014-02-21T23:59:59.000Z

480

E-Print Network 3.0 - advanced wall-fired combustion Sample Search...  

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

Biomass and Animal Waste Combustion Energy Engine Emission Fuel Cells... Gasification Internal Combustion Engine Performance Pollutants Formation (NOx, Hg) and...

Note: This page contains sample records for the topic "turbulent nuclear combustion" from the National Library of EnergyBeta (NLEBeta).
While these samples are representative of the content of NLEBeta,
they are not comprehensive nor are they the most current set.
We encourage you to perform a real-time search of NLEBeta
to obtain the most current and comprehensive results.


481

Using Parametrized Finite Combustion Stage Models to Characterize Combustion in Diesel Engines  

Science Journals Connector (OSTI)

Characterizing combustion in diesel engines is not only necessary when researching the instantaneous combustion phenomena but also when investigating the change of the combustion process under variable engine operating conditions. ... This project partly is financially supported by the Fundamental Research Funds for the Central Universities, Harbin Engineering University, China, HEUCF120307, and the International Science and Technology Cooperation Program of China. ... Proceedings of the Institution of Mechanical Engineers, Part A: Journal of Power and Energy (2011), 225 (3), 309-318 CODEN: PMAEET; ISSN:0957-6509. ...

Yu Ding; Douwe Stapersma; Hugo Grimmelius

2012-10-29T23:59:59.000Z

482

Conditional Moment Closure Modeling for a Three-Dimensional Turbulent Non-premixed Syngas Flame with a Cooling Wall  

Science Journals Connector (OSTI)

Conditional Moment Closure Modeling for a Three-Dimensional Turbulent Non-premixed Syngas Flame with a Cooling Wall ... In the experiment,(13) the burner is mounted to an air-cooled combustion chamber and the burner consists of a central fuel tube and an annular air tube. ... It can be seen that the velocity field at the pure-mixing entrance region is highly deflected by the flame holder, and the burned mixtures are partially impinged on the cooling wall (Tw = 600 K). ...

Gunhong Kim; Sungmo Kang; Yongmo Kim; Kwan-Soo Lee

2008-09-13T23:59:59.000Z

483

Oxygen-Enriched Combustion for Military Diesel Engine Generators  

Broader source: Energy.gov [DOE]

Substantial increases in brake power and considerably lower peak pressure can result from oxygen-enriched diesel combustion

484

Trash or treasure? Putting coal combustion waste to work  

SciTech Connect (OSTI)

The use of coal combustion wastes from power plants in construction materials, leaching and the impact of regulations are discussed.

Tenenbaum, D.J.

2009-11-15T23:59:59.000Z

485

Traveling-Wave Thermoacoustic Engines With Internal Combustion  

DOE Patents [OSTI]

Thermoacoustic devices are disclosed wherein, for some embodiments, a combustion zone provides heat to a regenerator using a mean flow of compressible fluid. In other embodiments, burning of a combustible mixture within the combustion zone is pulsed in phase with the acoustic pressure oscillations to increase acoustic power output. In an example embodiment, the combustion zone and the regenerator are thermally insulated from other components within the thermoacoustic device.

Weiland, Nathan Thomas (Blacksburg, VA); Zinn, Ben T. (Atlanta, GA); Swift, Gregory William (Sante Fe, NM)

2004-05-11T23:59:59.000Z

486

Advanced Combustion Modeling with STAR-CD using Transient Flemelet...  

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

occurs - Spray modeling is required * Autoignition, combustion, pollutant formation chemistry - Kinetic modeling required for various fuels - Soot, NOx models required *...

487

Simulation of High Efficiency Clean Combustion Engines and Detailed...  

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

ongoing work exploring fuel chemistry, analysis of and improving simulation methodologies for high efficiency clean combustion regimes, and computational performance...

488

Impact of Extreme Injection Pressure and EGR on the Combustion...  

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

Analyse of the Injection System * Simulation * Hydraulic Characterisation * Optical Spray Diagnostics Engine Investigations * Experimental Results * Optical Combustion...

489

Heat Transport by Turbulent Rayleigh-Benard Convection  

SciTech Connect (OSTI)

We have developed a research program dedicated to the quantitative laboratory study of turbulent convection.

None

2008-10-03T23:59:59.000Z

490

Great Plains Turbulence Environment: Its Origins, Impact, and Simulation  

SciTech Connect (OSTI)

This paper summarizes the known impacts of nocturnal turbulence on wind turbine performance and operations.

Kelley, N. D.; Jonkman, B. J.; Scott, G. N.

2006-12-01T23:59:59.000Z

491

Combustion Air Preheat Should Be More Than Simply Recycling Energy  

E-Print Network [OSTI]

Combustion air preheat can and should result in fuel savings far in excess of the energy added to the combustion air. In a typical installation of air preheat on a fired tubular reactor, the addition of 2.5 million BTU/hr to the combustion air...

Grantom, R. L.

