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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

Simulation of lean premixed turbulent combustion  

E-Print Network [OSTI]

turbulent methane combustion. Proc. Combust. Inst. , 29:in premixed turbulent combustion. Proc. Combust. Inst. ,for zero Mach number combustion. Combust. Sci. Technol. ,

2008-01-01T23:59:59.000Z

3

Turbulent Combustion Luc Vervisch  

E-Print Network [OSTI]

;19 "Perfect" combustion modes: Fuel + Oxidizer () Products Engines, gas turbines... Laboratory experiment1 Turbulent Combustion Modeling Luc Vervisch INSA de Rouen, IUF, CORIA-CNRS Quelques problèmes rencontrés en chimie numérique : Hydrologie - Combustion - Atmosphère 16 décembre, INRIA Rocquencourt #12

Kern, Michel

4

Four Lectures on Turbulent Combustion  

E-Print Network [OSTI]

Four Lectures on Turbulent Combustion N. Peters Institut f¨ur Technische Mechanik RWTH Aachen Turbulent Combustion: Introduction and Overview 1 1.1 Moment Methods in Modeling Turbulence with Combustion and Velocity Scales . . . . . . . . . . . 11 1.4 Regimes in Premixed Turbulent Combustion

Peters, Norbert

5

TURBULENT FRBRNNING MVK130 Turbulent Combustion  

E-Print Network [OSTI]

TURBULENT F?RBR?NNING MVK130 Turbulent Combustion Poäng: 3.0 Betygskala: TH Valfri för: M4 to combustion, McGraw-Hill 1996. #12;

6

TURBULENT FRBRNNING MVK 130 Turbulent Combustion  

E-Print Network [OSTI]

TURBULENT F?RBR?NNING MVK 130 Turbulent Combustion Antal poäng: 3.0. Valfri för: M4. Kursansvarig program med hänsyn till de modeller som används. Litteratur S.R. Turns: An introduction to combustion, Mc

7

Advanced Computational Methods for Turbulence and Combustion...  

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

Advanced Computational Methods for Turbulence and Combustion Advanced Computational Methods for Turbulence and Combustion Bell.png Key Challenges: Development and application of...

8

Fifteen Lectures on Laminar and Turbulent Combustion  

E-Print Network [OSTI]

Fifteen Lectures on Laminar and Turbulent Combustion N. Peters RWTH Aachen Ercoftac Summer School in Combustion Systems 1 Lecture 2: Calculation of Adiabatic Flame Temperatures and Chemical Equilibria 20: Laminar Diffusion Flames: Different Flow Geometries 156 Lecture 11: Turbulent Combustion: Introduction

Peters, Norbert

9

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

10

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

11

NUMERICAL MODELING OF TURBULENT FLOW IN A COMBUSTION TUNNEL  

E-Print Network [OSTI]

1VJcDonald, H. (1979) Combustion r 1 iodeJing in Two and1979) Practical Turbulent-Combustion Interaction Models forInternation on Combustors. Combustion The 17th Symposium

Ghoniem, A.F.

2013-01-01T23:59:59.000Z

12

Modeling of combustion noise spectrum from turbulent premixed flames  

E-Print Network [OSTI]

Modeling of combustion noise spectrum from turbulent premixed flames Y. Liu, A. P. Dowling, T. D, Nantes, France 2321 #12;Turbulent combustion processes generate sound radiation due to temporal changes, this temporal correlation and its role in the modeling of combustion noise spectrum are studied by analyzing

Paris-Sud XI, Université de

13

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

E-Print Network [OSTI]

comparison of terascale combustion simulation data. Mathe-premixed hydrogen ?ames. Combustion and Flame, [7] J. L.of Large Scale Turbulent Combustion Peer-Timo Bremer 1 ,

Bremer, Peer-Timo

2010-01-01T23:59:59.000Z

14

Turbulence-Chemistry Interaction in Lean Premixed Hydrogen Combustion  

E-Print Network [OSTI]

alternatives to traditional petroleum and natural gas fuels. Burning under lean condi- tions reduces of conditions expected from gas turbine combustors. At these higher turbulence in- tensities, hydrogen flamesTurbulence-Chemistry Interaction in Lean Premixed Hydrogen Combustion A. J. Aspden1,2 , M. S. Day2

Bell, John B.

15

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

16

Combustion-turbulence interaction in the turbulent boundary layer over a hot surface  

SciTech Connect (OSTI)

The turbulence-combustion interaction in a reacting turbulent boundary layer over a heated flat plate was studied. Ethylene/air mixture with equivalence ratio of 0.35 was used. The free stream velocity was 10.5 m/s and the wall temperature was 1250/sup 0/K. Combustion structures visualization was provided by high-speed schlieren photographs. Fluid density statistics were deduced from Rayleigh scattering intensity measurements. A single-component laser Doppler velocimetry system was used to obtain mean and root-mean-square velocity distributions, the Reynolds stress, the streamwise and the cross-stream turbulent kinetic energy diffusion, and the production of turbulent kinetic energy by Reynolds stress. The combustion process was dominated by large-scale turbulent structures of the boundary layer. Combustion causes expansion of the boundary layer. No overall self-similarity is observed in either the velocity or the density profiles. Velocity fluctuations were increased in part of the boundary layer and the Reynolds stress was reduced. The turbulent kinetic energy diffusion pattern was changed significantly and a modification of the boundary layer assumption will be needed when dealing with this problem analytically. 11 figures, 1 table.

Ng, T.T.; Cheng, R.K.; Robben, F.; Talbot, L.

1982-01-01T23:59:59.000Z

17

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

18

PDF Modeling of Turbulent Lean Premixed Combustion  

SciTech Connect (OSTI)

The joint velocity-scalar-frequency probability density function (PDF) methodology is employed for prediction of a bluff-body stabilized lean premixed methane-air flame. A reduced mechanism with CO and NO chemistry is used to describe fuel oxidation. The predicted mean and rms values of the velocity, temperature and concentrations of major and minor species are compared with laboratory measurements. This technical effort was performed in support of the National Energy Technology Laboratorys on-going research in Assessment of Turbo-Chemistry Models for Gas Turbine Combustion Emissions under the RDS contract DE-AC26-04NT41817.

Yilmaz, S.L.; Givi, P.; Strakey, P.A.

2007-10-01T23:59:59.000Z

19

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

E-Print Network [OSTI]

A Topological Framework for the Interactive Exploration of Large Scale Turbulent Combustion Peer a new topological framework for the analysis of large scale, time-varying, turbulent combustion consumption thresh- olds for an entire time-dependent combustion simulation. By computing augmented merge

Knowles, David William

20

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

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

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

22

Numerical Simulation of Premixed Turbulent Methane Combustion John B. Bell, Marcus S. Day and Joseph F. Grcar  

E-Print Network [OSTI]

LBNL-49331 Numerical Simulation of Premixed Turbulent Methane Combustion John B. Bell, Marcus S of Premixed Turbulent Methane Combustion Abstract In this paper we study the behavior of a premixed turbulent an adaptive time-dependent low Mach number combustion algorithm based on a second-order projection formulation

23

Analysis of the Effect of Geometry Generated Turbulence on HCCI Combustion by Multi-Zone Modeling  

SciTech Connect (OSTI)

This paper illustrates the applicability of a sequential fluid mechanics, multi-zone chemical kinetics model to analyze HCCI experimental data for two combustion chamber geometries with different levels of turbulence: a low turbulence disc geometry (flat top piston), and a high turbulence square geometry (piston with a square bowl). The model uses a fluid mechanics code to determine temperature histories in the engine as a function of crank angle. These temperature histories are then fed into a chemical kinetic solver, which determines combustion characteristics for a relatively small number of zones (40). The model makes the assumption that there is no direct linking between turbulence and combustion. The results show that the multi-zone model yields good results for both the disc and the square geometries. The model makes good predictions of pressure traces and heat release rates. The experimental results indicate that the high turbulence square geometry has longer burn duration than the low turbulence disc geometry. This difference can be explained by the sequential multi-zone model, which indicates that the cylinder with the square bowl has a thicker boundary layer that results in a broader temperature distribution. This broader temperature distribution tends to lengthen the combustion, as cold mass within the cylinder takes longer to reach ignition temperature when compressed by the expansion of the first burned gases. The multi-zone model, which makes the basic assumption that HCCI combustion is controlled by chemical kinetics, is therefore capable of explaining the experimental results obtained for different levels of turbulence, without considering a direct interaction between turbulence and combustion. A direct connection between turbulence and HCCI combustion may still exists, but it seems to play a relatively minor role in determining burn duration at the conditions analyzed in this paper.

Aceves, S M; Flowers, D L; Martinez-Frias, J; Espinosa-Loza, F; Christensen, M; Johansson, B; Hessel, R P

2004-12-13T23:59:59.000Z

24

Combined pdf-sdf approach to partially premixed turbulent combustion  

SciTech Connect (OSTI)

Partially premixed turbulent flames can develop flow regimes where triple flames emerge consisting of essentially premixed and non-premixed zones. The description of such phenomena requires a criterion for the detection of such zones. Such a criterion can be based on a wide range of variables including reaction rates, mass fractions of radicals, etc. These variables are not necessarily suitable for the limit of infinitely fast reactions, for instance, reaction rates are obviously not bounded in this limit. Hence a new single scalar variable based on geometric properties of mixture fraction and non-conserved variables is constructed, that allows the detection of finite rate and, in particular, triple flame domains and is bounded in the limit of infinitely fast reactions. This is first done for systems with simplified chemistry described by two variables and then generalized to combustion with complex chemistry. A pdf-sdf formalism is then outlined for the local thermodynamic state conditioned upon the degree of finite rate effects.

Jacqueline H. Chen; Hong G. Im

2000-07-30T23:59:59.000Z

25

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

26

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.

Im, Hong G [University of Michigan] [University of Michigan; Trouve, Arnaud [University of Maryland] [University of Maryland; Rutland, Christopher J [University of Wisconsin] [University of Wisconsin; Chen, Jacqueline H [Sandia National Laboratories] [Sandia National Laboratories

2012-08-13T23:59:59.000Z

27

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

28

Flow Turbulence Combust (2009) 82:437453 DOI 10.1007/s10494-008-9145-3  

E-Print Network [OSTI]

engines, industrial burners and furnaces, and gas turbine combustors. Combustion of hydrocarbon fuels is very complicated. A high-fidelity combustion model needs to describe adequately all the physical turbulent combustion models and efficient algorithms for combustion chemistry have been developed

29

Lattice Boltzmann equation simulations of turbulence, mixing, and combustion  

E-Print Network [OSTI]

We explore the capability of lattice Boltzmann equation (LBE) method for complex fluid flows involving turbulence, mixing, and reaction. In the first study, LBE schemes for binary scalar mixing and multi-component reacting flow with reactions...

Yu, Huidan

2006-04-12T23:59:59.000Z

30

NUMERICAL MODELING OF TURBULENT FLOW IN A COMBUSTION TUNNEL  

E-Print Network [OSTI]

combustion in a 1 ean propane~a1 of high sp r mi xture thatned for a and temperature propane~ai due to r mixture at anrecorded photographically propane~air this Fig. The mixture,

Ghoniem, A.F.

2013-01-01T23:59:59.000Z

31

Proceedings of the Combustion Institute, Volume 28, 2000/pp. 903910 TURBULENT FLAME DYNAMICS OF HOMOGENEOUS SOLID PROPELLANT  

E-Print Network [OSTI]

903 Proceedings of the Combustion Institute, Volume 28, 2000/pp. 903­910 TURBULENT FLAME DYNAMICS University Park, PA 16802, USA A comprehensive numerical analysis has been conducted to study the combustion development and its influence on propellant combustion. The formulation is based on the Favre

Apte, Sourabh V.

32

The role of presumed probability density function in the simulation of non premixed turbulent combustion  

E-Print Network [OSTI]

Flamelet Progress Variable (FPV) combustion models allow the evaluation of all thermo chemical quantities in a reacting flow by computing only the mixture fraction Z and a progress variable C. When using such a method to predict a turbulent combustion in conjunction with a turbulence model, a probability density function (PDF) is required to evaluate statistical averages (e.g., Favre average) of chemical quantities. The choice of the PDF is a compromise between computational costs and accuracy level. The aim of this paper is to investigate the influence of the PDF choice and its modeling aspects in the simulation of non premixed turbulent combustion. Three different models are considered: the standard one, based on the choice of a beta distribution for Z and a Dirac distribution for C; a model employing a beta distribution for both Z and C; a third model obtained using a beta distribution for Z and the statistical most likely distribution (SMLD) for C. The standard model, although widely used, doesn't take in...

Coclite, Alessandro; De Palma, Pietro; Cutrone, Luigi

2013-01-01T23:59:59.000Z

33

Sandia National Laboratories: The CRF's Turbulent Combustion Lab (TCL)  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -theErikGroundbreakingStandardsTCES Sandia Researchers WinTVATestTexaspast,

34

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

35

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

36

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

37

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

38

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

39

Numerical analysis of turbulent heat transfer in a nuclear reactor coolant channel  

E-Print Network [OSTI]

NUMERICAL ANALYSIS OF TURBULENT HEAT TRANSFER IN A NUCLEAR REACTOR COOLANT CHANNEL A Thesis Clarence William Garrard, Jr. Submitted to the Graduate College of the Texas A&M University in partial fulfillment of' the requirements for the degree... of' MASTER OF SC1ENCE May, 1965 Ma)or Subject Nuclear Engineering NUMERICAL ANALYSIS OF TURBULENT HEAT TRANSFER 1N A NUCLEAR REACTOR COOLANT CHANNEL A Thesis By Clarence William Garrard, Jr. Approved as to style and content by; Head...

Garrard, Clarence William

1965-01-01T23:59:59.000Z

40

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

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

TURBULENT COMBUSTION MODELING OF COAL:BIOMASS BLENDS IN A SWIRL BURNER I -PRELIMINARY RESULTS  

E-Print Network [OSTI]

fractions has been developed for accurate simulation of coal:manure combustion. This model treats coal and manure off gasses separately. This model has been incorporated into the PCGC-2(Pulverized Coal Gasification and Combustion - 2 Dimensional, from Brigham Young University) code. Numerical results

Daripa, Prabir

42

COMBUSTIBILITY OF HIGH-PURITY, NUCLEAR-GRADE GRAPHITE  

E-Print Network [OSTI]

graphite-moderated nuclear reactors, primarily bex~use of the accidents at Windscale in 1957 [1] and

M. B. Richards

43

Simulation of Turbulent Combustion Fields of Shock-Dispersed Aluminum Using the AMR Code  

SciTech Connect (OSTI)

We present a Model for simulating experiments of combustion in Shock-Dispersed-Fuel (SDF) explosions. The SDF charge consisted of a 0.5-g spherical PETN booster, surrounded by 1-g of fuel powder (flake Aluminum). Detonation of the booster charge creates a high-temperature, high-pressure source (PETN detonation products gases) that both disperses the fuel and heats it. Combustion ensues when the fuel mixes with air. The gas phase is governed by the gas-dynamic conservation laws, while the particle phase obeys the continuum mechanics laws for heterogeneous media. The two phases exchange mass, momentum and energy according to inter-phase interaction terms. The kinetics model used an empirical particle burn relation. The thermodynamic model considers the air, fuel and booster products to be of frozen composition, while the Al combustion products are assumed to be in equilibrium. The thermodynamic states were calculated by the Cheetah code; resulting state points were fit with analytic functions suitable for numerical simulations. Numerical simulations of combustion of an Aluminum SDF charge in a 6.4-liter chamber were performed. Computed pressure histories agree with measurements.

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

2006-11-02T23:59:59.000Z

44

A Multi-FhJid CFD Turbulent Entrainment Combustion Model: Formulation and One-Dimensional Results  

E-Print Network [OSTI]

and physical processes that occur during combustion. Short time scales and extremes in temperature and pressure chamber and to predict conditions at the time of spark [1,2]. However, only in the last several years has controlled PREPRINT 1997 SAE Fall Fuels and Lubricants Meeting #12;models of Magnuussen [

45

AMR Code Simulations of Turbulent Combustion in Confined and Unconfined 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 gas dynamic 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 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 vented two-room structure and in an unconfined height-of-burst explosion. Computed pressure histories are in reasonable (but not perfect) agreement 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

2009-05-29T23:59:59.000Z

46

Turbulence, orbit equivalence, and the classification of nuclear C  

E-Print Network [OSTI]

We bound the Borel cardinality of the isomorphism relation for nuclear ... These results depend intimately on the classification theory of nuclear simple C?-...

2012-04-24T23:59:59.000Z

47

Turbulence and turbulent mixing in natural fluids  

E-Print Network [OSTI]

Turbulence and turbulent mixing in natural fluids begins with big bang turbulence powered by spinning combustible combinations of Planck particles and Planck antiparticles. Particle prograde accretion on a spinning pair releases 42% of the particle rest mass energy to produce more fuel for turbulent combustion. Negative viscosity and negative turbulence stresses work against gravity, creating mass-energy and space-time from the vacuum. Turbulence mixes cooling temperatures until a quark-gluon strong-force SF freeze-out. Gluon-viscosity anti-gravity ({\\Lambda}SF) exponentially inflates the fireball to preserve big bang turbulence information at scales larger than ct as the first fossil turbulence. Cosmic microwave background CMB temperature anisotropies show big bang turbulence fossils along with fossils of weak plasma turbulence triggered (10^12 s) as plasma viscous forces permit gravitational fragmentation on supercluster to galaxy mass scales (10^13 s). Turbulent morphologies and viscous-turbulent lengths a...

Gibson, Carl H

2010-01-01T23:59:59.000Z

48

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

49

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.

50

Turbulence  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear SecurityTensile Strain Switched Ferromagnetism in Layered NbS2TopoPortalBRDFTunable ThermalTurbines

51

COMBUSTION RESEARCH PROGRAM. CHAPTER FROM ENERGY & ENVIRONMENT ANNUAL REPORT 1977  

E-Print Network [OSTI]

Applied to Turbulent Combustion Flows J. W. Daily and C.Metals from Pulverized Coal Combustion P. Sherman and F.Applied to Turbulent Combustion Flows J. W. Daily and C.

Authors, Various

2011-01-01T23:59:59.000Z

52

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

E-Print Network [OSTI]

The objective of this research project was to identify and determine the effect of jet burner operating variables that influence combustion of low-BTU gases. This was done by simulating the combustion of a low-BTU fuel in a jet flame and predicting...

Carney, Christopher Mark

1995-01-01T23:59:59.000Z

53

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

54

Combustion Energy Frontier Research Center Post-Doctoral Position...  

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

University and Sandia National Laboratories on advanced simulations of turbulent combustion. The project involves two simulation methodologies: direct numerical simulation...

55

Modeling Compressed Turbulence  

SciTech Connect (OSTI)

From ICE to ICF, the effect of mean compression or expansion is important for predicting the state of the turbulence. When developing combustion models, we would like to know the mix state of the reacting species. This involves density and concentration fluctuations. To date, research has focused on the effect of compression on the turbulent kinetic energy. The current work provides constraints to help development and calibration for models of species mixing effects in compressed turbulence. The Cambon, et al., re-scaling has been extended to buoyancy driven turbulence, including the fluctuating density, concentration, and temperature equations. The new scalings give us helpful constraints for developing and validating RANS turbulence models.

Israel, Daniel M. [Los Alamos National Laboratory

2012-07-13T23:59:59.000Z

56

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

57

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

58

Standard guide for pyrophoricity/combustibility testing in support of pyrophoricity analyses of metallic uranium spent nuclear fuel  

E-Print Network [OSTI]

1.1 This guide covers testing protocols for testing the pyrophoricity/combustibility characteristics of metallic uranium-based spent nuclear fuel (SNF). The testing will provide basic data for input into more detailed computer codes or analyses of thermal, chemical, and mechanical SNF responses. These analyses would support the engineered barrier system (EBS) design bases and safety assessment of extended interim storage facilities and final disposal in a geologic repository. The testing also could provide data related to licensing requirements for the design and operation of a monitored retrievable storage facility (MRS) or independent spent fuel storage installation (ISFSI). 1.2 This guide describes testing of metallic uranium and metallic uranium-based SNF in support of transportation (in accordance with the requirements of 10CFR71), interim storage (in accordance with the requirements of 10CFR72), and geologic repository disposal (in accordance with the requirements of 10CFR60/63). The testing described ...

American Society for Testing and Materials. Philadelphia

2007-01-01T23:59:59.000Z

59

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.

60

A filtered tabulated chemistry model for LES of premixed combustion  

E-Print Network [OSTI]

A filtered tabulated chemistry model for LES of premixed combustion B. Fiorinaa , R. Vicquelina to turbulent combustion regimes by including subgrid scale wrinkling effects in the flame front propagation Simulation, Turbulent premixed combustion, Tabulated chemistry 1. Introduction Flame ignition and extinction

Paris-Sud XI, Université de

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

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

62

Fuel NOx pollution production during the combustion of a low caloric value fuel gas  

E-Print Network [OSTI]

this thesis. TABLE OF CONTENTS Page ABSTRACT ACKNOWLEDGMENTS TABLE OF CONTENTS LIST OF TABLES LIST OF FIGURES LIST OF NOMENCLATURE INTRODUCTION LITERATURE REVIEW In VI VI I I IX Xl Turbulent combustion characteristics Importance and mechanisms... combustion characteristics 2. Importance and mechanisms of NO? formation and control. 3. Physical properties and combustion characteristics of LCVG Each of these areas is discussed in the following sections. Turbulent combustion characteristics Turbulent...

Caraway, John Phillip

2012-06-07T23:59:59.000Z

63

FLAME SURFACE DENSITIES IN PREMIXED COMBUSTION AT MEDIUM TO HIGH  

E-Print Network [OSTI]

premixed combustion diagrams. Small-scale transport of heat and species may be more important and chemistryFLAME SURFACE DENSITIES IN PREMIXED COMBUSTION AT MEDIUM TO HIGH TURBULENCE INTENSITIES O¨ MER L in turbulent premixed propane= air flames were determined experimentally. The instantaneous flame fronts were

Gülder, ?mer L.

