| Phase Transformations in the Oxygen-Enriched Case Layer of Beta Titanium Alloys Formed During Oxidation (Preprint) |
Aug 2012 |
16 pages |
| Authors:
J Tiley; A Behera; K Mahdak; H Mohseni; S Nag; R Banerjee; UNIVERSITY OF NORTH TEXAS DENTON
|
 | The formation of an oxide layer along together with alpha precipitation in the subsurface oxygenenriched zone, during the oxidation of a Beta-Ti alloy, has been investigated using SEM, (S)TEM, and nanoindentation. Just below the nanocrystalline oxide layer, a two-phase mixture consisting of nanoscale equiaxed alpha grains and rutile grains is formed. Further below, the morphology of the alpha precipitates transitions to more lath-like with their size-scale, nucleation density, and the ... |
|
| Shock Equation of State of Multi-Constituent Epoxy-Metal Particulate Composites |
May 2012 |
15 pages |
| Authors:
Jennifer L Jordan; Eric B Herbold; Gerrit Sutherland; Andrew Frazer; John Borg; D W Richards; AIR FORCE RESEARCH LAB EGLIN AFB FL MUNITIONS DIRECTORATE
|
| The shock properties of epoxy-based particulate composites have been extensively studied in the literature. Generally, these materials only have a single particulate phase; typically alumina. This paper presents equation of state experiments conducted on five epoxy-based particulate composites. The shock stress and shock velocity states were measured for five different composites: two epoxy-aluminum two-phase composites, with various amounts of aluminum, and three epoxy-aluminummetal composites, where the metal constituent was either ... |
|
| Oxidation Resistance, Electrical and Thermal Conductivity, and Spectral Emittance of Fully Dense HfB2 and ZrB2 with SiC, TaSi2, and LaB6 Additives |
26 Jan 2012 |
100 pages |
| Authors:
Robert F Speyer; GEORGIA INST OF TECH ATLANTA SCHOOL OF MATERIALS SCIENCE AND MECHANICAL ENGINEERING
|
| The oxidation resistances of ZrB2 containing SiC, TaB2, and TaSi2 additions of various concentrations were studied using isothermal thermogravimetry at 1200, 1400, and 1500 deg C. Theoretically-dense ZrB2-SiC two-phase microstructures were isothermally oxidized for 90 min in a thermogravimetric analyzer in flowing air in the range 1500-1900 deg C. The oxidation resistances of theoretically-dense HfB2-SiC test specimens were evaluated via isothermal thermogravimetry at 1600, 1700 and 1800 deg C. The ... |
|
| Optimal Control of Shock Wave Attenuation in Single- and Two-Phase Flow with Application to Ignition Overpressure in Launch Vehicles |
Dec 2011 |
143 pages |
| Authors:
Nathan D Moshman; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| NASA and private launch providers have a need to understand and control ignition overpressure blast waves that are generated by a solid grain rocket during ignition. Research in accurate computational fluid dynamics prediction of the launch environment is underway. A clearer picture is emerging from empirical data which more precisely categorizes all the dissipative mechanisms present in droplet-shock interactions. In this dissertation, water droplets and their effects due to vaporization ... |
|
| Physics-Based Modeling and Measurement of High-Flux Condensation Heat Transfer |
Sep 2011 |
109 pages |
| Authors:
Issam Mudawar; Sung-Min Kim; Joseph Kim; PURDUE UNIV LAFAYETTE IN
|
| This report examines condensation of FC-72 along parallel, square micro-channels with a hydraulic diameter of 1 mm and a length of 29.9 cm, which are formed in the top surface of a solid copper plate. Using high-speed video imaging and photomicrographic techniques, five distinct flow regimes are identified: smooth-annular, wavy-annular, transition, slug, and bubbly, with the smooth-annular and wavy-annular regimes being most prevalent. A theoretical control-volume-based model is proposed based ... |
|
| CROSSTEX - Wave Breaking, Boundary Layer Processes, the Resulting Sediment Transport and Beach Profile Evolution |
04-Nov-2009 |
|
| Authors:
John Trowbridge; Tian-Jian Hsu; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF APPLIED OCEAN PHYSICS AND ENGINEERING
|
 | The proposal for this project was submitted from WHOI to ONR by Tom Hsu under John Trowbridge's sponsorship while Hsu was a post-doc at WHOI. WHOI continued to administer the project when Tom Hsu left WHOI, but virtually all of the work was done by Hsu, and virtually all of the funding was spent by Hsu in his new positions at the Universities of Florida and Delaware. Hsu's October 2009 ... |
