| Simulating Tsunamis in the Indian Ocean with Real Bathymetry by using a High- Order Triangular Discontinuous Galerkin Oceanic Shallow Water Model |
Mar-2009 |
113 pages |
| Authors:
Dimitrios Alevras; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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 | The discontinuous Galerkin (DG) method has been accepted in the last decade by the geosciences community as an important component of geophysical fluid dynamics. The high-order accuracy, geometric flexibility to use unstructured grids, local conservation, and monotonicity properties of the DG method make it a prime candidate for the construction of future ocean and shallow water models. This study focuses on formatting real bathymetry data of the Indian Ocean in ... |
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| 2008 Program of Study: Perspectives and Challenges in GFD (Geophysical Fluid Dynamics) |
Mar-2009 |
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| Authors:
Raffaele Ferrari; Raymond T Pierrehumbert; Herbert E Huppert; Christopher J Garrett; Stephan Fauve; Kerry Emanuel; Stephen W Childress; George Veronis; Neil J Balmforth; Charles Doering; John Marshall; Timour Radko; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF PHYSICAL OCEANOGRAPHY
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 | PRINCIPAL LECTURES. Steve Childress: Dynamo Theory and GFD; Charlie Doering: Convection, Stability and Turbulence; Kerry Emanuel: Waves and Vortices Driven by Interfacial Fluxes; Stephan Fauve: Turbulent Dynamos: experiments, nonlinear saturation of the magnetic field and field reversals; Raffaele Ferrari: Energetics of a Turbulent Ocean; Chris Garrett: Ocean Mixing, Internal Tides and Tidal Power; Herbert Huppert: Gravity Currents and Solidification; John Marshall: GFD Experiments in Climate; Ray Pierrehumbert: Atmospheric Escape; Timour ... |
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| Stochastic Analysis and Control of Transonic Helicopter Aerodynamics and Supersonic Projectiles |
02-Feb-2009 |
6 pages |
| Authors:
Sivaguru S Sritharan; WYOMING UNIV LARAMIE
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| The main goal of this project is to develop a systematic mathematical theory for the robust real time feedback control and stochastic analysis of unsteady transonic aerodynamics of helicopter rotor blades, supersonic ballistic projectiles and propagation of blast waves in the presence of adverse external disturbances. The proposed work builds upon similar scientific advances by the principal investigator in the context of incompressible fluid dynamics, magneto-hydrodynamics and combustion models during ... |
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| Microfluidic Power Generation |
28-Mar-2008 |
177 pages |
| Authors:
Aaron J Sprecher; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH GRADUATE SCHOOL OF ENGINEERING AND MANAGEMENT
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| This thesis includes the detailed mathematical calculations used to determine the feasibility of harnessing electrical energy from the blood flow through human capillaries. The designs are inspired by human physiology and well established electromagnetic energy harvesting techniques and the fabrication methods have been proposed for the various components of the device. The fabrication and the design of these components have also been extensively analyzed using calculations based on the governing ... |
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| A Static Aeroelastic Analysis of a Flexible Wing Mini Unmanned Aerial Vehicle |
27 MAR 2008 |
111 pages |
| Authors:
Nathan A. Pitcher; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH SCHOOL OF ENGINEERING AND MANAGEMENT/DEPT OF ENGINEERING PHYSICS
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| The static aeroelastic behavior of the Nighthawk mini unmanned aerial vehicle is examined using a combined experimental and computational approach. Three wings are examined. In order of increasing stiffness they are: a flexible wing, a stiff wing, and a fictitious rigid wing with zero deflection. Photogrammetry is used during wind tunnel testing to measure the average deflected shape of the flexible and stiff wings during flight. The independent variables during ... |
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| Algorithm Development and Application of High Order Numerical Methods for Shocked and Rapid Changing Solutions |
06 DEC 2007 |
18 pages |
| Authors:
Chi-Wang Shu; BROWN UNIV PROVIDENCE RI DIV OF APPLIED MATHEMATICS