64

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

65

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. 24 figures.

Oppenheim, A.K.; Maxson, J.A.; Hensinger, D.M.

1993-12-21T23:59:59.000Z

66

US National Technical Meeting of the Combustion Institute  

E-Print Network [OSTI]

7th US National Technical Meeting of the Combustion Institute Hosted by the Georgia Institute of Turbulent Spray Combustion C. Heye, H. Koo and V. Raman1 1 Department of Aerospace Engineering of two-phase combustion. In particular, the effect of droplet Stokes number on flame evolution

Raman, Venkat

67

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

68

Simulation of lean premixed turbulent combustion  

E-Print Network [OSTI]

fuels such as hydrogen or syngas. Lean premixed systems havefuels such as hydrogen or syngas, which is obtained from

2008-01-01T23:59:59.000Z

69

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

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

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

70

Turbulent Combustion in Type Ia Supernova Models  

E-Print Network [OSTI]

We review the astrophysical modeling of type Ia supernova explosions and describe numerical methods to implement numerical simulations of these events. Some results of such simulations are discussed.

F. K. Roepke; W. Hillebrandt

2006-09-15T23:59:59.000Z

71

Section 10: Turbulence and reactive flows 1 Section 10: Turbulence and reactive flows  

E-Print Network [OSTI]

premixed combustion is recently a theme of interest in gas turbines and other industrial applications flames #12;2 Section 10: Turbulence and reactive flows for gas turbine application. In: International Gas combustion LES in- cluding thickened flame model A. Hosseinzadeh, A. Sadiki, J. Janicka (TU Darmstadt) Lean

Kohlenbach, Ulrich

72

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

73

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

74

Oscillatory Flame Response in Acoustically Coupled Fuel Droplet Combustion  

E-Print Network [OSTI]

CombustionCombustion . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .Coupled Droplet Combustion . . . . . . . . . . . . Burning

Sevilla Esparza, Cristhian Israel

2013-01-01T23:59:59.000Z

75

Radiation-turbulence interactions in pulverized-coal flames. Quarterly report No. III, March 15, 1994--June 15, 1994  

SciTech Connect (OSTI)

The work concerns the development of computer codes for the simulation of radiation turbulence interactions in coal flames. Experimental studies in tandem with the turbulence calculations are based on optical observation of scattered light from coal particles under combustion conditions.

Menguec, M.P.; McDonough, J.M.

1994-09-01T23:59:59.000Z

76

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

77

COMBUSTION RESEARCH - FY-1979  

E-Print Network [OSTI]

Optical Measurement of Combustion Products by Zeeman Atomicand T. Hadeishi . . . . . Combustion Sources offrom Pulverized Coal Combustion J. Pennucci, R. Greif, F.

,

2012-01-01T23:59:59.000Z

78

Advanced Combustion  

SciTech Connect (OSTI)

The activity reported in this presentation is to provide the mechanical and physical property information needed to allow rational design, development and/or choice of alloys, manufacturing approaches, and environmental exposure and component life models to enable oxy-fuel combustion boilers to operate at Ultra-Supercritical (up to 650{degrees}C & between 22-30 MPa) and/or Advanced Ultra-Supercritical conditions (760{degrees}C & 35 MPa).

Holcomb, Gordon R. [NETL

2013-03-11T23:59:59.000Z

79

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

80

Combustion Group Group members  

E-Print Network [OSTI]

Combustion Group Group members: Thierry Poinsot, Emilien Courtine, Luc Vervisch, Benjamin Farcy 2014 #12;Combustion Group Combustion Physics and Modeling Pollutants, Emissions, and Soot Formation Thermoacoustics and Combustion Dynamics Research focus § Examine mechanisms responsible for flame stabilization

Wang, Wei

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

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

82

Combustion Theory and Modelling Vol. 11, No. 5, October 2007, 697714  

E-Print Network [OSTI]

Combustion Theory and Modelling Vol. 11, No. 5, October 2007, 697­714 Flame propagation in a small, to the emerging micro-combustion technology, and to the understanding of the effect of small scales; Turbulent combustion 1. Introduction The propagation of premixed flames in the presence of a flow whose

Heil, Matthias

83

AME 514 Applications of Combustion and Reacting Flows -Spring 2015 Instructor: Paul Ronney  

E-Print Network [OSTI]

transpiration 3) Turbulent combustion (3 lectures) i) Premixed-gas flames ii) Non premixed flames iii) EdgeAME 514 ­ Applications of Combustion and Reacting Flows - Spring 2015 Instructor: Paul Ronney of Combustion) to new and rapidly evolving science and technology areas including microscale reacting flows

84

Center for Turbulence Research Annual Research Briefs 2008  

E-Print Network [OSTI]

combustion engines and gas-turbine aircraft engines. Therefore, the ability to perform accurate numerical relevant to combustion modeling for future research. 2. Mathematical model 2.1. Governing equations The gas, or collision and coalescence with other droplets. The resulting vapor in the gas phase undergoes turbulent

Prinz, Friedrich B.

85

Sandia National Laboratories: Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy AdvancedEnergyEnergyMappingCombustion Renewable Systems On

86

Regenerative combustion device  

DOE Patents [OSTI]

A regenerative combustion device having a combustion zone, and chemicals contained within the combustion zone, such as water, having a first equilibrium state, and a second combustible state. Means for transforming the chemicals from the first equilibrium state to the second combustible state, such as electrodes, are disposed within the chemicals. An igniter, such as a spark plug or similar device, is disposed within the combustion zone for igniting combustion of the chemicals in the second combustible state. The combustion products are contained within the combustion zone, and the chemicals are selected such that the combustion products naturally chemically revert into the chemicals in the first equilibrium state following combustion. The combustion device may thus be repeatedly reused, requiring only a brief wait after each ignition to allow the regeneration of combustible gasses within the head space.

West, Phillip B.

2004-03-16T23:59:59.000Z

87

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

88

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...

89

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

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

for Combustion Engines: Exploiting New Combustion Regimes Stretch Efficiency for Combustion Engines: Exploiting New Combustion Regimes 2013 DOE Hydrogen and Fuel Cells Program and...

90

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

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

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

91

Observations of Edge Turbulence  

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

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92

Radiosonde measurements of turbulence  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared at 278, 298, and 323Program2 RadiometerTurbulence detection on

93

COMBUSTION RESEARCH - FY-1979  

E-Print Network [OSTI]

XBL 803-181) product combustion gas mixtures is in samplethrough reaction in the post-combustion gases. The selectiveaddition to the post-combustion gases have been investigated

,

2012-01-01T23:59:59.000Z

94

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

95

http://rcc.its.psu.edu/hpc Simulation of In-Cylinder Processes in Internal Combustion Engines  

E-Print Network [OSTI]

http://rcc.its.psu.edu/hpc Simulation of In-Cylinder Processes in Internal Combustion Engines into clean and efficient turbulent combustion remains imperative. A single grand challenge was identified in a 2006 DOE workshop on clean and efficient combustion of 21st century transportation fuels [1]: "The

Bjørnstad, Ottar Nordal

96

Combustion 2000  

SciTech Connect (OSTI)

This report is a presentation of work carried out on Phase II of the HIPPS program under DOE contract DE-AC22-95PC95144 from June 1995 to March 2001. The objective of this report is to emphasize the results and achievements of the program and not to archive every detail of the past six years of effort. These details are already available in the twenty-two quarterly reports previously submitted to DOE and in the final report from Phase I. The report is divided into three major foci, indicative of the three operational groupings of the program as it evolved, was restructured, or overtaken by events. In each of these areas, the results exceeded DOE goals and expectations. HIPPS Systems and Cycles (including thermodynamic cycles, power cycle alternatives, baseline plant costs and new opportunities) HITAF Components and Designs (including design of heat exchangers, materials, ash management and combustor design) Testing Program for Radiative and Convective Air Heaters (including the design and construction of the test furnace and the results of the tests) There are several topics that were part of the original program but whose importance was diminished when the contract was significantly modified. The elimination of the subsystem testing and the Phase III demonstration lessened the relevance of subtasks related to these efforts. For example, the cross flow mixing study, the CFD modeling of the convective air heater and the power island analysis are important to a commercial plant design but not to the R&D product contained in this report. These topics are of course, discussed in the quarterly reports under this contract. The DOE goal for the High Performance Power Plant System ( HIPPS ) is high thermodynamic efficiency and significantly reduced emissions. Specifically, the goal is a 300 MWe plant with > 47% (HHV) overall efficiency and {le} 0.1 NSPS emissions. This plant must fire at least 65% coal with the balance being made up by a premium fuel such as natural gas. To achieve these objectives requires a change from complete reliance of coal-fired systems on steam turbines (Rankine cycles) and moving forward to a combined cycle utilizing gas turbines (Brayton cycles) which offer the possibility of significantly greater efficiency. This is because gas turbine cycles operate at temperatures well beyond current steam cycles, allowing the working fluid (air) temperature to more closely approach that of the major energy source, the combustion of coal. In fact, a good figure of merit for a HIPPS design is just how much of the enthalpy from coal combustion is used by the gas turbine. The efficiency of a power cycle varies directly with the temperature of the working fluid and for contemporary gas turbines the optimal turbine inlet temperature is in the range of 2300-2500 F (1260-1371 C). These temperatures are beyond the working range of currently available alloys and are also in the range of the ash fusion temperature of most coals. These two sets of physical properties combine to produce the major engineering challenges for a HIPPS design. The UTRC team developed a design hierarchy to impose more rigor in our approach. Once the size of the plant had been determined by the choice of gas turbine and the matching steam turbine, the design process of the High Temperature Advanced Furnace (HITAF) moved ineluctably to a down-fired, slagging configuration. This design was based on two air heaters: one a high temperature slagging Radiative Air Heater (RAH) and a lower temperature, dry ash Convective Air Heater (CAH). The specific details of the air heaters are arrived at by an iterative sequence in the following order:-Starting from the overall Cycle requirements which set the limits for the combustion and heat transfer analysis-The available enthalpy determined the range of materials, ceramics or alloys, which could tolerate the temperatures-Structural Analysis of the designs proved to be the major limitation-Finally the commercialization issues of fabrication and reliability, availability and maintenance. The program that has s

A. Levasseur; S. Goodstine; J. Ruby; M. Nawaz; C. Senior; F. Robson; S. Lehman; W. Blecher; W. Fugard; A. Rao; A. Sarofim; P. Smith; D. Pershing; E. Eddings; M. Cremer; J. Hurley; G. Weber; M. Jones; M. Collings; D. Hajicek; A. Henderson; P. Klevan; D. Seery; B. Knight; R. Lessard; J. Sangiovanni; A. Dennis; C. Bird; W. Sutton; N. Bornstein; F. Cogswell; C. Randino; S. Gale; Mike Heap

2001-06-30T23:59:59.000Z

97

Numerical investigation of high-pressure combustion in rocket engines using Flamelet/Progress-variable models  

E-Print Network [OSTI]

The present paper deals with the numerical study of high pressure LOx/H2 or LOx/hydrocarbon combustion for propulsion systems. The present research effort is driven by the continued interest in achieving low cost, reliable access to space and more recently, by the renewed interest in hypersonic transportation systems capable of reducing time-to-destination. Moreover, combustion at high pressure has been assumed as a key issue to achieve better propulsive performance and lower environmental impact, as long as the replacement of hydrogen with a hydrocarbon, to reduce the costs related to ground operations and increase flexibility. The current work provides a model for the numerical simulation of high- pressure turbulent combustion employing detailed chemistry description, embedded in a RANS equations solver with a Low Reynolds number k-omega turbulence model. The model used to study such a combustion phenomenon is an extension of the standard flamelet-progress-variable (FPV) turbulent combustion model combined ...

Coclite, A; De Palma, P; Pascazio, G

2015-01-01T23:59:59.000Z

98

Combustion Byproducts Recycling Consortium  

SciTech Connect (OSTI)

This paper discusses the roles and responsibilities of each position within the Combustion Byproducts Recyclcing Consortium.

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

2008-08-31T23:59:59.000Z

99

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 (PETC) Direct Utilization Advanced Research and Technology Development Program, and the International Energy Agency (IEA) Coal Combustion Science Project. Specific tasks include: coal devolatilization, coal char combustion, and fate of mineral matter during coal combustion. 91 refs., 40 figs., 9 tabs.

Hardesty, D.R. (ed.); Baxter, L.L.; Fletcher, T.H.; Mitchell, R.E.

1990-11-01T23:59:59.000Z

100

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:...

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

COAL DESULFURIZATION PRIOR TO COMBUSTION  

E-Print Network [OSTI]

90e COAL DESULFURIZATION PRIOR TO COMBUSTION J. Wrathall, T.of coal during combustion. The process involves the additionCOAL DESULFURIZATION PRIOR TO COMBUSTION Lawrence Berkeley

Wrathall, J.

2013-01-01T23:59:59.000Z

102

Transport Properties for Combustion Modeling  

E-Print Network [OSTI]

a critical role in combustion processes just as chemicalparameters are essential for combustion modeling; molecularwith Application to Combustion. Transport Theor Stat 2003;

Brown, N.J.

2010-01-01T23:59:59.000Z

103

Rotary internal combustion engine  

SciTech Connect (OSTI)

This patent describes an improved rotary internal combustion engine comprising: (a) a combustion chamber which is generally circular in cross-section and which has a ring-like peripheral wall; (b) a driven shaft member journaled for rotation and disposed to pass eccentrically through the combustion chamber; (c) a compression chamber which is generally circular in cross-section positioned with a ring-like wall is adjacent to and spatially offset with the combustion chamber such that the driven shaft passes centrally therethrough; and (d) a circular combustion rotor fixed concentrically to the shaft member for rotation eccentrically within the combustion chamber. The combustion rotor is positioned such that the space between the periphery of the rotor and the periphery of the combustion chamber results in a crescent shape.

Crittenden, W.

1987-01-27T23:59:59.000Z

104

Maintain Combustion Systems  

E-Print Network [OSTI]

Energy is consumed, and wasted, in liberal amounts in the combustion processes which supply heat energy to boilers and process heaters. Close attention to combustion systems can be extremely beneficial: Optimum air to fuel ratios, i.e., maintaining...

Fletcher, R. J.

1979-01-01T23:59:59.000Z

105

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

106

Impingement characteristics of a combustion nozzle  

E-Print Network [OSTI]

INTRODUCTION The radial jet reattachment (RJR) nozzle utilizes a nozzle which is aerodynamically shaped in such a way that it produces a jet which separates from the nozzle in a radial direction, and due to turbulent viscous mixing, reattaches... will be substituted in place of natural gas in objectives 3 and 4. The results from this study will be useful for combustion experiments using the RJR concept. R7R DESCRIPTION The 1UR nozzle is aerodynamically shaped in such a way that it produces a jet which...

Dietz, Erik Carl

1992-01-01T23:59:59.000Z

107

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

2010-06-05T23:59:59.000Z

108

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

109

LES of a Hydrogen-Enriched Lean Turbulent Premixed Flame  

E-Print Network [OSTI]

LES of a Hydrogen-Enriched Lean Turbulent Premixed Flame Francisco E. Hern´andez-P´erez , Clinton the observed behaviour is examined. Hydrogen-hydrocarbon fuel blends appear to be a promising option to synergistically pave the way toward pure hydrogen-based combustion systems while alleviating green-house gas

Groth, Clinton P. T.

110

Center for Turbulence Research Annual Research Briefs 2008  

E-Print Network [OSTI]

simulation of a 20 sector of a Pratt & Whitney gas turbine engine, encompassing the fan, low- and high-pressure compressors, combustor, high- and low-pressure turbines, and the exit nozzle as illustrated in Fig. 1 of turbulent combustion in a gas turbine engine combustor By D. You, F. Ham AND P. Moin 1. Motivation

Prinz, Friedrich B.

111

Quantum Gravity and Turbulence  

E-Print Network [OSTI]

We apply recent advances in quantum gravity to the problem of turbulence. Adopting the AdS/CFT approach we propose a string theory of turbulence that explains the Kolmogorov scaling in 3+1 dimensions and the Kraichnan and Kolmogorov scalings in 2+1 dimensions. In the gravitational context, turbulence is intimately related to the properties of spacetime, or quantum, foam.

Vishnu Jejjala; Djordje Minic; Y. Jack Ng; Chia-Hsiung Tze

2010-05-18T23:59:59.000Z

112

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

113

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

114

Advanced Combustion and Fuels  

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

DOEVTO 2011 - 2015 Multi- Year Program Plan * Inadequate data and predictive tools for fuel property effects on combustion and engine efficiency optimization (Fuels & Lubricants...

115

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

116

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

117

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

118

Pdf modeling of turbulent nonpremixed methane jet flames  

SciTech Connect (OSTI)

An expanded model of turbulent nonpremixed combustion is presented. In the model, the scalar mixing and reactions are described by a probability density function (pdf) submodel capable of handling five scalars, while the turbulent velocity field is described by a second-order moment closure. Two plausible chemical reaction models are considered: a five-scalar, four-step, reduced reaction mechanism, and a four-scalar constrained equilibrium model. Detailed comparisons of model predictions with laser Raman experimental dat provide a valuable evaluation of the model's ability in predicting nonequilibrium chemistry in turbulent nonpremixed flames. Overall, the model fails to predict greater departure from chemical equilibrium as mixing rates are increased. Interestingly, this failure is not due to the chemical model, both of which perform satisfactorily. Instead, the failure to predict greater departure from chemical equilibrium is a subtle artifact of the current Monte Carlo simulation of turbulent mixing and chemical reaction.

Chen, J.Y.; Kollmann, W.; Dibble, R.W. (Sandia National Labs., Livermore, CA (USA). Combustion Research Faclity)

1989-01-01T23:59:59.000Z

119

Turbulent partially premixed combustion: DNS analysis and RANS simulation  

E-Print Network [OSTI]

and air are separated and only meet in the reacting region through molecular diffusion. The compression-ignition diesel engine is one example. In the premixed mode, fuel and oxidizer (air) are fully mixed at molecular level before they are consumed... men- tioned problems by intentionally introducing partially premixed burning mode. For example, the direct-injection spark-ignited and multiple-injection diesel [124] and lean, fast mixing gas turbine combustors [127], involve uneven mixing of fuel...

Ruan, S.

2013-03-12T23:59:59.000Z

120

EXPERIMENTAL STUDY OF COMBUSTION IN A TURBULENT BOUNDARY LAYER  

E-Print Network [OSTI]

evaporation, but the thermophoretic migration of particlesboundary layer due to thermophoretic motion and evaporation

Cheng, R.K.

2011-01-01T23:59:59.000Z

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.


121

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

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

models were investigated along with chemical kinetic mechanisms simulating a biodiesel-fueled engine deer09ren.pdf More Documents & Publications Low Temperature...

122

Evaluation of a reduced mechanism for turbulent premixed combustion  

E-Print Network [OSTI]

as alternative fuels for power generation using indus- trial gas-turbines [1]. These are typically multi-component fuels, involving CO; H2; H2O; CH4; CO2; O2 and N2, with their composi- reaction set usually involves more than hundreds of reactions and tens... ]. The supplementary material of this arti- cle provides a CHEMKIN compatible subroutine to calculate these reaction rates. 2.3. Flow configuration and boundary conditions A sketch of the computational domain is given in Fig. 1. The computational domain is discretized...

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

2014-07-21T23:59:59.000Z

123

Assessment of Combustion and Turbulence Models for the Simulation of  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:YearRound-Up fromDepartmentTie Ltd: Scope Change #1 |MarketingVI,ProgramGoAroundMayDepartment

124

Advanced Computational Methods for Turbulence and Combustion Project at  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr May JunDatastreamsmmcrcalgovInstrumentsruc Documentation RUCProductstwrmrAre theAdministrator Referencesalkali metalsTiO2(110).CSP

125

COMBUSTION SOURCES OF NITROGEN COMPOUNDS  

E-Print Network [OSTI]

Rasmussen, R.A. (1976). Combustion as a source of nitrousx control for stationary combustion sources. Prog. Energy,CA, March 3-4, 1977 COMBUSTION SOURCES OF NITROGEN COMPOUNDS

Brown, Nancy J.

2011-01-01T23:59:59.000Z

126

Optical monitor for observing turbulent flow  

DOE Patents [OSTI]

The present invention provides an apparatus and method for non-invasively monitoring turbulent fluid flows including anisotropic flows. The present invention uses an optical technique to filter out the rays travelling in a straight line, while transmitting rays with turbulence induced fluctuations in time. The output is two dimensional, and can provide data regarding the spectral intensity distribution, or a view of the turbulence in real time. The optical monitor of the present invention comprises a laser that produces a coherent output beam that is directed through a fluid flow, which phase-modulates the beam. The beam is applied to a temporal filter that filters out the rays in the beam that are straight, while substantially transmitting the fluctuating, turbulence-induced rays. The temporal filter includes a lens and a photorefractive crystal such as BaTiO.sub.3 that is positioned in the converging section of the beam near the focal plane. An imaging system is used to observe the filtered beam. The imaging system may take a photograph, or it may include a real time camera that is connected to a computer. The present invention may be used for many purposes including research and design in aeronautics, hydrodynamics, and combustion.

Albrecht, Georg F. (Livermore, CA); Moore, Thomas R. (Rochester, NY)

1992-01-01T23:59:59.000Z

127

Optimized Algorithms Boost Combustion Research  

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

Optimized Algorithms Boost Combustion Research Optimized Algorithms Boost Combustion Research Methane Flame Simulations Run 6x Faster on NERSC's Hopper Supercomputer November 25,...

128

ALS Evidence Confirms Combustion Theory  

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

ALS Evidence Confirms Combustion Theory ALS Evidence Confirms Combustion Theory Print Wednesday, 22 October 2014 11:43 Researchers recently uncovered the first step in the process...