|
| Progress Toward a Multidimensional Representation of the 5.56-mm Interior Ballistics |
Aug-2009 |
34 pages |
| Authors:
John R Schmidt; Michael J Nusca; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| There is significant experimental evidence that burning particles of various chemical compositions and sizes are ejected from gun primers and that these particles interact with the propellant grains during main charge ignition. This explicit ignition phenomenon is thought to be incompatible with the implicit treatment of primer function used in conventional interior ballistics codes and models. Generally, the primer efflux is treated as a hot gas that evolves from a ... |
|
| Equipment for Naval Hydrodynamic Studies |
13-Jul-2009 |
6 pages |
| Authors:
Eric Terrill; W K Melville; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
|
| Due to difficulties and uncertainties in accurately representing the bubbly flow around a ship in a laboratory facility, there is a need for full-scale (or near full-scale) measurements of bubbly flows generated around surface ships. These needs are parallel to components of ONR's ship hydromechnics program (Free-Surface Phenomena and Two-Phase Flows) which ...seeks to understand the physical mechanisms underlying interactions of two-phase water flow around ships and in their wakes ... |
|
| Progress Toward a Multidimensional Representation of Mortar Interior Ballistics |
Jun-2009 |
38 pages |
| Authors:
John R Schmidt; Michael J Nusca; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Lumped-parameter interior ballistics (IB) codes have had limited success in simulating the IB of mortars due to the complex nature of the firing event. Only near the end of the firing event does the mortar conform to the conventional ballistics model for which lumped-parameter codes were designed. Modified lumped-parameter models are capable of simulating some key mortar variables. There are significant pressure waves developed in mortars, which are due in ... |
|
| Mortar Interior Ballistics: Sensitivity Studies Using IBHVG2 and Progress Toward a Multidimensional Representation |
Jun-2009 |
38 pages |
| Authors:
John R Schmidt; Michael J Nusca; Albert W Horst; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| Traditionally, the interior ballistic (IB) modeling of mortars has been difficult to achieve because a mortar projectile contains certain energetic components internal to the tail boom. After ignition, high pressure generated by the igniter causes the canister to burst and release hot gases and burning particles into the larger chamber called the launch tube. Subsequently, any external charges ignite and produce gases which accelerate the projectile. A recent advancement to ... |
|
| Characterization of Convective Boiling in Branching Channel Heat Sinks |
06-May-2009 |
17 pages |
| Authors:
Deborah V Pence; James A Liburdy; Vinod Narayanan; OREGON STATE UNIV CORVALLIS
|
| Convective boiling and gas-liquid flows in branching microscale flow networks within disk-shaped heat sinks were studied experimentally. Void fraction and flow regime variations as a function of branch level were reported for gas-liquid flows and compared with existing void fraction correlations and regime maps, respectively. Two methods for assessing void fraction were used, with void fraction assessed using two-dimensional high-speed images providing the best assessment. Void fraction in convective boiling ... |
|
| Combat Support Execution Planning and Control. An Assessment of Initial Implementations in Air Force Exercises |
Jan-2009 |
|
| Authors:
Kristin F Lynch; William A Williams; RAND CORP SANTA MONICA CA
|
| In response to the CSC2 issues discovered during operations in Serbia in 1999, the Deputy Chief of Staff for Installations and Logistics (AF/IL) asked RAND PAF to study the current (AS-IS) operational architecture and develop a future (TO-BE) CSC2 operational architecture (Leftwich et al., 2002). PAF researchers documented current processes, identified areas in need of change, and developed processes for a well-defined, closed-loop TO-BE CSC2 operational architecture that incorporated the ... |
|
| Two-Phase Flow in High-Heat-Flux Micro-Channel Heat Sink for Refrigeration Cooling Applications. Part 1: Micro-Channel Heat Sink for Direct Refrigeration Cooling |
