| Thermal Analysis of a Power Conditioning Unit for a Howitzer |
Aug-2009 |
19 pages |
| Authors:
C Kessler; J A Cordes; ARMY ARMAMENT RESEARCH DEVELOPMENT AND ENGINEERING CENTER PICATINNY ARSENAL NJ MUNITIONS ENGINEERING TECHNOLOGY CENTER
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 | This report describes a thermal analysis for a power conditioning unit for the M119 A1 howitzer. The analysis includes conduction, convection, and radiation as described by the Army's rigorous environmental standards. The analysis was completed using computational fluid dynamics in the STAR-CCM+ software package. The analysis estimated the maximum temperature of various components. Most components are predicted to exceed their allowable operating temperature. Some components are predicted to fail with ... |
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| Convective Evaporation Through Water-Permeable Membranes for Rapid Beverage Chilling |
Dec-2008 |
8 pages |
| Authors:
D Pickard; M Izenson; W Chen; C W Haering; J Sung; CREARE INC HANOVER NH
|
| This paper presents the results of a Phase III SBIR project that aims to produce a lightweight, evaporative beverage chiller. Soldiers equipped with this Individual Cooling Element (ICE) will be able to cool their beverages by at least 11 deg C (20 deg F) in hot, arid environments where relief from heat stress is critical. Testing and analysis showed that it was feasible to meet performance goals for high cooling ... |
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| 2007 Program of Study: Boundary Layers |
Jun-2008 |
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| Authors:
Claudia Cenedese; John A Whitehead; Joseph Pedlosky; Steven Lentz; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
 | The topic of the Principal Lectures for the forty-ninth year of the program was Boundary Layers. The subject centers around those problems in which the boundary conditions lead to a large gradient near the boundary. Nine of this year's principal lectures were given by Joe Pedlosky and the tenth was given by Steve Lentz. The fluid mechanics of boundary layers was reviewed, first starting from its classical roots and then ... |
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| Fabrication of Ultra Fine Eutectic Structure Using Rapid Quenching Method and Plasma Sintering Technique |
23 MAY 2008 |
7 pages |
| Authors:
Kazuyuki Kakegawa; CHIBA UNIV (JAPAN)
|
| It is well known that cooling a melt of eutectic composition forms a characteristic structure. In this structure two phases entangles each other, which is called eutectic structure. Such structure is due to an alternate switching of crystallizing components from the melt. The size is generally small "below micrometer". The structure is self-forming composite, which can be used for many composite materials. Kakegawa et al. emphasized the effect of diffusion ... |
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| Efficacy of Body Ventilation System for Reducing Strain in Warm and Hot Climates |
MAR 2008 |
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| Authors:
Troy D. Chinevere; Bruce S. Cadarette; Daniel A. Goodman; Brett R. Ely; Samuel N. Cheuvront; Michael N. Sawka; ARMY RESEARCH INST OF ENVIRONMENTAL MEDICINE NATICK MA THERMAL AND MOUNTAIN MEDICINE DIVISION
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| This study determined whether a torso-vest forced ambient air body ventilation system (BVS) reduced physiological strain during exercise-heat stress. Seven heat-acclimated volunteers attempted nine, 2-h treadmill walks at 200 W/sq m in three environments, -40 C, 20% rh (HD), 35 C, 75% rh (HW), and 30 C, 50% rh, (WW) wearing the Army Combat Uniform, interceptor body armor (IBA) and Kevlar helmet. Three trials in each environment were BVS turned ... |
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| The Role of Subtropical Intrusion in the Development of Typhoon Usagi (5W) 2007 |
MAR 2008 |
118 pages |
| Authors:
Raymund P. DeLeon; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| During July 2007, fields from both the NCEP GFS final analyses and ECMWF model of OW and SF analyses suggests the development of two distinct areas with sub-tropical intrusion from remnants of a decaying baroclinic system in the WNP. This analysis of the formation of Usagi points to sub-tropical intrusion of a strong lower-tropospheric baroclinic system undergoing decay as potential seedlings for typhoon formation in areas of high sea surface ... |