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| We have investigated high order finite difference weighted essentially non-oscillatory (WENO) schemes, finite volume WENO schemes and discontinuous Galerkin finite element methods, for solving partial differential equations with discontinuous or rapidly changing solutions. Algorithm development, analysis, implementation and applications have been carried out. Research has been performed in all areas listed in the original proposal, and progress and results consistent with the original objectives have been obtained. There are 53 ... |
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| A Film Cooling Model for a RP-1/GOX Staged Combustion Liquid Rocket Engine (Preprint) |
07 NOV 2007 |
31 pages |
| Authors:
Philip A. Haberlen; Daniel A. Greisen; William E. Anderson; REDSTONE ARSENAL HUNTSVILLE AL
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| An experimental study of supercritical RP-1 film cooling was conducted in a RP-1/GOX rocket combustor. A heat sink test section, heavily instrumented with dual Type E coaxial thermocouples, was used for measurement of wall temperature and derived gas-side wall heat flux. Varying amounts of fuel, ranging from about 40% to 70% of the total fuel flowrate, were injected as a film coolant downstream of a coaxial injector element. An existing ... |
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| Advancements in Theoretical Models of Confined Vortex Flowfields |
29 MAR 2007 |
67 pages |
| Authors:
Joshua W. Batterson; Brian A. Maicke; Joseph Majdalani; TENNESSEE UNIV SPACE INST TULLAHOMA
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| In this article, we review some of the theoretical solutions used to describe swirl dominated flows in both unidirectional and bidirectional flow orientations. This short survey starts with the Rankine vortex and culminates in the presentation of a compressible solution of the bidirectional vortex. After classifying representative swirl motions as external or internal depending on physical boundary conditions, their commonalities are identified along with their relevance to either geophysical or ... |
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| 2006 Program of Study: Ice |
MAR 2007 |
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| Authors:
Neil J. Balmforth; John S. Wettlaufer; Grae Worster; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF PHYSICAL OCEANOGRAPHY
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| Ice was the topic under discussion at Walsh Cottage during the 2006 Geophysical Fluid Dynamics Summer Study Program. Professor Grae Worster (University of Cambridge) was the principal lecturer, and navigated our path through the fluid dynamics of icy processes in GFD. Towards the end of Grae's lectures, we also held the 2006 GFD Public Lecture. This was given by Greg Dash of the University of Washington, on matters of ice ... |
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| Testing of UHTC Samples in the VKI Plasmatron |
25 OCT 2006 |
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| Authors:
Douglas G. Fletcher; C. Asma; J. Thoemel; P. Collin; Jochen Marschall; VON KARMAN INST FOR FLUID DYNAMICS RHODE-SAINT-GENESE (BELGIUM) DEPT OF AEROSPACE
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| This report results from a contract tasking Von Karman Institute for Fluid Dynamics (VKI) as follows: The proposed activity involves testing of Ultra-High Temperature Ceramic (UHTC) material samples in the VKI Plasmatron, which is an Inductively-Coupled Plasma (ICP) facility. ICP facilities are electrondeless, so the plasma stream produced for material testing and characterization is of very high purity. The VKI Plasmatron has the largest installed power capability of this type ... |
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| Dynamic-Active Flow Control - Phase I |
18 OCT 2006 |
61 pages |
| Authors:
Julio Soria; MONASH UNIV CLAYTON (AUSTRALIA) DEPT OF MECHANICAL ENGINEERING
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| This is the report of an investigation of active flow control using a wall-normal, zero-net-mass-flux (ZNMF) jet located at the leading edge of an airfoil. |
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| An Analysis of Mechanisms Underlying Flow Unsteadiness in Chemical Oxygen-Iodine Laser Mixing Systems |
12 MAR 2006 |
15 pages |
| Authors:
Timothy J. Madden; AIR FORCE RESEARCH LAB KIRTLAND AFB NM DIRECTED ENERGY DIRECTORATE