01-Sep-2008 |
340 pages |
| Authors:
Issam Mudawar; Jaeseon Lee; Myung Ki Sung; PURDUE UNIV LAFAYETTE IN SCHOOL OF MECHANICAL ENGINEERING
|
| This report examines the pressure drop and heat transfer characteristics of two-phase micro-channel heat sinks. New models and correlations are proposed for both saturated and subcooled boiling conditions. These tools are shown to provide accurate predictions of pressure drop, two-phase heat transfer coefficient and critical heat flux. Also discussed in this report is a new hybrid cooling system that combines the cooling attributes of micro-channel flow and jet impingement. It ... |
|
| Two-Phase Flow in High-Heat-Flux Micro-Channel Heat Sink for Refrigeration Cooling Applications. Part 2: Low Temperature Hybrid Micro-Channel/Micro-Jet Impingement Cooling |
01-Sep-2008 |
172 pages |
| Authors:
Issam Mudawar; Jaeseon Lee; Myung Ki Sung; PURDUE UNIV LAFAYETTE IN SCHOOL OF MECHANICAL ENGINEERING
|
| This report examines the pressure drop and heat transfer characteristics of two-phase micro-channel heat sinks. New models and correlations are proposed for both saturated and subcooled boiling conditions. These tools are shown to provide accurate predictions of pressure drop, two-phase heat transfer coefficient and critical heat flux. Also discussed in this report is a new hybrid cooling system that combines the cooling attributes of micro-channel flow and jet impingement. It ... |
|
| Investigation of Small-Caliber Primer Function Using a Multiphase Computational Model |
01-Jul-2008 |
36 pages |
| Authors:
John R Schmidt; Michael J Nusca; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD WEAPONS AND MATERIALS RESEARCH DIRECTORATE
|
| This report describes further development in the formulation of a primer model that is compatible with the ARL-NGEN3 code and small caliber weapons that takes in account multidimensional, multiphase interior ballistics codes, which employ coupled Eulerian-Lagrangian schemes to explicitly treat both the gas and solid phase. The model is based on the One Dimensional Turbulence modeling approach that has recently emerged as a powerful tool in multiphase simulations. Initial results ... |
|
| Implementation of Discontinuous Galerkin Methods for the Level Set Equation on Unstructured Meshes |
01-Jan-2008 |
15 pages |
| Authors:
Matthew W Farthing; Christopher E Kees; ENGINEER RESEARCH AND DEVELOPMENT CENTER VICKSBURG MS INFORMATION TECHNOLOGY LAB
|
| Level set methods are often used to capture interface behavior in two-phase, incompressible flow models. While level set techniques for structured computational grids have been widely investigated, approaches for unstructured meshes are less mature. This report details the formulation and implementation of a discontinuous Galerkin-based approach that is suitable for unstructured meshes and offers potential gains in accuracy and efficiency over more traditional level set techniques. |
|
| Computational Simulation of High-Speed Projectiles in Air, Water, and Sand |
03 DEC 2007 |
34 pages |
| Authors:
Jack R. Edwards; NORTH CAROLINA STATE UNIV AT RALEIGH
|
| The development of a comprehensive computational fluid dynamics approach for conducting simulations of projectile penetration into water-saturated sand is reported. High resolution upwind schemes suitable for a fluid dynamic system consisting of gas, liquid, and dispersed solids phases are derived and are combined with a time-derivative preconditioning strategy for efficient time integration at all flow speeds. A solids-stress model based on Mohr-Coulomb critical-state theory is used to account for compaction ... |
|
| Fractional Factorial Controlled Sequential Bifurcation: Efficient Factor Screening Through Divide and Discard |
DEC 2007 |
112 pages |
| Authors:
Regine P. Oh; NAVAL POSTGRADUATE SCHOOL CENTER FOR DEFENSE TECHNOLOGY AND EDUCATION FOR THE MILITARY SERVICES MONTEREY CA
|
| On any given day, organizations use software simulations to make better decisions. Software simulations of real world systems are often large and rich with many parameters potentially affecting outcomes. Faced with a multitude of parameters, decision makers may not know or may lose sight of the few truly critical factors. Thus, screening algorithms are essential in order to identify the factors that most impact outcome measures. This enables experimenters to ... |
|