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| An Experimental Investigation Into The Effect Of Plasma On The Flow Features Of An Axisymmetric Jet |
OCT 2007 |
387 pages |
| Authors:
Richard E. Huffman; AIR FORCE INST OF TECH WRIGHT-PATTERSON AFB OH
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| The main goal of the research presented was to determine the differences between a plasma field and neutral field flow structure (both mean and turbulent effects) for varying Mach number. The overall objective was to describe the effect of radio frequency capacitively coupled plasma on the flow features of compressible axisymmetric jets in Nitrogen. Three flows were investigated: perfectly expanded jets, highly underexpanded jets, and jets created by a constant-diameter ... |
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| Angiogenic Signaling in Living Breast Tumor Models |
JUN 2007 |
28 pages |
| Authors:
Edward Brown; ROCHESTER UNIV NY
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| In this grant we propose to elucidate the signaling pathway that translates VEGFR activation into elevated vessel permeability, in endothelial cells within living breast tumor models. The working hypothesis is that the signaling pathway involved is a constitutively active form of the pathway shown for healthy mesenteric microvessels. Progress to date includes the training of personnel in the laboratory, the completion of instrumentation development for a novel method for the ... |
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| Severe Weather Forecasting for Laughlin AFB, TX |
MAR 2007 |
99 pages |
| Authors:
Eric J. Cercone; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
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| A sounding climatology of a variety of parameters commonly used to forecast deep, moist convection using upper-air observations is developed. The data set includes 0000 and 1200 UTC rawinsonde data (approximately 3629 soundings) from Laughlin AFB, TX from April September 1995 2004. Cloud-to-ground lightning data, surface observations, and severe weather reports from the Storm Prediction Center (SPC) SeverePlot2 Program were used to categorize soundings as representative of conditions for no ... |
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| Studies in Forecasting Upper-Level Turbulence |
SEP 2006 |
191 pages |
| Authors:
Christopher T. Kuhl; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
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| Encounters with turbulence generated by complex topography, convection, or mechanical forcing present a significant threat to military aircraft operations. Properly forecasting the initiation, duration, and intensity of such encounters is a tremendous challenge to forecasters often resulting in the over-forecasting of turbulence. Over-forecasting the presence or intensity of turbulence can result in unnecessary mission delays, cancellations, and re-routing. The lack of observations and the fact that turbulence is a microscale ... |
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| 2005 Program of Study: Fast Times and Fine Scales |
JUL 2006 |
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| Authors:
Oliver Buhler; Charles Doering; Joseph Keller; George C. Papanicolaou; Eric V. Eijnden; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
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| The 2005 GFD program was entitled "Fast Times and Fine Scales" with a focus on asymptotic and stochastic modeling methods that exploit a physical scale separation of some kind. An extremely strong application pool resulted in the appointment of the unusually large class of eleven GFD Fellows for the summer. The first week consisted of principal lectures from Joe Keller on waves in fluids, ray methods, and a variety of ... |
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| Angiogenic Signaling in Living Breast Tumor Models |
JUN 2006 |
23 pages |
| Authors:
Edward Brown; ROCHESTER UNIV NY
|
| In this grant we propose to elucidate the signaling pathway that translates VEGFR activation into elevated vessel permeability, in endothelial cells within living breast tumor models. The working hypothesis is that the signaling pathway involved is a constitutively active form of the pathway shown for healthy mesenteric microvessels. Progress to date includes the recruitment of personnel to the new laboratory, the development and testing of a novel method for the ... |