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| 3-dimensional Navier-Stokes simulations of chemical oxygen-iodine laser (COIL) hardware are performed to elucidate the unsteady fluid dynamic aspects of these flowfields. Reacting (COIL) and non-reacting flow simulations are performed on varying resolution grids to explore the unsteadiness and comparisons to experimental data are made. |
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| 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
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| 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 ... |
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| Active Control of Transverse Jets for Film Cooling Applications: A Limited Statement of Work |
FEB 2006 |
30 pages |
| Authors:
D. E. Nikitopoulos; LOUISIANA STATE UNIV BATON ROUGE DEPT OF MECHANICAL ENGINEERING
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| The objective of this project was to initiate investigation of film cooling flow control in order to improve its performance through active excitation of the film-cooling jet. A theoretical analysis was conducted and mechanisms that can play a defining role in film cooling control were identified on the basis of fundamental fluid-dynamics, prior experiments and preliminary numerical simulations. A cold flow wind-tunnel experiment incorporating a scaled-up, single film-cooling jet on ... |
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| Ocean Prediction with the Hybrid Coordinate Ocean Model (HYCOM) |
2006 |
18 pages |
| Authors:
Eric P. Chassignet; Harley E. Hurlburt; Ole M. Smedstad; George R. Halliwell; Patrick J. Hogan; Alan J. Wallcraft; Rainer Bleck; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
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| This chapter provides an overview of the effort centered on the HYbrid Coordinate Ocean Model (HYCOM) to develop an eddy-resolving, real-time global and basin-scale ocean prediction system in the context of the Global Ocean Data Assimilation Experiment (GODAE). The long-term goal is an eddy-resolving, fully global ocean prediction system with data assimilation based on HYCOM to be transitioned to the Naval Oceanographic Office at 1/12 degree equatorial resolution in 2007 ... |
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| A Consortium for Ocean Circulation and Climate Estimation |
15 DEC 2005 |
14 pages |
| Authors:
Detlef Stammer; SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA PHYSIOLOGICAL RESEARCH LAB
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| Our goal was to bring ocean state estimation from its early experimental status to a practical and quasi-operational tool for studying large-scale ocean dynamics, for designing observational strategies and for examining the ocean's role in climate variability. Our central technical goal was a complete global-scale ocean state estimation over at least the 15 year period 1985-2000 at 1140 resolution with a complete error description and regional refinements to support CLIVAR ... |
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| Current Status and Future Directions in the Use of High-Resolution Atmospheric Models for Support of T&E |
Dec-2005 |
29 pages |
| Authors:
James Bowers; Elford Astling; Thomas Warner; Scot Swerdlin; Terri Betancourt; ARMY DUGWAY PROVING GROUND UT
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| Right from the beginning of the computer age, high performance computers have been dedicated to weather research and forecasting. ATEC and the National Center for Atmospheric Research have partnered on the development of one of the highest-resolution operational weather-prediction systems in the world, ATEC 4DWX. Weather models need to be closely coupled to special-applications models - transport and diffusion, parachute drift, sound propagation. The mobile version is used to support ... |
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| 2004 Program of Study: Tides |
28 SEP 2005 |
327 pages |
| Authors:
Neil J. Balmforth; Stefan Llewellyn-Smith; Myrl Hendershott; Christopher Garrett; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
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| The summer of 2004 saw the GFD program tackle "Tides". Myrl Hendershott (Scripps Institution of Oceanography) gave a fabulous introduction to the subject in the first week of the course, laying the foundations from astronomy and classical geophysical fluid dynamics. In the second week, Chris Garrett (University of Victoria) admirably followed up with recent developments on the subject, including the recent observations from satellite altimetry, their implications to mixing and ... |
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| Experimental Investigation of a Lift Augmented Ground Effect Platform |
