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Sample records for aerodynamics hybrid laminar

  1. Aerodynamic Design for Swept-wing Laminar Flow 

    E-Print Network [OSTI]

    Belisle, Michael Joseph

    2013-11-08

    (SARGE), a natural laminar flow and passive laminar flow control wing glove flight experiment funded by the NASA Environmentally Responsible Aviation initiative. The experiment seeks to raise the technology readiness level of the spanwise...

  2. Hybrid method for aerodynamic shape optimization in automotive industry

    E-Print Network [OSTI]

    Dumas, Laurent

    Hybrid method for aerodynamic shape optimization in automotive industry Freedeerique Muyl precisely the reduction of their drag coefficient, becomes one of the main topics of the automotive research

  3. HYBRID LAMINAR FLOW TECHNOLOGY Partner: EADS Airbus (D) (Coordinator), Apparatebau Gauting (D), EADS Airbus (F), Aerospace Systems and

    E-Print Network [OSTI]

    Berlin,Technische Universität

    HYBRID LAMINAR FLOW TECHNOLOGY (HYLTEC) Partner: EADS Airbus (D) (Coordinator), Apparatebau Gauting Task1 Operational flight tests, lab tests, manufacturing issues Task2 Laminar flow retrofit studies high drag HLFC via suction causes laminar flow therefore lower drag HYLTEC topics: Consequences

  4. Laminar Flame Speeds of Nano-Aluminum/Methane Hybrid Mixtures 

    E-Print Network [OSTI]

    Sikes, Travis

    2014-12-12

    An existing flame speed bomb, which uses optical techniques to measure laminar flame speed, was employed to study the fundamental phenomena of flame propagation through a uniformly dispersed aerosol. In a previous thesis ...

  5. Error estimation and anisotropic mesh refinement for 3d laminar aerodynamic flow simulations

    E-Print Network [OSTI]

    Hartmann, Ralf

    Leichta,b , Ralf Hartmann,a,b aInstitute of Aerodynamics and Flow Technology, DLR (German Aerospace Center.Leicht@dlr.de (Tobias Leicht), Ralf.Hartmann@dlr.de (Ralf Hartmann) Preprint submitted to Journal of Computational

  6. Aerodynamic Shape Design of Nozzles Using a Hybrid Optimization Method

    E-Print Network [OSTI]

    Xing, X.Q.

    A hybrid design optimization method combining the stochastic method based on simultaneous perturbation stochastic approximation (SPSA) and the deterministic method of Broydon-Fletcher-Goldfarb-Shanno (BFGS) is developed ...

  7. Optimized Natural-Laminar-Flow Airfoils and D. W. Zingg

    E-Print Network [OSTI]

    Zingg, David W.

    Optimized Natural-Laminar-Flow Airfoils J. Driver and D. W. Zingg University of Toronto Institute-Krylov aerodynamic shape optimization algorithm has been modified to incorporate the prediction of laminar natural-laminar-flow airfoils. In particular, the optimization algorithm is able to design an airfoil

  8. 21st AIAA Computational Fluid Dynamics Conference, June 24-27, 2013, San Diego, CA Toward High-Fidelity Aerodynamic Shape

    E-Print Network [OSTI]

    Zingg, David W.

    High-Fidelity Aerodynamic Shape Optimization for Natural Laminar Flow Ramy Rashad and David W. Zingg-constrained drag minimization of airfoils at various flight conditions, leading to natural laminar flow designs. I the feasibility of natural laminar flow (NLF) as a key enabler of environmentally responsible commercial aviation

  9. PERSISTENTLY LAMINAR TANGLES MARK BRITTENHAM

    E-Print Network [OSTI]

    Brittenham, Mark

    PERSISTENTLY LAMINAR TANGLES MARK BRITTENHAM University of North Texas Department of Mathematics laminar. Being persisently laminar immediately implies, for example that every knot K obtained by tangle be generalized to provide many more examples of persistently laminar tangles. 1. The lamination Oertel

  10. PERSISTENTLY LAMINAR TANGLES MARK BRITTENHAM

    E-Print Network [OSTI]

    Brittenham, Mark

    PERSISTENTLY LAMINAR TANGLES MARK BRITTENHAM University of North Texas Department of Mathematics is persistent for K. We call such a tangle persistently laminar. Being persisently laminar immediately implies that the construction of the lamination L #12;can be generalized to provide many more examples of persistently laminar

  11. Structure of Laminar Sooting Inverse Diffusion Flames

    E-Print Network [OSTI]

    Mikofski, Mark A

    2007-01-01

    Combust. Structure of Laminar Sooting Inverse Diffusion2002, p. 252. Structure of Laminar Sooting Inverse Diffusion219-226. Structure of Laminar Sooting Inverse Diffusion

  12. Fluvial and submarine morphodynamics of laminar and near-laminar flows: a synthesis

    E-Print Network [OSTI]

    Lajeunesse, Eric

    Fluvial and submarine morphodynamics of laminar and near-laminar flows: a synthesis ERIC LAJEUNESSE of purely laminar or nearly laminar flow with an erodible bed. This paper provides a survey and synthesis of a wide range of laminar or near-laminar flow analogues of morphologies observed in the field. Laminar

  13. Advanced Flow Diagnostics and Experimental Aerodynamics Laboratory Department of Aerospace Engineering

    E-Print Network [OSTI]

    Hu, Hui

    of complex thermal-flow phenomena: ­ Renewable Energy, wind energy, wind turbine aeromechanics. ­ Bio-flows and micro-scale heat transfer. ­ Icing physics, aircraft icing, power line icing and wind turbine icing. ­ Low-speed aerodynamics, laminar boundary layer separation, transition and flow control. ­ Wind

  14. FREE CONVECTIVE LAMINAR FLOW WITHIN THE TROMBE WALL CHANNEL

    E-Print Network [OSTI]

    Akbari, H.

    2011-01-01

    Foreign FREE CONVECTIVE LAMINAR FLOW WITHIN THE TROMBE WALLEnergy. -i- FREE CONVECTIVE LAMINAR FLOW WITHIN THE TROMBEABSTRACT Free convective laminar heat transfer between the

  15. Flame Height Measurement of Laminar Inverse Diffusion Flames

    E-Print Network [OSTI]

    Mikofski, Mark A.; Williams, Timothy C.; Shaddix, Christopher R.; Blevins, Linda G.

    2006-01-01

    Flame Height Measurement of Laminar Inverse Diffusion Flamesinverse diffusion flame, laminar, flame height, OH, laserair and methane-air laminar inverse diffusion flames were

  16. Numerical simulation of laminar reacting flows with complex chemistry

    E-Print Network [OSTI]

    Day, M.S.

    2011-01-01

    of two-dimensional axisymmetric laminar diff usion flames byof a confined axisymmetric laminar diffusion flame using aalgorithms for premixed laminar steady-state flames. Comb.

  17. Laminar circuit organization and response modulation in mouse visual cortex

    E-Print Network [OSTI]

    Olivas, Nicholas D; Quintanar-Zilinskas, Victor; Nenadic, Zoran; Xu, Xiangmin

    2012-01-01

    Callaway, E. M. (2000). Laminar sources of synap- tic inputSvoboda, K. , et al. (2011). Laminar analysis of excitatoryand Svoboda, K. (2005). Laminar and columnar organization of

  18. Sandia Energy - Rotor Aerodynamic Design

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

    Aerodynamic Design Home Stationary Power Energy Conversion Efficiency Wind Energy Rotor Innovation Rotor Aerodynamic Design Rotor Aerodynamic DesignTara Camacho-Lopez2015-05-28T16:...

  19. Spiral Laminar Flow: A revolution in understanding?

    E-Print Network [OSTI]

    Greenaway, Alan

    Blood Flow Spiral laminar flow #12;Spiral flow in the Aorta (MRI) Computational Fluid Dynamics 0 10 20Spiral Laminar Flow: A revolution in understanding? Reintroduction of natural blood flow Laminar Flow through Runoff (3months) Proximal Anastomosis SLF TM Graft Distal Anastomosis Post-op Angios

  20. NEUROSYSTEMS Functional and laminar dissociations between muscarinic

    E-Print Network [OSTI]

    NEUROSYSTEMS Functional and laminar dissociations between muscarinic and nicotinic cholinergic was already greatest in the absence of pharmacological stimulation. Our results indicate that laminar position of receptors across the six layers of cortex, stimulating nAChR and mAChR with laminar specificity might offer

  1. LAMINAR: PRACTICAL FINE-GRAINED DECENTRALIZED INFORMATION

    E-Print Network [OSTI]

    Witchel, Emmett

    LAMINAR: PRACTICAL FINE-GRAINED DECENTRALIZED INFORMATION FLOW CONTROL (DIFC) Indrajit Roy, Donald} {} Information flow in a lattice #12;In this talk: Laminar A practical way to provide end-to-end security guarantees. #12;Outline Comparison with current DIFC systems Laminar: programming model Design: PL + OS

  2. Predicting aerodynamic characteristic of typical wind turbine airfoils using CFD

    SciTech Connect (OSTI)

    Wolfe, W.P. [Sandia National Labs., Albuquerque, NM (United States); Ochs, S.S. [Iowa State Univ., Ames, IA (United States). Aerospace Engineering Dept.

    1997-09-01

    An investigation was conducted into the capabilities and accuracy of a representative computational fluid dynamics code to predict the flow field and aerodynamic characteristics of typical wind-turbine airfoils. Comparisons of the computed pressure and aerodynamic coefficients were made with wind tunnel data. This work highlights two areas in CFD that require further investigation and development in order to enable accurate numerical simulations of flow about current generation wind-turbine airfoils: transition prediction and turbulence modeling. The results show that the laminar-to turbulent transition point must be modeled correctly to get accurate simulations for attached flow. Calculations also show that the standard turbulence model used in most commercial CFD codes, the k-e model, is not appropriate at angles of attack with flow separation. 14 refs., 28 figs., 4 tabs.

  3. Analysis of the laminar flamelet concept for nonpremixed laminar flames

    SciTech Connect (OSTI)

    Claramunt, K.; Consul, R.; Carbonell, D.; Perez-Segarra, C.D.

    2006-06-15

    The goal of this paper is to investigate the application of the laminar flamelet concept to the multidimensional numerical simulation of nonpremixed laminar flames. The performance of steady and unsteady flamelets is analyzed. The deduction of the mathematical formulation of flamelet modeling is exposed and some commonly used simplifications are examined. Different models for the scalar dissipation rate dependence on the mixture fraction variable are analyzed. Moreover, different criteria to evaluate the Lagrangian-type flamelet lifetime for unsteady flamelets are investigated. Inclusion of phenomena such as differential diffusion with constant Lewis number for each species and radiation heat transfer are also studied. A confined co-flow axisymmetric nonpremixed methane/air laminar flame experimentally investigated by McEnally and Pfefferle (Combust. Sci. Technol. 116-117 (1996) 183-209) and numerically investigated by Bennett, McEnally, Pfefferle, and Smooke (Combust. Flame 123 (2000) 522-546), Consul, Perez-Segarra, Claramunt, Cadafalch, and Oliva (Combust. Theory Modelling 7 (3) (2003) 525-544), and Claramunt, Consul, Perez-Segarra, and Oliva (Combust. Flame 137 (2004) 444-457) has been used as a test case. Results obtained using the flamelet concept have been compared to data obtained from the full resolution of the complete transport equations using primitive variables. Finite-volume techniques over staggered grids are used to discretize the governing equations. A parallel multiblock algorithm based on domain decomposition techniques running with loosely coupled computers has been used. To assess the quality of the numerical solutions presented in this paper, a verification process based on the generalized Richardson extrapolation technique and on the grid convergence index (GCI) has been applied. (author)

  4. Research Report Spikes, synchrony, and attentive learning by laminar

    E-Print Network [OSTI]

    Rucci, Michele

    Research Report Spikes, synchrony, and attentive learning by laminar thalamocortical circuits dynamics, spike-timing-dependent plasticity (STDP), and acetylcholine modulation; detailed laminar thalamic and beta frequency domains. In particular, the model predicts how laminar circuits of multiple cortical

  5. DEPARTMENT OF ENGINEERING SCIENCE High Pressure Laminar Burning

    E-Print Network [OSTI]

    DEPARTMENT OF ENGINEERING SCIENCE High Pressure Laminar Burning Velocity Measurements S. P data Cellularity Real residuals Results Future plans High Pressure Laminar Burning Velocity temperature 725 K High Pressure Laminar Burning Velocity Measurements October 27, 2008 Page 3 #12;System

  6. Some Observations Regarding Steady Laminar Flows Past Bluff Bodies

    E-Print Network [OSTI]

    Fornberg, Bengt

    Some Observations Regarding Steady Laminar Flows Past Bluff Bodies Bengt Fornberg Department, 2013. February 4, 2014 Abstract Steady laminar flows past simple objects, such as a cylinder

  7. Fifteen Lectures on Laminar and Turbulent Combustion

    E-Print Network [OSTI]

    Peters, Norbert

    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

  8. FORMATION OF ROLL WAVES IN LAMINAR SHEET FLOW

    E-Print Network [OSTI]

    Julien, Pierre Y.

    FORMATION OF ROLL WAVES IN LAMINAR SHEET FLOW by Pierre Y. Julien and David M. Hartley January 1985 . . . . . . . . . . . . . . . . . . . . . . . . . 1 I1. THEORY ON THE STABILITY OF LAMINAR SHEET FLOW . . . . . . . . . 3 2.1 Steady uniform laminar of the Coefficients fj and y for Laminar Sheet Flow . . . . . . . . . . . . . . 26 APPENDIX I1 .Experimental Data

  9. Computational Aerodynamics and Aeroacoustics for Wind Turbines

    E-Print Network [OSTI]

    Computational Aerodynamics and Aeroacoustics for Wind Turbines #12;#12;Computational Aerodynamics and Aeroacoustics for Wind Turbines Wen Zhong Shen Fluid Mechanics Department of Mechanical Engineering TECHNICAL Shen, Wen Zhong Computational Aerodynamics and Aeroacoustics for Wind Turbines Doctor Thesis Technical

  10. Freight Wing Trailer Aerodynamics

    SciTech Connect (OSTI)

    Graham, Sean (Primary Investigator); Bigatel, Patrick

    2004-10-17

    Freight Wing Incorporated utilized the opportunity presented by this DOE category one Inventions and Innovations grant to successfully research, develop, test, patent, market, and sell innovative fuel and emissions saving aerodynamic attachments for the trucking industry. A great deal of past scientific research has demonstrated that streamlining box shaped semi-trailers can significantly reduce a truck's fuel consumption. However, significant design challenges have prevented past concepts from meeting industry needs. Market research early in this project revealed the demands of truck fleet operators regarding aerodynamic attachments. Products must not only save fuel, but cannot interfere with the operation of the truck, require significant maintenance, add significant weight, and must be extremely durable. Furthermore, SAE/TMC J1321 tests performed by a respected independent laboratory are necessary for large fleets to even consider purchase. Freight Wing used this information to create a system of three practical aerodynamic attachments for the front, rear and undercarriage of standard semi trailers. SAE/TMC J1321 Type II tests preformed by the Transportation Research Center (TRC) demonstrated a 7% improvement to fuel economy with all three products. If Freight Wing is successful in its continued efforts to gain market penetration, the energy and environmental savings would be considerable. Each truck outfitted saves approximately 1,100 gallons of fuel every 100,000 miles, which prevents over 12 tons of CO2 from entering the atmosphere. If all applicable trailers used the technology, the country could save approximately 1.8 billion gallons of diesel fuel, 18 million tons of emissions and 3.6 billion dollars annually.

  11. Laminar Flow Control Flight Experiment Design 

    E-Print Network [OSTI]

    Tucker, Aaron 1975-

    2012-11-29

    Demonstration of spanwise-periodic discrete roughness element laminar flow control (DRE LFC) technology at operationally relevant flight regimes requires extremely stable flow conditions in flight. A balance must be struck ...

  12. Integrated External Aerodynamic and Underhood Thermal Analysis...

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

    External Aerodynamic and Underhood Thermal Analysis for Heavy Vehicles Integrated External Aerodynamic and Underhood Thermal Analysis for Heavy Vehicles 2012 DOE Hydrogen and Fuel...

  13. Aerodynamic characteristics of seven symmetrical airfoil sections...

    Office of Scientific and Technical Information (OSTI)

    180-degree angle of attack for use in aerodynamic analysis of vertical axis wind turbines Citation Details In-Document Search Title: Aerodynamic characteristics of seven...

  14. Roles for Wnts and their receptors in topographic mapping and laminar termination

    E-Print Network [OSTI]

    Richman, Alisha

    2011-01-01

    Zhang Y, Meister M, Sanes JR. Laminar restriction of retinalsemaphorin signaling controls laminar stratification in thesignaling in tectal laminar formation. CSH Meeting on Axon

  15. Laminar flame speeds of moist syngas mixtures

    SciTech Connect (OSTI)

    Das, Apurba K. [Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Kumar, Kamal; Sung, Chih-Jen [Department of Mechanical Engineering, University of Connecticut, Storrs, CT 06269 (United States)

    2011-02-15

    This work experimentally investigates the effect of the presence of water vapor on the laminar flame speeds of moist syngas/air mixtures using the counterflow twin-flame configuration. The experimental results presented here are for fuel lean syngas mixtures with molar percentage of hydrogen in the hydrogen and carbon monoxide mixture varying from 5% to 100%, for an unburned mixture temperature of 323 K, and under atmospheric pressure. At a given equivalence ratio, the effect of varying amount of water vapor addition on the measured laminar flame speed is demonstrated. The experimental laminar flame speeds are also compared with computed values using chemical kinetic mechanisms reported in the literature. It is found that laminar flame speed varies non-monotonically with addition of water for the carbon monoxide rich mixtures. It first increases with increasing amount of water addition, reaches a maximum value, and then decreases. An integrated reaction path analysis is further conducted to understand the controlling mechanism responsible for the non-monotonic variation in laminar flame speed due to water addition. On the other hand, for higher values of H{sub 2}/CO ratio the laminar flame speed monotonically decreases with increasing water addition. It is shown that the competition between the chemical and thermal effects of water addition leads to the observed response. Furthermore, reaction rate sensitivity analysis as well as binary diffusion coefficient sensitivity analysis are conducted to identify the possible sources of discrepancy between the experimental and predicted values. The sensitivity results indicate that the reaction rate constant of H{sub 2}+OH = H{sub 2}O+H is worth revisiting and refinement of binary diffusion coefficient data of N{sub 2}-H{sub 2}O, N{sub 2}-H{sub 2}, and H{sub 2}-H{sub 2}O pairs can be considered. (author)

  16. Numerical Simulation of Laminar Reacting Flows with Complex Chemistry

    E-Print Network [OSTI]

    Bell, John B.

    Numerical Simulation of Laminar Reacting Flows with Complex Chemistry M S Day and J B Bell Lawrence Simulation of Laminar Reacting Flows 2 1. Introduction Detailed modelling of time-dependent reacting ows

  17. Numerical Simulation of Laminar Reacting Flows with Complex Chemistry

    E-Print Network [OSTI]

    Bell, John B.

    Numerical Simulation of Laminar Reacting Flows with Complex Chemistry M S Day and J B Bell Lawrence: 47.40.Fw, 82.40.Py Submitted to: Combust. Theory Modelling #12;Numerical Simulation of Laminar

  18. TURBULENT-LAMINAR PATTERNS IN PLANE COUETTE Dwight Barkley

    E-Print Network [OSTI]

    Barkley, Dwight

    @limsi.fr Abstract Regular patterns of turbulent and laminar fluid motion arise in plane Couette flow near the lowest and is the kinematic viscosity of the fluid. See figure 1. For all val- ues of ¡£¢ , laminar Couette flow at an angle to the streamwise direction. Fluid flows exhibiting coexisting turbulent and laminar regions have

  19. Transverse Diffusion of Laminar Flow Profiles To Produce Capillary Nanoreactors

    E-Print Network [OSTI]

    Krylov, Sergey

    Transverse Diffusion of Laminar Flow Profiles To Produce Capillary Nanoreactors Victor Okhonin, Xin We introduce transverse diffusion of laminar flow profiles (TDLFP), the first generic method the capillary by pressure as a series of consecutive plugs. Due to the laminar nature of flow inside

  20. The Timetable of Laminar Neurogenesis Contributes to the Specification of

    E-Print Network [OSTI]

    Polleux, Franck

    The Timetable of Laminar Neurogenesis Contributes to the Specification of Cortical Areas in Mouse on either side of the 17-18 border suggesting that there might be different timetables of laminar compute the timetable of laminar histogenesis from birthdating experiments. Here we report the results

  1. AIAA 2004-2311 Toward Practical Laminar Flow Control--

    E-Print Network [OSTI]

    AIAA 2004-2311 Toward Practical Laminar Flow Control-- Remaining Challenges William S. Saric rights reserved. 1 American Institute of Aeronautics and Astronautics #12;Toward Practical Laminar Flow Arizona State University Tempe AZ 85287-6106 ABSTRACT Different laminar flow control strategies

  2. Starting laminar plumes: Comparison of laboratory and numerical modeling

    E-Print Network [OSTI]

    van Keken, Peter

    Starting laminar plumes: Comparison of laboratory and numerical modeling Judith Vatteville Institut, France (davaille@fast.u-psud.fr) [1] A detailed comparison of starting laminar plumes in viscous fluids. Davaille (2009), Starting laminar plumes: Comparison of laboratory and numerical modeling, Geochem. Geophys

  3. The Time-Dependent NavierStokes Equations Laminar Flows

    E-Print Network [OSTI]

    John, Volker

    Chapter 6 The Time-Dependent Navier­Stokes Equations ­ Laminar Flows Remark 6.1. Motivation to distinguish between laminar and turbulent flows. It does not exist an exact definition of these terms. From the point of view of simulations, a flow is considered to be laminar, if on reasonable grids all flow

  4. Laminar: Practical Fine-Grained Decentralized Information Flow Control

    E-Print Network [OSTI]

    Witchel, Emmett

    Laminar: Practical Fine-Grained Decentralized Information Flow Control Indrajit Roy Donald E-grained program data structures. This paper describes Laminar, the first system to implement de- centralized the labeled data in lexically scoped secu- rity regions. Laminar enforces the security policies specified

  5. Persistently laminar branched surfaces Ying-Qing Wu

    E-Print Network [OSTI]

    Wu, Ying-Qing

    Persistently laminar branched surfaces Ying-Qing Wu Abstract We define sink marks for branched that a non 2-bridge Mon- tesinos knot K has a persistently laminar branched surface unless it is equivalent that there are many persistently laminar tangles. 1 Introduction Essential lamination plays an important role

  6. Laminar Entrained Flow Reactor (Fact Sheet)

    SciTech Connect (OSTI)

    Not Available

    2014-02-01

    The Laminar Entrained Flow Reactor (LEFR) is a modular, lab scale, single-user reactor for the study of catalytic fast pyrolysis (CFP). This system can be employed to study a variety of reactor conditions for both in situ and ex situ CFP.

  7. CFD-based Optimization for Automotive Aerodynamics

    E-Print Network [OSTI]

    Dumas, Laurent

    Chapter 1 CFD-based Optimization for Automotive Aerodynamics Laurent Dumas Abstract The car drag- ments. An overview of the main characteristics of automotive aerodynamics and a detailed presentation.dumas@upmc.fr) 1 #12;2 Laurent Dumas 1.1 Introducing Automotive Aerodynamics 1.1.1 A Major Concern for Car

  8. CFD analysis of laminar oscillating flows

    SciTech Connect (OSTI)

    Booten, C. W. Charles W.); Konecni, S.; Smith, B. L.; Martin, R. A.

    2001-01-01

    This paper describes a numerical simulations of oscillating flow in a constricted duct and compares the results with experimental and theoretical data. The numerical simulations were performed using the computational fluid dynamics (CFD) code CFX4.2. The numerical model simulates an experimental oscillating flow facility that was designed to test the properties and characteristics of oscillating flow in tapered ducts, also known as jet pumps. Jet pumps are useful devices in thermoacoustic machinery because they produce a secondary pressure that can counteract an unwanted effect called streaming, and significantly enhance engine efficiency. The simulations revealed that CFX could accurately model velocity, shear stress and pressure variations in laminar oscillating flow. The numerical results were compared to experimental data and theoretical predictions with varying success. The least accurate numerical results were obtained when laminar flow approached transition to turbulent flow.

  9. TIMEINTEGRATION METHODS IN COMPUTATIONAL AERODYNAMICS

    E-Print Network [OSTI]

    Stanford University

    flow & % #12;' $ Aerodynamic Flow computations AIRPLANE DENSITY from 0.6250 to 1.1000 AIRPLANE CP from AIRPLANE DENSITY from 0.6250 to 1.1000 AIRPLANE DENSITY from 0.0000 to 2.0000 Density contours for transonic and supersonic flow over the MD-11 and Hermes Space Shuttle & % #12;' $ Mach Number Contours

  10. The role of Krüppel-Like factor 2 in mediating the atheroprotective functions of pulsatile laminar flow in vascular endothelium

    E-Print Network [OSTI]

    Young, Angela Chien-hsin

    2008-01-01

    M. Mitsumata, et al. (2000). "Laminar shear stress inhibitsdisturbed flow and steady laminar flow." Physiol Genomics 9(of endothelial growth arrest by laminar shear stress." Proc

  11. Soot particle size measurements in laminar premixed ethylene flames with laser-induced incandescence and scanning mobility particle sizer

    E-Print Network [OSTI]

    Yin, Chung-Yuan

    2009-01-01

    Size Measurements in Laminar Premixed Ethylene Flames withof soot aggregate sampled from a laminar acetyleneSize Measurements in Laminar Premixed Ethylene Flames with

  12. TOWARDS A UNIFIED THEORY OF NEOCORTEX: Laminar Cortical Circuits for Vision and Cognition

    E-Print Network [OSTI]

    Grossberg, Stephen

    TOWARDS A UNIFIED THEORY OF NEOCORTEX: Laminar Cortical Circuits for Vision and Cognition Stephen laminar neocortical circuits give rise to biological intelligence. These circuits embody two new and revolutionary computational paradigms: Complementary Computing and Laminar Computing. Circuit properties include

  13. Demonstration of a plasma mirror based on a laminar flow water film

    E-Print Network [OSTI]

    Panasenko, Dmitriy

    2012-01-01

    Benjamin, “Wave Formation in Laminar Flow down an Inclineda plasma mirror based on a laminar flow water film. DmitriyA plasma mirror based on a laminar water film with low flow

  14. Preconditioned Multigrid Simulation of an Axisymmetric Laminar Diffusion Flame \\Lambda

    E-Print Network [OSTI]

    Zhang, Jun

    kinetics models or turbulent reacting flows. In this work we are interested in a simple model of laminar structure more accurately, we use the vorticity­velocity formulation of the fluid flow equations [1, 3Preconditioned Multigrid Simulation of an Axisymmetric Laminar Diffusion Flame \\Lambda Samir Karaa

  15. DETAILED CHEMISTRY MODELING OF LAMINAR DIFFUSION FLAMES ON PARALLEL COMPUTERS

    E-Print Network [OSTI]

    . The gas­jet diffusion flame is the basic element of many combustion systems, such as gas turbines, ram­speed, three­dimensional, turbulent reacting systems, gas­jet laminar diffusion flames constitute a problem jets, and industrial furnaces. Furthermore, the fundamental understand­ ing of laminar diffusion flames

  16. Aerodynamic characteristics of seven symmetrical airfoil sections...

    Office of Scientific and Technical Information (OSTI)

    axis wind turbines Sheldahl, R E; Klimas, P C 17 WIND ENERGY; DARRIEUS ROTORS; TURBINE BLADES; AERODYNAMICS; AIRFOILS; COMPARATIVE EVALUATIONS; DATA COMPILATION;...

  17. AERODYNAMIC AND ELECTROMECHANICAL DESIGN, MODELING AND IMPLEMENTATION OF

    E-Print Network [OSTI]

    Kochersberger, Kevin

    AERODYNAMIC AND ELECTROMECHANICAL DESIGN, MODELING AND IMPLEMENTATION OF PIEZOCOMPOSITE AIRFOILS, Macro-Fiber Composite, Unimorph, Bimorph © Onur Bilgen, 2010 #12;AERODYNAMIC AND ELECTROMECHANICAL of the aerodynamic and electromechanical systems that are necessary for a practical implementation

  18. Sandia Energy - Rotor Aerodynamic Design

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach Home RoomPreservation of Fe(II)Geothermal EnergyRenewable Energy IntegrationRisk and SafetyAerodynamic

  19. Laminar Flow-Based Electrochemical Microreactor for Efficient Regeneration of Nicotinamide Cofactors for Biocatalysis

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Laminar Flow-Based Electrochemical Microreactor for Efficient Regeneration of Nicotinamide the more widespread use of biocatalysis.2 Here, we utilize multistream laminar flow in a microreactor the occurrence of laminar flow in microscale channels: Multistream laminar flow enables focusing of a reagent

  20. Laminar-Turbulent Transition: Calculation of Minimum Critical Reynolds Number in Channel Flow

    E-Print Network [OSTI]

    Laminar-Turbulent Transition: Calculation of Minimum Critical Reynolds Number in Channel Flow) for laminar-turbulent transition in pipe and channel flows. For pipe flow, the minimum critical Reynolds laminar to turbulent flow Rc2 Rc from turbulent to laminar flow Rc(min) minimum Rc Re Reynolds number = UH

  1. Inductively coupled plasma torch with laminar flow cooling

    DOE Patents [OSTI]

    Rayson, Gary D. (Las Cruces, NM); Shen, Yang (Las Cruces, NM)

    1991-04-30

    An improved inductively coupled gas plasma torch. The torch includes inner and outer quartz sleeves and tubular insert snugly fitted between the sleeves. The insert includes outwardly opening longitudinal channels. Gas flowing through the channels of the insert emerges in a laminar flow along the inside surface of the outer sleeve, in the zone of plasma heating. The laminar flow cools the outer sleeve and enables the torch to operate at lower electrical power and gas consumption levels additionally, the laminar flow reduces noise levels in spectroscopic measurements of the gaseous plasma.

  2. Conceptual design for a laminar-flying-wing aircraft

    E-Print Network [OSTI]

    Saeed, Tariq Issam

    2012-06-12

    The laminar-flying-wing aircraft appears to be an attractive long-term prospect for reducing the environmental impact of commercial aviation. In assessing its potential, a relatively straightforward initial step is the conceptual design of a...

  3. The effects of surface instabilities on laminar film condensation

    E-Print Network [OSTI]

    Gerstmann, Joseph

    1965-01-01

    Heat transfer rates for laminar film condensation of Freon-1l3 were measured on the underside of horizontal surfaces, inclined surfaces, and vertical surfaces. Several distinct regimes of flow were observed. On the underside ...

  4. 16.100 Aerodynamics, Fall 2002

    E-Print Network [OSTI]

    Darmofal, David L.

    This course extends fluid mechanic concepts from Unified Engineering to the aerodynamic performance of wings and bodies in sub/supersonic regimes. 16.100 generally has four components: subsonic potential flows, including ...

  5. Inequality design limits in optimal aerodynamic shapes 

    E-Print Network [OSTI]

    Seaman, Charles Knight

    1968-01-01

    INEQUALITY DESIGN LIMITS IN OPTIMAL AERODYNAMIC SHAPES A Thesis By CHARLES KNIGHT SEAMAN Submitted to the Graduate College of the Texas A&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE May 1968... Major Subject: Aerospace Engineering INEQUALITY DESIGN LIMITS IN OPTIMAL AERODYNAMIC SHAPES A Thesis By CHARLES KNIGHT SEAMAN Approved as to style and content by: (Chairman of Committee) (Head of Department) (Member) (Member) May 1968...

  6. Reconstruction and Visualization of Fiber and Laminar Structure in the Normal Human Heart from Ex Vivo DTMRI Data

    E-Print Network [OSTI]

    Rohmer, Damien; Sitek, Arkadiusz; Gullberg, Grant T.

    2006-01-01

    Visualization of Fiber and Laminar Structure in the NormalY, McCulloch AD, Covell JW. Laminar fiber architecture andfunction of human myocardial laminar sheets in vivo. Magn

  7. A New Type of Steady and Stable, Laminar, Premixed Flame in Ultra-Lean, Hydrogen-Air Combustion

    E-Print Network [OSTI]

    Grcar, Joseph F

    2008-01-01

    for Modeling Steady, Laminar, One-Dimensional PremixedType of Steady and Stable, Laminar, Premixed Flame in Ultra-to support another kind of laminar ?ame that is steady and

  8. Hybrid Identities

    E-Print Network [OSTI]

    Montclair, Sani

    2012-01-01

    Hybrid Identity; Family, Photography and History in Colonialintersectional politics of hybrid identity is the primarycreated a distinctively hybrid culture, one where language,

  9. Type I Planet Migration in Nearly Laminar Disks

    E-Print Network [OSTI]

    H. Li; S. H. Lubow; S. Li; D. N. C. Lin

    2008-12-02

    We describe 2D hydrodynamic simulations of the migration of low-mass planets ($\\leq 30 M_{\\oplus}$) in nearly laminar disks (viscosity parameter $\\alpha laminar disks. For $\\alpha \\ga 10^{-3}$, density feedback effects are washed out and Type I migration persists. The critical masses are in good agreement with the analytic model of Rafikov (2002). In addition, for $\\alpha \\la 10^{-4}$ steep density gradients produce a vortex instability, resulting in a small time-varying eccentricity in the planet's orbit and a slight outward migration. Migration in nearly laminar disks may be sufficiently slow to reconcile the timescales of migration theory with those of giant planet formation in the core accretion model.

  10. Advances on Matroid Secretary Problems: Free Order Model and Laminar Case

    E-Print Network [OSTI]

    Jaillet, Patrick

    Advances on Matroid Secretary Problems: Free Order Model and Laminar Case Patrick Jaillet Jos´e A are interviewed. Furthermore, we consider the classical matroid secretary problem for the special case of laminar

  11. Laminar flow cells for single-molecule studies of DNA-protein interactions

    E-Print Network [OSTI]

    Cai, Long

    Laminar flow cells for single-molecule studies of DNA-protein interactions Laurence R Brewer1 in which the interactions of proteins with DNA have been studied within the confines of laminar flow cells

  12. The effects of laminar mixing on reaction fronts and patterns I. Introduction

    E-Print Network [OSTI]

    Solomon, Tom

    The effects of laminar mixing on reaction fronts and patterns I. Introduction A wide variety scales that are often smaller than a micron. For small Re, the flow is laminar; in this situation

  13. Advances on Matroid Secretary Problems: Free Order Model and Laminar Case

    E-Print Network [OSTI]

    Jaillet, Patrick

    Advances on Matroid Secretary Problems: Free Order Model and Laminar Case Patrick Jaillet1 , Jos are interviewed. Furthermore, we consider the classical matroid secretary problem for the special case of laminar

  14. Bubble transport in three-dimensional laminar gravity-driven flow mathematical formulation

    E-Print Network [OSTI]

    Pilon, Laurent

    Bubble transport in three-dimensional laminar gravity-driven flow ­ mathematical formulation, growth and shrinkage in three-dimensional flows. The flow is assumed to be laminar for the sake

  15. Laminar and Columnar Distribution of Geniculo-cortical Fibers in the Macaque Monkey

    E-Print Network [OSTI]

    Hubel, David

    Laminar and Columnar Distribution of Geniculo-cortical Fibers in the Macaque Monkey DAVID H-Heimer modiikation of the Nauta method. We hoped to correlate the laminar distribution of axon terminals

  16. Interactions between Soot and CH* in a Laminar Boundary Layer Type Diffusion Flame in Microgravity 

    E-Print Network [OSTI]

    Fuentes, Andres; Legros, Guillaume; Claverie, Alain; Joulain, Pierre; Vantelon, Jean-Pierre; Torero, Jose L

    A three-dimensional laminar non-buoyant diffusion flame was studied with the objective of improving the understanding of the soot production. The flame originated from a porous ethylene burner discharging into a laminar ...

  17. Natural versus forced convection in laminar starting plumes Michael C. Rogers and Stephen W. Morris

    E-Print Network [OSTI]

    Morris, Stephen W.

    fluid from a small, submerged outlet. The plumes were laminar and spanned a wide range of plume, the most important fac- tor determining jet or plume behaviour and evolution is whether the flow is laminar orNatural versus forced convection in laminar starting plumes Michael C. Rogers and Stephen W. Morris

  18. Analysis of Thermal Dispersion in an Array of Parallel Plates with Fully-Developed Laminar Flow

    E-Print Network [OSTI]

    Fleck, Norman A.

    basic heat transfer problems are addressed, each for steady fully-developed laminar fluid flow: (a1 Analysis of Thermal Dispersion in an Array of Parallel Plates with Fully-Developed Laminar Flow dispersion, parallel plate array, fully-developed laminar flow, Peclet number #12;2 Notation a molecular

  19. Distinct large-scale turbulent-laminar states in transitional pipe flow

    E-Print Network [OSTI]

    Barkley, Dwight

    ) When fluid flows through a channel, pipe, or duct, there are two basic forms of motion: smooth laminarDistinct large-scale turbulent-laminar states in transitional pipe flow David Moxey1 and Dwight alternat- ing turbulent-laminar flow states on long length scales in subcri- tical shear flows (12

  20. A laminar cortical model of stereopsis and three-dimensional surface perception

    E-Print Network [OSTI]

    Grossberg, Stephen

    A laminar cortical model of stereopsis and three-dimensional surface perception Stephen Grossberg University 677 Beacon Street, Boston, MA 02215, USA Running title: Laminar cortical model of depth perception;1 Abstract A laminar cortical model of stereopsis and later stages of 3D surface perception is developed

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

    E-Print Network [OSTI]

    Chung, Yongmann M.

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

  2. A multi-level local defect correction technique for laminar flame simulation

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    A multi-level local defect correction technique for laminar flame simulation J.H.M. ten Thije to solve the low-Mach number approximation of the conservation laws for laminar flames. Elements of our, describing expansion of the gas mixture due to combustion. Boundary value problems for laminar flames

  3. Polymer Brushes Patterned with Micrometer-Scale Chemical Gradients Using Laminar Co-Flow

    E-Print Network [OSTI]

    Braun, Paul

    Polymer Brushes Patterned with Micrometer-Scale Chemical Gradients Using Laminar Co-Flow Hyung as narrow as 5 m was created by controlling these parameters. The chemical gradient by laminar co validates the numerical procedures established in this study. Flow of multiple laminar streams of reactive

  4. Context-Sensitive Binding by the Laminar Circuits of V1 and V2

    E-Print Network [OSTI]

    Grossberg, Stephen

    Context-Sensitive Binding by the Laminar Circuits of V1 and V2: A Unified Model of Perceptual A detailed neural model is presented of how the laminar circuits of visual cortical areas V1 and V2 implement specific laminar circuits allow the responses of visual cortical neurons to be determined not only

  5. Active Control of Instabilities in Laminar BoundaryLayer Flow--Part I: An Overview

    E-Print Network [OSTI]

    Erlebacher, Gordon

    Active Control of Instabilities in Laminar Boundary­Layer Flow-- Part I: An Overview Ronald D laminar flow in a region of the flow in which the natural instabilities, if left unattended, lead have been restricted to maintaining laminar flow through use of a technique termed ``wave cancellation

  6. Interpolation between DarcyWeisbach and Darcy for laminar and turbulent flows

    E-Print Network [OSTI]

    Walter, M.Todd

    Interpolation between Darcy­Weisbach and Darcy for laminar and turbulent flows W.L. Hogarth a, *, J the square of the velocity is proportional to the hydraulic gradient and if the flow is laminar, which­Weisbach; Porous media; Open channels; Turbulent flow; Laminar flow 1. Introduction Grassed waterways

  7. A Flamelet Description of Premixed Laminar Flames and the Relation with Flame Stretch

    E-Print Network [OSTI]

    Eindhoven, Technische Universiteit

    1 A Flamelet Description of Premixed Laminar Flames and the Relation with Flame Stretch L.P.H. de of Mathematics and Computing Science, PO Box 513, 5600MB Eindhoven, The Netherlands ABSTRACT ­ A laminar flamelet description is derived for premixed laminar flames. The full set of 3D instationary combustion equations

  8. Near-limit laminar burning velocities of microgravity premixed hydrogen flames

    E-Print Network [OSTI]

    Qiao, Li

    Near-limit laminar burning velocities of microgravity premixed hydrogen flames with chemically of chemically-passive fire suppressants on laminar premixed hydrogen flames were investigated by combined use that provides at least 450 ms of 10À2 g. Near-limit laminar burning velocities were measured for outwardly

  9. Efficient numerical methods for the instationary solution of laminar reacting gas

    E-Print Network [OSTI]

    Vuik, Kees

    Efficient numerical methods for the instationary solution of laminar reacting gas flow problems Universiteit Delft Efficient numerical methods for the instationary solution of laminar reacting gas flow of laminar reacting gas flow problems Sander van Veldhuizen Production processes of high-purity, high

  10. How laminar frontal cortex and basal ganglia circuits interact to control planned and reactive saccades

    E-Print Network [OSTI]

    Crawford, Doug

    How laminar frontal cortex and basal ganglia circuits interact to control planned and reactive reactive behaviors are insufficient. This paper proposes a new model, called TELOS, to explain how laminar). In amphibians and all land vertebrates, the BG interact with a laminar structure, the optic tectum (OT), or its

  11. Under consideration for publication in J. Fluid Mech. 1 Averaging method for nonlinear laminar

    E-Print Network [OSTI]

    Lautrup, Benny

    Under consideration for publication in J. Fluid Mech. 1 Averaging method for nonlinear laminar Copenhagen Ã?, Denmark (Received October 10, 2002) We study laminar Ekman boundary layers in rotating systems method to describe laminar and turbulent boundary layers in rotating fluids. They used a self

  12. ContextSensitive Binding by the Laminar Circuits of V1 and V2

    E-Print Network [OSTI]

    Grossberg, Stephen

    Context­Sensitive Binding by the Laminar Circuits of V1 and V2: Unified Model Perceptual Grouping is presented how laminar circuits visual cortical areas implement context­sensitive binding processes such perceptual grouping and attention. model proposes how specific laminar circuits allow responses visual

  13. The antiinflammatory effect of laminar flow: The role of PPAR , epoxyeicosatrienoic acids,

    E-Print Network [OSTI]

    Hammock, Bruce D.

    The antiinflammatory effect of laminar flow: The role of PPAR , epoxyeicosatrienoic acids Contributed by Bruce D. Hammock, September 16, 2005 We previously reported that laminar flow activates. Inclusion of AUDA in the perfusing media enhanced, but overexpression of sEH reduced, the laminar flow

  14. Stereopsis and 3D Surface Perception by Spiking Neurons in Laminar Cortical Circuits

    E-Print Network [OSTI]

    Grossberg, Stephen

    Stereopsis and 3D Surface Perception by Spiking Neurons in Laminar Cortical Circuits: A Method, USA Running title: Spiking laminar cortical model of depth perception Neural Networks, in pressNAPSE program of DARPA (HR0011-09-C- 0001). #12;2 Abstract A laminar cortical model of stereopsis and 3D surface

  15. A numerical study on the effects of pressure and gravity in laminar ethylene diffusion flames

    E-Print Network [OSTI]

    Gülder, Ömer L.