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| Computations of Chaotic Flows in Micromixers |
07 APR 2006 |
39 pages |
| Authors:
Carolyn R. Kaplan; Junhui Liu; David R. Mott; Elaine S. Oran; NAVAL RESEARCH LAB WASHINGTON DC CENTER FOR REACTIVE FLOW AND DYNAMICAL SYSTEMS
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| Three-dimensional simulations of the incompressible Navier-Stokes equations are used to examine the effects of repeating sequences of herringbone ridges in a microchannel. The calculations show how the presence of the structures leads to an asymmetrical pattern of transverse vortices in the velocity field, how this pattern repeats as the fluid moves over each similar sequence of ridges, how this velocity field stretches and folds fluid elements, and how this can ... |
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| Characteristics of the Contraction of the Boeing/AFOSR Mach-6 Quiet Tunnel |
DEC 2005 |
105 pages |
| Authors:
Matthew P. Borg; PURDUE UNIV LAFAYETTE IN SCHOOL OF AERONAUTICS AND ASTRONAUTICS
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| The Boeing/AFOSR Mach-6 Quiet Tunnel continues to be developed to simulate the low noise of the free-flight environment. An investigation of the flow entering the contraction of this facility was necessary to determine whether disturbances in the driver tube are of sufficient amplitude to propagate downstream into the test section of the tunnel. Significant free convection was found in the nominally stagnant pre-run air of the contraction and leads to ... |
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| Velocity Averaging, Kinetic Formulations and Regularizing Effects in Quasilinear PDEs |
31 OCT 2005 |
29 pages |
| Authors:
Eitan Tadmor; Terence Tao; MARYLAND UNIV COLLEGE PARK DEPT OF MATHEMATICS
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| We prove new velocity averaging results for second-order multidimensional equations. In particular, we improve previous regularity statements for nonlinear conservation laws, and we derive completely new regularity results for convection-diffusion and elliptic equations driven by degenerate, non-isotropic diffusion. |
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| Analysis of Aerosol Aging in the Rotating Drum Chamber |
AUG 2005 |
76 pages |
| Authors:
Janon F. Embury; Tiffany A. Sutton; EDGEWOOD CHEMICAL BIOLOGICAL CENTER ABERDEEN PROVING GROUND MD
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| Two of the most recent theories describing aero-sol mechanics in the rotating drum chamber were compared with experimental measurements. Both theories predicted nearly the same results but did not match out measurements. Possible causes for the discrepancies were investigated, and it was found that convective diffusion accounts for the difference with the stirred settling model predicting measurements reasonably in the limit where rotation rate becomes zero. Once rotation begins, transport ... |
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| A Description of the Advanced Research WRF Version 2 |
01-Jun-2005 |
101 pages |
| Authors:
Wei Wang; William C Skamarock; Joseph B Klemp; Jimy Dudhia; David O Gill; Dale M Barker; Jordan G Powers; NATIONAL CENTER FOR ATMOSPHERIC RESEARCH BOULDER CO MESOSCALE AND MICROSCALE METEOROLOGY DIV
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| The development of the Weather Research and Forecasting (WRF) modeling system is a multiagency effort intended to provide a next-generation mesoscale forecast model and data assimilation system that will advance both the understanding and prediction of mesoscale weather and accelerate the transfer of research advances into operations. The model is being developed as a collaborative effort ort among the NCAR Mesoscale and Microscale Meteorology (MMM) Division, the National Oceanic and ... |
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| Vertical Gradient Freezing Using Submerged Heater Growth With Rotation and With Weak Magnetic and Electric Fields |
18 APR 2005 |
10 pages |
| Authors:
D. F. Bliss; A. M. Holmes; X. Wang; N. Ma; G. W. Iseler; NORTH CAROLINA STATE UNIV AT RALEIGH DEPT OF MECHANICAL AND AEROSPACE ENGINEERING
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| Investigations for the melt growth gallium-antimonide (GaSb) semiconductor crystals are underway at the US Air Force Research Laboratory at Hanscom Air Force Base by the vertical gradient freeze (VGF) method utilizing a submerged heater. Electromagnetic stirring can be induced in the gallium-antimonide melt just above the crystal growth interface by applying a weak radial electric current in the melt together with a weak axial magnetic field. A force convection in ... |