129

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: ? 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. ? 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. ? 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). ? 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. ? 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. ? 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

130

Consider Compressed Combustion  

E-Print Network [OSTI]

, and costs. In addition, overall advantages for applications involving energy sharing, such as cogeneration are even greater. Thus, compressed combustion should be considered seriously as an economical alternative to conventional heaters, especially in energy...

Crowther, R. H.

1982-01-01T23:59:59.000Z

131

Combustion Air Control  

E-Print Network [OSTI]

calibration and tune-up: ? A measure of combustion efficiency must be selected as a target operating goal for the combustion control system. Possible measures and typical targets include: Stack Gas Excess Air, 15% Stack Gas Opacity, 0.3 RN Stack Gas CO... Fuel Flows ? Preheater Inlet Temperature ? Btu Flow (Fuel Flow ? Preheater Outlet Temperature Controller Measurement) ? Ambient Temperature ? Oxygen in the Stack ? Boiler Master Controller Output ? Opac i ty Normalize the steam, air and fuel flow...

Hughart, C. L.

1979-01-01T23:59:59.000Z

132

Simulation of turbulent explosion of hydrogen-air mixtures  

E-Print Network [OSTI]

]. 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

133

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

134

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

135

Dry low combustion system with means for eliminating combustion noise  

DOE Patents [OSTI]

A combustion system including a plurality of axially staged tubular premixers to control emissions and minimize combustion noise. The combustion system includes a radial inflow premixer that delivers the combustion mixture across a contoured dome into the combustion chamber. The axially staged premixers having a twist mixing apparatus to rotate the fluid flow and cause improved mixing without causing flow recirculation that could lead to pre-ignition or flashback.

Verdouw, Albert J.; Smith, Duane; McCormick, Keith; Razdan, Mohan K.

2004-02-17T23:59:59.000Z

136

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.

137

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

138

Internal combustion engine system  

SciTech Connect (OSTI)

This patent describes an internal combustion engine system comprising: an engine body including a main combustion engine for transmitting the power generated by explosion pressure to a pumping piston and a power transmission apparatus for transmitting to a power crank shaft power that is increased by the ratio of the cross-sectional area of a combustion chamber piston to a power piston. The stroke distance of the combustion chamber piston is equal to that of the power piston; a swash plate-type stirling engine coupled to an exhaust gas outlet of the main combustion engine to be driven by exhaust heat therefrom; a one-stage screw-type compressor coupled by a driving shaft to the swash plate-type stirling engine, thereby generating a great amount of compressed air; a turbo-charger mounted adjacent to a gas outlet of the stirling engine to force a supply of fresh air into the combustion chamber of the main combustion engine; a booster being mounted between a compressed air source and the power transmission apparatus to amplify the air pressure derived from the compressed air source and then provide the amplified air pressure to the power transmission apparatus by operation of a cam in accordance with the rotation of the first crankshaft; compressed air sources being mounted between the compressor and the booster for storing a great amount of compressed air from the compressor; and an accumulator in communication with the power transmission apparatus through a fluid oil pipe, thereby maintaining constant control of the oil pressure in the power transmission apparatus.

Nam, C.W.

1987-01-27T23:59:59.000Z

139

Ris-R-1188(EN) Turbulence and turbulence-  

E-Print Network [OSTI]

Ris-R-1188(EN) Turbulence and turbulence- generated structural loading in wind turbine clusters to ensure sufficient structural sustainability of the wind turbines exposed to "wind farm flow turbulence intensity inside the wind farm and direct-wake turbulence intensity are being devised and a method

140

Internal combustion engine  

DOE Patents [OSTI]

An improved engine is provided that more efficiently consumes difficult fuels such as coal slurries or powdered coal. The engine includes a precombustion chamber having a portion thereof formed by an ignition plug. The precombustion chamber is arranged so that when the piston is proximate the head, the precombustion chamber is sealed from the main cylinder or the main combustion chamber and when the piston is remote from the head, the precombustion chamber and main combustion chamber are in communication. The time for burning of fuel in the precombustion chamber can be regulated by the distance required to move the piston from the top dead center position to the position wherein the precombustion chamber and main combustion chamber are in communication.

Baker, Quentin A. (P.O. Box 6477, San Antonio, TX 78209); Mecredy, Henry E. (1630-C W. 6th, Austin, TX 78703); O'Neal, Glenn B. (6503 Wagner Way, San Antonio, TX 78256)

1991-01-01T23:59:59.000Z

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.


141

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

142

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.

143

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

144

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

145

Theoretical studies on hydrogen ignition and droplet combustion  

E-Print Network [OSTI]

1.2 Droplet Combustion . . . . . . . . . . . . .Combustion . . . . . . . . . . . . . . . . . . . . . . . . . .Lewis, B. and von Elbe, G. Combustion, Flames and Explosions

Del lamo, Gonzalo

2006-01-01T23:59:59.000Z

146

Project Sponsors: UCI Combustion  

E-Print Network [OSTI]

that fuel dilution with CO2 hinders all the NOx routes but has a more significant effect on the thermal mechanisms that lead the formation and emission of NOx in specific applications. · Test the effect of fuel. Combustion System divided into several chemical reactors. Chemical reactor networks to predict NOx emissions

Mease, Kenneth D.

147

Combustion of black liquor  

SciTech Connect (OSTI)

This patent describes an improvement in the combustion of black liquor in an existing Tomlison recovery boiler unit in which black liquor is sprayed into a furnace in which it is successively dried, pyrolyzed and converted to a bed of solid carbonaceous residue, using a primary air stream and a secondary air stream and the residue is subsequently converted to a smelt. The improvement comprises: the addition of between an effective amount up to 5% oxygen by volume to the primary air stream directed at the bed of solid carbonaceous residue, the amount of oxygen added being sufficient to increase the adiabatic flame temperature, the combustion rate of the solid carbonaceous material, the rate of pyrolysis, the temperature in the lower portion of the furnace, the the drying rate of black liquor droplets, and to decrease the temperature of the gases entering the heat transfer surfaces in the upper portion of the furnace and the rate of deposit formation on the surfaces and wherein the amount of black liquor combusted is increased as compared with the amount combusted in the same furnace operated without the addition of oxygen to the primary air.

Mullen, W.T.

1989-08-15T23:59:59.000Z

148

Combined Cycle Combustion Turbines  

E-Print Network [OSTI]

Combined Cycle Combustion Turbines Steven Simmons February 27 2014 1 #12;CCCT Today's Discussion 1 Meeting Pricing of 4 advanced units using information from Gas Turbine World Other cost estimates from E E3 EIA Gas Turbine World California Energy Commission Date 2010 Oct 2012, Dec 2013 Apr 2013 2013 Apr

149

Fragments, Combustion and Earthquakes  

E-Print Network [OSTI]

This paper is devoted to show the advantages of introducing a geometric viewpoint and a non extensive formulation in the description of apparently unrelated phenomena: combustion and earthquakes. Here, it is shown how the introduction of a fragmentation analysis based on that formulation leads to find a common point for description of these phenomena

Oscar Sotolongo-Costa; Antonio Posadas

2005-03-16T23:59:59.000Z

150

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

151

Solution Combustion Synthesis Impregnated Layer Combustion Synthesis is a Novel  

E-Print Network [OSTI]

Systems ·Not suitable for nano-material synthesis Reactive Sample Volume Combustion Product Heaters Self-Propagating High-Temperature Synthesis (SHS) Volume Combustion Synthesis (VCS) Example: TiC #12;· Molecular level;Conventional Combustion System: Characteristics: · Exothermic nature of reaction · High temperature (2000 °C

Mukasyan, Alexander

152

Development of Advanced Combustion Technologies for Increased...  

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

Investigation of fuel effects on low-temperature combustion, particularly HCCI PCCI combustion deer09gehrke.pdf More Documents & Publications The Role of Advanced Combustion in...

153

COMBUSTION-GENERATED INDOOR AIR POLLUTION  

E-Print Network [OSTI]

Pollutants from Indoor Combustion Sources: I. Field Measure-Characteristics in Two Stage Combustion, paper presented atInternational) on Combustion, August, 1974, Tokyo, Japan. 8

Hollowell, C.D.

2011-01-01T23:59:59.000Z

154

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...

155

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

156

GRAVITATIONALLY UNSTABLE FLAMES: RAYLEIGH-TAYLOR STRETCHING VERSUS TURBULENT WRINKLING  

SciTech Connect (OSTI)

In this paper, we provide support for the Rayleigh-Taylor-(RT)-based subgrid model used in full-star simulations of deflagrations in Type Ia supernovae explosions. We use the results of a parameter study of two-dimensional direct numerical simulations of an RT unstable model flame to distinguish between the two main types of subgrid models (RT or turbulence dominated) in the flamelet regime. First, we give scalings for the turbulent flame speed, the Reynolds number, the viscous scale, and the size of the burning region as the non-dimensional gravity (G) is varied. The flame speed is well predicted by an RT-based flame speed model. Next, the above scalings are used to calculate the Karlovitz number (Ka) and to discuss appropriate combustion regimes. No transition to thin reaction zones is seen at Ka = 1, although such a transition is expected by turbulence-dominated subgrid models. Finally, we confirm a basic physical premise of the RT subgrid model, namely, that the flame is fractal, and thus self-similar. By modeling the turbulent flame speed, we demonstrate that it is affected more by large-scale RT stretching than by small-scale turbulent wrinkling. In this way, the RT instability controls the flame directly from the large scales. Overall, these results support the RT subgrid model.

Hicks, E. P. [Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA) and the Department of Physics and Astronomy, Northwestern University, Evanston, IL 60208 (United States); Rosner, R., E-mail: eph2001@columbia.edu [Computation Institute, University of Chicago, 5735 S. Ellis Ave., Chicago, IL 60637 (United States)

2013-07-10T23:59:59.000Z

157

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

Martín, Pino

158

Plasmatron Fuel Reformer Development and Internal Combustion...  

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

Plasmatron Fuel Reformer Development and Internal Combustion Engine Vehicle Applications Plasmatron Fuel Reformer Development and Internal Combustion Engine Vehicle Applications...

159

Transonic Combustion ? - Injection Strategy Development for...  

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

Transonic Combustion - Injection Strategy Development for Supercritical Gasoline Injection-Ignition in a Light Duty Engine Transonic Combustion - Injection Strategy...

160

Stretch Efficiency - Thermodynamic Analysis of New Combustion...  

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

Stretch Efficiency - Thermodynamic Analysis of New Combustion Regimes (Agreement 10037) Stretch Efficiency - Thermodynamic Analysis of New Combustion Regimes (Agreement 10037)...

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

Improving alternative fuel utilization: detailed kinetic combustion...  

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

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

162

Solar wind versus magnetosheath turbulence.  

E-Print Network [OSTI]

order statistics (Number of data points ~ 105) 22 4 !" !" = # # # $ $ b b F ! ! " ! # )()( tbtb bSolar wind versus magnetosheath turbulence. Observations of Alfven vortices. O. Alexandrova A properties of turbulence (hydrodynamics) is independent on the energy injection & dissipation energy

Demoulin, Pascal

163

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

164

Strong Imbalanced Turbulence  

E-Print Network [OSTI]

We consider stationary, forced, imbalanced, or cross-helical MHD Alfvenic turbulence where the waves traveling in one direction have higher amplitudes than the opposite waves. This paper is dedicated to so-called strong turbulence, which cannot be treated perturbatively. Our main result is that the anisotropy of the weak waves is stronger than the anisotropy of a strong waves. We propose that critical balance, which was originally conceived as a causality argument, has to be amended by what we call a propagation argument. This revised formulation of critical balance is able to handle the imbalanced case and reduces to old formulation in the balanced case. We also provide phenomenological model of energy cascading and discuss possibility of self-similar solutions in a realistic setup of driven turbulence.

A. Beresnyak; A. Lazarian

2008-07-07T23:59:59.000Z

165

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

166

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

167

Internal combustion engine using premixed combustion of stratified charges  

DOE Patents [OSTI]

During a combustion cycle, a first stoichiometrically lean fuel charge is injected well prior to top dead center, preferably during the intake stroke. This first fuel charge is substantially mixed with the combustion chamber air during subsequent motion of the piston towards top dead center. A subsequent fuel charge is then injected prior to top dead center to create a stratified, locally richer mixture (but still leaner than stoichiometric) within the combustion chamber. The locally rich region within the combustion chamber has sufficient fuel density to autoignite, and its self-ignition serves to activate ignition for the lean mixture existing within the remainder of the combustion chamber. Because the mixture within the combustion chamber is overall premixed and relatively lean, NO.sub.x and soot production are significantly diminished.

Marriott, Craig D. (Rochester Hills, MI); Reitz, Rolf D. (Madison, WI

2003-12-30T23:59:59.000Z

168

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

169

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

170

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 was developed for the design of low emission combustion systems required for Vision 21 clean energy plants. Vision 21 combustion systems, such as combustors for gas turbines, combustors for indirect fired cycles, furnaces and sequestrian-ready combustion systems, will require innovative low emission designs and low development costs if Vision 21 goals are to be realized. The simulation tool will greatly reduce the number of experimental tests; this is especially desirable for gas turbine combustor design since the cost of the high pressure testing is extremely costly. In addition, the software will stimulate new ideas, will provide the capability of assessing and adapting low-emission combustors to alternate fuels, and will greatly reduce the development time cycle of combustion systems. The revolutionary combustion simulation software is able to accurately simulate the highly transient nature of gaseous-fueled (e.g. natural gas, low BTU syngas, hydrogen, biogas etc.) turbulent combustion and assess innovative concepts needed for Vision 21 plants. In addition, the software is capable of analyzing liquid-fueled combustion systems since that capability was developed under a concurrent Air Force Small Business Innovative Research (SBIR) program. The complex physics of the reacting flow field are captured using 3D Large Eddy Simulation (LES) methods, in which large scale transient motion is resolved by time-accurate numerics, while the small scale motion is modeled using advanced subgrid turbulence and chemistry closures. In this way, LES combustion simulations can model many physical aspects that, until now, were impossible to predict with 3D steady-state Reynolds Averaged Navier-Stokes (RANS) analysis, i.e. very low NOx emissions, combustion instability (coupling of unsteady heat and acoustics), lean blowout, flashback, autoignition, etc. LES methods are becoming more and more practical by linking together tens to hundreds of PCs and performing parallel computations with fine grids (millions of cells). Such simulations, performed in a few weeks or less, provide a very cost-effective complement to experimental testing. In 5 years, these same calculations can be performed in 24 hours or less due to the expected increase of computing power and improved numerical techniques. This project was a four-year program. 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 CFD-ACE+ code. University expertise (Georgia Tech and University of California, 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 implemented into the final release (licensed) version of the combustion LES software 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 DoE SIMVAL cases, and compared predictions with measurements from NETL. In addition to comparisons with NOx and CO exit measurements, comparisons were made to measured pressure oscillations. Potential areas of improvement for combustion and turbulence models were identified. In conclusion, this program advanced the state-of-the-art in combustion LES an

Clifford E. Smith; Steven M. Cannon; Virgil Adumitroaie; David L. Black; Karl V. Meredith

2005-01-01T23:59:59.000Z

171

Wave turbulent statistics in non-weak wave turbulence  

E-Print Network [OSTI]

In wave turbulence, it has been believed that statistical properties are well described by the weak turbulence theory, in which nonlinear interactions among wavenumbers are assumed to be small. In the weak turbulence theory, separation of linear and nonlinear time scales derived from the weak nonlinearity is also assumed. However, the separation of the time scales is often violated even in weak turbulent systems where the nonlinear interactions are actually weak. To get rid of this inconsistency, closed equations are derived without assuming the separation of the time scales in accordance with Direct-Interaction Approximation (DIA), which has been successfully applied to Navier--Stokes turbulence. The kinetic equation of the weak turbulence theory is recovered from the DIA equations if the weak nonlinearity is assumed as an additional assumption. It suggests that the DIA equations is a natural extension of the conventional kinetic equation to not-necessarily-weak wave turbulence.

Naoto Yokoyama

2011-05-08T23:59:59.000Z

172

Sandia National Laboratories: hydrocarbon combus-tion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia,evaluatingfullhigher-performance spar caphydrocarbon combus-tion

173

Sandia National Laboratories: Combustion Research Facility  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy AdvancedEnergyEnergyMappingCombustion Renewable Systems

174

Sandia National Laboratories: Combustion Research Facility  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy AdvancedEnergyEnergyMappingCombustion Renewable SystemsFour

175

Sandia National Laboratories: Combustion Research Facility  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy AdvancedEnergyEnergyMappingCombustion Renewable

176

Sandia National Laboratories: Combustion Research Facility  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy AdvancedEnergyEnergyMappingCombustion

177

Sandia National Laboratories: Combustion Research Facility  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy AdvancedEnergyEnergyMappingCombustionBiofuels On November

178

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

179

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

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

II experiments address the main irreversibilities in unrestrained combustion * 'Internal' heat transfer - Products to reactants heat transfer over large Ts - dS Q Q(1T C -...

180

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

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.


181

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

182

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

183

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...

184

ALS Evidence Confirms Combustion Theory  

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

ALS Evidence Confirms Combustion Theory Print Researchers recently uncovered the first step in the process that transforms gas-phase molecules into solid particles like soot and...

185

Combustion Energy Frontier Research Center  

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

Position in Direct Numerical Simulations of Low-Dimensional Reacting Flows The Combustion EFRC seeks outstanding applicants for the position of post-doctoral research...

186

Utilization ROLE OF COAL COMBUSTION  

E-Print Network [OSTI]

, materials left after combustion of coal in conventional and/ or advanced clean-coal technology combustors and advanced clean-coal technology combustors. This paper describes various coal combustion products produced (FGD) products from pulverized coal and advanced clean-coal technology combustors. Over 70% of the CCPs

Wisconsin-Milwaukee, University of

187

Turbulent Reconnection and Its Implications  

E-Print Network [OSTI]

Magnetic reconnection is a process of magnetic field topology change, which is one of the most fundamental processes in magnetized plasmas. In most astrophysical environments the Reynolds numbers are large and therefore the transition to turbulence is inevitable. This turbulence must be taken into account for any theory of magnetic reconnection, since the initially laminar configurations can transit to the turbulence state, what is demonstrated by 3D high resolution numerical simulations. We discuss ideas of how turbulence can modify reconnection with the focus on the Lazarian & Vishniac (1999) reconnection model and present numerical evidence supporting the model and demonstrate that it is closely connected to the concept of Richardson diffusion and compatible with the Lagrangian dynamics of magnetized fluids. We point out that the Generalized Ohm's Law, that accounts for turbulent motion, predicts the subdominance of the microphysical plasma effects for a realistically turbulent media. We show that on o...

Lazarian, Alex; Vishniac, Ethan T; Kowal, Grzegorz

2015-01-01T23:59:59.000Z

188

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

189

Turbulence in Atomic Hydrogen  

E-Print Network [OSTI]

Understanding the properties of interstellar turbulence is a great intellectual challenge and the urge to solve this problem is partially motivated by a necessity to explain the star formation mystery. This review deals with a recently suggested inversion technique as applied to atomic hydrogen. This technique allows to determine 3D turbulence statistics through the variations of 21 cm intensity. We claim that a radio interferometer is an ideal tool for such a study as its visibility function is directly related to the statistics of galactic HI. Next, we show how galactic rotation curve can be used to study the turbulence slice by slice and relate the statistics given in galactic coordinates and in the velocity space. The application of the technique to HI data reveals a shallow spectrum of the underlying HI density that is not compatible with a naive Kolmogorov picture. We show that the random density corresponding to the found spectrum tends to form low contrast filaments that are elongated towards the observer.

A. Lazarian

1998-04-02T23:59:59.000Z

190

COMBUSTION RESEARCH PROGRAM. CHAPTER FROM ENERGY & ENVIRONMENT ANNUAL REPORT 1977  

E-Print Network [OSTI]

of Combustion in Internal Combustion Engines," Paper 750890,clean burning internal combustion engines. Another importantthat occur in an internal combustion engine. Our goal is the

Authors, Various

2011-01-01T23:59:59.000Z

191

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...

192

Low Temperature Combustion Demonstrator for High Efficiency Clean...  

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

Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion 2009 DOE Hydrogen Program...

193

Low Temperature Combustion Demonstrator for High Efficiency Clean...  

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

Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion Presentation from the U.S....

194

Low-Temperature Combustion Demonstrator for High-Efficiency Clean...  

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

Low-Temperature Combustion Demonstrator for High-Efficiency Clean Combustion Low-Temperature Combustion Demonstrator for High-Efficiency Clean Combustion 2010 DOE Vehicle...