    A numerical study on the effects of pressure and gravity in laminar ethylene diffusion flames Marc 26 March 2011 Keywords: High-pressure Zero-gravity Laminar ethylene diffusion flames Soot modeling were studied numeri- cally in coflow ethylene­air laminar diffusion flames between 0.5 and 5 atm

  16. A comparison of computational and experimental lift-off heights of coflow laminar diffusion flames

    E-Print Network [OSTI]

    Long, Marshall B.

    A comparison of computational and experimental lift-off heights of coflow laminar diffusion flames*), and excited-state OH (denoted OH*) are imaged in coflow laminar diffusion flames. Measurements are made both was performed, which indicates that the lift-off height is sensitive to the laminar flame speed

  17. American Institute of Aeronautics and Astronautics Effects of Surface Roughness on Laminar Separation Bubble over a

    E-Print Network [OSTI]

    Wang, Zhi Jian "ZJ"

    1 American Institute of Aeronautics and Astronautics Effects of Surface Roughness on Laminar Engineering and CFD Center, Iowa State University, Ames, IA 50011 Laminar separation bubbles (LSBs) are often of surface roughness on laminar separation and turbulent transition can provide insights into the design

  18. Estimation of population ring rates and current source densities from laminar electrode

    E-Print Network [OSTI]

    Einevoll, Gaute T.

    Estimation of population ring rates and current source densities from laminar electrode recordings Neuroscience, 2007-2008 #12;1 Introduction Recordings of extracellular potentials with laminar electrodes, i), Schroeder et al. (2001), Ulbert et al. (2001), Buzsaki (2004), Einevoll et al. (2007). The laminar

  19. Computational Study of Turbulent Laminar Patterns in Couette Flow Dwight Barkley*

    E-Print Network [OSTI]

    Barkley, Dwight

    Computational Study of Turbulent Laminar Patterns in Couette Flow Dwight Barkley* Mathematics, 91403 Orsay, France (Received 29 March 2004; published 7 January 2005) Turbulent-laminar patterns near--undergoes a discontinuous transition from laminar flow to turbulence as the Reynolds number is increased. Because of its

  20. E ective boundary conditions for laminar ows over periodic rough boundaries

    E-Print Network [OSTI]

    Achdou, Yves

    E#27;ective boundary conditions for laminar #29;ows over periodic rough boundaries Yves Achdou #3 are proposed for a laminar #29;ow over a rough wall with periodic roughness elements. These e#27;ective is such an approach ? In this paper, we wish to answer these questions for laminar #29;ows over periodic rough walls

  1. Interpolation between DarcyWeisbach and Darcy for laminar and turbulent flows

    E-Print Network [OSTI]

    Interpolation between Darcy­Weisbach and Darcy for laminar and turbulent flows W.L. Hogarth a,*, J is laminar, which is the usual case, the velocity is proportional to the hydraulic gradient. This last result: Darcy; Darcy­Weisbach; Porous media; Open channels; Turbulent flow; Laminar flow 1. Introduction Grassed

  2. Pressure-Driven Laminar Flow in Tangential Microchannels: an Elastomeric Microfluidic

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Pressure-Driven Laminar Flow in Tangential Microchannels: an Elastomeric Microfluidic Switch Rustem, Massachusetts 02138 This paper describes laminar fluid flow through a three- dimensional elastomeric pressure and changing this aspect ratio. Second, the flow direction of an indi- vidual laminar stream

  3. Laminar drag reduction in microchannels using ultrahydrophobic surfaces Jia Ou, Blair Perot, and Jonathan P. Rothstein

    E-Print Network [OSTI]

    Rothstein, Jonathan

    Laminar drag reduction in microchannels using ultrahydrophobic surfaces Jia Ou, Blair Perot for the laminar flow of water through microchannels using hydrophobic surfaces with well-defined micron flow is laminar and not turbulent, there are currently few demon- strated methods for significantly

  4. A numerical study on the effects of pressure and gravity in laminar ethylene diffusion flames

    E-Print Network [OSTI]

    Groth, Clinton P. T.

    A numerical study on the effects of pressure and gravity in laminar ethylene diffusion flames Marc xxxx Keywords: High-pressure Zero-gravity Laminar ethylene diffusion flames Soot modeling a b s t r a c in coflow ethylene­air laminar diffusion flames between 0.5 and 5 atm. Computations were per- formed

  5. Laminar Flow of a Sheared Vortex Crystal: Scars in Flat Geometry M.-Carmen Miguel,1

    E-Print Network [OSTI]

    Miguel-Lopez, Carmen

    Laminar Flow of a Sheared Vortex Crystal: Scars in Flat Geometry M.-Carmen Miguel,1 Adil Mughal,2 November 2010; published 15 June 2011) We consider the laminar flow of a vortex crystal in the Corbino disk geometry. Laminar flow can be induced by thermal fluctuations melting the crystal, but also by shear stress

  6. Compressible laminar streaks with wall suction Pierre Ricco, Daniel Shah, and Peter D. Hicks

    E-Print Network [OSTI]

    Matthews, Adrian

    Compressible laminar streaks with wall suction Pierre Ricco, Daniel Shah, and Peter D. Hicks laminar streaks with wall suction Pierre Ricco,1 Daniel Shah,2 and Peter D. Hicks3 1 Department May 2013) The response of a compressible laminar boundary layer subject to free-stream vor- tical

  7. Soot formation in high pressure laminar diffusion flames Ahmet E. Karatas *, mer L. Glder

    E-Print Network [OSTI]

    Gülder, Ömer L.

    Review Soot formation in high pressure laminar diffusion flames Ahmet E. Karatas¸ *, Ömer L. Gülder online 30 June 2012 Keywords: High pressure soot formation High pressure combustion Laminar diffusion laminar co-flow diffusion flames burning at elevated pressures. First, a brief review of soot formation

  8. Laminar Cortical Dynamics of Cognitive and Motor Working Memory, Sequence Learning and Performance

    E-Print Network [OSTI]

    Grossberg, Stephen

    Laminar Cortical Dynamics of Cognitive and Motor Working Memory, Sequence Learning and Performance cells, cerebral cortex, laminar computing * Authors are listed in alphabetical order. 1 Supported share the same type of circuit design. It proposes how the laminar circuits of lateral prefrontal cortex

  9. Three-dimensionality of sand ripples under steady laminar shear flow

    E-Print Network [OSTI]

    Three-dimensionality of sand ripples under steady laminar shear flow V. Langlois and A. Valance laminar shear flow using a process-based stability approach. The hydrodynamics of the problem is solved under steady laminar shear flow, J. Geophys. Res., 110, F04S09, doi:10.1029/2004JF000278. 1

  10. Six Degree of Freedom Morphing Aircraft Dynamical Model with Aerodynamics 

    E-Print Network [OSTI]

    Niksch, Adam

    2010-01-14

    model of a morphing aircraft is needed. This paper develops an aerodynamic model and a dynamic model of a morphing flying wing aircraft. The dynamic model includes realistic aerodynamic forces, consisting of lift, drag, and pitching moment about...

  11. The Aerodynamic Performance Of Platoons: A Final Report

    E-Print Network [OSTI]

    Zabat, Michael; Stabile, Nick; Farascaroli, Stefano; Browand, Frederick

    1995-01-01

    iii) Measurements of aerodynamic forces in a crosswind.The presence of a crosswind is another important platoon

  12. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOE Patents [OSTI]

    Maschke, A.W.

    1984-04-16

    A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow through the assembly.

  13. Electrostatic quadrupole focused particle accelerating assembly with laminar flow beam

    DOE Patents [OSTI]

    Maschke, Alfred W. (East Moriches, NY)

    1985-01-01

    A charged particle accelerating assembly provided with a predetermined ratio of parametric structural characteristics and with related operating voltages applied to each of its linearly spaced focusing and accelerating quadrupoles, thereby to maintain a particle beam traversing the electrostatic fields of the quadrupoles in the assembly in an essentially laminar flow throughout the assembly.

  14. RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS

    E-Print Network [OSTI]

    Paris-Sud XI, Université de

    RICH METHANE PREMIXED LAMINAR FLAMES DOPED BY LIGHT UNSATURATED HYDROCARBONS PART I: ALLENE developed in our laboratory for the reactions of C3-C4 unsaturated hydrocarbons. The main reaction pathways2007 #12;3 INTRODUCTION Soots and polyaromatic hydrocarbons (PAH), which are present in the exhaust gas

  15. WENO schemes on arbitrary unstructured meshes for laminar, transitional and turbulent flows

    SciTech Connect (OSTI)

    Tsoutsanis, Panagiotis, E-mail: panagiotis.tsoutsanis@cranfield.ac.uk; Antoniadis, Antonios Foivos, E-mail: a.f.antoniadis@cranfield.ac.uk; Drikakis, Dimitris, E-mail: d.drikakis@cranfield.ac.uk

    2014-01-01

    This paper presents the development and implementation of weighted-essentially-non-oscillatory (WENO) schemes for viscous flows on arbitrary unstructured grids. WENO schemes up to fifth-order accurate have been implemented in conjunction with hybrid and non-hybrid unstructured grids. The schemes are investigated with reference to numerical and experimental results for the Taylor–Green vortex, as well as for laminar and turbulent flows around a sphere, and the turbulent shock-wave boundary layer interaction flow problem. The results show that the accuracy of the schemes depends on the arbitrariness of shape and orientation of the unstructured mesh elements, as well as the compactness of directional stencils. The WENO schemes provide a more accurate numerical framework compared to second-order and third-order total variation diminishing (TVD) methods, however, the fifth-order version of the schemes is computationally too expensive to make the schemes practically usable. On the other hand, the third-order variant offers an excellent numerical framework in terms of accuracy and computational cost compared to the fifth-order WENO and second-order TVD schemes. Parallelisation of the CFD code (henceforth labelled as UCNS3D), where the schemes have been implemented, shows that the present methods offer very good scalable performance.

  16. AIAA 99--1467 LOW ORDER AERODYNAMIC

    E-Print Network [OSTI]

    Peraire, Jaime

    speeds and more flexible blading, aeroelasticity has become a critical consideration in the design of com will operate within stability boundaries, and thus has a large impact on the design process. Appropriate blade ten per blade passage, making it appropriate for con­ trol applications. The aerodynamic model

  17. AIAA 20031068 Aerodynamic Design of Cascades by

    E-Print Network [OSTI]

    Liu, Feng

    is developed for the aerodynamic design of cascade blades in a two-dimensional, inviscid, and compressible flow cascade blade design cases are tested. The results show that the method is effective and efficient for turbomachinery blade design. The effect of shape functions on the performance of the design method is discussed

  18. Airfoil Optimization Using Practical Aerodynamic Design Requirements

    E-Print Network [OSTI]

    Zingg, David W.

    to climate change, and rising jet fuel prices are negatively impacting profits of commercial carriers, the design objective of improving aircraft fuel efficiency has become increasingly impor- tant. If it can be shown that a novel aerodynamic shape will provide the greatest improvement in aircraft fuel efficiency

  19. Aerodynamic beam generator for large particles

    DOE Patents [OSTI]

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

    2002-01-01

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

  20. Electromyographic responses to aerodynamic vs. drop handlebars 

    E-Print Network [OSTI]

    Layne, Donald Jodel

    1996-01-01

    that there are no metabolic changes associated with the use of aerodynamic handlebars. These findings are contradicted by anecdotal evidence of specific fatigue and pain in regions such as the upper thigh, buttocks and low back. This anecdotal evidence may point out...

  1. Freight Wing Trailer Aerodynamics Final Technical Report

    SciTech Connect (OSTI)

    Sean Graham

    2007-10-31

    Freight Wing Incorporated utilized the opportunity presented by a DOE category two Inventions and Innovations grant to commercialize and improve upon aerodynamic technology for semi-tuck trailers, capable of decreasing heavy vehicle fuel consumption, related environmental damage, and U.S. consumption of foreign oil. Major project goals included the demonstration of aerodynamic trailer technology in trucking fleet operations, and the development and testing of second generation products. A great deal of past scientific research has demonstrated that streamlining box shaped semi-trailers can significantly reduce a truck’s fuel consumption. However, significant design challenges have prevented past concepts from meeting industry needs. Freight Wing utilized a 2003 category one Inventions and Innovations grant to develop practical solutions to trailer aerodynamics. Fairings developed for the front, rear, and bottom of standard semi-trailers together demonstrated a 7% improvement to fuel economy in scientific tests conducted by the Transportation Research Center (TRC). Operational tests with major trucking fleets proved the functionality of the products, which were subsequently brought to market. This category two grant enabled Freight Wing to further develop, test and commercialize its products, resulting in greatly increased understanding and acceptance of aerodynamic trailer technology. Commercialization was stimulated by offering trucking fleets 50% cost sharing on trial implementations of Freight Wing products for testing and evaluation purposes. Over 230 fairings were implemented through the program with 35 trucking fleets including industry leaders such as Wal-Mart, Frito Lay and Whole Foods. The feedback from these testing partnerships was quite positive with product performance exceeding fleet expectations in many cases. Fleet feedback also was also valuable from a product development standpoint and assisted the design of several second generation products intended to further improve efficiency, lower costs, and enhance durability. Resulting products demonstrated a 30% efficiency improvement in full scale wind tunnel tests. The fuel savings of our most promising product, the “Belly Fairing” increased from 4% to 6% in scientific track and operational tests. The project successfully demonstrated the economic feasibility of trailer aerodynamics and positioned the technology to realize significant public benefits. Scientific testing conducted with partners such as the EPA Smartway program and Transport Canada clearly validated the fuel and emission saving potential of the technology. The Smartway program now recommends trailer aerodynamics as a certified fuel saving technology and is offering incentives such as low interest loans. Trailer aerodynamics can save average trucks over 1,100 gallons of fuel an 13 tons of emissions every 100,000 miles, a distance many trucks travel annually. These fuel savings produce a product return on investment period of one to two years in average fleet operations. The economic feasibility of the products was validated by participating fleets, several of which have since completed large implementations or demonstrated an interest in volume orders. The commercialization potential of the technology was also demonstrated, resulting in a national distribution and manufacturing partnership with a major industry supplier, Carrier Transicold. Consequently, Freight Wing is well positioned to continue marketing trailer aerodynamics to the trucking industry. The participation of leading fleets in this project served to break down the market skepticism that represents a primary barrier to widespread industry utilization. The benefits of widespread utilization of the technology could be quite significant for both the transportation industry and the public. Trailer aerodynamics could potentially save the U.S. trucking fleet over a billion gallons of fuel and 20 million tons of emissions annually.

  2. Gyrotactic trapping in laminar and turbulent Kolmogorov flow

    E-Print Network [OSTI]

    Francesco Santamaria; Filippo De Lillo; Massimo Cencini; Guido Boffetta

    2014-10-07

    Phytoplankton patchiness, namely the heterogeneous distribution of microalgae over multiple spatial scales, dramatically impacts marine ecology. A spectacular example of such heterogeneity occurs in thin phytoplankton layers (TPLs), where large numbers of photosynthetic microorganisms are found within a small depth interval. Some species of motile phytoplankton can form TPLs by gyrotactic trapping due to the interplay of their particular swimming style (directed motion biased against gravity) and the transport by a flow with shear along the direction of gravity. Here we consider gyrotactic swimmers in numerical simulations of the Kolmogorov shear flow, both in laminar and turbulent regimes. In the laminar case, we show that the swimmer motion is integrable and the formation of TPLs can be fully characterized by means of dynamical systems tools. We then study the effects of rotational Brownian motion or turbulent fluctuations (appearing when the Reynolds number is large enough) on TPLs. In both cases we show that TPLs become transient, and we characterize their persistence.

  3. Hybrid Control of a Turret Wake Bojan Vukasinovic

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    Effects of hybrid flow control and its active and passive components on the aerodynamic characteristics flow control is further assisted by global flow alterations induced by a passive forward partition housing for pointing and tracking laser beams from airborne platforms. An optical aperture is therefore

  4. Design Study for a Laminar-Flying-Wing Aircraft

    E-Print Network [OSTI]

    Saeed, T. I.; Graham, W. R.

    2015-05-20

    , compared to 14.6) over a conventional competitor designed, using the same methods, for the same mission. Both weight ratio and engine efficiency could be improved by reducing aspect ratio, but at the cost of an aero- dynamic efficiency penalty... , Nashville, TN. †Research Student, Department of Engineering. Current post: Research Associate, Department of Aero- nautics, Imperial College, London. ‡Senior Lecturer, Department of Engineering, Member AIAA. 1 of 34 Laminar-Flying-Wing Aircraft, Saeed...

  5. Topological Charge and the Laminar Structure of the QCD Vacuum

    E-Print Network [OSTI]

    H. B. Thacker

    2006-11-30

    Monte Carlo studies of pure glue SU(3) gauge theory using the overlap-based topological charge operator have revealed a laminar structure in the QCD vacuum consisting of extended, thin, coherent, locally 3-dimensional sheets of topological charge embedded in 4D space, with opposite sign sheets interleaved. In this talk I discuss the interpretation of these Monte Carlo results in terms of our current theoretical understanding of theta-dependence and topological structure in asymptotically free gauge theories.

  6. Laminar shocks in high power laser plasma interactions

    SciTech Connect (OSTI)

    Cairns, R. A. [University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom)] [University of St. Andrews, North Haugh, St. Andrews, Fife KY16 9SS (United Kingdom); Bingham, R.; Norreys, P.; Trines, R. [Central Laser Facility, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX (United Kingdom)] [Central Laser Facility, STFC, Rutherford Appleton Laboratory, Harwell Oxford, Didcot, Oxfordshire OX11 0QX (United Kingdom)

    2014-02-15

    We propose a theory to describe laminar ion sound structures in a collisionless plasma. Reflection of a small fraction of the upstream ions converts the well known ion acoustic soliton into a structure with a steep potential gradient upstream and with downstream oscillations. The theory provides a simple interpretation of results dating back more than forty years but, more importantly, is shown to provide an explanation for recent observations on laser produced plasmas relevant to inertial fusion and to ion acceleration.

  7. A Study of mixing in computer simulated laminar flow systems 

    E-Print Network [OSTI]

    McFarland, Allison Anne

    1984-01-01

    1984 Major Subject: Chemical Engineering A STUDY OF MIXING IN COMPUTER SIMULATED LAMINAR FLOW SYSTEMS A Thesis by ALLISON ANNE MCFARLAND Approved as to style and content by: Gary B. Tatterson (Chairman) ries J. Glover (Member) A. Ted Watson...: Dr. Gary B. Tatterson Mixing is a process that reduces nonuniformities or gradients in composition, properties, or temperature of material in bulk. It is a basic part of many chemical engineering processes, yet the theoretical understanding...

  8. Type I planet migration in nearly laminar disks

    SciTech Connect (OSTI)

    Li, Hui; Li, Shengtai; Lubow, S H; Lin, D

    2008-01-01

    We describe two-dimensional hydrodynamic simulations of the migration of low-mass planets ({<=}30 M{sub {circle_plus}}) in nearly laminar disks (viscosity parameter {alpha} < 10{sup -3}) over timescales of several thousand orbit periods. We consider disk masses of 1, 2, and 5 times the minimum mass solar nebula, disk thickness parameters of H/r = 0.035 and 0.05, and a variety of {alpha} values and planet masses. Disk self-gravity is fully included. Previous analytic work has suggested that Type I planet migration can be halted in disks of sufficiently low turbulent viscosity, for {alpha} {approx} 10{sup -4}. The halting is due to a feedback effect of breaking density waves that results in a slight mass redistribution and consequently an increased outward torque contribution. The simulations confirm the existence of a critical mass (M{sub {alpha}} {approx} 10M{sub {circle_plus}}) beyond which migration halts in nearly laminar disks. For {alpha} {approx}> 10{sup -3}, density feedback effects are washed out and Type I migration persists. The critical masses are in good agreement with the analytic model of Rafikov. In addition, for {alpha} {approx}> 10{sup -4} steep density gradients produce a vortex instability, resulting in a small time-varying eccentricity in the planet's orbit and a slight outward migration. Migration in nearly laminar disks may be sufficiently slow to reconcile the timescales of migration theory with those of giant planet formation in the core accretion model.

  9. Device for reducing vehicle aerodynamic resistance

    DOE Patents [OSTI]

    Graham, Sean C.

    2006-03-07

    A device for reducing vehicle aerodynamic resistance for vehicles having a generally rectangular flat front face comprising a plurality of load bearing struts of a predetermined size attached to the flat front face adjacent the sides and top thereof, a pair of pliable opposing flat sheets having an outside edge portion attached to the flat front face adjacent the sides thereof and an upper edge with a predetermined curve; the opposing flat sheets being bent and attached to the struts to form effective curved airfoil shapes, and a top pliable flat sheet disposed adjacent the top of the flat front face and having predetermined curved side edges, which, when the top sheet is bent and attached to the struts to form an effective curved airfoil shape, mate with the curved upper edges of the opposing sheets to complete the aerodynamic device.

  10. Device for reducing vehicle aerodynamic resistance

    DOE Patents [OSTI]

    Graham, Sean C.

    2006-08-22

    A device for reducing vehicle aerodynamic resistance for vehicles having a generally rectangular body disposed above rear wheels, comprising a plurality of load bearing struts attached to the bottom of the rectangular body adjacent its sides, a plurality of opposing flat sheets attached to the load bearing struts, and angled flaps attached to the lower edge of the opposing sheets defining an obtuse angle with the opposing flat sheets extending inwardly with respect to the sides of the rectangular body to a predetermined height above the ground, which, stiffen the opposing flat sheets, bend to resist damage when struck by the ground, and guide airflow around the rear wheels of the vehicle to reduce its aerodynamic resistance when moving.

  11. Device for reducing vehicle aerodynamic resistance

    DOE Patents [OSTI]

    Graham, Sean C.

    2005-02-15

    A device for a vehicle with a pair of swinging rear doors, which converts flat sheets of pliable material hinged to the sides of the vehicle adjacent the rear thereof into effective curved airfoils that reduce the aerodynamic resistance of the vehicle, when the doors are closed by hand, utilizing a plurality of stiffeners disposed generally parallel to the doors and affixed to the sheets and a plurality of collapsible tension bearings struts attached to each stiffener and the adjacent door.

  12. Aerodynamics of a rigid curved kite wing

    E-Print Network [OSTI]

    Maneia, Gianmauro; Tordella, Daniela; Iovieno, Michele

    2013-01-01

    A preliminary numerical study on the aerodynamics of a kite wing for high altitude wind power generators is proposed. Tethered kites are a key element of an innovative wind energy technology, which aims to capture energy from the wind at higher altitudes than conventional wind towers. We present the results obtained from three-dimensional finite volume numerical simulations of the steady air flow past a three-dimensional curved rectangular kite wing (aspect ratio equal to 3.2, Reynolds number equal to 3x10^6). Two angles of incidence -- a standard incidence for the flight of a tethered airfoil (6{\\deg}) and an incidence close to the stall (18{\\deg}) -- were considered. The simulations were performed by solving the Reynolds Averaged Navier-Stokes flow model using the industrial STAR-CCM+ code. The overall aerodynamic characteristics of the kite wing were determined and compared to the aerodynamic characteristics of the flat rectangular non twisted wing with an identical aspect ratio and section (Clark Y profil...

  13. Roles for Wnts and their receptors in topographic mapping and laminar termination

    E-Print Network [OSTI]

    Richman, Alisha

    2011-01-01

    tectum may be assigned termination sites on a "first come,Mapping and Laminar Termination A dissertation submitted inTermination ..

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

    E-Print Network [OSTI]

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

    2011-04-27

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

  15. Aerodynamic Focusing Of High-Density Aerosols

    SciTech Connect (OSTI)

    Ruiz, D. E.; Fisch, Nathaniel

    2014-02-24

    High-density micron-sized particle aerosols might form the basis for a number of applications in which a material target with a particular shape might be quickly ionized to form a cylindrical or sheet shaped plasma. A simple experimental device was built in order to study the properties of high-density aerosol focusing for 1#22; m silica spheres. Preliminary results recover previous findings on aerodynamic focusing at low densities. At higher densities, it is demonstrated that the focusing properties change in a way which is consistent with a density dependent Stokes number.

  16. The Aerodynamic, Dual- Wavelength Optical Spectrometer

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power AdministrationRobust,Field-effectWorking With U.S. CoalMexicoConferencePriceshieldingFocus TheAerodynamic,

  17. Wind Turbine Blade Flow Fields and Prospects for Active Aerodynamic Control: Preprint

    SciTech Connect (OSTI)

    Schreck, S.; Robinson, M.

    2007-08-01

    This paper describes wind turbine flow fields that can cause adverse aerodynamic loading and can impact active aerodynamic control methodologies currently contemplated for wind turbine applications.

  18. Mechanisms of the anti-inflammation action of pulsatile laminar flow : role of AMPK in epigenetic modifications

    E-Print Network [OSTI]

    Flores, Leona Marie

    2010-01-01

    laminar flow in a circular cylindrical tube, with the assumptions that blood is an incompressible Newtonian fluid, the flowLaminar Shear Flow Experiments A parallel-plate flow system was used to impose fluid

  19. Active Control of Instabilities in Laminar BoundaryLayer Flow --Part II: Use of Sensors and Spectral Controller

    E-Print Network [OSTI]

    Erlebacher, Gordon

    Active Control of Instabilities in Laminar Boundary­Layer Flow -- Part II: Use of Sensors growth and stabilize the instabilities within the laminar boundary layer. This scenario is shown in Fig

  20. The laminar flow tube reactor as a quantitative tool for nucleation studies: Experimental results and theoretical analysis of homogeneous

    E-Print Network [OSTI]

    Ford, Ian

    The laminar flow tube reactor as a quantitative tool for nucleation studies: Experimental results, United Kingdom Received 24 March 2000; accepted 2 June 2000 A laminar flow tube reactor was designed

  1. Elongational-flow-induced scission of DNA nanotubes in laminar flow Rizal F. Hariadi*

    E-Print Network [OSTI]

    Winfree, Erik

    -induced scission are pro- foundly affected by the fluid flow and the polymer bond strengths. In this paper, laminarElongational-flow-induced scission of DNA nanotubes in laminar flow Rizal F. Hariadi* Department libraries in shotgun ge- nome sequencing 2­4 . The fluid-flow-induced mechanical shearing of prion fibrils

  2. Pressure-Driven Laminar Flow in Tangential Microchannels: an Elastomeric Microfluidic

    E-Print Network [OSTI]

    Gardel, Margaret

    , Massachusetts 02138 This paper describes laminar fluid flow through a three- dimensional elastomericPressure-Driven Laminar Flow in Tangential Microchannels: an Elastomeric Microfluidic Switch Rustem-to-face (typically at a 90° angle), with the fluid flows in tangential contact. There are two ways to control fluid

  3. Formation of Two-Dimensional Sand Ripples under Laminar Shear Flow Vincent Langlois and Alexandre Valance

    E-Print Network [OSTI]

    Formation of Two-Dimensional Sand Ripples under Laminar Shear Flow Vincent Langlois and Alexandre sand bed patterns under a laminar and steady shear flow. Several issues are addressed here: (i fluid is investigated theoretically. The sand transport is described taking into account both the local

  4. A LEAN METHANE PREMIXED LAMINAR FLAME DOPED WITH COMPONENTS OF DIESEL FUEL

    E-Print Network [OSTI]

    Boyer, Edmond

    A LEAN METHANE PREMIXED LAMINAR FLAME DOPED WITH COMPONENTS OF DIESEL FUEL PART I: N-BUTYLBENZENE E better understand the chemistry involved during the combustion of components of diesel fuel flow rate analyses. Keywords: Premixed laminar flame, methane, n-butylbenzene, modelling, diesel fuel

  5. Journal of Power Sources 128 (2004) 5460 Microfluidic fuel cell based on laminar flow

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    2004-01-01

    Journal of Power Sources 128 (2004) 54­60 Microfluidic fuel cell based on laminar flow Eric R compartments. While these PEM-type fuel cell designs have great promise to become the power source of choice a novel microfluidic fuel cell concept that utilizes the occurrence of multi-stream laminar flow

  6. AIR-BREATHING LAMINAR FLOW BASED MICROFLUIDIC FUEL CELL Ranga S. Jayashree1

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    AIR-BREATHING LAMINAR FLOW BASED MICROFLUIDIC FUEL CELL Ranga S. Jayashree1 , Lajos Gancs2 , Eric R of the laminar flow-based microfluidic fuel cell. A 5-mm thick graphite plate (anode, fuel cell grade graphite bipolar plate purchased from Fuel Cell Stores.com) was cleaned by sonication in large portions of Milli

  7. Impinging laminar jets at moderate Reynolds numbers and separation distances Jeffrey M. Bergthorson,

    E-Print Network [OSTI]

    Impinging laminar jets at moderate Reynolds numbers and separation distances Jeffrey M. Bergthorson an experimental and numerical study of impinging, incompressible, axisym- metric, laminar jets, where the jet axis velocities along the centerline of the flow field. The jet-nozzle pressure drop is measured simultaneously

  8. Applications of Laminar Weak-Link Mechanisms for Ultraprecision Synchrotron Radiation Instruments

    SciTech Connect (OSTI)

    Shu, D.; Toellner, T. S.; Alp, E. E.; Maser, J.; Ilavsky, J.; Shastri, S. D.; Lee, P. L.; Narayanan, S.; Long, G. G. [Advanced Photon Source, Argonne National Laboratory, Argonne, IL 60439 (United States)

    2007-01-19

    Unlike traditional kinematic flexure mechanisms, laminar overconstrained weak-link mechanisms provide much higher structure stiffness and stability. Using a laminar structure configured and manufactured by chemical etching and lithography techniques, we are able to design and build linear and rotary weak-link mechanisms with ultrahigh positioning sensitivity and stability for synchrotron radiation applications. Applications of laminar rotary weak-link mechanism include: high-energy-resolution monochromators for inelastic x-ray scattering and x-ray analyzers for ultra-small-angle scattering and powder-diffraction experiments. Applications of laminar linear weak-link mechanism include high-stiffness piezo-driven stages with subnanometer resolution for an x-ray microscope. In this paper, we summarize the recent designs and applications of the laminar weak-link mechanisms at the Advanced Photon Source.

  9. Laminar-Flow Fluid Mixer for Fast Fluorescence Kinetics Studies Suzette A. Pabit and Stephen J. Hagen

    E-Print Network [OSTI]

    Hagen, Stephen J.

    Laminar-Flow Fluid Mixer for Fast Fluorescence Kinetics Studies Suzette A. Pabit and Stephen J i.d.) at a speed 20 cm/s, under laminar flow conditions (Re 14). Construction from a fused silica studies of fast protein and nucleic acid interactions and folding. We have constructed a laminar coaxial

  10. Lawrence Berkeley National Laboratory report LBNL-725E 1 A New Type of Steady and Stable, Laminar, Premixed Flame

    E-Print Network [OSTI]

    Bell, John B.

    Lawrence Berkeley National Laboratory report LBNL-725E 1 A New Type of Steady and Stable, Laminar-air mixtures are found to support another kind of laminar flame that is steady and stable beside flat flames;Nomenclature fuel equivalence ratio 1 Introduction There is growing evidence that a new type of laminar

  11. The relative contributions of radial and laminar optic flow to the perception of linear self-motion

    E-Print Network [OSTI]

    Jenkin, Michael R. M.

    The relative contributions of radial and laminar optic flow to the perception of linear self seen location too early. In this article we assess how the radial and laminar components the relative amounts of radial and laminar flow visible. They were then presented with visual motion compatible

  12. Running as fast as it can: How spiking dynamics form object groupings in the laminar circuits of visual cortex

    E-Print Network [OSTI]

    Grossberg, Stephen

    1 Running as fast as it can: How spiking dynamics form object groupings in the laminar circuits laminar cortical circuits Submitted: July 6, 2009 Revised: January 5, 2010 Technical Report CAS/CNS-0009 timing across many interacting cells. Some models have demonstrated spiking dynamics in recurrent laminar

  13. CH(A-X) and OH(A-X) Optical Emission in an Axisymmetric Laminar Diffusion Flame

    E-Print Network [OSTI]

    Long, Marshall B.

    CH(A-X) and OH(A-X) Optical Emission in an Axisymmetric Laminar Diffusion Flame J. LUQUE, J. B an axisymmetric laminar diffusion flame [K. T. Walsh, M. B. Long, M. A. Tanoff, and M. D. Smooke, Twenty axisymmetric laminar methane/air diffusion flame studied here has been exten- sively characterized both

  14. Morphodynamic modeling of erodible laminar channels Olivier Devauchelle, Christophe Josserand, Pierre-Yves Lagre, and Stphane Zaleski

    E-Print Network [OSTI]

    Morphodynamic modeling of erodible laminar channels Olivier Devauchelle, Christophe Josserand in time. It is also shown, through a simplified stability analysis, that a laminar river can generate reflects the meandering and braiding tendencies of laminar rivers indicated by F. Métivier and P. Meunier J

  15. On 2-coverings and 2-packings of laminar families J. Cheriyan T. Jordan y R. Ravi z

    E-Print Network [OSTI]

    Cheriyan, Joseph

    On 2-coverings and 2-packings of laminar families J. Cheriyan T. Jordan y R. Ravi z January 24: laminar family of subsets, 1-covers, 2-covers, 1-packings, 2-packings, NP-hard, approximation algorithm grant CCR{9625297. 1 #12;1 Introduction Coverings and packings of laminar families by edges Let H

  16. Effects of gravity and pressure on laminar coflow methaneair diffusion flames at pressures from 1 to 60 atmospheres

    E-Print Network [OSTI]

    Gülder, Ömer L.

    Effects of gravity and pressure on laminar coflow methane­air diffusion flames at pressures from 1 characteristics and flame structure of coflow methane­air laminar diffusion flames between 1 and 60 atm were these effects through the numerical analysis of laminar diffusion flames at pressures ranging from 1 to 60 atm

  17. Experimental and theoretical scaling laws for transverse diffusive broadening in two-phase laminar flows in microchannels

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Experimental and theoretical scaling laws for transverse diffusive broadening in two-phase laminar in pressure-driven laminar flow in microchannels at high Pe´clet numbers. Confocal fluorescent microscopy, such as described in this letter, is required for the rational use of laminar flows for performing spatially

  18. Formation of Liquid Methane-Water Mixture during Combustion of a Laminar Methane Jet at Supercritical Pressures

    E-Print Network [OSTI]

    Gülder, Ömer L.

    Formation of Liquid Methane-Water Mixture during Combustion of a Laminar Methane Jet in laminar jet flames of methane at elevated pressures in a high-pressure combustion chamber, we have MPa, after the laminar methane jet flame had been stabilized on a co-flow circular nozzle-type burner

  19. Soot formation in laminar ethane diffusion flames at pressures from 0.2 to 3.3 MPa

    E-Print Network [OSTI]

    Gülder, Ömer L.

    Soot formation in laminar ethane diffusion flames at pressures from 0.2 to 3.3 MPa Paul M formation and the structure of the temperature field were studied in co-flow ethane-air laminar diffusion; Laminar ethane diffusion flame; Pressure depen- dence of soot formation; Temperature of high

  20. Methods of reducing vehicle aerodynamic drag

    SciTech Connect (OSTI)

    Sirenko V.; Rohatgi U.

    2012-07-08

    A small scale model (length 1710 mm) of General Motor SUV was built and tested in the wind tunnel for expected wind conditions and road clearance. Two passive devices, rear screen which is plate behind the car and rear fairing where the end of the car is aerodynamically extended, were incorporated in the model and tested in the wind tunnel for different wind conditions. The conclusion is that rear screen could reduce drag up to 6.5% and rear fairing can reduce the drag by 26%. There were additional tests for front edging and rear vortex generators. The results for drag reduction were mixed. It should be noted that there are aesthetic and practical considerations that may allow only partial implementation of these or any drag reduction options.

  1. Experimental study of Markstein number effects on laminar flamelet velocity in turbulent premixed flames

    SciTech Connect (OSTI)

    Weiss, M.; Zarzalis, N. [Division of Combustion Technology, Engler-Bunte-Institute, University of Karlsruhe (TH), Karlsruhe (Germany); Suntz, R. [Institute for Chemical Technology, University of Karlsruhe (TH), Karlsruhe (Germany)

    2008-09-15

    Effects of turbulent flame stretch on mean local laminar burning velocity of flamelets, u{sub n}, were investigated experimentally in an explosion vessel at normal temperature and pressure. In this context, the wrinkling, A{sub t}/A{sub l}, and the burning velocity, u{sub t}, of turbulent flames were measured simultaneously. With the flamelet assumption the mean local laminar burning velocity of flamelets, u{sub n}=u{sub t} x (A{sub t}/A{sub l}){sup -1}, was calculated for different turbulence intensities. The results were compared to the influence of stretch on spherically expanding laminar flames. For spherically expanding laminar flames the stretched laminar burning velocity, u{sub n}, varied linearly with the Karlovitz stretch factor, yielding Markstein numbers that depend on the mixture composition. Six different mixtures with positive and negative Markstein numbers were investigated. The measurements of the mean local laminar burning velocity of turbulent flamelets were used to derive an efficiency parameter, I, which reflects the impact of the Markstein number and turbulent flame stretch - expressed by the turbulent Karlovitz stretch factor - on the local laminar burning velocity of flamelets. The results showed that the efficiency is reduced with increasing turbulence intensity and the reduction can be correlated to unsteady effects. (author)

  2. A viscous instability in axially symmetric laminar shear flows

    E-Print Network [OSTI]

    Shakura, Nikolai

    2015-01-01

    A viscous instability in shearing laminar axisymmetric hydrodynamic flows around a gravitating center is described. In the linearized hydrodynamic equations written in the Boussinesq approximation with microscopic molecular transport coefficients, the instability arises when the viscous dissipation is taken into account in the energy equation. Using the local WKB approximation, we derive a third-order algebraic dispersion equation with two modes representing the modified Rayleigh modes R+ and R-, and the third X-mode. We show that in thin accretion flows the viscosity destabilizes one of the Rayleigh modes in a wide range of wavenumbers, while the X-mode always remains stable. In Keplerian flows, the instability increment is found to be a few Keplerian rotational periods at wavelengths with $kr\\sim 10-50$. This instability may cause turbulence in astrophysical accretion discs even in the absence of magnetic field.

  3. On the cover: Seven aqueous streams, each colored with a different dye, converge in a microchannel and proceed in parallel laminar flow, without turbulent mixing.

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    and proceed in parallel laminar flow, without turbulent mixing. Using laminar flows of reagents is the basis Capillaries Using Multiphase Laminar Flow Patterning Paul J. A. Kenis, Rustem F. Ismagilov, George M. Whitesides* The reaction of species in solutions flowing laminarly (without turbulent mix- ing) inside

  4. Computational Aerodynamic Analysis of Offshore Upwind and Downwind Turbines

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

    Zhao, Qiuying; Sheng, Chunhua; Afjeh, Abdollah

    2014-01-01

    Aerodynamic interactions of the model NREL 5?MW offshore horizontal axis wind turbines (HAWT) are investigated using a high-fidelity computational fluid dynamics (CFD) analysis. Four wind turbine configurations are considered; three-bladed upwind and downwind and two-bladed upwind and downwind configurations, which operate at two different rotor speeds of 12.1 and 16?RPM. In the present study, both steady and unsteady aerodynamic loads, such as the rotor torque, blade hub bending moment, and base the tower bending moment of the tower, are evaluated in detail to provide overall assessment of different wind turbine configurations. Aerodynamic interactions between the rotor and tower are analyzed,more »including the rotor wake development downstream. The computational analysis provides insight into aerodynamic performance of the upwind and downwind, two- and three-bladed horizontal axis wind turbines.« less

  5. Error estimation and adaptive mesh refinement for aerodynamic flows

    E-Print Network [OSTI]

    Hartmann, Ralf

    Error estimation and adaptive mesh refinement for aerodynamic flows Ralf Hartmann1 and Paul Houston, 38108 Braunschweig, Germany Ralf.Hartmann@dlr.de 2 School of Mathematical Sciences University

  6. MULTITARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS

    E-Print Network [OSTI]

    Hartmann, Ralf

    MULTI­TARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS RALF HARTMANN of Scientific Computing, TU Braunschweig, Germany (Ralf.Hartmann@dlr.de). 1 #12; 2 R. HARTMANN

  7. Error estimation and adaptive mesh refinement for aerodynamic flows

    E-Print Network [OSTI]

    Hartmann, Ralf

    Error estimation and adaptive mesh refinement for aerodynamic flows Ralf Hartmann, Joachim Held), Lilien- thalplatz 7, 38108 Braunschweig, Germany, e-mail: Ralf.Hartmann@dlr.de 1 #12;2 Ralf Hartmann

  8. MULTITARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS

    E-Print Network [OSTI]

    Hartmann, Ralf

    MULTITARGET ERROR ESTIMATION AND ADAPTIVITY IN AERODYNAMIC FLOW SIMULATIONS RALF HARTMANN Abstract, Germany (Ralf.Hartmann@dlr.de). 1 #12;2 R. HARTMANN quantity under consideration. However, in many

  9. Aerodynamic optimization of a solar powered race vehicle

    E-Print Network [OSTI]

    Augenbergs, Peteris K

    2006-01-01

    Aerodynamic optimization was performed on Tesseract, the MIT Solar Electric Vehicle Team's 2003-2005 solar car using Wind Tunnel 8 at Jacobs/Sverdrup Drivability Test Facility in Allen Park, MI. These tests include angle ...

  10. Particle Size Classification of Glass Particles Using Aerodynamic Jet Vectoring

    E-Print Network [OSTI]

    Smith, Barton L.

    Particle Size Classification of Glass Particles Using Aerodynamic Jet Vectoring Zachary E. Humes blowing and suction control flows­flows that are a fraction of the jet flow rate­to sharply change

  11. Aerodynamic performance measurements in a counter-rotating aspirated compressor

    E-Print Network [OSTI]

    Onnée, Jean-François

    2005-01-01

    This thesis is an experimental investigation of the aerodynamic performances of a counter-rotating aspirated compressor. This compressor is implemented in a blow-down facility, which gives rigorous simulation of the ...

  12. Full-scale wind turbine rotor aerodynamics research

    SciTech Connect (OSTI)

    Simms, D A; Butterfield, C P

    1994-11-01

    The United States Department of Energy and the National Renewable Energy Laboratory (NREL) are conducting research to improve wind turbine technology at the NREL National Wind Technology Center (NWTC). One program, the Combined Experiment, has focused on making measurements needed to understand aerodynamic and structural responses of horizontal-axis wind turbines (HAWT). A new phase of this program, the Unsteady Aerodynamics Experiment, will focus on quantifying unsteady aerodynamic phenomena prevalent in stall-controlled HAWTs. Optimally twisted blades and innovative instrumentation and data acquisition systems will be used in these tests. Data can now be acquired and viewed interactively during turbine operations. This paper describes the NREL Unsteady Aerodynamics Experiment and highlights planned future research activities.