SEP 2005 |
108 pages |
| Authors:
Roberto T. Igue; AIR FORCE INST OF TECH WRIGHT-PATTERSONAFB OH SCHOOL OF ENGINEERING
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| This experimental study investigated the feasibility of applying the concept of a skirtless hovercraft into the production of an operational vehicle. A 0.255 m diameter prototype was designed, built and tested. An air bearing table was used as a testing platform, virtually eliminating the influence of friction and providing one degree of freedom for the experiments. Static tests were performed at various heights and craft configurations, providing a wide range ... |
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| Computation and Modeling of Insect Flight |
23 AUG 2005 |
8 pages |
| Authors:
Z. J. Wang; CORNELL UNIV ITHACA NY DEPT OF THEORETICAL AND APPLIED MECHANICS
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| Here are some of the highlights in our three year's work supported by this grant: 1) New lessons from a dragonfly flight, namely, designing flapping flight at low Reynolds number need not follow the traditional rule, but instead, could make use of drag as well as lift. 2) Two new Navier-Stokes codes for efficiently simulating multiple wings and ground effects. 3) Experiments of dragonfly flight provided data to our computational ... |
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| Combustion Control in Industrial Multi-Swirl Stabilized Spray Combustor |
21 AUG 2005 |
98 pages |
| Authors:
Ephralm J. Gutmark; Guoqiang Li; CINCINNATI UNIV OH
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| The focus of this study is to investigate the emission characteristics and combustion dynamics of multiple swirl spray combustors either in premixing or non-premixed combustion (e.g. Lean Direct Injection), and correlate these combustion characteristics (emissions, combustion instability and lean flammability) to the fluids dynamics (flow structures and its evolution). This study covers measurement of velocity flow field, temperature field, and combustion under effects of various parameters, including inlet flow Reynolds ... |
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| High Resolution Modeling of the Gulf of Mexico |
JUL 2005 |
4 pages |
| Authors:
Patrick J. Hogan; NAVAL RESEARCH LAB STENNIS SPACE CENTER MS OCEANOGRAPHY DIV
|
| An advanced, high-resolution numerical ocean model is employed to investigate the dynamics and physical characteristics of the deep and shallow circulation in the Gulf of Mexico. The resolution of the ocean model (approx. 4 kilometers) and revolutionary hybrid (quasi-isopycnic) vertical coordinate makes it an excellent candidate to form the ocean model core of an ocean acoustic tomography program that can provide near real-time subsurface ocean data to augment satellite data ... |
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| The Effects of Near-Wall Control on the Structure and Dynamics of Wall-Bounded Turbulent Flows |
31 MAY 2005 |
27 pages |
| Authors:
Kenneith Bruer; BROWN UNIV PROVIDENCE RI DIV OF ENGINEERING
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| Improved understanding of unsteady flow physics has led to a wealth of flow control applications in which fluid perturbations are deliberately introduced into a large-scale flow with the goal of affecting its global characteristics. Research into these methods has included separation control, enhanced mixing, and reduction of turbulent skin friction. Interest in turbulence control has grown due to numerical computations at low Reynolds number flow [3, 4, 5] which indicate ... |
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| Swarming in Two and Three Dimensions |
28 MAY 2005 |
6 pages |
| Authors:
Andrea L. Bertozzi; DUKE UNIV DURHAM NC DEPT OF MATHEMATICS
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| The future of military action will increasingly require new methods based on 'swarming' tactics in which a multitude of small units or 'pods' can operate in clusters with an overlaying network transmitting information. This project aims at developing concise spatio-temporal models of the large scale dynamics of swarm. The focus is on 'fluid-like' swarms in which the individual units have fairly distributed but localized density. The models have some connection ... |
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| Buoyancy-Driven Fluid Flow Generated by Bacterial Metabolism and its Proposed Relationship to Increased Bacterial Growth in Space |
18 MAR 2005 |
22 pages |
| Authors:
Robert B. Brown; David M. Klaus; Paul Todd; AIR FORCE ACADEMY COLORADO SPRINGS CO DEPT OF ASTRONAUTICS