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| Evaluation of Two Different k-e-vv-f Turbulence Models for Natural Convection in a Rectangular Cavity |
14 APR 2005 |
7 pages |
| Authors:
S. K. Choi; E. K. Kim; S. O. Kim; KOREA ATOMIC ENERGY RESEARCH INST
|
| A numerical study of natural convection in a rectangular cavity with the k-e-vv-f models is presented. The primary emphasis of the study is placed on the investigation of accuracy and numerical stability of the k-e-vv-f models for a natural convection problem. Both the original vv-f model [1] and its modified one [2] are considered. Both models are applied to the prediction of natural convection in a rectangular cavity together with ... |
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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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| Analysis and Forecasts of 300 hPa Divergence Associated With Severe Convection Using ETA-212 and MM5 Model Data |
MAR 2005 |
135 pages |
| Authors:
Scott C. Lisko; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
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| This study investigates severe weather events occurring in the Midwest, Central, and Northeastern United States from May through September 2004. Severe weather events are pinpointed using tornado and hail reports and correlating them with NEXRAD radar data to determine maximum intensity of the event. Severe storms that occur within 30 minutes of a model forecast hour are catalogued for further investigation. Once these events are diagnosed, ETA-212 and MM5 model ... |
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| Spatial Structure of Summertime Ionospheric Plasma Near Magnetic Noon |
31 JAN 2005 |
14 pages |
| Authors:
R. W. Sims; S. E. Pryse; W. F. Denig; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
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| Results are presented from a multi-instrument study of the spatial distribution of the summertime, polar ionospheric electron density under conditions of relatively stable IMF Bz |
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| The Role of the Halted Baroclinic Mode at the Central Equatorial Pacific in El Nino Event |
2005 |
10 pages |
| Authors:
Jilin Sun; Peter Chu; Qinyu Liu; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF OCEANOGRAPHY
|
| The role of halted "baroclinic modes" in the central equatorial Pacific is analyzed. It is found that dominant anomaly signals corresponding the "baroclinic modes" occur in the upper layer of the equatorial Pacific, in a two-and-a-half layer oceanic model, in assimilated results of a simple OGCM and in the ADCP observation of TAO. A second "baroclinic mode" is halted in the central equatorial Pacific corresponding to a positive SST anomaly ... |
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| Experimental Measurement to Determine Fine Dry-Bulb and Wet-Bulb Thermocouple Response Times |
20 DEC 2004 |
38 pages |
| Authors:
Jonathan W. Kaufman; Kambiz Farahmand; Katherine Stuble; Coleen Chin; NAVAL AIR WARFARE CENTER AIRCRAFT DIV PATUXENT RIVER MD
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| An experimental apparatus was built and used to measure the response time of very fine wet-bulb thermocouples in air. Rapid response solenoid valves (15 m/sec response time) were used to control airflow, through tubing into which wet-bulb thermocouples were placed. Thermocouple wire (type T, 0.005 cm diameter) was used to fabricate thermocouples for testing. The thermocouple tip (bead) was covered with a wick (cotton fiber) to build a wet-bulb. The ... |
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| Parametric Study of Heating in Ferrite Core Using Solid Works Simulation Tools |
SEP 2004 |
13 pages |
| Authors:
Gregory K. Ovrebo; ARMY RESEARCH LAB ADELPHI MD
|
| This report shows a comparison of simulation of steady-state heating in a ferrite core using two different analysis tools, a wide range of different heating and convection parameters. The tools, CosmosWorks and FloWorks, are associated with the SolidWorks solid modeling software. It is shown that FlowWorks is the better tool for heat-transfer problems with convection. |
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| Prediction of Times of Facial and Finger Freezing During Cold Air Exposure |