  13. DOE Project on Heavy Vehicle Aerodynamic Drag

    SciTech Connect (OSTI)

    McCallen, R; Salari, K; Ortega, J; Castellucci, P; Pointer, D; Browand, F; Ross, J; Storms, B

    2007-01-04

    Class 8 tractor-trailers consume 11-12% of the total US petroleum use. At highway speeds, 65% of the energy expenditure for a Class 8 truck is in overcoming aerodynamic drag. The project objective is to improve fuel economy of Class 8 tractor-trailers by providing guidance on methods of reducing drag by at least 25%. A 25% reduction in drag would present a 12% improvement in fuel economy at highway speeds, equivalent to about 130 midsize tanker ships per year. Specific goals include: (1) Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles; (2) Develop innovative drag reducing concepts that are operationally and economically sound; and (3) Establish a database of experimental, computational, and conceptual design information, and demonstrate the potential of new drag-reduction devices. The studies described herein provide a demonstration of the applicability of the experience developed in the analysis of the standard configuration of the Generic Conventional Model. The modeling practices and procedures developed in prior efforts have been applied directly to the assessment of new configurations including a variety of geometric modifications and add-on devices. Application to the low-drag 'GTS' configuration of the GCM has confirmed that the error in predicted drag coefficients increases as the relative contribution of the base drag resulting from the vehicle wake to the total drag increases and it is recommended that more advanced turbulence modeling strategies be applied under those circumstances. Application to a commercially-developed boat tail device has confirmed that this restriction does not apply to geometries where the relative contribution of the base drag to the total drag is reduced by modifying the geometry in that region. Application to a modified GCM geometry with an open grille and radiator has confirmed that the underbody flow, while important for underhood cooling, has little impact on the drag coefficient of the vehicle. Furthermore, the evaluation of the impact of small changes in radiator or grille dimensions has revealed that the total drag is not particularly sensitive to those changes. This observation leads to two significant conclusions. First, a small increase in radiator size to accommodate heat rejection needs related to new emissions restrictions may be tolerated without significant increases in drag losses. Second, efforts to reduce drag on the tractor requires that the design of the entire tractor be treated in an integrated fashion. Simply reducing the size of the grille will not provide the desired result, but the additional contouring of the vehicle as a whole which may be enabled by the smaller radiator could have a more significant effect.

  14. Influence of suprathermal background electrons on strong auroral double layers: Laminar and turbulent regimes

    SciTech Connect (OSTI)

    Newman, D. L.; Goldman, M. V.; Sen, N. [Center for Integrated Plasma Studies, University of Colorado at Boulder, Boulder, Colorado 80309 (United States); Andersson, L.; Ergun, R. E. [Laboratory for Atmospheric and Space Physics, University of Colorado at Boulder, Boulder, Colorado 80309 (United States)

    2008-07-15

    A series of one-dimensional Vlasov simulations [Newman et al., Phys. Plasmas 15, 072902 (2008), this issue] show that a sufficiently dense and hot suprathermal electron population can stabilize strong laminar double layers over long periods while regulating their strength and velocity. When suprathermals are less dense or absent, the double layers tend to be sporadic and turbulent. A detailed comparison of the laminar and turbulent regimes reveals that the disruption of the laminar state can be triggered by kinetically modified Buneman instabilities on the low-potential side of the double layer, and by density perturbations that develop into nonlinear coherent shocklike structures on the high-potential side. These findings suggest that the suprathermal electrons may be responsible for suppressing both of these routes to disruption of the laminar state.

  15. Dynamics on the Laminar-Turbulent Boundary and the Origin of the Maximum Drag Reduction Asymptote

    E-Print Network [OSTI]

    Graham, Michael D.

    Dynamical trajectories on the boundary in state space between laminar and turbulent plane channel flow—edge states—are computed for Newtonian and viscoelastic fluids. Viscoelasticity has a negligible effect on the properties ...

  16. Sooting Behaviour Dynamics of a Non-Bouyant Laminar Diffusion Flame 

    E-Print Network [OSTI]

    Fuentes, Andres; Legros, Guillaume; Rouvreau, Sebastien; Joulain, Pierre; Vantelon, Jean-Pierre; Torero, Jose L; Fernandez-Pello, Carlos

    2007-01-01

    Local soot concentrations in non-buoyant laminar diffusion flames have been demonstrated to be the outcome of two competitive processes, soot formation and soot oxidation. It was first believed that soot formation was the controlling mechanism...

  17. Soot Volume Fraction Measurements in a Three-Dimensional Laminar Diffusion Flame established in Microgravity 

    E-Print Network [OSTI]

    Legros, Guillaume; Joulain, Pierre; Jean-Pierre, Vantelon; Fuentes, Andres; Bertheau, Denis; Torero, Jose L

    2005-05-03

    A methodology for the estimation of the soot volume fraction in a three-dimensional laminar diffusion flame is presented. All experiments are conducted in microgravity and have as objective producing quantitative data ...

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

    E-Print Network [OSTI]

    Kondepudi, Sekhar

    1988-01-01

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

  19. Computations of Laminar Flow Control on Swept Wings as a Companion to Flight Test Research 

    E-Print Network [OSTI]

    Rhodes, Richard G.

    2010-01-14

    The high cost of energy has resulted in a renewed interest in the study of reducing skin-friction drag in aeronautical applications. Laminar Flow Control (LFC) refers to any technique which alters the basic-state flow-field ...

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

    SciTech Connect (OSTI)

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

    2010-12-15

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

  1. Erosion of a granular bed driven by laminar fluid flow

    E-Print Network [OSTI]

    A. E. Lobkovsky; A. V. Orpe; R. Molloy; A. Kudrolli; D. H. Rothman

    2008-05-01

    Motivated by examples of erosive incision of channels in sand, we investigate the motion of individual grains in a granular bed driven by a laminar fluid to give us new insights into the relationship between hydrodynamic stress and surface granular flow. A closed cell of rectangular cross-section is partially filled with glass beads and a constant fluid flux $Q$ flows through the cell. The refractive indices of the fluid and the glass beads are matched and the cell is illuminated with a laser sheet, allowing us to image individual beads. The bed erodes to a rest height $h_r$ which depends on $Q$. The Shields threshold criterion assumes that the non-dimensional ratio $\\theta$ of the viscous stress on the bed to the hydrostatic pressure difference across a grain is sufficient to predict the granular flux. Furthermore, the Shields criterion states that the granular flux is non-zero only for $\\theta >\\theta_c$. We find that the Shields criterion describes the observed relationship $h_r \\propto Q^{1/2}$ when the bed height is offset by approximately half a grain diameter. Introducing this offset in the estimation of $\\theta$ yields a collapse of the measured Einstein number $q^*$ to a power-law function of $\\theta - \\theta_c$ with exponent $1.75 \\pm 0.25$. The dynamics of the bed height relaxation are well described by the power law relationship between the granular flux and the bed stress.

  2. Cooperative phenomena in laminar fluids: Observation of streamlines

    SciTech Connect (OSTI)

    Fink, Martin A.; Kretschmer, M.; Hoefner, H.; Konopka, U.; Morfill, G.E.; Ratynskaia, S. [Max Planck Institute for extraterrestrial Physics, Giessenbachstrasse, 85741 Garching (Germany); Fortov, V.; Petrov, O.; Usachev, A.; Zobnin, A. [Institute for High Energy Density, Russian Academy of Sciences, ul. Izhorskaya 13/19, 125412 Moscow (Russian Federation)

    2005-10-31

    Complex plasmas are an ideal model system to investigate laminar fluids as they allow to study fluids at the kinetic level. At this level we are able to identify streamlines particle by particle. This gives us the ability to research the behaviour of these streamlines as well as the behaviour of each individual particle of the streamline.We carried out our experiments in a modified GEC-RF-Reference cell. We trapped the particles within two glass rings and forced them to form a circular flow by using several stripe electrodes. In this flow the particles behave like an ideal fluid and form streamlines. By putting an obstacle into the flow we reduce the cross-section. To pass through this constricted cross-section some streamlines have to reconnect. After the obstacle the streamlines split up again. An analysis how streamlines split up and reconnect as result of external pressure on the fluid in our system is presented here.Streamlines also occur if two clouds of particles penetrate each other. We call this 'Lane formation'. Results from our PK-4 experiment are presented here also.

  3. Flamelet mathematical models for non-premixed laminar combustion

    SciTech Connect (OSTI)

    Carbonell, D.; Perez-Segarra, C.D.; Oliva, A.; Coelho, P.J.

    2009-02-15

    Detailed numerical calculations based on the solution of the full transport equations have been compared with flamelet calculations in order to analyse the flamelet concept for laminar diffusion flames. The goal of this work is to study the interactive (Lagrangian Flamelet Model and Interactive Steady Flamelet Model), and non-interactive (Steady Flamelet Model and Enthalpy Defect Flamelet Model) flamelet models considering both differential diffusion and non-differential diffusion situations, and adiabatic and non-adiabatic conditions. Moreover, a new procedure has been employed to obtain enthalpy defects in the flamelet library, the application of which has been found to be encouraging. The effect of using in-situ, local or stoichiometric scalar dissipation rate conditions, and also the effect of using local or stoichiometric conditions to evaluate the flamelet-like time has been analysed. To improve slow species predictions using the non-interactive models, their transport equations are solved with the reaction terms calculated from the flamelet library, also considering local or stoichiometric conditions in the so-called Extended Flamelet Models. (author)

  4. Hybrid Mesons

    E-Print Network [OSTI]

    C. A. Meyer; E. S. Swanson

    2015-03-04

    A review of the theoretical and experimental status of hybrid hadrons is presented. The states $\\pi_1(1400)$, $\\pi_1(1600)$, and $\\pi_1(2015)$ are thoroughly reviewed, along with experimental results from GAMS, VES, Obelix, COMPASS, KEK, CLEO, Crystal Barrel, CLAS, and BNL. Theoretical lattice results on the gluelump spectrum, adiabatic potentials, heavy and light hybrids, and transition matrix elements are discussed. These are compared with bag, string, flux tube, and constituent gluon models. Strong and electromagnetic decay models are described and compared to lattice gauge theory results. We conclude that while good evidence for the existence of a light isovector exotic meson exists, its confirmation as a hybrid meson awaits discovery of its iso-partners. We also conclude that lattice gauge theory rules out a number of hybrid models and provides a reference to judge the success of others.

  5. Rheology of sediment transported by a laminar flow

    E-Print Network [OSTI]

    M. Houssais; C. P. Ortiz; D. J. Durian; D. J. Jerolmack

    2015-09-28

    Understanding the dynamics of fluid-driven sediment transport remains challenging, as it is an intermediate region between a granular material and a fluid flow. Boyer \\textit{et al.}\\citep{Boyer2011} proposed a local rheology unifying dense dry-granular and viscous-suspension flows, but it has been validated only for neutrally-buoyant particles in a confined system. Here we generalize the Boyer \\textit{et al.}\\citep{Boyer2011} model to account for the weight of a particle by addition of a pressure $P_0$, and test the ability of this model to describe sediment transport in an idealized laboratory river. We subject a bed of settling plastic particles to a laminar-shear flow from above, and use Refractive-Index-Matching to track particles' motion and determine local rheology --- from the fluid-granular interface to deep in the granular bed. Data from all experiments collapse onto a single curve of friction $\\mu$ as a function of the viscous number $I_v$ over the range $10^{-5} \\leq I_v \\leq 1$, validating the local rheology model. For $I_v < 10^{-5}$, however, data do not collapse. Instead of undergoing a jamming transition with $\\mu \\rightarrow \\mu_s$ as expected, particles transition to a creeping regime where we observe a continuous decay of the friction coefficient $\\mu \\leq \\mu_s$ as $I_v$ decreases. The rheology of this creep regime cannot be described by the local model, and more work is needed to determine whether a non-local rheology model can be modified to account for our findings.

  6. Product design and development of an aerodynamic hydration system for bicycling and triathlon

    E-Print Network [OSTI]

    Cote, Mark (Mark Brian)

    2007-01-01

    Proper hydration and aerodynamic performance are both essential needs of a competitive cyclist or triathlete. Several aerodynamic systems have been developed for use on bicycles but few have been designed to be truly ...

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

    E-Print Network [OSTI]

    Suryanarayanan, Arun

    2010-07-14

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

  8. Variation in the aerodynamic drag coefficient due to changes in the shape of an automobile 

    E-Print Network [OSTI]

    Williams, John Gilbert

    1968-01-01

    . in Gage Bridge Calibration Results 22 Total Strain Gage Bridge Calibration Results 23 13 14 Exterior of' Com'bination Box. Combination Box, Strain Indicator, and Connecting Cables 25 26 15 16 17 Aerodynamic Drag ? Top and. Windows Up... Aerodynamic Drag ? Top and Windows Down Aerodynamic Drag ? Top Down, Windows Up Aerodynamic Drag - Top Up, Windows Down 31 19 Bas"'c Circuit - Combination of Wheat. tone Bridge Outputs 'v Figure Page 20 Equivalent Circui. t - Combination of Vneatstone...

  9. Courses for Breadth Requirement of Aerospace Engineering M.S. Degree Aerodynamics,

    E-Print Network [OSTI]

    Gao, Grace Xingxin

    Mechanics, Combustion and Propulsion (AFMCP) AE 410/CSE 461: Computational Aerodynamics AE 412/ME 411 515: Wing Theory AE 538/ ME 501: Combustion Fundamentals AE 598 AAA: Advanced Applied Aerodynamics AE 598 CAA: Aeroacoustics AE 598 CFD: Advanced Computational Aerodynamics AE 598 GSE: Diagnostics

  10. Effect of Dynamic Stall on the Aerodynamics of Vertical-Axis Wind Turbines

    E-Print Network [OSTI]

    McCalley, James D.

    Effect of Dynamic Stall on the Aerodynamics of Vertical-Axis Wind Turbines Frank Scheurich of the aerodynamic performance of vertical-axis wind turbines pose a significant challenge for computational fluid of the aerodynamics of a vertical- axis wind turbine that consists of three curved rotor blades that are twisted

  11. Formation of a laminar electron flow for 300 GHz high-power pulsed gyrotron

    SciTech Connect (OSTI)

    Yamaguchi, Yuusuke; Tatematsu, Yoshinori; Saito, Teruo; Ikeda, Ryosuke; Mudiganti, Jagadish C.; Ogawa, Isamu; Idehara, Toshitaka [Research Center for Development of Far-Infrared Region, University of Fukui, 3-9-1 Bunkyo, Fukui-shi 910-8507 (Japan)

    2012-11-15

    This paper describes the design of a triode magnetron injection gun for use in a 200 kW, 300 GHz gyrotron. As power and frequency increase, the performance of the gyrotron becomes quite sensitive to the quality of the electron beam. Formation of a laminar electron flow is essential for the realization of a high quality beam with a small velocity spread. In this study, a new method is developed for a quantitative evaluation of the laminarity and is applied to optimize the electrode design. The laminarity depends not only on conventional design parameters such as the cathode slant angle but also on the spatial distribution of the electric field along the beam trajectory. In the optimized design, the velocity pitch factors, {alpha}, larger than 1.2 are obtained at 65 kV, 10 A with spreads, {Delta}{alpha}, less than 5%.

  12. Spraying Powder Materials by the High-Enthalpy Laminar Plasma Flow

    SciTech Connect (OSTI)

    Khutsishvili, M.; Kikvadze, L.

    2008-03-19

    One of the most promising engineering solutions of the problem of spraying powder materials is the proposed method of plasma spraying by the laminar plasma jet. Laminar plasma flow is characterized by small jet angle divergence; the powder particles are penetrated and accelerated mainly in the axial direction. The molten powder particles are transported almost to the surface of a treated work-piece inside the laminar plasma flow in an atmosphere of the plasma-forming gas with the acceleration on the entire transfer area, which leads to an increase in the particles velocity, a decrease of their oxidability, an increase in the powder deposition efficiency, density, adhesion strength with the surface to be coated.

  13. Manufacturing all-polymer laminar flow-based fuel cells A.S. Hollinger, P.J.A. Kenis*

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Manufacturing all-polymer laminar flow-based fuel cells A.S. Hollinger, P.J.A. Kenis* Department, Urbana, IL 61801, USA h i g h l i g h t s Manufactured a lightweight, all-polymer direct methanol April 2013 Keywords: Manufacturing Polymer Laminar flow Microfluidic Fuel cell Stack a b s t r a c

  14. INTRODUCTION 1.1 Aerodynamics of Rotors in Forward Flight

    E-Print Network [OSTI]

    design. In order to capture the above physical phenomena, the influence of the inflow, blade dynamics1 CHAPTER I INTRODUCTION 1.1 Aerodynamics of Rotors in Forward Flight The prediction of rotor blade. Shock induced separation and shock motion along the chord of the blade may occur. Because the inboard

  15. Aerodynamic Optimization Under a Range of Operating Conditions

    E-Print Network [OSTI]

    Zingg, David W.

    Aerodynamic Optimization Under a Range of Operating Conditions David W. Zingg and Samy Elias. This can be achieved through multipoint optimization. The desired performance objective and operating conditions must be speci ed, and the resulting optimization problem must be solved in such a manner

  16. OUTLINE FOR Chapter 5 AERODYNAMICS (W4-2-1)

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    Vortex Filament Vortex line Vortex filament: a infinitesimal vortex tube. Vortex tube Reference: "Low Vortex in 3D Airfoil / Lifting Line theory 4 #12;2013/6/3 3 INDUCED VELOCITY, EFFECTIVE ANGLE OF ATTACK4_2_4) OUTLINE FOR Chapter 5 AERODYNAMICS (W4-3-1) #12;2013/6/3 5 Helmholtz Vortex Theorem

  17. Aerodynamic Drag Reduction Apparatus For Wheeled Vehicles In Ground Effect

    DOE Patents [OSTI]

    Ortega, Jason M. (Pacifica, CA); Salari, Kambiz (Livermore, CA)

    2005-12-13

    An apparatus for reducing the aerodynamic drag of a wheeled vehicle in a flowstream, the vehicle having a vehicle body and a wheel assembly supporting the vehicle body. The apparatus includes a baffle assembly adapted to be positioned upstream of the wheel assembly for deflecting airflow away from the wheel assembly so as to reduce the incident pressure on the wheel assembly.

  18. Journal of Wind Engineering and Industrial Aerodynamics 96 (2008) 503523

    E-Print Network [OSTI]

    Manuel, Lance

    2008-01-01

    Journal of Wind Engineering and Industrial Aerodynamics 96 (2008) 503­523 On the propagation of uncertainty in inflow turbulence to wind turbine loads Korn Saranyasoontorn, Lance Manuelà Department of Civil or design of wind turbines in normal operating states, it is common to use well-established standard

  19. Journal of Wind Engineering and Industrial Aerodynamics 92 (2004) 789804

    E-Print Network [OSTI]

    Manuel, Lance

    2004-01-01

    Journal of Wind Engineering and Industrial Aerodynamics 92 (2004) 789­804 Efficient models for wind of wind turbines against extreme loads is the focus of this study. A procedure to establish nominal loads-axis wind turbine. Only operating loads--here, flapwise (out-of-plane) bending moments--at a blade root

  20. Plasma Aerodynamic Control Effectors for Improved Wind Turbine Performance

    SciTech Connect (OSTI)

    Mehul P. Patel; Srikanth Vasudevan; Robert C. Nelson; Thomas C. Corke

    2008-08-01

    Orbital Research Inc is developing an innovative Plasma Aerodynamic Control Effectors (PACE) technology for improved performance of wind turbines. The PACE system is aimed towards the design of "smart" rotor blades to enhance energy capture and reduce aerodynamic loading and noise using flow-control. The PACE system will provide ability to change aerodynamic loads and pitch distribution across the wind turbine blade without any moving surfaces. Additional benefits of the PACE system include reduced blade structure weight and complexity that should translate into a substantially reduced initial cost. During the Phase I program, the ORI-UND Team demonstrated (proof-of-concept) performance improvements on select rotor blade designs using PACE concepts. Control of both 2-D and 3-D flows were demonstrated. An analytical study was conducted to estimate control requirements for the PACE system to maintain control during wind gusts. Finally, independent laboratory experiments were conducted to identify promising dielectric materials for the plasma actuator, and to examine environmental effects (water and dust) on the plasma actuator operation. The proposed PACE system will be capable of capturing additional energy, and reducing aerodynamic loading and noise on wind turbines. Supplementary benefits from the PACE system include reduced blade structure weight and complexity that translates into reduced initial capital costs.

  1. Unsteady Aerodynamic Models for Agile Flight at Low Reynolds Numbers

    E-Print Network [OSTI]

    Rowley, Clarence W.

    for Wagner's and Theodorsen's models, making them compatible with modern control-system analysis. A number thanks are to my advisor, Clancy Rowley, who has been both a role model and a source of encouragementUnsteady Aerodynamic Models for Agile Flight at Low Reynolds Numbers Steven L. Brunton

  2. AERODYNAMICS AND DESIGN FOR ULTRA-LOW REYNOLDS NUMBER FLIGHT

    E-Print Network [OSTI]

    Stanford University

    AERODYNAMICS AND DESIGN FOR ULTRA-LOW REYNOLDS NUMBER FLIGHT A DISSERTATION SUBMITTED at Reynolds numbers below 10,000, here termed ultra-low Reynolds numbers. The effects of airfoil geometry at ultra-low Reynolds numbers. To further explore this design space, the flow solver has been coupled

  3. Journal of Wind Engineering and Industrial Aerodynamics 91 (2003) 15111528

    E-Print Network [OSTI]

    Kareem, Ahsan

    2003-01-01

    flutter was made by Bleich [1] utilizing airfoil flutter theory after the Tacoma Narrows Bridge disaster in aerodynamic tailoring of long span bridges: an advanced analysis framework Xinzhong Chen*, Ahsan Kareem Nat Fitzpatrick Hall, Notre Dame, IN 46556-0767, USA Abstract Significant developments in bridge aeroelastic

  4. AERODYNAMICS (II) Time: Tuesday. 14:00 -17:00

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    of forces and moments on, and heat transfer to, bodies moving through a fluid at transonic, supersonic and hypersonic flows. - Lift, drag and moments on the airplanes, missiles . - Aerodynamic heating of space ducts. - Jet engine inlets for transonic, supersonic and hypersonic aircraft. - Ramjet engines

  5. Aerodynamic performance measurements of a film-cooled turbine stage

    E-Print Network [OSTI]

    Keogh, Rory (Rory Colm), 1968-

    2001-01-01

    The goal of this research is to measure the aerodynamic performance of a film-cooled turbine stage and to quantify the loss caused by film-cooling. A secondary goal of the research is to provide a detailed breakdown of the ...

  6. CLARKSON UNIVERSITY AERODYNAMIC FLOW CONTROL OF A HIGH LIFT SYSTEM

    E-Print Network [OSTI]

    Bollt, Erik

    CLARKSON UNIVERSITY AERODYNAMIC FLOW CONTROL OF A HIGH LIFT SYSTEM WITH DUAL SYNTHETIC JET ARRAYS Flow Control of a High Lift System with Dual Synthetic Jet Arrays' presented by Robert Bruce Alstrom the performance of the latest generation aircraft by reducing their fuel consumption and improving their high

  7. Body Force Model for the Aerodynamics of Inclined Perforated Surfaces

    E-Print Network [OSTI]

    Liu, Feng

    Body Force Model for the Aerodynamics of Inclined Perforated Surfaces Juntao Xiong, Andrew Johnson of perforated surfaces inclined to a freestream. The goal is to characterize the key parameters affecting perforations. The model simulates the effects of the perforated surfaces by locally applying a body force term

  8. An Evolutionary Geometry Parametrization for Aerodynamic Shape Optimization

    E-Print Network [OSTI]

    Zingg, David W.

    and greenhouse gas emissions, there is an increase in demand for efficient aircraft with possibly novel, unconventional aerodynamic configurations. Based on improvements in computational fluid dynamics (CFD) and high is not an ideal treatment for an automated optimization process, especially when an unconventional configuration

  9. Evaluation of a hybrid kinetics/mixing-controlled combustion model for turbulent premixed and diffusion combustion using KIVA-2

    SciTech Connect (OSTI)

    Nguyen, H.L.; Wey, Mingjyh.

    1990-01-01

    Two dimensional calculations were made of spark ignited premixed-charge combustion and direct injection stratified-charge combustion in gasoline fueled piston engines. Results are obtained using kinetic-controlled combustion submodel governed by a four-step global chemical reaction or a hybrid laminar kinetics/mixing-controlled combustion submodel that accounts for laminar kinetics and turbulent mixing effects. The numerical solutions are obtained by using KIVA-2 computer code which uses a kinetic-controlled combustion submodel governed by a four-step global chemical reaction (i.e., it assumes that the mixing time is smaller than the chemistry). A hybrid laminar/mixing-controlled combustion submodel was implemented into KIVA-2. In this model, chemical species approach their thermodynamics equilibrium with a rate that is a combination of the turbulent-mixing time and the chemical-kinetics time. The combination is formed in such a way that the longer of the two times has more influence on the conversion rate and the energy release. An additional element of the model is that the laminar-flame kinetics strongly influence the early flame development following ignition.

  10. A unifying method for sizing throttling valves under laminar or transitional flow conditions

    SciTech Connect (OSTI)

    Baumann, H.D. (H.D. Baumann Assoc., Ltd., Portsmouth, NH (United States))

    1993-03-01

    The mass flow passing through a given valve will decrease in Reynolds number ranges below approximately 10,000 due to the transition from fully developed turbulent to laminar flow. The objective of this study is to provide a uniform prediction method to establish, with reasonable accuracy, the ratio between the turbulent and transitional or laminar flow rate passing through a given valve, taking into account the valve's hydraulic diameter and the initial turbulent velocity head loss coefficient. Experimental data from prior research tends to support a proposed unified sizing method that is applicable for all single-stage valves regardless of size or type.

  11. Chaotic self-sustaining structure embeded in turbulent-laminar interface

    E-Print Network [OSTI]

    Teramura, Toshiki

    2015-01-01

    An iterface structure between turbulence and laminar flow is investigated in two-dimensional channel flow. This spatially localized structure not only sustains itself, but also converts laminar state into turbulence actively. In other words, this coherent structure has a functionality to generate inhomogeneity by its inner dynamics. The dynamics of this functional coherent structure is isolated using the filtered simulation, and a physical perspective of its dynamics is summarized in a phenomenological model called an "ejection-jet" cycle, which includes multiscale interaction process.

  12. Chaotic self-sustaining structure embeded in turbulent-laminar interface

    E-Print Network [OSTI]

    Toshiki Teramura; Sadayoshi Toh

    2015-03-16

    An iterface structure between turbulence and laminar flow is investigated in two-dimensional channel flow. This spatially localized structure not only sustains itself, but also converts laminar state into turbulence actively. In other words, this coherent structure has a functionality to generate inhomogeneity by its inner dynamics. The dynamics of this functional coherent structure is isolated using the filtered simulation, and a physical perspective of its dynamics is summarized in a phenomenological model called an "ejection-jet" cycle, which includes multiscale interaction process.

  13. The lengths distribution of laminar phases for type-I intermittency in the presence of noise

    E-Print Network [OSTI]

    A. E. Hramov; A. A. Koronovskii; M. K. Kurovskaja; A. A. Ovchinnikov; S. Boccaletti

    2008-01-26

    We consider a type of intermittent behavior that occurs as the result of the interplay between dynamical mechanisms giving rise to type-I intermittency and random dynamics. We analytically deduce the laws for the distribution of the laminar phases, with the law for the mean length of the laminar phases versus the critical parameter deduced earlier [PRE 62 (2000) 6304] being the corollary fact of the developed theory. We find a very good agreement between the theoretical predictions and the data obtained by means of both the experimental study and numerical calculations. We discuss also how this mechanism is expected to take place in other relevant physical circumstances.

  14. Development of Integrated Motor Assist Hybrid System: Development of the 'Insight', a Personal Hybrid Coupe

    SciTech Connect (OSTI)

    Kaoru Aoki; Shigetaka Kuroda; Shigemasa Kajiwara; Hiromitsu Sato; Yoshio Yamamoto

    2000-06-19

    This paper presents the technical approach used to design and develop the powerplant for the Honda Insight, a new motor assist hybrid vehicle with an overall development objective of just half the fuel consumption of the current Civic over a wide range of driving conditions. Fuel consumption of 35km/L (Japanese 10-15 mode), and 3.4L/100km (98/69/EC) was realized. To achieve this, a new Integrated Motor Assist (IMA) hybrid power plant system was developed, incorporating many new technologies for packaging and integrating the motor assist system and for improving engine thermal efficiency. This was developed in combination with a new lightweight aluminum body with low aerodynamic resistance. Environmental performance goals also included the simultaneous achievement of low emissions (half the Japanese year 2000 standards, and half the EU2000 standards), high efficiency, and recyclability. Full consideration was also given to key consumer attributes, including crash safety performance, handling, and driving performance.

  15. Pipette-friendly laminar flow patterning for cell-based assays Erwin Berthier, Jay Warrick, Ben Casavant and David J. Beebe*

    E-Print Network [OSTI]

    Beebe, David J.

    destination for loaded fluid and balances the pressure applied to each branch for laminar flow patterningPipette-friendly laminar flow patterning for cell-based assays Erwin Berthier, Jay Warrick, Ben Laminar flow patterning (LFP) is a characteristic method of microfluidic systems that allows two (or more

  16. Technical notes Experiments in Fluids 22 (1997) 351--353 Springer-Verlag 1997 Vortex stretching in a laminar boundary layer flow

    E-Print Network [OSTI]

    Wesfreid, José Eduardo

    1997-01-01

    in a laminar boundary layer flow P. Petitjeans, J. E. Wesfreid, J. C. Attiach Abstract A new technique the effects of stretching on a controlled vorticity sheet coming from a laminar boundary layer flow on a flat. A diffuser keeps the flow laminar with a minimum of perturbation. The key elements of the channel

  17. The Dynamics and Interaction of Laminar Thermal Plumes This article has been downloaded from IOPscience. Please scroll down to see the full text article.

    E-Print Network [OSTI]

    Moses, Elisha

    The Dynamics and Interaction of Laminar Thermal Plumes This article has been downloaded from LETTERS Europhys. Lett., 14-(1))pp. 55-60 (1991) 1 January 1991 The Dynamics and Interaction of Laminar tension, capillarity, PACS. 47.25Q- Convection and heat transfer. PACS. 47.15 - Laminar flows (inc

  18. 45th AIAA Aerospace Science Meeting and Exhibit, 8-11 January 2007, Reno, Nevada Verified Computations of Laminar Premixed Flames

    E-Print Network [OSTI]

    Computations of Laminar Premixed Flames Ashraf N. Al-Khateeb , Joseph M. Powers , and Samuel Paolucci all detailed continuum physics in the re- action zone for one-dimensional steady laminar premixed/or unsteady laminar premixed flame simulations in the literature. I. Introduction It is well understood

  19. TOPLAS3701-04 ACM-TRANSACTION October 8, 2014 21:58 Practical Fine-Grained Information Flow Control Using Laminar 1

    E-Print Network [OSTI]

    McKinley, Kathryn S.

    Control Using Laminar 1 DONALD E. PORTER, Stony Brook University 2 MICHAEL D. BOND, Ohio State University. This article describes Laminar, the first 12 system to implement DIFC using a unified set of abstractions with secrecy and integrity labels and access the 14 labeled data in security methods. Laminar enforces

  20. A three-dimensional numerical model of a micro laminar flow fuel cell with a bridge-shaped microchannel cross-section

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    A three-dimensional numerical model of a micro laminar flow fuel cell with a bridge: Membraneless fuel cell Laminar flow fuel cell Numerical model Convection-diffusion equations Electrode kinetics equations COMSOL a b s t r a c t The operation of a laminar flow fuel cell (LFFC) involves complex interplay

  1. Development of imaging methods to quantify the laminar microstructure in rat hearts 

    E-Print Network [OSTI]

    Hudson, Kristen Kay

    2004-11-15

    can be investigated and its laminar structure can be quantified. Many of the techniques that have been used to view the microstructure of the heart require the use of toxic or caustic chemicals for fixation or staining. An efficient imaging method...

  2. A Power-Law Formulation of Laminar Flow in Short Pipes Max Sherman

    E-Print Network [OSTI]

    A Power-Law Formulation of Laminar Flow in Short Pipes Max Sherman Indoor Environment Program ABSTRACT This report develops a theoretical description of the hydrodynamic relationship based on a power pipes can be described with a simple power law dependence on pressure, but that the exponent

  3. On the notion of laminar and weakly turbulent elementary fluid flows: a simple mathematical model

    E-Print Network [OSTI]

    Gianluca Argentini

    2006-08-28

    An elementary analytical fluid flow is composed by a geometric domain, a list of analytical constraints and by the function which depends on the physical properties, as Reynolds number, of the considered fluid. For this object, notions of laminar or weakly turbulent behavior are described using a simple mathematical model.

  4. Copyright 2009 by ASME Laminar fully developed flow in streamwise-periodic

    E-Print Network [OSTI]

    Bahrami, Majid

    1 Copyright ©2009 by ASME ABSTRACT Laminar fully developed flow in streamwise-sections [1-5]. It has been experimentally and numerically observed that the entrance lengths of fluid flow theoretical works for such ducts often focus on the periodically fully-developed fluid flow and heat transfer

  5. Physica A 385 (2007) 4658 Accumulating particles at the boundaries of a laminar flow

    E-Print Network [OSTI]

    Schindler, Michael

    2007-01-01

    Physica A 385 (2007) 46­58 Accumulating particles at the boundaries of a laminar flow Michael in stationary flows through channels of variable width at small Reynolds number. The combined influence for the particle density. It is shown that for extended spherical particles the shape of the fluid domain gives

  6. The impact of small-scale turbulence on laminar magnetic reconnection

    SciTech Connect (OSTI)

    Watson, P. G.; Oughton, S.; Craig, I. J. D. [School of Physics, University of Sydney, NSW 2006 (Australia); Department of Mathematics, University of Waikato, Private Bag 3105, Hamilton (New Zealand)

    2007-03-15

    Initial states in incompressible two-dimensional magnetohydrodynamics that are known to lead to strong current sheets and (laminar) magnetic reconnection are modified by the addition of small-scale turbulent perturbations of various energies. The evolution of these states is computed with the aim of ascertaining the influence of the turbulence on the underlying laminar solution. Two main questions are addressed here: (1) What effect does small-scale turbulence have on the energy dissipation rate of the underlying solution? (2) What is the threshold turbulent perturbation level above which the original laminar reconnective dynamics is no longer recognizable. The simulations show that while the laminar dynamics persist the dissipation rates are largely unaffected by the turbulence, other than modest increases attributable to the additional small length scales present in the new initial condition. The solutions themselves are also remarkably insensitive to small-scale turbulent perturbations unless the perturbations are large enough to undermine the integrity of the underlying cellular flow pattern. Indeed, even initial states that lead to the evolution of small-scale microscopic sheets can survive the addition of modest turbulence. The role of a large-scale organizing background magnetic field is also addressed.

  7. MAGNETIC TRANSPORT ON THE SOLAR ATMOSPHERE BY LAMINAR AND TURBULENT AMBIPOLAR DIFFUSION

    SciTech Connect (OSTI)

    Hiraki, Y. [National Institute for Fusion Science (NIFS), Toki, Gifu (Japan); Krishan, V. [Raman Research Institute, Bangalore 560 080 (India); Masuda, S., E-mail: hiraki.yasutaka@nifs.ac.j [Solar-Terrestrial Environment Laboratory, Nagoya University, Nagoya, Aichi (Japan)

    2010-09-10

    The lower solar atmosphere consists of partially ionized turbulent plasmas harboring velocity field, magnetic field, and current density fluctuations. The correlations among these small-scale fluctuations give rise to large-scale flows and magnetic fields which decisively affect all transport processes. The three-fluid system consisting of electrons, ions, and neutral particles supports nonideal effects such as the Hall effect and ambipolar diffusion. Here, we study magnetic transport by the laminar- and turbulent-scale ambipolar diffusion processes using a simple model of the magnetic induction equation. Based on a linear analysis of the induction equation, we perform a one-dimensional numerical simulation to study the laminar ambipolar effect on medium-scale magnetic field structures. The nonlinearity of the laminar ambipolar diffusion creates magnetic structures with sharp gradients in the scale of hundreds of kilometers. We expect that these can be amenable to processes such as magnetic reconnection and energy release therefrom for heating and flaring of the solar plasma. Analyzing the characteristic timescales of these processes, we find that the turbulent diffusion timescale is smaller by several orders of magnitude than the laminar diffusion timescale. The effect of the modeled turbulent ambipolar diffusion on the obtained field structures is briefly discussed.

  8. On the extraction of laminar flame speed and Markstein length from outwardly propagating spherical flames

    SciTech Connect (OSTI)

    Chen, Zheng [State Key Laboratory for Turbulence and Complex Systems, Department of Mechanics and Aerospace Engineering, College of Engineering, Peking University, Beijing 100871 (China)

    2011-02-15

    Large discrepancies among the laminar flame speeds and Markstein lengths of methane/air mixtures measured by different researchers using the same constant-pressure spherical flame method are observed. As an effort to reduce these discrepancies, one linear model (LM, the stretched flame speed changes linearly with the stretch rate) and two non-linear models (NM I and NM II, the stretched flame speed changes non-linearly with the stretch rate) for extracting the laminar flame speed and Markstein length from propagating spherical flames are investigated. The accuracy and performance of the LM, NM I, and NM II are found to strongly depend on the Lewis number. It is demonstrated that NM I is the most accurate for mixtures with large Lewis number (positive Markstein length) while NM II is the most accurate for mixtures with small Lewis number (negative Markstein length). Therefore, in order to get accurate laminar flame speed and Markstein length from spherical flame experiments, different non-linear models should be used for different mixtures. The validity of the theoretical results is further demonstrated by numerical and experimental studies. The results of this study can be used directly in spherical flame experiments measuring the laminar flame speed and Markstein length. (author)

  9. Measurement of laminar burning speeds and Markstein lengths using a novel methodology

    SciTech Connect (OSTI)

    Tahtouh, Toni; Halter, Fabien; Mounaim-Rousselle, Christine [Institut PRISME, Universite d'Orleans, 8 rue Leonard de Vinci-45072, Orleans Cedex 2 (France)

    2009-09-15

    Three different methodologies used for the extraction of laminar information are compared and discussed. Starting from an asymptotic analysis assuming a linear relation between the propagation speed and the stretch acting on the flame front, temporal radius evolutions of spherically expanding laminar flames are postprocessed to obtain laminar burning velocities and Markstein lengths. The first methodology fits the temporal radius evolution with a polynomial function, while the new methodology proposed uses the exact solution of the linear relation linking the flame speed and the stretch as a fit. The last methodology consists in an analytical resolution of the problem. To test the different methodologies, experiments were carried out in a stainless steel combustion chamber with methane/air mixtures at atmospheric pressure and ambient temperature. The equivalence ratio was varied from 0.55 to 1.3. The classical shadowgraph technique was used to detect the reaction zone. The new methodology has proven to be the most robust and provides the most accurate results, while the polynomial methodology induces some errors due to the differentiation process. As original radii are used in the analytical methodology, it is more affected by the experimental radius determination. Finally, laminar burning velocity and Markstein length values determined with the new methodology are compared with results reported in the literature. (author)

  10. Nonlinear effects in the extraction of laminar flame speeds from expanding spherical flames

    SciTech Connect (OSTI)

    Kelley, A.P.; Law, C.K.

    2009-09-15

    Various factors affecting the determination of laminar flames speeds from outwardly propagating spherical flames in a constant-pressure combustion chamber were considered, with emphasis on the nonlinear variation of the stretched flame speed to the flame stretch rate, and the associated need to nonlinearly extrapolate the stretched flame speed to yield an accurate determination of the laminar flame speed and Markstein length. Experiments were conducted for lean and rich n-butane/air flames at 1atm initial pressure, demonstrating the complex and nonlinear nature of the dynamics of flame evolution, and the strong influences of the ignition transient and chamber confinement during the initial and final periods of the flame propagation, respectively. These experimental data were analyzed using the nonlinear relation between the stretched flame speed and stretch rate, yielding laminar flame speeds that agree well with data determined from alternate flame configurations. It is further suggested that the fidelity in the extraction of the laminar flame speed from expanding spherical flames can be facilitated by using small ignition energy and a large combustion chamber. (author)

  11. Laminar Flame Speed Measurments of Synthetic Gas Blends with Hydrocarbon Impurities 

    E-Print Network [OSTI]

    Keesee, Charles Lewis

    2015-04-09

    New laminar flame speed measurements have been taken for a wide range of synthetic gas, or syngas, mixtures. These experiments began with two baseline mixtures. The first of these baseline mixtures was a bio-syngas surrogate with a 50/50 H2/CO split...

  12. Power law and composite power law friction factor correlations for laminar and turbulent gasliquid

    E-Print Network [OSTI]

    Joseph, Daniel D.

    new unpublished, and data for gas and heavy oil from PDVSA-Intevep. Dimensionless pressure gradients oil are compiled and processed for power law and composite power law friction factor correlations reduce to the power laws for laminar flow when the Reynolds number is low and to turbulent flow when

  13. On projected NewtonKrylov solvers for instationary laminar reacting gas flows

    E-Print Network [OSTI]

    Vuik, Kees

    deposition (CVD) [8] and flows with combustion [19] requires the simultaneous solution of many strongly and considerations apply to laminar combustion as well. Assuming continuum flow, the mathematical model consists for advection, diffusion and reaction, equations (1) are very stiff. In that case, most commercial CFD codes

  14. Solution of Laminar Diffusion Flames Using a Parallel Adaptive Mesh Refinement Algorithm

    E-Print Network [OSTI]

    Groth, Clinton P. T.

    scheme to resolve fine-scale features of laminar flames is demonstrated. I. Introduction Combustion associated with our understanding of and ability to predict combustion phenomena. Over the last 10-15 years, the application of computational fluid dynamics (CFD) methods to reactive flows has yielded an improved

  15. Characterization of Limiting Factors in Laminar Flow-Based Membraneless Microfuel Cells

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    are underway to develop and optimize microscale fuel cells as high-energy-density power source alternatives, where fuel and oxidant are oxidized and re- duced, respectively, is essential for fuel cell optimization reports the analysis of a microflu- idic fuel cell based on laminar flow using an external reference

  16. Membraneless Hydrogen Bromine Laminar Flow Battery for Large-Scale Energy Storage

    E-Print Network [OSTI]

    Poonen, Bjorn

    Membraneless Hydrogen Bromine Laminar Flow Battery for Large-Scale Energy Storage by William Allan and examined for its potential to provide low cost energy storage using the rapid reaction kinetics of hydrogen by . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . David E. Hardt Chairman, Department Committee on Graduate Theses #12;2 #12;Membraneless Hydrogen Bromine

  17. Hybrid Mesons

    E-Print Network [OSTI]

    Bernhard Ketzer

    2012-08-25

    The SU(3)_flavor constituent quark model has been quite successful to explain the properties as well as the observed spectrum of mesons with pseudoscalar and vector quantum numbers. Many radial and orbital excitations of quark-antiquark systems predicted by the model, however, have not yet been observed experimentally or assigned unambiguously. In addition, a much richer spectrum of mesons is expected from QCD, in which quarks interact which each other through the exchange of colored self-interacting gluons. Owing to this particular structure of QCD, configurations are allowed in which an excited gluonic field contributes to the quantum numbers J^{PC} of the meson. States with a valence color-octet qqbar' pair neutralized in color by an excited gluon field are termed hybrids. The observation of such states, however, is difficult because they will mix with ordinary qqbar' states with the same quantum numbers, merely augmenting the observed spectrum for a given J^{PC}. Since the gluonic field may carry quantum numbers other than 0^{++}, however, this can give rise to states with "exotic" quantum numbers J^{PC}=0^{--}, 0^{+-}, 1^{-+}, 2^{+-},... The lowest-lying hybrid multiplet is expected to contain a state with exotic quantum numbers J^{PC}=1^{-+}. The identification of such a state is considered a "smoking gun" for the observation of non-qqbar mesons. The search for hybrid states has been a central goal of hadron spectroscopy in the last 20 years. Ongoing and upcoming high-statistics experiments are expected to shed new light on the existence of such states in nature. In this paper, theoretical predictions for masses and decay modes as well as recent experimental evidence for hybrid meson states and future experimental directions are discussed.