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| Previous investigations have reported that bacterial growth increases in space flight; however, the underlying physical mechanisms responsible for these changes have not been fully determined. As bacteria consume nutrients, they excrete by-products whose presence can influence the onset of exponential growth and affect final cell population density. It is assumed that these metabolic processes create a reduced-density fluid zone and/or a solute gradient around each cell. On Earth, this density ... |
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| Frontiers in Applied and Computational Mathematics `05' |
MAR 2005 |
69 pages |
| Authors:
Miura; AIR FORCE OFFICE OF SCIENTIFIC RESEARCH ARLINGTON VA
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| Partial contents: Mathematical Biology-A Newcomer to Applied Mathematics, Scale-Invariant Adaptation , Coupled Cell Systems: Theory and Examples, Effective Scientific Simulations, Simulating Rare Events in Lightware Systems with Importance Sampling, Sound Source Location, Industry-Driven Challenges in Applied Mathematics, Waves of Excitation in Nueral Field Models, Impact of a Solid into a Viscoelastic Micellar Fluid, Shocks in Driven Liquid Films, Modeling Network Interactions Between the Hypothelalamus and Pituitary, Chaotic Desynchronization of Multi-Strain ... |
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| Advances in the Visualization and Analysis of Boundary Layer Flow in Swimming Fish |
FEB 2005 |
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| Authors:
Erik J. Anderson; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| In biology, the importance of fluid drag, diffusion, and heat transfer both internally and eternally, suggest the boundary layer as an important subject of the investigation the complexities of biological systems present significant and unique challenges to analysis by experimental fluid dynamics. |
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| Equations for Finite-Difference, Time-Domain Simulation of Sound Propagation in Moving Inhomogeneous Media and Numerical Implementation |
FEB 2005 |
16 pages |
| Authors:
Vladimir E. Ostashev; D. K. Wilson; Lanbo Liu; David F. Aldridge; Neil P. Symons; NEW MEXICO STATE UNIV LAS CRUCES DEPT OF PHYSICS
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| Finite-difference, time-domain (FDTD) calculations are typically performed with partial differential equations that are first order in time. Equation sets appropriate for FDTD calculations in a moving inhomogeneous medium with an emphasis on the atmosphere! are derived and discussed in this paper. Two candidate equation sets, both derived from linearized equations of fluid dynamics, are proposed. The first, which contains three coupled equations for the sound pressure, vector acoustic velocity, and ... |
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| On Lagrangian Meshless Methods in Free-Surface Flows |
JAN 2005 |
73 pages |
| Authors:
Jon P. Silverberg; CALIFORNIA UNIV BERKELEY COMPUTATIONAL MARINE MECHANICS LABORATORY
|
| Classically, fluid dynamics have been dealt with analytically because of the lack of numerical resources (Yeung, 1982). With the development of computational ability, many formulations have been developed which typically use the traditional Navier-Stokes equations along with an Eulerian grid. Today, there exists the possibility of using a moving grid (Lagrangian) along with a meshless discretization. The first issue in meshless fluid dynamics is the equations of motion. There are ... |
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| Parallel, Fully Automatic hp-Adaptive 3D Finite Element Package |
2005 |
35 pages |
| Authors:
M. Paszynski; L. Demkowicz; AIR FORCE OFFICE OF SCIENTIFIC RESEARCHARLINGTON VA
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| The paper presents a description of par3Dhp - a 3D, parallel, fully automatic hp-adaptive finite element code for elliptic and Maxwell problems. The parallel implementation is an extension of the sequential code 3Dhp90, which generates, in a fully automatic mode, optimal hp meshes for various boundary value problems. The system constitutes an infrastructure for a class of parallel hp adaptive computations. Its modular structure allows for an independent parallelization of ... |
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| NRL Fact Book |
31 DEC 2004 |
131 pages |
| Authors:
David M. Schubert; NAVAL RESEARCH LAB WASHINGTON DC
|