| Numerical Prediction of UV Radiation from Two-Phase Plumes at High Altitudes (Preprint) |
27 AUG 2007 |
23 pages |
| Authors:
Natalia E. Gimelshein; Robert B. Lyons; James G. Reuster; Sergey F. Gimelshein; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| A multi-step continuum-kinetic approach is used to model a steady state plume flow from a Star 27 motor at an altitude of 188 km. Two-way coupled Navier-Stokes equations and the DSMC method are used to predict the interaction between plume and atmospheric gases and micron-sized alumina particles from the thruster. A Monte Carlo radiation code that accounts for photon scattering on particles is used to calculate UV radiation based on ... |
|
| Constitutive Modelling of the Shock Behaviour of a Highly Porous Material |
JUL 2007 |
|
| Authors:
A. D. Resnyansky; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION EDINBURGH (AUSTRALIA) WEAPONS SYSTEMS DIV
|
| The report studies the constitutive behaviour of highly porous materials. This study is driven by efforts for the development and validation of a multi-phase modelling capability in DSTO, which aims at an enhanced evaluation of blast mitigation by porous materials. A two-phase model is employed for the description of a porous material, for which experimental shock velocity data are widely available in literature. The method deriving Hugoniots from the shock ... |
|
| Plume Simulation, Contamination, and Microfluidics (Preprint) |
SEP 2006 |
12 pages |
| Authors:
Andrew Ketsdever; Ingrid Wysong; Sergey Gimelshein; Alina Alexeenko; Marc Young; Natalia Gimselshein; Taylor Lilley; Cedric Ngalande; AIR FORCE RESEARCH LAB EDWARDS AFB CA SPACE AND MISSILE PROPULSION DIV
|
| This research project pursues basic understanding of rarefied gas flows, leading to Air Force tools for plumes, spacecraft, and micro-devices. It develops, applies, and validates kinetic and molecular-level models of improved physical realism for nonequilibrium processes such as collisional interaction of gases, gas-particulate mixtures, and gas surface interaction that arise in high temperature, multi-species, chemically reacting rarefied flowfields such as rocket plumes. These phenomena are not accurately addressed by standard ... |
|
| Study of Properties of the Microwave Streamer Discharge in a High-Speed Flow of Gas and in Two-Phase Medium |
01 AUG 2006 |
102 pages |
| Authors:
Kirill V. Khodataev; FEDERAL STATE UNITARY FIRM MOSCOW RADIO-TECHNICAL INST (RUSSIA)
|
| This report results from a contract tasking Federal State Unitary Firm 'MRTI' of RAS as follows: The contractor will investigate the use of undercritical streamer microwave discharges for ignition of fuel-air mixtures. The system of microwave radiation initiated spark filaments can uniformly fill a volume with streamers of several thousand degrees Kelvin. Thus, quick ignition of fuel-air mixtures over the whole cross-section of the discharge is anticipated. Experimental and theoretical ... |
|
| Meso and Micro Scale Propulsion Concepts for Small Spacecraft |
28 JUL 2006 |
28 pages |
| Authors:
R. A. Yetter; V. Yang; I. A. Aksay; F. L. Dryer; PENNSYLVANIA STATE UNIV UNIVERSITY PARK DEPT OF MECHANICAL AND NUCLEAR ENGINEERING
|
| Combustion of liquid nitromethane and RK315A was experimentally studied in a meso-scale combustor with a volume of 108 cubic mm and diameter of 5 mm. The meso-scale combustor utilized a vortex combustion concept, which has been demonstrated to be useful for stabilizing combustion of gaseous hydrocarbon air mixtures in small volumes. The monopropellants were injected tangentially from the backend of the cylindrical combustor and the combustion products exited the chamber ... |
|
| Advanced Hybrid Cooling Loop Technology for High Performance Thermal Management |
Jun-2006 |
9 pages |
| Authors:
Chanwoo Park; Aparna Vallury; Jeffrey Perez; ARMY TANK-AUTOMOTIVE RESEARCH AND DEVELOPMENT COMMAND WARREN MI
|
| Advanced hybrid cooling loop technology has been developed for the high performance cooling systems for such as U.S. Army next generation vehicles, Future Combat System (FCS) and Directed Energy Weapons (DEW), high power Solid State Laser Systems. The hybrid cooling loop combines the active liquid pumping with the passive capillary liquid management in the sintered wick structure of the evaporator and its liquid/vapor separation. The prototype hybrid cooling loop using ... |