  18. Inclusion of nonlinear aerodynamics in the FLAP code

    SciTech Connect (OSTI)

    Weber, T. (Solar Energy Research Inst., Golden, CO (USA)) [Solar Energy Research Inst., Golden, CO (USA)

    1989-11-01

    Horizontal axis wind turbines usually operate with significant portions of the blade in deep stall. This contradicts the assumption in the FLAP code that a linear relation exists between the angle of attack and the lift coefficient. The objective of this paper is to determine the importance of nonlinear aerodynamics in the prediction of loads. The FLAP code has been modified to include the nonlinear relationships between the lift and drag coefficients with the angle of attack. The modification affects the calculation of the induced velocities and the aerodynamic loads. This requires an iterative procedure to determine the induced velocities instead of a closed form solution. A more advanced tower interference model has also been added that accounts for both upwind and downwind tower effects. 7 refs., 14 figs.

  19. Aerodynamic Lightweight Cab Structure Components | Department of Energy

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Home Page on Google Bookmark EERE: Alternative Fuels Data Center Home Page on Delicious Rank EERE:FinancingPetroleum Based Fuels Research at NREL AdvancedEnergyAdvocate - IssueAerodynamic

  20. Hybrid type checking

    E-Print Network [OSTI]

    Flanagan, C

    2006-01-01

    O’Callahan and J. -D. Choi. Hybrid dynamic data race detec-subtyping is sound, the hybrid compilation algorithmHybrid Type Checking Cormac Flanagan Department of Computer

  1. The Effects of Charge Motion and Laminar Flame Speed on Late Robust Combustion in a Spark-Ignition Engine

    E-Print Network [OSTI]

    Cheng, Wai K.

    The effects of charge motion and laminar flame speeds on combustion and exhaust temperature have been studied by using an air jet in the intake flow to produce an adjustable swirl or tumble motion, and by replacing the ...

  2. DOEs Effort to Reduce Truck Aerodynamic Drag through Joint...

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

    Washington D.C. vss14salari.pdf More Documents & Publications DOEs Effort to Reduce Truck Aerodynamic Drag through Joint Experiments and Computations Vehicle Technologies...

  3. DOEs Effort to Reduce Truck Aerodynamic Drag through Joint...

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

    Meeting vss006salari2012o.pdf More Documents & Publications DOEs Effort to Reduce Truck Aerodynamic Drag through Joint Experiments and Computations Vehicle Technologies...

  4. DOEs Effort to Reduce Truck Aerodynamic Drag through Joint...

    Energy Savers [EERE]

    Truck Aerodynamic Drag through Joint Experiments and Computations 2011 DOE Hydrogen and Fuel Cells Program, and Vehicle Technologies Program Annual Merit Review and Peer...

  5. Dispersion of swimming algae in laminar and turbulent channel flows: theory and simulations

    E-Print Network [OSTI]

    Croze, O A; Ahmed, M; Bees, M A; Brandt, L

    2012-01-01

    Algal swimming is often biased by environmental cues, e.g. gravitational and viscous torques drive cells towards downwelling fluid (gyrotaxis). In view of biotechnological applications, it is important to understand how such biased swimming affects cell dispersion in a flow. Here, we study the dispersion of gyrotactic swimming algae in laminar and turbulent channel flows. By direct numerical simulation (DNS) of cell motion within upwelling and downwelling channel flows, we evaluate time-dependent measures of dispersion for increasing values of the flow Peclet (Reynolds) numbers, Pe (Re). Furthermore, we derive an analytical `swimming Taylor-Aris dispersion' theory, using flow-dependent transport parameters given by existing microscopic models. In the laminar regime, DNS results and analytical predictions compare very well, providing the first confirmation that cells' response to flow is best described by the generalized-Taylor-dispersion microscopic model. We predict that cells drift along a channel faster th...

  6. Investigation on the properties of a laminar grating as a soft x-ray beam splitter

    SciTech Connect (OSTI)

    Liu Ying; Fuchs, Hans-Joerg; Liu Zhengkun; Chen Huoyao; He Shengnan; Fu Shaojun; Kley, Ernst-Bernhard; Tuennermann, Andreas

    2010-08-10

    Laminar-type gratings as soft x-ray beam splitters for interferometry are presented. Gold-coated grating beam splitters with 1000 lines/mm are designed for grazing incidence operation at 13.9nm. They are routinely fabricated using electron beam lithography and ion etching techniques. The laminar grating is measured to have almost equal absolute efficiencies of about 20% in the zeroth and -1st orders, which enables a fringe visibility up to 0.99 in the interferometer. The discrepancy of the grating profiles between the optimized theoretical and the experimental results is analyzed according to the comparison of the optimized simulation results and the measurement realization of the grating efficiencies. By a precise control of the grating profile, the grating efficiency in the -1st order and the fringe visibility could be improved to 25% and 1, respectively.

  7. Analysis of the flamelet concept in the numerical simulation of laminar partially premixed flames

    SciTech Connect (OSTI)

    Consul, R.; Oliva, A.; Perez-Segarra, C.D.; Carbonell, D.; de Goey, L.P.H.

    2008-04-15

    The aim of this work is to analyze the application of flamelet models based on the mixture fraction variable and its dissipation rate to the numerical simulation of partially premixed flames. Although the main application of these models is the computation of turbulent flames, this work focuses on the performance of flamelet concept in laminar flame simulations removing, in this way, turbulence closure interactions. A well-known coflow methane/air laminar flame is selected. Five levels of premixing are taken into account from an equivalence ratio {phi}={infinity} (nonpremixed) to {phi}=2.464. Results obtained using the flamelet approaches are compared to data obtained from the detailed solution of the complete transport equations using primitive variables. Numerical simulations of a counterflow flame are also presented to support the discussion of the results. Special emphasis is given to the analysis of the scalar dissipation rate modeling. (author)

  8. An experimental investigation regarding the laminar to turbulent flow transition in helically coiled pipes

    SciTech Connect (OSTI)

    Cioncolini, Andrea; Santini, Lorenzo [Department of Nuclear Engineering, Politecnico di Milano, via Ponzio 34/3, 20133 Milano (Italy)

    2006-03-01

    An experimental study was carried out to investigate the transition from laminar to turbulent flow in helically coiled pipes. Twelve coils have been tested, with ratios of coil diameter to tube diameter ranging from 6.9 to 369, and the interaction between turbulence emergence and coil curvature has been analyzed from direct observation of the experimental friction factor profiles. The experimental data compare favorably with existing results and reveal new features that apparently were not observed in previous research. (author)

  9. The Laminar Flame Speedup by Neon-22 Enrichment in White Dwarf Supernovae

    E-Print Network [OSTI]

    David A. Chamulak; Edward F. Brown; Francis X. Timmes

    2006-12-18

    Carbon-oxygen white dwarfs contain neon-22 formed from alpha-captures onto nitrogen during core He burning in the progenitor star. In a white dwarf (type Ia) supernova, the neon-22 abundance determines, in part, the neutron-to-proton ratio and hence the abundance of radioactive nickel-56 that powers the lightcurve. The neon-22 abundance also changes the burning rate and hence the laminar flame speed. We tabulate the flame speedup for different initial carbon and neon-22 abundances and for a range of densities. This increase in the laminar flame speed--about 30% for a neon-22 mass fraction of 6%--affects the deflagration just after ignition near the center of the white dwarf, where the laminar speed of the flame dominates over the buoyant rise, and in regions of lower density ~ 10^7 g/cm3 where a transition to distributed burning is conjectured to occur. The increase in flame speed will decrease the density of any transition to distributed burning.

  10. Mechanical and statistical study of the laminar hole formation in transitional plane Couette flow

    E-Print Network [OSTI]

    Rolland, Joran

    2015-01-01

    This article is concerned with the numerical study and modelling of two aspects the formation of laminar holes in transitional turbulence of plane Couette flow (PCF). On the one hand, we consider quenches: sudden decreases of the Reynolds number R which force the formation of holes. The Reynolds number is decreased from featureless turbulence to the range of existence of the oblique laminar-turbulent bands [Rg;Rt]. The successive stages of the quench are studied by means of visualisations and measurements of kinetic energy and turbulent fraction. The behaviour of the kinetic energy is explained using a kinetic energy budget: it shows that viscosity causes quasi modal decay until lift-up equals it and creates a new balance. Moreover, the budget confirms that the physical mechanisms at play are independent of the way the quench is performed. On the other hand we consider the natural formation of laminar holes in the bands, near Rg. The Direct Numerical simulations (DNS) show that holes in the turbulent bands pr...

  11. Laminar and turbulent nozzle-jet flows and their acoustic near-field

    SciTech Connect (OSTI)

    Bühler, Stefan; Obrist, Dominik; Kleiser, Leonhard

    2014-08-15

    We investigate numerically the effects of nozzle-exit flow conditions on the jet-flow development and the near-field sound at a diameter-based Reynolds number of Re{sub D} = 18?100 and Mach number Ma = 0.9. Our computational setup features the inclusion of a cylindrical nozzle which allows to establish a physical nozzle-exit flow and therefore well-defined initial jet-flow conditions. Within the nozzle, the flow is modeled by a potential flow core and a laminar, transitional, or developing turbulent boundary layer. The goal is to document and to compare the effects of the different jet inflows on the jet flow development and the sound radiation. For laminar and transitional boundary layers, transition to turbulence in the jet shear layer is governed by the development of Kelvin-Helmholtz instabilities. With the turbulent nozzle boundary layer, the jet flow development is characterized by a rapid changeover to a turbulent free shear layer within about one nozzle diameter. Sound pressure levels are strongly enhanced for laminar and transitional exit conditions compared to the turbulent case. However, a frequency and frequency-wavenumber analysis of the near-field pressure indicates that the dominant sound radiation characteristics remain largely unaffected. By applying a recently developed scaling procedure, we obtain a close match of the scaled near-field sound spectra for all nozzle-exit turbulence levels and also a reasonable agreement with experimental far-field data.

  12. Characterization of an aerodynamic lens for transmitting particles greater than 1 micrometer in diameter into the Aerodyne aerosol mass spectrometer

    E-Print Network [OSTI]

    Williams, L. R.

    We have designed and characterized a new inlet and aerodynamic lens for the Aerodyne aerosol mass spectrometer (AMS) that transmits particles between 80 nm and more than 3 ?m in vacuum aerodynamic diameter. The design of ...

  13. Advances in Modeling of Aerodynamic Forces on Bridge Xinzhong Chen1

    E-Print Network [OSTI]

    Kareem, Ahsan

    Advances in Modeling of Aerodynamic Forces on Bridge Decks Xinzhong Chen1 and Ahsan Kareem2 be pushing the envelope of the current linear aerodynamics which has successfully served thus far state-of-the-art in this field, may serve as a building block for developing new analysis tools

  14. Aerodynamic Shape Optimization of Airfoils in Ultra-Low Reynolds Number Flow using

    E-Print Network [OSTI]

    Stanford University

    Aerodynamic Shape Optimization of Airfoils in Ultra-Low Reynolds Number Flow using Simultaneous;Aerodynamic Shape Optimization of Airfoils in Ultra-Low Reynolds Number Flow using Simultaneous Pseudo Abstract. The paper presents numerical results of optimized airfoils at ultra-low Reynolds numbers

  15. Fluidic Control of a Turret Wake: Aerodynamic and Aero-Optical Effects

    E-Print Network [OSTI]

    Gordeyev, Stanislav

    Fluidic Control of a Turret Wake: Aerodynamic and Aero-Optical Effects Bojan Vukasinovic and Ari, Missouri 63166 DOI: 10.2514/1.J050085 Effects of direct small-scale actuation on aerodynamic and aero of separation. Effects of actuation on aero-optical distortions are assessed from the flow dynamics, using

  16. WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES

    E-Print Network [OSTI]

    Leu, Tzong-Shyng "Jeremy"

    1 WIND-TUNNEL STUDY ON AERODYNAMIC PERFORMANCE OF SMALL VERTICAL-AXIS WIND TURBINES J. J. Miau*1 were carried out to study the aerodynamic performance of three vertical axis wind turbines (VAWTs vertical-axis wind turbines (VAWT) have attracted a great deal of attention, because of their potential

  17. Transitions between turbulent and laminar superfluid vorticity states in the outer core of a neutron star

    E-Print Network [OSTI]

    C. Peralta; A. Melatos; M. Giacobello; A. Ooi

    2006-07-08

    We investigate the global transition from a turbulent state of superfluid vorticity to a laminar state, and vice versa, in the outer core of a neutron star. By solving numerically the hydrodynamic Hall-Vinen-Bekarevich-Khalatnikov equations for a rotating superfluid in a differentially rotating spherical shell, we find that the meridional counterflow driven by Ekman pumping exceeds the Donnelly-Glaberson threshold throughout most of the outer core, exciting unstable Kelvin waves which disrupt the rectilinear vortex array, creating a vortex tangle. In the turbulent state, the torque exerted on the crust oscillates, and the crust-core coupling is weaker than in the laminar state. This leads to a new scenario for the rotational glitches observed in radio pulsars: a vortex tangle is sustained in the differentially rotating outer core by the meridional counterflow, a sudden spin-up event brings the crust and core into corotation, the vortex tangle relaxes back to a rectilinear vortex array, then the crust spins down electromagnetically until enough meridional counterflow builds up to reform a vortex tangle. The turbulent-laminar transition can occur uniformly or in patches; the associated time-scales are estimated from vortex filament theory. We calculate numerically the global structure of the flow with and without an inviscid superfluid component, for Hall-Vinen and Gorter-Mellink forms of the mutual friction. We also calculate the post-glitch evolution of the angular velocity of the crust and its time derivative, and compare the results with radio pulse timing data, predicting a correlation between glitch activity and Reynolds number.

  18. Demonstration of a plasma mirror based on a laminar flow water film

    SciTech Connect (OSTI)

    Panasenko, Dmitriy; Shu, Anthony; Gonsalves, Anthony; Nakamura, Kei; Matlis, Nicholas; Toth, Csaba; Leemans, Wim

    2011-07-22

    A plasma mirror based on a laminar water film with low flow speed 0.5-2 cm/s has been developed and characterized, for use as an ultrahigh intensity optical reflector. The use of flowing water as atarget surface automatically results in each laser pulse seeing a new interaction surface and avoids the need for mechanical scanning of the target surface. In addition, the breakdown of water does notproduce contaminating debris that can be deleterious to vacuum chamber conditions and optics, such as is the case when using conventional solid targets. The mirror exhibits 70percent reflectivity, whilemaintaining high-quality of the reflected spot.

  19. Demonstration of a plasma mirror based on a laminar flow water film

    SciTech Connect (OSTI)

    Panasenko, Dmitriy; Shu, Anthony J.; Gonsalves, Anthony; Nakamura, Kei; Matlis, Nicholas H.; Toth, Csaba; Leemans, Wim P. [Lawrence Berkeley National Laboratory, University of California, Berkeley, California 94720 (United States)

    2010-08-15

    A plasma mirror based on a laminar water film with low flow speed (0.5-2 cm/s) has been developed and characterized, for use as an ultrahigh intensity optical reflector. The use of flowing water as a target surface automatically results in each laser pulse seeing a new interaction surface and avoids the need for mechanical scanning of the target surface. In addition, the breakdown of water does not produce contaminating debris that can be deleterious to vacuum chamber conditions and optics, such as is the case when using conventional solid targets. The mirror exhibits 70% reflectivity, while maintaining high-quality of the reflected spot.

  20. Development of a stable dielectric-barrier discharge enhanced laminar plasma jet generated at atmospheric pressure

    SciTech Connect (OSTI)

    Tang Jie; Li Shibo; Zhao Wei; Wang Yishan [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics of CAS, Xi'an (China); Duan Yixiang [State Key Laboratory of Transient Optics and Photonics, Xi'an Institute of Optics and Precision Mechanics of CAS, Xi'an (China); Research Center of Analytical Instrumentation, Sichuan University, Chengdu (China)

    2012-06-18

    A stable nonthermal laminar atmospheric-pressure plasma source equipped with dielectric-barrier discharge was developed to realize more efficient plasma generation, with the total energy consumption reduced to nearly 25% of the original. Temperature and emission spectra monitoring indicates that this plasma is uniform in the lateral direction of the jet core region. It is also found that this plasma contains not only abundant excited argon atoms but also sufficient excited N{sub 2} and OH. This is mainly resulted from the escape of abundant electrons from the exit, due to the sharp decrease of sustaining voltage and the coupling between ions and electrons.

  1. Experimental and numerical study of laminar forced convection heat transfer for a dimpled heat sink 

    E-Print Network [OSTI]

    Park, Do Seo

    2009-05-15

    of the copper plate. The outer surface of the test section consisted of fiberglass to reduce heat loss to the outside surroundings. The blower was turned on and air was forced through the test setup. The flow rate through the test section was controlled... STUDY OF LAMINAR FORCED CONVECTION HEAT TRANSFER FOR A DIMPLED HEAT SINK A Thesis by DO SEO PARK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree of MASTER...

  2. Aeroacoustics and aerodynamic performance of a rotor with flatback airfoils.

    SciTech Connect (OSTI)

    Paquette, Joshua A.; Barone, Matthew Franklin; Christiansen, Monica; Simley, Eric

    2010-06-01

    The aerodynamic performance and aeroacoustic noise sources of a rotor employing flatback airfoils have been studied in field test campaign and companion modeling effort. The field test measurements of a sub-scale rotor employing nine meter blades include both performance measurements and acoustic measurements. The acoustic measurements are obtained using a 45 microphone beamforming array, enabling identification of both noise source amplitude and position. Semi-empirical models of flatback airfoil blunt trailing edge noise are developed and calibrated using available aeroacoustic wind tunnel test data. The model results and measurements indicate that flatback airfoil noise is less than drive train noise for the current test turbine. It is also demonstrated that the commonly used Brooks, Pope, and Marcolini model for blunt trailing edge noise may be over-conservative in predicting flatback airfoil noise for wind turbine applications.

  3. Sparse polynomial surrogates for aerodynamic computations with random inputs

    E-Print Network [OSTI]

    Savin, Eric; Peter, Jacques

    2015-01-01

    This paper deals with some of the methodologies used to construct polynomial surrogate models based on generalized polynomial chaos (gPC) expansions for applications to uncertainty quantification (UQ) in aerodynamic computations. A core ingredient in gPC expansions is the choice of a dedicated sampling strategy, so as to define the most significant scenarios to be considered for the construction of such metamodels. A desirable feature of the proposed rules shall be their ability to handle several random inputs simultaneously. Methods to identify the relative "importance" of those variables or uncertain data shall be ideally considered as well. The present work is more particularly dedicated to the development of sampling strategies based on sparsity principles. Sparse multi-dimensional cubature rules based on general one-dimensional Gauss-Jacobi-type quadratures are first addressed. These sets are non nested, but they are well adapted to the probability density functions with compact support for the random in...

  4. Vacuum chamber with a supersonic flow aerodynamic window

    DOE Patents [OSTI]

    Hanson, Clark L. (Livermore, CA)

    1982-01-01

    A supersonic flow aerodynamic window, whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  5. Vacuum chamber with a supersonic-flow aerodynamic window

    DOE Patents [OSTI]

    Hanson, C.L.

    1980-10-14

    A supersonic flow aerodynamic window is disclosed whereby a steam ejector situated in a primary chamber at vacuum exhausts superheated steam toward an orifice to a region of higher pressure, creating a barrier to the gas in the region of higher pressure which attempts to enter through the orifice. In a mixing chamber outside and in fluid communication with the primary chamber, superheated steam and gas are combined into a mixture which then enters the primary chamber through the orifice. At the point of impact of the ejector/superheated steam and the incoming gas/superheated steam mixture, a barrier is created to the gas attempting to enter the ejector chamber. This barrier, coupled with suitable vacuum pumping means and cooling means, serves to keep the steam ejector and primary chamber at a negative pressure, even though the primary chamber has an orifice to a region of higher pressure.

  6. Aerodynamic testing of a rotating wind turbine blade

    SciTech Connect (OSTI)

    Butterfield, C.P.; Nelsen, E.N.

    1990-01-01

    Aerodynamic, load, flow-visualization, and inflow measurements were taken on a downwind horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor recorded video images of tufts attached to the low-pressure side of the blade. Strain gages, mounted every 10% of the blade's span, provided load and pressure measurements. Pressure taps at 32 chordwise positions recorded pressure distributions. Wind inflow was measured via a vertical-plane array of anemometers located 10 m upwind. The objectives of the test were to address whether airfoil pressure distributions measured on a rotating blade differed from those measured in the wind tunnel, if radial flow near or in the boundary layer of the airfoil affected pressure distributions, if dynamic stall could result in increased dynamic loads, and if the location of the separation boundary measured on the rotating blade agreed with that measured in two-dimensional flow in the wind tunnel. 6 refs., 9 figs., 1 tab.

  7. A comparative investigation of laminar separation bubbles at low Reynolds numbers in wind tunnels and free flight environments 

    E-Print Network [OSTI]

    Blohowiak, James Russell

    1988-01-01

    Attention has turned towards low Reynolds number aerodynamics with the recent increase in practical low speed applications. High altitude aircraft, sailplanes, ultra-light aircraft, and small RPV's (Remotely Piloted Vehicles) are current pro...

  8. Hybrid and multifield inflation

    E-Print Network [OSTI]

    Sfakianakis, Evangelos I

    2014-01-01

    In this thesis I study the generation of density perturbations in two classes of inflationary models: hybrid inflation and multifield inflation with non-minimal coupling to gravity. In the case of hybrid inflation, we ...

  9. Hybrid Power Test Bed

    SciTech Connect (OSTI)

    NONE

    1996-06-01

    This document describes efforts by the National Renewable Energy Laboratory to simulate hybrid power systems. Hybrid power systems combine multiple power sources such as wind turbines, photovoltaic (PV) arrays, diesel generators, and battery storage systems. They typically are used in remote areas, away from major electric grids. The Hybrid Power Test Bed is designed to assist the U.S. wind industry in developing and testing hybrid power generation systems. Test bed capabilities, features, and equipment are described.

  10. Mesoscale hybrid calibration artifact

    SciTech Connect (OSTI)

    Tran, Hy D. (Albuquerque, NM); Claudet, Andre A. (Albuquerque, NM); Oliver, Andrew D. (Waltham, MA)

    2010-09-07

    A mesoscale calibration artifact, also called a hybrid artifact, suitable for hybrid dimensional measurement and the method for make the artifact. The hybrid artifact has structural characteristics that make it suitable for dimensional measurement in both vision-based systems and touch-probe-based systems. The hybrid artifact employs the intersection of bulk-micromachined planes to fabricate edges that are sharp to the nanometer level and intersecting planes with crystal-lattice-defined angles.

  11. A comparison of baseline aerodynamic performance of optimally-twisted versus non-twisted HAWT blades

    SciTech Connect (OSTI)

    Simms, D.A.; Robinson, M.C.; Hand, M.M.; Fingersh, L.J.

    1995-01-01

    NREL has completed the initial twisted blade field tests of the ``Unsteady Aerodynamics Experiment.`` This test series continues systematic measurements of unsteady aerodynamic phenomena prevalent in stall-controlled horizontal axis wind turbines (HAWTs). The blade twist distribution optimizes power production at a single angle of attack along the span. Abrupt transitions into and out of stall are created due to rapid changes in inflow. Data from earlier experiments have been analyzed extensively to characterize the steady and unsteady response of untwisted blades. In this report, a characterization and comparison of the baseline aerodynamic performance of the twisted versus non-twisted blade sets will be presented for steady flow conditions.

  12. Hybrid Systems Frits Vaandrager

    E-Print Network [OSTI]

    Vaandrager, Frits

    on these data, the computer may decide to turn on a heating system, switch off a pump, etc. When a dangerous1 Hybrid Systems Frits Vaandrager 1 Introduction Hybrid systems are systems that intermix discrete. The specification, design and analysis of hybrid systems require a synthesis of ideas, concepts, mathe­ matical

  13. Hybrid armature projectile

    DOE Patents [OSTI]

    Hawke, Ronald S. (Livermore, CA); Asay, James R. (Los Lunas, NM); Hall, Clint A. (Albuquerque, NM); Konrad, Carl H. (Albuquerque, NM); Sauve, Gerald L. (Berthoud, CO); Shahinpoor, Mohsen (Albuquerque, NM); Susoeff, Allan R. (Pleasanton, CA)

    1993-01-01

    A projectile for a railgun that uses a hybrid armature and provides a seed block around part of the outer surface of the projectile to seed the hybrid plasma brush. In addition, the hybrid armature is continuously vaporized to replenish plasma in a plasma armature to provide a tandem armature and provides a unique ridge and groove to reduce plasama blowby.

  14. Corn Hybrid Virginia Corn &

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    Virginia Corn Hybrid and Management Trials 2007 Virginia Corn & Small Grain Management #12;VIRGINIA CORN HYBRID AND MANAGEMENT TRIALS IN 2007 Coordinators of Virginia Corn Hybrid Trials in 2007 Wade Thomason, Extension Specialist, Department of Crop and Soil Environmental Sciences, Virginia Tech Harry

  15. Corn Hybrid Virginia Corn &

    E-Print Network [OSTI]

    Liskiewicz, Maciej

    Virginia Corn Hybrid Management and Trials 2006 Virginia Corn & Small Grain Management #12;#12;Virginia Corn Hybrid and Management Trials 2006 Coordinators of Virginia Corn Hybrid Trials in 2006 Wade Thomason, Extension Specialist, Department of Crop and Soil Environmental Sciences, Virginia Tech Harry

  16. High-order accurate simulation of low-Mach laminar flow past two side-by-side cylinders using spectral difference method

    E-Print Network [OSTI]

    Jameson, Antony

    High-order accurate simulation of low-Mach laminar flow past two side-by-side cylinders using applications on simulating laminar flow past two side-by-side cylinders at various spacings. The high-by-side cylinders Investigations of the fluid flow and vortex dynamics about sim- ple configurations of two

  17. Chapter 1 x Introduction 7 1.12 For low-speed (laminar) flow in a tube of radius ro, the velocity u takes the form

    E-Print Network [OSTI]

    Bahrami, Majid

    Chapter 1 x Introduction 7 1.12 For low-speed (laminar) flow in a tube of radius ro, the velocity u is the length of the pipe and C is a dimensionless constant which has the theoretical laminar-flow value of (1

  18. MEMBRANELESS FUEL CELL BASED ON LAMINAR FLOW Eric R. Choban, Piotr Waszczuk, Larry J. Markoski, Andrzej Wieckowski, and Paul J.A. Kenis*

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    MEMBRANELESS FUEL CELL BASED ON LAMINAR FLOW Eric R. Choban, Piotr Waszczuk, Larry J. Markoski in this area focus on downscaling of existing fuel cell technology such as the well-known proton exchange membrane (PEM) fuel cells. Here we study a novel concept for fuel cells: the use of laminar flow instead

  19. Characterization of Fuego for laminar and turbulent natural convection heat transfer.

    SciTech Connect (OSTI)

    Francis, Nicholas Donald, Jr. (,; .)

    2005-08-01

    A computational fluid dynamics (CFD) analysis is conducted for internal natural convection heat transfer using the low Mach number code Fuego. The flow conditions under investigation are primarily laminar, transitional, or low-intensity level turbulent flows. In the case of turbulent boundary layers at low-level turbulence or transitional Reynolds numbers, the use of standard wall functions no longer applies, in general, for wall-bounded flows. One must integrate all the way to the wall in order to account for gradients in the dependent variables in the viscous sublayer. Fuego provides two turbulence models in which resolution of the near-wall region is appropriate. These models are the v2-f turbulence model and a Launder-Sharma, low-Reynolds number turbulence model. Two standard geometries are considered: the annulus formed between horizontal concentric cylinders and a square enclosure. Each geometry emphasizes wall shear flow and complexities associated with turbulent or near turbulent boundary layers in contact with a motionless core fluid. Overall, the Fuego simulations for both laminar and turbulent flows compared well to measured data, for both geometries under investigation, and to a widely accepted commercial CFD code (FLUENT).

  20. Laminar burning velocities at high pressure for primary reference fuels and gasoline: Experimental and numerical investigation

    SciTech Connect (OSTI)

    Jerzembeck, S.; Peters, N. [RWTH, Aachen (Germany); Pepiot-Desjardins, P.; Pitsch, H. [Department of Mechanical Engineering, Stanford University, CA (United States)

    2009-02-15

    Spherical flames of n-heptane, iso-octane, PRF 87 and gasoline/air mixtures are experimentally investigated to determine laminar burning velocities and Markstein lengths under engine-relevant conditions by using the constant volume bomb method. Data are obtained for an initial temperature of 373 K, equivalence ratios varying from {phi}=0.7 to {phi}=1.2, and initial pressures from 10 to 25 bar. To track the flame front in the vessel a dark field He-Ne laser Schlieren measurement technique and digital image processing were used. The propagating speed with respect to the burned gases and the stretch rate are determined from the rate of change of the flame radius. The laminar burning velocities are obtained through a linear extrapolation to zero stretch. The experimentally determined Markstein numbers are compared to theoretical predictions. A reduced chemical kinetic mechanism for n-heptane and iso-octane was derived from the Lawrence Livermore comprehensive mechanisms. This mechanism was validated for ignition delay times and flame propagation at low and high pressures. In summary an overall good agreement with the various experimental data sets used in the validation was obtained. (author)

  1. Response of a laminar premixed flame to flow oscillations: A kinematic model and thermoacoustic instability results

    SciTech Connect (OSTI)

    Fleifil, M.; Annaswamy, A.M.; Ghoneim, A.F.; Ghoneim, Z.A.

    1996-09-01

    Combustion instability is a resonance phenomenon that arises due to the coupling between the system acoustics and the unsteady heat release. The constructive feedback between the two processes, which is known to occur as a certain phase relationship between the pressure and the unsteady heat release rate is satisfied, depends on many parameters among which is the acoustic mode, the flame holder characteristics, and the dominant burning pattern. In this paper, the authors construct an analytical model to describe the dynamic response of a laminar premixed flame stabilized on the rim of a tube to velocity oscillation. They consider uniform and nonuniform velocity perturbations superimposed on a pipe flow velocity profile. The model results show that the magnitude of heat release perturbation and its phase with respect to the dynamic perturbation dependent primarily on the flame Strohal number, representing the ratio of the dominant frequency times the tube radius to the laminar burning velocity. In terms of this number, high-frequency perturbations pass through the flame while low frequencies lead to a strong response. The phase with respect to the velocity perturbation behaves in the opposite way. Results of this model are shown to agree with experimental observations and to be useful in determining how the combustion excited model is selected among all the acoustic unstable modes. The model is then used to obtain a time-domain differential equation describing the relationship between the velocity perturbation and the heat release response over the entire frequency range.

  2. Laminar burn rates of gun propellants measured in the high-pressure strand burner

    SciTech Connect (OSTI)

    Reaugh, J. E., LLNL

    1997-10-01

    The pressure dependence of the laminar burn rate of gun propellants plays a role in the design and behavior of high-performance guns. We have begun a program to investigate the effects of processing variables on the laminar burn rates, using our high-pressure strand burner to measure these rates at pressures exceeding 700 MPa. We have burned JA2 and M43 propellant samples, provided by Dr. Arpad Juhasz, ARL, from propellant lots previously used in round-robin tests. Our results at room temperature are in accord with other measurements. In addition, we present results measured for propellant that has been preheated to 50 C before burning. We used our thermochemical equilibrium code, CHEETAH, to help interpret the simultaneous pressure and temperature measurements taken during the testing, and show examples of its use. It has been modified to provide performance measures and equations of state for the products that are familiar to the gun-propellant community users of BLAKE.

  3. The hydrogen hybrid option

    SciTech Connect (OSTI)

    Smith, J.R.

    1993-10-15

    The energy efficiency of various piston engine options for series hybrid automobiles are compared with conventional, battery powered electric, and proton exchange membrane (PEM) fuel cell hybrid automobiles. Gasoline, compressed natural gas (CNG), and hydrogen are considered for these hybrids. The engine and fuel comparisons are done on a basis of equal vehicle weight, drag, and rolling resistance. The relative emissions of these various fueled vehicle options are also presented. It is concluded that a highly optimized, hydrogen fueled, piston engine, series electric hybrid automobile will have efficiency comparable to a similar fuel cell hybrid automobile and will have fewer total emissions than the battery powered vehicle, even without a catalyst.

  4. Comparative Study of Hybrid Powertrains on Fuel Saving, Emissions, and Component Energy Loss in HD Trucks

    SciTech Connect (OSTI)

    Gao, Zhiming; FINNEY, Charles E A; Daw, C Stuart; LaClair, Tim J; Smith, David E

    2014-01-01

    We compared parallel and series hybrid powertrains on fuel economy, component energy loss, and emissions control in Class 8 trucks over both city and highway driving. A comprehensive set of component models describing battery energy, engine fuel efficiency, emissions control, and power demand interactions for heavy duty (HD) hybrids has been integrated with parallel and series hybrid Class 8 trucks in order to identify the technical barriers of these hybrid powertrain technologies. The results show that series hybrid is absolutely negative for fuel economy benefit of long-haul trucks due to an efficiency penalty associated with the dual-step conversions of energy (i.e. mechanical to electric to mechanical). The current parallel hybrid technology combined with 50% auxiliary load reduction could elevate 5-7% fuel economy of long-haul trucks, but a profound improvement of long-haul truck fuel economy requires additional innovative technologies for reducing aerodynamic drag and rolling resistance losses. The simulated emissions control indicates that hybrid trucks reduce more CO and HC emissions than conventional trucks. The simulated results further indicate that the catalyzed DPF played an important role in CO oxidations. Limited NH3 emissions could be slipped from the Urea SCR, but the average NH3 emissions are below 20 ppm. Meanwhile our estimations show 1.5-1.9% of equivalent fuel-cost penalty due to urea consumption in the simulated SCR cases.

  5. Unsteady Aerodynamic and Dynamic Analysis of the Meridian UAS in a Rolling-Yawing Motion

    E-Print Network [OSTI]

    Lykins, Ryan

    2014-05-31

    The nonlinear and unsteady aerodynamic effects of operating the Meridian unmanned aerial system (UAS) in crosswinds and at high angular rates is investigated in this work. The Meridian UAS is a large autonomous aircraft, with a V-tail configuration...

  6. Challenges in Simulation of Aerodynamics, Hydrodynamics, and Mooring-Line Dynamics of Floating Offshore Wind Turbines

    SciTech Connect (OSTI)

    Matha, D.; Schlipf, M.; Cordle, A.; Pereira, R.; Jonkman, J.

    2011-10-01

    This paper presents the current major modeling challenges for floating offshore wind turbine design tools and describes aerodynamic and hydrodynamic effects due to rotor and platform motions and usage of non-slender support structures.

  7. Physically-based aerodynamic flight of birds: an interactive approach to behavioral flocking 

    E-Print Network [OSTI]

    Ringham, Michael Lynn

    1996-01-01

    This thesis describes a method for simulating the flight of birds in a flock with the use of physically-based aerodynamics. The resulting flocking behavior dramatically improves on results previously obtained in computer graphics and animation...

  8. FY2003 Annual Report: DOE Project on Heavy Vehicle Aerodynamic Drag

    SciTech Connect (OSTI)

    McCallen, R C; Salari, K; Ortega, J; DeChant, L J; Roy, C J; Payne, J J; Hassan, B; Pointer, W D; Browand, F; Hammache, M; Hsu, T; Ross, J; Satran, D; Heineck, J; Walker, S; Yaste, D; Englar, R; Leonard, A; Rubel, M; Chatelain, P

    2003-10-24

    Objective: {sm_bullet} Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles. {sm_bullet} Establish a database of experimental, computational, and conceptual design information, and demonstrate potential of new drag-reduction devices.

  9. Influence of low-speed aerodynamic performance on airport community noise

    E-Print Network [OSTI]

    March, Andrew I. (Andrew Irving)

    2008-01-01

    Properly assessing proposed aviation policies requires a thorough trade study of noise, emissions, fuel consumption, and cost. Aircraft low-speed aerodynamic performance is an important driver of all these impacts, and ...

  10. An acoustic and aerodynamic study of stops in tonal and non-tonal dialects of Korean

    E-Print Network [OSTI]

    Lee, Hyunjung

    2010-03-29

    ABSTRACT This study investigates the acoustic and aerodynamic properties of well&ndashknown three&ndashway distinction of Korean voiceless stops in two dialects, which differ in their tonal systems: non&ndashtonal Seoul Korean (standard Korean...

  11. An aerodynamic surface to deploy and position a stall deterrent spoiler 

    E-Print Network [OSTI]

    Brown, Jeffrey Reed

    1974-01-01

    AN AERODYNAMIC SURFACE TO DEPLOY AND POSITION A STALL DETERRENT SPOILER A Thesis JEFFREY REED BROWN Submitted to the Graduate College of Texas A8M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE... December 1974 Major Subject: Aerospace Engineering AN AERODYNAMIC SURFACE TO DEPLOY AND POSITION A STALL DETERRENT SPOILER A Thesis by JEFFREY REED BROWN Approved as to style and content by: Chairman of Committee Head o Departm nt Member Member...

  12. TiO{sub 2} Film Deposition by Atmospheric Thermal Plasma CVD Using Laminar and Turbulence Plasma Jets

    SciTech Connect (OSTI)

    Ando, Yasutaka; Tobe, Shogo [Ashikaga Institute of Technology, 268-1 Omae, Ashikaga, Tochigi 326-8558 (Japan); Tahara, Hirokazu [Osaka Institute of Technology, 5-16-1 Omiya, Asahi-Ku, Osaka 535-8585 (Japan)

    2008-02-21

    In this study, to provide continuous plasma atmosphere on the substrate surface in the case of atmospheric thermal plasma CVD, TiO{sub 2} film deposition by thermal plasma CVD using laminar plasma jet was carried out. For comparison, the film deposition using turbulence plasma jet was conducted as well. Consequently, transition of the plasma jet from laminar to turbulent occurred on the condition of over 3.5 1/min in Ar working gas flow rate and the plasma jet became turbulent on the condition of over 10 1/min. In the case of the turbulent plasma jet use, anatase rich titanium oxide film could be obtained though plasma jet could not contact with the surface of the substrate continuously even on the condition that feedstock material was injected into the plasma jet. On the other hand,, in the case of laminar gas flow rate, the plasma jet could contact with the substrate continuously without melt down of the substrate during film deposition. Besides, titanium oxide film could be obtained even in the case of the laminar plasma jet use. From these results, this technique was thought to have high potential for atmospheric thermal plasma CVD.

  13. Effect of tube spacing on the vortex shedding characteristics of laminar flow past an inline tube array: A numerical study

    E-Print Network [OSTI]

    Luo, Xiaoyu

    Effect of tube spacing on the vortex shedding characteristics of laminar flow past an inline tube the tubes. Complex flow dynamic phenomena such as reattachment of shear layers, in- duced separation, vortex Accepted 27 October 2008 Available online 14 November 2008 a b s t r a c t The effect of tube spacing

  14. Membraneless Vanadium Redox Fuel Cell Using Laminar Flow Rosaria Ferrigno, Abraham D. Stroock, Thomas D. Clark, Michael Mayer, and

    E-Print Network [OSTI]

    Mayer, Michael

    Membraneless Vanadium Redox Fuel Cell Using Laminar Flow Rosaria Ferrigno, Abraham D. Stroock This communication describes a small redox fuel cell fabricated using a design that omits the membrane normally used this concept by operating a millimeter-scale redox fuel cell that uses the redox couples V(V)/V(IV) (cathodic

  15. Laminar tendon composites with enhanced mechanical properties Kyle A. Alberti Jeong-Yun Sun Widusha R. Illeperuma

    E-Print Network [OSTI]

    Suo, Zhigang

    Laminar tendon composites with enhanced mechanical properties Kyle A. Alberti · Jeong-Yun Sun University, 4 Colby Street, Medford, MA 02155, USA e-mail: qiaobing.xu@tufts.edu J.-Y. Sun Á W. R. Illeperuma.-Y. Sun Á W. R. Illeperuma Á Z. Suo Kavli Institute for Bionano Science and Technology, Harvard University

  16. IS THE MAGNETIC FIELD IN THE HELIOSHEATH LAMINAR OR A TURBULENT SEA OF BUBBLES?

    SciTech Connect (OSTI)

    Opher, M. [Astronomy Department, Boston University, Boston, MA (United States); Drake, J. F. [Department of Physics and the Institute for Physical Science and Technology, University of Maryland, College Park, MD (United States); Swisdak, M.; Schoeffler, K. M. [Institute for Research in Electronics and Applied Physics, University of Maryland, College Park, MD (United States); Richardson, J. D. [Kavli Institute for Astrophysics and Space Research, Massachusetts Institute of Technology, Cambridge, MA (United States); Decker, R. B. [John Hopkins Applied Physics Laboratory, Laurel, MD (United States); Toth, G., E-mail: mopher@bu.edu [University of Michigan, Ann Arbor, MI (United States)

    2011-06-10

    All current global models of the heliosphere are based on the assumption that the magnetic field in the heliosheath, in the region close to the heliopause (HP), is laminar. We argue that in that region the heliospheric magnetic field is not laminar but instead consists of magnetic bubbles. We refer to it as the bubble-dominated heliosheath region. Recently, we proposed that the annihilation of the 'sectored' magnetic field within the heliosheath as it is compressed on its approach to the HP produces anomalous cosmic rays and also energetic electrons. As a product of the annihilation of the sectored magnetic field, densely packed magnetic islands (which further interact to form magnetic bubbles) are produced. These magnetic islands/bubbles will be convected with ambient flows as the sector region is carried to higher latitudes filling the heliosheath. We further argue that the magnetic islands/bubbles will develop upstream within the heliosheath. As a result, the magnetic field in the heliosheath sector region will be disordered well upstream of the HP. We present a three-dimensional MHD simulation with very high numerical resolution that captures the north-south boundaries of the sector region. We show that due to the high pressure of the interstellar magnetic field a north-south asymmetry develops such that the disordered sectored region fills a large portion of the northern part of the heliosphere with a smaller extension in the southern hemisphere. We suggest that this scenario is supported by the following changes that occurred around 2008 and from 2009.16 onward: (1) the sudden decrease in the intensity of low energy electrons (0.02-1.5 MeV) detected by Voyager 2, (2) a sharp reduction in the intensity of fluctuations of the radial flow, and (3) the dramatic differences in intensity trends between galactic cosmic ray electrons (3.8-59 MeV) at Voyager 1 and 2. We argue that these observations are a consequence of Voyager 2 leaving the sector region of disordered field during these periods and crossing into a region of unipolar laminar field.