| The NRL Fact Book is a reference source for information about the Naval Research Laboratory (NRL). It is updated annually and the revised version is placed on NRL's Web site (http://www.nrl.navy.mil) each year. It is printed every other year. The Fact Book contains the following sections: an introduction to the Naval Research Laboratory, including its mission, current research, and major research capabilities and facilities; the Executive Directorate; the Business Operations ... |
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| Computationally Based Design and Screening of Hypergolic Multiamines |
DEC 2004 |
9 pages |
| Authors:
Michael J. McQuaid; William H. Stevenson; Darren M. Thompson; ARMY RESEARCH LAB ABERDEEN PROVING GROUND MD
|
| Seeking to identify structural features of saturated, (all) tertiary, alkyl multiamines (STAMs) that correlate with hypergolic ignition delays, conformers of STAMS whose ignition delays have been measured were established through density functional theory-based calculations. Examined from the standpoint of lone pair/(C-N and C-C) bond orientations, a correlation is suggested. Conformers of 1,3-dimethylimidizolidine (DMIZ), a notional hypergol whose synthesis and testing was originally recommended for other reasons, were therefore characterized. On ... |
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| Critical Orifice Theory, Design and Implementation |
17 NOV 2004 |
14 pages |
| Authors:
Leo W. Stockham; Dirk Plante; NORTHROP GRUMMAN INFORMATION TECHNOLOGY HERNDON VA
|
| If flow through an orifice's minimum area is maintained at Mach 1, the volume flow rate is only a function of the temperature and the pressure upstream of the orifice. Such a critical orifice is useful in air sampling when ambient conditions do not change rapidly. Under those conditions, a critical orifice will passively keep the volume flow rate constant at a known value. This can eliminate measuring sampler flow ... |
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| First-In-Flight Full-Scale Application of Active Flow Control: The XV-15 Tiltrotor Download Reduction |
18 OCT 2004 |
35 pages |
| Authors:
Hassan M. Nagib; John W. Kiedaisch; Israel J. Wygnanski; Aaron D. Stalker; Tom Wood; ILLINOIS INST OF TECH CHICAGO
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| In June 2003, before being retired to the Smithsonian Museum Annex, near Dulles Airport, the only remaining XV-15 tiltrotor aircraft was used for a series of flight tests to demonstrate the effectiveness of Active Flow control (AFC) in reducing the download during hover. The flaps/ailerons were retrofitted with actuators delivering zero-mass-flux periodic jets emanating fro slots positioned tangential to the surface. The flight tests followed two extensive sets of model ... |
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| Vortex Whistle in Radial Intake |
OCT 2004 |
26 pages |
| Authors:
Man-Chun Tse; PRATT AND WHITNEY CANADA CORP LONGUEUIL (QUEBEC)
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| In a radial-to-axial intake with inlet guide vanes (IGV) at the entry, a strong flow circulation Gamma can be generated from the tangential flow components created by the IGVs when their setting exceed about halfclosing (approx. 45 deg.). The circulation is convected downstream in the gaspath. As the flow area of the gaspath is reduced towards the axial-exit, the initial circulation is stretched. This increases the vorticity intensity as a ... |
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| Introduction to Magneto-Fluid-Dynamics for Aerospace Applications |
08 JUL 2004 |
416 pages |
| Authors:
VON KARMAN INST FOR FLUID DYNAMICS RHODE-SAINT-GENESE (BELGIUM)
|
| This is a new Lecture Series that will introduce magneto-hydro- dynamics (MHD) fundamentals and will report on the current State-of-the-Art research activities throughout Europe Russia and the US. Specific topics include: Electromagnetic Theory; Governing Equations; Numerical Modeling; Hypersonic Boundary Layer Interactions; Experimental Approach to Plasma ; Physical Aspects of Traditional MHD; Hypersonics and Propulsion MHD; and Plasma Flow Control for boundary Layers. |
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| Dynamics of Droplet-Droplet and Droplet-Film Collision |
22 JUN 2004 |
19 pages |
| Authors:
C. K. Law; PRINCETON UNIV NJ
|
| The physical phenomena of droplet-droplet and droplet-film collision in the head-on orientation were studied experimentally and computationally, with emphasis on the transition between bouncing and merging of the liquid surfaces. Experimentally, the droplets (~300 m diameter) were generated using the ink-jet printing technique, and imaged using stroboscopy and high-speed cine-photography for the droplet-droplet and droplet-film collision events respectively. Computationally, the collision event was simulated using the front-tracking technique. For the ... |