195

High Efficiency, Clean Combustion  

SciTech Connect (OSTI)

Energy use in trucks has been increasing at a faster rate than that of automobiles within the U.S. transportation sector. According to the Energy Information Administration (EIA) Annual Energy Outlook (AEO), a 23% increase in fuel consumption for the U.S. heavy duty truck segment is expected between 2009 to 2020. The heavy duty vehicle oil consumption is projected to grow between 2009 and 2050 while light duty vehicle (LDV) fuel consumption will eventually experience a decrease. By 2050, the oil consumption rate by LDVs is anticipated to decrease below 2009 levels due to CAFE standards and biofuel use. In contrast, the heavy duty oil consumption rate is anticipated to double. The increasing trend in oil consumption for heavy trucks is linked to the vitality, security, and growth of the U.S. economy. An essential part of a stable and vibrant U.S. economy is a productive U.S. trucking industry. Studies have shown that the U.S. gross domestic product (GDP) is strongly correlated to freight transport. Over 90% of all U.S. freight tonnage is transported by diesel power and over 75% is transported by trucks. Given the vital role that the trucking industry plays in the economy, improving the efficiency of the transportation of goods was a central focus of the Cummins High Efficient Clean Combustion (HECC) program. In a commercial vehicle, the diesel engine remains the largest source of fuel efficiency loss, but remains the greatest opportunity for fuel efficiency improvements. In addition to reducing oil consumption and the dependency on foreign oil, this project will mitigate the impact on the environment by meeting US EPA 2010 emissions regulations. Innovation is a key element in sustaining a U.S. trucking industry that is competitive in global markets. Unlike passenger vehicles, the trucking industry cannot simply downsize the vehicle and still transport the freight with improved efficiency. The truck manufacturing and supporting industries are faced with numerous challenges to reduce oil consumption and greenhouse gases, meet stringent emissions regulations, provide customer value, and improve safety. The HECC program successfully reduced engine fuel consumption and greenhouse gases while providing greater customer valve. The US EPA 2010 emissions standard poses a significant challenge for developing clean diesel powertrains that meet the DoE Vehicle Technologies Multi-Year Program Plan (MYPP) for fuel efficiency improvement while remaining affordable. Along with exhaust emissions, an emphasis on heavy duty vehicle fuel efficiency is being driven by increased energy costs as well as the potential regulation of greenhouse gases. An important element of the success of meeting emissions while significantly improving efficiency is leveraging Cummins component technologies such as fuel injection equipment, aftertreatment, turbomahcinery, electronic controls, and combustion systems. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 55% peak brake thermal efficiency for the engine plus aftertreatment system. The first step in developing high efficiency clean products has been supported by the DoE co-sponsored HECC program. The objectives of the HECC program are: (1) To design and develop advanced diesel engine architectures capable of achieving US EPA 2010 emission regulations while improving the brake thermal efficiency by 10% compared to the baseline (a state of the art 2007 production diesel engine). (2) To design and develop components and subsystems (fuel systems, air handling, controls, etc) to enable construction and development of multi-cylinder engines. (3) To perform an assessment of the commercial viability of the newly developed engine technology. (4) To specify fuel properties conducive to improvements in emissions, reliability, and fuel efficiency for engines using high-efficiency clean combustion (HECC) technologies. To demonstrate the technology is compatible with B2

Donald Stanton

2010-03-31T23:59:59.000Z

196

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.

197

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

198

COMBUSTION-GENERATED INDOOR AIR POLLUTION  

E-Print Network [OSTI]

x A Emission Characteristics in Two Stage Combustion. PaperInternational) on Combustion, Tokyo (August, 1974). Chang,fll , J I ___F J "J LBL-S9lS COMBUSTION-GENERATED INDOOR AIR

Hollowell, C.D.

2010-01-01T23:59:59.000Z

199

Protostellar outflow-driven turbulence  

E-Print Network [OSTI]

Protostellar outflows crisscross the regions of star cluster formation, stirring turbulence and altering the evolution of the forming cluster. We model the stirring of turbulent motions by protostellar outflows, building on an observation that the scaling law of supersonic turbulence implies a momentum cascade analogous to the energy cascade in Kolmogorov turbulence. We then generalize this model to account for a diversity of outflow strengths, and for outflow collimation, both of which enhance turbulence. For a single value of its coupling coefficient the model is consistent with turbulence simulations by Li & Nakamura and, plausibly, with observations of the NGC 1333 cluster-forming region. Outflow-driven turbulence is strong enough to stall collapse in cluster-forming regions for several crossing times, relieving the mismatch between star formation and turbulent decay rates. The predicted line-width-size scaling implies radial density indices between -1 and -2 for regions supported by outflow-driven turbulence, with a tendency for steeper profiles in regions that are more massive or have higher column densities.

Christopher D. Matzner

2007-01-01T23:59:59.000Z

200

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

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

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

202

Scalar dissipation rate based flamelet modelling of turbulent premixed flames  

E-Print Network [OSTI]

). . . . . . . . . . . . . . 94 6.10 Comparison of turbulent flame speed expressions to the experimen- tal database of Abdel-Gayed et al. (1987) for two values of flame stretch parameter, K: (i) K = 0.053 and (ii) K = 0.15. . . . . . . 95 x LIST OF FIGURES 7.1 The regime diagram... space variable for c xix Chapter 1 Introduction Combustion is a phenomenon that occurs all around us: a burning candle, a do- mestic boiler, an aircraft engine etc., to name a few instances. Since the dawn of the industrial age, energy derived from...

Kolla, Hemanth

2010-03-16T23:59:59.000Z

203

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

204

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...

205

Progress of the Engine Combustion Network  

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

DOE Office of Vehicle Technologies Program Manager: Gurpreet Singh Introducing the Engine Combustion Network Introducing the Engine Combustion Network * Collaborative modeling...

206

Optimization of Advanced Diesel Engine Combustion Strategies  

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

combustion regimes Approach: Acquire high speed chemi- luminescence movies to understand spatial progression of combustion and the mode of reaction front propagation....

207

Hydrogen engine and combustion control process  

DOE Patents [OSTI]

Hydrogen engine with controlled combustion comprises suction means connected to the crankcase reducing or precluding flow of lubricating oil or associated gases into the combustion chamber.

Swain, Michael R. (Coral Gables, FL); Swain, Matthew N. (Miami, FL)

1997-01-01T23:59:59.000Z

208

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

209

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,...

210

Advanced Combustion Technologies | Department of Energy  

Energy Savers [EERE]

Science & Innovation Clean Coal Advanced Combustion Technologies Advanced Combustion Technologies Joe Yip, a researcher at FE's National Energy Technology Laboratory, uses...

211

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...

212

Optimization of Advanced Diesel Engine Combustion Strategies  

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

- UW-ERC 1 "University Research in Advanced Combustion and Emissions Control" Optimization of Advanced Diesel Engine Combustion Strategies Profs. Rolf Reitz, D. Foster, J....

213

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...

214

Improved Solvers for Advanced Engine Combustion Simulation  

Broader source: Energy.gov [DOE]

Document: ace076_mcnenly_2013_o.pdfTechnology Area: Advanced Combustion; Combustion and Emissions ControlPresenter: Matthew McNenlyPresenting Organization: Lawrence Livermore National Laboratory ...

215

Advanced Combustion and Fuels | Department of Energy  

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

Combustion and Fuels Advanced Combustion and Fuels 2013 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies Program Annual Merit Review and Peer Evaluation Meeting...

216

Combustion-gas recirculation system  

DOE Patents [OSTI]

A combustion-gas recirculation system has a mixing chamber with a mixing-chamber inlet and a mixing-chamber outlet. The combustion-gas recirculation system may further include a duct connected to the mixing-chamber inlet. Additionally, the combustion-gas recirculation system may include an open inlet channel with a solid outer wall. The open inlet channel may extend into the mixing chamber such that an end of the open inlet channel is disposed between the mixing-chamber inlet and the mixing-chamber outlet. Furthermore, air within the open inlet channel may be at a pressure near or below atmospheric pressure.

Baldwin, Darryl Dean (Lacon, IL)

2007-10-09T23:59:59.000Z

217

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...

218

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

219

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

220

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

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

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

222

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

223

Sandia National Laboratories: Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0Energy AdvancedEnergyEnergyMapping

224

Predictive modeling of combustion processes  

E-Print Network [OSTI]

Recently, there has been an increasing interest in improving the efficiency and lowering the emissions from operating combustors, e.g. internal combustion (IC) engines and gas turbines. Different fuels, additives etc. are ...

Sharma, Sandeep, Ph. D. Massachusetts Institute of Technology

2009-01-01T23:59:59.000Z

225

Fuels for Advanced Combustion Engines  

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

2011-2015 MYPP Goals (cross-cut w Advanced Combustion Engines) - By 2015, improve the fuel economy of light-duty gasoline vehicles by 25% and of light-duty diesel vehicles by 40%...

226

Fuels for Advanced Combustion Engines  

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

2011-1015 MYPP Goals (cross-cut w Advanced Combustion Engines) - By 2015, improve the fuel economy of light-duty gasoline vehicles by 25% and of light-duty diesel vehicles by 40%...

227

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

228

Modelling paradigms for MILD combustion  

E-Print Network [OSTI]

agreement because it does not include the effects of reaction zone interactions. Keywords: MILD combustion, Flameless combustion, Direct numerical simulation (DNS), Perfectly stirred reactor (PSR), presumed PDF, LES, RANS, Modelling 2 1 Introduction Moderate... ). In most RANS studies, the mean velocity and temperature fields show consistent trends with the experi- mental results. However, quantitative agreement of the calculated and measured tempera- ture values becomes unsatisfactory as the dilution level...

Minamoto, Y.; Swaminathan, N.

2014-04-26T23:59:59.000Z

229

Twenty-Seventh Symposium (International) on Combustion/The Combustion Institute, 1998/pp. 28152820 FINGERING INSTABILITY IN SOLID FUEL COMBUSTION  

E-Print Network [OSTI]

2815 Twenty-Seventh Symposium (International) on Combustion/The Combustion Institute, 1998/pp. 2815­2820 FINGERING INSTABILITY IN SOLID FUEL COMBUSTION: THE CHARACTERISTIC SCALES OF THE DEVELOPED STATE ORY ZIK, Israel We present new results on the fingering instability in solid fuel combustion. The instability

Moses, Elisha

230

Turbulence Effects at Small Scales  

E-Print Network [OSTI]

It is most natural to assume that mysterious Small Ionized and Neutral Structures (SINS) indiffuse ISM arise from turbulence. There are two obvious problem with such an explanation, however. First of all, it is generally believed that at the small scales turbulence should be damped. Second, turbulence with Kolmogorov spectrum cannot be the responsible for the SINS. We consider, however, effects, that provide spectral index flatter than the Kolmogorov one and allow action at very small scales. These are the shocks that arise in high Mach number turbulence and transfer of energy to small scales by instabilities in cosmic rays. Our examples indicate that the origin of SINS may be discovered through systematic studies of astrophysical turbulence.

A. Beresnyak; A. Lazarian

2006-10-26T23:59:59.000Z

231

Effects of molecular transport on turbulence-chemistry interactions in a hydrogen-argon-air jet diffusion flame  

SciTech Connect (OSTI)

A numerical simulation of entrainment, turbulent advection, molecular import and chemical kinetics in a turbulent diffusion flame is used to investigate effects of molecular transport on turbulence-chemistry interactions. A fun finite-rate chemical mechanism is used to represent the combustion of a hydrogen-argon mixture issuing into air. Results based on incorporation of differential diffusion and variable Lewis number are compared to cases with the former effect, or both-effects, suppressed. Significant impact on radical species production and on NO emission index (based on a reduced mechanism for thermal NO) is found. A reduced mechanism for hydrogen-air combustion, omitting both effects and incorporating other simplifications, performs comparably except that its NO predictions agree well with the case of full chemistry and molecular transport, possibly due to cancellation of errors.

Menon, S.; Calhoon, W.H. Jr.; Goldin, G. [Georgia Inst. of Tech., Atlanta, GA (United States). School of Aerospace Engineering; Kerstein, A.R. [Sandia National Labs., Livermore, CA (United States)

1994-01-01T23:59:59.000Z

232

SPH compressible turbulence  

E-Print Network [OSTI]

In this paper an SPH version of the alpha turbulence model devised by Holm and his colleagues is formulated for compressible flow with a resolution that varies in space and time. The alpha model involves two velocity fields. One velocity field is obtained from the momentum equation, the other by averaging this velocity field as in the version of SPH called XSPH. The particles (fluid elements) are moved with the averaged velocity. In analogy to the continuum alpha model we obtain a particle Lagrangian from which the SPH alpha equations can be derived. The system satisfies a discrete Kelvin circulation theorem identical to that obtained with no velocity averaging. In addition, the energy, linear and angular momentum are conserved. We show that the continuum equivalent of the SPH equations are identical to the continuum alpha model, and we conjecture that they will have the same desirable features of the continuum modelincluding the reduction of energy in the high wave number modes even when the dissipation is zero. Regardless of issues concerning turbulence modelling, the SPH alpha model is a powerful extension of the XSPH algorithm which reduces disorder at short length scales and retains the constants of the motion. The SPH alpha model is simple to implement.

J. J. Monaghan

2002-04-08T23:59:59.000Z

233

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

Gas-Phase Combustion .41 Gas-Phase combustionfor traditional gas- phase combustion modeling are presented

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

234

Generating Resources Combined Cycle Combustion Turbine  

E-Print Network [OSTI]

11/17/2014 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 #12;11/17/2014 4 Combined Cycle Combustion Turbine Background Primary Components Gas-fired combustion

235

COMBUSTION ISSUES AND APPROACHES FOR CHEMICAL MICROTHRUSTERS  

E-Print Network [OSTI]

1 COMBUSTION ISSUES AND APPROACHES FOR CHEMICAL MICROTHRUSTERS Richard A. Yetter, Vigor Yang, Ming and the effects of downsizing on combustion performance. In particular, combustion of liquid nitromethane in a thruster combustion chamber with a volume of 108 mm3 and diameter of 5 mm was experimentally investigated

Yang, Vigor

236

Residential Wood Residential wood combustion (RWC) is  

E-Print Network [OSTI]

Residential Wood Combustion Residential wood combustion (RWC) is increasing in Europe because PM2.5. Furthermore, other combustion- related sources of OA in Europe may need to be reassessed. Will it affect global OA emission estimates? Combustion of biofuels is globally one of the major OA sources

237

The Combustion Institute 5001 Baum Boulevard  

E-Print Network [OSTI]

The Combustion Institute 5001 Baum Boulevard Pittsburgh, Pennsylvania, USA 15213-1851 CENTRAL STATES SECTION OF THE COMBUSTION INSTITUTE CALL FOR PAPERS TECHNICAL MEETING - SPRING 2002 COMBUSTION 7-9, 2002 #12;CENTRAL STATES SECTION OF THE COMBUSTION INSTITUTE www.cssci.org CALL FOR PAPERS

Tennessee, University of

238

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

239

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

240

HCCl 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 has 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.

Aceves, S M; Flowers, D L; Martinez-Frias, J; Smith, J R; Dibble, R; Au, M; Girard, J

2001-05-04T23:59:59.000Z

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

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

242

Wave Decay in MHD Turbulence  

E-Print Network [OSTI]

We present a model for nonlinear decay of the weak wave in three-dimensional incompressible magnetohydrodynamic (MHD) turbulence. We show that the decay rate is different for parallel and perpendicular waves. We provide a general formula for arbitrarily directed waves and discuss particular limiting cases known in the literature. We test our predictions with direct numerical simulations of wave decay in three-dimensional MHD turbulence, and discuss the influence of turbulent damping on the development of linear instabilities in the interstellar medium and on other important astrophysical processes.

Andrey Beresnyak; Alex Lazarian

2008-05-06T23:59:59.000Z

243

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

244

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

245

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

246

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

247

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

248

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

249

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)

250

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

251

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

252

Droplet Combustion and Non-Reactive Shear-Coaxial Jets with Transverse Acoustic Excitation  

E-Print Network [OSTI]

Related Works in Droplet Combustion . . . . . . . .of Acoustics on Droplet Combustion . . . . . . . . . . . .Fuel Droplet Combustion . . . . . . . . . . . . . . .

Teshome, Sophonias

2012-01-01T23:59:59.000Z

253

Structural Analysis of Combustion Models  

E-Print Network [OSTI]

Using ReactionKinetics, a Mathematica based package a few dozen detailed models for combustion of hydrogen, carbon monoxide and methanol are investigated. Essential structural characteristics are pulled out, and similarities and differences of the mechanisms are highlighted. These investigations can be used before or parallel with usual numerical investigations, such as pathway analysis, sensitivity analysis, parameter estimation, or simulation.

Tth, J; Zsly, I

2013-01-01T23:59:59.000Z

254

Method and apparatus for detecting combustion instability in continuous combustion systems  

DOE Patents [OSTI]

An apparatus and method to sense the onset of combustion stability is presented. An electrode is positioned in a turbine combustion chamber such that the electrode is exposed to gases in the combustion chamber. A control module applies a voltage potential to the electrode and detects a combustion ionization signal and determines if there is an oscillation in the combustion ionization signal indicative of the occurrence of combustion stability or the onset of combustion instability. A second electrode held in a coplanar but spaced apart manner by an insulating member from the electrode provides a combustion ionization signal to the control module when the first electrode fails. The control module broadcasts a notice if the parameters indicate the combustion process is at the onset of combustion instability or broadcasts an alarm signal if the parameters indicate the combustion process is unstable.

Benson, Kelly J.; Thornton, Jimmy D.; Richards, George A.; Straub, Douglas L.

2006-08-29T23:59:59.000Z

255

Using Biofuel Tracers to Study Alternative Combustion Regimes  

E-Print Network [OSTI]

1979. J.B. Heywood, Internal Combustion Engine Fundamentals.Introduction to Internal Combustion Engines (3rd Edition).Coefficient in the Internal Combustion Engine, SAE Paper

Mack, John Hunter; Flowers, Daniel L.; Buchholz, Bruce A.; Dibble, Robert W.

2006-01-01T23:59:59.000Z

256

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

J. B. (1988) Internal Combustion Engine Fundamentals.novel microwave internal combustion engine ignition source,in the Internal Combustion Engine." SAE Technical Paper

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

257

Combustion Air Zone (CAZ) Best Practices | Department of Energy  

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

Combustion Air Zone (CAZ) Best Practices Combustion Air Zone (CAZ) Best Practices Combustion Air Zone (CAZ) Best Practices Webinar. Presentation More Documents & Publications...

258

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-...

259

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...

260

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...

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

Using Biofuel Tracers to Study Alternative Combustion Regimes  

E-Print Network [OSTI]

1979. J.B. Heywood, Internal Combustion Engine Fundamentals.Ignition Engine with Optimal Combustion Control. US PatentIntroduction to Internal Combustion Engines (3rd Edition).

Mack, John Hunter; Flowers, Daniel L.; Buchholz, Bruce A.; Dibble, Robert W.

2006-01-01T23:59:59.000Z

262

COMBUSTION SOURCES OF UNREGULATED GAS PHASE NITROGENEOUS SPECIES  

E-Print Network [OSTI]

SAE Paper 750173, 1975. L. , Fifteenth Symposium Combustion,The Combustion Institute, International Pittsburgh, on 64.chemistry of products of combustion: nitrogenous The

Matthews, Ronald D.

2013-01-01T23:59:59.000Z

263

COMBUSTION OF COAL IN AN OPPOSED FLOW DIFFUSION BURNER  

E-Print Network [OSTI]

J.M. , liThe F1uidised Combustion of Coal," Sixteenth Sm osium {International} on Combustion, August 1976 (to beof Various Polymers Under Combustion Conditions," Fourteenth

Chin, W.K.

2010-01-01T23:59:59.000Z

264

Using Biofuel Tracers to Study Alternative Combustion Regimes  

E-Print Network [OSTI]

Simulation of Natural Gas HCCI Combustion: Gas Compositionfor heating the flowing gas. Combustion timing is consideredup. Exhaust gas samples were collected at varying combustion

Mack, John Hunter; Flowers, Daniel L.; Buchholz, Bruce A.; Dibble, Robert W.

2006-01-01T23:59:59.000Z

265

Free Energy and Internal Combustion Engine Cycles  

E-Print Network [OSTI]

The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

Harris, William D

2012-01-01T23:59:59.000Z

266

Free Energy and Internal Combustion Engine Cycles  

E-Print Network [OSTI]

The performance of one type (Carnot) of Internal Combustion Engine (ICE) cycle is analyzed within the framework of thermodynamic free energies. ICE performance is different from that of an External Combustion Engine (ECE) which is dictated by Carnot's rule.

William D. Harris

2012-01-11T23:59:59.000Z

267

Formation mechanisms of combustion chamber deposits  

E-Print Network [OSTI]

Combustion chamber deposits are found in virtually all internal combustion engines after a few hundred hours of operation. Deposits form on cylinder, piston, and head surfaces that are in contact with fuel-air mixture ...

O'Brien, Christopher J. (Christopher John)

2001-01-01T23:59:59.000Z

268

Light Duty Efficient, Clean Combustion  

SciTech Connect (OSTI)

Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energy's Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of the following objectives were met with fuel efficiency improvement targets exceeded: (1) Improve light duty vehicle (5000 lb. test weight) fuel efficiency by 10.5% over today's state-of-the-art diesel engine on the FTP city drive cycle; (2) Develop and design an advanced combustion system plus aftertreatment system that synergistically meets Tier 2 Bin 5 NOx and PM emissions standards while demonstrating the efficiency improvements; (3) Maintain power density comparable to that of current conventional engines for the applicable vehicle class; and (4) Evaluate different fuel components and ensure combustion system compatibility with commercially available biofuels. Key accomplishments include: (1) A 25% improvement in fuel efficiency was achieved with the advanced LDECC engine equipped with a novel SCR aftertreatment system compared to the 10.5% target; (2) An 11% improvement in fuel efficiency was achieved with the advanced LDECC engine and no NOx aftertreamtent system; (3) Tier 2 Bin 5 and SFTP II emissions regulations were met with the advanced LDECC engine equipped with a novel SCR aftertreatment system; (4) Tier 2 Bin 5 emissions regulations were met with the advanced LDECC engine and no NOx aftertreatment, but SFTP II emissions regulations were not met for the US06 test cycle - Additional technical barriers exist for the no NOx aftertreatment engine; (5) Emissions and efficiency targets were reached with the use of biodiesel. A variety of biofuel feedstocks (soy, rapeseed, etc.) was investigated; (6) The advanced LDECC engine with low temperature combustion was compatible with commercially available biofuels as evaluated by engine performance testing and not durability testing; (7) The advanced LDECC engine equipped with a novel SCR aftertreatment system is the engine system architecture that is being further developed by the Cummins product development organization. Cost reduction and system robustness activities have been identified for future deployment; (8) The new engine and aftertreatment component technologies are being developed by the Cummins Component Business units (e.g. fuel system, turbomachinery, aftertreatment, electronics, etc.) to ensure commercial viability and deployment; (9) Cummins has demonstrated that the technologies developed for this program are scalable across the complete light duty engine product offerings (2.8L to 6.7L engines); and (10) Key subsystems developed include - sequential two stage turbo, combustions system for low temperature combustion, novel SCR aftertreatment system with feedback control, and high pressure common rail fuel system. An important element of the success of this project was leveraging Cummins engine component technologies. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 40% improvement in thermal efficiency for the engine plus aftertreatment system. The 40% improvement is in-line with the current light duty vehicle efficiency targets set by the 2010 DoE Vehicle Technologies MYPP and supported through co-operative projects such as the Cummins Advanced Technology Powertrains for Light-Duty Vehicles (ATP-LD) started in 2010.