AUG 2004 |
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| Authors:
Peter Tikuisis; Allan A. Keefe; DEFENCE RESEARCH AND DEVELOPMENT TORONTO (CANADA)
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| The Cold Exposure Survival Model (CESM) has undergone various modifications since its inception as a decision aid for Search and Rescue. The present change is the addition of the prediction of the risk of frostbite of the cheek and finger. This risk is not confined to just the casualty, but it might also apply to the rescuers. Hence, predictions on the risk of frostbite and its rate of onset would ... |
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| Evidence for Solar-Production as a Source of Polar-Cap Plasma |
02 APR 2004 |
11 pages |
| Authors:
S. E. Pryse; R. W. Sims; J. Moen; L. Kersley; D. Lorentzen; AIR FORCE RESEARCH LAB HANSCOM AFB MA SPACE VEHICLES DIRECTORATE
|
| The focus of the study is a region of enhanced ionospheric densities observed by the EISCAT Svalbard radar in the polar F-region near local magnetic noon under conditions of IMF Bz<0. Multi-instrument observations, using optical, spacecraft and radar instrumentation, together with radio tomographic imaging, have been used to identify the source of the enhancement and establish the background ionospheric conditions. Soft-particle precipitation was ruled out as a candidate for the ... |
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| Effectiveness of Two Forecast Models for Stratiform Precipitation |
APR 2004 |
38 pages |
| Authors:
Jeffrey E. Passner; ARMY RESEARCH LAB WHITE SANDS MISSILE RANGE NM
|
| The U.S. Army Research Laboratory has developed a mesoscale weather model called the Battlescale Forecast Model (BFM). After model initialization, the BFM produces forecast variables for a 24-h period. Since the Army required a longer-term prediction, the Mesoscale Model Version 5 (MM5) gridded data are received from the U.S. Air Force Weather Agency to provide forecast information for up to a 48-h period. Due to the importance of precipitation on ... |
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| Dynamical Mass Constraints on Low-Mass Pre-Main-Sequence Stellar Evolutionary Tracks: An Eclipsing Binary in Orion with a 1.0 M(solar) Primary and a 0.7 M(solar) Secondary |
APR 2004 |
30 pages |
| Authors:
Keivan G. Stassun; Robert D. Mathieu; Luiz Paulo Vaz; Nicholas Stroud; Frederick J. Vrba; NAVAL OBSERVATORY FLAGSTAFF AZ
|
| We report the discovery of a double-lined, spectroscopic, eclipsing binary in the Orion star-forming region. We analyze the system spectroscopically and photometrically to empirically determine precise, distance-independent masses, radii, effective temperatures, and luminosities for both components. The measured masses for the primary and secondary, accurate to approx. 1%, are 1.01 and 0.73 M(solar), respectively; thus, the primary is a definitive pre-main- sequence solar analog, and the secondary is the lowest-mass ... |
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| Dynamical Mass Constraints on Low-Mass Pre-Main-Sequence Stellar Evolutionary Tracks: An Eclipsing Binary in Orion With a 1.0 M Primary and a 0.7 M Secondary |
30 DEC 2003 |
30 pages |
| Authors:
Keivan G. Stassun; Robert D. Mathieu; Luiz P. Vaz; Nicholas Stroud; Frederick J. Vrba; NAVAL OBSERVATORY FLAGSTAFF AZ
|
| We report the discovery of a double-lined, spectroscopic, eclipsing binary in the Orion star-forming region. We analyze the system spectroscopically and photometrically to empirically determine precise, distance-independent masses, radii, effective temperatures, and luminosities for both components. The measured masses for the primary and secondary, accurate to approximately 1%, are 1.01 and 0.73 M , respectively; thus, the primary is a definitive pre main- sequence solar analog, and the secondary is ... |
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| Turbulence Parameterizations for Convective Boundary Layers in High- Resolution Mesoscale Models |
DEC 2003 |
160 pages |
| Authors:
Michelle K. Whisenhant; NAVAL POSTGRADUATE SCHOOL MONTEREY CA DEPT OF METEOROLOGY
|
| Several issues associated with grid resolution and the sub-grid scale (SGS) parameterizations in a mesoscale model are addressed in this study. Of particular concern is related to increasingly high-resolution mesoscale atmospheric numerical models, in that sub-grid scale parameterization of atmospheric processes becomes unclear when the grid resolution becomes comparable to the length scale of the phenomenon. These issues are studied through the careful analysis of in situ observations and mesoscale ... |