1980-01-01T23:59:59.000Z

492

ME 374C Combustion Engine Processes ABET EC2000 syllabus  

E-Print Network [OSTI]

combustion engines, fuels, carburetion, combustion, exhaust emissions, knock, fuel injection, and factors engine, although diesels and 2-strokes are also discussed. Topics Covered (# of classes per topic): 1 of an Engineering System 4. Introduction to Engine Modeling 5. Fuels 6. Combustion and Knock 7. 4-stroke SI Engines

Ben-Yakar, Adela

493

Fast computation of multi-scale combustion systems  

Science Journals Connector (OSTI)

...consider a detailed combustion mechanism for air...The mean specific heat (under constant...being the specific heat of species i (mass...with a detailed combustion mechanism, where...between retrieved data and detailed solution...combustion mechanism for hydrocarbons. Moreover, on...

2011-01-01T23:59:59.000Z

494

Paper # A02 Topic: Laminar Flames US Combustion Meeting  

E-Print Network [OSTI]

been focused on synthetic fuel gas (syngas) combustion. Syngas is derived from coal throughPaper # A02 Topic: Laminar Flames 1 5th US Combustion Meeting Organized by the Western States Section of the Combustion Institute and Hosted by the University of California at San Diego March 25

Seitzman, Jerry M.

495

NOTE / NOTE Variability in organic matter lost by combustion in  

E-Print Network [OSTI]

) to the atmosphere through combustion of biomass. An estimated 1470 ± 59 km2 of peatland burns annually in boreal libère du carbone (C) directement dans l'atmosphère par la combustion de biomasse. AnnuellementNOTE / NOTE Variability in organic matter lost by combustion in a boreal bog during the 2001

Benscoter, Brian W.

496

Combustion Model for a CFB Boiler with Consideration of Post-Combustion in the Cyclone  

Science Journals Connector (OSTI)

Severe post combustion in the cyclone of CFB boilers could destroy heat absorbing balance among ... rarely considered in the design phase of a CFB boiler. Based on our previous experiment results ... added into a...

S. H. Li; H. R. Yang; H. Zhang; Y. X. Wu…

2010-01-01T23:59:59.000Z

497

Control of Combustion Processes in an Internal Combustion Engine by Low-Temperature Plasma  

Science Journals Connector (OSTI)

A new method of operation of internal combustion engines enhances power and reduces fuel consumption and exhaust toxicity. Low-temperature plasma control combines working processes of thermal engines and steam machines into a single process.

E. A. Olenev

2002-07-01T23:59:59.000Z

498

Control of Combustion Processes in an Internal Combustion Engine by Low-Temperature Plasma  

Science Journals Connector (OSTI)

A new method of operation of internal combustion engines enhances power and reduces fuel consumption and exhaust toxicity. Low-temperature plasma control combines working processes of thermal engines and steam...

E. A. Olenev

2002-07-01T23:59:59.000Z

499

Chapter 17 - Nuclear Fusion  

Science Journals Connector (OSTI)

Publisher Summary Nuclear fusion, the joining of light nuclei of hydrogen into heavier nuclei of helium, has potential environmental, safety and proliferation characteristics as an energy source, as well as adequate fuel to power civilization for times long compared to human history. It is, however, more challenging to convert to an energy source than nuclear fission. This chapter introduces the physics, advantages, difficulties, progress, economics and prospects for fusion energy power plants. Nuclear fusion is the process, in which light nuclei can release large amounts of energy if they combine, or fuse, into heavier nuclei. The principal nuclear reactions which have been considered for reactor concepts involve reactions of isotopes of the two lightest elements: hydrogen and helium. The fuel costs for fusion reactors will be negligible in comparison with the value of the electricity produced. It is difficult to precisely assess the cost of fusion-generated electricity until there is experience with an operating power plant, since the cost will be dependent upon the reliability and the frequency and expense of maintenance, both of which are likely to improve with the hindsight of experience. A fusion reactor does not directly emit CO2 or other greenhouse gases, or any combustion products that contribute to acid rain, and the indirect emissions due to factors like fuel gathering and transport, plant construction and maintenance, and activated parts storage would be small. Thus, fusion power would not have appreciable adverse effects upon global warming, atmospheric quality or acidification of the oceans, lakes and streams.

Larry R. Grisham

2008-01-01T23:59:59.000Z

500

Nuclear reactor characteristics and operational history  

Gasoline and Diesel Fuel Update (EIA)

Nuclear > U.S. reactor operation status tables Nuclear > U.S. reactor operation status tables Nuclear Reactor Operational Status Tables Release date: November 22, 2011 Next release date: November 2012 See also: Table 1. Capacity and Generation, Table 2. Ownership Data Table 3. Nuclear Reactor Characteristics and Operational History PDF XLS Plant Name Generator ID Type Reactor Supplier and Model Construction Start Grid Connection Original Expiration Date License Renewal Application License Renewal Issued Extended Expiration Arkansas Nuclear One 1 PWR Babcock&Wilcox, Lower Loop 10/1/1968 8/17/1974 5/20/2014 2/1/2000 6/20/2001 5/20/2034 Arkansas Nuclear One 2 PWR Combustion Eng. 7/1/1971 12/26/1978 7/17/2018 10/15/2003 6/30/2005 7/17/2038