|
| A Thermodynamically Complete Model for One-Dimensional Two-Phase Flows With Heat Exchange |
MAY 2006 |
|
| Authors:
A. D. Resnyansky; DEFENCE SCIENCE AND TECHNOLOGY ORGANISATION EDINBURGH (AUSTRALIA)
|
| This publication reports on a compact presentation of a one-dimensional model for the description of two-phase flows with heat exchange. This model was proposed earlier in the form of a system of equations, containing the heat conduction and entropy conservation equations for each phase. In this report the system is formulated in a form that is consistent with the formulation of the preceding report of the author. The present system ... |
|
| On Boundary Condition Capturing for Multiphase Interfaces |
31 MAR 2006 |
26 pages |
| Authors:
Jeong-Mo Hong; Tamar Shinar; Myungjoo Kang; Ronald Fedkiw; STANFORD UNIV CA DEPT OF COMPUTER SCIENCE
|
| This paper begins with an overview of the boundary condition capturing approach to solving problems with interfaces. Although, the authors' original motivation was to extend the ghost fluid method from compressible to incompressible flow, the elliptic nature of incompressible flow quickly quenched the idea that ghost cells could be defined and used in the usual manner. Instead the boundary conditions had to be implicitly captured by the matrix formulation itself, ... |
|
| Atomization of Wall-Bounded Two-Phase Flows (PREPRINT) |
08 MAR 2006 |
15 pages |
| Authors:
Malissa D. Lightfoot; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| The current understanding of droplet generation processes from liquid films is reviewed. Films are defined as liquids with one free and one wall-bound surface. In many of the systems where films occur, atomization is an undesirable side-effect of the two-phase flow. The motivation for this study, however, is a process where atomization from the film is the goal--a gas-centered swirl coaxial rocket injector. Because atomization is often unwanted in film ... |
|
| Parameterization of a Two-Phase Sheet Flow Model and Application to Nearshore Morphology |
NOV 2005 |
5 pages |
| Authors:
Steve Elgar; Tian-Jian Hsu; Daniel M. Hanes; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF APPLIED OCEAN PHYSICS AND ENGINEERING
|
| The overall objective is to develop and test with laboratory and field observations a model that predicts sediment transport and morphological change in the nearshore for a range of wave conditions and sediment characteristics. The specific objectives of this project were to: 1. parameterize the wave-induced bottom stress and sediment transport rate using a two-phase sheet flow model, 2. couple the sediment transport model with a time-domain Boussinesq hydrodynamic model ... |
|
| Atomization Mechanism of Wall-Bounded Two-Phase Flows |
19 OCT 2005 |
14 pages |
| Authors:
M. D. Lightfoot; AIR FORCE RESEARCH LAB EDWARDS AFB CA PROPULSION DIRECTORATE
|
| The current understanding of droplet generation processes from liquid films is reviewed. Films are defined as liquids with one free and one wall-bound surface. In many of the systems where films occur, atomization is an undesirable side-effect of the two-phase flow. The motivation for this study, however, is a process where atomization from the film is the goal -- a gas-centered swirl coaxial rocket injector. Because atomization is often unwanted ... |
|
| Calibration of Smart Weapon Motion Sensors for High-Speed Manufacturing Lines |
SEP 2005 |
32 pages |
| Authors:
Delvin Peterson; Mark Costello; OREGON STATE UNIV CORVALLIS
|
| Accelerometers and gyroscopes are used in many smart weapon sensor suites. If dominant sensor error sources such as misposition. bias. cross axis sensitivity, and scale factor can be quickly and efficiently identified and loaded onto the sensor suites, quality feedback can be achieved at significant cost savings. The work reported here describes a relatively simple sensor calibration device suitable for a high volume production line environment. It consists of a ... |
|
| Spatially Adaptive Techniques for Level Set Methods and Incompressible Flow |
03 MAY 2005 |
42 pages |
| Authors:
Frank Losasso; Ronald Fedkiw; Stanley Osher; STANFORD UNIV CA DEPT OF COMPUTER SCIENCE
|