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| Examination of Flow Around Second-Generation Controlled Diffusion Compressor Blades in Cascade at Stall |
JUN 2004 |
75 pages |
| Authors:
Kevin D. Fitzgerald; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| The flow around second-generation controlled-diffusion blades in cascade at stall was examined experimentally through the use of a two-component laser-Doppler velocimeter. Blade surface pressure measurements were also preformed at mid span on the blades at various Reynolds numbers. Flow visualization techniques were used to observe and record the flow on the surface of the blade. A correlation between the experimental results and computational fluid dynamic predictions was attempted in order ... |
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| PBG Cavity in NV-Diamond for Large Scale Type II Quantum Computing |
22 APR 2004 |
32 pages |
| Authors:
Selim Shahriar; MASSACHUSETTS INST OF TECH CAMBRIDGE RESEARCH LAB OF ELECTRONICS
|
| The objective of this project was to investigating the feasibility of realizing a type II quantum computer (QC) on a large scale, using nitrogen- vacancy color centers in diamond (NV-Diamond). To see the basic mechanism behind this scheme, consider a small volume of this medium. A laser beam incident on this volume can interact with all the centers in this volume. However, each center has a transition frequency that is ... |
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| Widening of the Electron Avalanche in a Barrier Discharge Due to the Photoemission |
07 APR 2004 |
2 pages |
| Authors:
Yu. B. Golubovskii; V. A. Maiorov; J. Behnke; J. F. Behnke; SAINT PETERSBURG STATE UNIV (RUSSIA)
|
| The evolution of the narrow electron avalanche in a harrier discharge is studied via two-dimensional fluid model. If the photoemission is taken into account as a primary source of electrons at the cathode, the electron avalanche initiates a quasi-homogeneous glow discharge. This discharge is about 10 ns in duration; it covers all the electrode area. |
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| On the Radial Instability of a Homogeneous Barrier Discharge in Nitrogen |
07 APR 2004 |
2 pages |
| Authors:
V. A. Maiorov; Yu. B. Golubovskii; J. Behnke; J. F. Behnke; SAINT PETERSBURG STATE UNIV (RUSSIA)
|
| The temporal development of small radial disturbances of the cathode current in a barrier discharge in nitrogen is studied by means of a 2D fluid model. It was found that Townsend discharge mode is stable, whereas in glow mode disturbances of all radii grow with time. Therefore, the domain of discharge homogeneity coincides with that of existence of Townsend discharge. The homogeneity domains are obtained for both linearly increasing and ... |
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| 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 ... |
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| The Effect of Surface Topography on the Nonlinear Dynamics of Rossby Waves |
24 MAR 2004 |
10 pages |
| Authors:
S. I. Abarzhi; O. Desjardins; H. Pitsch; CALIFORNIA INST OF TECH PASADENA
|
| Boussinesq convection in rotating systems attracts a sustained attention of the fluid dynamics community, because it has intricate non-linear dynamics (Cross & Hohenberg 1993) and plays an important role in geophysical and astrophysical applications, such as the motion of the liquid outer core of Earth, the Red Spot in Jupiter, the giant cells in the Sun etc. (Alridge et al. 1990). A fundamental distinction between the real geo- and astrophysical ... |
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| Numerical Simulation of Protoplanetary Vortices |
24 MAR 2004 |
10 pages |
| Authors:
H. Lin; J. A. Barranco; P. S. Marcus; CALIFORNIA UNIV BERKELEY DEPT OF ASTRONOMY
|
| The fluid dynamics within a protoplanetary disk has been attracting the attention of many researchers for a few decades. Previous works include, to list only a few among many others, the well-known alpha-prescription of Shakura & Sunyaev (1973), the convective and instability study of Stone & Balbus (1996) and Hawley et al. (1999), the Rossby wave approach of Lovelace et al (1999), as well as a recent work by Klahr ... |
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| Nanostructured Shape Memory Alloys: Composite Materials with Shape Memory Alloy Constituents |
MAR 2004 |
18 pages |