  17. Comparison of direct numerical simulation of lean premixed methane-air flames with strained laminar flame calculations.

    SciTech Connect (OSTI)

    Chen, Jacqueline H.; Hawkes, Evatt R.

    2004-08-01

    Direct numerical simulation (DNS) with complex chemistry was used to study statistics of displacement and consumption speeds in turbulent lean premixed methane-air flames. The main focus of the study is an evaluation of the extent to which a turbulent flame in the thin reaction zones regime can be described by an ensemble of strained laminar flames. Conditional averages with respect to strain for displacement and consumption speeds are presented over a wide range of strain typically encountered in a turbulent flame, compared with previous studies that either made local pointwise comparisons or conditioned the data on small strain and curvature. The conditional averages for positive strains are compared with calculated data from two different canonical strained laminar configurations to determine which is the optimal representation of a laminar flame structure embedded in a turbulent flame: the reactant-to-product (R-to-P) configuration or the symmetric twin flame configuration. Displacement speed statistics are compared for the progress-variable isosurface of maximum reaction rate and an isosurface toward the fresh gases, which are relevant for both modeling and interpretation of experiment results. Displacement speeds in the inner reaction layer are found to agree very well with the laminar R-to-P calculations over a wide range of strain for higher Damkhler number conditions, well beyond the regime in which agreement was expected. For lower Damkhler numbers, a reduced response to strain is observed, consistent with previous studies and theoretical expectations. Compared with the inner layer, broader and shifted probability density functions (PDFs) of displacement speed were observed in the fresh gases, and the agreement with the R-to-P calculations deteriorated. Consumption speeds show a poorer agreement with strained laminar calculations, which is attributed to multidimensional effects and a more attenuated unsteady response to strain fluctuations; however, they also show less departure from the unstrained laminar value, suggesting that detailed modeling of this quantity may not be critical for the conditions considered. For all quantities investigated, including CO production, the R-to-P laminar configuration provides an improved description relative to the twin flame configuration, which predicts qualitatively incorrect trends and overestimates extinction.

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

    E-Print Network [OSTI]

    Joshi, Rakshitha U; Bhardwaj, Rajneesh

    2015-01-01

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

  19. Linear and non-linear forced response of a conical, ducted, laminar premixed flame

    SciTech Connect (OSTI)

    Karimi, Nader; Brear, Michael J.; Jin, Seong-Ho; Monty, Jason P. [Department of Mechanical Engineering, University of Melbourne, Parkville, 3010 Vic. (Australia)

    2009-11-15

    This paper presents an experimental study on the dynamics of a ducted, conical, laminar premixed flame subjected to acoustic excitation of varying amplitudes. The flame transfer function is measured over a range of forcing frequencies and equivalence ratios. In keeping with previous works, the measured flame transfer function is in good agreement with that predicted by linear kinematic theory at low amplitudes of acoustic velocity excitation. However, a systematic departure from linear behaviour is observed as the amplitude of the velocity forcing upstream of the flame increases. This non-linearity is mostly in the phase of the transfer function and manifests itself as a roughly constant phase at high forcing amplitude. Nonetheless, as predicted by non-linear kinematic arguments, the response always remains close to linear at low forcing frequencies, regardless of the forcing amplitude. The origin of this phase behaviour is then sought through optical data post-processing. (author)

  20. Super Stability of Laminar Vortex Flow in Superfluid 3He-B

    E-Print Network [OSTI]

    V. B. Eltsov; R. de Graaf; P. J. Heikkinen; J. J. Hosio; R. Hanninen; M. Krusius; V. S. L'vov

    2010-05-04

    Vortex flow remains laminar up to large Reynolds numbers (Re~1000) in a cylinder filled with 3He-B. This is inferred from NMR measurements and numerical vortex filament calculations where we study the spin up and spin down responses of the superfluid component, after a sudden change in rotation velocity. In normal fluids and in superfluid 4He these responses are turbulent. In 3He-B the vortex core radius is much larger which reduces both surface pinning and vortex reconnections, the phenomena, which enhance vortex bending and the creation of turbulent tangles. Thus the origin for the greater stability of vortex flow in 3He-B is a quantum phenomenon. Only large flow perturbations are found to make the responses turbulent, such as the walls of a cubic container or the presence of invasive measuring probes inside the container.

  1. Laminar-turbulent patterning in wall-bounded shear flows: a Galerkin model

    E-Print Network [OSTI]

    Seshasayanan, K

    2015-01-01

    On its way to turbulence, plane Couette flow - the flow between counter-translating parallel plates - displays a puzzling steady oblique laminar-turbulent pattern. We approach this problem via Galerkin modelling of the Navier-Stokes equations. The wall-normal dependence of the hydrodynamic field is treated by means of expansions on functional bases fitting the boundary conditions exactly. This yields a set of partial differential equations for the spatiotemporal dynamics in the plane of the flow. Truncating this set beyond lowest nontrivial order is numerically shown to produce the expected pattern, therefore improving over what was obtained at cruder effective wall-normal resolution. Perspectives opened by the approach are discussed.

  2. Experimental investigation of sound generation by a protuberance in a laminar boundary layer

    SciTech Connect (OSTI)

    Kobayashi, M.; Asai, M.; Inasawa, A. [Department of Aerospace Engineering, Tokyo Metropolitan University, 6-6 Asahigaoka, Hino, Tokyo 191-0065 (Japan)

    2014-08-15

    Sound radiation from a two-dimensional protuberance glued on the wall in a laminar boundary layer was investigated experimentally at low Mach numbers. When the protuberance was as high as the boundary-layer thickness, a feedback-loop mechanism set in between protuberance-generated sound and Tollmien-Schlichting (T-S) waves generated by the leading-edge receptivity to the upstream-propagating sound. Although occurrence of a separation bubble immediately upstream of the protuberance played important roles in the evolution of instability waves into vortices interacting with the protuberance, the frequency of tonal vortex sound was determined by the selective amplification of T-S waves in the linear instability stage upstream of the separation bubble and was not affected by the instability of the separation bubble.

  3. DNS of laminar-turbulent boundary layer transition induced by solid obstacles

    E-Print Network [OSTI]

    Orlandi, Paolo; Bernardini, Matteo

    2015-01-01

    Results of numerical simulations obtained by a staggered finite difference scheme together with an efficient immersed boundary method are presented to understand the effects of the shape of three-dimensional obstacles on the transition of a boundary layer from a laminar to a turbulent regime. Fully resolved Direct Numerical Simulations (DNS), highlight that the closer to the obstacle the symmetry is disrupted the smaller is the transitional Reynolds number. It has been also found that the transition can not be related to the critical roughness Reynolds number used in the past. The simulations highlight the differences between wake and inflectional instabilities, proving that two-dimensional tripping devices are more efficient in promoting the transition. Simulations at high Reynolds number demonstrate that the reproduction of a real experiment with a solid obstacle at the inlet is an efficient tool to generate numerical data bases for understanding the physics of boundary layers. The quality of the numerical ...

  4. Stochastic analysis of the time evolution of Laminar-Turbulent bands of plane Couette flow

    E-Print Network [OSTI]

    Rolland, Joran

    2015-01-01

    This article is concerned with the time evolution of the oblique laminar-turbulent bands of transitional plane Couette flow under the influence of turbulent noise. Our study is focused on the amplitude of modulation of turbulence. In order to guide the numerical study of the flow, we first perform an analytical and numerical analysis of a Stochastic Ginzburg-Landau equation for a complex order parameter. The modulus of this order parameter models the amplitude of modulation of turbulence. Firstly, we compute the autocorrelation function of said modulus once the band is established. Secondly, we perform a calculation of average and fluctuations around the exponential growth of the order parameter. This type of analysis is similar to the Stochastic Structural Stability Theory. We then perform numerical simulations of the Navier-Stokes equations in order to confront these predictions with the actual behaviour of the bands. Computation of the autocorrelation function of the modulation of turbulence shows quantita...

  5. Formula Hybrid International Competition

    E-Print Network [OSTI]

    Carver, Jeffrey C.

    , and computerized control systems. But the greatest obstacle of all was that hybrid cars could not meet newlyFormula Hybrid International Competition May 4, 5, 6, 2009 #12;09 annual third We are thrilled to have 30 cars competing this year. The competition is the result of the hard work of many people

  6. Hybrid Quantum Cloning Machine

    E-Print Network [OSTI]

    Satyabrata Adhikari; A. K. Pati; Indranil Chakrabarty; B. S. Choudhury

    2007-06-14

    In this work, we introduce a special kind of quantum cloning machine called Hybrid quantum cloning machine. The introduced Hybrid quantum cloning machine or transformation is nothing but a combination of pre-existing quantum cloning transformations. In this sense it creates its own identity in the field of quantum cloners. Hybrid quantum cloning machine can be of two types: (i) State dependent and (ii) State independent or Universal. We study here the above two types of Hybrid quantum cloning machines. Later we will show that the state dependent hybrid quantum-cloning machine can be applied on only four input states. We will also find in this paper another asymmetric universal quantum cloning machine constructed from the combination of optimal universal B-H quantum cloning machine and universal anti-cloning machine. The fidelities of the two outputs are different and their values lie in the neighborhood of ${5/6} $

  7. NWTC Aerodynamics Studies Improve Energy Capture and Lower Costs of Wind-Generated Electricity

    SciTech Connect (OSTI)

    2015-08-01

    Researchers at the National Wind Technology Center (NWTC) at the National Renewable Energy Laboratory (NREL) have expanded wind turbine aerodynamic research from blade and rotor aerodynamics to wind plant and atmospheric inflow effects. The energy capture from wind plants is dependent on all of these aerodynamic interactions. Research at the NWTC is crucial to understanding how wind turbines function in large, multiple-row wind plants. These conditions impact the cumulative fatigue damage of turbine structural components that ultimately effect the useful lifetime of wind turbines. This work also is essential for understanding and maximizing turbine and wind plant energy production. Both turbine lifetime and wind plant energy production are key determinants of the cost of wind-generated electricity.

  8. Hybrid Automata-based CEGAR for Rectangular Hybrid Systems

    E-Print Network [OSTI]

    Liberzon, Daniel

    Hybrid Automata-based CEGAR for Rectangular Hybrid Systems Pavithra Prabhakar, Sridhar Duggirala- example guided abstraction-refinement (CEGAR) for systems modelled as rectangular hybrid automata. The main difference, between our ap- proach and previous proposals for CEGAR for hybrid automata

  9. HYBRID LIMIT CYCLES AND HYBRID POINCARE-BENDIXSON

    E-Print Network [OSTI]

    Johansson, Karl Henrik

    HYBRID LIMIT CYCLES AND HYBRID POINCAR´E-BENDIXSON Slobodan N. Simi´c Department of Electrical regular hybrid systems with no branching (Simi´c et al., 2000a). The first one provides a condition for asymptotic stability of hybrid closed orbits in terms of contraction-expansion rates of resets and flows

  10. Hybrid 2012 Innovative Hybrid Approaches to the Processing of

    E-Print Network [OSTI]

    EACL 2012 Hybrid 2012 Innovative Hybrid Approaches to the Processing of Textual Data Proceedings@aclweb.org ii #12;Introduction The hybrid approach term covers a large set of situations in which different of the dedicated task. Hybrid approaches are commonly used in various NLP applications (i.e., automatic creation

  11. Hybrid Systems State estimation for hybrid systems: applications

    E-Print Network [OSTI]

    Tomlin, Claire

    Hybrid Systems State estimation for hybrid systems: applications to aircraft tracking I. Hwang, H of a stochastic linear hybrid system, given only the continuous system output data, is studied. Well established techniques for hybrid estimation, known as the multiple model adaptive estimation algorithm

  12. Effects of CO addition on the characteristics of laminar premixed CH{sub 4}/air opposed-jet flames

    SciTech Connect (OSTI)

    Wu, C.-Y. [Advanced Engine Research Center, Kao Yuan University, Kaohsiung County, 821 (China); Chao, Y.-C.; Chen, C.-P.; Ho, C.-T. [Department of Aeronautics and Astronautics, National Cheng Kung University, Tainan, 701 (China); Cheng, T.S. [Department of Mechanical Engineering, Chung Hua University, Hsinchu, 300 (China)

    2009-02-15

    The effects of CO addition on the characteristics of premixed CH{sub 4}/air opposed-jet flames are investigated experimentally and numerically. Experimental measurements and numerical simulations of the flame front position, temperature, and velocity are performed in stoichiometric CH{sub 4}/CO/air opposed-jet flames with various CO contents in the fuel. Thermocouple is used for the determination of flame temperature, velocity measurement is made using particle image velocimetry (PIV), and the flame front position is measured by direct photograph as well as with laser-induced predissociative fluorescence (LIPF) of OH imaging techniques. The laminar burning velocity is calculated using the PREMIX code of Chemkin collection 3.5. The flame structures of the premixed stoichiometric CH{sub 4}/CO/air opposed-jet flames are simulated using the OPPDIF package with GRI-Mech 3.0 chemical kinetic mechanisms and detailed transport properties. The measured flame front position, temperature, and velocity of the stoichiometric CH{sub 4}/CO/air flames are closely predicted by the numerical calculations. Detailed analysis of the calculated chemical kinetic structures reveals that as the CO content in the fuel is increased from 0% to 80%, CO oxidation (R99) increases significantly and contributes to a significant level of heat-release rate. It is also shown that the laminar burning velocity reaches a maximum value (57.5 cm/s) at the condition of 80% of CO in the fuel. Based on the results of sensitivity analysis, the chemistry of CO consumption shifts to the dry oxidation kinetics when CO content is further increased over 80%. Comparison between the results of computed laminar burning velocity, flame temperature, CO consumption rate, and sensitivity analysis reveals that the effect of CO addition on the laminar burning velocity of the stoichiometric CH{sub 4}/CO/air flames is due mostly to the transition of the dominant chemical kinetic steps. (author)

  13. Aerodynamic Drag of Heavy Vehicles (Class 7-8): Simulation and Benchmarking

    SciTech Connect (OSTI)

    Rose McCallen, Dan Flowers, Tim Dunn; Jerry Owens; Fred Browand; Mustapha Hammache; Anthony Leonard; Mark Brady; Kambiz Salari; Walter Rutledge; James Ross; Bruce Storms; J. T. Heineck, David Driver; James Bell; Steve Walker; Gregory Zilliac

    2000-06-19

    This paper describes research and development for reducing the aerodynamic drag of heavy vehicles by demonstrating new approaches for the numerical simulation and analysis of aerodynamic flow. Experimental validation of new computational fluid dynamics methods are also an important part of this approach. Experiments on a model of an integrated tractor-trailer are underway at NASA Ames Research Center and the University of Southern California (USC). Companion computer simulations are being performed by Sandia National Laboratories (SNL), Lawrence Livermore National Laboratory (LLNL), and California Institute of Technology (Caltech) using state-of-the-art techniques.

  14. EVOLUTION OF L HYBRID WAVES

    E-Print Network [OSTI]

    Karney, Charles

    . INTRODUCTIO In typical lower hybrid heating schemes, lower hybrid waves are launched at the wall sf tokamak. In this paper we study the C numerically, and determine the consequences of our results for lower hybrid heating hybrid heating of a tokamak. 11. THE CMKDV EQUAT The two-dimensional steady-state propagation of a single

  15. Hybrid matrix fiber composites

    DOE Patents [OSTI]

    Deteresa, Steven J.; Lyon, Richard E.; Groves, Scott E.

    2003-07-15

    Hybrid matrix fiber composites having enhanced compressive performance as well as enhanced stiffness, toughness and durability suitable for compression-critical applications. The methods for producing the fiber composites using matrix hybridization. The hybrid matrix fiber composites include two chemically or physically bonded matrix materials, whereas the first matrix materials are used to impregnate multi-filament fibers formed into ribbons and the second matrix material is placed around and between the fiber ribbons that are impregnated with the first matrix material and both matrix materials are cured and solidified.

  16. arXiv:0911.4733v1[cond-mat.mtrl-sci]24Nov2009 Aerodynamical Effects in Snow Crystal Growth

    E-Print Network [OSTI]

    Libbrecht, Kenneth G.

    arXiv:0911.4733v1[cond-mat.mtrl-sci]24Nov2009 Aerodynamical Effects in Snow Crystal Growth K. G review several aspects of aerodynamics that affect the growth, morphology, and symmetry of snow crystals. We derive quantitative estimates for aerodynamical forces that orient falling snow crystals, estimate

  17. Numerical simulation of laminar plasma dynamos in a cylindrical von Karman flow

    SciTech Connect (OSTI)

    Khalzov, I. V.; Brown, B. P.; Schnack, D. D.; Forest, C. B. [University of Wisconsin, 1150 University Avenue, Madison, Wisconsin 53706 (United States); Ebrahimi, F. [University of New Hampshire, 8 College Road, Durham, New Hampshire 03824 (United States)

    2011-03-15

    The results of a numerical study of the magnetic dynamo effect in cylindrical von Karman plasma flow are presented with parameters relevant to the Madison Plasma Couette Experiment. This experiment is designed to investigate a broad class of phenomena in flowing plasmas. In a plasma, the magnetic Prandtl number Pm can be of order unity (i.e., the fluid Reynolds number Re is comparable to the magnetic Reynolds number Rm). This is in contrast to liquid metal experiments, where Pm is small (so, Re>>Rm) and the flows are always turbulent. We explore dynamo action through simulations using the extended magnetohydrodynamic NIMROD code for an isothermal and compressible plasma model. We also study two-fluid effects in simulations by including the Hall term in Ohm's law. We find that the counter-rotating von Karman flow results in sustained dynamo action and the self-generation of magnetic field when the magnetic Reynolds number exceeds a critical value. For the plasma parameters of the experiment, this field saturates at an amplitude corresponding to a new stable equilibrium (a laminar dynamo). We show that compressibility in the plasma results in an increase of the critical magnetic Reynolds number, while inclusion of the Hall term in Ohm's law changes the amplitude of the saturated dynamo field but not the critical value for the onset of dynamo action.

  18. Effect of a uniform electric field on soot in laminar premixed ethylene/air flames

    SciTech Connect (OSTI)

    Wang, Y.; Yao, Q. [Key Laboratory of Thermal Science and Power Engineering of Ministry of Education, Department of Thermal Engineering, Tsinghua University, 100084 Beijing (China); Nathan, G.J. [School of Mechanical Engineering, Centre for Energy Technology, The University of Adelaide, S.A. 5005 (Australia); Alwahabi, Z.T.; King, K.D.; Ho, K. [School of Chemical Engineering, Centre for Energy Technology, The University of Adelaide, S.A. 5005 (Australia)

    2010-07-15

    The effect of a nominally uniform electric field on the initially uniform distribution of soot has been assessed for laminar premixed ethylene/air flames from a McKenna burner. An electrophoretic influence on charged soot particles was measured through changes to the deposition rate of soot on the McKenna plug, using laser extinction (LE). Soot volume fraction was measured in situ using laser-induced incandescence (LII). Particle size and morphologies were assessed through ex situ transmission electron microscopy (TEM) using thermophoretic sampling particle diagnostics (TSPD). The results show that the majority of these soot particles are positively charged. The presence of a negatively charged plug was found to decrease the particle residence times in the flame and to influence the formation and oxidation progress. A positively charged plug has the opposite effect. The effect on soot volume fraction, particles size and morphology with electric field strength is also reported. Flame stability was also found to be affected by the presence of the electric field, with the balance of the electrophoretic force and drag force controlling the transition to unstable flame flicker. The presence of charged species generated by the flame was found to reduce the dielectric field strength to one seventh that of air. (author)

  19. Effects of multi-component diffusion and heat release on laminar diffusion flame liftoff

    SciTech Connect (OSTI)

    Li, Zhiliang; Chen, Ruey-Hung [Department of Mechanical, Materials and Aerospace Engineering, University of Central Florida, Orlando, FL 32816-2450 (United States); Phuoc, Tran X. [National Energy Technology Laboratory, Department of Energy, P.O. Box 10940, MS 84-340, Pittsburgh, PA 15261 (United States)

    2010-08-15

    Numerical simulations were conducted of the liftoff and stabilization phenomena of laminar jet diffusion flames of inert-diluted C{sub 3}H{sub 8} and CH{sub 4} fuels. Both non-reacting and reacting jets were investigated, including multi-component diffusivities and heat release effects (buoyancy and gas expansion). The role of Schmidt number for non-reacting jets was investigated, with no conclusive Schmidt number criterion for liftoff previously arrived at in similarity solutions. The cold-flow simulation for He-diluted CH{sub 4} fuel does not predict flame liftoff; however, adding heat release reaction lead to the prediction of liftoff, which is consistent with experimental observations. Including reaction was also found to improve liftoff height prediction for C{sub 3}H{sub 8} flames, with the flame base location differing from that in the similarity solution - the intersection of the stoichiometric and iso-velocity (equal to 1-D flame speed) is not necessary for flame stabilization (and thus liftoff). Possible mechanisms other than that proposed for similarity solution may better help to explain the stabilization and liftoff phenomena. (author)

  20. Electric fields effect on liftoff and blowoff of nonpremixed laminar jet flames in a coflow

    SciTech Connect (OSTI)

    Kim, M.K.; Ryu, S.K.; Won, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Chung, S.H. [Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

    2010-01-15

    The stabilization characteristics of liftoff and blowoff in nonpremixed laminar jet flames in a coflow have been investigated experimentally for propane fuel by applying AC and DC electric fields to the fuel nozzle with a single-electrode configuration. The liftoff and blowoff velocities have been measured by varying the applied voltage and frequency of AC and the voltage and the polarity of DC. The result showed that the AC electric fields extended the stabilization regime of nozzle-attached flame in terms of jet velocity. As the applied AC voltage increased, the nozzle-attached flame was maintained even over the blowout velocity without having electric fields. In such a case, a blowoff occurred directly without experiencing a lifted flame. While for the DC cases, the influence on liftoff was minimal. There existed three different regimes depending on the applied AC voltage. In the low voltage regime, the nozzle-detachment velocity of either liftoff or blowoff increased linearly with the applied voltage, while nonlinearly with the AC frequency. In the intermediate voltage regime, the detachment velocity decreased with the applied voltage and reasonably independent of the AC frequency. At the high voltage regime, the detachment was significantly influenced by the generation of discharges. (author)

  1. Lean methane premixed laminar flames doped by components of diesel fuel II: n-propylcyclohexane

    SciTech Connect (OSTI)

    Pousse, E.; Porter, R.; Warth, V.; Glaude, P.A.; Fournet, R.; Battin-Leclerc, F. [Departement de Chimie-Physique des Reactions, Nancy Universite, CNRS, ENSIC, 1 rue Grandville, BP 20451, 54001 Nancy Cedex (France)

    2010-01-15

    For a better understanding of the chemistry involved during the combustion of components of diesel fuel, the structure of a laminar lean premixed methane flame doped with n-propylcyclohexane has been investigated. The inlet gases contained 7.1% (molar) methane, 36.8% oxygen, and 0.81% n-propylcyclohexane (C{sub 9}H{sub 18}), corresponding to an equivalence ratio of 0.68 and a C{sub 9}H{sub 18}/CH{sub 4} ratio of 11.4%. The flame has been stabilized on a burner at a pressure of 6.7 kPa (50 Torr) using argon as diluent, with a gas velocity at the burner of 49.2 cm/s at 333 K. Quantified species included the usual methane C{sub 0}-C{sub 2} combustion products, but also 17 C{sub 3}-C{sub 5} hydrocarbons, seven C{sub 1}-C{sub 3} oxygenated compounds, and only four cyclic C{sub 6+} compounds, namely benzene, 1,3-cyclohexadiene, cyclohexene, and methylenecyclohexane. A new mechanism for the oxidation of n-propylcyclohexane has been proposed. It allows the proper simulation of profiles of most of the products measured in flames, as well as the satisfactory reproduction of experimental results obtained in a jet-stirred reactor. The main reaction pathways of consumption of n-propylcyclohexane have been derived from rate-of-production analysis. (author)

  2. A lean methane premixed laminar flame doped with components of diesel fuel. I. n-Butylbenzene

    SciTech Connect (OSTI)

    Pousse, E.; Glaude, P.A.; Fournet, R.; Battin-Leclerc, F. [Departement de Chimie-Physique des Reactions, Nancy Universite, CNRS, ENSIC, 1 rue Grandville, BP 20451, 54001 Nancy Cedex (France)

    2009-05-15

    To better understand the chemistry involved in the combustion of components of diesel fuel, the structure of a laminar lean premixed methane flame doped with n-butylbenzene has been investigated. The inlet gases contained 7.1% (molar) methane, 36.8% oxygen, and 0.96% n-butylbenzene corresponding to an equivalence ratio of 0.74 and a ratio C{sub 10}H{sub 14}/CH{sub 4} of 13.5%. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as diluent, with a gas velocity at the burner of 49.2 cm/s at 333 K. Quantified species included the usual methane C{sub 0}-C{sub 2} combustion products, but also 16 C{sub 3}-C{sub 5} hydrocarbons, and 7 C{sub 1}-C{sub 3} oxygenated compounds, as well as 20 aromatic products. A new mechanism for the oxidation of n-butylbenzene is proposed whose predictions are in satisfactory agreement with measured species profiles in flames and flow reactor experiments. The main reaction pathways of consumption of n-butylbenzene have been derived from flow rate analyses. (author)

  3. A numerical study of soot aggregate formation in a laminar coflow diffusion flame

    SciTech Connect (OSTI)

    Zhang, Q.; Thomson, M.J. [Department of Mechanical and Industrial Engineering, University of Toronto, 5 King's College Road, Toronto, Ontario, M5S 3G8 (Canada); Guo, H.; Liu, F.; Smallwood, G.J. [Institute for Chemical Process and Environmental Technology, National Research Council of Canada, Building M-9, 1200 Montreal Road, Ottawa, Ontario, K1A 0R6 (Canada)

    2009-03-15

    Soot aggregate formation in a two-dimensional laminar coflow ethylene/air diffusion flame is studied with a pyrene-based soot model, a detailed sectional aerosol dynamics model, and a detailed radiation model. The chemical kinetic mechanism describes polycyclic aromatic hydrocarbon formation up to pyrene, the dimerization of which is assumed to lead to soot nucleation. The growth and oxidation of soot particles are characterized by the HACA surface mechanism and pyrene-soot surface condensation. The mass range of the solid soot phase is divided into thirty-five discrete sections and two equations are solved in each section to model the formation of the fractal-like soot aggregates. The coagulation model is improved by implementing the aggregate coagulation efficiency. Several physical processes that may cause sub-unitary aggregate coagulation efficiency are discussed. Their effects on aggregate structure are numerically investigated. The average number of primary soot particles per soot aggregate n{sub p} is found to be a strong function of the aggregate coagulation efficiency. Compared to the available experimental data, n{sub p} is well reproduced with a constant 20% aggregate coagulation efficiency. The predicted axial velocity, OH mole fraction, and C{sub 2}H{sub 2} mole fraction are validated against experimental data in the literature. Reasonable agreements are obtained. Finally, a sensitivity study of the effects of particle coalescence on soot volume fraction and soot aggregate nanostructure is conducted using a coalescence cutoff diameter method. (author)

  4. Aromatic and polycyclic aromatic hydrocarbon formation in a laminar premixed n-butane flame

    SciTech Connect (OSTI)

    Marinov, N.M.; Pitz, W.J.; Westbrook, C.K.; Vincitore, A.M.; Castaldi, M.J.; Senkan, S.M.; Melius, C.F.

    1998-07-01

    Experimental and detailed chemical kinetic modeling work has been performed to investigate aromatic and polycyclic aromatic hydrocarbon (PAH) formation pathways in a premixed, rich, sooting, n-butane-oxygen-argon burner stabilized flame. An atmospheric pressure, laminar flat flame operated at an equivalence ratio of 2.6 was used to acquire experimental data for model validation. Gas composition analysis was conducted by an on-line gas chromatograph/mass spectrometer technique. Measurements were made in the main reaction and post-reaction zones for a number of low molecular weight species, aliphatics, aromatics, and polycyclic aromatic hydrocarbons (PAHs) ranging from two to five-fused aromatic rings. Reaction flux and sensitivity analysis were used to help identify the important reaction sequences leading to aromatic and PAH growth and destruction in the n-butane flame. Reaction flux analysis showed the propargyl recombination reaction was the dominant pathway to benzene formation. The consumption of propargyl by H atoms was shown to limit propargyl, benzene, and naphthalene formation in flames as exhibited by the large negative sensitivity coefficients. Naphthalene and phenanthrene production was shown to be plausibly formed through reactions involving resonantly stabilized cyclopentadienyl and indenyl radicals. Many of the low molecular weight aliphatics, combustion by-products, aromatics, branched aromatics, and PAHs were fairly well simulated by the model. Additional work is required to understand the formation mechanisms of phenyl acetylene, pyrene, and fluoranthene in the n-butane flame. 73 refs.

  5. Autoignited laminar lifted flames of propane in coflow jets with tribrachial edge and mild combustion

    SciTech Connect (OSTI)

    Choi, B.C.; Kim, K.N.; Chung, S.H.

    2009-02-15

    Characteristics of laminar lifted flames have been investigated experimentally by varying the initial temperature of coflow air over 800 K in the non-premixed jets of propane diluted with nitrogen. The result showed that the lifted flame with the initial temperature below 860 K maintained the typical tribrachial structure at the leading edge, which was stabilized by the balance mechanism between the propagation speed of tribrachial flame and the local flow velocity. For the temperature above 860 K, the flame was autoignited without having any external ignition source. The autoignited lifted flames were categorized in two regimes. In the case with tribrachial edge structure, the liftoff height increased nonlinearly with jet velocity. Especially, for the critical condition near blowout, the lifted flame showed a repetitive behavior of extinction and reignition. In such a case, the autoignition was controlled by the non-adiabatic ignition delay time considering heat loss such that the autoignition height was correlated with the square of the adiabatic ignition delay time. In the case with mild combustion regime at excessively diluted conditions, the liftoff height increased linearly with jet velocity and was correlated well with the square of the adiabatic ignition delay time. (author)

  6. Rich methane laminar flames doped with light unsaturated hydrocarbons. Part II: 1,3butadiene

    E-Print Network [OSTI]

    Gueniche, Hadj-Ali; Fournet, René; Battin-Leclerc, Frédérique

    2007-01-01

    In line with the study presented in the part I of this paper, the structure of a laminar rich premixed methane flame doped with 1,3-butadiene has been investigated. The flame contains 20.7% (molar) of methane, 31.4% of oxygen and 3.3% of 1,3-butadiene, corresponding to an equivalence ratio of 1.8, and a ratio C4H6 / CH4 of 16 %. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 600 K close to the burner up to 2150 K. Quantified species included usual methane C0-C2 combustion products and 1,3-butadiene, but also propyne, allene, propene, propane, 1,2-butadiene, butynes, vinylacetylene, diacetylene, 1,3-pentadiene, 2-methyl-1,3-butadiene (isoprene), 1-pentene, 3-methyl-1-butene, benzene and toluene. In order to model these new results, some improvements have been made to a mechanism previously developed in our laboratory for the reactions of C3-C4 unsaturated hydrocarbons. The main reacti...

  7. Rich methane laminar flames doped with light unsaturated hydrocarbons. Part III : cyclopentene

    E-Print Network [OSTI]

    Gueniche, Hadj-Ali; Fournet, René; Battin-Leclerc, Frédérique

    2008-01-01

    In line with the studies presented in the parts I and II of this paper, the structure of a laminar rich premixed methane flame doped with cyclopentene has been investigated. The gases of this flame contains 15.3% (molar) of methane, 26.7% of oxygen and 2.4% cyclopentene corresponding to an equivalence ratio of 1.79 and a ratio C5H8 / CH4 of 16 %. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as dilutant, with a gas velocity at the burner of 36 cm/s at 333 K. The temperature ranged from 627 K close to the burner up to 2027 K. Quantified species included usual methane C0-C2 combustion products, but also propyne, allene, propene, propane, 1-butene, 1,3-butadiene, 1,2-butadiene, vinylacetylene, diacetylene, cyclopentadiene, 1,3-pentadiene, benzene and toluene. A new mechanism for the oxidation of cyclopentene has been proposed. The main reaction pathways of consumption of cyclopentene and of formation of benzene and toluene have been derived from flow rate analyses.

  8. The response of buoyant laminar diffusion flames to low-frequency forcing

    SciTech Connect (OSTI)

    Williams, Timothy C.; Shaddix, Christopher R.; Schefer, Robert W. [Combustion Research Facility, Sandia National Laboratories, Livermore, CA 94550 (United States); Desgroux, Pascale [Physicochimie des Processus de Combustion et de l'Atmosphere, Universite des Sciences et Technologies de Lille, Villeneuve d'Ascq Cedex (France)

    2007-12-15

    Buoyant jet diffusion flames are frequently used to investigate phenomena associated with flares or fires, such as the formation and emission of soot, polycyclic aromatic hydrocarbons (PAH), and carbon monoxide (CO). To systematically investigate the influence of transient vortex-flame interactions on these processes, laminar jet flames may be periodically forced. Previous work has demonstrated that forcing the fuel stream at a (low) frequency close to the natural buoyant instability frequency will trigger the production of vortices on the air side of the high-temperature reaction zone, coupling the overall flame response to the forcing frequency. In the work reported here, measurements in methane/air and ethylene/air slot flames show that over a substantial range of forcing frequencies and amplitudes, the dominant, air-side vortex production is locked at precisely one-half the excitation frequency of the fuel stream. This phenomenon is examined in detail through the utilization of several laser diagnostic techniques, yielding measurements of both the frequency response of the flames and phase-locked images of the internal flame structure. Under some conditions the subharmonic response of the flame leads to transient separation of the PAH and soot layers from the surrounding high-temperature flame zone, potentially affecting the soot formation and radiation processes. This data should provide useful information for comparison with detailed modeling aimed to improve the understanding of the complex nature of the buoyant instability in jet flames. (author)

  9. Buoyancy effects on conjugate heat transfer due to a laminar impinging jet: Preliminary results

    SciTech Connect (OSTI)

    Altieri, G.; De Luca, V.; Ruocco, G.

    1999-07-01

    A numerical analysis for fluid flow and conjugate conduction/convection heat transfer from a laminar, planar gas jet impingement (JI) on a finite thickness, discretely heated substrate is performed, which includes the effect of buoyancy. The competition between transfer of heat by conduction in the plate and by convection in the fluid is examined. A combination of assisting or opposing mixed convection is modeled, and the related flow field as well as local heat transfer rate is studied as a function of the mixed convection parameter, the Richardson number, for a given geometry and a thermal-fluid base-case. Preliminary evaluations of the heat transfer rate are presented as local Nusselt number distributions, for nonbuoyant, assisted and opposed impinging jets, along the impinged substrate. The complex, non-monotonic progresses of these results justify the inclusion of the conduction mechanism in the substrate, in order to correctly quantify the driving parameters for the heat transfer control. The presented calculations are in fair accordance with existing literature which is limited to pure fluid jet impingement. The inclusion of the conduction mechanism confirms the absence of the conjugate effect when an opposing cooling jet configuration is realized.

  10. Introduction Hybrid ICNs

    E-Print Network [OSTI]

    Schenato, Luca

    analysis Experimental results Conclusion Real-Time Networks and Protocols for Industrial Automation Lucia-Time Networks & Protocols for Industrial Automation Hybrid ICNs Modeling of real wireless components IEEE 802 Simulative analysis Experimental results Conclusion Industrial Communication Networks Nowadays Industrial

  11. Assimilating hybridized architecture

    E-Print Network [OSTI]

    Wu, Jane C., 1977-

    2005-01-01

    The thesis searches for means of operation to deal with hybridized architecture. As a conceptual framework, sociology theory appears to be an insightful precedent, for it analyzes and classifies how multiple constituents ...

  12. Heavy Hybrid mesons Masses

    E-Print Network [OSTI]

    F. Iddir; L. Semlala

    2006-11-25

    We estimate the ground state masses of the heavy hybrid mesons using a phenomenological QCD-type potential. 0^{- -},1^{- -},0^{- +},1^{- +} and 0^{+ -} J^{PC} states are considered.

  13. Hybrid adsorptive membrane reactor

    DOE Patents [OSTI]

    Tsotsis, Theodore T. (Huntington Beach, CA); Sahimi, Muhammad (Altadena, CA); Fayyaz-Najafi, Babak (Richmond, CA); Harale, Aadesh (Los Angeles, CA); Park, Byoung-Gi (Yeosu, KR); Liu, Paul K. T. (Lafayette Hill, PA)

    2011-03-01

    A hybrid adsorbent-membrane reactor in which the chemical reaction, membrane separation, and product adsorption are coupled. Also disclosed are a dual-reactor apparatus and a process using the reactor or the apparatus.

  14. Diesel hybridization and emissions.

    SciTech Connect (OSTI)

    Pasquier, M.; Monnet, G.

    2004-04-21

    The CTR Vehicle Systems and Fuels team a diesel hybrid powertrain. The goal of this experiment was to investigate and demonstrate the potential of diesel engines for hybrid electric vehicles (HEVs) in a fuel economy and emissions. The test set-up consisted of a diesel engine coupled to an electric motor driving a Continuously Variable Transmission (CVT). This hybrid drive is connected to a dynamometer and a DC electrical power source creating a vehicle context by combining advanced computer models and emulation techniques. The experiment focuses on the impact of the hybrid control strategy on fuel economy and emissions-in particular, nitrogen oxides (NO{sub x}) and particulate matter (PM). The same hardware and test procedure were used throughout the entire experiment to assess the impact of different control approaches.

  15. A Computational Study of the Aerodynamics and Aeroacoustics of a Flatback Airfoil Using Hybrid RANS-LES

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity ofkandz-cm11 Outreach HomeA Better Anode Design to Improve Lithium-Ion Batteries Print Lithium-ion batteriesA

  16. Hybrid models of transport in crowded environments

    E-Print Network [OSTI]

    Battiato, Ilenia

    2010-01-01

    6.2.5 Hybrid algorithm . . . . . . . . . . . . . . .88 Chapter 5 Hybrid Model for Reactive Flow in a5.3.1 Hybrid validation . . . . . . . . . . . . . . . vii

  17. Hybrid silicon evanescent approach to optical interconnects

    E-Print Network [OSTI]

    2009-01-01

    Big Island, HI, USA, 2006 Hybrid silicon evanescent approach10.1007/s00339-009-5118-1 Hybrid silicon evanescent approachthe recently developed hybrid silicon evanescent platform (

  18. Quantifying the benefits of hybrid vehicles

    E-Print Network [OSTI]

    Turrentine, Tom; Delucchi, Mark; Heffner, Reid R.; Kurani, Kenneth S; Sun, Yongling

    2006-01-01

    Citroën Unveils 69mpg Diesel Hybrid Prototypes. 31 January.Citröen, have developed diesel-hybrid prototypes thatalso apply hybrid technologies to diesel vehicles, further

  19. Global Optimization Methods for the Aerodynamic Shape Design of Transonic Cascades

    E-Print Network [OSTI]

    Neumaier, Arnold

    Global Optimization Methods for the Aerodynamic Shape Design of Transonic Cascades T. Mengistu, Canada Email: mengistu@me.concordia.ca, ghaly@alcor.concordia.ca ABSTRACT Two global optimization shape optimization of transonic cascades; the objective being the redesign of an existing turbomachine

  20. The Natural Aerodynamic Sampling of Trace Explosives from the Human Body

    E-Print Network [OSTI]

    Settles, Gary S.

    The Natural Aerodynamic Sampling of Trace Explosives from the Human Body Gary S. Settles, Huban A. Gowadia, Sean B. Strine, and Timothy E. Johnson Gas Dynamics Lab, Mechanical Engineering Dept., 301D Reber developed for this purpose, their widespread use may be too slow for airport security use and may

  1. Numerical Investigation of Aerodynamic Performance and Loads of a Novel Dual Rotor Wind Turbine

    E-Print Network [OSTI]

    Hu, Hui

    Numerical Investigation of Aerodynamic Performance and Loads of a Novel Dual Rotor Wind Turbine-rotor wind turbine (DRWT) proposed by Rosenberg et al.1 Assuming that the turbine operates in isolation. Comparisons are drawn with the corresponding analyses of a com- parable conventional single-rotor wind turbine

  2. Fan Aerodynamic Performance Guarantees: Do Your Policies, Procedures and Penalties Provide Adequate Certainty? 

    E-Print Network [OSTI]

    Kaufman, S. G.; Martin, V.; Falk, M. A.

    2004-01-01

    With few exceptions, fan vendors do not provide a written guarantee regarding aerodynamic performance. Some fan vendors even go so far as to state in their terms and conditions of sale that fan performance is not guaranteed unless it is specifically...

  3. Supersonic Bi-Directional Flying Wing Configuration with Low Sonic Boom and High Aerodynamic Efficiency

    E-Print Network [OSTI]

    Zha, Gecheng

    that propagates to ground from the shock waves created by a supersonic airplane and its components. PlotkinSupersonic Bi-Directional Flying Wing Configuration with Low Sonic Boom and High Aerodynamic@miami.edu Abstract In this paper, a parametric study is conducted to optimize a business jet using supersonic bi

  4. Five Year Plan Update Staff 631 Helicopter Aerodynamics I X X X X X X

    E-Print Network [OSTI]

    Bernstein, Joseph B.

    788W Smart Fluids and Applications X X X Aerodynamics & Propulsion Sedwick 663 Intro to Plasmas X X X Lee 652 Computational Structural Mechanics X X X X X X Lee 653 Nonlinear Finite Element Analysis X X Wereley 654 Mechanics of Composite Structures X X X Balachandran/Hubbard 655 Structural

  5. Co-Flow Jet Airfoil Trade Study Part I : Energy Consumption and Aerodynamic Efficiency

    E-Print Network [OSTI]

    Zha, Gecheng

    Co-Flow Jet Airfoil Trade Study Part I : Energy Consumption and Aerodynamic Efficiency Alexis airfoils. A trade study is performed for a series of CFJ airfoils based on the NACA 23121 airfoil Static pressure Air density m Mass flow M Mach number Pitching Moment P Pumping power Free stream

  6. Benchmark of aerodynamic cycling helmets using a refined wind tunnel test protocol for helmet drag research

    E-Print Network [OSTI]

    Sidelko, Stephanie

    2007-01-01

    The study of aerodynamics is very important in the world of cycling. Wind tunnel research is conducted on most of the equipment that is used by a rider and is a critical factor in the advancement of the sport. However, to ...

  7. Aerodynamic and Performance Measurements on a SWT-2.3-101 Wind Turbine

    SciTech Connect (OSTI)

    Medina, P.; Singh, M.; Johansen, J.; Jove, A.R.; Machefaux, E.; Fingersh, L. J.; Schreck, S.

    2011-10-01

    This paper provides an overview of a detailed wind turbine field experiment being conducted at NREL under U.S. Department of Energy sponsorship. The purpose of the experiment is to obtain knowledge about the aerodynamics, performance, noise emission and structural characteristics of the Siemens SWT-2.3-101 wind turbine.