| Since the seminal work of [92] on coupling the level set method of [69] to the equations for two-phase incompressible flow, there has been a great deal of interest in this area. That work demonstrated the most powerful aspects of the level set method, i.e. automatic handling of topological changes such as merging and pinching, as well as robust geometric information such as normals and curvature. Interestingly, this work also ... |
|
| Advanced Solver Methods for Subsurface Environmental Problems |
2005 |
35 pages |
| Authors:
Hector Klie; Mary F. Wheeler; TEXAS UNIV AT AUSTIN DEPT OF MATHEMATICS AND INST OF COMPUTATIONAL ENGINEERING AND SCIENCES
|
| The present report outlines recent results relative to the development of new linear and nonlinear approaches for solving groundwater flow problems. Efficient and robust simulation of complex processes in environmental applications is crucial for understanding, forecasting and performing opportune and reliable decisions. This research effort focuses on developing efficient solvers for two main models in groundwater flow: Richards' equation and air-water coupled equation systems. To achieve this goal, two main ... |
|
| Static and Dynamic Strength of Scarf-Repaired Thick-Section Composite Plates |
SEP 2004 |
38 pages |
| Authors:
Bazle A. Gama; Stephane Mahdi; Curt Cichanowski; Shridhar Yarlagadda; John W. Gillespie Jr; DELAWARE UNIV NEWARK CENTER FOR COMPOSITE MATERIALS
|
| One of the many challenges facing weapon developers is the requirement for a highly lethal, lightweight, and compact large caliber gun system. One concept recently investigated by the U.S. Army is that of a swing- chamber gun, necessitating the use of telescoped ammunition. Such ammunition not only reduces the volume available for the propellant change, but also places severe geometric constraints on both the distribution of the propellant and the ... |
|
| Multidimensional, Two-Phase Simulations of Notional Telescoped Ammunition Propelling Charge |
SEP 2004 |
24 pages |
| Authors:
Michael J. Nusca; Albert W. Horst; James F. Newill; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| One of the many challenges facing weapon developers is the requirement for a highly lethal, lightweight, and compact large caliber gun system. One concept recently investigated by the U.S. Army is that of a swing- chamber gun, necessitating the use of telescoped ammunition. Such ammunition not only reduces the volume available for the propellant change, but also places severe geometric constraints on both the distribution of the propellant and the ... |
|
| Status of Advanced Boundary Layer Code Development for SRM Nozzle Ablation Including Two Phase Flow Effects |
AUG 2004 |
23 pages |
| Authors:
Brian Mclaughlin; Derek Gonzalez; Kent Hennessey; Mark Eagar; Al Murray; AEROJET SACRAMENTO CA
|
| Briefing charts overview of the Integrated High Payoff Rocket Propulsion Technology(IHPRPT) Phase III Solid Rocket Motor Modeling Program. |
|
| A Cartesian Adaptive Level Set Method for Two-Phase Flows |
24 MAR 2004 |
11 pages |
| Authors:
F. Ham; Y. N. Young; STANFORD UNIV CA
|
| Simulations of flows involving free surfaces have become ubiquitous in the literature. The evolution of both simulation methods and computer speed have allowed the investigation of many problems of increasing complexity and engineering relevance. For 2D simulations, it is reasonably common to use grid resolutions of 512 x 512 or larger. See for example the 2D planar breaking wave simulations of Chen et al. (1999), or the axisymmetric drop breakup ... |
|
| "Hypothetical" Heavy Particles Dynamics in LES of Turbulent Dispersed Two-Phase Channel Flow |
24 MAR 2004 |
7 pages |
| Authors:
M. Gorokhovski; A. Chtab; ROUEN UNIV MONT SAINT AIGNON (FRANCE)
|
| The extensive experimental study of dispersed two-phase turbulent flow in a vertical channel has been performed in Eaton's research group in the Mechanical Engineering Department at Stanford University (see Kulick et al. (1994) and Fessler et al (1994)). In Wang & Squires (1996), this study motivated the validation of LES approach with Lagrangian tracking of round particles governed by drag forces. While the computed velocity of the flow have been ... |
|
| Modeling Primary Breakup: A Three-Dimensional Eulerian Level Set/Vortex Sheet Method for Two-Phase Interface Dynamics |
24 MAR 2004 |
12 pages |
| Authors:
M. Herrmann; GERMAN RESEARCH FOUNDATION (DFG) BONN (GERMANY)
|