Donald Stanton

2010-12-31T23:59:59.000Z

269

Light Duty Efficient, Clean Combustion  

SciTech Connect (OSTI)

Cummins has successfully completed the Light Duty Efficient Clean Combustion (LDECC) cooperative program with DoE. This program was established in 2007 in support of the Department of Energys Vehicles Technologies Advanced Combustion and Emissions Control initiative to remove critical barriers to the commercialization of advanced, high efficiency, emissions compliant internal combustion (IC) engines for light duty vehicles. Work in this area expanded the fundamental knowledge of engine combustion to new regimes and advanced the knowledge of fuel requirements for these diesel engines to realize their full potential. All of the following objectives were met with fuel efficiency improvement targets exceeded: 1. Improve light duty vehicle (5000 lb. test weight) fuel efficiency by 10.5% over todays state-ofthe- art diesel engine on the FTP city drive cycle 2. Develop & design an advanced combustion system plus aftertreatment system that synergistically meets Tier 2 Bin 5 NOx and PM emissions standards while demonstrating the efficiency improvements. 3. Maintain power density comparable to that of current conventional engines for the applicable vehicle class. 4. Evaluate different fuel components and ensure combustion system compatibility with commercially available biofuels. Key accomplishments include: ? A 25% improvement in fuel efficiency was achieved with the advanced LDECC engine equipped with a novel SCR aftertreatment system compared to the 10.5% target ? An 11% improvement in fuel efficiency was achieved with the advanced LDECC engine and no NOx aftertreamtent system ? Tier 2 Bin 5 and SFTP II emissions regulations were met with the advanced LDECC engine equipped with a novel SCR aftertreatment system ? Tier 2 Bin 5 emissions regulations were met with the advanced LDECC engine and no NOx aftertreatment, but SFTP II emissions regulations were not met for the US06 test cycle Additional technical barriers exist for the no NOx aftertreatment engine ? Emissions and efficiency targets were reached with the use of biodiesel. A variety of biofuel feedstocks (soy, rapeseed, etc.) was investigated. ? The advanced LDECC engine with low temperature combustion was compatible with commercially available biofuels as evaluated by engine performance testing and not durability testing. ? The advanced LDECC engine equipped with a novel SCR aftertreatment system is the engine system architecture that is being further developed by the Cummins product development organization. Cost reduction and system robustness activities have been identified for future deployment. ? The new engine and aftertreatment component technologies are being developed by the Cummins Component Business units (e.g. fuel system, turbomachinery, aftertreatment, electronics, etc.) to ensure commercial viability and deployment ? Cummins has demonstrated that the technologies developed for this program are scalable across the complete light duty engine product offerings (2.8L to 6.7L engines) ? Key subsystems developed include sequential two stage turbo, combustions system for low temperature combustion, novel SCR aftertreatment system with feedback control, and high pressure common rail fuel system An important element of the success of this project was leveraging Cummins engine component technologies. Innovation in component technology coupled with system integration is enabling Cummins to move forward with the development of high efficiency clean diesel products with a long term goal of reaching a 40% improvement in thermal efficiency for the engine plus aftertreatment system. The 40% improvement is in-line with the current light duty vehicle efficiency targets set by the 2010 DoE Vehicle Technologies MYPP and supported through co-operative projects such as the Cummins Advanced Technology Powertrains for Light- Duty Vehicles (ATP-LD) started in 2010.

Stanton, Donald W

2011-06-03T23:59:59.000Z

270

Stretch Efficiency for Combustion Engines: Exploiting New Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of Energy Strain Rate Characterization ofDepartmentRegimes | Department

271

Stretch Efficiency for Combustion Engines: Exploiting New Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of Energy Strain Rate Characterization ofDepartmentRegimes |

272

Stretch Efficiency for Combustion Engines: Exploiting New Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of Energy Strain Rate Characterization ofDepartmentRegimes |Regimes |

273

Introduction to statistical turbulence modelling. Overview, RWTH Aachen, 08./09.03.2010 Introduction to statistical turbulence modelling  

E-Print Network [OSTI]

transfer of Momentum Turbulent (Reynolds) stresses Heat Turbulent heat flux Mass Turbulent: Fundamental equations Averaging Flow equations Turbulence equations Part II: Characteristics, RWTH Aachen, 08.03.2010 Reynolds' experiment: Inject dye into pipe flow Observe filament at different

274

FLUIDIZED BED COMBUSTION UNIT FOR OIL SHALE  

E-Print Network [OSTI]

combustion performance using oil shale as fuel in direct burning process. It is a steel column of 18 cm

M. Hammad; Y. Zurigat; S. Khzai; Z. Hammad; O. Mubydeem

275

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...

276

Separation of regenerated catalyst from combustion products  

SciTech Connect (OSTI)

A method and apparatus for separating regenerated catalyst from gaseous combustion products within a regenerator. The apparatus comprises a downcomer within the regenerator vessel through which the catalyst and gaseous combustion products flow. Means are provided at the lower end of the downcomer for utilizing the momentum of the catalyst particles to separate them from the gaseous combustion products.

Benslay, R. M.

1984-10-16T23:59:59.000Z

277

Combustion joining of refractory materials: Carboncarbon composites  

E-Print Network [OSTI]

Combustion joining of refractory materials: Carbon­carbon composites Jeremiah D.E. White Department­carbon composite is achieved by employing self-sustained, oxygen-free, high-temperature combustion reactions to a used "core" to produce a brake that meets the performance specifications. The combustion-joining (CJ

Mukasyan, Alexander

278

INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING  

E-Print Network [OSTI]

INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING FOR GAS TURBINE Prepared For: California Energy REPORT (FAR) INTEGRAL CATALYTIC COMBUSTION/FUEL REFORMING FOR GAS TURBINE CYCLES EISG AWARDEE University://www.energy.ca.gov/research/index.html. #12;Page 1 Integral Catalytic Combustion/Fuel Reforming for Gas Turbine Cycles EISG Grant # 99

279

Understanding Combustion Processes Through Microgravity Research  

E-Print Network [OSTI]

such as Lewis number effects. Examples from premixed-gas combustion, non-premixed gas-jet flames, droplet. COMPARISON OF TIME SCALES FOR PREMIXED-GAS COMBUSTION To determine the conditions where gravity can affectUnderstanding Combustion Processes Through Microgravity Research Paul D. Ronney Department

280

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

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

ME 6990 -Combustion Catalog Data: ME 6990: Combustion. Sem. 2. Class 3, Credit 3 (el.).  

E-Print Network [OSTI]

ME 6990 - Combustion Catalog Data: ME 6990: Combustion. Sem. 2. Class 3, Credit 3 (el.). Physical and chemical aspects of basic combustion phenomena. Classification of flames. Measurement of laminar flame. Fuels. Atomization and evaporation of liquid fuels. Theories of ignition, stability and combustion

Panchagnula, Mahesh

282

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

E-Print Network [OSTI]

Supersonic combustion studies using a multivariate quadrature based method for combustion modeling function (PDF) of thermochemical variables can be used for accurately computing the combustion source term of predictive models for supersonic combustion is a critical step in design and development of scramjet engines

Raman, Venkat

283

Low Temperature Combustion Demonstrator for High Efficiency Clean Combustion  

SciTech Connect (OSTI)

The project which extended from November 2005 to May of 2010 demonstrated the application of Low Temperature Combustion (LTC) with engine out NOx levels of 0.2 g/bhp-hr throughout the program target load of 12.6bar BMEP. The project showed that the range of loads could be extended to 16.5bar BMEP, therefore matching the reference lug line of the base 2007 MY Navistar 6.4L V8 engine. Results showed that the application of LTC provided a dramatic improvement over engine out emissions when compared to the base engine. Furthermore LTC improved thermal efficiency by over 5% from the base production engine when using the steady state 13 mode composite test as a benchmark. The key enablers included improvements in the air, fuel injection, and cooling systems made in Phases I and II. The outcome was the product of a careful integration of each component under an intelligent control system. The engine hardware provided the conditions to support LTC and the controller provided the necessary robustness for a stable combustion. Phase III provided a detailed account on the injection strategy used to meet the high load requirements. During this phase, the control strategy was implemented in a production automotive grade ECU to perform cycle-by-cycle combustion feedback on each of the engine cylinders. The control interacted on a cycle base with the injection system and with the Turbo-EGR systems according to their respective time constants. The result was a unique system that could, first, help optimize the combustion system and maintain high efficiency, and secondly, extend the steady state results to the transient mode of operation. The engine was upgraded in Phase IV with a Variable Valve Actuation system and a hybrid EGR loop. The impact of the more versatile EGR loop did not provide significant advantages, however the application of VVA proved to be an enabler to further extend the operation of LTC and gain considerable benefits in fuel economy and soot reduction. Finally, the transient demonstration was performed in Phase IV. The project demonstrated the achievement of meeting US10 emissions without NOx aftertreatment. The successful execution of the project has served to highlight the effectiveness of closely matched combustion predictive tools to engine testing. It has further served to highlight the importance of key technologies and future areas of research and development. In this regard, recommendations are made towards further improvements in the areas of engine hardware, fuel injection systems, controls and fuels.

Ojeda, William de

2010-07-31T23:59:59.000Z

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

Martín, 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

Martín, Pino

286

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

287

Coal combustion by wet oxidation  

SciTech Connect (OSTI)

The combustion of coal by wet oxidation was studied by the Center for Waste Management Programs, of Michigan Technological University. In wet oxidation a combustible material, such as coal, is reacted with oxygen in the presence of liquid water. The reaction is typically carried out in the range of 204/sup 0/C (400/sup 0/F) to 353/sup 0/C (650/sup 0/F) with sufficient pressure to maintain the water present in the liquid state, and provide the partial pressure of oxygen in the gas phase necessary to carry out the reaction. Experimental studies to explore the key reaction parameters of temperature, time, oxidant, catalyst, coal type, and mesh size were conducted by running batch tests in a one-gallon stirred autoclave. The factors exhibiting the greatest effect on the extent of reaction were temperature and residence time. The effect of temperature was studied from 204/sup 0/C (400/sup 0/F) to 260/sup 0/C (500/sup 0/F) with a residence time from 600 to 3600 seconds. From this data, the reaction activation energy of 2.7 x 10/sup 4/ calories per mole was determined for a high-volatile-A-Bituminous type coal. The reaction rate constant may be determined at any temperature from the activation energy using the Arrhenius equation. Additional data were generated on the effect of mesh size and different coal types. A sample of peat was also tested. Two catalysts were evaluated, and their effects on reaction rate presented in the report. In addition to the high temperature combustion, low temperature desulfurization is discussed. Desulfurization can improve low grade coal to be used in conventional combustion methods. It was found that 90% of the sulfur can be removed from the coal by wet oxidation with the carbon untouched. Further desulfurization studies are indicated.

Bettinger, J.A.; Lamparter, R.A.; McDowell, D.C.

1980-11-15T23:59:59.000Z

288

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

289

Turbulence and Magnetic Fields in Clouds  

E-Print Network [OSTI]

We discuss several categories of models which may explain the IMF, including the possible role of turbulence and magnetic fields.

Shantanu Basu

2004-11-15T23:59:59.000Z

290

Combustion in Homogeneous Charge Compression Ignition Engines: Experiments and Detailed Chemical Kinetic Simulations  

SciTech Connect (OSTI)

Homogeneous charge compression ignition (HCCI) engines are being considered as an alternative to diesel engines. The HCCI concept involves premixing fuel and air prior to induction into the cylinder (as is done in current spark-ignition engine) then igniting the fuel-air mixture through the compression process (as is done in current diesel engines). The combustion occurring in an HCCI engine is fundamentally different from a spark-ignition or Diesel engine in that the heat release occurs as a global autoignition process, as opposed to the turbulent flame propagation or mixing controlled combustion used in current engines. The advantage of this global autoignition is that the temperatures within the cylinder are uniformly low, yielding very low emissions of oxides of nitrogen (NO{sub x}, the chief precursors to photochemical smog). The inherent features of HCCI combustion allows for design of engines with efficiency comparable to, or potentially higher than, diesel engines. While HCCI engines have great potential, several technical barriers exist which currently prevent widespread commercialization of this technology. The most significant challenge is that the combustion timing cannot be controlled by typical in-cylinder means. Means of controlling combustion have been demonstrated, but a robust control methodology that is applicable to the entire range of operation has yet to be developed. This research focuses on understanding basic characteristics of controlling and operating HCCI engines. Experiments and detailed chemical kinetic simulations have been applied to the characterize some of the fundamental operational and design characteristics of HCCI engines. Experiments have been conducted on single and multi-cylinder engines to investigate general features of how combustion timing affects the performance and emissions of HCCI engines. Single-zone modeling has been used to characterize and compare the implementation of different control strategies. Multi-zone modeling has been applied to investigate combustion chamber design with respect to increasing efficiency and reducing emissions in HCCI engines.

Flowers, D L

2002-06-07T23:59:59.000Z

291

COMBUSTION RESEARCH PROGRAM. CHAPTER FROM ENERGY & ENVIRONMENT ANNUAL REPORT 1977  

E-Print Network [OSTI]

of Combustion in Internal Combustion Engines," Paper 750890,that occur in an internal combustion engine. Our goal is theLAG process in an internal combustion engine, con- ducted at

Authors, Various

2011-01-01T23:59:59.000Z

292

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

293

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

294

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

295

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

296

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

Martín, Pino

297

Numerical Study of a Turbulent Hydraulic Jump  

E-Print Network [OSTI]

Numerical Study of a Turbulent Hydraulic Jump Qun Zhao, Shubhra Misra, Ib. A. Svendsen and James T of a Turbulent Hydraulic Jump p.1/14 #12;Objective Our ultimate goal is to study the breaking waves. Numerical Study of a Turbulent Hydraulic Jump p.2/14 #12;A moving bore Qiantang Bore China (Courtesy of Dr J

Zhao, Qun

298

Stability, Energetics, and Turbulent Transport in  

E-Print Network [OSTI]

fields" Department of Astrophysical Sciences Spring Colloquium Steve Cowley (UK Atomic Energy Authority of solar-wind turbulence" Chris Chen (UC Berkeley) 2:40pm "Energy spectra in MHD turbulenceStability, Energetics, and Turbulent Transport in Astrophysical, Fusion, and Solar Plasmas 8

Torquato, Salvatore

299

Method and device for diagnosing and controlling combustion instabilities in internal combustion engines operating in or transitioning to homogeneous charge combustion ignition mode  

SciTech Connect (OSTI)

This invention is a method of achieving stable, optimal mixtures of HCCI and SI in practical gasoline internal combustion engines comprising the steps of: characterizing the combustion process based on combustion process measurements, determining the ratio of conventional and HCCI combustion, determining the trajectory (sequence) of states for consecutive combustion processes, and determining subsequent combustion process modifications using said information to steer the engine combustion toward desired behavior.

Wagner, Robert M [Knoxville, TN; Daw, Charles S [Knoxville, TN; Green, Johney B [Knoxville, TN; Edwards, Kevin D [Knoxville, TN

2008-10-07T23:59:59.000Z

300

Effects of Advanced Combustion Technologies on Particulate Matter...  

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

Effects of Advanced Combustion Technologies on Particulate Matter Emissions Characteristics Effects of Advanced Combustion Technologies on Particulate Matter Emissions...

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

Turbulence transport with nonlocal interactions  

SciTech Connect (OSTI)

This preliminary report describes a variety of issues in turbulence transport analysis with particular emphasis on closure procedures that are nonlocal in wave-number and/or physical space. Anomalous behavior of the transport equations for large scale parts of the turbulence spectrum are resolved by including the physical space nonlocal interactions. Direct and reverse cascade processes in wave-number space are given a much richer potential for realistic description by the nonlocal formulations. The discussion also describes issues, many still not resolved, regarding new classes of self-similar form functions.

Linn, R.R.; Clark, T.T.; Harlow, F.H.; Turner, L.

1998-03-01T23:59:59.000Z

302

Combustion diagnostic for active engine feedback control  

DOE Patents [OSTI]

This invention detects the crank angle location where combustion switches from premixed to diffusion, referred to as the transition index, and uses that location to define integration limits that measure the portions of heat released during the combustion process that occur during the premixed and diffusion phases. Those integrated premixed and diffusion values are used to develop a metric referred to as the combustion index. The combustion index is defined as the integrated diffusion contribution divided by the integrated premixed contribution. As the EGR rate is increased enough to enter the low temperature combustion regime, PM emissions decrease because more of the combustion process is occurring over the premixed portion of the heat release rate profile and the diffusion portion has been significantly reduced. This information is used to detect when the engine is or is not operating in a low temperature combustion mode and provides that feedback to an engine control algorithm.

Green, Jr., Johney Boyd (Knoxville, TN); Daw, Charles Stuart (Knoxville, TN); Wagner, Robert Milton (Knoxville, TN)

2007-10-02T23:59:59.000Z

303

TOXIC SUBSTANCES FROM COAL COMBUSTION  

SciTech Connect (OSTI)

The Clean Air Act Amendments of 1990 identify a number of hazardous air pollutants (HAPs) as candidates for regulation. Should regulations be imposed on HAP emissions from coal-fired power plants, a sound understanding of the fundamental principles controlling the formation and partitioning of toxic species during coal combustion will be needed. With support from the Federal Energy Technology Center (FETC), the Electric Power Research Institute, the Lignite Research Council, and VTT (Finland), Physical Sciences Inc. (PSI) has teamed with researchers from USGS, MIT, the University of Arizona (UA), the University of Kentucky (UK), the University of Connecticut (UC), the University of Utah (UU) and the University of North Dakota Energy and Environmental Research Center (EERC) to develop a broadly applicable emissions model useful to regulators and utility planners. The new Toxics Partitioning Engineering Model (ToPEM) will be applicable to all combustion conditions including new fuels and coal blends, low-NO combustion systems, and new power generation x plants. Development of ToPEM will be based on PSI's existing Engineering Model for Ash Formation (EMAF). This report covers the reporting period from 1 July 1998 through 30 September 1998. During this period distribution of all three Phase II coals was completed. Standard analyses for the whole coal samples were also completed. Mssbauer analysis of all project coals and fractions received to date has been completed in order to obtain details of the iron mineralogy. The analyses of arsenic XAFS data for two of the project coals and for some high arsenic coals have been completed. Duplicate splits of the Ohio 5,6,7 and North Dakota lignite samples were taken through all four steps of the selective leaching procedure. Leaching analysis of the Wyodak coal has recently commenced. Preparation of polished coal/epoxy pellets for probe/SEM studies is underway. Some exploratory mercury LIII XAFS work was carried out during August at the Advanced Photon Source (APS), the new synchrotron facility at Argonne National Laboratory, Chicago, IL. Further analysis of small-scale combustion experiments conducted at PSI in Phase I was completed this quarter. The results of these experiments for the first time suggest almost complete vaporization of certain trace elements (Se, Zn) from coal combustion in the flame zone, in accordance with theoretical equilibrium predictions. Other elements (As, Sb, Cr) appeared considerably less volatile and may react with constituents in the bulk ash at combustion temperatures. The combustion section of the University of Arizona's Downflow Combustor was completely rebuilt. The University of Utah worked on setting up EPA Method 26A to give the capability to measure chlorine in flue gas. The chlorine kinetic calculations performed as part of the Phase I program were found to have an error in the initial conditions. Therefore, the calculations were re-done this quarter with the correct starting conditions. Development of a quasi-empirical emissions model based on reported emissions of particulate matter from field measurements was continued this quarter. As a first step in developing the ToPEM, we developed a sub-model that calculates the evaporation of major elements (Na, K, Fe, Si, Al, Ca and Mg) from both inherent and extraneous minerals of coal. During this quarter, this sub-model was included into EMAF, which formed the ToPEM. Experimental data from the Phase I program were used to test and modify the sub-model and the ToPEM.

A KOLKER; AF SAROFIM; CL SENIOR; FE HUGGINS; GP HUFFMAN; I OLMEZ; J LIGHTY; JOL WENDT; JOSEPH J HELBLE; MR AMES; N YAP; R FINKELMAN; T PANAGIOTOU; W SEAMES

1998-12-08T23:59:59.000Z

304

Combustor nozzle for a fuel-flexible combustion system  

DOE Patents [OSTI]

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

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

2011-03-22T23:59:59.000Z

305

Stretch Efficiency for Combustion Engines: Exploiting New Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of Energy Strain Rate Characterization ofDepartmentRegimes | Department of

306

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

307

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

308

Finite-rate chemistry and transient effects in Direct Numerical Simulations of turbulent non-premixed flames  

SciTech Connect (OSTI)

Three-dimensional Direct Numerical Simulations (DNS) of turbulent non-premixed 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 chosen to model methane-air combustion, and (2) a two-step reaction model to simulate radical production and consumption and to compare against the single-step model. The model problem consists of the interaction between an initially unstrained 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 with 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 the observed high concentrations of reaction intermediates.