  8. An approach for the development of an aerodynamic-structural interaction numerical simulation for aeropropulsion systems

    SciTech Connect (OSTI)

    Naziar, J.; Couch, R.; Davis, M.

    1996-01-01

    Traditionally, aeropropulsion structural performance and aerodynamic performance have been designed separately and later mated together via flight testing. In today`s atmosphere of declining resources, it is imperative that more productive ways of designing and verifying aeropropulsion performance and structural interaction be made available to the aerospace industry. One method of obtaining a more productive design and evaluation capability is through the use of numerical simulations. Currently, Lawrence Livermore National Laboratory has developed a generalized fluid/structural interaction code known as ALE3D. This code is capable of characterizing fluid and structural interaction for components such as the combustor, fan/stators, inlet and/or nozzles. This code solves the 3D Euler equations and has been applied to several aeropropulsion applications such as a supersonic inlet and a combustor rupture simulation. To characterize aerodynamic-structural interaction for rotating components such as the compressor, appropriate turbomachinery simulations would need to be implemented within the ALE3D structure. The Arnold Engineering Development Center is currently developing a three-dimensional compression system code known as TEACC (Turbine Engine Analysis Compressor Code). TEACC also solves the 3D Euler equations and is intended to simulate dynamic behavior such as inlet distortion, surge or rotating stall. The technology being developed within the TEACC effort provides the necessary turbomachinery simulation for implementation into ALE3D. This paper describes a methodology to combine three-dimensional aerodynamic turbomachinery technology into the existing aerodynamic-structural interaction simulation, ALE3D to obtain the desired aerodynamic and structural integrated simulation for an aeropropulsion system.

  9. Aerodynamic Design Criteria for Class 8 Heavy Vehicles Trailer Base Devices to Attain Optimum Performance

    SciTech Connect (OSTI)

    Salari, K; Ortega, J

    2010-12-13

    Lawrence Livermore National Laboratory (LLNL) as part of its Department of Energy (DOE), Energy Efficiency and Renewable Energy (EERE), and Vehicle Technologies Program (VTP) effort has investigated class 8 tractor-trailer aerodynamics for many years. This effort has identified many drag producing flow structures around the heavy vehicles and also has designed and tested many new active and passive drag reduction techniques and concepts for significant on the road fuel economy improvements. As part of this effort a database of experimental, computational, and conceptual design for aerodynamic drag reduction devices has been established. The objective of this report is to provide design guidance for trailer base devices to improve their aerodynamic performance. These devices are commonly referred to as boattails, base flaps, tail devices, and etc. The information provided here is based on past research and our most recent full-scale experimental investigations in collaboration with Navistar Inc. Additional supporting data from LLNL/Navistar wind tunnel, track test, and on the road test will be published soon. The trailer base devices can be identified by 4 flat panels that are attached to the rear edges of the trailer base to form a closed cavity. These devices have been engineered in many different forms such as, inflatable and non-inflatable, 3 and 4-sided, closed and open cavity, and etc. The following is an in-depth discussion with some recommendations, based on existing data and current research activities, of changes that could be made to these devices to improve their aerodynamic performance. There are 6 primary factors that could influence the aerodynamic performance of trailer base devices: (1) Deflection angle; (2) Boattail length; (3) Sealing of edges and corners; (4) 3 versus 4-sided, Position of the 4th plate; (5) Boattail vertical extension, Skirt - boattail transition; and (6) Closed versus open cavity.

  10. Wave theories of non-laminar charged particle beams: from quantum to thermal regime

    E-Print Network [OSTI]

    Renato Fedele; Fatema Tanjia; Dusan Jovanovic; Sergio De Nicola; Concetta Ronsivalle

    2013-04-01

    The standard classical description of non-laminar charge particle beams in paraxial approximation is extended to the context of two wave theories. The first theory is the so-called Thermal Wave Model (TWM) that interprets the paraxial thermal spreading of the beam particles as the analog of the quantum diffraction. The other theory, hereafter called Quantum Wave Model (QWM), that takes into account the individual quantum nature of the single beam particle (uncertainty principle and spin) and provides the collective description of the beam transport in the presence of the quantum paraxial diffraction. QWM can be applied to beams that are sufficiently cold to allow the particles to manifest their individual quantum nature but sufficiently warm to make overlapping-less the single-particle wave functions. In both theories, the propagation of the beam transport in plasmas or in vacuo is provided by fully similar set of nonlinear and nonlocal governing equations, where in the case of TWM the Compton wavelength (fundamental emittance) is replaced by the beam thermal emittance. In both models, the beam transport in the presence of the self-fields (space charge and inductive effects) is governed by a suitable nonlinear nonlocal 2D Schroedinger equation that is used to obtain the envelope beam equation in quantum and quantum-like regimes, respectively. An envelope equation is derived for both TWM and QWM regimes. In TWM we recover the well known Sacherer equation whilst, in QWM we obtain the evolution equation of the single-particle spot size, i.e., single quantum ray spot in the transverse plane (Compton regime). We show that such a quantum evolution equation contains the same information carried out by an evolution equation for the beam spot size (description of the beam as a whole). This is done by defining the lowest QWM state reachable by a system of overlapping-less Fermions.

  11. Conditional analysis of lifted hydrogen jet diffusion flame experimental data and comparison to laminar flame solutions

    SciTech Connect (OSTI)

    Cheng, T.S. [Department of Mechanical Engineering, Chung Hua University, Hsinchu 300 (China); Wehrmeyer, J.A. [Aerospace Testing Alliance, Arnold Air Force Base, TN 37389 (United States); Pitz, R.W. [Department of Mechanical Engineering, Vanderbilt University, Nashville, TN 37235 (United States)

    2007-09-15

    Simultaneous point measurements of temperature, mixture fraction, major species, and OH concentrations in a lifted turbulent hydrogen jet flame are reprocessed to obtain the Favre average and conditional mean profiles. Large discrepancies between the Favre average and the ensemble average temperature, H{sub 2}O, and OH mole fractions are found at the lifted flame base, due to density weighting of fairly large samples of unreacted mixtures. Conditional statistics are used to reveal the reaction zone structure in mixture fraction coordinates. The cross-stream dependence of conditional reactive scalars, which is most notable at the lifted flame base and decreases to negligible levels with increasing streamwise positions, could be attributed to radial differences in both the Damkoehler number and the level of partial premixing. Conditional results indicate that the lifted flame is stabilized at the outer region of the jet characterized by low strain rates and lean mixtures. Comparison of the measured conditional mean OH vs H{sub 2}O with a series of stretched laminar partially premixed flame and diffusion flame calculations reveals that strong partial premixing takes place at the lifted flame base and the strain rates vary from a=14,000 to 100 s{sup -1}. The level of partial premixing and the strain rate decrease with increasing downstream locations. The range of estimated scalar dissipation rates ({chi}{approx}1-0.13 s{sup -1}) at a further downstream location (x/D=33.3) is in agreement with reported values and the flame composition reaches an equilibrium condition at x/D=194.4. These results combined with previously reported data provide a benchmark data set for evaluation and refinement of turbulent combustion models for lifted hydrogen jet flame predictions. (author)

  12. Hybrid baryons in QCD

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

    Dudek, Jozef J.; Edwards, Robert G.

    2012-03-21

    In this study, we present the first comprehensive study of hybrid baryons using lattice QCD methods. Using a large basis of composite QCD interpolating fields we extract an extensive spectrum of baryon states and isolate those of hybrid character using their relatively large overlap onto operators which sample gluonic excitations. We consider the spectrum of Nucleon and Delta states at several quark masses finding a set of positive parity hybrid baryons with quantum numbers $N_{1/2^+},\\,N_{1/2^+},\\,N_{3/2^+},\\, N_{3/2^+},\\,N_{5/2^+},\\,$ and $\\Delta_{1/2^+},\\, \\Delta_{3/2^+}$ at an energy scale above the first band of `conventional' excited positive parity baryons. This pattern of states is compatible withmore »a color octet gluonic excitation having $J^{P}=1^{+}$ as previously reported in the hybrid meson sector and with a comparable energy scale for the excitation, suggesting a common bound-state construction for hybrid mesons and baryons.« less

  13. "Hybrid" Black Holes

    E-Print Network [OSTI]

    Valeri P. Frolov; Andrei V. Frolov

    2014-12-30

    We discuss a solution of the Einstein equations, obtained by gluing the external Kerr metric and the internal Weyl metric, describing an axisymmetric static vacuum distorted black hole. These metrics are glued at the null surfaces representing their horizons. For this purpose we use the formalism of massive thin null shells. The corresponding solution is called a "hybrid" black hole. The massive null shell has an angular momentum which is the origin of the rotation of the external Kerr spacetime. At the same time, the shell distorts the geometry inside the horizon. The inner geometry of the "hybrid" black hole coincides with the geometry of the interior of a non-rotating Weyl-distorted black hole. Properties of the "hybrid" black holes are briefly discussed.

  14. Porosity in hybrid materials

    SciTech Connect (OSTI)

    Schaefer, D.W.; Beaucage, G.; Loy, D. [Sandia National Labs., Albuquerque, NM (United States)

    1995-12-31

    Multicomponent, or hybrid composites are emerging as precursors to porous materials. Sacrifice of an ephemeral phase can be used to generate porosity, the nature of which depends on precursor structure. Retention of an organic constituent, on the other hand, can add desirable toughness to an otherwise brittle ceramic. We use small-angle x-ray and neutron scattering to examine porosity in both simple and hybrid materials. We find that microphase separation controls porosity in almost all systems studied. Pore distributions are controlled by the detailed bonding within and between phases as well as the flexibility of polymeric constituents. Thus hybridization opens new regions of pore distributions not available in simple systems. We look at several sacrificial concepts and show that it is possible to generate multimodal pore size distributions due to the complicated phase structure in the precursor.

  15. Investigation of nitrogen dilution effects on the laminar burning velocity and flame stability of syngas fuel at atmospheric condition

    SciTech Connect (OSTI)

    Prathap, C.; Ray, Anjan; Ravi, M.R. [Department of Mechanical Engineering, Indian Institute of Technology, Delhi, New Delhi 110016 (India)

    2008-10-15

    The objective of this investigation was to study the effect of dilution with nitrogen on the laminar burning velocity and flame stability of syngas fuel (50% H{sub 2}-50% CO by volume)-air (21% O{sub 2}-79% N{sub 2} by volume) mixtures. The syngas fuel composition considered in this work comprised x% N{sub 2} by volume and (100-x)% an equimolar mixture of CO and H{sub 2}. The proportion x (i.e., %N{sub 2}) was varied from 0 to 60% while the H{sub 2}/CO ratio was always kept as unity. Spherically expanding flames were generated by centrally igniting homogeneous fuel-air gas mixtures in a 40-L cylindrical combustion chamber fitted with optical windows. Shadowgraphy technique with a high-speed imaging camera was used to record the propagating spherical flames. Unstretched burning velocity was calculated following the Karlovitz theory for weakly stretched flames. Also, Markstein length was calculated to investigate the flame stability conditions for the fuel-air mixtures under consideration. Experiments were conducted for syngas fuel with different nitrogen proportions (0-60%) at 0.1 MPa (absolute), 302{+-}3K, and equivalence ratios ranging from 0.6 to 3.5. All the measurements were compared with the numerical predictions obtained using RUN-1DL and PREMIX with a contemporary chemical kinetic scheme. Dilution with nitrogen in different proportions in syngas resulted in (a) decrease in laminar burning velocity due to reduction in heat release and increase in heat capacity of unburned gas mixture and hence the flame temperature, (b) shift in occurrence of peak laminar burning velocity from {phi}=2.0 for 0% N{sub 2} dilution to {phi}=1.4 for 60% N{sub 2} dilution, (c) augmentation of the coupled effect of flame stretch and preferential diffusion on laminar burning velocity, and (d) shift in the equivalence ratio for transition from stable to unstable flames from {phi}=0.6 for 0% N{sub 2} dilution to {phi}=1.0 for 60% N{sub 2} dilution. The present work also indicated that if the fuel mole fraction in the wide range of fuel-air mixtures investigated is less than 22%, then those fuel mixtures are in the unstable regime with regard to preferential diffusion. (author)

  16. Effect of Blending on High-Pressure Laminar Flame Speed Measurements, Markstein Lengths, and Flame Stability of Hydrocarbons 

    E-Print Network [OSTI]

    Lowry, William Baugh

    2012-02-14

    for teaching me what hard work means and how to do it. vi NOMENCLATURE Abbreviations g1855g3043 Specific heat (KJ/kg-K) Di,j Diffusivity of species i into j (m 2/s) g1860 Specific enthalpy (KJ/kg) Le Lewis Number g1865g4662 " Mass... burning rate per unit area (kg/m2-s) g1839g3050 Molecular weight (kg/kmol) X Mole fraction (kmol/kmol) g1851 Mass fraction (kg/kg) Subscripts b Burned condition i For species i L Laminar flame u Unburned condition Superscripts o Un...

  17. Corn Hybrids for Texas. 

    E-Print Network [OSTI]

    Rogers, J. S.; McAfee, T. E.

    1954-01-01

    Corn Hybrids for Terns ST LOCATIONS AREA I AREA II ARE4 Ill AREA IV 2Prdrie View 7.Tylw lZ.Lockhart 17.Waxahachie 22San Antonio 3.Cleveland 8.Mt. Pbctont I3Brsnha B.Garland 23Lamposas 4.Colbqe Sta. 9Sulphw Spp. 14Holland l9.0reenvilb 24...Stephenville ,J* 5.K'rbyvilb I0.Cbrkdb 15.Tanpk 2ODetiion 25.Wllothe TEXAS AGRICULTURAL EXPERIMENT STATION R. D. LEWIS. DIRECTOR, COLLEGE STATION, TEXAS DIGEST The Texas corn acreage planted to hybrids increased from less than 1 percent of the total acrea...

  18. Hybrid Cryptography Alexander W. Dent

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Hybrid Cryptography Alexander W. Dent January 3, 2009 Version 1.1 This version is an update asymmet­ ric encryption schemes can benefit from a formalisation of the prin­ ciples of hybrid cryptography. The main focus of research in hybrid cryptography has been in producing e#cient asymmetric

  19. Hybrid Cryptography Alexander W. Dent

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Hybrid Cryptography Alexander W. Dent January 3, 2009 Version 1.1 This version is an update asymmet- ric encryption schemes can benefit from a formalisation of the prin- ciples of hybrid cryptography. The main focus of research in hybrid cryptography has been in producing efficient asymmetric

  20. Hybrid & Hydrogen Vehicle Research Laboratory

    E-Print Network [OSTI]

    Lee, Dongwon

    Hybrid & Hydrogen Vehicle Research Laboratory www.vss.psu.edu/hhvrl Joel R. Anstrom, Director 201 The Pennsylvania Transportation Institute Hybrid and Hydrogen Vehicle Research Laboratory will contribute to the advancement of hybrid and hydrogen vehicle technology to promote the emerging hydrogen economy by providing

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

    SciTech Connect (OSTI)

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

    2005-03-01

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

  2. Stochastic model for aerodynamic force dynamics on wind turbine blades in unsteady wind inflow

    E-Print Network [OSTI]

    Luhur, Muhammad Ramzan; Kühn, Martin; Wächter, Matthias

    2015-01-01

    The paper presents a stochastic approach to estimate the aerodynamic forces with local dynamics on wind turbine blades in unsteady wind inflow. This is done by integrating a stochastic model of lift and drag dynamics for an airfoil into the aerodynamic simulation software AeroDyn. The model is added as an alternative to the static table lookup approach in blade element momentum (BEM) wake model used by AeroDyn. The stochastic forces are obtained for a rotor blade element using full field turbulence simulated wind data input and compared with the classical BEM and dynamic stall models for identical conditions. The comparison shows that the stochastic model generates additional extended dynamic response in terms of local force fluctuations. Further, the comparison of statistics between the classical BEM, dynamic stall and stochastic models' results in terms of their increment probability density functions gives consistent results.

  3. Sand transverse dune aerodynamics: 3D Coherent Flow Structures from a computational study

    E-Print Network [OSTI]

    Bruno, Luca

    2015-01-01

    The engineering interest about dune fields is dictated by the their interaction with a number of human infrastructures in arid environments. The aerodynamic behaviour of sand dunes in atmospheric boundary layer belongs to the class of bluff bodies. Because of their simple geometry and their frequent occurrence in desert area, transverse sand dunes are usually adopted in literature as a benchmark to investigate dune aerodynamics by means of both computational or experimental approach, usually in nominally 2D setups. The writers suspect the flow in the wake is characterised by 3D features and affected by wind tunnel setup - e.g. blockage effect, duct side wall boundary layer, incoming velocity profile - when experimental studies are carried out. The present study aims at evaluating the 3D flow features of an idealised transverse dune under different setup conditions by means of computational simulations and to compare the obtained results with experimental measurements.

  4. Progress in Reducing Aerodynamic Drag for Higher Efficiency of Heavy Duty Trucks (Class 7-8)

    SciTech Connect (OSTI)

    Rose McCallen; Richard Couch; Juliana Hsu; Fred Browand; Mustapha Hammache; Anthony Leonard; Mark Brady; Kambiz Salari; Walter Rutledge; James Ross; Bruce Storms; J.T. Heineck; David Driver; James Bell; Gregory Zilliac

    1999-12-31

    This paper describes research and development for reducing the aerodynamic drag of heavy vehicles by demonstrating new approaches for the numerical simulation and analysis of aerodynamic flow. In addition, greater use of newly developed computational tools holds promise for reducing the number of prototype tests, for cutting manufacturing costs, and for reducing overall time to market. Experimental verification and validation of new computational fluid dynamics methods are also an important part of this approach. Experiments on a model of an integrated tractor-trailer are underway at NASA Ames Research Center and the University of Southern California. Companion computer simulations are being performed by Sandia National Laboratories, Lawrence Livermore National Laboratory, and California Institute of Technology using state-of-the-art techniques, with the intention of implementing more complex methods in the future.

  5. FY 2004 Annual Report: DOE Project on Heavy Vehicle Aerodynamic Drag

    SciTech Connect (OSTI)

    McCallen, R C; Salari, K; Ortega, J; Castellucci, P; Eastwood, C; Whittaker, K; DeChant, L J; Roy, C J; Payne, J L; Hassan, B; Pointer, W D; Browand, F; Hammache, M; Hsu, T; Ross, J; Satran, D; Heineck, J T; Walker, S; Yaste, D; Englar, R; Leonard, A; Rubel, M; Chatelain, P

    2004-11-18

    The objective of this report is: (1) Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles; and (2) Establish a database of experimental, computational, and conceptual design information, and demonstrate potential of new drag-reduction devices. The approaches used were: (1) Develop and demonstrate the ability to simulate and analyze aerodynamic flow around heavy truck vehicles using existing and advanced computational fluid dynamics (CFD) tools; (2) Through an extensive experimental effort, generate an experimental data base for code validation; (3) Using experimental data base, validate computations; (4) Provide industry with design guidance and insight into flow phenomena from experiments and computations; and (5) Investigate aero devices (e.g., base flaps, tractor-trailer gap stabilizer, underbody skirts and wedges, blowing and acoustic devices), provide industry with conceptual designs of drag reducing devices, and demonstrate the full-scale fuel economy potential of these devices.

  6. DOE Project on Heavy Vehicle Aerodynamic Drag FY 2005 Annual Report

    SciTech Connect (OSTI)

    McCallen, R C; Salari, K; Ortega, J; Castellucci, P; Eastwood, C; Paschkewitz, J; Pointer, W D; DeChant, L J; Hassan, B; Browand, F; Radovich, C; Merzel, T; Plocher, D; Ross, J; Storms, B; Heineck, J T; Walker, S; Roy, C J

    2005-11-14

    Class 8 tractor-trailers consume 11-12% of the total US petroleum use. At high way speeds, 65% of the energy expenditure for a Class 8 truck is in overcoming aerodynamic drag. The project objective is to improve fuel economy of Class 8 tractor-trailers by providing guidance on methods of reducing drag by at least 25%. A 25% reduction in drag would present a 12% improvement in fuel economy at highway speeds, equivalent to about 130 midsize tanker ships per year. Specific goals include: (1) Provide guidance to industry in the reduction of aerodynamic drag of heavy truck vehicles; and (2) Establish a database of experimental, computational, and conceptual design information, and demonstrate the potential of new drag-reduction devices.

  7. July 2004 Working Group Meeting on Heavy Vehicle Aerodynamic Drag: Presentation, Summary of Comments, and Conclusions

    SciTech Connect (OSTI)

    McCallen, R; Salari, K; Ortega, J; Castellucci, P; Eastwood, C; DeChant, L; Hassan, B; Browand, F; Arcas, D; Ross, J; Heineck, J; Storms, B; Walker, S; Leonard, A; Roy, C; Whitfield, D; Pointer, D; Sofu, T; Englar, R; Funk, R

    2004-08-17

    A Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held in Portland, Oregon on July 1, 2004. The purpose of the meeting was to provide a summary of achievements, discuss pressing issues, present a general overview of future plans, and to provide a forum for dialogue with the Department of Energy (DOE) and industry representatives. The meeting was held in Portland, because the DOE Aero Team participated in an exclusive session on Heavy Truck Vehicle Aerodynamic Drag at the 34th AIAA Fluid Dynamics Conference and Exhibit in Portland on the morning of July 1st, just preceding our Working Group meeting. Even though the paper session was on the last day of the Conference, the Team presented to a full room of interested attendees.

  8. Aerodynamic Models For Hurricanes I. Model description and horizontal motion of hurricane

    E-Print Network [OSTI]

    Leonov, Arkady I

    2008-01-01

    Aerodynamic models are developed to describe coherent structures and transport processes in hurricanes moving over open seas. The models consist of the lower boundary layer and upper adiabatic layer. Except friction at the air/sea interface,proposed modeling avoids the common turbulent approximations while using explicitly or implicitly basic stability constraints. The models analyze dynamics of upper hurricane adiabatic layer, dynamics and transport processes in hurricane boundary layer, and genesis and maturing of hurricane. The proposed modeling provides a rude enough but consistent analytical description of basic processes in hurricanes. The present paper qualitatively describes the model of mature hurricane, briefly discusses the basic thermodynamic relations and aerodynamic equations, and establishes the principles of horizontal motion for mature hurricane.

  9. Hybrid Quantum Computation

    E-Print Network [OSTI]

    Arun Sehrawat; Daniel Zemann; Berthold-Georg Englert

    2010-09-25

    We present a hybrid model of the unitary-evolution-based quantum computation model and the measurement-based quantum computation model. In the hybrid model part of a quantum circuit is simulated by unitary evolution and the rest by measurements on star graph states, thereby combining the advantages of the two standard quantum computation models. In the hybrid model, a complicated unitary gate under simulation is decomposed in terms of a sequence of single-qubit operations, the controlled-Z gates, and multi-qubit rotations around the z-axis. Every single-qubit- and the controlled-Z gate are realized by a respective unitary evolution, and every multi-qubit rotation is executed by a single measurement on a required star graph state. The classical information processing in our model only needs an information flow vector and propagation matrices. We provide the implementation of multi-control gates in the hybrid model. They are very useful for implementing Grover's search algorithm, which is studied as an illustrating example.

  10. Nonpremixed ignition, laminar flame propagation, and mechanism reduction of n-butanol, iso-butanol, and methyl butanoate

    SciTech Connect (OSTI)

    Lu, Wei; Kelley, A. P.; Law, C. K.

    2011-01-01

    The non-premixed ignition temperature of n-butanol (CH{sub 3}CH{sub 2}CH{sub 2}CH{sub 2}OH), iso-butanol ((CH{sub 3}){sub 2}CHCH{sub 2}OH) and methyl butanoate (CH{sub 3}CH{sub 2}CH{sub 2}COOCH{sub 3}) was measured in a liquid pool assembly by heated oxidizer in a stagnation flow for system pressures of 1 and 3 atm. In addition, the stretch-corrected laminar flame speeds of mixtures of air–n-butanol/iso-butanol/methyl butanoate were determined from the outwardly propagating spherical flame at initial pressures of up to 2 atm, for an extensive range of equivalence ratio. The ignition temperature and laminar flame speeds of n-butanol and methyl butanoate were computationally simulated with three recently developed kinetic mechanisms in the literature. Dominant reaction pathways to ignition and flame propagation were identified and discussed through a chemical explosive mode analysis (CEMA) and sensitivity analysis. The detailed models were further reduced through a series of systematic strategies. The reduced mechanisms provided excellent agreement in both homogeneous and diffusive combustion environments and greatly improved the computation efficiency.

  11. Determination, correlation, and mechanistic interpretation of effects of hydrogen addition on laminar flame speeds of hydrocarbon–air mixtures

    SciTech Connect (OSTI)

    Tang, C. L.; Huang, Z. H.; Law, C. K.

    2010-08-30

    The stretch-affected propagation speeds of expanding spherical flames of n-butane–air mixtures with hydrogen addition were measured at atmospheric pressure and subsequently processed through a nonlinear regression analysis to yield the stretch-free laminar flame speeds. Based on a hydrogen addition parameter (RH) and an effective fuel equivalence ratio (?F), these laminar flame speeds were found to increase almost linearly with RH, for ?F between 0.6 and 1.4 and RHRH from 0 to 0.5, with the slope of the variation assuming a minimum around stoichiometry. These experimental results also agree well with computed values using a detailed reaction mechanism. Furthermore, a mechanistic investigation aided by sensitivity analysis identified that kinetic effects through the global activation energy, followed by thermal effects through the adiabatic flame temperature, have the most influence on the increase in the flame speeds and the associated linear variation with RH due to hydrogen addition. Nonequidiffusion effects due to the high mobility of hydrogen, through the global Lewis number, have the least influence. Further calculations for methane, ethene, and propane as the fuel showed similar behavior, leading to possible generalization of the phenomena and correlation.

  12. DOE's effort to reduce truck aerodynamic drag : joint experiments and computations lead to smart design.

    SciTech Connect (OSTI)

    Yaste, David M (NASA Ames Research Center, Moffet Field, CA); Salari, Kambiz (Lawrence Livermore National Laboratory, Livermore, CA); Hammache, Mustapha (University of Southern California, Los Angeles, CA); Browand, Fred (University of Southern California, Los Angeles, CA); Pointer, W. David (Argonne National Laboratory, Argonne, IL); Ortega, Jason M. (Lawrence Livermore National Laboratory, Livermore, CA); McCallen, Rose (Lawrence Livermore National Laboratory, Livermore, CA); Walker, Stephen M (NASA Ames Research Center, Moffet Field, CA); Heineck, James T (NASA Ames Research Center, Moffet Field, CA); Hassan, Basil; Roy, Christopher John (Auburn University, Auburn, AL); Storms, B. (NASA Ames Research Center, Moffet Field, CA); Satran, D. (NASA Ames Research Center, Moffet Field, CA); Ross, James (NASA Ames Research Center, Moffet Field, CA); Englar, Robert (Georgia Tech Research Institute, Atlanta, GA); Chatalain, Philippe (Caltech, Pasadena, CA); Rubel, Mike (Caltech, Pasadena, CA); Leonard, Anthony (Caltech, Pasadena, CA); Hsu, Tsu-Ya (University of Southern California, Los Angeles, CA); DeChant, Lawrence Justin.

    2004-06-01

    At 70 miles per hour, overcoming aerodynamic drag represents about 65% of the total energy expenditure for a typical heavy truck vehicle. The goal of this US Department of Energy supported consortium is to establish a clear understanding of the drag producing flow phenomena. This is being accomplished through joint experiments and computations, leading to the smart design of drag reducing devices. This paper will describe our objective and approach, provide an overview of our efforts and accomplishments, and discuss our future direction.

  13. DOE's Effort to Reduce Truck Aerodynamic Drag-Joint Experiments and Computations Lead to Smart Design

    SciTech Connect (OSTI)

    McCallen, R; Salari, K; Ortega, J; DeChant, L; Hassan, B; Roy, C; Pointer, W; Browand, F; Hammache, M; Hsu, T; Leonard, A; Rubel, M; Chatalain, P; Englar, R; Ross, J; Satran, D; Heineck, J; Walker, S; Yaste, D; Storms, B

    2004-06-17

    At 70 miles per hour, overcoming aerodynamic drag represents about 65% of the total energy expenditure for a typical heavy truck vehicle. The goal of this US Department of Energy supported consortium is to establish a clear understanding of the drag producing flow phenomena. This is being accomplished through joint experiments and computations, leading to the 'smart' design of drag reducing devices. This paper will describe our objective and approach, provide an overview of our efforts and accomplishments, and discuss our future direction.

  14. Working group meeting on heavy vehicle aerodynamic drag: presentations and summary of comments and conclusion

    SciTech Connect (OSTI)

    Browand, F; Gutierrez, W; Leonard, A; McBride, D; McCallen, R; Ross, J; Roth, K; Rutledge, W; Salari, K

    1998-09-28

    The first Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held at Sandia National Laboratories (SNL) in Albuquerque, New Mexico on August 28, 1998. The purpose of the meeting was to review the proposed Multi-Year Program Plan (MYPP) and provide an update on the Group"s progress. In addition, the technical details of each organization"s activities were presented and discussed. Presentations were given by representatives from the Department of Energy (DOE) Office of Transportation Technology Office of Heavy Vehicle Technology (OHVT), Lawrence Livermore National Laboratory (LLNL), SNL, University of Southern California (USC), California Institute of Technology (Caltech), and NASA Ames Research Center. These presenters are part of a DOE appointed Technical Team assigned to developing the MYPP. The goal of the MYPP is to develop and demonstrate the ability to simulate and analyze aerodynamic flow around heavy truck vehicles using existing and advanced computational tools (A Multi-Year Program Plan for the Aerodynamic Design of Heavy Vehicles, R. McCallen, D. McBride, W. Rutledge, F. Browand, A. Leonard, .I. Ross, UCRL-PROP- 127753 Dr. Rev 2, May 1998). This report contains the technical presentations (viewgraphs) delivered at the Meeting, briefly summarizes the comments and conclusions from the Meeting participants, and outlines the future actions.

  15. A Multi-Year Program Plan for the Aerodynamic Design of Heavy Vehicles

    SciTech Connect (OSTI)

    None

    2001-09-01

    The project tasks and deliverables are as follows: Computations and Experiments--(1) Simulation and analysis of a range of generic shapes, simplified to more complex, representative of tractor and integrated tractor-trailer flow characteristics using computational tools, (2) The establishment of an experimental data base for tractor-trailer models for code/computational method development and validation. The first shapes to be considered will be directed towards the investigation of tractor-trailer gaps and mismatch of tractor-trailer heights. (3) The evaluation and documentation of effective computational approaches for application to heavy vehicle aerodynamics based on the benchmark results with existing and advanced computational tools compared to experimental data, and (4) Computational tools and experimental methods for use by industry, National Laboratories, and universities for the aerodynamic modeling of heavy truck vehicles. Evaluation of current and new technologies--(1) The evaluation and documentation of current and new technologies for drag reduction based on published literature and continued communication with the heavy vehicle industry (e.g., identification and prioritization of tractor-trailer drag-sources, blowing and/or suction devices, body shaping, new experimental methods or facilities), and the identification and analysis of tractor and integrated tractor-trailer aerodynamic problem areas and possible solution strategies. (2) Continued industrial site visits. It should be noted that ''CFD tools'' are not only the actual computer codes, but descriptions of appropriate numerical solution methods. Part of the project effort will be to determine the restrictions or avenues for technology transfer.

  16. Working group meeting on heavy vehicle aerodynamic drag: presentations and summary of comments and

    SciTech Connect (OSTI)

    Browand, F; Gutierrez, W; Leonard, A; McBride, D; McCallen, R; Ross, J; Roth, K; Rutledge, W; Salari, K.

    1998-09-28

    The first Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held at Sandia National Laboratories (SNL) in Albuquerque, New Mexico on August 28, 1998. The purpose of the meeting was to review the proposed Multi-Year Program Plan (MYPP) and provide an update on the Group s progress. In addition, the technical details of each organization s activities were presented and discussed. Presentations were given by representatives from the Department of Energy (DOE) Office of Transportation Technology Office of Heavy Vehicle Technology (OHVT), Lawrence Livermore National Laboratory (LLNL), SNL, University of Southern California (USC), California Institute of Technology (Caltech), and NASA Ames Research Center. These presenters are part of a DOE appointed Technical Team assigned to developing the MYPP. The goal of the MYPP is to develop and demonstrate the ability to simulate and analyze aerodynamic flow around heavy truck vehicles using existing and advanced computational tools (A Multi-Year Program Plan for the Aerodynamic Design of Heavy Vehicles, R. McCallen, D. McBride, W. Rutledge, F. Browand, A. Leonard, .I. Ross, UCRL-PROP- 127753 Dr. Rev 2, May 1998). This report contains the technical presentations (viewgraphs) delivered at the Meeting, briefly summarizes the comments and conclusions from the Meeting participants, and outlines the future actions.

  17. Corn Hybrids for Texas. 

    E-Print Network [OSTI]

    Rogers, J. S.; Bockholt, A. J.; Collier, J. W.

    1957-01-01

    practices which would bring their corn into tassel around June 1. This can be done by planting adapted hybrids at the dates recom- mended in Table 1. When planting is delayed, or if it is necessary to replant, hybrids with earlier maturity should... 90 ' 65.2 Coker 911 67.3 Texas 28 64.9 Texas 26 62.7 Texas 17W 73.0 Tennessee 29 67.5 Texas 9W 74.0 North Carolina 29 65.9 Georgia lOlW 70.7 Dixie 18 63.0 Asgrow lOlW 59.0 TRF 3 62.2 Coker 811 40.0 Surcropper 47.6 - - Averase yield 67...

  18. Pulsed hybrid field emitter

    DOE Patents [OSTI]

    Sampayan, S.E.

    1998-03-03

    A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays. 11 figs.

  19. Pulsed hybrid field emitter

    DOE Patents [OSTI]

    Sampayan, Stephen E. (Manteca, CA)

    1998-01-01

    A hybrid emitter exploits the electric field created by a rapidly depoled ferroelectric material. Combining the emission properties of a planar thin film diamond emitter with a ferroelectric alleviates the present technological problems associated with both types of emitters and provides a robust, extremely long life, high current density cathode of the type required by emerging microwave power generation, accelerator technology and display applications. This new hybrid emitter is easy to fabricate and not susceptible to the same failures which plague microstructure field emitter technology. Local electrode geometries and electric field are determined independently from those for optimum transport and brightness preservation. Due to the large amount of surface charge created on the ferroelectric, the emitted electrons have significant energy, thus eliminating the requirement for specialized phosphors in emissive flat-panel displays.

  20. Hybrid electroluminescent devices

    DOE Patents [OSTI]

    Shiang, Joseph John (Niskayuna, NY); Duggal, Anil Raj (Niskayuna, NY); Michael, Joseph Darryl (Schenectady, NY)

    2010-08-03

    A hybrid electroluminescent (EL) device comprises at least one inorganic diode element and at least one organic EL element that are electrically connected in series. The absolute value of the breakdown voltage of the inorganic diode element is greater than the absolute value of the maximum reverse bias voltage across the series. The inorganic diode element can be a power diode, a Schottky barrier diode, or a light-emitting diode.

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

    E-Print Network [OSTI]

    Bazán, Fermín S. V.

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

  2. Air-Breathing Laminar Flow-Based Microfluidic Fuel Cell Ranga S. Jayashree, Lajos Gancs, Eric R. Choban,, Alex Primak, Dilip Natarajan,

    E-Print Network [OSTI]

    Kenis, Paul J. A.

    Air-Breathing Laminar Flow-Based Microfluidic Fuel Cell Ranga S. Jayashree, Lajos Gancs, Eric R-based microfluidic fuel cell. Micro fuel cells have long been recognized as promising high energy density power sources for portable applications. Many advances in micro fuel cell development have been made, ranging

  3. Remote hybrid power systems

    SciTech Connect (OSTI)

    Barley, C.D.; Winn, C.B. [Colorado State Univ., Fort Collins, CO (United States)

    1997-12-31

    This paper provides an overview of the emerging technology of remote, stand-alone electrical power systems featuring a renewable source (wind or photovoltaics [PV]) as well as a diesel generator, with or without an energy storage device. Other stand-alone power systems are discussed briefly, mainly to emphasize the domain of hybrid systems. The history of hybrid systems is reviewed, beginning with the first wind/diesel system in the late 1970s. Other topics include issues arising from the characteristics of diesel engine/generator sets; simple vs. complex systems; the various energy storage technologies that have been used or proposed; control strategies; modeling; optimization; and some {open_quotes}nuts & bolts{close_quotes} details. The bibliography includes over 130 references which are cited throughout the topical discussions. It is concluded that the technical feasibility of hybrid systems has been demonstrated through many prototype installations, and that areas for further improvements include higher reliability and more economical energy storage devices. 139 refs., 7 figs., 1 tab.

  4. Hybrid Computer Architectures Motivations for Research

    E-Print Network [OSTI]

    Kavi, Krishna

    Hybrid Computer Architectures Motivations for Research What Is a Hybrid Processor? Hybrid commercial hybrid chips provide fixed processing cores and Field Programmable Gate Array (FPGA) elements an Application Specific Integrated Service (ASIC) can provide. How Do We Use Them? Hybrid chips seem uniquely

  5. Hybrid solar lighting distribution systems and components

    DOE Patents [OSTI]

    Muhs, Jeffrey D. (Lenoir City, TN); Earl, Dennis D. (Knoxville, TN); Beshears, David L. (Knoxville, TN); Maxey, Lonnie C. (Powell, TN); Jordan, John K. (Oak Ridge, TN); Lind, Randall F. (Lenoir City, TN)

    2011-07-05

    A hybrid solar lighting distribution system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates all components.

  6. Hybrid solar lighting systems and components

    DOE Patents [OSTI]

    Muhs, Jeffrey D. (Lenoir City, TN); Earl, Dennis D. (Knoxville, TN); Beshears, David L. (Knoxville, TN); Maxey, Lonnie C. (Powell, TN); Jordan, John K. (Oak Ridge, TN); Lind, Randall F. (Lenoir City, TN)

    2007-06-12

    A hybrid solar lighting system and components having at least one hybrid solar concentrator, at least one fiber receiver, at least one hybrid luminaire, and a light distribution system operably connected to each hybrid solar concentrator and each hybrid luminaire. A controller operates each component.

  7. Commercial viability of hybrid vehicles : best household use and cross national considerations.

    SciTech Connect (OSTI)

    Santini, D. J.; Vyas, A. D.

    1999-07-16

    Japanese automakers have introduced hybrid passenger cars in Japan and will soon do so in the US. In this paper, we report how we used early computer simulation model results to compare the commercial viability of a hypothetical near-term (next decade) hybrid mid-size passenger car configuration under varying fuel price and driving patterns. The fuel prices and driving patterns evaluated are designed to span likely values for major OECD nations. Two types of models are used. One allows the ''design'' of a hybrid to a specified set of performance requirements and the prediction of fuel economy under a number of possible driving patterns (called driving cycles). Another provides an estimate of the incremental cost of the hybrid in comparison to a comparably performing conventional vehicle. In this paper, the models are applied to predict the NPV cost of conventional gasoline-fueled vehicles vs. parallel hybrid vehicles. The parallel hybrids are assumed to (1) be produced at high volume, (2) use nickel metal hydride battery packs, and (3) have high-strength steel bodies. The conventional vehicle also is assumed to have a high-strength steel body. The simulated vehicles are held constant in many respects, including 0-60 time, engine type, aerodynamic drag coefficient, tire rolling resistance, and frontal area. The hybrids analyzed use the minimum size battery pack and motor to meet specified 0-60 times. A key characteristic affecting commercial viability is noted and quantified: that hybrids achieve the most pronounced fuel economy increase (best use) in slow, average-speed, stop-and-go driving, but when households consistently drive these vehicles under these conditions, they tend to travel fewer miles than average vehicles. We find that hours driven is a more valuable measure than miles. Estimates are developed concerning hours of use of household vehicles versus driving cycle, and the pattern of minimum NPV incremental cost (or benefit) of selecting the hybrid over the conventional vehicle at various fuel prices is illustrated. These results are based on data from various OECD motions on fuel price, annual miles of travel per vehicle, and driving cycles assumed to be applicable in those nations. Scatter in results plotted as a function of average speed, related to details of driving cycles and the vehicles selected for analysis, is discussed.

  8. Enhancement of a laminar premixed methane/oxygen/nitrogen flame speed using femtosecond-laser-induced plasma

    SciTech Connect (OSTI)

    Yu Xin; Peng Jiangbo; Yi Yachao; Zhao Yongpeng; Chen Deying; Yu Junhua [National Key Laboratory of Science and Technology on Tunable Laser, Harbin Institute of Technology, Harbin 150080 (China); Institute of Opto-electronics, Harbin Institute of Technology, Harbin 150080 (China); Yang Peng; Sun Rui [Institute of Combustion Engineering, Harbin Institute of Technology, Harbin 150001 (China)

    2010-07-05

    We first investigate the effects of femtosecond-laser-induced plasma on the flame speed of a laminar premixed methane/oxygen/nitrogen flame with a wide range of the equivalence ratios (0.8-1.05) at atmospheric pressure. It is experimentally found that the flame speed increases 20.5% at equivalence ratios 1.05. The self-emission spectra from the flame and the plasma are studied and an efficient production of active radicals under the action of femtosecond (fs)-laser pulses has been observed. Based on the experimental data obtained, the presence of oxygen atom and hydrocarbon radicals is suggested to be a key factor enhancing flame speed.

  9. A New Type of Steady and Stable, Laminar, Premixed Flame in Ultra-Lean, Hydrogen-Air Combustion

    SciTech Connect (OSTI)

    Grcar, Joseph F; Grcar, Joseph F

    2008-06-30

    Ultra-lean, hydrogen-air mixtures are found to support another kind of laminar flame that is steady and stable beside flat flames and flame balls. Direct numerical simulations are performed of flames that develop into steadily and stably propagating cells. These cells were the original meaning of the word"flamelet'' when they were observed in lean flammability studies conducted early in the development of combustion science. Several aspects of these two-dimensional flame cells are identified and are contrasted with the properties of one-dimensional flame balls and flat flames. Although lean hydrogen-air flames are subject to thermo-diffusive effects, in this case the result is to stabilize the flame rather than to render it unstable. The flame cells may be useful as basic components of engineering models for premixed combustion when the other types of idealized flames are inapplicable.