| Atomization processes play an important role in a wide variety of technical applications and natural phenomena, ranging from inkjet printers, gas turbines, direct injection IC- engines, and cryogenic rocket engines to ocean wave breaking and hydrothermal features. The atomization process of liquid jets and sheets is usually divided into two consecutive steps: the primary and the secondary breakup. During primary breakup, the liquid jet or sheet exhibits large scale coherent ... |
|
| A Eulerlan-Lagrangian Model to Simulate Two-Phase/Particulate Flows |
24 MAR 2004 |
11 pages |
| Authors:
S. V. Apte; K. Mahesh; T. Lundgren; MINNESOTA UNIV MINNEAPOLIS
|
| Figure 1 shows a snapshot of liquid fuel spray coming out of an injector nozzle in a realistic gas-turbine combustor. Here the spray atomization was simulated using a stochastic secondary breakup model (Apte et al. 2003a) with point-particle approximation for the droplets. Very close to the injector, it is observed that the spray density is large and the droplets cannot be treated as point-particles. The volume displaced by the liquid ... |
|
| Quantitative High Resolution Electron Scattering From Polymers |
05 JAN 2004 |
6 pages |
| Authors:
Matthew R. Libera; STEVENS INST OF TECH HOBOKEN NJ
|
| This project developed and applied quantitative methods to determine the structure of polymers and polymer-based materials using high spation resolution electron-scattering techniques. The traditional approach to studying polymer morphology using the electron microscope has involved preferential scattering using heavy element stains. We and others have shown that such staining approaches introduce artifactual structure which interferes with the study of intrinsic polymer morphology at length scales of order 5 nm and ... |
|
| Internal Aerodynamics in Solid Rocket Propulsion (L'aerodynamique interne de la propulsion par moteurs-fusees a propergols solides) (CD-ROM) |
JAN 2004 |
|
| Authors:
NATO RESEARCH AND TECHNOLOGY ORGANIZATION NEUILLY-SUR-SEINE (FRANCE)
|
| ELECTRONIC FILE CHARACTERISTICS: 318 files; HyperText Markup Language (.HTML), MS PowerPoint SlideShow (.PPS), and Adobe Acrobat (.PDF). PHYSICAL DESCRIPTION: 1 computer laser optical disc (CD-ROM); 4 3/4 in.; 323 MB. SYSTEMS DETAIL NOTE: ABSTRACT: These RTO-AVT/VKI Special Course notes provide the state of the art in internal aerodyanamics in solid rocket propulsion, in a way accessible to attendees coming from both academic and industrial areas. Two families of solid motors ... |
|
| Numerical Methods for Granular Flows and Related Problems |
10 MAY 2003 |
7 pages |
| Authors:
Pierre A. Gremaud; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
|
| This project has led to significant progress on several critical questions related to granular flows. First, a high order code based on Discontinuous Galerkin method has been produced to study granular in axisymmetric hoppers. Before that, only ad hoc discretization methods were used. This led to the discovery of several new phenomena (such as shock formation and propagation). Several weaknesses of established models were also brought to the fore. Second, ... |
|
| Single Naval Fuel At-Sea Feasibility Study - Phase One |
25 OCT 2002 |
56 pages |
| Authors:
Robert M. Giannini; Calvin J. Martin; Richard Strucke; Richard A. Kamin; Douglas F. Mearns; NAVAL AIR SYSTEMS COMMAND PATUXENT RIVER MD
|
| The U.S. Navy has completed the first of a two-phase study to determine the feasibility of converting to JP-5, MIL-DTL-5624, NATO F-44, as the single naval fuel at-sea. This naval single battlefield fuel would be needed in all aircraft propulsion, ship propulsion, electrical power generation systems, and USMC ground force equipment. JP-5 was chosen as the single fuel because the aircraft requirements are the most stringent of all the naval ... |
|
| Microstructure and Dynamic Behavior Correlation in Two-Phase TiB2+Al2O3 Ceramic |
OCT 2002 |
104 pages |
| Authors:
Naresh N. Thadhani; Min Zhou; GEORGIA INST OF TECH ATLANTA SCHOOL OFMATERIALS SCIENCE AND ENGINEERING
|
| The high-strain-rate deformation and damage response of four types of microstructurally-biased two-phase (nominally 30:70) TiB2+Al2O3 ceramics, produced by SHS or mechanical milling techniques, have been investigated in this work. The microstructural-bias includes differences in phase (grain) size and phase distribution, such that in one case a continuous (interconnected) TiB2 network surrounds the Al2O3 phase (qualitatively termed TA'), and in the other case the TiB2 and Al2O3 phases are interdispersed and ... |