Mahalingam, S. [Colorado Univ., Boulder, CO (United States). Dept. of Mechanical Engineering; Chen, J.H. [Sandia National Labs., Livermore, CA (United States); Vervisch, L. [Institut de Mecanique des Fluides, Numeriques (France)

1994-01-01T23:59:59.000Z

309

Turbulent Compressibilty of Protogalactic Gas  

E-Print Network [OSTI]

The star formation rate in galaxies should be related to the fraction of gas that can attain densities large enough for gravitational collapse. In galaxies with a turbulent interstellar medium, this fraction is controlled by the effective barotropic index $gamma = dlog P/dlog (rho)$ which measures the turbulent compressibility. When the cooling timescale is smaller than the dynamical timescale, gamma can be evaluated from the derivatives of cooling and heating functions, using the condition of thermal equilibrium. We present calculations of gamma for protogalaxies in which the metal abundance is so small that H_2 and HD cooling dominates. For a heating rate independent of temperature and proportional to the first power of density, the turbulent gas is relatively "hard", with $gamma >= 1$, at large densities, but moderately "soft", $gamma <= 0.8$, at densities below around $10^4 cm^(-3)$. At low temperatures the density probability distribution should fall ra pidly for densities larger than this value, which corresponds physically to the critical density at which collisional and radiative deexcitation rate s of HD are equal. The densities attained in turbulent protogalaxies thus depend on the relatively large deuterium abundance in our universe. We expect the same physical effect to occur in higher metallicity gas with different coolants. The case in which adiabatic (compressional) heating due to cloud collapse dominates is also discussed, and suggests a criterion for the maximum mass of Population III stars.

John Scalo; Anirban Biswas

2001-11-09T23:59:59.000Z

310

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

311

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

312

Advanced Combustion | Argonne National Laboratory  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmospheric Optical Depth (AOD)ProductssondeadjustsondeadjustAbout the Building TechnologiesS1!4TCombustion Advanced Combustion

313

The Role of Advanced Combustion in Improving Thermal Efficiency |  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion |Energy Usage »of EnergyThe Energy DepartmentCategory 2 NuclearThe Road to

314

Sandia National Laboratories: internal combustion engine fuel efficiency  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1developmentturbine blade manufacturing therenewables Sandia,internal combustion

315

Multicylinder Diesel Engine for Low Temperature Combustion Operation |  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious RankCombustion | Department ofT ib l L d F S i DOEToward a Peaceful Nuclear FutureSlide 1Energy

316

An ignition and combustion model based on the level-set method for spark ignition engine multidimensional modeling  

SciTech Connect (OSTI)

To improve the prediction accuracy of the spark ignition and combustion processes in spark ignition engines, improved ignition and flame propagation models have been developed and implemented in the CFD code, KIVA-3V. An equation to calculate the spark ignition kernel growth rate is derived that considers the effects of the spark ignition discharge energy and flow turbulence on the ignition kernel growth. In addition, a flamelet combustion model based on the G equation combustion model was developed and implemented. To test the ignition and combustion models, they were applied to a homogeneous charge pancake-shaped-combustion-chamber engine, in which experimental heat flux data from probes in the engine head and cylinder liner were available. By comparing the flame arrival timings with the simulation predictions, the ignition and combustion models were validated. In addition, the models were also applied to a homogeneous charge propane-fueled SI engine. Good agreement with experimental cylinder pressures and NO{sub x} data was obtained as a function of ignition timing, engine speed, and EGR levels. (author)

Tan, Zhichao; Reitz, Rolf D. [Engine Research Center, University of Wisconsin-Madison, 1500 Engineering Drive, Madison, WI 53706 (United States)

2006-04-15T23:59:59.000Z

317

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

318

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

319

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

320

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

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

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

322

Combustion Control and Diagnostics Sensor Testing in a Thermal Barrier Coated Combustor  

SciTech Connect (OSTI)

The combustion control and diagnostics sensor (CCADS) continues to be developed as an in-situ combustion sensor, with immediate application to natural gas fired turbines. In-situ combustion monitoring is also expected to benefit advanced power plants of the future, fueled by coal-derived syngas, liquified natural gas (LNG), hydrogen, or hydrogen blend fuels. The in-situ monitoring that CCADS provides can enable the optimal operation of advanced, fuel-flexible turbines for minimal pollutant emissions and maximum efficiency over the full operating range of an advanced turbine. Previous work has demonstrated CCADS as a useful sensor for in-situ monitoring of natural gas combustion, including detection of important combustion events such as flashback and lean blowoff, in experimental combustors without thermal barrier coatings (TBC). Since typical TBC materials are electrical insulators at room temperature, and CCADS operation requires conduction of electrical current to the walls of the combustor, a TBC on the combustion liner was identified as a potential barrier to CCADS operation in commercial application. This paper reports on CCADS experiments in a turbulent lean premixed combustor with a yttria-stabilized zirconia (YSZ) thermal barrier coating on the combustor wall. The tests were conducted at 0.1 MPa (1 atm), with a 15V excitation voltage on the CCADS electrodes. The results confirm that for a typical thermal barrier coating, CCADS operates properly, and the total measured average resistance is close to that of an uncoated combustor. This result is consistent with previous materials studies that found the electrical resistance of typical TBC materials considerably decreases at combustor operating temperatures.

Chorpening, B.T.; Dukes, M.G.; Robey, E.H.; Thornton, J.D.

2007-05-01T23:59:59.000Z

323

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

324

Investigation of Flow, Turbulence, and Dispersion within Built Environments  

E-Print Network [OSTI]

T. Hydrogen-fueled internal combustion engines. Progress incontrol technology in internal combustion engines (ICEs) wasHydrogen use in internal combustion engines. 2001. http://

Pan, Hansheng

2011-01-01T23:59:59.000Z

325

Engine valve actuation for combustion enhancement  

DOE Patents [OSTI]

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-strokes combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

2008-03-04T23:59:59.000Z

326

Engine Valve Actuation For Combustion Enhancement  

DOE Patents [OSTI]

A combustion chamber valve, such as an intake valve or an exhaust valve, is briefly opened during the compression and/or power strokes of a 4-stroke combustion cycle in an internal combustion engine (in particular, a diesel or CI engine). The brief opening may (1) enhance mixing withing the combustion chamber, allowing more complete oxidation of particulates to decrease engine emissions; and/or may (2) delay ignition until a more desirable time, potentially allowing a means of timing ignition in otherwise difficult-to-control conditions, e.g., in HCCI (Homogeneous Charge Compression Ignition) conditions.

Reitz, Rolf Deneys (Madison, WI); Rutland, Christopher J. (Madison, WI); Jhavar, Rahul (Madison, WI)

2004-05-18T23:59:59.000Z

327

Stretch Efficiency - Thermodynamic Analysis of New Combustion...  

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

6 Managed by UT-Battelle for the Department of Energy 1 2 Largest losses: wall heat transfer, unrecovered exhaust energy, and combustion irreversibility * Availability ...

328

Plasmatron Fuel Reformer Development and Internal Combustion...  

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

and Internal Combustion Engine Vehicle Applications* L. Bromberg MIT Plasma Science and Fusion Center Cambridge MA 02139 * Work supported by US Department of Energy, Office of...

329

Spray Combustion Cross-Cut Engine Research  

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

Understanding direct-injection sprays CFD model improvement for engine designoptimization 2 The role of spray combustion research for high- efficiency engines. Future...

330

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...

331

Vehicle Technologies Office: 2014 Advanced Combustion Engine...  

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

Advanced Combustion Engine research and development (R&D) subprogram within the DOE Vehicle Technologies Office (VTO) provides support and guidance for many cutting-edge automotive...

332

Fuel Modification t Facilitate Future Combustion Regimes?  

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

University of Wisconsin -- Engine Research Center Fuel Modification to Facilitate Future Combustion Regimes? David E. Foster Phil and Jean Myers Professor Engine Research Center...

333

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...

334

Advanced Combustion Concepts - Enabling Systems and Solutions...  

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

Evaluation Meeting ace066yilmaz2013o.pdf More Documents & Publications Advanced Combustion Concepts - Enabling Systems and Solutions (ACCESS) for High Efficiency Light Duty...

335

Combustion with reduced carbon in the ash  

DOE Patents [OSTI]

Combustion of coal in which oxygen is injected into the coal as it emerges from burner produces ash having reduced amounts of carbon.

Kobayashi, Hisashi; Bool III, Lawrence E.

2005-12-27T23:59:59.000Z

336

Inclusion of turbulence in solar modeling  

E-Print Network [OSTI]

The general consensus is that in order to reproduce the observed solar p-mode oscillation frequencies, turbulence should be included in solar models. However, until now there has not been any well-tested efficient method to incorporate turbulence into solar modeling. We present here two methods to include turbulence in solar modeling within the framework of the mixing length theory, using the turbulent velocity obtained from numerical simulations of the highly superadiabatic layer of the sun at three stages of its evolution. The first approach is to include the turbulent pressure alone, and the second is to include both the turbulent pressure and the turbulent kinetic energy. The latter is achieved by introducing two variables: the turbulent kinetic energy per unit mass, and the effective ratio of specific heats due to the turbulent perturbation. These are treated as additions to the standard thermodynamic coordinates (e.g. pressure and temperature). We investigate the effects of both treatments of turbulence on the structure variables, the adiabatic sound speed, the structure of the highly superadiabatic layer, and the p-mode frequencies. We find that the second method reproduces the SAL structure obtained in 3D simulations, and produces a p-mode frequency correction an order of magnitude better than the first method.

L. H. Li; F. J. Robinson; P. Demarque; S. Sofia; D. B. Guenther

2001-11-07T23:59:59.000Z

337

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

338

Fuels and Combustion Strategies for High-Efficiency Clean-Combustion...  

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

Mixing-Controlled Combustion Strategies for High-Efficiency Clean-Combustion Engines Optical-Engine and Surrogate-Fuels Research for an Improved Understanding of Fuel Effects on...

339

Method and apparatus for active control of combustion rate through modulation of heat transfer from the combustion chamber wall  

DOE Patents [OSTI]

The flame propagation rate resulting from a combustion event in the combustion chamber of an internal combustion engine is controlled by modulation of the heat transfer from the combustion flame to the combustion chamber walls. In one embodiment, heat transfer from the combustion flame to the combustion chamber walls is mechanically modulated by a movable member that is inserted into, or withdrawn from, the combustion chamber thereby changing the shape of the combustion chamber and the combustion chamber wall surface area. In another embodiment, heat transfer from the combustion flame to the combustion chamber walls is modulated by cooling the surface of a portion of the combustion chamber wall that is in close proximity to the area of the combustion chamber where flame speed control is desired.

Roberts Jr., Charles E.; Chadwell, Christopher J.

2004-09-21T23:59:59.000Z

340

Combustion Synthesis of Silicon Carbide 389 Combustion Synthesis of Silicon Carbide  

E-Print Network [OSTI]

by which combustion synthesis can occur: self - propagating high-temperature synthesis (SHS) and volume of the SHS mode (Fig.1a) is that locally initiated, the self-sustained reaction rapidly propagatesCombustion Synthesis of Silicon Carbide 389 X Combustion Synthesis of Silicon Carbide Alexander S

Mukasyan, Alexander

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

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

342

Real-time combustion controller  

DOE Patents [OSTI]

A method and system are disclosed for regulating the air to fuel ratio supplied to a burner to maximize the combustion efficiency. Optical means are provided in close proximity to the burner for directing a beam of radiation from hot gases produced by the burner to a plurality of detectors. Detectors are provided for sensing the concentration of, inter alia, CO, CO{sub 2}, and H{sub 2}O. The differences between the ratios of CO to CO{sub 2} and H{sub 2}O to CO are compared with a known control curve based on those ratios for air to fuel ratios ranging from 0.85 to 1.30. The fuel flow is adjusted until the difference between the ratios of CO to CO{sub 2} and H{sub 2}O to CO fall on a desired set point on the control curve. 20 figs.

Lindner, J.S.; Shepard, W.S.; Etheridge, J.A.; Jang, P.R.; Gresham, L.L.

1997-02-04T23:59:59.000Z

343

Combustion fume structure and dynamics  

SciTech Connect (OSTI)

The focus of this research program is on elucidating the fundamental processes that determine the particle size distribution, composition, and agglomerate structures of coal ash fumes. The ultimate objective of this work is the development and validation of a model for the dynamics of combustion fumes, describing both the evolution of the particle size distribution and the particle morphology. The study employs model systems to address the fundamental questions and to provide rigorous validation of the models to be developed. This first phase of the project has been devoted to the development of a detailed experimental strategy that will allow agglomerates with a broad range of fractal dimensions to be studied in the laboratory. (VC)

Flagan, R.C.

1992-08-01T23:59:59.000Z

344

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

345

Adaptive low Mach number simulations of nuclear flame microphysics  

E-Print Network [OSTI]

Adaptive low Mach number simulations of nuclear flame microphysics J. B. Bell, M. S. Day, C. A of nuclear flames in Type Ia su- pernovae. This model is based on a low Mach number formulation nuclear burning. The formulation presented here generalizes low Mach number models used in combustion

Bell, John B.

346

Towards a detailed soot model for internal combustion engines  

SciTech Connect (OSTI)

In this work, we present a detailed model for the formation of soot in internal combustion engines describing not only bulk quantities such as soot mass, number density, volume fraction, and surface area but also the morphology and chemical composition of soot aggregates. The new model is based on the Stochastic Reactor Model (SRM) engine code, which uses detailed chemistry and takes into account convective heat transfer and turbulent mixing, and the soot formation is accounted for by SWEEP, a population balance solver based on a Monte Carlo method. In order to couple the gas-phase to the particulate phase, a detailed chemical kinetic mechanism describing the combustion of Primary Reference Fuels (PRFs) is extended to include small Polycyclic Aromatic Hydrocarbons (PAHs) such as pyrene, which function as soot precursor species for particle inception in the soot model. Apart from providing averaged quantities as functions of crank angle like soot mass, volume fraction, aggregate diameter, and the number of primary particles per aggregate for example, the integrated model also gives detailed information such as aggregate and primary particle size distribution functions. In addition, specifics about aggregate structure and composition, including C/H ratio and PAH ring count distributions, and images similar to those produced with Transmission Electron Microscopes (TEMs), can be obtained. The new model is applied to simulate an n-heptane fuelled Homogeneous Charge Compression Ignition (HCCI) engine which is operated at an equivalence ratio of 1.93. In-cylinder pressure and heat release predictions show satisfactory agreement with measurements. Furthermore, simulated aggregate size distributions as well as their time evolution are found to qualitatively agree with those obtained experimentally through snatch sampling. It is also observed both in the experiment as well as in the simulation that aggregates in the trapped residual gases play a vital role in the soot formation process. (author)

Mosbach, Sebastian; Celnik, Matthew S.; Raj, Abhijeet; Kraft, Markus [Department of Chemical Engineering and Biotechnology, University of Cambridge, Pembroke Street, Cambridge CB2 3RA (United Kingdom); Zhang, Hongzhi R. [Department of Chemical Engineering, University of Utah, 1495 East 100 South, Kennecott Research Building, Salt Lake City, UT 84112 (United States); Kubo, Shuichi [Frontier Research Center, Toyota Central R and D Labs., Inc., Nagakute, Aichi 480-1192 (Japan); Kim, Kyoung-Oh [Higashifuji Technical Center, Toyota Motor Corporation, Mishuku 1200, Susono, Shizuoka 480-1193 (Japan)

2009-06-15T23:59:59.000Z

347

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

348

NISTIR 6458 Characterization of the Inlet Combustion Air in  

E-Print Network [OSTI]

NISTIR 6458 Characterization of the Inlet Combustion Air in NIST's Reference Spray Combustion January 2000 #12;ii Contents page Introduction 1 Reference Spray Combustion Facility 3 Numerical;1 Characterization of the Inlet Combustion Air in NIST's Reference Spray Combustion Facility: Effect of Vane Angle

Magee, Joseph W.

349

Autoignition in turbulent two-phase flows  

E-Print Network [OSTI]

on the principle of generating a charge that is enough well-mixed to allow for either premixed or partially premixed combustion. One of such methods is known as Homogeneous Charge Compression Ignition (HCCI) combustion, in which a lean, homogeneous fuel / air... that characterize diffusion flames and which are responsible for NOx emissions. In practical compression-ignition engines, HCCI- type combustion is achieved by exploiting a technique known as diesel low tem- 3 perature combustion. A straightforward implementation...

Borghesi, Giulio

2013-01-08T23:59:59.000Z

350

Mimicking a turbulent signal: sequential multiaffine processes  

E-Print Network [OSTI]

An efficient method for the construction of a multiaffine process, with prescribed scaling exponents, is presented. At variance with the previous proposals, this method is sequential and therefore it is the natural candidate in numerical computations involving synthetic turbulence. The application to the realization of a realistic turbulent-like signal is discussed in detail. The method represents a first step towards the realization of a realistic spatio-temporal turbulent field.

L. Biferale; G. Boffetta; A. Celani; A. Crisanti; A. Vulpiani

1997-11-03T23:59:59.000Z

351

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

352

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

353

Modeling autoignition in non-premixed turbulent combustion using a stochastic  

E-Print Network [OSTI]

such as homogeneous-charge compression-ignition (HCCI) engines have been developed. In both die- sel and HCCI engines of the scalar dissipation rate characterizes the autoignition pro- cess. In HCCI engines, mixture

Pitsch, Heinz

354

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

355

European Research Community On Flow Turbulence And Combustion ERCOFTAC Bulletin 30 45  

E-Print Network [OSTI]

systems. Reported examples of applications include the measurements of droplets in a spray jet [1], bubbles in water flow [2], cavitation bubbles [3], solid particles in a mixing tank [4]. Such experiments require a sufficiently high degree of transparency of the multiphase system in order to allow illumination

Gui, Lichuan

356

FLUIDIZED BED COMBUSTION UNIT FOR OIL SHALE  

E-Print Network [OSTI]

A fluidized bed combustion unit has been designed and installed to study the fluidized bed combustion performance using oil shale as fuel in direct burning process. It is a steel column of 18 cm inside diameter and 130 cm height fitted with a perforated plate air distributor of 611 holes, each of 1

M. Hammad; Y. Zurigat; S. Khzai; Z. Hammad; O. Mubydeem

357

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

358

Sensitivity Analysis of Combustion Timing of Homogeneous  

E-Print Network [OSTI]

to predict the start of combustion in a homogeneous charge compression ignition (HCCI) engine. Qualitative and quantitative information on the individual effects of fuel and exhaust gas recirculation on the HCCI combustion-injection gasoline HCCI engine, we find that temperature is the dominant factor in determining the start

Stefanopoulou, Anna

359

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

360

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

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

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

362

Sandia combustion research program: Annual report, 1987  

SciTech Connect (OSTI)

More than a decade ago, in response to a national energy crisis, Sandia proposed to the US Department of Energy a new, ambitious program in combustion research. Our strategy was to apply the rapidly increasing capabilities in lasers and computers to combustion science and technology. 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 universities, industry, and national laboratories--to improve our understanding and control of combustion. This report includes descriptions of several research projects which have been stimulated by Working Groups and involve the on-site participation of industry scientists. DOE's Industry Technology Fellowship Program has been instrumental in the success of some of the joint efforts. The remainder of this report presents research results of calendar year 1987, separated thematically into nine categories. Refereed journal articles appearing in print during 1987, along with selected other publications, are included at the end of Section 10. In addition to our ''traditional'' research--chemistry, reacting flow, diagnostics, engine combustion, and coal combustion--you will note continued progress in somewhat recent themes: pulse combustion, high temperature materials, and energetic materials, for example. Moreover, we have just started a small, new effort to understand combustion-related issues in the management of toxic and hazardous materials.

Palmer, R.E.; Sanders, B.R.; Ivanetich, C.A. (eds.)

1988-01-01T23:59:59.000Z

363

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

364

Injector tip for an internal combustion engine  

DOE Patents [OSTI]

This invention relates to a the tip structure of a fuel injector as used in a internal combustion engine. Internal combustion engines using Homogeneous Charge Compression Ignition (HCCI) technology require a tip structure that directs fuel spray in a downward direction. This requirement necessitates a tip design that is capable of withstanding mechanical stresses associated with the design.

Shyu, Tsu Pin; Ye, Wen

2003-05-20T23:59:59.000Z

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

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

367

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

368

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

Martín, Pino

369

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

Martín, Pino

370

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

371

2003 Laser Diagnostic in Combustion Conference  

SciTech Connect (OSTI)

The GRC Laser Diagnostics in Combustion aims at bringing together scientists and engineers working in the front edge of research and development to discuss and find new ways to solve problems connected to combustion diagnostics. Laser-based techniques have proven to be very efficient tools for studying combustion processes thanks to features as non-intrusiveness in combination with high spatial and temporal resolution. Major tasks for the community are to develop and apply techniques for quantitative measurements with high precision e.g of species concentrations, temperatures, velocities and particles characteristics (size and concentration). These issues are of global interest, considering that the major part of the World's energy conversion comes from combustion sources and the influence combustion processes have on the environment and society.

Mark G. Allen

2004-09-10T23:59:59.000Z

372

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

373

A hybrid 2-zone/WAVE engine combustion model for simulating combustion instabilities during dilute operation  

SciTech Connect (OSTI)

Internal combustion engines are operated under conditions of high exhaust gas recirculation (EGR) to reduce NO x emissions and promote enhanced combustion modes such as HCCI. However, high EGR under certain conditions also promotes nonlinear feedback between cycles, leading to the development of combustion instabilities and cyclic variability. We employ a two-zone phenomenological combustion model to simulate the onset of combustion instabilities under highly dilute conditions and to illustrate the impact of these instabilities on emissions and fuel efficiency. The two-zone in-cylinder combustion model is coupled to a WAVE engine-simulation code through a Simulink interface, allowing rapid simulation of several hundred successive engine cycles with many external engine parametric effects included. We demonstrate how this hybrid model can be used to study strategies for adaptive feedback control to reduce cyclic combustion instabilities and, thus, preserve fuel efficiency and reduce emissions.

Edwards, Kevin Dean [ORNL; Wagner, Robert M [ORNL; Chakravarthy, Veerathu K [ORNL; Daw, C Stuart [ORNL; Green Jr, Johney Boyd [ORNL

2006-01-01T23:59:59.000Z

374

COMBUSTION RESEARCH Chapter from the Energy and Environment Division Annual Report 1980  

E-Print Network [OSTI]

Heat Transfer with Combustion R. Greif, H. Heperkan, J.H. Stewart . . . COMBUSTION CHEMISTRY AND POLLUTANTInternational) on Combustion, The Combustion institute,

Authors, Various

2013-01-01T23:59:59.000Z

375

Simulating flame lift-off characteristics of diesel and biodiesel fuels using detailed chemical-kinetic mechanisms and LES turbulence model.  