| Authors:
Wendy C. Crone; Arhur B. Ellis; John H. Perepezko; WISCONSIN UNIV-MADISON OFFICE OF RESEARCH ADMINISTRATION
|
| Composite materials are critical for many engineering applications because of the resultant properties that arise from the combination of dissimilar constituent materials. A particularly exciting class of constituent materials is shape memory alloys (SMAs), which continue to be explored because of their unique superelastic capabilities. These alloys already have wide ranging applications in the aerospace, biomedical, and microelectronics industries. For example, control of flight using SMAs has been demonstrated with ... |
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| Experimental Data Acquisition and Quantitative Visualization of Turbulent Jet Mixing Layers |
20 FEB 2004 |
14 pages |
| Authors:
William K. George; STATE UNIV OF NEW YORK AT STONY BROOK RESEARCH FOUNDATION
|
| This AFOSR/DURIP sponsored funding was used to upgrade the data acquisition, graphics and image processing capabilities of the Turbulence Research Laboratory (TRL) of the State University of New York at Buffalo. The proposed upgrades were of immediate benefit to the research sponsored by AFOSR (Investigation into the Dynamics of the Jet Mixing Layer) as well as a number of on-going and anticipated investigations. The AFOSR sponsored effort enhanced on- going ... |
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| Conceptual Models of the Climate 2003 Program of Study: Non-Newtonian Geophysical Fluid Dynamics |
FEB 2004 |
|
| Authors:
NeiI J. Balmforth; John Hinch; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA DEPT OF PHYSICAL OCEANOGRAPHY
|
| Non-Newtonian fluids occur commonly in our world. These fluids, such as toothpaste, saliva, oils, mud and lava, exhibit a number of behaviors that are different from Newtonian fluids and have a number of additional material properties. In general, these differences arise because the fluid has a microstructure that influences the flow. In section 2 we will present a collection of some of the interesting phenomena arising from flow nonlinearities, the ... |
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| Effects of Dynamic Forcing on Hillslope Water Balance Models |
2004 |
17 pages |
| Authors:
C. E. Kees; L. E. Band; M. W. Farthing; NORTH CAROLINA STATE UNIV AT RALEIGH CENTER FOR RESEARCH IN SCIENTIFIC COMPUTATION
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| Recently there has been much interest in scaling water flow and species transport at the continuum level to the watershed. A particularly simple and, therefore, appealing approach is based on the water mass balance at the hillslope scale. Such models require parameterization of closure relations ( flux-storage relations) based on field data. In several recent studies, this data was instead generated by steady-state numerical simulations of the hillslope. In this ... |
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| Magneto-Aerodynamic Hypersonics |
DEC 2003 |
7 pages |
| Authors:
F. Witzeman; AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH AIR VEHICLES DIRECTORATE
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| Favorable interactions of electromagnetic fields and weakly ionized air for flow control have been recognized since the late 1950s. Potential applications of flow control to hypersonic flight vehicles were recently demonstrated by Russian research and concepts. The scientific knowledge base of this interdisciplinary area (i.e., fluid dynamics, electromagnetics, and chemical and thermal nonequilibrium gas dynamics) is extremely sparse. Therefore, controversy and even misunderstandings are abundant in the research community. This ... |
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| Localized Flow Control in High Speed Flows Using Laser Energy Deposition |
30 NOV 2003 |
25 pages |
| Authors:
Doyle D. Knight; Hong Yan; Greg Elliott; Graham Candler; Alexander Zheltovodov; RUTGERS - THE STATE UNIV PISCATAWAY NJDEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| The capability for localized flow control in high speed flows using laser energy deposition has been investigated in a collaborative computational and experimental program. Three proposed applications have been comprehensively studied. First, two models of laser energy deposition in air have been developed and validated by comparison with experiment. The first model is an engineering approach wherein the laser energy deposition is treated as an energy release in a perfect ... |
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Reports by Keyword(s)
FLUID DYNAMICS