|
| International Symposium on Applications of Laser Techniques to Fluid Mechanics (11th) Held in Lisbon, Portugal on 8-11 Jul 2002 (CD-ROM) |
11-Jul-2002 |
|
| Authors:
INSTITUTO SUPERIOR TECNICO LISBON (PORTUGAL)
|
| ELECTRONIC FILE CHARACTERISTICS: 177 files; Adobe Acrobat (.PDF). PHYSICAL DESCRIPTION: 1 computer laser optical disc (CD-ROM); 4 3/4 in.; 204 MB. SYSTEMS DETAIL NOTE: Flash is needed to run the CD-ROM correctly. ABSTRACT: The Final Proceedings for Eleventh International Symposium on Applications of Laser Techniques to Fluid Mechanics, 8 July 2002-11 July 2002 This is an interdisciplinary conference. Approximately forty formal sessions are planned, and contributed papers are welcome in ... |
|
| Nonlinear Solvers for Subsurface Flow Problems |
08 JUL 2002 |
8 pages |
| Authors:
C. T. Kelley; E. W. Jenkins; Kathleen R. Kavanagh; Charlie Berger; Stacy Howington; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MATHEMATICS
|
| The aims of this project are development of linear and nonlinear solvers and temporal integration methods in the context of 3D simulations of subsurface flow and transport. In the period covered by this report, the Principal Investigator and his students completed the initial phase of development of a two-level preconditioner, applied those results to unsaturated and multiphase flow problems, and derived condition number estimates. They also have applied their work ... |
|
| Design of a Toroidal Device with a High Temperature Superconductor Coil for Non-neutral Plasma Trap |
24 JUN 2002 |
6 pages |
| Authors:
Yuichi Ogawa; Junji Morikawa; Hitoshi Nihei; Daisaku Ozawa; Zensho Yoshida; TOKYO UNIV (JAPAN)
|
| The non-neutral plasma confinement device with a floating internal coil is under construction, where the high temperature superconductor (HTS) Ag-sheathed BSCCO-2223 is employed as the floating coil. We have two topics with this device: one is a trap of a non-neutral plasma consisting of one species, and another is an exploration of a high beta plasma based on two-fluid MHD relaxation theory. In the latter case the plasma should be ... |
|
| Proposed Non-neutralized Two-Fluid Plasma Experiment |
24 JUN 2002 |
6 pages |
| Authors:
Haruhiko Himura; Zensho Yoshida; Masayuki Fukao; Junji Morikawa; Yuichi Ogawa; TOKYO UNIV (JAPAN) GRADUATE SCHOOL OF FRONTIER SCIENCES
|
| An experimental test of generating ion flow under a complete charge non-neutral condition is proposed. On the experiment a quasi-neutral plasma is injected into a pure electron plasma which is confined in a Malmberg type trap. So far, the device named BX-U (Beam Experiment Upgrade) confines only electrons having density of 10(exp 11-12) /cu m for ^0.3 s with B(z)^ 50 G. After completing a plasma gun, the first series ... |
|
| Numerical Models for Condenser and Evaporator Components of Fuel Cells |
19 APR 2002 |
105 pages |
| Authors:
S. M. Ghiaasiaan; J. H. Yan; B. B. McCord; GEORGIA INST OF TECH ATLANTA SCHOOL OFMECHANICAL ENGINEERING
|
| The objective of this project was to develop analytical models and computer programs for the design and analysis of evaporator and condenser components of modern fuel cells. Mechanistic models were developed for boiling and two-phase flow phenomena in Microchannel-based boilers. The modeled systems included straight Microchannel with known inlet/exit boundary conditions; helicoidally micro-channels with known inlet/exit boundary conditions; straight, parallel micro-channels connected to common inlet and exit plena; and straight, ... |
|
| Experimental Procedures for the Measurement of Polymer Solubility and Rheological Properties |
NOV 2001 |
29 pages |
| Authors:
Wendel J. Shuely; Brian S. Ince; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
|
| The rheological evaluation of viscoelastic polymer solutions is important in characterizing two-phase flow, aerodynamic breakup, dynamic contact angle and spreading behavior, and adhesive transfer of solutions between surfaces. The preparation and property measurement of polymer solutions is an important aspect of several of these investigations and rather than report these methods separately, the development of these techniques is documented in this methodology report. The experimental procedures and calibration techniques developed ... |
|
Reports by Keyword(s)
TWO PHASE FLOW