SciTech Connect (OSTI)

Combustion in direct-injection diesel engines occurs in a lifted, turbulent diffusion flame mode. Numerous studies indicate that the combustion and emissions in such engines are strongly influenced by the lifted flame characteristics, which are in turn determined by fuel and air mixing in the upstream region of the lifted flame, and consequently by the liquid breakup and spray development processes. From a numerical standpoint, these spray combustion processes depend heavily on the choice of underlying spray, combustion, and turbulence models. The present numerical study investigates the influence of different chemical kinetic mechanisms for diesel and biodiesel fuels, as well as Reynolds-averaged Navier-Stokes (RANS) and large eddy simulation (LES) turbulence models on predicting flame lift-off lengths (LOLs) and ignition delays. Specifically, two chemical kinetic mechanisms for n-heptane (NHPT) and three for biodiesel surrogates are investigated. In addition, the RNG k-{epsilon} (RANS) model is compared to the Smagorinsky based LES turbulence model. Using adaptive grid resolution, minimum grid sizes of 250 {micro}m and 125 {micro}m were obtained for the RANS and LES cases respectively. Validations of these models were performed against experimental data from Sandia National Laboratories in a constant volume combustion chamber. Ignition delay and flame lift-off validations were performed at different ambient temperature conditions. The LES model predicts lower ignition delays and qualitatively better flame structures compared to the RNG k-{epsilon} model. The use of realistic chemistry and a ternary surrogate mixture, which consists of methyl decanoate, methyl 9-decenoate, and NHPT, results in better predicted LOLs and ignition delays. For diesel fuel though, only marginal improvements are observed by using larger size mechanisms. However, these improved predictions come at a significant increase in computational cost.

Som, S; Longman, D. E.; Luo, Z; Plomer, M; Lu, T; Senecal, P.K.; Pomraning, E (Energy Systems); (Univ. of Connecticut); (CONVERGENT Science)

2012-01-01T23:59:59.000Z

376

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

377

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

378

GENERAL TECHNICAL REPORT PSW-GTR-245 Caracterizacin de Combustibles  

E-Print Network [OSTI]

información del inventario de combustibles leñosos registrando las intercepciones de estos combustibles de forestales, inventario de combustibles, incendios forestales. Introducción. Los incendios son uno de los

Standiford, Richard B.

379

AN EXPERIMENTAL AND THEORETICAL STUDY OF HEAT TRANSFER WITH COMBUSTION  

E-Print Network [OSTI]

HDyna.mics of the Exothermic Process in Combustion,n 15thSymposium (International) on Combustion, Tokyo, 1974. H, S.Methods L Glassman, Combustion, Academic Press, 1977. D. J.

Heperkan, Hasan A.

2013-01-01T23:59:59.000Z

380

Sub-millimeter sized methyl butanoate droplet combustion: Microgravity experiments  

E-Print Network [OSTI]

-dependent, sphero-symmetric droplet combustion simulation that includes detailed gas phase chemical kineticsSub-millimeter sized methyl butanoate droplet combustion: Microgravity experiments and detailed 2012 Abstract Combustion characteristics of isolated sub-millimeter sized methyl butanoate (MB

Walter, M.Todd

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

Turbulent electron transport in edge pedestal by electron temperature gradient turbulence  

SciTech Connect (OSTI)

We present a model for turbulent electron thermal transport at the edge pedestal in high (H)-mode plasmas based on electron temperature gradient (ETG) turbulence. A quasi-linear analysis of electrostatic toroidal ETG modes shows that both turbulent electron thermal diffusivity and hyper-resistivity exhibits the Ohkawa scaling in which the radial correlation length of turbulence becomes the order of electron skin depth. Combination of the Ohkawa scales and the plasma current dependence results in a novel confinement scaling inside the pedestal region. It is also shown that ETG turbulence induces a thermoelectric pinch, which may accelerate the density pedestal formation.

Singh, R. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Institute for Plasma Research, Bhat Gandhinagar, Gujarat 2382 428 (India); Jhang, Hogun [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of)] [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); Diamond, P. H. [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of) [WCI Center for Fusion Theory, National Fusion Research Institute, Daejeon 305-333 (Korea, Republic of); CMTFO and CASS, University of California, San Diego 92093-0424, California (United States)

2013-11-15T23:59:59.000Z

382

Sandia National Laboratories: combustion science  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia, NREL Releasehy-drogen power Portable

383

Piston-Liner Crevice Geometry Effect on HCCI Combustion by Multi-Zone Analysis  

SciTech Connect (OSTI)

A multi-zone model has been developed that accurately predicts HCCI combustion and emissions. The multizone methodology is based on the observation that turbulence does not play a direct role on HCCI combustion. Instead, chemical kinetics dominates the process, with hotter zones reacting first, and then colder zones reacting in rapid succession. Here, the multi-zone model has been applied to analyze the effect of piston crevice geometry on HCCI combustion and emissions. Three different pistons of varying crevice size were analyzed. Crevice sizes were 0.26, 1.3 and 2.1 mm, while a constant compression ratio was maintained (17:1). The results show that the multi-zone model can predict pressure traces and heat release rates with good accuracy. Combustion efficiency is also predicted with good accuracy for all cases, with a maximum difference of 5% between experimental and numerical results. Carbon monoxide emissions are underpredicted, but the results are better than those obtained in previous publications. The improvement is attributed to the use of a 40-zone model, while previous publications used a 10-zone model. Hydrocarbon emissions are well predicted. For cylinders with wide crevices (1.3 and 2.1 mm), HC emissions do not decrease monotonically as the relative air/fuel ratio ({lambda}) increases. Instead, maximum HC emissions are obtained for an intermediate value of {lambda}. The model predicts this relative air/fuel ratio for maximum HC emissions with very good accuracy. The results show that the multi-zone model can successfully predict the effect of crevice geometry on HCCI combustion, and therefore it has applicability to the design of HCCI engines with optimum characteristics for high efficiency, low emissions and low peak cylinder pressure.

Aceves, S M; Flowers, D L; Espinosa-Loza, F; Martinez-Frias, J; Dibble, R W; Christensen, M; Johansson, B; Hessel, R P

2002-09-04T23:59:59.000Z

384

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

385

Pressurized fluidized-bed combustion  

SciTech Connect (OSTI)

The US DOE pressurized fluidized bed combustion (PFBC) research and development program is designed to develop the technology and data base required for the successful commercialization of the PFBC concept. A cooperative program with the US, West Germany, and the UK has resulted in the construction of the 25 MWe IEA-Grimethorpe combined-cycle pilot plant in England which will be tested in 1981. A 13 MWe coal-fired gas turbine (air cycle) at Curtis-Wright has been designed and construction scheduled. Start-up is planned to begin in early 1983. A 75 MWe pilot plant is planned for completion in 1986. Each of these PFBC combined-cycle programs is discussed. The current status of PFB technology may be summarized as follows: turbine erosion tolerance/hot gas cleanup issues have emerged as the barrier technology issues; promising turbine corrosion-resistant materials have been identified, but long-term exposure data is lacking; first-generation PFB combustor technology development is maturing at the PDU level; however, scale-up to larger size has not been demonstrated; and in-bed heat exchanger materials have been identified, but long-term exposure data is lacking. The DOE-PFB development plan is directed at the resolution of these key technical issues. (LCL)

Not Available

1980-10-01T23:59:59.000Z

386

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

387

Stochastic superparameterization in quasigeostrophic turbulence  

SciTech Connect (OSTI)

In this article we expand and develop the authors' recent proposed methodology for efficient stochastic superparameterization algorithms for geophysical turbulence. Geophysical turbulence is characterized by significant intermittent cascades of energy from the unresolved to the resolved scales resulting in complex patterns of waves, jets, and vortices. Conventional superparameterization simulates large scale dynamics on a coarse grid in a physical domain, and couples these dynamics to high-resolution simulations on periodic domains embedded in the coarse grid. Stochastic superparameterization replaces the nonlinear, deterministic eddy equations on periodic embedded domains by quasilinear stochastic approximations on formally infinite embedded domains. The result is a seamless algorithm which never uses a small scale grid and is far cheaper than conventional SP, but with significant success in difficult test problems. Various design choices in the algorithm are investigated in detail here, including decoupling the timescale of evolution on the embedded domains from the length of the time step used on the coarse grid, and sensitivity to certain assumed properties of the eddies (e.g. the shape of the assumed eddy energy spectrum). We present four closures based on stochastic superparameterization which elucidate the properties of the underlying framework: a null hypothesis stochastic closure that uncouples the eddies from the mean, a stochastic closure with nonlinearly coupled eddies and mean, a nonlinear deterministic closure, and a stochastic closure based on energy conservation. The different algorithms are compared and contrasted on a stringent test suite for quasigeostrophic turbulence involving two-layer dynamics on a ?-plane forced by an imposed background shear. The success of the algorithms developed here suggests that they may be fruitfully applied to more realistic situations. They are expected to be particularly useful in providing accurate and efficient stochastic parameterizations for use in ensemble-based state estimation and prediction.

Grooms, Ian, E-mail: grooms@cims.nyu.edu [Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States); Majda, Andrew J., E-mail: jonjon@cims.nyu.edu [Center for Atmosphere Ocean Science, Courant Institute of Mathematical Sciences, New York University, 251 Mercer St., New York, NY 10012 (United States); Center for Prototype Climate Modelling, NYU-Abu Dhabi (United Arab Emirates)

2014-08-15T23:59:59.000Z

388

Progress in Energy and Combustion Science 34 (2008) 377416 Discrete reaction waves: Gasless combustion of solid powder mixtures  

E-Print Network [OSTI]

; Self-propagating high-temperature synthesis; Combustion synthesis; Discrete and quasi, which have been observed in a variety of processes including combustion synthesis of materials, burning Elsevier Ltd. All rights reserved. Keywords: Heterogeneous combustion wave; Mechanisms of flame propagation

Mukasyan, Alexander

389

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...

390

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...

391

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,...

392

Fuel Formulation Effects on Diesel Fuel Injection, Combustion...  

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

Formulation Effects on Diesel Fuel Injection, Combustion, Emissions and Emission Control Fuel Formulation Effects on Diesel Fuel Injection, Combustion, Emissions and Emission...

393

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...

394

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...

395

Idling Emissions Reduction Technology with Low Temperature Combustion...  

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

Idling Emissions Reduction Technology with Low Temperature Combustion of DI Biodiesel and PFI n-Butanol Idling Emissions Reduction Technology with Low Temperature Combustion of DI...

396

Vehicle Technologies Office Merit Review 2014: Internal Combustion...  

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

4: Internal Combustion Engine Energy Retention (ICEER) Vehicle Technologies Office Merit Review 2014: Internal Combustion Engine Energy Retention (ICEER) Presentation given by...

397

AMO Fuel and Feedstock Flexibility: Fuel-Flexible Combustion...  

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

AMO Fuel and Feedstock Flexibility: Fuel-Flexible Combustion System for Refinery and Chemical Plant Process Heaters AMO Fuel and Feedstock Flexibility: Fuel-Flexible Combustion...

398

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...

399

Using Biofuel Tracers to Study Alternative Combustion Regimes  

E-Print Network [OSTI]

Simulation of Natural Gas HCCI Combustion: Gas CompositionPeroxide (DTBP) Additive on HCCI Combustion of Fuel BlendsCharge Compression Ignition (HCCI) Engines: Key Research and

Mack, John Hunter; Flowers, Daniel L.; Buchholz, Bruce A.; Dibble, Robert W.

2006-01-01T23:59:59.000Z

400

Large Eddy Simulation (LES) Applied to Advanced Engine Combustion...  

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

Advanced Engine Combustion Research Large Eddy Simulation (LES) Applied to Advanced Engine Combustion Research 2012 DOE Hydrogen and Fuel Cells Program and Vehicle Technologies...

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

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...

402

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

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

Hydrogen 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...

403

High Efficiency Clean Combustion Engine Designs for Gasoline...  

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

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

404

Use of Low Cetane Fuel to Enable Low Temperature Combustion  

Broader source: Energy.gov [DOE]

Document: ace011_ciatti_2013_o.pdfTechnology Area: Advanced Combustion; Combustion and Emissions ControlPresenter: Steve CiattiPresenting Organization: Argonne National Laboratory (ANL...

405

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

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

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...

406

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.

407

Vehicle Technologies Office: Materials for High-Efficiency Combustion...  

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

High-Efficiency Combustion Engines Vehicle Technologies Office: Materials for High-Efficiency Combustion Engines The Vehicle Technologies Office (VTO) is supporting work to improve...

408

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

409

CRADA with Cummins on Characterization and Reduction of Combustion...  

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

Cummins on Characterization and Reduction of Combustion Variations CRADA with Cummins on Characterization and Reduction of Combustion Variations 2012 DOE Hydrogen and Fuel Cells...

410

alternative combustion regimes: Topics by E-print Network  

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

is a Novel Materials Science Websites Summary: Systems Not suitable for nano-material synthesis Reactive Sample Volume Combustion Product Heaters Self Combustion Product:...

411

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 -...

412

Heavy-Duty Engine Combustion Optimization for High Thermal Efficiency...  

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

Combustion Optimization for High Thermal Efficiency Targeting EPA 2010 Emissions Heavy-Duty Engine Combustion Optimization for High Thermal Efficiency Targeting EPA 2010 Emissions...

413

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...

414

asme internal combustion: Topics by E-print Network  

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

Conference on Fluidised Bed Combustion Fossil Fuels Websites Summary: COMBUSTION OF HIGH-PVC SOLID WASTE WITH HCl RECOVERY Loay Saeed, Antti Tohka, Ron Zevenhoven*...

415

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...

416

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...

417

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...

418

Vehicle Technologies Office: 2008 Advanced Combustion R&D Annual...  

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

Combustion R&D Annual Progress Report Vehicle Technologies Office: 2008 Advanced Combustion R&D Annual Progress Report 2008advcombustionengine.pdf More Documents & Publications...

419

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,...

420

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...

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

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...

422

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,...

423

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...

424

Glow Plug Integrated Piezo-Ceramic Combustion Sensor for Diesel...  

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

Glow Plug Integrated Piezo-Ceramic Combustion Sensor for Diesel Engines Glow Plug Integrated Piezo-Ceramic Combustion Sensor for Diesel Engines 2005 Diesel Engine Emissions...

425

A University Consortium on Low Temperature Combustion (LTC) for...  

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

Low Temperature Combustion (LTC) for High Efficiency, Ultra-Low Emission Engines A University Consortium on Low Temperature Combustion (LTC) for High Efficiency, Ultra-Low Emission...

426

Computationally Efficient Modeling of High-Efficiency Clean Combustion...  

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

& Publications Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines Computationally Efficient Modeling of High-Efficiency Clean Combustion Engines...

427

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...

428

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...

429

Improving Combustion Software to Solve Detailed Chemical Kinetics...  

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

Combustion Software to Solve Detailed Chemical Kinetics for HECC Improving Combustion Software to Solve Detailed Chemical Kinetics for HECC 2012 DOE Hydrogen and Fuel Cells Program...

430

2008 Annual Merit Review Results Summary - 7. Combustion Research...  

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

7. Combustion Research 2008 Annual Merit Review Results Summary - 7. Combustion Research DOE Vehicle Technologies Annual Merit Review 2008meritreview7.pdf More Documents &...

431

Advanced Post-Combustion CO2 Capture Prepared for the  

E-Print Network [OSTI]

Advanced Post-Combustion CO2 Capture Prepared for the Clean Air Task Force under a grant from...................................................................................... 3 2. Current Status of Post-Combustion Capture

432

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....

433

High-Efficiency Clean Combustion Engine Designs for Compression...  

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

High-Efficiency Clean Combustion Engine Designs for Compression Ignition Engines High-Efficiency Clean Combustion Engine Designs for Compression Ignition Engines Presentation from...

434

2013 Annual Merit Review Results Report - Advanced Combustion...  

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

Advanced Combustion Engine Technologies 2013 Annual Merit Review Results Report - Advanced Combustion Engine Technologies Merit review of DOE Vehicle Technologies research...

435

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

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

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

436

Multicylinder Diesel Engine for Low Temperature Combustion Operation...  

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

Multicylinder Diesel Engine for Low Temperature Combustion Operation Multicylinder Diesel Engine for Low Temperature Combustion Operation Fuel injection strategies to extend low...

437

2012 Annual Merit Review Results Report - Advanced Combustion...  

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

Advanced Combustion Engine Technologies 2012 Annual Merit Review Results Report - Advanced Combustion Engine Technologies Merit review of DOE Vehicle Technologies research...

438

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

of Emissions from HCCI Engines using a Consistent 3-Zoneof Microwave Plasma Combustion Engine (Part I: Concept ofPlasma Combustion Engine (Part II: Engine Performance of

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

439

2011 Annual Merit Review Results Report - Advanced Combustion...  

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

Advanced Combustion Engine Technologies 2011 Annual Merit Review Results Report - Advanced Combustion Engine Technologies Merit review of DOE Vehicle Technologies research...

440

Advanced Combustion Modeling with STAR-CD using Transient Flemelet...  

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

Combustion Modeling with STAR-CD using Transient Flemelet Models: TIF and TPV Advanced Combustion Modeling with STAR-CD using Transient Flemelet Models: TIF and TPV Presentation...

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.


441

Particulate Produced from Advanced Combustion Operation in a...  

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

Produced From Advanced Combustion Operation in a Compression Ignition Engine P-1 Particulate Produced From Advanced Combustion Operation in a Compression Ignition Engine P-1...

442

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...

443

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

444

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

445

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

446

Cyclone separator having boundary layer turbulence control  

DOE Patents [OSTI]

A cyclone separator including boundary layer turbulence control that is operable to prevent undue build-up of particulate material at selected critical areas on the separator walls, by selectively varying the fluid pressure at those areas to maintain the momentum of the vortex, thereby preventing particulate material from inducing turbulence in the boundary layer of the vortical fluid flow through the separator.

Krishna, Coimbatore R. (Mt. Sinai, NY); Milau, Julius S. (Port Jefferson, NY)

1985-01-01T23:59:59.000Z

447

Annual Report: Advanced Combustion (30 September 2012)  

SciTech Connect (OSTI)

The Advanced Combustion Project addresses fundamental issues of fire-side and steam-side corrosion and materials performance in oxy-fuel combustion environments and provides an integrated approach into understanding the environmental and mechanical behavior such that environmental degradation can be ameliorated and long-term microstructural stability, and thus, mechanical performance can lead to longer lasting components and extended power plant life. The technical tasks of this effort are Oxy-combustion Environment Characterization, Alloy Modeling and Life Prediction, and Alloy Manufacturing and Process Development.

Hawk, Jeffrey [NETL] [NETL; Richards, George

2012-09-30T23:59:59.000Z

448

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

449

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

450

Sandia National Laboratories: combustion chemistry  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia, NREL Releasehy-drogen power Portable Hydrogenchemistry Direct

451

Sandia National Laboratories: combustion intermediates  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia, NREL Releasehy-drogen power Portable Hydrogenchemistry

452

Sandia National Laboratories: combustion modeling  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia, NREL Releasehy-drogen power Portable Hydrogenchemistrymodeling

453

Sandia National Laboratories: combustion simulation  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia, NREL Releasehy-drogen power Portablecombustion simulation Direct

454

Sandia National Laboratories: advanced combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1development Sandia, NREL Release Wave EnergyLinksZparts of the

455

Sandia National Laboratories: Diesel Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0EnergySandia InvolvesDOE-BERPressure, Not ChemistryDiesel

456

Sandia National Laboratories: Engine Combustion  

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

AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE:1 First Use of Energy for All Purposes (Fuel and Nonfuel),Feet) Year Jan Feb Mar Apr MayAtmosphericNuclear Security Administration the1 -the Mid-Infrared0EnergySandiaConsortiumActMicrogrid SPIDERSCombustion Direct

457

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

458

Combustion systems for power-MEMS applications  

E-Print Network [OSTI]

As part of an effort to develop a micro-scale gas turbine engine for power generation and micro-propulsion applications, this thesis presents the design, fabrication, experimental testing, and modeling of the combustion ...

Spadaccini, Christopher M. (Christopher Michael), 1974-

2004-01-01T23:59:59.000Z

459

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

460

Smouldering Combustion Phenomena in Science and Technology  

E-Print Network [OSTI]

Smouldering is the slow, low-temperature, flameless form of combustion of a condensed fuel. It poses safety and environmental hazards and allows novel technological application but its fundamentals remain mostly unknown ...

Rein, Guillermo

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

Engine combustion control via fuel reactivity stratification  

DOE Patents [OSTI]

A compression ignition engine uses two or more fuel charges having two or more reactivities to control the timing and duration of combustion. In a preferred implementation, a lower-reactivity fuel charge is injected or otherwise introduced into the combustion chamber, preferably sufficiently early that it becomes at least substantially homogeneously dispersed within the chamber before a subsequent injection is made. One or more subsequent injections of higher-reactivity fuel charges are then made, and these preferably distribute the higher-reactivity matter within the lower-reactivity chamber space such that combustion begins in the higher-reactivity regions, and with the lower-reactivity regions following thereafter. By appropriately choose the reactivities of the charges, their relative amounts, and their timing, combustion can be tailored to achieve optimal power output (and thus fuel efficiency), at controlled temperatures (and thus controlled NOx), and with controlled equivalence ratios (and thus controlled soot).

Reitz, Rolf Deneys; Hanson, Reed M; Splitter, Derek A; Kokjohn, Sage L

2013-12-31T23:59:59.000Z

462

Predicting combustion properties of hydrocarbon fuel mixtures  

E-Print Network [OSTI]

In this thesis, I applied computational quantum chemistry to improve the accuracy of kinetic mechanisms that are used to model combustion chemistry. I performed transition state theory calculations for several reactions ...