  10. Laminar round jet diffusion flame buoyant instabilities: Study on the disappearance of varicose structures at ultra-low Froude number

    SciTech Connect (OSTI)

    Boulanger, Joan [Gas Turbine Laboratory, Institute for Aerospace Research, Ottawa, Ontario (Canada)

    2010-04-15

    At very low Froude number, buoyancy instabilities of round laminar jet diffusion flames disappear (except for small tip oscillations referred to as flickering) and those flames look stable and smooth. This study examines the contributions of the different phenomena in the flow dynamics that may explain this effect. It is observed that, at ultra-low Froude/Reynolds numbers, the material influenced by buoyancy is the plume of the flame and not the flame itself (reaction zone) that is short. Therefore, the vorticity creation zone does not profit from the reaction neighbourhood promoting a sharp gradient of density. Expansion and stretch are also important as they push vorticity creation terms more inside the flame and closer to the burner rim compared to moderate Froude flames. In these latter, the vorticity is continuously created around the flame reaction zone, along its developed height and closer to the vertical direction (in average). (author)

  11. Explosion bomb measurements of ethanol-air laminar gaseous flame characteristics at pressures up to 1.4 MPa

    SciTech Connect (OSTI)

    Bradley, D.; Lawes, M.; Mansour, M.S. [School of Mechanical Engineering, University of Leeds, Leeds LS2 9JT (United Kingdom)

    2009-07-15

    The principal burning characteristics of a laminar flame comprise the fuel vapour pressure, the laminar burning velocity, ignition delay times, Markstein numbers for strain rate and curvature, the stretch rates for the onset of flame instabilities and of flame extinction for different mixtures. With the exception of ignition delay times, measurements of these are reported and discussed for ethanol-air mixtures. The measurements were in a spherical explosion bomb, with central ignition, in the regime of a developed stable, flame between that of an under or over-driven ignition and that of an unstable flame. Pressures ranged from 0.1 to 1.4 MPa, temperatures from 300 to 393 K, and equivalence ratios were between 0.7 and 1.5. It was important to ensure the relatively large volume of ethanol in rich mixtures at high pressures was fully evaporated. The maximum pressure for the measurements was the highest compatible with the maximum safe working pressure of the bomb. Many of the flames soon became unstable, due to Darrieus-Landau and thermo-diffusive instabilities. This effect increased with pressure and the flame wrinkling arising from the instabilities enhanced the flame speed. Both the critical Peclet number and the, more rational, associated critical Karlovitz stretch factor were evaluated at the onset of the instability. With increasing pressure, the onset of flame instability occurred earlier. The measured values of burning velocity are expressed in terms of their variations with temperature and pressure, and these are compared with those obtained by other researchers. Some comparisons are made with the corresponding properties for iso-octane-air mixtures. (author)

  12. Quantifying the benefits of hybrid vehicles

    E-Print Network [OSTI]

    Turrentine, Tom; Delucchi, Mark; Heffner, Reid R.; Kurani, Kenneth S; Sun, Yongling

    2006-01-01

    secrets, but the price of hybrid cars and trucks are betweenCosts of hybrid vehicles Depending on whether a car companydiesel-hybrid prototypes that attained 70 MPG (Green Car

  13. Issue 5: High Interest in Hybrid Cars

    E-Print Network [OSTI]

    Ong, Paul M.; Haselhoff, Kim

    2005-01-01

    2005). “High Interest in Hybrid Cars. ” SCS Fact Sheet, Vol.May 2005 High Interest in Hybrid Cars I NTRODUCTION PublicThe unique features of a hybrid car mean that it is more

  14. Hybrid Silicon Photonic Integrated Circuit Technology

    E-Print Network [OSTI]

    2013-01-01

    and J. E. Bowers, “Hybrid silicon evanescent devices,”and J. E. Bowers, “A hybrid AlGaInAs-silicon evanescentColdren, and J. E. Bowers, “Hybrid III/V sili- con photonic

  15. A hybrid tissue-engineered heart valve

    E-Print Network [OSTI]

    Alavi, SH; Kheradvar, A

    2015-01-01

    load-bearing component of the hybrid lea?et, and it shouldin the left ventricle. Hybrid tissue was also previouslyA Hybrid Tissue-Engineered Heart Valve S. Hamed Alavi, PhD,

  16. Hybrid Publicly Verifiable Computation James Alderman

    E-Print Network [OSTI]

    International Association for Cryptologic Research (IACR)

    Hybrid Publicly Verifiable Computation James Alderman , Christian Janson, Carlos Cid , and Jason introduce Hybrid PVC (HPVC) which, with a single setup stage, provides a flexible solution to outsourced for such systems. Keywords-- Hybrid Publicly Verifiable Computation, Verifiable Delegable Computation, Dual

  17. Hybrid Silicon Photonics for Optical Interconnects

    E-Print Network [OSTI]

    2011-01-01

    Promising Technology for the hybrid silicon laser in 2007.Electrically pumped hybrid AlGaInAs-silicon evanescentA. Yariv, “Electrically pumped hybrid evanescent Si/InGaAsP

  18. Development of Pneumatic Aerodynamic Devices to Improve the Performance, Economics, and Safety of Heavy Vehicles

    SciTech Connect (OSTI)

    Robert J. Englar

    2000-06-19

    Under contract to the DOE Office of Heavy Vehicle Technologies, the Georgia Tech Research Institute (GTRI) is developing and evaluating pneumatic (blown) aerodynamic devices to improve the performance, economics, stability and safety of operation of Heavy Vehicles. The objective of this program is to apply the pneumatic aerodynamic aircraft technology previously developed and flight-tested by GTRI personnel to the design of an efficient blown tractor-trailer configuration. Recent experimental results obtained by GTRI using blowing have shown drag reductions of 35% on a streamlined automobile wind-tunnel model. Also measured were lift or down-load increases of 100-150% and the ability to control aerodynamic moments about all 3 axes without any moving control surfaces. Similar drag reductions yielded by blowing on bluff afterbody trailers in current US trucking fleet operations are anticipated to reduce yearly fuel consumption by more than 1.2 billion gallons, while even further reduction is possible using pneumatic lift to reduce tire rolling resistance. Conversely, increased drag and down force generated instantaneously by blowing can greatly increase braking characteristics and control in wet/icy weather due to effective ''weight'' increases on the tires. Safety is also enhanced by controlling side loads and moments caused on these Heavy Vehicles by winds, gusts and other vehicles passing. This may also help to eliminate the jack-knifing problem if caused by extreme wind side loads on the trailer. Lastly, reduction of the turbulent wake behind the trailer can reduce splash and spray patterns and rough air being experienced by following vehicles. To be presented by GTRI in this paper will be results developed during the early portion of this effort, including a preliminary systems study, CFD prediction of the blown flowfields, and design of the baseline conventional tractor-trailer model and the pneumatic wind-tunnel model.

  19. Aerodynamics overview of the ground transportation systems (GTS) project for heavy vehicle drag reduction

    SciTech Connect (OSTI)

    Gutierrez, W.T.; Hassan, B.; Croll, R.H.; Rutledge, W.H.

    1995-12-31

    The focus of the research was to investigate the fundamental aerodynamics of the base flow of a tractor trailer that would prove useful in fluid flow management. Initially, industry design needs and constraints were defined. This was followed by an evaluation of state-of-the-art Navier-Stokes based computational fluid dynamics tools. Analytical methods were then used in combination with computational tools in a design process. Several geometries were tested at 1:8 scale in a low speed wind tunnel. In addition to the baseline geometry, base add-on devices of the class of ogival boattails and slants were analyzed.

  20. Systematic approach to analyzing and reducing aerodynamic drag of heavy vehicles

    SciTech Connect (OSTI)

    McCallen, R.; Browand, F.; Leonard, A.; Rutledge, W.

    1997-09-16

    This paper presents an approach for reducing aerodynamic drag of heavy vehicles by systematically analyzing trailer components using existing computational tools and moving on to the analyses of integrated tractor-trailers using advanced computational tools. Experimental verification and validation are also an important part of this approach. The project is currently in the development phase while we are in the process of constructing a Multi-Year Program Plan. Projects I and 2 as described in this paper are the anticipated project direction. Also included are results from past and current related activities by the project participants which demonstrate the analysis approach.

  1. Aerodynamic Models for Hurricanes II. Model of the upper hurricane layer

    E-Print Network [OSTI]

    Leonov, Arkady I

    2008-01-01

    This second paper of the series (see the first one in [1]) models the dynamics and structure of upper hurricane layer in adiabatic approximation. Formulation of simplified aerodynamic model allows analytically express the radial istributions of pressure and wind speed components. The vertical evolution of these distributions and hurricane structure in the layer are described by a coupled set of equations for the vertical mass flux and vertical momentum balance, averaged over the eye wall cross section. Several realistic predictions of the model are demonstrated, including the change of directions for the component of radial wind speed and angular velocity of hurricane with altitude.

  2. Hybrid classical-quantum formulations ask for hybrid notions

    E-Print Network [OSTI]

    Carlos Barceló; Raúl Carballo-Rubio; Luis J. Garay; Ricardo Gómez-Escalante

    2013-01-28

    We reappraise some of the hybrid classical-quantum models proposed in the literature with the goal of retrieving some of their common characteristics. In particular, first, we analyze in detail the Peres-Terno argument regarding the inconsistency of hybrid quantizations of the Sudarshan type. We show that to accept such hybrid formalism entails the necessity of dealing with additional degrees of freedom beyond those in the straight complete quantization of the system. Second, we recover a similar enlargement of degrees of freedom in the so-called statistical hybrid models. Finally, we use Wigner's quantization of a simple model to illustrate how in hybrid systems the subsystems are never purely classical or quantum. A certain degree of quantumness (classicality) is being exchanged between the different sectors of the theory, which in this particular unphysical toy model makes them undistinguishable.

  3. Hybrid conformal field theories

    E-Print Network [OSTI]

    Marco Bertolini; Ilarion V. Melnikov; M. Ronen Plesser

    2013-07-26

    We describe a class of (2,2) superconformal field theories obtained by fibering a Landau-Ginzburg orbifold CFT over a compact Kaehler base manifold. While such models are naturally obtained as phases in a gauged linear sigma model, our construction is independent of such an embedding. We discuss the general properties of such theories and present a technique to study the massless spectrum of the associated heterotic compactification. We test the validity of our method by applying it to hybrid phases of linear models and comparing spectra among the phases.

  4. Advanced Coal Wind Hybrid: Economic Analysis

    E-Print Network [OSTI]

    Phadke, Amol

    2008-01-01

    Source: Velocity Suite, Global Energy Data Advanced Coal Wind Hybrid: Economic Analysis 6.3.2 Comparison with Non-hybrid Competing

  5. Advanced Hybrid Water Heater using Electrochemical Compressor...

    Energy Savers [EERE]

    Advanced Hybrid Water Heater using Electrochemical Compressor Advanced Hybrid Water Heater using Electrochemical Compressor Xergy is using its Electro Chemical Compression (ECC)...

  6. Advanced Coal Wind Hybrid: Economic Analysis

    E-Print Network [OSTI]

    Phadke, Amol

    2008-01-01

    of Figures Figure ES-1. Advanced Coal Wind Hybrid: Basicviii Figure 1. Advanced-Coal Wind Hybrid: Basic29 Figure 9. Sensitivity to Coal

  7. Hybrid Rotaxanes: Interlocked Structures for Quantum Computing...

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

    Hybrid Rotaxanes: Interlocked Structures for Quantum Computing? Hybrid Rotaxanes: Interlocked Structures for Quantum Computing? Print Wednesday, 26 August 2009 00:00 Rotaxanes are...

  8. Advanced Coal Wind Hybrid: Economic Analysis

    E-Print Network [OSTI]

    Phadke, Amol

    2008-01-01

    of Figures Figure ES-1. Advanced Coal Wind Hybrid: Basicviii Figure 1. Advanced-Coal Wind Hybrid: Basic21 Figure 6. Comparison of ACWH and CCGT-Wind

  9. Quantifying the benefits of hybrid vehicles

    E-Print Network [OSTI]

    Turrentine, Tom; Delucchi, Mark; Heffner, Reid R.; Kurani, Kenneth S; Sun, Yongling

    2006-01-01

    century. Hybrid electric vehicles (HEVs) reduce emissionsas plug-in HEVs and full electric vehicles to market. In theon their design, hybrid electric vehicles employ electric

  10. Hybrid spread spectrum radio system

    DOE Patents [OSTI]

    Smith, Stephen F. (London, TN) [London, TN; Dress, William B. (Camas, WA) [Camas, WA

    2010-02-09

    Systems and methods are described for hybrid spread spectrum radio systems. A method, includes receiving a hybrid spread spectrum signal including: fast frequency hopping demodulating and direct sequence demodulating a direct sequence spread spectrum signal, wherein multiple frequency hops occur within a single data-bit time and each bit is represented by chip transmissions at multiple frequencies.

  11. Design Criteria Document Hybrid Spectrometer

    E-Print Network [OSTI]

    Johnson, Peter D.

    Design Criteria Document for the Hybrid Spectrometer (HYSPEC) SNS SING14B-00-DC0001-R00 Date: 15 contract DE-AC05-00OR22725 #12;DESIGN CRITERIA DOCUMENT FOR THE HYBRID SPECTROMETER (HYSPEC) August 2005 or reflect those of the United States government or any agency thereof. #12;SING14B-00-DC0001-R00 DESIGN

  12. Design Criteria Document Hybrid Spectrometer

    E-Print Network [OSTI]

    Johnson, Peter D.

    Design Criteria Document for the Hybrid Spectrometer (HYSPEC) SNS SING14B-00-DC0001-R01 Date: 1 contract DE-AC05-00OR22725 #12;DESIGN CRITERIA DOCUMENT FOR THE HYBRID SPECTROMETER (HYSPEC) Mark Hagen or reflect those of the United States government or any agency thereof. #12;SING14B-00-DC0001-R01 DESIGN

  13. Massive Hybrid Stars with Strangeness

    E-Print Network [OSTI]

    Tatsuyuki Takatsuka; Tetsuo Hatsuda; Kota Masuda

    2014-02-19

    How massive the hybrid stars could be is discussed by a "3-window model" proposed from a new strategy to construct the equation of state with hadron-quark transition. It is found that hybrid stars have a strong potentiality to generate a large mass compatible with two-solar-mass neutron star observations.

  14. Essays On Hybrid Bundle Pricing 

    E-Print Network [OSTI]

    Meyer, Jeffrey Dean

    2011-10-21

    model of optimal pricing for hybrid bundles by a monopolist. My results show that an increase in quality variability of the service is generally associated with a higher optimal hybrid bundle price and a lower optimal price of the good, but lower overall...

  15. Cavitation as a complementary tool for automotive aerodynamics J.F. Beaudoin, O. Cadot, J.L. Aider, K. Gosse, P. Paranthoen, B. Hamelin,

    E-Print Network [OSTI]

    Wesfreid, José Eduardo

    Cavitation as a complementary tool for automotive aerodynamics J.F. Beaudoin, O. Cadot, J.L. Aider of this pollution is related to the increasing number of road vehicles and their gas emissions. For the automotive with a variable slant angle. As depicted in Fig. 1, it exhibits the main features of automotive aerodynamics

  16. Coupling a Mesoscale Numerical Weather Prediction Model with Large-Eddy Simulation for Realistic Wind Plant Aerodynamics Simulations (Poster)

    SciTech Connect (OSTI)

    Draxl, C.; Churchfield, M.; Mirocha, J.; Lee, S.; Lundquist, J.; Michalakes, J.; Moriarty, P.; Purkayastha, A.; Sprague, M.; Vanderwende, B.

    2014-06-01

    Wind plant aerodynamics are influenced by a combination of microscale and mesoscale phenomena. Incorporating mesoscale atmospheric forcing (e.g., diurnal cycles and frontal passages) into wind plant simulations can lead to a more accurate representation of microscale flows, aerodynamics, and wind turbine/plant performance. Our goal is to couple a numerical weather prediction model that can represent mesoscale flow [specifically the Weather Research and Forecasting model] with a microscale LES model (OpenFOAM) that can predict microscale turbulence and wake losses.

  17. Aerodynamically induced radial forces in a centrifugal gas compressor: Part 2 -- Computational investigation

    SciTech Connect (OSTI)

    Flathers, M.B.; Bache, G.E.

    1999-10-01

    Radial loads and direction of a centrifugal gas compressor containing a high specific speed mixed flow impeller and a single tongue volute were determined both experimentally and computationally at both design and off-design conditions. The experimental methodology was developed in conjunction with a traditional ASME PTC-10 closed-loop test to determine radial load and direction. The experimental study is detailed in Part 1 of this paper (Moore and Flathers, 1998). The computational method employs a commercially available, fully three-dimensional viscous code to analyze the impeller and the volute interaction. An uncoupled scheme was initially used where the impeller and volute were analyzed as separate models using a common vaneless diffuser geometry. The two calculations were then repeated until the boundary conditions at a chosen location in the common vaneless diffuser were nearly the same. Subsequently, a coupled scheme was used where the entire stage geometry was analyzed in one calculation, thus eliminating the need for manual iteration of the two independent calculations. In addition to radial load and direction information, this computational procedure also provided aerodynamic stage performance. The effect of impeller front face and rear face cavities was also quantified. The paper will discuss computational procedures, including grid generation and boundary conditions, as well as comparisons of the various computational schemes to experiment. The results of this study will show the limitations and benefits of Computational Fluid Dynamics (CFD) for determination of radial load, direction, and aerodynamic stage performance.

  18. Advanced Aerodynamic Devices to Improve the Performance, Economics, Handling, and Safety of Heavy Vehicles

    SciTech Connect (OSTI)

    Robert J. Englar

    2001-05-14

    Research is being conducted at the Georgia Tech Research Institute (GTRI) to develop advanced aerodynamic devices to improve the performance, economics, stability, handling and safety of operation of Heavy Vehicles by using previously-developed and flight-tested pneumatic (blown) aircraft technology. Recent wind-tunnel investigations of a generic Heavy Vehicle model with blowing slots on both the leading and trailing edges of the trailer have been conducted under contract to the DOE Office of Heavy Vehicle Technologies. These experimental results show overall aerodynamic drag reductions on the Pneumatic Heavy Vehicle of 50% using only 1 psig blowing pressure in the plenums, and over 80% drag reductions if additional blowing air were available. Additionally, an increase in drag force for braking was confirmed by blowing different slots. Lift coefficient was increased for rolling resistance reduction by blowing only the top slot, while downforce was produced for traction increase by blowing only the bottom. Also, side force and yawing moment were generated on either side of the vehicle, and directional stability was restored by blowing the appropriate side slot. These experimental results and the predicted full-scale payoffs are presented in this paper, as is a discussion of additional applications to conventional commercial autos, buses, motor homes, and Sport Utility Vehicles.

  19. DOE's effort to reduce truck aerodynamic drag through joint experiments and computations.

    SciTech Connect (OSTI)

    Salari, Kambiz (Lawrence Livermore National Laboratory); Browand, Fred (University of Southern California); Sreenivas, Kidambi (University of Tennessee, Chattanooga); Pointer, W. David (Argonne National Laboratory); Taylor, Lafayette (University of Tennessee, Chattanooga); Pankajakshan, Ramesh (University of Tennessee, Chattanooga); Whitfield, David (University of Tennessee, Chattanooga); Plocher, Dennis (University of Southern California); Ortega, Jason M. (Lawrence Livermore National Laboratory); Merzel, Tai (University of Southern California); McCallen, Rose (Lawrence Livermore National Laboratory); Walker, Stephen M (NASA Ames Research Center); Heineck, James T (NASA Ames Research Center); Hassan, Basil; Roy, Christopher John (Auburn University); Storms, B. (NASA Ames Research Center); Ross, James (NASA Ames Research Center); Englar, Robert (Georgia Tech Research Institute); Rubel, Mike (Caltech); Leonard, Anthony (Caltech); Radovich, Charles (University of Southern California); Eastwood, Craig (Lawrence Livermore National Laboratory); Paschkewitz, John (Lawrence Livermore National Laboratory); Castellucci, Paul (Lawrence Livermore National Laboratory); DeChant, Lawrence Justin.

    2005-08-01

    Class 8 tractor-trailers are responsible for 11-12% of the total US consumption of petroleum. Overcoming aero drag represents 65% of energy expenditure at highway speeds. Most of the drag results from pressure differences and reducing highway speeds is very effective. The goal is to reduce aerodynamic drag by 25% which would translate to 12% improved fuel economy or 4,200 million gal/year. Objectives are: (1) In support of DOE's mission, provide guidance to industry in the reduction of aerodynamic drag; (2) To shorten and improve design process, establish a database of experimental, computational, and conceptual design information; (3) Demonstrate new drag-reduction techniques; and (4) Get devices on the road. Some accomplishments are: (1) Concepts developed/tested that exceeded 25% drag reduction goal; (2) Insight and guidelines for drag reduction provided to industry through computations and experiments; (3) Joined with industry in getting devices on the road and providing design concepts through virtual modeling and testing; and (4) International recognition achieved through open documentation and database.

  20. Computerized method and system for designing an aerodynamic focusing lens stack

    DOE Patents [OSTI]

    Gard, Eric (San Francisco, CA); Riot, Vincent (Oakland, CA); Coffee, Keith (Diablo Grande, CA); Woods, Bruce (Livermore, CA); Tobias, Herbert (Kensington, CA); Birch, Jim (Albany, CA); Weisgraber, Todd (Brentwood, CA)

    2011-11-22

    A computerized method and system for designing an aerodynamic focusing lens stack, using input from a designer related to, for example, particle size range to be considered, characteristics of the gas to be flowed through the system, the upstream temperature and pressure at the top of a first focusing lens, the flow rate through the aerodynamic focusing lens stack equivalent at atmosphere pressure; and a Stokes number range. Based on the design parameters, the method and system determines the total number of focusing lenses and their respective orifice diameters required to focus the particle size range to be considered, by first calculating for the orifice diameter of the first focusing lens in the Stokes formula, and then using that value to determine, in iterative fashion, intermediate flow values which are themselves used to determine the orifice diameters of each succeeding focusing lens in the stack design, with the results being output to a designer. In addition, the Reynolds numbers associated with each focusing lens as well as exit nozzle size may also be determined to enhance the stack design.

  1. Aerodynamic pressure and flow-visualization measurement from a rotating wind turbine blade

    SciTech Connect (OSTI)

    Butterfield, C.P.

    1988-11-01

    Aerodynamic, load, flow-visualization, and inflow measurements have been made on a 10-m, three-bladed, downwind, horizontal-axis wind turbine (HAWT). A video camera mounted on the rotor was used to record nighttime and daytime video images of tufts attached to the low-pressure side of a constant-chord, zero-twist blade. Load measurements were made using strain gages mounted at every 10% of the blade's span. Pressure measurements were made at 80% of the blade's span. Pressure taps were located at 32 chordwise positions, revealing pressure distributions comparable with wind tunnel data. Inflow was measured using a vertical-plane array of eight propvane and five triaxial (U-V-W) prop-type anemometers located 10 m upwind in the predominant wind direction. One objective of this comprehensive research program was to study the effects of blade rotation on aerodynamic behavior below, near, and beyond stall. To this end, flow patterns are presented here that reveal the dynamic and steady behavior of flow conditions on the blade. Pressure distributions are compared to flow patterns and two-dimensional wind tunnel data. Separation boundary locations are shown that change as a function of spanwise location, pitch angle, and wind speed. 6 refs., 23 figs., 1 tab.

  2. Wankel engine for hybrid powertrain

    SciTech Connect (OSTI)

    Butti, A.; Site, V.D.

    1995-12-31

    The Wankel engine is suited to be used to drive hybrid propulsion systems. The main disadvantage of hybrid propulsion systems is the complexity that causes a high weight and large dimensions. For these reason hybrid systems are more suitable for large size vehicle (buses, vans) rather than for small passenger cars. A considerable reduction of hybrid systems weight and dimensions can be obtained using a Wankel rotary engine instead of a conventional engine. The Wankel engine is light, compact, simple, and produces low noise and low vibrations. Therefore a Wankel engine powered hybrid system is suited to be used on small cars. In this paper a 1,000 kg parallel hybrid car with continuously variable transmission and a 6,000 kg series hybrid minibus both equipped with Wankel engines are considered. The Wankel engine works at steady state to minimize fuel consumption and exhaust emissions. The simulation of the behavior of these two vehicles during a ECE + EUDC test cycle is presented in order to evaluate the performances of the systems.

  3. Comparative study of laminar and turbulent flow model with different operating parameters for radio frequency-inductively coupled plasma torch working at 3??MHz frequency at atmospheric pressure

    SciTech Connect (OSTI)

    Punjabi, Sangeeta B.; Sahasrabudhe, S. N.; Das, A. K.; Joshi, N. K.; Mangalvedekar, H. A.; Kothari, D. C.

    2014-01-15

    This paper provides 2D comparative study of results obtained using laminar and turbulent flow model for RF (radio frequency) Inductively Coupled Plasma (ICP) torch. The study was done for the RF-ICP torch operating at 50?kW DC power and 3?MHz frequency located at BARC. The numerical modeling for this RF-ICP torch is done using ANSYS software with the developed User Defined Function. A comparative study is done between laminar and turbulent flow model to investigate how temperature and flow fields change when using different operating conditions such as (a) swirl and no swirl velocity for sheath gas flow rate, (b) variation in sheath gas flow rate, and (c) variation in plasma gas flow rate. These studies will be useful for different material processing applications.

  4. Hybrid powertrain controller

    DOE Patents [OSTI]

    Jankovic, Miroslava (Birmingham, MI); Powell, Barry Kay (Belleville, MI)

    2000-12-26

    A hybrid powertrain for a vehicle comprising a diesel engine and an electric motor in a parallel arrangement with a multiple ratio transmission located on the torque output side of the diesel engine, final drive gearing connecting drivably the output shaft of transmission to traction wheels of the vehicle, and an electric motor drivably coupled to the final drive gearing. A powertrain controller schedules fuel delivered to the diesel engine and effects a split of the total power available, a portion of the power being delivered by the diesel and the balance of the power being delivered by the motor. A shifting schedule for the multiple ratio transmission makes it possible for establishing a proportional relationship between accelerator pedal movement and torque desired at the wheels. The control strategy for the powertrain maintains drivability of the vehicle that resembles drivability of a conventional spark ignition vehicle engine powertrain while achieving improved fuel efficiency and low exhaust gas emissions.

  5. Hybrid powertrain system

    DOE Patents [OSTI]

    Grillo, Ricardo C.; O'Neil, Walter K.; Preston, David M.

    2005-09-20

    A hybrid powertrain system is provided that includes a first prime mover having a rotational output, a second prime mover having a rotational output, and a transmission having a main shaft supporting at least two main shaft gears thereon. The transmission includes a first independent countershaft drivingly connected to the first prime mover and including at least one ratio gear supported thereon that meshes with a respective main shaft gear. A second independent countershaft is drivingly connected to the second prime mover and includes at least one ratio gear supported thereon that meshes with a respective main shaft gear. The ratio gears on the first and second countershafts cooperate with the main shaft gears to provide at least one gear ratio between the first and second countershafts and the main shaft. A shift control mechanism selectively engages and disengages the first and second countershafts for rotation with the main shaft.

  6. Hybrid vehicle control

    DOE Patents [OSTI]

    Shallvari, Iva; Velnati, Sashidhar; DeGroot, Kenneth P.

    2015-07-28

    A method and apparatus for heating a catalytic converter's catalyst to an efficient operating temperature in a hybrid electric vehicle when the vehicle is in a charge limited mode such as e.g., the charge depleting mode or when the vehicle's high voltage battery is otherwise charge limited. The method and apparatus determine whether a high voltage battery of the vehicle is incapable of accepting a first amount of charge associated with a first procedure to warm-up the catalyst. If it is determined that the high voltage battery is incapable of accepting the first amount of charge, a second procedure with an acceptable amount of charge is performed to warm-up the catalyst.

  7. Hybrid dark energy

    E-Print Network [OSTI]

    J. S. Alcaniz; R. Silva; F. C. Carvalho; Zong-Hong Zhu

    2008-07-16

    Extending previous results [Phys. Rev. Lett. 97, 081301 (2006)], we explore the cosmological implications of a new quintessence scenario driven by a slow rolling homogeneous scalar field whose equation of state behaved as freezing over the entire cosmic evolution, is approaching -1 today, but will become thawing in the near future, thereby driving the Universe to an eternal deceleration. We argue that such a mixed behavior, named \\emph{hybrid}, may reconcile the slight preference of current observational data for freezing potentials with the impossibility of defining observables in the String/M-theory context due to the existence of a cosmological event horizon in asymptotically de Sitter universes as, e.g., pure freezing scenarios.

  8. Nonminimally coupled hybrid inflation

    SciTech Connect (OSTI)

    Koh, Seoktae [Center for Quantum Spacetime, Sogang University, Shinsu-dong 1, Mapo-gu, 121-742, Seoul (Korea, Republic of); Minamitsuji, Masato [Department of Physics, Graduate School of Science and Technology, Kwansei Gakuin University, Sanda 669-1337 (Japan)

    2011-02-15

    We discuss the hybrid inflation model where the inflaton field is nonminimally coupled to gravity. In the Jordan frame, the potential contains {phi}{sup 4} term as well as terms in the original hybrid inflation model. In our model, inflation can be classified into the type (I) and the type (II). In the type (I), inflation is terminated by the tachyonic instability of the waterfall field, while in the type (II) by the violation of slow-roll conditions. In our model, the reheating takes place only at the true minimum and even in the case (II) finally the tachyonic instability occurs after the termination of inflation. For a negative nonminimal coupling, inflation takes place in the vacuum-dominated region, in the large field region, or near the local minimum/maximum. Inflation in the vacuum-dominated region becomes either the type (I) or (II), resulting in a blue or red spectrum of the curvature perturbations, respectively. Inflation around the local maximum can be either the type (I) or the type (II), which results in the red spectrum of the curvature perturbations, while around the local minimum it must be the type (I), which results in the blue spectrum. In the large field region, to terminate inflation, potential in the Einstein frame must be positively tilted, always resulting in the red spectrum. We then numerically solve the equations of motion to investigate the whole dynamics of inflaton and confirm that the spectrum of curvature perturbations changes from red to blue ones as scales become smaller.

  9. Hybrid Systems: From Verification to Falsification

    E-Print Network [OSTI]

    Kavraki, Lydia E.

    Hybrid Systems: From Verification to Falsification Erion Plaku, Lydia E. Kavraki, and Moshe Y}@cs.rice.edu Abstract. We propose HyDICE, Hybrid DIscrete Continuous Exploration, a multi-layered approach for hybrid. The discrete search uses the discrete transitions of the hybrid system and coarse-grained decompositions

  10. Hybrid Abstractions that Preserve Timed Languages

    E-Print Network [OSTI]

    Pappas, George J.

    Hybrid Abstractions that Preserve Timed Languages Paulo Tabuada1 and George J. Pappas2 1 Instituto@ee.upenn.edu Abstract. In this paper we consider the problem of extracting an ab- straction from a hybrid control system that determine when trajectories of the original hybrid system can be generated by the abstracted hybrid system

  11. Hybrid Geometric Reduction of Hybrid Systems Aaron D. Ames and Shankar Sastry

    E-Print Network [OSTI]

    Sastry, S. Shankar

    Hybrid Geometric Reduction of Hybrid Systems Aaron D. Ames and Shankar Sastry Abstract-- This paper presents a unifying framework in which to carry out the hybrid geometric reduction of hybrid systems, generalizing classical reduction to a hybrid setting. I. INTRODUCTION The reduction of mechanical systems

  12. Hybrid Charmonium and the $?-?$ Puzzle

    E-Print Network [OSTI]

    Leonard S. Kisslinger; Diana Parno; Seamus Riordan

    2008-11-21

    Using the method of QCD Sum Rules, we estimate the energy of the lowest hybrid Charmonium state, and find it to be at the energy of the $\\Psi'(2S)$ state, about 600 Mev above the $J/\\Psi(1S)$ state. Since our solution is not consistent with a pure hybrid at this energy, we conclude that the $\\Psi'(2S)$ state is probably an admixed $c \\bar{c}$ and hybrid $c \\bar{c}g$ state. From this conjecture we find a possible explanation of the famous $\\rho-\\pi$ puzzle.

  13. Hybrid tomography for conductivity imaging

    E-Print Network [OSTI]

    T. Widlak; O. Scherzer

    2012-03-20

    Hybrid imaging techniques utilize couplings of physical modalities -- they are called hybrid, because, typically, the excitation and measurement quantities belong to different modalities. Recently there has been an enormous research interest in this area because these methods promise very high resolution. In this paper we give a review on hybrid tomography methods for \\emph{electrical conductivity} imaging. The reviewed imaging methods utilize couplings between electric, magnetic and ultrasound modalities. By this it is possible to perform high-resolution electrical impedance imaging and to overcome the low-resolution problem of electric impedance tomography.

  14. Hybrid Vehicle Program. Final report

    SciTech Connect (OSTI)

    None

    1984-06-01

    This report summarizes the activities on the Hybrid Vehicle Program. The program objectives and the vehicle specifications are reviewed. The Hybrid Vehicle has been designed so that maximum use can be made of existing production components with a minimum compromise to program goals. The program status as of the February 9-10 Hardware Test Review is presented, and discussions of the vehicle subsystem, the hybrid propulsion subsystem, the battery subsystem, and the test mule programs are included. Other program aspects included are quality assurance and support equipment. 16 references, 132 figures, 47 tables.

  15. An experimental investigation of ethylene/O{sub 2}/diluent mixtures: Laminar flame speeds with preheat and ignition delays at high pressures

    SciTech Connect (OSTI)

    Kumar, Kamal; Mittal, Gaurav; Sung, Chih-Jen [Department of Mechanical and Aerospace Engineering, Case Western Reserve University, Cleveland, OH 44106 (United States); Law, Chung K. [Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08544 (United States)

    2008-05-15

    The atmospheric pressure laminar flame speeds of premixed ethylene/O{sub 2}/N{sub 2} mixtures were experimentally measured over equivalence ratios ranging from 0.5 to 1.4 and mixture preheat temperatures varying from 298 to 470 K in a counterflow configuration. Ignition delay measurements were also conducted for ethylene/O{sub 2}/N{sub 2}/Ar mixtures using a rapid compression machine at compressed pressures from 15 to 50 bar and in the compressed temperature range from 850 to 1050 K. The experimental laminar flame speeds and ignition delays were then compared to the computed values using two existing chemical kinetic mechanisms. Results show that while the laminar flame speeds are reasonably predicted at room temperature conditions, the discrepancy becomes larger with increasing preheat temperature. A comparison of experimental and computational ignition delay times was also conducted and discussed. Sensitivity analysis further shows that the ignition delay is highly sensitive to the reactions of the vinyl radical with molecular oxygen. The reaction of ethylene with the HO{sub 2} radical was also found to be important for autoignition under the current experimental conditions. (author)

  16. Hybridization and the Typological Paradigm 

    E-Print Network [OSTI]

    Carlson, Charles

    2012-02-14

    chemical cues, whether conspecifics in their immediate vicinity have high parasite loads and also whether this has an effect on mating and association behavior toward both conspecific and hybrid mates. Our hypothesis being that females will have greater...

  17. Compositional Variation Within Hybrid Nanostructures

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

    of the metal-alloy tip component of a hybrid nanostructure with that of free-standing metal-alloy nanoparticles. Transmission electron microscopy (TEM) image of PtCo-CdS...

  18. Hybrid Zero-capacity Channels

    E-Print Network [OSTI]

    Sergii Strelchuk; Jonathan Oppenheim

    2012-07-04

    There are only two known kinds of zero-capacity channels. The first kind produces entangled states that have positive partial transpose, and the second one - states that are cloneable. We consider the family of 'hybrid' quantum channels, which lies in the intersection of the above classes of channels and investigate its properties. It gives rise to the first explicit examples of the channels, which create bound entangled states that have the property of being cloneable to the arbitrary finite number of parties. Hybrid channels provide the first example of highly cloneable binding entanglement channels, for which known superactivation protocols must fail - superactivation is the effect where two channels each with zero quantum capacity having positive capacity when used together. We give two methods to construct a hybrid channel from any binding entanglement channel. We also find the low-dimensional counterparts of hybrid states - bipartite qubit states which are extendible and possess two-way key.

  19. Hybrid Fuel Cell Technology Overview

    SciTech Connect (OSTI)

    None available

    2001-05-31

    For the purpose of this STI product and unless otherwise stated, hybrid fuel cell systems are power generation systems in which a high temperature fuel cell is combined with another power generating technology. The resulting system exhibits a synergism in which the combination performs with an efficiency far greater than can be provided by either system alone. Hybrid fuel cell designs under development include fuel cell with gas turbine, fuel cell with reciprocating (piston) engine, and designs that combine different fuel cell technologies. Hybrid systems have been extensively analyzed and studied over the past five years by the Department of Energy (DOE), industry, and others. These efforts have revealed that this combination is capable of providing remarkably high efficiencies. This attribute, combined with an inherent low level of pollutant emission, suggests that hybrid systems are likely to serve as the next generation of advanced power generation systems.

  20. Global optimization of hybrid systems

    E-Print Network [OSTI]

    Lee, Cha Kun

    2006-01-01

    Systems that exhibit both discrete state and continuous state dynamics are called hybrid systems. In most nontrivial cases, these two aspects of system behavior interact to such a significant extent that they cannot be ...

  1. A Lean Methane Prelixed Laminar Flame Doped witg Components of Diesel Fuel. Part I: n)Butylbenzene

    E-Print Network [OSTI]

    Pousse, Emir; Fournet, René; Battin-Leclerc, Frédérique; 10.1016/j.combustflame.2008.09.012

    2009-01-01

    To better understand the chemistry involved during the combustion of components of diesel fuel, the structure of a laminar lean premixed methane flame doped with n-butylbenzene has been investigated. The inlet gases contained 7.1% (molar) of methane, 36.8% of oxygen and 0.96% of n-butylbenzene corresponding to an equivalence ratio of 0.74 and a ratio C10H14 / CH4 of 13.5%. The flame has been stabilized on a burner at a pressure of 6.7 kPa using argon as diluent, with a gas velocity at the burner of 49.2 cm/s at 333 K. Quantified species included the usual methane C0-C2 combustion products, but also 16 C3-C5 hydrocarbons, 7 C1-C3 oxygenated compounds, as well as 20 aromatic products, namely benzene, toluene, phenylacetylene, styrene, ethylbenzene, xylenes, allylbenzene, propylbenzene, cumene, methylstyrenes, butenylbenzenes, indene, indane, naphthalene, phenol, benzaldehyde, anisole, benzylalcohol, benzofuran, and isomers of C10H10 (1-methylindene, dihydronaphtalene, butadienylbenzene). A new mechanism for the...

  2. N-BODY SIMULATION OF PLANETESIMAL FORMATION THROUGH GRAVITATIONAL INSTABILITY OF A DUST LAYER IN LAMINAR GAS DISK

    SciTech Connect (OSTI)

    Michikoshi, Shugo; Kokubo, Eiichiro [Center for Computational Astrophysics, National Astronomical Observatory of Japan, Osawa, Mitaka, Tokyo 181-8588 (Japan); Inutsuka, Shu-ichiro, E-mail: michikoshi@cfca.j, E-mail: kokubo@th.nao.ac.j, E-mail: inutsuka@nagoya-u.j [Department of Physics, Graduate School of Science, Nagoya University, Furo-cho, Chikusa-ku, Nagoya, Aichi 464-8602 (Japan)

    2010-08-20

    We investigate the formation process of planetesimals from the dust layer by the gravitational instability in the gas disk using local N-body simulations. The gas is modeled as a background laminar flow. We study the formation process of planetesimals and its dependence on the strength of the gas drag. Our simulation results show that the formation process is divided into three stages qualitatively: the formation of wake-like density structures, the creation of planetesimal seeds, and their collisional growth. The linear analysis of the dissipative gravitational instability shows that the dust layer is secularly unstable although Toomre's Q value is larger than unity. However, in the initial stage, the growth time of the gravitational instability is longer than that of the dust sedimentation and the decrease in the velocity dispersion. Thus, the velocity dispersion decreases and the disk shrinks vertically. As the velocity dispersion becomes sufficiently small, the gravitational instability finally becomes dominant. Then wake-like density structures are formed by the gravitational instability. These structures fragment into planetesimal seeds. The seeds grow rapidly owing to mutual collisions.

  3. Observation of multi-scale oscillation of laminar lifted flames with low-frequency AC electric fields

    SciTech Connect (OSTI)

    Ryu, S.K.; Kim, Y.K.; Kim, M.K.; Won, S.H. [School of Mechanical and Aerospace Engineering, Seoul National University, Seoul 151-742 (Korea); Chung, S.H. [Clean Combustion Research Center, King Abdullah University of Science and Technology, Thuwal (Saudi Arabia)

    2010-01-15

    The oscillation behavior of laminar lifted flames under the influence of low-frequency AC has been investigated experimentally in coflow jets. Various oscillation modes were existed depending on jet velocity and the voltage and frequency of AC, especially when the AC frequency was typically smaller than 30 Hz. Three different oscillation modes were observed: (1) large-scale oscillation with the oscillation frequency of about 0.1 Hz, which was independent of the applied AC frequency, (2) small-scale oscillation synchronized to the applied AC frequency, and (3) doubly-periodic oscillation with small-scale oscillation embedded in large-scale oscillation. As the AC frequency decreased from 30 Hz, the oscillation modes were in the order of the large-scale oscillation, doubly-periodic oscillation, and small-scale oscillation. The onset of the oscillation for the AC frequency smaller than 30 Hz was in close agreement with the delay time scale for the ionic wind effect to occur, that is, the collision response time. Frequency-doubling behavior for the small-scale oscillation has also been observed. Possible mechanisms for the large-scale oscillation and the frequency-doubling behavior have been discussed, although the detailed understanding of the underlying mechanisms will be a future study. (author)

  4. Autoignited laminar lifted flames of methane, ethylene, ethane, and n-butane jets in coflow air with elevated temperature

    SciTech Connect (OSTI)

    Choi, B.C.; Chung, S.H.

    2010-12-15

    The autoignition characteristics of laminar lifted flames of methane, ethylene, ethane, and n-butane fuels have been investigated experimentally in coflow air with elevated temperature over 800 K. The lifted flames were categorized into three regimes depending on the initial temperature and fuel mole fraction: (1) non-autoignited lifted flame, (2) autoignited lifted flame with tribrachial (or triple) edge, and (3) autoignited lifted flame with mild combustion. For the non-autoignited lifted flames at relatively low temperature, the existence of lifted flame depended on the Schmidt number of fuel, such that only the fuels with Sc > 1 exhibited stationary lifted flames. The balance mechanism between the propagation speed of tribrachial flame and local flow velocity stabilized the lifted flames. At relatively high initial temperatures, either autoignited lifted flames having tribrachial edge or autoignited lifted flames with mild combustion existed regardless of the Schmidt number of fuel. The adiabatic ignition delay time played a crucial role for the stabilization of autoignited flames. Especially, heat loss during the ignition process should be accounted for, such that the characteristic convection time, defined by the autoignition height divided by jet velocity was correlated well with the square of the adiabatic ignition delay time for the critical autoignition conditions. The liftoff height was also correlated well with the square of the adiabatic ignition delay time. (author)

  5. Hybrid particles and associated methods

    SciTech Connect (OSTI)

    Fox, Robert V; Rodriguez, Rene; Pak, Joshua J; Sun, Chivin

    2015-02-10

    Hybrid particles that comprise a coating surrounding a chalcopyrite material, the coating comprising a metal, a semiconductive material, or a polymer; a core comprising a chalcopyrite material and a shell comprising a functionalized chalcopyrite material, the shell enveloping the core; or a reaction product of a chalcopyrite material and at least one of a reagent, heat, and radiation. Methods of forming the hybrid particles are also disclosed.