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| Arctic Mixed Layer Dynamics |
20 NOV 2003 |
5 pages |
| Authors:
James H. Morison; UNIV OF WASHINGTON SEATTLE POLAR SCIENCE CENTER
|
| ONR grant N00014-98-1-0037, "Arctic Mixed Layer Dynamics," is the last in a series of Arctic Mixed Layer Grants extending over more than 20 years. Throughout that time our approach has been to bring new tools to bear on fundamental questions about mixing in the upper ocean, particularly the mixed layer and underice planetary boundary layer. Over the years we have sought to understand the heat and mass balance of the ... |
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| Supersonic Turbulent Fuel-Air Mixing and Evaporation |
20 OCT 2003 |
70 pages |
| Authors:
Fadi Moukalled; AMERICAN UNIV BEIRUT (LEBANON)
|
| This report results from a contract tasking American University of Beirut as follows: The contractor will numerically investigate turbulent fuel- air mixing in a supersonic stream. The fuel injection angle will be varied from 0 to go degrees (relative to the air stream) and the air stream Mach number will be varied from 2 to 5. A finite volume pressure based method capable of modeling turbulent multi-phase flow at all ... |
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| Bounds on Turbulent Transport |
JUL 2003 |
|
| Authors:
John A. Whitehead; Friedrich Busse; Louis Howard; Charles Doering; Peter Constantin; WOODS HOLE OCEANOGRAPHIC INSTITUTION MA
|
| The subject of "Bounds on Turbulent Transport" was introduced in a series of ten lectures. The six lecturers constitute almost all of the contributors to this subject. The subject was introduced and foundations were laid by five lectures by F. H. Busse. In the middle of the first week, L. Howard reviewed his historical first approach to this subject and described more recent advances. Additional lectures by P. Constantine, R. ... |
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| Meteorologial Techniques |
13 JUN 2003 |
233 pages |
| Authors:
Mark R. Mireles; Kirth L. Pederson; Charles H. Elford; AIR FORCE WEATHER AGENCY OFFUTT AFB NE
|
| Contains weather forecasting techniques of interest to military meteorologists, in three chapters: surface weather elements, flight weather elements, and convective weather. Includes both general specific rules of thumb, results of research, lessons learned from experience, etc, gathered from military and other sources. Updates and supersedes earlier AFWA/TN-98/002, Meteorological Techniques. |
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| Meteorologial Techniques |
13 JUN 2003 |
237 pages |
| Authors:
Mark R. Mireles; Kirth L. Pederson; Charles H. Elford; AIR FORCE WEATHER AGENCY OFFUTT AFB NE
|
| Contains weather forecasting techniques of interest to military meteorologists, in three chapters: surface weather elements, flight weather elements, and convective weather includes both general specific rules of thumb, results of research lessons learned from experience, etc gathered from military and other sources. |
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| Terminal Convective Weather Forecast (TCWF) 2000 Demonstration Report |
JUN 2003 |
104 pages |
| Authors:
Danny Sims; Starr McGettigan; Cynthia Fidalgo; WILLIAM J HUGHES TECHNICAL CENTER ATLANTIC CITY NJ
|
| The Terminal Convective Weather Forecast (TCWF) 2000 Demonstration was conducted during the convective season at Air Traffic Control (ATC) facilities in Memphis, TN. The demonstration was conducted by ACB-630 to ascertain the TCWF overall utility, ease of use, readability, and perceived benefit to ATC tasking. TCWF was developed at the Massachusetts Institute of Technology Lincoln Laboratory (MIT/LL) under FAA Aviation Weather Research Program funding. The product provides a graphical 0 ... |
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| Stress Based Control of a Single-Degree-of-Freedom SMA Actuated Arm |
JUN 2003 |
6 pages |
| Authors:
T. M. Seigler; Mohammad H. Elahinia; Donald J. Leo; Daniel J. Inman; VIRGINIA POLYTECHNIC INST AND STATE UNIV BLACKSBURG DEPT OF MECHANICAL ENGINEERING
|