Goldsmith, Claude Franklin, III

2010-01-01T23:59:59.000Z

463

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

464

Flex-flame burner and combustion method  

SciTech Connect (OSTI)

A combustion method and apparatus which produce a hybrid flame for heating metals and metal alloys, which hybrid flame has the characteristic of having an oxidant-lean portion proximate the metal or metal alloy and having an oxidant-rich portion disposed above the oxidant lean portion. This hybrid flame is produced by introducing fuel and primary combustion oxidant into the furnace chamber containing the metal or metal alloy in a substoichiometric ratio to produce a fuel-rich flame and by introducing a secondary combustion oxidant into the furnace chamber above the fuel-rich flame in a manner whereby mixing of the secondary combustion oxidant with the fuel-rich flame is delayed for a portion of the length of the flame.

Soupos, Vasilios (Chicago, IL); Zelepouga, Serguei (Hoffman Estates, IL); Rue, David M. (Chicago, IL); Abbasi, Hamid A. (Naperville, IL)

2010-08-24T23:59:59.000Z

465

Advanced Combustion Concepts - Enabling Systems and Solutions...  

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

concepts. * Target Multi Mode Combustion Engine is based on the GM Ecotec 2.0 L DI Turbo platform * Base Engine HW design, improvements for target engine configuration and...

466

Two phase exhaust for internal combustion engine  

DOE Patents [OSTI]

An internal combustion engine having a reciprocating multi cylinder internal combustion engine with multiple valves. At least a pair of exhaust valves are provided and each supply a separate power extraction device. The first exhaust valves connect to a power turbine used to provide additional power to the engine either mechanically or electrically. The flow path from these exhaust valves is smaller in area and volume than a second flow path which is used to deliver products of combustion to a turbocharger turbine. The timing of the exhaust valve events is controlled to produce a higher grade of energy to the power turbine and enhance the ability to extract power from the combustion process.

Vuk, Carl T. (Denver, IA)

2011-11-29T23:59:59.000Z

467

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

468

Combustion properties of Kraft Black Liquors  

SciTech Connect (OSTI)

In a previous study of the phenomena involved in the combustion of black liquor droplets a numerical model was developed. The model required certain black liquor specific combustion information which was then not currently available, and additional data were needed for evaluating the model. The overall objectives of the project reported here was to provide experimental data on key aspects of black liquor combustion, to interpret the data, and to put it into a form which would be useful for computational models for recovery boilers. The specific topics to be investigated were the volatiles and char carbon yields from pyrolysis of single black liquor droplets; a criterion for the onset of devolatilization and the accompanying rapid swelling; and the surface temperature of black liquor droplets during pyrolysis, combustion, and gasification. Additional information on the swelling characteristics of black liquor droplets was also obtained as part of the experiments conducted.

Frederick, W.J. Jr.; Hupa, M. (Aabo Akademi, Turku (Finland))

1993-04-01T23:59:59.000Z

469

Active combustion control : modeling, design and implementation  

E-Print Network [OSTI]

Continuous combustion systems common in propulsion and power generation applications are susceptible to thermoacoustic instability, which occurs under lean burn conditions close to the flammability where most emissions and ...

Park, Sungbae, 1973-

2004-01-01T23:59:59.000Z

470

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

471

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...

472

Nanoparticle Emissions from Internal Combustion Engines  

E-Print Network [OSTI]

Nanoparticle Emissions from Internal Combustion Engines Professor David B. Kittelson Department Meeting Ultra Fine Particles in the Atmosphere 15 March 2000 Engine Exhaust Particle Emissions: Some Perkins Engine Company #12;Emissions of Ultrafine and Nanoparticles from Engines Current emission

Minnesota, University of

473

Advanced Combustion Concepts - Enabling Systems and Solutions...  

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

advanced control concepts and enabling system to manage multi-modemulti-fuel combustion events and achieve an up to 30 percent fuel economy improvement deer11yilmaz.pdf...

474

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

475

Teaching About Nature's Nuclear Reactors  

E-Print Network [OSTI]

Naturally occurring nuclear reactors existed in uranium deposits on Earth long before Enrico Fermi built the first man-made nuclear reactor beneath Staggs Field in 1942. In the story of their discovery, there are important lessons to be learned about scientific inquiry and scientific discovery. Now, there is evidence to suggest that the Earth's magnetic field and Jupiter's atmospheric turbulence are driven by planetary-scale nuclear reactors. The subject of planetocentric nuclear fission reactors can be a jumping off point for stimulating classroom discussions about the nature and implications of planetary energy sources and about the geomagnetic field. But more importantly, the subject can help to bring into focus the importance of discussing, debating, and challenging current thinking in a variety of areas.

Herndon, J M

2005-01-01T23:59:59.000Z

476

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

477

Internal combustion engine and method for control  

DOE Patents [OSTI]

In one exemplary embodiment of the invention an internal combustion engine includes a piston disposed in a cylinder, a valve configured to control flow of air into the cylinder and an actuator coupled to the valve to control a position of the valve. The internal combustion engine also includes a controller coupled to the actuator, wherein the controller is configured to close the valve when an uncontrolled condition for the internal engine is determined.

Brennan, Daniel G

2013-05-21T23:59:59.000Z

478

Dust Combustion Safety Issues for Fusion Applications  

SciTech Connect (OSTI)

This report summarizes the results of a safety research task to identify the safety issues and phenomenology of metallic dust fires and explosions that are postulated for fusion experiments. There are a variety of metal dusts that are created by plasma erosion and disruptions within the plasma chamber, as well as normal industrial dusts generated in the more conventional equipment in the balance of plant. For fusion, in-vessel dusts are generally mixtures of several elements; that is, the constituent elements in alloys and the variety of elements used for in-vessel materials. For example, in-vessel dust could be composed of beryllium from a first wall coating, tungsten from a divertor plate, copper from a plasma heating antenna or diagnostic, and perhaps some iron and chromium from the steel vessel wall or titanium and vanadium from the vessel wall. Each of these elements has its own unique combustion characteristics, and mixtures of elements must be evaluated for the mixtures combustion properties. Issues of particle size, dust temperature, and presence of other combustible materials (i.e., deuterium and tritium) also affect combustion in air. Combustion in other gases has also been investigated to determine if there are safety concerns with inert atmospheres, such as nitrogen. Several coolants have also been reviewed to determine if coolant breach into the plasma chamber would enhance the combustion threat; for example, in-vessel steam from a water coolant breach will react with metal dust. The results of this review are presented here.

L. C. Cadwallader

2003-05-01T23:59:59.000Z

479

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 675C. 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

480

Fuels and Combustion Strategies for High-Efficiency Clean-Combustion...  

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

tools for understanding fuel-property effects on - Combustion - Engine efficiency optimization - Emissions Partners Project lead: Sandia - C.J. Mueller (PI); C.J. Polonowski...

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

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

482

Investigation on Flame Characteristics and Burner Operability Issues of Oxy-Fuel Combustion  

SciTech Connect (OSTI)

Oxy-fuel combustion has been used previously in a wide range of industrial applications. Oxy- combustion is carried out by burning a hydrocarbon fuel with oxygen instead of air. Flames burning in this configuration achieve higher flame temperatures which present opportunities for significant efficiency improvements and direct capture of CO{sub 2} from the exhaust stream. In an effort to better understand and characterize the fundamental flame characteristics of oxy-fuel combustion this research presents the experimental measurements of flame stability of various oxyfuel flames. Effects of H{sub 2} concentration, fuel composition, exhaust gas recirculation ratio, firing inputs, and burner diameters on the flame stability of these fuels are discussed. Effects of exhaust gas recirculation i.e. CO{sub 2} and H{sub 2}O (steam) acting as diluents on burner operability are also presented. The roles of firing input on flame stability are then analyzed. For this study it was observed that many oxy-flames did not stabilize without exhaust gas recirculation due to their higher burning velocities. In addition, the stability regime of all compositions was observed to decrease as the burner diameter increased. A flashback model is also presented, using the critical velocity gradient g{sub F}) values for CH{sub 4}-O{sub 2}-CO{sub 2} flames. The scaling relation (𝐠{sub F} = 𝐜 𝐒{sub 𝐋}{sup 2}/𝛂) for different burner diameters was obtained for various diameter burners. The report shows that results correlated linearly with a scaling value of c =0.0174. The second part of the study focuses on the experimental measurements of the flow field characteristics of premixed CH{sub 4}/21%O{sub 2}/79%N{sub 2} and CH{sub 4}/38%O{sub 2}/72%CO{sub 2} mixtures at constant firing input of 7.5 kW, constant, equivalence ratio of 0.8, constant swirl number of 0.92 and constant Reynolds Numbers. These measurements were taken in a swirl stabilized combustor at atmospheric pressure. The flow field visualization using Particle Imaging Velocimetry (PIV) technique is implemented to make a better understanding of the turbulence characteristics of CH{sub 4}/air and CH{sub 4}/38%O{sub 2}/72%CO{sub 2} combustion. The velocity fluctuations, turbulence intensities and local propagation velocities along the combustion chamber have been determined. The turbulent intensities increase as we move away from the combustor axis. CH{sub 4}-38%O{sub 2}-72%CO{sub 2} flames have low radial velocity and turbulent intensity distributions at different axial distances when compared with CH{sub 4}-Air flames.

Choudhuri, Ahsan

2013-05-30T23:59:59.000Z

483

Combustion Engineering IGCC Repowering Project  

SciTech Connect (OSTI)

C-E gasification process uses an entrained-flow, two-stage, slagging bottom gasifier. Figure 1 shows a schematic of the gasifier concept. Some of the coal and all of the char is fed to the combustor section, while the remaining coal is fed to the reducter section of the gasifier. The coal and char in the combustor is mixed with air and the fuel-rich mixture is burned creating the high temperature necessary to gasify the coal and melt the mineral matter in the coal. The slag flows through a slag tap at the bottom of the combustor into a water-filled slag tank where it is quenched and transformed into an inert, glassy, granular material. This vitrified slag is non-leaching, making it easy to dispose of in an environmentally acceptable manner. The hot gas leaving the combustor enters the second stage called the reductor. In the reducter, the char gasification occurs along the length of the reductor zone until the temperature falls to a point where the gasification kinetics become too slow. Once the gas temperature reaches this level, essentially no further gasification takes place and the gases subsequently are cooled with convective surface to a temperature low enough to enter the cleanup system. Nearly all of the liberated energy from the coal that does not produce fuel gas is collected and recovered with steam generating surface either in the walls of the vessel or by conventional boiler convective surfaces in the backpass of the gasifier. A mixture of unburned carbon and ash (called char) is carried out of the gasifier with the product gas strewn. The char is collected and recycled back to the gasifier where it is consumed. Thus, there is no net production of char which results in negligible carbon loss. The product gas enters a desulfurization system where it is cleaned of sulfur compounds present in the fuel gas. The clean fuel gas is now available for use in the gas turbine combuster for an integrated coal gasification combined cycle (IGCC) application.

Andrus, H.E.; Thibeault, P.R.; Gibson, C.R.

1992-11-01T23:59:59.000Z

484

Combustion Engineering IGCC Repowering Project  

SciTech Connect (OSTI)

C-E gasification process uses an entrained-flow, two-stage, slagging bottom gasifier. Figure 1 shows a schematic of the gasifier concept. Some of the coal and all of the char is fed to the combustor section, while the remaining coal is fed to the reducter section of the gasifier. The coal and char in the combustor is mixed with air and the fuel-rich mixture is burned creating the high temperature necessary to gasify the coal and melt the mineral matter in the coal. The slag flows through a slag tap at the bottom of the combustor into a water-filled slag tank where it is quenched and transformed into an inert, glassy, granular material. This vitrified slag is non-leaching, making it easy to dispose of in an environmentally acceptable manner. The hot gas leaving the combustor enters the second stage called the reductor. In the reducter, the char gasification occurs along the length of the reductor zone until the temperature falls to a point where the gasification kinetics become too slow. Once the gas temperature reaches this level, essentially no further gasification takes place and the gases subsequently are cooled with convective surface to a temperature low enough to enter the cleanup system. Nearly all of the liberated energy from the coal that does not produce fuel gas is collected and recovered with steam generating surface either in the walls of the vessel or by conventional boiler convective surfaces in the backpass of the gasifier. A mixture of unburned carbon and ash (called char) is carried out of the gasifier with the product gas strewn. The char is collected and recycled back to the gasifier where it is consumed. Thus, there is no net production of char which results in negligible carbon loss. The product gas enters a desulfurization system where it is cleaned of sulfur compounds present in the fuel gas. The clean fuel gas is now available for use in the gas turbine combuster for an integrated coal gasification combined cycle (IGCC) application.

Andrus, H.E.; Thibeault, P.R.; Gibson, C.R.

1992-01-01T23:59:59.000Z

485

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

486

Stabilization of turbulent lifted jet flames assisted by pulsed high voltage discharge  

SciTech Connect (OSTI)

To reduce fuel consumption or the pollutant emissions of combustion (furnaces, aircraft engines, turbo-reactors, etc.), attempts are made to obtain lean mixture combustion regimes. These lead to poor stability of the flame. Thus, it is particularly interesting to find new systems providing more flexibility in aiding flame stabilization than the usual processes (bluff-body, stabilizer, quarl, swirl, etc.). The objective is to enlarge the stability domain of flames while offering flexibility at a low energy cost. Evidence is presented that the stabilization of a turbulent partially premixed flame of more than 10 kW can be enhanced by pulsed high-voltage discharges with power consumption less than 0.1% of the power of the flame. The originality of this work is to demonstrate that very effective stabilization of turbulent flames is obtained when high-voltage pulses with very short rise times are used (a decrease by 300% in terms of liftoff height for a given exit jet velocity can be reached) and to provide measurements of minimum liftoff height obtained with discharge over a large range of the stability domain of the lifted jet flame.

Criner, K.; Cessou, A.; Louiche, J.; Vervisch, P. [CORIA UMR 6614 CNRS-Universite et INSA de Rouen, University of Rouen, 76801 Saint Etienne du Rouvray (France)

2006-01-01T23:59:59.000Z

487

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

488

Pulse combustion: an assessment of opportunities for increased efficiency  

SciTech Connect (OSTI)

The results of a literature review on pulse combustion are discussed. Current, near-future, and potential opportunities for pulse combustion applications are summarized, and the barriers to developing and using pulse combustion technology are discussed, along with research and development needs. Also provided are the proceedings of a pulse combustion workshop held in May, 1984 in Seattle, Washington. (LEW)

Brenchley, D.L.; Bomelburg, H.J.

1984-12-01T23:59:59.000Z

489

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

490

Improved Economic Performance Municipal Solid Waste Combustion Plants  

E-Print Network [OSTI]

Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based Combustion Control #12;#12;Improved Economic Performance of Municipal Solid Waste Combustion Plants by Model Based-of-the-art and challenges in the operation of MSWC plants . . . 1 1.1.1 The aims of municipal solid waste combustion

Van den Hof, Paul

491

Using Biofuel Tracers to Study Alternative Combustion Regimes  

E-Print Network [OSTI]

Section B (NIMB) Using Biofuel Tracers to Study Alternativeinjection. We investigate biofuel HCCI combustion, and use

Mack, John Hunter; Flowers, Daniel L.; Buchholz, Bruce A.; Dibble, Robert W.

2006-01-01T23:59:59.000Z

492

Using Biofuel Tracers to Study Alternative Combustion Regimes  

E-Print Network [OSTI]

Internal Combustion Engines The methods described below for tracing fuel component carbon in the emissions

Mack, John Hunter; Flowers, Daniel L.; Buchholz, Bruce A.; Dibble, Robert W.

2006-01-01T23:59:59.000Z

493

Microwave-Assisted Ignition for Improved Internal Combustion Engine Efficiency  

E-Print Network [OSTI]

internal combustion engine applications. Advanced engines can achieve higher efficiencies and reduced emissions

DeFilippo, Anthony Cesar

2013-01-01T23:59:59.000Z

494

Free Energy Cascade in Gyrokinetic Turbulence  

SciTech Connect (OSTI)

In gyrokinetic theory, the quadratic nonlinearity is known to play an important role in the dynamics by redistributing (in a conservative fashion) the free energy between the various active scales. In the present study, the free energy transfer is analyzed for the case of ion temperature gradient driven turbulence. It is shown that it shares many properties with the energy transfer in fluid turbulence. In particular, one finds a (strongly) local, forward (from large to small scales) cascade of free energy in the plane perpendicular to the background magnetic field. These findings shed light on some fundamental properties of plasma turbulence, and encourage the development of large-eddy-simulation techniques for gyrokinetics.

Banon Navarro, A.; Morel, P.; Albrecht-Marc, M.; Carati, D. [Universite Libre de Bruxelles, Faculte des Sciences, Physique Statistique et Plasmas CP 231, EURATOM Association, Campus Plaine, 1050 Brussels (Belgium); Merz, F.; Goerler, T.; Jenko, F. [Max-Planck-Institut fuer Plasmaphysik, EURATOM Association, 85748 Garching (Germany)

2011-02-04T23:59:59.000Z

495

Coshcous turbulence and its thermalization  

SciTech Connect (OSTI)

Dissipation rate {mu}[cosh(k/k{sub c}) - 1] in Fourier space, which reduces to the Newtonian viscosity dissipation rate {nu}k{sup 2} for small k/k{sub c}, can be scaled to make a hydrodynamic system either actually or potentially converge to its Galerkin truncation. The former case acquires convergence to the truncation at a finite wavenumber k{sub G}; the latter realizes as the wavenumber grows to infinity. Intermittency reduction and vitiation of extended self-similarity (ESS) in the partially thermalized regime of turbulence are confirmed and clarified. Onsager's pictures of intermittent versus nonintermittent flows are visualized from thermalized numerical fields, showing cleanly spotty versus mistily uniform properties, the latter of which destroys self-organization and so the ESS property.

Zhu, Jian-zhou [Los Alamos National Laboratory; Taylor, Mark [SNL

2008-01-01T23:59:59.000Z

496

Assessment of ISLOCA risk-methodology and application to a combustion engineering plant  

SciTech Connect (OSTI)

Inter-system loss-of-coolant accidents (ISLOCAs) have been identified as important contributors to offsite risk for some nuclear power plants. A methodology has been developed for identifying and evaluating plant-specific hardware designs, human factors issues, and accident consequence factors relevant to the estimation of ISOLOCA core damage frequency and risk. This report presents a detailed of description of the application of this analysis methodology to a Combustion Engineering plant.

Kelly, D.L.; Auflick, J.L.; Haney, L.N. [EG and G Idaho, Inc., Idaho Falls, ID (United States)

1992-04-01T23:59:59.000Z

497

Proceedings of the Combustion Institute, Volume 28, 2000/pp. 16631669 COMBUSTION CHEMISTRY OF PROPANE: A CASE STUDY OF DETAILED  

E-Print Network [OSTI]

1663 Proceedings of the Combustion Institute, Volume 28, 2000/pp. 1663­1669 COMBUSTION CHEMISTRY Detailed chemical reaction mechanisms describing hydrocarbon combustion chemistry are conceptually to small-hydrocarbon combustion data are secure foundations upon which to optimize the rate parameters

Wang, Hai

498

Combustion, Explosion, and Shock Waves, Vol. 46, No. 3, pp. , 2010 Combustion of Heterogeneous Nanostructural Systems (Review)  

E-Print Network [OSTI]

Combustion, Explosion, and Shock Waves, Vol. 46, No. 3, pp. ­, 2010 Combustion of Heterogeneous submitted November 26, 2009. The current status of research in the field of combustion of heterogeneous mechanisms of combustion in such systems and prospects of their further applications are discussed. Key words

Mukasyan, Alexander

499

BIBLIOGRAPHY ON INTERNAL COMBUSTION ENGINES 1. F. Obert, Internal Combustion Engines and Air Pollution, Intext Educational Publishers, 1973  

E-Print Network [OSTI]

BIBLIOGRAPHY ON INTERNAL COMBUSTION ENGINES 1. F. Obert, Internal Combustion Engines and Air, The Internal Combustion Engine, International Textbook Company, 1961. (A basic text now out of print and somewhat dated.) 3. C.F. Taylor, The Internal Combustion Engine in Theory and Practice. Volumes I and II, M

Goldwasser, Shafi

500

A numerical study comparing the combustion and emission characteristics of biodiesel with petrodiesel.  

SciTech Connect (OSTI)

Combustion and emission characteristics of compression ignition engines strongly depend upon inner-nozzle flow and spray behavior. These processes control the fuel-air mixing, which in turn is critical for the combustion process. Previous studies by us highlighted the differences in the physical and chemical properties of petrodiesel and biodiesel, which significantly altered the inner-nozzle flow and spray structure. The current study is another step in this direction to gain a fundamental understanding on the influence of fuel properties on the combustion and emission characteristics of the compression ignition engine. n-Heptane and methyl butanoate were selected as surrogates for diesel and biodiesel fuels, respectively, because the chemical kinetic pathways were well-understood. Liquid length and flame lift-off length for diesel and biodiesel fuels were validated against data available in the literature. Liquid lengths were always higher for biodiesel because of its higher heat of vaporization, which resulted in increased interplay between spray and combustion processes under all conditions investigated. Ambient air entrainment was also lower for biodiesel mainly because of slower atomization and breakup. The mechanism for flame stabilization is further analyzed by estimating the turbulent burning velocity for both of the fuels. This analysis revealed that neither flame propagation nor isolated ignition kernels upstream and detached from high-temperature regions can be the mechanism for flame stabilization. Flame propagation speeds were observed to be similar for both fuels. Biodiesel predicted lower soot concentrations, which were also reflected in reduced C{sub 2}H{sub 2} mole fractions. Although prompt NO{sub x} was higher for biodiesel, total NO{sub x} was lower because of reduced thermal NO{sub x}. The ignition delay and NO{sub x} emissions predicted by these simulations do not agree with trends reported in the literature; hence, this study highlights the need for better fuel surrogates for diesel and biodiesel fuels.

Som, S.; Longman, D. (Energy Systems)

2011-04-01T23:59:59.000Z