  6. Directed mammalian gene regulatory networks using expression and comparative genomic hybridization microarray data from radiation hybrids

    E-Print Network [OSTI]

    2009-01-01

    generation whole genome-radiation hybrid map spanning theA high- resolution radiation hybrid map of the human genomeRecently we have used radiation hybrids to map loci based on

  7. Laboratory evaluation of fan/filter units' aerodynamic and energy performance

    SciTech Connect (OSTI)

    Xu, Tengfang; Jeng, Ming-Shan

    2004-07-27

    The paper discusses the benefits of having a consistent testing method to characterize aerodynamic and energy performance of FFUs. It presents evaluation methods of laboratory-measured performance of ten relatively new, 1220 mm x 610 mm (or 4 ft x 2 ft) fan-filter units (FFUs), and includes results of a set of relevant metrics such as energy performance indices (EPI) based upon the sample FFUs tested. This paper concludes that there are variations in FFUs' performance, and that using a consistent testing and evaluation method can generate compatible and comparable FFU performance information. The paper also suggests that benefits and opportunities exist for our method of testing FFU energy performance to be integrated in future recommended practices.

  8. MicroRNA-101 mediates the suppressive effect of laminar shear stress on mTOR expression in vascular endothelial cells

    SciTech Connect (OSTI)

    Chen, Kui; Fan, Wendong; Wang, Xing; Ke, Xiao [Division of Cardiology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080 (China)] [Division of Cardiology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080 (China); Wu, Guifu, E-mail: eecpchina@yahoo.com.cn [Key Laboratory on Assisted Circulation, Ministry of Health, Guangzhou 510080 (China)] [Key Laboratory on Assisted Circulation, Ministry of Health, Guangzhou 510080 (China); Hu, Chengheng, E-mail: huchenghengpci@yahoo.com.cn [Division of Cardiology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080 (China)] [Division of Cardiology, First Affiliated Hospital of Sun Yat-sen University, Guangzhou 510080 (China)

    2012-10-12

    Highlights: Black-Right-Pointing-Pointer Laminar shear stress upregulates miR-101 expression in vascular endothelial cells. Black-Right-Pointing-Pointer miR-101 represses mTOR expression through a specific 3 Prime UTR binding site. Black-Right-Pointing-Pointer Overexpression of miR-101 inhibits G1/S transition and endothelial cell proliferation. Black-Right-Pointing-Pointer Blockade of miR-101 attenuates the suppressive effect of laminar flow on mTOR expression. -- Abstract: Shear stress associated with blood flow plays an important role in regulating gene expression and cell function in endothelial cells (ECs). MicroRNAs (miRNAs) are highly conserved, small non-coding RNAs that negatively regulate the expression of target genes by binding to the mRNA 3 Prime -untranslated region (3 Prime UTR) at the posttranscriptional level involved in diverse cellular processes. This study demonstrates that microRNA-101 in response to laminar shear stress (LSS) is involved in the flow regulation of gene expression in ECs. qRT-PCR analysis showed that miR-101 expression was significantly upregulated in human umbilical vein endothelial cells (HUVECs) exposed to 12 dyn/cm{sup 2} laminar shear stress for 12 h. We found that transfection of miR-101 significantly decreased the luciferase activity of plasmid reporter containing the 3 Prime UTR of mammalian target of rapamycin (mTOR) gene. Western analysis revealed that the protein level of mTOR was significantly reduced in ECs transfected with miR-101. Furthermore, miR-101 overexpression induced cell cycle arrest at the G1/S transition and suppressed endothelial cell proliferation. Finally, transfection of miR-101 inhibitors attenuated the suppressive effects of LSS on mTOR expression, which identified the efficacy of loss-of-function of miR-101 in laminar flow-treated ECs. In conclusion, we have demonstrated that upregulation of miR-101 in response to LSS contributes to the suppressive effects of LSS on mTOR expression and EC proliferation. These studies advance our understanding of the posttranscriptional mechanisms by which shear stress modulates endothelial homeostasis.

  9. Investigation of Tractor Base Bleeding for Heavy Vehicle Aerodynamic Drag Reduction

    SciTech Connect (OSTI)

    Ortega, J; Salari, K; Storms, B

    2007-10-25

    One of the main contributors to the aerodynamic drag of a heavy vehicle is tractor-trailer gap drag, which arises when the vehicle operates within a crosswind. Under this operating condition, freestream flow is entrained into the tractor-trailer gap, imparting a momentum exchange to the vehicle and subsequently increasing the aerodynamic drag. While a number of add-on devices, including side extenders, splitter plates, vortex stabilizers, and gap sealers, have been previously tested to alleviate this source of drag, side extenders remain the primary add-on device of choice for reducing tractor-trailer gap drag. However, side extenders are not without maintenance and operational issues. When a heavy vehicle pivots sharply with respect to the trailer, as can occur during loading or unloading operations, the side extenders can become crushed against the trailer. Consequently, fleet operators are forced to incur additional costs to cover the repair or replacement of the damaged side extenders. This issue can be overcome by either shortening the side extenders or by devising an alternative drag reduction concept that can perform just as effectively as side extenders. To explore such a concept, we investigate tractor base bleeding as a means of reducing gap drag. Wind tunnel measurements are made on a 1:20 scale heavy vehicle model at a vehicle width-based Reynolds number of 420,000. The tractor bleeding flow, which is delivered through a porous material embedded within the tractor base, is introduced into the tractor-trailer gap at bleeding coefficients ranging from 0.0-0.018. To determine the performance of tractor base bleeding under more realistic operating conditions, computational fluid dynamics simulations are performed on a full-scale heavy vehicle within a crosswind for bleeding coefficients ranging from 0.0-0.13.

  10. Effects of Vehicle Image in Gasoline-Hybrid Electric Vehicles

    E-Print Network [OSTI]

    Heffner, Reid R.; Kurani, Ken; Turrentine, Tom

    2005-01-01

    of Vehicle Image in Gasoline-Hybrid Electric Vehicles Reidof Vehicle Image in Gasoline-Hybrid Electric Vehicles Reidhigh demand for gasoline-hybrid electric vehicles (HEVs)?

  11. Ultracapacitor Technologies and Application in Hybrid and Electric Vehicles

    E-Print Network [OSTI]

    Burke, Andy

    2009-01-01

    The parallel hybrid passenger car (VW Golf) combined an EDLCpassenger cars using the ultracapacitors in micro-hybrid,passenger car using both carbon/carbon and hybrid carbon

  12. Hybrid Traffic Data Collection Roadmap: Objectives and Methods

    E-Print Network [OSTI]

    Bayen, Alexandre

    2013-01-01

    information environment. Hybrid Traffic Data CollectionBibliography Bibliography Hybrid Traffic Data Collection19, no. 1, p. 15–25, 2003. Hybrid Traffic Data Collection

  13. System Simulations of Hybrid Electric Vehicles with Focus on...

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

    System Simulations of Hybrid Electric Vehicles with Focus on Emissions System Simulations of Hybrid Electric Vehicles with Focus on Emissions Comparative simulations of hybrid...

  14. Are batteries ready for plug-in hybrid buyers?

    E-Print Network [OSTI]

    Axsen, Jonn; Kurani, Kenneth S.; Burke, Andrew

    2008-01-01

    and Impacts of Hybrid Electric Vehicle Options for Compactof Plug-In Hybrid Electric Vehicles, Volume 1: Nationwideand Impacts of Hybrid Electric Vehicle Options, EPRI, Palo

  15. Are Batteries Ready for Plug-in Hybrid Buyers?

    E-Print Network [OSTI]

    Axsen, Jonn; Kurani, Kenneth S; Burke, Andy

    2009-01-01

    and Impacts of Hybrid Electric Vehicle Options for Compactof Plug-In Hybrid Electric Vehicles, Volume 1: Nationwideand Impacts of Hybrid Electric Vehicle Options, EPRI, Palo

  16. Are Batteries Ready for Plug-in Hybrid Buyers?

    E-Print Network [OSTI]

    Axsen, Jonn; Burke, Andy; Kurani, Kenneth S

    2010-01-01

    and impacts of hybrid electric vehicle options for compactof plug-in hybrid electric vehicles, vol. 1: nationwideimpacts of hybrid electric vehicle options. Report #1000349,

  17. Optimum Performance of Direct Hydrogen Hybrid Fuel Cell Vehicles

    E-Print Network [OSTI]

    Zhao, Hengbing; Burke, Andy

    2009-01-01

    in batteries, ultracapacitors, fuel cells and hybrid vehicleBattery, Hybrid and Fuel Cell Electric Vehicle SymposiumBattery, Hybrid and Fuel Cell Electric Vehicle Symposium

  18. Hybrid power source

    DOE Patents [OSTI]

    Singh, Harmohan N.

    2012-06-05

    A hybrid power system is comprised of a high energy density element such as a fuel-cell and high power density elements such as a supercapacitor banks. A DC/DC converter electrically connected to the fuel cell and converting the energy level of the energy supplied by the fuel cell. A first switch is electrically connected to the DC/DC converter. First and second supercapacitors are electrically connected to the first switch and a second switch. A controller is connected to the first switch and the second switch, monitoring charge levels of the supercapacitors and controls the switching in response to the charge levels. A load is electrically connected to the second switch. The first switch connects the DC/DC converter to the first supercapacitor when the second switch connects the second supercapacitor to the load. The first switch connects the DC/DC converter to the second supercapacitor when the second switch connects the first supercapacitor to the load.

  19. Test, Evaluation, and Demonstration of Practical Devices/Systems to Reduce Aerodynamic Drag of Tractor/Semitrailer Combination Unit Trucks

    SciTech Connect (OSTI)

    Scott Smith; Karla Younessi; Matt Markstaller; Dan Schlesinger; Bhaskar Bhatnagar; Donald Smith; Bruno Banceu; Ron Schoon; V.K. Sharma; Mark Kachmarsky; Srikant Ghantae; Michael Sorrels; Conal Deedy; Justin Clark; Skip Yeakel; Michael D. Laughlin; Charlotte Seigler; Sidney Diamond

    2007-04-30

    Class 8 heavy-duty trucks account for over three-quarters of the total diesel fuel used by commercial trucks (trucks with GVWRs more than 10,000 pounds) in the United States each year. At the highway speeds at which these trucks travel (i.e., 60 mph or greater), aerodynamic drag is a major part of total horsepower needed to move the truck down the highway, Reductions in aerodynamic drag can yield measurable benefits in fuel economy through the use of relatively inexpensive and simple devices. The goal of this project was to examine a number of aerodynamic drag reduction devices and systems and determine their effectiveness in reducing aerodynamic drag of Class 8 tractor/semitrailer combination-units, thus contributing to DOE's goal of reducing transportation petroleum use. The project team included major heavy truck manufacturers in the United States, along with the management and industry expertise of the Truck Manufacturers Association as the lead investigative organization. The Truck Manufacturers Association (TMA) is the national trade association representing the major North American manufacturers of Class 6-8 trucks (GVWRs over 19,500 lbs). Four major truck manufacturers participated in this project with TMA: Freightliner LLC; International Truck and Engine Corporation; Mack Trucks Inc.; and Volvo Trucks North America, Inc. Together, these manufacturers represent over three-quarters of total Class 8 truck sales in the United States. These four manufacturers pursued complementary research efforts as part of this project. The project work was separated into two phases conducted over a two-year period. In Phase I, candidate aerodynamic devices and systems were screened to focus research and development attention on devices that offered the most potential. This was accomplished using full-size vehicle tests, scale model tests, and computational fluid dynamics analyses. In Phase II, the most promising devices were installed on full-size trucks and their effect on fuel economy was determined, either through on-road testing or full-size wind tunnel testing. All of the manufacturers worked with devices and systems that offer practical solutions to reduce aerodynamic drag, accounting for functionality, durability, cost effectiveness, reliability, and maintainability. The project team members and their roles and responsibilities are shown in Figure 2-1. Figure 2-2 shows the Phase I and II project schedules for all four projects and associated management activities.

  20. Modification of laminar flow ultrafine condensation particle counters for the enhanced detection of 1 nm condensation nuclei

    SciTech Connect (OSTI)

    Kuang, C.; Chen, M.; McMurry, P. H.; Wang, J.

    2011-10-01

    This paper describes simple modifications to thermally diffusive laminar flow ultrafine condensation particle counters (UCPCs) that allow detection of {approx}1 nm condensation nuclei with much higher efficiencies than have been previously reported. These nondestructive modifications were applied to a commercial butanol based UCPC (TSI 3025A) and to a diethylene glycol-based UCPC (UMN DEG-UCPC). Size and charge dependent detection efficiencies using the modified UCPCs (BNL 3025A and BNL DEGUCPC) were measured with high resolution mobility classified aerosols composed of NaCl, W, molecular ion standards of tetraalkyl ammonium bromide, and neutralizer-generated ions. With negatively charged NaCl aerosol, the BNL 3025A and BNL DEGUCPC achieved detection efficiencies of 37% (90x increase over TSI 3025A) at 1.68 nm mobility diameter (1.39 nm geometric diameter) and 23% (8x increase over UMN DEG-UCPC) at 1.19 nm mobility diameter (0.89 nm geometric diameter), respectively. Operating conditions for both UCPCs were identified that allowed negatively charged NaCl and W particles, but not negative ions of exactly the same mobility size, to be efficiently detected. This serendipitous material dependence, which is not fundamentally understood, suggests that vapor condensation might sometimes allow for the discrimination between air 'ions' and charged 'particles.' As a detector in a scanning mobility particle spectrometer (SMPS), a UCPC with this strong material dependence would allow for more accurate measurements of sub-2 nm aerosol size distributions due to the reduced interference from neutralizer-generated ions and atmospheric ions, and provide increased sensitivity for the determination of nucleation rates and initial particle growth rates.

  1. Methyl Formate Oxidation: Speciation Data, Laminar Burning Velocities, Ignition Delay Times and a Validated Chemical Kinetic Model

    SciTech Connect (OSTI)

    Dooley, S.; Burke, M. P.; Chaos, M.; Stein, Y.; Dryer, F. L.; Zhukov, V. P.; Finch, O.; Simmie, J. M.; Curran, H. J.

    2010-07-16

    The oxidation of methyl formate (CH{sub 3}OCHO) has been studied in three experimental environments over a range of applied combustion relevant conditions: 1. A variable-pressure flow reactor has been used to quantify reactant, major intermediate and product species as a function of residence time at 3 atm and 0.5% fuel concentration for oxygen/fuel stoichiometries of 0.5, 1.0, and 1.5 at 900 K, and for pyrolysis at 975 K. 2. Shock tube ignition delays have been determined for CH{sub 3}OCHO/O{sub 2}/Ar mixtures at pressures of ? 2.7, 5.4, and 9.2 atm and temperatures of 1275–1935 K for mixture compositions of 0.5% fuel (at equivalence ratios of 1.0, 2.0, and 0.5) and 2.5% fuel (at an equivalence ratio of 1.0). 3. Laminar burning velocities of outwardly propagating spherical CH{sub 3}OCHO/air flames have been determined for stoichiometries ranging from 0.8–1.6, at atmospheric pressure using a pressure-release-type high-pressure chamber. A detailed chemical kinetic model has been constructed, validated against, and used to interpret these experimental data. The kinetic model shows that methyl formate oxidation proceeds through concerted elimination reactions, principally forming methanol and carbon monoxide as well as through bimolecular hydrogen abstraction reactions. The relative importance of elimination versus abstraction was found to depend on the particular environment. In general, methyl formate is consumed exclusively through molecular decomposition in shock tube environments, while at flow reactor and freely propagating premixed flame conditions, there is significant competition between hydrogen abstraction and concerted elimination channels. It is suspected that in diffusion flame configurations the elimination channels contribute more significantly than in premixed environments.

  2. Rotordynamic evaluation of hybrid damper seals with metal mesh elements 

    E-Print Network [OSTI]

    Bhamidipati, Laxmi Narasimha Kameswara Sarma

    2003-01-01

    Metal mesh hybrid damper seals (MHS) were proposed to be an alternative for brush hybrid pocket damper seals (PDS) in turbomachinery. The metal mesh hybrid damper seal is a hybrid of the pocket damper seal and the metal ...

  3. Effects of tone on the three-way laryngeal distinction in Korean: An acoustic and aerodynamic comparison of the Seoul and South Kyungsang dialects

    E-Print Network [OSTI]

    Lee, Hyunjung; Jongman, Allard

    2012-08-01

    The three-way laryngeal distinction among voiceless Korean stops has been well documented for the Seoul dialect. The present study compares the acoustic and aerodynamic properties of this stop series between two dialects, non-tonal Seoul and tonal...

  4. CRADA Final Report: Process development for hybrid solar cells

    E-Print Network [OSTI]

    Ager, Joel W

    2011-01-01

    the high efficiency, high voltage hybrid tandem solar celltarget efficiency of 30%, the hybrid tandem solar cells have

  5. Ultracapacitor Technologies and Application in Hybrid and Electric Vehicles

    E-Print Network [OSTI]

    Burke, Andy

    2009-01-01

    in series hybrids using gasoline and diesel engines anddiesel powered buses and consistently better fuel economy than hybrid

  6. Hybrid Ventilation Optimization and Control Research and Development...

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

    Hybrid Ventilation Optimization and Control Research and Development Hybrid Ventilation Optimization and Control Research and Development Credit: Massachusetts Institute of...

  7. Advanced Electric Systems and Aerodynamics for Efficiency Improvements in Heavy Duty Trucks

    SciTech Connect (OSTI)

    Larry Slone; Jeffrey Birkel

    2007-10-31

    The Advanced Electric Systems and Aerodynamics for Efficiency Improvements in Heavy Duty Trucks program (DE-FC26-04NT42189), commonly referred to as the AES program, focused on areas that will primarily benefit fuel economy and improve heat rejection while driving over the road. The AES program objectives were to: (1) Analyze, design, build, and test a cooling system that provided a minimum of 10 percent greater heat rejection in the same frontal area with no increase in parasitic fan load. (2) Realize fuel savings with advanced power management and acceleration assist by utilizing an integrated starter/generator (ISG) and energy storage devices. (3) Quantify the effect of aerodynamic drag due to the frontal shape mandated by the area required for the cooling system. The program effort consisted of modeling and designing components for optimum fuel efficiency, completing fabrication of necessary components, integrating these components into the chassis test bed, completing controls programming, and performance testing the system both on a chassis dynamometer and on the road. Emission control measures for heavy-duty engines have resulted in increased engine heat loads, thus introducing added parasitic engine cooling loads. Truck electrification, in the form of thermal management, offers technological solutions to mitigate or even neutralize the effects of this trend. Thermal control offers opportunities to avoid increases in cooling system frontal area and forestall reduced fuel economy brought about by additional aerodynamic vehicle drag. This project explored such thermal concepts by installing a 2007 engine that is compliant with current regulations and bears additional heat rejection associated with meeting these regulations. This newer engine replaced the 2002 engine from a previous project that generated less heat rejection. Advanced power management, utilizing a continuously optimized and controlled power flow between electric components, can offer additional fuel economy benefits to the heavy-duty trucking industry. Control software for power management brings added value to the power distribution and energy storage architecture on board a truck with electric accessories and an ISG. The research team has built upon a previous truck electrification project, formally, 'Parasitic Energy Loss Reduction and Enabling Technologies for Class 7/8 Trucks', DE-FC04-2000AL6701, where the fundamental concept of electrically-driven accessories replacing belt/gear-driven accessories was demonstrated on a Kenworth T2000 truck chassis. The electrical accessories, shown in Figure 1, were controlled to provide 'flow on demand' variable-speed operation and reduced parasitic engine loads for increased fuel economy. These accessories also provided solutions for main engine idle reduction in long haul trucks. The components and systems of the current project have been integrated into the same Kenworth T2000 truck platform. Reducing parasitic engine loading by decoupling accessory loads from the engine and driving them electrically has been a central concept of this project. Belt or gear-driven engine accessories, such as water pump, air conditioning compressor, or air compressor, are necessarily tied to the engine speed dictated by the current vehicle operating conditions. These conventional accessory pumps are sized to provide adequate flow or pressure at low idle or peak torque speeds, resulting in excess flow or pressure at cruising or rated speeds. The excess flow is diverted through a pressure-minimizing device such as a relief valve thereby expending energy to drive unnecessary and inefficient pump operation. This inefficiency causes an increased parasitic load to the engine, which leads to a loss of usable output power and decreased fuel economy. Controlling variable-speed electric motors to provide only the required flow or pressure of a particular accessory system can yield significant increases in fuel economy for a commercial vehicle. Motor loads at relatively high power levels (1-5 kW, or higher) can be efficiently provided

  8. Conditions when hybridization might predispose populations

    E-Print Network [OSTI]

    COMMENTARY Conditions when hybridization might predispose populations for adaptive radiation O (Sch- warzer et al., 2012), perhaps just as a consequence of many young species in geographical et al., 2011; Genner & Turner, 2012). Whether these species radiations happen despite hybridization

  9. Hybrid solar-fossil fuel power generation

    E-Print Network [OSTI]

    Sheu, Elysia J. (Elysia Ja-Zeng)

    2012-01-01

    In this thesis, a literature review of hybrid solar-fossil fuel power generation is first given with an emphasis on system integration and evaluation. Hybrid systems are defined as those which use solar energy and fuel ...

  10. CONDUCTIVE POLYCARBONATE NANOCOMPOSITES with HYBRID NANOFILLERS

    E-Print Network [OSTI]

    Collins, Gary S.

    CONDUCTIVE POLYCARBONATE NANOCOMPOSITES with HYBRID NANOFILLERS Catherine Smith, Brooks Lively, Wei of polymers. Emerging technologies have demonstrated the crucial need for highly conductive polymer combination between polycarbonate (PC) and hybrid concentrations of CNT and GNP nanofillers was investigated

  11. Hybrid Cotangent Bundle Reduction of Simple Hybrid Mechanical Systems with Symmetry

    E-Print Network [OSTI]

    Ames, Aaron

    Hybrid Cotangent Bundle Reduction of Simple Hybrid Mechanical Systems with Symmetry Aaron D. Ames the notion of a simple hybrid mechanical system, which generalizes mechanical systems to include unilateral constraints on the configuration space. From such a system we obtain, explicitly, a simple hybrid system

  12. Are hybrid species more fit than ancestral parent species in the current hybrid species habitats?

    E-Print Network [OSTI]

    Rieseberg, Loren

    Are hybrid species more fit than ancestral parent species in the current hybrid species habitats? L Columbia, Vancouver, BC, Canada Introduction Hybridization is receiving renewed attention as an important). For homoploid hybridization in plants, where chromosome number remains the same, models and empirical evi- dence

  13. Hybrid Zones and Sexual Selection 503 HYBRID ZONES AND SEXUAL SELECTION: INSIGHTS FROM

    E-Print Network [OSTI]

    Hybrid Zones and Sexual Selection 503 HYBRID ZONES AND SEXUAL SELECTION: INSIGHTS FROM THE AWASH BABOON HYBRID ZONE (Papio hamadryas anubis x P. h. hamadryas) Thore J. Bergman and Jacinta C. Beehner, have focused on the impact of sexual selection on populations of naturally occurring hybrid animals

  14. Hybrid Routhian Reduction of Lagrangian Hybrid Systems Aaron D. Ames and Shankar Sastry

    E-Print Network [OSTI]

    Ames, Aaron

    Hybrid Routhian Reduction of Lagrangian Hybrid Systems Aaron D. Ames and Shankar Sastry Department,sastry}@eecs.berkeley.edu Abstract-- This paper extends Routhian reduction to a hybrid setting, i.e., to systems that display both with unilateral constraints on the set of admissible configurations. This naturally yields the notion of a hybrid

  15. Modeling and Analysis ofModeling and Analysis of Hybrid Control SystemsHybrid Control Systems

    E-Print Network [OSTI]

    Johansson, Karl Henrik

    Modeling and Analysis ofModeling and Analysis of Hybrid Control SystemsHybrid Control Systems Karl.kth.se/~kallej MOVEP 2006, Bordeaux, France Karl H. Johansson, Hybrid control systems, MOVEP, Bordeaux on commands and autonomous actions #12;Karl H. Johansson, Hybrid control systems, MOVEP, Bordeaux, 2006

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

    SciTech Connect (OSTI)

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

    2010-09-15

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

  17. Helping HAN for hybrid rockets

    SciTech Connect (OSTI)

    Ramohalli, K.; Dowler, W.

    1995-01-01

    Hydroxyl amine nitrate (HAN) is a powerful oxidizer for hybrid rocket flight motors. Miscible with water up to 95% by mass, it also has high density and has been extensively characterized for materials compatibility, safety, transportation, storage and handling. Before any serious attempt to use the proposed oxidizer in hybrids, though, the usual performance figures must first be obtained. The simplest are time-independent, equilibrium rocket performance numbers that include chamber temperature, temperature at the nozzle throat, and key species in the exhaust. These numbers must be followed by several other important performance evaluation, including burning rates, pressure dependence, susceptibility to instabilities and temperature sensitivity.

  18. Distributed Theorem Proving for Distributed Hybrid Systems

    E-Print Network [OSTI]

    Platzer, André

    system with a varying number of arbitrarily many cars. 1 Introduction Hybrid systems with joint discrete a multi-agent system, e.g., distributed car control systems. Such systems form distributed hybrid systemsDistributed Theorem Proving for Distributed Hybrid Systems David W. Renshaw, Sarah M. Loos

  19. Hybrid Signcryption Schemes With Outsider Security

    E-Print Network [OSTI]

    Dent, Alexander W.

    Hybrid Signcryption Schemes With Outsider Security (Extended Abstract) Alexander W. Dent.dent@rhul.ac.uk Abstract. This paper expands the notion of a KEM­DEM hybrid en- cryption scheme to the signcryption setting by introducing the notion of a signcryption KEM, a signcryption DEM and a hybrid signcryption scheme. We present

  20. Hybrid Ockhamist Temporal Logic Patrick Blackburn

    E-Print Network [OSTI]

    Goranko, Valentin

    Hybrid Ockhamist Temporal Logic Patrick Blackburn INRIA, Lorraine Campus Scientifique, BP 239 Nancy Johannesburg, South Africa vfg@na.rau.ac.za Abstract We introduce hybrid Ockhamist temporal logic, which combines the mechanisms of hybrid logic with Ockhamist semantics by employing nominals, satisfaction

  1. Hybrid Diverter Sheath Model Jeff Hammel

    E-Print Network [OSTI]

    Wurtele, Jonathan

    Hybrid Diverter Sheath Model Jeff Hammel Plasma Theory and Simulation Group APS ­ Division using a particle-fluid hybrid model. Electrons are modeled as an inertia-less (Boltzmann) fluid gyrokinetic code. The modeling methodology for the iterative nonlinear solver is presented. The hybrid model

  2. Hybrid Model Structures Aaron David Ames

    E-Print Network [OSTI]

    Ames, Aaron

    Hybrid Model Structures by Aaron David Ames B.A. (University of St. Thomas) 2001 B.S. (University of California, Berkeley Fall 2006 #12;Hybrid Model Structures Copyright 2006 by Aaron David Ames #12;Abstract Hybrid Model Structures by Aaron David Ames Masters of Arts in Mathematics University of California

  3. Hybrid organicinorganic materials for photonic applications

    E-Print Network [OSTI]

    Gilchrist, James F.

    Hybrid organic­inorganic materials for photonic applications Partha P. Banerjee,1,* Dean R. Evans,2 18015, USA *pbanerjee1@udayton.edu Abstract: This novel joint feature issue on "Hybrid organic that this feature issue encourages and stimulates further research to into hybrid materials with enhanced linear

  4. Hybrid organicinorganic materials for novel photonic applications

    E-Print Network [OSTI]

    Gilchrist, James F.

    Hybrid organic­inorganic materials for novel photonic applications Partha P. Banerjee,1, * Dean R. ID 192915); published 31 July 2013 This novel joint feature issue on "Hybrid organic that this feature issue encourages and stim- ulates further research into hybrid materials with enhanced linear

  5. Inflow Characterization and Aerodynamics Measurements on a SWT-2.3-101 Wind Turbine: Preprint

    SciTech Connect (OSTI)

    Medina, P.; Singh, M.; Johansen, J.; Jove, A.; Fingersh, L.; Schreck, S.

    2012-01-01

    Post processing techniques for aerodynamic data acquired from a Siemens SWT-2.3-101 turbine have been developed and applied in this paper. The turbine is installed at the National Wind Technology Center (NWTC) as part of Cooperative Research And Development Agreement between Siemens Wind Power and the National Renewable Energy Laboratory (NREL) under U.S. Department of Energy (DOE) sponsorship. The results indicate that the use of these corrections is essential for accurate analysis of the data. An example of local inflow angles, velocities, and inflow velocity over the rotor plane derived from measurements from a 5-hole probe is also presented. Finally the pressure measurements are used to characterize unsteady phenomenon, namely, rotational augmentation and dynamic stall on an inboard station. The results show that the rotational augmentation can considerably increase the attached flow regime compared to the 2D CFD results. The dynamic stall event was seen to significantly delay the stall. Furthermore, the nondimensionalized vortex convection derived from the dynamic stall event was found to agree well with results from others studies.

  6. ADVANCED HYBRID PARTICULATE COLLECTOR

    SciTech Connect (OSTI)

    Ye Zhuang; Stanley J. Miller; Michelle R. Olderbak; Rich Gebert

    2001-12-01

    A new concept in particulate control, called an advanced hybrid particulate collector (AHPC), is being developed under funding from the U.S. Department of Energy. The AHPC combines the best features of electrostatic precipitators (ESPs) and baghouses in an entirely novel manner. The AHPC concept combines fabric filtration and electrostatic precipitation in the same housing, providing major synergism between the two methods, both in the particulate collection step and in transfer of dust to the hopper. The AHPC provides ultrahigh collection efficiency, overcoming the problem of excessive fine-particle emissions with conventional ESPs, and solves the problem of reentrainment and re-collection of dust in conventional baghouses. Phase I of the development effort consisted of design, construction, and testing of a 5.7-m{sup 3}/min (200-acfm) working AHPC model. Results from both 8-hr parametric tests and 100-hr proof-of-concept tests with two different coals demonstrated excellent operability and greater than 99.99% fine-particle collection efficiency. Since all of the developmental goals of Phase I were met, the approach was scaled up in Phase II to a size of 255 m{sup 3}/min (9000 acfm) (equivalent in size to 2.5 MW) and was installed on a slipstream at the Big Stone Power Plant. For Phase II, the AHPC at Big Stone Power Plant was operated continuously from late July 1999 until mid-December 1999. The Phase II results were highly successful in that ultrahigh particle collection efficiency was achieved, pressure drop was well controlled, and system operability was excellent. For Phase III, the AHPC was modified into a more compact configuration, and components were installed that were closer to what would be used in a full-scale commercial design. The modified AHPC was operated from April to July 2000. While operational results were acceptable during this time, inspection of bags in the summer of 2000 revealed some membrane damage to the fabric that appeared to be caused by electrical effects. Subsequently, extensive theoretical, bench-scale, and pilot-scale investigations were completed to find an approach to prevent bag damage without compromising AHPC performance. Results showed that the best bag protection and AHPC performance were achieved by using a perforated plate installed between the discharge electrodes and bags. This perforated-plate design was then installed in the 2.5-MW AHPC at Big Stone Power Plant in Big Stone City, South Dakota, and the AHPC was operated from March to June 2001. Results showed that the perforated-plate design solved the bag damage problem and offered even better AHPC performance than the previous design. All of the AHPC performance goals were met, including ultrahigh collection efficiency, high air-to-cloth ratio, reasonable pressure drop, and long bag-cleaning interval.

  7. Models for asymmetric hybrid brane

    E-Print Network [OSTI]

    D. Bazeia; M. A. Marques; R. Menezes

    2015-10-15

    We deal with relativistic models described by a single real scalar field, searching for topological structures that behave asymmetrically, connecting minima with distinct profile. We use such features to build a new braneworld scenario, in which the source scalar field contributes to generate asymmetric hybrid brane.

  8. Hybrid mesons and auxiliary fields

    E-Print Network [OSTI]

    Fabien Buisseret; Vincent Mathieu

    2006-09-29

    Hybrid mesons are exotic mesons in which the color field is not in the ground state. Their understanding deserves interest from a theoretical point of view, because it is intimately related to nonperturbative aspects of QCD. Moreover, it seems that some recently detected particles, such as the $\\pi_1(1600)$ and the Y(4260), are serious hybrid candidates. In this work, we investigate the description of such exotic hadrons by applying the auxiliary fields technique to the widely used spinless Salpeter Hamiltonian with appropriate linear confinement. Instead of the usual numerical resolution, this technique allows to find simplified analytical mass spectra and wave functions of the Hamiltonian, which still lead to reliable qualitative predictions. We analyse and compare two different descriptions of hybrid mesons, namely a two-body $q\\bar q$ system with an excited flux tube, or a three-body $q\\bar q g$ system. We also compute the masses of the $1^{-+}$ hybrids. Our results are shown to be in satisfactory agreement with lattice QCD and other effective models.

  9. DOE Laminar Final Report

    Office of Scientific and Technical Information (OSTI)

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantity of NaturalDukeWakefield MunicipalTechnical Report:Speeding accessby a contractorEnergy,DEC03t933 OSTlandFinal Technical

  10. Hybrid chirped pulse amplification system

    DOE Patents [OSTI]

    Barty, Christopher P.; Jovanovic, Igor

    2005-03-29

    A hybrid chirped pulse amplification system wherein a short-pulse oscillator generates an oscillator pulse. The oscillator pulse is stretched to produce a stretched oscillator seed pulse. A pump laser generates a pump laser pulse. The stretched oscillator seed pulse and the pump laser pulse are directed into an optical parametric amplifier producing an optical parametric amplifier output amplified signal pulse and an optical parametric amplifier output unconverted pump pulse. The optical parametric amplifier output amplified signal pulse and the optical parametric amplifier output laser pulse are directed into a laser amplifier producing a laser amplifier output pulse. The laser amplifier output pulse is compressed to produce a recompressed hybrid chirped pulse amplification pulse.

  11. Hybrid Inflation Exit through Tunneling

    E-Print Network [OSTI]

    Bjorn Garbrecht; Thomas Konstandin

    2006-10-24

    For hybrid inflationary potentials, we derive the tunneling rate from field configurations along the flat direction towards the waterfall regime. This process competes with the classically rolling evolution of the scalar fields and needs to be strongly subdominant for phenomenologically viable models. Tunneling may exclude models with a mass scale below 10^12 GeV, but can be suppressed by small values of the coupling constants. We find that tunneling is negligible for those models, which do not require fine tuning in order to cancel radiative corrections, in particular for GUT-scale SUSY inflation. In contrast, electroweak scale hybrid inflation is not viable, unless the inflaton-waterfall field coupling is smaller than approximately 10^-11.

  12. Hybrid quantum repeater with encoding

    E-Print Network [OSTI]

    Nadja K. Bernardes; Peter van Loock

    2012-11-02

    We present an encoded hybrid quantum repeater scheme using qubit-repetition and Calderbank-Shor-Steane codes. For the case of repetition codes, we propose an explicit implementation of the quantum error-correction protocol. Moreover, we analyze the entangled-pair distribution rate for the hybrid quantum repeater with encoding and we clearly identify a triple trade-off between the efficiency of the codes, the memory decoherence time, and the local gate errors. Finally, we show that in the presence of reasonable imperfections our system can achieve rates of roughly 24 Hz per memory for 20 km repeater spacing, a final distance of 1280 km, and a final fidelity of about 0.95.

  13. Planar slot coupled microwave hybrid

    DOE Patents [OSTI]

    Petter, Jeffrey K. (Williston, VT)

    1991-01-01

    A symmetrical 180.degree. microwave hybrid is constructed by opening a slot line in a ground plane below a conducting strip disposed on a dielectric substrate, creating a slot coupled conductor. Difference signals propagating on the slot coupled conductor are isolated on the slot line leaving sum signals to propagate on the microstrip. The difference signal is coupled from the slot line onto a second microstrip line for transmission to a desired location. The microstrip branches in a symmetrical fashion to provide the input/output ports of the 180.degree. hybrid. The symmetry of the device provides for balance and isolation between sum and difference signals, and provides an advantageous balance between the power handling capabilities and the bandwidth of the device.

  14. Hybrid metric-Palatini gravity

    E-Print Network [OSTI]

    Capozziello, Salvatore; Koivisto, Tomi S; Lobo, Francisco S N; Olmo, Gonzalo J

    2015-01-01

    Recently, the phenomenology of f(R) gravity has been scrutinized motivated by the possibility to account for the self-accelerated cosmic expansion without invoking dark energy sources. Besides, this kind of modified gravity is capable of addressing the dynamics of several self-gravitating systems alternatively to the presence of dark matter. It has been established that both metric and Palatini versions of these theories have interesting features but also manifest severe and different downsides. A hybrid combination of theories, containing elements from both these two formalisms, turns out to be also very successful accounting for the observed phenomenology and is able to avoid some drawbacks of the original approaches. This article reviews the formulation of this hybrid metric-Palatini approach and its main achievements in passing the local tests and in applications to astrophysical and cosmological scenarios, where it provides a unified approach to the problems of dark energy and dark matter.

  15. Superheat Control: A Hybrid Approach 

    E-Print Network [OSTI]

    Elliot, M.S.; Rasmussen, B.P.; Walton, Z.; Bolding, B.

    2009-01-01

    , poorly tuned EEVs can still exhibit undesirable behavior, and frequent valve adjustments raise concerns about device longevity. In this work, we propose a cascaded control approach, which regulates evapo- rator pressure and superheat and is achieved... with a feedback control device that uses a hybrid of mechanical and electronic feedback. Analysis of the fundamental dynamic behavior of evapo- rator superheat motivates this approach, while experimental evaluation of two separate systems demonstrates...

  16. Moisture absorption in hybrid composites 

    E-Print Network [OSTI]

    Clark, Dan Laro

    1983-01-01

    Moisture Analysis for Steady State Boundary Conditions", Journal of Com osite Materials, Vol. 15, March 1981, pp. 142-152. 7. Weitsman, Y. , Priorate Communication, Texas A&M University, January 1983. 8. Wirth, Patricia E. and Rodin, Ervin Y. , "A... of Department) December 1983 111. ABSTRACT Moisture Absorption in Hybrid Composites (December 1983) Dan Laro Clark, B. S. Aerospace Engineering Texas A&M University Co-Chairmen of Advisory Comnittee: Dr. Y. Weitsman Dr. W. J. Horn This thesis presents...

  17. Compositional Variation Within Hybrid Nanostructures

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

    AFDC Printable Version Share this resource Send a link to EERE: Alternative Fuels Data Center Home Page to someone by E-mail Share EERE: Alternative Fuels Data Center Home Page on Facebook Tweet about EERE: Alternative Fuels Data Center Home Page on Twitter Bookmark EERE: Alternative Fuels Data Center Homesum_a_epg0_fpd_mmcf_m.xls" ,"Available from WebQuantityBonneville Power Administration would like submit the following commentsMethodsCompositional Variation Within Hybrid

  18. September 2002 Working Group Meeting on Heavy Vehicle Aerodynamic Drag: Presentations and Summary of Comments and Conclusions

    SciTech Connect (OSTI)

    McCallen, R

    2002-09-01

    A Working Group Meeting on Heavy Vehicle Aerodynamic Drag was held at NASA Ames Research Center on September 23, 2002. The purpose of the meeting was to present and discuss technical details on the experimental and computational work in progress and future project plans. Representatives from the Department of Energy (DOE)/Office of Energy Efficiency and Renewable Energy/Office of FreedomCAR & Vehicle Technologies, Lawrence Livermore National Laboratory (LLNL), Sandia National Laboratories (SNL), NASA Ames Research Center (NASA), University of Southern California (USC), California Institute of Technology (Caltech), Georgia Tech Research Institute (GTRI), Argonne National Laboratory (ANL), Freightliner, and Portland State University participated in the meeting. This report contains the technical presentations (viewgraphs) delivered at the Meeting, briefly summarizes the comments and conclusions, and outlines the future action items. The meeting began with an introduction by the Project Lead Rose McCallen of LLNL, where she emphasized that the world energy consumption is predicted to relatively soon exceed the available resources (i.e., fossil, hydro, non-breeder fission). This short fall is predicted to begin around the year 2050. Minimizing vehicle aerodynamic drag will significantly reduce our Nation's dependence on foreign oil resources and help with our world-wide fuel shortage. Rose also mentioned that educating the populace and researchers as to our world energy issues is important and that our upcoming United Engineering Foundation (UEF) Conference on ''The Aerodynamics of Heavy Vehicles: Trucks, Busses, and Trains'' was one way our DOE Consortium was doing this. Mentioned were the efforts of Fred Browand from USC in organizing and attracting internationally recognized speakers to the Conference. Rose followed with an overview of the DOE project goals, deliverables, and FY03 activities. The viewgraphs are attached at the end of this report. Sid Diamond of DOE discussed the reorganization of the Office of Energy Efficiency and Renewable Energy and that the Office of Heavy Vehicle Technology is now part of the Office of FreedomCAR & Vehicle Technologies. Sid reviewed the FY03 budget and provided information on some plans for FY04. The soon to be posted DOE request for proposals from industry for projects related to parasitic energy losses was discussed. A minimum of 50% cost share by industry will be required and the proposal must be submitted by industry. Collaborative efforts in aerodynamic drag with members of the DOE consortium are encouraged. Sid also mentioned interest in aerodynamic drag contribution due to wheel wells and underbody flow. Sid also mentioned his continued interest in the application of our computational and experimental expertise to the area of locomotive and railcar aerodynamics for the reduction of drag effects and thus, the reduction of fuel consumption by trains. In summary, the technical presentations at the meeting included a review of experimental results and plans by GTRI, USC, and NASA Ames, the computational results from LLNL and SNL for the integrated tractor-trailer benchmark geometry called the Ground Transportation System (GTS) model, and by LLNL for the tractor-trailer gap and trailer wake flow, and turbulence model development and benchmark simulations being investigated by Caltech. USC is also investigating an acoustic drag reduction device that has been named ''Mozart'', GTRI continues their investigation of a blowing device, and LLNL presented their ideas for 2 new base drag reduction devices. ANL presented their plans for a DOE supported Cooperative Research and Development Agreement (CRADA) with Paccar Truck Company utilizing commercial software tools to simulate the flow and drag for an actual tractor and showed the results of some preliminary griding attempts. The attendees also had the opportunity to tour the 12-ft pressure wind tunnel the machine shop were the Generic Conventional Model (GCM, a.k.a. SLRT) was being readied for the scheduled November experiments. Much of

  19. Hybrid and Plug-in Electric Vehicles

    SciTech Connect (OSTI)

    2014-05-20

    Hybrid and plug-in electric vehicles use electricity either as their primary fuel or to improve the efficiency of conventional vehicle designs. This new generation of vehicles, often called electric drive vehicles, can be divided into three categories: hybrid electric vehicles (HEVs), plug-in hybrid electric vehicles(PHEVs), and all-electric vehicles (EVs). Together, they have great potential to reduce U.S. petroleum use.

  20. Hybrid States from Constituent Glue Model

    E-Print Network [OSTI]

    F. Iddir; L. Semlala

    2007-12-11

    The hybrid meson is one of the most interesting new hadron specie beyond the naive quark model. It acquire a great attention both from the theoretical and experimental efforts. Many good candidates have been claimed to be observed, but there is no absolute confirmation about existence of hybrid mesons. In the present work we propose new calculations of the masses and decay widths of the hybrid mesons in the context of constituent gluon model.