| In this paper a nonlinear stress-based controller is designed to position a single-degree-of-freedom shape memory alloy (SMA) actuated manipulator. A three part model was constructed based on the dynamics/kinematics of the arm, the thermomechanical behavior of SMA's and a heat transfer model consisting of electrical heating and natural convection. A variable structure controller is designed to calculate a desiredness based on position error. The desired stress is compared with the ... |
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| The Effects of Air-Borne Water Mist on a Forced Convection Boundary Layer Flame over a Non-Charring Solid |
30 MAY 2003 |
27 pages |
| Authors:
Chuka C. Ndubizu; Ramagopal Ananth; Patricia A. Tatem; NAVY TECHNOLOGY CENTER FOR SAFETY AND SURVIVABILITY WASHINGTON DC
|
| This report presents preliminary results of an experimental study of water mist suppression of forced flow boundary layer flames over a non-charring solid, where fine water mist was introduced with the incoming air. In this configuration, extinguishment at high mist flow rates is achieved only by flame blow-off. With small droplets (^5O micrometer) at low mist flow rates, the time- averaged local burning rate seems to be suppressed in the ... |
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| The Development and Validation of Simple Empirical Models of Impingement Cooling from Full Surface Heat Transfer Coefficient Distributions |
MAR 2003 |
|
| Authors:
David R. H. Gillespie; Changmin M. Son; Peter T. Ireland; Geoffrey M. Dailey; OXFORD UNIV (UNITED KINGDOM) DEPT OF ENGINEERING SCIENCE
|
| A simple heat transfer model of a cast passage impingement cooling system with film-cooling extraction is presented. This was derived from detailed local Nusselt number distributions on all surfaces of the system, measured in a large-scale model using transient liquid crystal techniques. These data were averaged over physically sensible regions correlated to local flow conditions. An energy balance technique was use to calculate the convective efficiency. A second conventional plate ... |
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| The Importance of Cooling Technology in Propulsion and Power Systems |
MAR 2003 |
7 pages |
| Authors:
Thomas A. Auxier; PRATT AND WHITNEY EAST HARTFORD CT
|
| Turbine cooling is the breakthrough technology for gas turbine engines and although the turbine engine and cooling are considered mature technologies, to date they have only achieved about 60 to 70% of the cycle advantage available. Moreover, great improvements have been made in hot section materials and protective coatings, yet without hot section cooling, the high thrust to weight war fighter engine and the high by-pass ratio turbofan engine would ... |
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| Labrador Sea - Convection Data CD-Rom |
JAN 2003 |
10 pages |
| Authors:
Gerd Krahmann; Martin Visbeck; LAMONT-DOHERTY EARTH OBSERVATORY PALISADES NY
|
| This project goal was to collect and assemble all available field data from the ONR sponsored Labrador Sea Deep Convection, Experiment, and to make this data available to interested scientists in the form of an internet site and as CD-ROMs. Maintain LabSea www site at LDEO server. |
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| Some Statistical Properties of the Decay Phase of SEP-Events |
2003 |
5 pages |
| Authors:
K. Kechskemety; E. I. Daibog; S. W. Kahler; Yu I. Logachev; AIR FORCE RESEARCH LAB HANSCOM AFB MA
|
| Generalized parameters characterizing the state of the interplanetary medium (IM) include the functional form and the rate of decline of charged particle flux in solar energetic particle (SEP) events. The shape of the particle flux decline is of particular importance: power-law time dependence indicates the dominance of diffusive propagation, whereas exponential-law, decline emphasizes adiabatic deceleration and convection. A statistical investigation extended for a long period suggests that about 90% of ... |
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| Uncertainty Analysis for Fluid Mechanics with Applications |
FEB 2002 |
50 pages |
| Authors:
Robert W. Walters; Luc Huyse; NATIONAL AERONAUTICS AND SPACE ADMINISTRATION HAMPTON VA LANGLEY RESEARCH CENTER
|
| This paper reviews uncertainty analysis methods and their application to fundamental problems in fluid dynamics. Probabilistic (Monte-Carlo, Moment methods, Polynomial Chaos) and non-probabilistic methods (Interval Analysis Propagation of error using sensitivity derivatives) are described and implemented. Results are presented for a model convection equation with a source term, a model non-linear convection-diffusion equation; supersonic flow over wedges, expansion corners, and an airfoil; and two-dimensional laminar boundary layer flow. |
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| Effect of Marangoni Convection on InSb Single Crystal Growth by Horizontal Bridgman Method |
JAN 2002 |
6 pages |
| Authors:
K. Kodera; A. Kinoshita; K. Arafune; Y. Nakae; A. Hirata; WASEDA UNIV TOKYO (JAPAN)
|
| It is necessary to clarify the effect of Marangoni convection on single crystal growth from a melt in order to improve the quality of the grown crystal. Particularly, the deviation of crystal-melt (C-M) interface from a planar shape is a major problem because it may deteriorate the quality of the grown crystal. In this paper, we investigated the effect of thermal and solutal Marangoni convection on C-M interface shape in ... |
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| Airplane and Drop Experiments on Crystallization of InxGa1-xSb Semiconductor under Different Gravity Conditions |
JAN 2002 |
7 pages |
| Authors:
Krishnan Balakrishnan; Yasuhiro Hayakawa; Hideki Komatsu; Noriaki Murakami; Tetsuo Nakamura; VICTORIA UNIV (BRITISH COLUMBIA)
|
| Melting and crystallization experiments of InGaSb were done under the reduced gravity condition (10(exp -2) G) in an airplane and at the normal gravity condition (lG) in the laboratory. Crystallized InGaSb was found to contain many needle crystals in both the cases. Reduced gravity condition was found to be more conducive for crystal growth than the normal gravity condition. Formation of spherical projections on the surface of InGaSb during its ... |
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| The Contribution of Symmetrization to the Intensification of Tropical Cyclones |
DEC 2001 |
69 pages |
| Authors:
Henry A. Miller; NAVAL POSTGRADUATE SCHOOL MONTEREY CA
|
| Operational ability to forecast tropical cyclone motion is much better than the ability to forecast intensity change. Several recent works have studied the mechanisms that bring about the symmetrization of various types of asymmetries in tropical cyclones. This study was conducted to add to that knowledge by examining the transfers of kinetic energy between scales and how those energy transfers alter the wind structure of the cyclone. Adding to the ... |
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| Coherent Spatial Patterns and Material Transport in Oceanic Flows |
08 NOV 2001 |
8 pages |
| Authors:
James C. McWilliams; CALIFORNIA UNIV LOS ANGELES INST OF GEOPHYSICS AND PLANETARY PHYSICS
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| The main subject of the grant is spontaneous emergence, dynamics, and properties of the coherent spatial patterns in oceanic flows. The oceanic regimes include convection with rotation, wind-driven circulation of the midaltitude ocean, thermohaline circulation, coastal currents near the U. S. West Coast, planetary boundary layers, and surface gravity waves. Consideration is also given to interactions between the coherent patters, material transport, and spontaneous low-frequency variability. Some of the results ... |
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| Modeling and Numerical Methods for Material Growth and Convection |
21 OCT 2001 |
4 pages |
| Authors:
Russel E. Caflisch; CALIFORNIA UNIV LOS ANGELES DEPT OF MATHEMATICS
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| Under support from this grant, substantial progress was made on a number of research projects, including the level set methods, modeling and simulation for material growth, Monte Carlo methods for rarefied gas dynamics, boundary value problem for Prandtl equations and image processing. |
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| The Mesoscale Evolution of Explosive Cyclogenesis: A Numerical Study of the March 1993 Storm of the Century |
17 SEP 2001 |
227 pages |
| Authors:
Karl D. Pfeiffer; NORTH CAROLINA STATE UNIV AT RALEIGH
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| The early, overwater cyclogenesis of the March 12-14 1993 Storm of the Century (SOC93) is investigated using mesoscale simulation datasets. Numerical results indicate that the convective available potential energy for initial development; ;is supplied by a mid-level cold pool that develops in western Texas through evaporative cooling and convective overturning in the elevated mixed layer (EML). The EML and mountain-plains solenoid (MPS) endemic to the Mexican plateau interact with a ... |
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Reports by Keyword(s)
CONVECTION
